Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to i...Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to its therapeutic properties,but its exact role and molecular mechanisms in treatment of reproductive dysfunction remain unclear.Methods:During this study,36 rats were randomly divided into six groups(n=6):control,CYP-induced(60 mg/kg),standard(leuprolide 3 mg/kg)and three treatment groups receiving aqueous,ethanolic,and oil extracts(50 mg/kg or 20 mL/kg)for post-toxicity induction.Results:The finding represented that exposure of CYP significantly increased oxidative stress,disrupted testicular architecture,and markedly reduced testosterone levels(P<0.05).Importantly,Crocus sativus L.treatment alleviated these changes by increasing the expression of Nrf2(nuclear factor erythroid 2-related factor 2),restoring the activity of antioxidant enzymes,and enhancing testicular histomorphology.Surprisingly,molecular docking established a high binding affinity of Crocus sativus L.phytoconstituents such as gallic acid,cinnamic acid and quercetin to the Nrf2-Keap1 complex.It is worth noting that,Crocus sativus L.exhibited a high level of protection against reproductive toxicity caused by CYP in male rats,which was mediated by the activation of Nrf2 pathway,reduction of oxidative damage,and favorable ADMET characteristics.Conclusion:Notably,this research provides a more valid,safe,and effective method of developing new drugs for reproductive disorders,however,further investigation is needed to support the research findings and implement it in clinical practice.展开更多
Saline aquifers are considered as highly favored reservoirs for CO_(2)sequestration due to their favorable properties.Understanding the impact of saline aquifer properties on the migration and distribution of CO_(2)pl...Saline aquifers are considered as highly favored reservoirs for CO_(2)sequestration due to their favorable properties.Understanding the impact of saline aquifer properties on the migration and distribution of CO_(2)plume is crucial.This study focuses on four key parameters-permeability,porosity,formation pressure,and temperature-to characterize the reservoir and analyse the petrophysical and elastic response of CO_(2).First,we performed reservoir simulations to simulate CO_(2)saturation,using multiple sets of these four parameters to examine their significance on CO_(2)saturation and the plume migration speed.Subsequently,the effect of these parameters on the elastic properties is tested using rock physics theory.We established a relationship of compressional wave velocity(V_(p))and quality factor(Q_(p))with the four key parameters,and conducted a sensitivity analysis to test their sensitivity to V_(p) and Q_(p).Finally,we utilized visco-acoustic wave equation simulated time-lapse seismic data based on the computed V_(p) and Q_(p) models,and analysed the impact of CO_(2) saturation changes on seismic data.As for the above nu-merical simulations and analysis,we conducted sensitivity analysis using both homogeneous and heterogeneous models.Consistent results are found between homogeneous and heterogeneous models.The permeability is the most sensitive parameter to the CO_(2)saturation,while porosity emerges as the primary factor affecting both Q_(p) and V_(p).Both Q_(p) and V_(p) increase with the porosity,which contradicts the observations in gas reservoirs.The seismic simulations highlight significant variations in the seismic response to different parameters.We provided analysis for these observations,which serves as a valuable reference for comprehensive CO_(2)integrity analysis,time-lapse monitoring,injection planning and site selection.展开更多
The copper complexing of dissolved organic matter released from hydrochar(HDOM)affects the former’s environmental behavior.In this study,how hydrothermal temperatures(180,220 and 260℃)influence the molecular-level c...The copper complexing of dissolved organic matter released from hydrochar(HDOM)affects the former’s environmental behavior.In this study,how hydrothermal temperatures(180,220 and 260℃)influence the molecular-level constitutions and Cu(II)binding features of HDOM were elucidated via fourier transform ion cyclotron resonance mass spectrometry and multi-spectroscopic analysis.The findings demonstrated that the almost HDOM molecules had the traits of lower polarity and higher hydrophobicity.As the hydrothermal temperature increased,the molecules with particularly high relative strength gradually disappeared,average molecular weight,percentages of CHON and aliphatic compounds of HDOM reduced while the percentages of CHO and aromatic compounds increased.In general,the fluorescence quenching of Cu(II)weakened as hydrothermal temperature rose and the Cu(II)binding stability constants of fluorophores in HDOM were 4.50–5.31.In addition,the Cu(II) binding order of fluorophores in HDOM showed temperature heterogeneities, andpolysaccharides or aromatic rings of non-fluorescent substances had the fastest responsesto Cu(II) binding. Generally, fluorescent components tend to bind Cu(II) at relatively traceconcentrations (0–40 μmol/L), whereas non-fluorescent substances tend to the bind Cu(II)at relatively higher concentrations (50–100 μmol/L). This study contributed to the predictionof the potential environmental behaviors and risks of Cu(II) at the molecular level afterhydrochar application.展开更多
Sweet potatoes are significant cash crops,however,their yield and quality are greatly compromised by viral diseases.In this study,the complete genomic sequences of two Sweet Potato Virus 2(SPV2)isolates from infected ...Sweet potatoes are significant cash crops,however,their yield and quality are greatly compromised by viral diseases.In this study,the complete genomic sequences of two Sweet Potato Virus 2(SPV2)isolates from infected sweet potato leaves in the Shandong(designated as SPV2-SDYT,GenBank No.PQ855660.1)and Jiangsu(designated as SPV2-JSXZ,GenBank No.PQ855661.1)provinces in China were obtained using 5′RACE and RT-PCR amplification.Consistency,phylogeny,codon usage bias,recombination,and selection pressure analyses were conducted using the SPV2-SDYT and SPV2-JSXZ genome sequences.The complete genome sequences of SPV2-SDYT and SPV2-JSXZ were 10561 nucleotides(nt)in length,with respective nucleotide and amino acid identities of 99.25%and 99.12%,respectively.Both isolates were closely related to the SPV2 isolate from China(SPV2-LN).In both SPV2-SDYT and SPV2-JSXZ,the identity of the P1 protein was the highest,whereas that of the P3 protein was the lowest.There were 26 codons with relatively synonymous codon usage(RSCU)values greater than 1 in SPV2-SDYT and 27 codons with RSCU values greater than 1 in SPV2-JSXZ.High-frequency codons in their genomes were predominantly found to end with A/U.Recombination analysis revealed no major recombination sites in either SPV2-SDYT or SPV2-JSXZ.Further selection pressure analysis showed that the non-synonymous substitution rate/synonymous substitution rate(dN/dS)value of all 10 SPV2 proteins was less than 1.This is the first report on the evolutionary relationships of the 17 known SPV2 isolates.Our findings lay the molecular groundwork for preventing and controlling SPV2 infection in root-tuber crops.These findings also contribute to our understanding of the spread and evolution of SPV2,its pathogenic mechanisms,and the development of antiviral strategies against it.展开更多
