In recent years,polarization remote sensing has garnered increasing attention,particularly within the realm of meteorology.To accurately simulate polarization information,the vector discrete-ordinate radiative transfe...In recent years,polarization remote sensing has garnered increasing attention,particularly within the realm of meteorology.To accurately simulate polarization information,the vector discrete-ordinate radiative transfer(VDISORT)model developed earlier by the community is further enhanced to an advanced version(referred to as A-VDISORT)through an improved ocean surface reflection.The Fresnel reflection matrix,which includes wind-generated roughness and shading effects,is served by an ocean bidirectional reflection distribution function(BRDF).The simulation from AVDISORT is compared with SCIATRAN for a Rayleigh scattering atmosphere,and the influence of water-leaving radiance is analyzed by the PSTAR(Polarized System for Transfer of Atmospheric Radiation) model.For GaoFen-5 Directional Polarimetric Camera(DPC) observations with polarization and multi-angle information,clear-sky pixel recognition over the ocean is first carried out.The DPC reflectance of clear conditions is normalized and compared with the observations.It is shown that A-VDISORT has a high simulation accuracy with a bias of –0.0053.The difference between simulation and observation exhibits a standard normal probability distribution function.展开更多
Hybrid organic-inorganic perovskite photodetectors have gained significant attention due to their superior potential for optoelectronic applications,offering various advantages such as low-cost processing,high charge ...Hybrid organic-inorganic perovskite photodetectors have gained significant attention due to their superior potential for optoelectronic applications,offering various advantages such as low-cost processing,high charge carrier mobility,and lightweight properties.However,these perovskite photodetectors exhibit relatively low absorption in the near-infrared(NIR)range,which limits their potential applications.Here,to address this challenge,the integration of gold nanorods(Au NRs)utilizing localized surface plasmon resonance(LSPR)effects in the NIR range has been developed,leading to enhanced light absorption in the active region and higher photocurrent generation.Additionally,∼7.9 nm of thin polyethyleneimine ethoxylated(PEIE)interlayers were incorporated into the Au NR photodetectors,suppressing dark current by blocking charge injection.As a result,the synergistic effect of the Au NR/PEIE hybrid layer has led to a high-performance photodetector with a responsivity of 0.360 A/W and a detectivity of 1.81×10^(10) Jones,demonstrating a noticeable enhancement compared to the control device.Finite-difference time-domain(FDTD)simulations,morphological characterizations,and photoluminescence studies further support the mechanism for enhancing the performance of the device.We believe that our plasmon-enhanced protocol holds strong potential as a promising platform for perovskite optoelectronic devices.展开更多
Carbonyl sulfide(COS)is an effective tracer for estimating Gross Primary Productivity(GPP)in the carbon cycle.As the largest contribution to the atmosphere,anthropogenic COS emissions must be accurately quantified.In ...Carbonyl sulfide(COS)is an effective tracer for estimating Gross Primary Productivity(GPP)in the carbon cycle.As the largest contribution to the atmosphere,anthropogenic COS emissions must be accurately quantified.In this study,an anthropogenic COS emission inventory from 2015 to 2021 was constructed by applying the bottom-up approach based on activity data from emission sources.China’s anthropogenic COS emissions increased from approximately 171 to 198 Gg S yr^(-1)from 2015-2021,differing from the trends of other pollutants.Despite an initial decline in COS emissions across sectors during the early stage of the COVID-19 pandemic,a rapid rebound in emissions occurred following the resumption of economic activities.In 2021,industrial sources,coal combustion,agriculture and vehicle exhaust accounted for 76.8%,12.3%,10.5%and 0.4%of total COS emissions,respectively.The aluminum industry was the primary COS emitter among industrial sources,contributing40.7% of total emissions.Shandong,Shanxi,and Zhejiang were the top three provinces in terms of anthropogenic COS emissions,reaching 39,21 and 17 Gg S yr-1,respectively.Provincial-level regions(hereafter province)with high COS emissions are observed mainly in the eastern and coastal regions of China,which,together with the wind direction,helps explain the pattern of high COS concentrations in the Western Pacific Ocean in winter.The Green Contribution Coefficient of COS(GCCCOS)was used to assess the relationship between GDP and COS emissions,highlighting the disparity between GDP and COS contributions to green development.As part of this analysis,relevant recommendations are proposed to address this disparity.The COS emission inventory in our study can be used as input for the Sulfur Transport and Deposition Model(STEM),reducing uncertainties in the atmospheric COS source?sink budget and promoting understanding of the atmosphere sulfur cycle.展开更多
AIM:To evaluate alterations in conjunctival vascular density(CVD)and macular capillary density(MCD)in female patients with type 2 diabetes mellitus(T2DM)and gestational diabetes mellitus(GDM)using optical coherence to...AIM:To evaluate alterations in conjunctival vascular density(CVD)and macular capillary density(MCD)in female patients with type 2 diabetes mellitus(T2DM)and gestational diabetes mellitus(GDM)using optical coherence tomography angiography(OCTA).METHODS:A total of 60 female participants were recruited,comprising 20 patients with T2DM,20 patients with GDM,and 20 healthy age-matched controls(HCs).OCTA was used to assess superficial and deep retinal and conjunctival capillary plexuses.Subsequently,changes in MCD were analyzed using a circular segmentation method(C1-C6),a hemispheric quadrant segmentation method[superior right(SR),superior left(SL),inferior left(IL),and inferior right(IR)],and the early treatment diabetic retinopathy study(ETDRS)segmentation method(S,I,R,L).RESULTS:OCTA unequivocally demonstrated that the variations in CVD among HCs,T2DM,and GDM groups were statistically significant(P<0.001).In the superficial retinal capillary plexus(sRCP),significant differences were observed in the densities of total microvascular(TMI),microvasculature(MIR),and macrovascular(MAR)between patients with T2DM and HCs(P<0.05).Furthermore,the GDM group exhibited a more substantial reduction in MIR density compared to the T2DM group(P<0.01).In the deep retinal capillary plexus(dRCP),significant differences in the densities of TMI and MIR were identified between the T2DM group and HCs(P<0.05),with a notable difference in TMI density also observed between the GDM and T2DM groups(P<0.01).In the receiver operating characteristic(ROC)curve analysis,the area under the ROC curve(AUC)for TMI in sRCP between the T2DM group and HCs was 0.975,with a 95%confidence interval(CI)of 0.941–1.The AUC for MIR was highest in dRCP,with an AUC value of 0.914 and a 95%CI ranging from 0.847 to 0.981.In comparing the GDM and T2DM groups,the AUC for I region was maximized in sRCP,achieving a value of 0.978 with a 95%CI of 0.953–1.Additionally,the AUC for R region was maximized in dRCP,reaching a value of 0.99 with a 95%CI of 0.975 to 1.CONCLUSION:The sRCP and dRCP densities show higher diagnostic sensitivity for T2DM and GDM.OCTA holds potential as a significant instrument for the early diagnosis and differentiation of T2DM and GDM.展开更多
