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991.
There is accumulating evidence that the changes which occur in the metabolism of some micronutrients in diabetes mellitus might have a specific role in the pathogenesis and complications of this disease. Magnesium deficiency is the most evident disturbance of metal metabolism in insulin-dependent diabetes mellitus. Hypomagnesemia has been linked both to the acute metabolic and late chronic complication of diabetes. Of particular concern, is the association between hypomagnesemia and ischemic heart disease and severe retinopathy in humans with diabetes mellitus. Appropriate magnesium supplementation might prove beneficial in normalizing the low plasma and tissue magnesium levels and prevent or retard the development of vascular complications in diabetic patients. However, well designed and documented experiments need to be performed before the rationales for such therapy are well established.  相似文献   
992.
基于H.323框架标准协议的远程医疗系统在进行数据传输时,常常需要使用UDP(用户数据报协议),但往往因网络物理信道条件恶劣或者过于拥塞造成数据传输过程中数据包大量丢失。针对该问题,基于有限域理论,我们得出一种数据恢复率高、实现简单的远程医疗数据传输FEC算法。在算法允许的毛包度范围内,可对传输过程中丢失的数据包进行恢复,保证远程医疗系统数据传输的实时性和有效性。  相似文献   
993.
应用原子吸收光谱技术测定34例慢性肾衰患者补锌前后血清和头发微量元素的含量.结果表明:补锌后患者血清和头发Zn、Se、Co明显升高,Al降低.血清Cu明显降低,发Cu降低不显著.患者的一些临床症状得到改善.  相似文献   
994.
Objective. To compare scapular orientation during both the concentric (elevation) and eccentric (lowering) phases of scapular plane abduction in subjects with and without shoulder impingement.

Design. Mixed model analysis of variance with one between-subjects factor (group) and within-subjects factors of phase, humeral angle, and trial.

Background. Abnormal scapular kinematics have been identified in shoulder impingement patients during the concentric phase of arm elevation, and under static conditions. Because abnormal scapular motion is observed clinically during the eccentric phase of arm elevation, analysis of this phase of motion is warranted.

Methods. Twenty-six symptomatic and 26 healthy subjects performed five repetitions of humeral scapular plane abduction. An electromagnetic tracking device described three-dimensional scapular kinematics during arm elevation and lowering. Angular values for scapular anterior/posterior tipping in the sagittal plane, upward/downward rotation in the scapular plane, and internal/external rotation in the transverse plane were calculated. Scapular orientation relative to the thorax at humeral angles of 40°, 60°, 80°, 100°, and 120° was statistically tested for effects of phase and trial, or for interactions of phase with group or humeral angle.

Results. Internal rotation was significantly increased in the eccentric phase for both groups at the 100° angle (P<0.05) and for the symptomatic group only at the 120° angle (P<0.05). Scapular anterior tipping was significantly decreased during the eccentric phase in both groups at the 80° (P<0.001), 100° (P<0.0001), and 120° (P<0.0001) angles.

Conclusions. Small but statistically significant differences in scapular tipping and internal rotation during the eccentric phase of arm elevation were identified at higher humeral angles in both subject groups, while no significant phase differences for scapular upward rotation or for scapular variables at lower humeral angles were found. Averaged across phases, the symptomatic group demonstrated significant reductions in upward rotation at lower humeral elevation angles, and significant increases in anterior tipping at higher elevation angles as compared to the healthy group.

Relevance Normal and abnormal scapular kinematics during varying types of motion need to be understood in order to optimally design rehabilitation programs for individuals with impingement syndrome.  相似文献   

