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Magnetic resonance spectroscopy (MRS), an application of the methods of nuclear magnetic resonance (NMR), is a functional imaging modality that provides a view of localized biochemistry in vivo. A number of studies applying MRS to the neurochemistry of schizophrenia have been reported, which encompass a range of patient populations, states of medication, anatomic regions, nuclear species, and MRS techniques. A brief review of the history and methodology of NMR and MRS is presented. Comparison is made of MRS capabilities with other functional imaging modalities. Aspects of the neurochemistry of schizophrenia relevant to MRS studies are reviewed, as are the reported MRS studies involving patients with schizophrenia. Areas of consistent findings include decreased phosphomonoesters and increased phosphodiesters in frontal lobes, and decreases in the putative neuronal cell marker, N-acetylaspartate, in temporal lobes. Studies of neurotransmitters such as glutamate, gamma-aminobutyric acid, and glutamine have generated inconsistent results. New insights into alterations in neurochemistry in schizophrenia have been provided by MRS. Studies of neurotransmitters have future potential with improvements in field strength and in spectral editing techniques. MRS has the potential to measure brain medication levels and simultaneous effects on neurochemistry. MRS may assist in characterizing high-risk populations, and ultimately guide medication use.  相似文献   

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Over the past decade, there has been a major increase in behavioral diabetes research. This review focuses on 6 areas: self-treatment, psychosocial impact, diabetes-specific assessment, psychological stress, weight loss intervention, and neuropsychological effects. There has been great progress in identifying factors that predict self-treatment behaviors and psychological adjustment. This research has produced a number of diabetes-specific assessment tools. Psychological stress appears to affect both the etiology and the control of diabetes, but underlying mechanisms remain unclear. Weight loss studies demonstrate the potential benefits of behavioral interventions for diabetes management. Both acute and chronic abnormalities in diabetic blood glucose cause neuropsychological impairments and may cause permanent deficits. The challenge for the next decade is to translate these findings into interventions that improve the quality of life and physical well-being for individuals with diabetes. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

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A decade ago the three major granting agencies produced a policy statement that governs research ethics in most venues in Canada; they have recently (2010) circulated a revised statement: The Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans. 2nd Edition (TCPS-2). There are both major and minor revisions, including changes to the guiding principles, that will have an impact on psychological research. This paper outlines some of the changes and compares them with the Canadian Code of Ethics for Psychologists (3rd Ed.), which is also about to undergo a revision process. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

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Assessment of suicide enzyme activity would have considerable impact on the planning and the individualization of suicide gene therapy of malignant tumors. This may be done by determining the pharmacokinetics of specific substrates. We generated ganciclovir (GCV)-sensitive human mammary carcinoma cell lines after transfection with a retroviral vector bearing the herpes simplex virus thymidine kinase (HSV-tk) gene. Thereafter, uptake measurements and HPLC analyses were performed up to 48 h in an HSV-tk-expressing cell line and in a wild-type cell line using tritiated GCV. HSV-tk-expressing cells showed higher GCV uptake and phosphorylation than control cells, whereas in wild-type MCF7 cells no phosphorylated GCV was detected. In bystander experiments the total GCV uptake was related to the amount of HSV-tk-expressing cells. Furthermore, the uptake of GCV correlated closely with the growth inhibition (r = 0.92). Therefore, the accumulation of specific substrates may serve as an indicator of the HSV-tk activity and of therapy outcome. Inhibition and competition experiments demonstrated slow transport of GCV by the nucleoside carriers. The slow uptake and low affinity to HSV-tk indicate that GCV is not an ideal substrate for the nucleoside transport systems or for HSV-tk. This may be the limiting factor for therapy success, necessitating the search for better substrates of HSV-tk.  相似文献   

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《工程科学学报》2019,(6):695-708
综述了近年来钢包工作衬用耐火材料的研究现状及最新进展,尤其对传统钢包工作衬用耐火材料的应用背景及存在问题进行了分析和汇总.在此基础上,进一步提出了适用于超低氧钢(或洁净钢)冶炼用耐火材料的研发方向,即通过耐火原料组分选择和结构匹配设计,实现对耐火材料性能的精确控制.新型钢包工作衬用耐火材料需兼顾优异热机械性能的同时,还应具备钢水净化的功能.  相似文献   

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综述了近年来钢包工作衬用耐火材料的研究现状及最新进展, 尤其对传统钢包工作衬用耐火材料的应用背景及存在问题进行了分析和汇总.在此基础上, 进一步提出了适用于超低氧钢(或洁净钢)冶炼用耐火材料的研发方向, 即通过耐火原料组分选择和结构匹配设计, 实现对耐火材料性能的精确控制.新型钢包工作衬用耐火材料需兼顾优异热机械性能的同时, 还应具备钢水净化的功能.   相似文献   

