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91.
In the last 10 years, we have witnessed an extensive development of instrumental techniques in analytical methods for determination of various molecules and ions at very low concentrations. Nevertheless, the presence of interfering components of complex samples hampered the applicability of new analytical strategies. Thus, additional sample pre-treatment steps were proposed to overcome the problem. Solid sorbents were used for clean-up samples but insufficient selectivity of commercial materials limited their utility. Here, the application of molecularly imprinted polymers (MIPs) or ion-imprinted polymers (IIPs) in the separation processes have recently attracted attention due to their many advantages, such as high selectivity, robustness, and low costs of the fabrication process. Bulk or monoliths, microspheres and core-shell materials, magnetically susceptible and stir-bar imprinted materials are applicable to different modes of solid-phase extraction to determine target analytes and ions in a very complex environment such as blood, urine, soil, or food. The capability to perform a specific separation of enantiomers is a substantial advantage in clinical analysis. The ion-imprinted sorbents gained interest in trace analysis of pollutants in environmental samples. In this review, the current synthetic approaches for the preparation of MIPs and IIPs are comprehensively discussed together with a detailed characterization of respective materials. Furthermore, the use of sorbents in environmental, food, and biomedical analyses will be emphasized to point out current limits and highlight the future prospects for further development in the field. 相似文献
92.
S. Akash Prabhu Aruna K. Kunhiraman T.B. Naveen R. Ajay Rakkesh Marloes Peeters 《Sustainable Chemistry and Pharmacy》2022
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93.
C.L. Sonego M.A.R. Scheffer O.L. Chagas Júnior B.M. Vetromilla L.P. Fernandes A. Ozkomur A.N. Silva Júnior S.A.Q. Miguens Júnior P.A.G. Hernandez 《International journal of oral and maxillofacial surgery》2018,47(10):1330-1335
This study was performed to evaluate the compressive mechanical strength of rigid internal fixation (RIF) using 1.5-mm L-shaped plates fixed with monocortical screws in sagittal split osteotomy (SSO). Thirty synthetic hemimandibles, which had all undergone a 5-mm advancement, were divided into three groups: three 12-mm bicortical titanium screws were placed in an inverted L pattern in group A; one straight 2.0-mm system spaced titanium plate fixed with four 5-mm monocortical screws was used in group B; two 1.5-mm system L-shaped titanium plates, each fixed with four 5-mm monocortical screws, were used in group C. The models were subjected to compressive and progressive mechanical tests with forces applied in the area between the second premolar and first molar to verify resistance in Newtons (N). A displacement speed of 1 mm/min was applied, with a maximum 10 mm displacement of the distal segment or until disruption of the fixation. The deformity and/or eventual rupture of the plates were evaluated, and consequently their technical stability was determined. The results showed that the modified fixation technique tested in this study on synthetic mandibles resulted in adequate stability and superior mechanical behaviour compared to simulated osteosynthesis with the use of a straight 2.0-mm titanium plate. 相似文献
94.
95.
目的 分析中药复方辅助化疗治疗晚期结直肠癌的用药规律。方法 借助中国知网、万方数据、重庆维普以及中国生物医学文献数据库数据平台,搜索晚期结直肠化疗并中药经方治疗等相关文献,进行质量评价,剔除低质量文献,罗列组方建立Excel数据库,进行高频药物及其性味归经的描述性统计,基于SPSS Statistics 26.0关联规则及因子分析,SPSS Modeler 18.0聚类分析,Cytoscape软件直观网络图,进行数据挖掘整理与分析。结果 研究纳入相关文献148篇,处方155首,药物191味,用药总频次1823次,核心中药27味(使用频率 ≥ 10%),以白术所用最广。性味以甘温为首,归经以脾经为最。以置信度95%、支持度15%、提升度 > 1进行关联规则分析得到常用三药组合17组。聚类分析以欧式平方距离24为标准得到潜在聚类方剂3个。结论 中药复方用药以清补健脾,甘温扶正;平解邪毒,调气畅腑;肝脾同调,肺胃同治为规律,正合晚期结直肠癌化疗后脾虚毒恋、痰瘀互结之证。研究归纳出中药辅助化疗治疗晚期结直肠癌的用药组方规律,予以临床一定的理论依据及借鉴意义。 相似文献
96.
A certified reference material (CRM) [2KRISS CRM # 108-10-018] for the analysis of ochratoxin A (OTA) in doenjang (fermented soybean paste and popular food in Korea) was produced to ensure the reliability of analytical results in testing laboratories. A home-made doenjang was chosen as a raw material after testing its OTA level. The raw material was freeze-dried, pulverized, sieved and homogenized. An isotope-dilution-liquid chromatography/tandem mass spectrometric method (ID-LC/MS/MS) which was previously developed and validated in this laboratory was used as a higher-order reference method for characterization, homogeneity studies, and short-term stability studies. The CRM had good between-bottle homogeneity with 0.56% relative standard deviation among 10 selected units. The stability of the CRM at −70 °C (the storage condition in our laboratory) and at −20 °C (the possible storage temperature at user sites) were tested for up to 8 months. No change in the OTA content was observed within the measurement uncertainty. The stability of the CRM at room temperature (for regular use and transportation) was also tested and confirmed. The certified value was (49.50 ± 1.17) μg/kg, where the expanded uncertainty was in the confidence level of 95%. 相似文献
97.
98.
G. D. Rajitha Gunaratne Riaz Khan Daniel Fick Brett Robertson Narendra Dahotre Charlie Ironside 《Journal of medical engineering & technology》2017,41(1):1-12
Osteotomy is the surgical cutting of bone. Some obstacles to laser osteotomy have been melting, carbonisation and subsequent delayed healing. New cooled scanning techniques have resulted in effective bone cuts without the strong thermal side effects, which were observed by inappropriate irradiation techniques with continuous wave and long pulsed lasers. With these new techniques, osteotomy gaps histologically healed with new bone formation without any noticeable or minimum thermal damage. No significant cellular differences in bone healing between laser and mechanical osteotomies were noticed. Some studies even suggest that the healing rate may be enhanced following laser osteotomy compared to conventional mechanical osteotomy. Additional research is necessary to evaluate different laser types with appropriate laser setting variables to increase ablation rates, with control of depth, change in bone type and damage to adjacent soft tissue. Laser osteotomy has the potential to become incorporated into the armamentarium of bone surgery. 相似文献
99.
100.
In the classical theory of thermoelectricity, the performance integrals for a fully self-compatible material depend on the dimensionless figure of merit zT. Usually these integrals are evaluated for constraints z = const. and zT = const., respectively. In this paper we discuss the question from a mathematical point of view whether there is an optimal temperature characteristics of the figure of merit. We solve this isoperimetric variational problem for the best envelope of a family of curves z(T)T. 相似文献