A complex mechatronics system Bayesian plan of demonstration test is studied based on the mixed beta distribution. During product design and improvement various information is appropriately considered by introducing i...A complex mechatronics system Bayesian plan of demonstration test is studied based on the mixed beta distribution. During product design and improvement various information is appropriately considered by introducing inheritance factor, moreover, the inheritance factor is thought as a random variable, and the Bayesian decision of the qualification test plan is obtained, and the correctness of a Bayesian model presented is verified. The results show that the quantity of the test is too conservative according to classical methods under small binomial samples. Although traditional Bayesian analysis can consider test information of related or similar products, it ignores differences between such products. The method has solved the above problem, furthermore, considering the requirement in many practical projects, the differences among this method, the classical method and Bayesian with beta distribution are compared according to the plan of reliability acceptance test.展开更多
Wheat(Triticum aestivum L.)is a staple crop critical for global food security,yet its productivity is significantly affected by abiotic stresses such as drought,salinity,and waterlogging,which are exacerbated by clima...Wheat(Triticum aestivum L.)is a staple crop critical for global food security,yet its productivity is significantly affected by abiotic stresses such as drought,salinity,and waterlogging,which are exacerbated by climate change.This study evaluated the effects of these stresses on vegetative growth,physiological responses,and yield.Field experiments were conducted using a Randomized Complete Block Design(RCBD)at the Mona Reclamation Experimental Project(MREP),WAPDA,Bhalwal,Sargodha,Punjab Pakistan.Stress treatments included three levels of drought(25%,50%,and 75%field capacity),salinity(4,8,and 12 dS/m),and waterlogging(24,48,and 72 h).Key parameters measured included plant height,leaf area,tiller number,stomatal conductance,chlorophyll content,and antioxidant enzyme activities.The results revealed that drought stress caused a 46%reduction in yield,while salinity and waterlogging reduced yield by 54%and 35%,respectively,with statistically significant differences(p 0.05).Key<physiological changes included a significant reduction in stomatal conductance(from 0.55 to 0.15 mmol m^(2)/s under drought stress,p 0.01)and chlorophyll content(from 48 to 28 SPAD units under drought,p 0.01).Biochemical<<responses indicated elevated levels of malondialdehyde(MDA)and hydrogen peroxide(H2O2),with significant increases in antioxidant enzyme activities,particularly superoxide dismutase(SOD)and catalase(CAT).These findings underscore the need for developing stress-tolerant wheat varieties and implementing agronomic practices to mitigate the impact of abiotic stresses on wheat yield.展开更多
Accumulating evidence suggests that oxidative stress and the Wnt/β-catenin pathway participate in stroke-induced disruption of the blood-brain barrier.However,the potential links between them following ischemic strok...Accumulating evidence suggests that oxidative stress and the Wnt/β-catenin pathway participate in stroke-induced disruption of the blood-brain barrier.However,the potential links between them following ischemic stroke remain largely unknown.The present study found that cerebral ischemia leads to oxidative stress and repression of the Wnt/β-catenin pathway.Meanwhile,Wnt/β-catenin pathway activation by the pharmacological inhibito r,TWS119,relieved oxidative stress,increased the levels of cytochrome P4501B1(CYP1B1)and tight junction-associated proteins(zonula occludens-1[ZO-1],occludin and claudin-5),as well as brain microvascular density in cerebral ischemia rats.Moreove r,rat brain microvascular endothelial cells that underwent oxygen glucose deprivation/reoxygenation displayed intense oxidative stress,suppression of the Wnt/β-catenin pathway,aggravated cell apoptosis,downregulated CYP1B1and tight junction protein levels,and inhibited cell prolife ration and migration.Overexpression ofβ-catenin or knockdown ofβ-catenin and CYP1B1 genes in rat brain mic rovascular endothelial cells at least partly ameliorated or exacerbated these effects,respectively.In addition,small interfering RNA-mediatedβ-catenin silencing decreased CYP1B1 expression,whereas CYP1B1 knoc kdown did not change the levels of glycogen synthase kinase 3β,Wnt-3a,andβ-catenin proteins in rat brain microvascular endothelial cells after oxygen glucose deprivatio n/reoxygenation.Thus,the data suggest that CYP1B1 can be regulated by Wnt/β-catenin signaling,and activation of the Wnt/β-catenin/CYP1B1 pathway contributes to alleviation of oxidative stress,increased tight junction levels,and protection of the blood-brain barrier against ischemia/hypoxia-induced injury.展开更多
We quantified cell membrane permeability (electrical conduc-tivity-EC, water soluble sugar-WSS, and amino acids-AA) and integrity (phospholipids,α-tocopherol and lipid peroxidation) along with food reserve deteri...We quantified cell membrane permeability (electrical conduc-tivity-EC, water soluble sugar-WSS, and amino acids-AA) and integrity (phospholipids,α-tocopherol and lipid peroxidation) along with food reserve deterioration (total proteins, total sugar, and total starch) of neem seeds collected from various mother tree age classes and stored for 65 days in airtight plastic containers at ambient room temperature (35±5°C). Results show that the activities were higher in fresh seeds (EC 267.56-2950.01 μS/g, WSS 19.96-19.48 mg/g and AA 5.40-5.35 mg/g) and declined with increasing duration of storage period (EC 153.37-195.17 μS/g, WSS 3.13-4.17 mg/g and AA 4.29-4.49 mg/g after 35 days and EC 144.02-161.56 μS/g, WSS 2.06-2.40 mg/g and AA 3.98-4.27 mg/g after 65 days of storage). Phospholipids andα-tocopherol were higher in fresh seed (0.073-0.093 OD at 710 nm and 0.080-0.105 OD, respectively) and declined as storage duration in-creased (0.033-0.042 OD at 710 nm and 00.0010-0.0020 OD, respec-tively). Dead seeds showed reduced amounts of phospholipids and minimum activity ofα- tocopherol (antioxidants). The level of MDA was lower in fresh seeds (0.0066-0.0087 OD at 600-535 nm) and increased as storage duration increased (0.0248-0.0268 OD after 65 days of stor-age). The higher amount of MDA indicated that seeds died due to rancid-ity of the oil inside the seed. Neem seed cake was assessed for deteriora-tion of food reserves (total proteins, total sugar, and total starch), concen-trations of which were higher in fresh seed and declined as storage dura-tion increased. Germination was higher in fresh seeds and after 65 days, no germination was received perhaps due to deterioration of biochemi-cals in seeds. Patterns of seed deterioration were similar across all seed lots.展开更多
The mechanical behaviour of a quasi-brittle material,i.e.Pietra Serena sandstone,was investigated both numerically and experimentally in order to build a reliable numerical modelling system applicable to more complex ...The mechanical behaviour of a quasi-brittle material,i.e.Pietra Serena sandstone,was investigated both numerically and experimentally in order to build a reliable numerical modelling system applicable to more complex cases.The Karagozian and Case concrete(KCC)model was exploited as the material constitutive law and a new method to utilise this model for efficient and accurate simulation of quasibrittle materials is discussed.The capability of this model is evaluated by comparing the results of the numerical simulations with the corresponding experimental results,and the method itself is critically assessed.展开更多
