Controlled release from a mechanically-stimulated thermosensitive self-heating composite hydrogel

Temperature has been extensively explored as a trigger to control the delivery of a payload from environment-sensitive polymers. The need for an external heat source only allows limited spatiotemporal control over the delivery process. We propose a new approach by using the dissipative properties of a hydrogel matrix as an internal heat source when the material is mechanically loaded. The system is comprised of a highly dissipative hydrogel matrix and thermo-sensitive nanoparticles that shrink upon an increase in temperature. Exposing the hydrogel to a cyclic mechanical loading for a period of 5 min leads to an increase of temperature of the nanoparticles. The concomitant decrease in the volume of the nanoparticles increases the permeability of the hydrogel network facilitating the release of its payload. As a proof-of-concept, we showed that the payload of the hydrogel is released after 5–8 min following the initiation of the mechanical loading. This delivery method would be particularly suited for the release of growth factor as it has been shown that cell receptor to growth factor is activated 5–20 min following a mechanical loading.     

改良头皮冠状切口在颧骨复合体骨折中的应用

目的:探讨改良头皮冠状切口在各类颧骨复合体骨折坚固内固定术中的应用。方法:将87例颧骨复合体骨折病例分为改良组和传统组,分别应用改良冠状切口(42例)与传统切口(45例)进行复位和固定,对比分析改良冠状切口的优越性、可能并发症及预防措施。结果:改良组切口均Ⅰ期愈合,随访3⁶个月,面部瘢痕不明显,开口度恢复理想,咬合关系正常,术后秃发率及颞部凹陷率较低,无1例出现面神经功能障碍。传统组中,2例术后第5天出现创区感染,切口延期愈合,术后肿胀反应明显;4例患者术后3月时仍存在面神经功能障碍,术后秃发率及颞部凹陷率较高。结论:改良冠状切口较传统切口具有切口隐蔽、术野暴露好、复位精确、美观效果好、面神经损伤率低等优点,值得推广应用。     

重组人红细胞生成素对大鼠急性心肌梗死的影响

目的:观察重组人红细胞生成素(rHuEPO)对心肌梗死大鼠心功能和心肌梗死面积的影响,并探讨其机制. 方法:16只Wistar大鼠随机分心肌梗死组和治疗组,结扎左冠前降支制备急性心肌梗死模型,治疗组围手术期连续3 d腹腔注射rHuEPO[3000 IU/(kg*d)], 14 d后以相同剂量再连续注射3 d;术后2 d及3 wk二维超声心动图检查心功能;术后3 wk处死大鼠,TTC测定心肌梗死面积,免疫组化检测缺血区毛细血管密度、Bcl-2和Bax的表达. 结果: 术后2 d两组之间心功能无明显差异,术后3 wk对照组左室射血分数(LVEF)和左室收缩末期内径(LVDs)改善程度明显劣于治疗组(P<0.05). 与对照组相比,术后3 wk治疗组梗死面积明显减少[分别为(26.0±0.9)%,(28.1±1.5)%, P<0.05]、毛细血管密度显著增加[分别为(10.4±1.5)/视野,(6.3±0.7)/视野,P<0.05],Bcl-2蛋白表达增加(A值分别为0.116±0.005,0.103±0.007, P<0.05),而Bax表达减弱(A值分别为0.125±0.010,0.147±0.014,P<0.05). 结论:rHuEPO能缩小大鼠心肌梗死面积,改善心肌梗死后心功能,其机制可能与减少缺血区心肌细胞凋亡以及促进缺血区毛细血管生成有关.     

