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To create a safe and effective aerobic dance exercise (ADE) program, the intensity, and difficulty level of each step, and muscle activation during the program must be considered. This study evaluated the muscle activity levels of the lower extremities when major ADE movements were repeated at a fixed speed. The subjects were seven females 21-22 years old who were familiar with the ADE movements. Eleven low impact steps and nine high impact steps representative of the ADE movements were selected, and while the movements were performed, the surface electromyograms (EMG) of six muscles in the lower extremities were measured using a telemeter electromyograph. The EMG data for 10 cycles of each step were full wave rectified and integrated. Then, the average value per unit time was calculated, and normalized (%EMGmax) by the EMG integral value during isometric maximum voluntary contraction (EMGmax). The EMGmax was measured for each of the six muscles to evaluate the muscle activity level, and determine which muscles were activated at higher or lower levels in response to the specific steps. The highest levels of total muscle activity detected in the six muscles were for: double hop, jumping jack, and pendulum. The results of this study may help create ADE programs that consider the differences in muscle activation in the lower extremities.
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Ampakines are a class of pharmacological agents acting as positive modulators of AMPA receptors. Currently, clinical indications studied for ampakines involve many diseases including the respiratory depression and psychoneurosis, etc. The studies using CX516 and CX546 as tool compounds have shown that ampakines could be classified into "high impact ampakines"and "low impact ampakines". The two subclasses of ampakines differ in the chemical structures, influences on receptor dynamics, receptor-ligand bindings, synaptic transmissions, neurotrophin regulations and side effects. According to the available literature, the low impact ampakines have better clinical application prospects than high impact ampakines because of their high safety and good tolerance. The above different characteristics of the two subclasses of ampakines are reviewed in this paper.
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Objective To study effects of different types of high-impact exercises on the increment of bone mineral density (BMD) and bone mineral content (BMC) . Methods Thirty-nine male volunteers, including 13 hoopsters, 13 paratroopers, and 13 common college students as the control, were recruited and divided into two subgroups (subgroup 1:20-22 years old; subgroup 2:23-25 years old). Their BMDs and BMCs on calcaneus, first through fifth metatarsus, hip, and lumbar spine (L1-4) were evaluated. Results The BMC of calcaneus, the first and second metatarsals, total lumbar spine, and total hip in the hoopster group was significantly higher than that in the control group and paratrooper group. The hoopster group obtained statistically higher BMD at the lumbar spine, hip, and femoral neck than the other two groups. However, the BMCs and BMDs of the paratrooper group and control group had no significant differences at almost all measured anatomical locations. Conclusions BMC and BMD are not always in positive correlation with vertical ground reaction forces during normal exercises. Compared with parachuting training, playing basketball as a kind of variable load exercise can effectively increase BMC and BMD, and is more beneficial for reducing the risk of osteoporotic fracture.
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Two randomized controlled trials of acupuncture concerning polycystic ovary syndrome (PCOS) and stress urinary incontinence (SUI) were published simultaneously in the 24th issue, 2017 of The Journal of the American Medical Association (JAMA). A trial involving PCOS indicated that active acupuncture did not increase live birth compared with sham acupuncture; meanwhile, another trial referring to SUI showed that electroacupuncture resulted in less urine leakage compared with sham electroacupuncture. With an eye to the negative and positive results of acupuncture, three pivotal factors should be contemplated: (1) proper illness for acupuncture, that is, a problem need to be solved in current medical science, and acupuncture may really work for it; (2) proper pre-studied primary outcome, which is better be objective and repeatedly measurable to reveal the therapeutic effect of acupuncture truly and objectively; (3) proper sham control, which can blind the patients to the upmost extent with minimal biological effects. Through the publication of clinical trials of acupuncture in high-impact journals in recent years, researchers should have confidence in their clinical trials by pondering over these three pivotal factors.
