The Yuhuang hydrothermal field(YHF)is located between the Indomed and Gallieni fracture zones near the top of the off-axis slope on the south rift wall of Segment 29 on the ultraslow Southwest Indian Ridge(SWIR).Previ...The Yuhuang hydrothermal field(YHF)is located between the Indomed and Gallieni fracture zones near the top of the off-axis slope on the south rift wall of Segment 29 on the ultraslow Southwest Indian Ridge(SWIR).Previous studies have shown that sulfides in the YHF formed during different mineralization episodes and the YHF has the greatest potential for the formation of large-scale seafloor massive sulfide deposits.However,the sulfide chronology and hydrothermal activity of the YHF remain poorly constrained.In this study,mineralogical analyses and 230Th/U dating were performed.Hydrothermal activity may start about(35.9±2.3)ka from the southwest part of the YHF and may cease about(708±81)a ago from the northeast part of the YHF.The 74 nonzero chronological data from hydrothermal sulfide samples provide the first quantitative characterization of the spatial and temporal history along the SWIR.Hydrothermal activity in the SWIR has been relatively active over the past20 ka.In contrast,between 40 ka and 100 ka,hydrothermal activity was relatively infrequently and short in duration.The maximum activity occurred at 15–11 ka,9–7 ka,6–0.2 ka.There was a slight positive correlation between the maximal age and estimated surface area or estimated tonnage.The minimum mass accumulation rate of YHF is about 278 t/a,which is higher than most HFs related to ultramafic systems.The ultraslow spreading SWIR has the greatest potential to form large-scale seafloor massive sulfides(SMS)deposits.The results of this study provide new insights into the metallogenic mechanism of hydrothermal sulfides along ultraslow-spreading ridges.展开更多
We successfully fabricate a high performanceβ-phase(In_(0.09)Ga_(0.91))_(2)O_(3)single-crystalline film deep ultraviolet(DUV)solar-blind photodetector.The 2-inches high crystalline quality film is hetero-grown on the...We successfully fabricate a high performanceβ-phase(In_(0.09)Ga_(0.91))_(2)O_(3)single-crystalline film deep ultraviolet(DUV)solar-blind photodetector.The 2-inches high crystalline quality film is hetero-grown on the sapphire substrates using the plasma-assisted molecular beam epitaxy(PA-MBE).The smooth InGaO single crystalline film is used to construct the solar-blind DUV detector,which utilized an interdigitated Ti/Au electrode with a metal-semiconductor-metal structure.The device exhibits a low dark current of 40 pA(0 V),while its UV photon responsivity exceeds 450 A/W(50 V)at the peak wavelength of 232 nm with illumination intensity of 0.21 m W/cm^(2)and the UV/VIS rejection ratio(R232 nm/R380 nm)exceeds 4×10^(4).Furthermore,the devices demonstrate ultrafast transient characteristics for DUV signals,with fast-rising and fast-falling times of 80 ns and 420 ns,respectively.This excellent temporal dynamic behavior can be attributed to indium doping can adjust the electronic structure of Ga_(2)O_(3)alloys to enhance the performance of InGaO solar-blind detectors.Additionally,a two-dimensional DUV scanning image is captured using the InGaO photodetector as a sensor in an imaging system.Our results pave the way for future applications of two-dimensional array DUV photodetectors based on the large-scale InGaO heteroepitaxially grown alloy wide bandgap semiconductor films.展开更多
Background:Inflammatory bowel disease(IBD)is a chronic inflammatory disease of the gastrointestinal tract.The destruction of the intestinal epithelial barrier is one of the major pathological processes in IBD patholog...Background:Inflammatory bowel disease(IBD)is a chronic inflammatory disease of the gastrointestinal tract.The destruction of the intestinal epithelial barrier is one of the major pathological processes in IBD pathology.Growing evidence indicated that epithelial cell ferroptosis is linked to IBD and is considered a target process.Methods:RAS-selective lethal 3(RSL3)was used to induce ferroptosis in intestinal epithelial cell line No.6(IEC-6)cells,and cell ferroptosis and the effects of tanshinone IIA(Tan IIA)were determined by cell counting kit-8(CCK-8),reactive oxygen species(ROS)staining,Giemsa staining and transmission electron microscope(TEM).The cell viability of natural product library compounds was determined by CCK-8.The expression of ferroptosis-related genes were detected by real-time quantitative polymerase chain reaction(RT-qPCR)and western blot.Results:Treatment of IEC-6 cells results in the accumulation of ROS and typical morphological characteristics of ferroptosis.RSL3 treatment caused rapid cellular cytotoxicity which could be reversed by ferrostatin-1(Fer-1)in IEC-6 cells.Natural product library screening revealed that Tan IIA is a potent inhibitor of IEC-6 cell ferroptosis.Tan IIA could significantly protect the RSL3-induced ferroptosis of IEC-6 cells.Furthermore,the ferroptosis suppressors,glutathione peroxidase 4(GPX4),solute carrier family 7 member 11(SLC7A11),and miR-17-92 were found to be early response genes in RSL3-treated cells.Treatment of IEC-6 cells with Tan IIA resulted in upregulation of GPX4,SLC7A11,and miR-17-92.Conclusion:Our study demonstrated that Tan IIA protects IEC-6 cells from ferroptosis through the upregulation of GPX4,SLC7A11,and miR-17-92.The findings might provide a theoretical grounding for the future application of Tan IIA to treat or prevent IBD.展开更多
