This article reviews research advances in the application of early enteral nutrition(EEN)in elderly patients with severe acute pancreatitis(SAP).Elderly SAP patients are associated with higher mor tality rates due to ...This article reviews research advances in the application of early enteral nutrition(EEN)in elderly patients with severe acute pancreatitis(SAP).Elderly SAP patients are associated with higher mor tality rates due to age-related immune dysfunction,whereas EEN has been demonstrated to improve clinical prognosis,reduce infection and complication rates,and shor ten hospital stays.However,ongoing debates exist regarding the optimal timing,route selection,and complication management of EEN.Through a systematic review of the literature,this study synthesizes current evidence on EEN in elderly SAP populations,critically examines unresolved clinical controversies,and proposes future research priorities to inform evidence-based practice.展开更多
Transplant rejection remains a leading cause of graft failure after organ transplantation.Current immunosuppressive therapies can reduce acute rejection,but their lack of specificity often leads to systemic side effec...Transplant rejection remains a leading cause of graft failure after organ transplantation.Current immunosuppressive therapies can reduce acute rejection,but their lack of specificity often leads to systemic side effects and long-term complications.Therefore,novel strategies for localized and durable immune regulation are urgently needed.Nanomedicine offers a promising approach by enabling the precise delivery of therapeutic agents to specific cells or tissues involved in the rejection process.Through rational design,nanoparticles can be engineered to carry immunosuppressive molecules and selectively target transplanted organs,immune organs such as lymph nodes and spleen,or key immune cells,including dendritic cells,macrophages,and T lymphocytes.These delivery systems improve drug bioavailability,reduce off-target effects,and allow controlled or responsive drug release in complex immune environments.In this review,we summarize recent advances in nanoparticle-based interventions for transplant rejection.We discuss the design and classification of nanoparticles,delivery strategies tailored to different graft types,and therapeutic mechanisms targeting various stages and components of the immune response.Examples of both systemic and local administration routes are presented,demonstrating the versatility of nanomedicine in addressing diverse clinical scenarios.Despite encouraging progress in preclinical studies,several challenges continue to limit clinical translation.These include variability in nanoparticle behavior across species,difficulties in large-scale manufacturing,and the lack of standardized regulatory frameworks.Continued efforts in materials innovation,biological validation,and interdisciplinary collaboration are essential to fully realize the clinical potential of nanomedicine in transplantation.展开更多
Hydrogen energy,as the ultimate clean energy,effectively avoids the greenhouse effect.Chemical looping hydrogen production(CLHP),a versatile energy conversion and production technology,has garnered extensive attention...Hydrogen energy,as the ultimate clean energy,effectively avoids the greenhouse effect.Chemical looping hydrogen production(CLHP),a versatile energy conversion and production technology,has garnered extensive attention.CLHP demands redox catalysts with high oxygen capacity,regulatable reactivity,and structural integrity even under harsh operational conditions.Currently,sintering,agglomeration,and inactivation of redox catalysts during cyclic lattice oxygen release and restoration are challenging,hindering the wide industrialization of the chemical looping(CL)process.Moreover,the precise control of activity and reaction rate of the redox catalysts to flexibly accommodate the demands of various reaction substrates remains unclear.This paper introduces the design of a nano-scaled redox catalyst featuring a unique core-shell structure.By precisely controlling the shell thickness,a series of hierarchical Fe_(2)O_(3)@SiO_(2)redox catalysts were successfully synthesized.Building on this achievement,an in-depth investigation was conducted into the impact of the thickness and spatial structure of the inert support on the stability and mass transfer rate of the redox catalyst,aiming to achieve a perfect balance between these two factors during the CLHP process.A thin shell(70 nm)exhibits excellent cyclic stability,maintaining consistent performance in 30 consecutive redox cycles,while a thicker shell(200 nm)undergoes rapid deactivation due to the formation of a substantial amount of iron silicate.In-situ transmission electron microscopy(TEM)reveals that the SiO_(2)shell effectively restricts the agglomeration of Fe_(2)O_(3).The unique core-shell structure and controllable shell thickness offer novel insights into the flexible design of efficient and durable hierarchical redox catalysts with spatial structure.展开更多
The composites prepared by combining lightweight carbon materials with magnetic metals have demonstrated excellent dielectric and magnetic properties,indicating potential applications in the field of electromagnetic w...The composites prepared by combining lightweight carbon materials with magnetic metals have demonstrated excellent dielectric and magnetic properties,indicating potential applications in the field of electromagnetic wave(EMW)absorption.However,the rational microstructure design and component optimization of these composites in regulating their magnetic-dielectric balance to achieve high-performance EMW absorption remains challenging.Herein,hierarchical yolk-shell Fe@SiO_(2)@NC composites with dual impedance matching layers and dual built-in electric fields were prepared by self-template aggregation and in situ reduction strategies.The introduction of a SiO_(2)wave-transparent layer into a conventional dielectric-magnetic system has resulted in the successful realization of nanoscale precise impedance matching regulation in absorbers,thereby enabling effective ultra-wideband EMW absorption.The dual impedance matching layers of the internal void layer and the SiO_(2)wave-transparent layer facilitate multiple scattering and reflection of EMWs within the absorbers,and the dual built-in electric fields of Fe/SiO_(2)and SiO_(2)/NC can effectively enhance interfacial polarization effect to attenuate EMWs.The predominantly optimized Fe@SiO_(2)@NC-2 exhibits an ultra-wide effective absorption bandwidth(EAB)of 7.10 GHz and an impressive minimum reflection loss(RL_(min))of−64.83 dB,indicating that optimizing the impedance matching via quantitative design can maximize the EMW absorption performance.This work provides a straightforward yet effective approach for constructing multi-component materials with hierarchical yolk-shell structure,which offers valuable insight into the microstructure design and component optimization of innovative EMW absorption materials.展开更多
