过氧化氢-乙醚法制备脱蛋白骨的理化性质研究

目的探讨过氧化氢-乙醚法制备脱蛋白骨（deproteinized bone，DPB）的理化性质。方法采用过氧化氢-乙醚法将大白兔干骺端松质骨脱脂、脱蛋白制作成生物衍生骨材料——DPB。倒置相差显微镜、体视学显微镜、扫描电子显微镜观察DPB材料外表面、孔隙内表面结构、孔径大小和孔间交通情况。pH计检测仪检测DPB材料的培养液pH值。光学显微镜观察微生物生长情况。微量凯氏定氮法检测DPB材料中蛋白质含量。结果倒置相差显微镜、体视学显微镜、扫描电子显微镜观察结果显示，DPB材料具有原骨组织的三维多孔一网架结构系统。计算机图像分析系统结果显示，孔隙率为（83．26±5．35）％；孔径最大径为（315．11±17．51）μm，最小径为（109．37±11．33）μm。浸泡DPB材料组培养液pH为7．383±0．015，空白对照组培养液pH为7．380±0．020。光学显微镜下观察结果显示，DPB材料的培养液未发现细菌或霉菌生长。DPB蛋白质含量为（20．4±1.2）％。结论由松质骨来源制作的DPB是一种较理想的组织工程骨生物支架材料。     

Icodextrin as salvage therapy in peritoneal dialysis patients with refractory fluid overload

Background  

Icodextrin is a high molecular weight, starch-derived glucose polymer, which is capable of inducing sustained ultrafiltration over prolonged (12–16 hour) peritoneal dialysis (PD) dwells. The aim of this study was to evaluate the ability of icodextrin to alleviate refractory, symptomatic fluid overload and prolong technique survival in PD patients.     

Dissociation of the neural correlates of recognition memory according to familiarity, recollection, and amount of recollected information

The present experiment used fMRI to investigate whether neural correlates of recognition memory behave in a manner consistent with the proposal that recognition decisions are based on a unidimensional memory strength variable. A modified Remember/Know recognition test was used in which participants could indicate two levels of recollection. Participants were required to indicate whether a test item was new, familiar (known), elicited recollection of general contextual details from the study episode (R1 response), or elicited a specific recollection of the item with which it was paired at study (R2 response). Little evidence could be found to support the view that Remember/Know/New judgments reflect variations along a single strength dimension. Instead, the findings replicated prior research in indicating that the neural correlates of recollection and familiarity can be doubly dissociated. Two recollection-sensitive regions - left lateral inferior parietal and left fusiform cortex - were found to be sensitive to amount of information recollected, as operationalized in the contrast between R2 and R1 responses. It is proposed that these regions may support the representation of recollected information.     

Nutrition education in the context of the United Nations Standing Committee on Nutrition activities and publications, 1985-2006

The United Nations System Standing Committee on Nutrition (SCN) is a forum where United Nations (UN) agencies, bilateral partners, and nongovernmental agencies meet to harmonize and coordinate nutrition policy and programs. This report reviews the positions taken regarding nutrition education throughout SCN publications, annual sessions, and thematic working groups. The first Nutrition Policy Paper, published in 1985, was a State-of-the-Art Review that investigated 6 aspects of a nutrition education system. Later SCN publications and meetings have further addressed how to conduct effective nutrition education to maximize impact. For nutrition education to be worthwhile, it must reach significant audiences and lead to behavioral change, conditions which in turn require feasibility studies and investments in terms of personnel and resources. The SCN plays an important role to these ends through: 1) the advocacy opportunity offered by the SCN Annual Session; 2) the expertise of the working groups; and 3) the dissemination channels offered by the SCN publications and Web site.     

Comparison of the neural correlates of retrieval success in tests of cued recall and recognition memory

The neural correlates of successful retrieval on tests of word stem recall and recognition memory were compared. In the recall test, subjects viewed word stems, half of which were associated with studied items and half with unstudied items, and for each stem attempted to recall a corresponding study word. In the recognition test, old/new judgments were made on old and new words. The neural correlates of successful retrieval were identified by contrasting activity elicited by correctly endorsed test items. Old > new effects common to the two tasks were found in medial and lateral parietal and right entorhinal cortex. Common new > old effects were identified in medial and left frontal cortex, and left anterior intra-parietal sulcus. Greater old > new effects were evident for cued recall in inferior parietal regions abutting those demonstrating common effects, whereas larger new > old effects were found for recall in left frontal cortex and the anterior cingulate. New > old effects were also found for the recall task in right lateral anterior prefrontal cortex, where they were accompanied by old > new effects during recognition. It is concluded that successful recall and recognition are associated with enhanced activity in a common set of recollection-sensitive parietal regions, and that the greater activation in these regions during recall reflects the greater dependence of that task on recollection. Larger new > old effects during recall are interpreted as reflections of the greater opportunity for iterative retrieval attempts when retrieval cues are partial rather than copy cues.