灰色关联分析方法在评估试卷质量中的应用

目的：在教学系统中,试卷质量是一个重要的指标因素,本文旨在探讨评估试卷质量的客观方法。方法：利用灰色关联分析模型。结果：对教研室几年来的试卷质量进行了分析,得到各年度试卷从优到劣的排列顺序是1998（r（5）＝0．83）,1997（r（4）＝0.67）,1996（r（3）＝0．55）,1995（r（2）＝0．51）,1994（r（1）＝0．48）。结论：灰色关联分析是一处理多因素问题的好方法。     

Carcinoma of the pancreas occuring in a child: a case report with description of gray scale ultrasound findings.

This is a report of the gray scale ultrasound findings of pancreatic carcinoma occurring in a child. Although this tumor is rare, the preoperative diagnosis can be made if the physician is aware of this possibility. 99 mTc sulfur colloid radionuclide scan, liver spleen scan, gallium scan, and ultrasound examinations are helpful in distinguishing the site of origin of upper abdominal masses.     

Cross-validation of the factor structure of the McGill Pain Questionnaire

Low back pain patients' responses to the McGill Pain Questionnaire (MPQ) were factor analyzed using the principal factor method and direct oblique rotation procedures. Four factors were extracted that accounted for 55% of the total variance. Coefficients of congruence were computed in order to relate the current factors with those extracted in a previous factor analytic investigation. The results provided positive evidence that the sensory pressure, evaluative, and affective-sensory factors that were previously identified are stable dimensions underlying the MPQ responses of low back pain patients. However, it is necessary to conduct further cross-validation studies using patients from a wide variety of treatment settings.     

A large scale (N=400) investigation of gray matter differences in schizophrenia using optimized voxel-based morphometry

BACKGROUND: Many studies have employed voxel-based morphometry (VBM) of MRI images as an automated method of investigating cortical gray matter differences in schizophrenia. However, results from these studies vary widely, likely due to different methodological or statistical approaches. OBJECTIVE: To use VBM to investigate gray matter differences in schizophrenia in a sample significantly larger than any published to date, and to increase statistical power sufficiently to reveal differences missed in smaller analyses. METHODS: Magnetic resonance whole brain images were acquired from four geographic sites, all using the same model 1.5T scanner and software version, and combined to form a sample of 200 patients with both first episode and chronic schizophrenia and 200 healthy controls, matched for age, gender and scanner location. Gray matter concentration was assessed and compared using optimized VBM. RESULTS: Compared to healthy controls, schizophrenia patients showed significantly less gray matter concentration in multiple cortical and subcortical regions, some previously unreported. Overall, we found lower concentrations of gray matter in regions identified in prior studies, most of which reported only subsets of the affected areas. CONCLUSIONS: Gray matter differences in schizophrenia are most comprehensively elucidated using a large, diverse and representative sample.     

Multimodal multi-center analysis of electroconvulsive therapy effects in depression: Brainwide gray matter increase without functional changes

BackgroundElectroconvulsive therapy (ECT) is an effective treatment for severe depression and induces gray matter (GM) increases in the brain. Small-scale studies suggest that ECT also leads to changes in brain functioning, but findings are inconsistent. In this study, we investigated the influence of ECT on changes in both brain structure and function and their relation to clinical improvement using multicenter neuroimaging data from the Global ECT-MRI Research Collaboration (GEMRIC).MethodsWe analyzed T1-weighted structural magnetic resonance imaging (MRI) and functional resting-state MRI data of 88 individuals (49 male) with depressive episodes before and within one week after ECT. We performed voxel-based morphometry on the structural data and calculated fractional amplitudes of low-frequency fluctuations, regional homogeneity, degree centrality, functional connectomics, and hippocampus connectivity for the functional data in both unimodal and multimodal analyses. Longitudinal effects in the ECT group were compared to repeated measures of healthy controls (n = 27).ResultsWide-spread increases in GM volume were found in patients following ECT. In contrast, no changes in any of the functional measures were observed, and there were no significant differences in structural or functional changes between ECT responders and non-responders. Multimodal analysis revealed that volume increases in the striatum, supplementary motor area and fusiform gyrus were associated with local changes in brain function.ConclusionThese results confirm wide-spread increases in GM volume, but suggest that this is not accompanied by functional changes or associated with clinical response. Instead, focal changes in brain function appear related to individual differences in brain volume increases.     

In vitro responses of neurons in the periaqueductal gray to hypoxia and hypercapnia

Hypoxia-sensitive neurons in the caudal hypothalamus (CH) have been shown to project to the periaqueductal gray (PAG) which, in turn, sends descending projections to an area of the ventrolateral medulla (VLM) containing neurons inherently excited by hypoxia. The purpose of this study was to determine if neurons in the PAG are excited by hypoxia or hypercapnia in an in vitro environment. Extracellular responses to hypoxia and hypercapnia of neurons located throughout the PAG were recorded in a rat brain slice (400–500 μm thick) preparation. Hypoxic (10% O₂/5% CO₂/85% N₂) and hypercapnic (7% CO₂/93% O₂) stimuli were delivered to the tissue through gas bubbled into the brain slice chamber. A majority (39 of 53) of the neurons tested responded to hypoxia. Of these neurons, 92% responded to hypoxia with an increase in firing rate. Neurons in the dorsolateral/lateral regions increased firing rates to a greater extent than neurons located in ventrolateral regions. All neurons tested (n=6) also responded to hypoxia after perfusion of the tissue with a low Ca²⁺/high Mg²⁺ solution to block classic synaptic transmission. Only a small proportion (7/33) of neurons tested responded to hypercapnia. These findings indicate that neurons in the periaqueductal gray region of the brain have an inherent responsiveness to hypoxia and, thus, may contribute to the overall coordination of cardiorespiratory responses to systemic hypoxia.     

Dynamic radionuclide imaging as a means of evaluating vascular perfusion of the upper extremity: a preliminary report

Vascular competence in the upper extremities of 44 patients was evaluated by three-phase bone scans consisting of rapid sequence dynamic radionuclide imaging (DRI), an immediate postinjection "blood pool" image, and a 3- to 4-hour delayed image. Findings were correlated with definitive anatomy determined by arteriography, operative findings, or both, in 50 extremities. DRI provided the correct diagnosis in all but four extremities (92%). Limited resolution precluded precise anatomic definition of aneurysms in three limbs and of digital artery occlusion, with adequate collateral circulation in the fourth limb. The greatest value of DRI was its provision of quantitative information about relative blood flow and preferential perfusion in every instance. We believe DRI to be a useful adjunct to preoperative and postoperative assessment of arterial perfusion.     

超声在颈部囊肿诊断中的临床应用

目的 探讨超声在颈部囊肿诊断中的临床应用。方法 颈部囊肿性占位性病变病例73例，男性38例，女性35例，年龄3-25岁，平均年龄18.8岁。应用超声进步诊断。结果 超声诊断颈部囊肿符合率为97.3%（71/73），其中，鳃裂囊肿符合率为97.5%（39/40），甲状舌管囊肿符合率为97.0%（32/33）。结论 超声诊断戏曲部囊肿具有临床应用价值。     

超声用于颈部肿瘤手术前的诊断价值

目的探讨超声应用于颈部肿瘤手术前的价值。方法颈部肿瘤病例285例,男性148例,女性137例;年龄3~75岁,平均年龄43.3岁。采用超声进行诊断,与病理诊断进行比较。结果超声诊断颈部肿瘤符合率为98.9%(282/285)。结论颈部肿瘤超声手术方案的确定具有重要的指导意义。