Background: Paracetamol exerts toxic effects on liver cells through its metabolism into N-acetyl-p-benzoquinone imine (NAPQI), which is detoxified by conjugation with cellular glutathione (GSH). Once GSH is depleted, ...Background: Paracetamol exerts toxic effects on liver cells through its metabolism into N-acetyl-p-benzoquinone imine (NAPQI), which is detoxified by conjugation with cellular glutathione (GSH). Once GSH is depleted, NAPQI stimulates a range of oxidative reactions that result in cell necrosis. The aim of the present investigation is to find a new strategy that would selectively protect normal hepatic tissues and sensitize liver cancer cells to the toxic effects of paracetamol or its metabolite. This may lead to the development of a targeted therapy for liver cancer. Methods: The anti-proliferative effects of paracetamol and buthionine sulfoximine BSO (a glutathione depleting agent) alone and in combination on the liver cancer cells HepG2 and normal rat hepatocytes were investigated by sulphorhodamine-B assay. Effects on cell cycle regulation and induction of apoptosis were tested by flow cytometry. The level of prostaglandin expression was measured by ELISA. Results: The present study showed that both agents alone or in combination have anti-proliferative effects on both cell types. Surprisingly, BSO showed a cytoprotective effects on normal hepatocytes treated with high concentrations (1.75 and 2 mM) of paracetamol. This was confirmed by cell cycle analysis that recorded decreased fraction of sub-G1 cells indicating reduction of apoptosis in normal hepatocytes. Analysis of prostaglandin E2 revealed differential effects of paracetamol on normal and liver cancer cells. A significant increase in PGE2 level over the control was observed in normal hepatocytes whereas a significant decrease was seen in HepG2 cells after treatment with paracetamol. Conclusion: These results indicate that combination of paracetamol/BSO has differential effects on liver cancer cells and normal hepatocytes, which opens the avenue for a new effective and selective combination for management of liver cancer.展开更多
Needle chlorosis(NC)in Pinus taeda L.systems in Brazil becomes more frequent after second and third harvest rotation cycles.In a study to identify factors contributing to yellowing needle chorosis(YNC),trees were grow...Needle chlorosis(NC)in Pinus taeda L.systems in Brazil becomes more frequent after second and third harvest rotation cycles.In a study to identify factors contributing to yellowing needle chorosis(YNC),trees were grown in soils originating from contrasting parent materials,and soils and needles(whole,green and chlorotic portions)from 1-and 2-year-old branches and the first and second needle flush release at four sites with YNC on P.taeda were analyzed for various elements and properties.All soils had very low base levels(Ca^(2+),Mg^(2+)and K^(+))and P,suggesting a possible lack of multiple elements.YNC symptoms started at needle tips,then extended toward the needle base with time.First flush needles had longer portions with YNC than second flush needles did.Needles from the lower crown also had more symptoms along their length than those higher in the canopy.Symptoms were similar to those reported for Mg.In chlorotic portions,Mg and Ca concentrations were well below critical values;in particular,Mg levels were only one third of the critical value of 0.3 g kg^(-1).Collectively,results suggest that Mg deficiency is the primary reason for NC of P.taeda in various parent soils in Brazil.展开更多
To reduce CO_(2) emissions in response to global climate change,shale reservoirs could be ideal candidates for long-term carbon geo-sequestration involving multi-scale transport processes.However,most current CO_(2) s...To reduce CO_(2) emissions in response to global climate change,shale reservoirs could be ideal candidates for long-term carbon geo-sequestration involving multi-scale transport processes.However,most current CO_(2) sequestration models do not adequately consider multiple transport mechanisms.Moreover,the evaluation of CO_(2) storage processes usually involves laborious and time-consuming numerical simulations unsuitable for practical prediction and decision-making.In this paper,an integrated model involving gas diffusion,adsorption,dissolution,slip flow,and Darcy flow is proposed to accurately characterize CO_(2) storage in depleted shale reservoirs,supporting the establishment of a training database.On this basis,a hybrid physics-informed data-driven neural network(HPDNN)is developed as a deep learning surrogate for prediction and inversion.By incorporating multiple sources of scientific knowledge,the HPDNN can be configured with limited simulation resources,significantly accelerating the forward and inversion processes.Furthermore,the HPDNN can more intelligently predict injection performance,precisely perform reservoir parameter inversion,and reasonably evaluate the CO_(2) storage capacity under complicated scenarios.The validation and test results demonstrate that the HPDNN can ensure high accuracy and strong robustness across an extensive applicability range when dealing with field data with multiple noise sources.This study has tremendous potential to replace traditional modeling tools for predicting and making decisions about CO_(2) storage projects in depleted shale reservoirs.展开更多
There have been several studies on sulfur depletion in dense cores like TMC-1(Taurus Molecular Cloud 1),employing updated reaction networks for sulfur species to explain the missing sulfur in the gas within dense clou...There have been several studies on sulfur depletion in dense cores like TMC-1(Taurus Molecular Cloud 1),employing updated reaction networks for sulfur species to explain the missing sulfur in the gas within dense clouds.Most of these studies used a C/O ratio of 0.7 or lower.We present NSRT(NanShan 26m Radio Telescope)observations of TMC-1 alongside results from time-dependent chemical simulations using an updated chemical network.Our findings highlight the impact of the C/O ratio on the gas-phase evolution of C2S and C3S.The simulation results show that the C/O ratio is an important parameter,playing a fundamental role in determining the gas-phase abundances of sulfur species in dense cores.展开更多
