• 【使用远程聚焦显微镜快速测量Langendorff灌注心脏的肌节长度和细胞方向。】 复制标题 收藏 收藏
    DOI:10.1161/CIRCRESAHA.113.301704 复制DOI
    作者列表:Botcherby EJ,Corbett A,Burton RA,Smith CW,Bollensdorff C,Booth MJ,Kohl P,Wilson T,Bub G
    BACKGROUND & AIMS: RATIONALE:Sarcomere length (SL) is a key indicator of cardiac mechanical function, but current imaging technologies are limited in their ability to unambiguously measure and characterize SL at the cell level in intact, living tissue. OBJECTIVE:We developed a method for measuring SL and regional cell orientation using remote focusing microscopy, an emerging imaging modality that can capture light from arbitrary oblique planes within a sample. METHODS AND RESULTS:We present a protocol that unambiguously and quickly determines cell orientation from user-selected areas in a field of view by imaging 2 oblique planes that share a common major axis with the cell. We demonstrate the effectiveness of the technique in establishing single-cell SL in Langendorff-perfused hearts loaded with the membrane dye di-4-ANEPPS. CONCLUSIONS:Remote focusing microscopy can measure cell orientation in complex 2-photon data sets without capturing full z stacks. The technique allows rapid assessment of SL in healthy and diseased heart experimental preparations.
    背景与目标: 理由:鞘管长度(SL)是心脏机械功能的关键指标,但是当前的成像技术在完整的活组织中无法在细胞水平上明确测量和表征SL的能力有限。
    目的:我们开发了一种使用远程聚焦显微镜测量SL和区域细胞取向的方法,该方法是一种新兴的成像方式,可以捕获样品中任意倾斜平面的光。
    方法和结果:我们提出了一种协议,该协议通过对2个与细胞共享主轴线的倾斜平面进行成像,从视野中的用户选择区域中明确,快速地确定细胞方向。我们证明了该技术在用膜染料di-4-ANEPPS加载的Langendorff灌注心脏中建立单细胞SL的有效性。
    结论:远程聚焦显微镜可以测量复杂的2光子数据集中的细胞方向,而无需捕获完整的z堆栈。该技术可以快速评估健康和患病心脏实验制剂中的SL。
  • 【视觉区域V2中的交叉方向抑制。】 复制标题 收藏 收藏
    DOI:10.1038/ncomms15739 复制DOI
    作者列表:Rowekamp RJ,Sharpee TO
    BACKGROUND & AIMS: :Object recognition relies on a series of transformations among which only the first cortical stage is relatively well understood. Already at the second stage, the visual area V2, the complexity of the transformation precludes a clear understanding of what specifically this area computes. Previous work has found multiple types of V2 neurons, with neurons of each type selective for multi-edge features. Here we analyse responses of V2 neurons to natural stimuli and find three organizing principles. First, the relevant edges for V2 neurons can be grouped into quadrature pairs, indicating invariance to local translation. Second, the excitatory edges have nearby suppressive edges with orthogonal orientations. Third, the resulting multi-edge patterns are repeated in space to form textures or texture boundaries. The cross-orientation suppression increases the sparseness of responses to natural images based on these complex forms of feature selectivity while allowing for multiple scales of position invariance.
    背景与目标: :对象识别依赖于一系列转换,其中只有第一个皮质阶段才被相对较好地理解。在第二阶段,即可视区域V2中,转换的复杂性使得无法清楚地了解此区域的具体计算方式。先前的工作发现了多种类型的V2神经元,每种类型的神经元对多边缘特征具有选择性。在这里,我们分析了V2神经元对自然刺激的反应,并发现了三个组织原则。首先,可以将V2神经元的相关边缘分组为正交对,表明本地翻译的不变性。其次,兴奋性边缘具有附近的正交方向的抑制性边缘。第三,所得的多边缘图案在空间中重复以形成纹理或纹理边界。基于这些复杂形式的特征选择性,交叉方向抑制会增加对自然图像的响应的稀疏性,同时允许多个尺度的位置不变性。
  • 【定向的认知表现:一个案例研究。】 复制标题 收藏 收藏
    DOI:10.1016/j.cortex.2007.06.005 复制DOI
    作者列表:Valtonen J,Dilks DD,McCloskey M
    BACKGROUND & AIMS: :Although object orientation in the human brain has been discussed extensively in the literature, the nature of the underlying cognitive representation(s) remains uncertain. We investigated orientation perception in BC, a patient with bilateral occipital and parietal damage from a herpes encephalitis infection. Our results show that in addition to general inaccuracy in discriminating and reproducing line orientations, her errors take the form of left-right mirror reflections across a vertical coordinate axis. We propose that in BC, the cognitive impairment is in failing to represent the direction of tilt for line orientations. Our results suggest that there exists a level of representation in the human brain at which line orientations are represented compositionally, such that the direction of a line orientation's tilt from a vertical mental reference meridian is coded independently of the magnitude of its angular displacement. Reflection errors across a vertical axis were observed both in visual and tactile line orientation tasks, demonstrating that these errors arise at a supra-modal level of representation not restricted to vision, or, alternatively, that visual-like representations are being constructed from the tactile input.