Global climate change is the most serious challenge that modern society faces.Soil-biochar carbon sequestration is a promising natural solution for capturing carbon.This study monitored the CO_(2) emissions of five bi...Global climate change is the most serious challenge that modern society faces.Soil-biochar carbon sequestration is a promising natural solution for capturing carbon.This study monitored the CO_(2) emissions of five biochar incubated Malaysian Tropical soils(MT-Soil).The recalcitrance index of palm kernel shell biochar(PKS)was higher than that of wood chip biochar(WCB),bamboo biochar(BB),coconut shell biochar(CHB)and rice husk biochar(RHB),and was different from the observed CO_(2) emission characteristics(WCB>CHB>RHB>BB>PKS).Thus,the carbon sequestration potential of biochar could not be evaluated solely by the recalcitrance index.This CO_(2) emission is linked not only to the total organic carbon(TOC)and total carbon(TC)of the biochar but also associated with mobile matter(MM),water holding capacity(WHC),available phosphorus(AP),exchangeable potassium(AK),and nitrogen content.The multiple linear regression analysis(MLRA)shows that the weights of these factors on CO_(2) emissions are as follows:TC>pH>MM>WHC>AP>AK.The results show that in addition to biochar stability,pore structure and available phosphorus release also affect carbon dynamics through indirect effects on microbial activity.This means that to minimize CO_(2) emissions during application of biochar,it is necessary to use soil that is rich in phosphorus and biochar that has undeveloped pore structure and high stable carbon.Finally,this study provides valuable theoretical underpinnings biochar application in MT-Soil.展开更多
Coconut(Cocos nucifera L.)is a key tropical economic tree valued for its fruit flavor,particularly 2-acetyl-1-pyrroline(2AP),a vital aroma metabolite.To enhance high-aromatic coconut breeding efforts,it is essential t...Coconut(Cocos nucifera L.)is a key tropical economic tree valued for its fruit flavor,particularly 2-acetyl-1-pyrroline(2AP),a vital aroma metabolite.To enhance high-aromatic coconut breeding efforts,it is essential to deeply understand the hereditary factors governing the production of 2AP.In this study,a genome-wide association analysis identifies 32 loci that exhibit significant associations with 2AP content based on single nucleotide polymorphism(SNP)variations from 168 aromatic coconut germplasm resources.Transcriptome analysis then pinpoints 22 candidate genes near significant loci involved in 2AP metabolism.Proteins encoded by these genes are involved in amino acid metabolism,glycolysis,and secondary metabolism.Among these,Asparagine synthetase coding gene ASN1,Gamma-glutamylcysteine synthetase coding gene GSH1,and UbiA prenyltransferase coding gene UBIA are enriched in the linkage region constructed by significant locus Chr04_61490504.In particular,the SNP mutation of CnASN1 leads to amino acid changes in the functional region of the coding protein,potentially resulting in differences in 2AP content among haplotype populations.Identifying variations in related candidate genes,particularly the gene CnASN1,provides molecular markers closely associated with 2AP synthesis for coconut breeding and offers further insights into the metabolic mechanisms of 2AP.展开更多
BACKGROUND Dental implants are widely used to replace missing teeth.Currently,clinicians assess osseointegration success by measuring the implant’s stability within the bone and monitoring the marginal tissue height....BACKGROUND Dental implants are widely used to replace missing teeth.Currently,clinicians assess osseointegration success by measuring the implant’s stability within the bone and monitoring the marginal tissue height.Diabetes,especially type 2 diabetes mellitus(T2DM),has been reported to impair implant healing,drastically reducing implant success rates.AIM To analyze the high-risk factors for inflammatory response and prognosis after dental implantation in patients with T2DM,and provide strong evidence for reducing the incidence of postimplant peri-implantitis(PI).METHODS We performed a retrospective review of 146 patients with T2DM who had dental implants placed at Tianjin Fifth Central Hospital,between September 2021 and September 2023,which was regarded as the observation group.Moreover,60 ageand gender-matched individuals with normal blood glucose levels served as the control group.The general information,postoperative periodontal indices,and levels of inflammatory factors were comprehensively analyzed and compared.Furthermore,the incidence of postimplant PI was counted,and multivariate logistic regression was used to identify the determinants of postimplant PI.RESULTS In terms of the periodontal indices,the probing depth,modified sulcus bleeding index,and marginal bone loss in the observation cohorts began to increase significantly at 6 months and 3 months,respectively,after the completion of dental implant restoration.The T2DM cases demonstrated significantly elevated counts of leukocytes,lymphocytes,and neutrophils compared to the controls at 24 hours postoperatively.Moreover,the TNF-α,IL-1β,and IL-6 concentrations started to increase significantly in the gingival crevicular fluid 3 months after the completion of dental implant restoration in both cohorts,with the observation group exhibiting higher levels than the controls at each time point.63 out of the 146 cases developed PI.Multivariate logistic regression analysis indicated that high glycosylated hemoglobin levels,smoking,daily tooth-brushing frequency of less than once,and the anterior tooth as the implant site independently contributed to postimplant PI in T2DM cases,while a tooth-brushing duration of≥3 minutes was a protective factor.CONCLUSION Patients with T2DM are at risk of developing PI following dental implantation.Clinically,it is necessary to enhance the identification of risk factors for postimplant PI,improve risk prediction,prevention,and control,and formulate targeted intervention countermeasures to reduce the occurrence of postimplant PI.展开更多
BACKGROUND Diabetic encephalopathy(DE)is a common and serious complication of diabetes that can cause death in many patients and significantly affects the lives of individuals and society.Multiple studies investigatin...BACKGROUND Diabetic encephalopathy(DE)is a common and serious complication of diabetes that can cause death in many patients and significantly affects the lives of individuals and society.Multiple studies investigating the pathogenesis of DE have been reported.However,few studies have focused on scientometric analysis of DE.AIM To analyze literature on DE using scientometrics to provide a comprehensive picture of research directions and progress in this field.METHODS We reviewed studies on DE or cognitive impairment published between 2004 and 2023.The latter were used to identify the most frequent keywords in the keyword analysis and explore the hotspots and trends of DE.RESULTS Scientometric analysis revealed 1308 research papers on DE,a number that increased annually over the past 20 years,and that the primary topics explored were domain distribution,knowledge structure,evolution,and emergence of research topics related to DE.The inducing factors,comorbidities,pathogenesis,treatment,and animal models of DE help clarify its occurrence,development,and treatment.An increasing number of studies on DE may be a result of the recent increase in patients with diabetes,unhealthy lifestyles,and unhealthy eating habits,which have aggravated the incidence of this disease.CONCLUSION We identified the main inducing factors and comorbidities of DE,though other complex factors undoubtedly increase social and economic burdens.These findings provide vital references for future studies.展开更多
