Substrate is an important abiotic factor for burrowing shellfish,as it not only provides them with shelter,but also impose significant effect on their physiological metabolism.However,the physiological responses of bu...Substrate is an important abiotic factor for burrowing shellfish,as it not only provides them with shelter,but also impose significant effect on their physiological metabolism.However,the physiological responses of burrowing clams within various substrates get less attention due to difficulty in carrying out physiological tests in buried conditions.Consequently,this study investigated the burrowing behavior,feeding physiology and energy budget of Paphia undulata,which is an important aquaculture bivalve species in south China.The clams were exposed to mud and sand substrates with variable physical properties in the laboratory,to determine the suitable substrate conditions for this species.The results showed that the percentage of burrowing clams,digging index,burrowing time,burrowing depth and scope for growth(SFG)were higher in mud substrates with≥40%water content.Likewise,burrowing percentage,digging index,and burrowing depths were higher in substrates with≤40%sand content.Moreover,the burrowing depth had significant effect on the feeding physiology and SFG of P.undulata as clams burrowed at 6.3±1.8 cm had higher clearance rates and SFG as compared to other buried depths.This study further revealed that low water content in the sediment inhibited physiological performances of P.undulata by impairing feeding or absorption,hence reducing the SFG.In conclusion,mud substrate with≥40%water content or with≤40%sand content is suitable for proper burrowing and growth of P.undulata.Our findings therefore provide fundamental knowledge that will be applicable in the improvement of bottom aquaculture and conservation of P.undulata.展开更多
Background: Fatigue is commonly reported by cancer patients. In some instances it can persist after treatment is completed. In order to develop effective treatment strategies it is important to understand the mechanis...Background: Fatigue is commonly reported by cancer patients. In some instances it can persist after treatment is completed. In order to develop effective treatment strategies it is important to understand the mechanisms underlying the development of fatigue and to be able to predict those that may be at greatest risk of experiencing fatigue during and following treatment. The current paper examines predisposing factors for fatigue including altered fatty acid homeostasis in a cohort of breast cancer radiotherapy patients. Methodology: Patients had undergone breast-conserving surgery and adjuvant breast irradiation. Prior to radiotherapy the patients were free from significant fatigue. Levels of fatigue were determined prior to and following radiotherapy using the Functional Assessment of Cancer Therapy fatigue subscale. Plasma fatty acid levels, urinary and plasma amino acid levels, blood biochemistry factors and general health and lifestyle characteristics were assessed. Results: Following radiotherapy, significant fatigue affected approximately one third of the 26 patients and these subjects were then assigned to the fatigued cohort. Univariate analysis revealed that higher levels of the fatty acids myristic acid and eicosadienoic acid were present for the fatigued cohort prior to radiotherapy. Multivariate analysis also revealed that fatty acid homeostasis was altered between the fatigued and non-fatigued groups at baseline. Orthogonal partial least squares discriminant analysis of the general health, lifestyle and metabolic data revealed that the fatigued and non-fatigued patients could be clustered into two clearly separate groups. Conclusions: The results supported the proposition that the fatigued patients had an underlying metabolic homeostasis which may predispose them to the development of fatigue. Biochemical and general health profiling of breast cancer patients has the potential to identify those at most risk of developing significant fatigue following radiotherapy.展开更多
The foundations of proteomics are to study gene products and their regulatory roles within cells. Paradoxically, the only evidence that sperm cells make new proteins is through mitochondrial protein synthesis. Yet des...The foundations of proteomics are to study gene products and their regulatory roles within cells. Paradoxically, the only evidence that sperm cells make new proteins is through mitochondrial protein synthesis. Yet despite this, spermatozoa are the perfect candidates for mass spectrometry and hence, proteomic analysis. These enterprising cells use a plethora of post-translational modifications in order to gain functionality following their production within the testis. By using a combination of two-dimensional polyacrylamide gel electrophoresis （2D-PAGE）, and more recently liquid chromatography-mass spectrometry （LC-MS）/MS, recent advances in sperm cell biology, through the use of proteomics, is making unparalleled progress. The protein inventory lists being generated have shed light on transmembrane proteins, kinases and chaperones never previously recognized. In addition, the ability to isolate either phosphopeptides or glycopeptides and quantify the differences between cells of two different populations make proteomic analysis of spermatozoa a real chance to finally answer some age old questions.展开更多
To investigate the functions of fructokinase(FRK)in apple(Malus domestica)carbohydrate metabolism,we cloned the coding sequences of MdFRK1 and MdFRK2 from the‘Royal Gala’apple.The results showed that MdFRK2 expressi...To investigate the functions of fructokinase(FRK)in apple(Malus domestica)carbohydrate metabolism,we cloned the coding sequences of MdFRK1 and MdFRK2 from the‘Royal Gala’apple.The results showed that MdFRK2 expression was extremely high in shoot tips and young fruit.Analyses of heterologously expressed proteins revealed that MdFRK2 had a higher affinity for fructose than did MdFRK1,with Km values of 0.1 and 0.62 mM for MdFRK2 and MdFRK1,respectively.The two proteins,however,exhibited similar Vmax values when their activities were significantly inhibited by high concentrations of fructose.MdFRK2 ectopic expression was associated with a general decrease in fructose concentration in transgenic lines.In leaves,increased FRK activity similarly resulted in reduced concentrations of glucose and sucrose but no alterations in sorbitol concentration.When compared with those in the untransformed control,genes involved in sorbitol synthesis(A6PR)and the degradation pathway(SDH1/2)were significantly upregulated in transgenic lines,whereas those involved in sucrose synthesis(SPS1)and other degradation processes(SUSY4,NINV1/2,and HxK2)were downregulated.The activity of enzymes participating in carbohydrate metabolism was proportional to the level of gene expression.However,the growth performance and photosynthetic efficiency did not differ between the transgenic and wild-type plants.These results provide new genetic evidence to support the view that FRK plays roles in regulating sugar and sorbitol metabolism in Rosaceae plants.展开更多
General decline of understory cover can result from increased abundance of and foraging pressure by deer.But population size and degree of aggregation can increase for unpalatable understory plants that escape foragin...General decline of understory cover can result from increased abundance of and foraging pressure by deer.But population size and degree of aggregation can increase for unpalatable understory plants that escape foraging pressure.Clonal reproduction can enable unpalatable plant species to increase their population sizes while trending toward spatially aggregated distributions.However,the details of the relationship between clonal reproduction in unpalatable plants and their dynamics under intensive deer herbivory are not clear.We compared the population structures and spatial patterns of two coexisting unpalatable plant species,Arisaema ovale(with clonal reproduction)and A.peninsulae(without clonal reproduction)in a riparian forest intensively grazed by Sika deer,and examined the null hypothesis that the extent of spatial aggregation and local population size would not differ between the clonal and non-clonal Arisaema species.In a 0.36-ha plot,A.ovale had a larger population size(1087 individuals)with a higher abundance ratio of small plants(p<0.01)than A.peninsulae(84 individuals).Analyses of spatial point processes showed that both populations were spatially aggregated(p<0.05).The spatial aggregation of A.peninsulae,however,became weaker than that of A.ovale,when we excluded one dense patch originating from irregular seed dispersion.These results,excluding the aggregated distribution observed in A.peninsulae,suggested a substantial contribution of clonal reproduction to the expansion of the local A.ovale population following intensive grazing by Sika deer.展开更多
