Drought is one of the abiotic stresses limiting the production of soybean(Glycine max).Elucidation of the genetic and molecular basis of the slow-wilting(SW)trait of this crop offers the prospect of its genetic improv...Drought is one of the abiotic stresses limiting the production of soybean(Glycine max).Elucidation of the genetic and molecular basis of the slow-wilting(SW)trait of this crop offers the prospect of its genetic improvement.A panel of 188 accessions and a set of recombinant inbred lines produced from a cross between cultivars Liaodou 14 and Liaodou 21 were used to identify quantitative-trait loci(QTL)associated with SW.Plants were genotyped by Specific-locus amplified fragment sequencing and seedling leaf wilting was assessed under three water-stress treatments.A genome-wide association study identified 26 SW-associated single-nucleotide polymorphisms(SNPs),including three located in a 248-kb linkage-disequilibrium(LD)block on chromosome 2.Linkage mapping revealed a major-effect QTL,qSW2,associated with all three treatments and adjacent to the LD block.Fine mapping in a BC_(2)F_(3) population derived from a backcross between Liaodou 21 and R26 confined qSW2 to a 60-kb interval.Gene expression and sequence variation analysis identified the gene Glyma.02 g218100,encoding an auxin transcription factor,as a candidate gene for qSW2.Our results will contribute significantly to improving drought-resistant soybean cultivars by providing genetic information and resources.展开更多
Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of astrocytes.These events a...Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of astrocytes.These events are significantly slower than the excitatory postsynaptic currents.Parameters of slow inward currents are determined by seve ral factors including the mechanisms of astrocytic activation and glutamate release,as well as the diffusion pathways from the release site towards the extra synaptic recepto rs.Astrocytes are stimulated by neuronal network activity,which in turn excite neurons,forming an astrocyte-neuron feedback loop.Mostly as a consequence of brain edema,astrocytic swelling can also induce slow inward currents under pathological conditions.There is a growing body of evidence on the roles of slow inward currents on a single neuron or local network level.These events often occur in synchro ny on neurons located in the same astrocytic domain.Besides synchronization of neuronal excitability,slow inward currents also set synaptic strength via eliciting timing-dependent synaptic plasticity.In addition,slow inward currents are also subject to non-synaptic plasticity triggered by long-la sting stimulation of the excitatory inputs.Of note,there might be important regionspecific differences in the roles and actions triggering slow inward currents.In greater networks,the pathophysiological roles of slow inward currents can be better understood than physiological ones.Slow inward currents are identified in the pathophysiological background of autism,as slow inward currents drive early hypersynchrony of the neural networks.Slow inward currents are significant contributors to paroxysmal depolarizational shifts/interictal spikes.These events are related to epilepsy,but also found in Alzheimer's disease,Parkinson's disease,and stroke,leading to the decline of cognitive functions.Events with features overlapping with slow inward currents(excitatory,N-methyl-Daspartate-receptor mediated currents with astrocytic contribution) as ischemic currents and spreading depolarization also have a well-known pathophysiological role in worsening consequences of stroke,traumatic brain injury,or epilepsy.One might assume that slow inward currents occurring with low frequency under physiological conditions might contribute to synaptic plasticity and memory formation.However,to state this,more experimental evidence from greater neuronal networks or the level of the individual is needed.In this review,I aimed to summarize findings on slow inward currents and to speculate on the potential functions of it.展开更多
The paper presents the change in grain-size composition of lignite under cyclic freezing-thawing (FTC) and wetting-drying (WDC). The article shows that in the spring and autumn periods the lignites can be subjected to...The paper presents the change in grain-size composition of lignite under cyclic freezing-thawing (FTC) and wetting-drying (WDC). The article shows that in the spring and autumn periods the lignites can be subjected to repeated freezing-thawing and wetting-drying, which determines the possibility of changing their grain-size composition and structure. Experimental studies in laboratory conditions on the influence of cyclic freezing-thawing (FTC) and wetting-drying (WDC) on the quality indicators of lignites have been carried out, their granulometric (fractional) composition has been studied. Freezing-thawing cycle conditions are as follows (FTC): minimum exposure temperature: -20°C;maximum: +5°C;relative humidity: 30%;number of processing cycles: 3. Wetting-drying cycles are as follows (WDC): drying temperatures are +20, +40, +60, +80°C, drying time 90 minutes, the coals are further subjected to rain (soaking) for a period of water saturation to humidity of 30% - 40% and dry again. The number of wetting-drying cycles is 3 times. The tests have revealed the destructive effects of FTC and WDC on the samples of lower metamorphic grade coal, and the cycles of wet-dry lead to the much higher yield of fine sizes (-6+0;-13+0 mm) than the cycles of freeze-thaw. Furthermore, it is found that the increase in the yield of fines depends on the heating temperature: coal disintegration proceeds more intensively at a higher temperature of drying.展开更多
Objective:This study compared spindles,cytoskeleton,and developmental potential between vitrified and slow-frozen oocytes using PolScope and electron microscopy.Methods:Oocytes were randomly divided into control,slow ...Objective:This study compared spindles,cytoskeleton,and developmental potential between vitrified and slow-frozen oocytes using PolScope and electron microscopy.Methods:Oocytes were randomly divided into control,slow freeze-thaw,and vitrification freeze-thaw groups(0,1,and 3 h).PolScope was used to observe spindles,angle of spindles to the first polar bodies,surface areas of oocytes,and lining and outer ret of zona pellucida.Surfaces and ultrastructure of oocytes were observed by scanning electron microscopy and transmission electron microscopy.These measures were used to characterize the impacts of two freezing methods on the developmental capacity of human oocytes.Results:The visible frequency of spindle formation was 92.4%,56.4%,11.2%,24.8%,and 61.1%in control group,slow freeze-thaw group,and the three vitrification freeze-thaw groups(0,1,and 3 h),respectively.Compared to oocytes in the slow freeze group,the angle of the spindle to the first polar body in oocytes in the 3-h vitrification freeze-thaw group was less(37.3°vs.68°,P=0.023).No significant differences were observed between the surface area of oocytes,or lining and outer ret of oocyte zona pellucida between freeze-thaw in these same two groups.Microvilli appeared normal.However,protrusions on oocyte surfaces were increased,and microvilli were laid down on the membrane surface in the 3-h vitrification freeze-thaw group in comparison to the slow-freeze group.Similar comparisons showed better recovery of perivitelline space and mitochondria between the 3-h vitrified and slow-frozen groups.Bipronuclear(2PN)fertilization rate observed in the slow-freeze group(65.7%)was lower than the rate seen in controls(79.2%,P=0.041).No significant differences were observed in 2PN fertilization,cleavage,and blastocyst formation rates between the 3-h vitrification freeze-thaw and control groups.Conclusions:Results suggest that vitrification freeze-thaw for oocyte cryopreservation was a better choice than slow freeze-thaw.展开更多
