Chemical composition of nanoporous layer formed by electrochemical etching of p-type GaAs

Abstract : We have performed a detailed characterization study of electrochemically etched p-type GaAs in a hydrofluoric acid-based electrolyte. The samples were investigated and characterized through cathodoluminescence (CL), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). It was found that after electrochemical etching, the porous layer showed a major decrease in the CL intensity and a change in chemical composition and in the crystalline phase. Contrary to previous reports on p-GaAs porosification, which stated that the formed layer is composed of porous GaAs, we report evidence that the porous layer is in fact mainly constituted of porous As2O3. Finally, a qualitative model is proposed to explain the porous As2O3 layer formation on p-GaAs substrate

RXRB is a MHC-encoded susceptibility gene associated with anti-topoisomerase I antibody-positive systemic sclerosis

Systemic sclerosis (SSc) is a systemic autoimmune and connective tissue disorder associated with the human leukocyte antigen (HLA) locus. However, the functional relationship between HLA gene(s) and disease development remains unknown. To elucidate major histocompatibility complex (MHC)-linked SSc genetics, we performed genotyping of MHC-borne microsatellites and HLA-DPB1 alleles using DNA obtained from 318 anti-topoisomerase I antibody-positive patients and 561 healthy controls, all of Japanese descent. Those results revealed 2 MHC haplotypes associated with SSc. Exome sequencing and targeted analysis of these risk haplotypes identified rs17847931 in retinoid X receptor beta (RXRB) as a susceptibility variant (P=1.3×10(-15); odds ratio (OR)=9.4) with amino acid substitution p.V95A on the risk haplotype harboring HLA-DPB1*13:01. No identical variant in the other haplotype including DPB1*09:01 was observed, though that haplotype also showed a significant association (P=8.5×10(-22); OR =4.3) with SSc. Furthermore, the number of risk factors was shown to be a predominant factor, as individuals with 2 factors had elevated risk (P=6.7 × 10(-13); OR=30.2). We concluded that RXRB may be involved in anti-fibrotic activity in skin and chromatin remodeling

Genetic Variation of HvCBF Genes and Their Association with Salinity Tolerance in Tibetan Annual Wild Barley

The evaluation of both the genetic variation and the identification of salinity tolerant accessions of Tibetan annual wild barley (hereafter referred to as Tibetan barley) (Hordeum vulgare L. ssp. Spontaneum and H. vulgare L. ssp. agriocrithum) are essential for discovering and exploiting novel alleles involved in salinity tolerance. In this study, we examined tissue dry biomass and the Na+ and K+ contents of 188 Tibetan barley accessions in response to salt stress. We investigated the genetic variation of transcription factors HvCBF1, HvCBF3 and HvCBF4 within these accessions, conducting association analysis between these three genes and the respective genotypic salt tolerance. Salt stress significantly reduced shoot and root dry weight by 27.6% to 73.1% in the Tibetan barley lines. HvCBF1, HvCBF3 and HvCBF4 showed diverse sequence variation in amplicon as evident by the identification of single nucleotide polymorphisms (SNPs) and 3, 8 and 13 haplotypes, respectively. Furthermore, the decay of Linkage disequilibrium (LD) of chromosome 5 was 8.9 cM (r2<0.1). Marker bpb-4891 and haplotype 13 (Ps 610) of the HvCBF4 gene were significantly (P<0.05) and highly significantly (P<0.001) associated with salt tolerance. However, HvCBF1 and HvCBF3 genes were not associated with salinity tolerance. The accessions from haplotype 13 of the HvCBF4 gene showed high salinity tolerance, maintaining significantly lower Na+/K+ ratios and higher dry weight. It is thus proposed that these Tibetan barley accessions could be of value for enhancing salinity tolerance in cultivated barley

Efficacy of Reduced-Intensity Chemotherapy With Oxaliplatin and Capecitabine on Quality of Life and Cancer Control Among Older and Frail Patients With Advanced Gastroesophageal Cancer: The GO2 Phase 3 Randomized Clinical Trial

Importance Older and/or frail patients are underrepresented in landmark cancer trials. Tailored research is needed to address this evidence gap. Objective The GO2 randomized clinical trial sought to optimize chemotherapy dosing in older and/or frail patients with advanced gastroesophageal cancer, and explored baseline geriatric assessment (GA) as a tool for treatment decision-making. Design, Setting, and Participants This multicenter, noninferiority, open-label randomized trial took place at oncology clinics in the United Kingdom with nurse-led geriatric health assessment. Patients were recruited for whom full-dose combination chemotherapy was considered unsuitable because of advanced age and/or frailty. Interventions There were 2 randomizations that were performed: CHEMO-INTENSITY compared oxaliplatin/capecitabine at Level A (oxaliplatin 130 mg/m2 on day 1, capecitabine 625 mg/m2 twice daily on days 1-21, on a 21-day cycle), Level B (doses 0.8 times A), or Level C (doses 0.6 times A). Alternatively, if the patient and clinician agreed the indication for chemotherapy was uncertain, the patient could instead enter CHEMO-BSC, comparing Level C vs best supportive care. Main Outcomes and Measures First, broad noninferiority of the lower doses vs reference (Level A) was assessed using a permissive boundary of 34 days reduction in progression-free survival (PFS) (hazard ratio, HR = 1.34), selected as acceptable by a forum of patients and clinicians. Then, the patient experience was compared using Overall Treatment Utility (OTU), which combines efficacy, toxic effects, quality of life, and patient value/acceptability. For CHEMO-BSC, the main outcome measure was overall survival. Results A total of 514 patients entered CHEMO-INTENSITY, of whom 385 (75%) were men and 299 (58%) were severely frail, with median age 76 years. Noninferior PFS was confirmed for Levels B vs A (HR = 1.09 [95% CI, 0.89-1.32]) and C vs A (HR = 1.10 [95% CI, 0.90-1.33]). Level C produced less toxic effects and better OTU than A or B. No subgroup benefited from higher doses: Level C produced better OTU even in younger or less frail patients. A total of 45 patients entered the CHEMO-BSC randomization: overall survival was nonsignificantly longer with chemotherapy: median 6.1 vs 3.0 months (HR = 0.69 [95% CI, 0.32-1.48], P = .34). In multivariate analysis in 522 patients with all variables available, baseline frailty, quality of life, and neutrophil to lymphocyte ratio were independently associated with OTU, and can be combined in a model to estimate the probability of different outcomes. Conclusions and Relevance This phase 3 randomized clinical trial found that reduced-intensity chemotherapy provided a better patient experience without significantly compromising cancer control and should be considered for older and/or frail patients. Baseline geriatric assessment can help predict the utility of chemotherapy but did not identify a group benefiting from higher-dose treatment. Trial Registration isrctn.org Identifier: ISRCTN4468790