Mesenchymal stem cells(MSCs)have been widely used in regenerative medicine and clinical therapy due to their capabilities of proliferation,differentiation,and immune regulation.However,during in vitro expansion,MSCs a...Mesenchymal stem cells(MSCs)have been widely used in regenerative medicine and clinical therapy due to their capabilities of proliferation,differentiation,and immune regulation.However,during in vitro expansion,MSCs are prone to aging,which largely limits their application.Prostaglandin E-2(PGE-2)is a key effector secreted by MSCs to exert immunomodulatory effects.By screening the compound library for PGE-2 secretion,the antioxidant trolox was verified as a stimulator of MSCs to secrete PGE-2.The effect of antioxidant trolox on biological characteristics of MSCS,including aging,proliferation,and gene expression,was examined.The results demonstrated that trolox can resist aging,promote proliferation,and enhance PGE-2 secretion of MSCs without affecting their surface marker expression.Furthermore,trolox treatment up-regulates miR-17-92 clusters in MSCs and may contribute to its anti-aging effects.Thus,trolox addition might be beneficial for MSCs expansion and their application.展开更多
Epithelial-mesenchymal transition(EMT) and mesenchymal-epithelial transition(MET) are essential for embryonic development and also important in cancer progression. In a conventional model, epithelial-like cancer c...Epithelial-mesenchymal transition(EMT) and mesenchymal-epithelial transition(MET) are essential for embryonic development and also important in cancer progression. In a conventional model, epithelial-like cancer cells transit to mesenchymal-like tumor cells with great motility via EMT transcription factors; these mesenchymallike cells migrate through the circulation system, relocate to a suitable site and then convert back to an epithelial-like phenotype to regenerate the tumor. However, recent findings challenge this conventional model and support the existence of a stable hybrid epithelial/mesenchymal(E/M) tumor population. Hybrid E/M tumor cells exhibit both epithelial and mesenchymal properties, possess great metastatic and tumorigenic capacity and are associated with poorer patient prognosis. The hybrid E/M model and associated regulatory networks represent a conceptual change regarding tumor metastasis and organ colonization. It may lead to the development of novel treatment strategies to ultimately stop cancer progression and improve disease-free survival.展开更多
Simulating the typical carbonation step in a mineral CO_2 sequestration, precipitated calcium carbonate(PCC) was prepared by bubbling CO_2 gas into a rich Ca solution. These carbonation reactions were conducted at thr...Simulating the typical carbonation step in a mineral CO_2 sequestration, precipitated calcium carbonate(PCC) was prepared by bubbling CO_2 gas into a rich Ca solution. These carbonation reactions were conducted at three p H ranges, namely 10.0–9.0, 9.0–8.0, and 8.0–7.0, in which temperature and CO_2 flow rate are additional experimental variables. The PCC obtained in experiments was examined by Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD). It was found that supersaturation determined by p H value and flow rate of CO_2 has significant influence on polymorph of PCC. Vaterite was preferably formed at high supersaturation, while dissolution of metastable vaterite and crystallization of calcite occurred at low supersaturation. High temperature is a critical factor for the formation of aragonite. At 70 °C, vaterite, calcite and aragonite were observed to coexist in PCC because transformation from vaterite to aragonite via calcite occurred at this temperature. Scanning electron microscopy(SEM) technology was performed on prepared PCC, and various morphologies consistent with polymorphs were observed.展开更多
