93 research outputs found
Keeping up to date: An academic researcher's information journey
Keeping up to date with research developments is a central activity of academic researchers, but researchers face difficulties in managing the rapid growth of available scientific information. This study examined how researchers stay up to date, using the information journey model as a framework for analysis and investigating which dimensions influence information behaviors. We designed a 2-round study involving semistructured interviews and prototype testing with 61 researchers with 3 levels of seniority (PhD student to professor). Data were analyzed following a semistructured qualitative approach. Five key dimensions that influence information behaviors were identified: level of seniority, information sources, state of the project, level of familiarity, and how well defined the relevant community is. These dimensions are interrelated and their values determine the flow of the information journey. Across all levels of professional expertise, researchers used similar hard (formal) sources to access content, while soft (interpersonal) sources were used to filter information. An important “pain point” that future information tools should address is helping researchers filter information at the point of need
Study the Influence of Treatment Interruptions in the Radical Irradiation of Breast Cancer
Hypofractionated radiotherapy (HFRT) in breast cancer treatment regimen (40 Grey /15 fractions/3 weeks) is more convenient for patients, especially those coming from remote areas to radiotherapy facilities and for healthcare providers, than conventional fractionation (50 Gy/25 fractions/5weeks). So the effect of radiotherapy interruption on treatment outcome (loco-regional control (LRC)& overall survival (OS)) during hypofractionated schedule is the issue of our study. Materials and Methods: We studied retrospectively 174 female patients with breast cancer who received PORT at the Clinical Oncology & Nuclear Medicine Department, Faculty of Medicine, Mansoura University, Egypt, from January-2012 to December-2016. We determined the treatment outcome (OS&LRC) from the follow-up (FU) of the studied patients, as the patient still survived or died, and recurrence till now occurred or not, and were estimated with the Kaplan-Meier (K-M) method and Logrank test, respectively. Then we calculated surviving fraction (SF) and tumor control probability (TCP) with regard to biologically effective dose (BED), for all patients, using breast cancer radiobiological parameters. Results: When comparing patients without radiotherapy gap with patients with radiotherapy gaps, the results showed a decrease in LRC rate in patients with radiotherapy treatment interruptions by 15 % (P=0.019, a significant value), but no detrimental effect on OS because of the very limited number of the studied patients. Curves of the relationship between (SF&OTT) and (TCP&OTT) confirmed the detrimental effect of unscheduled gap during radiotherapy fractions on the treatment outcome. Also we found a significant-P value for (marital status, start day of radiotherapy fractions, time, number, and duration of gaps); it means these factors affect LRC during radiotherapy interruptions.Conclusions: Interruptions during postoperative hypofractionated irradiation of 7breast cancer (40 Gy/15 fractions/3weeks) should be avoided and if they are inevitable, they should not be prolonged more than two days, as they will adversely affect the treatment outcome (LRC)
Researchers' attitudes towards the use of social networking sites
Purpose: The purpose of this paper is to better understand why many researchers do not have a profile on social networking sites (SNS), and whether this is the result of conscious decisions. / Design/methodology/approach: Thematic analysis was conducted on a large qualitative data set from researchers across three levels of seniority, four countries and four disciplines to explore their attitudes toward and experiences with SNS. / Findings: The study found much greater scepticism toward adopting SNS than previously reported. Reasons behind researchers’ scepticism range from SNS being unimportant for their work to not belonging to their culture or habits. Some even felt that a profile presented people negatively and might harm their career. These concerns were mostly expressed by junior and midlevel researchers, showing that the largest opponents to SNS may unexpectedly be younger researchers. / Research limitations/implications: A limitation of this study was that the authors did not conduct the interviews, and therefore reframing or adding questions to specifically unpack comments related to attitudes, feelings or the use of SNS in academia was not possible. / Originality/value: By studying implicit attitudes and experiences, this study shows that instead of being ignorant of SNS profiles, some researchers actively opt for a non-use of profiles on SNS
Adverse effects of anti-tuberculosis drugs on HepG2 cell bioenergetics
