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1.
A preliminary report presenting the results of fibular strut grafting in the severely resorbed mandibular and maxillary region is presented. Thirteen patients were treated due to severe resorption of alveolar and basilar bone of 49 segments of the mandible and the maxilla. Two patients additionally had pathological fractures of the mandible. In 10 cases the strut graft was harvested by means of a new minimally invasive technique. After modelling the fibular bone it was fixed to the recipient site by miniscrews or implants. After a mean follow-up period of 20 months (max. 31, min. 11 months) a retrospective analysis of clinical and radiological findings was carried out. It showed that a mean augmentation of 16 mm was achieved. Compared to other studies the fibular strut graft was resorbed less, and due to the primary stability it could be used for the treatment of fractures of the mandible. No more than natural resorption was observed when the patients received their prostheses fixed to dental implants.  相似文献   
2.
OBJECTIVE: Encouraging results on myocardial preconditioning in experimental models of infarction, stunning or prolonged ischemia raise the question whether preconditioning techniques may enhance conventional cardioplegic protection used for routine coronary surgery. METHODS: A prospective clinical trial was conducted to investigate the effect of additional ischemic normothermic preconditioning prior to cardioplegic arrest applying cold blood cardioplegia in patients scheduled for routine coronary surgery (3 vessel disease, left ventricular ejection fraction > 50%). Two cross clamp periods of 5 min with the hearts beating in sinus rhythm were applied followed by 10 min of reperfusion, each (n = 7, group I). Inducing moderate hypothermia cold blood cardioplegia was delivered antegradely. In control groups, cold intermittent blood cardioplegia (n = 7, group II) was used alone. Coronary sinus effluents were analyzed for release of creatine kinase (CK), CK-MB, lactate, and troponin T at 1, 3, 6, 9, and 12 h. In addition, postoperative catecholamine requirements were monitored. RESULTS: The procedure was tolerated well, and no perioperative myocardial infarction in any of the groups studied occurred. Concentrations of lactate tended to be higher in group I, but this difference was not significant. In addition, no significant differences for concentrations of CK, CK-MB, and troponin T were found. Following ischemic preconditioning an increased dosage of dopamine was required within the first 12 h postoperatively (group I: 2.63 +/- 1.44 microg/kg/min, group II: 0.89 +/- 1.06 microg/kg/min). CONCLUSIONS: Combining ischemic preconditioning and cardioplegic protection with cold blood cardioplegia does not appear to ameliorate myocardial protection when compared to cardioplegic protection applying cold blood cardioplegia alone. Inversely, contractile function seemed to be impaired when applying this protocol of ischemic preconditioning.  相似文献   
3.
Si/SiGe n-type modulation-doped field-effect transistors grown on a very thin strain-relieved Si/sub 0.69/Ge/sub 0.31/ buffer on top of a Si(100) substrate were fabricated and characterized. This novel type of virtual substrate has been created by means of a high dose He ion implantation localized beneath a 95-nm-thick pseudomorphic SiGe layer on Si followed by a strain relaxing annealing step at 850/spl deg/C. The layers were grown by molecular beam epitaxy. Electron mobilities of 1415 cm/sup 2//Vs and 5270 cm/sup 2//Vs were measured at room temperature and 77 K, respectively, at a sheet carrier density of about 3/spl times/10/sup 12//cm/sup 2/. The fabricated transistors with Pt-Schottky gates showed good dc characteristics with a drain current of 330 mA/mm and a transconductance of 200 mS/mm. Cutoff frequencies of f/sub t/=49 GHz and f/sub max/=95 GHz at 100 nm gate length were obtained which are quite close to the figures of merit of a control sample grown on a conventional, thick Si/sub 0.7/Ge/sub 0.3/ buffer.  相似文献   
4.
The inhibitory effect of plant sterols, fatty acids and lecithin on cholesterol intestnal absorption was studied in the unanesthetized rat using a single pass perfusion technique. Bile was excluded from the perfused intestine. Cholesterol absorption did not change following the additions of cholestanol, cholestanone, lanosterol, stigmasterol and β-sitosterol. A 3-fold increase in the molarity of cholestanol and β-sitosterol or the separate additions of the saturated short and medium chain fatty acids, butyric and octanoic, also did not change cholesterol absorption. The unsaturated long chain fatty acids, oleic, linoleic, linolenic and arachidonic, inhibited cholesterol absorption. Lecithin additions at concentrations of 0.1–1.5 mM caused a progressive, dose-related inhibition of cholesterol absorption. The inhibitory effect of these agents on cholesterol absorption is likely to have been caused by changes in cholesterol solubility in the micelle and shifts in the partition coefficient of cholesterol away from the cell membrane to the micelle.  相似文献   
5.
