Biomechanical and biological properties of the implant material carbon-carbon composite covered with pyrolytic carbon

The aim of this study was to test C/C material (carbonized, graphitized or covered with pyrolytic carbon) designated for the use in orthopaedic and bone surgery. Using an in vitro assay we confirmed, that the cell proliferation was exhibited the mostly on the C/C composite coated with pyrolitic carbon and afterwards polished. The two latest of subsequent water extracts of this material had a slightly inhibiting effect on the cells metabolic activity. Biocompatibility test in vivo performed subcutaneously on rats did not show big differences between three tested implants (C/C composite, epoxy resine, titanium alloy), on the other hand the plates tested on pigs demonstrated foreign-body reaction induced by wear C/C composite material. Such debris were found both in the neighborhood of the implant as well as in the lymphatic node.     

Predicting Properties of Congestion Events for a Queueing System With fBm Traffic

In packet networks, congestion events tend to persist, producing large delays and long bursts of consecutive packet loss resulting in perceived performance degradations. The length and rate of these events have a significant effect on network quality of service (QoS). The packet delay resulting from these congestion events also influences QoS. In this paper a technique for predicting these properties of congestion events in the presence of fractional Brownian motion (fBm) traffic is developed.     

Soil mapping using remote sensing techniques

Advancements in space technology opened application possibilities of remote sensing in soil mapping. Reviewing the achievements in this field, various techniques of remote sensing applications are outlined and their merits and limitations discussed in the context of soil mapping of Mahaboobnagar area. The products of different techniques including visual interpretation of imageries,I ² S and computer analysis of LANDSAT digital data are compared with aerial photo interpretation and soil map drawn by conventional method. The study reveals that both airborne and spaceborne data afford greater accuracy, economy and efficiency than the conventional method at reconnaissance level of mapping. The efficiency in terms of time spent on soil mapping by computer techniques, aerial photo-interpretation and conventional method was in the ratio of 1:5:10. A case study of erosion mapping by remote sensing techniques is also presented. Further scope for expanding application possibilities through future generation satellites and microwave sensing is highlighted.     

基于弹性网络回归的地震动参数排序与比选

为合理选取地震动参数以有效减小结构损伤预测的不确定性,基于弹性网络回归技术对多个地震动参数进行了比选.基于多种地震动参数以及大量单自由度(SDOF)模型的增量动力分析结果建立弹性网络回归模型,定义回归模型中回归系数值以及回归系数值为非零值的个数分别为地震动参数的敏感性系数和频数.基于地震动参数敏感性和频数分析结果对多种地震动参数进行排序,研究结构恢复力模型、地震动集和结构极限状态对地震动参数排序结果的影响.基于一座8层钢框架结构分析结果验证了基于弹性网络回归的地震动参数比选方法的有效性.结果表明:选取代表性的地震动参数加入最小二乘回归模型时,不同结构极限状态下回归分析中残差标准差显著减小.基于大量SDOF体系的地震动参数排序结果比选出了受地震动集、结构恢复力模型和结构极限状态影响较小的地震动参数.结果可为结构抗震能力预测用地震动参数的比选提供理论基础.     

Follow-up of albumin excretion during pregnancy and post partum in type 1 diabetic patients in comparison with health pregnant probands

