对肌肉运动拉伤防治方法的探索

文中对学校体育运动过程中,较为普遍的一种运动损伤:肌肉拉伤,进行系统研究,对其发生的过程和机理进行了较为详尽的剖析、描述,并且对于运动过程中肌肉产生拉伤后的应急方式,做了较为细致的分析,本研究不仅为学校体育运动过程中的肌肉拉伤情况,提供解决方法,同时,对于从事锻炼和运动训练所引发的肌肉拉伤,也可以提供适当的参考与帮助.     

一次空压机漏油事故的分析与处理

本文对空压机在生产中出现的一次设备漏油事故发生过程和处理方法进行了较为详细的介绍,并对产生的原因进行了分析。     

井喷中钻井液技术的预防和处理措施

油气钻探过程中,地层中承压的流体失去控制,喷出井口或是窜至其它低压地层里的现象称为井喷,它是钻探施工过程中较为常见的恶性事故。本文根据井喷发生根本原因,从钻井液的角度来阐述井喷发生的征兆,并提出预防和处理的方案。     

模拟烟气中气态痕量元素污染物发生方法的研究现状

目前燃煤电厂对于SO₂、NO_x和PM等主要污染物已经有较为成熟的控制方法,但针对具有长期环境危害性的痕量污染物尚缺乏有效的排放控制手段。为全面掌握痕量污染物在煤燃烧过程中的释放、迁移和转化规律并开发相应的控制技术,建立稳定可靠的模拟烟气痕量污染物发生方法是开展相关研究的前提条件。通过文献调研,对常见痕量污染物的四种发生方法进行了总结、归纳和对比:溶液蒸发法较为简单易用,但产物中易含有副产物,这些副产物会带来一定的影响;燃烧法产生的痕量污染物最接近实际情况,但受实验条件影响较大,并且产物成分较为复杂;升华法获得的产物浓度较为准确,但适用范围较窄,仅用于某几种气态痕量污染物的发生;氢化物氧化法可准确地控制产物的发生速率,但也仅适用于少量痕量污染物,并且装置较为复杂。分析比较了不同方法的适用情形,最后提出多种方法联用的思路以期得到更加接近实际情形并且成分可控的结果。      

非煤矿山井下电气设备保护接地管理分析

随着科学技术的发展,大量的电气设备在矿产开采过程中得到了应用,电气设备的使用有效提高了矿山开采的自动化和机械化水平,能够减少矿山开采过程中人力资源的消耗,也能有效提高矿山开采的稳定性和安全性。在非煤矿井下矿山的开采过程中,倘若电气设备存在运行故障,会对矿山开采人员造成生命威胁。由于井下矿山开采条件较为恶劣,且地面较为潮湿,电气设备在使用过程中需要经常移动,这就要求我们要做好矿山开采机电设备的接地保护工作,这样才能有效减少矿山开采安全事故的发生。接下来本文在研究过程中,就对非煤矿山井下电气设备接地保护的必要性以及具体的管理措施进行分析。     

基于Arduino的电解铝多功能天车的防撞系统的设计研究

多功能天车发生碰撞的问题在铝电解生产过程中时有发生,直接关系到铝电解生产的平稳运行。本文就现有终端限位及机械缓冲器存在的缺陷,提出一套电气防撞系统。首先就目前应用较为广泛的几种测距方式进行比较,其次阐述了设计过程中需要解决的问题及该防撞系统的工作原理;设计了以Arduino数据采集器为基础的防撞系统,利用激光测距方式实时测量多功能天车距离,达到自动报警、减速、停止运行,消除了作业过程中发生撞击的事故,提高了大车运行安全性。     

超前支护在采矿工程中的应用探究

近些年来我国科学技术不断进步,社会主义现代化建设性也越来越好,各行各业的发展都需要着大量的矿产资源,我国的各大矿井生产力水平也得到了不断的提升。我国地大物博,有非常广阔的矿产资源,然而在实际的矿产资源开采过程中也经常发生着各种安全事故,尤其是巷道的生产过程事故率越来越高。在矿产资源开采过程中出现事故的原因有多种多样,较为常见的是巷道顶板并没有进行有效的支护,如果不能够及时确定顶板的稳定性,后期将会造成较大的隐患。超前支护技术在当前的采矿工作过程中较为常见,本文就关于当前超前支护在实际采矿工程中的应用进行了简要的分析和建议。     

