SubclassⅢsucrose nonfermenting1-related protein kinase 2s(SnRK2s)function in ABA and abiotic stress responses by unknown mechanisms.We found that osmotic stress/ABA-activated protein kinase 10(SAPK10),a member of ric...SubclassⅢsucrose nonfermenting1-related protein kinase 2s(SnRK2s)function in ABA and abiotic stress responses by unknown mechanisms.We found that osmotic stress/ABA-activated protein kinase 10(SAPK10),a member of rice SnRK2s,physically interacted with CBL-interacting protein kinase 1(OsCIPK1).OsCIPK1 expression was up-regulated by ABA and PEG treatment,and overexpression increased the ABA sensitivity of seed germination and root growth and plant osmotic stress tolerance.Osmotic stress or ABA-induced activation of OsCIPK1 is dependent on SAPK10.SAPK10 phosphorylates Thr-24 of OsCIPK1 in vitro,and this phosphorylation increases the activity of OsCIPK1 and positively regulates the function of OsCIPK1 in ABA responses and plant osmotic stress tolerance.This study suggests that OsCIPK1 is a direct phosphorylated substrate of SAPK10,and SAPK10-mediated phosphorylation of OsCIPK1 functions in ABA signaling and increases rice osmotic stress tolerance.展开更多
Matric suction is an important state variable required for the assessment of unsaturated soil properties.Tensiometers are commonly used for direct matric suction measurement but have a limited measuring range up to 90...Matric suction is an important state variable required for the assessment of unsaturated soil properties.Tensiometers are commonly used for direct matric suction measurement but have a limited measuring range up to 90 kPa due to the cavitation problem.Osmotic tensiometer(OT)can improve the measuring range of tensiometers by increasing the osmotic pressure of water to avoid the cavitation.However,the long-term water pressure decay that appeared in OTs caused a gradual decrease in their measuring range.In this study,crosslinked poly(acrylamide-co-acrylic acid)potassium salt(PAM-co-PAAK)was used for the preparation of OTs(five in total)to explore the mechanism of water pressure decay of OTs.The maximum water pressure in the OT versus the volume fraction of polymer filled in the OT was described based on the Flory-Huggins polymer theories and validated using WP4C dewpoint hygrometer.The long-term pressure decay of OT-1,OT-2,and OT-3 was observed for 130 d and constant pressures were found for OT-1 and OT-2,indicating that the pressure decay of OT was mainly caused by the stress relaxation of the polymer hydrogels,and standard linear solid(SLS)rheological model was appropriate to fit the decay data.For OT-1,OT-2 and OT-3,the theoretical osmotic pressure that was calculated based on the mass of retrieved polymer from OTs after 130-d pressure observation was higher than the actual osmotic pressure as observed,indicating that polymer leakage cannot explain the pressure decay of the OT.The ultravioletevisible(UVevisible)spectrophotometry examined the change in polymer concentrations in the water containers of OT-4 and OT-5 and demonstrated that there was no increase in polymer leakage during the period of pressure decay of OT-4 and OT-5.As a result,the pressure decay of OT was not caused by polymer leakage.The results of this research suggested that the viscoelastic properties of polymers should be taken into consideration in further OT development.展开更多
Nitraria sibirica Pall.is an important shrub with a strong salt-alkali tolerance,but the mechanism underlying this tolerance remains obscure.In this study,N.sibirica,with salt-sensitive Vigna radiata(Linn.)Wilczek as ...Nitraria sibirica Pall.is an important shrub with a strong salt-alkali tolerance,but the mechanism underlying this tolerance remains obscure.In this study,N.sibirica,with salt-sensitive Vigna radiata(Linn.)Wilczek as the control,was subjected to transient salt stress(100 mM NaCl),alkali stress(50 mM Na_(2)CO_(3)),and osmotic stress(175 mM mannitol).The ionic fluxes of Na^(+)and K^(+)in the root apical region were measured.Results show that,under salt and alkali stress,N.sibirica roots exhibited higher capacities to limit Na+influx and reduce K+efflux,thereby resulting in lower Na^(+)/K^(+)ratios compared with V.radiata roots.Alkali stress induced stronger Na^(+)influx and K+efflux in the root salt stress treatment;Na^(+)influx was mainly observed in the root cap,while K^(+)efflux was mainly observed in the elongation zone.While under osmotic stress,N.sibirica roots showed stronger Na+efflux and weaker K+efflux than V.radiata roots.Na+efflux was mainly observed in the root elongation zone,while K+efflux was in the root cap.These results reveal the ionic strategy of N.sibirica in response to transient salt,alkali,and osmotic stresses through the regulation of Na+/K+flux homeostasis.展开更多
The aim of the study was to develop actarit double-layered osmotic pump tablets to overcome the weak points of actarit common tablets, such as short half-life and large plasma concentration fluctuations. Single factor...The aim of the study was to develop actarit double-layered osmotic pump tablets to overcome the weak points of actarit common tablets, such as short half-life and large plasma concentration fluctuations. Single factor experiment and orthogonal test were applied to optimize the formulation;the pharmacokinetic study was performed in beagle dogs adopting actarit common tablets as reference tablets. The optimal formulation was as follows: drug layer: 150 mg actarit, 240 mg PEO-N80, 50 mg NaCl;push layer: 140 mg PEO-WSR303, 20 mg NaCl;coating solution: 30 g cellulose acetate and 6 g PEG 4000 in 1000 ml 94% acetone solution, 60 mg coating weight gain. The pharmacokinetic study showed that T max was prolonged by the contrast of commercial common tablets with constant drug release rate, but the bioavailability was equivalent. And a good in vivo –in vitro correlation of the actarit osmotic pump tablets was also established. The designed actarit osmotic pump tablets can be applied for rheumatoid arthritis, proposing a promising replacement for the marked common products.展开更多
Alfalfa is widely grown and is one of the most important forage crops in the world, but its growth and biomass production are markedly reduced under salt and drought stress, particularly during the early seedling stag...Alfalfa is widely grown and is one of the most important forage crops in the world, but its growth and biomass production are markedly reduced under salt and drought stress, particularly during the early seedling stage. To identify the mechanisms behind salt and drought responsiveness at the alfalfa seedling stage, the proteins expressed were analyzed under no-treatment, 200 mol L–1 Na Cl and 180 g L–1 PEG treatment conditions during the seedling stage. Out of more than 800 protein spots detected on two-dimensional electrophoresis(2-DE) g els, 35 proteins showed statistically significant responses(P<0.05) to Na Cl and PEG stress, which were selected for tandem mass spectrometric identification, owing to their good resolution and abundance levels, and 32 proteins were positively identified. The identified proteins were divided into seven functional categories: photosynthetic metabolism, protein biosynthesis, folding and assembly, carbohydrate metabolism-associated proteins, stress defense related protein, metabolism of nucleic acid, other function categories and unknown proteins. Our results suggested that these proteins may play roles in alfalfa adaptation to salt and drought stress. Further study of these proteins will provide insights into the molecular mechanisms of abiotic stress and the discovery of new candidate markers in alfalfa.展开更多
Intensively farmed crops used to experience numerous environmental stresses.Among these,shade and drought significantly influence the morpho-physiological and biochemical attributes of plants.However,the interactive e...Intensively farmed crops used to experience numerous environmental stresses.Among these,shade and drought significantly influence the morpho-physiological and biochemical attributes of plants.However,the interactive effect of shade and drought on the growth and development of soybean under dense cropping systems has not been reported yet.This study investigated the interactive effect of PEG-induced osmotic stress and shade on soybean seedlings.The soybean cultivar viz.,C-103 was subjected to PEG-induced osmotic stress from polyethylene glycol 6000(PEG-6000)under shading and non-shading conditions.PEG-induced osmotic stress significantly reduced the relative water contents,morphological parameters,carbohydrates and chlorophyll contents under both light environments.A significant increase was observed in osmoprotectants,reactive oxygen species and antioxidant enzymes in soybean seedlings.Henceforth,the findings revealed that,seedlings grown under non-shading conditions produced more malondialdehyde and hydrogen peroxide contents as compared to the shade-treated plants when subjected to PEG-induced osmotic stress.Likewise,the shaded plants accumulated more sugars and proline than non-shaded ones under drought stress.Moreover,it was found that nonshaded grown plants were more sensitive to PEG-induced osmotic stress than those exposed to shading conditions,which suggested that shade could boost the protective mechanisms against osmotic stress or at least would not exaggerate the adverse effects of PEG-induced osmotic stress in soybean seedlings.展开更多
