Comparative drug release studies of two cationic drugs from pH-responsive nanogels

pH-responsive nanogels consisting of methacrylic acid–ethyl acrylate (MAA–EA) cross-linked with di-allyl phthalate (DAP) were synthesized via the emulsion polymerization process. Delivery systems based on pH-responsive nanoparticles can control the release of rapidly metabolized drugs and/or have the ability to protect sensitive drugs, thereby making them ideal candidates for drug delivery applications. In this study, a drug selective electrode (DSE) was used to directly measure the concentration of procaine hydrochloride (PrHy) and imipramine hydrochloride (IMI) released from MAA–EA nanogels. With a single drug delivery system, drug release for two different drugs loaded via two distinctly different interaction forces was demonstrated. Drug release was conducted using the DSE under different pHs, MAA–EA molar ratio and DAP content. The release rate increased with pH for PrHy loaded nanogels and MAA–EA molar ratio but decreased with pH for IMI loaded nanogels and DAP content. PrHy was found to be hydrophobically bounded, while IMI was found to be electrostatically bounded onto the MAA–EA nanogels, which was further enhanced by hydrogen bonding.     

电阻抗断层成像应用技术研究

电阻抗断层成像（EIT）是一种全新的医学成像和图像监护技术.提出了我国EIT应用技术研究可能面临的一些问题和建议,涉及电极性能与评价方法,数据采集与图像增强,成像算法和特征信息识别与诊断判据等.希望能对我国EIT研究的发展有所帮助.     

NOVA M7血气分析仪代谢电极故障排除与测定结果的影响因素

血气分析仪是医院中不可缺少的临床检验设备之一,对临床医生具有重要的指导意义。本文主要通过二部分内容对血气分析仪在实际应用当中出现的问题及设备的操作维护进行了总结。这也是本人在实际工作中研究摸索出来的。文章的最后简单阐述了本人对未来血气分析仪技术的一种憧憬。总之,希望引进更先进技术,更好的服务于临床及科研项目,提高医疗护理质量。     

银质针热灸疗法治疗梨状肌综合征72例观察

目的:观察银质针热灸疗法治疗梨状肌综合征的临床疗效。方法:治疗组72例用银质针疗法加艾灸治疗,对照组64例用局部封闭治疗。结果:治疗组治愈率80.6%,总有效率100%;对照组分别为40.6%和90.6%。两组比较有极显著性差异(P<0.01)。结论:银质针热灸疗法治疗梨状肌综合征疗效较好。     

磺胺脒在多壁碳纳米管修饰电极上的伏安法测定

目的:制作碳纳米管修饰电极,并比较磺胺脒在裸玻碳电极和多壁碳纳米管修饰电极上的电化学行为差异。方法:循环伏安法。结果:与裸玻碳电极比较,多壁碳纳米管修饰电极能显著提高磺胺脒的氧化还原峰电流并减小其氧化还原峰电位的差值。氧化峰电流与磺胺脒的浓度在5.0×10~(-7)～1.0×10~(-4)mol·L~(-1)范围内呈线性关系,检出限为1.0×10~(-7)mol·L~(-1)。结论:多壁碳纳米管修饰电极对磺胺脒的电化学氧化还原具有很高的催化作用。     

聚结晶紫薄膜修饰电极对氧氟沙星的电催化作用

目的:利用循环伏安法电聚合制备出对氧氟沙星(OFX)具有良好电催化作用的聚结晶紫薄膜修饰电极(PCVE),建立一种对 OFX 进行定量测定的新的电化学分析方法。方法:在0.050 mol·L~(-1)硫酸钠溶液 0.08 mol·L~(-1)。醋酸-醋酸钠缓冲液(pH=4.4)体系中,于0.4～1.2 V 范围内,以100 mV·s~(-1)的扫描速率进行循环伏安分析。结果:氧氟沙星的线性范围为1.6×10~(-7)～2.0×10~(-4)mol·L~(-1),r=0.9995,检测限可达8.0×10~(-9)mol·L~(-1)。样品分析的 RSD 均小于2%(n=8),回收率为95.7%～102.1%。结论:PCVE 制备简单、稳定性好。该方法是一种灵敏、准确测定样品中微量 OFX 的新的电化学分析方法。     