    背景与目标: :尽管在文献中已经广泛讨论了人脑中的面向对象,但是潜在的认知表示的性质仍然不确定。我们调查了卑诗省的方向性知觉,这是一例因疱疹性脑炎感染而导致双侧枕叶和顶突受损的患者。我们的结果表明,除了在识别和再现线条方向方面普遍存在误差外,她的错误还采用了沿垂直坐标轴的左右镜面反射的形式。我们认为,在卑诗省,认知障碍是无法代表直线方向的倾斜方向。我们的结果表明,在人脑中存在一种层次的表示形式,在该层次上线的方向被组成,这样,线的方向相对于垂直心理参考子午线的倾斜方向就被编码了,而与它的角位移的大小无关。在视觉和触觉线定向任务中都观察到了垂直轴上的反射误差,表明这些误差出现在超模态的表达水平上,而不仅限于视觉,或者从触觉构建了类似视觉的表达输入。
  • 【三代学术指导团队:护理学教师指导的新方法。】 复制标题 收藏 收藏
    DOI:10.1097/NNE.0000000000000777 复制DOI
    作者列表:Webber E,Vaughn-Deneen T,Anthony M
    BACKGROUND & AIMS: BACKGROUND:New faculty are often not prepared for a career in academia, and the transition can be challenging. They often come from practice environments where work expectations are clearly delineated. PROBLEM:Traditional mentoring programs typically pair new with experienced faculty members who are expected to provide guidance and advice. Results of the hierarchical dyad method have been mixed. APPROACH:Three generations of faculty formed a team composed of a tenured, a midcareer, and a new faculty member. The midcareer educator was better suited to help the novice prepare to teach, as they had recently been through the process, whereas the tenured faculty member was able to provide scholarship support to both. CONCLUSIONS:Providing new faculty with 2 mentors in a constellation format, along with the opportunity to network during structured mentoring meetings, contributed to a smooth onboarding of new faculty and provided scholarship support for the midcareer faculty member.
    背景与目标: 背景:新教师通常不为学术界的职业做好准备,而过渡可能会充满挑战。他们通常来自明确描述工作期望的实践环境。
    问题:传统的指导课程通常与新的经验丰富的教职员工配对,他们将提供指导和建议。分层二分法的结果好坏参半。
    方法:三代教师组成了一个由终身职位,中期职业和新员工组成的团队。中期职业教育家更适合于帮助新手准备教书,就像他们最近经历的那样,而终身任职的教师能够为这两个人提供奖学金支持。
    结论:以星座形式为新教师提供2名导师,并在结构化导师会议期间提供网络交流的机会,为新教师的顺利入职做出了贡献,并为职业中期教师提供了奖学金支持。
  • 【有意识地纠正进行选定的肩部康复练习的高架运动员的肩orientation骨方向:通过表面肌电图测量对斜方肌激活的影响。】 复制标题 收藏 收藏
    DOI:10.2519/jospt.2013.4283 复制DOI
    作者列表:De Mey K,Danneels LA,Cagnie B,Huyghe L,Seyns E,Cools AM
    BACKGROUND & AIMS: STUDY DESIGN:Controlled laboratory study. OBJECTIVES:To assess the effect of conscious correction of scapular orientation on the activation of the 3 sections of the trapezius muscle during shoulder exercises in overhead athletes with scapular dyskinesis. BACKGROUND:Previous research has led to the recommendation of 4 exercises for training of the trapezius muscle: prone extension, sidelying external rotation, sidelying forward flexion, and prone horizontal abduction with external rotation. However, the extent to which conscious correction of scapular orientation impacts trapezius muscle activation levels during these exercises is unknown. METHODS:Absolute (upper trapezius [UT], middle trapezius [MT], lower trapezius [LT]) and relative (UT/MT and UT/LT) muscle activation levels were determined with surface electromyography in 30 asymptomatic overhead athletes with scapular dyskinesis, during 4 selected exercises performed with and without conscious correction of scapular orientation. Repeated-measures analyses of variance were used to determine if a voluntary scapular orientation correction strategy influenced the activation levels of the different sections of the trapezius during each exercise. RESULTS:With conscious correction of scapular orientation, activation levels of the 3 sections of the trapezius muscle significantly increased during prone extension (mean ± SD difference: UT, 5.9% ± 8.6% maximal voluntary isometric contraction [MVIC]; MT, 13.8% ± 11.0% MVIC; LT, 9.8% ± 10.8% MVIC; P<.05) and sidelying external rotation (UT, 2.2% ± 4.4% MVIC; MT, 6.7% ± 10.6% MVIC; LT, 13.3% ± 24.4% MVIC; P<.05). There was no difference between conditions for sidelying forward flexion and prone horizontal abduction with external rotation. The UT/MT and UT/LT ratios were similar between conditions for all 4 exercises. CONCLUSION:Conscious correction of scapular orientation during the prone extension and sidelying external rotation exercises can be used to increase the activation level in the 3 sections of the trapezius in overhead athletes with scapular dyskinesis. Although lack of kinematic data limits the interpretation of the results, this study suggests that conscious correction of scapular orientation can be performed without altering the favorable UT/MT and UT/LT ratios that have been previously reported for these exercises.
