纳米二氧化硅水分散体的制备及复配

通过粒子紧密堆积数学模型计算得到不同粒径硅溶胶粒子间的最优配比，在此基础上合成了3种不同单分散粒径的硅溶胶。将不同粒径硅溶胶按数学模型计算的比例加入到钾水玻璃中，复配制备了不同纳米二氧化硅水分散体。与由单一粒径硅溶胶形成的膜相比，由不同粒径硅溶胶复配后形成的膜，呈现出较高的结构致密性和憎水性，与由粒子紧密堆积模型推导结果吻合。     

纳米MgTiO3对Mg(Ca)TiO3微波介质陶瓷烧结行为及介电性能的影响

为了降低MgTiO3CaTiO3陶瓷体系的烧结温度,以钛酸丁酯、醋酸镁为原料,采用溶胶凝胶法制备MgTiO3陶瓷纳米粉体。通过DTA、XRD、FTIR、SEM等观察到纳米MgTiO3陶瓷粉体颗粒分布均匀,粒度约为100 nm,并且成相良好。以MgTiO3纳米粉体按不同比例掺入固相合成的MgTiO3CaTiO3陶瓷体系中,并对该纳米复相陶瓷的烧结性能和介电性能进行了研究。结果表明：当MgTiO3纳米粉体的掺杂摩尔分数为20%时,体系的烧结温度从1 350 ℃降至1 250 ℃,体积密度达到理论密度的97%以上,并且具有良好的介电性能：εr=19.3, tan σ= 1.31×10-3(1.23 MHz)。     

纯镁微弧氧化-HF-硅溶胶复合处理涂层细胞相容性研究

目的:对纯镁微弧氧化经HF-硅溶胶复合处理涂层进行成骨细胞生物相容性检测,评价纯镁表面微弧氧化经不同复合处理涂层后的细胞相容性。方法:实验分为3组,纯镁微弧氧化组为对照组(A组)、纯镁微弧氧化-硅溶胶复合处理组(B组)、纯镁微弧氧化-HF-硅溶胶复合处理组(C组)。将MC3T3-E1系成骨细胞接种在3组材料表面,分别通过扫描电镜、激光共聚焦、CCK-8、ALP对成骨细胞的生长、黏附、增殖以及活性进行检测。结果:扫描电镜和激光共聚焦显示B组和C组表面细胞的生长和黏附均优于A组,C组优于B组。CCK-8和ALP的检测结果显示3组材料表面细胞的增殖、活性为C组＞B组＞A组,3组的比较差异均具有统计学意义。结论:3组材料均具有良好的生物相容性,而纯镁微弧氧化-HF-硅溶胶复合处理后的生物相容性最佳。     

Investigation et gestion d’un foyer de saturnisme infantile dans un quartier de la commune du Port, Île de la Réunion

BackgroundA national survey conducted in 2008–2009 by the French Institute for Public Health Surveillance for detection of lead impact in childhood identified a high blood lead level in a young boy living in the town of “Le Port”, Reunion Island. Previously, cases of lead-poisoning on the island had been exceptional; only a dozen cases were reported in the 1980s in adults, related to the use of lead-containing instruments for food preparations.MethodsThe family of the index case was invited to participate in screening tests and an environmental investigation was conducted using a standardized questionnaire. Screening was then broadened to the neighborhood of the index case and samples of soil outside the home and in the immediate vicinity were taken. The environmental survey was then extended with soil samples taken from the entire geographical area. Information was then provided to local inhabitants (87 families and 287 people) in order to encourage lead blood testing for all children under six years and all pregnant women living in the area.ResultsThe index case lived in the neighborhood of “The Oasis”, a shantytown of Le Port. The results of soil analysis revealed heterogeneous pollution of superficial soils by lead throughout the area of the shantytown, the highest level recorded (5200 mg/kg) reached more than 300 times the background level of the natural soils of the island. The screening identified 76 cases of childhood lead-poisoning (blood lead level greater or equal to 100 μg/L) among 148 samples (51%). All cases of blood poisoning involved children under the age of 15 years. The median age of children with a positive test was 5.6 years; the median blood lead level was 196 μg/L [102–392 μg/L].ConclusionThe main hypothesis to explain the contamination of the soil in the area of the shantytown is the presence of waste deposits (car batteries) and diffuse activities of metal recovery. The authorities managed to remove all the families from the environmental exposure to lead by rapidly ensuring rehousing outside the contaminated area.     

