BACKGROUND & AIMS: :Novel treatment strategies for tuberculosis are urgently needed. Many different preclinical models assessing anti-tuberculosis drug activity are available, but it is yet unclear which combination of models is most predictive of clinical treatment efficacy. The aim of this study was to determine the role of our in vitro time kill-kinetics assay as an asset to a predictive preclinical modeling framework assessing anti-tuberculosis drug activity. The concentration- and time-dependent mycobacterial killing capacities of six anti-tuberculosis drugs were determined during exposure as single drugs or in dual, triple and quadruple combinations towards a Mycobacterium tuberculosis Beijing genotype strain and drug resistance was assessed. Streptomycin, rifampicin and isoniazid were most active against fast-growing M. tuberculosis. Isoniazid with rifampicin or high dose ethambutol were the only synergistic drug combinations. The addition of rifampicin or streptomycin to isoniazid prevented isoniazid resistance. In vitro ranking showed agreement with early bactericidal activity in tuberculosis patients for some but not all anti-tuberculosis drugs. The time-kill kinetics assay provides important information on the mycobacterial killing dynamics of anti-tuberculosis drugs during the early phase of drug exposure. As such, this assay is a valuable component of the preclinical modeling framework.

背景与目标： 迫切需要新的结核病治疗策略。有许多不同的评估抗结核药物活性的临床前模型，但尚不清楚哪种模型组合最能预测临床治疗效果。这项研究的目的是确定我们的体外时间杀伤动力学测定法作为评估抗结核药物活性的预测性临床前建模框架的资产的作用。在暴露于结核分枝杆菌北京基因型菌株的过程中，确定了六种抗结核药物的浓度和时间依赖性的分枝杆菌杀伤能力，并评估了耐药性。链霉素，利福平和异烟肼对快速生长的结核分枝杆菌最有效。异烟肼与利福平或高剂量乙胺丁醇是唯一的协同药物组合。在异烟肼中添加利福平或链霉素可防止异烟肼耐药性。体外排名显示，对于某些 (但不是所有) 抗结核药物，结核病患者的早期杀菌活性一致。时间杀伤动力学测定法提供了有关药物暴露早期抗结核药物的分枝杆菌杀伤动力学的重要信息。因此，该测定是临床前建模框架的有价值的组成部分。

