BACKGROUND:Organ fibrosis has been viewed as one of the major medical problems, which can lead to progressive dysfunction of the liver, lung, kidney, skin, heart, and eventually death of patients. Fibrosis is initiate...BACKGROUND:Organ fibrosis has been viewed as one of the major medical problems, which can lead to progressive dysfunction of the liver, lung, kidney, skin, heart, and eventually death of patients. Fibrosis is initiated by a variety of pathological, physiological, biochemical, and physical factors. Regardless of their different etiologies, they all share a common pathogenetic process: excessive activation of the key profibrotic cytokine, transforming growth factor-β (TGF-β). Peroxisome proliferator-activated receptor γ (PPARγ), a ligand-activated transcription factor of the nuclear receptor superfamily, has received particular attention in recent years, because the activation of PPARγ by both natural and synthetic agonists could effectively inhibit TGF-β-induced profibrotic effects in many organs. DATA SOURCES: The English-language medical databases, PubMed, Elsevier and SpringerLink were searched for articles on PPARγ, TGF-β, and fibrosis, and related topics. RESULTS: TGF-β is recognized as a key profibrotic cytokine. Excessive activation of TGF-β increases synthesis of extracellular matrix proteins and decreases their degradation, associated with a gradual destruction of normal tissue architecture and function, whereas PPARγ agonists inhibit TGF-β signal transduction and are effective antifibrogenic agents in many organs including the liver, lung, kidney, skin and heart. CONCLUSIONS: The main antifibrotic activity of PPARγ agonists is to suppress the TGF-β signaling pathway by so-called PPARγ-dependent effect. In addition, PPARγ agonists, especially 15d-PGJ2, also exert potentially antifibrotic activity independent of PPARγ activation. TGF-β1/Smads signaling not only plays many essential roles in multiple developmental processes, butalso forms cross-talk networks with other signal pathways, and their inhibition by PPARγ agonists certainly affects the cytokine networks and causes non-suspected side-effects. Anti-TGF-β therapies with PPARγ agonists may have to be carefully tailored to be tissue-and target gene-specific to minimize side-effects, indicating a great challenge to the medical research at present.展开更多
针对低光照图像整体对比度低、细节显示不够清晰的问题,提出一种结合自适应伽马(Gamma)变换和带颜色恢复的多尺度Retinex(multi-scale Retinex with color restoration,MSRCR)算法的低光照图像增强方法。首先,为了动态地拉伸图像灰度值...针对低光照图像整体对比度低、细节显示不够清晰的问题,提出一种结合自适应伽马(Gamma)变换和带颜色恢复的多尺度Retinex(multi-scale Retinex with color restoration,MSRCR)算法的低光照图像增强方法。首先,为了动态地拉伸图像灰度值范围和提高图像对比度,进行RGB到HSV的颜色空间转换,采用多尺度融合方法提取图像的光照分量,并结合Gamma校正曲线实现图像自适应Gamma变换,提升图像的对比度;其次,针对自适应Gamma增强后的图像亮度较低的问题,采用MSRCR算法进一步提升图像亮度,并结合小波重构方法融合自适应Gamma变换后的图像和MSRCR增强后的图像;最后,由于小波重构后的图像局部存在过曝、过饱和的缺陷,结合基于模拟退火的自适应融合方法,将自适应Gamma变换后的图像和小波重构后的图像进行融合,得到最终的增强图像。所提方法既提高了低光照图像的对比度,使图像更有质感,又提升了图像的整体亮度,使暗部区域细节更加清晰;同时,弥补了MSRCR算法易出现色偏、颜色失真的缺陷。将所提方法应用于LOL低光照图像数据集,并与经典的图像增强算法进行对比。实验结果表明,所提方法使图像质量平均提高70%,图像结构相似性(structural similarity,SSIM)指数平均提高30%,图像信息熵平均提高20%,不仅提升了图像的对比度和亮度,而且避免了过曝、色偏、颜色失真等问题的出现。展开更多
Summary: The inhibitory mechanism of interferon-gamma (IFN-γ) on the fibroblasts from Tenon's capsule was studied. By using immunohistochemical SP method and pathological image system, the inhibitory effects of I...Summary: The inhibitory mechanism of interferon-gamma (IFN-γ) on the fibroblasts from Tenon's capsule was studied. By using immunohistochemical SP method and pathological image system, the inhibitory effects of IFN-γ on the expression of transforming growth factor beta receptor I in the in vitro cultured fibroblasts from Tenon's capsule were quantitatively analyzed. The results showed that IFN-γ could reduce the expression of transforming growth factor beta receptor I in the fibroblasts with the following dose-effect relationship: Y=1937.5-134.2 Igx (r=-0.971, P<0.01). It was concluded that IFN-γ could inhibit the expression of transforming growth factor beta receptor I in the fibroblasts from Tenon's capsule. The modulation of the transforming growth factor beta receptor I expression by IFN-γ may be beneficial to the alleviation of the hyperplasia of scar after trabeculectomy.展开更多
The present paper deals with the evaluation of the q-Analogues of Laplece transforms of a product of basic analogues of q2-special functions. We apply these transforms to three families of q-Bessel functions. Several ...The present paper deals with the evaluation of the q-Analogues of Laplece transforms of a product of basic analogues of q2-special functions. We apply these transforms to three families of q-Bessel functions. Several special cases have been deducted.展开更多
In this paper, we present a new representation of gamma function as a series of complex delta functions. We establish the convergence of this representation in the sense of distributions. It turns out that the gamma f...In this paper, we present a new representation of gamma function as a series of complex delta functions. We establish the convergence of this representation in the sense of distributions. It turns out that the gamma function can be defined over a space of complex test functions of slow growth denoted by Z. Some properties of gamma function are discussed by using the properties of delta function.展开更多