Globozoospermia is a severe form of teratozoospermia characterized by round-headed spermatozoa with an absent acrosome, an aberrant nuclear membrane and midpiece defects. Globozoospermia is diagnosed by the presence o...Globozoospermia is a severe form of teratozoospermia characterized by round-headed spermatozoa with an absent acrosome, an aberrant nuclear membrane and midpiece defects. Globozoospermia is diagnosed by the presence of 100% round-headed spermatozoa on semen analysis, and patients with this condition are absolutely infertile. The objective of this study was to investigate the differences in protein expression between human round- headed and normal spermatozoa. Two-dimensional （2-D） fluorescence difference gel electrophoresis （DIGE） coupled with mass spectrometry （MS） was used in this study. Over 61 protein spots were analysed in each paired normal/round-headed comparison, using DIGE technology along with an internal standard. In total, 35 protein spots identified by tandem mass spectrometry （MS/MS） exhibited significant changes （paired t-test, P 〈 0.05） in the expression level between normal and round-headed spermatozoa. A total of nine proteins were found to be upregulated and 26 proteins were found to be downregulated in round-headed spermatozoa compared with normal spermatozoa. The differentially expressed proteins that we identified may have important roles in a variety of cellular processes and structures, including spermatogenesis, cell skeleton, metabolism and spermatozoa motility.展开更多
Alzheimer’s dementia(AD)and type 2 diabetes(T2D)are interrelated global public health problems,and the current epidemics of both AD and T2D are insulin resistance diseases.Thus,AD and T2D may share common risk factor...Alzheimer’s dementia(AD)and type 2 diabetes(T2D)are interrelated global public health problems,and the current epidemics of both AD and T2D are insulin resistance diseases.Thus,AD and T2D may share common risk factors such as an unhealthy diet,lifestyle,and obesity.Meat products is an important part of the diet of consumers worldwide.This systematic review and meta-analysis aims to assess and estimate the effect of meat products consumption on AD and T2D in humans.Web of Science,MEDLINE,PubMed,Cochrane Library,and Embase were searched from January 2012 to April 2024.29 articles reported 32 cohort studies with 1785769 subjects,with 3546 AD cases and 91092 T2D cases that met the inclusion criteria and were included in our analysis.Consumption of various meat products increased the risk of T2D(hazard ratios(HR)=1.19,95%confidence intervals(CI):1.13−1.26,P=0.000;I2=88.5%),consumption of smoked,grilled/roasted and fried meat products was more likely to induce T2D(HR=1.24,95%CI:1.18−1.30,P=0.000;I2=76.1%),but was borderline significant for the risk of AD(HR=1.11,95%CI:0.98−1.25,P=0.094;I2=58.8%),with consumption of mainly livestock and poultry products increasing the risk(HR=1.21,95%CI:1.03−1.42,P=0.017;I2=66.8%).The association between meat products consumption and AD risk was influenced by meat type and sample size,while the risk of T2D was influenced by meat type,follow-up and sex.A daily intake of 27,123 and 170 g of livestock products increased the risk of T2D by 10%,51%and 70%respectively,whereas the risk of T2D was reduced when the intake of various meat products was less than 23 g/day.展开更多
Transparent exopolymer particles(TEP)are abundant gel-like colloids pivotal in marine carbon cycling and water treatment processes.Their environmental roles are governed by hierarchical architectures,yet in-situ struc...Transparent exopolymer particles(TEP)are abundant gel-like colloids pivotal in marine carbon cycling and water treatment processes.Their environmental roles are governed by hierarchical architectures,yet in-situ structural characterization remains challenging due to transparency,fragility,and polymorphism.To address this,we developed an integrated image analysis suite combining advanced processing with statistical modeling,enabling simultaneous 2D/3D quantification of TEP morphology and intra-particle heterogeneity.This framework generates multidimensional descriptors(e.g.,fractal dimensions,density gradients)for individual aggregates and assemblies.Applied to cationmediated aggregation,it revealed divergent bridging behaviors.Mg2+induced moderate size changes(2.99-4.08μm),while Ca^(2+)drove exponential growth(1.81-187.76μm)when ionic strength increasing from 1 to 5 mmol/L.Concurrent form factor reductions(Mg:0.31 to 0.16;Ca:0.44 to 0.19)quantitatively distinguish aggregation pathways.The method deciphers ion-specific assembly mechanisms and resolves subtle colloidal interactions,establishing a paradigm for colloidal system analysis with possible applications extending beyond TEP research to other subjects such as microplastic aggregation.展开更多
This paper deals with the iterative learning control （ILC） design for multiple-input multiple-output （MIMO）,time-delay systems （TDS）.Two feedback ILC schemes are considered using the so-called two-dimensional ...This paper deals with the iterative learning control （ILC） design for multiple-input multiple-output （MIMO）,time-delay systems （TDS）.Two feedback ILC schemes are considered using the so-called two-dimensional （2D） analysis approach.It shows that continuous-discrete 2D Roesser systems can be developed to describe the entire learning dynamics of both ILC schemes,based on which necessary and sufficient conditions for their stability can be provided.A numerical example is included to validate the theoretical analysis.展开更多
With great superiorities in energy density,rate capability and structural stability,Na_(3)V_(2)(PO_(4))_(2) F_(3)(NVPF)has attracted much attentions as cathode of sodium ion battery(SIB),but it also faces challenges o...With great superiorities in energy density,rate capability and structural stability,Na_(3)V_(2)(PO_(4))_(2) F_(3)(NVPF)has attracted much attentions as cathode of sodium ion battery(SIB),but it also faces challenges on its poor intrinsic electronic conductivity and the controversial de/sodiation mechanism.Herein,a series of Zr-doped NVPF coated by N-doped carbon layer(~5 nm in thickness,homogenously)materials are fabricated by a sol-gel method,and the optimized heteroatom-doping amounts of Zr and N doping improve intrinsic properties on enlarging lattice distance and enhancing electronic conductivity,respectively.Specifically,among all samples of Na_(3) V_(2-x)Zr_(x)(PO_(4))_(2) F_(3)/NC(NVPF-Zr-x/NC,x=0,0.01,0.02,0.05,and 0.1),the optimized electrode of NVPF-Zr-0.02/NC delivers high reversible capacities(119.2 mAh g^(-1) at0.5 C),superior rate capability(98.1 mA h g^(-1) at 20 C)and excellent cycling performance.The structural evolution of NVPF-Zr-0.02/NC electrode,in-situ monitored by X-ray diffractometer,follows a step-wise Na-extraction/intercalation mechanism with reversible multi-phase changes,not just a solid-solutionreaction one.Full cells of NVPF-Zr-0.02/NC//hard carbon demonstrate high capacity(99.8 mA h g^(-1) at 0.5 C),high out-put voltage(3.5 V)and good cycling stability.This work is favorable to accelerate the development of high-performance cathode materials and explore possible redox reaction mechanisms of SIBs.展开更多
This paper is concerned with the (2+1)-dimensional Burgers' and heat types of equations.All of the geometic vector fields of the equations are obtained,an optimal system of the equation is presented.Especially,the...This paper is concerned with the (2+1)-dimensional Burgers' and heat types of equations.All of the geometic vector fields of the equations are obtained,an optimal system of the equation is presented.Especially,the Bcklund transformations (BTs) for the Burgers' equations are constructed based on the symmetry.Then,all of the symmetry reductions are provided in terms of the optimal system method,and the exact explicit solutions are investigated by the symmetry reductions and Bcklund transformations.展开更多
This work illustrates the application of the “Second Order Comprehensive Adjoint Sensitivity Analysis Methodology” (2<sup>nd</sup>-CASAM) to a mathematical model that can simulate the evolution and/or tr...This work illustrates the application of the “Second Order Comprehensive Adjoint Sensitivity Analysis Methodology” (2<sup>nd</sup>-CASAM) to a mathematical model that can simulate the evolution and/or transmission of particles in a heterogeneous medium. The model response is the value of the model’s state function (particle concentration or particle flux) at a point in phase-space, which would simulate a pointwise measurement of the respective state function. This paradigm model admits exact closed-form expressions for all of the 1<sup>st</sup>- and 2<sup>nd</sup>-order response sensitivities to the model’s uncertain parameters and domain boundaries. These closed-form expressions can be used to verify the numerical results of production and/or commercial software, e.g., particle transport codes. Furthermore, this paradigm model comprises many uncertain parameters which have relative sensitivities of identical magnitudes. Therefore, this paradigm model could serve as a stringent benchmark for inter-comparing the performances of all deterministic and statistical sensitivity analysis methods, including the 2<sup>nd</sup>-CASAM.展开更多
