100 research outputs found

    CHARACTERIZATION OF THE FUNCTION OF THE DEAD-BOX RNA HELICASE DBP2

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    In eukaryotes, there are highly coupled mechanisms that require RNA-binding proteins to facilitate gene expression. Proper RNA structure and ribonucleoprotein (RNP) complex formation are critical for gene expression. DEAD-box proteins are the largest class of RNA helicases that play fundamental roles in RNA and RNP structure remodeling. However, the precise biological role of the vast majority of the ~ 40 members in this family has not been completely described. Therefore, my research focused on characterizing the role of the DEAD-box RNA helicase Dbp2 during gene expression in S. cerevisiae

    Will mobile video become the killer application for 3G? - an empirical model for media convergence

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    Mobile carriers have continually rolled out 3G mobile video applications to increase their revenue and profits. The presumption is that video is superior to the already successful SMS, ringtones, and pictures, and can create greater value to users. However, recent market surveys revealed contradicting results. Motivated by this discrepancy, we propose in this paper a parsimonious model for user acceptance of mobile entertainment as digital convergence. Integrating research on Information Systems, Flow, and Media Psychology, we take a unique approach to user acceptance of digital convergence - platform migration. Our key proposition is that the interaction between media types and the platform-specific constraints is the key determinant of user evaluation. Particularly, users' involvement in the media is determined by both the entertaining time span on the original platform and the attentional constraint of the new platform. The mismatch between the two spans can result in lower level involvement, which in turn cause no or even negative user emotional responses. The model was tested with empirical data. We discuss the theoretical contributions, strategic and design implications, and future research directions derived from this theoretical framewor

    Urological Effects of Ketamine Abuse

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    Emerging evidence has shown that long-term and chronic ketamine use or abuse can lead to damages in the urinary tract, a spectrum of clinical presentations from mild irritative lower tract symptoms to painful gross haematuria and renal damages. First reported by a Hong Kong group of urologists in 2007, the phenomenon has since then been identified worldwide. Most of the ketamine abusers were adolescents and young adults, and the symptomatology resembled those of chemical cystitis or interstitial cystitis. Endoscopic features of ulcerative cystitis, radiological features of thickened and contracted bladder wall with or without obstruction to upper urinary tract, and histopathological features of inflammation and fibrosis and urothelial metaplasia changes were described. With increasing clinical experience in managing this group of patients, clinical pathways and medical and surgical treatment options have been developed. Animal studies on the effects of ketamine exposure on the urinary system have also been conducted to help us understand the underlying pathophysiology for this distinct entity

    Application of tri-colour, dual fusion fluorescence in situ hybridization (FISH) system for the characterization of BCR-ABL1 fusion in chronic myelogenous leukaemia (CML) and residual disease monitoring

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    <p>Abstract</p> <p>Background</p> <p>We studied the application of the <it>BCR-ABL1 </it>+ 9q34 tri-colour dual fusion fluorescence <it>in situ </it>hybridization (FISH) system in the characterization of fusion signal pattern and the monitoring of residual disease in chronic myelogenous leukaemia (CML). The signal constellation on metaphases with the tri-colour dual fusion system was defined. The knowledge of various signal patterns obtained from the different genetic rearrangements was further applied to the analysis of hybridization signals on interphase nuclei.</p> <p>Methods</p> <p><it>BCR-ABL1 </it>dual colour, dual fusion FISH (D-FISH) was performed on diagnostic samples of 22 CML patients. The tri-colour FISH system was performed on cases that showed aberrant signal patterns other than the classical 1 green (G) 1 orange (O) 2 fusions (F). Using the aqua band-pass filter, random signal overlap in interphase nuclei would be indicated by the presence of an aqua signal (<it>ASS1</it>), while genuine fusion was represented by the absence of the <it>ASS1 </it>signal.</p> <p>Results</p> <p>Using the D-FISH system, the signal patterns could be categorized into 4 groups: group 1 (n = 17) showed the classical 1G1O2F; group 2 (n = 2) showed 2G1O1F indicating <it>ABL1 </it>deletion; group 3 (n = 1) showed 1G2O1F indicating <it>BCR </it>deletion; group 4 (n = 2) with 1G1O1F indicating reciprocal <it>ABL1-BCR </it>deletion. The tri-colour dual fusion system correlated with the D-FISH system for cases with der(9) deletion. The added aqua-labelled <it>ASS1 </it>probe was useful in differentiating random signal overlap from genuine <it>BCR-ABL1 </it>fusion in the interphase cells (group 4).</p> <p>Conclusion</p> <p>Although the D-FISH probe was valuable in establishing the different patterns of aberrant signals and monitoring patients with the classic 2-fusion signals in CML, the tri-colour dual fusion probe should be used for patients with der(9) deletion to monitor response to treatment.</p

    Room-temperature InP/InGaAs nano-ridge lasers grown on Si and emitting at telecom bands

