503 research outputs found
The Long-Term Impact of First-Year Seminars
This study examined the net effects of participating in a residential first-year seminar (FYS) program by comparing the outcomes of participants with those of non-participants at the point of graduation, while controlling for background and pre-college variables. Outcome variables focused on student academic performance and self-reported gains as a result of their undergraduate education; they included: cumulative GPA; intellectual development; development of problem solving; development of social and civic engagement; institutional preparation for career path, graduate school, and interpersonal relationships and family living/personal development; and participation in faculty-mentored research. The study was based on a sample of 853 graduating seniors at a highly selective liberal arts college. Participation in a FYS was negatively associated with two outcomes--development of problem solving and institutional preparation for career path, on which FYS participants reported significantly smaller gains than non-participants. On the remaining outcome variables, participation in a FYS did not demonstrate any significant long-term effects
Synthetic biology: From the first synthetic cell to see its current situation and future development
OCT Application Before and After Cataract Surgery
Optical coherence tomography (OCT), especially anterior segment OCT (AS-OCT), plays an important role in ophthalmology. With the technology evolving from time-domain to spectral-domain, more and more detailed ocular information has become available. Anterior segment OCT provides particularly useful information for cataract surgeons. This chapter focuses mainly on AS-OCT evaluation of eyes before and after cataract surgery. Four aspects including: (1) anterior lens capsule and lens epithelium evaluation using spectral-domain OCT (SD-OCT); (2) investigation of clear corneal incision in femtosecond laser assisted cataract surgery using SD-OCT; (3) capsular block syndrome evaluation before and after treatment using SD-OCT; (4) IOL power calculation in post-myopic excimer laser eyes using SD-OCT, will be discussed in this chapter
Ignored adult primary hypothyroidism presenting chiefly with persistent ovarian cysts: a need for increased awareness
<p>Abstract</p> <p>Background</p> <p>Ovarian cysts are a common cause for gynecological surgery. However, some cysts are a direct result of endocrine disorders and do not require surgery. This report describes an unusual case in which persistent ovarian cysts are associated with primary hypothyroidism in a young woman. The data were collected by history-taking, physical examination, laboratory tests, ultrasound, magnetic resonance imaging and a histo-pathological study. In addition, the exons of the gene encoding the human follicle-stimulating hormone receptor were sequenced.</p> <p>Discussion</p> <p>The patient had markedly elevated levels of thyroid-stimulating hormone and follicle-stimulating hormone and an enlarged pituitary gland. After treatment with thyroid hormone replacement, regression of the enlarged pituitary and the ovarian cysts was observed. The possible mechanisms of the pathophysiology are discussed below.</p> <p>Summary</p> <p>It is necessary to consider hypothyroidism and other endocrine disorders in the differential diagnosis of adult patients with ovarian multiple cyst formation in order to prevent inadvertent ovarian surgery.</p
Correlation between Internet Addiction Disorder and Mental Health of Junior Middle School Students in Chengdu
Objective: To study the prevalence and main influencing factors of Internet addiction among junior middle school students in Chengdu, and to provide scientific basis for the prevention and intervention of Internet addiction. Methods: From September to December 2017, 3,607 junior middle school students were randomly selected from 8 middle schools in Chengdu by stratified cluster sampling, and investigated by selfmade questionnaire. SPSS 19.0 software was used for χ 2 test and multiple linear regression analysis. Results: 174 of 3,607 junior middle school students in Chengdu were diagnosed with Internet addiction, and the detection rate of Internet addiction was 4.8%. There were significant differences in the scores of mental health, learning pressure, parent-child relationship and peer relationship between Internet addiction and non-internet addiction junior middle school students (P < 0.05). The results of multiple linear regression showed that family economic status, learning pressure, depression and anxiety were positively correlated with internet addiction, while parent-child relationship, peer relationship and social support were negatively correlated with Internet addiction (P < 0.05, P < 0.01). Conclusion: The detection rate of Internet addiction among junior middle school students in Chengdu is at a low level. Junior middle school students with low social support and high depression and anxiety have a higher risk of Internet addiction, which can be reduced by improving their mental health
