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Soil and microbial C:N:P stoichiometries play vital roles in regulating P transformation in agricultural ecosystems:A review 被引量:5
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作者 Guanglei CHEN Jiahui YUAN +4 位作者 Shenqiang WANG Yuting LIANG Dengjun WANG Yiyong ZHU Yu WANG 《Pedosphere》 SCIE CAS CSCD 2024年第1期44-51,共8页
Stoichiometry plays a crucial role in biogeochemical cycles and can modulate soil nutrient availability and functions. In agricultural ecosystems,phosphorus(P) fertilizers(organic or chemical) are often applied to ach... Stoichiometry plays a crucial role in biogeochemical cycles and can modulate soil nutrient availability and functions. In agricultural ecosystems,phosphorus(P) fertilizers(organic or chemical) are often applied to achieve high crop yields. However, P is readily fixed by soil particles, leading to low P use efficiency. Therefore, understanding the role of carbon:nitrogen:P stoichiometries of soil and microorganisms in soil P transformation is of great significance for P management in agriculture. This paper provides a comprehensive review of the recent research on stoichiometry effect on soil P transformation in agricultural ecosystems. Soil microorganisms play an important role in the transformation of soil non-labile inorganic P to microbial biomass P by regulating microbial biomass stoichiometry. They also mobilize soil unavailable organic P into available P by changing ecoenzyme stoichiometry. Organic materials, such as manure and straw, play an important role in promoting the transformation of insoluble P into available P as well. Additionally, periphytic biofilms can reduce P loss from rice field ecosystems. Agricultural stoichiometries are different from those of natural ecosystems and thereby should receive more attention due to the influences of anthropogenic factors. Therefore, it is necessary to conduct further stoichiometry research on the soil biochemical mechanisms underlying P transformation in agricultural ecosystems. In conclusion, understanding stoichiometry impact on soil P transformation is crucial for P management in agricultural ecosystems. 展开更多
关键词 ecoenzyme microbial biomass microbial community MICROORGANISM p availability periphytic biofilm soil p transformation
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Effect of Nitrogen Fertilizers on Movement and Transformation of Phosphorus in an Acid Soil 被引量:17
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作者 DU Zhen-Yu ZHOU Jian-Min WANG Huo-Yan DU Chang-Wen CHEN Xiao-Qin 《Pedosphere》 SCIE CAS CSCD 2005年第4期424-431,共8页
The effects of two different nitrogen fertilizers (urea and NH4C1) with monocalcium phosphate (MCP) on the movement and transformation of fertilizer P in soil microsites along with soil pH changes at different dis... The effects of two different nitrogen fertilizers (urea and NH4C1) with monocalcium phosphate (MCP) on the movement and transformation of fertilizer P in soil microsites along with soil pH changes at different distances from the fertilizer application site were studied in an incubation experiment. A highly acidic red soil (Ultisol, pH 4.57) from south China with MCP fertilizer alone or in combination with NH4C1 or urea was added to the surface of soil cylinders and packed in wax blocks. After 7 and 28 days, the extraction and analysis of each 2 mm layer from the interface of the soil and fertilizer showed that added NH4C1 or urea did not change the movement distance of fertilizer P. However, P transformation was significantly affected (P 〈 0.05). After 7 days, at 0-8 mm distance from the fertilizer site the addition of urea significantly decreased the water-extractable P concentration; however, after 28 days the effect of N addition had disappeared. Also,at limited distances close to the fertilizer site NH4Cl application with MCP significantly increased acid-extractable P and available P, while with the addition of urea they significantly decreased. Compared with application of MCP alone,addition of urea significantly increased soil pH in fertilizer microsites, whereas the addition of NH4Cl significantly decreased soil pH. 展开更多
关键词 NH4CL p movement p transformation red soil UREA
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Deghosting towed streamer data in τ/p domain based on rough sea surface reflectivity 被引量:15