    背景与目标: 研究设计:受控实验室研究。
    目的:评估肩overhead骨运动障碍的高架运动员在肩部锻炼过程中有意识地纠正肩cap骨定向对斜方肌3节激活的影响。
    背景:先前的研究已提出推荐4种锻炼斜方肌的运动的方法:俯卧伸展,侧向外旋,侧向前屈,侧向外展俯卧。但是,在这些锻炼中,肩cap骨方向的有意识矫正影响斜方肌激活水平的程度尚不清楚。
    方法:采用表面肌电图测定30名无肩overhead骨运动障碍的无症状头顶上运动员的绝对(上斜方肌(UT),中斜方肌(MT),下斜方肌(LT))和相对(UT / MT和UT / LT)肌肉激活水平,在选择和不进行肩cap骨定向矫正的情况下进行的4次选定锻炼中。使用方差的重复测量分析来确定自愿性肩cap骨方向矫正策略是否在每次锻炼中影响了斜方肌不同部位的激活水平。
    结果:随着肩cap骨方向的有意识的矫正,斜方肌的3个部分的激活水平在俯卧伸展过程中显着增加(平均值±SD差异:UT,最大自愿等距收缩[MVIC] 5.9%±8.6%; MT,13.8%± MVIC为11.0%; LT,MVIC为9.8%±10.8%; P <.05)和侧向外旋转(UT,MVIC为2.2%±4.4%; MT,6.7%±10.6%MVIC; LT,13.3%±24.4%MVIC; P <.05)。侧向向前屈曲的条件与外旋倾向的水平外展的条件之间没有差异。所有4个练习的条件之间的UT / MT和UT / LT比率均相似。
    结论:俯卧伸展和侧卧外旋运动过程中对肩cap骨方向的有意识矫正可用于增加斜肩肌运动障碍的高架运动员斜方肌3个部分的激活水平。尽管缺乏运动学数据限制了结果的解释,但这项研究表明,可以在不改变先前针对这些练习报道的有利的UT / MT和UT / LT比值的情况下,有意识地进行肩cap骨定向矫正。
  • 【脂质环境中胰脂肪酶的结构和方向:PM-IRRAS和布鲁斯特角显微镜研究。】 复制标题 收藏 收藏
    DOI:10.1021/bi701831f 复制DOI
    作者列表:Allouche M,Castano S,Colin D,Desbat B,Kerfelec B
    BACKGROUND & AIMS: :Colipase is a key element in lipase-catalyzed dietary lipids hydrolysis. Although devoid of enzymatic activity, colipase promotes pancreatic lipase activity in the physiological intestinal conditions by anchoring the enzyme on the surface of lipid droplets. Polarization modulation infrared reflection absorption spectroscopy combined with Brewster angle microscopy studies was performed on colipase alone and in various lipid environments to obtain a global view of both conformation and orientation and to assess lipid perturbations. We clearly show that colipase fully inserts into a dilaurin monolayer and promotes the formation of lipid/protein domains, whereas in a phospholipid environment its insertion is only partial, limited to the polar head group. In a mixed 70% phosphatidylcholine/30% dilaurin environment, colipase adsorbs to but does not penetrate deeply into the film. It triggers the formation of diglyceride domains under which it would form a rather uniform layer. We also clearly demonstrate that colipase adopts a preferred orientation when dilaurin is present at the interface. In contrast, at a neutral phospholipid interface, the infrared spectra suggest an isotropic orientation of colipase which could explain its incapacity to reverse the inhibitory effects of these lipids on the lipase activity.