2021年7月发射的风云三号E星(FY-3E)是世界首颗民用晨昏轨道气象卫星,其搭载的WindRAD双频测风雷达具有全球海面风场探测能力。本文首先基于FY-3E/WindRAD L1级观测资料,研究了雷达海面后向散射和风场之间的非线性关系,分别建立了适用于...2021年7月发射的风云三号E星(FY-3E)是世界首颗民用晨昏轨道气象卫星,其搭载的WindRAD双频测风雷达具有全球海面风场探测能力。本文首先基于FY-3E/WindRAD L1级观测资料,研究了雷达海面后向散射和风场之间的非线性关系,分别建立了适用于C和Ku波段VV/HH极化的地球物理模式函数(GMF)。随后,结合最大似然估计法(MLE)对WindRAD散射计探测资料进行风场反演。利用海洋浮标、中法海洋卫星散射计(CSCAT)和美国国家环境预报中心(NCEP)模式风场资料对WindRAD反演风场进行验证。结果显示:WindRAD反演风速与浮标风速偏差约为0.2 m s^(-1),均方根误差(RMSE)在1.13~1.44 m s^(-1)之间,优于2 m s^(-1)的业务化应用的风速精度要求;两者风向偏差在1.4°~3.0°之间,RMSE在25.3°~30.1°之间。WindRAD和CSCAT风场具有较好的一致性,风速RMSE在1.37~1.6 m s^(-1)之间,风向RMSE在22.9°~25.9°之间。WindRAD和NCEP模式风速RMSE在1.87~2.23 m s^(-1)之间,风向RMSE在22.4°~27.1°之间。研究表明WindRAD散射计C和Ku波段VV/HH极化反演风场均具有较高的精度,充分显示了WindRAD载荷在全球海面风场探测方面的应用潜力和价值。展开更多
AIM： To establish a rapid and convenient animal model with hepatitis B virus （HBV） replication.METHODS： A naked DNA solution of HBV-replicationcompetent plasmid was transferred to BALB/C mice via the tail vein, us...AIM： To establish a rapid and convenient animal model with hepatitis B virus （HBV） replication.METHODS： A naked DNA solution of HBV-replicationcompetent plasmid was transferred to BALB/C mice via the tail vein, using a hydrodynamic in vivo transfection procedure. After injection, these mice were sacrificed on d 1, 3, 4, 5, 7 and 10. HBV DNA replication intermediates in the liver were analyzed by Southern blot hybridization. The expression of hepatitis B core antigen （HBcAg） and hepatitis B surface antigen （HBsAg） in the liver was checked by immunohistochemistry. Serum HBsAg and hepatitis B e antigen （HBeAg） was detected by enzyme- linked immunosorbent assay （ELISA）. Inhibition of HBV replication was compared in HBV replication model mice treated intraperitoneally with polyinosinic-polytidylin acid （polyIC） or phosphate-buffered saline （PBS）.RESULTS： After hydrodynamic in vivo transfection, HBV DNA replication intermediates in the mouse liver were detectable on d 1 and abundant on d 3 and 4, the levels were slightly decreased and remained relatively stable between d 5 and 7, and were almost undetectable on d 10. The expression patterns of HBcAg and HBsAg were similar to that of HBV replication intermediate DNA, except that they reached a peak on d 1 after injection. No obvious differences in HBV DNA replication intermediates were observed in the left, right and middle lobes of the liver. After treatment with polyIC, the level of HBV intermediate DNA in the liver was lower than that in the control mice injected with PBS.CONCLUSION： A rapid and convenient mouse model with a high level of HBV replication was developed and used to investigate the inhibitory effect of polyIC on HBV replication, which provides a useful tool for future functional studies of the HBV genome.展开更多
Chemical looping combustion （CLC） of carbonaceous compounds has been proposed, in the past decade, as an efficient method for CO2 capture without cost of extra energy penalties. The technique involves the use of a m...Chemical looping combustion （CLC） of carbonaceous compounds has been proposed, in the past decade, as an efficient method for CO2 capture without cost of extra energy penalties. The technique involves the use of a metal oxide as an oxygen carrier that transfers oxygen from combustion air to fuels. The combustion is carried out in a two-step process： in the fuel reactor, the fuel is oxidized by a metal oxide, and in the air reactor, the reduced metal is oxidized back to the original phase. The use of iron oxide as an oxygen carrier has been investigated in this article. Particles composed of 80 wt% Fe2O3, together with Al2O3 as binder, have been prepared by impregnation methods. X-ray diffraction （XRD） analysis reveals that Fe2O3 does not interact with the Al2O3 binder after multi-cycles. The reactivity of the oxygen carrier particles has been studied in twenty-cycle reduction-oxidation tests in a thermal gravimetrical analysis （TGA） reactor. The components in the outlet gas have been analyzed. It has been observed that about 85% of CH4 converted to CO2 and H2O during most of the reduction periods. The oxygen carrier has kept quite a high reactivity in the twenty-cycle reactions. In the first twenty reaction cycles, the reaction rates became slightly higher with the number of cyclic reactions increasing, which was confirmed by the scanning electron microscopy （SEM） test results. The SEM analysis revealed that the pore size inside the particle had been enlarged by the thermal stress during the reaction, which was favorable for diffusion of the gaseous reactants into the particles. The experimental results suggested that the Fe2O3/Al2O3 oxygen carrier was a promising candidate for a CLC system.展开更多
As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivat...As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivated wheat has been dramatically narrowed by genetic erosion under the modem cultivation system, resulting in vulnerability to biotic and abiotic stresses （Jiang et al., 1994; Friebe et al., 1996）. The wild relatives of wheat represent a large reservoir of superior genes, and transferring these alien genes to modem cultivars through chromosome engineering is a successful method of broadening the genetic diversity of wheat （Chen et al., 2003;展开更多
Carbon and few-layer MoS2 nanosheets co- modified TiO2 nanocomposites （defined as MoS2-C@TiO2） were prepared through a facile one-step pyrolysis reaction technique. In this unique nanostructure, the TiO2 nanosh- eet...Carbon and few-layer MoS2 nanosheets co- modified TiO2 nanocomposites （defined as MoS2-C@TiO2） were prepared through a facile one-step pyrolysis reaction technique. In this unique nanostructure, the TiO2 nanosh- eets with stable structure serve as the backbones, and carbon coating and few-layer MoS2 tightly adhere onto the surface of the TiO2. It needs to be pointed out that the carbon coating improves the overall electronic conductivity and the few-layer MoS2 facilitates the diffusion of lithium ions and offers more active sites for lithium-ion storage. As a result, when evaluated as lithium-ion battery anodes, the MoS2-C@TiO2 nanocomposites exhibit markedly enhanced lithium storage capability compared with pure TiO2. A high specific capacity of 180 mA.h.g-1 has been achieved during the preliminary cycles, and the specific capacity can maintain 160 mA.h.g-1 at a high current density of 1C （1C=167 mA.g-1） even after 300 discharge/ charge cycles, indicating the great potential of the MoS2- C@TiO2 on energy storage.展开更多