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Aim: The present study was undertaken to evaluate and compare the impact strength and transverse strength of the high‑impact denture base materials. A conventional heat polymerized acrylic resin was used as a control. Materials and Methods: The entire experiment was divided into four main groups with twenty specimens each according to denture base material selected Trevalon, Trevalon Hi, DPI Tuff and Metrocryl Hi. These groups were further subgrouped into the two parameters selected, impact strength and flexural strength with ten specimens each. These specimens were then subjected to transverse bend tests with the help of Lloyds instrument using a three point bend principle. Impact tests were undertaken using an Izod–Charpy digital impact tester. Results: This study was analyzed with one‑way analysis of variance using Fisher f‑test and Bonferroni t‑test. There was a significant improvement in the impact strength of high‑impact denture base resins as compared to control (Trevalon). However, in terms of transverse bend tests, only DPI Tuff showed higher transverse strength in comparison to control. Trevalon Hi and Metrocryl Hi showed a decrease in transverse strength. Conclusions: Within the limits of this in vitro study, (1) There is a definite increase in impact strength due to the incorporation of butadiene styrene rubber in this high strength denture base materials as compared to Trevalon used as a control. (2) Further investigations are required to prevent the unduly decrease of transverse strength. (3) It was the limitation of the study that the exact composition of the high‑impact resins was not disclosed by the manufacturer that would have helped in better understanding of their behavior.
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Introduction: Fracture of an acrylic resin complete denture base after aging, poses problem for patients, dentists and dental laboratory technicians. This study was performed to determine the effect of thermocycling on the flexural strength of a commercially available, heat-polymerized acrylic denture base material reinforced with glass fibers, carbon fibers, aramid fibers and high (HI) impact resins. Materials and Methods: Forty specimens were made of similar dimension from five groups of materials. Each group had eight specimens. A commercially available heat polymerized P.M.M.A denture base resin was selected as control and PMMA reinforced with glass, carbon, aramid fibres and HI impact resin were compared. All specimens were then subjected to thermocycling before testing. Flexural strength was evaluated with universal testing machine. The results were analyzed with Analysis of Variance (ANOVA) followed by Turkey HSD test. Results: All reinforced specimens and HI impact resins showed better flexural strength than the conventional acrylic resin after thermocycling. Specimens reinforced with glass fibers showed the highest flexural strength, followed by HI impact resin, carbon fibers and aramid fibers. After artificial aging, a significant improvement in the flexural strength of conventional acrylic resin was observed when it was reinforced with glass fibers. Conclusion: Within the limitations of this study, incorporation of 2% by weight of glass fibre in PMMA resin exhibited statistically significant maximum flexural strength followed by high impact resin, carbon, polyaramid reinforced P.M.M.A denture base resin. These can readily be used in the fabrication of dentures subjected to heavy masticatory loads.
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Academic Papers published with hospital-based data between 2004～2013 on top 5％ impact factor journals in all JCR 184 subject categories were reviewed in the study.All of them were differentiated to 3 groups according to the ways of collaboration between authors.The distribution of these papers institutions and subjects were studied and questionnaire survey to hospitals was also used.It's found that the multidisciplinary collaborating work is a key factor to publish high impact papers which showed the central tendency in subjects and institutions levels,active management measures on interdisciplinary development will contribute the outcome of high impact papers.
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As modalidades esportivas de alto impacto podem produzir um aumento exagerado e frequente na pressão intra-abdominal, um dos fatores desencadeadores da incontinência urinária de esforço (IUE) em atletas. Foi realizado um estudo com 20 atletas, sendo 10 de basquetebol e 10 de voleibol, do tipo quantitativo, observacional, transversal e comparativo, no qual foi comparada a capacidade de contração do assoalho pélvico (AP) entre atletas de voleibol e basquetebol, e então correlacionadas com sintomas de IUE. A avaliação das atletas foi composta por um questionário, a avaliação funcional do assoalho pélvico (AFA) e avaliação da capacidade de contração do AP através do Biofeedback Eletromiográfico Fênix®. Após a avaliação, não foi observada diferença estatisticamente significante com relação à capacidade de contração do assoalho pélvico entre atletas de basquetebol e voleibol; porém, ambas as modalidades apresentaram atletas com relatos de perda involuntária de urina mediante esforço físico, com maior proporção no grupo de atletas de basquetebol.
High impact sports can produce exaggerated and frequent increase of the intra-abdominal pressure, one of the triggering factors of stress urinary incontinence (SUI) in athletes. The study was carried out with 20 athletes; 10 of these being basketball and 10 volleyball athletes. The study was quantitative, observational, cross on and comparative, in which the ability of contraction of the pelvic floor (PF) among athletes in volleyball and basketball was compared, and later correlated with symptoms of stress urinary incontinence. The evaluation of the athletes was composed of a questionnaire, the functional evaluation of the pelvic floor (FEPF) and assessment of the ability of contraction of the PF through the Phoenix Electromyographic Biofeedback®. Statistically significant differences were not observed after the evaluation regarding the ability of contraction of the pelvic floor between basketball and volleyball athletes, but both groups presented athletes with reports of involuntary loss of urine due to physical exertion, with higher proportion in the group of basketball athletes.
