丹皮紫外指纹图谱共有峰率和变异峰率双指标序列分析

目的：采用指纹图谱共有峰率和变异峰率双指标序列分析法分析丹皮类药材紫外指纹图谱。方法：本文用3种溶剂氯仿、无水乙醇及水，系统提取丹皮等不同极性区间成分，测定其紫外指纹图谱，研究样品的异同。结果：该方法可以准确对丹皮类药材进行细致的鉴别。结论：利用共有峰率和变异峰率双指标序列分析法可以对两个或多个样本进行可靠的鉴别。     

Duplex ultrasound evaluation of cavernosal peak systolic velocity and waveform acceleration in the penile flaccid state: clinical significance in the assessment of the arterial supply in patients with erectile dysfunction

The aim of this paper was to establish if duplex ultrasound parameters obtained for assessment of the patency of cavernosal arteries in the penile flaccid state can give sufficient clinical information without the use of intracavernosal injection of vasodilatory drugs. We assessed mean cavernosal peak systolic velocity (PSV) in the penile flaccid state (basal PSV), and after PGE1 injection (dynamic PSV) in 339 unselected patients with erectile dysfunction. In 55 of these patients the waveform acceleration in the flaccid state was also assessed. The results of the study can be summarized as follows: (1) a significant relationship was found between basal and dynamic PSV in the 339 patients (r=0.477; p < 0.0001); (2) a basal PSV >12.5 cm/sec was predictive of a dynamic PSV >/=30 cm/sec in 129/139 (92.8%) of the patients, whereas in patients with a basal PSV or <30 cm/sec could be found; and (3) an acceleration >1 m/sec2 in the flaccid state was coupled to a dynamic PSV >30 cm/sec in 43/46 (93.5%) of the patients independent of the basal PSV. In conclusion, these results suggest that the combined duplex ultrasound assessment of PSV and waveform acceleration in the penile flaccid state can predict arterial dynamic inflow in the majority (51/55; 92.7%) of patients with erectile dysfunction, with less time and expense and less discomfort for the patient.     

儿童营养与骨骼发育的最新进展

人的骨骼成熟经过了婴儿、儿童、青少年期和青壮年的很长时间 ,最终取得了峰值骨量。近年来 ,大多数关于骨质疏松方面的研究焦点已经开始转移 ,重点研究影响生长发育期使骨峰值达到最大化的决定因素和骨质疏松发生的预防方面。本文综述了影响峰值骨量的因素、钙营养状况与儿童骨骼发育、饮奶对骨骼发育的影响和生长发育的影响 ,并对今后该领域的研究提出了展望     

质子束治疗中Bragg峰分布特性的SRIM模拟研究

目的 在质子治疗中，对SRIM 程序在模拟质子Bragg峰分布特性方面进行探讨。方法 基于SRIM 程序，对50～250 MeV的不同能量的质子束入射到水、聚苯乙烯，有机玻璃以及铝、铁等不同介质中的输运过程进行了模拟分析，对不同的质子入射能量、介质材料及厚度与其Bragg峰深度的关系进行了研究，并与专业的蒙特卡罗程序Fluka2011以及MCNPX模拟结果进行对比。结果 随着入射质子能量的增加，其Bragg峰深度逐步增大并伴随展宽增大；相同质子入射能量下不同介质的Bragg峰深度与水中的Bragg峰深度之比随质子的入射能量变化不大，近似为一常数，所得结果与成熟的Fluka及MCNPX程序模拟值是一致的。结论 SRIM程序在模拟质子束输运方面其精度是可行的，对于初学者可以采用简单易学的SRIM来替代繁琐的Fluka及MCNPX程序。     

The effect of induced joint restriction on plantar pressure during gait – a pilot study