A new design route was presented to fabricate cobalt aluminum-layered double hydroxide(CoAl-LDH)thin layers whichgrow on carbon spheres(CSs)through a growth method.The CoAl-LDH thin layers consist of nanoflakes with a...A new design route was presented to fabricate cobalt aluminum-layered double hydroxide(CoAl-LDH)thin layers whichgrow on carbon spheres(CSs)through a growth method.The CoAl-LDH thin layers consist of nanoflakes with a thickness of20nm.The galvanostatic charge-discharge test of the CoAl-LDH/CSs composite shows a great specific capacitance of1198F/g at1A/g(based on the mass of the CoAl-LDH/CSs composite)in6mol/L KOH solution,and the composite displays an impressive specificcapacitance of920F/g even at a high current density of10A/g.Moreover,the composite remains a specific capacitance of928F/gafter1000cycles at2A/g,and the specific capacitance retention is84%,indicating that the composite has high specific capacitance,excellent rate capability and good cycling stability in comparison to pristine CoAl-LDH.展开更多
Double-perovskite type oxide LaSrFeCoO（LSFCO） was used as oxygen carrier for chemical looping steam methane reforming（CL-SMR） due to its unique structure and reactivity. Two different oxidation routes,steam-oxidat...Double-perovskite type oxide LaSrFeCoO（LSFCO） was used as oxygen carrier for chemical looping steam methane reforming（CL-SMR） due to its unique structure and reactivity. Two different oxidation routes,steam-oxidation and steam-air-stepwise-oxidation, were applied to investigate the recovery behaviors of the lattice oxygen in the oxygen carrier. The characterizations of the oxide were determined by X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, hydrogen temperature-programmed reduction（H-TPR） and scanning electron microscopy（SEM）. The fresh sample LSFCO exhibits a monocrystalline perovskite structure with cubic symmetry and high crystallinity, except for a little impurity phase due to the antisite defect of Fe/Co disorder. The deconvolution distribution of XPS patterns indicated that Co,and Fe are predominantly in an oxidized state(Feand Fe) and(Coand Co), while O 1s exists at three species of lattice oxygen, chemisorbed oxygen and physical adsorbed oxygen. The double perovskite structure and chemical composition recover to the original state after the steam and air oxidation, while the Co ion cannot incorporate into the double perovskite structure and thus form the CoO just via individual steam oxidation. In comparison to the two different oxidation routes, the sample obtained by steam-oxidation exhibits even higher CHconversion, CO and Hselectivity and stronger hydrogen generation capacity.展开更多
Chemical-looping oxidative dehydrogenation(CL-ODH)is a process designed for the conversion of alkanes into olefins through cyclic redox reactions,eliminating the need for gaseous O_(2).In this work,we investigated the...Chemical-looping oxidative dehydrogenation(CL-ODH)is a process designed for the conversion of alkanes into olefins through cyclic redox reactions,eliminating the need for gaseous O_(2).In this work,we investigated the use of Ca_(2)MnO_(4)-layered perovskites modified with NaNO_(3) dopants,serving as redox catalysts(also known as oxygen carriers),for the CL-ODH of ethane within a temperature range of 700-780℃.Our findings revealed that the incorporation of NaNO_(3) as a modifier significantly-nhanced the selectivity for-thylene generation from Ca_(2)MnO_(4).At 750℃and a gas hourly space velocity of 1300 h^(-1),we achieved an-thane conversion up to 68.17%,accompanied by a corresponding-thylene yield of 57.39%.X-ray photoelectron spectroscopy analysis unveiled that the doping NaNO_(3) onto Ca_(2)MnO_(4) not only played a role in reducing the oxidation state of Mn ions but also increased the lattice oxygen content of the redox catalyst.Furthermore,formation of NaNO_(3) shell on the surface of Ca_(2)MnO_(4) led to a reduction in the concentration of manganese sites and modulated the oxygen-releasing behavior in a step-wise manner.This modulation contributed significantly to the enhanced selectivity for ethylene of the NaNO_(3)-doped Ca_(2)MnO_(4) catalyst.These findings provide compelling evidence for the potential of Ca_(2)MnO_(4)-layered perovskites as promising redox catalysts in the context of CL-ODH reactions.展开更多
A precursor of cobaltous dihydroxycarbonate was firstly prepared by precipitation reaction of cobalt sulfate solution and ammonium carbonate solution,and then a hydrothermal process for the precursor was conducted to ...A precursor of cobaltous dihydroxycarbonate was firstly prepared by precipitation reaction of cobalt sulfate solution and ammonium carbonate solution,and then a hydrothermal process for the precursor was conducted to obtain the spherical cobalt carbonate with low sulfur content.The experimental results show that the feeding method,final p H value of the precipitation reaction slurry and the concentration of the cobalt sulfate solution have obvious effects on the sulfur content,morphology and particle size distribution of the precursor.The sulfur content of the precursor is 0.0115 wt.%under the optimized conditions.The hydrothermal treatment with temperatures of 125-150℃can transform the precursor of cobaltous dihydroxycarbonate into spherical cobalt carbonate and decrease the sulfur content to 0.0030 wt.%in the obtained product.展开更多
Chemical looping dry reforming（CLDR） is an innovative technology for CO2 utilization using the chemical looping principle.The CLDR process consists of three stages,i.e.CH4 reduction,CO2 reforming,and air oxidation.S...Chemical looping dry reforming（CLDR） is an innovative technology for CO2 utilization using the chemical looping principle.The CLDR process consists of three stages,i.e.CH4 reduction,CO2 reforming,and air oxidation.Spinel nickel ferrite（NiFe2O4） was prepared and its multi-cycle performance as an oxygen carrier for CLDR was experimentally investigated.X-ray diffraction（XRD） and Laser Raman spectroscopy showed that a pure spinel crystalline phase（NiFe2O4） was obtained by a parallel flow co-precipitating method.NiFe2O4was reduced into Fe-Ni alloy and wustite（FexO） during the CH4 reduction process.Subsequent oxidation of the reduced oxygen carrier was performed with CO2 as an oxidant to form an intermediate state：a mixture of spinel Ni（1-x）Fe（2＋x）O4,Fe（2＋y）O4 and metallic Ni.And CO was generated in parallel during this stage.Approximate 185 mL of CO was generated for 1 g spinel NiFe2O4 in a single cycle.The intermediate oxygen carrier was fully oxidized in the air oxidation stage to form a mixture of Ni（1＋x）Fe（2-x）O4 and Fe2O3.Although the original state of oxygen carrier（NiFe2O4） was not fully regenerated and agglomeration was observed,a good recyclability was shown in 10 successive redox cycles.展开更多
