107 research outputs found

    Effects of eccentricity on seismic behavior of non-seismically designed reinforced concrete beam-column joint

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    The staggering numbers of eccentric reinforced concrete beam-column joints without seismic design details were used in existing RC frame building due to geometrical constraints, which implied high susceptibility of the building structures to anticipated seismic risk. Three exterior RC beam-column joints were fabricated and tested, which were applied reversed cyclic loads to simulate seismic action. In this study, the effects of stirrup ratio in joints and the eccentricity which is defined as the distance between the axis of the beam and column on seismic performance are investigated. The test results provide a further understanding of the failure mode and shear strength of exterior beam-column joints. It is shown that the eccentricity will significantly reduce the seismic performance and shear strength of the joints, which will cause the brittle failure of frame buildings, while the stirrups in the joint core can improve the seismic performance. To verify the availability of current codes in predicting the shear strength of eccentric beam-column joints with non-seismic detailed, the experimental results are compared with the predicted shear force of two nonseismic codes (HK code and Eurocode 2) and three seismic codes (Eurocode 8, NZS 3101 and ACI 318-14). The comparison results indicate that the existing non-seismic and seismic design codes of practice do not predict the shear strength of the exterior non-seismically designed joints precisely

    Loss of Yeast Peroxiredoxin Tsa1p Induces Genome Instability through Activation of the DNA Damage Checkpoint and Elevation of dNTP Levels

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    Peroxiredoxins are a family of antioxidant enzymes critically involved in cellular defense and signaling. Particularly, yeast peroxiredoxin Tsa1p is thought to play a role in the maintenance of genome integrity, but the underlying mechanism is not understood. In this study, we took a genetic approach to investigate the cause of genome instability in tsa1Δ cells. Strong genetic interactions of TSA1 with DNA damage checkpoint components DUN1, SML1, and CRT1 were found when mutant cells were analyzed for either sensitivity to DNA damage or rate of spontaneous base substitutions. An elevation in intracellular dNTP production was observed in tsa1Δ cells. This was associated with constitutive activation of the DNA damage checkpoint as indicated by phosphorylation of Rad9/Rad53p, reduced steady-state amount of Sml1p, and induction of RNR and HUG1 genes. In addition, defects in the DNA damage checkpoint did not modulate intracellular level of reactive oxygen species, but suppressed the mutator phenotype of tsa1Δ cells. On the contrary, overexpression of RNR1 exacerbated this phenotype by increasing dNTP levels. Taken together, our findings uncover a new role of TSA1 in preventing the overproduction of dNTPs, which is a root cause of genome instability

    The Stories We Tell Influence the Support We Receive:Examining the Reception of Support-Seeking Messages on Reddit

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    Although social support facilitates coping and recovering from stressful life events, people do not always get the support that they need. Prior research suggests that the way one talks about stressful events to others may influence the support they receive. Given that people are increasingly relying on online communities for social support, this study adopted a person-centered approach (latent profile analysis) to examine how narrative variables related to the motivational themes, emotional content, and organizational structure of randomly sampled support-seeking messages ( N  = 495) posted on Reddit (r/Anxiety and r/Depression) influenced the quantity (number of comments and post score) and quality (type of support in comments) of support that they received. We identified five distinct narrative profiles of support-seeking posts, which in turn differentially predicted the quality, but not quantity, of social support people received. While commenters provided high levels of emotional support to all forms of posts, we found that coherence was an important determinant of esteem support. A combination of coherence, as well as agency and affective tone, were important determinants of instrumental, informational, and network support. The ways in which one talks about their problems influence the way others support them.</p

    Dense Cranial Electroacupuncture Stimulation for Major Depressive Disorder—A Single-Blind, Randomized, Controlled Study

