上、下楼梯时认知任务介入对下肢协调性影响的研究

目的：探讨上、下楼梯时附加认知任务,年龄差异（组间）及任务难度（组内）对步态时空及下肢关节协调参数的影响。方法：18位健康老年人为老年组,18位健康大学生为年轻组,各组内均为9男9女,依次接受认知任务测试、上、下楼测试（单任务）及上、下楼合并认知任务测试（双任务）。结果：认知任务方面,两种任务情境下各年龄组上楼回答次数皆显著多于下楼。步态参数方面,两种任务情境下年轻组相对于老年组,以及各年龄组在单任务情境下相对于双任务,皆呈现较短步行时间、较快步行频率、速度及较大步行长度的情形。下肢协调性方面,年轻组上楼过渡时摆动期的膝‐踝协调稳定度在双任务下较单任务差,而处于双任务情境下,年轻组上楼过程中支撑期的膝‐踝协调稳定度比老年组差;年轻组下楼过程中摆动期的髋‐膝协调稳定度在ST 和DT 中都比老年组差,老年组膝‐踝协调稳定度比年轻组差,下楼过渡时,年轻组支撑期髋‐膝协调稳定度在两种任务情境下皆比老年组差。结论：老年人和年轻人会根据任务难度来选择是否专注于认知任务上,此外年轻人因有足够下肢肌力控制而采取较大胆动作策略,导致其上下楼梯时下肢协调稳定度较差,而老年人则趋向选择较保守的策略来维持下肢关节协调稳定度。     

Synthesis of Gold Nanoparticles Coated with Aspartic Acid and Their Conjugation with FVIII Protein and FVIII Antibody

Carboxylate-modified gold nanoparticles (GNPs) were synthesized in a simple one-step process based on the reduction of tetrachloroauric acid by aspartic acid in water. GNPs were identified by UV–Vis spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy. Conjugation of protein molecules with functionalized nanoparticles was performed through electrostatic interaction. The GNP–protein conjugates were characterized by gel electrophoresis. The interaction between functionalized GNPs and protein molecules lead to conformational transition of protein structure after conjugation of protein with GNPs. This process was investigated by fluorescence spectroscopy and circular dichroism spectroscopy.     

Immunoisolated Transplantation of Purified Langerhans Islet Cells in Testis Cortex of Male Rats for Treatment of Streptozotocin Induced Diabetes Mellitus

The objective of this study is to induce experimental diabetes mellitus by streptozotocin in normal adult Wistar rats via comparison of changes in body weight, consumption of food, volume of water, urine and levels of glucose, insulin and C-peptide in serum, between normal and diabetic rats. Intra-venous injection of 60 mg/kg dose of streptozotocin in 250–300 g (75–90 days) adult Wistar rats makes pancreas swell and causes degeneration in Langerhans islet β-cells and induces experimental diabetes mellitus in 2–4 days. For a microscopic study of degeneration of Langerhans islet β-cells of diabetic rats, biopsy from pancreas tissue of diabetic and normal rats, staining and comparison between them, were done. In this process, after collagenase digestion of pancreas, islets were isolated, dissociated and identified by dithizone method and then with enzymatic procedure by DNase and trypsin, the islet cells changed into single cells and β-cells were identified by immune fluorescence method and then assayed by flow-cytometer. Donor tissue in each step of work was prepared from 38 adult male Wistar rats weighted 250–300 g (75–90 days). Transplantation was performed in rats after 2–4 weeks of diabetes induction. In this study, the levels of insulin, C-peptide and glucose in diabetic rats reached to normal range as compared to un-diabetic rats in 20 days after transplantation of islet cells. Transplantation was performed under the cortex of testis as immunoisolated place for islet cells transplantation.     