Postoperative radiotherapy is a major treatment for patients with maxillary sinus carcinoma. However, the irregular resection cavity poses a technical difficulty for this treatment, causing uneven dose distribution to...Postoperative radiotherapy is a major treatment for patients with maxillary sinus carcinoma. However, the irregular resection cavity poses a technical difficulty for this treatment, causing uneven dose distribution to target volumes. In this study, we evaluated the dose distribution to target volumes and normal tissues in postoperative intensity-modulated radiotherapy (IMRT) after placing a water-filled balloon into the resection cavity. Three postoperative patients with advanced maxillary sinus carcinoma were selected in this trial. Water-filled balloons and supporting dental stents were fabricated according to the size of the maxillary resection cavity. Simulation CT scans were performed with or without water-filled balloons, IMRT treatment plans were established, and dose distribution to target volumes and organs at risk were evaluated. Compared to those in the treatment plan without balloons, the dose (D98) delivered to 98% of the gross tumor volume (GTV) increased by 2.1 Gy (P = 0.009), homogeneity index (HI) improved by 2.3% (P = 0.001), and target volume conformity index (TCI) of 68 Gy increased by 18.5% (P = 0.011) in the plan with balloons. Dosimetry endpoints of normal tissues around target regions in both plans were not significantly different (P > 0.05) except for the optic chiasm. In the plan without balloons, 68 Gy high-dose regions did not entirely cover target volumes in the ethmoid sinus, posteromedial wall of the maxillary sinus, or surgical margin of the hard palate. In contrast, 68 Gy high-dose regions entirely covered the GTV in the plan with balloons. These results suggest that placing a water-filled balloon in the resection cavity for postoperative IMRT of maxillary sinus c arcinoma can reduce low-dose regions and markedly and simultaneously increase dose homogeneity and conformity of target volumes.展开更多
Background:Scalp combing,as an ancient method of health care,has been used for thousands of years in traditional Chinese medicine.Although this method is considered to be beneficial for the blood circulation of the he...Background:Scalp combing,as an ancient method of health care,has been used for thousands of years in traditional Chinese medicine.Although this method is considered to be beneficial for the blood circulation of the head,the underlying mechanisms remain unclear.Methods:Both human participants and mice were used in this study.In participants,the scalp was stimulated by combing continuously for 5 min,and the temperature was measured using infrared thermal imaging before and after stimulation.In mice,the temperature was determined before and at 5,15,and 30 min after a 5-min scalp mechanical stimulation(SMS).Additionally,the vasculature of the mice was labeled with retro-orbital fluorescein isothiocyanate-dextran injection,and the capillaries were observed directly under a confocal microscope.Using in vivo CLARITY imaging and the spectrofluorometric detection of Evans Blue dye extravasation,the bloodebrain barrier permeability was assessed.Results:SMS increased the temperature of the left ear significantly in human(P=.0247)while can slightly increase the temperature of the right ear and the face without significant difference(P>.05).Moreover,SMS can significantly slow the decrease in the temperature of the external auditory canal at 5 min(P=.0153)and in body temperature at 15 min(P=.0295)after SMS whereas no significant difference in body temperature at 30 min(P>.05)compared with control mice.Furthermore,capillaries of the ear with a diameter of less than 8 mm were significantly dilated(P=.0006)following SMS and the number of dextran dots was higher at 15 min(P>.05)and 30 min(F=10.98,P=.037)after SMS intervention compared with control mice.Conclusion:Our study provides strong evidence to support the notion that scalp combing can improve extra-and intracranial blood circulation under healthy conditions.展开更多
Background:Stem CO_(2) efflux(E_(S))plays a critical role in the carbon budget of forest ecosystems.Thinning is a core practice for sustainable management of plantations.It is therefore necessary and urgent to study t...Background:Stem CO_(2) efflux(E_(S))plays a critical role in the carbon budget of forest ecosystems.Thinning is a core practice for sustainable management of plantations.It is therefore necessary and urgent to study the effect and mechanism of thinning intensity(TI)on E_(S).Methods:In this study,five TIs were applied in Larix principis-rupprechtii Mayr 21-,25-,and 41-year-old stands in North China in 2010.Portable infrared gas analyzer(Li-8100 A)was used to measure ES and its association with environmental factors at monthly intervals from May to October in 2013 to 2015.In addition,nutrients,wood structure and nonstructural carbon(NSC)data were measured in August 2016.Results:The results show that ES increased with increasing TI.The maximum ES values occurred at a TI of 35%(3.29,4.57 and 2.98μmol·m^(-2)·s^(-1))and were 1.54-,1.94-and 2.89-fold greater than the minimum E_(S) value in the CK stands(2.14,2.35 and 1.03μmol·m^(-2)·s^(-1))in July for the 21-,25-and 41-year-old forests,respectively.The E_(S) of the trees in low-density stands was more sensitive to temperature than that of the trees in high-density stands.Soluble sugars(SS)and temperature are the main factors affecting ES.When the stand density is low enough as 41-year-old L.principis-rupprechtii forests with TI 35%,bark thickness(BT)and humidity should be considered in addition to air temperature(T_(a)),wood temperature(T_(w)),sapwood width(SW),nitrogen concentration(N)and SS in the evaluation of ES.If a change in stand density is ignored,the CO_(2) released from individual 21-,25-and 41-year-old trees could be underestimated by 168.89%,101.94% and 200.49%,respectively.CO_(2) release was estimated based on the stem equation in combination with the factors influencing ES for reference.Conclusions:We suggest that it is not sufficient to conventional models which quantify ES only by temperature and that incorporating the associated drivers(e.g.density,SS,SW and N)based on stand density into conventional models can improve the accuracy of ES estimates.展开更多
基金supported by the Scientific Research Project of the Health Commission of Shanxi Province(No.2024003)。
文摘This article reviews research advances in the application of early enteral nutrition(EEN)in elderly patients with severe acute pancreatitis(SAP).Elderly SAP patients are associated with higher mor tality rates due to age-related immune dysfunction,whereas EEN has been demonstrated to improve clinical prognosis,reduce infection and complication rates,and shor ten hospital stays.However,ongoing debates exist regarding the optimal timing,route selection,and complication management of EEN.Through a systematic review of the literature,this study synthesizes current evidence on EEN in elderly SAP populations,critically examines unresolved clinical controversies,and proposes future research priorities to inform evidence-based practice.
