Extensive first-principles calculations have been performed to examine the electrochemical properties of Na-ion-intercalatable heterostructures formed by transitional metal dichalcogenides(MS_(2),where M=Ti,V,Nb and M...Extensive first-principles calculations have been performed to examine the electrochemical properties of Na-ion-intercalatable heterostructures formed by transitional metal dichalcogenides(MS_(2),where M=Ti,V,Nb and Mo)and blue phosphorus(BlueP),which have been reported as potential anode materials for rechargeable sodium-ion batteries.Upon formation of heterostructures,much improved structural stabilities have observed compared with the pristine MS_(2) and BlueP.Metallic T-TiS_(2),T-MoS_(2),H(T)-VS_(2) and H(T)-NbS_(2) would retain the conductive character after formation of heterostructures with BlueP,however,HTiS_(2)/BlueP and H-MoS_(2)/BlueP would undergo a semiconductor to metallic transition accompanied by Na intercalation.Moreover,the presence of relatively low diffusion barriers ranging from 0.04 eV to 0.08 eV,coupled with the suitable average open-circuit voltage spanning from 0.12 eV to 0.89 eV,guarantee exceptional charge-discharge rates and ensure the safety of battery performance.Among these heterostructures,H(T)-NbS_(2)/BlueP and T-TiS_(2)/BlueP exhibit best Na adsorption ability of up to 4 layers,corresponding to theoretical capacities of 570.2 and 746.7 mAh/g,respectively.These encouraging properties indicate that T-TiS_(2)/BlueP and H(T)-NbS_(2)/BlueP could serve as suitable anode materials for high-performance sodiumion batteries.展开更多
Pore structure characteristics,gas content,and micro-scale gas occurrence mechanisms were investigated in the Shan_(2)^(3)sub-member marine-continental transitional shale of the southeastern margin of the Ordos Basin ...Pore structure characteristics,gas content,and micro-scale gas occurrence mechanisms were investigated in the Shan_(2)^(3)sub-member marine-continental transitional shale of the southeastern margin of the Ordos Basin using scanning electron microscope images,lowtemperature N_(2)/CO_(2)adsorption and high-pressure mercury intrusion,methane isothermal adsorption experiments,and CH4-saturated nuclear magnetic resonance(NMR).Two distinct shale types were identified:organic pore-rich shale(Type OP)and microfracture-rich shale(Type M).The Type OP shale exhibited relatively well-developed organic matter pores,while the Type M shale was primarily characterized by a high degree of microfracture development.An experimental method combining methane isothermal adsorption on crushed samples and CH4-saturated NMR of plug samples was proposed to determine the adsorbed gas,free gas,and total gas content under high temperature and pressure conditions.There were four main research findings.(1)Marine-continental transitional shale exhibited substantial total gas content in situ,ranging from 2.58 to 5.73 cm^(3)/g,with an average of 4.35 cm^(3)/g.The adsorbed gas primarily resided in organic matter pores through micropore filling and multilayer adsorption,followed by multilayer adsorption in clay pores.(2)The changes in adsorbed and free pore volumes can be divided into four stages.Pores of<5 nm exclusively contain adsorbed gas,while those of 5-20 nm have a high proportion of adsorbed gas alongside free gas.Pores ranging from 20 to 100 nm have a high proportion of free gas and few adsorbed gas,while pores of>100 nm and microfractures are almost predominantly free gas.(3)The proportion of adsorbed gas in Type OP shale exceeds that in Type M,reaching 66%.(4)Methane adsorbed in Type OP shale demonstrates greater desorption capability,suggesting a potential for enhanced stable production,which finds support in existing production well data.However,it must be emphasized that high-gas-bearing intervals in both types present valuable opportunities for exploration and development.These data may support future model validations and enhance confidence in exploring and developing marine-continental transitional shale gas.展开更多
Objective:To explore the application effect of continuous nursing in elderly patients with chronic diseases.Methods:A total of 100 elderly patients with chronic diseases were selected and randomly divided into experim...Objective:To explore the application effect of continuous nursing in elderly patients with chronic diseases.Methods:A total of 100 elderly patients with chronic diseases were selected and randomly divided into experimental group and control group,50 cases in each group.Patients in the experimental group received continuous nursing,while patients in the control group received routine nursing.Comparison of two groups of patients’quality of life,health and nursing satisfaction.Results:the patient’s quality of life,health and nursing satisfaction were significantly higher than control group(p<0.05).Conclusion:Continuous nursing has a significant application effect in elderly patients with chronic diseases,which is worthy of further promotion and application.展开更多
Objective： To investigate the expressions of cytokeratin 19 （CK19） and cytokeratin 20 （CK20） in bladder transitional cell carcinoma （TCC） and their clinical significance. Methods： The expression of CK19 and CK...Objective： To investigate the expressions of cytokeratin 19 （CK19） and cytokeratin 20 （CK20） in bladder transitional cell carcinoma （TCC） and their clinical significance. Methods： The expression of CK19 and CK20 was detected in 54 cases of TCC by immunohistochemical methods and image processing techniques. Results： The expression of CK19 and CK20 was significantly stronger in the recurrent group than in the non-recurrent group （P〈0.01, P〈0.001, respectively）. Conclusion： The expression of CK19 and CK20 was obviously related with biological behaviors of TCC, suggesting that CK19 and CK20 could be used to predict the recurrence of TCC.展开更多
This article describes an experimental study on friction and heat transfer performances of a transitional airflow in a rectangular channel with stagger-arrayed short pin fins. Friction factors, average Nusselt numbers...This article describes an experimental study on friction and heat transfer performances of a transitional airflow in a rectangular channel with stagger-arrayed short pin fins. Friction factors, average Nusselt numbers and overall thermal performances of the transitional flow are obtained. The experimental study has showed that the pin fins enhance the heat transfer performance sig- nificantly, however increasing the flow frictional resistance considerably. After comparing the experimental results with the p...展开更多
In this study,we systematically explored the environmental significance of stable isotope characteristics and the controlling factors of precipitation stable isotopes in the source region of the Three Rivers(SRTR),the...In this study,we systematically explored the environmental significance of stable isotope characteristics and the controlling factors of precipitation stable isotopes in the source region of the Three Rivers(SRTR),the transitional zone of the Qinghai-Tibet Plateau in China.A total of 862 precipitation samples were collected from six fixed-point sampling locations between 2019 and 2021 in the SRTR.In June,the values of hydrogen(δD)and oxygen(δ^(18)O)stable isotopes were most enriched.The deuterium-excess(d-excess)in atmospheric precipitation was>0 in the SRTR;however,the maximum value of d-excess occurred in October.Moreover,the slopes of the local meteoric water line(LMWL)for Dari,Zaduo,Maduo,Qumalai,and Tuotuohe sites were lower than those of the global met-eoric water line(GMWL).In contrast,the slope of the LMWL for Zhimenda was higher than that of the GMWL.The altitude effects of oxygen(δ^(18)O)and hydrogen(δD)isotopes of precipitation were 0.70‰/100 m and 5.22‰/100 m,respectively.When the temperature was≤5℃,there was a significant temperature effect on stable oxygen isotope of precipitation(0.24‰/℃,P<0.05).Furthermore,even a minor increase(1%)in the weight of raindrops after falling results in a 0.82%rise in the evaporation enrichment rate ofδ^(18)O.Success-ive precipitation events also had a substantial influence on precipitation in the transitional region of the Qinghai-Tibet Plateau.The res-ults of this study provide a theoretical basis for revealing the impact mechanism of precipitation in the transitional zone of the Qinghai-Tibet Plateau under a warming climate.展开更多
