Some sufficient conditions for global exponential stability of delayed Hopfield neural networks.

In this paper, we have derived some sufficient conditions for existence and uniqueness of equilibrium and global exponential stability in delayed Hopfield neural networks by using a different approach from the usually used one where the existence, uniqueness of equilibrium and stability are proved in two separate steps, rather we first prove global exponential convergence to 0 of the difference between any two solutions of the original neural networks, the existence and uniqueness of equilibrium is the direct results of this procedure. We obtain the conditions by suitable construction of Lyapunov functionals and estimation of derivates of the Lyapunov functionals by the well-known Young's inequality and Holder's inequality. The proposed conditions are related to p-norms of vector or matrix, p in [1, infinity] and thus unify and generalize some results in the literature.     

皮肤光老化皱纹形成机制及维A酸类药物的拮抗作用

日光中长波紫外线 (UVA)长期反复照射是户外工作者暴露部位皮肤光老化及相关皮肤肿瘤多发的重要因素 ,皱纹形成是皮肤光老化的最重要特征 ,研究其作用机制对紫外线辐射损伤的防护有重要意义。基质金属蛋白酶 (matrixmetal loproteinases,MMPs)家族在各种生理、病理条件下细胞外基质降解和重塑中起着关键作用。我们研究了皮肤光老化皱纹形成与真皮成纤维细胞MMPs及MMPs组织抑制剂 (tissueinhibitorofmatrixmetallo proteinases,TIMPs)表达的关系 ,并同时观察了维A酸类药物的拮抗作用。一、材料与方法1 真皮成纤维细胞培养 :标本为健康…     

浅谈多媒体教学中存在的问题及对策

分析了目前多媒体教学中存在的一些问题，提出了一些提高多媒体教学质量的途径和方法。     

Innervation of the trapezius muscle: is cervical contribution important to its function?

OBJECTIVE: To study the effect of the cervical plexus and the accessory nerve to the function of the trapezius muscle. STUDY DESIGN AND SETTING: Eighteen adult male Sprague-Dawley rats were randomly divided into three groups. The neurotomies were performed in the left sides and the right sides served as within-subject controls. In group A, the accessory nerve was transected. The C2-5 were transected in group B, and both of the accessory nerve and C2-5 were cut in group C. The electrophysiologic, myophysiologic, and histologic changes of the muscles were measured. RESULTS: There were significant differences (P < 0.05) between the three groups in the recovery rates of the transverse area of the muscles. The CMAP recorded from the experimental sides in group B were similar to the control sides. The values of the maximum tension of the tetanus contraction between the two sides showed no differences either (P > 0.05). CONCLUSION: The accessory nerve supplies the most important motor input to the trapezius. Motor innervations of the cervical plexus are not very significant.     

Osteoclastogenesis in the nonadherent cell population of human bone marrow is inhibited by rhBMP-2 alone or together with rhVEGF.

During bone development and repair, angiogenesis, osteogenesis, and bone remodeling are closely associated processes that share some common mediators. In the present study nonadherent human bone marrow mononuclear cells under the induction of sRANKL and M-CSF, differentiated into osteoclasts with TRAP-positive staining, VNR expression, and Ca-P resorptive activity. The effects of various combinations of rhBMP-2 (0, 3, 30, and 300 ng/mL) and rhVEGF (0 and 25 ng/mL) on osteoclastogenesis potentials were examined in this experimental system. The percentages of TRAP-positive multiple nucleated cells represent osteoclast differentiation potential, and the percentages of resorptive areas in the Ca-P coated plates resemble osteoclast resorption capability. The presence of rhBMP-2 at 30 and 300 ng/mL showed inhibitory effects on osteoclast differentiation and their resorptive capability in the human osteoclast culture system. rhVEGF (25 ng/mL) enhanced the resorptive function of osteoclast whenever it was used alone or combined with 3 ng/mL rhBMP-2. However, rhVEGF-induced resorptive function was inhibited by 30 ng/mL and 300 ng/mL rhBMP-2 in a dose-dependent manner. Statistical analysis demonstrated that an interactive effect exists between rhBMP-2 and rhVEGF on human osteoclastogenesis. These findings suggested that an interactive regulation may exist between BMPs and VEGF signaling pathways during osteoclastogenesis; exact mechanisms are yet to be elucidated.     