In this work, the group contribution method of Chickos et al. was applied to estimate the fusion enthalpy of isonicotinic acid, and the obtained result(29.2 k J·mol^(-1)) showed a large difference with the value(...In this work, the group contribution method of Chickos et al. was applied to estimate the fusion enthalpy of isonicotinic acid, and the obtained result(29.2 k J·mol^(-1)) showed a large difference with the value(135 k J·mol^(-1)) as reported from literatures and as determined by differential scanning calorimetry(DSC). The results of DSC/TG measurement showed that the phase transition of isonicotinic acid from 187.27 °C to277.47 °C underwent a sublimation process, with a sublimation enthalpy of 128.03 k J·mol^(-1). An efficient analytical technique combining pyrolysis and gas chromatography/mass spectrometry(Py-GC/MS) was used to prove this conclusion.展开更多
This paper proposes a new model of facility location problem referred to as k-product uncapacitated facility location problem with multi-type clients. The k-product uncapacitated facility location problem with multi- ...This paper proposes a new model of facility location problem referred to as k-product uncapacitated facility location problem with multi-type clients. The k-product uncapacitated facility location problem with multi- type clients consists of two set of sites, one is the set of demand points where clients are located and the other is the set of sites where facilities of unlimited capacities can be set up to serve the clients. Each facility can provide only one kind of products. Each client needs to be served by a set of facilities depending on which products it needs. Each facility can be set up only for one of the k products with a non-negative fixed cost determined by the product it is designated to provide. There is also a nonnegative cost of shipping goods between each pair of locations. The problem is to determine the set of facilities to be set up and to find an assignment of each client to a set of facilities so that the sum of the setup costs and the shipping costs is minimized. Under the assumption that the setting costs is zero and the shipping costs are in facilities centered metric space, it is shown that the problem with two kinds of clients is NP-complete. Furthermore a heuristic algorithm with worst case performance ratio not more than 2-1/k is presented for any integer k.展开更多
This paper is based on the research on the use of off-the-ball attack technique in the college basketball training, mainly using the data statistic method, the literature data method and the expert interview method, t...This paper is based on the research on the use of off-the-ball attack technique in the college basketball training, mainly using the data statistic method, the literature data method and the expert interview method, taking the provincial college basketball league as the research object, Of the college basketball team selected four teams with a typical representative, namely the local University of Technology men’s basketball team, the University of Science and Technology Men’s Basketball Team, University of Finance Men’s Basketball Team and the XX University Basketball Team, the college basketball training Discussion on Off - ball Attack Technique.展开更多
Natural killer(NK)cells are predominant innate lymphocytes that initiate the early immune response during infection.NK cells undergo a metabolic switch to fuel augmented proliferation and activation following infectio...Natural killer(NK)cells are predominant innate lymphocytes that initiate the early immune response during infection.NK cells undergo a metabolic switch to fuel augmented proliferation and activation following infection.Tumor necrosis factor-alpha(TNFα)is a well-known inflammatory cytokine that enhances NK cell function;however,the mechanism underlying NK cell proliferation in response to TNFαis not well established.Here,we demonstrated that upon infection/inflammation,NK cells upregulate the expression of TNF receptor 2(TNFR2),which is associated with increased proliferation,metabolic activity,and effector function.Notably,IL-18 can induce TNFR2 expression in NK cells,augmenting their sensitivity toward TNFα.Mechanistically,TNFα-TNFR2 signaling upregulates the expression of CD25(IL-2Rα)and nutrient transporters in NK cells,leading to a metabolic switch toward aerobic glycolysis.Transcriptomic analysis revealed significantly reduced expression levels of genes involved in cellular metabolism and proliferation in NK cells from TNFR2 KO mice.Accordingly,our data affirmed that genetic ablation of TNFR2 curtails CD25 upregulation and TNFα-induced glycolysis,leading to impaired NK cell proliferation and antiviral function during MCMV infection in vivo.Collectively,our results delineate the crucial role of the TNFα-TNFR2 axis in NK cell proliferation,glycolysis,and effector function.展开更多