Cyclic freezing-thawing can lead to fracture development in coal,affecting its mechanical and consumer properties.To study crack formations in coal,an ultrasonic sounding method using shear polarized waves was propose...Cyclic freezing-thawing can lead to fracture development in coal,affecting its mechanical and consumer properties.To study crack formations in coal,an ultrasonic sounding method using shear polarized waves was proposed.Samples of three coal types(anthracite,lignite and hard coal)were tested.The research results show that,in contrast to the shear wave velocity,the shear wave amplitude is extremely sensitive to the formation of new cracks at the early stages of cyclic freezing-thawing.Tests also show an inverse correlation between coal compressive strength and its tendency to form cracks under temperature impacts;shear wave attenuation increases more sharply in high-rank coals after the first freezing cycle.Spectral analysis of the received signals also confirmed significant crack formation in anthracite after the first freeze-thaw cycle.The initial anisotropy was determined,and its decrease with an increase in the number of freeze-thaw cycles was shown.The data obtained forms an experimental basis for the development of new approaches to preserve coal consumer properties during storage and transportation under severe natural and climatic conditions.展开更多
Background:Disruption of the blood–brain barrier(BBB)after a stroke can lead to brain injury and neurological impairment.Previous work confirmed the involvement of the immunoproteasome subunit of low molecular mass p...Background:Disruption of the blood–brain barrier(BBB)after a stroke can lead to brain injury and neurological impairment.Previous work confirmed the involvement of the immunoproteasome subunit of low molecular mass peptide 2(LMP2)in the pathophysiology of ischemia stroke.However,the relationship between the immunoproteasome LMP2 and the BBB remains unclear.Methods:Adult male Sprague–Dawley rats were subjected to transient middle cerebral artery occlusion/reperfusion(MCAO/R).Three days before MCAO,the rats were treated with lentivirus-mediated LMP2 shRNA preparations by stereotactical injection into the ipsilateral hemispheric region.The rat brain microvascular endothelial cell(RBMVEC)line was exposed to oxygen–glucose deprivation/reperfusion(OGD/R)to mimic ischemic conditions in vitro.The RNA interference-mediated knockdown of LMP2 orβ-catenin was analysed in vivo and in vitro.Analysis of the quantity of extravasated Evans blue(EB)and cerebral fluorescent angiography were performed to evaluate the integrity of the BBB.Immunofluorescence and Western blotting were employed to detect the expression of target proteins.Cell migration was evaluated using a scratch migration assay.The results of immunofluorescence,Western blotting and cell migration were quantified using the software ImageJ(Version 1.53).Parametric data from different groups were compared using one-way ANOVA followed by the least significant difference(LSD)test.Results:Cerebral ischemia led to lower levels of structural components of the BBB such as tight junction proteins[occludin,claudin-1 and zonula occludens(ZO-1)]in the MCAO/R group compared with the sham group(P<0.001).However,inhibition of the immunoproteasome LMP2 restored the expression of these proteins,resulting in higher levels of occludin,claudin-1 and ZO-1 in the LMP2-shRNA group compared with the control-shRNA group(P<0.001).In addition,inhibition of the immunoproteasome LMP2 contributed to higher microvascular density and decreased BBB permeability[e.g.,the quantity of extravasated EB:LMP2-shRNA group(58.54±7.37)μg/g vs.control-shRNA group(103.74±4.32)μg/g,P<0.001],and promoted the upregulation of Wnt-3a andβ-catenin proteins in rats following MCAO/R.In vitro experiments,OGD/R induced marked upregulation of LMP2,proapoptotic protein Bax and cleaved caspase-3,and downregulation of occludin,claudin-1,ZO-1 and Bcl-2,as well as inhibition of the Wnt/β-catenin pathway Wnt-3a andβ-catenin proteins in RBMVECs,compared with the control group under normal culture conditions(P<0.001).However,silencing of LMP2 gene expression reversed these protein changes and promoted proliferation and migration of RBMVECs following OGD/R.Silencing ofβ-catenin by transfection of RBMVECs withβ-catenin-si RNA aggravated the downregulation of tight junction proteins,and reduced the proliferation and migration of RBMVECs following OGD/R,compared with the control-siRNA group(P<0.001).LMP2-si RNA andβ-catenin-si RNA co-transfection partly counteracted the beneficial effects of silencing LMP2-siRNA on the levels of tight junction proteins in RBMVECs exposed to OGD/R.Conclusions:This study suggests that inhibition of the immunoproteasome LMP2 ameliorates ischemia/hypoxia induced BBB injury,and that the molecular mechanism involves the immunoproteasome-regulated activation of the Wnt/β-catenin signalling pathway under ischemic conditions.展开更多
The rectifier filter circuit is widely applied.However,it is difficult to gain a global solution for the optimization design.4-D visual analysis and design optimization of the single-phase uncontrolled bridge rectifie...The rectifier filter circuit is widely applied.However,it is difficult to gain a global solution for the optimization design.4-D visual analysis and design optimization of the single-phase uncontrolled bridge rectifier with an LC filter are presented in this paper.展开更多
A new Gaussian approximation nonlinear filter called generalized cubature quadrature Kalman filter (GCQKF) is introduced for nonlinear dynamic systems. Based on standard GCQKF, two extensions are developed, namely squ...A new Gaussian approximation nonlinear filter called generalized cubature quadrature Kalman filter (GCQKF) is introduced for nonlinear dynamic systems. Based on standard GCQKF, two extensions are developed, namely square root generalized cubature quadrature Kalman filter (SR-GCQKF) and iterated generalized cubature quadrature Kalman filter (I-GCQKF). In SR-GCQKF, the QR decomposition is exploited to alter the Cholesky decomposition and both predicted and filtered error covariances have been propagated in square root format to make sure the numerical stability. In I-GCQKF, the measurement update step is executed iteratively to make full use of the latest measurement and a new terminal criterion is adopted to guarantee the increase of likelihood. Detailed numerical experiments demonstrate the superior performance on both tracking stability and estimation accuracy of I-GCQKF and SR-GCQKF compared with GCQKF.展开更多
A field-programmable gate array(FPGA)based high-speed broadband data acquisition system is designed.The system has a dual channel simultaneous acquisition function.The maximum sampling rate is 500 MSa/s and bandwidth ...A field-programmable gate array(FPGA)based high-speed broadband data acquisition system is designed.The system has a dual channel simultaneous acquisition function.The maximum sampling rate is 500 MSa/s and bandwidth is200 MHz,which solves the large bandwidth,high-speed signal acquisition and processing problems.At present,the data acquisition system is successfully used in broadband receiver test systems.展开更多
Syzygium campanulatum Korth is a plant, which is a rich source of secondary metabolites (especially flavanones, chalcone, and triterpenoids). In our present study, three conventional solvent extraction (CSE) techn...Syzygium campanulatum Korth is a plant, which is a rich source of secondary metabolites (especially flavanones, chalcone, and triterpenoids). In our present study, three conventional solvent extraction (CSE) techniques and supercritical fluid extraction (SFE) techniques were performed to achieve a maximum recovery of two flavanones, chalcone, and two triterpenoids from S. campanulatum leaves. Furthermore, a Box-Behnken design was constructed for the SFE technique using pressure, temperature, and particle size as independent variables, and yields of crude extract, individual and total secondary metabolites as the dependent variables. In the CSE procedure, twenty extracts were produced using ten different solvents and three techniques (maceration, soxhletion, and reflux). An enriched extract of five secondary metabolites was collected using n-hexane:methanol (1:1) soxhletion. Using food-grade ethanol as a modifier, the SFE methods produced a higher recovery (25.5%-84.9%) of selected secondary metabo- lites as compared to the CSE techniques (0.92%-66.00%).展开更多