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    BACKGROUND: Previous studies suggest that electroacupuncture possesses therapeutic benefits for depressive disorders. The purpose of this study was to determine whether dense cranial electroacupuncture stimulation (DCEAS) could enhance the antidepressant efficacy in the early phase of selective serotonin reuptake inhibitor (SSRI) treatment of major depressive disorder (MDD). METHODS: In this single-blind, randomized, controlled study, patients with MDD were randomly assigned to 9-session DCEAS or noninvasive electroacupuncture (n-EA) control procedure in combination with fluoxetine (FLX) for 3 weeks. Clinical outcomes were measured using the 17-item Hamilton Depression Rating Scale (HAMD-17), Clinical Global Impression-severity (CGI-S), and Self-rating Depression Scale (SDS) as well as the response and remission rates. RESULTS: Seventy-three patients were randomly assigned to n-EA (n = 35) and DCEAS (n = 38), of whom 34 in n-EA and 36 in DCEAS group were analyzed. DCEAS-treated patients displayed a significantly greater reduction from baseline in HAMD-17 scores at Day 3 through Day 21 and in SDS scores at Day 3 and Day 21 compared to patients receiving n-EA. DCEAS intervention also produced a higher rate of clinically significant response compared to n-EA procedure (19.4% (7/36) vs. 8.8% (3/34)). The incidence of adverse events was similar in the two groups. CONCLUSIONS: DCEAS is a safe and effective intervention that augments the antidepressant efficacy. It can be considered as an additional therapy in the early phase of SSRI treatment of depressed patients. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN88008690

    The Moderating Effect of Different Types of Internet Use on the Relationship between Transitional Aging Changes and Self-esteem of Older Adults

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    This study investigates the moderating effect of different types of Internet use regarding the relationship between three transitional aging changes and self-esteem of older adults. The current paper is still in progress; this is a research-in-progress paper. An aging population increases government expenditures and family responsibilities, thus drawing more attention from the academic community. Recent research posits that self-esteem tends to decline in individuals from the ages around 50-65 due to role loss, social loss, and dissatisfaction resulting from unaccomplished life goals. To address this issue, previous studies considered that the general use of the Internet may help to enhance self-esteem among older adults. To fill this research gap, the present study proposes that the cultural use of the Internet could moderate role loss of older adults, while social use of the Internet could mitigate social loss. Furthermore, economic use could moderate the dissatisfaction of unfulfilled life goals. Regarding various theoretical contributions, this is the first study to apply different types of Internet use, so as to investigate its moderating effect concerning the relationship between transitional aging changes and self-esteem. Findings of the present study can also help shed light on interventions for the caregiver in both community centers and the domestic environment to moderate the decline of self-esteem among older adults. The data will be collected through surveys distributed to District Elderly Community Centers (DECCs) in Hong Kong. Multiple regression analysis will then be utilized to test the moderating effect of each type of Internet use

    Is 'oil pulling' a 'snake oil'? : a clinical trial

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    The traditional Ayurveda practice of ‘oil pulling’ has become a recent phenomenon and concerns about its efficacy have been raised. Objectives: (1) to determine awareness about the practice of ‘oil pulling’ among a group of young adults, and to determine variations in awareness with respect to socio-demographic factors, oral health behaviours (oral hygiene and dental attendance) and use of natural health products; (2) to determine the effectiveness of ‘oil pulling’ and conventional oral hygiene practice compared to the use of conventional oral hygiene practice alone in terms of oral hygiene and (3) to determine the effectiveness of ‘oil pulling’ and conventional oral hygiene practice compared to the use of conventional oral hygiene practice alone in terms of gingival health. Methods: Group members recruited seventy-four young adults to participate in a clinical trial over a two-month period comparing the effectiveness of (a) ‘oil pulling’ and conventional oral hygiene methods (toothbrush and toothpaste) versus (b) conventional oral hygiene methods alone. Oral hygiene was assessed using the Plaque Index - PI (Silness and Löe, 1964) and the proportion of sites with visible plaque (PVP). Gingival health was assessed using the Gingival Index – GI (Silness and Löe,1963) and the proportion of sites with gingival bleeding (PGB). Participants were block randomized in groups of four to a cross over clinical trial and assessments were conducted at one-month and two-months. Results: Approximately a quarter (28.4%, 21) of participants was aware of the practice of ‘oil pulling’. Awareness of the practice was associated with reported use of natural dental/oral health products (p0.05). There were observed significant differences in gingival health among both the test and control groups from baseline to one-month (p0.05). No significant differences were observed in oral health parameters from one-month to two-month among neither the test nor control groups (p>0.05). Conclusion: Awareness of the practice of ‘oil pulling’ is relatively common and is associated with use of natural dental/oral health products. Findings from the clinical trial failed to support the adjunct use of ‘oil pulling’ in addition to conventional oral hygiene practices.published_or_final_versio