Phenotypic comparison and DNA sequencing analysis of a wild-type and a pediocin-resistant mutant of Listeria ivanovii
Listeria ivanovii is one of the two pathogenic species within the genus Listeria, the other being L. monocytogenes. In this study, we generated a stable pediocin resistant mutant Liv-r1 of a L. ivanovii strain, compared phenotypic differences between the wild-type and the mutant, localised the pediocin-induced mutations in the chromosome, and analysed the mechanisms behind the bacteriocin resistance. In addition to pediocin resistance, Liv-r1 was also less sensitive to nisin. The growth of Liv-r1 was significantly reduced with glucose and mannose, but less with cellobiose. The cells of Liv-r1 adsorbed less pediocin than the wild-type cells. Consequently, with less pediocin on the cell surface, the mutant was also less leaky, as shown as the release of intracellular lactate dehydrogenase to the supernatant. The surface of the mutant cells was more hydrophobic than that of the wild-type. Whole genome sequencing revealed numerous changes in the Liv-r1 chromosome. The mutations were found e.g., in genes encoding sigma-54-dependent transcription regulator and internalin B, as well as in genes involved in metabolism of carbohydrates such as glucose and cellobiose. Genetic differences observed in the mutant may be responsible for resistance to pediocin but no direct evidence is provided.Peer reviewe
In vitro study on human cytomegalovirus affecting early pregnancy villous EVT's invasion function
<p>Abstract</p> <p>Background</p> <p>Human cytomegalovirus (HCMV) is the most common pathogen in uterus during pregnancy, which may lead to some serious results such as miscarriage, stillbirth, cerebellar malformation, fetus developmental retardation, but its pathogenesis has not been fully explained. The hypofunction of extravillous cytotrophoblast (EVT) invasion is the essential pathologic base of some complications of pregnancy. c-erbB-2 is a kind of oncogene protein and closely linked with embryogenesis, tissue repair and regeneration. Matrix metalloproteinase (MMP) is one of the key enzymes which affect EVT migration and invasion function. The expression level changes of c-erbB-2, MMP-2 and MMP-9 can reflect the changes of EVT invasion function.</p> <p>Results</p> <p>To explore the influence of HCMV on the invasion function of EVT, we tested the protein expression level changes of c-erbB-2, MMP-2 and MMP-9 in villous explant cultured in vitro infected by HCMV, with the use of immunohistochemistry SP method and western blot. We confirmed that HCMV can reproduce and spread in early pregnancy villus; c-erbB-2 protein mainly expressed in normal early pregnancy villous syncytiotrophoblast (ST) remote plasma membrane and EVT, especially remote EVT cell membrane in villous stem cell column, little expressed in ST proximal end cell membrane and interstitial cells; MMP-2 protein primarily expressed in early pregnancy villous EVT endochylema and rarely in villous trophoblast (VT), ST and interstitial cells; MMP-9 protein largely expressed in early pregnancy villous mesenchyme, EVT and VT endochylema. Compared with control group, the three kinds of protein expression level in early pregnancy villus of virus group significantly decreased (P < 0.05).</p> <p>Conclusion</p> <p>HCMV can infect villus in vitro and cause the decrease of early pregnancy villous EVT's invasion function.</p
PhyloMap: an algorithm for visualizing relationships of large sequence data sets and its application to the influenza A virus genome
<p>Abstract</p> <p>Background</p> <p>Results of phylogenetic analysis are often visualized as phylogenetic trees. Such a tree can typically only include up to a few hundred sequences. When more than a few thousand sequences are to be included, analyzing the phylogenetic relationships among them becomes a challenging task. The recent frequent outbreaks of influenza A viruses have resulted in the rapid accumulation of corresponding genome sequences. Currently, there are more than 7500 influenza A virus genomes in the database. There are no efficient ways of representing this huge data set as a whole, thus preventing a further understanding of the diversity of the influenza A virus genome.</p> <p>Results</p> <p>Here we present a new algorithm, "PhyloMap", which combines ordination, vector quantization, and phylogenetic tree construction to give an elegant representation of a large sequence data set. The use of PhyloMap on influenza A virus genome sequences reveals the phylogenetic relationships of the internal genes that cannot be seen when only a subset of sequences are analyzed.</p> <p>Conclusions</p> <p>The application of PhyloMap to influenza A virus genome data shows that it is a robust algorithm for analyzing large sequence data sets. It utilizes the entire data set, minimizes bias, and provides intuitive visualization. PhyloMap is implemented in JAVA, and the source code is freely available at <url>http://www.biochem.uni-luebeck.de/public/software/phylomap.html</url></p
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