Objective:To evaluate the anti-oxidani and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica in in vitro conditions.Methods:In vitro DPPH radical scavenging activity and lipoxygenase(LOX)...Objective:To evaluate the anti-oxidani and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica in in vitro conditions.Methods:In vitro DPPH radical scavenging activity and lipoxygenase(LOX) inhibition assays were used to evaluate the anti-oxidant and anti-inflammatory activities respectively.Methanolic extract(MEMI),successive water extract (SWMI) and ethyl acetate fraction(EMEMI),n-butanol fraction(BMEMI) and water soluble fraction (WMEMI) of methanolic extract were evaluated along with respective reference standards. Results:In in ritro DPPH radical scavenging activity,the MEMI,EMEMI and BMEMI have offered significant antioxidant activity with IC<sub>50</sub> values of 13.37.3.55 and 14.19μig/mL respectively.Gallic acid,a reference standard showed significant antioxidant activity with IC? value of 1.88 and found to be more potent compared to all the extracts and fractions.In m vitro LOX inhibition assay,the MEMI,EMEMI and BMEMI have showed significant inhibition of LOX enzyme activity with IC<sub>50</sub> values of 96.71.63.21 and 107.44μg/mL respectively.While,reference drug Indometlhacin also offered significant inhibtion against LOX enzyme activity with IC<sub>50</sub> of 57.75.Furthermore,MEMI was found to more potent than SWMI and among the fractions EMEMI was found to possess more potent antioxidant and anti-inflammatory activity.Conclusions:These findings suggest that the MEMI and F.MEMT possess potent anti-oxidani and anti-inflammatory activities in in vitro conditions.展开更多
Crop phosphorus(P) deficiency and poor utilization of added P is a major agricultural problem due to reduced solubility of soil P and rapid fixation or precipitation of applied P fertilizer in alkaline and calcareous ...Crop phosphorus(P) deficiency and poor utilization of added P is a major agricultural problem due to reduced solubility of soil P and rapid fixation or precipitation of applied P fertilizer in alkaline and calcareous soils. The effects of P-enriched compost and single superphosphate(SSP) fertilization on maize and wheat yields and P use efficiency in a maize–wheat rotation system were studied for three years. On a three-year average, grain yields of maize and wheat after application of P-enriched compost were increased by 18% and 24%, respectively, in comparison with sole addition of a recommended dose of SSP fertilizer. P-enriched compost addition to soil increased maize and wheat yields by 12% and 17%, respectively, compared to P fertilizer plus FYM incorporation. Soil available P concentration and P uptake were affected significantly by the addition of P-enriched compost. On average, increases in P recovery, use efficiency, and agronomic efficiency of 52%, 18%, and 43% were recorded in maize and increases of 50%, 23%, and 49% in wheat. P-enriched compost application yielded 30% and 32%higher economic returns in maize and wheat than SSP fertilization alone.展开更多
The present study was designed to further investigate the C_(21) steroidal glycosides in Cynanchum plants.Two new steroidal glycosides based on a 13,14:14,15-disecopregnane-type aglycone,komaroside P(1) and komaroside...The present study was designed to further investigate the C_(21) steroidal glycosides in Cynanchum plants.Two new steroidal glycosides based on a 13,14:14,15-disecopregnane-type aglycone,komaroside P(1) and komaroside Q(2),together with three known compounds(3-5) were isolated from the whole herbs of Cynanchum komarovii.The aglycones of compounds 1 and 2 were two new disecopregnane.Their structures were elucidated on the basis of 1 D,2 D NMR spectroscopic data and acid hydrolysis.All the compounds(1-5) showed potent inhibitory activities against human leukemia cell lines(HL-60) with IC50 values ranging from 16.6 to 26.3 μmol·L^(-1),compared to the positive control 5-fluorouracil(6.4 μmol·L^(-1)).展开更多
Hypertension is a critical health problem and worse other cardiovascular diseases.It is mainly of two types:Primary or essential hypertension and Secondary hypertension.Hypertension is the primary possibility feature ...Hypertension is a critical health problem and worse other cardiovascular diseases.It is mainly of two types:Primary or essential hypertension and Secondary hypertension.Hypertension is the primary possibility feature for coronary heart disease,stroke and renal vascular disease.Herbal medicines have been used for millions of years for the management and treatment of hypertension with minimum side effects.Over aim to write this review is to collect information on the anti-hypertensive effects of natural herbs in animal studies and human involvement as well as to recapitulate the underlying mechanisms,from the bottom of cell culture and ex-vivo tissue data.According to WHO,natural herbs/shrubs are widely used in increasing order to treat almost all the ailments of the human body.Plants are the regular industrial units for the invention of chemical constituents,they used as immunity booster to enhance the natural capacity of the body to fight against different health prob-lems as well as herbal medicines and food products also.Eighty percent population of the world(around 5.6 billion people)consume medicines from natural plants for major health concerns.This review provides a bird’s eye analysis primarily on the traditional utilization,phytochemical constituents and pharmacological values of medicinal herbs used to normalize hypertension i.e.Hibiscus sabdariffa,Allium sativum,Andrographis paniculata,Apium graveolens,Bidenspilosa,Camel-lia sinensis,Coptis chinensis,Coriandrum sativum,Crataegus spp.,Crocus sativus,Cymbopogon citrates,Nigella sativa,Panax ginseng,Salviaemiltiorrhizae,Zingiber officinale,Tribulus terrestris,Rauwolfiaserpentina,Terminalia arjuna etc.展开更多
Present study was aimed to develop and validate a reverse-phase high-performance liquid chromatography method for simultaneous determination of sitagliptin phosphate and metformin hy-drochloride in a marketed formulat...Present study was aimed to develop and validate a reverse-phase high-performance liquid chromatography method for simultaneous determination of sitagliptin phosphate and metformin hy-drochloride in a marketed formulation. The drug separation was performed on Hibar-240, Li-chrosphere-100 C18 ODS (250 × 4.6 mm, 5 μm) column, at a flow rate of 1 mL/min. The mobile phase used was a mixture of methanol: potassium di-hydrogen phosphate buffer at a ratio of 70:30 v/v. The detection was carried out at a wavelength of 266 nm. The retention times of sitagliptin phosphate and metformin hydrochloride were found as 6.1 and 4.9 min respectively. Linear calibration curves with good correlation coefficients were obtained over the concentration ranges of 10 - 50 μg/mL for sitagliptin and 20 - 100 μg/mL for metformin. The limit of detection was 0.016 and 0.14 μg/mL and the limit of quantification was 0.048 and 0.42 μg/mL for sitagliptin phosphate and metformin hydrochloride respectively. Validation of the method demonstrated system selectivity, specificity, linearity, accuracy and precision. The developed method was found useful in the simultaneous analysis of sitagliptin phosphate and metformin hydrochloride in formulation.展开更多
