Challenges and Strategies in the Synthesis of Mesoporous Alumina Powders and Hierarchical Alumina Monoliths

A new rapid, very simple and one-step sol-gel strategy for the large-scale preparation of highly porous γ-Al₂O₃ is presented. The resulting mesoporous alumina materials feature high surface areas (400 m² g⁻¹), large pore volumes (0.8 mL g⁻¹) and the γ-Al₂O₃ phase is obtained at low temperature (500 °C). The main advantages and drawbacks of different preparations of mesoporous alumina materials exhibiting high specific surface areas and large pore volumes such as surfactant-nanostructured alumina, sol-gel methods and hierarchically macro-/mesoporous alumina monoliths have been analyzed and compared. The most reproducible synthesis of mesoporous alumina are given. Evaporation-Induced Self-Assembly (EISA) is the sole method to lead to nanostructured mesoporous alumina by direct templating, but it is a difficult method to scale-up. Alumina featuring macro- and mesoporosity in monolithic shape is a very promising material for in flow applications; an optimized synthesis is described.     

Threshold serum concentrations of tumour necrosis factor alpha (TNFα) as a potential marker of the presence of microangiopathy in children and adolescents with type 1 diabetes mellitus (T1DM)

The aim of this study was to estimate the threshold serum concentrations of advanced glycation end products (AGEs) and their soluble receptors (sRAGE) as well as tumour necrosis factor alpha (TNFα), vascular endothelial growth factor₁₆₅ (VEGF₁₆₅) and interleukin-12 (IL-12) in predicting the occurrence of microangiopathy in children and adolescents with type 1 diabetes mellitus (T1DM). We studied 88 children and adolescents (age range: 6–20 yrs) with T1DM and 32 control subjects (age range: 7–20 yrs). All study participants had their daily urinary albumin excretion, HbA1c and serum creatinine levels measured, and underwent an eye examination and 24-h blood pressure monitoring. Moreover, serum concentrations of AGEs, sRAGE, TNFα, VEGF₁₆₅ and IL-12 were measured. In order to calculate the threshold values of the studied parameters, the Receiver Operating Characteristic (ROC) curve analysis was used. The results of our study have shown that among all the studied parameters a discriminative ability was found for TNFα, VEGF₁₆₅, duration of the disease, serum AGEs concentrations and daily urinary albumin excretion. However, the highest value of the area under the ROC curve (AUC_ROC) in predicting the occurrence of diabetic microangiopathy was found for serum TNFα concentrations with its threshold value of 1.7 pg/ml [AUC_ROC = 0.88 (95% CI: 0.79–0.97)]. The sensitivity and specificity for this variable was at the level of 85.7% and 94.3%, respectively. In conclusion, according to our results serum TNFα concentrations over 1.7 pg/ml may point to the presence of diabetic microangiopathy in children and adolescents T1DM.     

Forskolin increases apical sodium conductance in cultured toad kidney cells (A6) by stimulating membrane insertion

The role of membrane traffic in the stimulation of apical Na⁺ permeability caused by increases in cytoplasmic cyclic AMP was assessed by measuring the effects of forskolin on transepithelial capacitance (C _T), transepithelial conductance (G _T), and short-circuit current (I _sc) in A6 cultured toad kidney cells. Apical water permeability was probed by recording cell volume changes after reducing the osmolality of the apical bath. We found that forskolin does not increase the osmotic water permeability of the apical membrane of A6 cells, and thus does not stimulate the insertion of water channels. Comparison of the effects of forskolin and insulin on Na⁺ transport demonstrated that both agents produce reversible increases in C _T, G _T and I _sc. G _T and C _T increased proportionally during the rising phase of the insulin response. However, a non-linear relationship between both parameters was recorded when forskolin was given in NaCl Ringer’s solution. The relationship between C _T and G _T became linear after the effects of forskolin on Cl^– conductances were eliminated by substituting Cl^– by an impermeant anion. In contrast, in Cl^–-containing Na⁺-free solutions, the non-linearity became more pronounced. Successive additions of insulin and forskolin caused additive increases in C _T. Because increases in C _T and Na⁺ transport occurred in the absence of stimulation of water permeability and increases of C _T and G _T were directly proportional when Na⁺ was the major permeating ion across the apical membrane, we suggest that the increase in apical Na⁺ permeability in the presence of either forskolin or insulin is due to the insertion of channels residing in intracellular pools. In contrast, the increased Cl^– permeability caused by forskolin may be related to the activation of channels already present in the membrane. Received: 28 October 1998 / Received after revision: 19 January 1999 / Accepted: 11 February 1999     