cis-1,2-Disubstituted cyclododecanes 2 were synthesized by sodium borohydride reduction of 2-monosubstituted cyclododecanones and their structures were confirmed by 1HNMR, ^13C NMR and elemental analysis. The higher c...cis-1,2-Disubstituted cyclododecanes 2 were synthesized by sodium borohydride reduction of 2-monosubstituted cyclododecanones and their structures were confirmed by 1HNMR, ^13C NMR and elemental analysis. The higher cis-selectivity of NaBH4 reduction of 2- monosubstituted cyclododecanones was rationalized by the mode of ＂corner position carbonyl participation＂. Crystal data for 2c： Mr = 263.21, monoclinic, space group P21/c, a = 1.11140（7）, b = 2.62590（17）, c = 0.91360（6） nm, β= 106.1840（10）°, V = 2.5606（3） nm^3, Dc = 1.366 g/cm^3, Z = 8, F（000） = 1104, μ（MoKα= 3.182 mm^-1, S = 0.837, the final R = 0.0460 and wR = 0.1033. Crystal X-ray diffraction analysis for 2c showed that its ring skeleton adopts [3333] conformation, in which the OH group presents at the side-exo position and the other one at the corner carbon. The 1H NMR data of 2 showed that 1-corner-R-2-side-exo-OH [3333] and 1-corner-OH-2-side-exo-R [3333] conformations coexist in dynamic equilibrium in the solution, but only the former presents in the crystal.展开更多
In order to study cavitation characteristics of a 2-D hydrofoil, the method that combines nonlinear cavitation model and mixed-iteration is used to predict and analyze the cavitation performance of hydrofoils. The cav...In order to study cavitation characteristics of a 2-D hydrofoil, the method that combines nonlinear cavitation model and mixed-iteration is used to predict and analyze the cavitation performance of hydrofoils. The cavitation elements are nonlinearly disposed based on the Green formula and perturbation potential panel method. At the same time, the method that combines cavity shape for fixed cavity length （CSCL） iteration and cavity shape for fixed cavitation number （CSCN） iteration is used to work out the thickness and length of hydrofoil cavitations. Through analysis of calculation results, it can be concluded that the jump of pressure and velocity potentially exist between cavitation end area and non-cavitations area on suction surface when cavitation occurs on hydrofoil. In certain angles of attack, the cavitation number has a negative impact on the length of cavitations. And under the same angle of attack and cavitation number, the bigger the thickness of the hydrofoil, the shorter the cavitations length.展开更多
In this paper, equivalent surface impedance boundary condition （ESIBC）, which takes fractal parameters （D, G） into SIBC, is implemented in the 4-component 2-D compact finite difference frequency domain （2-D CFDFD...In this paper, equivalent surface impedance boundary condition （ESIBC）, which takes fractal parameters （D, G） into SIBC, is implemented in the 4-component 2-D compact finite difference frequency domain （2-D CFDFD） method to an- alyze the propagation characteristics of lossy circular waveguide with fractal rough surface based on Weierstrass-Mandelbrot （W-M） function. Fractal parameters’ effects on attenuation constant are presented in the 3 mm lossy circular waveguide, and the attenuation constants of the first three modes vary monotonically with scaling constant （G） and decrease as the fractal dimension （D） increasing.展开更多
Based on chromatographic theory, the moment method and the time-domain fitting analysis were applied to measure and evaluate the adsorption equilibrium constant and mass transfer properties (axial dispersion coefficie...Based on chromatographic theory, the moment method and the time-domain fitting analysis were applied to measure and evaluate the adsorption equilibrium constant and mass transfer properties (axial dispersion coefficient and effective intra-particle diffusivity) for toluene and p-dichlorobenzene on silica gel adsorbent in the subcritical and supercritical CO2. An apparatus based on supercritical fluid chromatography was established and the experiments were performed at temperatures of 298.15-318.15 K and pressures of 7.5-17.8 MPa. The two methods have been compared. The results show that for the systems studied here the moment method can give reasonable values for both adsorption equilibrium constant and mass transfer properties, but the time-domain analysis only can obtain the adsorption equilibrium constant. The dependence of adsorption equilibrium constant and mass transfer properties on temperature and pressure was investigated.展开更多
Regardless of thermodynamic stability, less complex proteome than plasma, convenient and noninvasive sampling of urine, reproducibility and comparability of the data among laboratories are challenges for the urine pro...Regardless of thermodynamic stability, less complex proteome than plasma, convenient and noninvasive sampling of urine, reproducibility and comparability of the data among laboratories are challenges for the urine proteome analysis. Pretreatment of urine with 10 mM EDTA in conjunction with desalting methods to remove interfering molecules significantly improved the presentation of urine proteome on 2-D gels. Statistical analysis of the average ratio of the spot numbers on 2-D gels between EDTA-treated and non-treated samples were 1.35 ± 0.167, 1.26 ± 0.091, and 1.24 ± 0.095 for dialysis, ultrafiltration, and desalting column, respectively, with the p-value of 5.85 × 10–6 for the overall comparison. This result came from the fact that EDTA-treated samples showed better resolutions with less streaks and clearer spots on 2-D gels than the control samples. The results suggest that a simple and non-fractionating EDTA-treatment can be employed to the procedures for the high resolution 2-D gel analysis and other urinary proteomic analysis.展开更多
文摘Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to its therapeutic properties,but its exact role and molecular mechanisms in treatment of reproductive dysfunction remain unclear.Methods:During this study,36 rats were randomly divided into six groups(n=6):control,CYP-induced(60 mg/kg),standard(leuprolide 3 mg/kg)and three treatment groups receiving aqueous,ethanolic,and oil extracts(50 mg/kg or 20 mL/kg)for post-toxicity induction.Results:The finding represented that exposure of CYP significantly increased oxidative stress,disrupted testicular architecture,and markedly reduced testosterone levels(P<0.05).Importantly,Crocus sativus L.treatment alleviated these changes by increasing the expression of Nrf2(nuclear factor erythroid 2-related factor 2),restoring the activity of antioxidant enzymes,and enhancing testicular histomorphology.Surprisingly,molecular docking established a high binding affinity of Crocus sativus L.phytoconstituents such as gallic acid,cinnamic acid and quercetin to the Nrf2-Keap1 complex.It is worth noting that,Crocus sativus L.exhibited a high level of protection against reproductive toxicity caused by CYP in male rats,which was mediated by the activation of Nrf2 pathway,reduction of oxidative damage,and favorable ADMET characteristics.Conclusion:Notably,this research provides a more valid,safe,and effective method of developing new drugs for reproductive disorders,however,further investigation is needed to support the research findings and implement it in clinical practice.