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作者 张兴岩 潘冬明 +3 位作者 史文英 方中于 但志伟 张立霞 《Applied Geophysics》 SCIE CSCD 2015年第4期573-584,629,共13页
Currently, the deghosting of towed streamer seismic data assumes a flat sea level and a sea-surface reflection coefficient of-1; this decreases the precision of deghosting. A new method that considers the rough sea su... Currently, the deghosting of towed streamer seismic data assumes a flat sea level and a sea-surface reflection coefficient of-1; this decreases the precision of deghosting. A new method that considers the rough sea surface is proposed to suppress ghost reflections. The proposed deghosting method obtains the rough sea surface reflection coefficient using Gaussian statistics, and calculates the optimized deghosting operator in the r/p domain. The proposed method is closer to the actual sea conditions, offers an improved deghosting operator, removes the ghost reflections from marine towed seismic data, widens the bandwidth and restores the low-frequency information, and finally improves the signal-to- noise ratio and resolution of the seismic data. 展开更多
关键词 deghosting τ/p transform submarine tow cable sea surface reflection coefficient
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Phosphorus Changes and Sorption Characteristics in a Calcareous Soil Under Long-Term Fertilization 被引量:37
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作者 GUO Sheng-Li DANG Ting-Hui HAO Ming-De 《Pedosphere》 SCIE CAS CSCD 2008年第2期248-256,共9页
Knowledge of phosphorus (P) behavior in long-term fertilized soils is essential for programming fertilization practices and for sustaining environmental quality. The long-term (1984-1997) effects of various fertil... Knowledge of phosphorus (P) behavior in long-term fertilized soils is essential for programming fertilization practices and for sustaining environmental quality. The long-term (1984-1997) effects of various fertilization treatments on P changes and sorption isotherms as well as the relationship of soil properties to P sorption and P forms were evaluated in an Ustic Isohumisol, a calcareous soil, on the Loess Plateau, China. Compared to 1984, after 13 years of crop production, total soil P in the no-P treatments (control and N treatment) decreased by 5%-7%, but in the phosphorus fertilizer alone (P), nitrogen and phosphorus fertilizers in combination (NP), manure alone (M), and nitrogen and phosphorus fertilizers and manure in combination (NPM) treatments, it increased by 22%, 19%, 28%, and 58%, respectively. Residual fertilizer P was found mainly in NH4Ac-soluble P (Cas-P), followed by NaHCO3-soluble P (NaHCO3-P), and NH4F-soluble P (Al-P). Phosphorus sorption in the soils with different fertilization practices fit the Langmuir equations. Phosphorus sorption capacity in the no-P treatments increased, whereas it decreased in the P-included treatments (P, NP, and NPM treatments). Phosphorus sorption maximum (Qm) was significantly and negatively correlated to inorganic P including NaHCO3-P, Cas-P, NaOH-Na2CO3-soluble P (Fe-P), and Al-P (P ≤ 0.01). Moreover, long-term fertilization increased soil organic carbon in the NP, M, and NPM treatments and decreased pH in the NP and NPM treatments. Thus, the ability of the soil to release sorbed P to the environment increased under long-term P fertilization. 展开更多
关键词 calcareous soil long-term fertilization p accumulation p sorption p transformations
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Movement of Phosphorus in a Calcareous Soil as Affected by Humic Acid 被引量:5
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作者 DU Zhen-Yu WANG Qing-Hua +3 位作者 LIU Fang-Chun MA Hai-Lin MA Bing-Yao S.S.MALHI 《Pedosphere》 SCIE CAS CSCD 2013年第2期229-235,共7页
