The sedimentation equilibrium of heterogeneously associating systems and mixtures of non-interacting solutes: analysis without determination of molecular weight averages

In 8 healthy subjects (group A) and 4 subjects with respiratory symptoms (group B), the lung pressure-volume curve (P-V curve), maximum expiratory flow-volume curve (MEFVC) and respiratory resistance (Rrs) at all vital capacities were measured. To avoid laryngeal artifact on a mouth pressure, an intratracheal catheter was used for measurement of Rrs which was obtained with 3 cycles/sec oscillatory forced pressure. Group B did not show a different elastic recoil from group A. In comparison of the maximum expiratory flow (Vmax) at 80, 70, 60 and 50% of the total lung capacity (TLC). Vmax of group B showed lower values than that of group A. Rrs was almost the same in both groups from 70% TLC upwards, but Rrs of group B was higher than that of group A from 65%TLC downwards. Since the lung elastic recoil pressures (Pst (1)) in the two groups were not different and Rrs's were different significantly only at low lung volumes, the decrease in Vmax of group B was supposed to be due to the increased Rrs which might reflect small airway obstruction.     

自然山区大气景观模拟显示方法初探

提出了一个模拟大气、云雾等自然环境的照明模型，对视线距离较大，视野开阔的自然景物造型，如山体造型，更具有真实感效果，可获得模拟云、雾等天气特征的三维地形风景图。实验效果令人满意，并具有简单实用之特点。     

有界随机噪声参数激励下碰撞系统的矩稳定性

研究了单自由度线性单边碰撞系统在有界随机噪声参数激励下系统的矩稳定性问题.用Zhuravlev变换将碰撞系统转化为连续的非碰撞系统,然后用随机平均法得到了关于慢变量的随机微分方程.利用伊藤法则给出了系统一、二阶矩满足的常微分方程,根据微分方程的稳定性理论得到了系统一阶矩稳定充分必要条件的解析表达式和二阶矩稳定充分必要条件的数值算法,并对理论结果用数值方法进行了仿真计算.理论分析和数值仿真表明,无论是相对于一阶矩还是二阶矩的稳定性,随着随机激励振幅变大,系统的稳定性区域变小从而使得系统变得不稳定.而当调谐参数趋于零系统达到参数主共振情形时,系统的稳定性区域变得最小.当随机噪声强度逐渐变小趋于零时,由二种矩稳定性给出的稳定性区域变得一致.在一定的参数区域内,随机噪声使得系统稳定化.     

Characterisation of volatile compounds of farmed soft‐shelled turtle (Pelodiscus sinensis) by solid‐phase microextraction and the influence of matrix pH on the release of volatiles

Although farming and consuming of soft‐shelled turtle has been practised for centuries, the aroma‐impact compounds in the meat have not been determined. Furthermore, matrix pH, usually changing during processing and storage stage, was rarely investigated for the influence on volatile profiles. To these aims, soft‐shelled turtle meat was subjected to different pH conditions and the potential volatile compounds were analysed under different extraction conditions by headspace solid‐phase microextraction (HS‐SPME). A total of forty‐three volatiles were identified; in which, nonanal, (E, E)‐2, 4‐heptadienal, octanal, decanal, hexanal, (E)‐2‐nonenal, heptanal, 1‐octen‐3‐ol and o‐xylene were assigned as aroma‐impact compounds by high relative odour activity value (ROAV). Overly basic or acidic pH significantly (P < 0.05) facilitated the release of volatiles under moderate extraction conditions. The total volatilisation increased by 30.1% to 298% in pH‐shifted samples, while the highest one was found in pH 2 or pH 11. However, the results of principal components analysis (PCA) demonstrated that increased extraction time or temperature hindered the pH enhancement.     

热风和微波结合干燥荔枝加工工艺研究

本试验对以荔枝鲜果为原料,通过热风干燥和微波干燥相结合制作荔枝干果的加工工艺进行了研究。研究结果表明,荔枝鲜果经预处理后,用70℃的热风干燥至50％的水分含量,再以240g/kW的微波处理量进行干燥,所得荔枝干果品质最佳。采用PA＆PE复合包装袋加脱氧剂的包装方法,其保质效果最好,贮藏期在9个月以上。     

紫花地丁中芹菜素提取和清除自由基活性研究

为充分利用与开发紫花地丁资源,本文采用乙醇提取紫花地丁中芹菜素苷,经溶剂萃取和D-101大孔树脂吸附与分离,用酸水解后乙醚溶解和丙酮重结晶得到芹菜素.采用化学发光法研究了紫花地丁中芹菜素清除O-2.和.OH活性.实验结果表明,D-101树脂对紫花地丁芹菜素静态交换容量是30.2 mg/g,树脂吸附率为75.2%.经分离纯化的紫花地丁芹菜素对清除O-2.和.OH均有一定效果:当芹菜素浓度为4μg/mL时,其清除O-2·率为43.4%,且清除效果比Vc、VE都强;芹菜素浓度为9μg/mL时,清除.OH率为22.45%,其清除效果比Vc差,但比VE好.     

Vibrio mimicus infection associated with crayfish consumption, Spokane, Washington, 2010

We report a cluster of severe diarrheal disease caused by Vibrio mimicus infection among four persons who had consumed leftover crayfish the day after a private crayfish boil. Gastrointestinal illness caused by Vibrio mimicus has not been reported previously in Washington State. Three cases were laboratory confirmed by stool culture; using PCR, isolates were found to have ctx genes that encode cholera toxin (CT). Two of the cases were hospitalized under intensive care with a cholera-like illness. The illnesses were most likely caused by cross-contamination of cooked crayfish with uncooked crayfish; however, V. mimicus was not isolated nor were CT genes detected by PCR in leftover samples of frozen crayfish. Clinicians should be aware that V. mimicus can produce CT and that V. mimicus infection can cause severe illness.