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941.
Clinical policies, also known as practice parameters or practice guidelines, are gaining notoriety out of a desire to control escalating medical costs, lessen wide practice variations, and improve quality of care. The clinical policies are supposed to influence medical decision making by summarizing scientific data about a clinical problem in a format that is easily understood by patient and physician alike. Developing an evidence-based policy involves: a clearly defined clinical problem, a comprehensive literature review, a summary table of the data (known as an evidence table), a presentation of this data as outcome possibilities from alternative decisions (in the form of a balance sheet), and creation of clinical recommendations that incorporate both financial costs and patient preferences. Well-developed policies can be used by family physicians as guides in areas of clinical uncertainty and by medical educators as up-to-date literature syntheses for teaching critical appraisal and for outlining approaches to common problems. Explicit policy formulation also highlights the shortcomings of existing literature and can suggest more appropriate future research. The future of the clinical policy movement rests on its ability to reduce costs of care and improve patient outcomes. Explicit clinical policy formulation incurs significant development and implementation costs and the evidence on which many policies are based is lacking. Nevertheless, clinical policies in some form are likely to play an increasing role in medical care.  相似文献   
942.
Physics-based preconditioner for iterative algorithms in MoM-problems   总被引:1,自引:0,他引:1  
An efficient method to solve electromagnetic scattering problems involving several metallic scatterers or bodies composed of dielectric and metallic regions is proposed. For this, the block Jacobi preconditioner is combined with the iterative transpose-free quasi-minimum residual (TFQMR) algorithm. For best performance, the blocks for the preconditioner are chosen according to individual scatterers or groups of scatterers, or according to the electric and magnetic current basis functions for dielectric/metallic scatterers.  相似文献   
943.
This study examines the effect of antisense oligonucleotide to proliferating cell nuclear antigen (PCNA) on the formation of vein graft intimal hyperplasia in vivo, using localized administration. Twenty-four New Zealand white rabbits had a right carotid interposition bypass graft using the external jugular vein and were sacrificed on the 28th postoperative day. To determine the effect of PCNA on the development of intimal hyperplasia, 6 animals had their grafts coated with a pluronic gel containing 18 base antisense oligonucleotide to PCNA (1 mg/ml), 6 received a pluronic gel containing an 18 base nonsense oligonucleotide (1 mg/ml), and 12 animals were controls (6 with and 6 without pluronic gel). These grafts were harvested for morphology and videomorphometry. There was no change in the intimal thickness between the control and gel-treated groups. (70 +/- 4 microm versus 72 +/- 4 microm; mean +/- s.e.m.; p = ns). The presence of nonsense oligonucleotide had no further effect. Antisense PCNA produced a 26% decrease in intimal thickness to 50 +/- 4 microm in the treated vein grafts (p < 0.03) without a change in medial thickness. This study shows that a local single application of antisense oligonucleotide to PCNA will reduce the intimal hyperplasia in experimental vein grafts over 28 days.  相似文献   
944.
A H2/Cl2 fuel cell system with an aqueous electrolyte and gas diffusion electrodes has been investigated and the effects of electrolyte concentration and temperature on the open circuit voltage (OCV) and cell performance have been evaluated. Furthermore, the kinetics and long-term stability of Pt as electrocatalyst have been studied under various conditions. In addition, the long-term stability of Rh electrocatalyst has been evaluated. The OCV obtained showed that the Cl2 reduction is more reversible than O2 reduction. The ohmic drop was determining the cell performance at high current densities. An output power of about 0.5 W cm–2 was achieved with this system.  相似文献   
945.
946.
Although Klinefelter's syndrome is the most common sex chromosome anomaly, affecting one in 5-800 boys, our knowledge of the syndrome is still poor. This is reflected in the paucity of published literature as compared, for example, with the vastly greater number of publications on Turner's syndrome with its lower incidence of 1/2,500 girls. Klinefelter's syndrome is manifestly underdiagnosed. Existing knowledge mainly derives from cases characterised by prominent symptomatology. Early diagnosis is important if additional support and resources are to be made available to the patient and his family. Testosterone replacement therapy should be initiated as soon as clinical and laboratory evidence becomes available. In selected cases, testosterone treatment can be started already during adolescence. At present, there is no established treatment for the infertility which almost always accompanies the condition.  相似文献   
947.
A subset of patients with systemic mastocytosis (SM) develop acute myeloid leukaemia (AML). However, little is known about the biology of such leukaemias and their relationship to the mast cell (MC) lineage. We report on two female patients who suffered from SM and AML. According to FAB criteria, the leukaemias were classified as AML-M4 (patient 1) and AML-MO (patient 2). The coexistence of the two distinct neoplasms (AML and SM) was demonstrable by immunostaining of serial bone marrow (BM) sections with monoclonal antibodies (mAb). In particular, the MC infiltrates were found to react with mAb against MC-tryptase and MC growth factor receptor c-kit (CD117), but not with mAb to CD15 or CD34. In contrast, the AML blasts were immunoreactive for CD15 (patient 1) or CD34 (patient 2), but did not express tryptase. The c-kit point mutation Asp-->Val at codon 816, considered to play a role in the transformation of MC progenitors, was detected in patient 1 in a BM cell fraction containing 4% MC. However, no c-kit mutation was found in pure AML blasts (<1% MC). These findings argue against an evolution of the AML clone from neoplastic MC or MC-committed progenitors.  相似文献   
948.
The glycogen concentration in liver is altered in various pathophysiologic states. In fasted rats, it is higher in diabetic, and lower in adrenalectomized rats compared to control animals. In fed rats, it is lower in diabetic, and little changed in adrenalectomized animals compared to controls. We were interested in determining whether the activity of glycogenin, a self-glycosylating protein that initiates the synthesis of new glycogen molecules, could explain these differences in liver glycogen concentration. Glycogenin activity was measured by the incorporation of 14C-glucose from UDP-U-14C-glucose into an acid-precipitable product before and after amylase treatment of liver extracts. The glycogenin activity was similar in normal, diabetic and adrenalectomized fasted animals, regardless of the hepatic glycogen concentration. In fasted rats, glycogenin was present predominantly as the free-form of the enzyme, i.e., not attached to an amylase-digestible glycan, presumably glycogen. In contrast, in fed rats, the majority, if not all of the glycogenin was incorporated into a glycogen-like (proteoglycan) molecule. Proteoglycan synthase activity, previously identified in normal fed rats, also was present in diabetic and adrenalectomized fed rats, and the activity was similar. Thus, the altered ability to store hepatic glycogen in diabetic fed and fasted and adrenalectomized fasted rats cannot be explained by decreases in glycogenin or proteoglycan synthase activities, at least as measured using the present assays.  相似文献   
949.
950.
Research in child development has emerged as a major intellectual discipline and a topic of great interest and importance to society. The Society for Research in Child Development (SRCD) has been the leading scholarly society concerned with the advancement of this research. As part of its focus on a history of the field, the SRCD has undertaken an oral history project in which prominent members are interviewed. Of the 102 completed interviews, 47 are women's accounts, which document important contributions women have made to child development. The experiences reported by individual participants reflect themes in the general history of women in psychology and child development during the early and mid-1900s. Women encountered obstacles to their efforts, even as they were supported by others and struggled to achieve prominence amid the sometimes ambiguous or conflicting circumstances that characterized women's entry into child development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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