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1.
The aim of this study was to evaluate the yield of nucleated cells in bone marrow harvested by means of Downs' Islam aspiration needles with or without side-holes. Twenty marrow donors for HLA identical sibling transplants were studied. Bone marrow nucleated cells were harvested 50 ml in the right iliac bone with a Downs' Islam aspiration needle with or without side-holes and 50 ml in the left with another kind of needle by means of 5 ml aspirations in each donor. There were no significant difference between the number of nucleated cells by means of Downs' Islam aspiration needles with and without side-holes by cross-over analysis. All nucleated cell counts were 33.06 +/- 12.93 x 10(3)/microliter (mean +/- standard deviation) by means of the needle with side-holes and 32.90 +/- 15.25 x 10(3)/microliter by means of the needle without side-holes. The Downs' Islam aspiration needle without side-holes seems to be better in bone marrow harvest from normal volunteers than that with side-holes, because the former may be stronger than the latter.  相似文献   

2.
Early thrombosis of saphenous vein grafts can only reduce long-term patency. There exists a high risk category of patients who can be identified preoperatively where early failure is increased above the 10-20% which is attributed to technical errors. A venous side-arm indwelling catheter offers a safe means of reducing early thrombosis, promptly diagnosing the occlusion when it does occur, and more clearly delineating a course of corrective action. The venous side-arm catheter provides a means by which the vascular bed at highest risk may be regionally anticoagulated while allowing systemic clotting times to remain near normal. In addition, vasoactive drugs may be infused directly into the arterial tree and perhaps most importantly, rapid and atraumatic arteriograms can be obtained postoperatively at the bedside for evaluation of questionable perfusion. Regional heparinization and postoperative arterigraphy by means to the side-branch catheter technique was used in twelve patients who otherwise had an expected occlusion rate of 75% or more with an actual early occlusion incidence of zero.  相似文献   

3.
There is general agreement that the delivery of topical nasal medication by sprays is suboptimal. This study examines the distribution of spray to the anterior end of the middle turbinate as a guide to the distribution to the middle meatus by means of an endoscopic photographic comparison using dyed aqueous nasal spray. The technique was found to be reproducible. The effect of vigorously inhaling whilst spraying was studied by means of a randomized crossover trial and was found to have no significant effect. This technique could be used in conjunction with other means of assessing intranasal distribution when assessing improved topical nasal drug delivery systems.  相似文献   

4.
Tradeoff between changes of intraindividual variations of 2 drug formulations and of the difference between their means is a characteristic of a procedure suggested for the determination of individual bioequivalence [Schall and Luus 1993] and to be proposed by the Food and Drug Administration for adoption. Hauck et al. [1996] investigated properties of the tradeoff. Their procedure was applied and extended in the present study. The tradeoff was shown to be asymmetric. Notably, a small change in intrasubject variations can elicit, under various conditions, a comparatively large change in the allowable difference between means which can still be compatible with the declaration of bioequivalence. For instance, when the intraindividual coefficients of variations are 40% and 38% for the reference and test formulations, respectively, the allowable difference between means may increase, as a benefit, by 12.3%. A penalty by 11.2% is elicited if the intrasubject variations of the reference and test products are 40 and 42%, respectively. In addition, 4-period crossover trials were simulated. Ratios of estimated variances of the 2 formulations followed an F-distribution. Distributions of changes in allowable deviations between means were calculated from the tradeoff relationships; generally substantial changes were noted with high probabilities. For example, with an intraindividual variation of 30% there is an estimated 37% probability that a benefit of 10% increase, or larger, is gained by chance in the allowable difference between means, and an additional 36% probability that a penalty of a 10%, or larger, decrease in the allowable difference is suffered. With an intrasubject variation of 40%, the estimated probabilities are 42% and an additional 42% for a 10% expansion and contraction, respectively, of the allowable difference between means. Consequently, the strong asymmetry of the tradeoff could result in very large probabilities for benefits and penalties. Therefore, the investigated model assessing individual bioequivalence does not appear to be suitable for implementation.  相似文献   

5.
In some studies randomization at the patient level is not possible; randomization at the doctor's level can then be applied. However, statistical analysis at the level of the individual patient data can lead to wrong conclusions in such a study design. By basing the analysis on the averages per doctor a statistical test can be performed which guarantees the correct significance level. The correct sample size can be found by means of a correction factor that depends on the variation between the doctors. The data of a study with randomization at the doctor's level can be analysed in a more sophisticated way by means of so-called 'mixed models' that take account of possible variation between doctors.  相似文献   