This paper presents a system approach of mass balance calculations of ozone and other species under diffusion-convection-reaction processes to study the impacts of major ozone-depleting chemicals, chlorine (Cl) and ch...This paper presents a system approach of mass balance calculations of ozone and other species under diffusion-convection-reaction processes to study the impacts of major ozone-depleting chemicals, chlorine (Cl) and chlorine monoxide (ClO), and the effect of photolysis on ozone concentrations, ozone depletion, total ozone abundance, and ozone layer along the altitude in the stratosphere. The calculated ozone concentrations and profile of the layer followed a similar trend and were generally in good agreement with the measurements above the tropical area. The calculated peak of the layer was at the same mid-stratosphere at Z = 30 km with a peak concentration and total ozone abundance about 20% higher than the measured peak concentration of 8.0 ppm and total abundance of 399 DU. In the presence of Cl and ClO, the calculated ozone concentrations and total abundance were substantially reduced. Cl generally depleted more uniformly of ozone across the altitude, while ClO reduced substantially the ozone in the upper stratosphere and thus shifted the peak of the layer to a much lower elevation at Z = 14 km. Although both ClO and Cl are active ozone-depleting chemicals, ClO was found to have a more pronounced impact on ozone depletion and distribution than Cl. The possible explanations of these interesting phenomena were discussed and elaborated. The approach and calculations in this paper were shown to be useful in providing an initial insight into the structure and behavior of the complex ozone layer.展开更多
An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical react...An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical reaction equations was developed, validated, and used for studying the ozone concentrations, distribution and peak of the layer, ozone depletion and total ozone abundance in the stratosphere. The calculated ozone concentrations and profile at both the Equator and a 60˚N location were found to follow closely with the measured data. The calculated average ozone concentration was within 1% of the measured average, and the deviation of ozone profiles was within 14%. The monthly evolution of stratospheric ozone concentrations and distribution above the Equator was studied with results discussed in details. The influences of slow air movement in both altitudinal and radial directions on ozone concentrations and profile in the stratosphere were explored and discussed. Parametric studies of the influences of gas diffusivities of ozone D<sub>O3</sub> and active atomic oxygen D<sub>O</sub> on ozone concentrations and distributions were also studied and delineated. Having both influences through physical diffusion and chemical reactions, the diffusivity (and diffusion) of atomic oxygen D<sub>O</sub> was found to be more sensitive and important than that of ozone D<sub>O3</sub> on ozone concentrations and distribution. The 2-D ozone model present in this paper for stratospheric ozone and its layer and depletion is shown to be robust, convenient, efficient, and executable for analyzing the complex ozone phenomena in the stratosphere. .展开更多
Changes in refractive index and the corresponding changes in the characteristics of an optical waveguide in enabling propagation of light are the basis for many modern silicon photonic devices. Optical properties of t...Changes in refractive index and the corresponding changes in the characteristics of an optical waveguide in enabling propagation of light are the basis for many modern silicon photonic devices. Optical properties of these active nanoscale waveguides are sensitive to the little changes in geometry, external injection/biasing, and doping profiles, and can be crucial in design and manufacturing processes. This paper brings the active silicon waveguide for complete characterization of various distinctive guiding parameters, including perturbation in real and imaginary refractive index, mode loss, group velocity dispersion, and bending loss, which can be instrumental in developing optimal design specifications for various application-centric active silicon waveguides.展开更多
The accurate modeling of depletion,intricately tied to the solution of the neutron transport equation,is crucial for the design,analysis,and licensing of nuclear reactors and their fuel cycles.This paper introduces a ...The accurate modeling of depletion,intricately tied to the solution of the neutron transport equation,is crucial for the design,analysis,and licensing of nuclear reactors and their fuel cycles.This paper introduces a novel multi-group Monte-Carlo depletion calculation approach.Multi-group cross-sections(MGXS)are derived from both 3D whole-core model and 2D fuel subassembly model using the continuous-energy Monte-Carlo method.Core calculations employ the multi-group Monte-Carlo method,accommodating both homogeneous and specific local heterogeneous geometries.The proposed method has been validated against the MET-1000 metal-fueled fast reactors,using both the OECD/NEA benchmark and a new refueling benchmark introduced in this paper.Our findings suggest that microscopic MGXS,produced via the Monte-Carlo method,are viable for fast reactor depletion analyses.Furthermore,the locally heterogeneous model with angular-dependent MGXS offers robust predictions for core reactivity,control rod value,sodium void value,Doppler constants,power distribution,and concentration levels.展开更多
With the development of human society and the depletion of non-renewable energy sources,alternate energy resources are becoming an urgent demand.In recent years,energy storage and conversion devices have drawn wide at...With the development of human society and the depletion of non-renewable energy sources,alternate energy resources are becoming an urgent demand.In recent years,energy storage and conversion devices have drawn wide attention as a bridge between sustainable energy sources and daily life.展开更多
1.Foreword In light of the rapid depletion of fossil energy resources and the escalating environmental pollution crisis,there has been a significant surge in research focused on the development of technologies and mat...1.Foreword In light of the rapid depletion of fossil energy resources and the escalating environmental pollution crisis,there has been a significant surge in research focused on the development of technologies and materials for renewable energy conversion,utilization,and storage.This research area has gained paramount importance in addressing the pressing challenges of our time.展开更多