BACKGROUND & AIMS: BACKGROUND:Pre-injury disability must be determined when assessing whether treatment programs return people to pre-injury status, however there is little empirical evidence to support recommendations that this be done as soon as possible after injury to prevent recall bias. OBJECTIVES:To determine disagreement between recall of pre-injury disability at different time points post-injury and bias towards under- or overestimating pre-injury disability. METHODS:Self-reported pre-injury global disability was assessed within days, 6 months and 12 months post-injury in patients admitted to two level 1 adult trauma centres. Kappa statistics and multiple logistic regression models identified predictors of disagreement between time-points. RESULTS:Pre-injury disability was measured at all time-points in 801 patients. Pre-injury disability at baseline was rated as none, mild, moderate, marked and severe in 80%, 12%, 5.1%, 1.9% and 1.0% respectively. Absolute agreement between baseline and 6 and 12 months respectively, was 79% and 80%. Corresponding kappa values (95% confidence intervals) were 0.33 (0.26-0.40) and 0.32 (0-25-0.38). Patients over 65 years or not completing high school were more likely to report less pre-injury disability at 6 and 12 months than at baseline with adjusted odds ratios (95% confidence intervals) for these groups being 8.24 (4.32-15.72) and 1.93 (1.03-3.64) respectively. CONCLUSIONS:There was little evidence of recall bias in an adult trauma population if self-reported global pre-injury disability was assessed 6 months post-injury. The recall of pre-injury disability up to 6 months post-injury can be used to determine return to pre-injury status, if assessment is not feasible shortly after injury.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:Inconsistent evidence of a higher risk of adverse perinatal outcomes during off-hours compared to office hours necessitated a search for clear evidence of an association between time of birth and adverse perinatal outcomes. METHODS:A cross-sectional study conducted at a tertiary referral hospital compared perinatal outcomes across three working shifts over 24 h. A checklist and a questionnaire were used to record parturients' socio-demographic and obstetric characteristics, mode of delivery and perinatal outcomes, including 5th minute Apgar score, and early neonatal mortality. Risks of adverse outcomes included maternal age, parity, referral status and mode of delivery, and were assessed for their association with time of delivery and prevalence of fresh stillbirth as a proxy for poor perinatal outcome at a significance level of p = 0.05. RESULTS:Off-hour deliveries were nearly twice as likely to occur during the night shift (odds ratio (OR), 1.62; 95% confidence interval (CI), 1.50-1.72), but were unlikely during the evening shift (OR, 0.58; 95% CI, 0.45-0.71) (all p < 0.001). Neonatal distress (O.R, 1.48, 95% CI; 1.07-2.04, p = 0.02), early neonatal deaths (OR, 1.70; 95% CI, 1.07-2.72, p = 0.03) and fresh stillbirths (OR, 1.95; 95% CI, 1.31-2.90, p = 0.001) were more significantly associated with deliveries occurring during night shifts compared to evening and morning shifts. However, fresh stillbirths occurring during the night shift were independently associated with antenatal admission from clinics or wards, referral from another hospital, and abnormal breech delivery (OR 1.9; 95% CI, 1.3-2.9, p = 0.001, for fresh stillbirths; OR, 5.0; 95% CI 1.7-8.3, p < 0.001, for antenatal admission; OR, 95% CI, 1.1-2.9, p < 0.001, for referral form another hospital; and OR 1.6; 95% CI 1.02-2.6, p = 0.004, for abnormal breech deliveries). CONCLUSION:Off-hours deliveries, particularly during the night shift, were significantly associated with higher proportions of adverse perinatal outcomes, including low Apgar score, early neonatal death and fresh stillbirth, compared to morning and evening shifts. Labour room admissions from antenatal wards, referrals from another hospital and abnormal breech delivery were independent risk factors for poor perinatal outcome, particularly fresh stillbirths.

背景与目标：

BACKGROUND & AIMS: INTRODUCTION:Abnormal ankle-brachial index (ABI) is associated with increased morbidity and mortality in hemodialysis patients. However, whether the decrease in ABI over time carries the prognostic value is unknown. The aim of this study was to assess whether the decrease in ABI over time was a good predictor of poor cardiovascular (CV) prognosis in hemodialysis patients. METHODS:This study enrolled 234 routine hemodialysis patients and 173 patients completed the follow-up. The ABI was measured by an ABI-form device at baseline and at the first year follow-up. The ΔABI was defined as ABI measured at the first year follow-up minus ABI measured at baseline. Progressors of ABI were defined as patients with ΔABI < -0.3. CV events were defined as CV death, hospitalization for unstable angina, nonfatal myocardial infarction, hospitalization for arrhythmia, hospitalization for congestive heart failure and stroke. RESULTS:The follow-up period was 37.8 ± 11.1 months. In the multivariate analysis, progressors of ABI (hazard ratio, 2.71; 95% confidence interval, 1.10-6.68, P = 0.03), decreased albumin and increased high-sensitivity C-reactive protein were associated with increased CV events. CONCLUSIONS:This longitudinal study showed ΔABI < -0.3 was independently associated with an increase in CV events. Hence, a great decrease in ABI over time might be a useful indicator of poor CV prognosis in hemodialysis patients.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:Outcome in stroke trials is often based on a 3-month modified Rankin scale (mRS). How 3-month mRS relates to longer-term outcomes will depend on late recovery, delayed stroke-related deaths, recurrent strokes, and nonstroke deaths. We evaluated 3-month mRS and death/disability at 1 and 5 years in a population-based cohort study. METHODS AND RESULTS:In 3-month survivors of ischemic stroke (Oxford Vascular Study; 2002-2014), we related 3-month mRS to disability (defined as mRS >2) at 1 and 5 years and/or death rates (age/sex adjusted). Accrual of disability and index-stroke-related and nonstroke deaths in each poststroke year was categorized according to 3-month mRS. Among 1606 patients with acute ischemic stroke, 181 died within 3 months, but 126 index-stroke-related deaths and 320 other deaths occurred during the subsequent 4866 patient-years of follow-up up to 5 years. Although 69/126 (54.8%) post-3-month index-stroke-related deaths occurred after 1 year, mRS>2 at 1 year strongly predicted these deaths (adjusted hazard ratio=21.94, 95%CI 7.88-61.09, P<0.0001). Consequently, a 3-month mRS >2 was a strong independent predictor of death at both 1 year (adjusted hazard ratio=6.67, 95%CI 4.16-10.69, P<0.0001) and 5 years (adjusted hazard ratio=2.93, 95%CI 2.38-3.60, P<0.0001). Although mRS improved by ≥1 point from 3 months to 1 year in 317/1266 (25.0%) patients with 3-month mRS ≥1, improvement in mRS after 1 year was limited (improvement by ≥1 point: 91/858 [10.6%]; improvement to mRS ≤2: 13/353 [3.7%]). CONCLUSIONS:Our results reaffirm use of the 3-month mRS outcome in stroke trials. Although later recovery does occur, extending follow-up to 1 year would capture most long-term stroke-related disability. However, administrative mortality follow-up beyond 1 year has the potential to demonstrate translation of early disability gains into additional reductions in long-term mortality without much erosion by non-stroke-related deaths.

