844 research outputs found
Cannot Live without Facebook? An Expectation Confirmation Model with the Moderating Effects of Narcissism
Facebook provides an ideal channel for people to admire their own performance. People tend to show off themselves to others and confirming their feedback on Facebook. With behavior on Facebook, narcissism is now highlighted by many researchers. Hence, based on the expectation confirmation theory (ECT), our study looks into continuance Facebook usage behaviors. It explores the relationship between perceived feedback, confirmation, satisfaction, and continuance intentions, and most important of all, it examines the moderating effects of narcissistic traits on these relationships. Data are collected from 420 valid respondents through self-administered questionnaires. Results revealed that: (1) Continuance Facebook behavior intention is jointly influenced by perceived feedback and satisfaction, which in turn is determined by confirmation. Then, confirmation is influenced by perceived feedback; (2) Narcissism has the moderating effect on the relationships between feedback and confirmation as well as confirmation and satisfaction. Finally, interpretations and implication of these findings are discussed
Sperm quality and DNA integrity of coke oven workers exposed to polycyclic aromatic hydrocarbons
Objectives: The objective of this study was to assess sperm quality and deoxyribonucleic acid (DNA) integrity of coke oven workers exposed to polycyclic aromatic hydrocarbons (PAHs) as compared to control subjects. Material and methods: The coke oven workers (N = 52) and administrative staff (N = 35) of a steel plant served as the exposed and control groups, respectively. Exposure to PAHs was assessed by measuring 1-hydroxypyren. Analysis of sperm quality (concentration, motility, vitality, and morphology) was performed simultaneously with sperm DNA integrity analysis, including DNA fragmentation, denaturation, bulky DNA adducts, and 8-oxo-7,8-dihydro-2’-deoxyguanosine (8-oxo-dGuo). A questionnaire was conducted to collect demographic and potential confounding data. Results: The coke oven workers had lower percentages of sperm motility, vitality and normal morphology than the control group, but the difference was not significant. For DNA integrity, the coke oven workers had significantly higher concentrations of bulky DNA adducts and 8-oxo-dGuo than the control subjects (p = 0.009 and p = 0.048, respectively). However, DNA fragmentation percentages did not significantly increase as compared to those in the subjects from the control group (p = 0.232). There was no correlation between sperm quality parameters and DNA integrity indicators. Conclusions: Occupational exposure of the coke oven workers to PAHs was associated with decreased sperm DNA integrity. Int J Occup Med Environ Health 2016;29(6):915–92
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Measurements of Natural Carbonate Rare Earth Elements in Femtogram Quantities by Inductive Coupled Plasma Sector Field Mass Spectrometry
A rapid and precise standard-bracketing method has been developed for measuring femtogram quantity rare earth element (REE) levels in natural carbonate samples by inductively coupled plasma sector field mass spectrometry that does not require chemical separation steps. A desolvation nebulization system was used to effectively reduce polyatomic interference and enhance sensitivity. REE/Ca ratios are calculated directly from the intensities of the ion beams of 46Ca, 139La, 140Ce, 141Pr, 146Nd, 147Sm, 153Eu, 160Gd, 159Tb, 163Dy, 165Ho, 166Er, 169Tm, 172Yb, and 175Lu using external matrix-matched synthetic standards to correct for instrumental ratio drifting and mass discrimination. A routine measurement time of 3 min is typical for one sample containing 20-40 ppm Ca. Replicate measurements made on natural coral and foraminiferal samples with REE/Ca ratios of 2-242 nmol/mol show that external precisions of 1.9-6.5% (2 RSD) can be achieved with only 10-1000 fg of REEs in 10-20 μg of carbonate. We show that different sources for monthly resolved coral ultratrace REE variability can be distinguished using this method. For natural slow growth-rate carbonate materials, such as sclerosponges, tufa, and speleothems, the high sample throughput, high precision, and high temporal resolution REE records that can be produced with this procedure have the potential to provide valuable time-series records to advance our understanding of paleoclimatic and paleoenvironmental dynamics on different time scales
Changes in corneal curvature after wearing the orthokeratology lens
AbstractIntroductionThe orthokeratology lens (OK lens) is designed to reshape the cornea and correct refraction error. Owing to the convenience of ceasing the use of glasses during the day, the use of the OK lens is increasing in myopic children. In this study, changes in corneal curvature and astigmatism after wearing the OK lens were analyzed.MethodsThis retrospective cohort study included 65 children (130 eyes) who underwent full and regular examinations. None of the participants had any ocular disease other than myopia and astigmatism. The OK lenses used in this study were four-zone, reverse-geometry lenses. The corneal curvature of each patient was checked annually after the patients discontinued daily wearing of the OK lens for 10 days. Student t test and repeated measures analysis of variance (ANOVA) analyses were performed to compare the results.ResultsThe radius of corneal curvature showed a progressive annual increase with significant differences, both in the steepest and flattest radius of the corneal curvature (p < 0.001 and p = 0.001, respectively). The mean radius of the steepest and flattest corneal curvature increased significantly from baseline to the following years consecutively (all p < 0.001). Nevertheless, astigmatism did not change significantly in any of the tests.ConclusionCorneal curvature changed as the patients grew older. There was a statistically significant increase in the radius of the corneal curvature in the myopic children studied. For correct fit of OK lenses, the radius of the corneal curvature should be regularly checked prior to dispensing a new set of lenses