Single-species management ignores the interactions between species,and ecosystem-based fisheries management(EBFM)has become a main method to fisheries management.Understanding food web structures and species interacti...Single-species management ignores the interactions between species,and ecosystem-based fisheries management(EBFM)has become a main method to fisheries management.Understanding food web structures and species interactions is essential for the implementation of EBFM and maintenance of ecosystem functions.Overfishing is one of the main reasons behind the depletion,which could even lead to the depletion of some target species in local areas.So understanding the impacts of species depletion on food web structures is important for the implementation of EBFM.The impacts of species depletion can be transmitted through the food web and cause the local extinction of both target and non-target species.In this study,topological network analysis was applied to examine the impacts of species depletion on the food web structure of Haizhou Bay.Results showed that fine crayfish Leptochela gracilis,squid Loligo sp.,and Japanese snapping shrimp Alpheus japonicus have the highest numbers of outgoing links(48,32 and 31 respectively);thus,these species may be considered key prey species.Whitespotted conger Conger myriaster,fat greenling Hexagrammos otakii,and bluefin gurnard Chelidonichthys kumu were key predators with the highest number of incoming links(37,36 and 35 respectively).The competition graphs derived from the Haizhou Bay food web were highly connected(more than 40%predators sharing over 10 common prey species),and showed close trophic interaction between high trophic level fishes.Simulation analysis showed that the food web structure has small changes to the depletion of species in a highly complex food web.The most-connected target species did not necessarily indicate high structural importance;however,some species with low connectivity may demonstrate stronger trophic interactions and play important ecological roles in the food web.But most species were more sensitive to the depletion of the most-connected target species than other target species(for instance,for zooplankton,closeness centrality 13.876 in D6,but closeness centrality 82.143 in original food web).Therefore,EBFM should focus on the most-connected target species,but also on those species with few but strong links and feeding relationships in the food web.展开更多
We present here a kind of low-frequency oscillation in argon helicon discharge with a half helical antenna.This time-dependent instability shows a global quasi-periodic oscillation of plasma density and electron tempe...We present here a kind of low-frequency oscillation in argon helicon discharge with a half helical antenna.This time-dependent instability shows a global quasi-periodic oscillation of plasma density and electron temperature,with a typical frequency of a few tens of Hz which increases with external magnetic field as well as radiofrequency(RF)power.The relative oscillation amplitude decreases with magnetic field and RF power,but the rising time and pulse width do not change significantly under different discharge conditions.The oscillation can only be observed in some specific conditions of low magnetic fields and low RF power when the gas flows in from one end of the discharge area and out from another end.This global instability is suggested to be attributed to the pressure instability of neutral depletion,which is the result of compound action of gas depletion by heating expansion and gas replenishment from upstream.There are two kinds of oscillations,large and small amplitude oscillations,occurring in different discharge modes.This study could be a good verification of and complement to earlier experiments.This kind of spontaneous pulse phenomenon is also helpful in realizing a pulsing plasma source without a pulsed power supply.展开更多
Despite the diverse roles of tripartite motif(Trim)-containing proteins in the regulation of autophagy,the innate immune response,and cell differentiation,their roles in skeletal diseases are largely unknown.We recent...Despite the diverse roles of tripartite motif(Trim)-containing proteins in the regulation of autophagy,the innate immune response,and cell differentiation,their roles in skeletal diseases are largely unknown.We recently demonstrated that Trim21 plays a crucial role in regulating osteoblast(OB)differentiation in osteosarcoma.However,how Trim21 contributes to skeletal degenerative disorders,including osteoporosis,remains unknown.First,human and mouse bone specimens were evaluated,and the results showed that Trim21 expression was significantly elevated in bone tissues obtained from osteoporosis patients.Next,we found that global knockout of the Trim21 gene(KO,Trim2^(1-/-))resulted in higher bone mass compared to that of the control littermates.We further demonstrated that loss of Trim21 promoted bone formation by enhancing the osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)and elevating the activity of OBs;moreover,Trim21 depletion suppressed osteoclast(OC)formation of RAW264.7 cells.In addition,the differentiation of OCs from bone marrow-derived macrophages(BMMs)isolated from Trim21^(-/-)and Ctsk-cre;Trim21^(f/f)mice was largely compromised compared to that of the littermate control mice.Mechanistically,YAP1/β-catenin signaling was identified and demonstrated to be required for the Trim21-mediated osteogenic differentiation of BMSCs.More importantly,the loss of Trim21 prevented ovariectomy(OVX)-and lipopolysaccharide(LPS)-induced bone loss in vivo by orchestrating the coupling of OBs and OCs through YAP1 signaling.Our current study demonstrated that Trim21 is crucial for regulating OB-mediated bone formation and OC-mediated bone resorption,thereby providing a basis for exploring Trim21 as a novel dual-targeting approach for treating osteoporosis and pathological bone loss.展开更多
Undoped nickel-based catalysts supported on depleted uranium oxide allow one to carry out CO_(2)methanation process under extremely low reaction temperature under atmospheric pressure and powered by a contactless indu...Undoped nickel-based catalysts supported on depleted uranium oxide allow one to carry out CO_(2)methanation process under extremely low reaction temperature under atmospheric pressure and powered by a contactless induction heating.By adjusting the reaction conditions,the catalyst is able to perform CO_(2)methanation reaction under autothermal process operated inside a non-adiabatic reactor,without any external energy supply.Such autothermal process is possible thanks to the high apparent density of the UO_x which allows one to confine the reaction heat in a small catalyst volume in order to confine the exothermicity of the reaction inside the catalyst and to operate the reaction at equilibrium heat in-heat out.Such autothermal operation mode allows one to significantly reduce the complexity of the process compared to that operated using adiabatic reactor,where complete insulation is required to prevent heat disequilibrium,in order to reduce as much as possible,the heat exchange with the external medium.The catalyst displays an extremely high stability as a function of time on stream as no apparent deactivation.It is expected that such new catalyst with unprecedented catalytic performance could open new era in the field of heterogeneous catalysis where traditional supports show their limitations to operate catalytic processes under severe reaction conditions.展开更多