Effects of alirocumab on types of myocardial infarction: insights from the ODYSSEY OUTCOMES trial

Aims  The third Universal Definition of Myocardial Infarction (MI) Task Force classified MIs into five types: Type 1, spontaneous; Type 2, related to oxygen supply/demand imbalance; Type 3, fatal without ascertainment of cardiac biomarkers; Type 4, related to percutaneous coronary intervention; and Type 5, related to coronary artery bypass surgery. Low-density lipoprotein cholesterol (LDL-C) reduction with statins and proprotein convertase subtilisin–kexin Type 9 (PCSK9) inhibitors reduces risk of MI, but less is known about effects on types of MI. ODYSSEY OUTCOMES compared the PCSK9 inhibitor alirocumab with placebo in 18 924 patients with recent acute coronary syndrome (ACS) and elevated LDL-C (≥1.8 mmol/L) despite intensive statin therapy. In a pre-specified analysis, we assessed the effects of alirocumab on types of MI. Methods and results  Median follow-up was 2.8 years. Myocardial infarction types were prospectively adjudicated and classified. Of 1860 total MIs, 1223 (65.8%) were adjudicated as Type 1, 386 (20.8%) as Type 2, and 244 (13.1%) as Type 4. Few events were Type 3 (n = 2) or Type 5 (n = 5). Alirocumab reduced first MIs [hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77–0.95; P = 0.003], with reductions in both Type 1 (HR 0.87, 95% CI 0.77–0.99; P = 0.032) and Type 2 (0.77, 0.61–0.97; P = 0.025), but not Type 4 MI. Conclusion  After ACS, alirocumab added to intensive statin therapy favourably impacted on Type 1 and 2 MIs. The data indicate for the first time that a lipid-lowering therapy can attenuate the risk of Type 2 MI. Low-density lipoprotein cholesterol reduction below levels achievable with statins is an effective preventive strategy for both MI types.For complete list of authors see http://dx.doi.org/10.1093/eurheartj/ehz299</p

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

Effect of alirocumab on mortality after acute coronary syndromes. An analysis of the ODYSSEY OUTCOMES randomized clinical trial

Background: Previous trials of PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitors demonstrated reductions in major adverse cardiovascular events, but not death. We assessed the effects of alirocumab on death after index acute coronary syndrome. Methods: ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) was a double-blind, randomized comparison of alirocumab or placebo in 18 924 patients who had an ACS 1 to 12 months previously and elevated atherogenic lipoproteins despite intensive statin therapy. Alirocumab dose was blindly titrated to target achieved low-density lipoprotein cholesterol (LDL-C) between 25 and 50 mg/dL. We examined the effects of treatment on all-cause death and its components, cardiovascular and noncardiovascular death, with log-rank testing. Joint semiparametric models tested associations between nonfatal cardiovascular events and cardiovascular or noncardiovascular death. Results: Median follow-up was 2.8 years. Death occurred in 334 (3.5%) and 392 (4.1%) patients, respectively, in the alirocumab and placebo groups (hazard ratio [HR], 0.85; 95% CI, 0.73 to 0.98; P=0.03, nominal P value). This resulted from nonsignificantly fewer cardiovascular (240 [2.5%] vs 271 [2.9%]; HR, 0.88; 95% CI, 0.74 to 1.05; P=0.15) and noncardiovascular (94 [1.0%] vs 121 [1.3%]; HR, 0.77; 95% CI, 0.59 to 1.01; P=0.06) deaths with alirocumab. In a prespecified analysis of 8242 patients eligible for ≥3 years follow-up, alirocumab reduced death (HR, 0.78; 95% CI, 0.65 to 0.94; P=0.01). Patients with nonfatal cardiovascular events were at increased risk for cardiovascular and noncardiovascular deaths (P<0.0001 for the associations). Alirocumab reduced total nonfatal cardiovascular events (P<0.001) and thereby may have attenuated the number of cardiovascular and noncardiovascular deaths. A post hoc analysis found that, compared to patients with lower LDL-C, patients with baseline LDL-C ≥100 mg/dL (2.59 mmol/L) had a greater absolute risk of death and a larger mortality benefit from alirocumab (HR, 0.71; 95% CI, 0.56 to 0.90; Pinteraction=0.007). In the alirocumab group, all-cause death declined wit h achieved LDL-C at 4 months of treatment, to a level of approximately 30 mg/dL (adjusted P=0.017 for linear trend). Conclusions: Alirocumab added to intensive statin therapy has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for ≥3 years, if baseline LDL-C is ≥100 mg/dL, or if achieved LDL-C is low. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01663402

Global environmental change and food systems in Southern Africa: The dynamic challenges facing regional policy

Please help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected] En BestuurswetenskappeSkool vir Publieke Leierska