基金supported by the Natural Science Foundation of China(82151316,82171964,82230066,82202234,12326619)the Natural Science Foundation of Wuhan(2024040801020350)the Natural Science Foundation of Hubei(2021CFA046 and 2023AFB753).
文摘Transplant rejection remains a leading cause of graft failure after organ transplantation.Current immunosuppressive therapies can reduce acute rejection,but their lack of specificity often leads to systemic side effects and long-term complications.Therefore,novel strategies for localized and durable immune regulation are urgently needed.Nanomedicine offers a promising approach by enabling the precise delivery of therapeutic agents to specific cells or tissues involved in the rejection process.Through rational design,nanoparticles can be engineered to carry immunosuppressive molecules and selectively target transplanted organs,immune organs such as lymph nodes and spleen,or key immune cells,including dendritic cells,macrophages,and T lymphocytes.These delivery systems improve drug bioavailability,reduce off-target effects,and allow controlled or responsive drug release in complex immune environments.In this review,we summarize recent advances in nanoparticle-based interventions for transplant rejection.We discuss the design and classification of nanoparticles,delivery strategies tailored to different graft types,and therapeutic mechanisms targeting various stages and components of the immune response.Examples of both systemic and local administration routes are presented,demonstrating the versatility of nanomedicine in addressing diverse clinical scenarios.Despite encouraging progress in preclinical studies,several challenges continue to limit clinical translation.These include variability in nanoparticle behavior across species,difficulties in large-scale manufacturing,and the lack of standardized regulatory frameworks.Continued efforts in materials innovation,biological validation,and interdisciplinary collaboration are essential to fully realize the clinical potential of nanomedicine in transplantation.
基金financial support from the National Natural Science Foundation of China(52076209,22179027,22469006)the Foundation and Applied Foundation Research of Guangdong Province(2022B1515020045)the Heilongjiang Key Research and Development Project of China(JD22A026)。
文摘Hydrogen energy,as the ultimate clean energy,effectively avoids the greenhouse effect.Chemical looping hydrogen production(CLHP),a versatile energy conversion and production technology,has garnered extensive attention.CLHP demands redox catalysts with high oxygen capacity,regulatable reactivity,and structural integrity even under harsh operational conditions.Currently,sintering,agglomeration,and inactivation of redox catalysts during cyclic lattice oxygen release and restoration are challenging,hindering the wide industrialization of the chemical looping(CL)process.Moreover,the precise control of activity and reaction rate of the redox catalysts to flexibly accommodate the demands of various reaction substrates remains unclear.This paper introduces the design of a nano-scaled redox catalyst featuring a unique core-shell structure.By precisely controlling the shell thickness,a series of hierarchical Fe_(2)O_(3)@SiO_(2)redox catalysts were successfully synthesized.Building on this achievement,an in-depth investigation was conducted into the impact of the thickness and spatial structure of the inert support on the stability and mass transfer rate of the redox catalyst,aiming to achieve a perfect balance between these two factors during the CLHP process.A thin shell(70 nm)exhibits excellent cyclic stability,maintaining consistent performance in 30 consecutive redox cycles,while a thicker shell(200 nm)undergoes rapid deactivation due to the formation of a substantial amount of iron silicate.In-situ transmission electron microscopy(TEM)reveals that the SiO_(2)shell effectively restricts the agglomeration of Fe_(2)O_(3).The unique core-shell structure and controllable shell thickness offer novel insights into the flexible design of efficient and durable hierarchical redox catalysts with spatial structure.
基金financially supported by the National Natural Science Foundation of China(Nos.52172222 and 51972226)the National Natural Science Foundation of Tianjin City(No.20JCZDJC00570).
文摘The composites prepared by combining lightweight carbon materials with magnetic metals have demonstrated excellent dielectric and magnetic properties,indicating potential applications in the field of electromagnetic wave(EMW)absorption.However,the rational microstructure design and component optimization of these composites in regulating their magnetic-dielectric balance to achieve high-performance EMW absorption remains challenging.Herein,hierarchical yolk-shell Fe@SiO_(2)@NC composites with dual impedance matching layers and dual built-in electric fields were prepared by self-template aggregation and in situ reduction strategies.The introduction of a SiO_(2)wave-transparent layer into a conventional dielectric-magnetic system has resulted in the successful realization of nanoscale precise impedance matching regulation in absorbers,thereby enabling effective ultra-wideband EMW absorption.The dual impedance matching layers of the internal void layer and the SiO_(2)wave-transparent layer facilitate multiple scattering and reflection of EMWs within the absorbers,and the dual built-in electric fields of Fe/SiO_(2)and SiO_(2)/NC can effectively enhance interfacial polarization effect to attenuate EMWs.The predominantly optimized Fe@SiO_(2)@NC-2 exhibits an ultra-wide effective absorption bandwidth(EAB)of 7.10 GHz and an impressive minimum reflection loss(RL_(min))of−64.83 dB,indicating that optimizing the impedance matching via quantitative design can maximize the EMW absorption performance.This work provides a straightforward yet effective approach for constructing multi-component materials with hierarchical yolk-shell structure,which offers valuable insight into the microstructure design and component optimization of innovative EMW absorption materials.