We theoretically explore the tunability of magnomechanically induced transparency(MMIT) phenomenon and fastslow light effect in a hybrid cavity magnomechanical system in which a high-quality yttrium iron garnet(YIG) s...We theoretically explore the tunability of magnomechanically induced transparency(MMIT) phenomenon and fastslow light effect in a hybrid cavity magnomechanical system in which a high-quality yttrium iron garnet(YIG) sphere and an atomic ensemble are placed inside a microwave cavity. In the probe output spectrum, we can observe magnoninduced transparency(MIT) and MMIT due to the photon-magnon and phonon-magnon couplings. We further investigate the effect of atomic ensemble on the absorption spectrum. The results show that better transparency can be obtained by choosing appropriate atomic ensemble parameters. We give an explicit explanation for the mechanism of the Fano resonance phenomenon. Moreover, we discuss phenomena of slow-light propagation. The maximum group delay increases significantly with the increasing atom–cavity coupling strength, and the conversion between slow light and fast light can also be achieved by adjusting the atom–cavity coupling strength. These results may have potential applications for quantum information processing and high precision measurements.展开更多
Common problems in engineering projects that involve artificial ground freezing of soil or rock include inadequate thickness,strength and continuity of artificial frozen walls.It is difficult to evaluate the freezing ...Common problems in engineering projects that involve artificial ground freezing of soil or rock include inadequate thickness,strength and continuity of artificial frozen walls.It is difficult to evaluate the freezing state using only a few thermometer holes at fixed positions or with other existing approaches.Here we report a novel experimental design that investigates changes in ultrasonic properties(received waveform,wave velocity V_(p),wave amplitude,frequency spectrum,centroid frequency f_(c),kurtosis of the frequency spectrum KFS,and quality factor Q)measured during upward freezing,compared with those during uniform freezing,in order to determine the freezing state in 150 mm cubic blocks of Ardingly sandstone.Water content,porosity and density were estimated during upward freezing to ascertain water migration and changes of porosity and density at different stages.The period of receiving the wave increased substantially and coda waves changed from loose to compact during both upward and uniform freezing.The trend of increasing V_(p) can be divided into three stages during uniform freezing.During upward freezing,V_(p) increased more or less uniformly.The frequency spectrum could be used as a convenient and rapid method to identify different freezing states of sandstone(unfrozen,upward frozen,and uniformly frozen).The continuous changes in reflection coefficient r_(φ),refraction coefficient t_(φ) and acoustic impedance field are the major reason for larger reflection and refraction during upward freezing compared with uniform freezing.Wave velocity V_(p),wave amplitude A_(h),centroid frequency f_(c) and quality factor Q were adopted as ultrasonic parameters to evaluate quantitatively the temperature T of uniformly frozen sandstone,and their application within a radar chart is recommended.Determination of V_(p) provides a convenient method to evaluate the freezing state and calculate the cryofront height and frozen section thickness of upward frozen sandstone,with accuracies of 73.37%-99.23%.展开更多
Cold acclimation is a complex biological process leading to the development of freezing tolerance in plants.In this study,we demonstrated that cold-induced expression of protease inhibitor FmASP in a Citrus-relative s...Cold acclimation is a complex biological process leading to the development of freezing tolerance in plants.In this study,we demonstrated that cold-induced expression of protease inhibitor FmASP in a Citrus-relative species kumquat[Fortunella margarita(Lour.)Swingle]contributes to its freezing tolerance by minimizing protein degradation.Firstly,we found that only cold-acclimated kumquat plants,despite extensive leaf cellular damage during freezing,were able to resume their normal growth upon stress relief.To dissect the impact of cold acclimation on this anti-freezing performance,we conducted protein abundance assays and quantitative proteomic analysis of kumquat leaves subjected to cold acclimation(4◦C),freezing treatment(−10◦C)and post-freezing recovery(25◦C).FmASP(Against Serine Protease)and several non-specific proteases were identified as differentially expressed proteins induced by cold acclimation and associated with stable protein abundance throughout the course of low-temperature treatment.FmASP was further characterized as a robust inhibitor of multiple proteases.In addition,heterogeneous expression of FmASP in Arabidopsis confirmed its positive role in freezing tolerance.Finally,we proposed a working model of FmASP and illustrated how this extracellular-localized protease inhibitor protects proteins from degradation,therebymaintaining essential cellular function for post-freezing recovery.These findings revealed the important role of protease inhibition in freezing response and provide insights on how this role may help develop new strategies to enhance plant freezing tolerance.展开更多
The soil freezing and thawing process affects soil physical properties,such as heat conductivity,heat capacity,and hydraulic conductivity in frozen ground regions,and further affects the processes of soil energy,hydro...The soil freezing and thawing process affects soil physical properties,such as heat conductivity,heat capacity,and hydraulic conductivity in frozen ground regions,and further affects the processes of soil energy,hydrology,and carbon and nitrogen cycles.In this study,the calculation of freezing and thawing front parameterization was implemented into the earth system model of the Chinese Academy of Sciences(CAS-ESM)and its land component,the Common Land Model(CoLM),to investigate the dynamic change of freezing and thawing fronts and their effects.Our results showed that the developed models could reproduce the soil freezing and thawing process and the dynamic change of freezing and thawing fronts.The regionally averaged value of active layer thickness in the permafrost regions was 1.92 m,and the regionally averaged trend value was 0.35 cm yr–1.The regionally averaged value of maximum freezing depth in the seasonally frozen ground regions was 2.15 m,and the regionally averaged trend value was–0.48 cm yr–1.The active layer thickness increased while the maximum freezing depth decreased year by year.These results contribute to a better understanding of the freezing and thawing cycle process.展开更多
Previous studies have shown that the bulk topology of single-particle systems can be captured by the band inversion surface or by the spin inversion surface emerging on the time-averaged spin polarization.Most of the ...Previous studies have shown that the bulk topology of single-particle systems can be captured by the band inversion surface or by the spin inversion surface emerging on the time-averaged spin polarization.Most of the studies,however,are based on the single-particle picture even though the systems are fermionic and multi-bands.Here,we study the slow quench dynamics of topological systems with all the valence bands fully occupied,and show that the concepts of band inversion surface and spin inversion surface are still valid.More importantly,the many-particle nonadiabatic quench dynamics is shown to be reduced to a new and nontrivial three-level Landau-Zener model.This nontrivial three-level Landau-Zener problem is then solved analytically by applying the integrability condition and symmetry considerations,and thus adds a new member to the few models that are exactly solvable.Based on the analytical results,the topological spin texture revealed by the time-averaged spin polarization can be applied to characterize the bulk topology and thus provides a direct comparison for future experiments.展开更多
