1,100 research outputs found
Comparison of corneal flap thickness using a FS200 femtosecond laser and a moria SBK microkeratome
<b>AIM:</b> To evaluate differences in flap thickness resulting from use of an Alcon Wavelight FS200 femtosecond laser and a MORIA SBK microkeratome when making a 110-μm-thick corneal flap and to identify the potential factors that affect corneal flap thickness.<b>METHODS:</b> A prospective case study was performed on 120 eyes of 60 patients who were divided into two groups for LASIK, each group consisting of 60 eyes (30 patients). The corneal flaps were created using an Alcon Wavelight FS200 femtosecond laser or a MORIA SBK microkeratome. The central corneal flap thickness was calculated by subtraction pachymetry. Age, central corneal thickness (CCT), spherical equivalent refraction, mean keratometry, and corneal diameter were recorded preoperatively for analysis.<b>RESULTS:</b> Cutting of all flaps was easily performed without intraoperative complications. In the Alcon Wavelight FS200 femtosecond lasergroup, the mean right and left corneal flap thicknesses were 114.0±6.6 μm (range:98-126) and 111.4±7.6 μm (range:98-122), respectively. The difference (2.6±9.1 μm) in the corneal flap thickness between the right and left eyes was not significant (<i>t</i>=1.59, <i>P</i>=0.12). Stepwise regression analysis indicated that the resulting corneal flap thickness was unrelated to the patient’s age, preoperative CCT, spherical equivalent refraction, mean keratometry, or corneal diameter. In the MORIA SBK microkeratome group, the mean right and left corneal flap thicknesses were 110.6±7.4 μm (range:97-125 μm) and 108.2±6.1 μm (range:78-123 μm), respectively. The difference in the corneal flap thickness between the right and left eyes (2.4±6.5μm) was not significant (<i>t</i>=2.039, <i>P</i>=0.0506). The corneal flap thickness was positively correlated with the preoperative CCT through stepwise regression analysis (<i>r</i>=0.297,<i> P</i>=0.021). The corneal flap thickness was not related to age, spherical equivalent refraction, mean keratometry, or corneal diameter. The corneal flap thickness was estimated using the following equation:Tflap=67.77+0.076 CCT (<i>F</i>=5.63, <i>P</i>=0.021).<b>CONCLUSION:</b>Both the Alcon Wavelight FS200 femtosecond laser and the MORIA SBK microkeratome produced 110-μm-thick corneal flaps. The central corneal flap thickness was positively correlated with the preoperative CCT in MORIA SBK microkeratome surgery
Robust Optimization Design of Bolt-Shotcrete Support Structure in Tunnel
The uncertainty of rock and soil parameters is one of the key problems to limit the stability of tunnel support structure. Based on this, a robust optimization design method is proposed to reduce the sensitivity of support system to the uncertainty of rock and soil parameters. By defining the design parameters, noise factors and system response, a robust design system for bolt-shotcrete support structure is established. The non-dominant solutions of system robustness and support cost consist of the Pareto Front, then an knee point recognition method is designed to further filter all non-dominant solutions and determine the only optimal solution. The robust optimization design of the bolt-shotcrete support structure is carried out with a tunnel as the engineering background. The results show that the method can not only improve the stability and adaptability of the supporting structure, but also reduce the economic cost to the greatest extent, which provides a reference for the optimization design of other geotechnical engineering supporting structures
Does giving and receiving helping behavior fit matter? : the role of neighboring behavior fit in working residents' mental health
Ecological systems theory suggests that for individuals, the three domains of community, family, and work are connected and transfer resources among each other. In the community, residents receive and give helping behavior from and to their neighbors. Neighboring behavior underlies interactions among residents in the community, thereby influencing the work and family domains. Building on ecological systems theory, the authors propose that the compatibility of receiving and giving helping behavior among working residents is related to their mental health. Additionally, the authors propose that this congruence effect functions through work-family interference and