RESUMO
In order to examine the effects of work surface height (WSH) on muscle activity, posture and discomfort during simulated pipetting, an experimental study was conducted using electromyography, electrogoniometry, video techniques and also qualitative data. The experimental design consisted of one independent variable (WSH with six heights) and 13 dependent variables. The levels of muscle strain and discomfort were significantly lower at the shoulder when the WSHs were low but thumb muscle activities and neck flexion levels were markedly higher at these WSHs compared to higher WSHs. To reduce shoulder strain, without raising thumb and neck strain beyond acceptable limits, the findings suggest that the height of a laboratory workbench should be at the level of the pipette tip when held in a standing position with the hand at elbow height. It was also found that pipetting should not be done in a seated posture. PRACTITIONER SUMMARY: An experimental study was conducted to examine the effects of work surface height on upper extremity muscle activity, posture and discomfort during simulated pipetting. The findings suggest that the laboratory workbench height should be at the pipette-tip level when held in a standing position with the hand at elbow height.
Assuntos
Decoração de Interiores e Mobiliário , Laboratórios , Músculo Esquelético/fisiologia , Doenças Musculoesqueléticas/prevenção & controle , Doenças Profissionais/prevenção & controle , Postura/fisiologia , Adulto , Eletromiografia , Ergonomia , Feminino , Humanos , Masculino , Pescoço/fisiologia , Saúde Ocupacional , Extremidade Superior/fisiologia , Adulto JovemRESUMO
Exposure to ergonomic risk factors has been reported for laboratory workers over decades. However, these exposures are not well characterized with respect to the type of laboratory or work organization. This study compared biomechanical exposure to upper extremity (UE) postures and hand activity levels (HALs) in general hospital laboratories by job, work, and laboratory type. The study used observational data gathered using a revised version of the Posture, Activity, Tools, and Handling (PATH) method, generating frequencies of categorized exposures. Eighteen workers were observed in 11 job titles (seven laboratories) in a single hospital by two investigators over a 7 month period. A taxonomy was constructed to categorize the extent to which the laboratory operations were automated. Overall, there were markedly high exposures to postural strain for the distal UE, especially wrist/forearm deviation (73% of observations), gross grasp (71%), and pinch grip (49%). For the HAL categories, 61% of the observations were in the moderate range (3.3-<6.7). Shoulders and elbows tended to remain in the neutral postural range. Posture frequencies were similar among the job categories studied and laboratory types. HAL was higher when the hand was in a pinch grip. Manual operations represented a higher proportion of work time than semi-automated or automated operations. Biomechanical exposure can be documented more extensively and diversely when using the revised PATH approach along with the taxonomy, with respect to exposure variables, such as the type of job, work, or organization in the industry including the hospital laboratories.
Assuntos
Laboratórios Hospitalares , Doenças Musculoesqueléticas , Ergonomia , Humanos , Doenças Musculoesqueléticas/epidemiologia , Doenças Musculoesqueléticas/etiologia , Fatores de Risco , Extremidade SuperiorRESUMO
In this paper, we propose a platform for an insect-like flapping winged micro aerial vehicle with a resonant wing-driving system using extension springs (FMAVRES). The resonant wing-driving system is constructed using an extension spring instead of the conventional helical or torsion spring. The extension spring can be mounted more easily, compared with a torsion spring. Furthermore, the proposed resonant driving system has better endurance compared with systems with torsion springs. Using a prototype FMAVRES, it was found that torques generated for roll, pitch, and yaw control are linear to control input signals. Considering transient responses, each torque response as an actuator is modelled as a simple first-order system. Roll, pitch, and yaw control commands affect each other. They should be compensated in a closed loop controller design. Total weight of the prototype FMAVRES is 17.92 g while the lift force of it is 21.3 gf with 80% throttle input. Thus, it is expected that the new platform of FMAVRES could be used effectively to develop simple and robust flapping MAVs.