Aiming at large error when inertial devices measure the roll angle under high overload conditions,the article designs one kind of roll angle measurement system based on magneto-resistive sensor which calculates the ro...Aiming at large error when inertial devices measure the roll angle under high overload conditions,the article designs one kind of roll angle measurement system based on magneto-resistive sensor which calculates the roll angle by micro controller STM32.Experiment results of a triaxial turntable show that using magneto-resistive sensor to measure roll angle is feasible and of high accuracy,and it can calculate the roll angle of the conventional projectile with the error in 1°.展开更多
Background: Prenatal exposure to fentanyl may lead to Neonatal Abstinence Syndrome (NAS), a constellation of symptoms observed when newborns begin withdrawing from addictive substances such as opioids. The use of umbi...Background: Prenatal exposure to fentanyl may lead to Neonatal Abstinence Syndrome (NAS), a constellation of symptoms observed when newborns begin withdrawing from addictive substances such as opioids. The use of umbilical cord tissue segments (UC) for newborn toxicology has been increasing due to its apparent long detection window, sensitivity, and ease of collection. However, very little has been reported in the literature concerning the prevalence of in utero exposure to fentanyl and co-exposure with other commonly abused substances. Specific aim: The specific aims of this retrospective study are twofold. We will report prevalence of neonatal exposure to fentanyl for a nationwide high-risk population using UC submitted to a national reference laboratory for routine forensic toxicology analysis and the co-exposure patterns observed for these fentanyl-exposed neonates. Methods: A secondary analysis was performed using historical data for UC received between January 1, 2020 and December 31, 2020 for routine forensic toxicology analysis. Results: During the study period, our laboratory received 23,104 UC for analysis and 9667 (41.8%) of those UC were positive for at least one drug. The prevalence of fentanyl detection was 1.9% (n = 429). Of these 429 specimens there were 407 UC where both fentanyl and norfentanyl were detected. There were 14 UC where only fentanyl was detected and 8 UC where only norfentanyl was detected. When detected, the median concentrations of fentanyl and norfentanyl were 4029 pg/g (IQR: 1696, 9230 pg/g) and 10,756 pg/mg (IQR: 3925, 25,288 pg/g), respectively. Of the 429 positive fentanyl and/or norfentanyl UC, 33 (7.7%) were only positive for fentanyl and/or norfentanyl. Of the 396 polypositive UC, morphine was the highest co-exposure with 243 UC (56.6%) being positive for both fentanyls and morphine. The second most prevalent co-exposure observed was methamphetamine/amphetamine (n = 173;40.3%) followed by cannabinoids (n = 113;26.3%) and benzoylecgonine (cocaine metabolite;n = 106;24.7%). Conclusions: Nonmedical use of fentanyl is an alarming trend in this country including this maternal demographic reported here. Fentanyl was typically found with other commonly abused substances.展开更多
Tailoring grain size can improve the strength of polycrystals by regulating the proportion of grains to grain boundaries and the interaction area.As the grain size decreases to the nanoscale,the deformation mechanism ...Tailoring grain size can improve the strength of polycrystals by regulating the proportion of grains to grain boundaries and the interaction area.As the grain size decreases to the nanoscale,the deformation mechanism in polycrystals shifts from being primarily mediated by dislocations to deformation occurring within the grains and grain boundaries.However,the mechanism responsible for fine-grain strengthening in ferroelectric materials remains unclear,primarily due to the complex multi-field coupling effect arising from spontaneous polarization.Through molecular dynamics simulations,we investigate the strengthening mechanism of barium titanate(BaTiO3),with extremely fine-grain sizes.This material exhibits an inverse Hall–Petch relationship between grain size and strength,rooting in the inhomogeneous concentration of atomic strain and grain rotation.Furthermore,we present a theoretical model to predict the transition from the inverse Hall–Petch stage to the Hall–Petch stage based on strength variations with size,which aligns well with the simulation results.It has been found that the piezoelectric properties of the BaTiO3 are affected by polarization domain switching at various grain sizes.This study enhances our understanding of the atomic-scale mechanisms that contribute to the performance evolution of fine-grain nano-ferroelectric materials.It also provides valuable insights into the design of extremely small-scale ferroelectric components.展开更多
Background Boron(B)deficiency is an important factor for poor seed cotton yield and fiber quality.However,it is often missing in the plant nutrition program,particularly in developing countries.The current study inves...Background Boron(B)deficiency is an important factor for poor seed cotton yield and fiber quality.However,it is often missing in the plant nutrition program,particularly in developing countries.The current study investigated B’s effect on growth,yield,and fiber quality of Bt(CIM-663)and non-Bt(Cyto-124)cotton cultivars.The experimental plan consisted of twelve treatments:Control(CK);B at 1 mg·kg^(−1) soil application(SB1);2 mg·kg^(−1) B(SB2);3 mg·kg^(−1) B(SB3);0.2%B foliar spray(FB1);0.4%B foliar spray(FB2);1 mg·kg^(−1) B+0.2%B foliar spray(SB1+FB1);1 mg·kg^(−1) B+0.4%B foliar spray(SB1+FB2);2 mg·kg^(−1) B+0.2%B foliar spray(SB2+FB1);2 mg·kg^(−1) B+0.4%B foliar spray(SB2+FB2);3 mg·kg^(−1) B+0.2%B foliar spray(SB3+FB1);3 mg·kg^(−1) B+0.4%B foliar spray(SB3+FB2).Each treat-ment has three replications,one pot having two plants per replication.Results B nutrition at all levels and methods of application significantly(P≤0.05)affected the growth,physiological,yield,and fiber quality characteristics of both cotton cultivars.However,SB2 either alone or in combination with foliar spray showed superiority over others,particularly in the non-Bt cultivar which responded better to B nutrition.Maxi-mum improvement in monopodial branches(345%),sympodial branches(143%),chlorophyll-a(177%),chlorophyll-b(194%),photosynthesis(169%),and ginning out turn(579%)in the non-Bt cultivar was found with SB2 compared with CK.In Bt cultivar,although no consistent trend was found but integrated use of SB3 with foliar spray performed relatively better for improving cotton growth compared with other treatments.Fiber quality characteristics in both cultivars were improved markedly but variably with different B treatments.Conclusion B nutrition with SB2 either alone or in combination with foliar spray was found optimum for improving cotton’s growth and yield characteristics.展开更多
基金National Advanced Research Project of China(No.51319030302)National Advanced Research Foundation of China(No.9140A 19030506KG0166)
文摘A complex mechatronics system Bayesian plan of demonstration test is studied based on the mixed beta distribution. During product design and improvement various information is appropriately considered by introducing inheritance factor, moreover, the inheritance factor is thought as a random variable, and the Bayesian decision of the qualification test plan is obtained, and the correctness of a Bayesian model presented is verified. The results show that the quantity of the test is too conservative according to classical methods under small binomial samples. Although traditional Bayesian analysis can consider test information of related or similar products, it ignores differences between such products. The method has solved the above problem, furthermore, considering the requirement in many practical projects, the differences among this method, the classical method and Bayesian with beta distribution are compared according to the plan of reliability acceptance test.