浅析高陡岩质边坡地质灾害勘查

高陡岩质边坡地层岩性的金属成分往往较为复杂,一些特殊金属会让岩质的风化与卸荷作用较为剧烈。对于高陡岩质边坡的开挖,一般在进行作业过程中,如果遇到的地质条件较为复杂,那么高陡岩质边坡或所在的山区,就有可能形成严重的灾害现象,从而对整个地区的经济产生巨大的损失。因此,对于政府部门而言,高陡岩质边坡作业安全需要强抓不懈。高陡岩质边坡的地质灾害的勘查,可以有效的降低高陡岩坡自然灾害发生的几率。本文主要针对高陡岩质边坡主要事项进行阐述,希望在整个高陡岩质边坡的施工中,尽可能的降低地质灾害发生的几率,提升安全性能。     

离子型稀土矿浸出过程微细颗粒迁移规律及调控

离子型稀土矿在浸出过程中浸出剂与矿石表面水合机制较为复杂,颗粒间的桥式胶结因离子吸附交换过程中存在多种作用力与分散作用而容易发生断裂,从而使微细颗粒发生迁移和重新排列,并在孔喉处沉淀,产生堵塞现象,影响离子型稀土的浸出效率。为揭示离子型稀土矿在原地浸出过程中微细颗粒的迁移规律,并找到适宜的调控方法,以龙南足洞离子型稀土矿为研究对象,采用实验室柱式溶浸法,考察了浸出剂质量浓度、黏度、流速、水力梯度、矿体高度及矿体含水率对微细颗粒迁移的影响。结果表明,离子型稀土矿浸出过程微细颗粒的迁移是影响浸出效率的重要因素之一。在外力的作用下,微细颗粒在浸出过程中易随浸出剂发生迁移运动。当调控浸出剂质量浓度低于4%,浸出剂黏度不超过1.5 mPa?s,水力梯度小于0.75,浸出剂流速低于3 mL/min,原矿含水量大于11%时,矿体中微细颗粒迁移率较低,矿体渗透性保持良好,有利于浸出液的渗流和稀土离子的浸取。     

角钢成品辊断辊原因分析

在轧制角钢过程中,成品辊发生断裂的现象时有发生。一般情况下,轧辊断裂都发生在凹轧槽,而凸轧槽很少断裂。角钢成品辊的断裂与其孔型形状和受力特点有关。本文从上述两方面对轧制角钢的成品辊发生断裂进行分析,并给出断裂判据。 1 角钢成品辊的断裂形式角钢成品辊的材质为球墨铸铁,属脆性材料。轧辊在辊身部位断裂几乎都发生在凹轧槽的最底部,即轧槽的尖角处。而且在轧制过程中,突然发生断裂,轧辊的断口较为平齐。通过对某轧钢厂φ250轧机轧制3~#角钢的成品辊断裂后的观察,可见在轧辊断裂的横断面最边缘一周有一宽     

Management practices associated with low, medium, and high somatic cell counts in bulk milk

Management practices associated with bulk milk somatic cell counts (SCC) were studied for 201 dairy herds grouped into three categories according to bulk milk SCC. The cumulative production of fat-corrected milk over 305 d of lactation and category for bulk milk SCC were highly correlated; herds within the low category had the highest milk production. Differences in bulk milk SCC among the categories were well explained by the management practices studied. This correlation was not only true for the difference between the high (250,000 to 400,000) and low (< or = 150,000) categories for bulk milk SCC but also for the difference between the medium (150,000 to 250,000) and low categories and the high and medium categories. Management practices that are known to be important for herds in the high category for bulk milk SCC, such as dry cow treatment, milking technique, postmilking teat disinfection, and antibiotic treatment of clinical mastitis, were also found to be important in the explanation of the difference between herds in the medium and low categories for bulk milk SCC. More attention was paid to hygiene for herds in the low category than for herds in the medium or high category. Supplementation of the diet with minerals occurred more frequently for cows in the low category for bulk milk SCC than for cows in the medium and high categories.     