995.
996.
Three-dimensional printing (3DP) is one of the latest tools in the armamentarium of the modern spine surgeon. The yearning to be more precise and reliable whilst operating on the spine has led to an interest in this technology which has claimed to achieve these goals. 3D printing has been used pre-operatively for surgical planning and for resident or patient education. It has also found its way to the operation theatre where it is used to fabricate customized surgical tools or patient-specific implants. Several authors have highlighted significant benefits when 3D printing is used for specific indications in spine surgery. Novel applications of this technology in spine surgery have also been described and though still in a nascent stage, these are important for this technology to sustain itself in the future. However, major limitations have also come to light with this technology in use. This article seeks to review the current status and applications of 3D printing in spinal surgery and its major drawbacks while briefly describing the essentials of the technology. It is imperative that the modern spine surgeon knows about this important innovation and when and how it can be applied to improve surgical outcomes.  相似文献   
997.
To assess the ability of the transposable element Minos to act as a vector for genetic manipulation of the silkworm Bombyx mori, an extrachromosomal transposition assay based on three plasmids was performed. The three plasmids - helper, donor and target - were co-injected into preblastoderm embryos. Low molecular weight DNA was extracted from the embryos at the stage of blastokinesis and used to transform Escherichia coli. High frequency of transposition was observed in the presence of a helper plasmid possessing an intronless Minos transposase gene, whereas transposition did not occur in the presence of a helper plasmid with the intron-bearing transposase gene. Sequence analysis of the insertion sites showed that Minos always inserts into a TA dinucleotide. Although the insertions are distributed throughout the target gene, there was a preference for certain insertion sites. However, no consensus could be identified in the sequence flanking the target site. The results strongly suggest that the transposable element Minos has the potential to be used as a vector in the silkworm and probably in other lepidopteran insects.  相似文献   
998.
Three-dimensional (3D) high-resolution ultrasonography has proved to be useful for in vitro assessment of cartilage remodeling due to osteoarthritis. The diagnosis is performed by computation of the mean thickness of the cartilage, which reveals hypertrophy or thinning, and by 3D reconstruction of the data, which provides essential information about the size, extent, and localization of the lesion. In both cases, preliminary segmention of the cartilage is necessary. This article proposes an algorithm for automatic segmentation of the cartilage from 3D ultrasonic acquisitions of the rat patella, which includes the detection of the cartilage surface and the cartilage/bone interface. The method was designed on the assumption of regularity and smoothness of the interfaces. The use of a global threshold was sufficient to separate the patella area from the background. The cartilage/bone interface was detected by selection of regions of interest (ROIs) encompassing the interface, followed by the detection of the interface within these ROIs using the graph theory. The method was applied to 162 samples. The detection accuracy was judged to be very good or good in 99% of the cases for the cartilage surface and in 86% of the cases for the cartilage/bone interface. The mean cartilage thickness value in the central part of the patella obtained from the automatic detection method was compared to that obtained manually. The coefficient of correlation between the two measurements was 0.92. These results show that our method is reliable. Thus, fast processing of a large number of acquisitions and a more complete analysis of the cartilage surface become possible.  相似文献   
999.
目的探讨二维超声、三维超声诊断胎儿唇裂的价值。方法对我院门诊孕检的18~40周胎儿,常规二维超声观测胎儿鼻唇情况,然后应用三维超声实时动态面部成像。结果三维超声对18~24周胎儿唇裂成像清晰直观逼真,二维超声对18~24周胎儿唇裂,检查费时,检查者须有经验;三维超声对36~40周胎儿实时成像困难,二维超声则可通过非标准切面面部成像;三维超声及二维超声对24~36周胎儿均能有效成像。结论二维、三维超声均能对胎儿唇裂明确诊断。不同孕期二维超声与三维超声各有优势,三维超声在孕早期诊断唇裂有明显优势,二维超声在孕晚期略显优势。  相似文献   
1000.

BACKGROUND CONTEXT

Anterior vertebral body osteophytes are common with degeneration but their biomechanical influence on the whole lumbar spine remains unclear.

PURPOSE

To investigate the biomechanical influence of anterior vertebral body osteophytes on the whole lumbar spine.

STUDY DESIGN/SETTING

This is a study using finite element analysis.

OUTCOME MEASURES

Intersegmental rotation, maximum Mises stress, and intradiscal pressure on the intervertebral discs of different lumbar levels were calculated.

METHODS

A finite element model of an intact lumbar spine was constructed and validated against in vitro studies. The modified models, which had different degrees of anterior vertebral body osteophyte formation (OF) in combination with disc space narrowing, were applied with physiological loadings.

RESULTS

The lumbar levels with various degrees of OF altered the kinematics of these levels, which also affected the whole lumbar spine. In flexion and lateral bending, the segment that was one level inferior to the vertebra with OF showed a trend towards increased range of motion. On the intervertebral discs that were one level inferior to the OF level, a trend towards increase in the maximum von Mises stress was found on the annulus.

CONCLUSIONS

Segments adjacent to levels with anterior vertebral body osteophytes showed increased intersegmental rotation and maximum stress. Further clinical observation should be performed to verify the results in vivo.  相似文献   
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