Studies on the conformational properties of CP‐1042−55, the hinge region of CP‐10, using circular dichroism and RP‐HPLC

Abstract: The conformational properties of CP‐10^42?55, a peptide corresponding to the hinge region of CP‐10, were investigated using circular dichroism spectroscopy and reverse‐phase high‐performance liquid chromatography (RP‐HPLC). The circular dichroism studies indicated that CP‐10^42?55 formed considerable secondary structure in the presence of hydrophobic solution environments including 50% acetonitrile, 50% trifluoroethanol and 200 mm sodium dodecyl sulfate, which comprised a mixture of α‐helix and β‐sheet. The effect of temperature on the conformation of CP‐10^42?55 was investigated between 5 and 40°C, with very small changes in the spectra being observed.RP‐HPLC was then used to investigate the effect of temperature on the conformation of CP‐10^42?55 in the presence of a hydrophobic surface. Using a C₁₈‐adsorbent, CP‐10^42?55 exhibited a conformational transition at 25°C, which was associated with an increase in the chromatographic contact area and the binding affinity of the peptide for the stationary phase. In addition, near‐planar bandbroadening behaviour indicated that conformational species interconverted with rapid rate constants compared with the chromatographic time scale. These results indicated that the conformational change at 25°C in theRP‐HPLC system most likely corresponds to the unfolding of an α‐helical and/or β‐sheet structure to an extended coil structure. Therefore, the strong chemotactic properties of this peptide may be attributed to its ability to form considerable secondary structure in the presence of a hydrophobic environment.     

术中唤醒麻醉技术下脑功能区肿瘤继发癫痫切除术的临床研究

目的 探讨术中唤醒麻醉技术下脑功能区肿瘤继发癫痫切除术的适应证、技术要点及疗效. 方法 选择解放军第一五三医院神经外科自2006年6月至2012年6月收治的脑功能区33例胶质瘤及16例脑膜瘤继发癫痫患者,采用MRI进行肿瘤定位,弥散张量纤维束成像(DTT)显示白质纤维束与肿瘤位置关系,功能磁共振成像(fMRI)定位运动功能区,在全麻-唤醒-再全麻技术下开颅,实时B超、皮层脑电图(ECoG)定位肿瘤及致痫区,显微手术切除肿瘤及处理致病灶.结果 有44例患者顺利经过全麻-唤醒-再全麻的过程,其中28例术中持续保留喉罩；16例语言区肿瘤唤醒后拔除喉罩,语言区定位及功能测试后再置入喉罩全麻.年龄偏大的3例胶质瘤及2例脑膜瘤患者因唤醒时躁动、憋气,脑组织膨出明显,放弃唤醒麻醉.术中神经电生理监测(IOM)定位出脑功能区36例,皮层功能定位阴性8例；ECoG监测发现瘤周皮层致病灶31例.胶质瘤全切22例,次全切8例；脑膜瘤全切13例,次全切1例,术中未出现癫痫发作现象.术后暂时性神经功能障碍加重或新发功能障碍26例,均于1月内恢复；术前原有功能障碍均好转.癫病发作完全消失31例,发作次数明显减少13例. 结论 术中全麻唤醒下手术治疗功能区肿瘤继发癫痫疗效好、风险低.术前适应证的选择、术中合适的手术体位的摆放及有效预防癫痫发作是手术成功的重要因素.     