In this study,we investigated the chemical composition of dissolved solids in the Ca River basin,North-Central Vietnam.Water samples were collected from August 2017 to July 2018 at three hydrological stations located ...In this study,we investigated the chemical composition of dissolved solids in the Ca River basin,North-Central Vietnam.Water samples were collected from August 2017 to July 2018 at three hydrological stations located in the main stream of the Ca River.Carbonate weathering was found as the dominant process controlling the water chemistry in that area.The average concentrations of dissolved solids generally decreased from upstream to downstream,resulting in low concentrations of the major ions in the downstream basin.Variations in the concentrations of major chemical ions and suspended solids at discharge were also investigated.Major chemical weathering products were found to behave chemostatically with increasing discharges upstream.However,dilution behaviors of solutes were shown in both midstream and downstream.Primary evidence shows that water storage in reservoirs impacts a variety of suspended solids and dissolved solids in the Ca River.展开更多
A bench-scale biopiling experiment was conducted to hydrocarbon bioremediation in a chronically contaminated soil compare the ability of different techniques to enhance petroleum After 195 days, 10%-32% removal of TP...A bench-scale biopiling experiment was conducted to hydrocarbon bioremediation in a chronically contaminated soil compare the ability of different techniques to enhance petroleum After 195 days, 10%-32% removal of TPHs （total petroleum hydrocarbons） occurred in unamended soil （control）. Biostimulation by inorganic nutrient addition enhanced TPH removal （49%） confirming that bioremediation was nutrient limited and the soil contained a well-adapted hydrocarbonoclastic microbial community. The addition of organic amendments including green waste at 25% and 50% （w/w） and a commercial product called DaramendTM had a further biostimulatory effect （50%-66%, 34%-59% and 69%-80% TPH removal respectively）. Bioaugmentation using two commercially available petroleum hydrocarbon degrading microbial cultures with nutrients enhanced TPH removal in the case of RemActivTM （60%-69%）, but had a marginal effect using Recycler 102 （49%-55%）. The effect of a non-ionic surfactant in green waste amended soil was variable （52%-72% TPH reduction）, but its potential to enhance biodegradation presumably by promoting contaminant bioavailability was demonstrated. High degradation of artificially added polycyclic aromatic hydrocarbons （PAHs） occurred after 106 days （75%-84%）, but significant differences between the control and treatments were unapparent, suggesting that spiked soils do not reflect the behavior of contaminants in genuinely polluted and weathered soil.展开更多
Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth...Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth, temporal variation in cone yield, and seed quality in Korean pine plantation. In 2005, five thinning intensity levels (none, extreme, heavy, moderate and light) were set in 15 permanent plots in a 32-year-old Korean pine plantation at Mengjiagang Forest Farm, Jiamusi City, Heilongjiang Province. We recorded tree growth and seed cone production from 2013 to 2016, i.e., from 8 to 11 years after thinning. Except for height growth, thinning increased tree growth (diameter at breast height and crown size) and improved cone yield. The extreme thinning treatment (to 300 trees per hectare) resulted in the largest tree diameter, tree volume, crown size and 4-year cone production per tree. The highest cone yield per tree in the mast year (2014) was observed when stands were thinned to 500 trees per hectare (heavy thinning). Although the best cone and seed quality and the largest cone and seed mass per tree were recorded in the heavily thinned stand, no significant differences were found between heavy and moderate thinning stands (750 trees per hectare). At the stand level, the moderately thinned stand had the highest basal area, stock volume and seed cone production per stand. Our results suggest that thinning to 750 trees per hectare will improve timber and cone productivity in 40-year-old P. koraiensis stands.展开更多
This study aimed to elucidate the influence of inflow water on the salinity concentration process of a saline lake and the mass balance of Lake Issyk-Kul,a tectonic saltwater lake in Kyrgyzstan.Based on the survey res...This study aimed to elucidate the influence of inflow water on the salinity concentration process of a saline lake and the mass balance of Lake Issyk-Kul,a tectonic saltwater lake in Kyrgyzstan.Based on the survey results and meteorological data from 2012 to 2015,we analyzed the dissolved chemical composition loads due to water inflow.Then,we discussed the relationship between the increase in salinity and water inflow into the lake.Through the water quality analysis data,we used the tank model to estimate the river inflow and analyze the loads by the L-Q curve.The groundwater loads were then estimated from the average annual increase in salinity of the lake over a period of 30 a.The results suggest that Lake Issyk-Kul was temporarily freshened between about AD 1500 and 1800 when an outflowing river existed,and thereafter,it became a closed lake in AD 1800 and continued to remain a saline lake until present.The chemical components that cause salinization are supplied from the rivers and groundwater in the catchment area,and when they flow into the lake,Ca^(2+),HCO_(3)−and Mg^(2+)precipitate as CaCO_(3) and MgCO_(3).These compounds were confirmed to have been left on the lakeshore as evaporite.The model analysis showed that 1.67 mg/L of Ca^(2+)and Mg^(2+)supplied from rivers and groundwater are precipitated as evaporite and in other forms per year.On the other hand,salinity continues to remain in the lake water at a rate of 27.5 mg/L per year.These are the main causes of increased salinity in Lake Issyk-Kul.Since Na^(+)and Cl^(-)are considered to be derived from geothermal water,they will continue to flow in regardless of the effects of human activities.Therefore,as long as these components are accumulated in Lake Issyk-Kul as a closed lake,the salinity will continue to increase in the future.展开更多
Fatigue RevivaTM was developed to provide a source of amino acids for rapid uptake by the body while avoiding the need for digestion of proteins. Complex amino acid formulations have significant palatability issues an...Fatigue RevivaTM was developed to provide a source of amino acids for rapid uptake by the body while avoiding the need for digestion of proteins. Complex amino acid formulations have significant palatability issues and thus new products require significant development and testing. An initial pilot study with 18 professional male athletes and 21 males recruited from the general public was undertaken to evaluate product palatability and tolerance over a 30 day period. This investigation found that Fatigue RevivaTM was well tolerated in terms of palatability and usage across 39 participants with only two of the 39 subjects reporting an issue with taste and five reporting an issue with flatulence. The professional athlete cohort reported a significantly lower level of fatigue compared with the general public group prior to commencement of supplementation. The general public group reported a significant reduction in fatigue following the use of Fatigue RevivaTM over the 30-day period. Compliance was extremely poor amongst the professional athlete group and as a result, changes in fatigue could not be statistically assessed for this group over the study period. Preliminary assessment of the product indicated that it has the potential to significantly reduce fatigue. Minor modifications to the product were identified for future development.展开更多
