Preparation of Continuous Alumina Fiber with Nano Grains by the Addition of Iron Sol

Continuous alumina fiber exhibits excellent mechanical properties owing to its dense microstructure with fine grains. In this study, alumina fiber was prepared by the sol–gel method using iron sol as a nucleating agent. It was proposed that the α-Al₂O₃ grain size be adjusted based on the modification of colloidal particle size. The effect of holding temperature and reaction material ratio on the iron colloidal particle size was studied. The microstructure of alumina fiber was characterized by scanning electron microscopy (SEM). The experiment results indicated that iron colloidal particle size increases with the holding temperature and the NH₄HCO₃/Fe(NO₃)₃·9H₂O ratio. The alumina fiber with uniform nano α-Al₂O₃ grains was obtained by calcination at 1400 °C for 5 min. The mean grain size tends to rise with the mean colloidal particle size. Using the iron sol as a nucleating agent, the fiber with a mean grain size of 22.5 nm could be formed. The tensile strength of fibers increased with the decrease of grain size.     

Hair analysis by GC/MS/MS to verify abuse of drugs

Because of its peculiar characteristics, hair analysis provides a way of obtaining information that cannot be acquired by other commonly used forensic medical analyses, such as blood or urine analysis. In the keratin matrix many xenobiotics are incorporated permanently, in contrast to the situation with blood or urine where they are generally only detectable for a few hours or days. Therefore hair analysis should be the method of choice in the clinical and forensic toxicology field when the assessment of repeated or chronic exposure to a drug is required, e.g. in the case of criminal responsibility, revocation/restoration of a driving licence or in workplace testing. Some factors that can affect the concentrations of drugs in hair, such as passive contamination, age, ethnicity and cosmetic treatment, must be considered. Analytical methodology is also very important: GC/MS/MS has proved to be a highly sensitive and specific technique for the detection of very low concentrations of such drugs in hair. In this study five cases of the application of hair analyses using this technique for the determination of abused drugs (opiates, cocaine, amphetamine, anabolic steroids) are described.     

In situ gelling and mucoadhesive polymers: why do they need each other?

Introduction: Mucosal drug delivery is an attractive route of administration, particularly in overcoming deficits of conventional dosage forms including high first-pass metabolism and poor bioavailability. Fast drainage from the target mucosa, however, represents a major limitation as it prevents sufficient drug absorption. In order to address these problems, mucoadhesive in situ gelling drug delivery systems have been investigated as they facilitate easy application in combination with a longer residence time at the administration site resulting in more desirable therapeutic effects.

Areas covered: The present review evaluates the importance of the combination of mucoadhesive and in situ gelling polymers along with mechanisms of in situ gelation and mucoadhesion. In addition, an overview about recent applications in mucosal drug delivery is provided.

Expert opinion: In situ gelling and mucoadhesive polymers proved to be essential excipients in order to prolong the mucosal residence time of drug delivery systems. Due to this prolonged residence time both local and systemic therapeutic efficacy of numerous drugs can be substantially improved. Depending on the site of administration and the incorporated drug, combinations of different polymers with in situ gelling and mucoadhesive properties are needed to keep the delivery system as long as feasible at the target site.     

白及溶胶加磺胺嘧啶银治疗压疮的效果观察

目的探讨白及溶胶联合磺胺嘧啶银治疗压疮的临床效果。方法将41例Ⅲ期压疮患者分为治疗组与对照组。治疗组21例,采用白及溶胶联合磺胺嘧啶银治疗;对照组20例,采用湿润烧伤膏治疗。分别观察两组感染控制时间、肉芽组织形成时间、愈合时间及治愈率。结果两组治愈率均为100%。两组在感染控制时间、肉芽组织形成时间及创面愈合时间上比较差异均有统计学意义(P<0.05)。结论白及溶胶联合磺胺嘧啶银治疗压疮临床效果良好,值得推广应用。     

奥美沙坦联合比索洛尔治疗慢性心力衰竭的疗效观察

目的探讨奥美沙坦联合比索洛尔治疗慢性心力衰竭的临床疗效。方法选取我院在2009年8月至2012年8月收治的120例慢性心力衰竭的患者随机分为对照组和观察组,对照组患者单独使用奥美沙坦治疗,观察组患者给予奥美沙坦联合比索洛尔治疗,对比观察两组治疗方法的临床疗效。结果对照组患者治疗效果的总有效率为66.7%,治疗组患者治疗效果的总有效率为93.3%,治疗组取得的临床治疗疗效明显优于对照组,存在的差异性具有统计学意义(P<0.05);两组患者在不良反应发生率上无显著差异性(P>0.05)。结论奥美沙坦联合比索洛尔治疗慢性心力衰竭效果显著。     