    Next generation histology methods for three-dimensional imaging of fresh and archival human brain tissues

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    Current available tissue clearing techniques are mostly used for rodent tissues. Here, the authors develop OPTIClear solution for fresh and archival human brain tissue clearing and establish associated protocols for three-dimensional histological investigations

    Development of an Electronic Frailty Index for Predicting Mortality and Complications Analysis in Pulmonary Hypertension Using Random Survival Forest Model

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    The long-term prognosis of the cardio-metabolic and renal complications, in addition to mortality in patients with newly diagnosed pulmonary hypertension, are unclear. This study aims to develop a scalable predictive model in the form of an electronic frailty index (eFI) to predict different adverse outcomes. This was a population-based cohort study of patients diagnosed with pulmonary hypertension between January 1st, 2000 and December 31st, 2017, in Hong Kong public hospitals. The primary outcomes were mortality, cardiovascular complications, renal diseases, and diabetes mellitus. The univariable and multivariable Cox regression analyses were applied to identify the significant risk factors, which were fed into the non-parametric random survival forest (RSF) model to develop an eFI. A total of 2,560 patients with a mean age of 63.4 years old (interquartile range: 38.0-79.0) were included. Over a follow-up, 1,347 died and 1,878, 437, and 684 patients developed cardiovascular complications, diabetes mellitus, and renal disease, respectively. The RSF-model-identified age, average readmission, anti-hypertensive drugs, cumulative length of stay, and total bilirubin were among the most important risk factors for predicting mortality. Pair-wise interactions of factors including diagnosis age, average readmission interval, and cumulative hospital stay were also crucial for the mortality prediction. Patients who developed all-cause mortality had higher values of the eFI compared to those who survived ( < 0.0001). An eFI ≥ 9.5 was associated with increased risks of mortality [hazard ratio (HR): 1.90; 95% confidence interval [CI]: 1.70-2.12; < 0.0001]. The cumulative hazards were higher among patients who were 65 years old or above with eFI ≥ 9.5. Using the same cut-off point, the eFI predicted a long-term mortality over 10 years (HR: 1.71; 95% CI: 1.53-1.90; < 0.0001). Compared to the multivariable Cox regression, the precision, recall, area under the curve (AUC), and C-index were significantly higher for RSF in the prediction of outcomes. The RSF models identified the novel risk factors and interactions for the development of complications and mortality. The eFI constructed by RSF accurately predicts the complications and mortality of patients with pulmonary hypertension, especially among the elderly

    Yeast arginine methyltransferase Hmt1p regulates transcription elongation and termination by methylating Npl3p

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    The heterogeneous nuclear ribonucleoprotein Npl3p of budding yeast is a substrate of arginine methyltransferase Hmt1p, but the role of Hmt1p in regulating Npl3p’s functions in transcription antitermination and elongation were unknown. We found that mutants lacking Hmt1p methyltransferase activity exhibit reduced recruitment of Npl3p, but elevated recruitment of a component of mRNA cleavage/termination factor CFI, to the activated GAL10-GAL7 locus. Consistent with this, hmt1 mutants displayed increased termination at the defective gal10-Δ56 terminator. Remarkably, hmt1Δ cells also exhibit diminished recruitment of elongation factor Tho2p and a reduced rate of transcription elongation in vivo. Importantly, the defects in Npl3p and Tho2p recruitment, antitermination and elongation in hmt1Δ cells all were mitigated by substitutions in Npl3p RGG repeats that functionally mimic arginine methylation by Hmt1p. Thus, Hmt1p promotes elongation and suppresses termination at cryptic terminators by methylating RGG repeats in Npl3p. As Hmt1p stimulates dissociation of Tho2p from an Npl3p-mRNP complex, it could act to recycle these elongation and antitermination factors back to sites of ongoing transcription
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