China established Xiong’an New Area in Hebei Province in 2017,which is planned to accommodate about 5 million people,aiming to relieve Beijing City of the functions non-essential to its role as China’s capital and t...China established Xiong’an New Area in Hebei Province in 2017,which is planned to accommodate about 5 million people,aiming to relieve Beijing City of the functions non-essential to its role as China’s capital and to expedite the coordinated development of the Beijing-Tianjin-Hebei region.From 2017 to 2021,the China Geological Survey(CGS)took the lead in multi-factor urban geological surveys involving space,resources,environments,and disasters according to the general requirements of“global vision,international standards,distinctive Chinese features,and future-oriented goals”in Xiong’an New Area,identifying the engineering geologic conditions and geologic environmental challenges of this area.The achievements also include a 3D engineering geological structure model for the whole area,along with“one city proper and five clusters”,insights into the ecology and the background endowment of natural resources like land,geothermal resources,groundwater,and wetland of the area before engineering construction,a comprehensive monitoring network of resources and environments in the area,and the“Transparent Xiong’an”geological information platform that is open,shared,dynamically updated,and three-dimensionally visualized.China’s geologists and urban geology have played a significant role in the urban planning and construction of Xiong’an New Area,providing whole-process geological solutions for urban planning,construction,operation and management.The future urban construction of Xiong’an New Area will necessitate the theoretical and technical support of earth system science(ESS)from various aspects,and the purpose is to enhance the resilience of the new type of city and to provide support for the green,low-carbon,and sustainable development of this area.展开更多
Objective:To evaluate the feasibility,safety and efficacy of transcathcter closure of ventricular septal defect(VSD)in patients with aortic valve prolapse(AVP)and mild aortic regurgitation(AR).Methods:Between January ...Objective:To evaluate the feasibility,safety and efficacy of transcathcter closure of ventricular septal defect(VSD)in patients with aortic valve prolapse(AVP)and mild aortic regurgitation(AR).Methods:Between January 2008 and July 2014,transcatheter closure of VSD was attempted in 65 patients.Results:The total intermediate closure successful rate in all subjects was 96.9%.During the perioperative period,no death,major bleeding,pericardial tamponade,occluder dislodgement,residual shunt or hemolysis occurred.Two procedures had been forced to suspend due to significant aggregation of device related aortic regurgitation,three cases of transient complete left bundle branch block occurred but did not sustain.At 1-year followup,no patients had residual shunts and complications.Furthermore,grade of residual AR were relieved in 61.9%(39/63)cases and degree of AVP were ameliorated in 36.5%(23/63)patients;Conclusions:Transcatheter closure VSD in selected patients with AVP and mild AR is technically feasible and highly effective.Long term safety and efficacy needs to be assessed.展开更多
AIM To identify and assess the research situation of top 100 cited articles in nonalcoholic fatty liver disease(NAFl D).METHODS The global scientific research articles in the science Citation Index-Expanded relevant t...AIM To identify and assess the research situation of top 100 cited articles in nonalcoholic fatty liver disease(NAFl D).METHODS The global scientific research articles in the science Citation Index-Expanded relevant to NAFl D were retrieved and listed according to their citation times from the most to the least. The 100 most frequently cited original articles were selected to systematically evaluate their bibliometric parameters including times cited, publication year, journals, subject categories, and the highly related concepts of NAFl D, which reflected the history and current situation, publication distribution of leading countries and institutes as well as the research hotspots of NAFl D.RESULTS Top 100 cited articles in NAFl D were published from 1965 to 2015 with a citation ranging of 227 to 2151 times since publication, in which the United states was the most predominant country and Mayo Clin was the most productive institution. The majority of the top 100 cited articles were concentrated in s CI subject category of Gastroenterology and Hepatology. Hepatology and Gastroenterology is the top journal that published over half 100 top-cited articles. The significant peak of top cited articles present in the first half of the 2000 s while the highest mean number of citation presents in first half of the 1980 s. In addition, concepts related to pathology characteristics, epidemiology and medicalization, metabolic syndrome and its combination of symptoms including insulin resistance, biomarkersof lipid metabolism and obesity are listed as the highly related concepts.CONCLUSION The 100 top-cited articles marked with the leading countries, institutions, journals, hotspots and development trend in NAFl D field that could provide the foundation for further investigations.展开更多
ZnO-modified (Li, Na, K)NbO3 lead-free ceramics with a nominal composition of Li0.06(Na0.535K0.48)0.94NbO3+0.7mol% ZnO (LNKN-ZT) was synthesized normally at 930-1000℃. The Zn ions incorporated into the A-site at a hi...ZnO-modified (Li, Na, K)NbO3 lead-free ceramics with a nominal composition of Li0.06(Na0.535K0.48)0.94NbO3+0.7mol% ZnO (LNKN-ZT) was synthesized normally at 930-1000℃. The Zn ions incorporated into the A-site at a higher sintering temperaVare, which changed LNKN-Z7 to soft piezoelectric ceramics with the mechanical quality factor decreasing from 228 to 192. A phase transition from tetragonal to orthorhombic symmetry was identified by XRD analysis, and the corresponding calculation of lattice parameters was conducted at 970-980℃. Because of such transitional behavior and fine microstructure, the optimized values of piezoelectric coefficient, planar electromechanical coupling coefficient, and relative dielectric constant were obtained.展开更多
MgO-modified Li0.06(Na0.5K0.5)0.94NbO3O3 (L6NKN) lead-free piezoelectric ceramics were synthesized by normal sintering at a rela- tively low temperature of 1000℃. The crystalline phase, microstructure, and electr...MgO-modified Li0.06(Na0.5K0.5)0.94NbO3O3 (L6NKN) lead-free piezoelectric ceramics were synthesized by normal sintering at a rela- tively low temperature of 1000℃. The crystalline phase, microstructure, and electrical properties of the ceramics were investigated with a special emphasis on the influence of MgO content. The addition of MgO effectively improves the sintembility of the L6NKN ceramics. X-my diffr cfion analysis indicates that the morphotropic phase boundary (MPB) separating orthorhombic and tetragonal phases for the ceramics lies in the range of Mg doping content (x) from 0.3at% to 0.7at%. High electrical properties of the piezoelectric constant (d33=238 pC/N), planar electromechanical coupling coefficient (kp=41.5%), relative dielectric constant (εr=905), and remanent polarization (Pr=38.3 μC/cm2) are obtained from the specimen with x=0.5at%, which suggests that the Li0.06(Na0.5K0.5)0.94Nb(1-2x/5)MgxO3 (x=0.5at%) ceramic is a promising lead-free piezoelectric material.展开更多