Potato(Solanum tuberosum L.) is the fourth largest food crop in the world. Low temperatures cause serious damage to potato plants every year, and freezing tolerance has become a hot spot in potato research. Galactinol...Potato(Solanum tuberosum L.) is the fourth largest food crop in the world. Low temperatures cause serious damage to potato plants every year, and freezing tolerance has become a hot spot in potato research. Galactinol synthase(GolS) is a key enzyme in the synthesis of raffinose family oligosaccharides(RFOs), and plays an important role in the response of plants to abiotic stress. In this study, the ScGolS1 gene from Solanum commersonii was cloned and introduced into the S. tuberosum cultivars 'Atlantic' and 'Desiree' via Agrobacterium-mediated transformation. Phenotyping assays showed that overexpression of ScGolS1 could significantly improve freezing tolerance in transgenic potato plants.Further physiological and biochemical experiments showed that the transgenic lines had lower relative conductivity, malondialdehyde content,and 3,3-diaminobenzidine staining and a higher plant survival rate compared with wild type(WT) under cold stress. Moreover, the C-repeat binding factors(CBF1, CBF2 and CBF3), the downstream cold-responsive genes COR413 and COR47, and the ethylene-responsive factor(ERF)transcription factor genes ERF3, ERF4 and ERF6, which function in the ethylene signaling pathway, were all induced by freezing treatment and expressed at higher levels in the ScGolS1 overexpression lines compared with WT. Besides, the expression of some genes such as MIPS, STS and RS from the RFO metabolic pathway was up-regulated under cold stress, resulting in changes in the content of some soluble sugars. This indicated that ScGolS1 overexpression altered the sugar composition and enhanced freezing tolerance in transgenic potato by inducing the ethylene and CBF signaling pathways. These results provided theoretical support and genetic resources for freezing tolerance breeding in potato.展开更多
The calculation of frost heaving with ice lens formation is still not standard for construction projects using artificial ground freezing(AGF).In fine-grained material,ice lenses may initiate and lead to significant h...The calculation of frost heaving with ice lens formation is still not standard for construction projects using artificial ground freezing(AGF).In fine-grained material,ice lenses may initiate and lead to significant heaving at the ground surface,which should be considered in advance.However,the complex processes during ice lens formation are still not fully understood and difficult to capture in a simple approach.In the past,the semi-analytical approach of Konrad and Morgenstern used one soil constant,the“segregation potential(SP)”.It has been mainly and most successfully applied to the heave calculation of natural-induced soil freezing in cold regions.Its application to AGF has been so far unsuccessful.To solve this,a new semi-analytical approach is presented in this paper.It includes AGF conditions such as bottom-up freezing,temperature gradients to reach great freezing velocities,and a distinction between two freezing states.One is the freezing-up state until a certain frost body thickness is reached(thermal transient state),and the other is a holding phase where the frost body thickness is kept constant(thermal quasi-steady state).To test its ability,the results are applied to another freezing direction,the top-down freezing.The new approach is validated using two different frost-susceptible soils and,in total,50 frost heave tests.In the thermal transient region,where the SP is applicable,the two semi-analytical approaches are compared,showing improved performance of the current method by about 15%.展开更多
Since the 1990s,the Qinghai–Tibetan Plateau(QTP)has experienced a strikingly warming and wetter climate that alters the thermal and hydrological properties of frozen ground.A positive correlation between the warming ...Since the 1990s,the Qinghai–Tibetan Plateau(QTP)has experienced a strikingly warming and wetter climate that alters the thermal and hydrological properties of frozen ground.A positive correlation between the warming and thermal degradation in permafrost or seasonally frozen ground(SFG)has long been recognized.Still,a predictive relationship between historical wetting under warming climate conditions and frozen ground has not yet been well demonstrated,despite the expectation that it will become even more important because precipitation over the QTP has been projected to increase continuously in the near future.This study investigates the response of the thermal regime to historical wetting in both permafrost and SFG areas and examines their relationships separately using the Community Land Surface Model version 4.5.Results show that wetting before the 1990s across the QTP mainly cooled the permafrost body in the arid and semiarid zones,with significant correlation coefficients of 0.60 and 0.48,respectively.Precipitation increased continually at the rate of 6.16 mm decade–1 in the arid zone after the 1990s but had a contrasting warming effect on permafrost through a significant shortening of the thawing duration within the active layer.However,diminished rainfall in the humid zone after the 1990s also significantly extended the thawing duration of SFG.The relationship between the ground thawing index and precipitation was significantly negatively correlated(−0.75).The dual effects of wetting on the thermal dynamics of the QTP are becoming critical because of the projected increases in future precipitation.展开更多
The characteristics of the raindrop size distribution(DSD)during regional freezing rain(FR)events that occur throughout the phase change(from liquid to solid)are poorly understood due to limited observations.We invest...The characteristics of the raindrop size distribution(DSD)during regional freezing rain(FR)events that occur throughout the phase change(from liquid to solid)are poorly understood due to limited observations.We investigate the evolution of microphysical parameters and the key formation mechanisms of regional FR using the DSDs from five disdrometer sites in January 2018 in the Jianghan Plain(JHP)of Central China.FR is identified via the size and velocity distribution measured from a disdrometer,the discrete Fréchet distancemethod,surface temperature,human observations,and sounding data.With the persistence of precipitation,the emergence of graupel or snowflakes significantly reduces the proportion of FR.The enhancement of this regional FR event is mainly dominated by the increase in the number concentration of raindrops but weakly affected by the diameters.To improve the accuracy of quantitative precipitation estimation for the FR event,a modified second-degree polynomial relation between the shapeμand slopeΛof gamma DSDs is derived,and a new Z-R(radar reflectivity to rain rate)relationship is developed.The mean values of mass-weighted mean diameters(D_(m))and generalized intercepts(lgN_(w))in FR are close to the stratiform results in the northern region of China.Both the melting of tiny-rimed graupels and large-dry snowflakes are a response to the formation of this regional FR process in the JHP,dominated by the joint influence of the physical mechanism of warm rain,vapor deposition,and aggregation/riming coupled with the effect of weak convective motion in some periods.展开更多
BACKGROUND Impaired interstitial cells of Cajal(ICCs)are central to the pathophysiology of acute cholecystitis(AC).Common bile duct ligation is a common model of AC,producing acute inflammatory changes and decrease in...BACKGROUND Impaired interstitial cells of Cajal(ICCs)are central to the pathophysiology of acute cholecystitis(AC).Common bile duct ligation is a common model of AC,producing acute inflammatory changes and decrease in gallbladder contractility.AIM To investigate the origin of slow wave(SW)in the gallbladder and the effect of ICCs on gallbladder contractions during the process of AC.METHODS Methylene blue(MB)with light was used to establish selective impaired ICCs gallbladder tissue.Gallbladder motility was assessed using the frequency of SW and gallbladder muscle contractility in vitro in normal control(NC),AC12h,AC24h,and AC48h groups of guinea pigs.Hematoxylin and eosin and Massonstained gallbladder tissues were scored for inflammatory changes.ICCs pathological changes alterations were estimated using immunohistochemistry and transmission electron microscopy.The alterations of c-Kit,α-SMA,cholecystokinin A receptor(CCKAR),and connexin 43(CX43)were assessed using Western blot.RESULTS Impaired ICCs muscle strips resulted in the decrease in gallbladder SW frequency and contractility.The frequency of SW and gallbladder contractility were significantly lower in the AC12h group.Compared with the NC group,the density and ultrastructure of ICCs were remarkably impaired in the AC groups,especially in the AC12h group.The protein expression levels of c-Kit were significantly decreased in the AC12h group,while CCKAR and CX43 protein expression levels were significantly decreased in the AC48h group.CONCLUSION Loss ICCs could lead to a decrease in gallbladder SW frequency and contractility.The density and ultrastructure of ICCs were clearly impaired in the early stage of AC,while CCKAR and CX43 were significantly reduced at end stage.展开更多
