Spectral functions of Sr2IrO4: theory versus experiment

The spin-orbit Mott insulator Sr₂IrO₄ has attracted a lot of interest in recent years from theory and experiment due to its close connection to isostructural high-temperature copper oxide superconductors. Despite not being superconductive, its spectral features closely resemble those of the cuprates, including Fermi surface and pseudogap properties. In this article, we review and extend recent work in the theoretical description of the spectral function of pure and electron-doped Sr₂IrO₄ based on a cluster extension of dynamical mean-field theory ('oriented-cluster DMFT') and compare it to available angle-resolved photoemission data. Current theories provide surprisingly good agreement for pure and electron-doped Sr₂IrO₄, both in the paramagnetic and antiferromagnetic phases. Most notably, one obtains simple explanations for the experimentally observed steep feature around the M point and the pseudo-gap-like spectral feature in electron-doped Sr₂IrO₄.

Successful oral desensitization in children with cow's milk anaphylaxis: Clinical and laboratory evaluation up to nine-years follow-up

INTRODUCTION

Cow's milk protein allergy (CMPA) is the most common food allergy in children worldwide. Some children have severe and persistent CMPA, with near-fatal reactions after exposure to trace amounts of cow's milk-proteins (CMP). Strict avoidance diet is difficult, negatively affects quality of life and represents a conservative approach. Therefore, different therapeutic strategies are necessary.

OBJECTIVE

We aimed to assess long-term efficacy and safety of oral immunotherapy (OIT) in children with severe and long-lasting IgE-mediated CMPA.

MATERIALS AND METHODS

The authors present four case reports of patients with CMPA who underwent CMP-OIT, that have been under long-term follow-up up to nine years. We provide information about the clinical and laboratory evaluation. Skin prick tests (SPT), specific IgE and IgG4 were performed before, during, and after OIT. Immune profile after OIT was assessed by flow cytometry (lymphocyte subsets, regulatory T and B cells).

RESULTS

The success rate was 100%, and all patients currently have a free diet with minimal diary ingestion of 200mL CMP or equivalent. Specific IgE levels and SPT to CMP have progressively decreased, and specific IgG4 levels have increased. CD4⁺CD25⁺CD127^-/dim regulatory T cells were increased after OIT.

CONCLUSIONS

OIT ensured a clinical tolerance state after up to nine years, confirmed by both clinical and immune profile, allowing a diet without restrictions, with high satisfaction from patients and caregivers. We emphasize that OIT should be performed only by allergy experts in the hospital setting, and that only motivated families should be enrolled, since it is essential to ensure CMP daily intake at home.

Correction to: Toxicity prediction and assessment of an environmentally realistic pesticide mixture to Daphnia magna and Raphidocelis subcapitata

Acknowledgements This work was supported by LEAF (UID/AGR/04129/2013) and CESAM (UID/AMB/50017/2013) from FCT/MEC through national funds, and the cofunding by FEDER (POCI-01-0145-FEDER-007638), within the PT2020 Partnership Agreement and Compete2020.

Toxicity prediction and assessment of an environmentally realistic pesticide mixture to Daphnia magna and Raphidocelis subcapitata

In a regulatory perspective addressing the cumulative effect of co-occurring chemicals is the first and most important step in providing a more realistic hazard assessment of chemical cocktails to both man and environment. This study was conducted to show if joint effects on the immobilisation of the crustacean Daphnia magna and on the growth inhibition of algae Raphidocelis subcapitata follow additivity (concentration addition (CA) or independent action (IA) predictions) or if there is an interaction between chemicals in the organisms upon exposure to an environmentally realistic mixture of chlorpyrifos and terbuthylazine, with expected different molecular sites of action. A pattern of antagonism at lower doses and synergism at higher doses was found for acute immobility data, while no deviation from the additive conceptual models was observed in the algae inhibition test. Results in relation to the relevant set of regulatory acceptable concentrations (RACs) and environmental quality standards (EQSs) derived for individual chlorpyrifos and terbuthylazine were evaluated.

Interval colorectal cancer after colonoscopy

INTRODUCTION AND AIMS

Interval colorectal cancer (iCRC) can occur due to missed lesions or to a newly developed lesion. The present study aimed to assess the iCRC rate and its characteristics in our population and find possible explanations.

MATERIALS AND METHODS

A retrospective study was conducted on patients with colorectal cancer (CRC) diagnosed between January 2011 and January 2015 at our department. Demographics, endoscopic data, and tumor characteristics (location, histology, staging) were collected. We identified patients diagnosed with CCR who underwent colonoscopy at our department in the previous 10years and presented the disease (iCRC) before the date of their next recommended exam. The cases of iCRC were characterized and compared with other CRC cases. Possible explanations for the appearance of iCRC were analyzed.

