43 research outputs found
Sharp electroluminescence lines excited by tunneling injection into a large ensemble of quantum dots
We observe a strong bias-dependence of the electroluminescence spectra of an ensemble of self-assembled InAs quantum dots (QDs) excited by tunnelling injection of carriers from the n- and p-doped GaAs layers of a p-i-n diode. We show that the dot emission evolves from a broad band above flat-band condition to a series of sharp emission lines below a characteristic bias voltage. Also, we present a study of the electroluminescence under resonant bias excitation of the dots and demonstrate up-conversion luminescence. © 2007 American Institute of Physics
Sharp-line electroluminescence from individual quantum dots by resonant tunneling injection of carriers
We report sharp electroluminescence lines from individual self-assembled InAs quantum dots (QDs) excited by resonant tunneling injection of carriers from the n- and p-doped GaAs layers of a p-i-n diode. Bias-tunable tunneling of carriers into the dots provides a means of controlling injection and light emission from a small number of individual dots within a large ensemble. We also show that the extent of carrier energy relaxation prior to recombination can be controlled by tailoring the morphology of the QD layer. © 2006 American Institute of Physics
N terminus is key to the dominant negative suppression of CaV2 calcium channels: implications for episodic ataxia type 2
Expression of the calcium channels CaV2.1 and CaV2.2 is markedly suppressed by co-expression with truncated constructs containing Domain I. This is the basis for the phenomenon of dominant negative suppression observed for many of the episodic ataxia type 2 mutations in CaV2.1 that predict truncated channels. The process of dominant negative suppression has been shown previously to stem from interaction between the full-length and truncated channels and to result in downstream consequences of the unfolded protein response and endoplasmic reticulum-associated protein degradation. We have now identified the specific domain that triggers this effect. For both CaV2.1 and CaV2.2, the minimum construct producing suppression was the cytoplasmic N terminus. Suppression was enhanced by tethering the N terminus to the membrane with a CAAX motif. The 11-amino acid motif (including Arg52 and Arg54) within the N terminus, which we have previously shown to be required for G protein modulation, is also essential for dominant negative suppression. Suppression is prevented by addition of an N-terminal tag (XFP) to the full-length and truncated constructs. We further show that suppression of CaV2.2 currents by the N terminus-CAAX construct is accompanied by a reduction in CaV2.2 protein level, and this is also prevented by mutation of Arg52 and Arg54 to Ala in the truncated construct. Taken together, our evidence indicates that both the extreme N terminus and the Arg52, Arg54 motif are involved in the processes underlying dominant negative suppression
Non-alcoholic fatty liver disease and coexisting depression, anxiety and/or stress in adults:a systematic review and meta-analysis
Background: Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease, affecting 25-30% of the general population globally. The condition is even more prevalent in individuals with obesity and is frequently linked to the metabolic syndrome. Given the known associations between the metabolic syndrome and common mental health issues, it is likely that such a relationship also exists between NAFLD and mental health problems. However, studies in this field remain limited. Accordingly, the aim of this systematic review and meta-analysis was to explore the prevalence of one or more common mental health conditions (i.e., depression, anxiety, and/or stress) in adults with NAFLD. Methods: PubMed, EBSCOhost, ProQuest, Ovid, Web of Science, and Scopus were searched in order to identify studies reporting the prevalence of depression, anxiety, and/or stress among adults with NAFLD. A random-effects model was utilized to calculate the pooled prevalence and confidence intervals for depression, anxiety and stress. Results: In total, 31 studies were eligible for inclusion, involving 2,126,593 adults with NAFLD. Meta-analyses yielded a pooled prevalence of 26.3% (95% CI: 19.2 to 34) for depression, 37.2% (95% CI: 21.6 to 54.3%) for anxiety, and 51.4% (95% CI: 5.5 to 95.8%) for stress among adults with NAFLD. Conclusion: The present findings suggest a high prevalence of mental health morbidity among adults with NAFLD. Given the related public health impact, this finding should prompt further research to investigate such associations and elucidate potential associations between NAFLD and mental health morbidity, exploring potential shared underlying pathophysiologic mechanisms. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42021288934
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
Non-alcoholic fatty liver disease and coexisting depression, anxiety and/or stress in adults: a systematic review and meta-analysis
BackgroundNon-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease, affecting 25-30% of the general population globally. The condition is even more prevalent in individuals with obesity and is frequently linked to the metabolic syndrome. Given the known associations between the metabolic syndrome and common mental health issues, it is likely that such a relationship also exists between NAFLD and mental health problems. However, studies in this field remain limited. Accordingly, the aim of this systematic review and meta-analysis was to explore the prevalence of one or more common mental health conditions (i.e., depression, anxiety, and/or stress) in adults with NAFLD.MethodsPubMed, EBSCOhost, ProQuest, Ovid, Web of Science, and Scopus were searched in order to identify studies reporting the prevalence of depression, anxiety, and/or stress among adults with NAFLD. A random-effects model was utilized to calculate the pooled prevalence and confidence intervals for depression, anxiety and stress.ResultsIn total, 31 studies were eligible for inclusion, involving 2,126,593 adults with NAFLD. Meta-analyses yielded a pooled prevalence of 26.3% (95% CI: 19.2 to 34) for depression, 37.2% (95% CI: 21.6 to 54.3%) for anxiety, and 51.4% (95% CI: 5.5 to 95.8%) for stress among adults with NAFLD.ConclusionThe present findings suggest a high prevalence of mental health morbidity among adults with NAFLD. Given the related public health impact, this finding should prompt further research to investigate such associations and elucidate potential associations between NAFLD and mental health morbidity, exploring potential shared underlying pathophysiologic mechanisms.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, identifier CRD42021288934
