Tile C型骨盆骨折手术治疗及疗效分析

目的：探讨手术治疗Tile C型骨盆骨折的临床疗效及术中相关问题。方法：自2004年8月至2011年2月,收治23例Tile C型骨盆骨折患者。男15例,女8例;年龄31.0±8.2岁（17-51岁）。车祸伤17例,坠落伤5例,压砸伤1例。伤后就诊时间1.0h-3d。按照Tile骨盆骨折方法分型：C1型6例,C2型10例,C3型7例。按Denis等（1988）分类标准,Ⅰ区（骶骨翼区）骨折4例,Ⅱ区（骶孔区）骨折2例,Ⅲ区（骶管区）骨折2例。根据Matta评分系统及Majeed评分系统对患者的手术疗效进行随访。结果：所有患者随访时间28.5月（8-49月）。术中失血量380 mL（50 mL-1100 mL）。手术时间112 min（35-155 min）。按Matta等复位标准：优16例,良7例,所有骨折均愈合。Majeed功能评分：优14例,良7例,一般2例。结论：对于Tile C型骨盆骨折,根据其骨折类型,选择合适的手术及固定方式,能够获得良好的临床效果。     

Longitudinal gait development and variability of growing pigs reared on three different floor types

Biomechanical investigation into locomotor pathology in commercial pigs is lacking despite this being a major concern for the industry. Different floor types are used in modern, intensive pig production systems at different stages of the pigs’ production cycle. The general perception holds that slatted and/or hard solid concrete surfaces are inferior to soft straw-covered floors regarding healthy musculoskeletal development. Previous studies have compared pigs housed on different floor types using clinical, subjective assessment of leg weakness and lameness. However, reliability studies generally report a low repeatability of clinical lameness scoring. The objective of this study was to quantitatively assess the long-term effect of pen floors, reflected in the biomechanical gait characteristics and associated welfare of the pigs. A cohort of 24 pigs housed on one of three different floor types was followed from 37 to 90 kg average liveweight, with gait analysis (motion capture) starting at 63 kg. The three floor types were fully slatted concrete, partly slatted concrete and deep straw-bedded surfaces, all located within the same building. Pigs underwent five repeated camera-based motion captures, 7 to 10 days apart, during which 3D coordinate data of reflective skin markers attached to leg anatomical landmarks were collected. Pigs walked on the same solid concrete walkway during captures. One-way ANOVA and repeated measures ANOVA were used to analyse the gait data. Results revealed changes over time in the spatiotemporal gait pattern which were similar in magnitude and direction for the pigs from different floor types. Significant increases in elbow joint flexion with age were observed in all pigs (P⩽0.050; +6°). There were few differences between floor groups, except for the step-to-stride ratio in the hind legs being more irregular in pigs housed on partly slatted floors (P=0.012; 3.6 times higher s.d.) compared with those on 5 to 10 cm straw-bedding in all pen areas. As the level of clinical problems was generally low in this cohort, it may be that floors elicit problems only when there is a primary predisposing factor increasing weakness in susceptible tissues.     

阿尔泰山两河源自然保护区地面生地衣群落物种分布特征

用聚类分析和主成分分析法对阿尔泰山两河源自然保护区地面生地衣群落进行划分;根据优势地衣种类进行群落命名。应用典范对应分析法探讨了地面生地衣种类分布与环境间的关系。结果表明:阿尔泰山两河源自然保护区地面生地衣可分为以下4个群落:白腹地卷+硫石蕊+喇叭粉石蕊群落;茸珊瑚枝+长根地卷+黑瘿地卷群落;土星猫耳衣+软鹿蕊+膜地卷群落;雪岛衣+北方石蕊+绿皮地卷群落。各群落中的地面生地衣种类与盖度,在一定程度上反映了地面生地衣在阿尔泰山两河源保护区分布格局与环境的关系。典范对应分析结果表明,阿尔泰山地面生地衣群落物种分布受到土壤湿度、土壤pH、海拔高度、林冠层郁闭度和灌木层盖度等环境因素的影响,其中海拔、土壤湿度、林冠层郁闭度等对地衣物种分布的影响最大。     

Understory vegetation response to mechanical mastication and other fuels treatments in a ponderosa pine forest