文摘2021年7月发射的风云三号E星(FY-3E)是世界首颗民用晨昏轨道气象卫星,其搭载的WindRAD双频测风雷达具有全球海面风场探测能力。本文首先基于FY-3E/WindRAD L1级观测资料,研究了雷达海面后向散射和风场之间的非线性关系,分别建立了适用于C和Ku波段VV/HH极化的地球物理模式函数(GMF)。随后,结合最大似然估计法(MLE)对WindRAD散射计探测资料进行风场反演。利用海洋浮标、中法海洋卫星散射计(CSCAT)和美国国家环境预报中心(NCEP)模式风场资料对WindRAD反演风场进行验证。结果显示:WindRAD反演风速与浮标风速偏差约为0.2 m s^(-1),均方根误差(RMSE)在1.13~1.44 m s^(-1)之间,优于2 m s^(-1)的业务化应用的风速精度要求;两者风向偏差在1.4°~3.0°之间,RMSE在25.3°~30.1°之间。WindRAD和CSCAT风场具有较好的一致性,风速RMSE在1.37~1.6 m s^(-1)之间,风向RMSE在22.9°~25.9°之间。WindRAD和NCEP模式风速RMSE在1.87~2.23 m s^(-1)之间,风向RMSE在22.4°~27.1°之间。研究表明WindRAD散射计C和Ku波段VV/HH极化反演风场均具有较高的精度,充分显示了WindRAD载荷在全球海面风场探测方面的应用潜力和价值。
基金Supported by the National Science Fund for Distinguished Young Scholars from the National Natural Science Foundation of China,No.30325036a grant from the National Natural Science Foundation of China,No.30571640
文摘AIM： To establish a rapid and convenient animal model with hepatitis B virus （HBV） replication.METHODS： A naked DNA solution of HBV-replicationcompetent plasmid was transferred to BALB/C mice via the tail vein, using a hydrodynamic in vivo transfection procedure. After injection, these mice were sacrificed on d 1, 3, 4, 5, 7 and 10. HBV DNA replication intermediates in the liver were analyzed by Southern blot hybridization. The expression of hepatitis B core antigen （HBcAg） and hepatitis B surface antigen （HBsAg） in the liver was checked by immunohistochemistry. Serum HBsAg and hepatitis B e antigen （HBeAg） was detected by enzyme- linked immunosorbent assay （ELISA）. Inhibition of HBV replication was compared in HBV replication model mice treated intraperitoneally with polyinosinic-polytidylin acid （polyIC） or phosphate-buffered saline （PBS）.RESULTS： After hydrodynamic in vivo transfection, HBV DNA replication intermediates in the mouse liver were detectable on d 1 and abundant on d 3 and 4, the levels were slightly decreased and remained relatively stable between d 5 and 7, and were almost undetectable on d 10. The expression patterns of HBcAg and HBsAg were similar to that of HBV replication intermediate DNA, except that they reached a peak on d 1 after injection. No obvious differences in HBV DNA replication intermediates were observed in the left, right and middle lobes of the liver. After treatment with polyIC, the level of HBV intermediate DNA in the liver was lower than that in the control mice injected with PBS.CONCLUSION： A rapid and convenient mouse model with a high level of HBV replication was developed and used to investigate the inhibitory effect of polyIC on HBV replication, which provides a useful tool for future functional studies of the HBV genome.
基金Supported by the National Natural Science Foundation of China (No.50574046 and 50164002, )Natural Science Foun-dation of Yunnan Province (No. 2004E0012Q).
文摘Chemical looping combustion （CLC） of carbonaceous compounds has been proposed, in the past decade, as an efficient method for CO2 capture without cost of extra energy penalties. The technique involves the use of a metal oxide as an oxygen carrier that transfers oxygen from combustion air to fuels. The combustion is carried out in a two-step process： in the fuel reactor, the fuel is oxidized by a metal oxide, and in the air reactor, the reduced metal is oxidized back to the original phase. The use of iron oxide as an oxygen carrier has been investigated in this article. Particles composed of 80 wt% Fe2O3, together with Al2O3 as binder, have been prepared by impregnation methods. X-ray diffraction （XRD） analysis reveals that Fe2O3 does not interact with the Al2O3 binder after multi-cycles. The reactivity of the oxygen carrier particles has been studied in twenty-cycle reduction-oxidation tests in a thermal gravimetrical analysis （TGA） reactor. The components in the outlet gas have been analyzed. It has been observed that about 85% of CH4 converted to CO2 and H2O during most of the reduction periods. The oxygen carrier has kept quite a high reactivity in the twenty-cycle reactions. In the first twenty reaction cycles, the reaction rates became slightly higher with the number of cyclic reactions increasing, which was confirmed by the scanning electron microscopy （SEM） test results. The SEM analysis revealed that the pore size inside the particle had been enlarged by the thermal stress during the reaction, which was favorable for diffusion of the gaseous reactants into the particles. The experimental results suggested that the Fe2O3/Al2O3 oxygen carrier was a promising candidate for a CLC system.
基金supported by a grant from the National High Technology Research and Development Program("863" Program) of China(No. 2011AA100103)
文摘As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivated wheat has been dramatically narrowed by genetic erosion under the modem cultivation system, resulting in vulnerability to biotic and abiotic stresses （Jiang et al., 1994; Friebe et al., 1996）. The wild relatives of wheat represent a large reservoir of superior genes, and transferring these alien genes to modem cultivars through chromosome engineering is a successful method of broadening the genetic diversity of wheat （Chen et al., 2003;
基金financially supported by the National Natural Science Foundation of China(No.51472177)the China-EU Science and Technology Cooperation Project(No.SQ2013ZOA100006)
文摘Carbon and few-layer MoS2 nanosheets co- modified TiO2 nanocomposites （defined as MoS2-C@TiO2） were prepared through a facile one-step pyrolysis reaction technique. In this unique nanostructure, the TiO2 nanosh- eets with stable structure serve as the backbones, and carbon coating and few-layer MoS2 tightly adhere onto the surface of the TiO2. It needs to be pointed out that the carbon coating improves the overall electronic conductivity and the few-layer MoS2 facilitates the diffusion of lithium ions and offers more active sites for lithium-ion storage. As a result, when evaluated as lithium-ion battery anodes, the MoS2-C@TiO2 nanocomposites exhibit markedly enhanced lithium storage capability compared with pure TiO2. A high specific capacity of 180 mA.h.g-1 has been achieved during the preliminary cycles, and the specific capacity can maintain 160 mA.h.g-1 at a high current density of 1C （1C=167 mA.g-1） even after 300 discharge/ charge cycles, indicating the great potential of the MoS2- C@TiO2 on energy storage.