Objective： To explore the expression of anti-oncogene PTEN in bladder transitional cell carcinoma and its clinical significance. Methods： Using immunohistochemical S-P methods, the expression of PTEN gene was detect...Objective： To explore the expression of anti-oncogene PTEN in bladder transitional cell carcinoma and its clinical significance. Methods： Using immunohistochemical S-P methods, the expression of PTEN gene was detected in 62 specimens of bladder cancer and 18 specimens of normal bladder tissue. Results： In the 62 bladder cancers, the positive rate of PTEN was 53.2% （33/62）. All 18 normal bladder tissues were positive for the PTEN expression. The expression of PTEN was negatively correlated to tumor grades （P〈0.05）. Conclusion： The reduced expression of PETN might play an important role in carcinogenesis and progression of bladder cancer. Detection of PTEN might be useful for judgement of tumor development and prognosis.展开更多
This study was designed to investigate the different involvements of prostatic stromal cells from the normal transitional zone(TZ)or peripheral zone(PZ)in the carcinogenesis of prostate cancer(PCa)epithelial cells(PC-...This study was designed to investigate the different involvements of prostatic stromal cells from the normal transitional zone(TZ)or peripheral zone(PZ)in the carcinogenesis of prostate cancer(PCa)epithelial cells(PC-3)in vitro and in vivo co-culture models.Ultra-structures and gene expression profiles of primary cultures of human prostatic stromal cells from the normal TZ or PZ were analyzed by electron microscopy and microarray analysis.In vitro and in vivo co-culture models composed of normal TZ or PZ stromal cells and human PCa PC-3 cells were established.We assessed tumor growth and weight in the in vivo nude mice model.There are morphological and ultra-structural differences in stromal cells from TZ and PZ of the normal prostate.In all,514 differentially expressed genes were selected by microarray analysis;483 genes were more highly expressed in stromal cells from TZ and 31 were more highly expressed in those from PZ.Co-culture with PZ stromal cells and transforming growth factor-β1(TGF-β1)increased the tumor growth of PC-3 cells in vitro and in vivo,as well as Bcl-2 expression.On the other hand,stromal cells of TZ suppressed PC-3 cell tumor growth in the mouse model.We conclude that ultra-structures and gene expression differ between the stromal cells from TZ or PZ of the normal prostate,and stroma-epithelium interactions from TZ or PZ might be responsible for the distinct zonal localization of prostate tumor formation.展开更多
Organic matter(OM)nanopores developed in transitional facies shales,i.e.,the Upper Permian Longtan and Dalong Formations in the Yangtze Platform,China,were investigated to determine the corre-sponding influence of the...Organic matter(OM)nanopores developed in transitional facies shales,i.e.,the Upper Permian Longtan and Dalong Formations in the Yangtze Platform,China,were investigated to determine the corre-sponding influence of thermal maturity and OM types within the geological conditions.A suite of 16 core samples were taken from Type-Ⅲ Longtan shales and Type-Ⅱ Dalong shales from two wells covering a ma-turity(Ro,vitrinite reflectance)ranging from 1.22%to 1.43%and 2.62%to 2.97%,respectively.Integrated analysis of the shale samples was carried out,including field-emission scanning electron microscopy(FESEM),low-pressure N2 and CO2 adsorption,high-pressure CH4 adsorption,and mercury intrusion capillary pressure(MICP)analysis.The fluid inclusions of liquid and gas hydrocarbons trapped in calcite vein samples in Dalong shales of two wells were studied using laser Raman and fluorescence spectroscopy.FE-SEM images indicated that OM pores in different formations varied substantially in terms of shape,size,and distribution density.OM pores in Type-Ⅱ Dalong shales of Well XY1 were mainly micropore,sparsely distributed in the gas-prone kerogen with a spot-like and irregular shape,while bitumen rarely developed observable pores.In contrast,the morphology of OM pores in Type-Ⅲ Longtan shales were significantly different,which was due to differences in the OM type.The primary OM pores in some terrestrial woody debris in Longtan shales had a relatively larger pore diameter,ranging from hundreds of nanometers to a few micrometers and were al-most all rounded in shape,which might be one of the factors contributing to larger pore volume and gas adsorption capacity than Dalong shales of Well XY1.Comparing Dalong shales of Well XY1 with relatively lower thermal maturity,there were abundant spongy-like pores,densely developed in the pyrobitumen in Type-Ⅱ Dalong shales of Well EY1,with an irregular shape and diameter ranging from several to hundreds of nanometers.Many blue fluorescent oil inclusions and a small number of CH4 inclusions mixed with C2H6 could be observed within calcite veins in Dalong shales of Well XY1,whereas only CH4 inclusions could be identified within calcite veins in Dalong shales of Well EJ1.Therefore,thermal maturity not only controlled the type of hydrocarbons generated,but also makes a significant contribution to the formation of OM pores,resulting in larger pore volumes and adsorption capacity of Type-Ⅱ shale samples in the dry gas window.展开更多
Avoiding the folding defect and improving the die filling capability in the transitional region are desired in isothermal local loading forming of a large-scale Ti-alloy rib-web component（LTRC）. To achieve a high-pr...Avoiding the folding defect and improving the die filling capability in the transitional region are desired in isothermal local loading forming of a large-scale Ti-alloy rib-web component（LTRC）. To achieve a high-precision LTRC, the folding evolution and die filling process in the transitional region were investigated by 3 D finite element simulation and experiment using an equal-thickness billet（ETB）. It is found that the initial volume distribution in the second-loading region can greatly affect the amount of material transferred into the first-loading region during the second-loading step, and thus lead to the folding defect. Besides, an improper initial volume distribution results in non-concurrent die filling in the cavities of ribs after the second-loading step, and then causes die underfilling. To this end, an unequal-thickness billet（UTB） was employed with the initial volume distribution optimized by the response surface method（RSM）. For a certain eigenstructure, the critical value of the percentage of transferred material determined by the ETB was taken as a constraint condition for avoiding the folding defect in the UTB optimization process,and the die underfilling rate was considered as the optimization objective. Then, based on the RSM models of the percentage of transferred material and the die underfilling rate, non-folding parameter combinations and optimum die filling were achieved. Lastly, an optimized UTB was obtained and verified by the simulation and experiment.展开更多
This research examines the vortex behaviors and aerodynamic forces in dynamic stall phenomena at a transitional Reynolds number(Re=90000)using experimental and numerical approaches.Periodic sinusoidal pitching motion ...This research examines the vortex behaviors and aerodynamic forces in dynamic stall phenomena at a transitional Reynolds number(Re=90000)using experimental and numerical approaches.Periodic sinusoidal pitching motion at two different reduced frequencies is used to achieve the dynamic stall of a NACA 0012 airfoil.Several leading edge vortices form and detach in the dynamic stall stage.The flow then quickly transitions to a full separation zone in the stall stage when the angle of attack starts to decrease.There is discrepancy between the phaseaveraged and instantaneous flow field in that the small flow structures increased with angle of attack,which is a characteristic of the flow field at the transitional Reynolds number.The interaction between the streamwise vortices in the three-dimensional numerical results and the leading edge vortex are the main contribution to the turbulent flow.In addition,the leading edge vortex that supplies vortex lift is more stable at higher reduced frequency,which decreases the lift fluctuation in the dynamic stall stage.The leading edge vortex at higher reduced frequency is strong enough to stabilize the flow,even when the airfoil is in the down-stroke phase.展开更多