Sand production is a critical issue during the development of offshore oil and gas fields.Certain gas fields(e.g.the AB gas field)have high porosity and high permeability,and with water at the bottom of the reservoir,...Sand production is a critical issue during the development of offshore oil and gas fields.Certain gas fields(e.g.the AB gas field)have high porosity and high permeability,and with water at the bottom of the reservoir,the risk of sand production greatly increases at high differential pressures.Based on reservoir properties,geological conditions,production requirements,and well logging data,in this study an ultrasonic time difference method,a B index method,and a S index method are used together with a model of rock mass failure(accounting for water influx and pressure depletion)to qualitatively predict sand production.The results show that considered sample gas field has an overall high risk of sand production.The critical differential pressure(CDP)without water influx is in the range of 1.40 to 2.35 MPa,the CDP after water influx is from 0.60 to 1.41MPa.The CDP under pressure depletion is in the range of 1.20 to 1.92 MPa.The differential pressure charts of sand production are plotted,and the safe differential pressure windows with or without water influx are obtained.The model calculation results and the experimental results are consistent with the field production data,which indicates that the implemented prediction method could be taken as a reference for sand production prediction in similar deep water gas fields.展开更多
Background: Empagliflozin, a sodium-glucose co-transporter-2 (SGLT2) inhibitor is used as a monotherapy or in combination for lowering the elevated blood glucose level in patients with type 2 diabetes mellitus (T2DM)....Background: Empagliflozin, a sodium-glucose co-transporter-2 (SGLT2) inhibitor is used as a monotherapy or in combination for lowering the elevated blood glucose level in patients with type 2 diabetes mellitus (T2DM). It is often associated with certain adverse reactions (urinary tract infection (UTI), diabetes ketoacidosis (DKA), and genital infections). Thus, the Saudi Food and Drug Administration requested a post-authorisation safety study to monitor the safety of empagliflozin during the defined observation period. Methodology: The local, comparator, non-interventional, regulatory post-marketing study using “new user” design was conducted in patients with T2DM, treated with empagliflozin (10 or 25 mg) and dipeptidyl peptidase-4 (DPP-4) inhibitors (NCT03764631). Study was conducted from 2018 to 2020, wherein each patient was followed up for 12 months after the index period. Incidence and occurrence of DKA, severe UTIs, volume depletion and dehydration were observed along with metformin, insulin and treatment complexity status and adverse events in the index and Ramadan period. All data collected were analysed using descriptive statistics. Results: Among the 1502 patients enrolled (empagliflozin [n = 751] and DPP-4 inhibitors [n = 751]), 0.1% patients (n = 1) in each group and Conclusion: Empagliflozin was well tolerated over a period of 12 months, with no safety concerns and a favourable benefit/risk ratio.展开更多
This study attempts to investigate the interaction between lower and upper atmosphere, employing daily data of Total Ozone Column (TOC) and atmospheric parameter (cloud cover) over Nigeria from 1998-2012;in order to s...This study attempts to investigate the interaction between lower and upper atmosphere, employing daily data of Total Ozone Column (TOC) and atmospheric parameter (cloud cover) over Nigeria from 1998-2012;in order to study the dynamic effect of ozone on climate and vice versa. This is due to the fact that ozone and climate influence each other and the understanding of the dynamic effect of the interconnectivity is still an open research area. Monthly mean daily TOC and cloud cover data were obtained from the Earth Probe Total Ozone Mass Spectroscopy (EPTOMS) and the International Satellite Cloud Climatology Project (ISCCP)-D2 datasets respectively. Bivariate analysis and Mann Kendall trend tests were used in data analysis. MATLAB and ArcGIS software were employed in analyzing the data. Results reveal that TOC increased spatially from the coastal region to the north eastern region of the country. Seasonally, the highest value of TOC was observed at the peak of rainy season when cloud activity is very high, while the lowest value was recorded in dry season. These variations were attributed to rain producing mechanisms and atmospheric phenomena which influence the transport and distribution of ozone. Furthermore, the statistical analysis reveals significant relationship between TOC and low and middle cloud covers in contrast to high cloud cover. This relationship is consistent with previous studies using other atmospheric variables. This study has given scientific insight which is useful in understanding the coupling of the lower and upper atmosphere.展开更多
Silicon on insulator (SOI) technology permits a good solution to the miniaturization as the MOSFET size scales down. This paper is about to compare the electrical performance of nanoscale FD-SOI MOSFET at various gate...Silicon on insulator (SOI) technology permits a good solution to the miniaturization as the MOSFET size scales down. This paper is about to compare the electrical performance of nanoscale FD-SOI MOSFET at various gate lengths. The performance is compared and contrasted with the help of threshold voltage, subthreshold slope, on-state current and leakage current. Interestingly, by decreasing the gate length, the leakage current and on-state current are increased but the threshold voltage is decreased and the sub-threshold slope is degraded. Silvaco two-dimensional simulations are used to analyze the performance of the proposed structures.展开更多
This paper presents an engineering system approach of 2-D cylindrical model of mass balance calculations with convection,diffusion,and all potential photolysis,ozone generating and depleting chemical reactions conside...This paper presents an engineering system approach of 2-D cylindrical model of mass balance calculations with convection,diffusion,and all potential photolysis,ozone generating and depleting chemical reactions considered.This model was developed,validated,and tested under different conditions for the stratospheric ozone.The calculated ozone concentrations and profile in the stratosphere at both the Equator and mid-latitudinal location of 40°S were found to exhibit a similar and close profile and peak value of the published measured data.The discrepancy between the calculations and measurements for the average ozone concentration was shown to be less than 1%and the variation of distributions to be less than 19%.The latitudinal changes of ozone concentrations,distribution,and peak of the layer were found to shift from 9.41 ppm at mid-altitude of z=30 km at the Equator,to 7.81 ppm at z=34.5 km at 40°S,to 5.78 ppm at higher altitude z=39 km at the South Pole.The total ozone abundances at strategic latitudes at 0°S,20°S,40°S,60°S,and 90°S,were found to remain stable and not much changed,from 305 DU to 335 DU,except a smaller value of 288 DU at the South Pole.The possible explanations of ozone profile change and peak shifting as affected by solar/UV radiation,latitudinal locations,and ozone-depleting reactions were discussed and elaborated.The 2-D ozone Model presented in this paper is a robust,efficient,executable,and validated model for studying the complex ozone phenomena in the stratosphere.展开更多