肿瘤联合治疗仪的研制

介绍一种肿瘤联合治疗仪，它基于１＋１＝３或１＋１＋１＞３的肿瘤联合治疗增效原理，因其适应症广、疗效好、安全方便而成为目前较具前景的肿瘤治疗方法。该治疗仪结合ＰＣ机Ｗｉｎｄｏｗｓ操作平台，采取智能化温控装置，对腔内肿瘤病灶进行均匀、平稳的射频加热，并实现对治疗病例及数据的存储与统计管理。经临床使用，治疗仪工作稳定可靠，具有较高的应用价值。     

Septic Shock Induced From An Implantable Cardioverter-Defibrillator Lead-Associated Candida albicans Vegetation

In recent years, the use of implantable cardioverter-defibrillators has made a significant impact in the treatment of cardiac disease. With the advent of this therapy, infection has become a growing concern, with a reported incidence of 1–11%. Although device-related infections are most frequently caused by bacterial pathogens, fungal etiologies are uncommon and carry an exceedingly high mortality rate. To date, there is only one published report of an implantable cardioverter-defibrillator lead-associated infection secondary to Candida albicans. This case report presents the second such case. A review of the literature regarding fungal endocarditis as well as diagnosis and therapy of this rare and dangerous disease is discussed.     

A model for cochlear implant electrode insertion and force evaluation: results with a new electrode design and insertion technique

OBJECTIVES AND HYPOTHESIS: This study has the specific aim of evaluating the insertion characteristics of a new cochlear implant electrode. Techniques for evaluation of fluoroscopic real time mechanical insertion dynamics, histologic electrode position and trauma results, hydraulic force, and mechanical insertion forces are presented. In addition, this study should serve to present a novel model for cochlear implant electrode insertion evaluations. STUDY DESIGN: Prospective analysis using a series of analytical techniques. METHODS: All studies are conducted in fixed cadaveric temporal bones. Real time fluoroscopic insertion evaluations, histologic evaluations for trauma and electrode position in embedded bones, hydraulic measures, and mechanical intracochlear force measurements are conducted with a current and new electrode. RESULTS: The Contour Advance electrode provides a more reliable and less traumatic insertion when deployed with the Advance Off Stylet technique. This is largely because of a reduction in intracochlear outer wall force generation. Fluoroscopic and histologic analysis reveal a smooth insertion without reliance on cochlear outer wall contact. No hydraulic forces were detected when measured from the superior semicircular canal ampulla. CONCLUSION: The model used for this study provides valuable information to cochlear implant surgeons and design engineers. The Contour Advance electrode, inserted with the Advance Off Stylet technique, represents an improvement over the Contour electrode inserted with the standard insertion technique.     

Across-Site Variation in Detection Thresholds and Maximum Comfortable Loudness Levels for Cochlear Implants

In cochlear implants, variation across stimulation sites in psychophysical detection thresholds (T levels) and maximum comfortable loudness levels (C levels) can be large when narrow-bipolar (BP) stimulation is used. This across-site variation is typically smaller when monopolar (MP) stimulation is used. At least two models can account for across-site variation and the effects of electrode configuration on the magnitude of the variation. According to one model, across-site variation reflects site-to-site differences in the distances between the stimulating electrodes and the sites of action-potential initiation. Under this model, the lower across-site variation with MP stimulation is due to shallower current versus distance gradients. An alternative model assumes that T and C levels depend on integration of activity across the whole population of neurons and that MP stimulation activates neurons over a larger spatial extent than does BP stimulation. If T and C levels are determined by integration of activity across large overlapping populations of neurons, then their values at adjacent sites should be more similar than if these levels result from integration across smaller, more independent populations. We tested the models by examining the effects on across-site variation of three variables believed to affect the spatial extent of activation: electrode configuration, stimulus level within the dynamic range, and electrode-array design. T levels and C levels were measured in 13 subjects with Nucleus^® CI24M (straight array) and 9 subjects with Nucleus^® CI24R(CS) (Contour) cochlear implants using bipolar (BP) and monopolar (MP) electrode configurations. Site-to-site variation in T and C levels for BP stimulation was 2.1–3.3 times larger than that for MP stimulation. Contrary to the across-neuron integration hypothesis, no significant differences were found between across-site variation for T levels and that for C levels for the BP configuration. There was considerable overlap in site-to-site variation values for the two types of implants but mean site-to-site variation in C levels for CI24M implants was significantly lower than that for CI24R(CS) implants. Control studies suggested that these results were not an artifact of the scale, and not due to differences in inherent variability of the psychophysical measures, or to the method of quantifying across-site variation.