Based on 10 shale samples collected from 4 wells in Qinshui Basin,we investigate the full-sized pore structure and fractal characteristics of Marine-Continental transitional shale by performing organic geochemistry,mi...Based on 10 shale samples collected from 4 wells in Qinshui Basin,we investigate the full-sized pore structure and fractal characteristics of Marine-Continental transitional shale by performing organic geochemistry,mineralogical composition,Nitrogen gas adsorption(N2 adsorption)and Nuclear Magnetic Resonance(NMR)measurements and fractal analysis.Results show that the TOC content of the shale samples is relatively high,with an average value of 2.44wt%,and the thermal evolution is during the mature-over mature stage.The NMR T2 spectrum can be used to characterize the fullsized pore structure characteristics of shale.By combining N2 adsorption pore structure parameters and NMR T2 spectrums,the surface relaxivity of samples are calculated to be between 1.7877 um/s and 5.2272 um/s.On this basis,the T2 spectrums are converted to full-sized pore volume and surface area distribution curves.The statistics show that the pore volume is mainly provided by mesopore,followed by micropore,and the average percentages are 65.04%and 30.83%respectively;the surface area is mainly provided by micropore,followed by mesopore,and the average percentages are 60.8004%and 39.137%respectively;macropore contributes little to pore volume and surface area.The pore structure characteristics of shale have no relationship with TOC,but strong relationships with clay minerals content.NMR fractal dimensions Dmicro and Dmeso have strong positive relationships with the N2 adsorption fractal dimensions D1 and D2 respectively,indicating that Dmicro can be used to characterize the fractal characteristics of pore surface,and Dmeso can be used to characterize the fractal characteristics of pore structure.The shale surface relaxivity is controlled by multiple factors.The increasing of clay mineral content,pore surface area,pore surface fractal dimension and the decreasing of average pore size,will all lead to the decreasing of shale surface relaxivity.展开更多
Background:The Transitional Care Model(TCM)for nursing care has yet to be implemented in China despite its success in Western countries.However,rapid social changes have demanded an upgrade in the quality of nursing c...Background:The Transitional Care Model(TCM)for nursing care has yet to be implemented in China despite its success in Western countries.However,rapid social changes have demanded an upgrade in the quality of nursing care;in 2010,the Chinese government has acknowledged the need to implement the TCM in China.Objective:This study has the following objectives:(1)perform a thorough review of the literature regarding the development and implementation of the TCM in China's Mainland within the past 5 years;(2)provide a comprehensive discussion of the current status,problems,and strategies related to the implementation of the TCM in China's Mainland;and(3)suggest strategies pertaining to the future of the TCM in China.Design:The current pertinent literature is systematically reviewed.Data sources:Systematic and manual searches in computerized databases for relevant studies regarding the TCM led to the inclusion of 26 papers in this review.Review methods:Abstracts that satisfied the inclusion criteria were reviewed independently by the two authors of this manuscript,and discrepancies were resolved through discussion.The same reviewers independently assessed the paper in its entirety for selected abstracts.Results:The present English literature reviewrevealed a paucity of updated information about the development and implementation of the TCM in China's Mainland.Nevertheless,the dramatic growth of the TCM in the past 5 years has had a vital impact within the society and in nursing development.This review also revealed numerous issues regarding the focus of the TCM.Overall implications for practiceandrecommendations for future researchare discussed.Conclusion:Despite the potential of this nursing model to have a successful and beneficial impact in China's Mainland,it remains an under-researched topic.Further research on education and training as well as premium policies for nurses under the TCM are needed.展开更多
The evolution of shale reservoirs is mainly related to two functions:mechanical compaction controlled by ground stress and chemical compaction controlled by thermal effect.Thermal simulation experiments were conducted...The evolution of shale reservoirs is mainly related to two functions:mechanical compaction controlled by ground stress and chemical compaction controlled by thermal effect.Thermal simulation experiments were conducted to simulate the chemical compaction of marine-continental transitional shale,and X-ray diffraction(XRD),CO2 adsorption,N2 adsorption and high-pressure mercury injection(MIP)were then used to characterize shale diagenesis and porosity.Moreover,simulations of mechanical compaction adhering to mathematical models were performed,and a shale compaction model was proposed considering clay content and kaolinite proportions.The advantage of this model is that the change in shale compressibility,which is caused by the transformation of clay minerals during thermal evolution,may be considered.The combination of the thermal simulation and compaction model may depict the interactions between chemical and mechanical compaction.Such interactions may then express the pore evolution of shale in actual conditions of formation.Accordingly,the obtained results demonstrated that shales having low kaolinite possess higher porosity at the same burial depth and clay mineral content,proving that other clay minerals such as illite-smectite mixed layers(I/S)and illite are conducive to the development of pores.Shales possessing a high clay mineral content have a higher porosity in shallow layers(<3500 m)and a lower porosity in deep layers(>3500 m).Both the amount and location of the increase in porosity differ at different geothermal gradients.High geothermal gradients favor the preservation of high porosity in shale at an appropriate Ro.The pore evolution of the marine-continental transitional shale is divided into five stages.Stage 2 possesses an Ro of 1.0%-1.6%and has high porosity along with a high specific surface area.Stage 3 has an Ro of 1.6%-2.0%and contains a higher porosity with a low specific surface area.Finally,Stage 4 has an Ro of 2.0%-2.9%with a low porosity and high specific surface area.展开更多
The expression of KAI1/CD82 and MRP-1/CD9 in transitional cell carcinoma of bladder （TCCB） and its clinical significance were investigated. Immunohistochemistry was used to detect KAI1/CD82 and MRP-1/CD9 protein exp...The expression of KAI1/CD82 and MRP-1/CD9 in transitional cell carcinoma of bladder （TCCB） and its clinical significance were investigated. Immunohistochemistry was used to detect KAI1/CD82 and MRP-1/CD9 protein expression in 52 TCCB specimens. Correlation between the expression of KAI1/CD82 and MRP-1/CD9 to clinicopathologic factors was statistically analyzed. The results showed that the positive rate of KAI1/CD82 and MRP-1/CD9 in TCCB was 50% and 61.5%, respectively. The MRP-1/CD9 and KAI1/CD82 expression was significantly associated with grade of TCCB （P〈0.05）, but no correlation was found between MRP-1/CD9 or KAI1/CD82 expression and clinical stage of TCCB （P〉0.05）. The expression level of MRP-1/CD9 and KAI1/CD82 in recurrent TCCB samples was lower than that in non-recurrent samples （P〈0.05）. Meanwhile, the correlation between the KAI1/CD82 expression and MRP-1/CD9 expression was statistically significant （r=0.316, P〈0.05）. It was concluded that KAI1/CD82 and MRP-1/CD9 expression may be important prognostic indicators and potentially useful for assessing the biological behavior of TCCB.展开更多
