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Search Results: 1 - 10 of 158556 matches for " Feng-Hua Wang "
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Escin may exert a synergistic anti-inflammatory effect with glucocorticoids  [PDF]
Lei-Ming Zhang, Tian Wang, Hua-Ying Fan, Xin Yu, Bing Han, Mei Zhu, Feng-Hua Fu
Health (Health) , 2010, DOI: 10.4236/health.2010.22013
Abstract: Escin is a natural mixture of triterpenoid as- ponin isolated from the seed of the horse chestnut and demonstrates anti-oedematous and anti-inflammatory effects. As yet, the pre-cise mechanisms by which escin exerts its anti- inflammatory effects remain unclear. The data from current studies indicate that the anti-in-flammatory properties of escin were attributed to its ability to reduce the adhesiveness of neu-trophils and the associated release of inflam-matory mediators; its ability to decrease hista-minic and serotoninergic activities; its ability to inhibit phospholipase A2; its ability to decrease nuclear factor-κ B activation and down-regulate the expression of tumor necrosis factor-α. All these effects are similar to glucocorticoids. Mo- reover, escin depends on adrenal glands to ex-ert its anti-inflammatory effects. Also, our recent research showed that the serum corticosterone level in mice did not increase after a 7-day in-travenous injection of escin. The results sup-port the hypothesis that escin may exert a syn-ergistic anti-inflammatory effect with glucocor-ticoids. Confirming this hypothesis will play a role in elucidating the anti-inflammatory mech- anisms of escin.
Some Properties of Certain Subclasses of Analytic Functions with Complex Order
Zhi-Gang Wang,Feng-Hua Wen,Yong Sun
ISRN Mathematical Analysis , 2012, DOI: 10.5402/2012/403028
Abstract:
Calculating potential of mean force between like-charged nanoparticles: a comprehensive study on salt effects
Yuan-Yan Wu,Feng-Hua Wang,Zhi-Jie Tan
Physics , 2013, DOI: 10.1016/j.physleta.2013.05.011
Abstract: Ions are critical to the structure and stability of polyelectrolytes such as nucleic acids. In this work, we systematically calculated the potentials of mean force between two like-charged nanoparticles in salt solutions by Monte Carlo simulations. The pseudo-spring method is employed to calculate the potential of mean force and compared systematically with the inversed-Boltzmann method. An effective attraction is predicted between two like-charged nanoparticles in divalent/trivalent salt solution and such attraction becomes weakened at very high salt concentration. Our analysis reveals that for the system, the configuration of ion-bridging nanoparticles is responsible for the attraction, and the invasion of anions into the inter-nanoparticles region at high salt concentration would induce attraction weakening rather than the charge inversion effect. The present method would be useful for calculating effective interactions during nucleic acid folding.
RNA structure prediction: progress and perspective
Ya-Zhou Shi,Yuan-Yan Wu,Feng-Hua Wang,Zhi-Jie Tan
Physics , 2014, DOI: 10.1088/1674-1056/23/7/078701
Abstract: Many recent exciting discoveries have revealed the versatility of RNAs and their importance in a variety of cellular functions which are strongly coupled to RNA structures. To understand the functions of RNAs, some structure prediction models have been developed in recent years. In this review, the progress in computational models for RNA structure prediction is introduced and the distinguishing features of many outstanding algorithms are discussed, emphasizing three dimensional (3D) structure prediction. A promising coarse-grained model for predicting RNA 3D structure, stability and salt effect is also introduced briefly. Finally, we discuss the major challenges in the RNA 3D structure modeling.
Salt Contribution to the Flexibility of Single-stranded Nucleic Acid of Finite Length
Feng-Hua Wang,Yuan-Yan Wu,Zhi-Jie Tan
Quantitative Biology , 2012,
Abstract: Nucleic acids are negatively charged macromolecules and their structure properties are strongly coupled to metal ions in solutions. In this paper, the salt effects on the flexibility of single stranded (ss) nucleic acid chain ranging from 12 to 120 nucleotides are investigated systematically by the coarse grained Monte Carlo simulations where the salt ions are considered explicitly and the ss chain is modeled with the virtual bond structural model. Our calculations show that, the increase of ion concentration causes the structural collapse of ss chain and multivalent ions are much more efficient in causing such collapse, and trivalent and small divalent ions can both induce more compact state than a random relaxation state. We found that monovalent, divalent and trivalent ions can all overcharge ss chain, and the dominating source for such overcharging changes from ion exclusion volume effect to ion Coulomb correlations. In addition, the predicted Na and Mg dependent persistence length lp of ss nucleic acid are in accordance with the available experimental data, and through systematic calculations, we obtained the empirical formulas for lp as a function of Na, Mg and chain length.
