Magnetron Sputtered CsPbCl3 Perovskite Detectors as Real-Time Dosimeters for Clinical Radiotherapy

The aim of this study is to investigate the feasibility of manufacturing thin real-time relative dosimeters for clinical radiotherapy (RT) with potential applications for transmission monitoring in vivo dosimetry and pre-treatment dose verifications. Thin (≈1 μm) layers of a high sensitivity, wide bandgap semiconductor, the inorganic perovskite CsPbCl₃, have been grown for the first time by magnetron sputtering on plastic substrates equipped with electrode arrays. Prototype devices have been tested in real-time configuration to evaluate the dose delivered by a 6 MV photon beam from a linear accelerator. Linearity of the charge with the dose has been verified over three order of magnitudes, linearity of the current signal with the dose rate has been also successfully tested in the range 0.5-4.3 Gy/min. The combination of high sensitivity per unit volume and wide bandgap provides high signal-to-noise ratios, up to 70, even at moderate applied voltages. The Schottky diode configuration allows the detector to operate without bias voltage (null bias).The blocking-barrier structure allows to confine the active volume within sub-millimetric sizes, a quite attractive feature in view to increase granularity and achieve the high spatial resolutions required in modern RT techniques. All the above-mentioned features indeed pave the way to a novel generation of flexible, transmission, real time dosimeters for clinical radiotherapy.     

丁二酸酐交联羟基超支化聚(胺-酯)的反应及其交联膜的性质

以丁二酸酐(SA)为交联剂研究了端羟基超支化聚(胺-酯)(HPAE)的交联反应和交联膜的制备。结果表明:SA与HPAE的交联反应分为两个阶段,可以采用溶液法低温涂膜及高温交联得到HPAE/SA交联膜;改变SA的用量可控制膜的交联度,HPAE/SA交联膜的拉伸强度随SA用量的增大而提高,最高可达59.60 M Pa,膜表面的水接触角小于74.3°。     

复方环丙氟哌酸鼻腔膜的研制及临床疗效观察

本文以明胶海绵为衬底,用环丙氟哌酸和氢化考的松、云南白药酊、达克罗宁制备的鼻腔消炎止血药膜,制备简便,质量稳定。临床观察结果证明,具有给药方便、疗效高、疗程短、药物作用持久,无毒副作用等优点。     

Radiologic search for embolized leaflets of prosthetic heart valves: A report of two cases

In a radiologic search for embolized leaflets of Edwards-Duromedics bileaflet valves in 2 patients, the embolized fragments were localized in the iliac vessels using computed tomography. Sonography was successful in one case and standard X-ray films of the abdomen were negative in both cases.In vitro investigations with Björk-Shiley and Edwards-Duromedics leaflets suggested that standard X-ray films of the abdomen and pelvis should be considered as the first investigational technique. If negative, computed tomography of the lower abdomen should be done.     

Formation of Regular Hole Pattern in Polymer Films

Ordered macroporous materials recently have attracted much attention. A method that utilizes the condensation of monodisperse water droplets on a polymer solution is proposed for the preparation of honeycomb microporous films. Our results show that it is a general method that can be used for patterning a wide range of polymers. The presence of water vapor and polymer is necessary for the formation of regular holes in films. The formation of hexagonal packing instead of other kinds of packing takes place because the hexagonal packing has the lowest free energy. The formation mechanisms of regular hole pattern and imperfections in the hexagonal packing are proposed.

Hexagonal hole structures in a PMMA film.     

Functional Thin Polymer Films at High Pressure

Summary: A new thin‐film characterization setup was created based on the combination of a surface plasmon spectrometer with an electrochemical cell operated under high pressure of up to 200 MPa and at temperatures up to 120 °C. The examples given to document its performance include photoisomerization studies with poly(methyl methacrylate) (PMMA) films partly derivatized with disperse red (DR1), as well as, a preliminary account of the electropolymerization of EDOT under pressure and the assessment of the redox properties of the resulting thin PEDOT films.