Background:A shift from self-reports to wearable sensors for global physical activity(PA)surveillance has been recommended.The conventional use of a generic cut-point to assess moderate-to-vigorous PA(MVPA)is problema...Background:A shift from self-reports to wearable sensors for global physical activity(PA)surveillance has been recommended.The conventional use of a generic cut-point to assess moderate-to-vigorous PA(MVPA)is problematic as these cut-points are often derived from non-representative samples under non-ecological laboratory conditions.This study aimed to develop age-and sex-(age-sex)specific cut-points for MVPA based on population-standardized values as a feasible approach to assess the adherence to PA guidelines and to investigate its associations with all-cause mortality.Methods:A total of 7601 participants(20-85+years)were drawn from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Surveys(NHANES).Minutes per week of MVPA were assessed with a hip-worn accelerometer.Counts per minute(CPM)were used to define an age-sex specific target intensity,representing the intensity each person should be able to reach based on their age and sex.Age-sex specific MVPA cut-points were defined as any activity above 40%of the target intensity.These population-and free-living-based age-sex specific cut-points overcome many of the limitations of the standard generic cut-point approach.For comparison,we also calculated MVPA with a generic cut-point of 1952 CPM.Both approaches were compared for assessing adherence to PA guidelines and association of MVPA with allcause mortality(ascertained through December 2015).Results:Both approaches indicated that 37%of the sample met the 150+min/week guideline.The generic cut-point approach showed a trend to inactivity with age,which was less pronounced using the age-sex specific cut-points.Overall mortality rates were comparable using generic cutpoint(hazard ratio(HR)=0.61,95%confidence interval(95%CI):0.50-0.73)or age-sex specific cut-points(HR=0.57,95%CI:0.50-0.66)for the entire sample.The generic cut-point method revealed an age-and sex-related gap in the benefits of achieving 150+min/week of MVPA,with older adults showing an 18%greater reduction in mortality rates than younger adults,and a larger difference in women than in men.This disparity disappeared when using age-sex specific cut-points.Conclusion:Our findings underscore the value of age-sex specific cut-points for global PA surveillance.MVPA defined with age-sex specific thresholds was associated with all-cause mortality and the dose-response was similar for all ages and sexes.This aligns with the single recommendation of accumulating 150+min/week MVPA for all adults,irrespective of age and sex.This study serves as a proof of concept to develop this methodology for PA surveillance over more advanced open-source acceleration metrics and other national and international cohorts.展开更多
Enamel demineralization,the formation of white spot lesions,is a common issue in clinical orthodontic treatment.The appearance of white spot lesions not only affects the texture and health of dental hard tissues but a...Enamel demineralization,the formation of white spot lesions,is a common issue in clinical orthodontic treatment.The appearance of white spot lesions not only affects the texture and health of dental hard tissues but also impacts the health and aesthetics of teeth after orthodontic treatment.The prevention,diagnosis,and treatment of white spot lesions that occur throughout the orthodontic treatment process involve multiple dental specialties.This expert consensus will focus on providing guiding opinions on the management and prevention of white spot lesions during orthodontic treatment,advocating for proactive prevention,early detection,timely treatment,scientific follow-up,and multidisciplinary management of white spot lesions throughout the orthodontic process,thereby maintaining the dental health of patients during orthodontic treatment.展开更多
The thermal flux curve of phase-transition fluid(PF)was tested using differential scanning calorimetry,based on which a reaction kinetics model was established to reflect the relationship between phase transition conv...The thermal flux curve of phase-transition fluid(PF)was tested using differential scanning calorimetry,based on which a reaction kinetics model was established to reflect the relationship between phase transition conversion rate,temperature and time.A temperature field model for fractures and rock matrix considering phase transition heat was then constructed,and its reliability was verified using previously established temperature field models.Additionally,the new model was used to study the effects of different injection parameters and phase-transition fracturing performance parameters on the temperature variations in fractures and matrix.The study indicates that,at different positions and times,the cooling effect of the injected cold fluid and the exothermic effect during the phase transition alternately dominate the temperature within the fracture.At the initial stage of fracturing fluid injection,the temperature within the fracture is high,and the phase transition rate is rapid,resulting in a significant impact of exothermic phase transition on the reservoir rock temperature.In the later stage of injection,the fracture temperature decreases,the phase transition exothermic rate slows,and the cooling effect of the fracturing fluid on the reservoir rock intensifies.Phase transition heat significantly affects the temperature of the fracture.Compared to cases where phase transition heat is not considered,when it is taken into account,the temperature within the fracture increases to varying degrees at the end of fluid injection.As the phase transition heat increases from 20 J/g to 60 J/g,the maximum temperature rise in the fracture increases from 2.1℃ to 6.2℃.The phase transition heat and PF volume fraction are positively correlated with fracture temperature changes,while specific heat capacity is negatively correlated with temperature changes.With increasing injection time,the temperature and phase transition rate at the fracture opening gradually decrease,and the location of the maximum phase transition rate and temperature difference gradually shifts from the fracture opening to about 10 m from the opening.展开更多
High levels of Al and Ti in superalloy compositions normally lead to cracking formation during the laser powder bed fusion process,while these elements are key constituents of strengthening phases.In the current study...High levels of Al and Ti in superalloy compositions normally lead to cracking formation during the laser powder bed fusion process,while these elements are key constituents of strengthening phases.In the current study,a novel Co-based superalloy with the basic chemical composition of Co-Al-W-Ta-Ti resolved this contradiction,indicating that the part was formed without cracking and simultaneously contained a large amount of strengthening precipitates in the microstructure fabricated via laser powder bed fusion.The printability,microstructures,and mechanical properties of the sample were analysed before and after heat treatment,providing a potential superalloy that can replace Ni-based superalloys fabricated by additive manufacturing in aerospace and other industries with higher temperature and more efficiency.展开更多
Hepatitis B-associated hepatocellular carcinoma (HBV-HCC) remains an intractable high-mortality solidtumor cancer that accounted for 42% of global HCC cases in 2019. Despite some developments in systemic therapy,only ...Hepatitis B-associated hepatocellular carcinoma (HBV-HCC) remains an intractable high-mortality solidtumor cancer that accounted for 42% of global HCC cases in 2019. Despite some developments in systemic therapy,only a small subset of late-stage HCC patients responds positively to recently developed therapeutic innovations.MicroRNAs (miRNAs) act as an ancillary epigenetic system that can regulate genome expression in all cancerpathways including HCC. The molecular mechanisms of miRNA regulation in cancer pathogenesis offered researchersa new approach that was widely hoped would translate into miRNA-based drugs and diagnostics. Thirty years on,miRNA-based diagnostic and therapeutic agents for HCC remain a work-in-progress (WIP) and no current miRNAHCC clinical trial has progressed to Phase 4. The question remains why this is the case after 30 years and what is theway forward. The major findings and contribution of this paper are that it illustrates the complexity of the HBVmiRNA interactome in HBV-HCC in all cellular processes, as well as the ancillary role of miRNA in the epigeneticand immune systems. This is combined with a review of the outcomes and problems of clinical trials, to explain whymiRNA therapeutics and diagnostics have not progressed to approved drugs or serum-based diagnostic tests. The wayforward suggests a radical rethink might be so that involves the incorporation of AI, bioinformatics, andnanotechnology to solve the problem.展开更多