meaning in life. Using a two-stage field questionnaire survey, this study collected data from 220 full-time Chinese working residents. Using polynomial regression and response surface analysis, receiving-giving neighboring behavior fit was found to be positively associated with mental health. Furthermore, receiving-giving neighboring behavior fit enhances mental health by decreasing work-family interference and promoting meaning in life. When giving and receiving neighboring behavior are imbalanced, working residents have higher levels of mental health when they received more neighboring behavior than they gave, in comparison to the condition when they gave more neighboring behavior than they received. Work-family interference represents inter-role conflict in which pressures from the family and work domains are mutually incompatible. Including both work to family interference and family to work interference, work-family interferences reflect the stress that working residents experience in their family and work domains. By exploring the mediating role of work-family interference, this study shows how the spillover of the benefits of neighboring behavior into the family and work domains enhances working residents' mental health. This study highlights the importance of balancing receiving and giving neighboring behavior for maintaining mental health, thus contributing both theoretically and practically to ecological systems theory
Piperazine-2,3,5,6-tetraone
The molecule of the title compound, C4H2N2O4, is located around an inversion center and the four O atoms are in the 2,3,5,6-positions of the piperazine ring. In the crystal, bifurcated N—H⋯O hydrogen bonds link the molecules into a corrugated layer parallel to (101)
慢型克山病与扩张型心肌病患者抗氧化能力对比研究
Objective: To compare the serum levels of selenium, selenoprotein and malondialdehyde about Keshan disease (KSD) and dilated cardiomyopathy (DCM) patients and to investigate the relationship between the antioxidant capacity and myocardial injury. Methods: 26 KSD patients, 18 DCM patients, 24 healthy people in KSD areas and 22 healthy people in non-KSD areas were selected by all-round physical examination and electrocardiography. Blood samples were collected by informing consent and volunteering. The serum selenium was determined by using 2,3 - two amino-naphthalene fluorescence method. The serum selenoprotein and malondialdehyde were measured by using biotin double-antibody sandwich method of enzyme linked immunosorbent assay (ELISA) (according to kit instructions). Results: There were no statistical differences about the distribution of the gender and age in every subjects’ groups (P>0.05). The levels of serum selenium and selenoprotein in Keshan disease group and dilated cardiomyopathy group were significantly lower than those of healthy group whether in KSD areas or in non- KSD areas , and the serum malondialdehyde were higher than those in healthy controls. There were no statistical significance about the concentrations of serum selenium, selenoprotein and malondialdehyde between Keshan disease group and dilated cardiomyopathy group, KSD areas’ control group and non- KSD areas’ control group. Conclusion: The myocardial injury of KSD patients and dilated cardiomyopathy patients may be associated with the decrease of antioxidant ability because of the lower selenium levels.目的 对比研究慢型克山病与扩张型心肌病患者体内血清硒、硒蛋白和丙二醛浓度,探讨抗氧化能力与心肌损伤的关系。方法 选择慢型克山病患者26例,扩张型心肌病患者18例,同时在克山病病区选取24名经过全面查体和心电图描记无异常的健康人作为病区健康对照组,在非克山病区选择22名健康人作为非病区健康对照组。在知情同意、患者自愿情况下采集受检者血样,检测克山病患者、扩心病患者、病区健康人及非病区健康人的血清硒、硒蛋白水平及丙二醛浓度。血清硒含量测定采用2,3-二氨基萘荧光法;血清硒蛋白和丙二醛浓度测定采用生物素双抗体夹心酶联免疫吸附法(ELISA)(按试剂盒说明操作)。结果 各组调查对象性别及年龄分布均无统计学差异(P>0.05);克山病组和扩张型心肌病组血清硒、硒蛋白水平均明显低于病区健康对照组与非病区健康对照组,血清丙二醛浓度均高于病区健康对照组及非病区健康对照组;克山病组与扩张型心肌病组,病区健康对照组与非病区健康对照组血清硒、硒蛋白水平以及丙二醛浓度差异均无显著性。结论 慢型克山病和扩张型心肌病患者心肌损伤都可能与低硒导致的抗氧化能力降低有关
Tetraaquabis[2-(4-pyridylsulfanyl)acetato-κN]nickel(II)
In the centrosymmetric title complex, [Ni(C7H6NO2S)2(H2O)4], the NiII atom, located on a centre of inversion, is coordinated by two N atoms from two 2-(4-pyridylsulfanyl)acetate ligands and four water O atoms in an octahedral geometry. In the crystal, intermolecular O—H⋯O hydrogen bonds between the coordinated water molecules and the carboxylate group of the anionic 2-(4-pyridylsulfanyl)acetate ligands link these discrete mononuclear units into a three-dimensional network
Three new xanthone derivatives from an algicolous isolate of Aspergillus wentii