Monoclonal rat anti-Torpedo electroplax nicotinic acetylcholine receptor antibodies: immunochemical characterization

The interaction of Torpedo californica nicotinic acetylcholine receptor (nAcChoR) with three rat monoclonal antibodies (mcab) directed against nAcChoR (Gomez et al., 1979) was studied by use of four different radioimmunoassay protocols. Each mcab reacts poorly with formalin-fixed Staphylococcus aureus or S. aureus Protein A, which requires that an additional incubation with second antibody (goat anti-rat immunoglobulin G) is included in each radioimmunoassay paradigm. One mcab inhibits 125I-labeled alpha-bungarotoxin binding to nAcChoR, recognizes a subset of solubilized nAcChoR-toxin complexes, and shows higher titer against nAcChoR in the absence of toxin. Thus, it appears to be directed against nAcChoR antigenic determinants that at least partially overlap with toxin binding sites. Two other mcab react with nAcChoR in a toxin-independent manner. Receptor-mcab dissociation constants are less than 10 nM, according to each assay paradigm. Estimates of antibody titer or concentrations of antibody in stock hybridoma supernatants vary according to the assay used. This predictable result is attributed to differences in design and sensitivity of assay protocols. The data provide a basis for further utilization of monospecific antibodies as probes in characterization of nAcChoR structure and function.     

Sol-Gel Derived Silica-Titania Waveguide Films for Applications in Evanescent Wave Sensors—Comprehensive Study

Composite silica-titania waveguide films of refractive index ca. 1.8 are fabricated on glass substrates using a sol-gel method and dip-coating technique. Tetraethyl orthosilicate and tetraethyl orthotitanate with molar ratio 1:1 are precursors. Fabricated waveguides are annealed at 500 °C for 60 min. Their optical properties are studied using ellipsometry and UV-Vis spectrophotometry. Optical losses are determined using the streak method. The material structure and chemical composition, of the silica-titania films are analyzed using transmission electron microscopy (TEM) and electron dispersive spectroscopy (EDS), respectively. The surface morphology was investigated using atomic force microscopy (AFM) and scanning electron microscopy (SEM) methods. The results presented in this work show that the waveguide films are amorphous, and their parameters are stable for over a 13 years. The optical losses depend on their thickness and light polarization. Their lowest values are less than 0.06 dB cm⁻¹. The paper presents the results of theoretical analysis of scattering losses on nanocrystals and pores in the bulk and interfaces of the waveguide film. These results combined with experimental data clearly indicate that light scattering at the interface to a glass substrate is the main source of optical losses. Presented waveguide films are suitable for application in evanescent wave sensors.     

羟基磷灰石和二氧化钛纳米粒子溶胶的血液相容性

羟基磷灰石 (HAP)和二氧化钛 (TiO2 )纳米粒子是两种具有潜在应用前景的生物材料。本文通过溶血实验、小鼠出血和凝血时间、凝血酶原时间 (PT)和白陶土部分凝血活酶时间 (PTT)测定等对两种纳米粒子溶胶的血液相容性行了初步评价。结果显示 ,HAP纳米粒子溶胶、溶血实验阴性 ,显著延长小鼠的出血、凝血时间和大鼠白陶土部分凝血活酶时间和凝血酶原时间。TiO2 纳米粒子溶胶对小鼠的出、凝血时间无影响 ,溶血实验阴性。对大鼠白陶土部分凝血活酶时间和凝血酶原时间也无影响。两种纳米粒子溶胶均可使体外家兔红细胞发生凝聚。上述实验不同的结果主要与使用了不同的稳定剂有关 :HAP稳定剂为肝素 ,TiO2 稳定剂为聚氯乙烯 (PVC)。提示 ,在考虑纳米粒子溶胶的生物学应用前景时 ,除了纳米粒子本身的性质 ,筛选具备生物学惰性的稳定剂也是不容忽视的问题     

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)。     

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.