When humic acid (HA) and phosphorus (P) fertilizer are simultaneously applied to soil, HA may affect the movement of P. A laboratory incubation experiment was conducted to quantify the effects of a commercial HA produ... When humic acid (HA) and phosphorus (P) fertilizer are simultaneously applied to soil, HA may affect the movement of P. A laboratory incubation experiment was conducted to quantify the effects of a commercial HA product co-applied with monocalcium phosphate (MCP) on the distance of P movement and the concentration of P in various forms at different distances from the P fertilizer application site in a calcareous soil from northern China. Fertilizer MCP (at a rate equivalent to 26.6 kg P ha-1 ) was applied alone or in combination with HA (at 254.8 kg HA ha-1 ) to the surface of soil packed in cylinders (150 mm high and 50 mm internal diameter), and then incubated at 320 g kg-1 moisture content for 7 and 28 d periods. Extraction and analysis of each 2 mm soil layer in columns showed that the addition of HA to MCP increased the distance of P movement and the concentrations of water-extractable P, acid-extractable P and Olsen P in soil. The addition of HA to MCP could enhance P availability by increasing the distance of P movement and the concentration of extractable P in soil surrounding the P fertilizer. 展开更多
关键词 acid-extractable p LUVISOL monocalcium phosphate p transformation water-extractable p
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Medical Image Compression by Applying 3D DWT in PACS
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作者 Wang Si-xian Li Fei-peng +2 位作者 Zeng Fa-long Liao Meng-yang Li Hui 《Wuhan University Journal of Natural Sciences》 EI CAS 1999年第3期313-318,共6页
The process of image compression in a practical Picture Archiving and Communication System (PACS) was discussed with detail. To fully reduce the inter-slice correlation existing in the volumetric image sets generated ... The process of image compression in a practical Picture Archiving and Communication System (PACS) was discussed with detail. To fully reduce the inter-slice correlation existing in the volumetric image sets generated by CT and MR, 3D Discrete Wavelet Transformation (DWT) was introduced in our application. Instead of using a fixed quantizer of lossless low frequency and distinct loss of high frequency, an adaptive quantizer was devised taking MSE as the performance index. In the low frequency subband, DPCM was replaced withS+P transform to facilitate coding computation. Compared with JPEG or 2D DWT, our method is 20%–50% more efficient. Furthermore, preliminary tests showed that 33 dB may be the maximal distortion threshold for CT images. 展开更多
关键词 pACS 3D DWT S%pLUS%p transformation optimal bit allocation maximal distortion threshold
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Effects of bacteria on nitrogen and phosphorus release from river sediment 被引量:38
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作者 WU Qunhe ZHANG Renduo HUANG Shan ZHANG Hengjun 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第4期404-412,共9页
To better understand the mechanisms of eutrophication, we addressed the microbial processes that influence many key aspects of water-sediment systems. In this study, a large column experiment was conducted for 30 d. A... To better understand the mechanisms of eutrophication, we addressed the microbial processes that influence many key aspects of water-sediment systems. In this study, a large column experiment was conducted for 30 d. Along the column, solution samples were collected at different locations at different time. The samples were analyzed for physical, chemical, and biological properties of the sediment and overlying water. The results showed that the amount of nitrogen transforming bacteria was higher than that of phosphorous bacteria. The amount of nitrogen transforming bacteria was in the order: ammonifier 〉 denitrifying bacteria 〉 nitrobacteria and nitrosomonas. Principal component analysis indicated that the three main factors accounted for more than 90% overall contributions for bacterium growth, which represented nutrition, organics and oxygen, and pH and redox potential (Eh) of the environment. Corresponding to the bacteria, the concentrations of nitrogen in the system was in the order: ammonia (NH4+-N) 〉 nitrate (NO3^--N) 〉 nitrite (NO2^--N). The fluxes of N and P clearly showed a temporal release and adsorption processes in the water-sediment system. The large magnitude of N fluxes suggested that N might act as an important contamination source for the water quality. However, P exchange between the sediment and overlying water was less intensive during the experiment. 展开更多
关键词 EUTROpHICATION SEDIMENT p and N transforming bacteria
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Dysregulation of apoptosis in hepatocellular carcinoma cells 被引量:29
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作者 Isabel Fabregat 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第5期513-520,共8页
