Occupational factors associated with astrocytomas: a case-control study

The most malignant form of all brain tumors is the supratentorial astrocytoma. Little is known about its etiology, but exogenous factors have been blamed. In this case-control study, 78 astrocytoma patients have been compared with 197 clinical and 92 population controls. An extensive questionnaire was used to gather information about occupational and residential environment exposure. Inquiries concerning groups of or individual chemicals elicited low rates of affirmative response, with negligible differences between cases and controls. However, the questions "working at an airfield" and "living near a petrochemical plant" indicated elevated risks in comparison with both control groups; so too did "living near a municipal sewage treatment plant." These results focus attention on exposure to organic compounds and should be considered together with similar findings in current research. No other occupation, branch of industry, or vicinity questions showed differences between cases and controls, with the exception of "living in the neighborhood of a paper mill or a saw mill," which gave moderately increased relative risks. A separate report gives the results from the nonoccupational part of the study.     

Ontogeny of calbindin immunoreactivity in the human hippocampal formation with a special emphasis on granule cells of the dentate gyrus

Calbindin (CB) is a calcium-binding protein that is present in principal cells as well as in interneurons of the hippocampal formation of various species including humans. Studies with transgenic mice revealed that CB is essential for long-term potentiation and synaptic plasticity which are the cellular basis of learning and memory. In a previous study we have shown that CB expression in granule cells of the dentate gyrus correlates with the functional maturation of the hippocampal formation in the rat.     

Shape Optimization of the Diffuser Blade of an Axial Blood Pump by Computational Fluid Dynamics

Computational fluid dynamics (CFD) has been a viable and effective way to predict hydraulic performance, flow field, and shear stress distribution within a blood pump. We developed an axial blood pump with CFD and carried out a CFD‐based shape optimization of the diffuser blade to enhance pressure output and diminish backflow in the impeller–diffuser connecting region at a fixed design point. Our optimization combined a computer‐aided design package, a mesh generator, and a CFD solver in an automation environment with process integration and optimization software. A genetic optimization algorithm was employed to find the pareto‐optimal designs from which we could make trade‐off decisions. Finally, a set of representative designs was analyzed and compared on the basis of the energy equation. The role of the inlet angle of the diffuser blade was analyzed, accompanied by its relationship with pressure output and backflow in the impeller–diffuser connecting region.     

Band saw injury in a butcher

BACKGROUND: While treating an unusual amputation caused by a meat band saw in a 35-year-old butcher, we sought information from the medical literature that would be useful to other physicians who might encounter similar occupational injuries. METHODS: Using the Medline database and relevant search terms, we reviewed the literature concerning occupational saw blade injuries and porcine microbiology as they related to this injury. RESULTS: Among meat workers using powered cutting equipment, hand injuries and distal fingertip amputations appear to be common. The greatest risk for a wound infection after open exposure to raw pork meat appears primarily related to environmental flora rather than enteric-borne porcine pathogens. CONCLUSIONS: Decision-making strategy when formulating a treatment plan for debridement or reconstruction of saw blade amputations should rely on a detailed understanding of the injury and occupational environment to achieve an optimal patient outcome. When considering operative and antibiotic treatment for porcine meat-related amputation injury, surgeons should adhere to open fracture-related guidelines, since porcine-borne illnesses are most often caused by ingestion rather than transcutaneous inoculation.     

股骨近端防旋髓内钉螺旋刀片位置对老年股骨转子间骨折疗效的影响

目的探讨股骨近端防旋髓内钉(PFNA)螺旋刀片位置对老年股骨转子间骨折治疗效果的影响。方法对92例接受PFNA治疗的老年股骨转子间骨折患者按螺旋刀片在股骨头的放置位置不同分为:C/C组(44例,螺旋刀片正位及侧位均处于股骨头中心位置)和I/C组(48例,螺旋刀片正位处于股骨头下1/3位置、侧位处于股骨头中心位置)。比较两组患者术后的骨折复位情况、术后完全负重时间、螺旋刀片的尖顶距(TAD)、骨折愈合时间、术后并发症及末次随访时髋关节Harris评分。结果两组患者的术后复位情况、完全负重时间、骨折愈合时间、术后并发症发生情况、术后各时点髋关节Harris评分比较差异均无统计学意义(P0.05)。术后TAD:C/C组为(22.07±2.84)mm,I/C组为(25.29±3.41)mm,两组比较差异有统计学意义(P0.05)。结论 PFNA两种螺旋刀片的安置位置治疗老年股骨转子间骨折患者均可取得良好效果,但两组的TAD有明显差异。     

斜刃针刀治疗屈指肌腱鞘炎的解剖学及临床研究

目的探讨斜刃针刀在治疗屈指肌腱鞘炎上的解剖机理以及优势。方法观测各指屈指肌腱鞘环状韧带A1环的宽度及体表定位,分别采用特型斜刃针刀和I型4号针刀治疗屈指肌腱鞘炎患者各24例,3个月后随访患者疗效及症状的改善程度。结果环状韧带A1总体平均宽度约为7.0mm;治疗组总有效率优于对照组,有显著性差异(P0.05)。两组VAS评分治疗前后比较,均有极显著性差异(P0.01);治疗前后VAS评分差值组间比较,有显著性差异(P0.05)。结论斜刃针刀治疗屈指肌腱鞘炎的目的主要是通过切开腱纤维鞘A1环,解除对屈指肌腱的束缚,能显著改善屈指肌腱鞘炎患者的临床症状及体征,远期疗效优于I型4号针刀,值得临床推广。     

Thermal-Fluid-Solid Coupling Analysis on the Temperature and Thermal Stress Field of a Nickel-Base Superalloy Turbine Blade

Based on the establishment of the original and improved models of the turbine blade, a thermal-fluid-solid coupling method and a finite element method were employed to analyze the internal and external flow, temperature, and thermal stress of the turbine blade. The uneven temperature field, the thermal stress distribution characteristics of the composite cooling turbine blade under the service conditions, and the effect of the thickness of the thermal barrier coating (TBC) on the temperature and thermal stress distributions were obtained. The results show that the method proposed in this paper can better predict the ablation and thermal stress damage of turbine blades. The thermal stress of the blade is closely related to the temperature gradient and local geometric structure of the blade. The inlet area of the pressure side-platform of the blade, the large curvature region of the pressure tip of the blade, and the rounding between the blade body and the platform on the back of the blade are easily damaged by thermal stress. Cooling structure optimization and thicker TBC thickness can effectively reduce the high temperature and temperature gradient on the surface and inside of the turbine blade, thereby reducing the local high thermal stress.     

Longitudinal osteotomy of lateral sacrum for malignant iliac tumor using modified threadwire saw

A longitudinal osteotomy of lateral sacrum for malignant iliac tumors using modified threadwire saw is conducted. This procedure issignificantly wide, rapid and safe.