Reliability of serum hormones in premenopausal and postmenopausal women over a one-year period

Serum hormones have been intensively investigated in association with several chronic diseases, but limited information exists on the reliability of a number of hormone determinations. The one-year reproducibility of dehydroepiandrosterone sulfate (DHEAS), total and free testosterone, total estradiol, insulin, C-peptide, and prolactin was studied in 60 premenopausal and 47 postmenopausal women recruited in Varese province, Italy, 1991-1992. The hormonal determinations were made in blood samples collected twice, one year apart, after 12-h fast, in the same month, day, and hour and for premenopausal women on the same day of the luteal phase of the menstrual cycle. Samples from the first drawing were stored at -80 degrees C. Samples from both drawings were assayed simultaneously and in blind fashion. Total estradiol in postmenopause was not evaluated for limitation in the sensitivity of the laboratory method. The intraclass correlation coefficient in premenopausal women was 0.85 for DHEAS, 0.60 for total testosterone, 0.66 for free testosterone, 0.81 for insulin, 0.83 for C-peptide, 0.40 for prolactin, and 0.06 for total estradiol. In postmenopausal women, the coefficient was 0.90 for DHEAS, 0.88 for total testosterone, 0.71 for free testosterone, 0.67 for insulin, 0.73 for C-peptide, and 0.18 for prolactin. These data indicate that total estradiol measured during the luteal phase has a poor intraindividual reproducibility over time, and these findings may have important implications in studies of hormones in the etiology of chronic disease.     

Relational self-worth: differences in perceived worth as a person across interpersonal contexts among adolescents

Between 1988 and 1991, 644 serum samples were collected from 480 grizzly bears (Ursus arctos horribilis) and 40 black bears (Ursus americanus) from Alaska, United States of America, and were tested for selected canine viral infections and zoonoses. Antibody prevalence in grizzly bears was 0% for parvovirus, 8.3% (40/480) for distemper, 14% (68/480) for infectious hepatitis, 16.5% (79/480) for brucellosis, 19% (93/480) for tularaemia and 47% (225/478) for trichinellosis. In black bears, prevalence ranged from 0% for distemper and parvovirus to 27.5% for trichinellosis and 32% for tularaemia. Antibody prevalence for brucellosis (2.5%) and tularaemia (32%) were identical for grizzly bears and black bears from the geographical area of interior Alaska. Links between differences in prevalence and the origin of the grizzly bears were observed. Antibodies to canine distemper virus and infectious hepatitis virus were mainly detected in grizzly bears from Kodiak Island and the Alaskan Peninsula. Brucellosis antibodies were prevalent in grizzly bears from western and northern Alaska, whereas tularaemia antibodies were detected in grizzly bears from interior Alaska and the Arctic. There was a strong gradient for antibodies to Trichinella spp. from southern to northern Alaska. For most diseases, antibody prevalence increased with age. However, for several infections, no antibodies were detected in grizzly bears aged from 0 to 2 years, in contrast to the presence of those infections in black bears. Grizzly bears served as excellent sentinels for surveillance of zoonotic infections in wildlife in Alaska.     

Desire for control and achievement-related behaviors.

Tested a model that describes the relation between individual differences in the general desire to control events and performance in achievement-related tasks in 6 experiments with 304 undergraduates. All Ss were administered a desirability of control scale and this variable was tested in relationship to achievement-related behavior (aspiration level, response to challenge, persistence, and attributions for success and failure) outlined in the model. Results show that Ss high in the desire for control displayed higher levels of aspiration, had higher expectancies for their performances, and were able to set their expectancies in a more realistic manner than were Ss low in the desire for control. Ss high in desire for control were also found to respond to a challenging task with more effort and to persist longer at a difficult task than were Ss low in desire for control. Finally, a pattern of attributions for success and failure was uncovered for Ss high in desire for control that has been associated with high achievement levels. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Non-invasive measurement of pulsatile vessel diameter change and elastic properties in human arteries: a methodological study

A recently developed ultrasound phase-locked echo-tracking system makes it possible to measure non-invasive pulsatile vessel diameter changes, and, in combination with blood-pressure measurement, to calculate pressure strain elastic modulus (Ep) and stiffness (beta). The reproducibility in measurements of pulsatile diameter changes with this system was evaluated. Also the precision of indirect blood-pressure measurements, as compared to the simultaneously measured intra-arterial blood pressure was tested. The resulting reproducibility in pressure strain elastic modulus (Ep) and stiffness (beta) was evaluated. Intra-observer variabilities in measuring pulsatile diameter changes were 16% for the abdominal aorta, 10% for the common carotid artery, and 15% for the common femoral artery, respectively. Intra-observer variabilities for Ep and beta were 21% for both in the abdominal aorta, 17% for both in the common carotid artery, and 18% for both in the common femoral artery, respectively. There were only small differences in indirect and direct measurement of systolic blood pressure, whereas indirect blood pressure measurement systematically overestimated the diastolic blood pressure, on average by 20%. The variabilities in indirect blood pressure measurements were 2% for the systolic and 3% for the diastolic blood pressure, respectively. Inter-observer variability in the investigation of the common carotid artery was 10% for the pulsatile diameter changes, and 21% and 23% for Ep and beta, respectively. Thus, the echo-tracking system represents a reliable system for estimation of pressure strain elastic modulus and stiffness. However, Ep and beta are systematically underestimated by 25-30%, when used in combination with indirect blood pressure measurements.     