A coarse-grained model with implicit salt for RNAs: predicting 3D structure, stability and salt effect
Ya-Zhou Shi,Feng-Hua Wang,Yuan-Yan Wu,Zhi-Jie Tan
Quantitative Biology , 2014, DOI: 10.1063/1.4894752
Abstract: To bridge the gap between the sequences and 3-dimensional (3D) structures of RNAs, some computational models have been proposed for predicting RNA 3D structures. However, the existed models seldom consider the conditions departing from the room/body temperature and high salt (1M NaCl), and thus generally hardly predict the thermodynamics and salt effect. In this study, we propose a coarse-grained model with implicit salt for RNAs to predict 3D structures, stability and salt effect. Combined with Monte Carlo simulated annealing algorithm and a coarse-grained force field, the model folds 46 tested RNAs (less than or equal to 45 nt) including pseudoknots into their native-like structures from their sequences, with an overall mean RMSD of 3.5 {\AA} and an overall minimum RMSD of 1.9 {\AA} from the experimental structures. For 30 RNA hairpins, the present model also gives the reliable predictions for the stability and salt effect with the mean deviation ~ 1.0 degrees Celsius of melting temperatures, as compared with the extensive experimental data. In addition, the model could provide the ensemble of possible 3D structures for a short RNA at a given temperature/salt condition.
干细胞定向分化视网膜色素上皮治疗年龄相关性黄斑变性的研究进展
Advances in oriented differentiation of stem cells to retinal pigment epithelia in the treatment of age-related macular degeneration

阮熵,汪枫桦
RUAN Shang
, WANG Feng-Hua

- , 2018, DOI: 10.3969/j.issn.1674-8115.2018.09.020
Abstract: 年龄相关性黄斑变性( age-related macular degeneration,AMD)是与年龄相关致盲的重要眼病之一,分为干性和湿性。目前干性 AMD尚无有效的根本性治疗方法。视网膜色素上皮( retinal pigment epithelium,RPE)位于神经视网膜和脉络膜之间,对感光细胞的存活和正常功能的维持有重要意义。在 AMD中 RPE细胞的结构和生理功能的衰老导致 Bruchs膜、脉络膜血管和光感受器细胞退行性改变,从而影响其代谢和功能,最终导致感光细胞死亡,视功能不可逆损伤。自 1991年来研究者开始尝试 RPE细胞的替代治疗。随着多能干细胞体外诱导分化技术逐渐成熟,干细胞定向分化 RPE细胞的移植治疗正在成为填充和置换已受损细胞从而治疗 AMD的一种新策略。该文从 AMD的细胞替代治疗中 RPE干细胞的来源、 RPE细胞定向分化的鉴定、 RPE细胞的移植技术以及相关临床试验等方面对其研究进展进行综述。
:Age-related macular degeneration (AMD) is one of the leading causes of irreversible vision loss related with aging, including wet AMD and dry AMD. At present, there is still no effective treatment for dry AMD. Retinal pigment epithelium (RPE), located between the retina and the choroid, plays an important role in the survival of photoreceptor and maintenance of its physiological function. In AMD patients, the aging of RPE leads to degeneration and dysfunction of Bruch’s membrane, choroidal and photoreceptor, thus causing the loss of the retina photoreceptor cells. Since 1991, researchers have been trying various replacement therapies of RPE cells. With the development of technique for induction and differentiation of pluripotent stem cells (PSC) in vitro, the transplantation of stem cells differentiating into RPE cells is going to be a feasible strategy for replacing impaired RPE cells in AMD. This article reviewed the advances in the study of the source of RPE cells, identification of cell differentiation, transplantation and the related clinical trials in cell replacement therapy of AMD
Predicting 3D structure, flexibility and stability of RNA hairpins in monovalent and divalent ion solutions
Ya-Zhou Shi,Lei Jin,Feng-Hua Wang,Xiao-Long Zhu,Zhi-Jie Tan
Physics , 2015, DOI: 10.1016/j.bpj.2015.11.006
Abstract: A full understanding of RNA-mediated biology would require the knowledge of three-dimensional (3D) structures, structural flexibility and stability of RNAs. To predict RNA 3D structures and stability, we have previously proposed a three-bead coarse-grained predictive model with implicit salt/solvent potentials. In this study, we will further develop the model by improving the implicit-salt electrostatic potential and involving a sequence-dependent coaxial stacking potential to enable the model to simulate RNA 3D structure folding in divalent/monovalent ion solutions. As compared with the experimental data, the present model can predict 3D structures of RNA hairpins with bulge/internal loops (<77nt) from their sequences at the corresponding experimental ion conditions with an overall improved accuracy, and the model also makes reliable predictions for the flexibility of RNA hairpins with bulge loops of different length at extensive divalent/monovalent ion conditions. In addition, the model successfully predicts the stability of RNA hairpins with various loops/stems in divalent/monovalent ion solutions.
