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Blood doping is an illegal and unfair way of enhancing athletic performance by increasing the oxygen carrying capacity of the blood. Currently used methods usually involve stimulation of erythropoiesis. Gene therapy targeting the hypoxia inducible factor pathway may be an attractive alternative to traditional blood doping techniques. Hypoxia activates a large number of genes with essential roles in cell and tissue adaptation to low oxygen. Cobalt chloride is a well established chemical inducer of hypoxia-like responses such as erythropoiesis. Cobalt supplementation is not banned and therefore would not be detected by current anti-doping testing. Although there is as yet no direct or anecdotal evidence of cobalt chloride administration to athletes, its use should be warned against as being not only unfair but potentially dangerous.  相似文献   

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Nutritional supplement (NS) use is widespread in sport. This study applied an integrated social cognitive approach to examine doping attitudes, beliefs, and self‐reported doping use behavior across NS users (n = 96) and nonusers (n = 116). Following ethical approval, 212 competitive athletes (age mean = 21.4, s = 4.5; 137 males) completed self‐reported measures of doping‐related social cognitions and behaviors, presented in an online format where completion implied consent. Significantly more NS users (22.9%) reported doping compared with nonusers (6.0%; U = 4628.0, P < 0.05). NS users presented significantly more positive attitudes toward doping (U = 3152.0, P < 0.05) and expressed a significantly greater belief that doping is effective (U = 3152.0, P < 0.05). When presented with the scenario that performance‐enhancing substances are effective and increase the possibility of winning, NS users were significantly more in favor of competing in situations that allow doping (U = 3504.5, P < 0.05). In sum, doping use is three‐and‐a‐half times more prevalent in NS users compared with nonusers. This finding is accompanied by significant differences in doping attitudes, norms, and beliefs. Thus, this article offers support for the gateway hypothesis; athletes who engage in legal performance enhancement practices appear to embody an “at‐risk” group for transition toward doping. Education should be appropriately targeted.  相似文献   

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Although the general implications of this review would be that vitamin and mineral supplements are ineffective as ergogenic aids when added to the diet of an athlete who is well-nourished, there may be certain instances in which supplementation is warranted. For example, wrestlers on low calorie diets and high levels of energy expenditure may not be receiving a balanced intake of nutrients. Young male athletes and female athletes of all ages should be aware of iron-rich foods and include them in the daily diet. The female athlete who experiences a heavy menstrual flow may consider commercial iron preparations; hemoglobin and other hemotologic variables may be evaluated in order to determine the need for supplementation. More research is needed, particularly with large doses of the vitamin B-complex and vitamin C. Although some of the studies cited herein have used large doses, some athletes have been reported to consume massive dosages, for example, 10,000 mg of vitamin C daily. Unfortunately, there may be some adverse side effects of such massive doses, and it may not be ethical to conduct research with humans at those high intake levels. Do these massive dosages elicit a pharmacodynamic effect on some metabolic reactions that are favorable to physical performance? More research with vitamin E at altitude also appears to be warranted, as does iron supplementation to iron-deficient, but not anemic, athletes. As noted earlier, the current data base suggests that vitamin and mineral supplements are unnecessary for the athlete receiving a balanced diet. However, only with additional controlled research may we expand that data base to help answer some of the questions that still remain relative to nutrition and athletic performance. There are still a large number of athletes who believe that the "racers edge" may be found in a tablet.  相似文献   

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Schwartz J 《Military medicine》2005,170(10):855-858
Today's health care organizations must deal with managed care, government oversight, aging baby boomers, new technologies, and increasing pharmaceutical prices. It is imperative that health care organizations adopt some form of business strategy to manage the vast amount of information available. Two of the more popular strategies among health care organizations are the Balanced Scorecard and Total Quality Management. Which one of the strategies is best for an organization? The answer to this question is that it depends on the organization. This article provides the fundamentals of each strategy and contrasts their strengths and weaknesses, so that interested organizations can make informed decisions regarding the best strategy for each organization.  相似文献   