基金Project(21471162) supported by the National Natural Science Foundation of ChinaProject(2015H6016) supported by the Science and Technology Project of Fujian Province,China
文摘A new design route was presented to fabricate cobalt aluminum-layered double hydroxide(CoAl-LDH)thin layers whichgrow on carbon spheres(CSs)through a growth method.The CoAl-LDH thin layers consist of nanoflakes with a thickness of20nm.The galvanostatic charge-discharge test of the CoAl-LDH/CSs composite shows a great specific capacitance of1198F/g at1A/g(based on the mass of the CoAl-LDH/CSs composite)in6mol/L KOH solution,and the composite displays an impressive specificcapacitance of920F/g even at a high current density of10A/g.Moreover,the composite remains a specific capacitance of928F/gafter1000cycles at2A/g,and the specific capacitance retention is84%,indicating that the composite has high specific capacitance,excellent rate capability and good cycling stability in comparison to pristine CoAl-LDH.
基金The financial support of the National Natural Science Foundation of China(51406208,51406214)supported by the Science&Technology Research Project of Guangdong Province(2015A010106009)the support of Key Laboratory of Renewable Energy,Chinese Academy of Sciences(Y607j51001)
文摘Double-perovskite type oxide LaSrFeCoO（LSFCO） was used as oxygen carrier for chemical looping steam methane reforming（CL-SMR） due to its unique structure and reactivity. Two different oxidation routes,steam-oxidation and steam-air-stepwise-oxidation, were applied to investigate the recovery behaviors of the lattice oxygen in the oxygen carrier. The characterizations of the oxide were determined by X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, hydrogen temperature-programmed reduction（H-TPR） and scanning electron microscopy（SEM）. The fresh sample LSFCO exhibits a monocrystalline perovskite structure with cubic symmetry and high crystallinity, except for a little impurity phase due to the antisite defect of Fe/Co disorder. The deconvolution distribution of XPS patterns indicated that Co,and Fe are predominantly in an oxidized state(Feand Fe) and(Coand Co), while O 1s exists at three species of lattice oxygen, chemisorbed oxygen and physical adsorbed oxygen. The double perovskite structure and chemical composition recover to the original state after the steam and air oxidation, while the Co ion cannot incorporate into the double perovskite structure and thus form the CoO just via individual steam oxidation. In comparison to the two different oxidation routes, the sample obtained by steam-oxidation exhibits even higher CHconversion, CO and Hselectivity and stronger hydrogen generation capacity.
基金support of National Natural Science Foundation of China(22179027)gratefully acknowledged.This work was also supported by the Natural Science Foundation of Guangxi Province(2021GXNSFAA075063,2018GXNSFDA281005)+1 种基金the National Key Research and Development Program of China(2017YFE0105500)Science&Technology Research Project of Guangdong Province(2017A020216009).
文摘Chemical-looping oxidative dehydrogenation(CL-ODH)is a process designed for the conversion of alkanes into olefins through cyclic redox reactions,eliminating the need for gaseous O_(2).In this work,we investigated the use of Ca_(2)MnO_(4)-layered perovskites modified with NaNO_(3) dopants,serving as redox catalysts(also known as oxygen carriers),for the CL-ODH of ethane within a temperature range of 700-780℃.Our findings revealed that the incorporation of NaNO_(3) as a modifier significantly-nhanced the selectivity for-thylene generation from Ca_(2)MnO_(4).At 750℃and a gas hourly space velocity of 1300 h^(-1),we achieved an-thane conversion up to 68.17%,accompanied by a corresponding-thylene yield of 57.39%.X-ray photoelectron spectroscopy analysis unveiled that the doping NaNO_(3) onto Ca_(2)MnO_(4) not only played a role in reducing the oxidation state of Mn ions but also increased the lattice oxygen content of the redox catalyst.Furthermore,formation of NaNO_(3) shell on the surface of Ca_(2)MnO_(4) led to a reduction in the concentration of manganese sites and modulated the oxygen-releasing behavior in a step-wise manner.This modulation contributed significantly to the enhanced selectivity for ethylene of the NaNO_(3)-doped Ca_(2)MnO_(4) catalyst.These findings provide compelling evidence for the potential of Ca_(2)MnO_(4)-layered perovskites as promising redox catalysts in the context of CL-ODH reactions.
基金Project(51874372)supported by the National Natural Science Foundation of China
文摘A precursor of cobaltous dihydroxycarbonate was firstly prepared by precipitation reaction of cobalt sulfate solution and ammonium carbonate solution,and then a hydrothermal process for the precursor was conducted to obtain the spherical cobalt carbonate with low sulfur content.The experimental results show that the feeding method,final p H value of the precipitation reaction slurry and the concentration of the cobalt sulfate solution have obvious effects on the sulfur content,morphology and particle size distribution of the precursor.The sulfur content of the precursor is 0.0115 wt.%under the optimized conditions.The hydrothermal treatment with temperatures of 125-150℃can transform the precursor of cobaltous dihydroxycarbonate into spherical cobalt carbonate and decrease the sulfur content to 0.0030 wt.%in the obtained product.