Hepatocellular carcinoma (HCC) is a major health prob- lem, being the sixth most common cancer world-wide. Dysregulation of the balance between proliferation and cell death represents a pro-tumorigenic principle in ... Hepatocellular carcinoma (HCC) is a major health prob- lem, being the sixth most common cancer world-wide. Dysregulation of the balance between proliferation and cell death represents a pro-tumorigenic principle in hu- man hepatocarcinogenesis. This review updates the recent relevant contributions reporting molecular altera- tions for HCC that induce an imbalance in the regulation of apoptosis. Alterations in the expression and/or activation of p53 are frequent in HCC cells, which confer on them resistance to chemotherapeutic drugs. Many HCCs are also insensitive to apoptosis induced either by death receptor ligands, such as FasL or TRAIL, or by transforming growth factor-beta (TGF-β). Although the expression of some pro-apoptotic genes is decreased, the balance between death and survival is dysregulated in HCC mainly due to overactivation of anti-apoptotic pathways. Indeed, some molecules involved in counter- acting apoptosis, such as Bcl-X1, Mcl-1, c-IAP1, XIAP or survivin are over-expressed in HCC cells. Furthermore, some growth factors that mediate cell survival are upregulated in HCC, as well as the molecules involved in the machinery responsible for cleavage of their pro- forms to an active peptide. The expression and/or activation of the JAK/STAT, PI3K/AKT and RAS/ERKs path- ways are enhanced in many HCC cells, conferring on them resistance to apoptotic stimuli. Finally, recent evi- dence indicates that inflammatory processes, as well as the epithelial-mesenchymal transitions that occur in HCC cells to facilitate their dissemination, are related to cell survival. Therefore, therapeutic strategies to selectively inhibit anti-apoptotic signals in liver tumor cells have the potential to provide powerful tools to treat HCC. 展开更多
关键词 Hepatocellular carcinoma cells ApOpTOSIS Liver cancer p53 Transforming growth factor-beta Liver inflammation Epithelial-to-mesenchymal transition
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The gene expression patterns of BMPR2,EP300,TGFβ2,and TNFAIP3 in B-Lymphoma cells 被引量:1
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作者 Dong-Mei He Hong Wu +3 位作者 Xiu-Li Wu Li Ding Ling Xu Yang-Qiu Li 《Cancer Biology & Medicine》 SCIE CAS CSCD 2014年第3期202-207,共6页
Objective: The results of a previous study showed that a clear dysregulation was evident in the global gene expression of the BCL11A-suppressed B-lymphoma cells. In this study, the bone morphogenetic protein receptor,... Objective: The results of a previous study showed that a clear dysregulation was evident in the global gene expression of the BCL11A-suppressed B-lymphoma cells. In this study, the bone morphogenetic protein receptor, type II(BMPR2), E1 A binding protein p300(EP300), transforming growth factor-β2(TGFβ2), and tumor necrosis factor, and alpha-induced protein 3(TNFAIP3) gene expression patterns in B-cell malignancies were studied. Methods: The relative expression levels of BMPR2, EP300, TGFβ2, and TNFAIP3 mRNA in B-lymphoma cell lines, myeloid cell lines, as well as in cells from healthy volunteers, were determined by real-time quantitative reverse transcriptpolymerase chain reaction(qRT-PCR) with SYBR Green Dye. Glyceraldehyde-3-phosphate dehydrogenase(GAPDH) was used as reference. Results: The expression level of TGFβ2 mRNA in B-lymphoma cell lines was significantly higher than those in the cells from the healthy control(P<0.05). However, the expression level of TNFAIP3 mRNA in B-malignant cells was significantly lower than that of the healthy control(P<0.05). The expression levels of BMPR2 and EP300 mRNA showed no significant difference between B-malignant cell lines and the healthy group(P>0.05). In B-lymphoma cell lines, correlation analyses revealed that the expression of BMPR2 and TNFAIP3(r=0.882, P=0.04) had significant positive relation. The expression levels of BMPR2, EP300, and TNFAIP3 mRNA in cell lines from myeloid leukemia were significantly lower than those in the cells from the healthy control(P<0.05). The expression levels of TGFβ2 mRNA showed no significant difference between myeloid leukemia cell lines and the healthy control or B-malignant cell lines(P>0.05). The expression levels of BMPR2, EP300, and TNFAIP3 mRNA in B-lymphoma cells were significantly higher than those of the myeloid leukemia cells(P<0.05).Conclusion: Different expression patterns of BMPR2, EP300, TGFβ2, and TNFAIP3 genes in B-lymphoma cells exist. 展开更多