Preparation of mesoporous silica microparticles by sol–gel/emulsion route for protein release

Encapsulation of therapeutic proteins into particles from appropriate material can improve both stability and delivery of the drugs, and the obtained particles can serve as a platform for development of their new oral formulations. The main goal of this work was development of sol–gel/emulsion method for preparation of silica microcapsules capable of controlled release of encapsulated protein without loss of its native structure. For this purpose, the reported in literature direct sol–gel/W/O/W emulsion method of protein encapsulation was used with some modifications, because the original method did not allow to prepare silica microcapsules capable for protein release. The particles were synthesized using sodium silicate and tetraethoxysilane as silica precursors and different compositions of oil phase. In vitro kinetics of bovine serum albumin (BSA) release in buffer (pH 7.4) was studied by Fourier transform infrared (FTIR) and fluorescence spectrometry, respectively. Structural state of encapsulated BSA and after release was evaluated. It was found that the synthesis conditions influenced substantially the porous structure of the unloaded silica particles, release properties of the BSA-loaded silica particles and structural state of the encapsulated and released protein. The modified synthesis conditions made it possible to obtain the silica particles capable of controlled release of the protein during a week without loss of the protein native structure.     

A solid-phase radioimmunoassay for IgG gliadin antibodies using 125I-labelled staphylococcal protein A

A sensitive radioimmunoassay for IgG gliadin antibodies is described. Serum specimens were added to wells of plastic microtitre plates coated with gliadin. After removal of the unbound material, gliadin antibodies were detected by adding 125I-labelled staphylococcal protein A (125I-SpA). Serum specimens from coeliac patients on a normal diet or on a gluten-free diet were tested, as well as sera from an age-matched control group. Measurements to obtain precise quantitative values were made with gliadin antibody-rich serum as reference standard. High titres of gliadin antibodies were found in 18 out of 19 coeliac patients on a normal diet (95%); in patients on a strict gluten-free diet serum values did not exceed 2 S.D. of the control mean. Due to the high sensitivity of the method a low but detectable amount of gliadin antibody was present in the sera of all controls.     

硅胶管在泪道重建手术中的应用观察

目的探讨硅胶管在泪道重建手术的应用效果及注意问题。方法对26例(31只眼)慢性泪囊炎患者在泪囊鼻腔吻合术中植入硅胶管,随访6～25.5个月,平均11.8个月,观察治疗效果。结果26例(31只眼)随访半年以上,全部消除溢泪、溢脓症状,泪道冲洗通畅。结论在泪道手术中植入硅胶管道能提高手术成功率,无并发症发生。     

Improving the Durability of Lime Finishing Mortars by Modifying Them with Silicic Acid Sol

Lime materials are in great demand for the restoration of the walls of historical buildings. However, lime coatings have insufficient resistance during operation. The purpose of this work was the modification of lime mortars with silicic acid sol in order to obtain more durable crystalline materials for construction purposes. A technology has been developed for obtaining a silica-containing additive, which consists in passing a liquid glass solution with a density of 1.053 kg/m³ through a cationic column and obtaining a silicic acid sol with a pH of 3–4 and a charge of (−) 0.053 V. The regeneration time and the amount of sol have been determined. Regularities of change in the radius of particles of silicic acid sol depending on age are determined. It is established that at an early age (up to 5 days), the radius of sol particles can be determined in accordance with the Rayleigh equation, and at a later age, in accordance with the Heller equation. The results of the calculation show that at the age of 1–5 days, the radius of the sol particles is 17.1–17.9 nm, and then the particles become coarser and the particle radius is 131.2–143 nm at the age of 19 days. The work of adhesion of silicic acid sol to lime and the heat of wetting are estimated. It is shown that the work of adhesion of water to lime is 28.9 erg/cm², and that of the sol is 32.8 erg/cm². The amount of heat Q released when lime is wetted with SiO₂ sol is 15.0 kJ/kg, and when lime is wetted with water, it is 10.6 kJ/kg.     

Comparison between in vitro qualities of platelets washed with commercially available additive solutions and those washed with M‐sol

Background and Objectives We previously developed a novel additive solution (M‐sol) with a high ability to preserve the in vitro qualities of platelets (PLTs) in washed PLTs Here, we compared the ability of M‐sol with that of commercially available additive solutions (ASs) to preserve the in vitro qualities (pH, mean PLT volume, %disc, P‐selectin, %hypotonic shock response and aggregation) of PLTs at a low plasma concentration. Materials and Methods The platelet concentrate was divided into two equal aliquots (control group and test group). After centrifugation of both groups and removal of as much supernatant as possible, the pellet of the control group was resuspended in M‐sol and those of the test group were resuspended in other ASs, and subsequently stored in polyolefin bags with agitating at 20–24°C. Results Compared with those stored in M‐sol, the qualities of PLTs stored in PAS‐B (alternative name; PAS‐II or T‐sol), PAS‐ C (alternative name; PAS‐III or Intersol) or Plasma Lyte were degraded as early as 24 h after washing. The qualities of PLTs stored in PAS‐D (alternative name; Composol PS) or PAS‐E (alternative name; PAS‐IIIM or SSP+) were comparable to that of those stored in M‐sol 24 h after washing; however, the qualities had deteriorated 72 h after washing. Conclusions At a low plasma concentration (5% or less), the M‐sol showed a higher ability to preserve PLTs than the five ASs studied here. Although PAS‐D and PAS‐E are available as an AS for short‐term storage of washed PLTs, M‐sol is thought to be preferable for longer storage.