砷与5-氮胞苷对人淋巴细胞DNA损伤的联合作用

为探讨砷和5－氮胞苷对人淋巴细胞DNA损伤及修复的联合作用，应用单细胞凝胶电泳（SCGE）技术比较研究了5－氮胞苷与砷同时和前后作用于人类淋巴细胞产生的联合毒性，结果显示10μmol/L5-氮胞苷和10μmol/L砷单独处理人淋巴细胞2h引起明显的DNA泳动（彗星尾），但两试剂引起的DNA泳动（彗星尾）间无显差异，5－氮胞苷前处理与砷后处理2h引起的彗星尾与其单独处理组比较非常显，砷前处理与5－氮胞苷后处理引起的彗星尾与其单独处理组比较无显性差异，但较对照组差异显，10μmol/L5-氮胞苷和10μmol/L砷分别单独处理2h引起了人淋巴细胞显的DNA损伤（链断裂），5－氮胞苷与砷在对淋巴细胞DNA的损伤上表现为单纯相加作用。5－氮胞苷前处理显增加了细胞对砷的基因毒性的敏感性，或砷后处理显增加了5－氮胞苷引起的DNA损伤，5－氮胞苷后处理2h显抑制了细胞对砷所致DNA损伤的修复。     

生物高分子-氧化石墨烯三维多功能复合凝胶的制备及其血液净化性能

以生物高分子（壳聚糖、白蛋白、脱氧核糖核酸）为交联剂与氧化石墨烯片层进行三维自组装,冻干后得到生物高分子 氧化石墨烯复合凝胶。通过扫描电镜、原子力显微镜、纳米粒度分析仪等分析其物化性能。结果表明：生物高分子成功组装到氧化石墨烯片层上,并形成三维多孔结构,制备的凝胶显示出极好的血液相容性,有效抑制了红细胞的溶血现象,对阳离子毒性分子及重金属离子有较高的吸附量。     

Evaluation of wound healing activities of kefir products

Kefirs are natural probiotic compounds with antibacterial and anti-inflammatory properties which were tested in experimental burn injury. Kefir gels were prepared from an extract of continuously cultured kefir grains in MRS Broth medium for 24, 48 and 96h. Similar burn injuries were made on dorsal skin surface of 56 rats. After 24h the wounds were infected with Pseudomonas aeruginosa. The infected rats were divided in to 7 groups of 8 rats each. The base gel, silver sulfadiazine ointment, kefir 24h gel, kefir 48h gel, kefir 96h gel and kefir grains 96h gel were applied twice a day. Burn wound area was measured at baseline, one and two weeks. After two weeks the animals in all groups were sacrificed and whole skin wound areas were removed and percentage of epithelization, scar formation, inflammation and angiogenesis were evaluated. Results indicated that at the end of the 2nd week the percentage of wound size were lowest in order of kefir 96h gelgelgelgelgel groups. At the end of the 2nd week the percentage of inflammation was lower and percentage of epithelization and scar formation was higher in order of kefir 96h gel, kefir grains 96h gel, kefir 48h gel, kefir 24h gel, silver sulfadiazine 1%, base gel and untreated groups. In conclusion the kefir gel therapy was an effective therapeutic approach to improve outcomes after severe burn as compared to conventional silver sulfadiazine treatment.     

Evaluation of a Cornstarch-Based Ultrasound Gel Alternative for Low-Resource Settings

Background

Ultrasound is an ideal imaging modality for low-resource settings given its portability, ease of use, and wide range of applications. Commercially available ultrasound gels may be unavailable or cost prohibitive in low-resource settings.

Objective

Our aim was to investigate the quality of images obtained with an alternative ultrasound gel made from cornstarch and water in comparison with commercially available gel.

Methods

The cornstarch gel was made by heating water and cornstarch. The gel was used to obtain standard ultrasound images of the gallbladder, kidneys, bladder, heart, and neck vessels by the study investigators. Commercial gel was used as the control. Twenty-four ultrasound clips were shown to four blinded radiologists and two ultrasound-fellowship−trained emergency department physicians. They rated the images on adequacy (yes/no) and graded the images detail, resolution, and quality using a continuous 0−10 scale.

Results

A total of 144 video clips were shown to reviewers and 129 data-collection sheets were returned. There was no statistical difference in the proportion of images deemed to be of adequate quality: cornstarch-based gel = 0.97 (95% confidence interval [CI] 0.92−1.00) vs. commercially available gel = 0.85 (95% CI 0.75−0.94) (p = 0.053). The cornstarch gel was superior to commercial gel on all three image parameters: detail (p = 0.002), resolution (p = 0.018), and quality (p = 0.013).

Conclusions

In this study, a gel made from cornstarch and water was an acceptable coupling medium and provided equally adequate images as compared with commercial ultrasound gel. This inexpensive gel made from ubiquitous materials can be an acceptable alternative to commercial gel in low-resource settings.     