    背景与目标: :脂肪酶是脂肪酶催化的饮食脂质水解的关键元素。尽管缺乏酶促活性,但是在生理肠道条件下,固溶酶通过将酶锚定在脂质小滴的表面上来促进胰腺脂肪酶的活性。偏振调制红外反射吸收光谱法与布鲁斯特角显微镜研究相结合,仅在脂肪酶上和在各种脂质环境中进行,以获得构象和方向的整体视图并评估脂质的扰动。我们清楚地表明,固溶酶完全插入到二月桂酸酯单层中,并促进脂质/蛋白质结构域的形成,而在磷脂环境中,其插入仅是部分的,仅限于极性头基。在混合的70%磷脂酰胆碱/ 30%二月桂酸酯环境中,脂肪酶吸附但不会深深渗透到薄膜中。它触发了甘油二酯结构域的形成,在甘油二酯结构域下将形成相当均匀的层。我们还清楚地表明,当界面上存在双月桂酸酯时,椰油酶会采用一种优选的取向。相反,在中性磷脂界面处,红外光谱表明椰脂酶的各向同性取向,这可以解释其不能逆转这些脂质对脂酶活性的抑制作用。
  • 【罗伯特·伍德·约翰逊基金会护士护士学者计划的概述。】 复制标题 收藏 收藏
    DOI:10.1016/j.outlook.2016.12.008 复制DOI
    作者列表:Campbell J,Ladden MD,McBride AB,Cimino A,Kostas-Polston E,Deming K
    BACKGROUND & AIMS: BACKGROUND:The Robert Wood Johnson Foundation Nurse Faculty Scholars program was created to address the nursing faculty shortage and thereby decrease the nursing shortage. PURPOSE:The purpose of the study was to describe the program development, implementation, and ongoing outcome evaluation. METHODS:Data on scholarly productivity, impact of research, research funding, and leadership positions were compiled, including an h-index (impact of publications) comparison with a comparison group of other interdisciplinary faculty at the same institutions of the 90 current and alumni scholars. DISCUSSION:There is evidence of the achievements of the individual scholars; however, the effect of the synergy of the multiple components of the program is difficult to capture in traditional evaluation strategies. CONCLUSIONS:The sense of possibility and responsibility (to the profession, to improving the health of all Americans, and to one's school of nursing and university) was a significant outcome of the program. Lessons learned from the program are important for the leadership development and retention of nursing faculty.
    背景与目标: 背景:罗伯特伍德·约翰逊基金会护士护士学者计划的创建是为了解决护士短缺的问题,从而减少护士短缺。
    目的:本研究的目的是描述计划的制定,实施和持续的结果评估。
    方法:收集了有关学术生产率,研究影响,研究经费和领导职位的数据,包括与90名现任和校友学者相同机构中其他跨学科教授的比较组进行的h指数(出版物的影响)比较。
    讨论:有证据表明个别学者的成就。但是,在传统的评估策略中很难捕捉到该计划多个组成部分协同作用的效果。
    结论:这种可能性和责任感(对职业,对改善全体美国人的健康以及对自己的护理学校和大学的健康)是该计划的重要成果。从该计划中学到的经验对于领导力的发展和护士队伍的保留很重要。
  • 【在国家计划中选择新的精神科住院医师:对能力和属性的教师观点的定性研究。】 复制标题 收藏 收藏
    DOI:10.1007/s40596-020-01282-1 复制DOI
    作者列表:Poremski D,Tan GM,Lau BJ,Lee YW,Sim K
    BACKGROUND & AIMS: OBJECTIVE:Admission committees use multiple sources of information to select residents. However, the way in which faculty members use each data source remains unclear and highly context-specific. The present study seeks to understand how faculty members use various sources of information about candidates to make admission decisions to a National Psychiatry Residency Program. METHODS:The theory of core competencies was used as a foundation for this qualitative study. Framework analysis was used to structure the project and data presentation. Twenty key informants from the faculty were purposefully sampled in accordance with the initial theory. Open-ended semi-structured interviews were conducted to obtain their views about the essential competencies of psychiatrists and the ways in which these competencies could be reliably gauged. RESULTS:Participants described numerous competencies that they believed were essential to becoming competent psychiatrists. These competencies fell within the six core competencies of the Accreditation Council for Graduate Medical Education framework. However, several non-competency attributes (such as perseverance, empathy, and compassion) were also relevant in the selection process. To reduce the impact of self-presentation bias, to which these attributes were vulnerable, the faculty relied heavily on sources of information obtained from third parties, such as feedback from co-workers with first-hand experience of the candidate during their clinical placements. CONCLUSION:Faculty members place importance on informal informant-derived information about a candidate's non-competency attributes in addition to core competencies when deciding whether or not to select a candidate for admission into a residency training program.
