10 kHz microsecond pulsed X-ray generator utilising a hot-cathode triode with variable durations for biomedical radiography

A 10 kHz pulsed X-ray generator utilising a hot-cathode triode in conjunction with a new type of grid control device for controlling X-ray duration is described. The energy-storage condenser was charged up to 70 kV by a power supply, and the electric charges in the condenser were discharged to the X-ray tube repetitively by the grid control device. The maximum values of the grid voltage (negative value), the tube voltage, and the tube current were −1.5 kV, 70 kV, and 0.4 A, respectively. The duration of the flash X-ray pulse was primarily determined by the time constant of the grid control device and the cut-off voltage of thermoelectrons. The X-ray duration was controlled within a region of less than 1 ms; the X-ray intensity with a pulse width of 0.27 ms, a charged voltage of 70 kV, and a peak tube current of 0.4 A was 0.92 μC kg⁻¹ at 0.5 m per pulse. The maximum repetition rate was about 10 kHz, and the size of the focal spot was about 3.5×3.5 mm.     

临床路径开发对象的选择

开发对象选择是否正确是路径实施能否成功的前提之一。对于初步尝试临床路径这种管理模式的医院，在开发对象的选取上更应该重视，不能盲目随意选取。本要医院外科手术病例收容量，住院日分布情况进行分析，为医院选取临床路径开发对象提供方法和参考依据。     

Preference for IgG mAb Binding Insulin in Solution or on Surfaces is Related to Immunoglobulin Variable Region Structures

Studies on insulin autoantibodies often show a lack of correlation between enzyme-linked immunosorbent assays (ELISAs) and fluid phase radioimmunoassays (RIAs). Similarly, a set of IgG anti-insulin monoclonal antibodies (mAb) from BALB/c mice are found to differ in their binding in ELISAs and RIAs. To understand the structural basis for differential insulin binding, soluble and complexed biotinylated insulin is used to confirm binding properties independent of insulin-coated plastic and radioiodination. The binding properties of intact mAb are also present in Fab fragments, indicating ligand preference is not related to valence or to the Fc portion of Ig. Analysis of binding to soluble or bound ligand in relationship to antibody variable (V) region structures indicates that differential binding in the two assays is a property of heavy chain variable region structure. Studies also show that limited amino acid replacements arising during maturation of the immune response may change the binding preference for an individual mAb. These findings indicate that differences in detection of insulin binding in solid phase and fluid phase are not artefactual but reflect intrinsic structural features of immunoglobulin interaction with insulin.     

Executive functions and methylphenidate response in subtypes of attention-deficit/hyperactivity disorder.

BACKGROUND: Oculomotor tasks are a well-established means of studying executive functions and frontal-striatal functioning in both nonhuman primates and humans. Attention-deficit/hyperactivity disorder (ADHD) is thought to implicate frontal-striatal circuitry. We used oculomotor tests to investigate executive functions and methylphenidate response in two subtypes of ADHD. METHODS: Subjects were boys, aged 11.5-14 years, with ADHD-combined (n = 10), ADHD-inattentive (n = 12), and control subjects (n = 10). Executive functions assessed were motor planning (tapped with predictive saccades), response inhibition (antisaccades), and task switching (saccades-antisaccades mixed). RESULTS: The ADHD-combined boys were impaired relative to control subjects in motor planning (p < .003) and response inhibition (p < .007) but not in task switching (p > .92). They were also significantly impaired relative to ADHD-inattentive boys, making fewer predictive saccades (p < .03) and having more subjects with antisaccade performance in the impaired range (p < .04). Methylphenidate significantly improved motor planning and response inhibition in both subtypes. CONCLUSIONS: ADHD-combined but not ADHD-inattentive boys showed impairments on motor planning and response inhibition. These deficits might be mediated by brain structures implicated specifically in the hyperactive/impulsive symptoms. Methylphenidate improved oculomotor performance in both subtypes; thus, it was effective even when initial performance was not impaired.     

网络化环境中科学选择文献的个性化趋势

通过分析网络环境中科学文献的个性化趋势产生的原因，说明了个性的信息服务能更好地满足用户的信息需求，将成为网络信息服务的发展方向。     

用于异常检测的单级免疫学习算法

基于对多级免疫学习算法(M ILA)的批评性研究,提出了单级免疫学习算法(SILA)。该算法适用于低维度特征量的异常检测,提高了探测器训练的效率和效益,而且对M ackey-G lass时间序列数据的检测取得了很好的实验结果。     

Galanin receptor antagonists decrease fat preference in Brattleboro rat.

The Brattleboro rat eats spontaneously 46% of its diet per day in fat when given a choice of carbohydrate, protein and fat. An overexpression of galanin (GAL) has been also observed in the hypothalamic paraventricular nuclei (PVN). This associative correlation has led to a hypothesis of a functional relation between central galanin expression and the preference for a lipid diet. In the present experiments, the effects of two GAL receptor antagonists, C7 and galantide, on fat consumption and central overexpression of GAL were investigated. Both antagonists were injected into either the cerebral ventricles or directly above the PVN, and the diet consumption followed for the subsequent 24h. C7 decreased significantly fat consumption when injected into the ventricles or directly above the PVN. In contrast, galantide must be injected above the PVN to show the same effect. However, the two antagonists did not modify GAL mRNA expression in the PVN when they were injected 2h before sacrifice. These experiments confirm a functional link between the preferential consumption of fat and hypothalamic Galanin; different subtypes of the GAL receptor are probably involved, since both Galanin antagonists were differently efficient in decreasing spontaneous fat selection of the Brattleboro rat.     

军队优秀中青年医学科技人员成长与培养教育探讨

军队优秀中青年医学科技人员是实现军队医院现代化建设的关键。提出了军队中青年医学科技人员应具备的各种基本素质和能力，阐明了培养选择机制中公平竞争的重要性及培养过程中应注意的导向问题。     

Choosing Between and Interpreting the Heckit and Two-Part Models for Corner Solutions

This article addresses certain poor practices commonly seen in the applied health economics literature regarding the use of the Heckit and the two-part model. First, many articles invoke the Heckit to solve a supposed selection problem associated with masses of zero values in continuous variables, despite the fact that it has been shown elsewhere that no such selection problem exists when modeling observed actual, as opposed to latent potential, outcomes. Second, many applications incorrectly formulate the marginal effect tests in the Heckit and two-part model, thus undermining central conclusions. Finally, many researchers use a t-test of the inverse Mills coefficient to choose between the Heckit and two-part models despite its poor performace; we propose instead an adapted empirical mean square error test.     

《席弘赋》针灸学术思想探微

《席弘赋》是针灸名赋之一,作者从临床实用角度,阐述了席弘赋在辨证论治、针刺操作、临症配穴等方面的操作应用和席的学术思想.