A potential role of aminoglycoside resistance in endemic occurrence of Pseudomonas aeruginosa strains in lower airways of mechanically ventilated patients

Altogether, 98 Pseudomonas aeruginosa isolates from a 5-bed intensive care unit were fingerprinted with pulsed-field gel electrophoresis and tested for aminoglycoside resistance genes aac(6′)-Ib, aac(3″)-IIa, ant(2″)-Ia, armA, rmtA, and rmtB and integrons and virulence genes/operons phzI, phzII, phzM, phzS, apr, lasB, plcH, plcN, pilA, algD, toxA, exoS, exoT, exoY, and exoU. Two major clusters were identified (49 and 19 isolates), harbouring aac(6′)-Ib, bla_PSE-1, and ant(3″)-Ia genes or ant(2″)-Ia gene, respectively, on a class I integron. Most virulence genes except for exoU and pilA were found. Only 1 isolate of the minor cluster (8 isolates) and 1 of the 22 sporadic isolates carried integrons (without gene cassettes); virulence profile was highly variable. Comparing the resistance and virulence patterns of endemic and sporadic isolates suggests that integron-borne aminoglycoside resistance is more closely associated with the frequency than virulence. Consequently, aminoglycoside usage may have played a role in maintenance of the endemic clones.     

ZnO Films Incorporation Study on Macroporous Silicon Structure

In the present work, we developed hybrid nanostructures based on ZnO films deposited on macroporous silicon substrates using the sol–gel spin coating and ultrasonic spray pyrolysis (USP) techniques. The changes in the growth of ZnO films on macroporous silicon were studied using a UV-visible spectrometer, an X-ray diffractometer (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). XRD analysis revealed the beneficial influence of macroporous silicon on the structural properties of ZnO films. SEM micrographs showed the growth and coverage of ZnO granular and flake-like crystals inside the pores of the substrate. The root mean square roughness (RMS) measured by AFM in the ZnO grown on the macroporous silicon substrate was up to one order of magnitude higher than reference samples. These results prove that the methods used in this work are effective to cover porous and obtain nano-morphologies of ZnO. These morphologies could be useful for making highly sensitive gas sensors.     

A novel topical combination of minoxidil and spironolactone for androgenetic alopecia: Clinical,histopathological, and physicochemical study

Topical minoxidil 5% are effective in androgenetic alopecia (AGA). Spironolactone acts as an androgen antagonist by competitively blocking androgen receptors. Studying the effect of topical minoxidil 5% gel and spironolactone gel 1% in management of AGA. The study includes 60 patients diagnosed as AGA; (group I): treated with topical minoxidil gel 5%, (group II): with topical spironolactone gel 1% and group (III) treated with combined minoxidil 5% and spironolactone 1% gel. All patients were followed up monthly throughout the treatment period. Scalp biopsy was taken before and after 12 months. In group I, the clinical response was in 90% of patients with variable degrees in improvement, in group II, the clinical response was in 80% of patients, meanwhile, in group III the clinical response was in all patients (100%). Histopathological examination of skin biopsy after treatment revealed significant increase in anagen hair on the other hand, both telogen and vellus hair was significantly decreased meanwhile, the T/V ratio was significantly increased. The results of this work revealed that topical minoxidil gel 5% and topical spironolactone gel 1% were effective in treatment of AGA, while the combination of two agents was better in treatment.     

Experimental Investigation of an Intensified Heat Transfer Adsorption Bed (IHTAB) Reactor Prototype

The first experience in the operation of intensified heat transfer adsorption bed reactor designed for low-pressure adsorption processes is presented in this paper. This work aims to assess the possibility of fluidizing the porous media bed induced by the pressure difference between the evaporator and the adsorption reactor. The conducted experimental research allowed indicating the type of silica gel recommended to use in fluidized beds of adsorption chiller. The fixed bed of silica gel was observed for the lower pressure differences, while fluidization appeared in the case of the pressure difference between the evaporator and the adsorption chamber higher than 1000 Pa. The most significant differences in the adsorption process between the fixed bed and the fluidized bed are revealed in the changes of sorbent temperatures. The silica gel bed was fluidized with water vapor generated in the evaporator.     

汉族儿童TPMT基因全蛋白编码区SNP检测与分析

摘要：目的：分析汉族儿童巯嘌呤甲基转移酶（TPMT）基因的蛋白质编码区（CDS）突变,探讨其在急性白血病（AL）患儿中的单核苷酸多态性（SNP）。 方法：变性梯度凝胶电泳结合DNA测序检测103例AL患儿及111例对照组儿童的TPMT基因CDS碱基位点突变情况。 结果：汉族儿童TPMT基因筛查出2个蛋白编码区单核苷酸多态性（cSNPs）,分别为TPMT*3C（A719G）和*1S（C474T）。TPMT*3C AA、AG、GG基因型频率在AL患儿组中分别为95.1%、3.9%和1.0%,在对照组中分别为97.3%、2.7%和0,其G等位基因频率分别为2.9%和1.4%;TPMT*1S CC、CT、TT基因型频率在AL患儿组分别为5.8%、24.3%和69.9%,在对照组中分别为8.1%、28.8%和63.1%,其C等位基因频率分别为18.0%和22.5%。2个cSNPs基因型及等位基因频率在两组中分布差异无统计学意义（P＞0.05）。对照组筛查出C210T和TPMT*26（T622C）基因突变。 结论：汉族儿童存在TPMT*26突变基因型,且TPMT*3C、TPMT*1S可能均与儿童AL易感性无关。