One purpose of this study was to develop a paliperidone(PAL)tri-layer ascending release pushepull osmotic pump(TA-PPOP)tablet which could meet the needs of clinical applications.And another purpose was to investigate ...One purpose of this study was to develop a paliperidone(PAL)tri-layer ascending release pushepull osmotic pump(TA-PPOP)tablet which could meet the needs of clinical applications.And another purpose was to investigate whether different coating materials influenced in vivo performance of TA-PPOP.The ascending release mechanism of this trilayer delivery system on theory was elaborated.TA-PPOP was prepared by means of coating with cellulose acetate(CA)or ethyl cellulose(EC).Several important influence factors such as different core tablet compositions and different coating solution ingredients involved in the formulation procedure were investigated.The optimization of formulation and process was conducted by comparing different in vitro release behaviors of PAL.In vitro dissolution studies indicated that both the two formulations of different coating materials were able to deliver PAL at an ascending release rate during the whole 24 h test.The in vivo pharmacokinetics study showed that both self-made PPOP tablets with different coating had a good in vitro-in vivo correlation(IVIVC)and were bioequivalent with the brand product,which demonstrated no significant influence of the coating materials on the in vivo release acceleration of TA-PPOP.展开更多
In this investigation,time-released monolithic osmotic pump(TMOP)tablets containing diltiazem hydrochloride(DIL)were prepared on the basis of osmotic pumping mechanism.The developed dosage forms were coated by Kollido...In this investigation,time-released monolithic osmotic pump(TMOP)tablets containing diltiazem hydrochloride(DIL)were prepared on the basis of osmotic pumping mechanism.The developed dosage forms were coated by Kollidon®SR-Polyethylene Glycol(PEG)mixtures via compression-coated technology instead of spray-coating method to form the outer membrane.For more efficient formulation screening,a three-factor five-level central composite design(CCD)was introduced to explore the optimal TMOP formulation during the experiments.The in vitro tests showed that the optimized formulation of DIL-loaded TMOP had a lag time of 4 h and a following 20-h drug release at an approximate zero-order rate.Moreover,the releasemechanismwas proven based on osmotic pressure and its profile could be well simulated by a dynamic equation.After oral administration by beagle dogs,the comparison of parameters with the TMOP tablets and reference preparations show no significant differences for C_(max)(111.56±20.42,128.38±29.46 ng/ml)and AUC_(0-48 h)(1654.97±283.77,1625.10±313.58 ng h/ml)but show significant differences for T_(max)(13.00±1.16,4.00±0.82 h).These pharmacokinetic parameters were consistent with the dissolution tests that the TMOP tablets had turned out to prolong the lag time of DIL release.展开更多
Elementary osmotic pump(EOP)is a unique extended release(ER)drug delivery system based on the principle of osmosis.It has the ability to minimize the amount of the drug,accumulation and fluctuation in drug level durin...Elementary osmotic pump(EOP)is a unique extended release(ER)drug delivery system based on the principle of osmosis.It has the ability to minimize the amount of the drug,accumulation and fluctuation in drug level during chronic uses.Carbamazepine(CBZ),a poorly water-soluble antiepileptic drug,has serious side effects on overdoses and chronic uses.The aim of the present study was to design a new EOP tablet of CBZ containing a solubility enhancers and swellable polymer to reduce its side effects and enhance the patient compliance.Firstly,a combination of solubilizing carriers was selected to improve the dissolution of the slightly soluble drug.Then,designing the new EOP tablet and investigating the effect of different variables of core and coat formulations on drug release behavior by single parameter optimization and by Taguchi orthogonal design with analysis of variance(ANOVA),respectively.The results showed that CBZ solubility was successfully enhanced by a minimum amount of combined polyvinyl pyrrolidone(PVP K30)and sodium lauryl sulfate(SLS).The plasticizer amount and molecular weight(MW)together with the osmotic agent amount directly affect the release rate whereas the swellable polymer amount and viscosity together with the semi-permeable membrane(SPM)thickness inversely influence the release rate.In addition,the tendency of following zero order kinetics was mainly affected by the coat components rather than those of the core.Further,orifice size does not have any significant effect on the release behavior within the range of 0.1 mm to 0.8 mm.In this study we report the successful formulation of CBZ-EOP tablets,which were similar to the marketed product Tegretol CR 200 and able to satisfy the USP criterion limits and to deliver about 80%of CBZ at a rate of approximately zero order for up to 12 h.展开更多
The work aims to investigate the in vitro release,pharmacokinetics(PK),pharmacodynamics(PD)and PK-PD relationships of Salvianolic Acid B micro-porous osmotic pump pellets(SalB-MPOPs)in angina pectoris New Zealand Whit...The work aims to investigate the in vitro release,pharmacokinetics(PK),pharmacodynamics(PD)and PK-PD relationships of Salvianolic Acid B micro-porous osmotic pump pellets(SalB-MPOPs)in angina pectoris New Zealand White(NZW)rabbits,compared with those of SalB immediate-release pellets(SalB-IRPs).The SalB plasma concentrations and Superoxide dismutase levels(PD index)were recorded continuously at predetermined time interval after administration,and the related parameters were calculated by using Win-Nonlin software.The release profile of MPOPs was more sustained than that of IRPs.PK results indicated that the mean C_(max) was significantly lower,the SalB plasma concentrations were steadier,both area under concentration-time curve from 0 to 24 h(AUC_(0-24 h))and from 0 to infinity(AUC_(0-∞))were presented larger,and both the peak concentration time(T_(max))and mean residence time(MRT)were prolonged for MPOPs,as compared with those of IRPs.PD results suggested that peak drug effect(E_(max))was lower and the equilibration rate constant(k_(e0))between the central compartment and the effect compartment was higher of MPOPs vs.those of IRPs.PKePD relationships demonstrated that the effectconcentration-time(ECT)course of MPOPs was clockwise hysteresis loop,and that of IRPs was counter-clockwise hysteresis loop.Collectively,those results demonstrated that MPOPs were potential formulations in treating angina pectoris induced by atherosclerosis.展开更多
Osmotic pressure can break the fluid balance between intracellular and extracellular solutions.In hypo-osmotic so-lution,water molecules,which transfer into the cell and burst,are driven by the concentration differenc...Osmotic pressure can break the fluid balance between intracellular and extracellular solutions.In hypo-osmotic so-lution,water molecules,which transfer into the cell and burst,are driven by the concentration difference of solute across the semi-permeable membrane.The complicated dynamic processes of intermittent bursts have been previously observed.However,the underlying physical mechanism has yet to be thoroughly explored and analyzed.Here,the intermittent re-lease of inclusion in giant unilamellar vesicles was investigated quantitatively,applying the combination of experimental and theoretical methods in the hypo-osmotic medium.Experimentally,we adopted a highly sensitive electron multiplying charge-coupled device to acquire intermittent dynamic images.Notably,the component of the vesicle phospholipids af-fected the stretch velocity,and the prepared solution of vesicles adjusted the release time.Theoretically,we chose equations and numerical simulations to quantify the dynamic process in phases and explored the influences of physical parameters such as bilayer permeability and solution viscosity on the process.It was concluded that the time taken to achieve the balance of giant unilamellar vesicles was highly dependent on the molecular structure of the lipid.The pore lifetime was strongly related to the internal solution environment of giant unilamellar vesicles.The vesicles prepared in viscous solution were able to visualize long-lived pores.Furthermore,the line tension was measured quantitatively by the release velocity of inclusion,which was of the same order of magnitude as the theoretical simulation.In all,the experimental values well matched the theoretical values.Our investigation clarified the physical regulatory mechanism of intermittent pore forma-tion and inclusion release,which provides an important reference for the development of novel technologies such as gene therapy based on transmembrane transport as well as controlled drug delivery based on liposomes.展开更多