Ten-year linear trends in reproduction and wool production among inbred and noninbred lines of Rambouillet, Targhee, and Columbia sheep

To investigate the value of creating inbred lines for genetic improvement of sheep, 54 inbred, 1 randombred control, and 3 noninbred control lines were evaluated for lamb and wool production. Results were based on 19,438 dam and 23,625 lamb records from Rambouillet (R), Targhee (T), and Columbia (C) sheep collected over 9 yr (for T and C) and 10 yr (for R), starting in 1954. Average inbreeding in the inbred lines during the period was near 25% for lambs and 20% for ewes. The general trend in inbred lines for litter weight weaned (120 d) and number weaned (net reproductive rate), per ewe exposed to breeding, was downward as inbreeding increased. Trends in fleece weight generally also were down, regardless of concomitant increases in body weight. Declines were most pronounced in two lines developed by rapid inbreeding. Reproductive merit in the R and C noninbred controls also declined, but the declines were less than those for most inbred lines. Although the T noninbred control declined in fleece weight, trends for fleece weight in the R and C controls were positive and significantly different from the negative trends in the inbred lines. For the randombred control, slight downward trends in litter weight and number weaned were less (P < .05) than those for most inbred lines, indicating genetic declines in these traits for most inbred lines. Direct selection for an index of overall phenotypic merit, recurrent selection for combining ability for overall merit, and direct selection for body type, clean fleece weight, or staple length were all ineffective in preventing a decline in reproductive merit. Ending means (last 2 yr of production) revealed that litter weight weaned in the control groups of each breed was clearly superior to that in most inbred lines. Controls also were typically superior for fleece and body weight. Not one of the 54 inbred lines was superior (P < .05) to its respective noninbred control in weight of lamb weaned or net reproductive rate. Only four of the inbred lines were superior to the noninbred controls in fleece weight. These results, after at least 23 yr of development for most lines, reflect little encouragement for the costly development of many inbred lines for the purpose of improving lamb and wool production, especially when using the above selection criteria.     

Thumb duplication

PURPOSE: To assess the patterns of antimicrobial use, costs of antimicrobial therapy, and medical outcomes by institution in patients with community-acquired pneumonia. PATIENTS AND METHODS: The route, dose, and frequency of administration of all antimicrobial agents prescribed within 30 days of presentation were recorded for 927 outpatients and 1328 inpatients enrolled in the Pneumonia Patient Outcomes Research Team (PORT) multicenter, prospective cohort study. Total antimicrobial costs were estimated by summing drug costs, using average wholesale price for oral agents and institutional acquisition prices for parenteral agents, plus the costs associated with preparation and administration of parenteral therapy. Thirty-day outcome measures were mortality, subsequent hospitalization for outpatients, and hospital readmission for inpatients. RESULTS: Significant variation (P <0.05) in prescribing practices occurred for 17 of the 23 antimicrobial agents used in outpatients across 5 treatment sites, and for 18 of the 20 parenteral agents used in inpatients across 4 treatment sites. The median duration of antimicrobial therapy for treatment site ranged from 11 to 13 days for outpatients (P=0.01), and from 13 to 15 days for inpatients (P=0.49). The overall median cost of antimicrobial therapy was $12.90 for outpatients, and ranged from $10.80 to $58.90 among treatment sites (P <0.0001). The overall median cost of antimicrobial therapy was $228.70 for inpatients, and ranged from $183.70 to $315.60 among sites (P <0.0001). Mortality and hospital readmission for inpatients were not significantly different across sites after adjusting for baseline differences in patient demographic characteristics, comorbidity, and illness severity. Although subsequent hospitalization for outpatients differed by site, the rate was lowest for the site with the lowest antimicrobial costs. CONCLUSION: Variations in antimicrobial prescribing practices by treatment site exist for outpatients and inpatients with community-acquired pneumonia. Although variation in antimicrobial prescribing practices across institutions results in significant differences in antimicrobial costs, patients treated at institutions with the lowest antimicrobial costs do not demonstrate worse medical outcomes.     