Combining compost with sufficient chemical N fertilizer (CF) in agricultural lands is a popular practice to reduce the amount of inorganic nitrogen and accumulation of non-nutrient constituents in soils. A pot culture...Combining compost with sufficient chemical N fertilizer (CF) in agricultural lands is a popular practice to reduce the amount of inorganic nitrogen and accumulation of non-nutrient constituents in soils. A pot culture experiment was conducted to study the effects of 130 mg N of either solids waste compost (Scomp) or biosolids waste compost (Bcomp) complemented with 130 mg (CF, 1N) and 260 mg·N·pot-1 (CF, 2N) as 15N labeled (NH4)2SO4 (13.172 atom %) on growth and N uptake by Italian ryegrass. A separate soil incubation without plants was set up by only blends of Scomp and CF. The results from pot culture experiment show that total plant biomass and N uptake from Bcomp were significantly higher than Scomp alone. Scomp combined with CF improved yield and N uptake over those of Scomp alone. For Scomp + 1N treatment, plant nitrogen uptake derived from compost and CF accounted for 29% and 56% of added N from Scomp and CF, respectively. The incubation study indicates that 16.08 - 29.62 mg·N·kg-1·soil·day-1 from inorganic-N were immobilized into organic pools, while only 0.40 - 0.66 mg·N·kg-1·soil·day-1 from organic-N were mineralized to inorganic pools. Because a part of additional N could be tied up in organic form, combining solids compost with chemical N fertilizer therefore need to consider the effective use of compost-N.展开更多
This study examined the solid waste generation and recycling potential of the hotel sector in Hue City, Vietnam. The authors conducted waste measurement, waste composition, and questionnaire surveys for 45 target hote...This study examined the solid waste generation and recycling potential of the hotel sector in Hue City, Vietnam. The authors conducted waste measurement, waste composition, and questionnaire surveys for 45 target hotels over ten consecutive days. The waste generation rates (WGRs) by rooms, beds, guests, and workers were assessed by hotel class using the following three waste categories, considering informal waste collection: general waste (GW), separated recyclables (SRe), and separated food residue (SFR). The 5-star hotels exhibited the highest WGR per room at 1.61 kg/room/day, while 1-star hotels exhibited the lowest per-room WGR (0.39 kg/room/day). Spearman Rank correlation test revealed that hotel class and per-room, per-bed, and per-guest WGRs were significantly positively correlated (p < 0.01). The major components of GW were food waste (40.9% to 57.4%), paper (10.1% to 20.3%), and plastic (10.7% to 15.5%). The recycling and composting potentials remaining in the GW were 19.3% to 38.5% and 38.0% to 57.9%, respectively. Based on the WGRs and waste composition determined in this study, the estimated total amount of waste generated was 6.88 tons/day (6.26 to 7.62 tons/day, 95% CI), of which 4.37 (64%), 2.13 (31%), and 0.38 tons/day (6%) were GW, SFR, and SRe, respectively. The recycling and composting potentials remaining in GW were 0.94 (13%) and 2.57 tons/day (37%), respectively. High-class hotels should be considered as the highest priority targets for a “reduce, reuse, recycle” (3R) promotion campaign in the future, with estimated recycling and composting potentials of 0.27 (4%) and 1.10 tons/day (16%), respectively.展开更多
This study was conducted to provide a detailed description of waste generation and characteristics from a traditional market in Hue city, located in central Vietnam. The authors conducted a waste generation survey and...This study was conducted to provide a detailed description of waste generation and characteristics from a traditional market in Hue city, located in central Vietnam. The authors conducted a waste generation survey and a waste composition survey for 309 stalls/vendors in five markets by 17 business categories for 10 consecutive days. The waste generation rates by stall/vendor and by floor area were assessed in three waste categories: general waste, recyclable, and food residues. The general waste that would be sent to a landfill site was classified into 10 physical categories and 77 sub-categories. For general waste, food waste accounted for the largest part, followed by plastic and grass. By multiplying the waste generation rate by stall/vendor by the total number of stall/vendors in 23 markets, the authors estimated the total amounts of general waste, recyclable, food residue and total waste by business category. The total waste generated from market was 17.0 tons/day, of which 4.6 tons (27.1%) were collected by pig farmers for feeding livestock and 0.6 tons (3.6%) were sold to the recycling market. The composting potential accounted for 55.2% of total waste generation from the traditional market in Hue. The recycling potential accounted for 5.1%. The total disposal amount sent to the landfill site would be reduced from 69.2% to 8.8% of the total. The 95% confidence interval (CI) of total waste amount from 23 markets was also estimated using Monte Carlo simulation based on the mean and standard error of the waste generation rate. The range of 95% CI was 14.9 - 18.9 tons/day.展开更多
Zinc oxide (ZnO) and niobium oxide (NbOx) with a nano-island structure were deposited by a sputtering method on Al-coated glass substrates. Cells with a (ZnO or NbOx)/Al/glass|KNO3aq.|Al/ glass structure were assemble...Zinc oxide (ZnO) and niobium oxide (NbOx) with a nano-island structure were deposited by a sputtering method on Al-coated glass substrates. Cells with a (ZnO or NbOx)/Al/glass|KNO3aq.|Al/ glass structure were assembled, and electrochemical and photoelectrochemical properties were evaluated. The ZnO and NbOx electrodes had higher electrode potentials than the counter Al/glass electrode, and electron flows from the counter electrode to the ZnO and NbOx electrodes through the external circuit were commonly confirmed. In the ZnO-based cell, only faint photocurrent generation was seen, where Zn and Al elution from the ZnO electrode was found. In the NbOxbased cell, however, stable generation of electricity was successfully achieved, and electrode corrosion was not recognized even in microscopic observations. A photoelectrochemical conversion model was proposed based on potential-pH diagrams. In the case of nano-island structures formed at shorter NbOx deposition time, it was concluded that the photoelectrochemical reactions, which were proceeded in the immediate vicinity of the boundary among nano-islands, substrate, and electrolyte solution, were predominant for the photoelectrochemical conversion, and in the case of film structures with longer deposition time, the predominant reactions took place at the film surface.展开更多
Objectives:Rhizopus stolonifer,which causes soft rot of sweet potato,has resulted in substantial loss of economy postharvest.Materials and Methods:The antifungal effect and mechanism of cinnamaldehyde(CIN)against R.st...Objectives:Rhizopus stolonifer,which causes soft rot of sweet potato,has resulted in substantial loss of economy postharvest.Materials and Methods:The antifungal effect and mechanism of cinnamaldehyde(CIN)against R.stolonifer were explored by biochemical analysis and RNA-sequencing in this research,and the edible quality of CIN-treated sweet potato was evaluated.Results:The results showed that CIN inhibited the growth of R.stolonifer and reduced the incidence of soft rot in sweet potato at a minimum inhibitory concentration of 1000μL/L.The damage of the cell walls of R.stolonifer by CIN was associated with the upregulation of CHT1.Cytosolic leakage and malondialdehyde content increased following CIN-treatment,which was correlated with increased reactive oxygen species levels and decreased catalase activity.Upregulation of ERG genes and oxidative stress-related genes following CIN treatment was associated with impaired cell membrane integrity.The mitochondrial structure of R.stolonifer was damaged by CIN treatment resulting in decreased respiration rates and ATP production,which was correlated with lower expression levels of IDH1,COX4,and QCR7.Conclusions:Our research suggests that the inhibition of CIN on R.stolonifer was related to the disruption of its normal gene expression network,and CIN maintained the nutritional and edible quality of sweet potato.This study provides valuable insights into the antifungal mechanism of CIN on R.stolonifer and the maintenance of root quality,which contributes to the effcient use of CIN for controlling soft rot in sweet potato.展开更多