    背景与目标: 目的:入学委员会使用多种信息来源来选择居民。但是,教职员工使用每个数据源的方式仍然不清楚,并且具有高度的针对性。本研究旨在了解教职员工如何使用有关候选人的各种信息资源来决定是否入学《国家精神病学住院医师计划》。
    方法:核心能力理论被用作该定性研究的基础。框架分析用于构建项目和数据表示。根据最初的理论,有目的地抽取了来自该学院的20名关键线人。进行了不限成员名额的半结构化访谈,以获取他们对精神科医生基本能力的看法以及对这些能力的可靠衡量方式。
    结果:参与者描述了他们认为对成为合格的精神病医生必不可少的许多能力。这些能力属于研究生医学教育认可委员会框架的六项核心能力。但是,在选择过程中,一些不称职的属性(例如毅力,同情心和同情心)也很重要。为了减少这些因素易受其影响的自我表象偏见的影响,教师严重依赖于从第三方获得的信息来源,例如来自同事的反馈以及在临床实习期间候选人的第一手经验。
    结论:在决定是否选择候选人入学住院医师培训课程时,除核心能力外,教师还重视非正式的,基于信息提供者的非胜任属性的信息。
  • 【美国大学关于教师利益冲突的政策。】 复制标题 收藏 收藏
    影响因子 :
    发表时间:2000-11-01
    来源期刊:JAMA
    DOI:10.1001/jama.284.17.2203 复制DOI
    作者列表:Cho MK,Shohara R,Schissel A,Rennie D
    BACKGROUND & AIMS: CONTEXT:Despite federal regulations on faculty conflicts of interest in federally funded research, academic-industry ties are common, and evidence exists that financial considerations bias the research record. Public scrutiny of these ties is increasing, especially in cases where researchers have financial interests in the corporate sponsors of their clinical research. OBJECTIVE:To review policies on conflict of interest at major biomedical research institutions in the United States. DESIGN:Cross-sectional survey and content analysis study conducted from August 1998 to February 2000. SETTING AND PARTICIPANTS:The 100 US institutions with the most funding from the National Institutes of Health in 1998 were initially sampled; policies from 89 institutions were available and included in the analysis. MAIN OUTCOME MEASURES:Process for disclosure, review, and management of conflicts of interest and specified management strategies or limitations, according to the institutions' faculty/staff conflict of interest policies. RESULTS:Content of the conflict of interest policies varied widely across institutions. Fifty-five percent of policies (n = 49) required disclosures from all faculty while 45% (n = 40) required them only from principal investigators or those conducting research. Nineteen percent of policies (n = 17) specified limits on faculty financial interests in corporate sponsors of research, 12% (n = 11) specified limits on permissible delays in publication, and 4% (n = 4) prohibited student involvement in work sponsored by a company in which the faculty mentor had a financial interest. CONCLUSIONS:Most policies on conflict of interest in our sample of major research institutions in the United States lack specificity about the kinds of relationships with industry that are permitted or prohibited. Wide variation in management of conflicts of interest among institutions may cause unnecessary confusion among potential industrial partners or competition among universities for corporate sponsorship that could erode academic standards. It is in the long-term interest of institutions to develop widely agreed-on, clear, specific, and credible policies on conflicts of interest. JAMA. 2000;284:2203-2208.
    背景与目标: 背景:尽管联邦政府对联邦资助的研究中的教师利益冲突有规定,但学术界与学术界之间的联系很普遍,并且有证据表明,出于财务考虑,研究记录存在偏差。公众对这些联系的审查越来越多,特别是在研究人员对其临床研究的公司赞助商有经济利益的情况下。
    目的:审查美国主要生物医学研究机构的利益冲突政策。
    设计:1998年8月至2000年2月进行的横断面调查和内容分析研究。
    地点和参与者:1998年,美国国立卫生研究院资助最多的100家美国机构最初被抽样;已有来自89个机构的政策,该政策已包括在内。
    主要观察指标:根据研究机构的教职员工利益冲突政策,披露,审查和管理利益冲突以及指定的管理策略或限制的过程。
    结果:利益冲突政策的内容在各个机构之间差异很大。 55%的政策(n = 49)要求所有教职员工公开,而45%(n = 40)的政策仅要求主要研究人员或进行研究的人员公开。 19%的政策(n = 17)规定了公司研究赞助者对教师财务利益的限制,12%(n = 11)规定了允许出版延迟的限制,4%(n = 4)禁止学生参与赞助的工作由教师在其中有财务利益的公司提供。
    结论:在我们的美国主要研究机构样本中,大多数关于利益冲突的政策都缺乏关于允许或禁止的与产业的关系的具体性。机构间利益冲突的管理差异很大,可能会导致潜在的行业合作伙伴之间出现不必要的混乱,或者大学之间的企业赞助竞争可能会削弱学术水平。对于利益冲突,制定广泛商定,明确,具体和可信的政策符合机构的长远利益。贾玛2000; 284:2203-2208。
  • 【空间定位的台式X射线散射揭示了毛竹中组织特定的微纤维取向。】 复制标题 收藏 收藏
    DOI:10.1186/s13007-016-0155-1 复制DOI
    作者列表:Ahvenainen P,Dixon PG,Kallonen A,Suhonen H,Gibson LJ,Svedström K