BackgroundThe aim of this study was to analyse the effect of induced lower limb joint restriction on plantar pressures during gait. Focusing on restricting a single joint, without the effect of other co-morbidities, would provide better understanding as to the resultant plantar loadings during gait, which would be especially beneficial in patients requiring offloading procedures.Research QuestionDoes induced lower limb joint restriction affect plantar pressure distribution during gait?MethodsA prospective, quasi-experimental study was conducted, recruiting ten healthy, adult participants who were instructed to walk barefoot over a Tekscan HR Mat™. This procedure was repeated after separately inducing restriction of the hip, knee and ankle joints. Mean peak plantar pressure (MPP) and pressure-time integral (PTI) data were analysed to compare between unrestricted and restricted data.ResultsSignificant plantar pressure changes were observed in the heel and first metatarsal regions. Rearfoot PTIs were increased with restriction of the contralateral hip (left p <0.001) (right p =0.02) and knee joints (left p =0.01) (right p =0.04). Both MPPs (left p =0.01; right p =0.01) and PTIs (left p =0.004; right p =0.03) were increased in the first metatarsal when restricting the hip joint of the same limb. MPP was decreased in the left first metatarsal with induced knee (left p =0.01; right p =0.04) and ankle (left and right p <0.001) joint restriction. Finally, MPP was decreased in the right first metatarsal with knee (left and right p =0.01) and ankle (left p =0.04; right p =0.01) joint restriction.SignificanceLimited joint mobility may have a direct effect on plantar pressure, particularly with restriction in the hip and knee joints, hence careful attention should be given especially in patients with conditions involving plantar loadings. Results in this study also show that PTI changes during gait should be equally evaluated clinically along with peak plantar pressure analysis.     

Assessment of Left Ventricular Size and Function during Cardiac Surgery. An Intraoperative Evaluation of Six Two‐Dimensional Echocardiographic Methods with Real Time Three‐Dimensional Echocardiography as a Reference

Transesophageal echocardiography is recommended to monitor left ventricular (LV) size and function in various operations. Generally, two‐dimensional (2D) methods are applied intraoperatively. The aim of this study was to compare the accuracy and feasibility of 6 commonly used 2D methods to assess LV function during surgery. LV function in 120 consecutive patients was evaluated. Real time three‐dimensional transesophageal echocardiograpy (3DTEE) served as reference. End‐diastolic and end‐systolic volumes and ejection fraction (EF) were analyzed with Simpson's method of discs (monoplane [MP] and biplane [BP]), eyeball method, Teichholz' method, and speckle tracking (ST) methods. Furthermore, fractional area change (FAC) and peak systolic pressure rise (dP/dt) were determined. Each 2D method was evaluated regarding correlation and agreement with 3DE, intra‐ and interobserver variability and the time required for evaluation. Simpson BP showed the strongest correlation and best agreement with 3DE for EF (limits of agreement 3.7 ± 11.6%) and volumes. Simpson MP showed similar agreement with 3DE compared to ST (2.8 ± 14.5% vs. 2.0 ± 15.3% and 3.8 ± 14.4% vs. 1.9 ± 15.6%, respectively). Both the eyeball method and Teichholz' method showed wide limits of agreement (?1.5 ± 18.2% and 5.2 ± 22.1%, respectively). DP/dt did not correlate with 3DE. FAC and ST FAC showed similar agreement. Application of 3DE (429 ± 108 seconds) took the longest time, and the eyeball method took the shortest time (8 ± 5 seconds) for analysis. Simpson BP is the most accurate intraoperative 2D method to evaluate LV function, followed by long‐axis MP evaluations. Short‐axis views were less accurate but may be suited for monitoring. We do not recommend using dP/dt.     

The Burden of Iron Deficiency in Heart Failure: Therapeutic Approach

Heart failure (HF) is highlighted by its burdening symptom-limited exercise capacity and recurrent hospitalizations. Despite substantial advances regarding disease-modifying drugs in HF with reduced ejection fraction, additional therapeutic strategies to improve quality of life are invaluable. Currently, iron deficiency (ID) is overwhelmingly recognized in over 30% to 50% of patients with stable chronic HF, which worsens prognosis. The established pathophysiological mechanisms of progressive HF may be intertwined with increasing myocardial iron scarcity, wherein one begets the other. Most importantly, ID constitutes a novel target for symptom relief in carefully selected patients. In this regard, intravenous iron may be a safe and efficacious intervention, potentially reducing HF hospitalizations. We discuss the evidence and gaps in knowledge concerning iron therapy in HF and propose a practical, comprehensive, clinically oriented algorithm for timely adequate iron replenishment in different clinical scenarios. Finally, we further debate imperative decision-making before intervention and the drawbacks of such a strategy.     