连花清瘟制剂治疗社区获得性肺炎疗效及安全性的系统评价和Meta分析

目的 探究连花清瘟制剂治疗社区获得性肺炎的疗效和安全性。方法 系统检索PubMed、Embase、Cochrane Collaboration、中国知网、维普、万方医学网数据库中所有口服连花清瘟制剂治疗社区获得性肺炎的临床随机对照试验,时间为从建库至2023年2月,制订纳排标准并对检索结果进行筛选,采用风险评估工具（ROB）量表对最终纳入研究的方法学质量进行评价,使用R软件进行数据合并及Meta分析。结果 共纳入30篇文献,包含2 800例患者,在使用抗生素等常规治疗的基础上联合使用连花清瘟,结果显示加用连花清瘟可以提高治愈率［相对危险度（RR）=1.32,95%置信区间（95%CI）［1.23,1.42］,P<0.000 1］并缩短退热时间［均数差（MD）=-1.45,95%CI［-1.93,-0.97］,P<0.000 1］,以患者群体将退热时间分为普通人群及特殊人群亚组,结果均显示加用连花清瘟可以缩短退热时间（普通人群MD=-1.51,95%CI［-2.07,-0.94］,P<0.000 1,特殊人群MD=-1.22,95%CI［-2.16,-0.29］,P=0.010 6）,且不会增加不良反应发生率（RR=0.85,95%CI［0.62,1.15］,P<0.000 1）。使用剪补法补充9篇阴性结果虚拟文献后,加用连花清瘟仍然可以提高CAP的治愈率（RR=1.20,95%CI［1.13,1.29］,P<0.000 1）,结果稳定。结论 CAP治疗中使用抗生素的基础上加用连花清瘟可以提高治愈率并缩短退热时间。     

基于薄板样条和形状内容的医学图像非刚性配准方法研究

目的 针对医学图像非刚性点配准的现状,给出一种基于点特征的非刚性配准方法.方法 利用一种新的相似度测量方法--形状内容来解决两幅图像中点的对应关系,并利用点对应关系来估计非刚性映射函数.结果 利用薄板样条实现了医学图像的快速准确非刚性配准.结论 实验结果表明,上述方法获得了很好的配准效果.     

Integration of Merged Delayed‐Enhanced Magnetic Resonance Imaging and Multidetector Computed Tomography for the Guidance of Ventricular Tachycardia Ablation: A Pilot Study

MDCT/MRI Fusion for the Guidance of VT Ablation . Background: Delayed enhancement (DE) MRI can assess the fibrotic substrate of scar‐related VT. MDCT has the advantage of inframillimetric spatial resolution and better 3D reconstructions. We sought to evaluate the feasibility and usefulness of integrating merged MDCT/MRI data in 3D‐mapping systems for structure–function assessment and multimodal guidance of VT mapping and ablation. Methods: Nine patients, including 3 ischemic cardiomyopathy (ICM), 3 nonischemic cardiomyopathy (NICM), 2 myocarditis, and 1 redo procedure for idiopathic VT, underwent MRI and MDCT before VT ablation. Merged MRI/MDCT data were integrated in 3D‐mapping systems and registered to high‐density endocardial and epicardial maps. Low‐voltage areas (<1.5 mV) and local abnormal ventricular activities (LAVA) during sinus rhythm were correlated to DE at MRI, and wall‐thinning (WT) at MDCT. Results: Endocardium and epicardium were mapped with 391 ± 388 and 1098 ± 734 points per map, respectively. Registration of MDCT allowed visualization of coronary arteries during epicardial mapping/ablation. In the idiopathic patient, integration of MRI data identified previously ablated regions. In ICM patients, both DE at MRI and WT at MDCT matched areas of low voltage (overlap 94 ± 6% and 79 ± 5%, respectively). In NICM patients, wall‐thinning areas matched areas of low voltage (overlap 63 ± 21%). In patients with myocarditis, subepicardial DE matched areas of epicardial low voltage (overlap 92 ± 12%). A total number of 266 LAVA sites were found in 7/9 patients. All LAVA sites were associated to structural substrate at imaging (90% inside, 100% within 18 mm). Conclusion: The integration of merged MDCT and DEMRI data is feasible and allows combining substrate assessment with high‐spatial resolution to better define structure–function relationship in scar‐related VT. (J Cardiovasc Electrophysiol, Vol. 24, pp. 419‐426, April 2013)     

