聚醚砜耐高温摩阻材料的研究

用热塑性聚(氧-1,4-亚苯基磺酰基-1,4-亚苯基)(聚醚砜)树脂作粘接剂,制备耐高温摩阻材料,探索了材料的压制工艺。试验证实了:聚醚砜树脂和制成的摩阻材料,其耐热性和摩擦磨损性能,较大程度优于改性酚醛树脂和其制成的材料。通过近代表面分析手段对摩擦表面和磨屑进行了分析,并探讨了其磨损机理。     

Diabetic and nondiabetic hyperglycemia in the ICU

Hyperglycemia is a common feature in critically ill patients, whether they are diabetic or not, and it is associated with unfavorable outcome. The more severe the underlying disease, the more important the hyperglycemia appears to be although, we still cannot define whether hyperglycemia is just a marker of the severity of the acute illness or rather an active contributor to poor outcome. The review of the literature on this subject published from 2001 up today conveys a massive amount of information the interpretation of which is equivocal, due to the heterogeneity of patients (nondiabetic vs. diabetic, medical intensive care unit (ICU) pts vs. surgical ICU pts) and of interventions (dose and modality of insulin infusion).The association between high glucose level and mortality is strong in critically ill patients without a previous history of diabetes. Admission hyperglycemia seems to be an independent risk factor of in-hospital mortality in patients both with and without diabetes in cardiac, cardiothoracic and neurosurgical ICUs. No data are still available on general surgical ICU patients.Tight control of blood glucose levels has been demonstrated to improve outcome in both diabetic and nondiabetic critically ill patients. In surgical ICUs, tight glucose control improves mortality and reduces morbidity only among patients admitted in ICU for more than 5 days, while outcome is not improved in patients who stay in ICU for less than 3 days.However, it is not yet understood if such favorable effect is secondary to glucose control itself or if insulin plays a part, by means of its nonglucose, anabolic effects. More randomized controlled trials are needed, addressing specific issues—such as the optimal target glucose concentration and the most effective insulin regimen—especially in the general surgical patient.     

Evaluation of allergenicity of genetically modified soybean protein extract in a murine model of oral allergen-specific sensitization

Background With the development of genetically modified crop plants there has been a growing interest in the approaches available to assess the potential allergenicity of novel gene products. For additional assessment of the potential allergenicity of expressed proteins, informative data can be generated using animal models. Soybean is one of the major source of protein in human and animal nutrition, and has also been well characterized as a major allergenic source. Advances in biotechnology have resulted in an increasing number of genetically engineered foods, and among these soybean is one of the most widespread. Objective To develop and characterize a murine model of IgE‐mediated soybean sensitization induced by intragastric immunization, in the presence of Cholera Toxin, with wild‐type soybean extract (wt‐SE) or with genetically modified soybean extract (gm‐SE). Methods Balb/c mice born in our animal facilities, from females fed on soy‐free food, were fed with the same soy‐free food and used in all the experiments. Mice were sensitized by gavages with soybean extracts, and allergen‐specific IgE and IgG responses were studied by direct ELISA and ELISA inhibition. Antigen‐specific cell proliferation and cytokine production were evaluated in spleen cell cultures. Results Sensitization with both soybean extracts induced high levels of antigen‐specific IgE and IgG1 and low levels of specific IgG2a. Both wt‐SE and gm‐SE were able to inhibit the binding of specific IgE from mice immunized with gm‐SE to the same antigen used for the ELISA coating. A comparable proliferative response was obtained with the homologous as well as with the heterologous extracts. Conclusion In sensitized mice, we observed a predominantly T‐helper type 2 (Th2)‐type immune response, with increased soybean‐specific IgE and IgG1 antibodies and a concomitant increase of IL‐4 and IL‐5 production. Results obtained by specific IgE ELISA inhibition and by antigen‐specific T cell proliferation demonstrated that wt‐SE and gm‐SE shared B and T epitopes. The present murine model of soybean sensitization established by the oral route should provide valuable information about risk assessment for food allergy from new proteins of genetically modified foods.     

Chironomids fail to emerge from LAS-contaminated water

The effect of the surfactant LAS was investigated on chironomid emergence using six outdoor artificial channels. The concentrations of LAS were mostly between 1 and 2 mgl^-1 in the three treated channels. Chironomus yoshimatsui, Cricotopus tamapullus, Eukiefferiella coerescens, Eukiefferiella sp. and Thienemanniella majuscula were the major chironomids obtained with emergence traps. The number of midges trapped did not differ significantly between the treatment and the control for either of the species. On the other hand, the ratios of midges failing to emerge to the total midges trapped was significantly higher in the treatment than in the control for all of the species. The results show that chironomids emergence is difficult as a result of LAS treatment probably due to the lowered surface tension.     

Treatment of chronic hepatitis B

SUMMARY. Chronic infection with the hepatitis B virus (HBV) is a major cause of worldwide morbidity and mortality. A large number of therapeutic approaches has been tried, including interferon (IFN), nucleoside analogues and immunomodulators. To date controlled clinical trials have shown that only IFN is of long-term value but many patients fail to respond to treatment. New approaches to treating patients with IFN-resistant hepatitis B are currently undergoing clinical and experimental evaluation, and it seems likely that new therapeutic agents will be available in the near future.     