BACKGROUND Syphilis is a chronic,classic sexually transmitted disease caused by Treponema pallidum,which can invade almost all organs of the body and produce various symptoms and signs.Although there are some cases of...BACKGROUND Syphilis is a chronic,classic sexually transmitted disease caused by Treponema pallidum,which can invade almost all organs of the body and produce various symptoms and signs.Although there are some cases of colorectal bleeding caused by syphilis,small intestinal bleeding caused by syphilis is still rare.CASE SUMMARY A 58-year-old man had experienced recurrent abdominal pain and melena for 3 years.Repeated gastroenteroscopy and computed tomography angiography examinations failed to find bleeding lesions.During the same admission,multiple intestinal ulcers were found by capsule endoscopy,and syphilis was also diagnosed.With a history of atrial fibrillation and chronic pancreatitis,he had undergone mitral valve replacement and tricuspid valvuloplasty for valvular heart disease.After anti-syphilis treatment,the melena and abdominal pain disappeared and his hemoglobin gradually increased.It is considered that gastrointestinal bleeding,chronic pancreatitis,atrial fibrillation,and heart valvular disease may have been caused by syphilis.CONCLUSION This case report found that syphilis can mimic systemic disease and cause intestinal bleeding.In addition,treatment of the disease requires both sexual partners to be treated.Finally,although syphilis is easy to treat,it is more important to consider that bleeding could be caused by syphilis.展开更多
To investigate the overall damage characteristics and failure modes of a warship subjected to an underwater non-contact near-field explosion,a hull girder with a trapezoidal cross-section was designed,manufactured,and...To investigate the overall damage characteristics and failure modes of a warship subjected to an underwater non-contact near-field explosion,a hull girder with a trapezoidal cross-section was designed,manufactured,and tested.The design criteria and parameters were determined according to the similarity criterion.Dynamic responses of the girder freely floating on water were obtained under varying conditions,including stand-off distance,charge mass,and position of attack.Damage morphologies of the girder model were obtained.Based on our analysis,basic conditions for sagging damage of the hull girder are proposed.The aim of this study was to determine an efficient method of attack resulting in the most severe damage to the ship hull.The experimental results show that the girder mainly exhibits a first-order response when the first wet frequency of the girder is close to the frequency of the explosion bubble pulsation.The largest deformation was observed when the underwater explosion occurred directly below the midspan of the girder compared to other explosions of the same intensity at different attack positions.When the ratio of stand-off to maximum bubble radius(λ)satisfies 0.7≤λ<2,the bubble mainly causes sagging damage instead of hogging.Asλdecreases(1≤λ<2),the sagging damage increases under the same charge mass.However,asλdecreases further(0.7≤λ<1),the sagging deformation decreases.This is likely due to the impact of the liquid jet formed by the collapsing bubble,which causes the girder deformation to shift from sagging back to hogging deformation.The initial shock wave excites the high-frequency response of the girder structure but contributes very little to the overall velocity and displacement.However,bubble pulsation typically causes a low-frequency response,which will affect the velocity and displacement of the girder.The low-pressure region of the flow field formed by bubble pulsation and resonant coupling between the girder and the bubble are the predominant causes of damage to the overall girder structure.展开更多
BACKGROUND A few reports have revealed induction of rhabdomyolysis by a red yeast rice(RYR)supplement or by RYR in combination with abiraterone(an androgen biosynthesis inhibitor).CASE SUMMARY A 76-year-old man presen...BACKGROUND A few reports have revealed induction of rhabdomyolysis by a red yeast rice(RYR)supplement or by RYR in combination with abiraterone(an androgen biosynthesis inhibitor).CASE SUMMARY A 76-year-old man presented with progressive limb weakness,muscle soreness,and acute kidney injury(AKI).He had been taking the anti-prostate cancer drug abiraterone for 14 mo and had added a RYR supplement 3 mo before symptom onset.After being diagnosed with rhabdomyolysis-induced AKI,the patient discontinued these drugs and responded well to hemodialysis and hemoperfusion.After 23 d of treatment,creatine kinase levels returned to normal and serum creatinine levels decreased.CONCLUSION We speculate that statins,the main lipid-lowering component of RYR,or a combination of statins and abiraterone,will increase the risk of rhabdomyolysis.展开更多
The Closeby Habitable Exoplanet Survey(CHES) mission is proposed to discover habitable-zone Earth-like planets of nearby solar-type stars(~10 pc away from our solar system) via microarcsecond relative astrometry.The m...The Closeby Habitable Exoplanet Survey(CHES) mission is proposed to discover habitable-zone Earth-like planets of nearby solar-type stars(~10 pc away from our solar system) via microarcsecond relative astrometry.The major scientific objectives of CHES are:to search for Earth Twins or terrestrial planets in habitable zones orbiting100 FGK nearby stars;further to conduct a comprehensive survey and extensively characterize nearby planetary systems.The primary payload is a high-quality,low-distortion,high-stability telescope.The optical subsystem is a coaxial three-mirror anastigmat(TMA) with a 1.2 m-aperture,0°.44 × 0°.44 field of view and 500 nm-900 nm working wave band.The camera focal plane is composed of a mosaic of 81 scientific CMOS detectors each with4 k × 4 k pixels.The heterodyne laser interferometric calibration technology is employed to ensure microarcsecond level(1 μas) relative astrometry precision to meet the requirements for detection of Earth-like planets.The CHES satellite operates at the Sun-Earth L2 point and observes all the target stars for 5 yr.CHES will offer the first direct measurements of true masses and inclinations of Earth Twins and super-Earths orbiting our neighbor stars based on microarcsecond astrometry from space.This will definitely enhance our understanding of the formation of diverse nearby planetary systems and the emergence of other worlds for solar-type stars,and finally provide insights to the evolution of our own solar system.展开更多
The groundwater level has been continuously decreasing due to climate change and long-time overexploitation in the Xiong’an New Area,North China,which caused the enhanced mixing of groundwater in different aquifers a...The groundwater level has been continuously decreasing due to climate change and long-time overexploitation in the Xiong’an New Area,North China,which caused the enhanced mixing of groundwater in different aquifers and significant changes in regional groundwater chemistry characteristics.In this study,groundwater and sediment pore-water in drilling cores obtained from a 600 m borehole were investigated to evaluate hydrogeochemical processes in shallow and deep aquifers and paleo-environmental evolution in the past ca.3.10 Ma.Results showed that there was no obvious change overall in chemical composition along the direction of groundwater runoff,but different hydrochemical processes occurred in shallow and deep groundwater in the vertical direction.Shallow groundwater(<150 m)in the Xiong’an New Area was characterized by high salinity(TDS>1000 mg/L)and high concentrations of Mn and Fe,while deep groundwater had better water quality with lower salinity.The high TDS values mostly occurred in aquifers with depth<70 m and>500 m below land surface.Water isotopes showed that aquifer pore-water mostly originated from meteoric water under the influence of evaporation,and aquitard pore-water belonged to Paleo meteoric water.In addition,the evolution of the paleoclimate since 3.10 Ma BP was reconstructed,and four climate periods were determined by theδ18O profiles of pore-water and sporopollen records from sediments at different depths.It can be inferred that the Quaternary Pleistocene(0.78‒2.58 Ma BP)was dominated by the cold and dry climate of the glacial period,with three interglacial intervals of warm and humid climate.What’s more,this study demonstrates the possibilities of the applications of pore-water on the hydrogeochemical study and further supports the finding that pore-water could retain the feature of paleo-sedimentary water.展开更多
