Polarization sensitive spectroscopy of charged Quantum Dots

We present an experimental and theoretical study of the polarized photoluminescence spectrum of single semiconductor quantum dots in various charge states. We compare our high resolution polarization sensitive spectral measurements with a new many-carrier theoretical model, which was developed for this purpose. The model considers both the isotropic and anisotropic exchange interactions between all participating electron-hole pairs. With this addition, we calculate both the energies and polarizations of all optical transitions between collective, quantum dot confined charge carrier states. We succeed in identifying most of the measured spectral lines. In particular, the lines resulting from singly-, doubly- and triply- negatively charged excitons and biexcitons. We demonstrate that lines emanating from evenly charged states are linearly polarized. Their polarization direction does not necessarily coincide with the traditional crystallographic direction. It depends on the shells of the single carriers, which participate in the recombination process.Comment: 11 pages, 9 figures. Revised versio

The Long-Term Effects of Dietary Nutrient Intakes during the First 2 Years of Life in Healthy Infants from Developed Countries : An Umbrella Review

The role of both qualitative and quantitative early nutrient intakes on later health has been suggested for decades and supported by observational studies on humans, mainly preterm and low-birth-weight infants, and animal models. However, to date, no comprehensive review has been conducted to evaluate the full impact of nutritional variables on healthy full-term infants. This umbrella review considers meta-analyses and systematic reviews on the health effects of different nutritional exposures or interventions in the first 2 y of life of healthy full-term infants in developed countries. The systematic reviews and meta-analyses published by March 2018 in MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews were included. The following outcomes were considered: growth and obesity, cardiovascular disease, neurodevelopment, allergy and autoimmunity, infections, and malignancy. Breastfeeding and complementary feeding were considered separately and analyzed by means of their differences in delivering heterogeneous food-related variables. The resulting data on the long-term effect of early nutritional differences in healthy full-term infants were found to be inconclusive. Only breastfeeding has a beneficial effect, which is nevertheless slight and limited to just a few outcome measures, whereas the type and duration required to be effective are still unclear. As regards the complementary feeding period, no clear effects of different dietary interventions emerge in terms of health outcomes. Available evidence on the health effects of differences in early nutrition in healthy full-term infants still remains largely inconclusive

Sustained remission of eosinophilic esophagitis following discontinuation of dietary elimination in children

Eosinophilic esophagitis (EoE), when left untreated, may progress from an inflammatory to a fibrostenotic phenotype. Inflammation generally recurs after treatment withdrawal. Thus, long-term treatment has been recommended. Here, we describe a cohort of children with EoE who achieved clinical and histologic remission with elimination diets, and maintained sustained untreated remission (SUR) despite re-introduction of all eliminated food allergens

A quantitative assessment of mucosal eosinophils in the gastrointestinal tract of children without detectable organic disease

Background: Accurate measurements of mucosal eosinophil concentrations in gastrointestinal tracts of healthy children are necessary to differentiate health and disease states in general, and better define eosinophilic gastrointestinal diseases. Study: We retrospectively reviewed gastrointestinal biopsies from children with macroscopically normal endoscopies, who, after a minimal follow-up of one year, were not diagnosed with any organic disease. Peak eosinophil concentrations and distributions were assessed from each segment of the gastrointestinal tract. Results: Three centers (Italy, United Kingdom, and Israel) contributed 202 patients (median age 13 years IQR 9.5–15.5, range 1–18 years). Median (IQR, range) eosinophil concentrations (eos/mm2) were: esophagus 0 (0–0, 0–84), stomach 0 (0–4, 0–84), duodenal bulb 20 (13–30, 7–67), second part of duodenum 20 (13–29, 0–105), terminal ileum 29 (14–51, 0–247), cecum 53 (37–89, 10–232), ascending colon 55 (25–84, 0–236), transverse colon 38 (21–67, 4–181), descending colon 29 (17–59, 0–114), sigmoid colon 25 (13–40, 0–215) and rectum 13 (4–28, 0–152). Significant geographical variance was present, however, no differences in eosinophil concentrations were identified between children with resolving symptoms vs. those with functional diagnoses, nor across age groups. Conclusions: Standardized eosinophil concentrations from the gastrointestinal tracts of children without organic disease will serve to better define both health and disease states. No differences were found between resolved symptoms vs. functional diagnoses nor between age groups in this pediatric cohort