Subject(s)
Humans , Female , Young Adult , Basketball , Urinary Incontinence, Stress/etiology , Muscle Contraction , Pelvic Floor , VolleyballABSTRACT
Objective To reveal the research trends and hotspots of China's liver neoplasms literature from 2005 to 2010. Methods A bibliometric analysis was made based on the results of retrieving from the Chinese Medical Citation Index (CMCI). Results The number of China' s liver neoplasms literature increased regularly in the last 5 years. The fund articles accounted for 30% of total articles. This paper reports the highly cited articles, authors, institutions and journals. The top 5 provinces of publishing articles are Guangdong, Shanghai, Jiangsu, Shandong and Beijing. There are some major aspects of liver neoplasms research, such as treatment modalities, analysis of causes of disease, evaluation after radiation therapy, and experimental research. 3-dimensional conformal radiotherapy, radiofrequency ablation and chemoembolization have been becoming research hotspots. Conclusions The researches on liver neoplasms have been widely and deeply developing in China. A lot of research progresses were made. As the higher mortality of liver neoplasms, the research of comprehensive treatment is to be the further trend.
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OBJECTIVES: To evaluate the effect of reinforcing high-impact acrylic resin (Metrocryl HI)with zirconia powder in two different concentrations on the transverse strength, impact strength,surface hardness, water sorption and solubility. MATERIALS AND METHODS: Fifteenspecimens were prepared for each test, five from Metrocryl HI resin as control, five others wereprepared from the 5% zirconia-modified Metrocryl HI resin, and another five specimens wereprepared from the 15% zirconia-modified Metrocryl HI resin. Transverse strength was assessedwith a 3-point bending test using a screw-driven testing machine. For the impact strength, a Charpytester was used. Surface hardness testing was conducted using Vickers tester. The water sorptionand solubility test was performed according to International Standards Organization specificationNo. 1567 for denture base polymers. Micro-structural examination of two specimens, onerepresenting each ZrO2 concentration group, was carried out using scanning electron microscopy.RESULTS: As determined by ANOVA and Bonferroni multiple comparison tests, the additionof zirconia resulted in a highly significant increase in transverse strength of high-impact acrylicresin (P< 0.001). This increase was proportional to the concentration of zirconia. No significantdifference was detected in each of impact strength, surface hardness and water solubility (P>0.05). Although a significant increase in water sorption was demonstrated (P< 0.05), still its meanvalue lies within the specification limits. CONCLUSIONS: Reinforcement of high-impact acrylicresin with zirconia powder increases its transverse strength significantly.
OBJETIVOS: Avaliar o efeito do reforço de resina acrílica de alto impacto (Metrocryl HI) compó de zircônia em duas diferentes concentrações, a forças transversais, de impacto, dureza desuperfície, absorção de água e solubilidade. MATERIAIS E MÉTODOS: 15 espécimes forampreparados para cada teste, sendo cinco com resina Metrocryl HI como controle, cinco preparadoscom resina modificada em 5% e cinco preparados com resina modificada em 15%. As forçastransversas foram determinadas com um teste de dobramento por máquina de parafuso. Para asforças de impacto, um testgador Charpy foi usado. A dureza de superfície foi verificada comteste de Vickers. A absorção de água foi testada de acordo com especificações n.o 1 567 daOrganização Internacional de Standards para polímeros de bases de dentaduras. O examemicroestrutural dos dois espécimes, um representando cada grupo de concentração de ZrO2, foiefetuado usando microscopia eletrônica. RESULTADOS: Testes ANOVA e Bonferroni decomparação múltipla demonstraram que houve um aumento significante na resistência transversaldas resinas de alto impacto (P<0.05). Este aumento foi proporcional na concentração de zircônia.Não houve diferenças significativas na resistência ao impacto, na dureza superficial e nasolubilidade na água (P>0.05), permanecendo dentro dos limites das especificações.CONCLUSÕES: O reforço de resinas de alto impacto com zircônia em pó aumentasignificativamente a resistência transversal.