Participants in mixed-species bird flocks(MSFs)have been shown to associate with species that are similar in body size,diet,and evolutionary history,suggesting that facilitation structures these assemblages.In additio...Participants in mixed-species bird flocks(MSFs)have been shown to associate with species that are similar in body size,diet,and evolutionary history,suggesting that facilitation structures these assemblages.In addition,several studies have suggested that species in MsFs resemble each other in their plumage,but this question has not been systematically investigated for any MsF system.During the nonbreeding season of 2020 and 2021,we sampled 585 MSFs on 14 transects in 2 habitats of Tongbiguang Nature Reserve in western Yunnan Province,China.We performed social network analysis and the Multiple Regression Quadratic Assignment Procedure to evaluate the effect of 4 species traits(body size,overall plumage color,distinctive plumage patterns,and diet)and evolutionary history on species association strength at the whole-MSF and within-MSF levels.All 41 significant relationships showed that species with stronger associations were more similar in their various traits.Body size had the strongest effect on association strength,followed by phylogeny,plumage patterns,and plumage color;diet had the weakest effect.Our results are consistent with the hypotheses that the benefits of associating with phenotypically similar species outweigh the potential costs of interspecific competition,and that trait matching can occur in plumage characteristics,albeit more weakly than in other traits.Several explanations exist as to why similarities in plumage may occur in MSFs,including that they could reduce predators'ability to target phenotypically"odd"individuals.Whether trait matching in plumage occurs through assortative processes in ecological time or is influenced by co-evolution requires furtherstudy.展开更多
Objective:Based on the findings of the KEYNOTE-048 study,pembrolizumab in combination with platinum and fluorouracil is the standard first-line treatment for recurrent or metastatic head and neck squamous cell carcino...Objective:Based on the findings of the KEYNOTE-048 study,pembrolizumab in combination with platinum and fluorouracil is the standard first-line treatment for recurrent or metastatic head and neck squamous cell carcinoma(R/M HNSCC).The efficacy and safety of pembrolizumab combined with nab-paclitaxel and platinum in such patients remain unexplored.Methods:This single-arm phase 2 study enrolled patients with R/M HNSCC who received pembrolizumab(200 mg),nab-paclitaxel(260 mg/m^(2)),and either cisplatin(75 mg/m^(2))or carboplatin[area under the curve(AUC)5]every 21 d for up to six cycles,followed by pembrolizumab maintenance therapy.The primary endpoint was the objective response rate(ORR).Secondary endpoints included disease control rate(DCR),progression-free survival(PFS),duration of response(Do R),overall survival(OS),and safety.Exploratory multi-omics analyses were conducted.Results:Between April 23,2021,and August 20,2023,a total of 67 patients with R/M HNSCC were enrolled and received the study treatment.By the data cut-off date of March 2,2024,62(92.5%)patients had received cisplatin,while five(7.5%)patients had received carboplatin.The median follow-up duration was 12.7(range:2.3-34.8)months.The ORR was 62.7%,and the DCR was 88.1%.The median PFS,Do R,and OS were 9.7,13.0,and 18.7 months,respectively.The most common grade 3 adverse events(AEs)were leukopenia(22.4%)and neutropenia(28.4%).Genomic alterations correlated with efficacy outcomes,and dynamic changes in 17 plasma proteins were associated with treatment response.Upregulation of serum interferon(IFN)-γand interleukin(IL)8levels was linked to treatment-related AEs.Conclusions:Pembrolizumab in combination with nab-paclitaxel and platinum demonstrated promising efficacy and a manageable safety profile in patients with R/M HNSCC.Future studies are warranted to confirm these findings.展开更多
The impervious surface area （ISA） at the regional scale is one of the important environmental factors for examining the interaction and mechanism of Land Use/Cover Change （LUCC）-ecosystem processes-climate change ...The impervious surface area （ISA） at the regional scale is one of the important environmental factors for examining the interaction and mechanism of Land Use/Cover Change （LUCC）-ecosystem processes-climate change under the interactions of urbanization and global environmental change. Timely and accurate extraction of ISA from remotely sensed data at the regional scale is challenging. This study explored the ISA extraction based on MODIS and DMSP-OLS data and the incorporation of China＇s land use/cover data. ISA datasets in Beijing-Tianjin-Tangshan Metropolitan Area （BTTMA） in 2000 and 2008 at a spatial resolution of 250 m were developed, their spatiotemporal changes were analyzed, and their impacts on water quality were then evaluated. The results indicated that ISA in BTTMA increased rapidly along urban fringe, transportation corridors and coastal belt both in intensity and extents from 2000 to 2008. Three cities （Tangshan, Langfang and Qinhuangdao） in Hebei Province had higher ISA growth rates than Beijing due to the pressure of population-resour- ces-environments in the city resulting in increasingly transferring industries to the nearby areas. The dense ISA distribution in BTTMA has serious impacts on water quality in the Haihe River watershed. Meanwhile, the proportion of ISA in sub-watersheds has significantly linear relationships with the densities of river COD and NH3-N.展开更多
Runoff and soil losses from agricultural fields are investigated as major nonpoint sources of phosphorus (P) entering lakes of Eastern China. There is relatively little information on P transport from ricefield and cr...Runoff and soil losses from agricultural fields are investigated as major nonpoint sources of phosphorus (P) entering lakes of Eastern China. There is relatively little information on P transport from ricefield and cropland of Lake Taihu watershed in Eastern China. Soil and P in surface runoff from a series of plots in the watershed were evaluated under simulated rainfall conditions. The objectives of this study were to evaluate the effects of crop cover, slope, and fertilizer application on P concentrations in surface runoff and eroded soil. Accumulated sediment yields varied from 7.1 to 300 g/m2 for croplands, depending on management practices. For all experiment plots, weighted average concentrations of total-P (TP), dissolved P (DP) and particulate P (PP) are much higher than 0.02 mg/L, the limiting concentration for lake water. This result showed the potential contamination of lake water from agricultural surface runoff. Accumulated TP losses were 3.8 and 18.8 mg/m2 for ricefield and cropland, respectively. The estimated annual loss of TP was 0.74 kg/(hm2 · a) for cropland. Most of P loss is in the PP form, which accounts for more than 90% of TP loss for cropland.展开更多
AIM:To investigate the in vivo hepatoprotective effects and mechanisms of Gentiana manshurica Kitagawa (GM) in acetaminophen (APAP)-induced liver injury in mice.METHODS: GM (200, 150 or 50 mg/kg body weight) or N-acet...AIM:To investigate the in vivo hepatoprotective effects and mechanisms of Gentiana manshurica Kitagawa (GM) in acetaminophen (APAP)-induced liver injury in mice.METHODS: GM (200, 150 or 50 mg/kg body weight) or N-acetyl-L-cysteine (NAC; 300 mg/kg body weight) was administrated orally with a single dose 2 h prior to APAP (300 mg/kg body weight) injection in mice.RESULTS: APAP treatment significantly depleted hepatic glutathione (GSH), increased serum aspartate aminot ransferase (AST), alanine aminotransferase (ALT) and malonyldialdehyde (MDA) and 4-hydroxynonenal levels, and decreased hepatic activity of glutathione peroxidase (GSH-px) and superoxide dismutase (SOD). However, the pretreatment of GM signif icantly alleviated APAP-induced oxidative stress by increasing GSH content, decreasing serum ALT, AST and MDA, and retaining the activity of GSH-px and SOD in the liver. Furthermore, GM pretreatment can inhibit caspase-3 activation and phosphorylation of c-Jun-NH2-terminal protein kinase 2 (JNK1/2) and extracellular signalregulated kinase (ERK). GM also remarkably attenuated hepatocyte apoptosis confirmed by the terminal deoxynucleotidyl transferase mediated dUTP nick end-labeling method.CONCLUSION: Hepatoprotective effects of GM against APAP-induced acute toxicity are mediated either by preventing the decline of hepatic antioxidant status or its direct anti-apoptosis capacity. These results support that GM is a potent hepatoprotective agent.展开更多