基金supported by grants from the Mona Reclamation Experimental Project WAPDA,Pakistan.Researchers Supporting Project Number(RSP2024R410),King Saud University,Riyadh,Saudi Arabia.
文摘Wheat(Triticum aestivum L.)is a staple crop critical for global food security,yet its productivity is significantly affected by abiotic stresses such as drought,salinity,and waterlogging,which are exacerbated by climate change.This study evaluated the effects of these stresses on vegetative growth,physiological responses,and yield.Field experiments were conducted using a Randomized Complete Block Design(RCBD)at the Mona Reclamation Experimental Project(MREP),WAPDA,Bhalwal,Sargodha,Punjab Pakistan.Stress treatments included three levels of drought(25%,50%,and 75%field capacity),salinity(4,8,and 12 dS/m),and waterlogging(24,48,and 72 h).Key parameters measured included plant height,leaf area,tiller number,stomatal conductance,chlorophyll content,and antioxidant enzyme activities.The results revealed that drought stress caused a 46%reduction in yield,while salinity and waterlogging reduced yield by 54%and 35%,respectively,with statistically significant differences(p 0.05).Key<physiological changes included a significant reduction in stomatal conductance(from 0.55 to 0.15 mmol m^(2)/s under drought stress,p 0.01)and chlorophyll content(from 48 to 28 SPAD units under drought,p 0.01).Biochemical<<responses indicated elevated levels of malondialdehyde(MDA)and hydrogen peroxide(H2O2),with significant increases in antioxidant enzyme activities,particularly superoxide dismutase(SOD)and catalase(CAT).These findings underscore the need for developing stress-tolerant wheat varieties and implementing agronomic practices to mitigate the impact of abiotic stresses on wheat yield.
基金supported by the National Natural Science Foundation of China,No.81771250(to XC)the Natural Science Foundation of Fujian Province,Nos.2020J011059(to XC),2020R1011004(to YW),2021J01374(to XZ)+1 种基金Medical Innovation Project of Fujian Province,No.2021 CXB002(to XC)Fujian Research and Training Grants for Young and Middle-aged Leaders in Healthcare(to XC)。
文摘Accumulating evidence suggests that oxidative stress and the Wnt/β-catenin pathway participate in stroke-induced disruption of the blood-brain barrier.However,the potential links between them following ischemic stroke remain largely unknown.The present study found that cerebral ischemia leads to oxidative stress and repression of the Wnt/β-catenin pathway.Meanwhile,Wnt/β-catenin pathway activation by the pharmacological inhibito r,TWS119,relieved oxidative stress,increased the levels of cytochrome P4501B1(CYP1B1)and tight junction-associated proteins(zonula occludens-1[ZO-1],occludin and claudin-5),as well as brain microvascular density in cerebral ischemia rats.Moreove r,rat brain microvascular endothelial cells that underwent oxygen glucose deprivation/reoxygenation displayed intense oxidative stress,suppression of the Wnt/β-catenin pathway,aggravated cell apoptosis,downregulated CYP1B1and tight junction protein levels,and inhibited cell prolife ration and migration.Overexpression ofβ-catenin or knockdown ofβ-catenin and CYP1B1 genes in rat brain mic rovascular endothelial cells at least partly ameliorated or exacerbated these effects,respectively.In addition,small interfering RNA-mediatedβ-catenin silencing decreased CYP1B1 expression,whereas CYP1B1 knoc kdown did not change the levels of glycogen synthase kinase 3β,Wnt-3a,andβ-catenin proteins in rat brain microvascular endothelial cells after oxygen glucose deprivatio n/reoxygenation.Thus,the data suggest that CYP1B1 can be regulated by Wnt/β-catenin signaling,and activation of the Wnt/β-catenin/CYP1B1 pathway contributes to alleviation of oxidative stress,increased tight junction levels,and protection of the blood-brain barrier against ischemia/hypoxia-induced injury.
基金supported by Indian Council of Forestry Research and Education,Dehradun
文摘We quantified cell membrane permeability (electrical conduc-tivity-EC, water soluble sugar-WSS, and amino acids-AA) and integrity (phospholipids,α-tocopherol and lipid peroxidation) along with food reserve deterioration (total proteins, total sugar, and total starch) of neem seeds collected from various mother tree age classes and stored for 65 days in airtight plastic containers at ambient room temperature (35±5°C). Results show that the activities were higher in fresh seeds (EC 267.56-2950.01 μS/g, WSS 19.96-19.48 mg/g and AA 5.40-5.35 mg/g) and declined with increasing duration of storage period (EC 153.37-195.17 μS/g, WSS 3.13-4.17 mg/g and AA 4.29-4.49 mg/g after 35 days and EC 144.02-161.56 μS/g, WSS 2.06-2.40 mg/g and AA 3.98-4.27 mg/g after 65 days of storage). Phospholipids andα-tocopherol were higher in fresh seed (0.073-0.093 OD at 710 nm and 0.080-0.105 OD, respectively) and declined as storage duration in-creased (0.033-0.042 OD at 710 nm and 00.0010-0.0020 OD, respec-tively). Dead seeds showed reduced amounts of phospholipids and minimum activity ofα- tocopherol (antioxidants). The level of MDA was lower in fresh seeds (0.0066-0.0087 OD at 600-535 nm) and increased as storage duration increased (0.0248-0.0268 OD after 65 days of stor-age). The higher amount of MDA indicated that seeds died due to rancid-ity of the oil inside the seed. Neem seed cake was assessed for deteriora-tion of food reserves (total proteins, total sugar, and total starch), concen-trations of which were higher in fresh seed and declined as storage dura-tion increased. Germination was higher in fresh seeds and after 65 days, no germination was received perhaps due to deterioration of biochemi-cals in seeds. Patterns of seed deterioration were similar across all seed lots.