AIM: To evaluate two simple angle measurements for predicting lumbosacral transitional vertebra (LSTV) in magnetic resonance imaging (MRI) studies of the spine. METHODS: The lumbar spine MRI studies of 50 subjects wit...AIM: To evaluate two simple angle measurements for predicting lumbosacral transitional vertebra (LSTV) in magnetic resonance imaging (MRI) studies of the spine. METHODS: The lumbar spine MRI studies of 50 subjects with LSTV and 50 subjects with normal lumbosacral anatomy were retrospectively evaluated. In each study, the mid-sagittal T2-weighted image was used to measure the angle formed by a line parallel to the superior surface of the sacrum and a line perpendicular to the axis of the scan table (A-angle), as well as the angle formed by a line parallel to the superior endplate of the L3 vertebra and a line parallel to the superior surface of the sacrum (B-angle). RESULTS: The total study population consisted of 100 subjects (46 males, 54 females, 51 ± 16 years old). There were no differences in age and sex between the two groups. Both A-angle and B-angle were significantly increased in subjects with LSTV compared to controls (P < 0.05). The optimal cut-off values of A-angle and B-angle for the prediction of LSTV were 39.8° (sensitivity = 80%, specificity = 80%, accuracy = 83%; 95% confidence interval = 74%-89%, P = 0.0001) and 35.9° (sensitivity = 80%, specificity = 54%, accuracy = 69%; 95% confidence interval = 59%-78%, P = 0.0005), respectively. CONCLUSION: On sagittal MR images of the lumbar spine, an increased A-angle and/or B-angle should alert the radiologist to the presence of LSTV.展开更多
Based on core description,thin section identification,X-ray diffraction analysis,scanning electron microscopy,low-temperature gas adsorption and high-pressure mercury intrusion porosimetry,the shale lithofacies of Sha...Based on core description,thin section identification,X-ray diffraction analysis,scanning electron microscopy,low-temperature gas adsorption and high-pressure mercury intrusion porosimetry,the shale lithofacies of Shan23 sub-member of Permian Shanxi Formation in the east margin of Ordos Basin was systematically analyzed in this study.The Shan23 sub-member has six lithofacies,namely,low TOC clay shale(C-L),low TOC siliceous shale(S-L),medium TOC siliceous shale(S-M),medium TOC hybrid shale(M-M),high TOC siliceous shale(S-H),and high TOC clay shale(C-H).Among them,S-H is the best lithofacies,S-M and M-M are the second best.The C-L and C-H lithofacies,mainly found in the upper part of Shan23 sub-member,generally developed in tide-dominated delta facies;the S-L,S-M,S-H and M-M shales occurring in the lower part of Shan23 sub-member developed in tide-dominated estuarine bay facies.The S-H,S-M and M-M shales have good pore struc-ture and largely organic matter pores and mineral interparticle pores,including interlayer pore in clay minerals,pyrite inter-crystalline pore,and mineral dissolution pore.C-L and S-L shales have mainly mineral interparticle pores and clay mineral in-terlayer pores,and a small amount of organic matter pores,showing poorer pore structure.The C-H shale has organic mi-cro-pores and a small number of interlayer fissures of clay minerals,showing good micro-pore structure,and poor meso-pore and macro-pore structure.The formation of favorable lithofacies is jointly controlled by depositional environment and diagen-esis.Shallow bay-lagoon depositional environment is conducive to the formation of type II2 kerogen which can produce a large number of organic cellular pores.Besides,the rich biogenic silica is conducive to the preservation of primary pores and en-hances the fracability of the shale reservoir.展开更多
Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential su...Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential suitable agriculture area in the farming-grazing transitional zone in the northeastern China during the 20th century. Based on modem weather data, 1 km-resolution land cover data, historical climatic time series, and estimation by using similar historical climatic scenes, the following was concluded： 1） The climate conditions of suitable agriculture areas in the farming-grazing transitional zone in the northeastern China between 1971 and 2000 required an average annual temperature above 1℃ or ≥ 0℃ accumulated temperature above 2500℃-2700℃, and annual precipitation above 350 mm. 2） The northern boundary of the potential suitable agriculture area during the relatively warmer period of 1890-1910 was approximately located at the position of the 1961-2000 area. The northern boundary shifted back to the south by 75 km on average during the colder period of the earlier 20th century, whereas during the modem warm period of the 1990s, the area shifted north by 100 km on average. 3） The western and eastern boundaries of the suitable agricul^re area during the heaviest drought periods between 1920s and 1930s had shifted northeast by 250 km and 125 km, respectively, contrasting to the boundaries of 1951-2008. For the wettest period, that is, the 1890s to the 1910s, the shift of western and eastern boundaries was to the southwest by 125 km and 200 km, respectively, compared with that in the 1951-2008 period. This study serves as a reference for identifying a climatically sensitive area and planning future land use and agricultural production in the study area.展开更多
Objectives:To observe the effects of transitional care on the quality of life of chronic obstructive pulmonary disease(COPD)patients.Methods:A total of 114 COPD patients were recruited from the First Affiliated Hospit...Objectives:To observe the effects of transitional care on the quality of life of chronic obstructive pulmonary disease(COPD)patients.Methods:A total of 114 COPD patients were recruited from the First Affiliated Hospital,Sun Yat-sen University,Guangzhou,China and divided equally into an intervention group and control group.Following discharge,patients from the intervention group recieved threemonths intervention in addition to regular nursing care,while control group patients received regular nursing care only.Patients’quality of life was measured using the St.George’s respiratory questionnaire(SGRQ),the 12-item General Health Questionnaire(GHQ-12)and body mass index(BMI).Results:The symptoms section score,the activity section score,the impacts section score,the total score and the rate of mental disorders were significantly changed after the intervention while there was no statistical difference in BMI between groups.Conclusions:Transitional care can improve health-related quality of life in COPD patients who have recently suffered an exacerbation.展开更多
"Hu Huan-yong Line(Hu Line)"depicts a geographical pattern of China’s population distribution.Its essence is the regionality of humanland relationship and reflects basic characteristics and laws of human be..."Hu Huan-yong Line(Hu Line)"depicts a geographical pattern of China’s population distribution.Its essence is the regionality of humanland relationship and reflects basic characteristics and laws of human beings’adaptation to the natural environment.With the development of the times and the progress of modern science and technology,especially the rapid urbanization and construction of transportation network system in China,the connection between economic and geographical space has been continuously strengthened.The geographical transition zones from mountain areas to plains,i.e.,transitional geographical space,have promoted the changes in human-land relationships through population migration and agglomeration.Taking Sichuan-Yunnan provinces at the southern end of Hu Line as study area,this study analyzed the spatial correlation between population distribution and economy in this region,explored the pattern of geographical agglomeration and deagglomeration,and explained the changing characteristics of humanland relationship in transitional geographic space using global Moran’s I index,global regression model(GRM)and geographically weighted regression(GWR).The results show that population and Gross Domestic Product(GDP)have significant spatial dependence to this region,with obvious aggregation in geographical distribution and positive autocorrelation;comparing with the general least square model,the GWR model incorporating spatial effect was more suitable for revealing the distribution characteristics of geographical elements,with fine results and better fitting;the spatial model of population and GDP as well as the spatio-temporal evolution model of their changes,all of them strongly indicated that Normalized Difference Vegetation Index(NDVI)and road density were important factors governing the spatial differentiation of population and economy;under the rapid development of regional economy and continuous evolution of urban-rural relations,rural transformation and spatial reconstruction promoted the change of population migration and agglomeration.展开更多
基金supported by the Fund of Education Department of Shaanxi Provincial Government(No.23JP172)the National Natural Science Foundation of China(No.22309189)financial support from Xiaomi Young Talents Program.