    BACKGROUND & AIMS: BACKGROUND:Biological materials have a complex, hierarchical structure, with vital structural features present at all size scales, from the nanoscale to the macroscale. A method that can connect information at multiple length scales has great potential to reveal novel information. This article presents one such method with an application to the bamboo culm wall. Moso (Phyllostachys edulis) bamboo is a commercially important bamboo species. At the cellular level, bamboo culm wall consists of vascular bundles embedded in a parenchyma cell tissue matrix. The microfibril angle (MFA) in the bamboo cell wall is related to its macroscopic longitudinal stiffness and strength and can be determined at the nanoscale with wide-angle X-ray scattering (WAXS). Combining WAXS with X-ray microtomography (XMT) allows tissue-specific study of the bamboo culm without invasive chemical treatment. RESULTS:The scattering contribution of the fiber and parenchyma cells were separated with spatially-localized WAXS. The fiber component was dominated by a high degree of orientation corresponding to small MFAs (mean MFA 11°). The parenchyma component showed significantly lower degree of orientation with a maximum at larger angles (mean MFA 65°). The fiber ratio, the volume of cell wall in the fibers relative to the overall volume of cell wall, was determined by fitting the scattering intensities with these two components. The fiber ratio was also determined from the XMT data and similar fiber ratios were obtained from the two methods, one connected to the cellular level and one to the nanoscale. X-ray diffraction tomography was also done to study the differences in microfibril orientation between fibers and the parenchyma and further connect the microscale to the nanoscale. CONCLUSIONS:The spatially-localized WAXS yields biologically relevant, tissue-specific information. With the custom-made bench-top set-up presented, diffraction contrast information can be obtained from plant tissue (1) from regions-of-interest, (2) as a function of distance (line scan), or (3) with two-dimensional or three-dimensional tomography. This nanoscale information is connected to the cellular level features.
    背景与目标: 背景:生物材料具有复杂的层次结构,在从纳米到宏观的所有尺寸尺度上都具有重要的结构特征。一种可以在多个长度尺度上连接信息的方法具有揭示新颖信息的巨大潜力。本文介绍了一种这样的方法,并将其应用于竹茎壁。毛竹(Phyllostachys edulis)竹是商业上重要的竹种。在细胞水平上,竹茎壁由嵌入实质细胞组织基质中的血管束组成。竹细胞壁中的微纤丝角(MFA)与它的宏观纵向刚度和强度有关,并且可以通过广角X射线散射(WAXS)在纳米尺度上确定。将WAXS与X射线显微断层扫描(XMT)结合使用,可以对竹茎进行组织特异性研究,而无需进行侵入性化学治疗。
    结果:通过空间定位的WAXS分离了纤维和实质细胞的散射贡献。纤维组分主要由较高的取向度决定,该取向度对应于较小的MFA(平均MFA 11°)。薄壁组织的方向性明显降低,在较大角度时最大(平均MFA 65°)。纤维比率,即纤维中细胞壁的体积相对于细胞壁的总体积,是通过使散射强度与这两种成分相匹配来确定的。还从XMT数据确定了纤维比例,并且从两种方法获得了相似的纤维比例,一种方法连接到细胞水平,另一种方法连接到纳米级。还进行了X射线衍射断层扫描,以研究纤维与薄壁组织之间微纤维取向的差异,并进一步将微尺度连接到纳米尺度。
    结论:空间定位的WAXS产生生物学相关的组织特异性信息。通过提供定制的台式设备,可以从植物组织(1)的感兴趣区域,(2)作为距离的函数(线扫描)或(3)从植物组织获得衍射对比度信息。二维或三维断层扫描。该纳米级信息连接到细胞水平的特征。
  • 【配体定向对作为脱唾液酸糖蛋白的模型配体的聚(N-对-乙烯基苄基-o-β-D-吡喃半乳糖基-D-葡糖酰胺)肝细胞附着的影响。】 复制标题 收藏 收藏
    DOI:10.1163/156856296x00589 复制DOI
    作者列表:Cho CS,Goto M,Kobayashi A,Kobayashi K,Akaike T
    BACKGROUND & AIMS: The orientation effect of galactose ligand on hepatocyte attachment was investigated. Poly(N-p-vinylbenzyl-o-beta-D-galactopyranosyl-D-gluconamide )(PVLA), a beta-galactose-carrying styrene homopolymer, was used as a model ligand for the asialoglycoprotein receptors on hepatocytes. PVLA was transferred onto the poly(gamma-benzyl L-glutamate) (PBLG) or PBLG/poly(ethylene glycol) (PEG)PBLG Langmuir-Blodgett (LB) films as the monolayer level. The dichroic fluorescence values of the confocal microscope indicated that the PVLA transferred onto the LB films was located with a preferential orientation of its molecular axes with regard to the direction of the alpha-helix of polypeptide. Hepatocyte recognized well-oriented galactose moieties of the surface of PVLA through asialoglycoprotein receptors.