不同形状界面对界面射流的影响──彩色多普勒与激光荧光染料方法的研究

本文通过应用彩色多普勒及激光荧光染料显示射流方法研究了不同形状界面对射流的影响。结果表明对照组及平坦界面射流时，彩色多普勒与激光荧光染料两种方法无显著差异；在弯曲界面条件下，彩色多普勒射流小于激光荧光染料射流（Ｐ＜０．０１～０．０００１）。彩色多普勒研究表明不同形状界面射流大小分别与每搏容量相关好（ｒ＝０．８３～０．９９），但射流大小明显不同。凹形界面射流面积最小，平坦及凸形界面射流面积也小于对照组。研究提示不同形状界面可以导致界面射流不同程度地减小，并且彩色多普勒也不易对弯曲界面的射流完全成像。在临床上应用彩色多普勒对返流定量时，需考虑上述影响。     

Impact response of periodontal tissues

A new impact response method using a fracture of a pencil-lead to produce an excitation pulse is proposed. Impact excitations (rectangular pulse, triangular pulse and half-sine pulse) are strictly given in physical and mathematical definitions and complete solutions to the impact excitations are provided for Noyes' model of the human tooth. When a relatively long triangular pulse is applied to Noyes' model, which can express the physical characteristic of periodontal tissues, a sinusoidal damped vibration of a single degree-of-freedom model is approximately obtained. The acceleration response is characterised by the physical parameters (T, δ and A_o) and mechanical elements (m₁, c₁ and k) of which a single degree-of-freedom model is composed. By means of this method, the values of the parameters and elements in the cases of healthy maxillary, healthy mandibular and pathological mandibular incisors are obtained. The single degree-of-freedom model can express the high-frequency spectra of Noyes' model. The pathological tooth is characterised by a longer damped time constant and a larger acceleration maximum. This impact response method can effectively be applied to clinical diagnosis in view of the physical parameters and mechanical elements which have been derived.     

金属基底上聚合吡咯的电化学及电镜表征

用循环伏安法研究了吡咯在不同金属基底不同支持电解质中的聚合过程，对不同基底上制备的聚吡咯膜进行了电化学、扫描电镜、表面能谱等方面的研究，考察了聚吡咯膜电极对ＮＯ_３－离子的电位响应情况，结果表明，不同基底不同支持电解质在不同的吡咯浓度中表现出各异的伏安行为，经电化学处理的聚吡咯膜电极均对ＮＯ_３－呈Ｎｅｒｎｓｔ响应，扫描电镜观察表明除Ｐｔ基底外在其它基底上制备的聚吡咯膜均呈颗粒性球状堆集。     

Sustained low-grade pro-inflammatory state in unmedicated, remitted women with major depressive disorder as evidenced by elevated serum levels of the acute phase proteins C-reactive protein and serum amyloid A.

BACKGROUND: Major depressive disorder (MDD) shows increased coronary artery disease (CAD) risk of unknown mechanism(s). MDD is more common in women than men; CAD diagnosis can be difficult in women. Elevations of the inflammatory markers C-reactive protein (CRP) and serum amyloid A (SAA) predict increased CAD risk in populations; few data on these markers exist in MDD, particularly in remitted patients. METHODS: We measured fasting am serum CRP (high sensitivity, CRP(hs)) and SAA in 18 unmedicated, remitted women with MDD (mean age 41 +/- (SD)12, body mass index (BMI) 25.2 +/- 4.1 kg/m(2)) and 18 BMI-matched healthy control subjects (age 36 +/- 10, BMI 25.3 +/- 3.8 kg/m(2)) on 2 separate occasions, > or = 6 days apart. RESULTS: Repeat SAA and CRP(hs) measurements strongly correlated across study days (SAA: r = .83, p < .001; CRP(hs): r = .94, p < .001). Both SAA (5.30 +/- 3.39 vs. 2.84 +/- 1.87 mg/L, p < .005) and CRP(hs) (3.23 +/- 3.17 vs. 1.12 +/- 1.45 mg/L; p < .01) were significantly elevated in MDD women versus controls. CONCLUSIONS: Elevated SAA and CRP(hs) in remitted, unmedicated women with MDD indicate a pro-inflammatory state unrelated to current depressive symptoms or pharmacotherapy. These findings suggest that inflammatory mechanisms may in part underlie findings of increased CAD risk in MDD.     

约氏疟原虫感染不同小鼠免疫分子的应答差异

目的探讨在约氏疟原虫感染过程中不同宿主的免疫应答差异。方法以约氏疟原虫（致死型）感染DBA／2和BALB／c小鼠，计算红细胞感染率；收集感染前和感染后1、3、6、9、12、15、20d小鼠血清，并无菌取出脾脏，培养脾细胞。应用ELISA试剂盒检测小鼠血清中IFN-γ和IL-12水平，并通过Griess方法检测脾细胞培养上清中NO含量。结果DBA／2小鼠的原虫血症峰值水平明显低于BALB／c小鼠，并于感染后第20d左右自愈；BALB／c小鼠于原虫血症达到峰值水平后全部死亡；DBA／2小鼠的IFN-γ和IL-12水平于感染后1d即出现了有意义的升高并持续到第20d；BALB／c小鼠的IFN-γ和IL-12水平仅干感染后1d出现了有意义的升高；DBA／2小鼠NO的产生于感染后3d出现了有意义的升高，第6d达到峰值，而BALB／c小鼠的NO水平始终未见明显升高。结论DBA／2小鼠通过感染早期Th1细胞免疫应答的有效建立能够抑制原虫血症，IL-12是启动并维持Th1细胞免疫应答的关键性细胞因子。