Symmetry properties of tetraammine platinum（Ⅱ） with C2v and C4v point groups

Let G be a weighted graph with adjacency matrix A=[aij]. An Euclidean graph associated with a molecule is defined by a weighted graph with adjacency matrix D=[d/ij], where for i≠j, dij is the Euclidean distance between the nuclei i and j. In this matrix dij can be taken as zero if all the nuclei are equivalent. Otherwise, one may introduce different weights for different nuclei.Balasubramanian (1995) computed the Euclidean graphs and their automorphism groups for benzene, eclipsed and staggered forms of ethane and eclipsed and staggered forms of ferroeene. This paper describes a simple method, by means of which it is possible to calculate the automorphism group of weighted graphs. We apply this method to compute the symmetry of tetraammine platinum(Ⅱ) with C2v and C4v point groups.     

Antagonistic interaction between <Emphasis Type="Italic">Trichoderma asperellum</Emphasis> and <Emphasis Type="Italic">Phytophthora capsici</Emphasis> in vitro

Phytophthora capsici is a phytopathogen that causes a destructive pepper blight that is extremely difficult to control. Using a fungicide application against the disease is costly and relatively ineffective and there is also a huge environmental concern about the use of such chemicals. The genus Trichoderma has been known to have a potential biocontrol issue. In this paper we investigate the mechanism for causing the infection of T. asperellum against P. capsici. Trichoderma sp. (isolate CGMCC 6422) was developed to have a strong antagonistic action against hyphae of P. capsici through screening tests. The strain was identified as T. asperellum through using a combination of morphological characteristics and molecular data. T. asperellum was able to collapse the mycelium of the colonies of the pathogen through dual culture tests by breaking down the pathogenic hyphae into fragments. The scanning electron microscope showed that the hyphae of T. asperellum surrounded and penetrated the pathogens hyphae, resulting in hyphal collapse. The results show that seven days after inoculation, the hyphae of the pathogen were completely degraded in a dual culture. T. asperellum was also able to enter the P. capsici oospores through using oogonia and then developed hyphae and produced conidia, leading to the disintegration of the oogonia and oospores. Seven days after inoculation, an average 10.8% of the oospores were infected, but at this stage, the structures of oospores were still intact. Subsequently, the number of infected oospores increased and the oospores started to collapse. Forty-two days after inoculation, almost all the oospores were infected, with 9.3% of the structures of the oospores being intact and 90.7% of the oospores having collapsed.     

THE EPISTEMIC VALUE OF CURIOSITY

A bstract .  In this essay, Frederick Schmitt and Reza Lahroodi explore the value of curiosity for inquiry and knowledge. They defend an appetitive account of curiosity, viewing curiosity as a motivationally original desire to know that arises from having one's attention drawn to the object and that in turn sustains one's attention to it. Distinguishing curiosity from wonder, the authors explore several sources of the epistemic value of curiosity. First, curiosity is tenacious: curiosity whether a proposition is true leads to curiosity about related issues, thereby deepening our knowledge. Second, it is to some extent biased in favor of topics in which we already have a practical or epistemic interest. Third, and most important, curiosity is largely independent of our interests: it fixes our attention on objects in which we have no antecedent interest, thereby broadening our knowledge. Schmitt and Lahroodi elucidate the value of curiosity by outlining its role in levels of development — an approach indebted to John Dewey's explanation of the value of curiosity. Finally, they raise some questions about the implications of their account for educational practice.     

A system operator theorem on positive real operators

A new theorem expands the domain of the scalar immittance functions Z(p) to the operator Z(T) where T(s) is an invertible linear passive n-port system. Elements R, L, C of Z(p) are replaced by operators RI, LT, and [CT] ^{- 1}. All frequency transformations may be considered contained in this theorem when T is a scalar.     

Different effects of L-arginine on morphine tolerance in sham and ovariectomized female mice

Objective  

The roles of gonadal hormones and nitric oxide (NO) on the analgesic effects of morphine, tolerance to morphine, and their interactions have been widely investigated. In the present study, the effect of l-arginine (an NO precursor) on morphine tolerance in sham and ovariectomized (OVX) female mice was investigated.