文摘The mechanical behaviour of a quasi-brittle material,i.e.Pietra Serena sandstone,was investigated both numerically and experimentally in order to build a reliable numerical modelling system applicable to more complex cases.The Karagozian and Case concrete(KCC)model was exploited as the material constitutive law and a new method to utilise this model for efficient and accurate simulation of quasibrittle materials is discussed.The capability of this model is evaluated by comparing the results of the numerical simulations with the corresponding experimental results,and the method itself is critically assessed.
基金Russian Foundation for Basic Research,grant number 18-05-70002.
文摘Cyclic freezing-thawing can lead to fracture development in coal,affecting its mechanical and consumer properties.To study crack formations in coal,an ultrasonic sounding method using shear polarized waves was proposed.Samples of three coal types(anthracite,lignite and hard coal)were tested.The research results show that,in contrast to the shear wave velocity,the shear wave amplitude is extremely sensitive to the formation of new cracks at the early stages of cyclic freezing-thawing.Tests also show an inverse correlation between coal compressive strength and its tendency to form cracks under temperature impacts;shear wave attenuation increases more sharply in high-rank coals after the first freezing cycle.Spectral analysis of the received signals also confirmed significant crack formation in anthracite after the first freeze-thaw cycle.The initial anisotropy was determined,and its decrease with an increase in the number of freeze-thaw cycles was shown.The data obtained forms an experimental basis for the development of new approaches to preserve coal consumer properties during storage and transportation under severe natural and climatic conditions.
基金supported by the National Natural Science Foundation of China(81771250)the Natural Science Foundation of Fujian Province,China(2020J011059,2020R1011004)+1 种基金the Joint Funds for the Innovation of Science and Technology of Fujian Province,China(2017Y9065)the High-level hospital foster grants from Fujian Provincial Hospital,Fujian Province,China(2020HSJJ07)。
文摘Background:Disruption of the blood–brain barrier(BBB)after a stroke can lead to brain injury and neurological impairment.Previous work confirmed the involvement of the immunoproteasome subunit of low molecular mass peptide 2(LMP2)in the pathophysiology of ischemia stroke.However,the relationship between the immunoproteasome LMP2 and the BBB remains unclear.Methods:Adult male Sprague–Dawley rats were subjected to transient middle cerebral artery occlusion/reperfusion(MCAO/R).Three days before MCAO,the rats were treated with lentivirus-mediated LMP2 shRNA preparations by stereotactical injection into the ipsilateral hemispheric region.The rat brain microvascular endothelial cell(RBMVEC)line was exposed to oxygen–glucose deprivation/reperfusion(OGD/R)to mimic ischemic conditions in vitro.The RNA interference-mediated knockdown of LMP2 orβ-catenin was analysed in vivo and in vitro.Analysis of the quantity of extravasated Evans blue(EB)and cerebral fluorescent angiography were performed to evaluate the integrity of the BBB.Immunofluorescence and Western blotting were employed to detect the expression of target proteins.Cell migration was evaluated using a scratch migration assay.The results of immunofluorescence,Western blotting and cell migration were quantified using the software ImageJ(Version 1.53).Parametric data from different groups were compared using one-way ANOVA followed by the least significant difference(LSD)test.Results:Cerebral ischemia led to lower levels of structural components of the BBB such as tight junction proteins[occludin,claudin-1 and zonula occludens(ZO-1)]in the MCAO/R group compared with the sham group(P<0.001).However,inhibition of the immunoproteasome LMP2 restored the expression of these proteins,resulting in higher levels of occludin,claudin-1 and ZO-1 in the LMP2-shRNA group compared with the control-shRNA group(P<0.001).In addition,inhibition of the immunoproteasome LMP2 contributed to higher microvascular density and decreased BBB permeability[e.g.,the quantity of extravasated EB:LMP2-shRNA group(58.54±7.37)μg/g vs.control-shRNA group(103.74±4.32)μg/g,P<0.001],and promoted the upregulation of Wnt-3a andβ-catenin proteins in rats following MCAO/R.In vitro experiments,OGD/R induced marked upregulation of LMP2,proapoptotic protein Bax and cleaved caspase-3,and downregulation of occludin,claudin-1,ZO-1 and Bcl-2,as well as inhibition of the Wnt/β-catenin pathway Wnt-3a andβ-catenin proteins in RBMVECs,compared with the control group under normal culture conditions(P<0.001).However,silencing of LMP2 gene expression reversed these protein changes and promoted proliferation and migration of RBMVECs following OGD/R.Silencing ofβ-catenin by transfection of RBMVECs withβ-catenin-si RNA aggravated the downregulation of tight junction proteins,and reduced the proliferation and migration of RBMVECs following OGD/R,compared with the control-siRNA group(P<0.001).LMP2-si RNA andβ-catenin-si RNA co-transfection partly counteracted the beneficial effects of silencing LMP2-siRNA on the levels of tight junction proteins in RBMVECs exposed to OGD/R.Conclusions:This study suggests that inhibition of the immunoproteasome LMP2 ameliorates ischemia/hypoxia induced BBB injury,and that the molecular mechanism involves the immunoproteasome-regulated activation of the Wnt/β-catenin signalling pathway under ischemic conditions.
文摘The rectifier filter circuit is widely applied.However,it is difficult to gain a global solution for the optimization design.4-D visual analysis and design optimization of the single-phase uncontrolled bridge rectifier with an LC filter are presented in this paper.
基金supported by the National Natural Science Foundation of China(6147322711472222)+2 种基金the Aerospace Technology Support Fund of China(2014-HT-XGD)the Natural Science Foundation of Shaanxi Province(2015JM6304)the Aeronautical Science Foundation of China(20151353018)
文摘A new Gaussian approximation nonlinear filter called generalized cubature quadrature Kalman filter (GCQKF) is introduced for nonlinear dynamic systems. Based on standard GCQKF, two extensions are developed, namely square root generalized cubature quadrature Kalman filter (SR-GCQKF) and iterated generalized cubature quadrature Kalman filter (I-GCQKF). In SR-GCQKF, the QR decomposition is exploited to alter the Cholesky decomposition and both predicted and filtered error covariances have been propagated in square root format to make sure the numerical stability. In I-GCQKF, the measurement update step is executed iteratively to make full use of the latest measurement and a new terminal criterion is adopted to guarantee the increase of likelihood. Detailed numerical experiments demonstrate the superior performance on both tracking stability and estimation accuracy of I-GCQKF and SR-GCQKF compared with GCQKF.