DNA damage is frequently encountered in spermatozoa of subfertile males and is correlated with a range of adverse clinical outcomes including impaired fertilization, disrupted preimplantation embryonic development, in...DNA damage is frequently encountered in spermatozoa of subfertile males and is correlated with a range of adverse clinical outcomes including impaired fertilization, disrupted preimplantation embryonic development, increased rates of miscarriage and an enhanced risk of disease in the progeny. The etiology of DNA fragmentation in human spermatozoa is closely correlated with the appearance of oxidative base adducts and evidence of impaired spermiogenesis. We hypothesize that oxidative stress impedes spermiogenesis, resulting in the generation of spermatozoa with poorly remodelled chromatin. These defective cells have a tendency to default to an apeptotic pathway associated with motility loss, caspase activation, phosphatidylserine exteriorization and the activation of free radical generation by the mitochondria. The latter induces lipid peroxidation and oxidative DNA damage, which then leads to DNA fragmentation and cell death. The physical architecture of spermatozoa prevents any nucleases activated as a result of this apoptotic process from gaining access to the nuclear DNA and inducing its fragmentation. It is for this reason that a majority of the DNA damage encountered in human spermatozoa seems to be oxidative. Given the important role that oxidative stress seems to have in the etiology of DNA damage, there should be an important role for antioxidants in the treatment of this condition. If oxidative DNA damage in spermatozoa is providing a sensitive readout of systemic oxidative stress, the implications of these findings could stretch beyond our immediate goal of trying to minimize DNA damage in spermatozoa as a prelude to assisted conception therapy.展开更多
Ammonia is a vital emerging energy carrier and storage medium in the future hydrogen economy, even presenting relevant advantages compared with methanol due to the higher hydrogen content(17.6 wt% for ammonia versus 1...Ammonia is a vital emerging energy carrier and storage medium in the future hydrogen economy, even presenting relevant advantages compared with methanol due to the higher hydrogen content(17.6 wt% for ammonia versus 12.5 wt% for methanol). The rapidly growing demand for ammonia is still dependent on the conventional high-temperature and high-pressure Haber–Bosch process, which can deliver a conversion rate of about 10%–15%. However, the overall process requires a large amount of fossil fuels,resulting in serious environmental problems. Alternatively, electrochemical routes show the potential to greatly reduce the energy consumption, including sustainable energy sources and simplify the reactor design. Electrolytes perform as indispensable reaction medium during electrochemical processes, which can be further classified into solid oxide electrolytes, molten salt electrolytes, polymer electrolytes, and liquid electrolytes. In this review, recent developments and advances of the electrocatalytic ammonia synthesis catalyzed by a series of functional materials on the basis of aforementioned electrolytes have been summarized and discussed, along with the presentation and evaluation of catalyst preparation, reaction parameters and equipment.展开更多
Achieving more meaningful N2 conversion by reducing the energy input and carbon footprint is now being investigated through a method of N2 fixation instead of the Haber-Bosch process.Unfortunately,the electrochemical ...Achieving more meaningful N2 conversion by reducing the energy input and carbon footprint is now being investigated through a method of N2 fixation instead of the Haber-Bosch process.Unfortunately,the electrochemical N2 reduction reaction(NRR)method as a rising approach currently still shows low selectivity(Faradaic efficiency<10%)and high-energy consumption[applied potential at least-0.2 V versus the reversible hydrogen electrode(RHE)].Here,the role of molybdenum aluminum boride single crystals,belonging to a family of ternary transition metal aluminum borides known as MAB phases,is reported for the electrochemical NRR for the first time,at a low applied potential(-0.05 V versus RHE)under ambient conditions and in alkaline media.Due to the unique nano-laminated crystal structure of the MAB phase,these inexpensive materials have been found to exhibit excellent electrocatalytic performances(NH3 yield:9.2μg h^-1cm^-2mgcat^-1.,Faradaic efficiency:30.1%)at the low overpotential,and to display a high chemical stability and sustained catalytic performance.In conjunction,further mechanism studies indicate B and Al as main-group metals show a highly selective affinity to N2 due to the strong interaction between the B 2p/Al 3p band and the N 2p orbitals,while Mo exhibits specific catalytic activity toward the subsequent reduction reaction.Overall,the MAB-phase catalyst under the synergy of the elements within ternary compound can suppress the hydrogen evolution reaction and achieve enhanced NRR performance.The significance of this work is to provide a promising candidate in the future synthesis of ammonia.展开更多
Cell wall composition in monocotyledonous grasses has been identified as a key area of research for developing better feedstocks for forage and biofuel production.Setaria viridis and its close domesticated relative Se...Cell wall composition in monocotyledonous grasses has been identified as a key area of research for developing better feedstocks for forage and biofuel production.Setaria viridis and its close domesticated relative Setaria italica have been chosen as suitable monocotyledonous models for plants possessing the C4 pathway of photosynthesis including sorghum,maize,sugarcane,switchgrass and Miscanthus×giganteus.Accurate partial least squares regression（PLSR）models to predict S.italica stem composition have been generated,based upon Fourier transform mid-infrared（FTIR）spectra and calibrated with wet chemistry determinations of ground S.italica stem material measured using a modified version of the US National Renewable Energy Laboratory（NREL）acid hydrolysis protocol.The models facilitated a high-throughput screening analysis for glucan,xylan,Klason lignin and acid soluble lignin（ASL）in a collection of 183 natural S.italica variants and clustered them into classes,some possessing unique chemotypes.The predictive models provide a highly efficient screening tool for large scale breeding programs aimed at identifying lines or mutants possessing unique cell wall chemotypes.Genes encoding key catalytic enzymes of the lignin biosynthesis pathway exhibit a high level of conservation with matching expression profiles,measured by RT-q PCR,among accessions of S.italica,which closely mirror profiles observed in the different developmental regions of an elongating internode of S.viridis by RNASeq.展开更多