Plant mitochondrial phosphate transporters regulate phosphate transport and ATP synthesis. Determining whether they function in abiotic stress response process would shed light on their response to salt stress. We use...Plant mitochondrial phosphate transporters regulate phosphate transport and ATP synthesis. Determining whether they function in abiotic stress response process would shed light on their response to salt stress. We used the CRISPR/Cas9 gene-editing system to mutagenize two mitochondrial phosphate transporters, OsMPT3;1 and OsMPT3;2, to investigate their regulatory roles under salt stress. Two cas9(CRISPR-associated protein9)-free homozygous mutants, mpt33 and mpt30, were confirmed to be stable. Both OsMPT3;1 and OsMPT3;2 were markedly induced by salt stress, and their mutagenesis strongly inhibited growth and development, especially under salt stress. Mutagenesis sharply reduced the accumulation of ATP, phosphate, calcium, soluble sugar, and proline and increased osmotic potential, malondialdehyde, and Na^+ /K^+ ratio under salt stress. Both mutants demonstrate normal growth and development in the presence of ATP, revealing high sensitivity to exogenous ATP under salt stress. The mutants showed lowered rates of Na^+ efflux but also of K^+ and Ca^(2+) influx under salt stress. Mutagenesis of OsMPT3;2 altered the enrichment profiles of differentially expressed genes involved mainly in synthesis of secondary metabolites, metabolism of glycolysis, pyruvate, tricarboxylic acid cycle, in response to salt stress. The mutant displayed significant accumulation differences in 14 metabolites involved in 17 metabolic pathways, and strongly up-regulated the accumulation of glutamine, a precursor in proline synthesis, under salt stress. These findings suggest that the OsMPT3 gene modulates phosphate transport and energy supply for ATP synthesis and triggers changes in accumulation of ions and metabolites participating in osmotic regulation in rice under salt stress, thus increasing rice salt tolerance. This study demonstrates the effective application of CRISPR/Cas9 gene-editing to the investigation of plant functional genes.展开更多
AIM: To investigate the effects of dextrans of various molecular weights (Mw) during a 12 h cold storage time-course on energetics, histology and mucosal infiltration of fluorescein isothiocyanate (FITC)-dextran. METH...AIM: To investigate the effects of dextrans of various molecular weights (Mw) during a 12 h cold storage time-course on energetics, histology and mucosal infiltration of fluorescein isothiocyanate (FITC)-dextran. METHODS: Rodent intestines were isolated and received a standard University of Wisconsin vascular flush followed by intraluminal administration of a nutrientrich preservation solution containing dextrans of varying Mw: Group D1, 73 kdal; Group D2, 276 kdal; Group D3, 534 kdal; Group D4, 1185 kdal; Group D5, 2400 kdal. RESULTS: Using FITC-labeled dextrans, fluorescent micrographs demonstrated varying degrees of mucosal infiltration; lower Mw (groups D1-D3: 73-534 kdal) dextrans penetrated the mucosa as early as 2 h, whereas the largest dextran (D5: 2400 kdal) remained captive within the lumen and exhibited no permeability even after 12 h. After 12 h, median injury grades ranged from 6.5 to 7.5 in groups D1-D4 (73-1185 kdal) representing injury of the regenerative cryptal regions and submucosa; this was in contrast to group D5 (2400 kdal) which exhibited villus denudation (with intact crypts) corresponding to a median injury grade of 4 (P < 0.05). Analysis of tissue energetics reflected a strong positive correlation between Mw and adenosine triphosphate (r 2 = 0.809), total adenylates (r 2 = 0.865) and energy charge (r 2 = 0.667).CONCLUSION: Our data indicate that dextrans of Mw > 2400 kdal act as true impermeant agents during 12 h ischemic storage when incorporated into an intraluminal preservation solution.展开更多
Interstitial fluid movement in the brain parenchyma has been suggested to contribute to sustaining the metabolism in brain parenchyma and maintaining the function of neurons and glial cells.The pulsatile hydrostatic p...Interstitial fluid movement in the brain parenchyma has been suggested to contribute to sustaining the metabolism in brain parenchyma and maintaining the function of neurons and glial cells.The pulsatile hydrostatic pressure gradient may be one of the driving forces of this bulk flow.However,osmotic pressure- related factors have not been studied until now.In this prospective observational study,to elucidate the relationship between osmolality (mOsm/kg) in the serum and that in the cerebrospinal fluid (CSF),we simultaneously measured the serum and CSF osmolality of 179 subjects with suspected neurological conditions.Serum osmolality was 283.6 ± 6.5 mOsm/kg and CSF osmolality was 289.5 ± 6.6 mOsm/kg.Because the specific gravity of serum and CSF is known to be 1.024–1.028 and 1.004–1.007,respectively,the estimated average of osmolarity (mOsm/L) in the serum and CSF covered exactly the same range (i.e.,290.5–291.5 mOsm/L).There was strong correlation between CSF osmolality and serum osmolality,but the difference in osmolality between serum and CSF was not correlated with serum osmolality,serum electrolyte levels,protein levels,or quotient of albumin.In conclusion,CSF osmolarity was suggested to be equal to serum osmolarity.Osmolarity is not one of the driving forces of this bulk flow.Other factors such as hydrostatic pressure gradient should be used to explain the mechanism of bulk flow in the brain parenchyma.This study was approved by the Institutional Review Board of the Tohoku University Hospital (approval No.IRB No.2015-1-257) on July 29,2015.展开更多
In cryopreservation,the addition of cryoprotectant can change the intra-and extra-cellular osmotic pressure,affect the cell morphology,and induce blebs on the plasma membrane.In this study,the blebs of cells microenca...In cryopreservation,the addition of cryoprotectant can change the intra-and extra-cellular osmotic pressure,affect the cell morphology,and induce blebs on the plasma membrane.In this study,the blebs of cells microencapsulated in the alginate microsphere induced by osmotic shock were studied,and the effects of microencapsulation on bleb size and cell viability were determined.Firstly,a coaxial co-flow focusing device was applied to generate cell-laden microcapsules using alginate hydrogel in this paper.Then,cellular blebs induced by DMSO with various concentrations under microencapsulation were compared with that when non-encapsulated,and the dynamic process of cellular bleb was investigated.Finally,the qualitative relationship between bleb size and cell viability in the presence of DMSO was built,and thus the effects of microencapsulation on bleb size and viability were evaluated.The results show that the bleb size is smaller and the cell viability is higher,and cell microencapsulation can significantly inhibit the excessively large blebs generated on the cell membrane and reduce the osmotic damage to cells when loading cryoprotectant and then to improve cell viability during cryopreservation.This work can provide insights for optimizing cryoprotectant-loading protocols,offer a new avenue to study cell blebbing,and advance future research on cryopreservation of rare cells and biomaterials.展开更多
