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1.
Size, age and number of offspring at the first and subsequent tworeproductions were compared in Daphnia treated with cues frominvertebrate predators (adult Cyclopoida fed Daphnia)and from crushed conspecifics. Daphnia in the presence ofinvertebrate predators had earlier maturation, greater size atfirst and subsequent reproductions and a larger number of offspringthan control animals, while the opposite (later maturation andsmaller size at subsequent reproductions) happened when Daphnia were treated with homogenate from crushedconspecifics.  相似文献   
2.
Lead (Pb) toxicity affects the hepatic and renal systems resulting to homeostasis imbalance. Curcumin is a strong antioxidant but has restrained clinical applications due to its poor bioavailability. Nanomedicine showed promising potentials in drug delivery and has brought forth the use of cockle shell-derived aragonite calcium carbonate nanoparticles (CSCaCO3NP) to enhance the effectiveness and targeted delivery of curcumin (Cur). Thus, this study aimed at evaluating the therapeutic effect of curcumin-loaded CSCaCO3NP (Cur- CSCaCO3NP) on lead-induced hepato-renal toxicity in rats. Thirty-six male adults Sprague-Dawley rats were randomly assigned into five groups. All groups contained six rats each except for group A, which contained 12 rats. All rats apart from the rats in group A (control) were orally administered a flat dose of 50 mg/kg of lead for four weeks. Six rats from group A and B were euthanized after four weeks of lead induction. Oral administration of curcumin (100 mg/kg) for group C and Cur-CSCaCO3NP (50 and 100 mg/kg) for groups D and E respectively, commenced immediately after 4 weeks of lead induction which lasted for 4 weeks. All rats were euthanized at the 8th week of the experiment. Further, biochemical, histological and hematological analysis were performed. The findings revealed a biochemical, hematological and histological changes in lead-induced rats. However, treatments with the Cur-CSCaCO3NP and free curcumin reversed the aforementioned changes. Although, Cur-CSCaCO3NP presented better therapeutic effects on lead-induced toxicity in rats when compared to free curcumin as there was significant improvements in hematological, biochemical and histological changes which is parallel with attenuation of oxidative stress. The findings of the current study hold great prospects for Cur-CSCaCO3NP as a novel approach for effective oral treatment of lead-induced hepato-renal impairments.  相似文献   
3.
PurposeTo evaluate image quality of chest radiography for a number of systems in Belgium, using a contrast-detail (c-d) test object and Visual Grading Analysis (VGA) of an anthropomorphic phantom.MethodsThe study comprised 22 chest imaging systems in Belgium. C-d data were measured using Leeds TO20 test object, imaged using poly(methyl methacrylate) (PMMA) thicknesses of 9, 13 and 16 cm. Images of the Lungman phantom, with additional tissue-equivalent chest plates to represent different patient sizes, were then acquired. Perceived image quality was evaluated using VGA by three radiologists. Images were acquired at a patient equivalent position with system-specific exposure settings for Posterior-Anterior chest protocol. Incident air kerma (IAK) was measured using a solid-state dosemeter.ResultsC-d results showed large differences between the systems. Total number of visible discs ranged from 38 to 83 (for 9 cm PMMA) with a consistent average drop of 10% as PMMA thickness was systematically increased. However, no correlation was found between number of visible discs and IAK. Perceived image quality scored by the readers from the Lungman images decreased with increasing phantom thickness, however no correlation of VGA score with IAK was seen. Moderate correlation was found between the VGA score of one of the readers and the TO20 results, and no correlation for the rest.ConclusionsThe spread in dose and image quality measures was high and no correlation was seen between either image quality measure and IAK, suggesting the need for optimization. A more powerful tool is required for task-based optimization in chest radiography.  相似文献   
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5.
BackgroundChest pain is a common symptom in urgent primary care. The distinction between urgent and non-urgent causes can be challenging. A modified version of the HEART score, in which troponin is omitted (‘simplified HEART’) or replaced by the so-called ‘sense of alarm’ (HEART-GP), may aid in risk stratification.MethodThis study involved a retrospective, observational cohort of consecutive patients evaluated for chest pain at a large-scale, out-of-hours, regional primary care facility in the Netherlands, with 6‑week follow-up for major adverse cardiac events (MACEs). The outcome of interest is diagnostic accuracy, including positive predictive value (PPV) and negative predictive value (NPV).ResultsWe included 664 patients; MACEs occurred in 4.8% (n = 32). For  simplified HEART and HEART-GP, we found C‑statistics of 0.86 (95% confidence interval (CI) 0.80–0.91) and 0.90 (95% CI 0.85–0.95), respectively. Optimal diagnostic accuracy was found for a simplified HEART score ≥2 (PPV 9%, NPV 99.7%), HEART-GP score ≥3 (PPV 11%, NPV 99.7%) and HEART-GP score ≥4 (PPV 16%, NPV 99.4%). Physicians referred 157 patients (23.6%) and missed 6 MACEs. A simplified HEART score ≥2 would have picked up 5 cases, at the expense of 332 referrals (50.0%, p < 0.001). A HEART-GP score of ≥3 and ≥4 would have detected 5 and 3 MACEs and led to 293 (44.1%, p < 0.001) and 186 (28.0%, p = 0.18) referrals, respectively.ConclusionHEART-score modifications including the physicians’ ‘sense of alarm’ may be used as a risk stratification tool for chest pain in primary care in the absence of routine access to troponin assays. Further validation is warranted.Supplementary InformationThe online version of this article (10.1007/s12471-020-01529-4) contains supplementary material, which is available to authorized users.  相似文献   
6.
The physical mechanics of music making is important both in the prevention of injuries and in guiding how music is performed and taught. Electromyography has potential as a resource in understanding the loads involved in instrumental playing; however, only a small number of projects have been undertaken, and little is understood on the muscle activity used during bowing on string instruments. This study aimed to measure the muscle activity at the bowing shoulder of a cellist during cello playing and to establish if fine-wire EMG is useful in understanding muscle recruitment in string players without interfering with normal playing ability. This project used a combination of fine-wire and surface EMG to evaluate the muscular load placed on the right shoulder of a professional cellist whilst playing a set of various bowing exercises. The results indicated that different bowing techniques produced statistically different muscle activity levels, with the supraspinatus muscle in particular maintaining higher mean contraction (20% MVC) during all bowing patterns tested. Fine-wire EMG was useful in measuring shoulder muscle load and did not interfere with normal playing technique of the subject. Overall, the study presents a working protocol from which future studies may be able conduct further research.  相似文献   
7.