Survival and disability in stroke by stroke subtype based on computed tomographic findings in three rural Japanese communities

PURPOSE: We conducted an epidemiological study of survival and disability in stroke in three Japanese communities to seek community strategies for improvement in survival and disability. METHODS: A total of 297 first-ever strokes were identified between 1988 and 1992 in three rural communities (total population = 47,000) located in Akita and Ibaraki. We analyzed survival rates and activity of daily living by sex, age-group and stroke subtypes. Successful review of computed tomography (CT) for 84 percent of the strokes (249 out of 297) was possible and the data were used for subtype analyses. RESULTS: For all strokes (n = 297) survival rates were 85% for 30 day, 70% for one year, 62% for three year. The rates tended to be lower in women than in men. The rates were lowest in ages less than 60 at thirty day, and in ages 80 and older at the end of the first and third year. Intracerebral hemorrhage with ventricular rupture, subarachnoid hemorrhage and cortical cerebral infarction had lower survival rates than intracerebral hemorrhage without ventricular rupture and lacunar infarction. Based on Cox's proportional hazard model, risk ratio for death was 2.07 in ages 70-79, and 3.80 in ages 80 and older compared with ages 60-69. The risk ratio was 3.46 for intracerebral hemorrhage with ventricular rupture, 3.38 for subarachnoid hemorrhage and 2.46 for cortical cerebral infarction compared with lacunar infarction. The proportion of stroke survivors who need assistance from others in the first and third years tended to be higher in women than in men. The proportion was higher in older patients than in the younger, and higher for intracerebral hemorrhage with ventricular rupture and cortical cerebral infarction than in other subtypes of stroke. From logistic regression analysis, the odds ratio for disability in the first year was 6.55 for ages 80 and older compared with ages 60-69. The odds ratio was 5.61 for intracerebral hemorrhage with ventricular rupture, 4.53 for cortical cerebral infarction compared with lacunar infarction. In the third year the odds ratio was significant for ages 70-79, and decreased for intracerebral hemorrhage with ventricular rupture (odds ratio = 2.98), and increased for cortical cerebral infarction (odds ratio = 6.06). CONCLUSIONS: Survival and disability in stroke depended on age and stroke subtypes. Even after age adjustment, stroke subtypes with large cerebral involvement had worse prognosis than stroke subtypes. Community-based hypertension control programs are important to prevent any subtypes of stroke. Stroke subtypes as well as age should be taken into account to develop effective care and medical treatments for strokes.     

Incomplete arylamidase in psoriasis scales

The published data for overall cancer incidence for the registries of Birmingham (UK) and Connecticut (US) show remarkable similarity for men but diverge for women. The incidence of cancer of the endometrium, ovary and breast in Connecticut is higher than in Birmingham, and in each case the menopausal dislocation in the age-specific incidence plot of the Birmingham data is obscured in that for Connecticut. For endometrial cancer, the difference correlates with differences in the two countries in the use of oestrogen replacement therapy, recently implicated in the aetiology of endometrial cancer. The similarity in the pattern for ovarian and breast cancer, and the changing pattern of breast cancer incidence in Birmingham suggest a similar aetiological effect.     

Trends in hospital admissions and death rates for peptic ulcer in the United States from 1970 to 1978

During the period 1970-1978, admissions to short-term nonfederal hospitals in the U.S. for duodenal ulcer decreased by 43%, whereas admissions for gastric ulcer did not change significantly. The decline in admissions for duodenal ulcer was greatest for uncomplicated cases, less for those with hemorrhage, and least (and not significant) in those with perforation. During the period 1970-1977, U.S. Vital Statistics reports of deaths from peptic ulcer decreased 31%, with about equal declines in total deaths, those associated with hemorrhage, and those associated with hemorrhage, and those associated with perforation. The fall in death rate involved both gastric and duodenal ulcer in both men and women. The male/female ratio has been falling steadily, and now stands at about 1.2 for hospitalizations and about 1.5 for deaths. From 1970 to 1978 the percentage of persons over 60 yr of age rose from 14 to 15% in the U.S. population as a whole, from 23 to 29% in persons hospitalized for all causes, from 27 to 36% in those hospitalized for duodenal ulcer, and from 40 to 48% in those hospitalized for gastric ulcer.