背景与目标：

BACKGROUND & AIMS: PURPOSE:To evaluate the safety and efficacy of 5 seconds of mitomycin-C (MMC) application during photorefractive keratectomy (PRK) for low myopia. SETTING:Basir Eye Clinic, Tehran, Iran. DESIGN:Prospective randomized sham-controlled double-masked clinical trial. METHODS:Patients with low myopia and an ablation depth of less than 65 μm were recruited. One eye of each patient was included in the study and was randomly assigned to receive intraoperative topical MMC 0.02% for 5 seconds or a balanced salt solution in the same manner (control group). Corneal haze development during the 6 months after the PRK was the main outcome measure. RESULTS:Of the 184 eligible patients (MMC = 93; control = 91), 152 (78 and 74, respectively) completed the follow-up. The postoperative haze grade was significantly lower in the MMC group (P=.01). The mean endothelial cell density was not significantly different between the MMC group and the control group preoperatively (2879.97 cells/mm(2) ± 298.04 [SD] versus 2819.69 ± 303.89 cells/mm(2); P=.22) or 6 months postoperatively (2878.79 ± 283.04 cells/mm(2) versus 2878.79 ± 283.04 cells/mm(2); P=.25). No notable ocular complication occurred throughout the study. CONCLUSION:Short-time application of MMC 0.02% was safe and effective in preventing haze formation in eyes having PRK with an ablation depth of less than 65 μm compared with matched controls up to 6 months. FINANCIAL DISCLOSURE:No author has a financial or proprietary interest in any material or method mentioned.

背景与目标：

BACKGROUND & AIMS: :A novel approach to DNase I-sensitivity analysis was applied to examining genes of the spermatogenic pathway, reflective of the substantial morphological and genomic changes that occur during this program of differentiation. A new real-time PCR-based strategy that considers the nuances of response to nuclease treatment was used to assess the nuclease susceptibility through differentiation. Data analysis was automated with the K-Lab PCR algorithm, facilitating the rapid analysis of multiple samples while eliminating the subjectivity usually associated with C(t) analyses. The utility of this assay and analytical paradigm as applied to nuclease-sensitivity mapping is presented.