A novel diarylheptanoid bearing flavonol moiety,named officinin A(1),along with two known compounds galangin and kaempferide were isolated from the rhizomes of Alpina officinarum Hance.The structure elucidation was ac...A novel diarylheptanoid bearing flavonol moiety,named officinin A(1),along with two known compounds galangin and kaempferide were isolated from the rhizomes of Alpina officinarum Hance.The structure elucidation was accomplished by HRESI -MS,1D and 2D NMR methods.展开更多
Employing DEA model and Malmquist productivity index, this paper probes into the urban efficiencies of 24 typical resources-based cities in China and their changes from 2000 to 2008. The research finds that the overal...Employing DEA model and Malmquist productivity index, this paper probes into the urban efficiencies of 24 typical resources-based cities in China and their changes from 2000 to 2008. The research finds that the overall efficiencies of the resources-based cities are just at a general level, and only a few of them reach the optimal level. The scale efficiency is the major determining factor of the achievement of overall efficiency, the effect of which, nevertheless, is reducing. From the perspective of classification characteristics, the resources-based cities in northeastern region have been in the front rank in terms of overall efficiency, pure technical efficiency and scale efficiency. There is a certain positive correlation between urban population scale and urban efficiency. The analysis of urban efficiency changes shows that the changes in overall efficiency of resources-based cities from 2000 to 2008 had a weak improving tendency. Both the technical change index and productivity change index decreased, indicating that the urban efficiency did not improve during this period, and the tendency of technical recession and productivity decline was obvious. In terms of the classification of urban efficiency changes, the urban overall efficiency improved in each of the four regions from 2000 to 2008, among which western region witnessed the greatest increase. Cities with different resource types have improved their urban overall efficiencies except steel-based cities. The urban overall efficiency increased in resources-based cities of different scales, with greater improvement in small and medium-sized cities than in big cities.展开更多
A new jatrophane-type diterpenoid,7β,14β,15β-triacetoxy-3β-benzoyloxy-9-oxojatropha-5E,11E-diene,named euphornin N was isolated from Euphorbia helioscopia L.The structure and relative stereochemistry of the new co...A new jatrophane-type diterpenoid,7β,14β,15β-triacetoxy-3β-benzoyloxy-9-oxojatropha-5E,11E-diene,named euphornin N was isolated from Euphorbia helioscopia L.The structure and relative stereochemistry of the new compound was elucidated by spectroscopic methods.展开更多
The phase selection of ternary intermetallic compound τphase (Mg32(Al, Zn)49 ) and φ phase (Al2Mg5Zn2) in high zinc magnesium alloys was studied by using scanning electron microscope, X-ray diffractometer and differ...The phase selection of ternary intermetallic compound τphase (Mg32(Al, Zn)49 ) and φ phase (Al2Mg5Zn2) in high zinc magnesium alloys was studied by using scanning electron microscope, X-ray diffractometer and differential scanning calorimeter, etc. The results indicate that, when adding element Si in Mg-8Zn-4Al-0.3Mn (ZA84) alloy, φ phase is promoted, whereas τ phase is inhibited. The Chinese script-type Mg2Si and matrix microstructure are greatly refined, the formation of τ phase is facilitated and φ phase is restrained when modifier Al-AlP master alloy is added in ZA84 alloy containing Si. The kinetics study of phase selection indicates that there is a critical degree of undercooling of the melt. If the undercooling exceeds the critical value, τ phase preferentially forms while φ phase is restrained; otherwise, φ phase preferentially forms while τ phase is restrained.展开更多
Three new monophenanthrene compounds were isolated from an acetone extract of the tubers of Monomeria barbata Lindl. (Orchidaceae).Using spectroscopic methods,the structures of compounds 1-3 were determined as 1,4,7-t...Three new monophenanthrene compounds were isolated from an acetone extract of the tubers of Monomeria barbata Lindl. (Orchidaceae).Using spectroscopic methods,the structures of compounds 1-3 were determined as 1,4,7-trihydroxy-2-methoxy- 9,10-dihydrophenanthrene(1),1-(p-hydroxybenzoyl)-2-methoxy-4,7-dihydroxy-9,10-dihydrophenanthrene(2),1,3,8-tri(p-hydroxybenzyl) -4-methoxy-phenanthrene-4,7-diol(3).These compounds showed cytotoxicities on four tumor cell lines(HepG2, HL-60,Skov-3,A431).展开更多
In this study, a monthly dataset of temperature time series （1961-2010） from 12 meteorological stations across the Three-River Headwater Region of Qinghai Province （THRHR） was used to analyze the climate change. T...In this study, a monthly dataset of temperature time series （1961-2010） from 12 meteorological stations across the Three-River Headwater Region of Qinghai Province （THRHR） was used to analyze the climate change. The temperature variation and abrupt change analysis were examined by using moving average, linear regression, Spline interpolation, Mann-Kendall test and so on. Some important conclusions were obtained from this research, which mainly contained four aspects as follows. （1） There were several cold and warm fluctuations for the annual and seasonal average temperature in the THRHR and its three sub-headwater regions, but the temperature in these regions all had an obviously rising trend at the statistical significance level, especially after 2001. The spring, summer, autumn and annual average temperature increased evidently after the 1990s, and the winter average temperature exhibited an obvious upward trend after entering the 21st century. Except the standard value of spring temperature, the annual and seasonal temperature standard value in the THRHR and its three sub-headwater regions increased gradually, and the upward trend for the standard value of winter average temperature indicated significantly. （2） The tendency rate of annual average temperature in the THRHR was 0.36℃ 10a^-1, while the tendency rates in the Yellow River Headwater Region （YERHR）, Lancangjiang River Headwater Region （LARHR） and Yangtze River Headwater Region （YARHR） were 0.37℃ 10a^-1, 0.37℃ 10a^-1 and 0.34℃10a^-1 respectively. The temperature increased significantly in the south of Yushu County and the north of Nangqian County. The rising trends of temperature in winter and autumn were higher than the upward trends in spring and summer. （3） The abrupt changes of annual, summer, autumn and winter average temperature were found in the THRHR, LARHR and YARHR, and were detected for the summer and autumn average temperature in the YERHR. The abrupt changes of annual and summer average temperatures were mainly in the late 1990s, while the abrupt changes of autumn and winter average temperatures appeared primarily in the early 1990s and the early 21st century respectively. （4） With the global warming, the diversities of altitude and underlying surface in different parts of the Tibetan Plateau were possibly the main reasons for the high increasing rate of temperature in the THRHR.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.U2142212)National Key R&D Program of China(Grant No.2019QZKK,Qinghai Tibet KeKao)the National Natural Science Foundation of China(Grant No.U2242211)。
文摘In recent years,polarization remote sensing has garnered increasing attention,particularly within the realm of meteorology.To accurately simulate polarization information,the vector discrete-ordinate radiative transfer(VDISORT)model developed earlier by the community is further enhanced to an advanced version(referred to as A-VDISORT)through an improved ocean surface reflection.The Fresnel reflection matrix,which includes wind-generated roughness and shading effects,is served by an ocean bidirectional reflection distribution function(BRDF).The simulation from AVDISORT is compared with SCIATRAN for a Rayleigh scattering atmosphere,and the influence of water-leaving radiance is analyzed by the PSTAR(Polarized System for Transfer of Atmospheric Radiation) model.For GaoFen-5 Directional Polarimetric Camera(DPC) observations with polarization and multi-angle information,clear-sky pixel recognition over the ocean is first carried out.The DPC reflectance of clear conditions is normalized and compared with the observations.It is shown that A-VDISORT has a high simulation accuracy with a bias of –0.0053.The difference between simulation and observation exhibits a standard normal probability distribution function.
