磁致热疗肿瘤用磁场发生装置的研制

目的:设计一种磁感应致热疗肿瘤用的正弦波形磁场发生装置。方法:电路采用555时基芯片为核心,利用单运放与RC组成的电路,将脉冲波形信号转换为正弦波形信号,然后通过放大电路进行电流放大,加负载线圈后产生所需磁场。结果:所研制的磁场发生装置可调节产生频率范围为50～150 kHz的正弦波形磁场,加入微量纳米磁性粒子集合体后发生磁致产热现象。结论:所研制的磁场发生装置具有成本低,精度高,性能稳定,参数调整方便等优点,为研究磁致热疗肿瘤提供必要的手段。     

Correlation between Serum 25-Hydroxyvitamin D Level and Peripheral Arterial Stiffness in Chronic Kidney Disease Stage 3–5 Patients

Vitamin D deficiency and high brachial-ankle pulse wave velocity (baPWV) are each independently associated with higher incidence of mortality and cardiovascular (CV) disease or CV events, respectively. This study aimed to evaluate the relationship between serum 25-hydroxyvitamin D levels and baPWV in non-dialysis patients with stage 3–5 chronic kidney disease (CKD). We enrolled 180 CKD patients. A commercial enzyme-linked immunosorbent assay was used to measure 25-hydroxyvitamin D levels. BaPWV values were measured using an automatic pulse wave analyzer. Either left or right baPWV > 18.0 m/s was considered indicative of peripheral arterial stiffness (PAS). In this study, 73 (40.6%) patients were found to have PAS. Compared to those without PAS (control group), patients with PAS were older and had higher incidence of diabetes mellitus, higher systolic and diastolic blood pressure, higher levels of intact parathyroid hormone, and C-reactive protein, and lower levels of 25-hydroxyvitamin D. Multivariate logistic regression analysis found 25-hydroxyvitamin D levels (odds ratio [OR]: 0.895, 95% confidence interval [CI] 0.828–0.968, p = 0.005) and old age (OR: 1.140, 95% CI 1.088–1.194, p < 0.001) to be independently associated with PAS in patients with stage 3–5 CKD. Lower serum 25-hydroxyvitamin D levels and older age were associated with PAS in these patients.     

Development of a Flexible Metamaterial Film with High EM Wave Absorptivity by Numerical and Experimental Methods

The present study is intended to develop and test a cost-effective and efficient printing method for fabricating flexible metamaterial film with high electromagnetic wave absorptivity. The film can be easily applied to the surfaces with curved aspects. Firstly, numerical parametric study of the absorption characteristics of the film is performed for the range of frequency varying from 2.0 to 9.0 GHz based on commercial software package. Secondly, the flexible metamaterial films are fabricated, and experiments are conducted. The flexible metamaterial film consists of a flexible dielectric film made of polyimide (PI) and an array of split-ring resonators. The split-ring resonators of different geometric dimensions are fabricated on the PI film surface by using a silver nanoparticles ink jet printer. The performance of the flexible structure is then measured and dependence of operation frequency with higher absorptivity on the dimensions of the split-ring resonators is investigated. A comparison between the numerical and experimental data shows that the numerical predictions of the operation frequency with higher absorptivity closely agree with the experimental data.     

Polysomnographically determined sleep and body mass index in patients with insomnia

We assessed associations between polysomnographically determined sleep, especially the amount of slow-wave sleep (SWS), and body mass index (BMI) in patients with insomnia. One hundred and forty-one insomniacs and 55 healthy volunteers completed overnight polysomnographic recordings, and we measured height and body weight. No significant correlations were obtained between total sleep time and BMI among insomniacs. Compared with normal volunteers, insomnia patients exhibited longer sleep latency and shorter total sleep duration. While the two groups had no significant differences in BMI, insomniacs presented with more N1 but less time spend in SWS and rapid eye movement sleep (REMS). Based on their SWS time, we divided insomnia patients into three groups: short (26.99±13.88), intermediate (59.24±8.12), and long (102.21±26.17) SWS groups. The short-SWS group had significantly greater BMI than the long-SWS group. Further analyses with multiple linear regression showed a significant negative correlation between the amount of SWS and BMI scores in insomniacs, whereas no such correlation was found in healthy volunteers after controlling for potential confounds (e.g., age, sex and AHI). Our study suggests that low amounts of SWS may be associated with higher BMI in patients with insomnia.     