In most areas of China, affected by the environment of low temperature and high humidity, the wind speed sensor and wind direction sensor are frozen and cannot output data in autumn, winter or the alternation of winte...In most areas of China, affected by the environment of low temperature and high humidity, the wind speed sensor and wind direction sensor are frozen and cannot output data in autumn, winter or the alternation of winter and spring. In order to solve the freezing situation of the wind sensor, this paper designs a new type of antifreeze wind speed sensor. After meteorology performance testing and field observation tests, the correlation coefficient of the observation data is demonstrated, and the data curve is fitted. The result shows the sensor is stable, and has a good antifreeze effect, the data output is reliable.展开更多
The slow traffic system is an important component of urban transportation,and the prerequisite and necessary condition for Beijing to continue promoting“green priority”are establishing a good urban slow traffic syst...The slow traffic system is an important component of urban transportation,and the prerequisite and necessary condition for Beijing to continue promoting“green priority”are establishing a good urban slow traffic system.Shijingshan District of Beijing City is taken as a research object.By analyzing and processing population distribution data,POI data,and shared bicycle data,the shortcomings and deficiencies of the current slow traffic system in Shijingshan District are explored,and corresponding solutions are proposed,in order to provide new ideas and methods for future urban planning from the perspective of data.展开更多
[Objectives] This study was carried out to explore the combined effects of Fu Zi(Radix Aconiti Lateralis Praeparata, the secondary root of perennial herbaceous plant Acontium carmichaeli Dehx. of family Ranunculaceae)...[Objectives] This study was carried out to explore the combined effects of Fu Zi(Radix Aconiti Lateralis Praeparata, the secondary root of perennial herbaceous plant Acontium carmichaeli Dehx. of family Ranunculaceae) and Rou Gui(Cortex Cinnamomi, the bark of Cinnamamunz cassia Presl of family Lauraceae) on intestinal neurotransmitters and microflora in rats with slow transit constipation(STC). [Methods] Experimental rats were given loperamide hydrochloride by gavage to induce STC, and then treated with Fu Zi alone, Rou Gui alone, a combination of Fu Zi and Rou Gui(2:1 w/w), and prucalopride, respectively, for 14 days. Meanwhile, the general condition, the time to first black stool and the rate of intestinal propulsion of rats in each group were observed after STC was induced and after drug treatment, and the pathological changes in rat colon were observed via hematoxylin-eosin(HE) staining, and the levels of colonic 5-hydroxytryptamine(HT), vasoactive intestinal peptide(VIP) and substance P(SP) were detected by ELISA, and the changes in intestinal flora were detected by 16S rRNA Real-time PCR. [Results] Compared with healthy rats, the time to first black stool and the rate of intestinal propulsion, colonic 5-HT and SP levels significantly decreased(p<0.01), while their colonic VIP level significantly increased(p<0.01). Compared with STC rats, the time to first black stool, the rate of intestinal propulsion, colonic 5-HT and SP levels in Fu Zi-Rou Gui(2:1) treated rats and prucalopride treated rats significantly increased(p<0.01), while their colonic VIP level significantly decreased(p<0.01). There was no significant difference in alpha diversity between healthy rats and STC rats. However, analysis on beta diversity revealed that there were differences in microflora structure and composition between them. Compared with healthy rats, the relative abundance of Firmicutes and Proteobacteria in STC rats significantly increased, while that of Bacteroidetes decreased. Compared with STC rats, the relative abundance of Proteobacteria decreased and that of Bacteroidetes and Firmicutes increased in Fu Zi-Rou Gui(2:1) treated rats;the relative abundance of Bacteroidetes and Proteobacteria decreased while that of Firmicutes increased in Fu Zi treated rats;the relative abundance of Proteobacteria decreased while that of Bacteroidetes increased in Rou Gui treated rats;the relative abundance of Firmicutes and Proteobacteria decreased while that of Bacteroidetes increased in prucalopride treated rats. The intestinal flora in rats of all groups was dominated by Lactobacillus spp. and other genera of anaerobic bacteria. Compared with healthy rats, the relative abundance of Lactobacillus spp. and Clostridium spp. in STC rats decreased, while those of Blautia spp. and Ruminococcus spp. and Allobaculum spp. increased. Compared with STC rats, the relative abundance of Lactobacillus spp. in all rats treated with drugs increased. [Conclusions] The combination of Fu Zi and Rou Gui(2:1) can effectively improve intestinal motility in STC rats by regulating intestinal microbial community and the levels of colonic neurotransmitters.展开更多
To build an“ecological and livable city”,it is important to figure out the relationship between human activity and urban park space and create a high-quality urban park through the integration of“people”and“park...To build an“ecological and livable city”,it is important to figure out the relationship between human activity and urban park space and create a high-quality urban park through the integration of“people”and“park”.Taking Longhu Park in Huainan Province as an example,the study quantitatively analyzed and evaluated the characteristics and service quality of slow traffic space using importance-performance analysis(IPA)and space syntax,clarified the key indexes and areas to be optimized,and put forward corresponding design countermeasures and suggestions in combination with human activity demand.The results suggest that:①The mean performance of park recreation service quality is 3.63,less than the mean importance(3.95).Tourists pay special attention to the safety and convenience of slow traffic space,and the diversity and identiability of site functions is the focus“to be improved”.②The accessibility of Longhu Park shows a strong irregular shape in the southwest.The dead-end roads in the far lake area and the flora and fauna area on the northwest side have weak spatial perception,and the composite function carrying potential of slow traffic space is better reflected in a small range.Therefore,an optimization strategy for slow traffic space is proposed to enhance the continuity of road network,site identifiability,and functional diversification.The results will provide new thoughts of governance based on spatial humanism for the high-quality renewal of urban parks in the new era.展开更多
基金The study was supported by the National Natural Science Foundation of China(32101795,32301782)National Key Research and Development Program of China(2016YFD0100201-01)+2 种基金Liaoning Provincial Major Special Project of Agricultural Science and Technology(2022JH1/10200002,2021JH1/10400038)Key Research and Development Plan of Liaoning Science and Technology Department(2021JH2/1020027)Shenyang Seed Industry Innovation Project(22-318-2-12).