As a key technique in deep space navigation, radio interferometry can be used to determine the accurate location of a spacecraft in the plane-of-sky by measuring its signal propagation time delay between two remote st...As a key technique in deep space navigation, radio interferometry can be used to determine the accurate location of a spacecraft in the plane-of-sky by measuring its signal propagation time delay between two remote stations. To improve the measurement accuracy, differential phase delay without phase ambiguity is usually desired. Aiming at the difficulties of resolving phase ambiguity with few stations and narrowband downlink signals, a new method is proposed in this work by taking advantage of the Earth rotation. The high accurate differential phase delay between the spacecraft and a calibrator can be achieved not only in the in-beam observation mode but also in the out-of-beam observation mode. In this paper we firstly built the model of phase ambiguity resolution. Then, main measurement errors of the model are analyzed, which is followed by tests and validations of the model and method using the tracking data of the Cassini mission and Chang'E-3 mission. The results show that the phase ambiguities can be correctly resolved to generate a 10-picosecond level accuracy differential phase delay. Angular measurement accuracy of the Cassini reaches the milli-arc-second level, and the relative position accuracy between the Chang'E-3 rover and lander reaches the meter level.展开更多
The phase referencing Very Long Baseline Interferometry(VLBI)technique is a newly developed tool to measure the angular position of a deep space exploration probe in the plane-of-the-sky.Through alternating observatio...The phase referencing Very Long Baseline Interferometry(VLBI)technique is a newly developed tool to measure the angular position of a deep space exploration probe in the plane-of-the-sky.Through alternating observations between the probe and a nearby reference radio source,their accurate relative angular separation can be obtained from the radio images generated by this technique.To meet the requirements of the current orbit determination software,differential delay should be firstly derived from those radio images.A method to resolve the differential phase delay from the phase referencing VLBI technique is proposed in this paper,and as well the mathematical model for differential phase ambiguity resolution is established.This method is verified with practical measurement data from the Chang’E-3 mission.The differential phase delay between the Chang’E-3 lander and rover was derived from the phase referencing VLBI measurements,and was then imported into the Shanghai astronomical observatory Orbit Determination Program(SODP)to calculate the position of the rover relative to the lander on the lunar surface.The results are consistent with those acquired directly from radio images,indicating that the differential phase ambiguity has been correctly resolved.The proposed method can be used to promote applications of the phase referencing VLBI technique in future lunar or deep space explorations,and more accurate orbit determination becomes promising.展开更多
Background:Pyroptosis is the term for caspase-l-dependent cell death associated with pro-inflammatory cytokines.The role of alveolar macrophage (AM) pyroptosis in the pathogenesis of the acute lung injury and acute...Background:Pyroptosis is the term for caspase-l-dependent cell death associated with pro-inflammatory cytokines.The role of alveolar macrophage (AM) pyroptosis in the pathogenesis of the acute lung injury and acute respiratory distress syndrome (ALI/ARDS) remains unclear.Methods:C57BL/6 wild-type mice were assigned to sham,lipopolysaccharide (LPS) + vehicle,LPS + acetyl-tyrosyl-valyl-alanyl-aspartyl-chloromethylketone (Ac-YVAD-CMK) and LPS + Z-Asp-Glu-Val-Asp-fluoromethylketone groups.Mice were given intraperitoneal (IP) injections of LPS.Drugs were IP injected 1 h before LPS administration.Mice were sacrificed 16 h after LPS administration,and AMs were isolated.Western blot analysis for active caspase-1 and cleaved caspase-3,evaluation of lung injury and a cytokine release analysis were performed.AMs were treated with LPS and adenosine triphosphate (ATP);caspase-l-dependent cell death was evaluated using flow cytometry;the apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) pyroptosomes were examined by immunofluorescence.Results:The expression of activated caspase-1 in AMs was enhanced following LPS challenge compared with the sham group.In the ex vivo study,the caspase-1/propidium iodide-positive cells,caspase-1 specks and ASC pyroptosomes were up-regulated in AMs following LPS/ATP stimulation.The specific caspase-1 inhibitor Ac-YVAD-CMK inhibited the activation of caspase-1 and pyroptotic cell death.Ac-YVAD-CMK also reduced the lung injury,pulmonary edema and total protein in bronchoalveolar lavage fluid (BALF).In addition,Ac-YVAD-CMK significantly inhibited interleukin-β (IL-lβ) release both in serum and BALF and reduced the levels of IL-18,tumor necrosis factor-α (TNF-α),High Mobility Group Box 1 (HMGB1) in BALF during LPS-induced ALI/ARDS.Conclusions:This study reported AM pyroptosis during LPS-induced ALI/ARDS in mice and has demonstrated that Ac-YVAD-CMK can prevent AM-induced pyroptosis and lung injury.These preliminary findings may form the basis for further studies to evaluate this pathway as a target for prevention or reduction of ALI/ARDS.展开更多
Scaling, as the translation of information across spatial, temporal, and organizational scales, is essential to predictions and understanding in all sciences and has become a central issue in ecology. A large body of ...Scaling, as the translation of information across spatial, temporal, and organizational scales, is essential to predictions and understanding in all sciences and has become a central issue in ecology. A large body of theoretical and empirical evidence concerning allometric scaling in terrestrial individual plants and plant communities has been constructed around the fractal volume-filling theory of West, Brown, and Enquist (the WBE model). One of the most thought-provoking findings has been that the metabolic rates of plants, like those of animals, scale with their size as a 3/4 power law. The earliest, single most-important study cited in support of the application of the WBE model to terrestrial plants claims that whole-plant resource use in terrestrial plants scales as the 3/4 power of total mass, as predicted by the WBE model. However, in the present study we show that empirical data actually do not support such a claim. More recent studies cited as evidence for 3/4 scaling also suffer from several statistical and data-related problems. Using a forest biomass dataset including 1 266 plots of 17 main forest types across China, we explored the scaling exponents between tree productivity and tree mass and found no universal value across forest stands. We conclude that there is not sufficient evidence to support the existence of a single constant scaling exponent for the metabolism-biomass relationship for terrestrial plants.展开更多
The past few decades have seen a resurgence of Interest in biological allometry. Specifically, a number of recent studies has suggested a -4/3 Invariant scaling relationship between mass and density that Is universall...The past few decades have seen a resurgence of Interest in biological allometry. Specifically, a number of recent studies has suggested a -4/3 Invariant scaling relationship between mass and density that Is universally valid for tree-dominated communities, regardless of their phyietic affiliation or habitat. In the present study, we test this scaling relationship using a comprehensive forest biomass database, Including 1 266 plots of six blomes and 17 forest types across China. The present study shows that the scaling exponent of the massdensity relationship varies across different tree-dominated communities and habitats. This great variability In the scaling exponent makes any generalization unwarranted. Although Inappropriate regression methods can lead to flawed estimation of the scaling exponent, inconsistency of theoretical framework and empirical patterns may have undermined the validity of previous work.展开更多