Background

Gas trapping quantified on chest CT scans has been proposed as a surrogate for small airway disease in COPD. We sought to determine if measurements using paired inspiratory and expiratory CT scans may be better able to separate gas trapping due to emphysema from gas trapping due to small airway disease.

Methods

Smokers with and without COPD from the COPDGene Study underwent inspiratory and expiratory chest CT scans. Emphysema was quantified by the percent of lung with attenuation < −950HU on inspiratory CT. Four gas trapping measures were defined: (1) Exp−856, the percent of lung < −856HU on expiratory imaging; (2) E/I MLA, the ratio of expiratory to inspiratory mean lung attenuation; (3) RVC856-950, the difference between expiratory and inspiratory lung volumes with attenuation between −856 and −950 HU; and (4) Residuals from the regression of Exp−856 on percent emphysema.

Results

In 8517 subjects with complete data, Exp−856 was highly correlated with emphysema. The measures based on paired inspiratory and expiratory CT scans were less strongly correlated with emphysema. Exp−856, E/I MLA and RVC856-950 were predictive of spirometry, exercise capacity and quality of life in all subjects and in subjects without emphysema. In subjects with severe emphysema, E/I MLA and RVC856-950 showed the highest correlations with clinical variables.

Conclusions

Quantitative measures based on paired inspiratory and expiratory chest CT scans can be used as markers of small airway disease in smokers with and without COPD, but this will require that future studies acquire both inspiratory and expiratory CT scans.  相似文献   
8.
In Egypt, β-thalassemia is the most common hereditary hemolytic anemia. Cardiac dysfunction, secondary to iron overload with formation of oxygen free radicals, is the most common cause of death in β-thalassemia patients. This study was designed to determine whether the allelic genotype of apolipoprotein E (Apo E), which exhibits antioxidant properties, could represent a genetic risk factor for the development of left ventricular (LV) dysfunction in β-thalassemia major. Fifty Egyptian β-thalassemia major patients were subjected to echocardiography to assess LV function. Apo E genotyping by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was done for all patients in addition to 50 age and sex matched healthy control subjects. Patients were classified into three groups. Group I and II were clinically asymptomatic. Group II subjects had evidence of LV dilatation, while Group III patients had clinical and echocardiographic findings of LV failure. Apo E4 allele was significantly higher among Group II and III than in controls. In conclusion, Apo E4 allele can be considered as a genetic risk factor for LV dysfunctions in β-thalassemic patients. It could be used as predictive indicator for additional risk of LV failure, particularly in asymptomatic patients with LV dilatation, requiring a closer follow-up, to prevent further disease progression.  相似文献   
9.
目的:通过与常规x线胸片比较,探讨胸部x线断层容积成像技术在肺动脉畸形中的应用价值。方法:对20例临床及x线平片怀疑肺动脉畸形者,进一步进行胸部x线断层容积成像检查。其中11例被明确诊断为肺动脉畸形。以CT或超声心动结果为标准,对比两种图像对肺动脉畸形的明确诊断率,分析对比该11例患者的胸部x线断层容积成像图片和普通x线胸片,评价两种方法所获得的图像质量和图片优秀率。结果:20例疑似患者中,11例被CT或超声心动确诊为肺动脉畸形,其x线断层容积成像图片和普通x线胸片经主管技师和副主任医师双盲判读,x线断层容积成像11例均获明确诊断(100%),普通x线胸片明确诊断2例(18%),诊断准确率有明显差异(P=0.O001)。容积断层成像优质图像为10例,占总数的90.91%;良好1例,差为0例。11例x片中优秀7例,占总数的63.63%,其中良好3例,差1例。两种图像优秀率比较差异有统计学意义(P=0.0001)。结论:x线断层容积成像技术对肺动脉畸形的图像优秀率和诊断准确率均高于x线平片,对病变的显示更加清晰、立体,提高诊断准确率和客观性,具有重要的临床诊断价值。  相似文献   
10.
目的:探讨以胸痛为主要表现的胃食管反流病的病因、临床特点及诊治方法。方法:选择本院近年来诊治的36例已排除心源性及食管器质性病变,诊断为胃食管反流病的胸痛患者,予以埃索美拉唑20mg,每日两次;吗叮林10mg,每日三次治疗8周,观察其疗效并分别于2周,4周,8周记录症状缓解情况。结果:经抗反流治疗8周后,30例(83.33%)胸痛完全消失,4例(11.11%)明显缓解,2例(5.56%)无效,总有效率达94.44%。胸痛症状在治疗2周后积分下降不明显,而治疗4周,8周后显著改善,与治疗前比较有显著性差异(P〈0.01)。结论:胃食管反流病病因复杂、临床表现多样易误诊漏诊,胃镜检查结合24小时食管动态ph监测,必要时给予质子泵抑制剂试验性治疗可提高本病的确诊率。  相似文献   
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