文摘A field-programmable gate array(FPGA)based high-speed broadband data acquisition system is designed.The system has a dual channel simultaneous acquisition function.The maximum sampling rate is 500 MSa/s and bandwidth is200 MHz,which solves the large bandwidth,high-speed signal acquisition and processing problems.At present,the data acquisition system is successfully used in broadband receiver test systems.
文摘Syzygium campanulatum Korth is a plant, which is a rich source of secondary metabolites (especially flavanones, chalcone, and triterpenoids). In our present study, three conventional solvent extraction (CSE) techniques and supercritical fluid extraction (SFE) techniques were performed to achieve a maximum recovery of two flavanones, chalcone, and two triterpenoids from S. campanulatum leaves. Furthermore, a Box-Behnken design was constructed for the SFE technique using pressure, temperature, and particle size as independent variables, and yields of crude extract, individual and total secondary metabolites as the dependent variables. In the CSE procedure, twenty extracts were produced using ten different solvents and three techniques (maceration, soxhletion, and reflux). An enriched extract of five secondary metabolites was collected using n-hexane:methanol (1:1) soxhletion. Using food-grade ethanol as a modifier, the SFE methods produced a higher recovery (25.5%-84.9%) of selected secondary metabo- lites as compared to the CSE techniques (0.92%-66.00%).
文摘Objective:To evaluate the anti-oxidani and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica in in vitro conditions.Methods:In vitro DPPH radical scavenging activity and lipoxygenase(LOX) inhibition assays were used to evaluate the anti-oxidant and anti-inflammatory activities respectively.Methanolic extract(MEMI),successive water extract (SWMI) and ethyl acetate fraction(EMEMI),n-butanol fraction(BMEMI) and water soluble fraction (WMEMI) of methanolic extract were evaluated along with respective reference standards. Results:In in ritro DPPH radical scavenging activity,the MEMI,EMEMI and BMEMI have offered significant antioxidant activity with IC<sub>50</sub> values of 13.37.3.55 and 14.19μig/mL respectively.Gallic acid,a reference standard showed significant antioxidant activity with IC? value of 1.88 and found to be more potent compared to all the extracts and fractions.In m vitro LOX inhibition assay,the MEMI,EMEMI and BMEMI have showed significant inhibition of LOX enzyme activity with IC<sub>50</sub> values of 96.71.63.21 and 107.44μg/mL respectively.While,reference drug Indometlhacin also offered significant inhibtion against LOX enzyme activity with IC<sub>50</sub> of 57.75.Furthermore,MEMI was found to more potent than SWMI and among the fractions EMEMI was found to possess more potent antioxidant and anti-inflammatory activity.Conclusions:These findings suggest that the MEMI and F.MEMT possess potent anti-oxidani and anti-inflammatory activities in in vitro conditions.
文摘Crop phosphorus(P) deficiency and poor utilization of added P is a major agricultural problem due to reduced solubility of soil P and rapid fixation or precipitation of applied P fertilizer in alkaline and calcareous soils. The effects of P-enriched compost and single superphosphate(SSP) fertilization on maize and wheat yields and P use efficiency in a maize–wheat rotation system were studied for three years. On a three-year average, grain yields of maize and wheat after application of P-enriched compost were increased by 18% and 24%, respectively, in comparison with sole addition of a recommended dose of SSP fertilizer. P-enriched compost addition to soil increased maize and wheat yields by 12% and 17%, respectively, compared to P fertilizer plus FYM incorporation. Soil available P concentration and P uptake were affected significantly by the addition of P-enriched compost. On average, increases in P recovery, use efficiency, and agronomic efficiency of 52%, 18%, and 43% were recorded in maize and increases of 50%, 23%, and 49% in wheat. P-enriched compost application yielded 30% and 32%higher economic returns in maize and wheat than SSP fertilization alone.
基金supported by the National Natural Science Foundation of China(No.31370375)
文摘The present study was designed to further investigate the C_(21) steroidal glycosides in Cynanchum plants.Two new steroidal glycosides based on a 13,14:14,15-disecopregnane-type aglycone,komaroside P(1) and komaroside Q(2),together with three known compounds(3-5) were isolated from the whole herbs of Cynanchum komarovii.The aglycones of compounds 1 and 2 were two new disecopregnane.Their structures were elucidated on the basis of 1 D,2 D NMR spectroscopic data and acid hydrolysis.All the compounds(1-5) showed potent inhibitory activities against human leukemia cell lines(HL-60) with IC50 values ranging from 16.6 to 26.3 μmol·L^(-1),compared to the positive control 5-fluorouracil(6.4 μmol·L^(-1)).
文摘Hypertension is a critical health problem and worse other cardiovascular diseases.It is mainly of two types:Primary or essential hypertension and Secondary hypertension.Hypertension is the primary possibility feature for coronary heart disease,stroke and renal vascular disease.Herbal medicines have been used for millions of years for the management and treatment of hypertension with minimum side effects.Over aim to write this review is to collect information on the anti-hypertensive effects of natural herbs in animal studies and human involvement as well as to recapitulate the underlying mechanisms,from the bottom of cell culture and ex-vivo tissue data.According to WHO,natural herbs/shrubs are widely used in increasing order to treat almost all the ailments of the human body.Plants are the regular industrial units for the invention of chemical constituents,they used as immunity booster to enhance the natural capacity of the body to fight against different health prob-lems as well as herbal medicines and food products also.Eighty percent population of the world(around 5.6 billion people)consume medicines from natural plants for major health concerns.This review provides a bird’s eye analysis primarily on the traditional utilization,phytochemical constituents and pharmacological values of medicinal herbs used to normalize hypertension i.e.Hibiscus sabdariffa,Allium sativum,Andrographis paniculata,Apium graveolens,Bidenspilosa,Camel-lia sinensis,Coptis chinensis,Coriandrum sativum,Crataegus spp.,Crocus sativus,Cymbopogon citrates,Nigella sativa,Panax ginseng,Salviaemiltiorrhizae,Zingiber officinale,Tribulus terrestris,Rauwolfiaserpentina,Terminalia arjuna etc.