Tuberculosis (TB) is an intractable chronic infection. Disease treatment with anti-TB drugs remains challenging due to drug-induced hepatotoxicity. The toxicity of the anti-TB drugs rifampicin (RIF), isoniazid (INH) and pyrazinamide (PZA) either alone or in combination was investigated in HepG2 cells. Assays of intracellular adenosine triphosphate (ATP) levels at 4-, 24- and 48-h post-exposure to gradient concentrations of RIF, INH and PZA were conducted. Drug-induced effects on mitochondrial membrane potential (MMP), mitochondrial complex I and complex III activity, nicotinamide adenine dinucleotide (NAD+) levels and cellular lactate production were assessed. Decreased ATP levels were dose-dependent and correlated with drug exposure duration. Approximate 24-h IC50s were 0.5 mM, 70 mM and 84 mM for RIF, INH and PZA, respectively. Twenty-four hours post-drug treatment, reductions of MMP (p = 0.0005), mitochondrial complex I and III activities (p = 0.0001 and p = 0.0003, respectively), NAD+ levels (p = 0.0057) and increased lactate production (p < 0.0001) were observed. Drug combinations used to mimic cumulative drug treatments induced a synergistic inhibition of mitochondrial complex I activity. An assessment of cellular ultrastructure using transmission electron microscopy indicated drug-induced mitophagy. Collectively, our study suggests that hepatotoxicity of commonly employed anti-TB drugs is mediated by their curtailment of mitochondrial function
Lead Level in Pregnant Women Suffering from Pre-eclampsia in Dakahlia, Egypt
Abstract Background: Lead toxicity is a prevalent health problem in both developed and develop
Differential effect of vinorelbine versus paclitaxel on ERK2 kinase activity during apoptosis in MCF-7 cells
The effects of vinorelbine and paclitaxel on the activity of extracellular signal-regulated protein kinase2 (ERK2), a member of MAP kinase, and its role in the induction of bcl-2 phosphorylation and apoptosis were evaluated in MCF-7 cells. We demonstrated that ERK2 was activated rapidly by vinorelbine, and was inhibited by either paclitaxel or estramustine. A 3-fold increase of ERK2 kinase activity was observed within 30 min when MCF-7 cells were treated with 0.1 μM vinorelbine. In contrast, the same treatment with paclitaxel resulted in a significant decrease of ERK2 kinase activity. We also demonstrated that elevated bcl-2 phosphorylation induced by vinorelbine is paralleled by decrease of a complex formation between bcl-2 and bax, cleavage of poly (ADP) ribose polymerase (PARP) protein, activation of caspase-7, and apoptosis. The levels of bcl-2 phosphorylation, bax, and PARP were not significantly affected by 2′-amino-3′-methoxyflavone (PD 98059), an ERK kinase specific inhibitor. Thus, our data suggest that the apoptosis induced by vinorelbine in MCF-7 cells is mediated through the bcl-2 phosphorylation/bax/caspases pathways, and that activation of ERK2 by vinorelbine does not directly lead to the drug-mediated apoptosis. Since decrease of PARP occurred quickly following the treatment of MCF-7 cells with either 0.1 μM of vinorelbine or paclitaxel, this protein may serve as an early indicator of apoptosis induced not only by DNA damaging agents, but also by antimicrotubule drugs. http://www.bjcancer.com © 2001 Cancer Research Campaig
Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.
Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability
Insights into amine-based CO2 capture: an ab initio self-consistent reaction field investigation
Frequency of left ventricular hypertrophy in non-valvular atrial fibrillation
Left ventricular hypertrophy (LVH) is significantly related to adverse clinical outcomes in patients at high risk of cardiovascular events. In patients with atrial fibrillation (AF), data on LVH, that is, prevalence and determinants, are inconsistent mainly because of different definitions and heterogeneity of study populations. We determined echocardiographic-based LVH prevalence and clinical factors independently associated with its development in a prospective cohort of patients with non-valvular (NV) AF. From the "Atrial Fibrillation Registry for Ankle-brachial Index Prevalence Assessment: Collaborative Italian Study" (ARAPACIS) population, 1,184 patients with NVAF (mean age 72 \ub1 11 years; 56% men) with complete data to define LVH were selected. ARAPACIS is a multicenter, observational, prospective, longitudinal on-going study designed to estimate prevalence of peripheral artery disease in patients with NVAF. We found a high prevalence of LVH (52%) in patients with NVAF. Compared to those without LVH, patients with AF with LVH were older and had a higher prevalence of hypertension, diabetes, and previous myocardial infarction (MI). A higher prevalence of ankle-brachial index 640.90 was seen in patients with LVH (22 vs 17%, p = 0.0392). Patients with LVH were at significantly higher thromboembolic risk, with CHA2DS2-VASc 652 seen in 93% of LVH and in 73% of patients without LVH (p <0.05). Women with LVH had a higher prevalence of concentric hypertrophy than men (46% vs 29%, p = 0.0003). Logistic regression analysis demonstrated that female gender (odds ratio [OR] 2.80, p <0.0001), age (OR 1.03 per year, p <0.001), hypertension (OR 2.30, p <0.001), diabetes (OR 1.62, p = 0.004), and previous MI (OR 1.96, p = 0.001) were independently associated with LVH. In conclusion, patients with NVAF have a high prevalence of LVH, which is related to female gender, older age, hypertension, and previous MI. These patients are at high thromboembolic risk and deserve a holistic approach to cardiovascular prevention
A computational study of the suppression of ammonia volatility in aqueous systems using ionic additives
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