Summary
Bariatric surgery is one of the most effective treatments for morbid obesity, and a large body of research indicates significant long‐term weight loss. While overall mortality decreases in ...patients who received bariatric surgery, a number of studies have shown that suicide rates are higher in bariatric patients than in control groups. The objective of this study was to present a systematic review of suicide mortality after bariatric surgery and calculate an estimate for the suicide rate. Literature researches of the databases PubMed, Web of Knowledge, PsychInfo, ScienceDirect and Google Scholar were conducted. Thirty studies concerning bariatric surgery and completed suicides met the inclusion criteria. We included 28 studies in the estimation of a suicide rate for the bariatric population. Only one study (Tindle et al.) put a main focus on suicide after bariatric surgery; this was therefore chosen as an adequate reference figure for comparison. The other 27 chosen studies were compared with World Health Organization data and the suicide rate reported by Tindle et al. Twenty‐three thousand eight hundred eighty‐five people were included in the analysis. In the literature, we found a total of 95 suicides when examining 190,000 person‐years of post‐bariatric surgery data. Little information was provided describing the reasons for suicide and the time‐point of these events after surgery. We estimated a suicide rate of 4.1/10,000 person‐years (95% confidence interval 3.2, 5.1/10,000 person‐years). A comparison with Tindle et al. demonstrates that their rate is significantly higher than our estimate (P = 0.03). Bariatric surgery patients show higher suicide rates than the general population. Therefore, there is a great need to identify persons at risk and post‐operative psychological monitoring is recommended.
Neuroprosthetics is a multidisciplinary field at the interface between neurosciences and biomedical engineering, which aims at replacing or modulating parts of the nervous system that get disrupted ...in neurological disorders or after injury. Although neuroprostheses have steadily evolved over the past 60 years in the field of sensory and motor disorders, their application to higher-order cognitive functions is still at a relatively preliminary stage. Nevertheless, a recent series of proof-of-concept studies suggest that electrical neuromodulation strategies might also be useful in alleviating some cognitive and memory deficits, in particular in the context of dementia. Here, we review the evolution of neuroprosthetics from sensorimotor to cognitive disorders, highlighting important common principles such as the need for neuroprosthetic systems that enable multisite bidirectional interactions with the nervous system.
Global warming caused by burning of fossil fuels is indisputably one of mankind's greatest challenges in the 21st century. To reduce the ever‐increasing CO2 emissions released into the atmosphere, ...dry solid adsorbents with large surface‐to‐volume ratio such as carbonaceous materials, zeolites, and metal–organic frameworks have emerged as promising material candidates for capturing CO2. However, challenges remain because of limited CO2/N2 selectivity and long‐term stability. The effective adsorption of CO2 gas (≈12 mol kg−1) on individual sheets of 2D transition metal carbides (referred to as MXenes) is reported here. It is shown that exposure to N2 gas results in no adsorption, consistent with first‐principles calculations. The adsorption efficiency combined with the CO2/N2 selectivity, together with a chemical and thermal stability, identifies the archetype Ti3C2 MXene as a new material for carbon capture (CC) applications.
A combination of in situ heating and H2 exposure of single 2D transition metal carbide (MXene) sheets using environmental transmission electron microscopy (ETEM) shows that surface terminations inherent to the MXenes are depleted and enable new terminations. Accordingly, depleted 2D Ti3C2 MXene is demonstrated as an effective adsorber of CO2.
Inclusion of explicit solvent molecules (n = 1, 2, 3, 4) in DFT-PCM-CHCl3 calculations of 1H NMR chemical shifts for the amine compound valerolactam, serves as good example of great improvement of ...theoretical NMR predictions, concerning N-H protons, which are systematically underestimated using the PCM solvent model, with the difference between theoretical and experimental values in solution approaching acceptable values (CH2 = 0.1 ppm, N-H = −0.2 ppm) when four explicit solvent molecules are included (PCM+4CHCl3 model).