基金supported by the National Research Foundation of Korea(NRF)Grant funded by the Korean Government(Nos.2020R1A2C3003958 and 2021R1C1C2010169)the Basic Science Research Program(Priority Research Institute)through the NRF of Korea funded by the Ministry of Education(No.2021R1A6A1A10039823)the Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Ministry of Education(No.2020R1A6C101B194).
文摘Hybrid organic-inorganic perovskite photodetectors have gained significant attention due to their superior potential for optoelectronic applications,offering various advantages such as low-cost processing,high charge carrier mobility,and lightweight properties.However,these perovskite photodetectors exhibit relatively low absorption in the near-infrared(NIR)range,which limits their potential applications.Here,to address this challenge,the integration of gold nanorods(Au NRs)utilizing localized surface plasmon resonance(LSPR)effects in the NIR range has been developed,leading to enhanced light absorption in the active region and higher photocurrent generation.Additionally,∼7.9 nm of thin polyethyleneimine ethoxylated(PEIE)interlayers were incorporated into the Au NR photodetectors,suppressing dark current by blocking charge injection.As a result,the synergistic effect of the Au NR/PEIE hybrid layer has led to a high-performance photodetector with a responsivity of 0.360 A/W and a detectivity of 1.81×10^(10) Jones,demonstrating a noticeable enhancement compared to the control device.Finite-difference time-domain(FDTD)simulations,morphological characterizations,and photoluminescence studies further support the mechanism for enhancing the performance of the device.We believe that our plasmon-enhanced protocol holds strong potential as a promising platform for perovskite optoelectronic devices.
基金National Natural Science Foundation of China,No.42250205“CUG Scholar”Scientific Research Funds at China University of Geosciences,No.2019004+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDA23100202Scientific Research Foundation of China University of Geosciences,No.162301192642。
文摘Carbonyl sulfide(COS)is an effective tracer for estimating Gross Primary Productivity(GPP)in the carbon cycle.As the largest contribution to the atmosphere,anthropogenic COS emissions must be accurately quantified.In this study,an anthropogenic COS emission inventory from 2015 to 2021 was constructed by applying the bottom-up approach based on activity data from emission sources.China’s anthropogenic COS emissions increased from approximately 171 to 198 Gg S yr^(-1)from 2015-2021,differing from the trends of other pollutants.Despite an initial decline in COS emissions across sectors during the early stage of the COVID-19 pandemic,a rapid rebound in emissions occurred following the resumption of economic activities.In 2021,industrial sources,coal combustion,agriculture and vehicle exhaust accounted for 76.8%,12.3%,10.5%and 0.4%of total COS emissions,respectively.The aluminum industry was the primary COS emitter among industrial sources,contributing40.7% of total emissions.Shandong,Shanxi,and Zhejiang were the top three provinces in terms of anthropogenic COS emissions,reaching 39,21 and 17 Gg S yr-1,respectively.Provincial-level regions(hereafter province)with high COS emissions are observed mainly in the eastern and coastal regions of China,which,together with the wind direction,helps explain the pattern of high COS concentrations in the Western Pacific Ocean in winter.The Green Contribution Coefficient of COS(GCCCOS)was used to assess the relationship between GDP and COS emissions,highlighting the disparity between GDP and COS contributions to green development.As part of this analysis,relevant recommendations are proposed to address this disparity.The COS emission inventory in our study can be used as input for the Sulfur Transport and Deposition Model(STEM),reducing uncertainties in the atmospheric COS source?sink budget and promoting understanding of the atmosphere sulfur cycle.
基金Supported by National Natural Science Foundation of China(No.82160195,No.82460203)The Science and Technology Innovation Program of Changde City(No.2023YD25).
文摘AIM:To evaluate alterations in conjunctival vascular density(CVD)and macular capillary density(MCD)in female patients with type 2 diabetes mellitus(T2DM)and gestational diabetes mellitus(GDM)using optical coherence tomography angiography(OCTA).METHODS:A total of 60 female participants were recruited,comprising 20 patients with T2DM,20 patients with GDM,and 20 healthy age-matched controls(HCs).OCTA was used to assess superficial and deep retinal and conjunctival capillary plexuses.Subsequently,changes in MCD were analyzed using a circular segmentation method(C1-C6),a hemispheric quadrant segmentation method[superior right(SR),superior left(SL),inferior left(IL),and inferior right(IR)],and the early treatment diabetic retinopathy study(ETDRS)segmentation method(S,I,R,L).RESULTS:OCTA unequivocally demonstrated that the variations in CVD among HCs,T2DM,and GDM groups were statistically significant(P<0.001).In the superficial retinal capillary plexus(sRCP),significant differences were observed in the densities of total microvascular(TMI),microvasculature(MIR),and macrovascular(MAR)between patients with T2DM and HCs(P<0.05).Furthermore,the GDM group exhibited a more substantial reduction in MIR density compared to the T2DM group(P<0.01).In the deep retinal capillary plexus(dRCP),significant differences in the densities of TMI and MIR were identified between the T2DM group and HCs(P<0.05),with a notable difference in TMI density also observed between the GDM and T2DM groups(P<0.01).In the receiver operating characteristic(ROC)curve analysis,the area under the ROC curve(AUC)for TMI in sRCP between the T2DM group and HCs was 0.975,with a 95%confidence interval(CI)of 0.941–1.The AUC for MIR was highest in dRCP,with an AUC value of 0.914 and a 95%CI ranging from 0.847 to 0.981.In comparing the GDM and T2DM groups,the AUC for I region was maximized in sRCP,achieving a value of 0.978 with a 95%CI of 0.953–1.Additionally,the AUC for R region was maximized in dRCP,reaching a value of 0.99 with a 95%CI of 0.975 to 1.CONCLUSION:The sRCP and dRCP densities show higher diagnostic sensitivity for T2DM and GDM.OCTA holds potential as a significant instrument for the early diagnosis and differentiation of T2DM and GDM.