6.
李航生 《铝加工》2007,(3):50-51
通过对企业管理虚与实内在联系的探讨,道出了管理虚与实的本质,从不同角度简述了各自的重要性,从而引伸出管理是企业必不可少的永恒主题。企业在激烈的市场竞争中要不断做优做强,核心是要依靠管理来发挥和调动人力资源,培育打造企业团队。打造企业为百年老店,就是要从管理人手,夯实基础,强化管理,让管理真正出效益。  相似文献   

7.
Magnetic diagnostics of the working layer on rollers is considered. A diagnostic method is proposed on the basis of the coercive force (the residual magnetization of the material) and employed by means of the robotized Valok 2000 diagnostic complex. The diagnostic results are presented in graphical and numerical form, by means of charts of roller properties. The basic approach to interpretation of the magnetic charts is outlined. Sample charts are presented for rotors with various defects. The potential of magnetic diagnostics in intake and periodic monitoring of the rollers is demonstrated. The stability of roller manufacture and subsequent roller operation may be assessed by this means. The results permit the identification of rollers with problems, reduction in the accident rate, and optimization of roller preparation.  相似文献   

8.
刘玉珍  邹立河 《有色设备》2000,(4):17-18,23
严重损坏、只能报废的万吨水压机-横梁,经过对其损坏原因的深入分析,确定了在特定条件下的修复方案。在不整体预热、不拆卸的情况下焊修取得了成功。这一成功有很大的实用价值,对于类似设备的修复有一定的借鉴意义。  相似文献   

9.
Wrist arthroscopy provides an ideal means of evaluating intraarticular soft-tissue injuries of the wrist. Many lesions such as tears of the triangular fibrocartilage complex can be treated by arthroscopic means as well. Reduction of articular fractures of the distal radius and pin fixation, reduction of scaphoid fractures and intramedullary fixation, and arthroscopic reduction and transcutaneous pin stabilization of acute carpal dissociation patterns can all be accomplished with minimally invasive techniques under arthroscopic control. These measures often provide the athlete with shorter periods of immobilization and earlier return to athletic competition. Wrist arthroscopy provides a very useful adjunct to the treatment armamentarium of all sports medicine physicians.  相似文献   

10.
The composition of normal electrocorundum melt may be monitored by means of the constant component of the phase voltage.  相似文献   

11.
Intensive care, one of the greatest achievements of modern medicine, is not without its problems. In what sense could ethics contribute towards an intensive care medicine which would be humane and respectful of what it means to be sick? After having presented a phenomenology of what it means to be sick and in intensive care, the author proposes an ethical framework which could guide the decision-making of physicians specialized in the field. This framework has three levels. Level one deals with the basic values of benevolence and autonomy which are those of medicine itself. Level two deals with the implementation of these values, which bioethics sees as conflicting. Implementation is achieved by "conversation" between the physician and the patient. Finally, the physician is invited to question his or her own attitude towards the unavoidable dilemmas created by the paradoxes and contradictions of modern medicine.  相似文献   

12.
Researchers often statistically control for means when examining individual or age-associated differences in variances, assuming that the relation between the 2 is linear and invariant within and across individuals and age groups. We tested this assumption in the domain of working memory by applying variance-heterogeneity multilevel models to reaction times in the n-back task. Data are from the COGITO study, which comprises 101 younger and 103 older adults assessed in over 100 daily sessions. We found that relations between means and variances vary reliably across age groups and individuals, thereby contradicting the invariant linearity assumption. We argue that statistical control approaches need to be replaced by theoretical models that simultaneously estimate central tendency and dispersion of latencies and accuracies and illustrate this claim by applying the diffusion model to the same data. Finally, we note that differences in reliability between estimates for means and variances need to be considered when comparing their unique contributions to developmental outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
This paper describes the underlying structure of student ratings of instruction, using three units of analysis. Data were analyzed using individual ratings, class means, and deviations from class means. Course characteristics were then used as independent variables in the prediction of factor scores. Results indicated that the underlying structure of class means is different from the structure yielded by the other units of analysis. Course characteristics described a small percentage of the variance of the factor scores. The usual robust factor structure of ratings, assumed to be due to shared implicit theories about instructor behavior or item similarity, was questioned. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