The test of the Standard Model and search for New Physics signal are main aim of LHC experiment.With the increasing of the measurement accuracy at the LHC,it is a major task in future to exceed the current accuracy of...The test of the Standard Model and search for New Physics signal are main aim of LHC experiment.With the increasing of the measurement accuracy at the LHC,it is a major task in future to exceed the current accuracy of the theoretical predictions for important processes,in particular ones involving Higgs boson and top quark.In this review we briefly summarize some recent theoretical progress in Higgs boson and top quark physics,especially the fixed-order and resummation predictions in QCD at both the Tevatron and the LHC.展开更多
The tensile properties and deformation behavior of several cast Ni-based superalloys, respectively, in the equiaxed, columnar-crystal and single-crystal styles are comparatively studied. The effects of solidification ...The tensile properties and deformation behavior of several cast Ni-based superalloys, respectively, in the equiaxed, columnar-crystal and single-crystal styles are comparatively studied. The effects of solidification way, heat treatment and strain rate on the tensile properties are discussed in detail. It is found that the reduction of grain boundaries by the feasible solidification ways offers cast Ni-based superalloys the potential capability of improving the mechanical properties, the ultimate achievement of which is also confirmed to lie on the appropriate modifications of chemical composition and heat treatment. The prolongation of solid solution facilitates the precipitation of fine secondary γ' phase, whereas the extension of high-temperature aging leads to the coarsening of secondary γ' phase. The combination of these two aspects has a crucial influence on the tensile properties. Under tensile applied stress, the surface grains of DZ-A alloy deform slightly, while the inner grains deform heavily. This deformation inhomogeneity is ascribed to the occurrence of cracks or oblique grains near the surface of specimens and the sliding or decohesion of grain boundaries between the surface and inner grains. Regardless of strain rate, the ILTDM (intermediate-low-temperature ductility minimum) phe- nomenon always happens in the temperature range from 400 to 600 ℃ in all the investigated alloys, the occurrence of which is closely related to the strong strain-hardening behavior in the deformation process. Finally, the interaction of slip bands which are the main deformation mode below 600 ℃ is established to be the essential reason for the strain hardening.展开更多
Foliar δ^13C values, an indicator of long-term intercellular carbon dioxide concentration and, thus, of long-term water use efficiency (WUE) in plants, were measured for Pinus massoniana Lamb., P. elliottii Engelm....Foliar δ^13C values, an indicator of long-term intercellular carbon dioxide concentration and, thus, of long-term water use efficiency (WUE) in plants, were measured for Pinus massoniana Lamb., P. elliottii Engelm., Cunninghamia laceolata (Lamb.) Hook., and Schima superba Gardn. et Champ. in a restored forest ecosystem in the Jiazhu River Basin. Seasonal variation and the relationship between the foliar δ^13C values of the four species and environmental factors (monthly total precipitation, monthly average air temperature, relative humidity, atmospheric pressure, and monthly total solar radiation and evaporation) were investigated. The monthly δ^13C values and WUE of the four species increased with increasing precipitation, air temperature, solar radiation, and evaporation, whereas δ^13C values of the four species decreased with increasing relative humidity and atmospheric pressure. Despite significant differences in δ^13C seasonal means for the four species, our results demonstrate a significant convergence in the responses of δ^13C values and WUE to seasonal variations in environmental factors among the species investigated and that the δ^13C signature for each species gives a strong indication of environmental variables.展开更多
Hollow core slabs are becoming of increasing interest as the construction industry attempts to minimise the impact of its activities on the environment. By forming voids in the interior of a concrete slab, the amount ...Hollow core slabs are becoming of increasing interest as the construction industry attempts to minimise the impact of its activities on the environment. By forming voids in the interior of a concrete slab, the amount of concrete used can be reduced without significantly altering the capacity of the structure. In this study, we examined the inner force transfer mechanism of a column-supported cast-in-situ hollow core slab using finite element analysis. Both a hollow core slab and the corresponding solid slab were analysed using ANSYS and the results were compared. The orientation of the tube fillers causes the stiffness of the hollow slab to be orthotropic, potentially changing the distribution of load carried in the two orthogonal directions. Both the cross-section’s moments in the column strip and near the columns in the hollow core slab become larger than that in the solid floor. As well, the cross-section’s stiffness along the tube arrangement direction is larger than that of the radial cross-section, which causes the direction along the hole of the hollow core slab to carry more moment than the radial direction. The conversion factors of the two directions are proposed from the comparison for four typical areas of the hollow core slab, as are the moment distribution coefficients.展开更多
Background:Radiotherapy is commonly used to treat cancers.To date,there has been no study focusing on the effects of radiotherapy on hydatid disease in large animals.In this study,we aim to investigate the efficiency ...Background:Radiotherapy is commonly used to treat cancers.To date,there has been no study focusing on the effects of radiotherapy on hydatid disease in large animals.In this study,we aim to investigate the efficiency and safety of radiotherapy for treating hydatid disease caused by Echinococcus granulosus in naturally infected sheep.Methods:Ultrasound was used to screen naturally infected sheep in an echinococcosis endemic area in Xinjiang,China.A computer tomography(CT)scan confirmed the presence of hydatid cysts.Twenty sheep naturally infected with E.granulosus in the liver and/or lungs were randomly assigned into four groups receiving no irradiation,or X-ray irradiation of low(30 Gy),medium(45 Gy),and high dose(60 Gy),respectively.After three months of radiotherapy,a CT scan was performed to measure the changes in the cysts.The hepatic parasite cysts and host tissues were collected for histology and gene expression analysis.Results:In the animals subject to irradiation,no significant differences were observed in their appetite,daily activities,and weight before and after radiotherapy.Severe calcification was noticed in the cysts subject to a high dose of radiation compared with the groups subject to low and medium doses.Hematoxylin and eosin staining showed that irradiation contributed to the damage of the cyst structure and nucleus in the germinal layers.Quantitative PCR demonstrated that expression of TPX and HSP70 significantly decreased in a dose-dependent manner(P<0.05).The expression of the EPC1 decreased in the medium-and high-dose groups compared with the low-dose group(P<0.05).Meanwhile,the expression of radiation-related apoptosis genes caspase-3 and Gadd45 decreased with an increase in the irradiation dose.Conclusions:Radiotherapy is an option with satisfactory efficiency and safety for treating cystic echinococcosis in sheep with partial response or stable disease at month 3.In future,inhibition of cystic activity using radiotherapy may serve as a new regimen for treating hydatid disease.展开更多
基金supported by two projects initialed China Geological Survey:“Evaluation on Soil and Water Quality and Geological Survey in Xiong’an New Area(DD20189122)”“Monitoring and Evaluation on Carrying Capacity of Resource and Environment in Beijing-Tianjin-Hebei Coordinated Development Zone and Xiong’an New Area(DD20221727)”.