RESUMO
Deep-blue organic light-emitting diodes (OLEDs) with nearly 5% external quantum efficiency were demonstrated using a 1,4-(dinaphthalen-2-yl)-naphthalene (DNN) host. The 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl (BCzVBi) dopant that was used in this experiment effectively accepted energy from the DNN host via Förster energy transfer because the photoluminescence spectrum of the DNN host showed better spectra overlap with the ultraviolet-visible (UV-vis) absorption spectrum of the BCzVBi dopant than the photoluminescence spectrum of the 2-methyl-9,10-bis(naphthalen-2-yl)anthracene host did. Moreover, the DNN host had a higher energy bandgap (3.5 eV) than the BCzVBi dopant did (3.0 eV), while the MADN host had the same energy bandgap as the BCzVBi dopant. The optimized deep-blue device also had ETL of bis-(2-methyl-8-quinolinolate)-4-(phenylphenolato)aluminium which showed smoother sigma of 0.6 nm and higher Tg of 92 degrees than those of 4,7-diphenyl-1,10-phenanthroline (14.8 nm and 62 degrees C). The deep-blue device exhibited a peak current efficiency of 5.68 cd/A, a peak external quantum efficiency of 4.89%, and Commission Internationale d' Eclairage coordinates of (0.15, 0.13).
RESUMO
BACKGROUND: Globally, smoking is one of the biggest challenges in public health and is a known cause of several important diseases. Influenza is preventable via annual vaccination, which is the most effective and cost-beneficial method of prevention. However, subjects who smoke have some unhealthy behaviours such as alcohol, low physical activity, and low vaccination rate. In this study, we analyzed the relationship between smoking status and factors potentially related to the influenza vaccination coverage rate in the South Korean adult population. METHODS: The study included 13,565 participants aged >19 years, from 2010 to 2012 from the Korea National Health and Nutrition Examination Survey data. Univariate analyses were conducted to examine the association between influenza coverage rate and related factors. Multivariate analysis was obtained after adjusting for variables that were statistically significant. RESULTS: The overall vaccination rate was 27.3% (n=3,703). Older individuals (P<0.0001), women (P<0.0001), non-smokers (P<0.0001), light alcohol drinkers (P<0.0001), the unemployed (P<0.0001), and subjects with diabetes mellitus (P<0.0001), hypercholesterolemia (P<0.0001), and metabolic syndrome (P<0.0001) had higher influenza vaccination coverage than the others. In multivariate analyses, current smokers and heavy smokers showed lower vaccination rates (odds ratio, 0.734; 95% confidence interval, 0.63-0.854). CONCLUSION: In the current study, smokers and individuals with inadequate health-promoting behaviors had lower vaccination rates than the others did.
RESUMO
OBJECTIVES: The aim of this study was to investigate whether osteoporosis is more prevalent in elderly Korean people who have had a stroke and whether the association differs by sex. STUDY DESIGN: A total of 3806 elderly subjects (1951 men and 1855 women) from the Korea National Health and Nutrition Examination Survey were included in this study. Stroke history was determined by self-administered questionnaire. Bone mineral density (BMD) was measured at the lumbar spine, total hip, and neck of the femur using dual-energy X-ray absorptiometry. It was categorized as normal, osteopenia, or osteoporosis. RESULTS: In men who had had a stroke, the prevalence of osteoporosis was greater than that of both osteopenia and normal BMD, and the prevalence of osteopenia was greater than that of normal BMD (p<0.001). However, there were no significant differences in BMD level among women who had had a stroke. Men who had had a stroke undertook less vigorous exercise and moderate-or-vigorous exercise than did men who had not had a stroke (p=0.002 and 0.030, respectively). After adjusting for all covariates, the mean BMD at the lumbar spine, total hip and neck of the femur was lower in men who had had a stroke than in men who had not (p=0.034, 0.002, and 0.005, respectively). There were no significant differences in mean BMD at any of the three sites between women who had and women who had not had a stroke. CONCLUSION: Men who have had a stroke have a higher prevalence of osteopenia and osteoporosis, and have lower BMD at the total hip and femur neck than men who have not had a stroke.