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    Semiconductor nano-lasers grown on silicon and emitting at the telecom bands are advantageous ultra-compact coherent light sources for potential Si-based photonic integrated circuit applications. However, realizing room-temperature lasing inside nano-cavities at telecom bands is challenging and has only been demonstrated up to the E band. Here, we report on InP/InGaAs nano-ridge lasers with emission wavelengths ranging from the O, E, and S bands to the C band operating at room temperature with ultra-low lasing thresholds. Using a cycled growth procedure, ridge InGaAs quantum wells inside InP nano-ridges grown on patterned (001) Si substrates are designed as active gain materials. Room-temperature lasing at the telecom bands is achieved by transferring the InP/InGaAs nano-ridges onto a SiO2∕Si substrate for optical excitation. We also show that the operation wavelength of InP/InGaAs nano-lasers can be adjusted by altering the excitation power density and the length of the nano-ridges formed in a single growth run. These results indicate the excellent optical properties of the InP/InGaAs nano-ridges grown on (001) Si substrates and pave the way towards telecom InP/InGaAs nano-laser arrays on CMOS standard Si or silicon-on-insulator substrates

    Effectiveness of Nutritional Advice for Community-Dwelling Obese Older Adults With Frailty: A Systematic Review and Meta-Analysis

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    Objectives: This systematic review was aimed to examine the effectiveness of nutritional advise interventions compared with usual care, or exercise, or exercise combined with nutritional advice as a means of improving the body weight, body composition, physical function, and psychosocial well-being of frail, obese older adults. Methods: CINAHL, Cochrane Library, Embase, MEDLINE, PsycINFO, and Scopus databases were searched to identify relevant studies. The quality of the included studies was assessed using Cochrane's risk of bias tool 2. Meta-analysis was performed with respect to body weight and fat mass. Other outcomes were synthesized narratively. Results: Eight articles (from two studies) with a total of 137 participants were included in the review. The results revealed that nutritional advice was more effective than exercise in reducing body weight and fat mass. The nutritional advice was also beneficial in enhancing physical function and psychosocial well-being. However, it was less effective than exercise or combined interventions in increasing muscle strength and preventing lean mass loss. Conclusions: Nutritional advice is an essential intervention for reducing body weight and fat mass, for enhancing physical function, and for improving the psychosocial well-being of obese older adults experiencing frailty. The limited number of studies included in this review suggests that there is a need for more well-designed interventional studies in order to confirm these findings

    Chinese university students’ preferences for physical activity incentive programs: a discrete choice experiment

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    PurposeThis study aims to explore and compare Chinese university students’ preferences for various physical activity motivation programs.Patients and methodsA cross-sectional study was conducted in China from February 25 to March 25, 2022. Participants anonymously completed an online questionnaire based on a DCE. A total of 1,358 university students participated in the survey. The conditional logit model (CLM), willingness to accept (WTA), and propensity score matching (PSM) were used to assess college students’ preferences for different attributes and levels of physical activity incentive programs.ResultsRespondents identified the number of bonus, exercise time, and academic rewards as the three most significant attributes of the athletic incentive program. The importance of each attribute varied based on individual characteristics such as gender and BMI. In CLM, college students displayed a preference for a “¥4” bonus amount (OR: 2.04, 95% CI 1.95–2.13), “20 min” of exercise time (OR: 1.85, 95% CI 1.79–1.92), and “bonus points for comprehensive test scores” as academic rewards (OR: 1.33, 95% CI 1.28–1.37). According to the WTA results, college students were willing to accept the highest cost to obtain academic rewards tied to composite test scores.ConclusionThe number of bonus, exercise time, and academic rewards emerge as the three most crucial attributes of physical activity incentive programs. Furthermore, college students with different characteristics exhibit heterogeneity in their preferences for such programs. These findings can guide the development of programs and policies aimed at motivating college students to engage in physical activities

    Sex- and age-dependent association of SLC11A1 polymorphisms with tuberculosis in Chinese: a case control study

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    BACKGROUND: Host genetic factors are important determinants in tuberculosis (TB). The SLC11A1 (or NRAMP1) gene has been studied extensively for genetic association with TB, but with inconsistent findings. In addition, no study has yet looked into the effect of sex and age on the relationship between SLC11A1 polymorphisms and TB. METHODS: A case-control study was conducted. In total, 278 pulmonary TB patients and 282 sex- and age-matched controls without TB were recruited. All subjects were ethnic Chinese. On the basis of linkage disequilibrium pattern, three genetic markers from SLC11A1 and one from the nearby IL8RB locus were selected and examined for association with TB susceptibility. These markers were genotyped using single strand conformation polymorphism analysis or fragment analysis of amplified products. RESULTS: Statistically significant differences in allele (P = 0.0165, OR = 1.51) and genotype (P = 0.0163, OR = 1.59) frequencies of the linked markers SLC6a/b (classically called D543N and 3'UTR) of the SLC11A1 locus were found between patients and controls. With stratification by sex, positive associations were identified in the female group for both allele (P = 0.0049, OR = 2.54) and genotype (P = 0.0075, OR = 2.74) frequencies. With stratification by age, positive associations were demonstrated in the young age group (age ≤65 years) for both allele (P = 0.0047, OR = 2.52) and genotype (P = 0.0031, OR = 2.92) frequencies. All positive findings remained significant even after correction for multiple comparisons. No significant differences were noted in either the male group or the older age group. No significant differences were found for the other markers (one SLC11A1 marker and one IL8RB marker) either. CONCLUSION: This study confirmed the association between SLC11A1 and TB susceptibility and demonstrated for the first time that the association was restricted to females and the young age group

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
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