瞬时加速度波强与传统评价左心室收缩功能指标的比较

目的通过对左心室射血分数(LVEF)、左心室舒张末容积(EDV)、左心室收缩末容积(ESV)、瞬时加速度波强(W1)、6 min步行距离(6MWD)的比较,探索W1评价冠心病患者左心功能的价值。方法应用ProSoundα10彩色多普勒超声诊断仪检测患者EDV、ESV、LVEF、W1,随即测量患者6MWD,之后2 h内行冠状动脉造影,选择冠状动脉造影证实至少1支血管一处狭窄>50%患者83例作为研究对象。将入选者按6MWD分为2组(6 min运动距离正常组,6MWD>350 m;6 min运动距离减退组,6MWD<350 m),比较两组间EDV、ESV、LVEF、W1。结果两组EDV、ESV、W1、LVEF比较均有统计学意义(P<0.01);W1、LVEF与6MWD呈明显正相关(P<0.01);EDV、ESV与6MWD呈明显负相关(P<0.01)。结论 W1有望成为一项反映左心室收缩功能的超声指标。     

急性心肌梗死并左心衰竭与V_1导联P波终末电势变化

<正> 目前,急性心肌梗死(AMI)因心律失常致死的数量已减少,而在AMI的死亡原因中,心力衰竭变得更加突出。所以,AMI并发心力衰竭的正确诊断和有效治疗已成为降低AMI死亡率的关键问题。1 资料与方法1.1 资料 收集本科1988年1月至2002年12月根据临床症状,心电图和心肌酶学的变化明确诊断AMI抢救成功的并发症左心衰竭的62例患者的相关资料,其中男51例,女11例,年龄28～79岁,平均年龄55.6岁。前壁(包括前间壁、前壁、广泛前壁)38例,下壁10例,下壁+正后壁7例,前壁+下壁4例,非Q波型3例,所有患者均为首次发病。1.2 方法 所有患者在CCU病房中除了接受AMI常规治疗     

连续波充填技术的临床评价

目的评价连续波充填技术的临床疗效。方法选择牙髓病或根尖周病患者60例,按就诊顺序随机分为两组,分别采用连续波充填技术（CW组）和冷牙胶侧方加压充填技术（LC组）进行根管充填。术前、术后拍摄X线片。比较两组的根管充填时间、术中疼痛情况和根管充填效果。结果以牙为单位,CW组适充28例,超充1例,欠充1例;LC组中,适充27例,超充2例。欠充1例。CW组术中不适4例,LC组2例。以根管为单位,CW组根管充填时间平均每根管65．7s,LC组平均每根管203．8s（P〈0．05）。结论连续波充填技术临床操作简便有效,操作时间短。     

急性心肌梗死急诊介入治疗后早期T波倒置与Q—T离散度的关系

目的观察急性心肌梗死急诊介入治疗后早期T波倒置与Q—T离散度的关系。方法观察65例急性心肌梗死行急诊介入治疗患者,根据其是否在介入治疗后24h内出现T波倒置,将患者分为T波倒置组45例,未倒置组20例,分别观察肌酸激酶同工酶（CK—MB）、室性心律失常发生率、Q—T离散度及预后。结果T波倒置组肌酸激酶同工酶峰值减低、达酶峰时间提前、QTd及QTcd显著缩短,随访6个月,T波倒置组较未倒置组患者心功能改善明显,心血管事件发生率低。结论Q—T间期离散度变化和介入治疗后是否早期T波倒置均为心肌组织水平再灌注的简易临床指标,与临床预后有密切关系。     

Standard Terminologies for Photoplethysmogram Signals

Photoplethysmography is one of the optical techniques has been developed for experimental use in vasculardisease. It has several advantages over other traditional experimental approaches. Because of its non-invasive, safe, costeffectiveand easy-to-use properties, it is considered as a useful diagnostic tool. The further developments in the Photoplethysmographmay replace it among other tools used in the assessment of vascular diseases such as blood test and ultrasound.This overview discusses the different terminologies used for the photoplethysmograph and reveals the researchdiscontinuity among different disciplines. Moreover, it suggests standard terminologies as a resolution for a confusionpersisted for more than 50 years.     

Meta‐Analysis of P‐Wave Dispersion Values in Healthy Individuals: The Influence of Clinical Characteristics

Background: P‐wave dispersion (Pd) is an appealing marker for predicting the risk of developing atrial fibrillation. At present, no definitive cutoff value has been determined as to the diagnosis of high‐risk patients. Our aims were to evaluate P‐wave parameters of healthy subjects published in the literature, determine normal range and weighted means of Pd and P‐wave parameters, and investigate the influences of gender, age, and BMI on the weighted results. Methods: A systematic search of studies published in PubMed was conducted. Only studies which included control groups of healthy individuals were included. Results: Of the 657 studies initially identified, 80 were eligible for inclusion. The total number of participants was 6,827. The highest reported Pd values were 58.56 ± 16.24  ms; the lowest were 7 ± 2.7  ms. The weighted mean was 33.46 ± 9.65  ms; weighted median was 32.2  ms. Gender and age were not found to be associated with significant influences on P‐wave parameter values. High‐normal BMI was not found to be associated with increased P‐wave parameter values. Conclusions: Pd, Pmax, and Pmin span a wide range of values in healthy individuals. Seemingly, abnormal values were often reported in healthy adults. The high variability of P‐wave parameters in healthy individuals, and overlapping of the results with those reported for patients with increased risk for atrial fibrillation, might suggest that this technique has limited sensitivity and specificity. The variability between studies may stem from methodological issues and, therefore, there is a definite need for methodological standardization of Pd measurements. Ann Noninvasive Electrocardiol 2012;17(1):28–35