文摘China established Xiong’an New Area in Hebei Province in 2017,which is planned to accommodate about 5 million people,aiming to relieve Beijing City of the functions non-essential to its role as China’s capital and to expedite the coordinated development of the Beijing-Tianjin-Hebei region.From 2017 to 2021,the China Geological Survey(CGS)took the lead in multi-factor urban geological surveys involving space,resources,environments,and disasters according to the general requirements of“global vision,international standards,distinctive Chinese features,and future-oriented goals”in Xiong’an New Area,identifying the engineering geologic conditions and geologic environmental challenges of this area.The achievements also include a 3D engineering geological structure model for the whole area,along with“one city proper and five clusters”,insights into the ecology and the background endowment of natural resources like land,geothermal resources,groundwater,and wetland of the area before engineering construction,a comprehensive monitoring network of resources and environments in the area,and the“Transparent Xiong’an”geological information platform that is open,shared,dynamically updated,and three-dimensionally visualized.China’s geologists and urban geology have played a significant role in the urban planning and construction of Xiong’an New Area,providing whole-process geological solutions for urban planning,construction,operation and management.The future urban construction of Xiong’an New Area will necessitate the theoretical and technical support of earth system science(ESS)from various aspects,and the purpose is to enhance the resilience of the new type of city and to provide support for the green,low-carbon,and sustainable development of this area.
基金supported by National Nature Science Foundation of China(NO.81260052)Science and Technology Planning Project of Hainan Province of China(NO.812147)
文摘Objective:To evaluate the feasibility,safety and efficacy of transcathcter closure of ventricular septal defect(VSD)in patients with aortic valve prolapse(AVP)and mild aortic regurgitation(AR).Methods:Between January 2008 and July 2014,transcatheter closure of VSD was attempted in 65 patients.Results:The total intermediate closure successful rate in all subjects was 96.9%.During the perioperative period,no death,major bleeding,pericardial tamponade,occluder dislodgement,residual shunt or hemolysis occurred.Two procedures had been forced to suspend due to significant aggregation of device related aortic regurgitation,three cases of transient complete left bundle branch block occurred but did not sustain.At 1-year followup,no patients had residual shunts and complications.Furthermore,grade of residual AR were relieved in 61.9%(39/63)cases and degree of AVP were ameliorated in 36.5%(23/63)patients;Conclusions:Transcatheter closure VSD in selected patients with AVP and mild AR is technically feasible and highly effective.Long term safety and efficacy needs to be assessed.
基金The National Natural Science Foundation of China,No.81173393the Natural Science Foundation of Tianjin City,No.12JCZDJC25500the Innovation Team Program from Logistics University of People’s Armed Police Force,No.WHTD201310
文摘AIM To identify and assess the research situation of top 100 cited articles in nonalcoholic fatty liver disease(NAFl D).METHODS The global scientific research articles in the science Citation Index-Expanded relevant to NAFl D were retrieved and listed according to their citation times from the most to the least. The 100 most frequently cited original articles were selected to systematically evaluate their bibliometric parameters including times cited, publication year, journals, subject categories, and the highly related concepts of NAFl D, which reflected the history and current situation, publication distribution of leading countries and institutes as well as the research hotspots of NAFl D.RESULTS Top 100 cited articles in NAFl D were published from 1965 to 2015 with a citation ranging of 227 to 2151 times since publication, in which the United states was the most predominant country and Mayo Clin was the most productive institution. The majority of the top 100 cited articles were concentrated in s CI subject category of Gastroenterology and Hepatology. Hepatology and Gastroenterology is the top journal that published over half 100 top-cited articles. The significant peak of top cited articles present in the first half of the 2000 s while the highest mean number of citation presents in first half of the 1980 s. In addition, concepts related to pathology characteristics, epidemiology and medicalization, metabolic syndrome and its combination of symptoms including insulin resistance, biomarkersof lipid metabolism and obesity are listed as the highly related concepts.CONCLUSION The 100 top-cited articles marked with the leading countries, institutions, journals, hotspots and development trend in NAFl D field that could provide the foundation for further investigations.
基金supported by the Beijing Natural Science Foundation (No.2112028)the Research Fund for the Doctoral Pro-gram of Higher Education of China (No.20090006110010)the Doctoral Start-up Fund of Henan University of Science and Technology(No.09001542)
文摘ZnO-modified (Li, Na, K)NbO3 lead-free ceramics with a nominal composition of Li0.06(Na0.535K0.48)0.94NbO3+0.7mol% ZnO (LNKN-ZT) was synthesized normally at 930-1000℃. The Zn ions incorporated into the A-site at a higher sintering temperaVare, which changed LNKN-Z7 to soft piezoelectric ceramics with the mechanical quality factor decreasing from 228 to 192. A phase transition from tetragonal to orthorhombic symmetry was identified by XRD analysis, and the corresponding calculation of lattice parameters was conducted at 970-980℃. Because of such transitional behavior and fine microstructure, the optimized values of piezoelectric coefficient, planar electromechanical coupling coefficient, and relative dielectric constant were obtained.
基金supported by the Research Fund for the Doctoral Program of Higher Education of China (No20090006110010)the National Basic Research Priorities Program of China (No2007CB613301)the Program of University-Industry Cooperation Supported by the Ministry of Education and Guangdong Province of China (No2008B090500262)
文摘MgO-modified Li0.06(Na0.5K0.5)0.94NbO3O3 (L6NKN) lead-free piezoelectric ceramics were synthesized by normal sintering at a rela- tively low temperature of 1000℃. The crystalline phase, microstructure, and electrical properties of the ceramics were investigated with a special emphasis on the influence of MgO content. The addition of MgO effectively improves the sintembility of the L6NKN ceramics. X-my diffr cfion analysis indicates that the morphotropic phase boundary (MPB) separating orthorhombic and tetragonal phases for the ceramics lies in the range of Mg doping content (x) from 0.3at% to 0.7at%. High electrical properties of the piezoelectric constant (d33=238 pC/N), planar electromechanical coupling coefficient (kp=41.5%), relative dielectric constant (εr=905), and remanent polarization (Pr=38.3 μC/cm2) are obtained from the specimen with x=0.5at%, which suggests that the Li0.06(Na0.5K0.5)0.94Nb(1-2x/5)MgxO3 (x=0.5at%) ceramic is a promising lead-free piezoelectric material.
基金Supported by Science and Technology Innovation Joint Fund Project of Fujian Province,No.2018Y9116.