Sketch of the high‐pressure electrochemistry surface plasmon cell.     

Dexamethasone loaded bioresorbable films used in medical support devices: structure, degradation, crystallinity and drug release

Bioresorbable polymer films containing dexamethasone (DM) were prepared using a solution processing technique. Investigation of the films focused on cumulative DM release as affected by film morphology (drug location/dispersion in the film) and degradation processes. Two film structures were studied: A-type, a polymer film with large drug crystals located on the film’s surface, and B-type, a polymer film with small drug particles and crystals distributed within the bulk. The effect of the polymer’s degree of crystallinity on the drug release profile was also studied. Prototypical applications of these films are biodegradable medical support devices which combine mechanical support with drug release. In most of our studied systems the drug release profile from the film is determined mainly by both drug location/dispersion in the film and the polymer’s weight loss rate. All release profiles from A-type films exhibited a burst effect of approximately 30%, accompanied by a second release phase at a constant rate, whereas the release profiles from B-type films were determined mainly by the degradation profile of the host polymer, and did not exhibit any burst effect. A high degree of crystallinity is important for the current application, since good mechanical properties are required. This contributes to slower drug release rates, mainly at relatively low weight losses, whereas at high weight losses, where a porous structure is created, the crystallinity almost does not affect the rate of drug release. The shape of the porous structure that develops with degradation also affects the drug release profile from the B-type films.     

用银杏叶制剂EGB761治疗急性脑梗死的研究

目的探讨银杏叶制剂对急性脑梗死的治疗效果。方法随机选择银杏叶制剂配合治疗及常规药物治疗急性脑梗死患者各42例,对不同时期单光子发射电子计算机断层扫描(SPECT)、经颅多普勒超声检查(TCD)及血液流变学进行对比分析。结果银杏叶制剂配合治疗组治愈率及显效率明显高于常规药物治疗组(P＜0.01);银杏叶治疗组血液流变学指标全血粘度及血浆粘度均明显降低(P＜0.01);SPECT及TCD均示脑缺血病灶有不同程度改善,但常规药物治疗组血液流变学、SPECT、TCD改善均不明显。结论银杏叶制剂治疗急性脑梗死效果显著。     

口腔溃复平膜剂的研究

目的：优选口腔溃复平膜剂（黄柏，龙胆草，青黛等）最佳处方。建立膜剂中盐酸小檗碱含量的测定方法。方法：以膜剂外观和融化时间为指标。采用L9（3^4)正交试验筛选处方，反相液相色谱法测定膜剂中盐酸小檗碱的含量。结果：膜剂最佳处方为：中药提取液40mL,PVA0.588:PVA1788为4：1.5，甘油含量8%，CMC-Na0.25g；测定方法中盐酸小檗碱的平均回收率为97.7%。结论：膜剂的外观（包括可塑性，粘附性及抗拉强度）和融化时间等指标均符合质量标准的要求，采用反相液相色谱法可有效控制溃复平膜剂中盐酸小檗碱的含量。     

仙人掌清除·OH自由基及对DNA损伤的保护作用

目的研究野生仙人掌和食用仙人掌水提物清除·OH自由基及对DNA损伤的保护作用。方法采用现代生物化学发光技术,在CuSO4-Phen-Vc-H2O2-DNA化学发光体系中测定野生仙人掌和食用仙人掌清除·OH自由基及对DNA损伤的保护作用。采用紫外分光光度计测定野生仙人掌和食用仙人掌水提物中核酸和蛋白质的OD值。结果野生仙人掌能明显清除·OH自由基,抑制DNA的氧化损伤,对DNA氧化损伤的保护作用与其浓度之间存在正比性量效关系。食用仙人掌核酸和蛋白质的OD值为野生仙人掌的2.73倍和2.58倍,但不显示清除·OH自由基作用。结论野生仙人掌对·OH自由基引起的DNA损伤有明显的保护作用。食用仙人掌有较高的营养价值,但无抗DNA氧化损伤的作用。