文摘Background: Paracetamol exerts toxic effects on liver cells through its metabolism into N-acetyl-p-benzoquinone imine (NAPQI), which is detoxified by conjugation with cellular glutathione (GSH). Once GSH is depleted, NAPQI stimulates a range of oxidative reactions that result in cell necrosis. The aim of the present investigation is to find a new strategy that would selectively protect normal hepatic tissues and sensitize liver cancer cells to the toxic effects of paracetamol or its metabolite. This may lead to the development of a targeted therapy for liver cancer. Methods: The anti-proliferative effects of paracetamol and buthionine sulfoximine BSO (a glutathione depleting agent) alone and in combination on the liver cancer cells HepG2 and normal rat hepatocytes were investigated by sulphorhodamine-B assay. Effects on cell cycle regulation and induction of apoptosis were tested by flow cytometry. The level of prostaglandin expression was measured by ELISA. Results: The present study showed that both agents alone or in combination have anti-proliferative effects on both cell types. Surprisingly, BSO showed a cytoprotective effects on normal hepatocytes treated with high concentrations (1.75 and 2 mM) of paracetamol. This was confirmed by cell cycle analysis that recorded decreased fraction of sub-G1 cells indicating reduction of apoptosis in normal hepatocytes. Analysis of prostaglandin E2 revealed differential effects of paracetamol on normal and liver cancer cells. A significant increase in PGE2 level over the control was observed in normal hepatocytes whereas a significant decrease was seen in HepG2 cells after treatment with paracetamol. Conclusion: These results indicate that combination of paracetamol/BSO has differential effects on liver cancer cells and normal hepatocytes, which opens the avenue for a new effective and selective combination for management of liver cancer.
基金the National council for scientific and technological development(CNPq)and Higher Education Personnel Improvement Coordination(CAPES)。
文摘Needle chlorosis(NC)in Pinus taeda L.systems in Brazil becomes more frequent after second and third harvest rotation cycles.In a study to identify factors contributing to yellowing needle chorosis(YNC),trees were grown in soils originating from contrasting parent materials,and soils and needles(whole,green and chlorotic portions)from 1-and 2-year-old branches and the first and second needle flush release at four sites with YNC on P.taeda were analyzed for various elements and properties.All soils had very low base levels(Ca^(2+),Mg^(2+)and K^(+))and P,suggesting a possible lack of multiple elements.YNC symptoms started at needle tips,then extended toward the needle base with time.First flush needles had longer portions with YNC than second flush needles did.Needles from the lower crown also had more symptoms along their length than those higher in the canopy.Symptoms were similar to those reported for Mg.In chlorotic portions,Mg and Ca concentrations were well below critical values;in particular,Mg levels were only one third of the critical value of 0.3 g kg^(-1).Collectively,results suggest that Mg deficiency is the primary reason for NC of P.taeda in various parent soils in Brazil.
基金This work is funded by National Natural Science Foundation of China(Nos.42202292,42141011)the Program for Jilin University(JLU)Science and Technology Innovative Research Team(No.2019TD-35).The authors would also like to thank the reviewers and editors whose critical comments are very helpful in preparing this article.
文摘To reduce CO_(2) emissions in response to global climate change,shale reservoirs could be ideal candidates for long-term carbon geo-sequestration involving multi-scale transport processes.However,most current CO_(2) sequestration models do not adequately consider multiple transport mechanisms.Moreover,the evaluation of CO_(2) storage processes usually involves laborious and time-consuming numerical simulations unsuitable for practical prediction and decision-making.In this paper,an integrated model involving gas diffusion,adsorption,dissolution,slip flow,and Darcy flow is proposed to accurately characterize CO_(2) storage in depleted shale reservoirs,supporting the establishment of a training database.On this basis,a hybrid physics-informed data-driven neural network(HPDNN)is developed as a deep learning surrogate for prediction and inversion.By incorporating multiple sources of scientific knowledge,the HPDNN can be configured with limited simulation resources,significantly accelerating the forward and inversion processes.Furthermore,the HPDNN can more intelligently predict injection performance,precisely perform reservoir parameter inversion,and reasonably evaluate the CO_(2) storage capacity under complicated scenarios.The validation and test results demonstrate that the HPDNN can ensure high accuracy and strong robustness across an extensive applicability range when dealing with field data with multiple noise sources.This study has tremendous potential to replace traditional modeling tools for predicting and making decisions about CO_(2) storage projects in depleted shale reservoirs.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region (Grant No. 2022D01B221)he Xinjiang Tianchi Talent Program (2023)+4 种基金the NSRT operators for their assistance during the observationspartly supported by the OperationMaintenance and Upgrading Fund for Astronomical Telescopes and Facility Instrumentsbudgeted from the Ministry of Finance of China and administrated by the Chinese Academy of Sciencesthe Urumqi Nanshan Astronomy and Deep Space Exploration Observation and Research Station of Xinjiang (Grant No. XJYWZ2303)
文摘There have been several studies on sulfur depletion in dense cores like TMC-1(Taurus Molecular Cloud 1),employing updated reaction networks for sulfur species to explain the missing sulfur in the gas within dense clouds.Most of these studies used a C/O ratio of 0.7 or lower.We present NSRT(NanShan 26m Radio Telescope)observations of TMC-1 alongside results from time-dependent chemical simulations using an updated chemical network.Our findings highlight the impact of the C/O ratio on the gas-phase evolution of C2S and C3S.The simulation results show that the C/O ratio is an important parameter,playing a fundamental role in determining the gas-phase abundances of sulfur species in dense cores.