基金supported in part by the intramural research programs at the National Institute on Aging and National Cancer Institute(USA)supported by the Spanish Ministry of Science,Innovation and Universities under Beatriz Galindo's 2022 fellowship program(BG22/00075).
文摘Background:A shift from self-reports to wearable sensors for global physical activity(PA)surveillance has been recommended.The conventional use of a generic cut-point to assess moderate-to-vigorous PA(MVPA)is problematic as these cut-points are often derived from non-representative samples under non-ecological laboratory conditions.This study aimed to develop age-and sex-(age-sex)specific cut-points for MVPA based on population-standardized values as a feasible approach to assess the adherence to PA guidelines and to investigate its associations with all-cause mortality.Methods:A total of 7601 participants(20-85+years)were drawn from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Surveys(NHANES).Minutes per week of MVPA were assessed with a hip-worn accelerometer.Counts per minute(CPM)were used to define an age-sex specific target intensity,representing the intensity each person should be able to reach based on their age and sex.Age-sex specific MVPA cut-points were defined as any activity above 40%of the target intensity.These population-and free-living-based age-sex specific cut-points overcome many of the limitations of the standard generic cut-point approach.For comparison,we also calculated MVPA with a generic cut-point of 1952 CPM.Both approaches were compared for assessing adherence to PA guidelines and association of MVPA with allcause mortality(ascertained through December 2015).Results:Both approaches indicated that 37%of the sample met the 150+min/week guideline.The generic cut-point approach showed a trend to inactivity with age,which was less pronounced using the age-sex specific cut-points.Overall mortality rates were comparable using generic cutpoint(hazard ratio(HR)=0.61,95%confidence interval(95%CI):0.50-0.73)or age-sex specific cut-points(HR=0.57,95%CI:0.50-0.66)for the entire sample.The generic cut-point method revealed an age-and sex-related gap in the benefits of achieving 150+min/week of MVPA,with older adults showing an 18%greater reduction in mortality rates than younger adults,and a larger difference in women than in men.This disparity disappeared when using age-sex specific cut-points.Conclusion:Our findings underscore the value of age-sex specific cut-points for global PA surveillance.MVPA defined with age-sex specific thresholds was associated with all-cause mortality and the dose-response was similar for all ages and sexes.This aligns with the single recommendation of accumulating 150+min/week MVPA for all adults,irrespective of age and sex.This study serves as a proof of concept to develop this methodology for PA surveillance over more advanced open-source acceleration metrics and other national and international cohorts.
基金funded with National Key R&D Program of China(2022YFC2405904)National Natural Science Foundation of China(11932012,and 32171348).
文摘Enamel demineralization,the formation of white spot lesions,is a common issue in clinical orthodontic treatment.The appearance of white spot lesions not only affects the texture and health of dental hard tissues but also impacts the health and aesthetics of teeth after orthodontic treatment.The prevention,diagnosis,and treatment of white spot lesions that occur throughout the orthodontic treatment process involve multiple dental specialties.This expert consensus will focus on providing guiding opinions on the management and prevention of white spot lesions during orthodontic treatment,advocating for proactive prevention,early detection,timely treatment,scientific follow-up,and multidisciplinary management of white spot lesions throughout the orthodontic process,thereby maintaining the dental health of patients during orthodontic treatment.
基金Supported by the China Postdoctoral Science Foundation(2024M752803)the Open Fund of Key Laboratory of Deep Geothermal Resources of Ministry of Natural Resources(KLDGR2024B01)+1 种基金the National Natural Science Foundation of China(52179112)the Open Fund of National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)(PLN2023-02)。
文摘The thermal flux curve of phase-transition fluid(PF)was tested using differential scanning calorimetry,based on which a reaction kinetics model was established to reflect the relationship between phase transition conversion rate,temperature and time.A temperature field model for fractures and rock matrix considering phase transition heat was then constructed,and its reliability was verified using previously established temperature field models.Additionally,the new model was used to study the effects of different injection parameters and phase-transition fracturing performance parameters on the temperature variations in fractures and matrix.The study indicates that,at different positions and times,the cooling effect of the injected cold fluid and the exothermic effect during the phase transition alternately dominate the temperature within the fracture.At the initial stage of fracturing fluid injection,the temperature within the fracture is high,and the phase transition rate is rapid,resulting in a significant impact of exothermic phase transition on the reservoir rock temperature.In the later stage of injection,the fracture temperature decreases,the phase transition exothermic rate slows,and the cooling effect of the fracturing fluid on the reservoir rock intensifies.Phase transition heat significantly affects the temperature of the fracture.Compared to cases where phase transition heat is not considered,when it is taken into account,the temperature within the fracture increases to varying degrees at the end of fluid injection.As the phase transition heat increases from 20 J/g to 60 J/g,the maximum temperature rise in the fracture increases from 2.1℃ to 6.2℃.The phase transition heat and PF volume fraction are positively correlated with fracture temperature changes,while specific heat capacity is negatively correlated with temperature changes.With increasing injection time,the temperature and phase transition rate at the fracture opening gradually decrease,and the location of the maximum phase transition rate and temperature difference gradually shifts from the fracture opening to about 10 m from the opening.
基金supported by the Shenzhen-Hong Kong Sci-ence and Technology Innovation Cooperation Zone Shenzhen Park Project(Grant No.HZQB-KCZYB-2020030)the RGC Theme-based Research Scheme(Grant No.AoE/M-402/20)+1 种基金National Nat-ural Science Foundation of China(Grant No.52250710160)Shenzhen Science and Technology Innovation Committee(Grant Nos.KQTD20170328154443162,JCYJ20210324104610029,and JCYJ20220818100613028).
文摘High levels of Al and Ti in superalloy compositions normally lead to cracking formation during the laser powder bed fusion process,while these elements are key constituents of strengthening phases.In the current study,a novel Co-based superalloy with the basic chemical composition of Co-Al-W-Ta-Ti resolved this contradiction,indicating that the part was formed without cracking and simultaneously contained a large amount of strengthening precipitates in the microstructure fabricated via laser powder bed fusion.The printability,microstructures,and mechanical properties of the sample were analysed before and after heat treatment,providing a potential superalloy that can replace Ni-based superalloys fabricated by additive manufacturing in aerospace and other industries with higher temperature and more efficiency.
文摘Hepatitis B-associated hepatocellular carcinoma (HBV-HCC) remains an intractable high-mortality solidtumor cancer that accounted for 42% of global HCC cases in 2019. Despite some developments in systemic therapy,only a small subset of late-stage HCC patients responds positively to recently developed therapeutic innovations.MicroRNAs (miRNAs) act as an ancillary epigenetic system that can regulate genome expression in all cancerpathways including HCC. The molecular mechanisms of miRNA regulation in cancer pathogenesis offered researchersa new approach that was widely hoped would translate into miRNA-based drugs and diagnostics. Thirty years on,miRNA-based diagnostic and therapeutic agents for HCC remain a work-in-progress (WIP) and no current miRNAHCC clinical trial has progressed to Phase 4. The question remains why this is the case after 30 years and what is theway forward. The major findings and contribution of this paper are that it illustrates the complexity of the HBVmiRNA interactome in HBV-HCC in all cellular processes, as well as the ancillary role of miRNA in the epigeneticand immune systems. This is combined with a review of the outcomes and problems of clinical trials, to explain whymiRNA therapeutics and diagnostics have not progressed to approved drugs or serum-based diagnostic tests. The wayforward suggests a radical rethink might be so that involves the incorporation of AI, bioinformatics, andnanotechnology to solve the problem.