农村中学预防艾滋病健康教育效果评价

目的:在湖北省农村中学开展学生艾滋病健康教育,提高其对艾滋病的认知水平.方法:利用<学生艾滋病预防问卷>,采取随机整群抽样的方法抽取50名学生作为调查对象,分别在健康教育前后进行内容一致的基线调查,最后对教育效果进行评价.结果:健康教育后,学生对艾滋病相天知识、态度、行为及效能等方面都有不同程度的提高,其中行为因子在教育后有显著性提高(p＜0.05):学生对艾滋病非传播途径的认识、拒绝行为和沟通技能上都有明显变化(p＜0.05);但是学生对艾滋瘸患者的态度并没有显著性改变(p＞0.05).结论:在农村中学开展艾滋病健康教育是非常有效并且十分有必要.     

整形美容外科方法处理小面积深度烧伤

目的：探寻缩短小面积深度烧伤病程及减少局后遗疤痕的方法。方法：采用创面切除、直接缝合或整形外科的各种皮瓣修复缺损。结果：对68例74例创面临床治疗后，创面均一期愈合，术后愈合时间平均9天，经46例随访远期效果满意，取得了预期效果。结论：应用整形外科方法处理早期、中晚期小面积深度烧伤，可以缩短疗程、降低费用，改善小面积深度烧伤创面修复的，比传统方法更具优点。     

Variations in the course and microanatomical study of the lateral femoral cutaneous nerve and its clinical importance

The lateral femoral cutaneous nerve (LFCN), a branch from the lumbar plexus, may come to the clinician's or surgeon's attention. We studied this nerve to determine its location and its relationship with neighboring structures around the anterior superior iliac spine (ASIS) and the inguinal ligament (IL). Additionally, cross‐sectional microanatomy of the LFCN at the IL was studied. The LFCN was dissected in 47 lower limbs from formalin‐fixed cadavers. The distances from the ASIS to the point where the LFCN crossed the IL and the lateral border of the sartorius were measured. The distance between the ASIS and the point it pierced the deep fascia was also measured. Twelve nerve specimens at the IL were collected for histological sectioning and were stained with hematoxylin and eosin. On examination of the cross‐sectional area, the nonfascicular area was wider than the fascicular area because of an increased amount of thick collagen fibers. This study may be of help to clinicians managing meralgia paresthetica and may also assist in defining a safe area for surgical intervention on the anterolateral aspect of the thigh. Clin. Anat. 23:978–984, 2010. © 2010 Wiley‐Liss, Inc.     

Direct measurement of tibial cortical bone surface area

Cortical bone surface area estimation is generally performed by analysis of medical images but its accuracy has not yet been verified by direct bone measurements. This study was performed to evaluate the reproducibility of direct ex vivo estimations of cross sectional tibial cortical bone surface area. Ten tibiae were evaluated by two observers using direct 3D‐digitization at 38 and 66% of total tibial length using a ‘critical’ and a ‘general’ criterion for differentiation between cortical and cancellous bone. The results of the analysis using the more severe ‘critical’ differentiation criterion yielded high intra and interobserver agreement. Mean intraobserver reliability was demonstrated by R = 0.98 (Spearman rank correlation between 0.98 and 0.97; P < 0.01) and inter observer reliability by R = 0.91 (Spearman rank correlation between 0.95 and 0.88; P < 0.01). When using strict criteria to differentiate between cortical and cancellous bone, intra and interobserver reliability of the presented method of direct cortical bone surface area estimation is very high. The results indicate that cross‐sectional cortical bone surface estimation by direct 3D‐digitization can serve as a gold standard for validation of other estimations methods. Clin. Anat. 23:720–725, 2010. © 2010 Wiley‐Liss, Inc.