文摘This paper presents a system approach of mass balance calculations of ozone and other species under diffusion-convection-reaction processes to study the impacts of major ozone-depleting chemicals, chlorine (Cl) and chlorine monoxide (ClO), and the effect of photolysis on ozone concentrations, ozone depletion, total ozone abundance, and ozone layer along the altitude in the stratosphere. The calculated ozone concentrations and profile of the layer followed a similar trend and were generally in good agreement with the measurements above the tropical area. The calculated peak of the layer was at the same mid-stratosphere at Z = 30 km with a peak concentration and total ozone abundance about 20% higher than the measured peak concentration of 8.0 ppm and total abundance of 399 DU. In the presence of Cl and ClO, the calculated ozone concentrations and total abundance were substantially reduced. Cl generally depleted more uniformly of ozone across the altitude, while ClO reduced substantially the ozone in the upper stratosphere and thus shifted the peak of the layer to a much lower elevation at Z = 14 km. Although both ClO and Cl are active ozone-depleting chemicals, ClO was found to have a more pronounced impact on ozone depletion and distribution than Cl. The possible explanations of these interesting phenomena were discussed and elaborated. The approach and calculations in this paper were shown to be useful in providing an initial insight into the structure and behavior of the complex ozone layer.
文摘An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical reaction equations was developed, validated, and used for studying the ozone concentrations, distribution and peak of the layer, ozone depletion and total ozone abundance in the stratosphere. The calculated ozone concentrations and profile at both the Equator and a 60˚N location were found to follow closely with the measured data. The calculated average ozone concentration was within 1% of the measured average, and the deviation of ozone profiles was within 14%. The monthly evolution of stratospheric ozone concentrations and distribution above the Equator was studied with results discussed in details. The influences of slow air movement in both altitudinal and radial directions on ozone concentrations and profile in the stratosphere were explored and discussed. Parametric studies of the influences of gas diffusivities of ozone D<sub>O3</sub> and active atomic oxygen D<sub>O</sub> on ozone concentrations and distributions were also studied and delineated. Having both influences through physical diffusion and chemical reactions, the diffusivity (and diffusion) of atomic oxygen D<sub>O</sub> was found to be more sensitive and important than that of ozone D<sub>O3</sub> on ozone concentrations and distribution. The 2-D ozone model present in this paper for stratospheric ozone and its layer and depletion is shown to be robust, convenient, efficient, and executable for analyzing the complex ozone phenomena in the stratosphere. .
文摘Changes in refractive index and the corresponding changes in the characteristics of an optical waveguide in enabling propagation of light are the basis for many modern silicon photonic devices. Optical properties of these active nanoscale waveguides are sensitive to the little changes in geometry, external injection/biasing, and doping profiles, and can be crucial in design and manufacturing processes. This paper brings the active silicon waveguide for complete characterization of various distinctive guiding parameters, including perturbation in real and imaginary refractive index, mode loss, group velocity dispersion, and bending loss, which can be instrumental in developing optimal design specifications for various application-centric active silicon waveguides.
基金supported by the National Natural Science Foundation of China(Nos.12105170,12135008)Science and Technology on Reactor System Design Technology Laboratory.
文摘The accurate modeling of depletion,intricately tied to the solution of the neutron transport equation,is crucial for the design,analysis,and licensing of nuclear reactors and their fuel cycles.This paper introduces a novel multi-group Monte-Carlo depletion calculation approach.Multi-group cross-sections(MGXS)are derived from both 3D whole-core model and 2D fuel subassembly model using the continuous-energy Monte-Carlo method.Core calculations employ the multi-group Monte-Carlo method,accommodating both homogeneous and specific local heterogeneous geometries.The proposed method has been validated against the MET-1000 metal-fueled fast reactors,using both the OECD/NEA benchmark and a new refueling benchmark introduced in this paper.Our findings suggest that microscopic MGXS,produced via the Monte-Carlo method,are viable for fast reactor depletion analyses.Furthermore,the locally heterogeneous model with angular-dependent MGXS offers robust predictions for core reactivity,control rod value,sodium void value,Doppler constants,power distribution,and concentration levels.
文摘With the development of human society and the depletion of non-renewable energy sources,alternate energy resources are becoming an urgent demand.In recent years,energy storage and conversion devices have drawn wide attention as a bridge between sustainable energy sources and daily life.
文摘1.Foreword In light of the rapid depletion of fossil energy resources and the escalating environmental pollution crisis,there has been a significant surge in research focused on the development of technologies and materials for renewable energy conversion,utilization,and storage.This research area has gained paramount importance in addressing the pressing challenges of our time.
