The effect of floor slope on sub-maximal lifting capacity and technique

Inclined surfaces, where both the lifter and load are on the slope, may be encountered in a jobsite situation. The purpose of this study was to determine if facing up or down a sloped surface (10 degrees and 20 degrees ) would affect maximal acceptable weights of lift (MAWL) using a 10 min psychophysical approach with symmetric freestyle technique at 4 lifts/min. Seventeen healthy men and 18 women determined floor to knuckle height MAWL while facing uphill, downhill, and on a level surface. Motion capture was also performed to examine sagittal plane joint angles and foot placement relative to a milk crate. Slope did not alter MAWL (p>0.05) with the men lifting more than the women in every condition (p<0.001) (25 kg vs. 15 kg, respectively). Foot placement relative to the box was altered by slope such that both horizontal position behind and vertical position below the box increased as slope changed from the downhill to uphill conditions (both p<0.001). Forward torso lean as well as hip, knee, and ankle (plantar) flexion generally decreased as slope changed from the downhill to uphill conditions (all p<0.001). Torso and knee motion appeared to be protected compared to the other joints, changing the least. Though trends were the same in both sexes, interactions did exist in vertical foot position and hip angle (both p0.001). In conclusion, the body is highly adaptive to floor slope, maintaining MAWL at least in the short term. However, while slight technique differences exist between men and women, care should be taken by all when facing uphill due to the tendency to stand further from the load horizontally and when facing downhill due to increased torso lean.     

Cell Development Enhanced Bionic Silk Hydrogel on Remodeling Immune Pathogenesis of Spinal Cord Injury via M2 Polarization of Microglial

Due to the complex spatial-temporal pathophysiology of spinal cord injury (SCI), effective modulation of SCI-specific inflammatory pathogenesis to achieve desirable therapeutic effects on functional recovery still remains challenging. Herein, cell-enhanced photocrosslinked silk fibroin hydrogels with extracellular matrix-mimicking cues of mechanical properties and RGD (Arg-Gly-Asp) signals are gelled in situ to fill the lesion site to modulate injury-induced neuroinflammation and promote neurite regrowth after SCI. The bionic hydrogel system provides biomimetic mechanical cues to promote neuronal differentiation of neural stem/progenitor cells (NPCs) and neurite growth by activating YAP nuclear expression. Importantly, favored by the strong capacity of silk fibroin hydrogels on macrophage/microglia recruitment, NPCs encapsulated hydrogel (NPCs@SFRGD0.1) effectively promotes recruited macrophages/microglia to M2 polarization in the lesion site by releasing S100A4 and thereby remodels the inflammatory microenvironment after SCI. Moreover, NPCs@SFRGD0.1 successfully reduces glial scar formation and accelerates corticospinal tract axon regrowth to improve locomotor recovery. Overall, this work contributes to illustrating the therapeutic mechanism of NPCs development based biomaterial therapies on modulating inflammatory microenvironment and this NPCs enhanced silk fibroin hydrogel provides a promising therapeutic strategy for SCI.     

Driver injury severity outcome analysis in rural interstate highway crashes: a two-level Bayesian logistic regression interpretation

There is a high potential of severe injury outcomes in traffic crashes on rural interstate highways due to the significant amount of high speed traffic on these corridors. Hierarchical Bayesian models are capable of incorporating between-crash variance and within-crash correlations into traffic crash data analysis and are increasingly utilized in traffic crash severity analysis. This paper applies a hierarchical Bayesian logistic model to examine the significant factors at crash and vehicle/driver levels and their heterogeneous impacts on driver injury severity in rural interstate highway crashes. Analysis results indicate that the majority of the total variance is induced by the between-crash variance, showing the appropriateness of the utilized hierarchical modeling approach. Three crash-level variables and six vehicle/driver-level variables are found significant in predicting driver injury severities: road curve, maximum vehicle damage in a crash, number of vehicles in a crash, wet road surface, vehicle type, driver age, driver gender, driver seatbelt use and driver alcohol or drug involvement. Among these variables, road curve, functional and disabled vehicle damage in crash, single-vehicle crashes, female drivers, senior drivers, motorcycles and driver alcohol or drug involvement tend to increase the odds of drivers being incapably injured or killed in rural interstate crashes, while wet road surface, male drivers and driver seatbelt use are more likely to decrease the probability of severe driver injuries. The developed methodology and estimation results provide insightful understanding of the internal mechanism of rural interstate crashes and beneficial references for developing effective countermeasures for rural interstate crash prevention.     

A simulation study on the US rehabilitation service process for patients with modest-to-severe traumatic brain injury

Traumatic brain injury (TBI) is a devastating injury with severe consequences. In this paper, we conduct a simulation study on the commonly implemented care delivery process for TBI rehabilitation in the US, which covers three care categories: inpatient acute, outpatient sub-acute and general residential care. Our investigation is focused on assessing how coverage duration of publicly funded rehabilitation impacts two key system outcomes: sub-acute rehabilitation readmission and total rehabilitation spending. We develop prediction models on the above two outcomes for patients of different conditions. We introduce the notions of forceful transition and medical necessity adjustment, and embed the notions in a state-transition simulation model. Our simulation results suggest that to minimise the care spending, the duration of publicly insured outpatient sub-acute rehab be set smaller than what is currently implemented but not to the point where coverage should be completely removed. Our sensitivity analysis justifies the robustness of our results under variations on model parameters.     

