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排序方式: 共有566条查询结果,搜索用时 15 毫秒
1.
Marieke M. Hoog Antink Lisa Röpke Julia Bartels Christian Soltmann Andreas Kunzmann Kurosch Rezwan Stephen Kroll 《Ceramics International》2018,44(14):16561-16571
The growing demand for stony corals as ornamental aquarium animals requires defined aquacultural breeding strategies. For the sexual propagation of corals, material substrates are needed, that attract larvae and support their settlement and development. In this study, five types of highly porous ceramic materials were developed following the example of coral skeleton. The applicability of these settlement substrates was tested using larvae of the stony coral Pocillopora damicornis. Partial sintering of pressed clay pellets, freeze casting of clay and alumina-mullite based slurries and direct foaming of high alkane phase emulsified suspensions (HAPES) using alumina were employed. By the addition of mm-sized spherical polystyrene beads as sacrificial templates during freeze casting (alumina-mullite), superficial pores in the size of the larvae were created. The inorganic substrates featured open porosities between 35% (pressed clay) and 83% (foamed alumina), pore sizes ranging from nm to mm-scale and pore morphologies dominated by interparticle porosity (pressed), lamellar pores (freeze casting) and cellular pore types (direct foaming). The ceramic substrates were incubated in artificial sea water for 3 months to induce necessary biofilm formation and algae growth. Afterwards, individual substrates were exposed to 5 coral larvae, and their settlement behavior was monitored over 14 days. At the end of this period, all ceramic materials were successfully accepted as settlement substrates, with a mean settlement rate of 46.2%, and no significant differences between the substrate types. On samples with large surface superficial pores, a significantly reduced survival of settled larvae (79%) compared to the other porous materials (93–98%) was determined, suggesting a non-ideal surface topography. While alumina foam samples (HAPES) exhibit the most promising results in terms of settlement and survival of larvae, clay-based substrates provide a more economic solution for the sexual propagation of corals in aquaculture. 相似文献
2.
研究了硫酸耐尔蓝与十二烷基苯磺酸钠(SDBS)的反应,建立测定SDBS的双波长叠加紫外光度法。在pH=5.02缓冲溶液中,硫酸耐尔蓝与SDBS形成离子缔合物,在紫外区有正、负吸收峰,大正吸收波长位于304 nm,大负吸收波长位于280 nm,摩尔吸光系数分别为ε280为2.5×104L·mol-1·cm-1,ε304为2.2×104L·mol-1·cm-1,当用双波长叠加法时,ε280+304为4.7×104L·mol-1·cm-1,线性范围均为0.5~4 mg/L。研究了反应的适宜条件,用于环境水中SDBS的测定,回收率在98.9%~103.2%。 相似文献
3.
Yuming Guo Shilu Tong Adrian G. Barnett Xiaochuan Pan 《The Science of the total environment》2010,408(20):4446-1817
Background
A number of epidemiological studies have examined the adverse effect of air pollution on mortality and morbidity. Also, several studies have investigated the associations between air pollution and specific-cause diseases including arrhythmia, myocardial infarction, and heart failure. However, little is known about the relationship between air pollution and the onset of hypertension.Objective
To explore the risk effect of particulate matter air pollution on the emergency hospital visits (EHVs) for hypertension in Beijing, China.Methods
We gathered data on daily EHVs for hypertension, fine particulate matter less than 2.5 μm in aerodynamic diameter (PM2.5), particulate matter less than 10 μm in aerodynamic diameter (PM10), sulfur dioxide, and nitrogen dioxide in Beijing, China during 2007. A time-stratified case-crossover design with distributed lag model was used to evaluate associations between ambient air pollutants and hypertension. Daily mean temperature and relative humidity were controlled in all models.Results
There were 1,491 EHVs for hypertension during the study period. In single pollutant models, an increase in 10 μg/m3 in PM2.5 and PM10 was associated with EHVs for hypertension with odds ratios (overall effect of five days) of 1.084 (95% confidence interval (CI): 1.028, 1.139) and 1.060% (95% CI: 1.020, 1.101), respectively.Conclusion
Elevated levels of ambient particulate matters are associated with an increase in EHVs for hypertension in Beijing, China. 相似文献4.
Barregard L Horvat M Mazzolai B Sällsten G Gibicar D Fajon V Dibona S Munthe J Wängberg I Haeger Eugensson M 《The Science of the total environment》2006,368(1):326-334
As part of the European Mercury Emissions from Chlor Alkali Plants (EMECAP) project, we tested the hypothesis that contamination of ambient air with mercury around chlor alkali plants using mercury cells would increase the internal dose of mercury in people living close to the plants. Mercury in urine (U-Hg) was determined in 225 individuals living near a Swedish or an Italian chlor alkali plant, and in 256 age- and sex-matched individuals from two reference areas. Other factors possibly affecting mercury exposure were examined. Emissions and concentrations of total gaseous mercury (TGM) around the plants were measured and modeled. No increase in U-Hg could be demonstrated in the populations living close to the plants. This was the case also when the comparison was restricted to subjects with no dental amalgam and low fish consumption. The emissions of mercury to air doubled the background level, but contributed only about 2 ng/m(3) to long-term averages in the residential areas. The median U-Hg levels in subjects with dental amalgam were 1.2 microg/g creatinine (micro/gC) in Italy and 0.6 microg/gC in Sweden. In individuals without dental amalgam, the medians were 0.9 microg/gC and 0.2 microg/gC, respectively. The number of amalgam fillings, as well as chewing, fish consumption, and female sex were associated with higher U-Hg. The difference between the countries is probably due to higher fish consumption in Italy, demethylated methyl mercury (MeHg) being partly excreted in urine. Post hoc power calculations showed that if the background mercury exposure is low it may be possible to demonstrate an increase in U-Hg of as little as about 10 ng/m(3) as a contribution to ambient mercury from a point source. 相似文献
5.