文摘Extensive first-principles calculations have been performed to examine the electrochemical properties of Na-ion-intercalatable heterostructures formed by transitional metal dichalcogenides(MS_(2),where M=Ti,V,Nb and Mo)and blue phosphorus(BlueP),which have been reported as potential anode materials for rechargeable sodium-ion batteries.Upon formation of heterostructures,much improved structural stabilities have observed compared with the pristine MS_(2) and BlueP.Metallic T-TiS_(2),T-MoS_(2),H(T)-VS_(2) and H(T)-NbS_(2) would retain the conductive character after formation of heterostructures with BlueP,however,HTiS_(2)/BlueP and H-MoS_(2)/BlueP would undergo a semiconductor to metallic transition accompanied by Na intercalation.Moreover,the presence of relatively low diffusion barriers ranging from 0.04 eV to 0.08 eV,coupled with the suitable average open-circuit voltage spanning from 0.12 eV to 0.89 eV,guarantee exceptional charge-discharge rates and ensure the safety of battery performance.Among these heterostructures,H(T)-NbS_(2)/BlueP and T-TiS_(2)/BlueP exhibit best Na adsorption ability of up to 4 layers,corresponding to theoretical capacities of 570.2 and 746.7 mAh/g,respectively.These encouraging properties indicate that T-TiS_(2)/BlueP and H(T)-NbS_(2)/BlueP could serve as suitable anode materials for high-performance sodiumion batteries.
基金the Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance,China(No.2020CX030101)the National Natural Science Foundation of China(No.42222209)the Scientific Research and Technological Development Program of CNPC,China(No.2023ZZ0801).
文摘Pore structure characteristics,gas content,and micro-scale gas occurrence mechanisms were investigated in the Shan_(2)^(3)sub-member marine-continental transitional shale of the southeastern margin of the Ordos Basin using scanning electron microscope images,lowtemperature N_(2)/CO_(2)adsorption and high-pressure mercury intrusion,methane isothermal adsorption experiments,and CH4-saturated nuclear magnetic resonance(NMR).Two distinct shale types were identified:organic pore-rich shale(Type OP)and microfracture-rich shale(Type M).The Type OP shale exhibited relatively well-developed organic matter pores,while the Type M shale was primarily characterized by a high degree of microfracture development.An experimental method combining methane isothermal adsorption on crushed samples and CH4-saturated NMR of plug samples was proposed to determine the adsorbed gas,free gas,and total gas content under high temperature and pressure conditions.There were four main research findings.(1)Marine-continental transitional shale exhibited substantial total gas content in situ,ranging from 2.58 to 5.73 cm^(3)/g,with an average of 4.35 cm^(3)/g.The adsorbed gas primarily resided in organic matter pores through micropore filling and multilayer adsorption,followed by multilayer adsorption in clay pores.(2)The changes in adsorbed and free pore volumes can be divided into four stages.Pores of<5 nm exclusively contain adsorbed gas,while those of 5-20 nm have a high proportion of adsorbed gas alongside free gas.Pores ranging from 20 to 100 nm have a high proportion of free gas and few adsorbed gas,while pores of>100 nm and microfractures are almost predominantly free gas.(3)The proportion of adsorbed gas in Type OP shale exceeds that in Type M,reaching 66%.(4)Methane adsorbed in Type OP shale demonstrates greater desorption capability,suggesting a potential for enhanced stable production,which finds support in existing production well data.However,it must be emphasized that high-gas-bearing intervals in both types present valuable opportunities for exploration and development.These data may support future model validations and enhance confidence in exploring and developing marine-continental transitional shale gas.
文摘Objective:To explore the application effect of continuous nursing in elderly patients with chronic diseases.Methods:A total of 100 elderly patients with chronic diseases were selected and randomly divided into experimental group and control group,50 cases in each group.Patients in the experimental group received continuous nursing,while patients in the control group received routine nursing.Comparison of two groups of patients’quality of life,health and nursing satisfaction.Results:the patient’s quality of life,health and nursing satisfaction were significantly higher than control group(p<0.05).Conclusion:Continuous nursing has a significant application effect in elderly patients with chronic diseases,which is worthy of further promotion and application.
文摘Objective： To investigate the expressions of cytokeratin 19 （CK19） and cytokeratin 20 （CK20） in bladder transitional cell carcinoma （TCC） and their clinical significance. Methods： The expression of CK19 and CK20 was detected in 54 cases of TCC by immunohistochemical methods and image processing techniques. Results： The expression of CK19 and CK20 was significantly stronger in the recurrent group than in the non-recurrent group （P〈0.01, P〈0.001, respectively）. Conclusion： The expression of CK19 and CK20 was obviously related with biological behaviors of TCC, suggesting that CK19 and CK20 could be used to predict the recurrence of TCC.
基金National Natural Science Foundation of China (50806045)
文摘This article describes an experimental study on friction and heat transfer performances of a transitional airflow in a rectangular channel with stagger-arrayed short pin fins. Friction factors, average Nusselt numbers and overall thermal performances of the transitional flow are obtained. The experimental study has showed that the pin fins enhance the heat transfer performance sig- nificantly, however increasing the flow frictional resistance considerably. After comparing the experimental results with the p...
基金Under the auspices of the National Science Foundation for Distinguished Young Scholars(No.42425107)the Science and Technology Project of Gansu Province(No.24JRRA168,23ZDKA017)+1 种基金the Key Talent Project in Gansu Province(No.2025RCXM057)National Nature Science Foundation of China(No.42107063)。
文摘In this study,we systematically explored the environmental significance of stable isotope characteristics and the controlling factors of precipitation stable isotopes in the source region of the Three Rivers(SRTR),the transitional zone of the Qinghai-Tibet Plateau in China.A total of 862 precipitation samples were collected from six fixed-point sampling locations between 2019 and 2021 in the SRTR.In June,the values of hydrogen(δD)and oxygen(δ^(18)O)stable isotopes were most enriched.The deuterium-excess(d-excess)in atmospheric precipitation was>0 in the SRTR;however,the maximum value of d-excess occurred in October.Moreover,the slopes of the local meteoric water line(LMWL)for Dari,Zaduo,Maduo,Qumalai,and Tuotuohe sites were lower than those of the global met-eoric water line(GMWL).In contrast,the slope of the LMWL for Zhimenda was higher than that of the GMWL.The altitude effects of oxygen(δ^(18)O)and hydrogen(δD)isotopes of precipitation were 0.70‰/100 m and 5.22‰/100 m,respectively.When the temperature was≤5℃,there was a significant temperature effect on stable oxygen isotope of precipitation(0.24‰/℃,P<0.05).Furthermore,even a minor increase(1%)in the weight of raindrops after falling results in a 0.82%rise in the evaporation enrichment rate ofδ^(18)O.Success-ive precipitation events also had a substantial influence on precipitation in the transitional region of the Qinghai-Tibet Plateau.The res-ults of this study provide a theoretical basis for revealing the impact mechanism of precipitation in the transitional zone of the Qinghai-Tibet Plateau under a warming climate.