显微外科技术及带蒂包皮岛状皮瓣法在尿道下裂治疗中的应用

目的总结应用显微外科及带蒂包皮皮瓣一期修复尿道下裂的经验,提高手术成功率。方法回顾性分析38例一期尿道下裂修复手术及术后并发症。患儿年龄3～22岁,平均7．5岁。阴茎头冠状沟型12例,阴茎体型19例,阴茎根部型7例,其中6例曾在院外行阴茎下屈矫正术。应用显微外科技术,单纯选择带蒂包皮岛状皮瓣法一期修复尿道下裂32例,联合应用Duplay术式6例。结果随访3个月～2年,35例患儿术后阴茎外观满意,排尿通畅,无明显并发症:术后发生尿瘘2例,再次手术后治愈。1例术后3月出现尿道外口狭窄,经尿道扩张治愈。手术成功率为94．7％。结论应用显微外科及带蒂包皮岛状皮瓣一期修复尿道下裂,成功率高,并发症少,是治疗尿道下裂的良好方法。     

转化生长因子在前列腺增生中作用的研究

目的：探讨转化生长因子α(TGF-α)和转化生长因子β(TGF-β)在良性前列腺增生症组织中的表达及意义。方法：利用免疫组织化学方法研究TGF-α和TGF-β在40例BPH组织和5例正常前列腺组织中的表达。结果：TGF-α在BPH组织上皮和间质中的表达强阳性率均高于正常前列腺组织(P＜0．01)。且TGF-α在BPH组织上皮组织的表达明显高于其在间质中的表达(P＜0．01)。TGF-β在BPH组织上皮和间质中的表达明显高于正常前列腺组织(P＜0．01)。且TGF-β在BPH组织间质中的表达明显高于其在上皮组织中的表达(P＜0.01)。结论：TGF-α在前列腺组织中表达增高，尤其在腔上皮细胞的胞浆中高度表达，TGF-β在前列腺包织中表达增高，尤其在间质组织中的过度表达，提示其可能直接或间接参与了前列腺间质细胞的分化和增殖，参与了BPH的病理过程。     

hMSH2、hMLHl在胃癌中的表达及其临床意义

目的:探讨错配修复基因hMSH2、hMLH1蛋白的表达与胃癌临床病理学特性之间的关系。方法:采用免疫组织化学方法检测40例胃癌及50例胃炎组织中hMSH2、hMLH1蛋白的表达情况,并研究其与胃癌临床病理之间的关系。结果:40例胃癌标本中,hMSH2减低表达率为35%,hMLH1蛋白降低表达率为72.5%;淋巴结转移阳性的胃癌中,hMSH2、hMLH1蛋白表达明显减低。结论:hMSH2、hMLH1蛋白可能与早期胃癌和胃癌淋巴结转移有关。     

老年心功能不全血浆心钠素浓度的变化

采用放射免疫法测定31例老年心功能不全患者血浆心钠素(ANP)浓度,发现老年心功能不全组ANP明显低于对照组(P<0.01)。血浆ANP含量随心功能不全的严重程度而明显减少(P<0.05)。病程与ANP浓度呈负相关 (r=-0.441,P<0.05)。不同病种、不同受累部位及有或无房颤之间ANP差异无显著性(P<0.05)。     

Intracranial Extramedullary Hematopoiesis in β-thalassemia Major

A case of β-thalassemia major with a huge mass of hernatopoictic tissuc firmly attached tothe dura mater was reported This is the first case reported in China.