瓷表面处理方式对瓷修复体缺损美容修复影响的研究

目的：研究不同瓷表面粗化处理对Vita VMK95瓷粘结强度的影响。方法：瓷片按表面粗化方式分为6组，每组分别与树脂粘结，测剪切强度，统计分析所得数据。结果：喷砂后氢氟酸处理组粘结强度最高，喷砂后磷酸酸蚀组与不喷砂氢氟酸蚀组次之，单纯偶联剂处理组最低。结论：综合临床安全性考虑，喷砂后用磷酸处理是瓷修复体缺损后较好的瓷表面处理方法。     

Balance disorder and increased risk of falls in osteoporosis and kyphosis: significance of kyphotic posture and muscle strength

This controlled trial was designed to investigate the influence of osteoporosis-related kyphosis (O-K) on falls. Twelve community-dwelling women with O-K (Cobb angle, 50–65° measured from spine radiographs) and 13 healthy women serving as controls were enrolled. Mean age of the O-K group was 76 years (±5.1), height 158 cm (±5), and weight 61 kg (±7.9), and mean age of the control group was 71 years (±4.6), height 161 cm (±3.8), and weight 66 kg (±11.7). Quantitative isometric strength data were collected. Gait was monitored during unobstructed level walking and during stepping over an obstacle of four different heights randomly assigned (2.5%, 5%, 10%, and 15% of the subjects height). Balance was objectively assessed with computerized dynamic posturography consisting of the sensory organization test. Back extensor strength, grip strength, and all lower extremity muscle groups were significantly weaker in the O-K group than the control group ( P <0.05), except right ankle plantar flexors ( P =0.09). There was a significant difference in the anteroposterior and mediolateral displacements and velocities. The O-K subjects had less anteroposterior displacement, greater mediolateral displacement, reduced anteroposterior velocity, and increased mediolateral velocity compared with controls for all conditions of unobstructed and obstructed level walking. Obstacle height had a significant effect on all center-of-mass variables. The O-K subjects had significantly greater balance abnormalities on computerized dynamic posturography than the control group ( P =0.002). Data show that thoracic hyperkyphosis on a background of reduced muscle strength plays an important role in increasing body sway, gait unsteadiness, and risk of falls in osteoporosis.     

Factors related to spinal mobility in patients with postmenopausal osteoporosis

Quality of life in patients with spinal osteoporosis is impaired by the decline of spinal mobility. However, the factors related to the spinal mobility in these patients are still unclear. We evaluated the possible factors affecting spinal mobility in patients with postmenopausal osteoporosis. A total of 128 postmenopausal women with osteoporosis aged over 50 years (mean, 70 years) were included in this study. The thoracic and lumbar kyphosis angles and range of motion (ROM) of the total spine were measured in the upright position and at maximum flexion/extension with a computer-assisted device. The paravertebral muscle thicknesses (PVMT) of thoracic and lumbar spine in the upright position were measured using an ultrasound unit. The number of vertebral fractures was evaluated with radiographs of the spine. Isometric back extensor strength (BES) was evaluated with a strain-gauge dynamometer. Correlations between these variables were then analyzed. Age ( r =–0.412), lumbar kyphosis angle ( r =–0.284), BES ( r =0.369), PVMT at the lumbar spine ( r =0.227) and the number of vertebral fractures ( r =–0.260) showed significant correlations with total spinal ROM ( P <0.05). However, no significant correlations were observed between the total spinal ROM and PVMT at the thoracic spine ( r =–0.069) or thoracic kyphosis angle ( r =–0.138). Multiple regression analysis revealed that the BES was the most significant contributor to the total spinal ROM. The present study suggests a possible association between BES and spinal mobility in patients with postmenopausal osteoporosis.     