The osmotic pressure represented as a sign of plant tolerance or sensitive to salinity stress. In the following plants, the increase in OP seems to be a manner of defense mechanism to survive. OP increased in shoots o...The osmotic pressure represented as a sign of plant tolerance or sensitive to salinity stress. In the following plants, the increase in OP seems to be a manner of defense mechanism to survive. OP increased in shoots of maize, shoot and root of wheat and cotton plants was concomitant with shoot soluble sugar, root soluble protein and shoot and root amino acids of maize plants. However, in wheat the increase in OP was related with increase of root soluble sugar and protein of shoots and roots. In cotton plants, the elevation of OP was run parallel with increase soluble sugar of shoots and roots, shoot soluble protein and root amino acids. The increase in OP was related with a marked and significant reduction in the water content of these plants. However, the decrease in OP of shoot and root of broad bean was related with the reduction of shoots and roots soluble sugar, protein and root amino acids of broad bean. While the OP becomes more or less unchanged in shoots and tended to decrease in root of parsley plants, this concomitant with unchanged trend in the shoots amino acids and reduction in root soluble sugar and root amino acids. Run with previous trend values of OP and metabolites of parsley plants were related with stable values in shoot water content and reduction in root water content. With GA<sub>3</sub> and kinetin treatments mostly increase the values OP which parallel with increase and soluble sugar, soluble protein and amino acids contents of shoots and roots of maize, wheat, cotton, broad bean and parsley plants with NaCl increasing. This related with increase water uptake by roots in these plants. The results indicated that kinetin had a more effective to shoot maize, both organs of wheat, broad bean and parsley plants in response to salinity stress while GA<sub>3</sub> was more effective on cotton plants especially at higher levels of salinity. Thus plants strategy differed in their tolerance to salinity stress according to their species and differed also according to the different organs of the same plants and kinetin treatment induced highly positively affect than GA<sub>3</sub> treatments.展开更多
Osmotic stress promotes somatic embryogenesis of Fraxinus mandshurica,which leads to accumulation of reactive oxygen species(ROS).The single pieces of cotyledons of F.mandshurica were used as explants to induce somati...Osmotic stress promotes somatic embryogenesis of Fraxinus mandshurica,which leads to accumulation of reactive oxygen species(ROS).The single pieces of cotyledons of F.mandshurica were used as explants to induce somatic embryogenesis in osmotic-stress medium.Furthermore,the hydrogen peroxide H_(2)O_(2) content of explanted cells was varied by adding exogenous H_(2)O_(2) or catalase solution to assess the effects of the exogenous H_(2)O_(2)on somatic embryogenesis,intracellular H_(2)O_(2)accumulation,and the relationship between signaling mediated by ROS or reactive nitrogen species.The results revealed that exogenous H_(2)O_(2)(100?300μmol L^(–1))increased the number of somatic embryos.On 60th day of exogenous H_(2)O_(2)(200μmol L^(–1))treatment,the number of somatic embryos of explants treated,which was 136.54%,was higher than the control.Moreover,exogenous H_(2)O_(2)(100μmol L^(–1))significantly increased the intracellular H_(2)O_(2)content and enhanced the activities of superoxidase dismutase and peroxidase.Finally,exogenous H_(2)O_(2)(100μmol L^(–1))activated the intracellular non-enzymatic pathway for nitric oxide(NO)synthesis.The somatic embryogenesis in broadleaf trees increases with the change of endogenic ROS content,and depends on the upregulation of antioxidant enzymes.Both H_(2)O_(2)and NO,as signaling molecules,were found to be involved in the process of somatic embryogenesis in broadleaf trees.In the process of exogenous H_(2)O_(2)promoting somatic embryogenesis,NO synthesis depended on non-enzymatic reactions.These results provide a scientific basis for resolving the mechanism by which ROS levels are regulated during somatic embryogenesis of broadleaf trees and establish a reasonable and efficient technology system for regulating somatic embryogenesis of trees.展开更多
In plants,glycerol-3-phosphate dehydrogenase(GPDH)catalyzes the interconversion of glycerol-3-phosphate(G3P)and dihydroxyacetone phosphate(DHAP)coupled to the reduction/oxidation of the nicotinamide adenine dinucleoti...In plants,glycerol-3-phosphate dehydrogenase(GPDH)catalyzes the interconversion of glycerol-3-phosphate(G3P)and dihydroxyacetone phosphate(DHAP)coupled to the reduction/oxidation of the nicotinamide adenine dinucleotide(NADH)pool,and plays a central role in glycerolipid metabolism and stress response.Previous studies have focused mainly on the NAD+-dependent GPDH isoforms,neglecting the role of flavin adenine dinucleotide(FAD)-dependent GPDHs.We isolated and characterized three mitochondrialtargeted FAD-GPDHs in soybean,of which one isoform(GmGPDH12)showed a significant transcriptional response to NaCl and mannitol treatments,suggesting the existence of a major FAD-GPDH isoform acting in soybean responses to salt and osmotic stress.An enzyme kinetic assay showed that the purified GmGPDH12 protein possessed the capacity to oxidize G3P to DHAP in the presence of FAD.Overexpression and RNA interference of GmGPDH12 in soybean hairy roots resulted in elevated tolerance and sensitivity to salt and osmotic stress,respectively.G3P contents were significantly lower in GmGPDH12-overexpressing hair roots and higher in knockdown hair roots,indicating that GmGPDH12 was essential for G3P catabolism.A significant perturbation in redox status of NADH,ascorbic acid(ASA)and glutathione(GSH)pools was observed in GmGPDH12-knockdown plants under stress conditions.The impaired redox balance was manifested by higher reactive oxygen species generation and consequent cell damage or death;however,overexpressing plants showed the opposite results for these traits.GmGPDH12 overexpression contributed to maintaining constant respiration rates under salt or osmotic stress by regulating mRNA levels of key mitochondrial respiratory enzymes.This study provides new evidence for the roles of mitochondria-localized GmGPDH12 in conferring resistance to salt or osmotic stress by maintaining cellular redox homeostasis,protecting cells and respiration from oxidative injury.展开更多
Plants maintain water balance by varying hydraulic properties, and plasma membrane intrinsic proteins(PIPs) may be involved in this process. Leaf xylem and root hydraulic conductivity and the m RNA contents of four hi...Plants maintain water balance by varying hydraulic properties, and plasma membrane intrinsic proteins(PIPs) may be involved in this process. Leaf xylem and root hydraulic conductivity and the m RNA contents of four highly expressed Zm PIP genes(Zm PIP1;1, Zm PIP1;2, Zm PIP2;2, and Zm PIP2;5) in maize(Zea mays) seedlings were investigated. Under well-watered conditions, leaf hydraulic conductivity(K_(leaf)) varied diurnally and was correlated with whole-plant hydraulic conductivity. Similar diurnal rhythms of leaf transpiration rate(E), K_(leaf) and root hydraulic conductivity(K_(root)) in well-watered plants are important for maintaining whole-plant water balance. After 2 h of osmotic stress treatment induced by 10% polyethylene glycol 6000, the K_(root) of stressed plants decreased but K_(leaf) increased, compared with well-watered plants. The m RNA contents of four Zm PIPs were significantly up-regulated in the leaves of stressed plants, especially for Zm PIP1;2. Meanwhile, Zm PIP2;5 was significantly down-regulated in the roots of stressed plants. After 4 h of osmotic stress treatment, the E and leaf xylem water potentials of stressed plants unexpectedly increased. The increase in K_(leaf) and a partial recovery of K_(root) may have contributed to this process. The m RNA content of Zm PIP1;2 but not of the other three genes was up-regulated in roots at this time. In summary, the m RNA contents of these four Zm PIPs associated with K_(leaf) and K_(root) change in maize seedlings during short-term osmotic stress, especially for Zm PIP1;2 and Zm PIP2;5, which may help to further reveal the hydraulic resistance adjustment role of Zm PIPs.展开更多
基金supported by grants from the National Natural Science Foundation of China(31971824,32170316)。
文摘SubclassⅢsucrose nonfermenting1-related protein kinase 2s(SnRK2s)function in ABA and abiotic stress responses by unknown mechanisms.We found that osmotic stress/ABA-activated protein kinase 10(SAPK10),a member of rice SnRK2s,physically interacted with CBL-interacting protein kinase 1(OsCIPK1).OsCIPK1 expression was up-regulated by ABA and PEG treatment,and overexpression increased the ABA sensitivity of seed germination and root growth and plant osmotic stress tolerance.Osmotic stress or ABA-induced activation of OsCIPK1 is dependent on SAPK10.SAPK10 phosphorylates Thr-24 of OsCIPK1 in vitro,and this phosphorylation increases the activity of OsCIPK1 and positively regulates the function of OsCIPK1 in ABA responses and plant osmotic stress tolerance.This study suggests that OsCIPK1 is a direct phosphorylated substrate of SAPK10,and SAPK10-mediated phosphorylation of OsCIPK1 functions in ABA signaling and increases rice osmotic stress tolerance.