关键词 Bone morphogenetic protein receptor type II(BMpR2) E1A binding protein p300(Ep300) transforming growth factor-β2(TGFβ2) tumor necrosis factor and alpha-induced protein 3(TNFAIp3) B-lymphoma cells myeloid leukemia cells quantitative reverse transcription polymerase chain reaction(qRT-pCR)
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Dielectric polarization in MgFe_(2)O_(4) coating and bulk doping to enhance high-voltage cycling stability of Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2) cathode material
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作者 Xiaoqian Xu Yizhen Huang +7 位作者 Dan Li Qichang Pan Sijiang Hu Yahao Li Hongqiang Wang Youguo Huang Fenghua Zheng Qingyu Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第6期200-211,I0007,共13页
Charging P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)to 4.5 V for higher capacity is enticing.However,it leads to severe capacity fading,ascribing to the lattice oxygen evolution and the P2-O2 phase transformation.Here,the Mg Fe_... Charging P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)to 4.5 V for higher capacity is enticing.However,it leads to severe capacity fading,ascribing to the lattice oxygen evolution and the P2-O2 phase transformation.Here,the Mg Fe_(2)O_(4) coating and Mg,Fe co-doping were constructed simultaneously by Mg,Fe surface treatment to suppress lattice oxygen evolution and P2-O2 phase transformation of P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)at deep charging.Through ex-situ X-ray diffraction(XRD)tests,we found that the Mg,Fe bulk co-doping could reduce the repulsion between transition metals and Na+/vacancies ordering,thus inhibiting the P2-O2 phase transition and significantly reducing the irreversible volume change of the material.Meanwhile,the internal electric field formed by the dielectric polarization of Mg Fe_(2)O_(4) effectively inhibits the outward migration of oxidized O^(a-)(a<2),thereby suppressing the lattice oxygen evolution at deep charging,confirmed by in situ Raman and ex situ XPS techniques.P2-Na NM@MF-3 shows enhanced high-voltage cycling performance with capacity retentions of 84.8% and 81.3%at 0.1 and 1 C after cycles.This work sheds light on regulating the surface chemistry for Na-layered oxide materials to enhance the high-voltage performance of Na-ion batteries. 展开更多
关键词 p2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2) MgFe_(2)O_(4) Bulk doping Lattice oxygen evolution p2-O2 phase transformation
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Water quality model with multiform of N/P transport and transformation in the Yangtze River Estuary 被引量:10
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作者 王彪 卢士强 +2 位作者 林卫青 杨漪帆 王道增 《Journal of Hydrodynamics》 SCIE EI CSCD 2016年第3期423-430,共8页
As the Yangtze River Estuary and adjacent sea have been classified as a problem area with regard to eutrophication, it is important to explore the spatial and temporal variations of nitrogen and phosphorus (N/P) nut... As the Yangtze River Estuary and adjacent sea have been classified as a problem area with regard to eutrophication, it is important to explore the spatial and temporal variations of nitrogen and phosphorus (N/P) nutrients in this area. Based on danish hydraulic institute (DHI)'s open platform Ecolab, a hydrodynamic and water quality model was developed for the Yangtze River Estuary, in which the transport and transformation processes of different forms of N/P nutrients were considered. Validations against measured data show that the model is overall reliable. Preliminary application of the model suggests that the model can simulate the characteristics of high phosphorus concentration area in the Yangtze River Estuary, and the high concentration area is closely related to the resuspension process of particulate phosphorus. 展开更多
关键词 water quality model Yangtze River Estuary N/p transport and transformation
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Xueshuantong for Injection(Lyophilized,注射用血栓通)Alleviates Streptozotocin-Induced Diabetic Retinopathy in Rats 被引量:8