Occurrence or absence of centennial-scale climatic variability during Marine Isotope Stage(MIS)7e,the first peak interval of the Penultimate Interglacial,remains ambiguous due to the limited available high-resolved re...Occurrence or absence of centennial-scale climatic variability during Marine Isotope Stage(MIS)7e,the first peak interval of the Penultimate Interglacial,remains ambiguous due to the limited available high-resolved records.Here,we present a decadal-resolved stalagmiteδ^(18)O record from northern China spanning from 242.3 to 236.8 ka BP,covering MIS7e.The composite KLSδ^(18)O record,integrating this study with the previous record in the same cave,shows a descending trend from TerminationⅢto MIS7e,which follows the increasing Northern Hemisphere summer insolation(NHSI).This observation further emphasizes the important influence of NHSI on the glacial/interglacial transition.There are more large-amplitude,millennial-to centennial-scale variability occurring during TerminationⅢcompared with MIS7e,implying that ice-sheet decay potentially plays an important role in climatic excursions.Four centennial-scale summer monsoon collapses,peaking at~242.1,~240.8,~239.3 and~238.2 ka BP,are detected in our new record,indicating the pervasiveness of the intra-interglacial climatic instability.Given the lack of solar activity and freshwater outbursts data during MIS7e,it is not possible to conclude about the drivers of the identified abrupt climatic anomalous.Following the dynamic mechanisms of sub-millennial climatic anomalous during early Holocene,we tentatively propose that slowdown of the meridional overturning circulation caused by freshwater fluxes into North Atlantic and/or attenuated solar irradiance is the potential forcing for the abrupt climate events within MIS7e.Additionally,attenuated solar irradiance could also result in climatic anomalies through low-latitude processes.展开更多
Background:Diffusion cell test is one of the most commonly used in vitro model to detect the percutaneous absorption of cosmetic ingredients.Although PRC State Administration of Quality Supervision and Quarantine has ...Background:Diffusion cell test is one of the most commonly used in vitro model to detect the percutaneous absorption of cosmetic ingredients.Although PRC State Administration of Quality Supervision and Quarantine has issued the guideline for the in vitro test method for the percutaneous absorption of drug molecules,there is still a lack of guideline for the percutaneous absorption test of cosmetic components.Objective:In order to improve the standardized level and make the in vitro percutaneous absorption test of cosmetic ingredients more comparable,based on the international and domestic experience,Transdermal Drug Delivery Committee of the World Federation of Chinese Medicine Societies organized the experts to discuss and formed this consensus as reference for the percutaneous absorption test of cosmetic components.Materials and Methods:To standardize the in vitro diffusion cell test technique for transdermal penetration of functional cosmetic ingredients,the Transdermal Drug Delivery Professional Committee of the World Federation of Societies of Traditional Chinese Medicine has organized many discussions among experts.展开更多
To investigate the pharmacokinetics of effective components of Bu Yang Huang Wu Decoction(BYHWD)with different dosages of Astragalus(Yiqi groups and Huoxue groups)applicating in rats with middle cerebral artery occlus...To investigate the pharmacokinetics of effective components of Bu Yang Huang Wu Decoction(BYHWD)with different dosages of Astragalus(Yiqi groups and Huoxue groups)applicating in rats with middle cerebral artery occlusion(MCAO).Replicating the animal model of cerebral ischemia-reperfusion in rats,establishing the liquid-mass spectrometry method for the determination of BYHWD and researching the pharmacokinetics of effective components of yiqi groups of BYHWD with different dosages of astragalus(3.09,6.17,12.34 g/Kg)and Huoxue goups(2.32 g/Kg)when applicated seperately in the rats suffering from cerebral ischemia reperfusion injury after femoral vein administration.The pharmacokinetics of formononetin and paeoniflorin in the different dosage groups of BYHWD met the one-compartment model,and the t1/2 of formononetin and paeoniflorin in the low-dose Yiqi and Huoxue groups were(88.43±3.82,69.18±0.11)min,MRT were(138.56±4.83,113.62±2.42)min,and AUC0-twere(28488.35±4800.32,140614.80±23954.05)ng/mL min;The t1/2 of formononetin and paeoniflorin in the middle-dose Yiqi group and Huoxue group were(82.16±1.78,67.08±3.69)min,and MRT were(127.95±2.70,116.58±4.13),AUC0-t were(48619.25±6745.75,159026.00±15003.33)ng/mL min;The t1/2 of formononetin and paeoniflorin in the high-dose Yiqi and Huoxue groups were(80.29±1.12,69.69±0.87)min and MRT was(128.79±1.46,118.78±4.56)min AUC0-twere(109942.90±13101.83,189417.90±22311.00)ng/mL·min.The concentration rate of formononetin t1/2 brain was decreased with increase of Astragalus dose.However,no significant difference between these two variables was found during experiments.Furthermore,the experiments showed that the increasing dose of astragalus would affect the pharmacokinetic behavior of paeoniflorin in the Huoxue groups.More specifically,the result showed that paeoniflorin can be metabolized more slowly in the body when applicated in high dose of the jaundice administration groups.In this way,the effect of paeoniflorin can be lasted for longer time in the body and brain.展开更多