Bitter melon, Momordica charantia L, is a popular traditional medicinal fruit in tropical and subtropical countries. It has been linked with therapeutic effects, some of which are likely due to its flavonoids. To dete...Bitter melon, Momordica charantia L, is a popular traditional medicinal fruit in tropical and subtropical countries. It has been linked with therapeutic effects, some of which are likely due to its flavonoids. To determine its total flavonoid content (TFC) and to prepare extracts for use as nutritional supplements or ingredients for nutraceutical functional foods, various solvents have been used, including water, which is the preferred solvent because it is inexpensive, safe and environmentally friendly. The study aimed to extract bitter melon, using five solvents (ethanol, methanol, n-butanol, acetone and water) before and after the optimal conditions for water were determined in terms of extraction temperature, time, ratio of water to bitter melon (mL/g) and number of times the same material was extracted. The TFC of six varieties of bitter melon was also determined. Acetone was the best of the five solvents for extracting flavonoids from the Moonlight variety (23.2 mg Rutin Equivalents (RE)/g). Even after increasing the extraction by 88% (1.24 vs 0.66 mg RE/g) using optimised conditions for the aqueous extraction (two extractions at 40℃ for 15 min at a ratio of 100:1 mL/g of bitter melon powder), the flavonoids extracted from the Moonlight variety using water was very little (5.4%) compared to acetone. Furthermore, using acetone, it was shown that the Moonlight variety (23.2 mg RE/g) bought at a local market had higher levels of flavonoids than the greenhouse-grown Jade (15.3 mg RE/g), Niddhi (16.9 mg RE/g), Indra (15.0 mg RE/ g), Hanuman (3.9 mg RE/g) and White (6.9 mg RE/g) varieties. Therefore, acetone was the best solvent for extracting flavonoids from bitter melon and the aqueous extraction could only be improved to extract 5.4% of the flavonoids extracted with acetone from the Moonlight variety, which had the highest TFC of the six varieties of bitter melon.展开更多
基金Supported by the Guangxi Science and Technology Base and Talent Special Project (No.AD23026114)。
文摘Substrate is an important abiotic factor for burrowing shellfish,as it not only provides them with shelter,but also impose significant effect on their physiological metabolism.However,the physiological responses of burrowing clams within various substrates get less attention due to difficulty in carrying out physiological tests in buried conditions.Consequently,this study investigated the burrowing behavior,feeding physiology and energy budget of Paphia undulata,which is an important aquaculture bivalve species in south China.The clams were exposed to mud and sand substrates with variable physical properties in the laboratory,to determine the suitable substrate conditions for this species.The results showed that the percentage of burrowing clams,digging index,burrowing time,burrowing depth and scope for growth(SFG)were higher in mud substrates with≥40%water content.Likewise,burrowing percentage,digging index,and burrowing depths were higher in substrates with≤40%sand content.Moreover,the burrowing depth had significant effect on the feeding physiology and SFG of P.undulata as clams burrowed at 6.3±1.8 cm had higher clearance rates and SFG as compared to other buried depths.This study further revealed that low water content in the sediment inhibited physiological performances of P.undulata by impairing feeding or absorption,hence reducing the SFG.In conclusion,mud substrate with≥40%water content or with≤40%sand content is suitable for proper burrowing and growth of P.undulata.Our findings therefore provide fundamental knowledge that will be applicable in the improvement of bottom aquaculture and conservation of P.undulata.
文摘Background: Fatigue is commonly reported by cancer patients. In some instances it can persist after treatment is completed. In order to develop effective treatment strategies it is important to understand the mechanisms underlying the development of fatigue and to be able to predict those that may be at greatest risk of experiencing fatigue during and following treatment. The current paper examines predisposing factors for fatigue including altered fatty acid homeostasis in a cohort of breast cancer radiotherapy patients. Methodology: Patients had undergone breast-conserving surgery and adjuvant breast irradiation. Prior to radiotherapy the patients were free from significant fatigue. Levels of fatigue were determined prior to and following radiotherapy using the Functional Assessment of Cancer Therapy fatigue subscale. Plasma fatty acid levels, urinary and plasma amino acid levels, blood biochemistry factors and general health and lifestyle characteristics were assessed. Results: Following radiotherapy, significant fatigue affected approximately one third of the 26 patients and these subjects were then assigned to the fatigued cohort. Univariate analysis revealed that higher levels of the fatty acids myristic acid and eicosadienoic acid were present for the fatigued cohort prior to radiotherapy. Multivariate analysis also revealed that fatty acid homeostasis was altered between the fatigued and non-fatigued groups at baseline. Orthogonal partial least squares discriminant analysis of the general health, lifestyle and metabolic data revealed that the fatigued and non-fatigued patients could be clustered into two clearly separate groups. Conclusions: The results supported the proposition that the fatigued patients had an underlying metabolic homeostasis which may predispose them to the development of fatigue. Biochemical and general health profiling of breast cancer patients has the potential to identify those at most risk of developing significant fatigue following radiotherapy.
文摘The foundations of proteomics are to study gene products and their regulatory roles within cells. Paradoxically, the only evidence that sperm cells make new proteins is through mitochondrial protein synthesis. Yet despite this, spermatozoa are the perfect candidates for mass spectrometry and hence, proteomic analysis. These enterprising cells use a plethora of post-translational modifications in order to gain functionality following their production within the testis. By using a combination of two-dimensional polyacrylamide gel electrophoresis （2D-PAGE）, and more recently liquid chromatography-mass spectrometry （LC-MS）/MS, recent advances in sperm cell biology, through the use of proteomics, is making unparalleled progress. The protein inventory lists being generated have shed light on transmembrane proteins, kinases and chaperones never previously recognized. In addition, the ability to isolate either phosphopeptides or glycopeptides and quantify the differences between cells of two different populations make proteomic analysis of spermatozoa a real chance to finally answer some age old questions.
基金This work was supported by the Program for the National Natural Science Foundation of China(No.31372038)by the earmarked fund for the China Agriculture Research System(CARS-28).
文摘To investigate the functions of fructokinase(FRK)in apple(Malus domestica)carbohydrate metabolism,we cloned the coding sequences of MdFRK1 and MdFRK2 from the‘Royal Gala’apple.The results showed that MdFRK2 expression was extremely high in shoot tips and young fruit.Analyses of heterologously expressed proteins revealed that MdFRK2 had a higher affinity for fructose than did MdFRK1,with Km values of 0.1 and 0.62 mM for MdFRK2 and MdFRK1,respectively.The two proteins,however,exhibited similar Vmax values when their activities were significantly inhibited by high concentrations of fructose.MdFRK2 ectopic expression was associated with a general decrease in fructose concentration in transgenic lines.In leaves,increased FRK activity similarly resulted in reduced concentrations of glucose and sucrose but no alterations in sorbitol concentration.When compared with those in the untransformed control,genes involved in sorbitol synthesis(A6PR)and the degradation pathway(SDH1/2)were significantly upregulated in transgenic lines,whereas those involved in sucrose synthesis(SPS1)and other degradation processes(SUSY4,NINV1/2,and HxK2)were downregulated.The activity of enzymes participating in carbohydrate metabolism was proportional to the level of gene expression.However,the growth performance and photosynthetic efficiency did not differ between the transgenic and wild-type plants.These results provide new genetic evidence to support the view that FRK plays roles in regulating sugar and sorbitol metabolism in Rosaceae plants.
基金funded by a grant from The Yakumo Foundation for Environmental Science(2015,to Y.M.)