文摘Matric suction is an important state variable required for the assessment of unsaturated soil properties.Tensiometers are commonly used for direct matric suction measurement but have a limited measuring range up to 90 kPa due to the cavitation problem.Osmotic tensiometer(OT)can improve the measuring range of tensiometers by increasing the osmotic pressure of water to avoid the cavitation.However,the long-term water pressure decay that appeared in OTs caused a gradual decrease in their measuring range.In this study,crosslinked poly(acrylamide-co-acrylic acid)potassium salt(PAM-co-PAAK)was used for the preparation of OTs(five in total)to explore the mechanism of water pressure decay of OTs.The maximum water pressure in the OT versus the volume fraction of polymer filled in the OT was described based on the Flory-Huggins polymer theories and validated using WP4C dewpoint hygrometer.The long-term pressure decay of OT-1,OT-2,and OT-3 was observed for 130 d and constant pressures were found for OT-1 and OT-2,indicating that the pressure decay of OT was mainly caused by the stress relaxation of the polymer hydrogels,and standard linear solid(SLS)rheological model was appropriate to fit the decay data.For OT-1,OT-2 and OT-3,the theoretical osmotic pressure that was calculated based on the mass of retrieved polymer from OTs after 130-d pressure observation was higher than the actual osmotic pressure as observed,indicating that polymer leakage cannot explain the pressure decay of the OT.The ultravioletevisible(UVevisible)spectrophotometry examined the change in polymer concentrations in the water containers of OT-4 and OT-5 and demonstrated that there was no increase in polymer leakage during the period of pressure decay of OT-4 and OT-5.As a result,the pressure decay of OT was not caused by polymer leakage.The results of this research suggested that the viscoelastic properties of polymers should be taken into consideration in further OT development.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2019D01C069)Natural Science Foundation of Xinjiang University(No.62031224614)。
文摘Nitraria sibirica Pall.is an important shrub with a strong salt-alkali tolerance,but the mechanism underlying this tolerance remains obscure.In this study,N.sibirica,with salt-sensitive Vigna radiata(Linn.)Wilczek as the control,was subjected to transient salt stress(100 mM NaCl),alkali stress(50 mM Na_(2)CO_(3)),and osmotic stress(175 mM mannitol).The ionic fluxes of Na^(+)and K^(+)in the root apical region were measured.Results show that,under salt and alkali stress,N.sibirica roots exhibited higher capacities to limit Na+influx and reduce K+efflux,thereby resulting in lower Na^(+)/K^(+)ratios compared with V.radiata roots.Alkali stress induced stronger Na^(+)influx and K+efflux in the root salt stress treatment;Na^(+)influx was mainly observed in the root cap,while K^(+)efflux was mainly observed in the elongation zone.While under osmotic stress,N.sibirica roots showed stronger Na+efflux and weaker K+efflux than V.radiata roots.Na+efflux was mainly observed in the root elongation zone,while K+efflux was in the root cap.These results reveal the ionic strategy of N.sibirica in response to transient salt,alkali,and osmotic stresses through the regulation of Na+/K+flux homeostasis.
文摘The aim of the study was to develop actarit double-layered osmotic pump tablets to overcome the weak points of actarit common tablets, such as short half-life and large plasma concentration fluctuations. Single factor experiment and orthogonal test were applied to optimize the formulation;the pharmacokinetic study was performed in beagle dogs adopting actarit common tablets as reference tablets. The optimal formulation was as follows: drug layer: 150 mg actarit, 240 mg PEO-N80, 50 mg NaCl;push layer: 140 mg PEO-WSR303, 20 mg NaCl;coating solution: 30 g cellulose acetate and 6 g PEG 4000 in 1000 ml 94% acetone solution, 60 mg coating weight gain. The pharmacokinetic study showed that T max was prolonged by the contrast of commercial common tablets with constant drug release rate, but the bioavailability was equivalent. And a good in vivo –in vitro correlation of the actarit osmotic pump tablets was also established. The designed actarit osmotic pump tablets can be applied for rheumatoid arthritis, proposing a promising replacement for the marked common products.
基金supported by the National Key Basic Research Program of China (2014CB138703-2)the National Natural Science Foundation of China (31472139)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences (ASTIPIAS14)
文摘Alfalfa is widely grown and is one of the most important forage crops in the world, but its growth and biomass production are markedly reduced under salt and drought stress, particularly during the early seedling stage. To identify the mechanisms behind salt and drought responsiveness at the alfalfa seedling stage, the proteins expressed were analyzed under no-treatment, 200 mol L–1 Na Cl and 180 g L–1 PEG treatment conditions during the seedling stage. Out of more than 800 protein spots detected on two-dimensional electrophoresis(2-DE) g els, 35 proteins showed statistically significant responses(P<0.05) to Na Cl and PEG stress, which were selected for tandem mass spectrometric identification, owing to their good resolution and abundance levels, and 32 proteins were positively identified. The identified proteins were divided into seven functional categories: photosynthetic metabolism, protein biosynthesis, folding and assembly, carbohydrate metabolism-associated proteins, stress defense related protein, metabolism of nucleic acid, other function categories and unknown proteins. Our results suggested that these proteins may play roles in alfalfa adaptation to salt and drought stress. Further study of these proteins will provide insights into the molecular mechanisms of abiotic stress and the discovery of new candidate markers in alfalfa.
基金supported by the National Natural Science Foundation of China(31871552 and 31671445)the Sichuan Science and Technology Program,China(2018HH0108)the Sichuan Innovation Team Project of National Modern Agricultural Industry Technology System,China(sccxtd-2020-20)。
文摘Intensively farmed crops used to experience numerous environmental stresses.Among these,shade and drought significantly influence the morpho-physiological and biochemical attributes of plants.However,the interactive effect of shade and drought on the growth and development of soybean under dense cropping systems has not been reported yet.This study investigated the interactive effect of PEG-induced osmotic stress and shade on soybean seedlings.The soybean cultivar viz.,C-103 was subjected to PEG-induced osmotic stress from polyethylene glycol 6000(PEG-6000)under shading and non-shading conditions.PEG-induced osmotic stress significantly reduced the relative water contents,morphological parameters,carbohydrates and chlorophyll contents under both light environments.A significant increase was observed in osmoprotectants,reactive oxygen species and antioxidant enzymes in soybean seedlings.Henceforth,the findings revealed that,seedlings grown under non-shading conditions produced more malondialdehyde and hydrogen peroxide contents as compared to the shade-treated plants when subjected to PEG-induced osmotic stress.Likewise,the shaded plants accumulated more sugars and proline than non-shaded ones under drought stress.Moreover,it was found that nonshaded grown plants were more sensitive to PEG-induced osmotic stress than those exposed to shading conditions,which suggested that shade could boost the protective mechanisms against osmotic stress or at least would not exaggerate the adverse effects of PEG-induced osmotic stress in soybean seedlings.