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PURPOSE: To evaluate whether location of the gastro-esophageal junction (GEJ) could be determined with the same accuracy on radiography as by manometry with special reference to pH probe positioning. MATERIAL AND METHODS: Ninety patients with suspected esophageal motility disorders underwent simultaneous manometry and video-radiography. The lower esophageal sphincter pressure (LESP) and location was determined, and pressure recordings were made in the body of the esophagus. The GEJ and any structural changes were diagnosed on radiography during single-barium swallows and continuous barium drinking. Simultaneous radiographic and manometric investigations were performed with the pressure-catheter placed 5 cm proximal to the superior border of the GEJ located by manometry, and the distance to the radiographically determined superior border could be measured directly on the videotapes using a radiopaque metric ruler placed under the patient. RESULTS: On radiography, the GEJ proved to be situated < 2 cm distally as compared to its location determined by manometry in 95.6% of the patients, and the maximal difference was 2.5 cm. The LESP or structural changes had no significant influence on the results. CONCLUSION: The variation of location of GEJ on radiography as compared with manometric findings was sufficiently small to accept both methods as valid in the positioning of the pH probe properly.  相似文献   

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The syndrome of excited delirium has been implicated in some deaths-in-custody which also involved the use of electronic control devices (ECDs) (including those manufactured by TASER International) on subjects. This review is an update on recent studies of pathophysiologic changes related to these two separate but parallel topics: a) first, the use of ECDs during law-enforcement activities; and b) second, the occurrence of excited delirium during such activities. This is a narrative review of elements that may be of use in generating hypotheses relating to potential similarities or differences between the two topics. Differences between changes in most factors due to excited delirium versus those of ECD applications were not readily apparent in most cases. These factors include: direct and indirect effects on the cardiovascular system, respiration, rhabdomyolysis and muscle enzymes, hyperkalemia, acidosis, hyperglycemia, and increased hematocrit. One factor that may exhibit consistent differences, however, is increased body temperature, which is often evident during excited delirium (versus a lack of increase temperature during ECD exposures). Thus, on the basis of this review, a more detailed delineation of this factor could be a major focus for future forensic investigations of deaths-in-custody involving either excited delirium or ECD exposures.  相似文献   

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Purpose

To estimate the global prevalence of dental erosion and to evaluate whether there is scientific evidence that the use of isotonic drinks could increase the risk of this condition in athletes.

Methods

This study was registered in the PROSPERO (CRD42018091545) and it was performed following the PRISMA guidelines. A broad search was conducted in the following databases: PubMed, Scopus, Web of Science, Virtual Health Library (Lilacs) and Grey Literature using MeSH and free terms. Manual search was also performed in the references of included studies. Articles published up to October 04, 2019 were included. Two researchers individually selected the studies according to the eligibility criteria and performed data extraction and methodological evaluation. A random effects model was adopted in the meta-analysis.

Results

Nine studies were selected in which three were considered to have a moderate risk of bias and six were considered to have a low risk of bias. The results of the meta-analysis showed that the estimated global prevalence of dental erosion was 47.07% (95% CI 24.025–70.800) in athletes. It also demonstrated that there was no association between the use of isotonic drinks and dental erosion (95% CI 0.00 [??0.07, 0.08; p?=?0.95].

Conclusion

The estimated prevalence of dental erosion in athletes was considered high; however, there was no association between isotonic drink consumption and the prevalence of dental erosion.

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Purpose

To compare the time-zero stability of an anatomic anteromedial (AM) single-bundle ACL reconstruction to an anatomic central (CTR) single-bundle ACL reconstruction.

Methods

Twelve (6 paired) hip to knee cadaveric specimens were studied. Using custom ACL computer navigation software, a Lachman test and a previously validated, navigated mechanized pivot shift test were performed on 4 separate experimental groups in each specimen: (1) intact ACL, (2) ACL deficient with total medial and lateral meniscectomy, (3) following anatomic AM single-bundle ACL reconstruction, and (4) after anatomic CTR single-bundle ACL reconstruction. Maximum anterior tibial translation in each group was measured.

Results

Lachman: No significant difference was observed between the AM and CTR reconstructions (n.s.) or between reconstruction and the intact ACL (3.4?±?1.7?mm) (n.s.). Pivot Shift: Both the AM and CTR ACL reconstructions significantly reduced anterior translation relative to the ACL/menisci-deficient condition (lateral compartment: 8.9?±?3.8 mm and 6.75?±?4.6 mm vs. 17.25?±?3.5?mm, respectively; P?P?P?P?Conclusions It has been shown that there was no difference in the time-zero biomechanical stability between an anatomic anteromedial and anatomic central single-bundle ACL reconstruction. Given the current debate on the best anatomic ACL reconstruction technique, anatomic socket position in either the anteromedial or central locations provides similar time-zero biomechanics.  相似文献   

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