文摘Objective： To explore the expression of anti-oncogene PTEN in bladder transitional cell carcinoma and its clinical significance. Methods： Using immunohistochemical S-P methods, the expression of PTEN gene was detected in 62 specimens of bladder cancer and 18 specimens of normal bladder tissue. Results： In the 62 bladder cancers, the positive rate of PTEN was 53.2% （33/62）. All 18 normal bladder tissues were positive for the PTEN expression. The expression of PTEN was negatively correlated to tumor grades （P〈0.05）. Conclusion： The reduced expression of PETN might play an important role in carcinogenesis and progression of bladder cancer. Detection of PTEN might be useful for judgement of tumor development and prognosis.
基金the National Natural Science Foundation of China(No.30672109).
文摘This study was designed to investigate the different involvements of prostatic stromal cells from the normal transitional zone(TZ)or peripheral zone(PZ)in the carcinogenesis of prostate cancer(PCa)epithelial cells(PC-3)in vitro and in vivo co-culture models.Ultra-structures and gene expression profiles of primary cultures of human prostatic stromal cells from the normal TZ or PZ were analyzed by electron microscopy and microarray analysis.In vitro and in vivo co-culture models composed of normal TZ or PZ stromal cells and human PCa PC-3 cells were established.We assessed tumor growth and weight in the in vivo nude mice model.There are morphological and ultra-structural differences in stromal cells from TZ and PZ of the normal prostate.In all,514 differentially expressed genes were selected by microarray analysis;483 genes were more highly expressed in stromal cells from TZ and 31 were more highly expressed in those from PZ.Co-culture with PZ stromal cells and transforming growth factor-β1(TGF-β1)increased the tumor growth of PC-3 cells in vitro and in vivo,as well as Bcl-2 expression.On the other hand,stromal cells of TZ suppressed PC-3 cell tumor growth in the mouse model.We conclude that ultra-structures and gene expression differ between the stromal cells from TZ or PZ of the normal prostate,and stroma-epithelium interactions from TZ or PZ might be responsible for the distinct zonal localization of prostate tumor formation.
基金We would like to thank the National Key R&D program of China(No.2017YFE0103600)the National Natural Science Foundation of China(Nos.41830431,41672139)the China National Science and Technology Major Projects(No.2016ZX05034002-003)for financial assistance to this research.
文摘Organic matter(OM)nanopores developed in transitional facies shales,i.e.,the Upper Permian Longtan and Dalong Formations in the Yangtze Platform,China,were investigated to determine the corre-sponding influence of thermal maturity and OM types within the geological conditions.A suite of 16 core samples were taken from Type-Ⅲ Longtan shales and Type-Ⅱ Dalong shales from two wells covering a ma-turity(Ro,vitrinite reflectance)ranging from 1.22%to 1.43%and 2.62%to 2.97%,respectively.Integrated analysis of the shale samples was carried out,including field-emission scanning electron microscopy(FESEM),low-pressure N2 and CO2 adsorption,high-pressure CH4 adsorption,and mercury intrusion capillary pressure(MICP)analysis.The fluid inclusions of liquid and gas hydrocarbons trapped in calcite vein samples in Dalong shales of two wells were studied using laser Raman and fluorescence spectroscopy.FE-SEM images indicated that OM pores in different formations varied substantially in terms of shape,size,and distribution density.OM pores in Type-Ⅱ Dalong shales of Well XY1 were mainly micropore,sparsely distributed in the gas-prone kerogen with a spot-like and irregular shape,while bitumen rarely developed observable pores.In contrast,the morphology of OM pores in Type-Ⅲ Longtan shales were significantly different,which was due to differences in the OM type.The primary OM pores in some terrestrial woody debris in Longtan shales had a relatively larger pore diameter,ranging from hundreds of nanometers to a few micrometers and were al-most all rounded in shape,which might be one of the factors contributing to larger pore volume and gas adsorption capacity than Dalong shales of Well XY1.Comparing Dalong shales of Well XY1 with relatively lower thermal maturity,there were abundant spongy-like pores,densely developed in the pyrobitumen in Type-Ⅱ Dalong shales of Well EY1,with an irregular shape and diameter ranging from several to hundreds of nanometers.Many blue fluorescent oil inclusions and a small number of CH4 inclusions mixed with C2H6 could be observed within calcite veins in Dalong shales of Well XY1,whereas only CH4 inclusions could be identified within calcite veins in Dalong shales of Well EJ1.Therefore,thermal maturity not only controlled the type of hydrocarbons generated,but also makes a significant contribution to the formation of OM pores,resulting in larger pore volumes and adsorption capacity of Type-Ⅱ shale samples in the dry gas window.
基金supports of the National Natural Science Foundation of China (No. 51575449)Research Fund of the State Key Laboratory of Solidification Processing (NWPU) of China (No. 104-QP2014)+1 种基金the 111 Project (No. B08040)the Fundamental Research Funds for the Central Universities (3102015AX004)
文摘Avoiding the folding defect and improving the die filling capability in the transitional region are desired in isothermal local loading forming of a large-scale Ti-alloy rib-web component（LTRC）. To achieve a high-precision LTRC, the folding evolution and die filling process in the transitional region were investigated by 3 D finite element simulation and experiment using an equal-thickness billet（ETB）. It is found that the initial volume distribution in the second-loading region can greatly affect the amount of material transferred into the first-loading region during the second-loading step, and thus lead to the folding defect. Besides, an improper initial volume distribution results in non-concurrent die filling in the cavities of ribs after the second-loading step, and then causes die underfilling. To this end, an unequal-thickness billet（UTB） was employed with the initial volume distribution optimized by the response surface method（RSM）. For a certain eigenstructure, the critical value of the percentage of transferred material determined by the ETB was taken as a constraint condition for avoiding the folding defect in the UTB optimization process,and the die underfilling rate was considered as the optimization objective. Then, based on the RSM models of the percentage of transferred material and the die underfilling rate, non-folding parameter combinations and optimum die filling were achieved. Lastly, an optimized UTB was obtained and verified by the simulation and experiment.