In this paper, we investigate a class of quadratic Riemannian curvature functionals on closed smooth manifold M of dimension n ≥3 on the space of Riemannian metrics on M consisting of metrics with unit volume.We stud...In this paper, we investigate a class of quadratic Riemannian curvature functionals on closed smooth manifold M of dimension n ≥3 on the space of Riemannian metrics on M consisting of metrics with unit volume.We study the stability of these functionals at the metric with constant sectional curvature as its critical point.展开更多
基金The National Key R&D Program of China under contract No.2022YFE0140200the National Natural Science Foundation of China under contract Nos 42127807 and 42006074+1 种基金the China Ocean Mineral Resources R&D Association Project under contract Nos DY135-S1-1-02 and DY135-S1-1-01the Macao Science and Technology Development Fund under contract No.FDCT-002/2018/A1。
文摘The Yuhuang hydrothermal field(YHF)is located between the Indomed and Gallieni fracture zones near the top of the off-axis slope on the south rift wall of Segment 29 on the ultraslow Southwest Indian Ridge(SWIR).Previous studies have shown that sulfides in the YHF formed during different mineralization episodes and the YHF has the greatest potential for the formation of large-scale seafloor massive sulfide deposits.However,the sulfide chronology and hydrothermal activity of the YHF remain poorly constrained.In this study,mineralogical analyses and 230Th/U dating were performed.Hydrothermal activity may start about(35.9±2.3)ka from the southwest part of the YHF and may cease about(708±81)a ago from the northeast part of the YHF.The 74 nonzero chronological data from hydrothermal sulfide samples provide the first quantitative characterization of the spatial and temporal history along the SWIR.Hydrothermal activity in the SWIR has been relatively active over the past20 ka.In contrast,between 40 ka and 100 ka,hydrothermal activity was relatively infrequently and short in duration.The maximum activity occurred at 15–11 ka,9–7 ka,6–0.2 ka.There was a slight positive correlation between the maximal age and estimated surface area or estimated tonnage.The minimum mass accumulation rate of YHF is about 278 t/a,which is higher than most HFs related to ultramafic systems.The ultraslow spreading SWIR has the greatest potential to form large-scale seafloor massive sulfides(SMS)deposits.The results of this study provide new insights into the metallogenic mechanism of hydrothermal sulfides along ultraslow-spreading ridges.
基金the National Natural Science Foundation of China(Grant Nos.U22A2073,11974433,91833301,and 11974122)。
文摘We successfully fabricate a high performanceβ-phase(In_(0.09)Ga_(0.91))_(2)O_(3)single-crystalline film deep ultraviolet(DUV)solar-blind photodetector.The 2-inches high crystalline quality film is hetero-grown on the sapphire substrates using the plasma-assisted molecular beam epitaxy(PA-MBE).The smooth InGaO single crystalline film is used to construct the solar-blind DUV detector,which utilized an interdigitated Ti/Au electrode with a metal-semiconductor-metal structure.The device exhibits a low dark current of 40 pA(0 V),while its UV photon responsivity exceeds 450 A/W(50 V)at the peak wavelength of 232 nm with illumination intensity of 0.21 m W/cm^(2)and the UV/VIS rejection ratio(R232 nm/R380 nm)exceeds 4×10^(4).Furthermore,the devices demonstrate ultrafast transient characteristics for DUV signals,with fast-rising and fast-falling times of 80 ns and 420 ns,respectively.This excellent temporal dynamic behavior can be attributed to indium doping can adjust the electronic structure of Ga_(2)O_(3)alloys to enhance the performance of InGaO solar-blind detectors.Additionally,a two-dimensional DUV scanning image is captured using the InGaO photodetector as a sensor in an imaging system.Our results pave the way for future applications of two-dimensional array DUV photodetectors based on the large-scale InGaO heteroepitaxially grown alloy wide bandgap semiconductor films.
基金supported by the National Key Research and Development Program(Grant Number:2017YFA0105303)the Natural Science Foundation of Shandong Province(Grant Number:ZR2020MH327).