基金supported by the State Key Laboratory of Offshore Oil and Gas Exploitation, Open Fund Project (No. CCL2023RCPS0162RQN)the primary funding, National Natural Science Foundation of China (No. ZX20230400)
文摘Saline aquifers are considered as highly favored reservoirs for CO_(2)sequestration due to their favorable properties.Understanding the impact of saline aquifer properties on the migration and distribution of CO_(2)plume is crucial.This study focuses on four key parameters-permeability,porosity,formation pressure,and temperature-to characterize the reservoir and analyse the petrophysical and elastic response of CO_(2).First,we performed reservoir simulations to simulate CO_(2)saturation,using multiple sets of these four parameters to examine their significance on CO_(2)saturation and the plume migration speed.Subsequently,the effect of these parameters on the elastic properties is tested using rock physics theory.We established a relationship of compressional wave velocity(V_(p))and quality factor(Q_(p))with the four key parameters,and conducted a sensitivity analysis to test their sensitivity to V_(p) and Q_(p).Finally,we utilized visco-acoustic wave equation simulated time-lapse seismic data based on the computed V_(p) and Q_(p) models,and analysed the impact of CO_(2) saturation changes on seismic data.As for the above nu-merical simulations and analysis,we conducted sensitivity analysis using both homogeneous and heterogeneous models.Consistent results are found between homogeneous and heterogeneous models.The permeability is the most sensitive parameter to the CO_(2)saturation,while porosity emerges as the primary factor affecting both Q_(p) and V_(p).Both Q_(p) and V_(p) increase with the porosity,which contradicts the observations in gas reservoirs.The seismic simulations highlight significant variations in the seismic response to different parameters.We provided analysis for these observations,which serves as a valuable reference for comprehensive CO_(2)integrity analysis,time-lapse monitoring,injection planning and site selection.
基金supported by the National Natural Science Foundation of China(No.42307090)the Open Subject from State Environmental Protection Key Laboratory of Aquatic Ecosystem Health in theMiddle and Lower Reaches of Yangtze River(No.AEHKF2023008).
文摘The copper complexing of dissolved organic matter released from hydrochar(HDOM)affects the former’s environmental behavior.In this study,how hydrothermal temperatures(180,220 and 260℃)influence the molecular-level constitutions and Cu(II)binding features of HDOM were elucidated via fourier transform ion cyclotron resonance mass spectrometry and multi-spectroscopic analysis.The findings demonstrated that the almost HDOM molecules had the traits of lower polarity and higher hydrophobicity.As the hydrothermal temperature increased,the molecules with particularly high relative strength gradually disappeared,average molecular weight,percentages of CHON and aliphatic compounds of HDOM reduced while the percentages of CHO and aromatic compounds increased.In general,the fluorescence quenching of Cu(II)weakened as hydrothermal temperature rose and the Cu(II)binding stability constants of fluorophores in HDOM were 4.50–5.31.In addition,the Cu(II) binding order of fluorophores in HDOM showed temperature heterogeneities, andpolysaccharides or aromatic rings of non-fluorescent substances had the fastest responsesto Cu(II) binding. Generally, fluorescent components tend to bind Cu(II) at relatively traceconcentrations (0–40 μmol/L), whereas non-fluorescent substances tend to the bind Cu(II)at relatively higher concentrations (50–100 μmol/L). This study contributed to the predictionof the potential environmental behaviors and risks of Cu(II) at the molecular level afterhydrochar application.
基金Funding Statement:This work was funded by the National Natural Science Foundation of China(32100132)Shandong Province Natural Sciences Foundation of China(ZR2021QC008)+1 种基金Youth Innovation Team Program'in College of Shandong Province of China(2022KJ119)supported by Young Talent of Lifting Engineering for Science and Technology in Shandong,China(SDAST2024QT085).
文摘Sweet potatoes are significant cash crops,however,their yield and quality are greatly compromised by viral diseases.In this study,the complete genomic sequences of two Sweet Potato Virus 2(SPV2)isolates from infected sweet potato leaves in the Shandong(designated as SPV2-SDYT,GenBank No.PQ855660.1)and Jiangsu(designated as SPV2-JSXZ,GenBank No.PQ855661.1)provinces in China were obtained using 5′RACE and RT-PCR amplification.Consistency,phylogeny,codon usage bias,recombination,and selection pressure analyses were conducted using the SPV2-SDYT and SPV2-JSXZ genome sequences.The complete genome sequences of SPV2-SDYT and SPV2-JSXZ were 10561 nucleotides(nt)in length,with respective nucleotide and amino acid identities of 99.25%and 99.12%,respectively.Both isolates were closely related to the SPV2 isolate from China(SPV2-LN).In both SPV2-SDYT and SPV2-JSXZ,the identity of the P1 protein was the highest,whereas that of the P3 protein was the lowest.There were 26 codons with relatively synonymous codon usage(RSCU)values greater than 1 in SPV2-SDYT and 27 codons with RSCU values greater than 1 in SPV2-JSXZ.High-frequency codons in their genomes were predominantly found to end with A/U.Recombination analysis revealed no major recombination sites in either SPV2-SDYT or SPV2-JSXZ.Further selection pressure analysis showed that the non-synonymous substitution rate/synonymous substitution rate(dN/dS)value of all 10 SPV2 proteins was less than 1.This is the first report on the evolutionary relationships of the 17 known SPV2 isolates.Our findings lay the molecular groundwork for preventing and controlling SPV2 infection in root-tuber crops.These findings also contribute to our understanding of the spread and evolution of SPV2,its pathogenic mechanisms,and the development of antiviral strategies against it.