文摘One purpose of this study was to develop a paliperidone(PAL)tri-layer ascending release pushepull osmotic pump(TA-PPOP)tablet which could meet the needs of clinical applications.And another purpose was to investigate whether different coating materials influenced in vivo performance of TA-PPOP.The ascending release mechanism of this trilayer delivery system on theory was elaborated.TA-PPOP was prepared by means of coating with cellulose acetate(CA)or ethyl cellulose(EC).Several important influence factors such as different core tablet compositions and different coating solution ingredients involved in the formulation procedure were investigated.The optimization of formulation and process was conducted by comparing different in vitro release behaviors of PAL.In vitro dissolution studies indicated that both the two formulations of different coating materials were able to deliver PAL at an ascending release rate during the whole 24 h test.The in vivo pharmacokinetics study showed that both self-made PPOP tablets with different coating had a good in vitro-in vivo correlation(IVIVC)and were bioequivalent with the brand product,which demonstrated no significant influence of the coating materials on the in vivo release acceleration of TA-PPOP.
基金This work was supported by the State Key Laboratory(Longacting and Targeting Drug Delivery System)by the Special Construction Project(Taishan Scholar–Pharmacy Specially Recruited Experts).
文摘In this investigation,time-released monolithic osmotic pump(TMOP)tablets containing diltiazem hydrochloride(DIL)were prepared on the basis of osmotic pumping mechanism.The developed dosage forms were coated by Kollidon®SR-Polyethylene Glycol(PEG)mixtures via compression-coated technology instead of spray-coating method to form the outer membrane.For more efficient formulation screening,a three-factor five-level central composite design(CCD)was introduced to explore the optimal TMOP formulation during the experiments.The in vitro tests showed that the optimized formulation of DIL-loaded TMOP had a lag time of 4 h and a following 20-h drug release at an approximate zero-order rate.Moreover,the releasemechanismwas proven based on osmotic pressure and its profile could be well simulated by a dynamic equation.After oral administration by beagle dogs,the comparison of parameters with the TMOP tablets and reference preparations show no significant differences for C_(max)(111.56±20.42,128.38±29.46 ng/ml)and AUC_(0-48 h)(1654.97±283.77,1625.10±313.58 ng h/ml)but show significant differences for T_(max)(13.00±1.16,4.00±0.82 h).These pharmacokinetic parameters were consistent with the dissolution tests that the TMOP tablets had turned out to prolong the lag time of DIL release.
基金This work was financially supported by the major project of the National Science and Technology of China for new drugs development(2009ZX09310-004).
文摘Elementary osmotic pump(EOP)is a unique extended release(ER)drug delivery system based on the principle of osmosis.It has the ability to minimize the amount of the drug,accumulation and fluctuation in drug level during chronic uses.Carbamazepine(CBZ),a poorly water-soluble antiepileptic drug,has serious side effects on overdoses and chronic uses.The aim of the present study was to design a new EOP tablet of CBZ containing a solubility enhancers and swellable polymer to reduce its side effects and enhance the patient compliance.Firstly,a combination of solubilizing carriers was selected to improve the dissolution of the slightly soluble drug.Then,designing the new EOP tablet and investigating the effect of different variables of core and coat formulations on drug release behavior by single parameter optimization and by Taguchi orthogonal design with analysis of variance(ANOVA),respectively.The results showed that CBZ solubility was successfully enhanced by a minimum amount of combined polyvinyl pyrrolidone(PVP K30)and sodium lauryl sulfate(SLS).The plasticizer amount and molecular weight(MW)together with the osmotic agent amount directly affect the release rate whereas the swellable polymer amount and viscosity together with the semi-permeable membrane(SPM)thickness inversely influence the release rate.In addition,the tendency of following zero order kinetics was mainly affected by the coat components rather than those of the core.Further,orifice size does not have any significant effect on the release behavior within the range of 0.1 mm to 0.8 mm.In this study we report the successful formulation of CBZ-EOP tablets,which were similar to the marketed product Tegretol CR 200 and able to satisfy the USP criterion limits and to deliver about 80%of CBZ at a rate of approximately zero order for up to 12 h.
基金This study is financially supported by the major project of National Science and Technology of China for new drugs development(No.2009ZX09310-004)Jiangsu Province Ordinary College and University innovative research programs(No.CX10B-374Z).
文摘The work aims to investigate the in vitro release,pharmacokinetics(PK),pharmacodynamics(PD)and PK-PD relationships of Salvianolic Acid B micro-porous osmotic pump pellets(SalB-MPOPs)in angina pectoris New Zealand White(NZW)rabbits,compared with those of SalB immediate-release pellets(SalB-IRPs).The SalB plasma concentrations and Superoxide dismutase levels(PD index)were recorded continuously at predetermined time interval after administration,and the related parameters were calculated by using Win-Nonlin software.The release profile of MPOPs was more sustained than that of IRPs.PK results indicated that the mean C_(max) was significantly lower,the SalB plasma concentrations were steadier,both area under concentration-time curve from 0 to 24 h(AUC_(0-24 h))and from 0 to infinity(AUC_(0-∞))were presented larger,and both the peak concentration time(T_(max))and mean residence time(MRT)were prolonged for MPOPs,as compared with those of IRPs.PD results suggested that peak drug effect(E_(max))was lower and the equilibration rate constant(k_(e0))between the central compartment and the effect compartment was higher of MPOPs vs.those of IRPs.PKePD relationships demonstrated that the effectconcentration-time(ECT)course of MPOPs was clockwise hysteresis loop,and that of IRPs was counter-clockwise hysteresis loop.Collectively,those results demonstrated that MPOPs were potential formulations in treating angina pectoris induced by atherosclerosis.
基金Project supported by the Joint Funds of Xinjiang Natural Science Foundation,China (Grant No.2022D01C336)School Level Key Projects of Yili Normal University (Grant No.2020YSZD003)+1 种基金the National Natural Science Foundation of China (Grant Nos.11904167 and 22163011)the Postgraduate Scientific Research Innovation Project of Xinjiang, China (Grant No.XJ2022G230)
文摘Osmotic pressure can break the fluid balance between intracellular and extracellular solutions.In hypo-osmotic so-lution,water molecules,which transfer into the cell and burst,are driven by the concentration difference of solute across the semi-permeable membrane.The complicated dynamic processes of intermittent bursts have been previously observed.However,the underlying physical mechanism has yet to be thoroughly explored and analyzed.Here,the intermittent re-lease of inclusion in giant unilamellar vesicles was investigated quantitatively,applying the combination of experimental and theoretical methods in the hypo-osmotic medium.Experimentally,we adopted a highly sensitive electron multiplying charge-coupled device to acquire intermittent dynamic images.Notably,the component of the vesicle phospholipids af-fected the stretch velocity,and the prepared solution of vesicles adjusted the release time.Theoretically,we chose equations and numerical simulations to quantify the dynamic process in phases and explored the influences of physical parameters such as bilayer permeability and solution viscosity on the process.It was concluded that the time taken to achieve the balance of giant unilamellar vesicles was highly dependent on the molecular structure of the lipid.The pore lifetime was strongly related to the internal solution environment of giant unilamellar vesicles.The vesicles prepared in viscous solution were able to visualize long-lived pores.Furthermore,the line tension was measured quantitatively by the release velocity of inclusion,which was of the same order of magnitude as the theoretical simulation.In all,the experimental values well matched the theoretical values.Our investigation clarified the physical regulatory mechanism of intermittent pore forma-tion and inclusion release,which provides an important reference for the development of novel technologies such as gene therapy based on transmembrane transport as well as controlled drug delivery based on liposomes.