The kinetics of initial cholesterol uptake by everted rat proximal and distal small intestinal sacs were evaluated in vitro. The mucosal incubation solution consisted of 0.05 mM cholesterol solubilized in 4.8 mM sodium taurocholate micellar solution at pH 7.4. Experiments were performed at temperatures from 26 to 38 C. The rate of cholesterol uptake followed a linear relationship when plotted against time indicating an apparent zero-order kinetics mechanism for initial uptake. An Arrhenius plot of the results of uptake versus temperature remained linear over the entire range of temperatures studied. The large free energy of activation (20 kcal/mole) suggests that an energy barrier for cholesterol uptake exists at the enterocyte luminal cell membrane and may be an important limiting step in cholesterol uptake. It is proposed that a transient association between cholesterol and a component of the enterocyte luminal cell membrane is formed during initial uptake of cholesterol. The transient association may be an activated complex formed with proteins present at or within the luminal enterocyte cell membrane.  相似文献   
6.
Application of metallic glasses as structural materials has been limited by their poor ductility. To overcome brittle failure, nanocrystals are intentionally introduced to stabilize the glasses. In this study, we report on the application of ion irradiation to induce nanocrystalization in a Cu50Zr45Ti5 (CZT) alloy. Transmission electron microcopy, microindentation and nanoindentation have been used to characterize the CZT alloy irradiated with 140 keV He ions at room temperature. Hardness enhancement was observed near the projected range of the He ions, coinciding with the formation of nanocrystals. Such microstructural changes, however, were not observed in the near surface region, where the electronic stopping process is dominant.  相似文献   
7.
This paper reports the follow-up phase of a study of peer nominations begun in 1955 at the Naval OCS in Newport, Rhode Island. Over 700 trainees completed several peer nomination forms at various stages of training, 1 in particular on "success as a future Naval Officer" (FO). Subsequently, 639 trainees were identified who had gone on to duty as officers for about 3 yr. The average grade they secured on a key portion of the fitness report ratings assigned by their direct superior officers was used as a performance criterion; it had a split-half reliability of .90 In the prediction of this criterion, the FO peer nomination score from the 3rd wk. of training gave a validity of .40 which was as high as that for later FO scores and which was only slightly diminished after academic grades and popularity were partialed. The findings support the use of early peer nominations as a valid supplemental measure in predicting performance after training. (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
8.
Factors which might affect the absorption of vitamin K of dietary origin were investigated using everted small bowel sacs. Increasing the bile salt concentration to 20 mM or the addition of long chain fatty acids, monoolein, or lecithin all resulted in significant (P less than 0-05) decrease in the absorption rate of the vitamin. The addition of 2-5 mM short and medium chain fatty acids did not change the absorption rate of vitamin K-1 (P greater than 0-05). The absorption rate of vitamin K-1 appears to be modified by the presence of compounds in the incubation medium which either alter the partition of the vitamin between the micelle and the cell membrane or which change the permeation characteristics of the compound through the unstirred water layer or modify the physical characteristics of the cell membrane itself. It is possible that some of the above factors modify the absorption of lipid soluble compounds in general.  相似文献   
9.
Generic utterances (e.g., "Cows say 'moo"') have 2 distinctive semantic properties: (a) Generics are generally true, unlike indefinites (e.g., "Bears live in caves" is generic; "I saw some bears in the cave" is indefinite), and (b) generics need not be true of all category members, unlike universal quantifiers (e.g., all, every, each). This article examined whether preschool children and adults appreciate both these features, using a comprehension task (Study 1) and an elicited production task (Study 2). In both tasks, 4-year-old children--like adults--treated generics as distinct from both indefinites ("some") and universal quantifiers ("all"). In contrast, 3-year-olds did not differentiate among generics, "all," and "some." By 4 years of age, generics emerge as a distinct semantic device. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
10.
Two monomers, ethylenediamine (EDA) and diaminocyclohexane (DACH), were plasma‐polymerized in continuous‐wave (CW) and pulse modes. The influence of different plasma parameters on the deposition rate and film composition were investigated in detail and the changes in aminofunctionalization with varying pulse parameters were examined by FTIR, ESCA, and chemical‐derivatization techniques. It was shown that a varying duty cycle does not produce a considerable effect on the retention of amine groups into the film, while power and ton play a significant role in the polymerization process. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 979–990, 2004  相似文献   
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