Similarities in Skeletal Muscle Strength and Exercise Capacity Between Renal Transplant and Hemodialysis Patients

Exercise intolerance is common in hemodialysis (HD) and renal transplant (RTx) patients. Aim of the study was to assess to what extent exercise capacity and skeletal muscle strength of RTx patients differ from HD patients and healthy controls and to elucidate potential determinants of exercise capacity in RTx patients. Exercise capacity, muscle strength, lean body mass (LBM) and physical activity level (PAL) were measured by cycle-ergometry, isokinetic dynamometry, DEXA and Baecke Questionnaire, respectively, in 35 RTx, 16 HD and 21 controls. VO2peak and muscle strength of the RTx patients were significantly lower compared to controls (p<0.01), but not different compared to HD patients. In RTx patients, strength (p<0.001), PAL (p=0.001) and age (p=0.045) were significant predictors of VO2peak. Muscle strength was related to LBM (p=0.001) and age (p=0.001), whereas gender (p<0.001) and renal function (p=0.01) turned out to be significant predictors of LBM. No effects of corticosteroids were observed. Exercise capacity and muscle strength seem equally reduced in RTx and HD patients compared to controls. In RTx patients, muscle strength and PAL are highly related to exercise capacity. Renal function appears to be a significant predictor of LBM, and through the LBM, of muscle strength and exercise capacity.     

生物活性玻璃预处理对牙本质粘接界面耐久性的影响

目的:研究生物活性玻璃(bioactive glass, BG)预处理对维持牙本质粘接界面耐久性的作用。方法:选取30颗无龋坏第三磨牙,去除冠部釉质制备牙本质平面,随机均分对照组、BG组、三偏磷酸钠(sodium trimetaphosphate, STMP)-聚丙烯酸(polyacrylic acid, PAA)-BG组(S-P-BG组)。各组均使用35%(质量分数)磷酸酸蚀牙本质样本,BG组再使用0.5 g/L BG涂擦酸蚀后的牙本质样本;S-P-BG组先使用5%(质量分数)STMP、5%(质量分数)PAA浸泡酸蚀后的牙本质样本1 min,再使用0.5 g/L BG涂擦牙本质样本。各组样本使用3M Single Bond 2粘接剂及3M Z350XT复合树脂粘接,并制备微拉伸柱状样本,每颗牙的柱状样本按时间随机分为24 h、1个月、3个月组。各组样本保存在37 ℃人工唾液(artificial saliva, AS)中相应时间后,进行微拉伸粘接强度测试,并使用单因素方差分析及LSD法进行统计学分析,扫描电镜下观察粘接断裂界面形貌。另选取27颗无龋坏第三磨牙制备牙本质平面,随机分为对照组、BG组、S-P-BG组,并按上述分组处理牙本质样本,再使用含0.1%(质量分数)罗丹明B的3M Single Bond 2粘接剂完成粘接。去除样本牙根暴露髓腔,并保存在 37 ℃ AS中24 h、1个月、3个月后,髓腔内放置0.1(质量分数)荧光素钠溶液染色1 h,激光共聚焦显微镜观察粘接界面形态及混合层微渗漏。结果:AS中浸泡24 h、1个月后,3组微拉伸粘接强度间的差异无统计学意义(P>0.05);浸泡3个月后,S-P-BG组微拉伸粘接强度为(36.91±7.07) MPa,高于对照组粘接强度(32.73±8.06) MPa,且差异有统计学意义(P=0.026);对照组、BG组3个月的微拉伸粘接强度较24 h呈下降趋势,且差异有统计学意义(对照组P=0.017,BG组P=0.01);S-P-BG组3个月微拉伸粘接强度较24 h粘接强度[(37.99±7.98) MPa]下降,但差异无统计学意义(P>0.05)。扫描电镜观察24 h粘接断裂面,3组均未见明显矿化;1个月、3个月后,BG组、S-P-BG组的粘接界面可见矿物质形成,S-P-BG组无明显胶原暴露。激光共聚焦显微镜观察对照组、BG组与S-P-BG组树脂突形成的形态及数量无明显差异;3组样本粘接24 h后粘接界面混合层均有渗漏,3个月后对照组微渗漏增加,BG组和S-P-BG组混合层微渗漏减少。结论:BG预处理牙本质粘接界面能够在粘接界面形成矿物质,减少粘接混合层微渗漏;STMP、PAA 与BG共同预处理牙本质粘接界面,可能在一定程度上维持牙本质粘接修复的耐久性。     

The effect of vitamin D supplementation on cardiorespiratory fitness and muscle strength in male adults undergoing basic military training