基金supported by the National Natural Science Foundation of China (Nos.GZ 1280, 11722215 and 11721202)supported by the National Research Foundation of Korea (NRF) grant with funding from the Korean government (MSIT) (No.2011-0030013, No.2018R1A2B2007117)
文摘This research examines the vortex behaviors and aerodynamic forces in dynamic stall phenomena at a transitional Reynolds number(Re=90000)using experimental and numerical approaches.Periodic sinusoidal pitching motion at two different reduced frequencies is used to achieve the dynamic stall of a NACA 0012 airfoil.Several leading edge vortices form and detach in the dynamic stall stage.The flow then quickly transitions to a full separation zone in the stall stage when the angle of attack starts to decrease.There is discrepancy between the phaseaveraged and instantaneous flow field in that the small flow structures increased with angle of attack,which is a characteristic of the flow field at the transitional Reynolds number.The interaction between the streamwise vortices in the three-dimensional numerical results and the leading edge vortex are the main contribution to the turbulent flow.In addition,the leading edge vortex that supplies vortex lift is more stable at higher reduced frequency,which decreases the lift fluctuation in the dynamic stall stage.The leading edge vortex at higher reduced frequency is strong enough to stabilize the flow,even when the airfoil is in the down-stroke phase.
基金support from the National Science and Technology Major Project of China (Grant No. 2016ZX05034)
文摘Based on 10 shale samples collected from 4 wells in Qinshui Basin,we investigate the full-sized pore structure and fractal characteristics of Marine-Continental transitional shale by performing organic geochemistry,mineralogical composition,Nitrogen gas adsorption(N2 adsorption)and Nuclear Magnetic Resonance(NMR)measurements and fractal analysis.Results show that the TOC content of the shale samples is relatively high,with an average value of 2.44wt%,and the thermal evolution is during the mature-over mature stage.The NMR T2 spectrum can be used to characterize the fullsized pore structure characteristics of shale.By combining N2 adsorption pore structure parameters and NMR T2 spectrums,the surface relaxivity of samples are calculated to be between 1.7877 um/s and 5.2272 um/s.On this basis,the T2 spectrums are converted to full-sized pore volume and surface area distribution curves.The statistics show that the pore volume is mainly provided by mesopore,followed by micropore,and the average percentages are 65.04%and 30.83%respectively;the surface area is mainly provided by micropore,followed by mesopore,and the average percentages are 60.8004%and 39.137%respectively;macropore contributes little to pore volume and surface area.The pore structure characteristics of shale have no relationship with TOC,but strong relationships with clay minerals content.NMR fractal dimensions Dmicro and Dmeso have strong positive relationships with the N2 adsorption fractal dimensions D1 and D2 respectively,indicating that Dmicro can be used to characterize the fractal characteristics of pore surface,and Dmeso can be used to characterize the fractal characteristics of pore structure.The shale surface relaxivity is controlled by multiple factors.The increasing of clay mineral content,pore surface area,pore surface fractal dimension and the decreasing of average pore size,will all lead to the decreasing of shale surface relaxivity.
文摘Background:The Transitional Care Model(TCM)for nursing care has yet to be implemented in China despite its success in Western countries.However,rapid social changes have demanded an upgrade in the quality of nursing care;in 2010,the Chinese government has acknowledged the need to implement the TCM in China.Objective:This study has the following objectives:(1)perform a thorough review of the literature regarding the development and implementation of the TCM in China's Mainland within the past 5 years;(2)provide a comprehensive discussion of the current status,problems,and strategies related to the implementation of the TCM in China's Mainland;and(3)suggest strategies pertaining to the future of the TCM in China.Design:The current pertinent literature is systematically reviewed.Data sources:Systematic and manual searches in computerized databases for relevant studies regarding the TCM led to the inclusion of 26 papers in this review.Review methods:Abstracts that satisfied the inclusion criteria were reviewed independently by the two authors of this manuscript,and discrepancies were resolved through discussion.The same reviewers independently assessed the paper in its entirety for selected abstracts.Results:The present English literature reviewrevealed a paucity of updated information about the development and implementation of the TCM in China's Mainland.Nevertheless,the dramatic growth of the TCM in the past 5 years has had a vital impact within the society and in nursing development.This review also revealed numerous issues regarding the focus of the TCM.Overall implications for practiceandrecommendations for future researchare discussed.Conclusion:Despite the potential of this nursing model to have a successful and beneficial impact in China's Mainland,it remains an under-researched topic.Further research on education and training as well as premium policies for nurses under the TCM are needed.
文摘The evolution of shale reservoirs is mainly related to two functions:mechanical compaction controlled by ground stress and chemical compaction controlled by thermal effect.Thermal simulation experiments were conducted to simulate the chemical compaction of marine-continental transitional shale,and X-ray diffraction(XRD),CO2 adsorption,N2 adsorption and high-pressure mercury injection(MIP)were then used to characterize shale diagenesis and porosity.Moreover,simulations of mechanical compaction adhering to mathematical models were performed,and a shale compaction model was proposed considering clay content and kaolinite proportions.The advantage of this model is that the change in shale compressibility,which is caused by the transformation of clay minerals during thermal evolution,may be considered.The combination of the thermal simulation and compaction model may depict the interactions between chemical and mechanical compaction.Such interactions may then express the pore evolution of shale in actual conditions of formation.Accordingly,the obtained results demonstrated that shales having low kaolinite possess higher porosity at the same burial depth and clay mineral content,proving that other clay minerals such as illite-smectite mixed layers(I/S)and illite are conducive to the development of pores.Shales possessing a high clay mineral content have a higher porosity in shallow layers(<3500 m)and a lower porosity in deep layers(>3500 m).Both the amount and location of the increase in porosity differ at different geothermal gradients.High geothermal gradients favor the preservation of high porosity in shale at an appropriate Ro.The pore evolution of the marine-continental transitional shale is divided into five stages.Stage 2 possesses an Ro of 1.0%-1.6%and has high porosity along with a high specific surface area.Stage 3 has an Ro of 1.6%-2.0%and contains a higher porosity with a low specific surface area.Finally,Stage 4 has an Ro of 2.0%-2.9%with a low porosity and high specific surface area.
基金The project was supported by a grant from National Natural Sciences Foundation of China (No. 30571858).
文摘The expression of KAI1/CD82 and MRP-1/CD9 in transitional cell carcinoma of bladder （TCCB） and its clinical significance were investigated. Immunohistochemistry was used to detect KAI1/CD82 and MRP-1/CD9 protein expression in 52 TCCB specimens. Correlation between the expression of KAI1/CD82 and MRP-1/CD9 to clinicopathologic factors was statistically analyzed. The results showed that the positive rate of KAI1/CD82 and MRP-1/CD9 in TCCB was 50% and 61.5%, respectively. The MRP-1/CD9 and KAI1/CD82 expression was significantly associated with grade of TCCB （P〈0.05）, but no correlation was found between MRP-1/CD9 or KAI1/CD82 expression and clinical stage of TCCB （P〉0.05）. The expression level of MRP-1/CD9 and KAI1/CD82 in recurrent TCCB samples was lower than that in non-recurrent samples （P〈0.05）. Meanwhile, the correlation between the KAI1/CD82 expression and MRP-1/CD9 expression was statistically significant （r=0.316, P〈0.05）. It was concluded that KAI1/CD82 and MRP-1/CD9 expression may be important prognostic indicators and potentially useful for assessing the biological behavior of TCCB.