14.
With pulse oximetry it is possible to record the pulse-synchronic variation of the oxygen saturation due to variable blood flow during systole and diastole. In the present study on chicken embryos, the pulse rate based on oximetry was compared with the heart rate recorded by means of ECG. We conclude that the pulse curve detected by means of pulse oximetry can be used to determine the heart rate in chicken embryos between day 12 and day 20 of incubation.  相似文献   

15.
PURPOSE: Arteriography is the diagnostic test of choice before lower extremity revascularization, because it is a means of pinpointing stenotic or occluded arteries and defining optimal sites for the origin and termination of bypass grafts. We evaluated whether a duplex ultrasound scan, used as an alternative to arteriography, could be used as a means of accurately predicting the proximal and distal anastomotic sites in patients requiring peripheral bypass grafts and, therefore, replace standard preoperative arteriography. METHODS: Forty-one patients who required infrainguinal bypass grafts underwent preoperative duplex arterial mapping (DAM). Based on these studies, an observer blinded to the operation performed predicted what operation the patient required and the best site for the proximal and distal anastomoses. These predictions were compared with the actual anastomotic sites chosen by the surgeon. RESULTS: Whether a femoropopliteal or an infrapopliteal bypass graft was required was predicted correctly by means of DAM in 37 patients (90%). In addition, both anastomotic sites in 18 of 20 patients (90%) who had femoropopliteal bypass grafts and 5 of 21 patients (24%) who had infrapopliteal procedures were correctly predicted by means of DAM. CONCLUSION: DAM is a reliable means of predicting whether patients will require femoropopliteal or infrapopliteal bypass grafts, and, when a patient requires a femoropopliteal bypass graft, the actual location of both anastomoses can also be accurately predicted. Therefore, DAM appears able to replace conventional preoperative arteriography in most patients found to require femoropopliteal reconstruction. Patients who are predicted by means of DAM to require crural or pedal bypass grafts should still undergo preoperative contrast studies to confirm these results and to more precisely locate the anastomotic sites.  相似文献   

16.
介绍了在羰基铁粉的生产过程中通过控制其粉末粒度、颗粒结构、化学成分和制取温度等因素来达到控制羰基铁粉性能,特别是磁性能的方法。  相似文献   

17.
朱泰天  金致崇 《黄金》1991,12(8):1-3
本文介绍了朝鲜民主主义人民共和国金策工业大学金致崇教授发明的根据磁场调查勘查砂金的最新技术(简称KJ法)。这项技术是不用钻探和井探,而只用仪器探出砂金的矿体形状、大小、埋深及品位。  相似文献   

18.
BACKGROUND: Depressed baroreflex sensitivity obtained by means of a phenylephrine test plays a prognostic role in patients with a previous myocardial infarction. Our purpose was to evaluate the correlation and agreement between the baroreflex sensitivity obtained with phenylephrine and that obtained by two noninvasive methods: the alpha-index and sequence analysis. METHODS AND RESULTS: The alpha-index was measured by means of the spectral analysis of RR and systolic blood pressure variabilities in both the high- and low-frequency bands; sequences were identified from simultaneously recorded time series in which the RR and systolic blood pressure concurrently increased or decreased. Noninvasive baroreflex sensitivity tests were performed during both spontaneous and controlled respiration. Fifty-two consecutive patients with recent myocardial infarction underwent the analyses. Although the correlations between phenylephrine and either of the noninvasive methods were always significant, those found during controlled respiration had the highest r values (r=.70). However, the limits of agreement calculated by means of the Bland and Altman method were wide for both noninvasive methods. CONCLUSIONS: The results obtained by means of noninvasive baroreflex sensitivity assessments should not be used in clinical practice as an alternative to those obtained by the phenylephrine method.  相似文献   

19.
Immunogenetic analysis of Y-factor localization in mouse genome was carried out by means of skin grafts. The data obtained indicate to autosomal localization of Y-factor rather than Y-linked one. This leads to the conclusion that Y-factor is a sex-influenced factor, but not a sex-linked one. If the hypothesis about Y-factor localization in Y-chromosome is accepted, this gene will be identical in CGA and C57B1/6 strains and the variety of reactions, caused by T-antigen, will be determined by the genetical constitution of the male donors and the female recipients.  相似文献   

20.
鞍钢矿渣开发公司是专业处理钢铁渣罐的保产单位。结合该单位的实际情况 ,阐述了企业应依靠其资源 ,发挥其优势 ,找到经济效益的增长点 ,走振兴之路。  相似文献   

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