基金funded by postdoctoral funding to LZ from Guangxi University(A3360051014,A3360051010)from the Guangxi Key Laboratory of Forest Ecology and Conservation(AE33600102).
文摘Participants in mixed-species bird flocks(MSFs)have been shown to associate with species that are similar in body size,diet,and evolutionary history,suggesting that facilitation structures these assemblages.In addition,several studies have suggested that species in MsFs resemble each other in their plumage,but this question has not been systematically investigated for any MsF system.During the nonbreeding season of 2020 and 2021,we sampled 585 MSFs on 14 transects in 2 habitats of Tongbiguang Nature Reserve in western Yunnan Province,China.We performed social network analysis and the Multiple Regression Quadratic Assignment Procedure to evaluate the effect of 4 species traits(body size,overall plumage color,distinctive plumage patterns,and diet)and evolutionary history on species association strength at the whole-MSF and within-MSF levels.All 41 significant relationships showed that species with stronger associations were more similar in their various traits.Body size had the strongest effect on association strength,followed by phylogeny,plumage patterns,and plumage color;diet had the weakest effect.Our results are consistent with the hypotheses that the benefits of associating with phenotypically similar species outweigh the potential costs of interspecific competition,and that trait matching can occur in plumage characteristics,albeit more weakly than in other traits.Several explanations exist as to why similarities in plumage may occur in MSFs,including that they could reduce predators'ability to target phenotypically"odd"individuals.Whether trait matching in plumage occurs through assortative processes in ecological time or is influenced by co-evolution requires furtherstudy.
基金supported by the China National Major Project for New Drug Innovation(No.2017ZX09304015)the Beijing Hope Run Special Fund of the Cancer Foundation of China(No.LC2022A30)the Beijing Vlove Charity Foundation(No.JYKY2024-0200616033)。
文摘Objective:Based on the findings of the KEYNOTE-048 study,pembrolizumab in combination with platinum and fluorouracil is the standard first-line treatment for recurrent or metastatic head and neck squamous cell carcinoma(R/M HNSCC).The efficacy and safety of pembrolizumab combined with nab-paclitaxel and platinum in such patients remain unexplored.Methods:This single-arm phase 2 study enrolled patients with R/M HNSCC who received pembrolizumab(200 mg),nab-paclitaxel(260 mg/m^(2)),and either cisplatin(75 mg/m^(2))or carboplatin[area under the curve(AUC)5]every 21 d for up to six cycles,followed by pembrolizumab maintenance therapy.The primary endpoint was the objective response rate(ORR).Secondary endpoints included disease control rate(DCR),progression-free survival(PFS),duration of response(Do R),overall survival(OS),and safety.Exploratory multi-omics analyses were conducted.Results:Between April 23,2021,and August 20,2023,a total of 67 patients with R/M HNSCC were enrolled and received the study treatment.By the data cut-off date of March 2,2024,62(92.5%)patients had received cisplatin,while five(7.5%)patients had received carboplatin.The median follow-up duration was 12.7(range:2.3-34.8)months.The ORR was 62.7%,and the DCR was 88.1%.The median PFS,Do R,and OS were 9.7,13.0,and 18.7 months,respectively.The most common grade 3 adverse events(AEs)were leukopenia(22.4%)and neutropenia(28.4%).Genomic alterations correlated with efficacy outcomes,and dynamic changes in 17 plasma proteins were associated with treatment response.Upregulation of serum interferon(IFN)-γand interleukin(IL)8levels was linked to treatment-related AEs.Conclusions:Pembrolizumab in combination with nab-paclitaxel and platinum demonstrated promising efficacy and a manageable safety profile in patients with R/M HNSCC.Future studies are warranted to confirm these findings.
基金The Young Scientist Fund of National Natural Science Foundation of China, No.40901224 National Basic Research Program of China, No.2010CB950900+1 种基金 Open Fund of State Key Laboratory of Remote Sensing Science, No.2009KFJJ005 Open Fund of State Key Lab of Resources and Environmental Information System, No.A0725
文摘The impervious surface area （ISA） at the regional scale is one of the important environmental factors for examining the interaction and mechanism of Land Use/Cover Change （LUCC）-ecosystem processes-climate change under the interactions of urbanization and global environmental change. Timely and accurate extraction of ISA from remotely sensed data at the regional scale is challenging. This study explored the ISA extraction based on MODIS and DMSP-OLS data and the incorporation of China＇s land use/cover data. ISA datasets in Beijing-Tianjin-Tangshan Metropolitan Area （BTTMA） in 2000 and 2008 at a spatial resolution of 250 m were developed, their spatiotemporal changes were analyzed, and their impacts on water quality were then evaluated. The results indicated that ISA in BTTMA increased rapidly along urban fringe, transportation corridors and coastal belt both in intensity and extents from 2000 to 2008. Three cities （Tangshan, Langfang and Qinhuangdao） in Hebei Province had higher ISA growth rates than Beijing due to the pressure of population-resour- ces-environments in the city resulting in increasingly transferring industries to the nearby areas. The dense ISA distribution in BTTMA has serious impacts on water quality in the Haihe River watershed. Meanwhile, the proportion of ISA in sub-watersheds has significantly linear relationships with the densities of river COD and NH3-N.
文摘Runoff and soil losses from agricultural fields are investigated as major nonpoint sources of phosphorus (P) entering lakes of Eastern China. There is relatively little information on P transport from ricefield and cropland of Lake Taihu watershed in Eastern China. Soil and P in surface runoff from a series of plots in the watershed were evaluated under simulated rainfall conditions. The objectives of this study were to evaluate the effects of crop cover, slope, and fertilizer application on P concentrations in surface runoff and eroded soil. Accumulated sediment yields varied from 7.1 to 300 g/m2 for croplands, depending on management practices. For all experiment plots, weighted average concentrations of total-P (TP), dissolved P (DP) and particulate P (PP) are much higher than 0.02 mg/L, the limiting concentration for lake water. This result showed the potential contamination of lake water from agricultural surface runoff. Accumulated TP losses were 3.8 and 18.8 mg/m2 for ricefield and cropland, respectively. The estimated annual loss of TP was 0.74 kg/(hm2 · a) for cropland. Most of P loss is in the PP form, which accounts for more than 90% of TP loss for cropland.