基金supported by the National Key Research and Development Program of China(2016YFC0501203)the National Genetically Modified Organism Project(2016ZX08010005-9)。
文摘Plant mitochondrial phosphate transporters regulate phosphate transport and ATP synthesis. Determining whether they function in abiotic stress response process would shed light on their response to salt stress. We used the CRISPR/Cas9 gene-editing system to mutagenize two mitochondrial phosphate transporters, OsMPT3;1 and OsMPT3;2, to investigate their regulatory roles under salt stress. Two cas9(CRISPR-associated protein9)-free homozygous mutants, mpt33 and mpt30, were confirmed to be stable. Both OsMPT3;1 and OsMPT3;2 were markedly induced by salt stress, and their mutagenesis strongly inhibited growth and development, especially under salt stress. Mutagenesis sharply reduced the accumulation of ATP, phosphate, calcium, soluble sugar, and proline and increased osmotic potential, malondialdehyde, and Na^+ /K^+ ratio under salt stress. Both mutants demonstrate normal growth and development in the presence of ATP, revealing high sensitivity to exogenous ATP under salt stress. The mutants showed lowered rates of Na^+ efflux but also of K^+ and Ca^(2+) influx under salt stress. Mutagenesis of OsMPT3;2 altered the enrichment profiles of differentially expressed genes involved mainly in synthesis of secondary metabolites, metabolism of glycolysis, pyruvate, tricarboxylic acid cycle, in response to salt stress. The mutant displayed significant accumulation differences in 14 metabolites involved in 17 metabolic pathways, and strongly up-regulated the accumulation of glutamine, a precursor in proline synthesis, under salt stress. These findings suggest that the OsMPT3 gene modulates phosphate transport and energy supply for ATP synthesis and triggers changes in accumulation of ions and metabolites participating in osmotic regulation in rice under salt stress, thus increasing rice salt tolerance. This study demonstrates the effective application of CRISPR/Cas9 gene-editing to the investigation of plant functional genes.
基金Supported by Operating funds awarded by the Canadian Institutes of Health Research(to Churchill TA)salary award from Alberta Heritage Foundation for Medical Research(to Kokotilo MS)
文摘AIM: To investigate the effects of dextrans of various molecular weights (Mw) during a 12 h cold storage time-course on energetics, histology and mucosal infiltration of fluorescein isothiocyanate (FITC)-dextran. METHODS: Rodent intestines were isolated and received a standard University of Wisconsin vascular flush followed by intraluminal administration of a nutrientrich preservation solution containing dextrans of varying Mw: Group D1, 73 kdal; Group D2, 276 kdal; Group D3, 534 kdal; Group D4, 1185 kdal; Group D5, 2400 kdal. RESULTS: Using FITC-labeled dextrans, fluorescent micrographs demonstrated varying degrees of mucosal infiltration; lower Mw (groups D1-D3: 73-534 kdal) dextrans penetrated the mucosa as early as 2 h, whereas the largest dextran (D5: 2400 kdal) remained captive within the lumen and exhibited no permeability even after 12 h. After 12 h, median injury grades ranged from 6.5 to 7.5 in groups D1-D4 (73-1185 kdal) representing injury of the regenerative cryptal regions and submucosa; this was in contrast to group D5 (2400 kdal) which exhibited villus denudation (with intact crypts) corresponding to a median injury grade of 4 (P < 0.05). Analysis of tissue energetics reflected a strong positive correlation between Mw and adenosine triphosphate (r 2 = 0.809), total adenylates (r 2 = 0.865) and energy charge (r 2 = 0.667).CONCLUSION: Our data indicate that dextrans of Mw > 2400 kdal act as true impermeant agents during 12 h ischemic storage when incorporated into an intraluminal preservation solution.
文摘Interstitial fluid movement in the brain parenchyma has been suggested to contribute to sustaining the metabolism in brain parenchyma and maintaining the function of neurons and glial cells.The pulsatile hydrostatic pressure gradient may be one of the driving forces of this bulk flow.However,osmotic pressure- related factors have not been studied until now.In this prospective observational study,to elucidate the relationship between osmolality (mOsm/kg) in the serum and that in the cerebrospinal fluid (CSF),we simultaneously measured the serum and CSF osmolality of 179 subjects with suspected neurological conditions.Serum osmolality was 283.6 ± 6.5 mOsm/kg and CSF osmolality was 289.5 ± 6.6 mOsm/kg.Because the specific gravity of serum and CSF is known to be 1.024–1.028 and 1.004–1.007,respectively,the estimated average of osmolarity (mOsm/L) in the serum and CSF covered exactly the same range (i.e.,290.5–291.5 mOsm/L).There was strong correlation between CSF osmolality and serum osmolality,but the difference in osmolality between serum and CSF was not correlated with serum osmolality,serum electrolyte levels,protein levels,or quotient of albumin.In conclusion,CSF osmolarity was suggested to be equal to serum osmolarity.Osmolarity is not one of the driving forces of this bulk flow.Other factors such as hydrostatic pressure gradient should be used to explain the mechanism of bulk flow in the brain parenchyma.This study was approved by the Institutional Review Board of the Tohoku University Hospital (approval No.IRB No.2015-1-257) on July 29,2015.
基金partially supported by the National Natural Science Foundation of China (81571768)
文摘In cryopreservation,the addition of cryoprotectant can change the intra-and extra-cellular osmotic pressure,affect the cell morphology,and induce blebs on the plasma membrane.In this study,the blebs of cells microencapsulated in the alginate microsphere induced by osmotic shock were studied,and the effects of microencapsulation on bleb size and cell viability were determined.Firstly,a coaxial co-flow focusing device was applied to generate cell-laden microcapsules using alginate hydrogel in this paper.Then,cellular blebs induced by DMSO with various concentrations under microencapsulation were compared with that when non-encapsulated,and the dynamic process of cellular bleb was investigated.Finally,the qualitative relationship between bleb size and cell viability in the presence of DMSO was built,and thus the effects of microencapsulation on bleb size and viability were evaluated.The results show that the bleb size is smaller and the cell viability is higher,and cell microencapsulation can significantly inhibit the excessively large blebs generated on the cell membrane and reduce the osmotic damage to cells when loading cryoprotectant and then to improve cell viability during cryopreservation.This work can provide insights for optimizing cryoprotectant-loading protocols,offer a new avenue to study cell blebbing,and advance future research on cryopreservation of rare cells and biomaterials.
