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排序方式: 共有2154条查询结果,搜索用时 10 毫秒
1.
Detection of the center of the hip joint in computer-assisted surgery: an evaluation study of the Surgetics algorithm. 总被引:4,自引:0,他引:4
Eric Stindel Daniel Gil Jean-Louis Briard Philippe Merloz Frédéric Dubrana Christian Lefevre 《Computer aided surgery》2005,10(3):133-139
OBJECTIVE: The aim of this paper is to assess the accuracy of an algorithm implemented by PRAXIM in the SURGETICS navigation station for detection of the hip center. This study will assess the robustness and accuracy of the algorithm in various clinical situations such as those involving non-sphericity of the femoral head, motion of the pelvis during hip center detection, and restricted range of motion. MATERIALS AND METHODS: The localization of the hip center, based on kinematics, relies on the recording of n successive positions of the femoral rigid body in the localizer reference system during a passive circumduction motion of the hip joint. Therefore, the shape of the clouds of points acquired may vary from one acquisition to the next. To allow a comprehensive study of the consequences of these variations for hip center detection, we developed a simulator to generate numerous clouds of points. Results given subsequently for each test are the values of the difference between the femoral mechanical axis computed with C(c), the computed hip center, and the same axis computed with C(o), the reference hip center. RESULTS: Test 1: Sensitivity to noise. The errors ranged from 3.33 E - 12 (SD 3.29E - 12) for a noise of 0 mm to 8.18E - 1 (SD - 7.05E - 1) for a noise of 15 mm. Test 2: Sensitivity to the shape of the acquisition motion. All trajectories gave an error < 1 degrees . Test 3: Sensitivity to restricted range of motion. No value > 1 degrees was found during this test. Test 4: Sensitivity to the distance between two points of the cloud. No value > 0.5 degrees was found during this test. Test 5: Sensitivity to the number of points included in the cloud. No value > 1 degrees was found during this test. CONCLUSIONS: The Surgetics algorithm is robust to noise, can compensate for pelvic motion, and can be used even in the case of restricted range of motion. 相似文献
2.
B Kerboul J Le Saout C Lefevre D Miroux L Fabre J F Le Noac'h J M Rogero B Courtois 《Journal de chirurgie》1986,123(6-7):428-434
Results of three therapeutic modalities used for the treatment of a homogeneous series of patients with a Pouteau Colles fracture are analyzed. Orthopedic treatment provided deceiving results. Pinning was, on the contrary, very effective, intrafocal pinning with immediate mobilization of the wrist appearing perfectly effective. Few complications were reported in contrast to plastered immobilizations. Good results were obtained in 80% of cases and functional recovery was rapid, indicating that this method represents undoubted progress when compared with conventional therapies. 相似文献
3.
Characterization and isolation of SOB2, a human sperm protein with a potential role in oocyte membrane binding 总被引:2,自引:1,他引:1
Lefevre A; Martin Ruiz C; Chokomian S; Duquenne C; Finaz C 《Molecular human reproduction》1997,3(6):507-516
G12 monoclonal antibody (mAb), one of a library of constructed mAb directed
against human sperm proteins, was found by immunoperoxidase staining to
label the post-acrosomal and neck regions of fixed human cauda epididymal
and ejaculated spermatozoa. Epithelium and fluid of caput epididymis were
strongly labelled while there was no staining on testis and efferent ducts.
Western lot analysis revealed that G12 antibody reacted with proteins of
17.5, 18 and 19 kDa in human spermatozoa. This pattern seems to be specific
for mature human spermatozoa, as it has not been observed either in other
human tissues tested, or in spermatozoa from different animals. SOB2, the
corresponding protein, was isolated from NP40-extracted human spermatozoa
by using preparative electrophoresis, followed by isoelectrofocusing
according to its isoelectric point of 6.4 G12 Fab fragments strongly
inhibited binding of human spermatozoa to zona-free hamster oocytes (up to
86% inhibition at 200 micrograms/ml). Impairment of binding was dependent
on the concentration of purified G12 immunoglobulin (Ig)G1, and significant
even at 10 micrograms/ml. There was no inhibitory effect of G12 antibody on
sperm motility parameters or triggering of the acrosome reaction and it did
not inhibit binding to human zona pellucida. These results indicate that
SOB2 is likely to participate in membrane oocyte binding, and my be
potential candidate for the development of a contraceptive vaccine.
相似文献
4.