文摘General decline of understory cover can result from increased abundance of and foraging pressure by deer.But population size and degree of aggregation can increase for unpalatable understory plants that escape foraging pressure.Clonal reproduction can enable unpalatable plant species to increase their population sizes while trending toward spatially aggregated distributions.However,the details of the relationship between clonal reproduction in unpalatable plants and their dynamics under intensive deer herbivory are not clear.We compared the population structures and spatial patterns of two coexisting unpalatable plant species,Arisaema ovale(with clonal reproduction)and A.peninsulae(without clonal reproduction)in a riparian forest intensively grazed by Sika deer,and examined the null hypothesis that the extent of spatial aggregation and local population size would not differ between the clonal and non-clonal Arisaema species.In a 0.36-ha plot,A.ovale had a larger population size(1087 individuals)with a higher abundance ratio of small plants(p<0.01)than A.peninsulae(84 individuals).Analyses of spatial point processes showed that both populations were spatially aggregated(p<0.05).The spatial aggregation of A.peninsulae,however,became weaker than that of A.ovale,when we excluded one dense patch originating from irregular seed dispersion.These results,excluding the aggregated distribution observed in A.peninsulae,suggested a substantial contribution of clonal reproduction to the expansion of the local A.ovale population following intensive grazing by Sika deer.
基金financially supported by the Japan Society for the Promotion of Science (Grant no. R11604)
文摘In this study,we investigated the chemical composition of dissolved solids in the Ca River basin,North-Central Vietnam.Water samples were collected from August 2017 to July 2018 at three hydrological stations located in the main stream of the Ca River.Carbonate weathering was found as the dominant process controlling the water chemistry in that area.The average concentrations of dissolved solids generally decreased from upstream to downstream,resulting in low concentrations of the major ions in the downstream basin.Variations in the concentrations of major chemical ions and suspended solids at discharge were also investigated.Major chemical weathering products were found to behave chemostatically with increasing discharges upstream.However,dilution behaviors of solutes were shown in both midstream and downstream.Primary evidence shows that water storage in reservoirs impacts a variety of suspended solids and dissolved solids in the Ca River.
文摘A bench-scale biopiling experiment was conducted to hydrocarbon bioremediation in a chronically contaminated soil compare the ability of different techniques to enhance petroleum After 195 days, 10%-32% removal of TPHs （total petroleum hydrocarbons） occurred in unamended soil （control）. Biostimulation by inorganic nutrient addition enhanced TPH removal （49%） confirming that bioremediation was nutrient limited and the soil contained a well-adapted hydrocarbonoclastic microbial community. The addition of organic amendments including green waste at 25% and 50% （w/w） and a commercial product called DaramendTM had a further biostimulatory effect （50%-66%, 34%-59% and 69%-80% TPH removal respectively）. Bioaugmentation using two commercially available petroleum hydrocarbon degrading microbial cultures with nutrients enhanced TPH removal in the case of RemActivTM （60%-69%）, but had a marginal effect using Recycler 102 （49%-55%）. The effect of a non-ionic surfactant in green waste amended soil was variable （52%-72% TPH reduction）, but its potential to enhance biodegradation presumably by promoting contaminant bioavailability was demonstrated. High degradation of artificially added polycyclic aromatic hydrocarbons （PAHs） occurred after 106 days （75%-84%）, but significant differences between the control and treatments were unapparent, suggesting that spiked soils do not reflect the behavior of contaminants in genuinely polluted and weathered soil.
基金supported by National Key R&D Program of China(2017YFD0600601)
文摘Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth, temporal variation in cone yield, and seed quality in Korean pine plantation. In 2005, five thinning intensity levels (none, extreme, heavy, moderate and light) were set in 15 permanent plots in a 32-year-old Korean pine plantation at Mengjiagang Forest Farm, Jiamusi City, Heilongjiang Province. We recorded tree growth and seed cone production from 2013 to 2016, i.e., from 8 to 11 years after thinning. Except for height growth, thinning increased tree growth (diameter at breast height and crown size) and improved cone yield. The extreme thinning treatment (to 300 trees per hectare) resulted in the largest tree diameter, tree volume, crown size and 4-year cone production per tree. The highest cone yield per tree in the mast year (2014) was observed when stands were thinned to 500 trees per hectare (heavy thinning). Although the best cone and seed quality and the largest cone and seed mass per tree were recorded in the heavily thinned stand, no significant differences were found between heavy and moderate thinning stands (750 trees per hectare). At the stand level, the moderately thinned stand had the highest basal area, stock volume and seed cone production per stand. Our results suggest that thinning to 750 trees per hectare will improve timber and cone productivity in 40-year-old P. koraiensis stands.
基金This study was supported in part by a research grant from the Graduate School of Humanities,Hosei University and Japan Society for the Promotion of Science(JSPS,JP21K13150).
文摘This study aimed to elucidate the influence of inflow water on the salinity concentration process of a saline lake and the mass balance of Lake Issyk-Kul,a tectonic saltwater lake in Kyrgyzstan.Based on the survey results and meteorological data from 2012 to 2015,we analyzed the dissolved chemical composition loads due to water inflow.Then,we discussed the relationship between the increase in salinity and water inflow into the lake.Through the water quality analysis data,we used the tank model to estimate the river inflow and analyze the loads by the L-Q curve.The groundwater loads were then estimated from the average annual increase in salinity of the lake over a period of 30 a.The results suggest that Lake Issyk-Kul was temporarily freshened between about AD 1500 and 1800 when an outflowing river existed,and thereafter,it became a closed lake in AD 1800 and continued to remain a saline lake until present.The chemical components that cause salinization are supplied from the rivers and groundwater in the catchment area,and when they flow into the lake,Ca^(2+),HCO_(3)−and Mg^(2+)precipitate as CaCO_(3) and MgCO_(3).These compounds were confirmed to have been left on the lakeshore as evaporite.The model analysis showed that 1.67 mg/L of Ca^(2+)and Mg^(2+)supplied from rivers and groundwater are precipitated as evaporite and in other forms per year.On the other hand,salinity continues to remain in the lake water at a rate of 27.5 mg/L per year.These are the main causes of increased salinity in Lake Issyk-Kul.Since Na^(+)and Cl^(-)are considered to be derived from geothermal water,they will continue to flow in regardless of the effects of human activities.Therefore,as long as these components are accumulated in Lake Issyk-Kul as a closed lake,the salinity will continue to increase in the future.
文摘Fatigue RevivaTM was developed to provide a source of amino acids for rapid uptake by the body while avoiding the need for digestion of proteins. Complex amino acid formulations have significant palatability issues and thus new products require significant development and testing. An initial pilot study with 18 professional male athletes and 21 males recruited from the general public was undertaken to evaluate product palatability and tolerance over a 30 day period. This investigation found that Fatigue RevivaTM was well tolerated in terms of palatability and usage across 39 participants with only two of the 39 subjects reporting an issue with taste and five reporting an issue with flatulence. The professional athlete cohort reported a significantly lower level of fatigue compared with the general public group prior to commencement of supplementation. The general public group reported a significant reduction in fatigue following the use of Fatigue RevivaTM over the 30-day period. Compliance was extremely poor amongst the professional athlete group and as a result, changes in fatigue could not be statistically assessed for this group over the study period. Preliminary assessment of the product indicated that it has the potential to significantly reduce fatigue. Minor modifications to the product were identified for future development.