文摘Background:Inflammatory bowel disease(IBD)is a chronic inflammatory disease of the gastrointestinal tract.The destruction of the intestinal epithelial barrier is one of the major pathological processes in IBD pathology.Growing evidence indicated that epithelial cell ferroptosis is linked to IBD and is considered a target process.Methods:RAS-selective lethal 3(RSL3)was used to induce ferroptosis in intestinal epithelial cell line No.6(IEC-6)cells,and cell ferroptosis and the effects of tanshinone IIA(Tan IIA)were determined by cell counting kit-8(CCK-8),reactive oxygen species(ROS)staining,Giemsa staining and transmission electron microscope(TEM).The cell viability of natural product library compounds was determined by CCK-8.The expression of ferroptosis-related genes were detected by real-time quantitative polymerase chain reaction(RT-qPCR)and western blot.Results:Treatment of IEC-6 cells results in the accumulation of ROS and typical morphological characteristics of ferroptosis.RSL3 treatment caused rapid cellular cytotoxicity which could be reversed by ferrostatin-1(Fer-1)in IEC-6 cells.Natural product library screening revealed that Tan IIA is a potent inhibitor of IEC-6 cell ferroptosis.Tan IIA could significantly protect the RSL3-induced ferroptosis of IEC-6 cells.Furthermore,the ferroptosis suppressors,glutathione peroxidase 4(GPX4),solute carrier family 7 member 11(SLC7A11),and miR-17-92 were found to be early response genes in RSL3-treated cells.Treatment of IEC-6 cells with Tan IIA resulted in upregulation of GPX4,SLC7A11,and miR-17-92.Conclusion:Our study demonstrated that Tan IIA protects IEC-6 cells from ferroptosis through the upregulation of GPX4,SLC7A11,and miR-17-92.The findings might provide a theoretical grounding for the future application of Tan IIA to treat or prevent IBD.
基金supported by the Natural Science Foundation of Shandong Province(ZR2020MH327)Hebei Key Research and Development Program(19272405D)Jilin Scientific and Technological Development Program(Grant No.20190304041YY).
文摘Mesenchymal stem cells(MSCs)have been widely used in regenerative medicine and clinical therapy due to their capabilities of proliferation,differentiation,and immune regulation.However,during in vitro expansion,MSCs are prone to aging,which largely limits their application.Prostaglandin E-2(PGE-2)is a key effector secreted by MSCs to exert immunomodulatory effects.By screening the compound library for PGE-2 secretion,the antioxidant trolox was verified as a stimulator of MSCs to secrete PGE-2.The effect of antioxidant trolox on biological characteristics of MSCS,including aging,proliferation,and gene expression,was examined.The results demonstrated that trolox can resist aging,promote proliferation,and enhance PGE-2 secretion of MSCs without affecting their surface marker expression.Furthermore,trolox treatment up-regulates miR-17-92 clusters in MSCs and may contribute to its anti-aging effects.Thus,trolox addition might be beneficial for MSCs expansion and their application.
基金supported by operating grants from Canadian Breast Cancer Foundation-Ontario Regionthe Canadian Institutes of Health Research MOP111224 to LW
文摘Epithelial-mesenchymal transition(EMT) and mesenchymal-epithelial transition(MET) are essential for embryonic development and also important in cancer progression. In a conventional model, epithelial-like cancer cells transit to mesenchymal-like tumor cells with great motility via EMT transcription factors; these mesenchymallike cells migrate through the circulation system, relocate to a suitable site and then convert back to an epithelial-like phenotype to regenerate the tumor. However, recent findings challenge this conventional model and support the existence of a stable hybrid epithelial/mesenchymal(E/M) tumor population. Hybrid E/M tumor cells exhibit both epithelial and mesenchymal properties, possess great metastatic and tumorigenic capacity and are associated with poorer patient prognosis. The hybrid E/M model and associated regulatory networks represent a conceptual change regarding tumor metastasis and organ colonization. It may lead to the development of novel treatment strategies to ultimately stop cancer progression and improve disease-free survival.
基金Supported by the National Natural Science Foundation of China(41471412)
文摘Simulating the typical carbonation step in a mineral CO_2 sequestration, precipitated calcium carbonate(PCC) was prepared by bubbling CO_2 gas into a rich Ca solution. These carbonation reactions were conducted at three p H ranges, namely 10.0–9.0, 9.0–8.0, and 8.0–7.0, in which temperature and CO_2 flow rate are additional experimental variables. The PCC obtained in experiments was examined by Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD). It was found that supersaturation determined by p H value and flow rate of CO_2 has significant influence on polymorph of PCC. Vaterite was preferably formed at high supersaturation, while dissolution of metastable vaterite and crystallization of calcite occurred at low supersaturation. High temperature is a critical factor for the formation of aragonite. At 70 °C, vaterite, calcite and aragonite were observed to coexist in PCC because transformation from vaterite to aragonite via calcite occurred at this temperature. Scanning electron microscopy(SEM) technology was performed on prepared PCC, and various morphologies consistent with polymorphs were observed.