文摘BACKGROUND Syphilis is a chronic,classic sexually transmitted disease caused by Treponema pallidum,which can invade almost all organs of the body and produce various symptoms and signs.Although there are some cases of colorectal bleeding caused by syphilis,small intestinal bleeding caused by syphilis is still rare.CASE SUMMARY A 58-year-old man had experienced recurrent abdominal pain and melena for 3 years.Repeated gastroenteroscopy and computed tomography angiography examinations failed to find bleeding lesions.During the same admission,multiple intestinal ulcers were found by capsule endoscopy,and syphilis was also diagnosed.With a history of atrial fibrillation and chronic pancreatitis,he had undergone mitral valve replacement and tricuspid valvuloplasty for valvular heart disease.After anti-syphilis treatment,the melena and abdominal pain disappeared and his hemoglobin gradually increased.It is considered that gastrointestinal bleeding,chronic pancreatitis,atrial fibrillation,and heart valvular disease may have been caused by syphilis.CONCLUSION This case report found that syphilis can mimic systemic disease and cause intestinal bleeding.In addition,treatment of the disease requires both sexual partners to be treated.Finally,although syphilis is easy to treat,it is more important to consider that bleeding could be caused by syphilis.
基金supported by the National Natural Science Foundation of China(Grant No.51679244).
文摘To investigate the overall damage characteristics and failure modes of a warship subjected to an underwater non-contact near-field explosion,a hull girder with a trapezoidal cross-section was designed,manufactured,and tested.The design criteria and parameters were determined according to the similarity criterion.Dynamic responses of the girder freely floating on water were obtained under varying conditions,including stand-off distance,charge mass,and position of attack.Damage morphologies of the girder model were obtained.Based on our analysis,basic conditions for sagging damage of the hull girder are proposed.The aim of this study was to determine an efficient method of attack resulting in the most severe damage to the ship hull.The experimental results show that the girder mainly exhibits a first-order response when the first wet frequency of the girder is close to the frequency of the explosion bubble pulsation.The largest deformation was observed when the underwater explosion occurred directly below the midspan of the girder compared to other explosions of the same intensity at different attack positions.When the ratio of stand-off to maximum bubble radius(λ)satisfies 0.7≤λ<2,the bubble mainly causes sagging damage instead of hogging.Asλdecreases(1≤λ<2),the sagging damage increases under the same charge mass.However,asλdecreases further(0.7≤λ<1),the sagging deformation decreases.This is likely due to the impact of the liquid jet formed by the collapsing bubble,which causes the girder deformation to shift from sagging back to hogging deformation.The initial shock wave excites the high-frequency response of the girder structure but contributes very little to the overall velocity and displacement.However,bubble pulsation typically causes a low-frequency response,which will affect the velocity and displacement of the girder.The low-pressure region of the flow field formed by bubble pulsation and resonant coupling between the girder and the bubble are the predominant causes of damage to the overall girder structure.
基金Supported by the Natural Science Foundation of Shandong Province,No.ZR2021QH110.
文摘BACKGROUND A few reports have revealed induction of rhabdomyolysis by a red yeast rice(RYR)supplement or by RYR in combination with abiraterone(an androgen biosynthesis inhibitor).CASE SUMMARY A 76-year-old man presented with progressive limb weakness,muscle soreness,and acute kidney injury(AKI).He had been taking the anti-prostate cancer drug abiraterone for 14 mo and had added a RYR supplement 3 mo before symptom onset.After being diagnosed with rhabdomyolysis-induced AKI,the patient discontinued these drugs and responded well to hemodialysis and hemoperfusion.After 23 d of treatment,creatine kinase levels returned to normal and serum creatinine levels decreased.CONCLUSION We speculate that statins,the main lipid-lowering component of RYR,or a combination of statins and abiraterone,will increase the risk of rhabdomyolysis.
基金financially supported by the Strategic Priority Research Program on Space Science of the Chinese Academy of Sciences (Grant No. XDA 15020800)the National Natural Science Foundation of China (Grant Nos. 12033010, 41604152 and U1938111)Foundation of Minor Planets of the Purple Mountain Observatory and Youth Innovation Promotion Association CAS (Grant No. 2018178)。
文摘The Closeby Habitable Exoplanet Survey(CHES) mission is proposed to discover habitable-zone Earth-like planets of nearby solar-type stars(~10 pc away from our solar system) via microarcsecond relative astrometry.The major scientific objectives of CHES are:to search for Earth Twins or terrestrial planets in habitable zones orbiting100 FGK nearby stars;further to conduct a comprehensive survey and extensively characterize nearby planetary systems.The primary payload is a high-quality,low-distortion,high-stability telescope.The optical subsystem is a coaxial three-mirror anastigmat(TMA) with a 1.2 m-aperture,0°.44 × 0°.44 field of view and 500 nm-900 nm working wave band.The camera focal plane is composed of a mosaic of 81 scientific CMOS detectors each with4 k × 4 k pixels.The heterodyne laser interferometric calibration technology is employed to ensure microarcsecond level(1 μas) relative astrometry precision to meet the requirements for detection of Earth-like planets.The CHES satellite operates at the Sun-Earth L2 point and observes all the target stars for 5 yr.CHES will offer the first direct measurements of true masses and inclinations of Earth Twins and super-Earths orbiting our neighbor stars based on microarcsecond astrometry from space.This will definitely enhance our understanding of the formation of diverse nearby planetary systems and the emergence of other worlds for solar-type stars,and finally provide insights to the evolution of our own solar system.
基金The study was financially supported by the National Natural Science Foundation of China(41807220)the Open Fund Project of Hebei Key Laboratory of Geological Resources and Environment Monitoring and Protection(JCYKT201903)the projects of the China Geological Survey(DD20160239 and DD20189142).
文摘The groundwater level has been continuously decreasing due to climate change and long-time overexploitation in the Xiong’an New Area,North China,which caused the enhanced mixing of groundwater in different aquifers and significant changes in regional groundwater chemistry characteristics.In this study,groundwater and sediment pore-water in drilling cores obtained from a 600 m borehole were investigated to evaluate hydrogeochemical processes in shallow and deep aquifers and paleo-environmental evolution in the past ca.3.10 Ma.Results showed that there was no obvious change overall in chemical composition along the direction of groundwater runoff,but different hydrochemical processes occurred in shallow and deep groundwater in the vertical direction.Shallow groundwater(<150 m)in the Xiong’an New Area was characterized by high salinity(TDS>1000 mg/L)and high concentrations of Mn and Fe,while deep groundwater had better water quality with lower salinity.The high TDS values mostly occurred in aquifers with depth<70 m and>500 m below land surface.Water isotopes showed that aquifer pore-water mostly originated from meteoric water under the influence of evaporation,and aquitard pore-water belonged to Paleo meteoric water.In addition,the evolution of the paleoclimate since 3.10 Ma BP was reconstructed,and four climate periods were determined by theδ18O profiles of pore-water and sporopollen records from sediments at different depths.It can be inferred that the Quaternary Pleistocene(0.78‒2.58 Ma BP)was dominated by the cold and dry climate of the glacial period,with three interglacial intervals of warm and humid climate.What’s more,this study demonstrates the possibilities of the applications of pore-water on the hydrogeochemical study and further supports the finding that pore-water could retain the feature of paleo-sedimentary water.