文摘AIM: To evaluate two simple angle measurements for predicting lumbosacral transitional vertebra (LSTV) in magnetic resonance imaging (MRI) studies of the spine. METHODS: The lumbar spine MRI studies of 50 subjects with LSTV and 50 subjects with normal lumbosacral anatomy were retrospectively evaluated. In each study, the mid-sagittal T2-weighted image was used to measure the angle formed by a line parallel to the superior surface of the sacrum and a line perpendicular to the axis of the scan table (A-angle), as well as the angle formed by a line parallel to the superior endplate of the L3 vertebra and a line parallel to the superior surface of the sacrum (B-angle). RESULTS: The total study population consisted of 100 subjects (46 males, 54 females, 51 ± 16 years old). There were no differences in age and sex between the two groups. Both A-angle and B-angle were significantly increased in subjects with LSTV compared to controls (P < 0.05). The optimal cut-off values of A-angle and B-angle for the prediction of LSTV were 39.8° (sensitivity = 80%, specificity = 80%, accuracy = 83%; 95% confidence interval = 74%-89%, P = 0.0001) and 35.9° (sensitivity = 80%, specificity = 54%, accuracy = 69%; 95% confidence interval = 59%-78%, P = 0.0005), respectively. CONCLUSION: On sagittal MR images of the lumbar spine, an increased A-angle and/or B-angle should alert the radiologist to the presence of LSTV.
基金China National Science and Technology Major Project(2017ZX05035).
文摘Based on core description,thin section identification,X-ray diffraction analysis,scanning electron microscopy,low-temperature gas adsorption and high-pressure mercury intrusion porosimetry,the shale lithofacies of Shan23 sub-member of Permian Shanxi Formation in the east margin of Ordos Basin was systematically analyzed in this study.The Shan23 sub-member has six lithofacies,namely,low TOC clay shale(C-L),low TOC siliceous shale(S-L),medium TOC siliceous shale(S-M),medium TOC hybrid shale(M-M),high TOC siliceous shale(S-H),and high TOC clay shale(C-H).Among them,S-H is the best lithofacies,S-M and M-M are the second best.The C-L and C-H lithofacies,mainly found in the upper part of Shan23 sub-member,generally developed in tide-dominated delta facies;the S-L,S-M,S-H and M-M shales occurring in the lower part of Shan23 sub-member developed in tide-dominated estuarine bay facies.The S-H,S-M and M-M shales have good pore struc-ture and largely organic matter pores and mineral interparticle pores,including interlayer pore in clay minerals,pyrite inter-crystalline pore,and mineral dissolution pore.C-L and S-L shales have mainly mineral interparticle pores and clay mineral in-terlayer pores,and a small amount of organic matter pores,showing poorer pore structure.The C-H shale has organic mi-cro-pores and a small number of interlayer fissures of clay minerals,showing good micro-pore structure,and poor meso-pore and macro-pore structure.The formation of favorable lithofacies is jointly controlled by depositional environment and diagen-esis.Shallow bay-lagoon depositional environment is conducive to the formation of type II2 kerogen which can produce a large number of organic cellular pores.Besides,the rich biogenic silica is conducive to the preservation of primary pores and en-hances the fracability of the shale reservoir.
基金Under the auspices of China Global Change Research Program(No.2010CB950103)National Natural Science Foundation of China(No.40901099)
文摘Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential suitable agriculture area in the farming-grazing transitional zone in the northeastern China during the 20th century. Based on modem weather data, 1 km-resolution land cover data, historical climatic time series, and estimation by using similar historical climatic scenes, the following was concluded： 1） The climate conditions of suitable agriculture areas in the farming-grazing transitional zone in the northeastern China between 1971 and 2000 required an average annual temperature above 1℃ or ≥ 0℃ accumulated temperature above 2500℃-2700℃, and annual precipitation above 350 mm. 2） The northern boundary of the potential suitable agriculture area during the relatively warmer period of 1890-1910 was approximately located at the position of the 1961-2000 area. The northern boundary shifted back to the south by 75 km on average during the colder period of the earlier 20th century, whereas during the modem warm period of the 1990s, the area shifted north by 100 km on average. 3） The western and eastern boundaries of the suitable agricul^re area during the heaviest drought periods between 1920s and 1930s had shifted northeast by 250 km and 125 km, respectively, contrasting to the boundaries of 1951-2008. For the wettest period, that is, the 1890s to the 1910s, the shift of western and eastern boundaries was to the southwest by 125 km and 200 km, respectively, compared with that in the 1951-2008 period. This study serves as a reference for identifying a climatically sensitive area and planning future land use and agricultural production in the study area.
基金This study was supported by Natural Science Foundation of Guangdong Province,China(Project No.07001681).
文摘Objectives:To observe the effects of transitional care on the quality of life of chronic obstructive pulmonary disease(COPD)patients.Methods:A total of 114 COPD patients were recruited from the First Affiliated Hospital,Sun Yat-sen University,Guangzhou,China and divided equally into an intervention group and control group.Following discharge,patients from the intervention group recieved threemonths intervention in addition to regular nursing care,while control group patients received regular nursing care only.Patients’quality of life was measured using the St.George’s respiratory questionnaire(SGRQ),the 12-item General Health Questionnaire(GHQ-12)and body mass index(BMI).Results:The symptoms section score,the activity section score,the impacts section score,the total score and the rate of mental disorders were significantly changed after the intervention while there was no statistical difference in BMI between groups.Conclusions:Transitional care can improve health-related quality of life in COPD patients who have recently suffered an exacerbation.
基金funded by the National Natural Science Foundation of China(41930651,41971226,41871357)Science and Technology Service Network Program(STS)Project of Chinese Academy of Sciences(Y8R2020022)。
文摘"Hu Huan-yong Line(Hu Line)"depicts a geographical pattern of China’s population distribution.Its essence is the regionality of humanland relationship and reflects basic characteristics and laws of human beings’adaptation to the natural environment.With the development of the times and the progress of modern science and technology,especially the rapid urbanization and construction of transportation network system in China,the connection between economic and geographical space has been continuously strengthened.The geographical transition zones from mountain areas to plains,i.e.,transitional geographical space,have promoted the changes in human-land relationships through population migration and agglomeration.Taking Sichuan-Yunnan provinces at the southern end of Hu Line as study area,this study analyzed the spatial correlation between population distribution and economy in this region,explored the pattern of geographical agglomeration and deagglomeration,and explained the changing characteristics of humanland relationship in transitional geographic space using global Moran’s I index,global regression model(GRM)and geographically weighted regression(GWR).The results show that population and Gross Domestic Product(GDP)have significant spatial dependence to this region,with obvious aggregation in geographical distribution and positive autocorrelation;comparing with the general least square model,the GWR model incorporating spatial effect was more suitable for revealing the distribution characteristics of geographical elements,with fine results and better fitting;the spatial model of population and GDP as well as the spatio-temporal evolution model of their changes,all of them strongly indicated that Normalized Difference Vegetation Index(NDVI)and road density were important factors governing the spatial differentiation of population and economy;under the rapid development of regional economy and continuous evolution of urban-rural relations,rural transformation and spatial reconstruction promoted the change of population migration and agglomeration.