Michael Lefevre Author Vitae Penny M. Kris-EthertonAuthor Vitae Guixiang ZhaoAuthor Vitae Russell P. TracyAuthor Vitae 《Journal of the American Dietetic Association》2004,104(3):410-419
The cause of many myocardial infarctions is occlusive thrombosis, or a blood clot that stops blood flow in a coronary artery. Hemostasis involves a complex system of factors, which normally form and degrade blood clots, that work within a delicate balance. Emerging evidence suggests that some hemostatic factors, including factor VII, fibrinogen, and plasminogen activator inhibitor-1, are associated with increased risk for cardiovascular disease (CVD). Accumulating evidence suggests a relationship between dietary fatty acids and emerging hemostatic CVD risk factors, although much of this evidence is incomplete or conflicting. Dietary supplementation with marine n-3 fatty acids prolongs bleeding time and may decrease risk for thrombosis. Factor VII coagulant activity modestly decreases with reductions in saturated fatty acid (SFA) intake and thereby may contribute to the beneficial effects of low SFA diets. Large triglyceride-rich particles formed during postprandial lipemia can support the assembly and function of coagulation complexes and seem to play a role in the activation of factor VII, and thus may partially explain increased CVD risk associated with increased postprandial triglyceridemia. As our understanding of the role of dietary fatty acids and hemostasis evolves, it is likely that we will be able to make specific dietary recommendations to further decrease CVD risk. At this juncture, however, increasing marine n-3 fatty acids and decreasing certain SFAs are leading strategies to reduce hemostatic CVD risk factors. An array of dietary strategies that target multiple CVD risk factors could have a greater impact on CVD than a single risk factor intervention strategy. 相似文献
5.
Alcohol is an important risk factor for human oesophageal cancer. There is evidence from epidemiological studies that some
specific alcoholic drinks, e.g. Calvados apple brandy, are associated with a greater risk than others. Alcohol induces cytochrome
P450 2E1 (CYP2E1) and the hypothesis was tested that different alcoholic beverages, containing a variety of alcoholic compounds,
could differentially induce expression of cytochrome P450 enzymes. Twelve groups of five rats each were treated for 3 days
with different alcoholic beverages (ethanol alone, whisky, farm-produced or commercial Calvados brandy, beer, cider, wine)
adjusted to 4, 10 or 20% of ethanol in drinking water. Immunoblotting using a monoclonal antibody specific for rat CYP2E1
revealed a single protein band in liver microsomes. Densitometric quantitation of microsomal proteins demonstrated a significant
two-, three- and sixfold increase in band intensity after treatment with ethanol concentrations of 4, 10 and 20% respectively,
compared to control rats drinking water alone. There was a dose-dependent increase in liver microsomal metabolism of CYP2E1
substrates (para-nitrophenol and dimethylnitrosamine) in ethanol-treated rats. However, there were no significant differences
in the level of CYP2E1 protein or enzymatic activity between the different alcoholic beverages at the same ethanol concentration.
There was a slight increase in hepatic CYP1A-related enzymatic activities in the alcohol-treated rats compared to the controls,
but no difference between the treated groups either with dose of ethanol or type of beverage. These data show that induction
of CYP2E1 with acute alcohol treatment is predominantly determined by the ethanol content of the beverage.
Received: 10 February 1997 / Accepted: 26 May 1997 相似文献
6.
A L Claessens R M Malina J Lefevre G Beunen V Stijnen H Maes F M Veer 《Medicine and science in sports and exercise》1992,24(7):755-763
The growth and maturity status of 201 elite female gymnasts was considered. The subjects were participants at the 24 World Championship Artistic Gymnastics in 1987. In addition to age at menarche, weight, stature, biacromial, and bicristal breadths, the sitting height/stature ratio, and the Health-Carter anthropometric somatotype of gymnasts 13-20 yr of age were compared with reference data for a nationally representative sample of Flemish girls. Median age at menarche (probit analysis) in gymnasts is 15.6 +/- 2.1 yr compared with 13.2 +/- 1.2 yr in Flemish girls. Anthropometric dimensions increase with age until about 16 yr and then tend to plateau. In contrast to body size, there is little variation in somatotype with age. Compared with adolescent girls, elite gymnasts are considerably shorter and lighter with narrower shoulders and hips, but the differences are more apparent after 17 yr. Elite gymnasts do not differ from nonathletes in relative leg length, but they have proportionally broader shoulders relative to hips. Differences in somatotype occur primarily in endomorphy (especially lower in gymnasts) and to a lesser extent in mesomorphy (higher in gymnasts). 相似文献
7.