基金The National Key R&D Program of China under contract No.2018YFD0900904the National Natural Science Foundation of China under contract Nos 31772852 and 31802301。
文摘Single-species management ignores the interactions between species,and ecosystem-based fisheries management(EBFM)has become a main method to fisheries management.Understanding food web structures and species interactions is essential for the implementation of EBFM and maintenance of ecosystem functions.Overfishing is one of the main reasons behind the depletion,which could even lead to the depletion of some target species in local areas.So understanding the impacts of species depletion on food web structures is important for the implementation of EBFM.The impacts of species depletion can be transmitted through the food web and cause the local extinction of both target and non-target species.In this study,topological network analysis was applied to examine the impacts of species depletion on the food web structure of Haizhou Bay.Results showed that fine crayfish Leptochela gracilis,squid Loligo sp.,and Japanese snapping shrimp Alpheus japonicus have the highest numbers of outgoing links(48,32 and 31 respectively);thus,these species may be considered key prey species.Whitespotted conger Conger myriaster,fat greenling Hexagrammos otakii,and bluefin gurnard Chelidonichthys kumu were key predators with the highest number of incoming links(37,36 and 35 respectively).The competition graphs derived from the Haizhou Bay food web were highly connected(more than 40%predators sharing over 10 common prey species),and showed close trophic interaction between high trophic level fishes.Simulation analysis showed that the food web structure has small changes to the depletion of species in a highly complex food web.The most-connected target species did not necessarily indicate high structural importance;however,some species with low connectivity may demonstrate stronger trophic interactions and play important ecological roles in the food web.But most species were more sensitive to the depletion of the most-connected target species than other target species(for instance,for zooplankton,closeness centrality 13.876 in D6,but closeness centrality 82.143 in original food web).Therefore,EBFM should focus on the most-connected target species,but also on those species with few but strong links and feeding relationships in the food web.
基金National Natural Science Foundation of China(No.11975047).
文摘We present here a kind of low-frequency oscillation in argon helicon discharge with a half helical antenna.This time-dependent instability shows a global quasi-periodic oscillation of plasma density and electron temperature,with a typical frequency of a few tens of Hz which increases with external magnetic field as well as radiofrequency(RF)power.The relative oscillation amplitude decreases with magnetic field and RF power,but the rising time and pulse width do not change significantly under different discharge conditions.The oscillation can only be observed in some specific conditions of low magnetic fields and low RF power when the gas flows in from one end of the discharge area and out from another end.This global instability is suggested to be attributed to the pressure instability of neutral depletion,which is the result of compound action of gas depletion by heating expansion and gas replenishment from upstream.There are two kinds of oscillations,large and small amplitude oscillations,occurring in different discharge modes.This study could be a good verification of and complement to earlier experiments.This kind of spontaneous pulse phenomenon is also helpful in realizing a pulsing plasma source without a pulsed power supply.
基金supported by the Natural Science Foundation with grants from the National Key R&D Program of China(2018YFC2002500)National Natural Science Foundation of China(81602360,82072470,82350003,92049201)+6 种基金Key Laboratory Construction Project of Guangzhou Science and Technology Bureau(202102100007)supported by the Clinical Frontier Technology Program of the First Affiliated Hospital of Jinan University,China(No.JNU1AF-CFTP-2022-a01221)Natural Science Foundation of Guangdong Province(2021A1515012154,2019A1515011082,2017A030313665,2018A030313544,2020B1515120038)Science and Technology Projects in Guangzhou(201707010493,202102010069)Macao Foundation for Development of Science and Technology(0029/2019/A)Youth Talent Support Project of Guangzhou Association for Science&Technology(X20200301018)pilot project of clinical collaboration from National Administration of Traditional Chinese Medicine and National Health Commission of the People’s Republic of China and Logistics Support Department of the Central Military Commission。
文摘Despite the diverse roles of tripartite motif(Trim)-containing proteins in the regulation of autophagy,the innate immune response,and cell differentiation,their roles in skeletal diseases are largely unknown.We recently demonstrated that Trim21 plays a crucial role in regulating osteoblast(OB)differentiation in osteosarcoma.However,how Trim21 contributes to skeletal degenerative disorders,including osteoporosis,remains unknown.First,human and mouse bone specimens were evaluated,and the results showed that Trim21 expression was significantly elevated in bone tissues obtained from osteoporosis patients.Next,we found that global knockout of the Trim21 gene(KO,Trim2^(1-/-))resulted in higher bone mass compared to that of the control littermates.We further demonstrated that loss of Trim21 promoted bone formation by enhancing the osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)and elevating the activity of OBs;moreover,Trim21 depletion suppressed osteoclast(OC)formation of RAW264.7 cells.In addition,the differentiation of OCs from bone marrow-derived macrophages(BMMs)isolated from Trim21^(-/-)and Ctsk-cre;Trim21^(f/f)mice was largely compromised compared to that of the littermate control mice.Mechanistically,YAP1/β-catenin signaling was identified and demonstrated to be required for the Trim21-mediated osteogenic differentiation of BMSCs.More importantly,the loss of Trim21 prevented ovariectomy(OVX)-and lipopolysaccharide(LPS)-induced bone loss in vivo by orchestrating the coupling of OBs and OCs through YAP1 signaling.Our current study demonstrated that Trim21 is crucial for regulating OB-mediated bone formation and OC-mediated bone resorption,thereby providing a basis for exploring Trim21 as a novel dual-targeting approach for treating osteoporosis and pathological bone loss.
基金ORANO Chimie-Enrichissement Co.for the financial support of this project。
文摘Undoped nickel-based catalysts supported on depleted uranium oxide allow one to carry out CO_(2)methanation process under extremely low reaction temperature under atmospheric pressure and powered by a contactless induction heating.By adjusting the reaction conditions,the catalyst is able to perform CO_(2)methanation reaction under autothermal process operated inside a non-adiabatic reactor,without any external energy supply.Such autothermal process is possible thanks to the high apparent density of the UO_x which allows one to confine the reaction heat in a small catalyst volume in order to confine the exothermicity of the reaction inside the catalyst and to operate the reaction at equilibrium heat in-heat out.Such autothermal operation mode allows one to significantly reduce the complexity of the process compared to that operated using adiabatic reactor,where complete insulation is required to prevent heat disequilibrium,in order to reduce as much as possible,the heat exchange with the external medium.The catalyst displays an extremely high stability as a function of time on stream as no apparent deactivation.It is expected that such new catalyst with unprecedented catalytic performance could open new era in the field of heterogeneous catalysis where traditional supports show their limitations to operate catalytic processes under severe reaction conditions.