    背景与目标: 研究了半乳糖配体对肝细胞附着的定向作用。聚(N-对乙烯基苄基-o-β-D-吡喃半乳糖基-D-葡糖酰胺)(PVLA),一种携带β-半乳糖的苯乙烯均聚物,用作肝细胞上去唾液酸糖蛋白受体的模型配体。将PVLA转移到聚(γ-苄基L-谷氨酸)(PBLG)或PBLG /聚(乙二醇)(PEG)PBLG Langmuir-Blodgett(LB)薄膜上作为单层水平。共聚焦显微镜的二向色性荧光值表明,转移到LB膜上的PVLA的分子轴相对于多肽的α-螺旋方向优先取向。肝细胞通过去唾液酸糖蛋白受体识别出PVLA表面定向良好的半乳糖部分。

  • 【身体大小和方向对紫外线辐射的影响。】 复制标题 收藏 收藏
    DOI:10.1111/j.1600-0781.1996.tb00177.x 复制DOI
    作者列表:Parisi AV,Kimlin MG,Wong JC,Fleming RA
    BACKGROUND & AIMS: A method has been developed for determining the UV and erythemal exposures to the entire body. The difference between the ambient erythemal exposure and that to the body compared to the ambient exposure may be as high as 76%. The height, orientation, and overall height had a minimal effect on the exposure to the body with size, time of day and time of year having a significant effect. The diffuse component of UV to a side of the body ranged from 20% to 41% between different times of the year with different levels of cloud cover. The ratio of the body to the ambient erythemal exposures varied from 0.24 to 0.61, with the time of day and time of year with the smaller value for periods of high solar altitude.

    背景与目标: 已经开发出一种确定整个身体的紫外线和红斑暴露的方法。与环境暴露相比,环境红斑暴露与人体暴露之间的差异可能高达76%。身高,方向和整体身高对身体的暴露影响很小,而大小,一天中的时间和一年中的时间则有很大的影响。在一年中的不同时间,不同云量的覆盖下,紫外线扩散到身体一侧的比例在20%到41%之间。人体与周围红斑暴露的比例在0.24至0.61之间变化,在一天中的某个时间和一年中的某个时间,在太阳高度较高的时期该值较小。

  • 【研讨会,以提高教师的管理技能。】 复制标题 收藏 收藏
    DOI:10.1097/00001888-199705000-00107 复制DOI
    作者列表:Steinert Y,Nasmith L,Daigle N
    BACKGROUND & AIMS: -2
    背景与目标: -2
  • 【美国药学院和药学院的药学实践教师中,董事会认证的发生率和影响因素。】 复制标题 收藏 收藏
    DOI:10.1002/phar.1171 复制DOI
    作者列表:Toussaint KA,Watson K,Marrs JC,Sturpe DA,Anderson SL,Haines ST
    BACKGROUND & AIMS: :Board certification is a means of demonstrating expertise above the minimum licensing standards. For many health care professionals, this credential is a necessity. As pharmacists become involved in more advanced patient care services, board certification becomes an essential component to ensuring quality care. The prevalence of United States pharmacy practice faculty members who are board certified, however, is unknown. In addition, to our knowledge, factors that serve to motivate or discourage faculty from obtaining board certification have not been previously described; thus, 900 pharmacy practice faculty members listed in the American Association of Colleges of Pharmacy (AACP) online directory were invited to complete an online survey regarding motivators and barriers for board certification. In addition, a list of board-certified pharmacists, obtained from the Board of Pharmacy Specialties, was used to check the board certification status of all pharmacy practice faculty members listed in the AACP directory. In 2011, the prevalence of board certification among the 2867 pharmacy practice faculty members was 37% (1063 pharmacists), with the highest prevalence found among assistant professors (39.4%). A total of 322 faculty members (36% response rate) completed the survey; of these, 308 self-identified as pharmacy practice faculty, and their responses were included in the analysis. Current board certification in pharmacy specialties was reported by 163 respondents (52.9%); 14 (4.5%) were previously certified. Among the 308 respondents, the most common perceived reason why pharmacy practice faculty become board certified was the desire to be recognized as an expert in the field (71.5%). Those who were currently board certified indicated personal growth as the most important reason (60.1%). Those previously certified indicated no perceived benefit as the most common reason for not recertifying (71.4%). Among those never certified, no perceived need (52.0%) or benefit (44.8%) were the most common reasons for not becoming certified; however, a majority of those never certified (68%) stated that they would become board certified if there was no associated cost and they were confident they would pass. To increase the prevalence of board certification in pharmacy practice faculty at U.S. schools and colleges of pharmacy, the benefits of this credential must be addressed at each institution. Steps should be taken to assist and encourage board certification.