The objective of this note is to provide some(potentially useful) integral transforms(for example, Euler, Laplace, Whittaker etc.) associated with the generalized k-Bessel function defined by Saiful and Nisar [3]. We ...The objective of this note is to provide some(potentially useful) integral transforms(for example, Euler, Laplace, Whittaker etc.) associated with the generalized k-Bessel function defined by Saiful and Nisar [3]. We have also discussed some other transforms as special cases of our main results.展开更多
文摘BACKGROUND:Organ fibrosis has been viewed as one of the major medical problems, which can lead to progressive dysfunction of the liver, lung, kidney, skin, heart, and eventually death of patients. Fibrosis is initiated by a variety of pathological, physiological, biochemical, and physical factors. Regardless of their different etiologies, they all share a common pathogenetic process: excessive activation of the key profibrotic cytokine, transforming growth factor-β (TGF-β). Peroxisome proliferator-activated receptor γ (PPARγ), a ligand-activated transcription factor of the nuclear receptor superfamily, has received particular attention in recent years, because the activation of PPARγ by both natural and synthetic agonists could effectively inhibit TGF-β-induced profibrotic effects in many organs. DATA SOURCES: The English-language medical databases, PubMed, Elsevier and SpringerLink were searched for articles on PPARγ, TGF-β, and fibrosis, and related topics. RESULTS: TGF-β is recognized as a key profibrotic cytokine. Excessive activation of TGF-β increases synthesis of extracellular matrix proteins and decreases their degradation, associated with a gradual destruction of normal tissue architecture and function, whereas PPARγ agonists inhibit TGF-β signal transduction and are effective antifibrogenic agents in many organs including the liver, lung, kidney, skin and heart. CONCLUSIONS: The main antifibrotic activity of PPARγ agonists is to suppress the TGF-β signaling pathway by so-called PPARγ-dependent effect. In addition, PPARγ agonists, especially 15d-PGJ2, also exert potentially antifibrotic activity independent of PPARγ activation. TGF-β1/Smads signaling not only plays many essential roles in multiple developmental processes, butalso forms cross-talk networks with other signal pathways, and their inhibition by PPARγ agonists certainly affects the cytokine networks and causes non-suspected side-effects. Anti-TGF-β therapies with PPARγ agonists may have to be carefully tailored to be tissue-and target gene-specific to minimize side-effects, indicating a great challenge to the medical research at present.
文摘针对低光照图像整体对比度低、细节显示不够清晰的问题,提出一种结合自适应伽马(Gamma)变换和带颜色恢复的多尺度Retinex(multi-scale Retinex with color restoration,MSRCR)算法的低光照图像增强方法。首先,为了动态地拉伸图像灰度值范围和提高图像对比度,进行RGB到HSV的颜色空间转换,采用多尺度融合方法提取图像的光照分量,并结合Gamma校正曲线实现图像自适应Gamma变换,提升图像的对比度;其次,针对自适应Gamma增强后的图像亮度较低的问题,采用MSRCR算法进一步提升图像亮度,并结合小波重构方法融合自适应Gamma变换后的图像和MSRCR增强后的图像;最后,由于小波重构后的图像局部存在过曝、过饱和的缺陷,结合基于模拟退火的自适应融合方法,将自适应Gamma变换后的图像和小波重构后的图像进行融合,得到最终的增强图像。所提方法既提高了低光照图像的对比度,使图像更有质感,又提升了图像的整体亮度,使暗部区域细节更加清晰;同时,弥补了MSRCR算法易出现色偏、颜色失真的缺陷。将所提方法应用于LOL低光照图像数据集,并与经典的图像增强算法进行对比。实验结果表明,所提方法使图像质量平均提高70%,图像结构相似性(structural similarity,SSIM)指数平均提高30%,图像信息熵平均提高20%,不仅提升了图像的对比度和亮度,而且避免了过曝、色偏、颜色失真等问题的出现。
基金ThisprojectwassupportedbyagrantfromHubeiProvincialNaturalSciencesFoundationofChina (No .4 183) .
文摘Summary: The inhibitory mechanism of interferon-gamma (IFN-γ) on the fibroblasts from Tenon's capsule was studied. By using immunohistochemical SP method and pathological image system, the inhibitory effects of IFN-γ on the expression of transforming growth factor beta receptor I in the in vitro cultured fibroblasts from Tenon's capsule were quantitatively analyzed. The results showed that IFN-γ could reduce the expression of transforming growth factor beta receptor I in the fibroblasts with the following dose-effect relationship: Y=1937.5-134.2 Igx (r=-0.971, P<0.01). It was concluded that IFN-γ could inhibit the expression of transforming growth factor beta receptor I in the fibroblasts from Tenon's capsule. The modulation of the transforming growth factor beta receptor I expression by IFN-γ may be beneficial to the alleviation of the hyperplasia of scar after trabeculectomy.
文摘The present paper deals with the evaluation of the q-Analogues of Laplece transforms of a product of basic analogues of q2-special functions. We apply these transforms to three families of q-Bessel functions. Several special cases have been deducted.
文摘In this paper, we present a new representation of gamma function as a series of complex delta functions. We establish the convergence of this representation in the sense of distributions. It turns out that the gamma function can be defined over a space of complex test functions of slow growth denoted by Z. Some properties of gamma function are discussed by using the properties of delta function.
文摘The objective of this note is to provide some(potentially useful) integral transforms(for example, Euler, Laplace, Whittaker etc.) associated with the generalized k-Bessel function defined by Saiful and Nisar [3]. We have also discussed some other transforms as special cases of our main results.