基金This research is financially supported by the National Natural Science Foundation of China(Grant No.52174015)supported by the Program for Changjiang Scholars and Innovative Research Team in University(IRT_14R58).
文摘Sand production is a critical issue during the development of offshore oil and gas fields.Certain gas fields(e.g.the AB gas field)have high porosity and high permeability,and with water at the bottom of the reservoir,the risk of sand production greatly increases at high differential pressures.Based on reservoir properties,geological conditions,production requirements,and well logging data,in this study an ultrasonic time difference method,a B index method,and a S index method are used together with a model of rock mass failure(accounting for water influx and pressure depletion)to qualitatively predict sand production.The results show that considered sample gas field has an overall high risk of sand production.The critical differential pressure(CDP)without water influx is in the range of 1.40 to 2.35 MPa,the CDP after water influx is from 0.60 to 1.41MPa.The CDP under pressure depletion is in the range of 1.20 to 1.92 MPa.The differential pressure charts of sand production are plotted,and the safe differential pressure windows with or without water influx are obtained.The model calculation results and the experimental results are consistent with the field production data,which indicates that the implemented prediction method could be taken as a reference for sand production prediction in similar deep water gas fields.
文摘Background: Empagliflozin, a sodium-glucose co-transporter-2 (SGLT2) inhibitor is used as a monotherapy or in combination for lowering the elevated blood glucose level in patients with type 2 diabetes mellitus (T2DM). It is often associated with certain adverse reactions (urinary tract infection (UTI), diabetes ketoacidosis (DKA), and genital infections). Thus, the Saudi Food and Drug Administration requested a post-authorisation safety study to monitor the safety of empagliflozin during the defined observation period. Methodology: The local, comparator, non-interventional, regulatory post-marketing study using “new user” design was conducted in patients with T2DM, treated with empagliflozin (10 or 25 mg) and dipeptidyl peptidase-4 (DPP-4) inhibitors (NCT03764631). Study was conducted from 2018 to 2020, wherein each patient was followed up for 12 months after the index period. Incidence and occurrence of DKA, severe UTIs, volume depletion and dehydration were observed along with metformin, insulin and treatment complexity status and adverse events in the index and Ramadan period. All data collected were analysed using descriptive statistics. Results: Among the 1502 patients enrolled (empagliflozin [n = 751] and DPP-4 inhibitors [n = 751]), 0.1% patients (n = 1) in each group and Conclusion: Empagliflozin was well tolerated over a period of 12 months, with no safety concerns and a favourable benefit/risk ratio.
文摘This study attempts to investigate the interaction between lower and upper atmosphere, employing daily data of Total Ozone Column (TOC) and atmospheric parameter (cloud cover) over Nigeria from 1998-2012;in order to study the dynamic effect of ozone on climate and vice versa. This is due to the fact that ozone and climate influence each other and the understanding of the dynamic effect of the interconnectivity is still an open research area. Monthly mean daily TOC and cloud cover data were obtained from the Earth Probe Total Ozone Mass Spectroscopy (EPTOMS) and the International Satellite Cloud Climatology Project (ISCCP)-D2 datasets respectively. Bivariate analysis and Mann Kendall trend tests were used in data analysis. MATLAB and ArcGIS software were employed in analyzing the data. Results reveal that TOC increased spatially from the coastal region to the north eastern region of the country. Seasonally, the highest value of TOC was observed at the peak of rainy season when cloud activity is very high, while the lowest value was recorded in dry season. These variations were attributed to rain producing mechanisms and atmospheric phenomena which influence the transport and distribution of ozone. Furthermore, the statistical analysis reveals significant relationship between TOC and low and middle cloud covers in contrast to high cloud cover. This relationship is consistent with previous studies using other atmospheric variables. This study has given scientific insight which is useful in understanding the coupling of the lower and upper atmosphere.
文摘Silicon on insulator (SOI) technology permits a good solution to the miniaturization as the MOSFET size scales down. This paper is about to compare the electrical performance of nanoscale FD-SOI MOSFET at various gate lengths. The performance is compared and contrasted with the help of threshold voltage, subthreshold slope, on-state current and leakage current. Interestingly, by decreasing the gate length, the leakage current and on-state current are increased but the threshold voltage is decreased and the sub-threshold slope is degraded. Silvaco two-dimensional simulations are used to analyze the performance of the proposed structures.
文摘This paper presents an engineering system approach of 2-D cylindrical model of mass balance calculations with convection,diffusion,and all potential photolysis,ozone generating and depleting chemical reactions considered.This model was developed,validated,and tested under different conditions for the stratospheric ozone.The calculated ozone concentrations and profile in the stratosphere at both the Equator and mid-latitudinal location of 40°S were found to exhibit a similar and close profile and peak value of the published measured data.The discrepancy between the calculations and measurements for the average ozone concentration was shown to be less than 1%and the variation of distributions to be less than 19%.The latitudinal changes of ozone concentrations,distribution,and peak of the layer were found to shift from 9.41 ppm at mid-altitude of z=30 km at the Equator,to 7.81 ppm at z=34.5 km at 40°S,to 5.78 ppm at higher altitude z=39 km at the South Pole.The total ozone abundances at strategic latitudes at 0°S,20°S,40°S,60°S,and 90°S,were found to remain stable and not much changed,from 305 DU to 335 DU,except a smaller value of 288 DU at the South Pole.The possible explanations of ozone profile change and peak shifting as affected by solar/UV radiation,latitudinal locations,and ozone-depleting reactions were discussed and elaborated.The 2-D ozone Model presented in this paper is a robust,efficient,executable,and validated model for studying the complex ozone phenomena in the stratosphere.