基金the support of the Ministry of Higher Education Malaysia under the Fundamental Research Grant Scheme(FRGS)(No.FRGS/1/2022/TK01/UM/02/2)the Young Innovative Talent Project-Guangdong Scientific Research Platform and Projects for the Higher-educational Institution&Education Science Planning Scheme(No.KY2022036401)+3 种基金University-level scientific research institution project(No.KY2023000401)Characteristic innovation project of colleges and universities in Guangdong Province(No.2021KTSCX191)Science and Technology developing Project of Dongguan City(No.20211800904572)the Instrument of Dongguan city college and Universiti Malaya for technical support。
文摘Global climate change is the most serious challenge that modern society faces.Soil-biochar carbon sequestration is a promising natural solution for capturing carbon.This study monitored the CO_(2) emissions of five biochar incubated Malaysian Tropical soils(MT-Soil).The recalcitrance index of palm kernel shell biochar(PKS)was higher than that of wood chip biochar(WCB),bamboo biochar(BB),coconut shell biochar(CHB)and rice husk biochar(RHB),and was different from the observed CO_(2) emission characteristics(WCB>CHB>RHB>BB>PKS).Thus,the carbon sequestration potential of biochar could not be evaluated solely by the recalcitrance index.This CO_(2) emission is linked not only to the total organic carbon(TOC)and total carbon(TC)of the biochar but also associated with mobile matter(MM),water holding capacity(WHC),available phosphorus(AP),exchangeable potassium(AK),and nitrogen content.The multiple linear regression analysis(MLRA)shows that the weights of these factors on CO_(2) emissions are as follows:TC>pH>MM>WHC>AP>AK.The results show that in addition to biochar stability,pore structure and available phosphorus release also affect carbon dynamics through indirect effects on microbial activity.This means that to minimize CO_(2) emissions during application of biochar,it is necessary to use soil that is rich in phosphorus and biochar that has undeveloped pore structure and high stable carbon.Finally,this study provides valuable theoretical underpinnings biochar application in MT-Soil.
基金supported by the Major Science and Technology Project of Hainan Province(ZDKJ2021012)National Natural Science Foundation of China(32071805)the National Key Research and Development Program of China(2023YFD2200700)。
文摘Coconut(Cocos nucifera L.)is a key tropical economic tree valued for its fruit flavor,particularly 2-acetyl-1-pyrroline(2AP),a vital aroma metabolite.To enhance high-aromatic coconut breeding efforts,it is essential to deeply understand the hereditary factors governing the production of 2AP.In this study,a genome-wide association analysis identifies 32 loci that exhibit significant associations with 2AP content based on single nucleotide polymorphism(SNP)variations from 168 aromatic coconut germplasm resources.Transcriptome analysis then pinpoints 22 candidate genes near significant loci involved in 2AP metabolism.Proteins encoded by these genes are involved in amino acid metabolism,glycolysis,and secondary metabolism.Among these,Asparagine synthetase coding gene ASN1,Gamma-glutamylcysteine synthetase coding gene GSH1,and UbiA prenyltransferase coding gene UBIA are enriched in the linkage region constructed by significant locus Chr04_61490504.In particular,the SNP mutation of CnASN1 leads to amino acid changes in the functional region of the coding protein,potentially resulting in differences in 2AP content among haplotype populations.Identifying variations in related candidate genes,particularly the gene CnASN1,provides molecular markers closely associated with 2AP synthesis for coconut breeding and offers further insights into the metabolic mechanisms of 2AP.
基金Supported by Tianjin Municipality Health Science and Technology Project,No.TJWJ2023MS052.
文摘BACKGROUND Dental implants are widely used to replace missing teeth.Currently,clinicians assess osseointegration success by measuring the implant’s stability within the bone and monitoring the marginal tissue height.Diabetes,especially type 2 diabetes mellitus(T2DM),has been reported to impair implant healing,drastically reducing implant success rates.AIM To analyze the high-risk factors for inflammatory response and prognosis after dental implantation in patients with T2DM,and provide strong evidence for reducing the incidence of postimplant peri-implantitis(PI).METHODS We performed a retrospective review of 146 patients with T2DM who had dental implants placed at Tianjin Fifth Central Hospital,between September 2021 and September 2023,which was regarded as the observation group.Moreover,60 ageand gender-matched individuals with normal blood glucose levels served as the control group.The general information,postoperative periodontal indices,and levels of inflammatory factors were comprehensively analyzed and compared.Furthermore,the incidence of postimplant PI was counted,and multivariate logistic regression was used to identify the determinants of postimplant PI.RESULTS In terms of the periodontal indices,the probing depth,modified sulcus bleeding index,and marginal bone loss in the observation cohorts began to increase significantly at 6 months and 3 months,respectively,after the completion of dental implant restoration.The T2DM cases demonstrated significantly elevated counts of leukocytes,lymphocytes,and neutrophils compared to the controls at 24 hours postoperatively.Moreover,the TNF-α,IL-1β,and IL-6 concentrations started to increase significantly in the gingival crevicular fluid 3 months after the completion of dental implant restoration in both cohorts,with the observation group exhibiting higher levels than the controls at each time point.63 out of the 146 cases developed PI.Multivariate logistic regression analysis indicated that high glycosylated hemoglobin levels,smoking,daily tooth-brushing frequency of less than once,and the anterior tooth as the implant site independently contributed to postimplant PI in T2DM cases,while a tooth-brushing duration of≥3 minutes was a protective factor.CONCLUSION Patients with T2DM are at risk of developing PI following dental implantation.Clinically,it is necessary to enhance the identification of risk factors for postimplant PI,improve risk prediction,prevention,and control,and formulate targeted intervention countermeasures to reduce the occurrence of postimplant PI.
基金Supported by the Beijing Natural Sciences Foundation No.7242240Doctoral Startup Fund,No.2024BSZR052new teachers at the Beijing University of Chinese Medicine started the funding project,No.2022-JYB-XJSJJ-021.
文摘BACKGROUND Diabetic encephalopathy(DE)is a common and serious complication of diabetes that can cause death in many patients and significantly affects the lives of individuals and society.Multiple studies investigating the pathogenesis of DE have been reported.However,few studies have focused on scientometric analysis of DE.AIM To analyze literature on DE using scientometrics to provide a comprehensive picture of research directions and progress in this field.METHODS We reviewed studies on DE or cognitive impairment published between 2004 and 2023.The latter were used to identify the most frequent keywords in the keyword analysis and explore the hotspots and trends of DE.RESULTS Scientometric analysis revealed 1308 research papers on DE,a number that increased annually over the past 20 years,and that the primary topics explored were domain distribution,knowledge structure,evolution,and emergence of research topics related to DE.The inducing factors,comorbidities,pathogenesis,treatment,and animal models of DE help clarify its occurrence,development,and treatment.An increasing number of studies on DE may be a result of the recent increase in patients with diabetes,unhealthy lifestyles,and unhealthy eating habits,which have aggravated the incidence of this disease.CONCLUSION We identified the main inducing factors and comorbidities of DE,though other complex factors undoubtedly increase social and economic burdens.These findings provide vital references for future studies.