The role of cytochrome c oxidase subunit Va in non-small cell lung carcinoma cells: association with migration, invasion and prediction of distant metastasis
BACKGROUND: Lung cancer is one of the most lethal malignancies worldwide, but useful biomarkers of lung cancer are still insufficient. The aim of this study is to identify some membrane-bound protein(s) associated with migration and invasion in human non-small cell lung cancer (NSCLC) cells. METHODS: We classified four NSCLC cell lines into high and low migration/invasion groups by Transwell and Matrigel assays. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), we identified 10 membrane-associated proteins being significantly overexpressed in the high migration/invasion group. The expression of the target protein in the four NSCLC cell lines was then confirmed by reverse transcription polymerase chain reaction (RT-PCR), western blot and immunostaining. RNA interference technique was applied to observe the influence of the target protein on migration and invasion. Gelatin zymography was also performed to evaluate the activities of matrix metalloproteinase (MMP)-2 and MMP-9. Expression condition of the target protein on surgical specimens was further examined by immunohistochemical staining and the clinicopathologic data were analyzed. RESULTS: We identified a mitochondria-bound protein cytochrome c oxidase subunit Va (COX Va) because of its abundant presence found exclusively in tumorous areas. We also demonstrated that migration and invasion of NSCLC cells decreased substantially after knocking down COX Va by siRNA. Meanwhile, we found a positive correlation between COX Va expression, Bcl-2 expression and activities of MMP-2 and MMP-9 in NSCLC cells. Immunohistochemical staining of surgically resected lung adenocarcinomas in 250 consecutive patients revealed that strong COX Va expression was found in 54.8% (137/250) of patients and correlated positively with the status of lymph node metastasis (P = 0.032). Furthermore, strong COX Va expression was associated with the presence of distant metastasis (P = 0.033). CONCLUSIONS: Our current study showed that COX Va may play a role in migration and invasion of NSCLC cells and can be used as a biomarker to predict aggressiveness of NSCLC
The Clinical COPD Questionnaire Correlated with BODE Index-A Cross-Sectional Study
The Global initiative for Chronic Obstructive Lung Disease (GOLD) staging has widely used in the stratification of the severity of COPD, while BODE (body mass index, airflow obstruction, dyspnea, and exercise capacity) index was proven superior to FEV1 in predicting mortality, exacerbation and disease severity in patients with COPD. Clinical COPD Questionnaire (CCQ), a questionnaire with ten items categorized into three domains (symptoms, functional state and mental state) was developed to measure health status of COPD patients. However, little is known about the relationship between CCQ score and BODE index. We performed a prospective study with the inclusion of 89 patients who were clinically stable after a 6-week-therapy for COPD symptoms comparing their health status assessed by CCQ, BODE index and GOLD staging. We found that the total CCQ score was correlated with BODE score (P < 0.001) and GOLD staging (P < 0.001); of three CCQ domains, the functional status correlated the most with BODE index (rS = 0.670) and GOLD staging (rS = 0.531), followed by symptoms (rS = 0.482; rS = 0.346, respectively), and mental status (rS = 0.340; rS = 0.236, respectively). Our data suggest that CCQ is a reliable and convenient alternative tool to evaluate the severity of COPD
Enhancing Color Purity and Stable Efficiency of White Organic Light Diodes by Using Hole-Blocking Layer
The organic light-emitting diodes with triple hole-blocking layer (THBL) formation sandwich structure which generate white emission were fabricated. The 5,6,11,12-tetraphenylnapthacene (Rubrene), (4,4′-N,N′-dicarbazole)biphenyl (CBP), and 4,4′-bis(2,2′diphenylvinil)-1,1′-biphenyl (DPVBi) were used as emitting materials in the device. The function of CBP layer is not only an emitting layer but also a hole-blocking layer (HBL), and the Rubrene was doped into the CBP. The optimal configuration structure was indium tin oxide (ITO)/Molybdenum trioxide (MoO3) (5 nm)/[4,4-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB) (35 nm)/CBP (HBL1) (5 nm)/DPVBi (I) (10 nm)/CBP (HBL2) : Rubrene (4 : 1) (3 nm)/DPVBi (II) (30 nm)/CBP (HBL3) (2 nm)/4,7-diphenyl-1,10-phenanthroline (BPhen) (10 nm)/Lithium fluoride (LiF)/aluminum (Al). The result showed that the device with Rubrene doped in CBP (HBL2) exhibited a stable white emission with the color coordinates of (0.322, 0.368), and the coordinate with the slight shift of ±Δx,y = (0.001, 0.011) for applied voltage of 8–12 V was observed
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