雷击对碳纤维增强型航空复合材料损伤的影响

依据有限元仿真软件ABAQUS,建立碳纤维增强型复合材料(CFRP)层合板雷击损伤热-电耦合有限元仿真模型。利用叠加温度场的方法来近似表示内部受损状态,通过对比实验验证热-电耦合仿真方法的正确性与有效性。利用回归统计分析技术,定量分析雷电参数与CFRP雷击损伤的相关性,并绘制相关曲线。结果表明:雷电流比能是决定CFRP雷击损伤的关键因素,纤维破坏面积、分层面积与比能具有线性相关性,树脂破坏面积、分层厚度与比能具有对数相关性。     

Adventure tourism and adventure sports injury: the New Zealand experience

The primary aims of this study were to establish a client injury baseline for the New Zealand adventure tourism and adventure sport sector, and to examine patterns and trends in claims for injury during participation in adventure activities. Content analysis of narrative text data for compensated injuries occurring in a place for recreation and sport over a 12-month period produced over 15,000 cases involving adventure tourism and adventure sport. As found in previous studies in New Zealand, highest claim counts were observed for activities that are often undertaken independently, rather than commercially. Horse riding, tramping, surfing and mountain biking were found to have highest claim counts, while hang gliding/paragliding/parasailing and jet boating injuries had highest claim costs, suggesting greatest injury severity. Highest claim incidence was observed for horse riding, with female claimants over-represented for this activity. Younger male claimants comprised the largest proportion of adventure injuries, and falls were the most common injury mechanism.     

葡萄贮藏中SO2伤害与活性氧代谢的关系

以耐SO2品种巨峰和不耐SO2品种红地球葡萄为材料,研究了葡萄贮藏中SO2伤害与活性氧代谢的关系,结果表明,SO2伤害葡萄体内活性氧水平,GSH含理和ASP活性增加,SOD和CAT活性降低,与红地球相比,巨峰具有较高的SOD活性和GSH水平,受SO2伤害后,巨峰的ASP活性上升幅度大于红地球,其SOD活性和CAT活性的下降幅度低于红地球。     

大气混合污染物对大鼠肺脏中血红素氧合酶1表达的影响

通过观察大气污染物引起大鼠肺损伤的病理组织学变化,分析肺组织内血红素氧合酶1（HO-1）的表达量的变化,为大气污染所致肺损伤的生物学标记物的研究提供科学依据。实验方法如下：将30只Wistar大鼠,随机分为3个实验组（3d、7d、30d组）和3个对照组（3d、7d、30d组）,对实验组大鼠染尘染毒后提取所有大鼠肺组织,观察其病理组织学变化;RT-PCR技术检测各组肺组织中HO-1的mRNA表达;Western-blot技术检测各组肺组织中HO-1蛋白的表达。结果显示：实验组（7d及30d）的肺组织病理形态学评分显著高于对照组（7d及30d）,实验组（7d及30d）大鼠肺组织HO-1mRNA表达与对照组相比,具有显著性差异（P均〈0.05）。随着吸入大气混合污染物的时间延长,肺组织内的HO-1蛋白表达水平逐渐增高,实验组（7d及30d）与对照组（7d及30d）相比,差异有显著性意义（P〈0.05）。在吸入大气混合污染物后早期（7d）,HO-1转录水平升高。持续吸入混合大气污染物（30d）,大鼠肺组织出现明显的病理组织学变化,HO-1转录水平、蛋白表达水平均比对照组明显升高。得出结论：可将HO-1作为大气混合污染物所致的肺损伤的早期生物学标记物;采取某些手段增加肺组织HO-1的表达,可能会减少混合大气污染物对肺组织造成的损伤。     

An assessment of neck and upper extremity disorders by questionnaire and clinical examination

Abstract

To study the usefulness of a screening questionnaire for neck/upper extremity complaints, 165 women in either repetitive industrial, or mobile and varied work, were studied by the questionnaire and by a detailed clinical physical examination. A total of 94 subjects recorded complaintsin the questionnaire. In 140 subjects findingswere recorded at the examination. Most subjects with findings at the clinical examination of shoulders reported complaints in the questionnaire (sensitivity 80%). For the other anatomical regions, the sensitivity was rather low (42– 65%). For all regions, most subjects without findings reported no complaints (specificity 77–97%). A total of 75 subjects were given clinical diagnoses according to a set of predetermined diagnostic criteria. The capacity of the questionnaire to identify diagnoses of shoulders was higher (sensitivity 92%) than for the other regions (66–79%). Of subjects who did not qualify for diagnosis, a majority (specificity 71–81%) did not report complaints in the questionnaire. We conclude that the questionnaire approach gives a fairly good picture of the neck/upper extremity status of a working female population. However, a clear view of the size of a problem is obtained only by a detailed clinical examination, particularly as regards the neck, elbows and hands, for which the questionnaire gave an underestimate.     

Cryobank of plant genetic resources in Russian Academy of Sciences

Cryopreservation is the most reliable method for long-term storage of plant genetic resources. A review of cell injury by ice crystals and dehydration during a freeze–thaw cycle is given. For successful regeneration of plants and cultures after cryopreservation of their cells, the development of reliable cryopreservation procedure is required including preliminary cultivation, treatment by cryoprotectors, freezing by different methods, thawing and recultivation. Up to now 27 cell lines successfully resumed their growth after storage in liquid nitrogen and preserved their specific features and biosynthetic potential. Besides, shoot tips of 40 cultivars of potato, rose, strawberry and raspberry regenerated plants both in vitro and in vivo after cryopreservation. The longest storage duration was 25 years. Now in liquid nitrogen we continuously store 24 cell strains of rare medicinal plants, shoot tips of seven cultivars of strawberry and raspberry and seeds of 250 endangered plant species collected over all Russian territory.