背景与目标： : DNase I敏感性分析的新方法被用于检查生精途径的基因，反映了在此分化程序中发生的实质性形态和基因组变化。一种新的基于实时PCR的策略，该策略考虑了对核酸酶处理的细微差别，用于通过分化评估核酸酶的敏感性。使用K-Lab PCR算法自动进行数据分析，从而促进了对多个样品的快速分析，同时消除了通常与C(t) 分析相关的主观性。介绍了该分析方法和分析范例应用于核酸酶敏感性映射的实用性。

BACKGROUND & AIMS: OBJECTIVES:To evaluate the micro-shear bond strength to enamel and dentin, pH and hardness of two self-etching adhesives over a period of 60 weeks storage at different temperatures. MATERIALS AND METHODS:Two self-etching systems, an all-in-one adhesive, Clearfil Tri-S Bond (TS) and a two-step adhesive, Clearfil SE Bond (SE) were used in this study (both by Kuraray Medical, Osaka, Japan). Their micro-shear bond strengths to enamel and dentin were measured. The materials were then stored at 4, 23 or 37 degrees C. Their bond strengths were measured again after 1, 4, 16 and 60 weeks and compared to the base line. The nano-indentation hardness of the polymerized bonding, pH of SE primer and TS were also measured at the baseline and after 60 weeks of storage at three different temperatures. Bond-strength and hardness data were analyzed using ANOVA and post hoc tests at the significance level of 0.05. RESULTS:Two-way ANOVA analysis showed that both storage conditions and material type had significant effects on bond strength to enamel or dentin but the interactions of these factors were not significant for any of the substrates. One-way ANOVA post hoc tests revealed that the bond strength of adhesives stored at 37 degrees C significantly decreased during the storage period; with the earliest significant decreases observed at 4 weeks for TS and at 16 weeks for SE. After 60 weeks of storage, the hardness obtained for SE bonding resin was not significantly different with that at the baseline for 4, 23 and 37 degrees C groups, but there was a significant decrease observed in hardness for TS stored at 37 degrees C, compared to that at the baseline. The pH of both self-etching materials decreased when they were stored at 37 degrees C. CONCLUSION:Storage time and temperature significantly affected the bond strength of both materials through the time dependent hydrolysis and other changes that are likely to occur in the water-containing self-etching agents at high temperatures.

背景与目标：

BACKGROUND & AIMS: Extended-spectrum beta-lactamases (ESBLs) are found in numerous Enterobacteriaceae, mainly in Klebsiella pneumoniae. We investigated the pharmacodynamics of two new extended-spectrum cephalosporins, cefepime and cefpirome, alone and combined with either amikacin or gentamicin or ciprofloxacin by means of time-kill curves against ESBL-producing, aminoglycoside-resistant K. pneumoniae. When used alone, cefepime (8 and 16 mg/l) resulted in a 2 and 3 log decrease at 6 h, respectively, but at 24 h regrowth occurred. The combination of cefepime (8 mg/l) with amikacin (4 mg/l) resulted in a 4 log decrease at 6 h, but there were no surviving bacteria at 6 h when combined with amikacin (8 mg/l). The combination of cefepime (16 mg/l) with gentamicin (4 mg/l) resulted in a 4 log decrease in 24 h. The antimicrobial combination of cefepime (32 mg/l) with ciprofloxacin (2 mg/l) resulted in a 4 log decrease in 24 h. Cefpirome (8 mg/l) induced a 2 log decrease at 4 h; 32 mg/l cefpirome resulted in a 3 log decrease followed by regrowth at 24 h. The regrowth observed in the late phase with cefpirome alone disappeared when combined with aminoglycoside. When cefpirome (32 mg/l) was used in combination with ciprofloxacin (1 mg/l), it resulted in a 4 log decrease in 24 h.

背景与目标： 广谱 β-内酰胺酶 (ESBLs) 存在于许多肠杆菌科中，主要存在于肺炎克雷伯菌中。我们研究了两种新的广谱头孢菌素头孢吡肟和头孢匹罗单独使用的药效学，并通过对产生ESBL的氨基糖苷类耐药肺炎克雷伯菌的时间杀伤曲线与阿米卡星，庆大霉素或环丙沙星联合使用。单独使用时，头孢吡肟 (8和16 mg/l) 分别在6小时导致2和3 log降低，但在24小时发生再生。头孢吡肟 (8 mg/l) 与丁胺卡那霉素 (4 mg/l) 的组合在6 h时导致4对数下降，但与丁胺卡那霉素 (8 mg/l) 组合在6 h时没有存活细菌。头孢吡肟 (16 mg/l) 与庆大霉素 (4 mg/l) 的组合在24小时内导致4 log下降。头孢吡肟 (32 mg/l) 与环丙沙星 (2 mg/l) 的抗菌组合在24小时内导致4对数下降。头孢匹罗 (8 mg/l) 在4 h诱导2 log降低; 32 mg/l头孢匹罗导致3 log降低，然后在24 h再生长。与氨基糖苷类合用头孢匹罗在晚期观察到的再生消失。头孢匹罗 (32 mg/l) 与环丙沙星 (1 mg/l) 联合使用时，在24小时内导致4 log下降。