Titration of Mechanical Insufflation–Exsufflation Optimal Pressure Combinations in Neuromuscular Diseases by Flow/Pressure Waveform Analysis

IntroductionThe aim of this study was to assess several air-pressure settings for MI–E to determine their effect on peak cough flow (PCF), and to compare the best pressures with those are more common used in the literature (±40 cmH₂O) in patients with neuromuscular disorders (NMD).MethodsAdults with NMD in whom MI–E was indicated were recruited. Assisted PCF was measured by an external pneumotachograph. The protocol included 9 PCF measures per patient: 1 baseline (non-assisted), 4 with increasing inspiratory pressures without negative pressure (10, 20, 30 and 40 cmH₂O or maximum tolerated), and then 4 adding expiratory pressures (?10, ?20, ?30 and ?40 cmH₂O or maximum tolerated) with maximum inspiratory pressure previously achieved.ResultsTwenty one patients were included, 61% with amyotrophic lateral sclerosis (ALS). Mean PCFs with recommended pressures (±40 cmH₂O) were lower than the scored in the individualized steps of the titration protocol (197.7 ± 67 l/min vs 214.2 ± 60 l/min, p < 0.05). Regarding subgroups, mean PCF_max values in ALS patients with bulbar symptoms were significantly higher than those achieved with recommended pressures (163.6 ± 80 vs 189 ± 66 l/min, p < 0.05).ConclusionThe PCF_max obtained with the protocol did not always match the recommended settings. It may be advisable to perform MI–E titration assessed by non-invasive PCF monitoring in patients with NMD, especially in ALS with bulbar involvement to improve the therapy detecting airway collapse induced by high pressures.     

Differentiation between Streptococcus pneumoniae and other viridans group streptococci by matrix-assisted laser desorption/ionization time of flight mass spectrometry

ObjectivesMatrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is becoming the method of choice for bacterial identification. However, correct identification by MALDI-TOF of closely related microorganisms such as viridans streptococci is still cumbersome, especially in the identification of S. pneumoniae. By making use of additional spectra peaks for S. pneumoniae and other viridans group streptococci (VGS). We re-identified viridans streptococci that had been identified and characterized by molecular and phenotypic techniques by MALDI-TOF.MethodsVGS isolates (n = 579), 496 S. pneumoniae and 83 non-S. pneumoniae were analysed using MALDI-TOF MS and the sensitivity and specificity of MALDI-TOF MS was assessed. Hereafter, mass spectra analysis was performed. Presumptive identification of proteins represented by discriminatory peaks was performed by molecular weight matching and the corresponding nucleotides sequences against different protein databases.ResultsUsing the Bruker reference library, 495 of 496 S. pneumoniae isolates were identified as S. pneumoniae and one isolate was identified as non-S. pneumoniae. Of the 83 non-S. pneumoniae isolates, 37 were correctly identified as non-S. pneumoniae, and 46 isolates as S. pneumoniae. The sensitivity of the MALDI-TOF MS was 99.8% (95% confidence interval (CI) 98.9–100) and the specificity was 44.6% (95% CI 33.7–55.9). Eight spectra peaks were mostly present in one category (S. pneumoniae or other VGS) and absent in the other category and inversely. Two spectra peaks of these (m/z 3420 and 3436) were selected by logistic regression to generate three identification profiles. These profiles could differentiate between S. pneumoniae and other VGS with high sensitivity and specificity (99.4% and 98.8%, respectively).ConclusionsSpectral peaks analysis based identification is a powerful tool to differentiate S. pneumoniae from other VGS species with high specificity and sensitivity and is a useful method for pneumococcal identification in carriage studies. More research is needed to further confirm our findings. Extrapolation of these results to clinical strains need to be deeply investigated.