The analysis of the stress corrosion effects for H atom in the symmetrical tilt Ni Σ 5 (012) grain boundary structure

We employ a first-principles total energy method based on density functional theory as implemented in the Vienna ab-initio simulation package (VASP) for a detailed analysis of the symmetrical tilt Ni Σ 5 (012) GB with H impurity atoms in the structure of Σ 5 (012) GB. The effects of H segregation at the Ni Σ 5 (012) GB are investigated in details. The main goal of this study is to perform the ab initio simulations for the Ni Σ 5 (012) GB including the various impurity atoms at GB level as well as pure grain boundary models of Ni Σ 5 (012) GB. The grains can either be pushed apart or pulled together depending on the size of the impurity and nature of the local relaxations. Fundamental understanding of stress-corrosion cracking in metals and alloys including various impurity atoms is important to develop a new-structural material. Our calculations are compatible with the other first principle calculations. © 2017 Elsevier Ltd. All rights reserved

Self-supervised learning for few-shot medical image segmentation

Fully-supervised deep learning segmentation models are inflexible when encountering new unseen semantic classes and their fine-tuning often requires significant amounts of annotated data. Few-shot semantic segmentation (FSS) aims to solve this inflexibility by learning to segment an arbitrary unseen semantically meaningful class by referring to only a few labeled examples, without involving fine-tuning. State-of-the-art FSS methods are typically designed for segmenting natural images and rely on abundant annotated data of training classes to learn image representations that generalize well to unseen testing classes. However, such a training mechanism is impractical in annotation-scarce medical imaging scenarios. To address this challenge, in this work, we propose a novel self-supervised FSS framework for medical images, named SSL-ALPNet, in order to bypass the requirement for annotations during training. The proposed method exploits superpixel-based pseudo-labels to provide supervision signals. In addition, we propose a simple yet effective adaptive local prototype pooling module which is plugged into the prototype networks to further boost segmentation accuracy. We demonstrate the general applicability of the proposed approach using three different tasks: organ segmentation of abdominal CT and MRI images respectively, and cardiac segmentation of MRI images. The proposed method yields higher Dice scores than conventional FSS methods which require manual annotations for training in our experiments

Better together: data harmonization and cross-study analysis of abdominal MRI data from UK Biobank and the German National Cohort

OBJECTIVES: The UK Biobank (UKBB) and German National Cohort (NAKO) are among the largest cohort studies, capturing a wide range of health-related data from the general population, including comprehensive magnetic resonance imaging (MRI) examinations. The purpose of this study was to demonstrate how MRI data from these large-scale studies can be jointly analyzed and to derive comprehensive quantitative image-based phenotypes across the general adult population. MATERIALS AND METHODS: Image-derived features of abdominal organs (volumes of liver, spleen, kidneys, and pancreas; volumes of kidney hilum adipose tissue; and fat fractions of liver and pancreas) were extracted from T1-weighted Dixon MRI data of 17,996 participants of UKBB and NAKO based on quality-controlled deep learning generated organ segmentations. To enable valid cross-study analysis, we first analyzed the data generating process using methods of causal discovery. We subsequently harmonized data from UKBB and NAKO using the ComBat approach for batch effect correction. We finally performed quantile regression on harmonized data across studies providing quantitative models for the variation of image-derived features stratified for sex and dependent on age, height, and weight. RESULTS: Data from 8791 UKBB participants (49.9% female; age, 63 ± 7.5 years) and 9205 NAKO participants (49.1% female, age: 51.8 ± 11.4 years) were analyzed. Analysis of the data generating process revealed direct effects of age, sex, height, weight, and the data source (UKBB vs NAKO) on image-derived features. Correction of data source-related effects resulted in markedly improved alignment of image-derived features between UKBB and NAKO. Cross-study analysis on harmonized data revealed comprehensive quantitative models for the phenotypic variation of abdominal organs across the general adult population. CONCLUSIONS: Cross-study analysis of MRI data from UKBB and NAKO as proposed in this work can be helpful for future joint data analyses across cohorts linking genetic, environmental, and behavioral risk factors to MRI-derived phenotypes and provide reference values for clinical diagnostics

Chimpanzees (Pan troglodytes) Fail a What-Where-When Task but Find Rewards by Using a Location-Based Association Strategy

Recollecting the what-where-when of an episode, or episodic-like memory, has been established in corvids and rodents. In humans, a linkage between remembering the past and imagining the future has been recognised. While chimpanzees can plan for the future, their episodic-like memory has hardly been investigated. We tested chimpanzees (Pan troglodytes) with an adapted food-caching paradigm. They observed the baiting of two locations amongst four and chose one after a given delay (15 min, 1 h or 5 h). We used two combinations of food types, a preferred and a less preferred food that disappeared at different rates. The subjects had to base their choices on the time elapsed since baiting, and on their memory of which food was where. They could recover either their preferred food or the one that remained present. All animals failed to obtain the preferred or present foods above chance levels. They were like-wise unsuccessful at choosing baited cups above chance levels. The subjects, thus, failed to use any feature of the baiting events to guide their choices. Nonetheless, their choices were not random, but the result of a developed location-based association strategy. Choices in the second half of the study correlated with the rewards obtained at each location in the first half of the study, independent from the choices made for each location in the first half of the study. This simple location-based strategy yielded a fair amount of food. The animals' failure to remember the what-where-when in the presented set-up may be due to the complexity of the task, rather than an inability to form episodic-like memories, as they even failed to remember what was where after 15 minutes

