Chemical characteristics of brown carbon in atmospheric particles at a suburban site near Guangzhou, China

Light-absorbing organic carbon (or brown carbon, BrC) in atmospheric particles has received much attention for its potential role in global radiative forcing. While a number of field measurement campaigns have differentiated light absorption by black carbon (BC) and BrC, the chemical characteristics of BrC are not well understood. In this study, we present co-located real-time light absorption and chemical composition measurements of atmospheric particles to explore the relationship between the chemical and optical characteristics of BrC at a suburban site downwind of Guangzhou, China, from November to December 2014. BrC and BC contributions to light absorption were estimated using measurements from a seven-wavelength aethalometer, while the chemical composition of non-refractory PM1 was measured with a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). Using the absorption Ångström exponent (AAE) method, we estimated that BrC contributed 23.6&thinsp;% to the total aerosol absorption at 370&thinsp;nm, 18.1&thinsp;% at 470&thinsp;nm, 10.7&thinsp;% at 520&thinsp;nm, 10.7&thinsp;% at 590&thinsp;nm, and 10.5&thinsp;% at 660&thinsp;nm. Biomass burning organic aerosol (BBOA) has the highest mass absorption coefficient among sources of organic aerosols. Its contribution to total brown carbon absorption coefficient decreased but that of low-volatility oxygenated organic aerosol (LVOOA) increased with increasing wavelength, suggesting the need for wavelength-dependent light absorption analysis for BrC in association with its chemical makeup. Clear correlations of N-containing ion fragments with absorption coefficient were observed. These correlations also depended on their degrees of unsaturation/cyclization and oxygenation. While the current study relates light absorption by BrC to ion fragments, more detailed chemical characterization is warranted to constrain this relationship.</p

Reliability, validity and psychometric properties of the Greek translation of the Major Depression Inventory

BACKGROUND: The Major Depression Inventory (MDI) is a brief self-rating scale for the assessment of depression. It is reported to be valid because it is based on the universe of symptoms of DSM-IV and ICD-10 depression. The aim of the current preliminary study was to assess the reliability, validity and psychometric properties of the Greek translation of the MDI. METHODS: 30 depressed patients of mean age 23.41 (± 5.77) years, and 68 controls patients of mean age 25.08 (± 11.42) years, entered the study. In 18 of them, the instrument was re-applied 1–2 days later and the Translation and Back Translation made. Clinical diagnosis was reached with the use of the SCAN v.2.0 and the International Personality Disorders Examination (IPDE). The Center for Epidemiological Studies-Depression (CES-D) and the Zung Depression Rating Scale (ZDRS) were applied for cross-validation purposes. Statistical analysis included ANOVA, the Spearman Product Moment Correlation Coefficient, Principal Components Analysis and the calculation of Cronbach's α. RESULTS: Sensitivity and specificity were 0.86 and 0.94, respectively, at 26/27. Cronbach's α for the total scale was equal to 0.89. The Spearman's rho between MDI and CES-D was 0.86 and between MDI and ZDRS was 0.76. The factor analysis revealed two factors but the first accounted for 54% of variance while the second only for 9%. The test-retest reliability was excellent (Spearman's rho between 0.53 and 0.96 for individual items and 0.89 for total score). CONCLUSION: The current study provided preliminary evidence concerning the reliability and validity of the Greek translation of the MDI. Its properties are similar to those reported in the international literature, but further research is necessary

Management of toxic ingestions with the use of renal replacement therapy

Although rare, renal replacement therapy (RRT) for the treatment of the metabolic, respiratory and hemodynamic complications of intoxications may be required. Understanding the natural clearance of the medications along with their volume of distribution, protein binding and molecular weight will help in understanding the benefit of commencing RRT. This information will aid in choosing the optimal forms of RRT in an urgent setting. Overdose of common pediatric medications are discussed with suggestions on the type of RRT within this educational review

Locally Administrated Perindopril Improves Healing in an Ovariectomized Rat Tibial Osteotomy Model

Angiotensin-converting enzyme inhibitors are widely prescribed to regulate blood pressure. High doses of orally administered perindopril have previously been shown to improve fracture healing in a mouse femur fracture model. In this study, perindopril was administered directly to the fracture area with the goal of stimulating fracture repair. Three months after being ovariectomized (OVX), tibial fractures were produced in Sprague–Dawley rats and subsequently stabilized with intramedullary wires. Perindopril (0.4 mg/kg/day) was injected locally at the fractured site for a treatment period of 7 days. Vehicle reagent was used as a control. Callus quality was evaluated at 2 and 4 weeks post-fracture. Compared with the vehicle group, perindopril treatment significantly increased bone formation, increased biomechanical strength, and improved microstructural parameters of the callus. Newly woven bone was arranged more tightly and regularly at 4 weeks post-fracture. The ultimate load increased by 66.1 and 76.9% (p<0.01), and the bone volume over total volume (BV/TV) increased by 29.9% and 24.3% (p<0.01) at 2 and 4 weeks post-fracture, respectively. These findings suggest that local treatment with perindopril could promote fracture healing in ovariectomized rats