文摘Drought is one of the abiotic stresses limiting the production of soybean(Glycine max).Elucidation of the genetic and molecular basis of the slow-wilting(SW)trait of this crop offers the prospect of its genetic improvement.A panel of 188 accessions and a set of recombinant inbred lines produced from a cross between cultivars Liaodou 14 and Liaodou 21 were used to identify quantitative-trait loci(QTL)associated with SW.Plants were genotyped by Specific-locus amplified fragment sequencing and seedling leaf wilting was assessed under three water-stress treatments.A genome-wide association study identified 26 SW-associated single-nucleotide polymorphisms(SNPs),including three located in a 248-kb linkage-disequilibrium(LD)block on chromosome 2.Linkage mapping revealed a major-effect QTL,qSW2,associated with all three treatments and adjacent to the LD block.Fine mapping in a BC_(2)F_(3) population derived from a backcross between Liaodou 21 and R26 confined qSW2 to a 60-kb interval.Gene expression and sequence variation analysis identified the gene Glyma.02 g218100,encoding an auxin transcription factor,as a candidate gene for qSW2.Our results will contribute significantly to improving drought-resistant soybean cultivars by providing genetic information and resources.
基金funded by the National Research Developm ent and Innovation Office (NKFIH-K1468 73) (to BP)。
文摘Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of astrocytes.These events are significantly slower than the excitatory postsynaptic currents.Parameters of slow inward currents are determined by seve ral factors including the mechanisms of astrocytic activation and glutamate release,as well as the diffusion pathways from the release site towards the extra synaptic recepto rs.Astrocytes are stimulated by neuronal network activity,which in turn excite neurons,forming an astrocyte-neuron feedback loop.Mostly as a consequence of brain edema,astrocytic swelling can also induce slow inward currents under pathological conditions.There is a growing body of evidence on the roles of slow inward currents on a single neuron or local network level.These events often occur in synchro ny on neurons located in the same astrocytic domain.Besides synchronization of neuronal excitability,slow inward currents also set synaptic strength via eliciting timing-dependent synaptic plasticity.In addition,slow inward currents are also subject to non-synaptic plasticity triggered by long-la sting stimulation of the excitatory inputs.Of note,there might be important regionspecific differences in the roles and actions triggering slow inward currents.In greater networks,the pathophysiological roles of slow inward currents can be better understood than physiological ones.Slow inward currents are identified in the pathophysiological background of autism,as slow inward currents drive early hypersynchrony of the neural networks.Slow inward currents are significant contributors to paroxysmal depolarizational shifts/interictal spikes.These events are related to epilepsy,but also found in Alzheimer's disease,Parkinson's disease,and stroke,leading to the decline of cognitive functions.Events with features overlapping with slow inward currents(excitatory,N-methyl-Daspartate-receptor mediated currents with astrocytic contribution) as ischemic currents and spreading depolarization also have a well-known pathophysiological role in worsening consequences of stroke,traumatic brain injury,or epilepsy.One might assume that slow inward currents occurring with low frequency under physiological conditions might contribute to synaptic plasticity and memory formation.However,to state this,more experimental evidence from greater neuronal networks or the level of the individual is needed.In this review,I aimed to summarize findings on slow inward currents and to speculate on the potential functions of it.
文摘The paper presents the change in grain-size composition of lignite under cyclic freezing-thawing (FTC) and wetting-drying (WDC). The article shows that in the spring and autumn periods the lignites can be subjected to repeated freezing-thawing and wetting-drying, which determines the possibility of changing their grain-size composition and structure. Experimental studies in laboratory conditions on the influence of cyclic freezing-thawing (FTC) and wetting-drying (WDC) on the quality indicators of lignites have been carried out, their granulometric (fractional) composition has been studied. Freezing-thawing cycle conditions are as follows (FTC): minimum exposure temperature: -20°C;maximum: +5°C;relative humidity: 30%;number of processing cycles: 3. Wetting-drying cycles are as follows (WDC): drying temperatures are +20, +40, +60, +80°C, drying time 90 minutes, the coals are further subjected to rain (soaking) for a period of water saturation to humidity of 30% - 40% and dry again. The number of wetting-drying cycles is 3 times. The tests have revealed the destructive effects of FTC and WDC on the samples of lower metamorphic grade coal, and the cycles of wet-dry lead to the much higher yield of fine sizes (-6+0;-13+0 mm) than the cycles of freeze-thaw. Furthermore, it is found that the increase in the yield of fines depends on the heating temperature: coal disintegration proceeds more intensively at a higher temperature of drying.
基金supported by grants from the National Natural Science Foundation of China(No.81701419 and No.81571418).
文摘Objective:This study compared spindles,cytoskeleton,and developmental potential between vitrified and slow-frozen oocytes using PolScope and electron microscopy.Methods:Oocytes were randomly divided into control,slow freeze-thaw,and vitrification freeze-thaw groups(0,1,and 3 h).PolScope was used to observe spindles,angle of spindles to the first polar bodies,surface areas of oocytes,and lining and outer ret of zona pellucida.Surfaces and ultrastructure of oocytes were observed by scanning electron microscopy and transmission electron microscopy.These measures were used to characterize the impacts of two freezing methods on the developmental capacity of human oocytes.Results:The visible frequency of spindle formation was 92.4%,56.4%,11.2%,24.8%,and 61.1%in control group,slow freeze-thaw group,and the three vitrification freeze-thaw groups(0,1,and 3 h),respectively.Compared to oocytes in the slow freeze group,the angle of the spindle to the first polar body in oocytes in the 3-h vitrification freeze-thaw group was less(37.3°vs.68°,P=0.023).No significant differences were observed between the surface area of oocytes,or lining and outer ret of oocyte zona pellucida between freeze-thaw in these same two groups.Microvilli appeared normal.However,protrusions on oocyte surfaces were increased,and microvilli were laid down on the membrane surface in the 3-h vitrification freeze-thaw group in comparison to the slow-freeze group.Similar comparisons showed better recovery of perivitelline space and mitochondria between the 3-h vitrified and slow-frozen groups.Bipronuclear(2PN)fertilization rate observed in the slow-freeze group(65.7%)was lower than the rate seen in controls(79.2%,P=0.041).No significant differences were observed in 2PN fertilization,cleavage,and blastocyst formation rates between the 3-h vitrification freeze-thaw and control groups.Conclusions:Results suggest that vitrification freeze-thaw for oocyte cryopreservation was a better choice than slow freeze-thaw.
