InSb-based quantum dot nanostructures for mid-infrared photonic devices

Novel InSb quantum dot (QD) nanostructures grown by molecular beam epitaxy (MBE) are investigated in order to improve the performance of light sources and detectors for the technologically important mid-infrared (2-5 μm) spectral range. Unlike the InAs/GaAs system which has a similar lattice mismatch, the growth of InSb/InAs QDs by MBE is a challenging task due to Sb segregation and surfactant effects. These problems can be overcome by using an Sb-As exchange growth technique to realize uniform, dense arrays (dot density ~1012 cm-2) of extremely small (mean diameter ~2.5 nm) InSb submonolayer QDs in InAs. Light emitting diodes (LEDs) containing ten layers of InSb QDs exhibit bright electroluminescence peaking at 3.8 μm at room temperature. These devices show superior temperature quenching compared with bulk and quantum well (QW) LEDs due to a reduction in Auger recombination. We also report the growth of InSb QDs in InAs/AlAsSb ‘W’ QWs grown on GaSb substrates which are designed to increase the electron-hole (e-h) wavefunction overlap to ~75%. These samples exhibit very good structural quality and photoluminescence peaking near 3.0 μm at low temperatures

Understanding the Impact of COVID-19 on Agriculture and Food Supply Chains: System Dynamics Modeling for the Resilience of Smallholder Farmers

COVID-19 has caused severe agriculture and food supply chain disruptions; significantly affecting smallholder farmers who supply most of the world’s food; specifically their changes in vulnerability; resilience; and food loss and waste. Therefore; the objective of this study was to understand the complex causal and feedback relationships for this system by developing a dynamic hypothesis and causal loop diagrams utilizing the System Dynamics methodology. Results provide a roadmap for dialogue and a framework for case-specific model development and help to guide policy decisions for smallholder farmers’ survival during health crises

An Autopsy Study Describing Causes of Death and Comparing Clinico-Pathological Findings among Hospitalized Patients in Kampala, Uganda

Background: Information on causes of death in HIV-infected patients in Sub-Saharan Africa is mainly derived from observational cohort and verbal autopsy studies. Autopsy is the gold standard to ascertain cause of death. We conducted an autopsy study to describe and compare the clinical and autopsy causes of death and contributory findings in hospitalized HIV-infected and HIV-uninfected patients in Uganda. Methods: Between May and September 2009 a complete autopsy was performed on patients that died on a combined infectious diseases gastroenterology ward in Mulago Hospital in Kampala, Uganda. Autopsy cause of death and contributing findings were based on the macro- and microscopic post-mortem findings combined with clinical information. Clinical diagnoses were reported by the ward doctor and classified as confirmed, highly suspected, considered or not considered, based on information derived from the medical chart. Results are reported according to HIV serostatus. Results: Fifty-three complete autopsies were performed in 66 % HIV-positive, 21 % HIV-negative and 13 % patients with an unknown HIV serological status. Infectious diseases caused death in 83 % of HIV-positive patients, with disseminated TB as the main diagnosis causing 37 % of deaths. The spectrum of illness and causes of death were substantially different betwee

The Number of Shoulder and Elbow Questions on the Orthopedic In-Training Examination Is Increasing with Greater Emphasis on Critical Thinking over Recall