Sustained Remission of Eosinophilic Esophagitis Following Discontinuation of Dietary Elimination in Children

Eosinophilic esophagitis (EoE), when left untreated, may progress from an inflammatory to a fibrostenotic phenotype. Inflammation generally recurs after treatment withdrawal. Thus, long-term treatment has been recommended. Here, we describe a cohort of children with EoE who achieved clinical and histologic remission with elimination diets, and maintained sustained untreated remission (SUR) despite re-introduction of all eliminated food allergens. © 2020 AGA Institut

Pediatric Eosinophilic Esophagitis: Results of the European Retrospective Pediatric Eosinophilic Esophagitis Registry (RetroPEER)

OBJECTIVES: Recommendations for diagnosing and treating eosinophilic esophagitis (EoE) are evolving; however, information on real world clinical practice is lacking. To assess the practices of pediatric gastroenterologists diagnosing and treating EoE and to identify the triggering allergens in European children. METHODS: Retrospective anonymized data were collected from 26 European pediatric gastroenterology centers in 13 countries. Inclusion criteria were: Patients diagnosis with EoE, completed investigations prescribed by the treating physician, and were on stable medical or dietary interventions. RESULTS: In total, 410 patients diagnosed between December 1999 and June 2016 were analyzed, 76.3% boys. The time from symptoms to diagnosis was 12 ± 33.5 months and age at diagnosis was 8.9 ± 4.75 years. The most frequent indications for endoscopy were: dysphagia (38%), gastroesophageal reflux (31.2%), bolus impaction (24.4%), and failure to thrive (10.5%). Approximately 70.3% had failed proton pump inhibitor treatment. The foods found to be causative of EoE by elimination and rechallenge were milk (42%), egg (21.5%), wheat/gluten (10.9%), and peanut (9.9%). Elimination diets were used exclusively in 154 of 410 (37.5%), topical steroids without elimination diets in 52 of 410 (12.6%), both diet and steroids in 183 of 410 (44.6%), systemic steroids in 22 of 410 (5.3%), and esophageal dilation in 7 of 410 (1.7%). Patient refusal, shortage of endoscopy time, and reluctance to perform multiple endoscopies per patient were noted as factors justifying deviation from guidelines. CONCLUSIONS: In this "real world" pediatric European cohort, milk and egg were the most common allergens triggering EoE. Although high-dose proton pump inhibitor trials have increased, attempted PPI treatment is not universal

Pediatric eosinophilic esophagitis: results of the European Retrospective Pediatric Eosinophilic Esophagitis Registry (RetroPEER)

OBJECTIVES: Recommendations for diagnosing and treating eosinophilic esophagitis (EoE) are evolving; however, information on real world clinical practice is lacking. To assess the practices of pediatric gastroenterologists diagnosing and treating EoE and to identify the triggering allergens in European children. METHODS: Retrospective anonymized data were collected from 26 European pediatric gastroenterology centers in 13 countries. Inclusion criteria were: Patients diagnosis with EoE, completed investigations prescribed by the treating physician, and were on stable medical or dietary interventions. RESULTS: In total, 410 patients diagnosed between December 1999 and June 2016 were analyzed, 76.3% boys. The time from symptoms to diagnosis was 12 ± 33.5 months and age at diagnosis was 8.9 ± 4.75 years. The most frequent indications for endoscopy were: dysphagia (38%), gastroesophageal reflux (31.2%), bolus impaction (24.4%), and failure to thrive (10.5%). Approximately 70.3% had failed proton pump inhibitor treatment. The foods found to be causative of EoE by elimination and rechallenge were milk (42%), egg (21.5%), wheat/gluten (10.9%), and peanut (9.9%). Elimination diets were used exclusively in 154 of 410 (37.5%), topical steroids without elimination diets in 52 of 410 (12.6%), both diet and steroids in 183 of 410 (44.6%), systemic steroids in 22 of 410 (5.3%), and esophageal dilation in 7 of 410 (1.7%). Patient refusal, shortage of endoscopy time, and reluctance to perform multiple endoscopies per patient were noted as factors justifying deviation from guidelines. CONCLUSIONS: In this "real world" pediatric European cohort, milk and egg were the most common allergens triggering EoE. Although high-dose proton pump inhibitor trials have increased, attempted PPI treatment is not universal