BackgroundVitamin D deficiency (VDD) is ubiquitous in the Indian subcontinent. VDD has been shown to impair muscle functions. However, the association of VDD with cardiorespiratory endurance is uncertain. Hence, we enrolled and supplemented vitamin D in military recruits with VDD with an aim to evaluate effect of supplementation on cardiorespiratory endurance and muscle strength.MethodWe enrolled 90 military recruits with VDD and randomly allotted them to two groups equally. The group I received cholecalciferol granules 60,000 IU every fortnight for twelve weeks (cases), and the group II was observed as control. Muscle strength and cardiorespiratory endurance was assessed with a battery of tests (standing broad jump, bent arm hang test, 20 m shuttle run) at baseline and repeated at the end of training (nineteen weeks). Blood samples were collected for measurement of serum 25(OH)D and parathyroid hormone.ResultsIn Group I and Group II, there was significant increase in 25(OH) D levels (25.8 ± 7.1 and 17.3 ± 3.5 ng/ml, respectively), and in VO2 max (9.8 ± 8.8 and 12.7 ± 8.6 ml/kg/min, respectively) compared with the baseline values. However, no significant change was observed in muscle strength after supplementation. There was no difference between the groups in VO2 max and muscle strength at baseline and at the end of training.ConclusionVitamin D supplementation did not improve muscle strength and cardiorespiratory endurance in military recruits with VDD. A significant rise in 25(OH) D was observed even in those not supplemented with vitamin D.     

旋转强恒磁场对SD大鼠骨骼生长发育及相关激素的影响

目的探讨旋转强恒磁场（RCSMF）对SD大鼠的骨骼生长发育及相关激素的影响，为RCSMF促进人体增高的临床应用奠定基础。方法取25日龄的SD大鼠置RCSMF下，1．5h／d。每5天取血检测大鼠生长激素（GH）、类胰岛素生长因子（IGF-Ⅰ）、雌激素（E2）等与骨骼发育相关的激素，同时测量每组大鼠的身长、体重和尾长，并用骨形态计量学方法研究RCSMF对大鼠骨组织形态学和动态学参数的影响。结果RCSMF处理后大鼠的身长[实验组（25．28±0．41）cm。对照组（24．05±0．35）cm；P〈0．01]、体重[实验组（445．90±16．88）g，对照组（382．22±12．78）g；P〈0．01]、胫骨长[实验组（3．89±0．13）cm，对照组（3．66±0．10）cm；P〈0．01]和股骨长[实验组（3．65±0．08）cm，对照组（3．51±0．06）cm；P〈0．01]，上述多项参数以及骨骺板等相关形态计量学数据实验组明显高于对照组。回归分析身长与相关激素的关系显示：大鼠身长与GH、IGF—I和E2有显著相关性。结论RCSMF有促进骨骼生长发育的作用，其作用机理是通过刺激与骨骼生长发育相关激素的生成、释放，并影响软骨细胞的增殖功能来完成的。     

60岁以上老年人伤害死亡流行强度与特征

目的了解60岁以上老年人群伤害死亡流行病学特征，探讨老年人伤害防制对策，为开展伤害防制提供科学依据。方法以回顾性调查研究的方法对20012005年武进区居民伤害死亡资料进行分析。结果2001～2005年武进区全人群伤害死亡率分别为69．04／10万、62．39／10万、64．82／10万、62．97／10万、62．37／10万；60岁以上老年人伤害死亡率分别为188．65／10万、172．16／10万、149．97／10万、160．03／10万、148．03／10万；不同性别间伤害死亡有差异，但无显著性意义（X2为4．94，0．05〉P〉0．025）。在老年人伤害死亡主要原因中，死亡率位于前五位的依次为：车祸、自杀、意外跌落、其它意外和淹死。结论老年人是伤害死亡的高发人群．防制老年人伤害死亡需要多部门协调．社会、家庭和个人的共同努力。     

可膨胀石墨阻燃体系在聚丙烯中的作用

采用可膨胀石墨(EG)为主阻燃剂,包裹红磷(MRP)为阻燃协效剂制备阻燃聚丙烯(PP)。在mEG∶mMRP≥2时,阻燃效果最佳。阻燃剂(FR)含量达到30%后,阻燃效果大幅度提高,氧指数大于28。采用热失重和流变学方法分析了炭层质量,探讨了在mEG∶mMRP≥2时,阻燃效率最高的原因。相容剂马来酸酐接枝聚丙烯(PP-g-MAH)能够改善阻燃剂和聚丙烯之间的相容性,提高粘结力,改善炭层质量,提高材料的氧指数,PP-g-MAH用量为30%时,材料的氧指数达到31.4。