基金supported by the National Natural Science Foundation of China(42030110 and 61603008)the Innovation Group of Natural Fund of Hubei Province(2018CFA087)。
文摘As a key technique in deep space navigation, radio interferometry can be used to determine the accurate location of a spacecraft in the plane-of-sky by measuring its signal propagation time delay between two remote stations. To improve the measurement accuracy, differential phase delay without phase ambiguity is usually desired. Aiming at the difficulties of resolving phase ambiguity with few stations and narrowband downlink signals, a new method is proposed in this work by taking advantage of the Earth rotation. The high accurate differential phase delay between the spacecraft and a calibrator can be achieved not only in the in-beam observation mode but also in the out-of-beam observation mode. In this paper we firstly built the model of phase ambiguity resolution. Then, main measurement errors of the model are analyzed, which is followed by tests and validations of the model and method using the tracking data of the Cassini mission and Chang'E-3 mission. The results show that the phase ambiguities can be correctly resolved to generate a 10-picosecond level accuracy differential phase delay. Angular measurement accuracy of the Cassini reaches the milli-arc-second level, and the relative position accuracy between the Chang'E-3 rover and lander reaches the meter level.
基金the National Natural Science Foundation of China(Grant Nos.42030110,61603008 and U1831132)the Innovation Group of Natural Fund of Hubei Province(2018CFA087)。
文摘The phase referencing Very Long Baseline Interferometry(VLBI)technique is a newly developed tool to measure the angular position of a deep space exploration probe in the plane-of-the-sky.Through alternating observations between the probe and a nearby reference radio source,their accurate relative angular separation can be obtained from the radio images generated by this technique.To meet the requirements of the current orbit determination software,differential delay should be firstly derived from those radio images.A method to resolve the differential phase delay from the phase referencing VLBI technique is proposed in this paper,and as well the mathematical model for differential phase ambiguity resolution is established.This method is verified with practical measurement data from the Chang’E-3 mission.The differential phase delay between the Chang’E-3 lander and rover was derived from the phase referencing VLBI measurements,and was then imported into the Shanghai astronomical observatory Orbit Determination Program(SODP)to calculate the position of the rover relative to the lander on the lunar surface.The results are consistent with those acquired directly from radio images,indicating that the differential phase ambiguity has been correctly resolved.The proposed method can be used to promote applications of the phase referencing VLBI technique in future lunar or deep space explorations,and more accurate orbit determination becomes promising.
基金The author thanks the National Natural Science Foundation of China (No. 81470266).
文摘Background:Pyroptosis is the term for caspase-l-dependent cell death associated with pro-inflammatory cytokines.The role of alveolar macrophage (AM) pyroptosis in the pathogenesis of the acute lung injury and acute respiratory distress syndrome (ALI/ARDS) remains unclear.Methods:C57BL/6 wild-type mice were assigned to sham,lipopolysaccharide (LPS) + vehicle,LPS + acetyl-tyrosyl-valyl-alanyl-aspartyl-chloromethylketone (Ac-YVAD-CMK) and LPS + Z-Asp-Glu-Val-Asp-fluoromethylketone groups.Mice were given intraperitoneal (IP) injections of LPS.Drugs were IP injected 1 h before LPS administration.Mice were sacrificed 16 h after LPS administration,and AMs were isolated.Western blot analysis for active caspase-1 and cleaved caspase-3,evaluation of lung injury and a cytokine release analysis were performed.AMs were treated with LPS and adenosine triphosphate (ATP);caspase-l-dependent cell death was evaluated using flow cytometry;the apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) pyroptosomes were examined by immunofluorescence.Results:The expression of activated caspase-1 in AMs was enhanced following LPS challenge compared with the sham group.In the ex vivo study,the caspase-1/propidium iodide-positive cells,caspase-1 specks and ASC pyroptosomes were up-regulated in AMs following LPS/ATP stimulation.The specific caspase-1 inhibitor Ac-YVAD-CMK inhibited the activation of caspase-1 and pyroptotic cell death.Ac-YVAD-CMK also reduced the lung injury,pulmonary edema and total protein in bronchoalveolar lavage fluid (BALF).In addition,Ac-YVAD-CMK significantly inhibited interleukin-β (IL-lβ) release both in serum and BALF and reduced the levels of IL-18,tumor necrosis factor-α (TNF-α),High Mobility Group Box 1 (HMGB1) in BALF during LPS-induced ALI/ARDS.Conclusions:This study reported AM pyroptosis during LPS-induced ALI/ARDS in mice and has demonstrated that Ac-YVAD-CMK can prevent AM-induced pyroptosis and lung injury.These preliminary findings may form the basis for further studies to evaluate this pathway as a target for prevention or reduction of ALI/ARDS.
基金中国科学院知识创新工程项目,the Natural Resources Research, the Chinese Academy of Sciences,中国科学院资助项目
文摘Scaling, as the translation of information across spatial, temporal, and organizational scales, is essential to predictions and understanding in all sciences and has become a central issue in ecology. A large body of theoretical and empirical evidence concerning allometric scaling in terrestrial individual plants and plant communities has been constructed around the fractal volume-filling theory of West, Brown, and Enquist (the WBE model). One of the most thought-provoking findings has been that the metabolic rates of plants, like those of animals, scale with their size as a 3/4 power law. The earliest, single most-important study cited in support of the application of the WBE model to terrestrial plants claims that whole-plant resource use in terrestrial plants scales as the 3/4 power of total mass, as predicted by the WBE model. However, in the present study we show that empirical data actually do not support such a claim. More recent studies cited as evidence for 3/4 scaling also suffer from several statistical and data-related problems. Using a forest biomass dataset including 1 266 plots of 17 main forest types across China, we explored the scaling exponents between tree productivity and tree mass and found no universal value across forest stands. We conclude that there is not sufficient evidence to support the existence of a single constant scaling exponent for the metabolism-biomass relationship for terrestrial plants.
基金Supported by the Knowledge Innovation Program of the Institute of Geo- graphic Sciences and Natural Resources Research, the Chinese Academy of Sciences (CX10G-E01-02-01, CX10G-E01-08-02, and KZCX1-SW-01- 01A2), the National Natural Science Foundation of China (30330150).