基金the financial support by the National Natural Science Foundation of China(51406214 and51406208)supported by the Natural science Foundation of Guangdong Province(2015A030313719)the Science&Technology Research Project of Guangdong Province(2013B050800008)
文摘Chemical looping dry reforming（CLDR） is an innovative technology for CO2 utilization using the chemical looping principle.The CLDR process consists of three stages,i.e.CH4 reduction,CO2 reforming,and air oxidation.Spinel nickel ferrite（NiFe2O4） was prepared and its multi-cycle performance as an oxygen carrier for CLDR was experimentally investigated.X-ray diffraction（XRD） and Laser Raman spectroscopy showed that a pure spinel crystalline phase（NiFe2O4） was obtained by a parallel flow co-precipitating method.NiFe2O4was reduced into Fe-Ni alloy and wustite（FexO） during the CH4 reduction process.Subsequent oxidation of the reduced oxygen carrier was performed with CO2 as an oxidant to form an intermediate state：a mixture of spinel Ni（1-x）Fe（2＋x）O4,Fe（2＋y）O4 and metallic Ni.And CO was generated in parallel during this stage.Approximate 185 mL of CO was generated for 1 g spinel NiFe2O4 in a single cycle.The intermediate oxygen carrier was fully oxidized in the air oxidation stage to form a mixture of Ni（1＋x）Fe（2-x）O4 and Fe2O3.Although the original state of oxygen carrier（NiFe2O4） was not fully regenerated and agglomeration was observed,a good recyclability was shown in 10 successive redox cycles.
文摘Postoperative radiotherapy is a major treatment for patients with maxillary sinus carcinoma. However, the irregular resection cavity poses a technical difficulty for this treatment, causing uneven dose distribution to target volumes. In this study, we evaluated the dose distribution to target volumes and normal tissues in postoperative intensity-modulated radiotherapy (IMRT) after placing a water-filled balloon into the resection cavity. Three postoperative patients with advanced maxillary sinus carcinoma were selected in this trial. Water-filled balloons and supporting dental stents were fabricated according to the size of the maxillary resection cavity. Simulation CT scans were performed with or without water-filled balloons, IMRT treatment plans were established, and dose distribution to target volumes and organs at risk were evaluated. Compared to those in the treatment plan without balloons, the dose (D98) delivered to 98% of the gross tumor volume (GTV) increased by 2.1 Gy (P = 0.009), homogeneity index (HI) improved by 2.3% (P = 0.001), and target volume conformity index (TCI) of 68 Gy increased by 18.5% (P = 0.011) in the plan with balloons. Dosimetry endpoints of normal tissues around target regions in both plans were not significantly different (P > 0.05) except for the optic chiasm. In the plan without balloons, 68 Gy high-dose regions did not entirely cover target volumes in the ethmoid sinus, posteromedial wall of the maxillary sinus, or surgical margin of the hard palate. In contrast, 68 Gy high-dose regions entirely covered the GTV in the plan with balloons. These results suggest that placing a water-filled balloon in the resection cavity for postoperative IMRT of maxillary sinus c arcinoma can reduce low-dose regions and markedly and simultaneously increase dose homogeneity and conformity of target volumes.
基金The work was supported by the National Natural Science Foundation of China(81904049 and 81973690)Young Elite Scientists Sponsorship Program by China Association of Chinese Medicine(CACM-2018-QNRC2-C06).
文摘Background:Scalp combing,as an ancient method of health care,has been used for thousands of years in traditional Chinese medicine.Although this method is considered to be beneficial for the blood circulation of the head,the underlying mechanisms remain unclear.Methods:Both human participants and mice were used in this study.In participants,the scalp was stimulated by combing continuously for 5 min,and the temperature was measured using infrared thermal imaging before and after stimulation.In mice,the temperature was determined before and at 5,15,and 30 min after a 5-min scalp mechanical stimulation(SMS).Additionally,the vasculature of the mice was labeled with retro-orbital fluorescein isothiocyanate-dextran injection,and the capillaries were observed directly under a confocal microscope.Using in vivo CLARITY imaging and the spectrofluorometric detection of Evans Blue dye extravasation,the bloodebrain barrier permeability was assessed.Results:SMS increased the temperature of the left ear significantly in human(P=.0247)while can slightly increase the temperature of the right ear and the face without significant difference(P>.05).Moreover,SMS can significantly slow the decrease in the temperature of the external auditory canal at 5 min(P=.0153)and in body temperature at 15 min(P=.0295)after SMS whereas no significant difference in body temperature at 30 min(P>.05)compared with control mice.Furthermore,capillaries of the ear with a diameter of less than 8 mm were significantly dilated(P=.0006)following SMS and the number of dextran dots was higher at 15 min(P>.05)and 30 min(F=10.98,P=.037)after SMS intervention compared with control mice.Conclusion:Our study provides strong evidence to support the notion that scalp combing can improve extra-and intracranial blood circulation under healthy conditions.
基金funding from National Natural Science Foundation of China(No.31870387),China Scholarship Council.
文摘Background:Stem CO_(2) efflux(E_(S))plays a critical role in the carbon budget of forest ecosystems.Thinning is a core practice for sustainable management of plantations.It is therefore necessary and urgent to study the effect and mechanism of thinning intensity(TI)on E_(S).Methods:In this study,five TIs were applied in Larix principis-rupprechtii Mayr 21-,25-,and 41-year-old stands in North China in 2010.Portable infrared gas analyzer(Li-8100 A)was used to measure ES and its association with environmental factors at monthly intervals from May to October in 2013 to 2015.In addition,nutrients,wood structure and nonstructural carbon(NSC)data were measured in August 2016.Results:The results show that ES increased with increasing TI.The maximum ES values occurred at a TI of 35%(3.29,4.57 and 2.98μmol·m^(-2)·s^(-1))and were 1.54-,1.94-and 2.89-fold greater than the minimum E_(S) value in the CK stands(2.14,2.35 and 1.03μmol·m^(-2)·s^(-1))in July for the 21-,25-and 41-year-old forests,respectively.The E_(S) of the trees in low-density stands was more sensitive to temperature than that of the trees in high-density stands.Soluble sugars(SS)and temperature are the main factors affecting ES.When the stand density is low enough as 41-year-old L.principis-rupprechtii forests with TI 35%,bark thickness(BT)and humidity should be considered in addition to air temperature(T_(a)),wood temperature(T_(w)),sapwood width(SW),nitrogen concentration(N)and SS in the evaluation of ES.If a change in stand density is ignored,the CO_(2) released from individual 21-,25-and 41-year-old trees could be underestimated by 168.89%,101.94% and 200.49%,respectively.CO_(2) release was estimated based on the stem equation in combination with the factors influencing ES for reference.Conclusions:We suggest that it is not sufficient to conventional models which quantify ES only by temperature and that incorporating the associated drivers(e.g.density,SS,SW and N)based on stand density into conventional models can improve the accuracy of ES estimates.