Three new xanthone derivatives, yicathin A (1), yicathin B (2), and yicathin C (3), and three known anthraquinone derivatives, alatinone (4), 1,5-dihydroxy-3-methoxy-7-methylanthraquinone (5), and 5-hydroxy-1,3-dimethoxy-7-methylanthraquinone (6), were isolated from the cultures of Aspergillus wentii pt-1, an endophytic fungus isolated from the marine red alga Gymnogongrus flabelliformis. Their structures were unambiguously elucidated by NMR and mass spectroscopic methods as well as quantum chemical calculations. Compound 2 was active against Escherichia coli, and 3 could inhibit E. coli, Staphylococcus aureus, and Colletotrichum lagenarium.Three new xanthone derivatives, yicathin A (1), yicathin B (2), and yicathin C (3), and three known anthraquinone derivatives, alatinone (4), 1,5-dihydroxy-3-methoxy-7-methylanthraquinone (5), and 5-hydroxy-1,3-dimethoxy-7-methylanthraquinone (6), were isolated from the cultures of Aspergillus wentii pt-1, an endophytic fungus isolated from the marine red alga Gymnogongrus flabelliformis. Their structures were unambiguously elucidated by NMR and mass spectroscopic methods as well as quantum chemical calculations. Compound 2 was active against Escherichia coli, and 3 could inhibit E. coli, Staphylococcus aureus, and Colletotrichum lagenarium. Copyright (C) 2012 John Wiley & Sons, Ltd
Cationic liposomes induce cytotoxicity in HepG2 via regulation of lipid metabolism based on whole-transcriptome sequencing analysis
Abstract
Backgroud
Cationic liposomes (CLs) can be used as non-viral vectors in gene transfer and drug delivery. However, the underlying molecular mechanism of its cytotoxicity has not been well elucidated yet.
Methods
We herein report a systems biology approach based on whole-transcriptome sequencing coupled with computational method to identify the predominant genes and pathways involved in the cytotoxicity of CLs in HepG2 cell line.
Results
Firstly, we validated the concentration-dependent cytotoxicity of CLs with an IC50 of 120 μg/ml in HepG2 exposed for 24 h. Subsequently, we used whole-transcriptome sequencing to identify 220 (77 up- and 143 down-regulated) differentially expressed genes (DEGs). Gene ontology (GO) and pathway analysis showed that these DEGs were mainly related to cholesterol, steroid, lipid biosynthetic and metabolic processes. Additionally, “key regulatory” genes were identified using gene act, pathway act and co-expression network analysis, and expression levels of 11 interested altered genes were confirmed by quantitative real time PCR. Interestingly, no cell cycle arrest was observed through flow cytometry.
Conclusions
These data are expected to provide deep insights into the molecular mechanism of CLs cytotoxicity.https://deepblue.lib.umich.edu/bitstream/2027.42/144776/1/40360_2018_Article_230.pd
Physicochemical and antioxidant properties of 'Lycium barbarum' seed dreg polysaccharides prepared by continuous extraction
Lycium barbarum seed dreg polysaccharides (LBSDPs) were continuously extracted with four different solvents [hot buffer (HBSS), chelating agent (CHSS), dilute alkaline (DASS), and concentrated alkaline (CASS)]. The present study characterized the physicochemical and anti-oxidant based functional properties of different LBSDPs. The monosaccharide analysis revealed xylose (64.63%, 70.00%, 44.71%, and 66.67%) as the main sugar with the molecular weights of 5985, 7062, 5962, and 8762 Da in HBSS, CHSS, DASS, and CASS, respectively. Among the four polysaccharides, CASS had the strongest DPPH radical scavenging ability and reducing power; while, CHSS had the strongest ferrous ions chelating ability and HBSS showed the strongest OH radical scavenging ability. In terms of functional properties, HBSS and CASS had better solubility and oil holding capacity, while, CASS and CHSS had higher foam capacity and foam stability. Altogether, the polysaccharides extracted from L. barbarum seed dreg exhibit a potential application prospect in functional food and cosmetics industries
(E)-N′-(2-Chlorobenzylidene)-3,5-dihydroxybenzohydrazide dihydrate
In the Schiff base molecule of the title compound, C14H11ClN2O3·2H2O, the benzene rings form a dihedral angle of 20.6 (1)°. The water molecules of crystallization are involved in the formation of a three-dimensional hydrogen-bonding network via O—H⋯O and N—H⋯O hydrogen bonds
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