Questions: What influence does mechanical mastication and other fuel treatments have on: (1) canopy and forest floor response variables that influence understory plant development; (2) initial understory vegetation cover, diversity, and composition; and (3) shrub and non‐native species density in a second‐growth ponderosa pine forest. Location: Challenge Experimental Forest, northern Sierra Nevada, California, USA. Methods: We compared the effects of mastication only, mastication with supplemental treatments (tilling and prescribed fire), hand removal, and a control on initial understory vegetation response using a randomized complete block experimental design. Each block (n=4) contained all five treatments and understory vegetation was surveyed within 0.04‐ha plots for each treatment. Results: While mastication alone and hand removal dramatically reduced the midstory vegetation, these treatments had little effect on understory richness compared with control. Prescribed fire after mastication increased native species richness by 150% (+6.0 species m²) compared with control. However, this also increased non‐native species richness (+0.8 species m²) and shrub seedling density (+24.7 stems m²). Mastication followed by tilling resulted in increased non‐native forb density (+0.7 stems m²). Conclusions: Mechanical mastication and hand removal treatments aided in reducing midstory fuels but did not increase understory plant diversity. The subsequent treatment of prescribed burning not only further reduced fire hazard, but also exposed mineral soil, which likely promoted native plant diversity. Some potential drawbacks to this treatment include an increase of non‐native species and stimulation of shrub seed germination, which could alter ecosystem functions and compromise fire hazard reduction in the long‐term.     

Litter-dwelling beetles in primeval forests of Central Europe: Does deadwood matter?

We investigated the distribution pattern of litter dwelling beetles in four primeval forests of the Western Carpathians. The forests are situated in two mountain ranges and are either southerly exposed oak forests or northerly exposed beech forests. Beetles were extracted from leaf litter of plots close to coarse woody debris (c-CWD) and distant from coarse woody debris (d-CWD). We collected 2946 individuals of 172 species. Plots close to CWD usually were hot spots of species richness and beetle density, which could be increased two-fold and five-fold, respectively, when compared to d-CWD sites. The influence of CWD within each forest type was stronger than that of any other environmental factor. The c-CWD plots were characterised by both a higher presence of common species and a higher number of rare species. Especially, zoophagous and mycetophagous beetles were enhanced. The assemblage wide carrying capacity at c-CWD sites varied in respect to the gradients of temperature and moisture within a forest. A longer gradient provided a higher carrying capacity. We assume that the influence of downed deadwood on litter dwelling beetles will also be effective in commercial forests and stop the downward spiral with continuing loss of species.     

A new measure of trip risk integrating minimum foot clearance and dynamic stability across the swing phase of gait

Minimum toe clearance (MTC) is thought to quantify the risk of the toe contacting the ground during the swing phase of gait and initiating a trip, but there are methodological issues with this measure and the risk of trip-related falls has been shown to also be associated with gait speed and dynamic stability. This paper proposes and evaluates a new measure, trip risk integral (TRI), that circumvents many issues with MTC as typically calculated at a single point by considering minimum foot clearance across the entire swing phase and taking into account dynamic stability to estimate risk of falling due to a trip rather than risk of the foot contacting the floor. Shoes and floor surfaces were digitized and MTC and TRI calculated for unimpaired younger (N = 14, age = 26 ± 5), unimpaired older (N = 14, age = 73 ± 7), and older adults who had recently fallen (N = 11, age = 72 ± 5) walking on surfaces with no obstacles, visible obstacles, and hidden obstacles at slow, preferred, and fast gait speeds. MTC and TRI had significant (F ≥ 5, p ≤ 0.005) but differing effects of gait speed and floor surface. As gait speed increased (which increases risk of trip-related falls) MTC indicated less and TRI greater risk, indicating that TRI better quantifies risk of falling due to a trip. While MTC and TRI did not differ by subject group, strong speed-related effects of TRI (F ≥ 8, p ≤ 0.0007) resulted in improved TRI for fallers due to their slower self-selected preferred gait. This demonstrates that slower gait is both an important covariate and potential intervention for trip-related falls.     

Biomechanical comparison of sinus floor elevation and alternative treatment methods for dental implant placement

Objective: In this study, we compared the success of sinus lifting and alternative treatment methods in applying dental implants in cases lacking adequate bone due to pneumatization of the maxillary sinus. Methods: In a computer environment, 3D models were created using computerized tomography data from a patient. Additionally, implants and abutments were scanned at the macroscopic level, and the resulting images were transferred to the 3D models. Five different models were examined: a control model, lateral sinus lifting (LSL), short dental implant placement (SIP), tilted implant placement (TIP) and distal prosthetic cantilever (DC) use. Vertical and oblique forces were applied in each model. The compression, tension and von Mises stresses in each model were analyzed by implementing a finite element analysis method. Results: In our study, the LSL method was observed to be the closest to the control model. The TIP model showed high stress values under conditions of oblique forces but showed successful results under conditions of vertical forces, and the opposite results were observed in the SIP model. The DC model provided the least successful results among all models. Conclusions: Based on the results of this study, the LSL method should be the first choice among treatment options. Considering its successful results under conditions of oblique forces, the SIP method may be preferable to the TIP method. In contrast, every effort should be made to avoid the use of DCs.     