Background: It is critical for orthopedic surgery residents and residency programs to have a current understanding of the content and resources utilized by the Orthopedic In-Training Examination (OITE) to continuously guide study and educational efforts. This study presents an updated analysis of the shoulder and elbow section of the OITE. Methods: All OITE questions, answers, and references from 2013 to 2019 were reviewed. The number of shoulder and elbow questions per year was recorded, and questions were analyzed for topic, imaging modalities, cognitive taxonomy, and references. We compared our data to the results of a previous study that analyzed shoulder and elbow OITE questions from 2002 to 2007 to examine trends and changes in this domain overtime. Results: There were 177 shoulder and elbow questions (126 shoulder, 71.2%; 51 elbow, 28.8%) of 1863 OITE questions (9.5%) over a 7-year period. The most commonly tested topics included degenerative joint disease/stiffness/arthroplasty (31.6%), anatomy/biomechanics (16.9%), instability/athletic injury (15.3%), trauma (14.7%), and rotator cuff (13.6%). Half of all questions involved clinical management decisions (49.7%). A total of 417 references were cited from 56 different sources, the most common of which were the Journal of Shoulder and Elbow Surgery (23.3%), Journal of the American Academy of Orthopaedic Surgeons (20.4%), and Journal of Bone and Joint Surgery (American Volume) (16%). The average time lag from article publication to OITE reference was 7.7 years. Compared with a prior analysis from 2002 to 2007, there was a significant increase in the number of shoulder and elbow questions on the OITE (5.5% to 9.5%; P \u3c.001). Recent exams incorporated more complex multistep treatment questions (4.4% vs. 49.7%; P \u3c.001) and fewer recall questions (42.2% vs. 22%; P \u3c.001). There was a significant increase in the use of imaging modalities (53.3% vs. 79.1%; P \u3c.001). No significant differences in the distribution of question topics were found. Conclusions: The percentage of shoulder and elbow questions on the OITE has nearly doubled over the past decade with greater emphasis on critical thinking (eg, clinical management decisions) over recall of facts. These findings should prompt educators to direct didactic efforts (eg, morning conferences and journal club) toward case-based learning to foster critical thinking and clinical reasoning skills

Bronchiectasis in Europe:data on disease characteristics from the European Bronchiectasis registry (EMBARC)

Background: Bronchiectasis is a heterogeneous, neglected disease with few multicentre studies exploring the causes, severity, microbiology, and treatment of the disease across Europe. This aim of this study was to describe the clinical characteristics of bronchiectasis and compare between different European countries.Methods: EMBARC is an international clinical research network for bronchiectasis. We report on a multicentre, prospective, observational, non-interventional, cohort study (the EMBARC registry) conducted across 27 European countries and Israel. Comprehensive clinical data were collected from adult patients (aged ≥18 years) at baseline and annual follow-up visits using electronic case report form. Data from individual countries were grouped into four regions (the UK, northern and western Europe, southern Europe, and central and eastern Europe according to modified EU EuroVoc classification). Follow-up data were used to explore differences in exacerbation frequency between regions using a negative binomial regression model.Findings: Between Jan 12, 2015, and April 12, 2022, 16 963 individuals were enrolled. Median age was 67 years (IQR 57-74), 10 335 (60·9%) participants were female and 6628 (39·1%) were male. The most common cause of bronchiectasis in all 16 963 participants was post-infective disease in 3600 (21·2%); 6466 individuals (38·1%) were classified as idiopathic. Individuals with bronchiectasis experienced a median of two exacerbations (IQR 1-4) per year and 4483 (26·4%) patients had a hospitalisation for exacerbation in the previous year. When examining the percentage of all isolated bacteria, marked differences in microbiology were seen between countries, with a higher frequency of Pseudomonas aeruginosa and lower Haemophilus influenzae frequency in southern Europe, compared with higher H influenzae in the UK and northern and western Europe. Compared with other regions, patients in central and eastern Europe had more severe bronchiectasis measured by the Bronchiectasis Severity Index (51·3% vs 35·1% in the overall cohort) and more exacerbations leading to hospitalisations (57·9% vs 26·4% in the overall cohort). Overall, patients in central and eastern Europe had an increased frequency of exacerbations (adjusted rate ratio [RR] 1·12, 95% CI 1·01-1·25) and a higher frequency of exacerbations leading to hospitalisations (adjusted RR 1·71, 1·44-2·02) compared with patients in other regions. Treatment of bronchiectasis was highly heterogeneous between regions.Interpretation: Bronchiectasis shows important geographical variation in causes, microbiology, severity, and outcomes across Europe.</p

Measurement of the Rates of Synthesis of Three Components of Ribosomes of Mycobacterium fortuitum: A Theoretical Approach to qRT-PCR Experimentation