文摘Present study was aimed to develop and validate a reverse-phase high-performance liquid chromatography method for simultaneous determination of sitagliptin phosphate and metformin hy-drochloride in a marketed formulation. The drug separation was performed on Hibar-240, Li-chrosphere-100 C18 ODS (250 × 4.6 mm, 5 μm) column, at a flow rate of 1 mL/min. The mobile phase used was a mixture of methanol: potassium di-hydrogen phosphate buffer at a ratio of 70:30 v/v. The detection was carried out at a wavelength of 266 nm. The retention times of sitagliptin phosphate and metformin hydrochloride were found as 6.1 and 4.9 min respectively. Linear calibration curves with good correlation coefficients were obtained over the concentration ranges of 10 - 50 μg/mL for sitagliptin and 20 - 100 μg/mL for metformin. The limit of detection was 0.016 and 0.14 μg/mL and the limit of quantification was 0.048 and 0.42 μg/mL for sitagliptin phosphate and metformin hydrochloride respectively. Validation of the method demonstrated system selectivity, specificity, linearity, accuracy and precision. The developed method was found useful in the simultaneous analysis of sitagliptin phosphate and metformin hydrochloride in formulation.
基金National Natural Science Foundation of China(No.61004127)
文摘Aiming at large error when inertial devices measure the roll angle under high overload conditions,the article designs one kind of roll angle measurement system based on magneto-resistive sensor which calculates the roll angle by micro controller STM32.Experiment results of a triaxial turntable show that using magneto-resistive sensor to measure roll angle is feasible and of high accuracy,and it can calculate the roll angle of the conventional projectile with the error in 1°.
文摘Background: Prenatal exposure to fentanyl may lead to Neonatal Abstinence Syndrome (NAS), a constellation of symptoms observed when newborns begin withdrawing from addictive substances such as opioids. The use of umbilical cord tissue segments (UC) for newborn toxicology has been increasing due to its apparent long detection window, sensitivity, and ease of collection. However, very little has been reported in the literature concerning the prevalence of in utero exposure to fentanyl and co-exposure with other commonly abused substances. Specific aim: The specific aims of this retrospective study are twofold. We will report prevalence of neonatal exposure to fentanyl for a nationwide high-risk population using UC submitted to a national reference laboratory for routine forensic toxicology analysis and the co-exposure patterns observed for these fentanyl-exposed neonates. Methods: A secondary analysis was performed using historical data for UC received between January 1, 2020 and December 31, 2020 for routine forensic toxicology analysis. Results: During the study period, our laboratory received 23,104 UC for analysis and 9667 (41.8%) of those UC were positive for at least one drug. The prevalence of fentanyl detection was 1.9% (n = 429). Of these 429 specimens there were 407 UC where both fentanyl and norfentanyl were detected. There were 14 UC where only fentanyl was detected and 8 UC where only norfentanyl was detected. When detected, the median concentrations of fentanyl and norfentanyl were 4029 pg/g (IQR: 1696, 9230 pg/g) and 10,756 pg/mg (IQR: 3925, 25,288 pg/g), respectively. Of the 429 positive fentanyl and/or norfentanyl UC, 33 (7.7%) were only positive for fentanyl and/or norfentanyl. Of the 396 polypositive UC, morphine was the highest co-exposure with 243 UC (56.6%) being positive for both fentanyls and morphine. The second most prevalent co-exposure observed was methamphetamine/amphetamine (n = 173;40.3%) followed by cannabinoids (n = 113;26.3%) and benzoylecgonine (cocaine metabolite;n = 106;24.7%). Conclusions: Nonmedical use of fentanyl is an alarming trend in this country including this maternal demographic reported here. Fentanyl was typically found with other commonly abused substances.
基金supported by the National Natural Science Foundation of China(Nos.12172117,12372154)National Science and Technology Major Project(No.J2019-1II-0010-0054)+1 种基金National Numerical Windtunnel(No.NNW2019-JT01-023)High-Performance Computing Center of Hebei University。
文摘Tailoring grain size can improve the strength of polycrystals by regulating the proportion of grains to grain boundaries and the interaction area.As the grain size decreases to the nanoscale,the deformation mechanism in polycrystals shifts from being primarily mediated by dislocations to deformation occurring within the grains and grain boundaries.However,the mechanism responsible for fine-grain strengthening in ferroelectric materials remains unclear,primarily due to the complex multi-field coupling effect arising from spontaneous polarization.Through molecular dynamics simulations,we investigate the strengthening mechanism of barium titanate(BaTiO3),with extremely fine-grain sizes.This material exhibits an inverse Hall–Petch relationship between grain size and strength,rooting in the inhomogeneous concentration of atomic strain and grain rotation.Furthermore,we present a theoretical model to predict the transition from the inverse Hall–Petch stage to the Hall–Petch stage based on strength variations with size,which aligns well with the simulation results.It has been found that the piezoelectric properties of the BaTiO3 are affected by polarization domain switching at various grain sizes.This study enhances our understanding of the atomic-scale mechanisms that contribute to the performance evolution of fine-grain nano-ferroelectric materials.It also provides valuable insights into the design of extremely small-scale ferroelectric components.
文摘Background Boron(B)deficiency is an important factor for poor seed cotton yield and fiber quality.However,it is often missing in the plant nutrition program,particularly in developing countries.The current study investigated B’s effect on growth,yield,and fiber quality of Bt(CIM-663)and non-Bt(Cyto-124)cotton cultivars.The experimental plan consisted of twelve treatments:Control(CK);B at 1 mg·kg^(−1) soil application(SB1);2 mg·kg^(−1) B(SB2);3 mg·kg^(−1) B(SB3);0.2%B foliar spray(FB1);0.4%B foliar spray(FB2);1 mg·kg^(−1) B+0.2%B foliar spray(SB1+FB1);1 mg·kg^(−1) B+0.4%B foliar spray(SB1+FB2);2 mg·kg^(−1) B+0.2%B foliar spray(SB2+FB1);2 mg·kg^(−1) B+0.4%B foliar spray(SB2+FB2);3 mg·kg^(−1) B+0.2%B foliar spray(SB3+FB1);3 mg·kg^(−1) B+0.4%B foliar spray(SB3+FB2).Each treat-ment has three replications,one pot having two plants per replication.Results B nutrition at all levels and methods of application significantly(P≤0.05)affected the growth,physiological,yield,and fiber quality characteristics of both cotton cultivars.However,SB2 either alone or in combination with foliar spray showed superiority over others,particularly in the non-Bt cultivar which responded better to B nutrition.Maxi-mum improvement in monopodial branches(345%),sympodial branches(143%),chlorophyll-a(177%),chlorophyll-b(194%),photosynthesis(169%),and ginning out turn(579%)in the non-Bt cultivar was found with SB2 compared with CK.In Bt cultivar,although no consistent trend was found but integrated use of SB3 with foliar spray performed relatively better for improving cotton growth compared with other treatments.Fiber quality characteristics in both cultivars were improved markedly but variably with different B treatments.Conclusion B nutrition with SB2 either alone or in combination with foliar spray was found optimum for improving cotton’s growth and yield characteristics.