扰动对软土强度影响规律研究 总被引:2,自引:0,他引:2
在Z.Hong和K.Onitsuka扰动度定义的基础上,推导得到扰动后土体屈服应力与扰动度之间的关系,并分析不同灵敏度土体扰动对屈服应力衰减的规律。研究结果表明,扰动对高灵敏度土体屈服应力衰减影响非常大。在屈服应力与扰动度关系的基础上,分析土体十字板抗剪强度、静力触探锥尖阻力和压缩模量等参数与扰动度之间的关系;进行室内振动试验模拟土样扰动,而后进行不同振动时长的固结试验和无侧限抗压试验,室内振动试验结果验证了分析的可靠性和合理性。 相似文献
6.
海洋温深测量装置在海洋环境探测、海洋资源开发中有着重要意义。设计了一种海洋温深测量装置,该装置以ATMega128L单片机作为控制核心,利用温度传感器和压力传感器获取海洋的温深信息,并将所测数据实时存储在SD卡中,在装置回收后可由计算机读取所采集的数据,以便于对数据进行处理和应用。经测试,该测量装置可独立、准确、连续的测量、存储海洋温深信息,同时辅以时间信息,并凭借良好的接口设计,实现了与其他海洋测量装置集成的目的,达到了设计要求。 相似文献
7.
《Food Control》2015
Tree nut allergies are considered an important health issue in developed countries. To comply with the regulations on food labeling, reliable allergen detection methods are required. In this work we isolated almond-specific recombinant antibody fragments (scFv) from a commercial phage display library bypassing the use of live animals, hence being consistent with the latest policies on animal welfare. To this end an iterative selection procedure employing the Tomlinson I phage display library and a crude almond protein extract was carried out. Two different almond-specific scFv (named PD1F6 and PD2C9) were isolated after two rounds of biopanning, and an indirect phage ELISA was implemented to detect the presence of almond protein in foodstuffs. The isolated scFvs demonstrated to be highly specific and allowed detection of 40 ng mL−1 and 100 ng mL−1 of raw and roasted almond protein, respectively. The practical detection limit of the assay in almond spiked food products was 0.1 mg g−1 (110–120 ppm). The developed indirect phage ELISA was validated by analysis of 92 commercial food products, showing good correlation with the results obtained by a previously developed real-time PCR method for the detection of almond in foodstuffs. The selected phage clones can be affinity maturated to improve their sensitivity and genetically engineered to be employed in different assay formats. 相似文献
8.
在介绍黑龙江广播电视网络股份有限整合发展历程的基础上,指出广电网络长期以来所依赖的有线、无线、直播卫星服务垄断地位正受到来自电信IPTV尤其是互联网OTT的严峻挑战.为了应对新的竞争环境,龙江网络提出了四大网发展战略——广播电视基本业务融合网战略、超宽带的互联网战略、高安全度的数据专网战略及O2O电视购物服务网战略. 相似文献
9.
10.
Chirag Desai 《Drug development and industrial pharmacy》2015,41(10):1589-1607
Context: The clinical applications of cilostazol (CLZ) are limited by its low aqueous solubility (<5?µg/ml) and high biovariability.Objective: The aim of this study was to enhance the solubility of CLZ by forming inclusion complexes (ICs) with beta cyclodextrin (β-CD) and formulating them into oral disintegrating tablets.Methods: Phase solubility study of CLZ with β-CD was performed in water. Job’s plot was constructed to determine the stoichiometry of ICs. ICs, prepared by spray-drying technique, were characterized using Fourier transform infrared spectroscopy, differential scanning calorimetry, hot stage microscopy, powder X-ray diffraction and nuclear magnetic resonance. Molecular modeling studies were performed to understand the mode of interaction of CLZ with β-CD. The formulation process was undertaken using a reproducible design of experiment generated model, attained by variation of diluents and disintegrants at three levels. Tablets were evaluated for drug content, hardness, friability, disintegration time (DT), wetting time (WT) and dissolution profiles.Results and discussion: Phase solubility studies suggested an AL type curve with stability constant (Ks) of 922.52?M?1. Job’s plot revealed 1:2 stoichiometry. All analytical techniques confirmed inclusion complexation. Molecular modeling revealed dispersive van der Waals interaction energy as a major contributor for stabilization of complex. The spray-dried complexes showed higher solubility and faster dissolution compared to plain CLZ. The optimized formulation showed DT of 11.1?±?0.8?s, WT of 8.7?±?0.9?s and almost complete dissolution of CLZ in 15?min.Conclusion: The prepared tablets with low DT and fast dissolution will prove to be a promising drug delivery system with improved bioavailability and better patient compliance. 相似文献