基金the National Natural Science Foundation of China (Grant No. 62061028)the Opening Project of Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology (Grant No. ammt2021A4)+4 种基金the Foundation for Distinguished Young Scientists of Jiangxi Province (Grant No. 20162BCB23009)the Open Research Fund Program of the State Key Laboratory of LowDimensional Quantum Physics (Grant No. KF202010)the Interdisciplinary Innovation Fund of Nanchang University (Grant No. 9166-27060003-YB12)the Open Research Fund Program of Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education (Grant No. OEIAM202004)the Graduate Innovation Special Fund of Jiangxi Province (Grant No. YC2021-S054)。
文摘We theoretically explore the tunability of magnomechanically induced transparency(MMIT) phenomenon and fastslow light effect in a hybrid cavity magnomechanical system in which a high-quality yttrium iron garnet(YIG) sphere and an atomic ensemble are placed inside a microwave cavity. In the probe output spectrum, we can observe magnoninduced transparency(MIT) and MMIT due to the photon-magnon and phonon-magnon couplings. We further investigate the effect of atomic ensemble on the absorption spectrum. The results show that better transparency can be obtained by choosing appropriate atomic ensemble parameters. We give an explicit explanation for the mechanism of the Fano resonance phenomenon. Moreover, we discuss phenomena of slow-light propagation. The maximum group delay increases significantly with the increasing atom–cavity coupling strength, and the conversion between slow light and fast light can also be achieved by adjusting the atom–cavity coupling strength. These results may have potential applications for quantum information processing and high precision measurements.
基金supported by the National Natural Science Foundation of China(Grant Nos.51804157,51774183,and 11702094)the University of Sussex,UK.Both are gratefully acknowledged.
文摘Common problems in engineering projects that involve artificial ground freezing of soil or rock include inadequate thickness,strength and continuity of artificial frozen walls.It is difficult to evaluate the freezing state using only a few thermometer holes at fixed positions or with other existing approaches.Here we report a novel experimental design that investigates changes in ultrasonic properties(received waveform,wave velocity V_(p),wave amplitude,frequency spectrum,centroid frequency f_(c),kurtosis of the frequency spectrum KFS,and quality factor Q)measured during upward freezing,compared with those during uniform freezing,in order to determine the freezing state in 150 mm cubic blocks of Ardingly sandstone.Water content,porosity and density were estimated during upward freezing to ascertain water migration and changes of porosity and density at different stages.The period of receiving the wave increased substantially and coda waves changed from loose to compact during both upward and uniform freezing.The trend of increasing V_(p) can be divided into three stages during uniform freezing.During upward freezing,V_(p) increased more or less uniformly.The frequency spectrum could be used as a convenient and rapid method to identify different freezing states of sandstone(unfrozen,upward frozen,and uniformly frozen).The continuous changes in reflection coefficient r_(φ),refraction coefficient t_(φ) and acoustic impedance field are the major reason for larger reflection and refraction during upward freezing compared with uniform freezing.Wave velocity V_(p),wave amplitude A_(h),centroid frequency f_(c) and quality factor Q were adopted as ultrasonic parameters to evaluate quantitatively the temperature T of uniformly frozen sandstone,and their application within a radar chart is recommended.Determination of V_(p) provides a convenient method to evaluate the freezing state and calculate the cryofront height and frozen section thickness of upward frozen sandstone,with accuracies of 73.37%-99.23%.
基金sponsored by the National Natural Science Foundation of China(No.31200963)the Key Project of Hunan Provincial Education Department(No.18A091).
文摘Cold acclimation is a complex biological process leading to the development of freezing tolerance in plants.In this study,we demonstrated that cold-induced expression of protease inhibitor FmASP in a Citrus-relative species kumquat[Fortunella margarita(Lour.)Swingle]contributes to its freezing tolerance by minimizing protein degradation.Firstly,we found that only cold-acclimated kumquat plants,despite extensive leaf cellular damage during freezing,were able to resume their normal growth upon stress relief.To dissect the impact of cold acclimation on this anti-freezing performance,we conducted protein abundance assays and quantitative proteomic analysis of kumquat leaves subjected to cold acclimation(4◦C),freezing treatment(−10◦C)and post-freezing recovery(25◦C).FmASP(Against Serine Protease)and several non-specific proteases were identified as differentially expressed proteins induced by cold acclimation and associated with stable protein abundance throughout the course of low-temperature treatment.FmASP was further characterized as a robust inhibitor of multiple proteases.In addition,heterogeneous expression of FmASP in Arabidopsis confirmed its positive role in freezing tolerance.Finally,we proposed a working model of FmASP and illustrated how this extracellular-localized protease inhibitor protects proteins from degradation,therebymaintaining essential cellular function for post-freezing recovery.These findings revealed the important role of protease inhibition in freezing response and provide insights on how this role may help develop new strategies to enhance plant freezing tolerance.
基金This work was jointly funded by the National Natural Science Foundation of China(Grant Nos.42205168,41830967,and 42175163)the Youth Innovation Promotion Association CAS(2021073)the National Key Scientific and Technological Infrastructure project“Earth System Science Numerical Simulator Facility”(EarthLab).
文摘The soil freezing and thawing process affects soil physical properties,such as heat conductivity,heat capacity,and hydraulic conductivity in frozen ground regions,and further affects the processes of soil energy,hydrology,and carbon and nitrogen cycles.In this study,the calculation of freezing and thawing front parameterization was implemented into the earth system model of the Chinese Academy of Sciences(CAS-ESM)and its land component,the Common Land Model(CoLM),to investigate the dynamic change of freezing and thawing fronts and their effects.Our results showed that the developed models could reproduce the soil freezing and thawing process and the dynamic change of freezing and thawing fronts.The regionally averaged value of active layer thickness in the permafrost regions was 1.92 m,and the regionally averaged trend value was 0.35 cm yr–1.The regionally averaged value of maximum freezing depth in the seasonally frozen ground regions was 2.15 m,and the regionally averaged trend value was–0.48 cm yr–1.The active layer thickness increased while the maximum freezing depth decreased year by year.These results contribute to a better understanding of the freezing and thawing cycle process.
基金Project supported by the National Key Research and Development Program of China(Grant No.2021YFA1200700)the National Natural Science Foundation of China(Grant Nos.11905054,12275075 and 12105094)the Fundamental Research Funds for the Central Universities of China。
文摘Previous studies have shown that the bulk topology of single-particle systems can be captured by the band inversion surface or by the spin inversion surface emerging on the time-averaged spin polarization.Most of the studies,however,are based on the single-particle picture even though the systems are fermionic and multi-bands.Here,we study the slow quench dynamics of topological systems with all the valence bands fully occupied,and show that the concepts of band inversion surface and spin inversion surface are still valid.More importantly,the many-particle nonadiabatic quench dynamics is shown to be reduced to a new and nontrivial three-level Landau-Zener model.This nontrivial three-level Landau-Zener problem is then solved analytically by applying the integrability condition and symmetry considerations,and thus adds a new member to the few models that are exactly solvable.Based on the analytical results,the topological spin texture revealed by the time-averaged spin polarization can be applied to characterize the bulk topology and thus provides a direct comparison for future experiments.