BACKGROUND & AIMS: :Factor V(Leiden) is the most common abnormality detected in patients examined because of hereditary thrombophilia. The most widely used clot-based screening test is based on the activated partial thromboplastin (aPTT) time. This test has a low sensitivity. A comparison of the aPTT-based test with a Russell viper venom time test (RVVT) was performed in matched samples. All samples were analyzed by polymerase chain reaction (PCR) for the factor V(Leiden) defect. We studied 139 samples, of which 109 were PCR-negative; 30 were PCR-positive. Using the manufacturer's suggested threshold ratio of 2, the aPTT test showed a sensitivity of 0.43, a specificity of 0.86, and a positive predictive value (PPV) of 0.97. The RVVT test had a sensitivity of 1.0, a specificity of 0.95, and a PPV of 0.91. Segregation of a subpopulation of this study population into ABO group O vs non-group O showed an effect of ABO group on the aPTT test but not on the RVVT test, consistent with an influence of factor VIII clotting (factor VIII:C) on the aPTT test. The RVVT test seems superior to the unmodified aPTT test as a screening test for factor V(Leiden).

背景与目标： : 因子V(Leiden) 是由于遗传性血栓形成而在检查的患者中最常见的异常。最广泛使用的基于凝块的筛查测试是基于活化的部分凝血活酶 (aPTT) 时间。该测试灵敏度低。在匹配的样品中进行了基于aPTT的测试与Russell viper毒液时间测试 (RVVT) 的比较。所有样品均通过聚合酶链反应 (PCR) 分析因子V (莱顿) 缺陷。我们研究了139份样品，其中109份为PCR阴性; 30份为PCR阳性。使用制造商建议的阈值比率2，aPTT测试显示出0.43的敏感性，0.86的特异性和0.97的阳性预测值 (PPV)。RVVT测试的敏感性为1.0，特异性为0.95，PPV为0.91。将该研究人群的亚群分为ABO组O和非O组，显示ABO组对aPTT测试有影响，但对RVVT测试没有影响，这与因子VIII凝血 (因子VIII:C) 的影响一致aPTT测试。作为因子V(Leiden) 的筛选测试，RVVT测试似乎优于未修改的aPTT测试。