    背景与目标: :董事会认证是一种展示最低许可标准之上的专业知识的方式。对于许多医疗保健专业人员而言,此证书是必不可少的。随着药剂师参与更高级的患者护理服务,董事会认证已成为确保高质量护理的重要组成部分。但是,尚不知道获得董事会认证的美国药学实践教职人员的患病率。此外,据我们所知,以前没有描述过用来激励或劝​​阻教师获得董事会认证的因素;因此,邀请了美国药学院联合会(AACP)在线目录中列出的900名药学实践教师完成了有关董事会认证激励因素和障碍的在线调查。此外,还使用了从药房专业委员会获得的经董事会认证的药剂师名单,以检查ACPCP目录中列出的所有药学执业教职人员的董事会认证状态。 2011年,在2867名药学实践教师中,董事会认证的患病率为37%(1063位药剂师),在助理教授中患病率最高(39.4%)。共有322名教职员工(36%的回应率)完成了调查;其中,有308位自称药学专业的教师,他们的回答也包括在分析中。 163名受访者报告了当前的药学专业委员会认证(52.9%); 14(4.5%)位先前得到认证。在308位受访者中,药房实践教师获得董事会认证的最常见原因是希望获得该领域专家的认可(71.5%)。目前获得董事会认证的人指出,个人成长是最重要的原因(60.1%)。那些先前获得认证的人表示,没有被认可的利益是不进行重新认证的最普遍原因(71.4%)。在那些从未获得认证的人中,没有被认可的需求(52.0%)或收益(44.8%)是未获得认证的最常见原因;但是,大多数从未认证的人(68%)表示,如果没有相关成本,他们将成为董事会认证的人,他们有信心会通过。为了提高美国药学院和药学院药房实践教师的董事会认证普及率,必须在每个机构中都使用此证书的好处。应该采取步骤来协助和鼓励董事会认证。
  • 【功能不均等的中心体在果蝇神经干细胞的不对称分裂中驱动纺锤体定向。】 复制标题 收藏 收藏
    DOI:10.1016/j.devcel.2007.01.021 复制DOI
    作者列表:Rebollo E,Sampaio P,Januschke J,Llamazares S,Varmark H,González C
    BACKGROUND & AIMS: :Stem cell asymmetric division requires tight control of spindle orientation. To study this key process, we have recorded Drosophila larval neural stem cells (NBs) engineered to express fluorescent reporters for microtubules, pericentriolar material (PCM), and centrioles. We have found that early in the cell cycle, the two centrosomes become unequal: one organizes an aster that stays near the apical cortex for most of the cell cycle, while the other loses PCM and microtubule-organizing activity, and moves extensively throughout the cell until shortly before mitosis when, located near the basal cortex, it recruits PCM and organizes the second mitotic aster. Upon division, the apical centrosome remains in the stem cell, while the other goes into the differentiating daughter. Apical aster maintenance requires the function of Pins. These results reveal that spindle orientation in Drosophila larval NBs is determined very early in the cell cycle, and is mediated by asymmetric centrosome function.
    背景与目标: :干细胞不对称分裂需要严格控制主轴方向。为了研究这一关键过程,我们记录了果蝇幼虫神经干细胞(NBs),其被设计用于表达微管,中心小周材料(PCM)和中心小体的荧光报告基因。我们发现,在细胞周期的早期,两个中心体变得不相等:一个中心体在整个细胞周期的大部分时间内都组织着一个位于根尖皮质附近的紫,而另一个中心体失去了PCM和微管组织活性,并在整个细胞内广泛移动。直到有丝分裂之前不久,当它位于基底皮层附近时,它会募集PCM并组织第二个有丝分裂紫aster。分裂后,顶端中心体保留在干细胞中,而另一个进入分化中的女儿体内。尖端的aster维护需要使用Pins功能。这些结果表明,果蝇幼虫NB中纺锤体的方向是在细胞周期的早期确定的,并由不对称中心体功能介导。

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