基金Acknowledgment We thank Beijing Proteome Research Center, （Beijing, China） for its enthusiastic technological support and for the theory of 2-D DIGE. We also thank（Changsha, China） College of Life Sciences at Hunan Normal University for supporting the MS technology. Finally, we are very grateful to our collaborators for their help, as well as their valuable discussions and suggestions during the course of this work. This work was supported by two grants from the National Natural Science Foundation of China （NO. 30170480 and NO. 30470884）.
文摘Globozoospermia is a severe form of teratozoospermia characterized by round-headed spermatozoa with an absent acrosome, an aberrant nuclear membrane and midpiece defects. Globozoospermia is diagnosed by the presence of 100% round-headed spermatozoa on semen analysis, and patients with this condition are absolutely infertile. The objective of this study was to investigate the differences in protein expression between human round- headed and normal spermatozoa. Two-dimensional （2-D） fluorescence difference gel electrophoresis （DIGE） coupled with mass spectrometry （MS） was used in this study. Over 61 protein spots were analysed in each paired normal/round-headed comparison, using DIGE technology along with an internal standard. In total, 35 protein spots identified by tandem mass spectrometry （MS/MS） exhibited significant changes （paired t-test, P 〈 0.05） in the expression level between normal and round-headed spermatozoa. A total of nine proteins were found to be upregulated and 26 proteins were found to be downregulated in round-headed spermatozoa compared with normal spermatozoa. The differentially expressed proteins that we identified may have important roles in a variety of cellular processes and structures, including spermatogenesis, cell skeleton, metabolism and spermatozoa motility.
基金supported by the Agricultural Science and Technology Innovation Program,Institute of Food Science and Technology,Chinese Academy of Agricultural Sciences under Grant CAAS-ASTIP-2023-IFSTGuangdong Provincial Key R&D Programme(2023B0202080003).
文摘Alzheimer’s dementia(AD)and type 2 diabetes(T2D)are interrelated global public health problems,and the current epidemics of both AD and T2D are insulin resistance diseases.Thus,AD and T2D may share common risk factors such as an unhealthy diet,lifestyle,and obesity.Meat products is an important part of the diet of consumers worldwide.This systematic review and meta-analysis aims to assess and estimate the effect of meat products consumption on AD and T2D in humans.Web of Science,MEDLINE,PubMed,Cochrane Library,and Embase were searched from January 2012 to April 2024.29 articles reported 32 cohort studies with 1785769 subjects,with 3546 AD cases and 91092 T2D cases that met the inclusion criteria and were included in our analysis.Consumption of various meat products increased the risk of T2D(hazard ratios(HR)=1.19,95%confidence intervals(CI):1.13−1.26,P=0.000;I2=88.5%),consumption of smoked,grilled/roasted and fried meat products was more likely to induce T2D(HR=1.24,95%CI:1.18−1.30,P=0.000;I2=76.1%),but was borderline significant for the risk of AD(HR=1.11,95%CI:0.98−1.25,P=0.094;I2=58.8%),with consumption of mainly livestock and poultry products increasing the risk(HR=1.21,95%CI:1.03−1.42,P=0.017;I2=66.8%).The association between meat products consumption and AD risk was influenced by meat type and sample size,while the risk of T2D was influenced by meat type,follow-up and sex.A daily intake of 27,123 and 170 g of livestock products increased the risk of T2D by 10%,51%and 70%respectively,whereas the risk of T2D was reduced when the intake of various meat products was less than 23 g/day.
基金financial support from the National Natural Science Foundation of China(No.52270019,U24A20188,and 52370003).
文摘Transparent exopolymer particles(TEP)are abundant gel-like colloids pivotal in marine carbon cycling and water treatment processes.Their environmental roles are governed by hierarchical architectures,yet in-situ structural characterization remains challenging due to transparency,fragility,and polymorphism.To address this,we developed an integrated image analysis suite combining advanced processing with statistical modeling,enabling simultaneous 2D/3D quantification of TEP morphology and intra-particle heterogeneity.This framework generates multidimensional descriptors(e.g.,fractal dimensions,density gradients)for individual aggregates and assemblies.Applied to cationmediated aggregation,it revealed divergent bridging behaviors.Mg2+induced moderate size changes(2.99-4.08μm),while Ca^(2+)drove exponential growth(1.81-187.76μm)when ionic strength increasing from 1 to 5 mmol/L.Concurrent form factor reductions(Mg:0.31 to 0.16;Ca:0.44 to 0.19)quantitatively distinguish aggregation pathways.The method deciphers ion-specific assembly mechanisms and resolves subtle colloidal interactions,establishing a paradigm for colloidal system analysis with possible applications extending beyond TEP research to other subjects such as microplastic aggregation.
基金supported by the National Natural Science Foundation of China(No.60727002,60774003,60921001,90916024)the COSTIND(No.A2120061303)the National 973 Program(No.2005CB321902)
文摘This paper deals with the iterative learning control （ILC） design for multiple-input multiple-output （MIMO）,time-delay systems （TDS）.Two feedback ILC schemes are considered using the so-called two-dimensional （2D） analysis approach.It shows that continuous-discrete 2D Roesser systems can be developed to describe the entire learning dynamics of both ILC schemes,based on which necessary and sufficient conditions for their stability can be provided.A numerical example is included to validate the theoretical analysis.
基金the National Natural Science Foundation of China(21975154)the Shanghai Municipal Education Commission(Innovation Program(2019-01-07-00-09E00021)+2 种基金Innovative Research Team of High-level Local Universities in Shanghaisupported by The Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher LearningShanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power。
文摘With great superiorities in energy density,rate capability and structural stability,Na_(3)V_(2)(PO_(4))_(2) F_(3)(NVPF)has attracted much attentions as cathode of sodium ion battery(SIB),but it also faces challenges on its poor intrinsic electronic conductivity and the controversial de/sodiation mechanism.Herein,a series of Zr-doped NVPF coated by N-doped carbon layer(~5 nm in thickness,homogenously)materials are fabricated by a sol-gel method,and the optimized heteroatom-doping amounts of Zr and N doping improve intrinsic properties on enlarging lattice distance and enhancing electronic conductivity,respectively.Specifically,among all samples of Na_(3) V_(2-x)Zr_(x)(PO_(4))_(2) F_(3)/NC(NVPF-Zr-x/NC,x=0,0.01,0.02,0.05,and 0.1),the optimized electrode of NVPF-Zr-0.02/NC delivers high reversible capacities(119.2 mAh g^(-1) at0.5 C),superior rate capability(98.1 mA h g^(-1) at 20 C)and excellent cycling performance.The structural evolution of NVPF-Zr-0.02/NC electrode,in-situ monitored by X-ray diffractometer,follows a step-wise Na-extraction/intercalation mechanism with reversible multi-phase changes,not just a solid-solutionreaction one.Full cells of NVPF-Zr-0.02/NC//hard carbon demonstrate high capacity(99.8 mA h g^(-1) at 0.5 C),high out-put voltage(3.5 V)and good cycling stability.This work is favorable to accelerate the development of high-performance cathode materials and explore possible redox reaction mechanisms of SIBs.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11171041 and 10971018the Natural Science Foundation of Shandong Province under Grant No.ZR2010AM029+1 种基金the Promotive Research Fund for Young and Middle-Aged Scientists of Shandong Province under Grant No.BS2010SF001the Doctoral Foundation of Binzhou University under Grant No.2009Y01
文摘This paper is concerned with the (2+1)-dimensional Burgers' and heat types of equations.All of the geometic vector fields of the equations are obtained,an optimal system of the equation is presented.Especially,the Bcklund transformations (BTs) for the Burgers' equations are constructed based on the symmetry.Then,all of the symmetry reductions are provided in terms of the optimal system method,and the exact explicit solutions are investigated by the symmetry reductions and Bcklund transformations.