BACKGROUND: Except for the ribosomal protein L12 (rplL), ribosomal proteins are present as one copy per ribosome; L12 (rplL) is unusual because it is present as four copies per ribosome. Thus, the strategies used by Mycobacterium fortuitum to regulate ribosomal protein synthesis were investigated, including evaluations of the rates of chain elongations of 16S rRNA, rplL and ribosomal protein S12 (rpsL). METHODOLOGY: RNA was isolated from cell cultures and cDNA was prepared. The numbers of cDNA copies of 16S rRNA, precursor-16S rRNA and transcripts of rpsL and rplL were quantified by qRT-PCR and then related to the rates of 16S rRNA, rpsL and rplL chain elongations by means of a mathematical framework for coupled transcription/translation. PRINCIPAL FINDINGS: The rates of synthesis of 16S rRNA, rpsL and rplL respectively were found to be approximately 50 x 10(3) nucleotides h(-1), 1.6 x 10(3) amino acid residues h(-1) and 3.4 x 10(3) amino acid residues h(-1). The number of transcripts of rplL was approximately twice that of rpsL. These data account for the presence of one copy of rpsL and four copies of rplL per ribosome, and reveal that the rate of M. fortuitum ribosome synthesis was closer to that of M. tuberculosis than to E. coli. Except for rplJ, the elongation rate obtained for rpsL was inferred to be appropriate for all other proteins present as one copy per ribosome. SIGNIFICANCE: The results obtained provide the basis for a comprehensive view of the kinetics of ribosome synthesis, and of the ways that bacterial cells utilize genes encoding ribosomal proteins. The methodology also applies to proteins involved in transcription, energy generation and to bacterial proteins in general. The method proposed for measuring the fidelity of cDNA preparations is intrinsically much more sensitive than procedures that measure the integrity of 16S rRNA

The EMBARC European Bronchiectasis Registry:protocol for an international observational study

Bronchiectasis is one of the most neglected diseases in respiratory medicine. There are no approved therapies and few large-scale, representative epidemiological studies. The EMBARC (European Multicentre Bronchiectasis Audit and Research Collaboration) registry is a prospective, pan-European observational study of patients with bronchiectasis. The inclusion criterion is a primary clinical diagnosis of bronchiectasis consisting of: 1) a clinical history consistent with bronchiectasis; and 2) computed tomography demonstrating bronchiectasis. Core exclusion criteria are: 1) bronchiectasis due to known cystic fibrosis; 2) age <18 years; and 3) patients who are unable or unwilling to provide informed consent. The study aims to enrol 1000 patients by April 2016 across at least 20 European countries, and 10 000 patients by March 2020. Patients will undergo a comprehensive baseline assessment and will be followed up annually for up to 5 years with the goal of providing high-quality longitudinal data on outcomes, treatment patterns and quality of life. Data from the registry will be available in the form of annual reports. and will be disseminated in conference presentations and peer-reviewed publications. The European Bronchiectasis Registry aims to make a major contribution to understanding the natural history of the disease, as well as guiding evidence-based decision making and facilitating large randomised controlled trials.info:eu-repo/semantics/publishedVersio

Use of procalcitonin for the diagnosis of pneumonia in patients presenting with a chief complaint of dyspnoea: results from the BACH (Biomarkers in Acute Heart Failure) trial

Biomarkers have proven their ability in the evaluation of cardiopulmonary diseases.We investigated the utility of concentrations of the biomarker procalcitonin (PCT) alone and with clinical variables for the diagnosis of pneumonia in patients presenting to emergency departments (EDs) with a chief complaint of shortness of breath. The BACH trial was a prospective, international, study of 1641 patients presenting to EDs with dyspnoea. Blood samples were analysed for PCT and other biomarkers. Relevant clinical data were also captured. Patient outcomes were assessed at 90 days. The diagnosis of pneumonia was made using strictly validated guidelines. A model using PCT was more accurate [area under the curve (AUC) 72.3%] than any other individual clinical variable for the diagnosis of pneumonia in all patients, in those with obstructive lung disease, and in those with acute heart failure (AHF). Combining physician estimates of the probability of pneumonia with PCT values increased the accuracy to .86% for the diagnosis of pneumonia in all patients. Patients with a diagnosis of AHF and an elevated PCT concentration (.0.21 ng/mL) had a worse outcome if not treated with antibiotics (P ¼ 0.046), while patients with low PCT values (,0.05 ng/mL) had a better outcome if they did not receive antibiotic therapy (P ¼ 0.049). Procalcitonin may aid in the diagnosis of pneumonia, particularly in cases with high diagnostic uncertainty. Importantly, PCT may aid in the decision to administer antibiotic therapy to patients presenting with AHF in which clinical uncertainty exists regarding a superimposed bacterial infection