32 diabetic and 31 metabolic healthy pregnant women are studied to answer the following questions: Is there a difference in the albumin-excretion rate (AER) during the pregnancy in primary normoalbuminuric type 1 diabetics and non-diabetics? Is there a difference 6 months post partum between the 2 groups? The average age of the diabetics (D) is 28, of the non-diabetics (ND) 27 years; the diabetics suffer from diabetes mellitus 12.5 years. In the 16th week of pregnancy, we find a AER (D vs. ND) of 5.0 vs. 2.37 micrograms/min (not significant [n.s.]), creatinin in serum 0.77 vs. 0.75 mg/dl (p < 0.05), creatinin clearance 92.5 vs. 103.4 ml/min (n.s.). In the 28th and in the 34th to 38th week, there is no significant elevation of the AER compared to the 16th week; but there is a significant elevation in the diabetics vs. the non-diabetics. 6 months post partum, the AER (D vs. ND) are: 6.13 vs. 5.11 micrograms/min (n.s. vs. 16th week and D vs. ND); in each group one person is found with a positive microalbuminuria (MA): 48.2 micrograms/min (D) and 27.4 mg/min (ND). Another diabetic woman shows post partum an isolated higher value of creatinin in serum: 1.5 mg/dl (without MA). This parameter is post partum significant higher (0.97 [D], 0.96 [ND] mg/dl) than in the 16th week of pregnancy (0.77 [D], 0.75 [ND] mg/dl). The creatinin clearance decreases post partum (pp): 92.2 ml/min (pp) vs. 102.0 ml/min (28th week) in the diabetics (n.s.) and 80.6 ml/min (pp) vs. 111.0 ml/min (28th week) in the non-diabetics (p < 0.05). Concerning the studied renal parameters, there is a significant difference of the albumin-excretion rates during the pregnancy between preconceptional normoalbuminuric type 1 diabetic and non-diabetic women, but 6 months post partum, there is no significant difference. The diabetics show a significant increase of the creatinin in urine and in serum and no significant change of the creatinin clearance 6 months post partum.     

Synergistic effect of 5-fluorodeoxyuridine and quinazoline antifolates on murine leukemia self-cultured in vitro

The effect of thymidylate synthase inhibitors, fluorodeoxyuridine (FdUrd) and its two sulphonamide derivatives was examined in the culture of murine leukemia cells -- 5178Y (parental subline) and its fluorodeoxyuridine resistant subline 5178Y/F. A synergistic effect of the antimetabolites on cell survival was observed on exposure of the culture of either line to a slightly inhibitory concentration of FdUrd (1 nM) in combination with 2-desamino-2-methyl-10-propargyl-5,8-dideaza-pteroylsulphogluta mate or 2-desamino-2-methyl-10-propargyl-5,8-dideaza-pteroylsulphoglyci ne. This effect was accompanied by a marked reduction, in both cell lines of intracellular concentration of 5,10-methylenetetrahydro-pteroyl-polyglutamate, although its concentration in the resistant subline was 3 times as high as in the parental line. The inhibitory effect of combined drugs on the cellular pool of folates in 5178Y line depended also on the sequence of drug addition, whereas in the FdUrd resistant line this sequence was without any effect. The results obtained strongly suggest that under certain conditions inhibition of thymidylate synthesis by antifolates is intensified by a prior use of FdUrd.     

Quality indicators using hospital discharge data: state and national applications

BACKGROUND: Demand for information about the quality of health care has escalated. Yet many organizations lack well-specified quality measures, statistical expertise, or the requisite data to produce such information. The Healthcare Cost and Utilization Project Quality Indicators (HCUP QIs) represent one approach to measuring health care quality using readily available data on hospital inpatients. METHODS: The HCUP QIs, developed in 1994, address clinical performance rather than other dimensions of quality such as satisfaction or efficiency. The 33 indicators produce rates that represent measures of outcomes (mortality and complications), utilization, and access. In lieu of complex multivariate techniques, two methods were used: (1) restrictions in defining patient subgroups to isolate homogeneous at-risk populations and (2) standardization when populations are diverse. Stratified analyses are recommended when patient or hospital factors are believed to influence the outcome. A simple method for making statistical comparisons to national rates was developed. The HCUP QI software, available in both mainframe and microcomputer applications, have enabled organizations to use their own data to produce comparative statistics and examine trends over time. Results summarized at the individual hospital or aggregate level are being used to stimulate continuous quality improvement initiatives. CONCLUSIONS: The HCUP QIs offer a low-cost alternative for organizations that have access to administrative data. Current users include hospital associations, state health departments, statewide data organizations, and individual hospitals. Although the HCUP QIs are intended to serve as indicators, not definitive measures, of quality, they were designed to highlight quality concerns and to target areas for more intensive study.