文摘This work illustrates the application of the “Second Order Comprehensive Adjoint Sensitivity Analysis Methodology” (2<sup>nd</sup>-CASAM) to a mathematical model that can simulate the evolution and/or transmission of particles in a heterogeneous medium. The model response is the value of the model’s state function (particle concentration or particle flux) at a point in phase-space, which would simulate a pointwise measurement of the respective state function. This paradigm model admits exact closed-form expressions for all of the 1<sup>st</sup>- and 2<sup>nd</sup>-order response sensitivities to the model’s uncertain parameters and domain boundaries. These closed-form expressions can be used to verify the numerical results of production and/or commercial software, e.g., particle transport codes. Furthermore, this paradigm model comprises many uncertain parameters which have relative sensitivities of identical magnitudes. Therefore, this paradigm model could serve as a stringent benchmark for inter-comparing the performances of all deterministic and statistical sensitivity analysis methods, including the 2<sup>nd</sup>-CASAM.
基金Presented in part at the Third National Symposium of the Chinese Chemical Society on Organic Chemistry, Lanzhou, China, August, 2004 (for abstract, see Chin. J. Org. Chem., 2004, Suppl. 365)This project was supported by the National Natural Science Foundation of China (No. 20072053)
文摘cis-1,2-Disubstituted cyclododecanes 2 were synthesized by sodium borohydride reduction of 2-monosubstituted cyclododecanones and their structures were confirmed by 1HNMR, ^13C NMR and elemental analysis. The higher cis-selectivity of NaBH4 reduction of 2- monosubstituted cyclododecanones was rationalized by the mode of ＂corner position carbonyl participation＂. Crystal data for 2c： Mr = 263.21, monoclinic, space group P21/c, a = 1.11140（7）, b = 2.62590（17）, c = 0.91360（6） nm, β= 106.1840（10）°, V = 2.5606（3） nm^3, Dc = 1.366 g/cm^3, Z = 8, F（000） = 1104, μ（MoKα= 3.182 mm^-1, S = 0.837, the final R = 0.0460 and wR = 0.1033. Crystal X-ray diffraction analysis for 2c showed that its ring skeleton adopts [3333] conformation, in which the OH group presents at the side-exo position and the other one at the corner carbon. The 1H NMR data of 2 showed that 1-corner-R-2-side-exo-OH [3333] and 1-corner-OH-2-side-exo-R [3333] conformations coexist in dynamic equilibrium in the solution, but only the former presents in the crystal.
基金Supported by the National Natural Science Foundation of China （Grant No. 41176074） China Postdoctoral Science Foundation （Grant No.2012M512133） Specialized Research Fund for the Doctoral Program of Higher Education （Grant No.20102304120026）
文摘In order to study cavitation characteristics of a 2-D hydrofoil, the method that combines nonlinear cavitation model and mixed-iteration is used to predict and analyze the cavitation performance of hydrofoils. The cavitation elements are nonlinearly disposed based on the Green formula and perturbation potential panel method. At the same time, the method that combines cavity shape for fixed cavity length （CSCL） iteration and cavity shape for fixed cavitation number （CSCN） iteration is used to work out the thickness and length of hydrofoil cavitations. Through analysis of calculation results, it can be concluded that the jump of pressure and velocity potentially exist between cavitation end area and non-cavitations area on suction surface when cavitation occurs on hydrofoil. In certain angles of attack, the cavitation number has a negative impact on the length of cavitations. And under the same angle of attack and cavitation number, the bigger the thickness of the hydrofoil, the shorter the cavitations length.
文摘In this paper, equivalent surface impedance boundary condition （ESIBC）, which takes fractal parameters （D, G） into SIBC, is implemented in the 4-component 2-D compact finite difference frequency domain （2-D CFDFD） method to an- alyze the propagation characteristics of lossy circular waveguide with fractal rough surface based on Weierstrass-Mandelbrot （W-M） function. Fractal parameters’ effects on attenuation constant are presented in the 3 mm lossy circular waveguide, and the attenuation constants of the first three modes vary monotonically with scaling constant （G） and decrease as the fractal dimension （D） increasing.
基金Supported by research grant 02KJB530002 from Jiangsu Provincial Committee of Education.
文摘Based on chromatographic theory, the moment method and the time-domain fitting analysis were applied to measure and evaluate the adsorption equilibrium constant and mass transfer properties (axial dispersion coefficient and effective intra-particle diffusivity) for toluene and p-dichlorobenzene on silica gel adsorbent in the subcritical and supercritical CO2. An apparatus based on supercritical fluid chromatography was established and the experiments were performed at temperatures of 298.15-318.15 K and pressures of 7.5-17.8 MPa. The two methods have been compared. The results show that for the systems studied here the moment method can give reasonable values for both adsorption equilibrium constant and mass transfer properties, but the time-domain analysis only can obtain the adsorption equilibrium constant. The dependence of adsorption equilibrium constant and mass transfer properties on temperature and pressure was investigated.
文摘Regardless of thermodynamic stability, less complex proteome than plasma, convenient and noninvasive sampling of urine, reproducibility and comparability of the data among laboratories are challenges for the urine proteome analysis. Pretreatment of urine with 10 mM EDTA in conjunction with desalting methods to remove interfering molecules significantly improved the presentation of urine proteome on 2-D gels. Statistical analysis of the average ratio of the spot numbers on 2-D gels between EDTA-treated and non-treated samples were 1.35 ± 0.167, 1.26 ± 0.091, and 1.24 ± 0.095 for dialysis, ultrafiltration, and desalting column, respectively, with the p-value of 5.85 × 10–6 for the overall comparison. This result came from the fact that EDTA-treated samples showed better resolutions with less streaks and clearer spots on 2-D gels than the control samples. The results suggest that a simple and non-fractionating EDTA-treatment can be employed to the procedures for the high resolution 2-D gel analysis and other urinary proteomic analysis.