血管内超声对冠状动脉临界病变的临床应用

目的应用血管内超声(IVUS)对冠状动脉造影(CAG)提示冠状动脉临界病变的患者检查,评价IVUS在冠状动脉临界病变诊断及治疗中的应用价值。方法选择经CAG诊断为冠状动脉存在临界狭窄的78例患者,其中男性56例,女性22例;年龄34～71岁,平均年龄55.4岁。行IVUS检查和CAG,对照分析两种检查结果。结果CAG检测发现偏心性斑块31处,向心性斑块82处;而行IVUS检测发现偏心性斑块56处,向心性斑块57处。IVUS清楚显示软斑块54处,硬斑块23处,混合性斑块36例,其中探查血栓1处,溃疡2处;而CAG不能显示管腔形态及斑块特点。病变最窄处血管面积狭窄率IVUS所测值明显高于CAG,分别为68%±21%、58%±19%(P<0.05),两者比较差异具有统计学意义。结论对于CAG显示的临界狭窄病变,IVUS能更准确地判定管腔形态、病变性质及狭窄程度,对冠心病特别是有冠心病症状的患者的诊断及临床介入治疗有重要意义.     

多囊卵巢综合征患者复方醋酸环丙孕酮治疗前后激素和糖代谢变化的临床观察

为观察达英-35治疗多囊卵巢综合征(PCOS)在明显降低黄体生成素(LH)及睾酮(T)水平,改善患者内分泌状况的同时,是否改善其胰岛素抵抗(IR),35例PCOS患者服用复方醋酸环丙孕酮(达英-35)治疗3个周期,观察用药前后临床特征、血清激素水平、空腹血糖、空腹胰岛素(FIN)的变化.结果显示,治疗后34例PCOS患者月经恢复,多毛及痤疮评分下降(P<0.01),双侧卵巢体积明显缩小(P<0.01).血清LH、FSH、T水平和LH/FSH明显下降(P<0.01).FIN水平明显下降(P<0.01),IR也有相应降低(P<0.01),空腹血糖(FBG)和胰岛素敏感性指数(ISI)无明显改变(P>0.05).达英-35有很强的抗雄作用,明显改善了PCOS患者的内分泌状况和临床症状.     

早期帕金森病99Tcm-TRODAT-1多巴胺转运蛋白SPECT脑显像

目的　应用99Tcm TRODAT 1进行多巴胺转运蛋白 (DAT)SPECT脑显像 ,探讨其在早期诊断帕金森病中的应用价值。方法　对Hoehn Yahr分级为Ⅰ级的 7例偏侧帕金森病患者和 7例年龄匹配的健康志愿者进行99Tcm TRODAT 1SPECT脑显像。应用计算机感兴趣区 (ROI)技术半定量计算纹状体 /小脑、尾核 /小脑和壳核 /小脑放射性计数比值 ,分别代表纹状体、尾核和壳核的DAT功能水平 ,对帕金森病患者纹状体及其组成部分的DAT功能与健康志愿者的相应区域DAT功能进行比较 ,并对帕金森病患者患侧肢体对侧和同侧纹状体、尾核和壳核的DAT功能分别进行比较。结果　早期帕金森病患者双侧纹状体DAT功能均低于健康志愿者 (1.5 5± 0 .16,1.46± 0 .14 ,1.80± 0 .0 4,P <0 .0 5 ,P <0 .0 1) ,并以患侧肢体对侧纹状体功能降低明显 (P <0 .0 1) ;与健康志愿者相比 ,双侧尾核DAT功能降低 (2 .2 0± 0 .0 5 ,1.88± 0 .3 8,1.62± 0 .2 2 ,P <0 .0 5 ,P <0 .0 0 1) ;与健康志愿者相比 ,双侧壳核DAT功能降低 (1.92± 0 .10 ,1.61± 0 .15 ,1.43± 0 .2 0 ,P <0 .0 1,P <0 .0 0 1) ,且以患侧肢体对侧壳核DAT功能降低明显 (P <0 .0 5 )。所有受检者在显像过程中及显像后均无不良反应发生。结论　99Tcm TRODAT 1SPECT脑显像有助于临床早期诊