文摘In this work, the group contribution method of Chickos et al. was applied to estimate the fusion enthalpy of isonicotinic acid, and the obtained result(29.2 k J·mol^(-1)) showed a large difference with the value(135 k J·mol^(-1)) as reported from literatures and as determined by differential scanning calorimetry(DSC). The results of DSC/TG measurement showed that the phase transition of isonicotinic acid from 187.27 °C to277.47 °C underwent a sublimation process, with a sublimation enthalpy of 128.03 k J·mol^(-1). An efficient analytical technique combining pyrolysis and gas chromatography/mass spectrometry(Py-GC/MS) was used to prove this conclusion.
文摘This paper proposes a new model of facility location problem referred to as k-product uncapacitated facility location problem with multi-type clients. The k-product uncapacitated facility location problem with multi- type clients consists of two set of sites, one is the set of demand points where clients are located and the other is the set of sites where facilities of unlimited capacities can be set up to serve the clients. Each facility can provide only one kind of products. Each client needs to be served by a set of facilities depending on which products it needs. Each facility can be set up only for one of the k products with a non-negative fixed cost determined by the product it is designated to provide. There is also a nonnegative cost of shipping goods between each pair of locations. The problem is to determine the set of facilities to be set up and to find an assignment of each client to a set of facilities so that the sum of the setup costs and the shipping costs is minimized. Under the assumption that the setting costs is zero and the shipping costs are in facilities centered metric space, it is shown that the problem with two kinds of clients is NP-complete. Furthermore a heuristic algorithm with worst case performance ratio not more than 2-1/k is presented for any integer k.
文摘This paper is based on the research on the use of off-the-ball attack technique in the college basketball training, mainly using the data statistic method, the literature data method and the expert interview method, taking the provincial college basketball league as the research object, Of the college basketball team selected four teams with a typical representative, namely the local University of Technology men’s basketball team, the University of Science and Technology Men’s Basketball Team, University of Finance Men’s Basketball Team and the XX University Basketball Team, the college basketball training Discussion on Off - ball Attack Technique.
文摘Natural killer(NK)cells are predominant innate lymphocytes that initiate the early immune response during infection.NK cells undergo a metabolic switch to fuel augmented proliferation and activation following infection.Tumor necrosis factor-alpha(TNFα)is a well-known inflammatory cytokine that enhances NK cell function;however,the mechanism underlying NK cell proliferation in response to TNFαis not well established.Here,we demonstrated that upon infection/inflammation,NK cells upregulate the expression of TNF receptor 2(TNFR2),which is associated with increased proliferation,metabolic activity,and effector function.Notably,IL-18 can induce TNFR2 expression in NK cells,augmenting their sensitivity toward TNFα.Mechanistically,TNFα-TNFR2 signaling upregulates the expression of CD25(IL-2Rα)and nutrient transporters in NK cells,leading to a metabolic switch toward aerobic glycolysis.Transcriptomic analysis revealed significantly reduced expression levels of genes involved in cellular metabolism and proliferation in NK cells from TNFR2 KO mice.Accordingly,our data affirmed that genetic ablation of TNFR2 curtails CD25 upregulation and TNFα-induced glycolysis,leading to impaired NK cell proliferation and antiviral function during MCMV infection in vivo.Collectively,our results delineate the crucial role of the TNFα-TNFR2 axis in NK cell proliferation,glycolysis,and effector function.