Assuntos
Densidade Óssea/fisiologia , Doenças Ósseas Metabólicas/epidemiologia , Osteoporose/epidemiologia , Caracteres Sexuais , Acidente Vascular Cerebral/epidemiologia , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Doenças Ósseas Metabólicas/diagnóstico por imagem , Estudos Transversais , Feminino , Fêmur/diagnóstico por imagem , Colo do Fêmur/diagnóstico por imagem , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Osteoporose/diagnóstico por imagem , Peptídeos Cíclicos , Prevalência , República da Coreia/epidemiologia , Inquéritos e QuestionáriosRESUMO
Wound healing is composed of a complex process that requires harmonies of various cell populations where fibroblasts play the main role. Oligomeric procyanidins (OPC) are main components of grape (Vitis vinifera) seed extracts, and recent studies showed OPC's effects on inflammation, cell migration, and proliferation. We investigated the effect of OPC on fibroblasts to regulate wound healing process. Human dermal fibroblast known as Hs27 cells were treated with various concentrations of OPC (0, 2.5, 5, 10, and 20 µg/µl). Cell cytotoxicity was evaluated by the Cell Counting Kit assay, and the expression levels of secreted procollagen were analyzed. Procollagen levels in OPC treated cells exposed to transforming growth factor beta 1 (TGF-ß1) or ascorbic acid were evaluated using Western blot and immunocytochemistry. Relative mRNA expressions of procollagen, molecular chaperone such as HSP47, P4H were determined by real-time PCR in OPC treated cells. OPC showed no cytotoxicity on Hs27 cells at every concentration but inhibited procollagen secretion in a dose-dependent manner. The inhibitory effect also appeared under TGF-ß1 induced collagen overproduction. Immunocytochemistry showed that higher levels of intracytoplasmic procollagen were accumulated in TGF-ß1 treatment group, whereas ascorbic acid induced a release of accumulated procollagen under OPC treatment. The mRNA expressions of procollagen, molecular chaperone were not affected by OPC, but procollagen level was increased when exposed to TGF-ß1. OPC inhibits procollagen secretion from fibroblasts with no effects on cell proliferations even under the environment of TGF-ß1-induced collagen overproduction. OPC could regulate the diseases and symptoms of abnormal overabundant collagen production.
RESUMO
Job hazard analyses were conducted to assess exposure to musculoskeletal disorder (MSD) risk factors in seven workers of three dry-cleaning establishments. In accordance with the Washington State Ergonomics Rule, the analyses were performed in two separate steps: (1) observation and checklist approaches were made to identify a "caution zone job" in the seven workers' pressing operations across the three shops; and (2) detailed posture and motion analyses were undertaken to determine a "MSD hazard" in one worker's operation using a video technique. One "caution zone job" was identified and it was the pressing operation job in which five physical risk factors were found in the pressing operations. The detailed analyses confirmed that one "MSD hazard", i.e., awkward posture in shoulders, was prevalent in the pressing operations of the three dry-cleaning facilities. It would be desirable to reduce MSD risk factors including awkward shoulder posture in the dry-cleaning industry.
RESUMO
Three occupational safety and health (OSH) activities, one international and two national workshops, were documented as part of OSH activities conducted under the International Labor Organization/Korea Partnership Program in the year 2011-2012. This study aimed to provide information on what the three OSH activities were implemented and how they contributed to the improvement of OSH in Asian countries. The international workshop was useful for the participants to understand a variety of information on OSH as well as participatory action-oriented training (PAOT) approaches at the regional and global levels. The two national workshops were practical for participants to strengthen their knowledge and skills on the PAOT at the enterprise and national levels. The study shows that the three OSH activities contributed to the understanding of the participants on OSH and PAOT, and that the activities promoted the improvement of OSH across countries in Asia.
RESUMO
Over years it has been increasingly concerned with how upper extremity musculoskeletal disorders (UEMSDs) are attributed to psychosocial job stressors. A review study was conducted to examine associations between UEMSDs and psychosocial work factors, and to recommend what to consider for the associations. For studies in which the job demand-control-support (DCS) model or its variables were specifically employed, published papers were selected and reviewed. A number of studies have reported relationships between UEMSDs symptoms and psychosocial exposure variables. For example, the findings are: higher numbness in the upper extremity was significantly attributed to by less decision latitude at work; work demands were significantly associated with neck and shoulder symptoms while control over time was associated with neck symptoms; and the combination of high psychosocial demands and low decision latitude was a significant predictor for shoulder and neck pain in a female working population. Sources of bias, such as interaction or study design, were discussed. UEMSDs were shown to be associated with psychosocial work factors in various studies where the job DCS model was addressed. Nonetheless, this review suggests that further studies should be conducted to much more clarify the association between UEMSDs and psychosocial factors.
RESUMO
This study examined the inter-rater reliability of expert observations of ergonomic risk factors by four analysts. Ten jobs were observed at a hospital using a newly expanded version of the PATH method (Buchholz et al. 1996), to which selected upper extremity exposures had been added. Two of the four raters simultaneously observed each worker onsite for a total of 443 observation pairs containing 18 categorical exposure items each. For most exposure items, kappa coefficients were 0.4 or higher. For some items, agreement was higher both for the jobs with less rapid hand activity and for the analysts with a higher level of ergonomic job analysis experience. These upper extremity exposures could be characterised reliably with real-time observation, given adequate experience and training of the observers. The revised version of PATH is applicable to the analysis of jobs where upper extremity musculoskeletal strain is of concern.