BACKGROUND & AIMS: BACKGROUND:Because inguinal hernia repair is difficult for third-year students to comprehend, a 2-dimensional paper-cut was developed to teach the concepts of inguinal hernia in a time-effective manner before students' observation of herniorrhaphy in the operating room. METHODS:Using Adobe Illustrator 5.5 for MacIntosh, a 2-dimensional inexpensively printed paper-cut was created to allow students to perform their own simulated hernia repair before observing surgery. The exercise was performed using a no.15 scalpel or an iris scissors and was evaluated by comparing 10-question pre-tests and post-tests. RESULTS:Seventy-five students performed the exercise, most completing it within 15 minutes. The mean pre-test score was 7.4/10 and the mean post-test score was 9.1/10. Students performing the paper-cut reported better understanding when observing actual herniorrhaphy. CONCLUSIONS:A 2-dimensional paper-cut ("surgical origami") may be a time-effective method to prepare students for the observation of hernia repair.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:To define the anatomic characteristics of the congenitally malformed and severely stenotic aortic valve using trans-thoracic real time three-dimensional echocardiography, and to compare and contrast this with the valvar morphology as seen at surgery. DESIGN:Prospective cross-sectional observational study. SETTING:Tertiary centre for paediatric cardiology. METHODS:All patients requiring aortic valvotomy between December 2003 and July 2004 were evaluated prior to surgery with three-dimensional echocardiography. Full volume loop images were acquired using the Phillips Sonos 7500 system. A single observer analysed the images using "Q lab 4.1" software. The details were then compared with operative findings. RESULTS:We identified 8 consecutive patients, with a median age of 16 weeks, ranging from 1 day to 11 years, with median weight of 7.22 kilograms, ranging from 2.78 to 22 kilograms. The measured diameter of the valvar orifice, and the number of leaflets identified, corresponded closely with surgical assessment. The sites of fusion of the leaflets were correctly identified by the echocardiographic imaging in all cases. Fusion between the right and non-coronary leaflets was identified in half the patients. Dysplasia was observed in 3 patients, with 1 patient having nodules and 2 shown to have excrescences. At surgery, nodules were excised, and excrescences were trimmed. The dysplastic changes correlated well with operative findings, though statistically not significant. CONCLUSION:We recommend trans-thoracic real time three-dimensional echocardiography for the assessment of the congenitally malformed aortic valve, particularly to identify sites of fusion between leaflets and to measure the orificial diameter. The definition of nodularity, and the prognosis of nodules based on the mode of intervention, will need a comparative study of patients submitted to balloon dilation as well as those undergoing surgical valvotomy.

背景与目标：

BACKGROUND & AIMS: The present study examined the differences of self-ratings of 4 h sleep in three statesL-WE, where the percentage of waking time and urinary epinephrine are low (< 20% waking time); H-W, where the percentage of waking time and epinephrine levels increase along the basal regression line as determined by a previous study (20-100% waking time and < 7 ng/min); H-E, where epinephrine levels increase more than expected from the basal regression line for the two parameters (> 7 ng/min). Eight healthy male subjects participated twice in a 4 h polysomnograph experiment with four types of sleep onset (total of 64 observations). In group L-WE (52 observations for eight subjects), there were no excessively negative feelings on sleep latency, sleep depth, and feelings of sleep compared with usual sleep according to the questionnaire. Subjective sleep diagrams in group L-WE were similar to polysomnographic findings. Thus, group L-WE was thought objectively and subjectively to have a good sleep state. Groups H-W (eight observations for four subjects) and H-E (four observations for two subjects) had negative feelings regarding sleep depth and feelings of sleep compared with usual sleep. Approximately half the group H-W underrated their sleep compared with objective diagrams, while all cases in group H-E remarkably underrated their sleep in the subjective diagrams. The state of remarkable adrenal medullary secretory activity seen in group H-E and that of the slightly increased activity shown in group H-W were included in poor sleep states objectively and subjectively.

背景与目标： 本研究检查了三种状态下4 h睡眠自我评分的差异，其中清醒时间和尿肾上腺素的百分比较低 (< 20% 清醒时间); H-w，其中清醒时间和肾上腺素水平的百分比沿基础回归线增加，如先前的研究 (20-100% 清醒时间和 <7 ng/min); H-e，其中肾上腺素水平增加超过两个参数的基础回归线的预期 (> 7 ng/min)。八名健康的男性受试者两次参加了4小时多导睡眠图实验，其中有四种睡眠发作类型 (总共64个观察结果)。根据问卷，在l-we组 (八名受试者的52项观察结果) 中，与通常的睡眠相比，在睡眠潜伏期，睡眠深度和睡眠感觉方面没有过度负面的感觉。L组的主观睡眠图-我们与多导睡眠图的发现相似。因此，客观和主观地认为L-WE组具有良好的睡眠状态。与通常的睡眠相比，h-w组 (四名受试者的八次观察) 和h-e组 (两名受试者的四次观察) 对睡眠深度和睡眠感觉有负面感觉。与客观图相比，大约一半的h-w组低估了他们的睡眠，而h-e组的所有病例在主观图中都明显低估了他们的睡眠。客观和主观地将h-e组中明显的肾上腺髓质分泌活动状态和h-w组中显示的轻度活动状态包括在不良的睡眠状态中。