Biomechanical properties of the pelvic floor muscles of continent and incontinent women using an inverse finite element analysis

Pelvic disorders can be associated with changes in the biomechanical properties in the muscle, ligaments and/or connective tissue form fascia and ligaments. In this sense, the study of their mechanical behavior is important to understand the structure and function of these biological soft tissues. The aim of this study was to establish the biomechanical properties of the pelvic floor muscles of continent and incontinent women, using an inverse finite element analysis (FEA). The numerical models, including the pubovisceral muscle and pelvic bones were built from magnetic resonance (MR) images acquired at rest. The numerical simulation of Valsalva maneuver was based on the finite element method and the material constants were determined for different constitutive models (Neo-Hookean, Mooney-Rivlin and Yeoh) using an iterative process. The material constants (MPa) for Neo-Hookean (c₁) were 0.039 ± 0.022 and 0.024 ± 0.004 for continent vs. incontinent women. For Mooney-Rivlin (c₁) the values obtained were 0.026 ± 0.010 vs. 0.016 ± 0.003, and for Yeoh (c₁) the values obtained were 0.031 ± 0.023 vs. 0.016 ± 0.002, (p < 0.05). Muscle displacements obtained in the numerical simulations of Valsalva maneuver were compared with the muscle displacements obtained through additional dynamic MRI. Incontinent women presented a higher antero-posterior displacement than the continent women. The results were also similar between MRI and numerical simulations (40.27% vs. 42.17% for Neo-Hookean, 39.87% for Mooney-Rivlin and 41.61% for Yeoh). Using an inverse FEA coupled with MR images allowed to obtain the in vivo biomechanical properties of the pelvic floor muscles, leading to a relationship between them for the continent and incontinent women in a non-invasive manner.     

哀牢山湿性常绿阔叶林林冠和林地腐殖质理化特性、微生物量及酶活性比较

在热带、亚热带和温带高海拔潮湿生境的山地森林林冠层中,积累有较为丰富的林冠腐殖质(Canopy humus),是构成山地森林生态系统景观结构的重要组分,为丰富的附生植物提供了重要的生长基质和营养物质.通过对云南哀牢山山地湿性常绿阔叶林林冠腐殖质和其相应林下地表腐殖质的分析测定结果表明,由于林冠和林下地表腐殖质的来源、组成和空间分布的不同,它们之间的理化特性存在较大的差异,其中林冠腐殖质中有机C、全N及全Ca的含量、C/N以及阳离子交换量显著高于林下地表腐殖质,而全K和全Mg的含量则显著低于后者,全P含量差异不明显;林冠腐殖质的微生物量C、N和呼吸强度,以及蔗糖酶、脲酶和蛋白酶的活性均显著高于林下地表腐殖质,说明林冠腐殖质是一种具有较高生物活性的有机土类物质,在山地森林生态系统养分循环、林冠附生植物多样性格局形成及其维持方面具有重要的作用.     

补中益气汤联合生物反馈电刺激在产后盆底功能障碍患者的应用研究

目的:研究探讨补中益气汤联合生物反馈电刺激对产后盆底功能障碍患者的临床治疗效果及对其盆底肌肉张力的影响。方法:选择我院就诊的90例产后盆底功能障碍气虚证患者(2017年11月～2018年10月),按照随机数字表法划分为30例/组的A组、B组、C组,A组实施常规盆底肌锻炼,B组采用盆底治疗仪实施生物反馈电刺激治疗,C组实施生物反馈电刺激联合中药补中益气汤治疗,比较三组的疗效、盆底肌力评分、阴道最大收缩压、盆腔器官脱垂、尿失禁、性生活质量评分。结果:(1)组间临床疗效、证候疗效比较,C组的临床总有效率、证候改善总有效率均高于A组、B组(P0.05),而A组与B组之间比较均无统计学差异(P0.05)。(2)治疗后,C组的盆底肌力评分、阴道最大收缩压、性生活质量评分均高于A组、B组(P0.05),A组与B组之间比较均无统计学差异(P0.05)。(3)C组的盆腔器官脱垂、尿失禁等发生率均低于A组、B组(P0.05),而A组与B组比较均无统计学差异(P0.05)。结论:生物反馈电刺激联合补中益气汤治疗可有效改善产后盆底功能障碍患者的盆底肌力和阴道压力,达到良好的临床疗效,有利于预防盆腔器官脱垂、尿失禁的发生,改善其性生活质量。