A systematic review of the health, social and financial impacts of welfare rights advice delivered in healthcare settings
BACKGROUND: Socio-economic variations in health, including variations in health according to wealth and income, have been widely reported. A potential method of improving the health of the most deprived groups is to increase their income. State funded welfare programmes of financial benefits and benefits in kind are common in developed countries. However, there is evidence of widespread under claiming of welfare benefits by those eligible for them. One method of exploring the health effects of income supplementation is, therefore, to measure the health effects of welfare benefit maximisation programmes. We conducted a systematic review of the health, social and financial impacts of welfare rights advice delivered in healthcare settings. METHODS: Published and unpublished literature was accessed through searches of electronic databases, websites and an internet search engine; hand searches of journals; suggestions from experts; and reference lists of relevant publications. Data on the intervention delivered, evaluation performed, and outcome data on health, social and economic measures were abstracted and assessed by pairs of independent reviewers. Results are reported in narrative form. RESULTS: 55 studies were included in the review. Only seven studies included a comparison or control group. There was evidence that welfare rights advice delivered in healthcare settings results in financial benefits. There was little evidence that the advice resulted in measurable health or social benefits. This is primarily due to lack of good quality evidence, rather than evidence of an absence of effect. CONCLUSION: There are good theoretical reasons why income supplementation should improve health, but currently little evidence of adequate robustness and quality to indicate that the impact goes beyond increasing income
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Isorhapontigenin, a resveratrol analogue selectively inhibits ADP-stimulated platelet activation
Isorhapontigenin is a polyphenolic compound found in Chinese herbs and grapes. It is a methoxylated analogue of a stilbenoid, resveratrol, which is well-known for its various beneficial effects including anti-platelet activity. Isorhapontigenin possesses greater oral bioavailability than resveratrol and has also been identified to possess anti-cancer and anti-inflammatory properties. However, its effects on platelet function have not been reported previously. In this study, we report the effects of isorhapontigenin on the modulation of platelet function. Isorhapontigenin was found to selectively inhibit ADP-induced platelet aggregation with an IC50 of 1.85µM although it displayed marginal inhibition on platelet aggregation induced by other platelet agonists at 100µM. However, resveratrol exhibited weaker inhibition on ADP-induced platelet aggregation (IC50>100µM) but inhibited collagen induced platelet aggregation at 50µM and 100µM. Isorhapontigenin also inhibited integrin αIIbβ3 mediated inside-out and outside-in signalling and dense granule secretion in ADP-induced platelet activation but interestingly, no effect was observed on α-granule secretion. Isorhapontigenin did not exert any cytotoxicity on platelets at the concentrations of up to 100µM. Furthermore, it did not affect haemostasis in mice at the IC50 concentration (1.85µM). In addition, the mechanistic studies demonstrated that isorhapontigenin increased cAMP levels and VASP phosphorylation at Ser157 and decreased Akt phosphorylation. This suggests that isorhapontigenin may interfere with cAMP and PI3K signalling pathways that are associated with the P2Y12 receptor. Molecular docking studies emphasised that isorhapontigenin has greater binding affinity to P2Y12 receptor than resveratrol. Our results demonstrate that isorhapontigenin has selective inhibitory effects on ADP-stimulated platelet activation possibly via P2Y12 receptor
A three-dimensional soft tissue analysis of Class III malocclusion: a case-controlled cross-sectional study.
OBJECTIVE: The present study used the optical surface laser scanning technique to compare the facial features of patients aged 8-18 years presenting with Class I and Class III incisor relationship in a case-control design. MATERIALS AND METHODS: Subjects with a Class III incisor relationship, aged 8-18 years, were age and gender matched with Class I control and underwent a 3-dimensional (3-D) optical surface scan of the facial soft tissues. RESULTS: Landmark analysis revealed Class III subjects displayed greater mean dimensions compared to the control group most notably between the ages of 8-10 and 17-18 years in both males and females, in respect of antero-posterior (P = 0.01) and vertical (P = 0.006) facial dimensions. Surface-based analysis, revealed the greatest difference in the lower facial region, followed by the mid-face, whilst the upper face remained fairly consistent. CONCLUSION: Significant detectable differences were found in the surface facial features of developing Class III subjects