BACKGROUND & AIMS: BACKGROUND:Hamstring strains can be of 2 types with different injury mechanisms, 1 occurring during high-speed running and the other during stretching exercises. HYPOTHESIS:A stretching type of injury to the proximal rear thigh may involve specific muscle-tendon structures that could affect recovery time. STUDY DESIGN:Case series (prognosis); Level of evidence, 2. METHODS:Fifteen professional dancers with acute first-time hamstring strains were prospectively included in the study. All subjects were examined, clinically and with magnetic resonance imaging, on 4 occasions after injury: at day 2 to 4, 10, 21, and 42. The clinical follow-up period was 2 years. RESULTS:All dancers were injured during slow hip-flexion movements with extended knee and experienced relatively mild acute symptoms. All injuries were located proximally in the posterior thigh close to the ischial tuberosity. The injury involved the semimembranosus (87%), quadratus femoris (87%), and adductor magnus (33%). All injuries to the semimembranosus involved its proximal free tendon. There were no significant correlations between clinical or magnetic resonance imaging parameters and the time to return to preinjury level (median, 50 weeks; range, 30-76 weeks). CONCLUSION:Stretching exercises can give rise to a specific type of strain injury to the posterior thigh. A precise history and careful palpation provide the clinician enough information to predict a prolonged time until return to preinjury level. One factor underlying prolonged recovery time could be the involvement of the free tendon of the semimembranosus muscle.

背景与目标：

BACKGROUND & AIMS: :The authors respond to a proposal in this issue of Academic Medicine by Ray, Bishop, and Dow, who recommend adopting a free-market approach to the Match in which applicants and programs negotiate directly with each other to find and fill residency positions year-round. This Invited Commentary examines and responds to the reasons Ray and colleagues give for changing the Match and explores their proposal's implications and likelihood of success.The authors question Ray and colleagues' argument that assumptions underlying the National Resident Matching Program algorithm have been violated. The authors suggest there is insufficient evidence for the "July effect" and that the possibility for improvement in physician supply due to the year-round entry of graduates into the workforce ultimately faces the rate-limiting step of caps on residency positions allocated to programs. Most important, competency-based medical education, on which the free-market proposal depends, is not yet sufficiently developed.Nonetheless, the imbalanced ratio of applicants to positions in the Match is contributing to a rise in the numbers of student applications and program interviews. Although the proposed free-market approach might, as Ray and colleagues envision, curtail applications as well as reduce time and financial resources currently expended on the process, it would require significant changes on the part of applicants, residency programs, medical schools, and other stakeholders.Because the proposed free-market approach could reduce some negative effects of the imbalance of applicants and positions, it merits ongoing discussion along with other more immediate practical solutions to issues with the Match.

背景与目标： : 作者回应了Ray，Bishop和Dow在本期《学术医学》中的一项建议，他们建议采用自由市场的方法进行匹配，在该方法中，申请人和计划直接彼此进行谈判以找到并填补居住职位全年。这篇邀请的评论研究并回应了Ray和同事提出的改变比赛的原因，并探讨了他们的建议的含义和成功的可能性。作者质疑Ray和同事的论点，即违反了国家居民匹配计划算法的假设。作者认为，没有足够的证据证明 “7月效应”，并且由于毕业生全年进入劳动力市场而改善医生供应的可能性最终面临分配给住院医师职位上限的限速步骤程序。自由市场提案所依赖的最重要的基于能力的医学教育尚未得到充分发展。尽管如此，比赛中申请人与职位的不平衡比例正在导致学生申请和计划面试的数量增加。尽管如Ray及其同事所设想的那样，拟议的自由市场方法可能会减少申请并减少目前在该过程中花费的时间和财务资源，但这将需要申请人，居住计划，医学院，和其他利益相关者。由于提议的自由市场方法可以减少申请人和职位不平衡的一些负面影响，因此值得持续讨论以及其他更直接的实际解决方案来解决匹配问题。