文摘Combining compost with sufficient chemical N fertilizer (CF) in agricultural lands is a popular practice to reduce the amount of inorganic nitrogen and accumulation of non-nutrient constituents in soils. A pot culture experiment was conducted to study the effects of 130 mg N of either solids waste compost (Scomp) or biosolids waste compost (Bcomp) complemented with 130 mg (CF, 1N) and 260 mg·N·pot-1 (CF, 2N) as 15N labeled (NH4)2SO4 (13.172 atom %) on growth and N uptake by Italian ryegrass. A separate soil incubation without plants was set up by only blends of Scomp and CF. The results from pot culture experiment show that total plant biomass and N uptake from Bcomp were significantly higher than Scomp alone. Scomp combined with CF improved yield and N uptake over those of Scomp alone. For Scomp + 1N treatment, plant nitrogen uptake derived from compost and CF accounted for 29% and 56% of added N from Scomp and CF, respectively. The incubation study indicates that 16.08 - 29.62 mg·N·kg-1·soil·day-1 from inorganic-N were immobilized into organic pools, while only 0.40 - 0.66 mg·N·kg-1·soil·day-1 from organic-N were mineralized to inorganic pools. Because a part of additional N could be tied up in organic form, combining solids compost with chemical N fertilizer therefore need to consider the effective use of compost-N.
文摘This study examined the solid waste generation and recycling potential of the hotel sector in Hue City, Vietnam. The authors conducted waste measurement, waste composition, and questionnaire surveys for 45 target hotels over ten consecutive days. The waste generation rates (WGRs) by rooms, beds, guests, and workers were assessed by hotel class using the following three waste categories, considering informal waste collection: general waste (GW), separated recyclables (SRe), and separated food residue (SFR). The 5-star hotels exhibited the highest WGR per room at 1.61 kg/room/day, while 1-star hotels exhibited the lowest per-room WGR (0.39 kg/room/day). Spearman Rank correlation test revealed that hotel class and per-room, per-bed, and per-guest WGRs were significantly positively correlated (p < 0.01). The major components of GW were food waste (40.9% to 57.4%), paper (10.1% to 20.3%), and plastic (10.7% to 15.5%). The recycling and composting potentials remaining in the GW were 19.3% to 38.5% and 38.0% to 57.9%, respectively. Based on the WGRs and waste composition determined in this study, the estimated total amount of waste generated was 6.88 tons/day (6.26 to 7.62 tons/day, 95% CI), of which 4.37 (64%), 2.13 (31%), and 0.38 tons/day (6%) were GW, SFR, and SRe, respectively. The recycling and composting potentials remaining in GW were 0.94 (13%) and 2.57 tons/day (37%), respectively. High-class hotels should be considered as the highest priority targets for a “reduce, reuse, recycle” (3R) promotion campaign in the future, with estimated recycling and composting potentials of 0.27 (4%) and 1.10 tons/day (16%), respectively.
文摘This study was conducted to provide a detailed description of waste generation and characteristics from a traditional market in Hue city, located in central Vietnam. The authors conducted a waste generation survey and a waste composition survey for 309 stalls/vendors in five markets by 17 business categories for 10 consecutive days. The waste generation rates by stall/vendor and by floor area were assessed in three waste categories: general waste, recyclable, and food residues. The general waste that would be sent to a landfill site was classified into 10 physical categories and 77 sub-categories. For general waste, food waste accounted for the largest part, followed by plastic and grass. By multiplying the waste generation rate by stall/vendor by the total number of stall/vendors in 23 markets, the authors estimated the total amounts of general waste, recyclable, food residue and total waste by business category. The total waste generated from market was 17.0 tons/day, of which 4.6 tons (27.1%) were collected by pig farmers for feeding livestock and 0.6 tons (3.6%) were sold to the recycling market. The composting potential accounted for 55.2% of total waste generation from the traditional market in Hue. The recycling potential accounted for 5.1%. The total disposal amount sent to the landfill site would be reduced from 69.2% to 8.8% of the total. The 95% confidence interval (CI) of total waste amount from 23 markets was also estimated using Monte Carlo simulation based on the mean and standard error of the waste generation rate. The range of 95% CI was 14.9 - 18.9 tons/day.
文摘Zinc oxide (ZnO) and niobium oxide (NbOx) with a nano-island structure were deposited by a sputtering method on Al-coated glass substrates. Cells with a (ZnO or NbOx)/Al/glass|KNO3aq.|Al/ glass structure were assembled, and electrochemical and photoelectrochemical properties were evaluated. The ZnO and NbOx electrodes had higher electrode potentials than the counter Al/glass electrode, and electron flows from the counter electrode to the ZnO and NbOx electrodes through the external circuit were commonly confirmed. In the ZnO-based cell, only faint photocurrent generation was seen, where Zn and Al elution from the ZnO electrode was found. In the NbOxbased cell, however, stable generation of electricity was successfully achieved, and electrode corrosion was not recognized even in microscopic observations. A photoelectrochemical conversion model was proposed based on potential-pH diagrams. In the case of nano-island structures formed at shorter NbOx deposition time, it was concluded that the photoelectrochemical reactions, which were proceeded in the immediate vicinity of the boundary among nano-islands, substrate, and electrolyte solution, were predominant for the photoelectrochemical conversion, and in the case of film structures with longer deposition time, the predominant reactions took place at the film surface.
基金Scientifc Research Fund of Zhejiang Provincial Education Department(NO.Y202250109)the Key Projects of Ningbo Public Welfare Science and Technology Plan(No.202002N3081),China.
文摘Objectives:Rhizopus stolonifer,which causes soft rot of sweet potato,has resulted in substantial loss of economy postharvest.Materials and Methods:The antifungal effect and mechanism of cinnamaldehyde(CIN)against R.stolonifer were explored by biochemical analysis and RNA-sequencing in this research,and the edible quality of CIN-treated sweet potato was evaluated.Results:The results showed that CIN inhibited the growth of R.stolonifer and reduced the incidence of soft rot in sweet potato at a minimum inhibitory concentration of 1000μL/L.The damage of the cell walls of R.stolonifer by CIN was associated with the upregulation of CHT1.Cytosolic leakage and malondialdehyde content increased following CIN-treatment,which was correlated with increased reactive oxygen species levels and decreased catalase activity.Upregulation of ERG genes and oxidative stress-related genes following CIN treatment was associated with impaired cell membrane integrity.The mitochondrial structure of R.stolonifer was damaged by CIN treatment resulting in decreased respiration rates and ATP production,which was correlated with lower expression levels of IDH1,COX4,and QCR7.Conclusions:Our research suggests that the inhibition of CIN on R.stolonifer was related to the disruption of its normal gene expression network,and CIN maintained the nutritional and edible quality of sweet potato.This study provides valuable insights into the antifungal mechanism of CIN on R.stolonifer and the maintenance of root quality,which contributes to the effcient use of CIN for controlling soft rot in sweet potato.