基金supported by the National Natural Science Foundation of China (Grant Nos.42172208,41772184&41731174)the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No.XDB26020000)。
文摘Occurrence or absence of centennial-scale climatic variability during Marine Isotope Stage(MIS)7e,the first peak interval of the Penultimate Interglacial,remains ambiguous due to the limited available high-resolved records.Here,we present a decadal-resolved stalagmiteδ^(18)O record from northern China spanning from 242.3 to 236.8 ka BP,covering MIS7e.The composite KLSδ^(18)O record,integrating this study with the previous record in the same cave,shows a descending trend from TerminationⅢto MIS7e,which follows the increasing Northern Hemisphere summer insolation(NHSI).This observation further emphasizes the important influence of NHSI on the glacial/interglacial transition.There are more large-amplitude,millennial-to centennial-scale variability occurring during TerminationⅢcompared with MIS7e,implying that ice-sheet decay potentially plays an important role in climatic excursions.Four centennial-scale summer monsoon collapses,peaking at~242.1,~240.8,~239.3 and~238.2 ka BP,are detected in our new record,indicating the pervasiveness of the intra-interglacial climatic instability.Given the lack of solar activity and freshwater outbursts data during MIS7e,it is not possible to conclude about the drivers of the identified abrupt climatic anomalous.Following the dynamic mechanisms of sub-millennial climatic anomalous during early Holocene,we tentatively propose that slowdown of the meridional overturning circulation caused by freshwater fluxes into North Atlantic and/or attenuated solar irradiance is the potential forcing for the abrupt climate events within MIS7e.Additionally,attenuated solar irradiance could also result in climatic anomalies through low-latitude processes.
文摘Background:Diffusion cell test is one of the most commonly used in vitro model to detect the percutaneous absorption of cosmetic ingredients.Although PRC State Administration of Quality Supervision and Quarantine has issued the guideline for the in vitro test method for the percutaneous absorption of drug molecules,there is still a lack of guideline for the percutaneous absorption test of cosmetic components.Objective:In order to improve the standardized level and make the in vitro percutaneous absorption test of cosmetic ingredients more comparable,based on the international and domestic experience,Transdermal Drug Delivery Committee of the World Federation of Chinese Medicine Societies organized the experts to discuss and formed this consensus as reference for the percutaneous absorption test of cosmetic components.Materials and Methods:To standardize the in vitro diffusion cell test technique for transdermal penetration of functional cosmetic ingredients,the Transdermal Drug Delivery Professional Committee of the World Federation of Societies of Traditional Chinese Medicine has organized many discussions among experts.
基金National Natural Science Foundation of China(Grant No.81373973,81573872,81873228)Science and Technology Planning Project of Guangdong Province(Grant No.2017KZDXM018).
文摘To investigate the pharmacokinetics of effective components of Bu Yang Huang Wu Decoction(BYHWD)with different dosages of Astragalus(Yiqi groups and Huoxue groups)applicating in rats with middle cerebral artery occlusion(MCAO).Replicating the animal model of cerebral ischemia-reperfusion in rats,establishing the liquid-mass spectrometry method for the determination of BYHWD and researching the pharmacokinetics of effective components of yiqi groups of BYHWD with different dosages of astragalus(3.09,6.17,12.34 g/Kg)and Huoxue goups(2.32 g/Kg)when applicated seperately in the rats suffering from cerebral ischemia reperfusion injury after femoral vein administration.The pharmacokinetics of formononetin and paeoniflorin in the different dosage groups of BYHWD met the one-compartment model,and the t1/2 of formononetin and paeoniflorin in the low-dose Yiqi and Huoxue groups were(88.43±3.82,69.18±0.11)min,MRT were(138.56±4.83,113.62±2.42)min,and AUC0-twere(28488.35±4800.32,140614.80±23954.05)ng/mL min;The t1/2 of formononetin and paeoniflorin in the middle-dose Yiqi group and Huoxue group were(82.16±1.78,67.08±3.69)min,and MRT were(127.95±2.70,116.58±4.13),AUC0-t were(48619.25±6745.75,159026.00±15003.33)ng/mL min;The t1/2 of formononetin and paeoniflorin in the high-dose Yiqi and Huoxue groups were(80.29±1.12,69.69±0.87)min and MRT was(128.79±1.46,118.78±4.56)min AUC0-twere(109942.90±13101.83,189417.90±22311.00)ng/mL·min.The concentration rate of formononetin t1/2 brain was decreased with increase of Astragalus dose.However,no significant difference between these two variables was found during experiments.Furthermore,the experiments showed that the increasing dose of astragalus would affect the pharmacokinetic behavior of paeoniflorin in the Huoxue groups.More specifically,the result showed that paeoniflorin can be metabolized more slowly in the body when applicated in high dose of the jaundice administration groups.In this way,the effect of paeoniflorin can be lasted for longer time in the body and brain.
基金supported by National Natural Science Foundation of China(Grant No.11571304)
文摘In this paper, we investigate a class of quadratic Riemannian curvature functionals on closed smooth manifold M of dimension n ≥3 on the space of Riemannian metrics on M consisting of metrics with unit volume.We study the stability of these functionals at the metric with constant sectional curvature as its critical point.