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作者 LI Rui-lin WANG Jin-xin +5 位作者 CHAI Li-juan GUO Hong WANG Hong CHEN Lu HU Li-min WANG Shao-xia 《Chinese Journal of Integrative Medicine》 SCIE CAS CSCD 2020年第11期825-832,共8页
Objective To investigate the ameliorate effect and underlying mechanism of Xueshuantong for Injection(Lyophilized,注射用血栓通,XST)in streptozocin(STZ)-induced diabetic retinopathy(DR)rats.Methods Diabetes mellitus(DM... Objective To investigate the ameliorate effect and underlying mechanism of Xueshuantong for Injection(Lyophilized,注射用血栓通,XST)in streptozocin(STZ)-induced diabetic retinopathy(DR)rats.Methods Diabetes mellitus(DM)model was induced by intraperitoneal(i.p.)injection of STZ(60 mg/kg)in Sprague-Dawley rats.Diabetic rats were randomized into 3 groups(n=10)according to a random number table,including DM,XST50 and XST100 groups.XST treatment groups were daily i.p.injected with 50 or 100 mg/kg XST for 60 days,respectively.The control and DM groups were given i.p.injection with saline.Blood glucose level and body weight were recorded every week.Histological changes in the retina tissues were observed with hematoxylin-eosin staining.Apoptosis and inflammation related factors,including cleaved caspase-3,glial fifibrillary acidic protein(GFAP),tumor necrosis factor-α(TNF-α)and intercellular cell adhesion molecule-1(ICAM-1)were detected by Western blot or real-time polymerase chain reaction.Then,the levels of advanced glycation end product(AGE)and its receptor(RAGE)were investigated.Tight junctions proteins(Zonula occludens-1(ZO-1),Occludin and Claudin-5)of blood-retinal barrier were detected by Western blot.The levels of retinal fifibrosis,transforming growth factor-β1(TGF-β1)-Smad2/3 signaling pathway were evaluated at last.Results There was no signifificant difference in the body weight and blood glucose level between XST and DM groups(P>0.05).Compared with the DM group,XST treatment signifificantly increased the retinal thickness of rats(P<0.05 or P<0.01),and suppressed cleaved caspase-3 expression(P<0.01).XST increased the protein expressions of ZO-1,Occludin and Claudin-5 and decreased the mRNA expressions of matrix metalloproteinase 2(MMP-2)and MMP-9(P<0.05 or P<0.01).Moreover,XST signifificantly reduced the productions of AGE and RAGE proteins in the retina of rats(P<0.05 or P<0.01),suppressed the over-expression of TNF-α,and decreased the elevated level of ICAM-1 in retina of rats(P<0.05 or P<0.01).XST signifificantly reduced the levels ofα-smooth muscle actin(α-SMA),connective tissue growth factor(CTGF),TGF-β1 and phosphorylation of Smad2/3 protein in rats(P<0.05 or P<0.01).Conclusions XST had protective effects on DR with possible mechanisms of inhibiting the inflammation and apoptosis,up-regulating the expression of tight junction proteins,suppressing the productions of AGE and RAGE proteins,and blocking the TGF-β/Smad2/3 signaling pathway.XST treatment might play a role for the future therapeutic strategy against DR. 展开更多
关键词 Xueshuantong for Injection(Lyophilized) diabetic retinopathy panax notoginseng saponin transforming growth factor-βp/Smad2/3 signaling pathway Chinese medicine
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(p,q)-Analogue of Mittag-Leffler Function with(p,q)-Laplace Transform
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作者 Alok Jain Altaf Ahmad Bhat +1 位作者 Renu Jain Deepak Kumar Jain 《Analysis in Theory and Applications》 CSCD 2022年第3期351-360,共10页
The aim of this paper is to define(p,q)-analogue of Mittag-Leffler Function,by using(p,q)-Gamma function.Some transformation formulae are also derived by using the(p,q)-derivative.The(p,q)-analogue for this function p... The aim of this paper is to define(p,q)-analogue of Mittag-Leffler Function,by using(p,q)-Gamma function.Some transformation formulae are also derived by using the(p,q)-derivative.The(p,q)-analogue for this function provides elegant generalization of q-analogue of Mittag-Leffler function in connection with q-calculus.Moreover,the(p,q)-Laplace Transform of the Mittag-Leffler function has been obtained.Some special cases have also been discussed. 展开更多
关键词 (p q)-analogue of Mittag-Leffler function (p q)-Gamma function Q-CALCULUS (p q)-derivative operator (p q)-Laplace transform
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