基金Supported by National Natural Science Foundation of China,No.30660225 and No.30960511
文摘AIM:To investigate the in vivo hepatoprotective effects and mechanisms of Gentiana manshurica Kitagawa (GM) in acetaminophen (APAP)-induced liver injury in mice.METHODS: GM (200, 150 or 50 mg/kg body weight) or N-acetyl-L-cysteine (NAC; 300 mg/kg body weight) was administrated orally with a single dose 2 h prior to APAP (300 mg/kg body weight) injection in mice.RESULTS: APAP treatment significantly depleted hepatic glutathione (GSH), increased serum aspartate aminot ransferase (AST), alanine aminotransferase (ALT) and malonyldialdehyde (MDA) and 4-hydroxynonenal levels, and decreased hepatic activity of glutathione peroxidase (GSH-px) and superoxide dismutase (SOD). However, the pretreatment of GM signif icantly alleviated APAP-induced oxidative stress by increasing GSH content, decreasing serum ALT, AST and MDA, and retaining the activity of GSH-px and SOD in the liver. Furthermore, GM pretreatment can inhibit caspase-3 activation and phosphorylation of c-Jun-NH2-terminal protein kinase 2 (JNK1/2) and extracellular signalregulated kinase (ERK). GM also remarkably attenuated hepatocyte apoptosis confirmed by the terminal deoxynucleotidyl transferase mediated dUTP nick end-labeling method.CONCLUSION: Hepatoprotective effects of GM against APAP-induced acute toxicity are mediated either by preventing the decline of hepatic antioxidant status or its direct anti-apoptosis capacity. These results support that GM is a potent hepatoprotective agent.
文摘A novel diarylheptanoid bearing flavonol moiety,named officinin A(1),along with two known compounds galangin and kaempferide were isolated from the rhizomes of Alpina officinarum Hance.The structure elucidation was accomplished by HRESI -MS,1D and 2D NMR methods.
基金National Natural Science Foundation of China, No.40701044 National Key Technology R＆D Program, No.2008BAH31B01
文摘Employing DEA model and Malmquist productivity index, this paper probes into the urban efficiencies of 24 typical resources-based cities in China and their changes from 2000 to 2008. The research finds that the overall efficiencies of the resources-based cities are just at a general level, and only a few of them reach the optimal level. The scale efficiency is the major determining factor of the achievement of overall efficiency, the effect of which, nevertheless, is reducing. From the perspective of classification characteristics, the resources-based cities in northeastern region have been in the front rank in terms of overall efficiency, pure technical efficiency and scale efficiency. There is a certain positive correlation between urban population scale and urban efficiency. The analysis of urban efficiency changes shows that the changes in overall efficiency of resources-based cities from 2000 to 2008 had a weak improving tendency. Both the technical change index and productivity change index decreased, indicating that the urban efficiency did not improve during this period, and the tendency of technical recession and productivity decline was obvious. In terms of the classification of urban efficiency changes, the urban overall efficiency improved in each of the four regions from 2000 to 2008, among which western region witnessed the greatest increase. Cities with different resource types have improved their urban overall efficiencies except steel-based cities. The urban overall efficiency increased in resources-based cities of different scales, with greater improvement in small and medium-sized cities than in big cities.
文摘A new jatrophane-type diterpenoid,7β,14β,15β-triacetoxy-3β-benzoyloxy-9-oxojatropha-5E,11E-diene,named euphornin N was isolated from Euphorbia helioscopia L.The structure and relative stereochemistry of the new compound was elucidated by spectroscopic methods.
基金Project(50571092) supported by the National Natural Science Foundation of ChinaProject(0523020500) supported by the Excellent Young Scholars Foundation of Henan Province, China
文摘The phase selection of ternary intermetallic compound τphase (Mg32(Al, Zn)49 ) and φ phase (Al2Mg5Zn2) in high zinc magnesium alloys was studied by using scanning electron microscope, X-ray diffractometer and differential scanning calorimeter, etc. The results indicate that, when adding element Si in Mg-8Zn-4Al-0.3Mn (ZA84) alloy, φ phase is promoted, whereas τ phase is inhibited. The Chinese script-type Mg2Si and matrix microstructure are greatly refined, the formation of τ phase is facilitated and φ phase is restrained when modifier Al-AlP master alloy is added in ZA84 alloy containing Si. The kinetics study of phase selection indicates that there is a critical degree of undercooling of the melt. If the undercooling exceeds the critical value, τ phase preferentially forms while φ phase is restrained; otherwise, φ phase preferentially forms while τ phase is restrained.
基金supported by a program for New Century Excellent talents in University from MOE(No.NCET-08- 0925)a grant from the Natural Science Foundation of Yunnan Province(No.2007B021M)a grant from Yunnan University(No.2007Q003A)
文摘Three new monophenanthrene compounds were isolated from an acetone extract of the tubers of Monomeria barbata Lindl. (Orchidaceae).Using spectroscopic methods,the structures of compounds 1-3 were determined as 1,4,7-trihydroxy-2-methoxy- 9,10-dihydrophenanthrene(1),1-(p-hydroxybenzoyl)-2-methoxy-4,7-dihydroxy-9,10-dihydrophenanthrene(2),1,3,8-tri(p-hydroxybenzyl) -4-methoxy-phenanthrene-4,7-diol(3).These compounds showed cytotoxicities on four tumor cell lines(HepG2, HL-60,Skov-3,A431).
基金The National Science and Technology Support Plan, No.2009BAC61B01
文摘In this study, a monthly dataset of temperature time series （1961-2010） from 12 meteorological stations across the Three-River Headwater Region of Qinghai Province （THRHR） was used to analyze the climate change. The temperature variation and abrupt change analysis were examined by using moving average, linear regression, Spline interpolation, Mann-Kendall test and so on. Some important conclusions were obtained from this research, which mainly contained four aspects as follows. （1） There were several cold and warm fluctuations for the annual and seasonal average temperature in the THRHR and its three sub-headwater regions, but the temperature in these regions all had an obviously rising trend at the statistical significance level, especially after 2001. The spring, summer, autumn and annual average temperature increased evidently after the 1990s, and the winter average temperature exhibited an obvious upward trend after entering the 21st century. Except the standard value of spring temperature, the annual and seasonal temperature standard value in the THRHR and its three sub-headwater regions increased gradually, and the upward trend for the standard value of winter average temperature indicated significantly. （2） The tendency rate of annual average temperature in the THRHR was 0.36℃ 10a^-1, while the tendency rates in the Yellow River Headwater Region （YERHR）, Lancangjiang River Headwater Region （LARHR） and Yangtze River Headwater Region （YARHR） were 0.37℃ 10a^-1, 0.37℃ 10a^-1 and 0.34℃10a^-1 respectively. The temperature increased significantly in the south of Yushu County and the north of Nangqian County. The rising trends of temperature in winter and autumn were higher than the upward trends in spring and summer. （3） The abrupt changes of annual, summer, autumn and winter average temperature were found in the THRHR, LARHR and YARHR, and were detected for the summer and autumn average temperature in the YERHR. The abrupt changes of annual and summer average temperatures were mainly in the late 1990s, while the abrupt changes of autumn and winter average temperatures appeared primarily in the early 1990s and the early 21st century respectively. （4） With the global warming, the diversities of altitude and underlying surface in different parts of the Tibetan Plateau were possibly the main reasons for the high increasing rate of temperature in the THRHR.