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OBJECTIVE: The purpose of this study was to evaluate retrospectively the efficacy of a proposed panel of three cardiac markers (myoglobin, creatine kinase-MB mass [CK-MB], and cardiac troponin I) in the diagnosis of acute myocardial infarction (AMI) in patients with atraumatic chest pain. DESIGN: A total of 110 patients admitted for the evaluation of atraumatic chest pain were examined. Forty-one of these patients were diagnosed with AMI. RESULTS: Five of the 41 patients with AMI had abnormally elevated myoglobin levels, whereas values of CK-MB and/or cardiac troponin I remained negative. Creatine kinase-MB mass alone had a sensitivity of 92.7%, a specificity of 89.9%, a positive predictive value of 84.4%, and a negative predictive value of 95.0% for the diagnosis of AMI. Cardiac troponin I alone had a sensitivity of 90.2%, a specificity of 95.7%, a positive predictive value of 92.5%, and a negative predictive value of 94.3% for the diagnosis of AMI. Cardiac troponin I is a more specific marker for the diagnosis of AMI than CK-MB, particularly in patients with chronic renal failure who are evaluated for chest pain. The combination of CK-MB and cardiac troponin I increased the sensitivity to 100% and the negative predictive value to 100% and had a specificity of 88.4% and a positive predictive value of 83.7%. The panel was diagnostic for all patients with AMI within 12 hours after admission. CONCLUSIONS: Our preliminary results indicate that this panel is highly effective for evaluation of AMI in patients with atraumatic chest pain. Elevated myoglobin levels were useful in detecting patients at high risk for AMI who initially were not detected with other markers. The combination of CK-MB and cardiac troponin I provided much higher sensitivity and had a much higher negative predictive value for the evaluation of AMI than cardiac troponin I or CK-MB alone. The 100% negative predictive value is particularly important because it indicates that patients with negative CK-MB and cardiac troponin I values 12 hours after admission have a negligible likelihood of AMI.  相似文献   

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Advances in psychopharmacology have revolutionalized the management of emotional and behavioral disorders in children and adolescents. Recent developments in pediatric psychopharmacology and the prevalence of pharmacotherapy for various psychological disorders in children are examined, and clinical updates for classes of psychotropics are provided. Issues including monitoring and assessing drug effects, acceptability and satisfaction, and the social, political, and cultural issues surrounding the use of psychotropics in children are discussed. The authors conclude that the current clinical use of psychotropics in children exceeds extant efficacy and safety data. The involvement of practicing psychologists in pediatric psychopharmacology and the need for a firm empirical foundation for pediatric psychopharmacology are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Enterocytes were detached from various parts of the digestive tract of chickens by treatment with DTT or with hyaluronidase. Isolated enterocytes were exposed to suspensions of the V4 strain of Newcastle disease virus (NDV). Removal of virus from the supernatant fluid was taken as evidence of binding of virus to enterocytes and residual virus was measured both by infectivity assay and by ELISA. Enterocytes from duodenum, jejunum, ileum, caecum, and rectum bound the virus; enterocytes from oesophagus, crop and proventriculus did not.  相似文献   

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The attention in genetic research is shifting from the determination' of (rare) monogenic disorders to identification of genetic risk factors for important diseases at adult age. Mapping of all man's 80,000-100,000 genes will also provide more insight into the gene polymorphisms and mutations that are associated with various types of cancer, certain cardiovascular diseases, diabetes and neurodegenerative disorders, including Alzheimer dementia. Apart from new diagnostic possibilities, the DNA techniques create new prospects for the study of the pathogenesis of diseases and the devising of new strategies for treatment. Examples are familial hypercholesterolaemia, diabetes, breast cancer and colorectal carcinoma.  相似文献   

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Since the 21~(st) century,great attention has been paid to ultra fast cooling(UFC) technology in the whole world.The industries and the research institutions began to carry out investigations on basic theories and industrial applications.Since 2003,the RAL of Northeastern University has made some progresses on microstructure control theories,understanding of strengthening mechanisms and their industrial applications.In this paper,these achievements since the last Baosteel BAC in 2008 will be reported on ...  相似文献   

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Monochloramine has been suggested as an alternative disinfectant to chlorine to reduce levels of trihalomethanes in treated drinking water, but little is known of the toxicological properties and potential health implications of by-products specific to the chloramination process. Model aqueous fulvic acid solutions (200-400 mg C/liter), serving as surrogates for humic surface waters, were chloraminated over a range of molar Cl:C ratios from 1:40 to 1:2. The resulting by-products were extracted into diethyl ether at pH 2 and investigated with the Ames plate incorporation assay. Extractable mutagenicity increased with increasing chlorine and carbon dose up to about 30,000 revertants/liter at Cl:C ratios of 1:2. Mutagenicity was higher in Salmonella typhimurium strain TA100 than in strain TA98, and was decreased in the presence of S9, indicating that the mutagens formed were direct-acting and induced predominantly base-pair substitutions. Bovine serum albumin decreased slightly, and glutathione reduced greatly, the mutagenic activity detected in extracts. HPLC fractionation of the by-products indicated that most of the mutagenic activity was found in the earliest-eluting (most polar) fraction. The mutagenic by-products appeared to be qualitatively similar to 3-chloro-4-dichloromethyl-5-hydroxy-2-(5H)-furanone (MX) in their chromatographic behavior and responses to glutathione and bovine serum albumin, but were less readily detoxified by S9 than was MX.  相似文献   

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Introduces a special section of state-of-the-art reviews of occupational stress research. The author briefly discusses the historical origins of occupational health psychology, focusing on job strain, effort-reward imbalance, and methodological problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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高铝质陶瓷蓄热材料的研究开发   总被引:6,自引:0,他引:6  
按蓄热式热交换器使用性能的要求和高铝质耐火材料的特殊性能和优点,选择适当的原料配方、特殊的成型和烧结工艺,研制开发出性能较为优越的陶瓷球蓄热材料。  相似文献   

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运用物理方法进行金属材料新品种开发对于降低成本和金属材料成分的合理性设计具有重大意义.主要论述了热模拟试验机在金属材料研究中的应用,同时探讨了电镜(扫描电镜、透射电镜)的优缺点以及电镜在钢铁材料研究中的应用.  相似文献   

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