Riboflavin Ameliorates Cisplatin Induced Toxicities under Photoillumination

BACKGROUND: Cisplatin is an effective anticancer drug that elicits many side effects mainly due to induction of oxidative and nitrosative stresses during prolonged chemotherapy. The severity of these side effects consequently restricts its clinical use under long term treatment. Riboflavin is an essential vitamin used in various metabolic redox reactions in the form of flavin adenine dinucleotide and flavin mononucleotide. Besides, it has excellent photosensitizing property that can be used to ameliorate these toxicities in mice under photodynamic therapy. METHODS AND FINDINGS: Riboflavin, cisplatin and their combinations were given to the separate groups of mice under photoilluminated condition under specific treatment regime. Their kidney and liver were excised for comet assay and histopathological studies. Furthermore, Fourier Transform Infrared Spectroscopy of riboflavin-cisplatin combination in vitro was also conducted to investigate any possible interaction between the two compounds. Their comet assay and histopathological examination revealed that riboflavin in combination with cisplatin was able to protect the tissues from cisplatin induced toxicities and damages. Moreover, Fourier Transform Infrared Spectroscopy analysis of the combination indicated a strong molecular interaction among their constituent groups that may be assigned for the protective effect of the combination in the treated animals. CONCLUSION: Inclusion of riboflavin diminishes cisplatin induced toxicities which may possibly make the cisplatin-riboflavin combination, an effective treatment strategy under chemoradiotherapy in pronouncing its antineoplastic activity and sensitivity towards the cancer cells as compared to cisplatin alone

The pathogen recognition sensor, NOD2, is variably expressed in patients with pulmonary tuberculosis

Background: NOD2, an intracellular pathogen recognition sensor, modulates innate defences to muropeptides derived from various bacterial species, including Mycobacterium tuberculosis (MTB). Experimentally, NOD2 attenuates two key putative mycobactericidal mechanisms. TNF-alpha synthesis is markedly reduced in MTB-antigen stimulated-mononuclear cells expressing mutant NOD2 proteins. NOD2 agonists also induce resistance to apoptosis, and may thus facilitate the survival of MTB in infected macrophages. To further define a role for NOD2 in disease pathogenesis, we analysed NOD2 transcriptional responses in pulmonary leucocytes and mononuclear cells harvested from patients with pulmonary tuberculosis (PTB).Methods: We analysed NOD2 mRNA expression by real-time polymerase chain-reaction in alveolar lavage cells obtained from 15 patients with pulmonary tuberculosis and their matched controls. We compared NOD2 transcriptional responses, in peripheral leucocytes, before and after anti-tuberculous treatment in 10 patients. In vitro, we measured NOD2 mRNA levels in MTB-antigen stimulated-mononuclear cells.Results: No significant differences in NOD2 transcriptional responses were detected in patients and controls. In some patients, however, NOD2 expression was markedly increased and correlated with toll-like-receptor 2 and 4 expression. In whole blood, NOD2 mRNA levels increased significantly after completion of anti-tuberculosis treatment. NOD2 expression levels did not change significantly in mononuclear cells stimulated with mycobacterial antigens in vitro.Conclusion: There are no characteristic NOD2 transcriptional responses in PTB. Nonetheless, the increased levels of NOD2 expression in some patients with severe tuberculosis, and the increases in expression levels within peripheral leucocytes following treatment merit further studies in selected patient and control populations

Enhanced Fear Expression in a Psychopathological Mouse Model of Trait Anxiety: Pharmacological Interventions

The propensity to develop an anxiety disorder is thought to be determined by genetic and environmental factors. Here we investigated the relationship between a genetic predisposition to trait anxiety and experience-based learned fear in a psychopathological mouse model. Male CD-1 mice selectively bred for either high (HAB), or normal (NAB) anxiety-related behaviour on the elevated plus maze were subjected to classical fear conditioning. During conditioning both mouse lines showed increased fear responses as assessed by freezing behaviour. However, 24 h later, HAB mice displayed more pronounced conditioned responses to both a contextual or cued stimulus when compared with NAB mice. Interestingly, 6 h and already 1 h after fear conditioning, freezing levels were high in HAB mice but not in NAB mice. These results suggest that trait anxiety determines stronger fear memory and/or a weaker ability to inhibit fear responses in the HAB line. The enhanced fear response of HAB mice was attenuated by treatment with either the α2,3,5-subunit selective benzodiazepine partial agonist L-838,417, corticosterone or the selective neurokinin-1 receptor antagonist L-822,429. Overall, the HAB mouse line may represent an interesting model (i) for identifying biological factors underlying misguided conditioned fear responses and (ii) for studying novel anxiolytic pharmacotherapies for patients with fear-associated disorders, including post-traumatic stress disorder and phobias