A Genome-Scale DNA Repair RNAi Screen Identifies SPG48 as a Novel Gene Associated with Hereditary Spastic Paraplegia

We have identified a novel gene in a genome-wide, double-strand break DNA repair RNAi screen and show that is involved in the neurological disease hereditary spastic paraplegia

Association between bone mineral density and type 2 diabetes mellitus: a meta-analysis of observational studies

Type 2 diabetes mellitus (T2DM) influences bone metabolism, but the relation of T2DM with bone mineral density (BMD) remains inconsistent across studies. The objective of this study was to perform a meta-analysis and meta-regression of the literature to estimate the difference in BMD (g/cm2) between diabetic and non-diabetic populations, and to investigate potential underlying mechanisms. A literature search was performed in PubMed and Ovid extracting data from articles prior to May 2010. Eligible studies were those where the association between T2DM and BMD measured by dual energy X-ray absorptiometry was evaluated using a cross-sectional, cohort or case–control design, including both healthy controls and subjects with T2DM. The analysis was done on 15 observational studies (3,437 diabetics and 19,139 controls). Meta-analysis showed that BMD in diabetics was significantly higher, with pooled mean differences of 0.04 (95% CI: 0.02, 0.05) at the femoral neck, 0.06 (95% CI: 0.04, 0.08) at the hip and 0.06 (95% CI: 0.04, 0.07) at the spine. The differences for forearm BMD were not significantly different between diabetics and non-diabetics. Sex-stratified analyses showed similar results in both genders. Substantial heterogeneity was found to originate from differences in study design and possibly diabetes definition. Also, by applying meta-regression we could establish that younger age, male gender, higher body mass index and higher HbA1C were positively associated with higher BMD levels in diabetic individuals. We conclude that individuals with T2DM from both genders have higher BMD levels, but that multiple factors influence BMD in individuals with T2DM

Bartter- and Gitelman-like syndromes: salt-losing tubulopathies with loop or DCT defects

Salt-losing tubulopathies with secondary hyperaldosteronism (SLT) comprise a set of well-defined inherited tubular disorders. Two segments along the distal nephron are primarily involved in the pathogenesis of SLTs: the thick ascending limb of Henle’s loop, and the distal convoluted tubule (DCT). The functions of these pre- and postmacula densa segments are quite distinct, and this has a major impact on the clinical presentation of loop and DCT disorders – the Bartter- and Gitelman-like syndromes. Defects in the water-impermeable thick ascending limb, with its greater salt reabsorption capacity, lead to major salt and water losses similar to the effect of loop diuretics. In contrast, defects in the DCT, with its minor capacity of salt reabsorption and its crucial role in fine-tuning of urinary calcium and magnesium excretion, provoke more chronic solute imbalances similar to the effects of chronic treatment with thiazides. The most severe disorder is a combination of a loop and DCT disorder similar to the enhanced diuretic effect of a co-medication of loop diuretics with thiazides. Besides salt and water supplementation, prostaglandin E2-synthase inhibition is the most effective therapeutic option in polyuric loop disorders (e.g., pure furosemide and mixed furosemide–amiloride type), especially in preterm infants with severe volume depletion. In DCT disorders (e.g., pure thiazide and mixed thiazide–furosemide type), renin–angiotensin–aldosterone system (RAAS) blockers might be indicated after salt, potassium, and magnesium supplementation are deemed insufficient. It appears that in most patients with SLT, a combination of solute supplementation with some drug treatment (e.g., indomethacin) is needed for a lifetime

Multi-ethnic genome-wide association study for atrial fibrillation

Atrial fibrillation (AF) affects more than 33 million individuals worldwide and has a complex heritability. We conducted the largest meta-analysis of genome-wide association studies (GWAS) for AF to date, consisting of more than half a million individuals, including 65,446 with AF. In total, we identified 97 loci significantly associated with AF, including 67 that were novel in a combined-ancestry analysis, and 3 that were novel in a European-specific analysis. We sought to identify AF-associated genes at the GWAS loci by performing RNA-sequencing and expression quantitative trait locus analyses in 101 left atrial samples, the most relevant tissue for AF. We also performed transcriptome-wide analyses that identified 57 AF-associated genes, 42 of which overlap with GWAS loci. The identified loci implicate genes enriched within cardiac developmental, electrophysiological, contractile and structural pathways. These results extend our understanding of the biological pathways underlying AF and may facilitate the development of therapeutics for AF