E Dobremez Y Lefevre L Harper L Rebouissoux F Lavrand J M Bondonny P Vergnes 《Zeitschrift für Kinderchirurgie》2006,16(3):166-170
AIM: Conservative management of splenic rupture in haemodynamically stable children is now generally accepted. However, during follow-up, many complications can occur. The aim of this study was to describe the complications we observed and to propose a standardised follow-up adapted to them. METHODS: Between March 1992 and December 2002 we managed 65 children (aged between 3 and 15 years old) with accidental splenic rupture. Follow-up and treatment consisted of a 10-day bed rest with sonogram and Doppler controls on the 5th and 10th day and subsequently every month until complete healing. Complications included secondary haemorrhage in 3 cases, cystic evolution in 5 cases, and pseudo-aneurysm in 2 cases. All were treated by renewed bed rest. Three of the cysts resolved spontaneously, the other two underwent cystic resection and epiploplasty by laparotomy (n = 1) or laparoscopy (n = 1) and both pseudo-aneurysms were selectively embolised. There were no splenectomies. CONCLUSIONS: Complications essentially occurred in older children and were not related to gender, type of fracture, or extent of bleeding. Cystic evolution of the sub-capsular haematomas can appear up to 1 month after trauma. Peripheral pseudo-aneurysms which could be responsible for secondary haemorrhages were selectively embolised. We favour the use of the Doppler sonogram for follow-up until total recovery of these patients, even in low-grade traumas. Considering the number of complications encountered we do not believe the American evidence-based guidelines are suitable for our population. 相似文献
8.
9.
M Lefevre C L Keen B L?nnerdal L S Hurley B O Schneeman 《The Journal of nutrition》1986,116(9):1735-1746
Male Sprague-Dawley rats (10 per group) were fed diets adequate (control) or deficient (CuDef) in copper for 6 wk. In the CuDef group, plasma total cholesterol, high density lipoprotein (HDL) cholesterol and apoA-I levels were significantly higher than in controls. Apolipoprotein analysis of the HDL fractions revealed a relative enrichment of apoE in the CuDef group. Size analysis of 1.21 density lipoproteins by nondenaturing gradient gel electrophoresis demonstrated the presence of more material migrating in the size range of HDL1 in the CuDef group. Separation of HDL into apoE-rich and apoA-I-rich fractions by heparin-affinity chromatography confirmed the presence of increased apoE-rich HDL in the CuDef group. To determine the mechanism responsible for higher apoE-rich HDL in the CuDef group, the lipoprotein receptor binding activity in hepatic membranes from the control and CuDef group was assayed. Kinetic analysis of the binding data revealed that the lipoprotein binding assay was primarily measuring the activity of the HDL receptor, which is not apoE mediated. When corrected for differential enrichment of plasma membrane, hepatic membranes from the CuDef group bound significantly fewer lipoproteins than did controls. Furthermore, the hepatic receptor binding activity was negatively correlated with the proportion of HDL enriched with apoE. 相似文献
10.
Deparis X Frere B Lamizana M N'Guessan R Leroux F Lefevre P Finot L Hougard JM Carnevale P Gillet P Baudon D 《Journal of medical entomology》2004,41(5):914-921
In 2000, 22,000 French military personnel were deployed overseas. The French military health service implemented a vector control strategy including personal protection by the use of permethrin preimpregnated battlefield uniforms (BFUs) and the application on the skin of a topical repellent (50% DEET). In 2000, French forces used an industrial process to impregnate cloth with permethrin by soaking it before cut-out of the BFU. A study was implemented in four experimental huts in C?te d'Ivoire to assess the field efficacy of the impregnated BFUs and their resistance to washing. Taking into account the systematic variations in each variable in the field and using a modeling based on logistic regression and discriminant analysis, this study showed that after 6 h without reapplication, the protective effects of the use of DEET as skin repellent was not significant, perhaps due to the high density of Anopheles mosquitoes during the night catching sessions and an average time of effective repellency of < 2 or 3 h in the field. The analysis also showed that the French process of industrial impregnation of permethrin of the BFU offered in 2000 some protection from mosquito bites but not enough to reduce significantly the incidence of malaria among nonimmune troops. No positive or negative interaction was noted when DEET and the impregnated BFUs were used together. 相似文献