文摘The osmotic pressure represented as a sign of plant tolerance or sensitive to salinity stress. In the following plants, the increase in OP seems to be a manner of defense mechanism to survive. OP increased in shoots of maize, shoot and root of wheat and cotton plants was concomitant with shoot soluble sugar, root soluble protein and shoot and root amino acids of maize plants. However, in wheat the increase in OP was related with increase of root soluble sugar and protein of shoots and roots. In cotton plants, the elevation of OP was run parallel with increase soluble sugar of shoots and roots, shoot soluble protein and root amino acids. The increase in OP was related with a marked and significant reduction in the water content of these plants. However, the decrease in OP of shoot and root of broad bean was related with the reduction of shoots and roots soluble sugar, protein and root amino acids of broad bean. While the OP becomes more or less unchanged in shoots and tended to decrease in root of parsley plants, this concomitant with unchanged trend in the shoots amino acids and reduction in root soluble sugar and root amino acids. Run with previous trend values of OP and metabolites of parsley plants were related with stable values in shoot water content and reduction in root water content. With GA<sub>3</sub> and kinetin treatments mostly increase the values OP which parallel with increase and soluble sugar, soluble protein and amino acids contents of shoots and roots of maize, wheat, cotton, broad bean and parsley plants with NaCl increasing. This related with increase water uptake by roots in these plants. The results indicated that kinetin had a more effective to shoot maize, both organs of wheat, broad bean and parsley plants in response to salinity stress while GA<sub>3</sub> was more effective on cotton plants especially at higher levels of salinity. Thus plants strategy differed in their tolerance to salinity stress according to their species and differed also according to the different organs of the same plants and kinetin treatment induced highly positively affect than GA<sub>3</sub> treatments.
基金supported by the National Natural Science Foundation of China(31570596 and 31400535)the Fundamental Research Funds for the Central Universities(2572018BW02)+1 种基金the Innovation Project of State Key Laboratory of Tree Genetics and Breeding(Northeast Forestry University,2016C01)the National Key R&D Program of China(2017YFD0600600)。
文摘Osmotic stress promotes somatic embryogenesis of Fraxinus mandshurica,which leads to accumulation of reactive oxygen species(ROS).The single pieces of cotyledons of F.mandshurica were used as explants to induce somatic embryogenesis in osmotic-stress medium.Furthermore,the hydrogen peroxide H_(2)O_(2) content of explanted cells was varied by adding exogenous H_(2)O_(2) or catalase solution to assess the effects of the exogenous H_(2)O_(2)on somatic embryogenesis,intracellular H_(2)O_(2)accumulation,and the relationship between signaling mediated by ROS or reactive nitrogen species.The results revealed that exogenous H_(2)O_(2)(100?300μmol L^(–1))increased the number of somatic embryos.On 60th day of exogenous H_(2)O_(2)(200μmol L^(–1))treatment,the number of somatic embryos of explants treated,which was 136.54%,was higher than the control.Moreover,exogenous H_(2)O_(2)(100μmol L^(–1))significantly increased the intracellular H_(2)O_(2)content and enhanced the activities of superoxidase dismutase and peroxidase.Finally,exogenous H_(2)O_(2)(100μmol L^(–1))activated the intracellular non-enzymatic pathway for nitric oxide(NO)synthesis.The somatic embryogenesis in broadleaf trees increases with the change of endogenic ROS content,and depends on the upregulation of antioxidant enzymes.Both H_(2)O_(2)and NO,as signaling molecules,were found to be involved in the process of somatic embryogenesis in broadleaf trees.In the process of exogenous H_(2)O_(2)promoting somatic embryogenesis,NO synthesis depended on non-enzymatic reactions.These results provide a scientific basis for resolving the mechanism by which ROS levels are regulated during somatic embryogenesis of broadleaf trees and establish a reasonable and efficient technology system for regulating somatic embryogenesis of trees.
基金financially supported by National Natural Science Foundation of China(31701449,31971968,31971899,31501332)National Key Research and Development Program of China(2016YFD 0100500,2016YFD0100300,2016YFD0100201-21,JFYS2016ZY03003792-01-21)+7 种基金China Postdoctoral Science Foundation(2019M661243)Postdoctoral Project of Northeast Agricultural University(NEAUBH-19002)EUCLEG(727312,2017YFE0111000)Natural Science Foundation of Heilongjiang Province(QC2017013)Special Financial Aid to Post-doctor Research Fellow in Heilongjiang(LBH-TZ1714)Heilongjiang Academy of Agricultural Sciences Funds(2019YYYF019)International Postdoctoral Exchange Fellowship Program of China Postdoctoral Council(20180004)Heilongjiang Funds for Distinguished Young Scientists(JC2016004,JC2017006)。
文摘In plants,glycerol-3-phosphate dehydrogenase(GPDH)catalyzes the interconversion of glycerol-3-phosphate(G3P)and dihydroxyacetone phosphate(DHAP)coupled to the reduction/oxidation of the nicotinamide adenine dinucleotide(NADH)pool,and plays a central role in glycerolipid metabolism and stress response.Previous studies have focused mainly on the NAD+-dependent GPDH isoforms,neglecting the role of flavin adenine dinucleotide(FAD)-dependent GPDHs.We isolated and characterized three mitochondrialtargeted FAD-GPDHs in soybean,of which one isoform(GmGPDH12)showed a significant transcriptional response to NaCl and mannitol treatments,suggesting the existence of a major FAD-GPDH isoform acting in soybean responses to salt and osmotic stress.An enzyme kinetic assay showed that the purified GmGPDH12 protein possessed the capacity to oxidize G3P to DHAP in the presence of FAD.Overexpression and RNA interference of GmGPDH12 in soybean hairy roots resulted in elevated tolerance and sensitivity to salt and osmotic stress,respectively.G3P contents were significantly lower in GmGPDH12-overexpressing hair roots and higher in knockdown hair roots,indicating that GmGPDH12 was essential for G3P catabolism.A significant perturbation in redox status of NADH,ascorbic acid(ASA)and glutathione(GSH)pools was observed in GmGPDH12-knockdown plants under stress conditions.The impaired redox balance was manifested by higher reactive oxygen species generation and consequent cell damage or death;however,overexpressing plants showed the opposite results for these traits.GmGPDH12 overexpression contributed to maintaining constant respiration rates under salt or osmotic stress by regulating mRNA levels of key mitochondrial respiratory enzymes.This study provides new evidence for the roles of mitochondria-localized GmGPDH12 in conferring resistance to salt or osmotic stress by maintaining cellular redox homeostasis,protecting cells and respiration from oxidative injury.
基金financially supported by the National Natural Science Foundation of China (31400527, 31501276)the National High-Tech R&D Program of China (2011AA100504)+1 种基金the Project 111 of the Ministry of Education of China (B12007)the Fund of State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, China (K318009902-1408)
文摘Plants maintain water balance by varying hydraulic properties, and plasma membrane intrinsic proteins(PIPs) may be involved in this process. Leaf xylem and root hydraulic conductivity and the m RNA contents of four highly expressed Zm PIP genes(Zm PIP1;1, Zm PIP1;2, Zm PIP2;2, and Zm PIP2;5) in maize(Zea mays) seedlings were investigated. Under well-watered conditions, leaf hydraulic conductivity(K_(leaf)) varied diurnally and was correlated with whole-plant hydraulic conductivity. Similar diurnal rhythms of leaf transpiration rate(E), K_(leaf) and root hydraulic conductivity(K_(root)) in well-watered plants are important for maintaining whole-plant water balance. After 2 h of osmotic stress treatment induced by 10% polyethylene glycol 6000, the K_(root) of stressed plants decreased but K_(leaf) increased, compared with well-watered plants. The m RNA contents of four Zm PIPs were significantly up-regulated in the leaves of stressed plants, especially for Zm PIP1;2. Meanwhile, Zm PIP2;5 was significantly down-regulated in the roots of stressed plants. After 4 h of osmotic stress treatment, the E and leaf xylem water potentials of stressed plants unexpectedly increased. The increase in K_(leaf) and a partial recovery of K_(root) may have contributed to this process. The m RNA content of Zm PIP1;2 but not of the other three genes was up-regulated in roots at this time. In summary, the m RNA contents of these four Zm PIPs associated with K_(leaf) and K_(root) change in maize seedlings during short-term osmotic stress, especially for Zm PIP1;2 and Zm PIP2;5, which may help to further reveal the hydraulic resistance adjustment role of Zm PIPs.