基金supported by the National Natural Science Foundation of China (Grant No. 31561143006)China Agriculture Research System (Grant No. CARS-9)the Chinese Academy of Agricultural Sciences Innovation Project (Grant No. CAASASTIP-IVFCAAS)。
文摘Potato(Solanum tuberosum L.) is the fourth largest food crop in the world. Low temperatures cause serious damage to potato plants every year, and freezing tolerance has become a hot spot in potato research. Galactinol synthase(GolS) is a key enzyme in the synthesis of raffinose family oligosaccharides(RFOs), and plays an important role in the response of plants to abiotic stress. In this study, the ScGolS1 gene from Solanum commersonii was cloned and introduced into the S. tuberosum cultivars 'Atlantic' and 'Desiree' via Agrobacterium-mediated transformation. Phenotyping assays showed that overexpression of ScGolS1 could significantly improve freezing tolerance in transgenic potato plants.Further physiological and biochemical experiments showed that the transgenic lines had lower relative conductivity, malondialdehyde content,and 3,3-diaminobenzidine staining and a higher plant survival rate compared with wild type(WT) under cold stress. Moreover, the C-repeat binding factors(CBF1, CBF2 and CBF3), the downstream cold-responsive genes COR413 and COR47, and the ethylene-responsive factor(ERF)transcription factor genes ERF3, ERF4 and ERF6, which function in the ethylene signaling pathway, were all induced by freezing treatment and expressed at higher levels in the ScGolS1 overexpression lines compared with WT. Besides, the expression of some genes such as MIPS, STS and RS from the RFO metabolic pathway was up-regulated under cold stress, resulting in changes in the content of some soluble sugars. This indicated that ScGolS1 overexpression altered the sugar composition and enhanced freezing tolerance in transgenic potato by inducing the ethylene and CBF signaling pathways. These results provided theoretical support and genetic resources for freezing tolerance breeding in potato.
基金supported by the German Research Foundation(DFG)under the project“Investigation and calculation of frost heave considering specific boundary conditions of ground freezing”(Grant No.409760547).
文摘The calculation of frost heaving with ice lens formation is still not standard for construction projects using artificial ground freezing(AGF).In fine-grained material,ice lenses may initiate and lead to significant heaving at the ground surface,which should be considered in advance.However,the complex processes during ice lens formation are still not fully understood and difficult to capture in a simple approach.In the past,the semi-analytical approach of Konrad and Morgenstern used one soil constant,the“segregation potential(SP)”.It has been mainly and most successfully applied to the heave calculation of natural-induced soil freezing in cold regions.Its application to AGF has been so far unsuccessful.To solve this,a new semi-analytical approach is presented in this paper.It includes AGF conditions such as bottom-up freezing,temperature gradients to reach great freezing velocities,and a distinction between two freezing states.One is the freezing-up state until a certain frost body thickness is reached(thermal transient state),and the other is a holding phase where the frost body thickness is kept constant(thermal quasi-steady state).To test its ability,the results are applied to another freezing direction,the top-down freezing.The new approach is validated using two different frost-susceptible soils and,in total,50 frost heave tests.In the thermal transient region,where the SP is applicable,the two semi-analytical approaches are compared,showing improved performance of the current method by about 15%.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41905008, 41975007, and 42075081)the Innovation and Entrepreneurship Training Program for College Students of Chengdu University of Information Technology (CUIT) (202210621003, 202210621039, 202110621015)provided by the Scientific Research Foundation of CUIT (KYTZ202126)
文摘Since the 1990s,the Qinghai–Tibetan Plateau(QTP)has experienced a strikingly warming and wetter climate that alters the thermal and hydrological properties of frozen ground.A positive correlation between the warming and thermal degradation in permafrost or seasonally frozen ground(SFG)has long been recognized.Still,a predictive relationship between historical wetting under warming climate conditions and frozen ground has not yet been well demonstrated,despite the expectation that it will become even more important because precipitation over the QTP has been projected to increase continuously in the near future.This study investigates the response of the thermal regime to historical wetting in both permafrost and SFG areas and examines their relationships separately using the Community Land Surface Model version 4.5.Results show that wetting before the 1990s across the QTP mainly cooled the permafrost body in the arid and semiarid zones,with significant correlation coefficients of 0.60 and 0.48,respectively.Precipitation increased continually at the rate of 6.16 mm decade–1 in the arid zone after the 1990s but had a contrasting warming effect on permafrost through a significant shortening of the thawing duration within the active layer.However,diminished rainfall in the humid zone after the 1990s also significantly extended the thawing duration of SFG.The relationship between the ground thawing index and precipitation was significantly negatively correlated(−0.75).The dual effects of wetting on the thermal dynamics of the QTP are becoming critical because of the projected increases in future precipitation.
基金supported by the National Natural Science Foundation of China(Grant Nos.41875170 and 41675136)the National Key Research and Development Program of China(2018YFC1507201 and 2018YFC1507905)the Guangxi Key Research and Development Program(AB20159013)。
文摘The characteristics of the raindrop size distribution(DSD)during regional freezing rain(FR)events that occur throughout the phase change(from liquid to solid)are poorly understood due to limited observations.We investigate the evolution of microphysical parameters and the key formation mechanisms of regional FR using the DSDs from five disdrometer sites in January 2018 in the Jianghan Plain(JHP)of Central China.FR is identified via the size and velocity distribution measured from a disdrometer,the discrete Fréchet distancemethod,surface temperature,human observations,and sounding data.With the persistence of precipitation,the emergence of graupel or snowflakes significantly reduces the proportion of FR.The enhancement of this regional FR event is mainly dominated by the increase in the number concentration of raindrops but weakly affected by the diameters.To improve the accuracy of quantitative precipitation estimation for the FR event,a modified second-degree polynomial relation between the shapeμand slopeΛof gamma DSDs is derived,and a new Z-R(radar reflectivity to rain rate)relationship is developed.The mean values of mass-weighted mean diameters(D_(m))and generalized intercepts(lgN_(w))in FR are close to the stratiform results in the northern region of China.Both the melting of tiny-rimed graupels and large-dry snowflakes are a response to the formation of this regional FR process in the JHP,dominated by the joint influence of the physical mechanism of warm rain,vapor deposition,and aggregation/riming coupled with the effect of weak convective motion in some periods.
基金Supported by the Pudong New Area Clinical Traditional Chinese Medicine of Top Discipline Project,No.PDZY-2018-0603 and the Featured Clinical Discipline Project of Shanghai Pudong,No.PWYts2021-06.