文摘The past few decades have seen a resurgence of Interest in biological allometry. Specifically, a number of recent studies has suggested a -4/3 Invariant scaling relationship between mass and density that Is universally valid for tree-dominated communities, regardless of their phyietic affiliation or habitat. In the present study, we test this scaling relationship using a comprehensive forest biomass database, Including 1 266 plots of six blomes and 17 forest types across China. The present study shows that the scaling exponent of the massdensity relationship varies across different tree-dominated communities and habitats. This great variability In the scaling exponent makes any generalization unwarranted. Although Inappropriate regression methods can lead to flawed estimation of the scaling exponent, inconsistency of theoretical framework and empirical patterns may have undermined the validity of previous work.
基金supported by the National Natural Science Foundation of China (11375013 and 11135003)
文摘The test of the Standard Model and search for New Physics signal are main aim of LHC experiment.With the increasing of the measurement accuracy at the LHC,it is a major task in future to exceed the current accuracy of the theoretical predictions for important processes,in particular ones involving Higgs boson and top quark.In this review we briefly summarize some recent theoretical progress in Higgs boson and top quark physics,especially the fixed-order and resummation predictions in QCD at both the Tevatron and the LHC.
基金supported by the National Natural Science Foundation of China(No.51001101)the National Energy Administration Program of China(No.NY20150102)
文摘The tensile properties and deformation behavior of several cast Ni-based superalloys, respectively, in the equiaxed, columnar-crystal and single-crystal styles are comparatively studied. The effects of solidification way, heat treatment and strain rate on the tensile properties are discussed in detail. It is found that the reduction of grain boundaries by the feasible solidification ways offers cast Ni-based superalloys the potential capability of improving the mechanical properties, the ultimate achievement of which is also confirmed to lie on the appropriate modifications of chemical composition and heat treatment. The prolongation of solid solution facilitates the precipitation of fine secondary γ' phase, whereas the extension of high-temperature aging leads to the coarsening of secondary γ' phase. The combination of these two aspects has a crucial influence on the tensile properties. Under tensile applied stress, the surface grains of DZ-A alloy deform slightly, while the inner grains deform heavily. This deformation inhomogeneity is ascribed to the occurrence of cracks or oblique grains near the surface of specimens and the sliding or decohesion of grain boundaries between the surface and inner grains. Regardless of strain rate, the ILTDM (intermediate-low-temperature ductility minimum) phe- nomenon always happens in the temperature range from 400 to 600 ℃ in all the investigated alloys, the occurrence of which is closely related to the strong strain-hardening behavior in the deformation process. Finally, the interaction of slip bands which are the main deformation mode below 600 ℃ is established to be the essential reason for the strain hardening.
基金the Frontier Project,the Backbone Project,中国科学院知识创新工程项目,the Chinese Academy of Sciences,Natural Resources Research
文摘Foliar δ^13C values, an indicator of long-term intercellular carbon dioxide concentration and, thus, of long-term water use efficiency (WUE) in plants, were measured for Pinus massoniana Lamb., P. elliottii Engelm., Cunninghamia laceolata (Lamb.) Hook., and Schima superba Gardn. et Champ. in a restored forest ecosystem in the Jiazhu River Basin. Seasonal variation and the relationship between the foliar δ^13C values of the four species and environmental factors (monthly total precipitation, monthly average air temperature, relative humidity, atmospheric pressure, and monthly total solar radiation and evaporation) were investigated. The monthly δ^13C values and WUE of the four species increased with increasing precipitation, air temperature, solar radiation, and evaporation, whereas δ^13C values of the four species decreased with increasing relative humidity and atmospheric pressure. Despite significant differences in δ^13C seasonal means for the four species, our results demonstrate a significant convergence in the responses of δ^13C values and WUE to seasonal variations in environmental factors among the species investigated and that the δ^13C signature for each species gives a strong indication of environmental variables.
基金Project supported by the Australian Research Council Research Grant (No. DP0988940)the Natural Science Foundation of Jiangsu Province (No. BK2009394)+2 种基金the China Postdoctoral Science Foundation (No. 2011M500930)the Natural Science Surface Project of Jiangsu Provincial Universities (No. 11KJB560003)the Talent Introduction Fund of Nanjing Forestry University (No. 163050072)
文摘Hollow core slabs are becoming of increasing interest as the construction industry attempts to minimise the impact of its activities on the environment. By forming voids in the interior of a concrete slab, the amount of concrete used can be reduced without significantly altering the capacity of the structure. In this study, we examined the inner force transfer mechanism of a column-supported cast-in-situ hollow core slab using finite element analysis. Both a hollow core slab and the corresponding solid slab were analysed using ANSYS and the results were compared. The orientation of the tube fillers causes the stiffness of the hollow slab to be orthotropic, potentially changing the distribution of load carried in the two orthogonal directions. Both the cross-section’s moments in the column strip and near the columns in the hollow core slab become larger than that in the solid floor. As well, the cross-section’s stiffness along the tube arrangement direction is larger than that of the radial cross-section, which causes the direction along the hole of the hollow core slab to carry more moment than the radial direction. The conversion factors of the two directions are proposed from the comparison for four typical areas of the hollow core slab, as are the moment distribution coefficients.
基金This work was supported by the Open Project of State Key Lab Incubation Base of Xinjiang Major Diseases Research(No.:SKLIB-XJMDR-2015-Y3).
文摘Background:Radiotherapy is commonly used to treat cancers.To date,there has been no study focusing on the effects of radiotherapy on hydatid disease in large animals.In this study,we aim to investigate the efficiency and safety of radiotherapy for treating hydatid disease caused by Echinococcus granulosus in naturally infected sheep.Methods:Ultrasound was used to screen naturally infected sheep in an echinococcosis endemic area in Xinjiang,China.A computer tomography(CT)scan confirmed the presence of hydatid cysts.Twenty sheep naturally infected with E.granulosus in the liver and/or lungs were randomly assigned into four groups receiving no irradiation,or X-ray irradiation of low(30 Gy),medium(45 Gy),and high dose(60 Gy),respectively.After three months of radiotherapy,a CT scan was performed to measure the changes in the cysts.The hepatic parasite cysts and host tissues were collected for histology and gene expression analysis.Results:In the animals subject to irradiation,no significant differences were observed in their appetite,daily activities,and weight before and after radiotherapy.Severe calcification was noticed in the cysts subject to a high dose of radiation compared with the groups subject to low and medium doses.Hematoxylin and eosin staining showed that irradiation contributed to the damage of the cyst structure and nucleus in the germinal layers.Quantitative PCR demonstrated that expression of TPX and HSP70 significantly decreased in a dose-dependent manner(P<0.05).The expression of the EPC1 decreased in the medium-and high-dose groups compared with the low-dose group(P<0.05).Meanwhile,the expression of radiation-related apoptosis genes caspase-3 and Gadd45 decreased with an increase in the irradiation dose.Conclusions:Radiotherapy is an option with satisfactory efficiency and safety for treating cystic echinococcosis in sheep with partial response or stable disease at month 3.In future,inhibition of cystic activity using radiotherapy may serve as a new regimen for treating hydatid disease.