RESULTS

A total of 266 patients presented with CRC, 61.7% were men, and mean patient age was 70.7years. We identified 10 patients with iCRC: 6 were men, and mean patient age was 71.1years. Mean time for iCRC diagnosis after index colonoscopy was 3.5±1.84years. Tumor was located in the right colon in 50% of the patients with iCRC and in 24.5% of the patients without iCRC (P=.091). More patients with iCRC had a family history of CRC (50%) than the patients with reference CRC (3.1%) (P=.000).

CONCLUSIONS

In our case series, 3.76% of all CRC were iCRC. There were no statistically significant differences between patients with or without iCRC, with the exception of family history of CRC.

A morphoanatomical approach to the adaptive features of the epidermis and proboscis of a marine Polychaeta: Eulalia viridis (Phyllodocida: Phyllodocidae)

Eulalia viridis is a marine Polychaeta of the rocky intertidal that, despite its simple anatomy, is an active predator of much larger invertebrates, from which it extracts pieces of soft tissue through suction. This uncanny feeding strategy triggered the pursuit for the morphological mechanisms that enable adaptation to its environment. The evaluation of the worm anatomy and microanatomy, combining electron and optical microscopy, revealed a series of particular adaptations in the epidermis and in the proboscis (the heavily muscled eversible pharynx). Besides its function in feeding, the proboscis is the main sensory organ, being equipped with numerous sensorial papillae holding chemoreceptors. Additionally, the proboscis possesses tentacles that become exposed when the organ is everted. These provide fast release of mucus and toxins, from mucocytes and special serous cells, respectively (the latter involving both merocrine and apocrine processes), whenever contact with a prey occurs. In its turn, the epidermis provides protection by cuticle and mucus secretion and has a sensorial function that may be associated to the worm's uncommon green pigment cells. Eulalia viridis presents a series of elegant adaptive tools to cope with its environment that are evolutionarily designed to counterbalance its relatively simple body plan.

Impact of weight loss achieved through a multidisciplinary intervention on appetite in patients with severe obesity

The impact of lifestyle-induced weight loss (WL) on appetite in patients with obesity remains controversial. This study aimed to assess the short- and long-term impact of WL achieved by diet and exercise on appetite in patients with obesity. Thirty-five (22 females) adults with severe obesity (body mass index: 42.5 ± 5.0 kg/m²) underwent a 2-yr WL program focusing on diet and exercise. Body weight (BW), cardiovascular fitness (V̇o_2max), appetite feelings, and plasma concentrations of insulin, active ghrelin (AG), glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and cholecystokinin (CCK), in the fasting and postprandial states, were measured at baseline (B), week 4 (W4), and 1 and 2 yr (and average values for all fasting and postprandial time points computed). BW was significantly reduced and V̇o_2max (ml·kg^-1·min^-1) increased at all time points compared with B (3.5, 8.1, and 8.4% WL and 7, 11, and 8% increase at W4 and 1 and 2 yr, respectively). Basal hunger and average hunger and desire to eat were significantly increased at 1 and 2 yr. Basal fullness was significantly increased at W4, and average ratings were reduced at 1 yr. Average AG and PYY were significantly increased, and insulin was reduced, at all time points compared with B. Average GLP-1 was reduced at W4, and CCK was increased at 2 yr. After lifestyle-induced WL, patients with severe obesity will, therefore, have to deal with increased hunger in the long term. In conclusion, sustained WL at 2 yr achieved with diet and exercise is associated with increased hunger feelings and ghrelin concentration but also increased postprandial concentrations of satiety hormones.

Explorations on the ecological role of toxin secretion and delivery in jawless predatory Polychaeta

Motivated by biotechnological prospects, there is increasing evidence that we may just be scraping the tip of the iceberg of poisonous marine invertebrates, among which the Polychaeta are promising candidates for bioprospecting. Here we show that an inconspicuous phyllodocid uses toxins in its uncanny feeding strategy. The worm, a jawless active predator characterised by its bright green colour, preys on larger invertebrates (including conspecifics) by extracting tissue portions with its powerful proboscis through suction. The animal is even able to penetrate through the valves and plates of live molluscs and barnacles. Observations in situ and a series of experiments demonstrated that the worm compensates its simple anatomy with secretion of a novel toxin, or mixture of toxins, referred to by us as "phyllotoxins". These are carried by mucus and delivered via repeated contact with the tip of the proboscis until the prey is relaxed or immobilised (reversibly). Proteolytic action permeabilises material to toxins and softens tissue to enable extraction by suction. The findings show that toxins are a major ecological trait and therefore play a key role in evolutionary success and diversification of Polychaeta, demonstrating also that understanding adaptative features may become the best showcase for novel animal toxins.