文摘DNA damage is frequently encountered in spermatozoa of subfertile males and is correlated with a range of adverse clinical outcomes including impaired fertilization, disrupted preimplantation embryonic development, increased rates of miscarriage and an enhanced risk of disease in the progeny. The etiology of DNA fragmentation in human spermatozoa is closely correlated with the appearance of oxidative base adducts and evidence of impaired spermiogenesis. We hypothesize that oxidative stress impedes spermiogenesis, resulting in the generation of spermatozoa with poorly remodelled chromatin. These defective cells have a tendency to default to an apeptotic pathway associated with motility loss, caspase activation, phosphatidylserine exteriorization and the activation of free radical generation by the mitochondria. The latter induces lipid peroxidation and oxidative DNA damage, which then leads to DNA fragmentation and cell death. The physical architecture of spermatozoa prevents any nucleases activated as a result of this apoptotic process from gaining access to the nuclear DNA and inducing its fragmentation. It is for this reason that a majority of the DNA damage encountered in human spermatozoa seems to be oxidative. Given the important role that oxidative stress seems to have in the etiology of DNA damage, there should be an important role for antioxidants in the treatment of this condition. If oxidative DNA damage in spermatozoa is providing a sensitive readout of systemic oxidative stress, the implications of these findings could stretch beyond our immediate goal of trying to minimize DNA damage in spermatozoa as a prelude to assisted conception therapy.
基金supported by the Chinese National Natural Science Foundation (51402307)the Australian Research Council (ARC) Discovery Early Career Researcher Award (DE150101306)Linkage Project (LP160100927)
文摘Ammonia is a vital emerging energy carrier and storage medium in the future hydrogen economy, even presenting relevant advantages compared with methanol due to the higher hydrogen content(17.6 wt% for ammonia versus 12.5 wt% for methanol). The rapidly growing demand for ammonia is still dependent on the conventional high-temperature and high-pressure Haber–Bosch process, which can deliver a conversion rate of about 10%–15%. However, the overall process requires a large amount of fossil fuels,resulting in serious environmental problems. Alternatively, electrochemical routes show the potential to greatly reduce the energy consumption, including sustainable energy sources and simplify the reactor design. Electrolytes perform as indispensable reaction medium during electrochemical processes, which can be further classified into solid oxide electrolytes, molten salt electrolytes, polymer electrolytes, and liquid electrolytes. In this review, recent developments and advances of the electrocatalytic ammonia synthesis catalyzed by a series of functional materials on the basis of aforementioned electrolytes have been summarized and discussed, along with the presentation and evaluation of catalyst preparation, reaction parameters and equipment.
文摘Achieving more meaningful N2 conversion by reducing the energy input and carbon footprint is now being investigated through a method of N2 fixation instead of the Haber-Bosch process.Unfortunately,the electrochemical N2 reduction reaction(NRR)method as a rising approach currently still shows low selectivity(Faradaic efficiency<10%)and high-energy consumption[applied potential at least-0.2 V versus the reversible hydrogen electrode(RHE)].Here,the role of molybdenum aluminum boride single crystals,belonging to a family of ternary transition metal aluminum borides known as MAB phases,is reported for the electrochemical NRR for the first time,at a low applied potential(-0.05 V versus RHE)under ambient conditions and in alkaline media.Due to the unique nano-laminated crystal structure of the MAB phase,these inexpensive materials have been found to exhibit excellent electrocatalytic performances(NH3 yield:9.2μg h^-1cm^-2mgcat^-1.,Faradaic efficiency:30.1%)at the low overpotential,and to display a high chemical stability and sustained catalytic performance.In conjunction,further mechanism studies indicate B and Al as main-group metals show a highly selective affinity to N2 due to the strong interaction between the B 2p/Al 3p band and the N 2p orbitals,while Mo exhibits specific catalytic activity toward the subsequent reduction reaction.Overall,the MAB-phase catalyst under the synergy of the elements within ternary compound can suppress the hydrogen evolution reaction and achieve enhanced NRR performance.The significance of this work is to provide a promising candidate in the future synthesis of ammonia.
文摘Cell wall composition in monocotyledonous grasses has been identified as a key area of research for developing better feedstocks for forage and biofuel production.Setaria viridis and its close domesticated relative Setaria italica have been chosen as suitable monocotyledonous models for plants possessing the C4 pathway of photosynthesis including sorghum,maize,sugarcane,switchgrass and Miscanthus×giganteus.Accurate partial least squares regression（PLSR）models to predict S.italica stem composition have been generated,based upon Fourier transform mid-infrared（FTIR）spectra and calibrated with wet chemistry determinations of ground S.italica stem material measured using a modified version of the US National Renewable Energy Laboratory（NREL）acid hydrolysis protocol.The models facilitated a high-throughput screening analysis for glucan,xylan,Klason lignin and acid soluble lignin（ASL）in a collection of 183 natural S.italica variants and clustered them into classes,some possessing unique chemotypes.The predictive models provide a highly efficient screening tool for large scale breeding programs aimed at identifying lines or mutants possessing unique cell wall chemotypes.Genes encoding key catalytic enzymes of the lignin biosynthesis pathway exhibit a high level of conservation with matching expression profiles,measured by RT-q PCR,among accessions of S.italica,which closely mirror profiles observed in the different developmental regions of an elongating internode of S.viridis by RNASeq.
文摘Bitter melon, Momordica charantia L, is a popular traditional medicinal fruit in tropical and subtropical countries. It has been linked with therapeutic effects, some of which are likely due to its flavonoids. To determine its total flavonoid content (TFC) and to prepare extracts for use as nutritional supplements or ingredients for nutraceutical functional foods, various solvents have been used, including water, which is the preferred solvent because it is inexpensive, safe and environmentally friendly. The study aimed to extract bitter melon, using five solvents (ethanol, methanol, n-butanol, acetone and water) before and after the optimal conditions for water were determined in terms of extraction temperature, time, ratio of water to bitter melon (mL/g) and number of times the same material was extracted. The TFC of six varieties of bitter melon was also determined. Acetone was the best of the five solvents for extracting flavonoids from the Moonlight variety (23.2 mg Rutin Equivalents (RE)/g). Even after increasing the extraction by 88% (1.24 vs 0.66 mg RE/g) using optimised conditions for the aqueous extraction (two extractions at 40℃ for 15 min at a ratio of 100:1 mL/g of bitter melon powder), the flavonoids extracted from the Moonlight variety using water was very little (5.4%) compared to acetone. Furthermore, using acetone, it was shown that the Moonlight variety (23.2 mg RE/g) bought at a local market had higher levels of flavonoids than the greenhouse-grown Jade (15.3 mg RE/g), Niddhi (16.9 mg RE/g), Indra (15.0 mg RE/ g), Hanuman (3.9 mg RE/g) and White (6.9 mg RE/g) varieties. Therefore, acetone was the best solvent for extracting flavonoids from bitter melon and the aqueous extraction could only be improved to extract 5.4% of the flavonoids extracted with acetone from the Moonlight variety, which had the highest TFC of the six varieties of bitter melon.