Spatiotemporal Noise Triggering Infiltrative Tumor Growth under Immune Surveillance
Wei-Rong Zhong,Yuan-Zhi Shao,Li Li,Feng-Hua Wang,Zhen-Hui He
Quantitative Biology , 2008, DOI: 10.1209/0295-5075/82/20003
Abstract: A spatiotemporal noise is assumed to reflect the environmental fluctuation in a spatially extended tumor system. We introduce firstly the structure factor to reveal the invasive tumor growth quantitatively. The homogenous environment can lead to an expansive growth of the tumor cells, while the inhomogenous environment underlies an infiltrative growth. The different responses of above two cases are separated by a characteristic critical intensity of the spatiotemporal noise. Theoretical and numerical results present a close annotation to the clinical images.
自动乳腺全容积扫查对乳腺癌预后评估的价值
Value of automated breast volume scanner for evaluating prognosis of breast cancer

金叶,李凤华,王琳,
JIN Ye
, LI Feng-hua, WANG Lin, et al

- , 2015, DOI: 10.3969/j.issn.1674-8115.2015.09.025
Abstract: 目的 研究自动乳腺全容积扫查(ABVS)在乳腺癌预后评估中的价值。方法 分析81例乳腺癌ABVS图像,观察病灶的边缘、生长方式、后方回声、钙化及“汇聚征”等形态学表现,并与乳腺癌的预后指标包括病理级别、淋巴结、雌激素受体(ER)、孕激素受体(PR)及c-erbB-2等进行相关性分析。结果 51.85%(42/81)伴毛刺征,其中11.90%(5/42)的毛刺仅在冠状面察见,毛刺征组的ER/PR阳性率高、c-erbB-2阳性率低(均P<0.01);30.86% (25/81)有后方回声增强,多见于ER/PR阴性、c-erbB-2阳性的乳腺癌(均P<0.01);53.09%(43/81)伴微钙化,并与c-erbB-2阳性表达有关(P=0.018);45.68% (37/81)有“汇聚征”,常为低级别(Ⅰ/Ⅱ级)(P=0.023)、 ER/PR阳性、c-erbB-2阴性(均P<0.01)的乳腺癌。结论 ABVS通过形态特征特别是“汇聚征”能反映肿瘤的预后指标,能对乳腺癌进行有效的在体预后评估。
: Objective To investigate the value of automated breast volume scanner (ABVS) for evaluating the prognosis of breast cancer. Methods ABVS images of 81 cases of breast cancer were analyzed. Morphological manifestations such as the lesion margin, growth orientation, posterior echo, calcification status, and retraction phenomenon were observed and the correlation with prognostic factors of breast cancer such as pathological grade, lymph node, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (c-erbB-2) was analyzed. Results Among 81 cases, 42 (51.85%) had spiculate margin, and only 5 of them (11.90%) were found on the coronal plan. For patients with spiculate margin, the ER/PR positive rate was high (P<0.001) and c-erbB-2 positive rate was low (P<0.001). Among 81 cases, 25 (30.86%) had posterior enhancement and most of them were breast cancer patients with negative ER/PR and positive c-erbB-2 (P<0.001). Among 81 cases, 43 (53.09%) had microcalcification and was relevant to positive expression of c-erbB-2 (P=0.018). Among 81 cases, 37 (45.68%) had retraction phenomenon and most of them were breast cancer patients with low grades (grade Ⅰ/Ⅱ)(P=0.023), positive ER/PR, and negative c-erbB-2 (P<0.001). Conclusion ABVS can reflect prognostic factors of breast cancer based on morphological features, especially retraction phenomenon, and can efficiently evaluate the prognosis of breast cancer
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