文摘BACKGROUND Impaired interstitial cells of Cajal(ICCs)are central to the pathophysiology of acute cholecystitis(AC).Common bile duct ligation is a common model of AC,producing acute inflammatory changes and decrease in gallbladder contractility.AIM To investigate the origin of slow wave(SW)in the gallbladder and the effect of ICCs on gallbladder contractions during the process of AC.METHODS Methylene blue(MB)with light was used to establish selective impaired ICCs gallbladder tissue.Gallbladder motility was assessed using the frequency of SW and gallbladder muscle contractility in vitro in normal control(NC),AC12h,AC24h,and AC48h groups of guinea pigs.Hematoxylin and eosin and Massonstained gallbladder tissues were scored for inflammatory changes.ICCs pathological changes alterations were estimated using immunohistochemistry and transmission electron microscopy.The alterations of c-Kit,α-SMA,cholecystokinin A receptor(CCKAR),and connexin 43(CX43)were assessed using Western blot.RESULTS Impaired ICCs muscle strips resulted in the decrease in gallbladder SW frequency and contractility.The frequency of SW and gallbladder contractility were significantly lower in the AC12h group.Compared with the NC group,the density and ultrastructure of ICCs were remarkably impaired in the AC groups,especially in the AC12h group.The protein expression levels of c-Kit were significantly decreased in the AC12h group,while CCKAR and CX43 protein expression levels were significantly decreased in the AC48h group.CONCLUSION Loss ICCs could lead to a decrease in gallbladder SW frequency and contractility.The density and ultrastructure of ICCs were clearly impaired in the early stage of AC,while CCKAR and CX43 were significantly reduced at end stage.
文摘In most areas of China, affected by the environment of low temperature and high humidity, the wind speed sensor and wind direction sensor are frozen and cannot output data in autumn, winter or the alternation of winter and spring. In order to solve the freezing situation of the wind sensor, this paper designs a new type of antifreeze wind speed sensor. After meteorology performance testing and field observation tests, the correlation coefficient of the observation data is demonstrated, and the data curve is fitted. The result shows the sensor is stable, and has a good antifreeze effect, the data output is reliable.
基金Sponsored by Beijing Natural Science Foundation General Project(8212009)Construction of Philosophy and Social Sciences Base in Beijing-Research on Beijing Urban Renewal and Comprehensive Management of Old Community En-vironment2023 Education Reform Project of North China University of Technology(108051360023XN264-25).
文摘The slow traffic system is an important component of urban transportation,and the prerequisite and necessary condition for Beijing to continue promoting“green priority”are establishing a good urban slow traffic system.Shijingshan District of Beijing City is taken as a research object.By analyzing and processing population distribution data,POI data,and shared bicycle data,the shortcomings and deficiencies of the current slow traffic system in Shijingshan District are explored,and corresponding solutions are proposed,in order to provide new ideas and methods for future urban planning from the perspective of data.
基金Supported by The Natural Science Foundation of Guizhou Province (Qiankehe Jichu[2020]1Y362)Special Project for Scientific and Technological Research on Traditional Chinese Medicine and Ethnic Medicine of Guizhou Province(QZYY-2021-016)+1 种基金The Natural Science Foundation of Guizhou Province(Qiankehe Jichu-ZK[2022]Yiban 510)Young Science and Technology Talents Growth Project of Guizhou Provincial Department of Education (Qian Jiao He KY Zi[2022]No. 261)。
文摘[Objectives] This study was carried out to explore the combined effects of Fu Zi(Radix Aconiti Lateralis Praeparata, the secondary root of perennial herbaceous plant Acontium carmichaeli Dehx. of family Ranunculaceae) and Rou Gui(Cortex Cinnamomi, the bark of Cinnamamunz cassia Presl of family Lauraceae) on intestinal neurotransmitters and microflora in rats with slow transit constipation(STC). [Methods] Experimental rats were given loperamide hydrochloride by gavage to induce STC, and then treated with Fu Zi alone, Rou Gui alone, a combination of Fu Zi and Rou Gui(2:1 w/w), and prucalopride, respectively, for 14 days. Meanwhile, the general condition, the time to first black stool and the rate of intestinal propulsion of rats in each group were observed after STC was induced and after drug treatment, and the pathological changes in rat colon were observed via hematoxylin-eosin(HE) staining, and the levels of colonic 5-hydroxytryptamine(HT), vasoactive intestinal peptide(VIP) and substance P(SP) were detected by ELISA, and the changes in intestinal flora were detected by 16S rRNA Real-time PCR. [Results] Compared with healthy rats, the time to first black stool and the rate of intestinal propulsion, colonic 5-HT and SP levels significantly decreased(p<0.01), while their colonic VIP level significantly increased(p<0.01). Compared with STC rats, the time to first black stool, the rate of intestinal propulsion, colonic 5-HT and SP levels in Fu Zi-Rou Gui(2:1) treated rats and prucalopride treated rats significantly increased(p<0.01), while their colonic VIP level significantly decreased(p<0.01). There was no significant difference in alpha diversity between healthy rats and STC rats. However, analysis on beta diversity revealed that there were differences in microflora structure and composition between them. Compared with healthy rats, the relative abundance of Firmicutes and Proteobacteria in STC rats significantly increased, while that of Bacteroidetes decreased. Compared with STC rats, the relative abundance of Proteobacteria decreased and that of Bacteroidetes and Firmicutes increased in Fu Zi-Rou Gui(2:1) treated rats;the relative abundance of Bacteroidetes and Proteobacteria decreased while that of Firmicutes increased in Fu Zi treated rats;the relative abundance of Proteobacteria decreased while that of Bacteroidetes increased in Rou Gui treated rats;the relative abundance of Firmicutes and Proteobacteria decreased while that of Bacteroidetes increased in prucalopride treated rats. The intestinal flora in rats of all groups was dominated by Lactobacillus spp. and other genera of anaerobic bacteria. Compared with healthy rats, the relative abundance of Lactobacillus spp. and Clostridium spp. in STC rats decreased, while those of Blautia spp. and Ruminococcus spp. and Allobaculum spp. increased. Compared with STC rats, the relative abundance of Lactobacillus spp. in all rats treated with drugs increased. [Conclusions] The combination of Fu Zi and Rou Gui(2:1) can effectively improve intestinal motility in STC rats by regulating intestinal microbial community and the levels of colonic neurotransmitters.
基金Sponsored by National Key Research and Development Project(2018YFD1100203)Research Topics of Huainan Municipal People’s Government Development Research Center,Innovation Topics of Huainan Urban Renewal Strategy Research(K2110098).
文摘To build an“ecological and livable city”,it is important to figure out the relationship between human activity and urban park space and create a high-quality urban park through the integration of“people”and“park”.Taking Longhu Park in Huainan Province as an example,the study quantitatively analyzed and evaluated the characteristics and service quality of slow traffic space using importance-performance analysis(IPA)and space syntax,clarified the key indexes and areas to be optimized,and put forward corresponding design countermeasures and suggestions in combination with human activity demand.The results suggest that:①The mean performance of park recreation service quality is 3.63,less than the mean importance(3.95).Tourists pay special attention to the safety and convenience of slow traffic space,and the diversity and identiability of site functions is the focus“to be improved”.②The accessibility of Longhu Park shows a strong irregular shape in the southwest.The dead-end roads in the far lake area and the flora and fauna area on the northwest side have weak spatial perception,and the composite function carrying potential of slow traffic space is better reflected in a small range.Therefore,an optimization strategy for slow traffic space is proposed to enhance the continuity of road network,site identifiability,and functional diversification.The results will provide new thoughts of governance based on spatial humanism for the high-quality renewal of urban parks in the new era.