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In this work we report DFT and MP2 1H NMR calculations using the GIAO method and TMS as reference, for a series of nitrogenated compounds in chloroform solution to assess the ability of available theoretical models to reproduce experimental 1H NMR spectra measured in CDCl3 solution, focusing on CHn and N-H proton signals which are relevant in conformational analysis studies. The Polarizable Continuum Model (PCM) may not work successfully to predict N-H chemical shifts in solution. Only when a few explicit solvent molecules are used in DFT-PCM-CHCl3 geometry optimizations a good agreement with experimental N-H chemical shifts measured in solution is reached, indicating that this is a reliable computational procedure for the prediction of the full NMR spectra of organic molecules containing N-H group. However, finding adequate DFT optimized solvated solute structures which reproduce well both N-H and CHn proton NMR signals can become a hard-computational task.
At present, no evidence-based lexicon exists for pediatric intracranial tumors. The Visually AcceSAble Rembrandt Images terminology describes reproducible MR imaging features of adult gliomas for ...prediction of tumor grade, molecular markers, and survival. Our aim was to assess the interrater reliability of the pre-resection features of Visually AcceSAble Rembrandt Images in pediatric brain tumors.
Fifty consecutive pre-resection brain MR imaging examinations of pediatric intracranial neoplasms were independently reviewed by 3 neuroradiologists. The intraclass correlation coefficient for continuous variables and the Krippendorf alpha were used to evaluate the interrater agreement. Subgroup analysis was performed for 30 gliomas.
Parameters with almost perfect agreement (α > .8) included tumor location (F1) and proportion of enhancing tumor (F5). Parameters with substantial agreement (α = .61-.80) were side of tumor epicenter (F2), involvement of eloquent brain (F3), enhancement quality (F4), proportion of non-contrast-enhancing tumor (F6), and deep white matter invasion (F21). The other parameters showed either moderate (α = .41-.60;
= 11), fair (α = .21-.40;
= 5), or slight agreement (α = 0-.20;
= 1). Subgroup analysis of 30 gliomas showed almost perfect agreement for tumor location (F1), involvement of eloquent brain (F3), and proportion of enhancing tumor (F5); and substantial agreement for side of tumor epicenter (F2), enhancement quality (F4), proportion of noncontrast enhancing tumor (F6), cysts (F8), thickness of enhancing margin (F11), and deep white matter invasion (F21). The intraclass correlation coefficient for measurements in the axial plane was excellent in both the main group (0.984 F29 and 0.982 F30) and the glioma subgroup (0.973 F29 and 0.973 F30).
Nine features of Visually AcceSAble Rembrandt Images have an acceptable interrater agreement in pediatric brain tumors. For the subgroup of pediatric gliomas, 11 features of Visually AcceSAble Rembrandt Images have an acceptable interrater agreement. The low degree of reproducibility of the remainder of the features necessitates the use of features tailored to the pediatric age group and is likely related to the more heterogeneous imaging morphology of pediatric brain tumors.
Mixing different elements at the nanoscale to obtain alloy nanostructures with fine-tuned physical and chemical properties offers appealing opportunities for nanotechnology and nanoscience. However, ...despite widespread successful application of alloy nanoparticles made by colloidal synthesis in heterogeneous catalysis, nanoalloy systems have been used very rarely in solid-state devices and nanoplasmonics-related applications. One reason is that such applications require integration in arrays on a surface with compelling demands on nanoparticle arrangement, uniformity in surface coverage, and optimization of the surface density. These cannot be fulfilled even using state-of-the-art self-assembly strategies of colloids. As a solution, we present here a generic bottom-up nanolithography-compatible fabrication approach for large-area arrays of alloy nanoparticles on surfaces. To illustrate the concept, we focus on Au-based binary and ternary alloy systems with Ag, Cu, and Pd, due to their high relevance for nanoplasmonics and complete miscibility, and characterize their optical properties. Moreover, as an example for the relevance of the obtained materials for integration in devices, we demonstrate the superior and hysteresis-free plasmonic hydrogen-sensing performance of the AuPd alloy nanoparticle system.
Using a combination of complementary in situ X-ray photoelectron spectroscopy and X-ray diffraction, we study the fundamental mechanisms underlying the chemical vapor deposition (CVD) of hexagonal ...boron nitride (h-BN) on polycrystalline Cu. The nucleation and growth of h-BN layers is found to occur isothermally, i.e., at constant elevated temperature, on the Cu surface during exposure to borazine. A Cu lattice expansion during borazine exposure and B precipitation from Cu upon cooling highlight that B is incorporated into the Cu bulk, i.e., that growth is not just surface-mediated. On this basis we suggest that B is taken up in the Cu catalyst while N is not (by relative amounts), indicating element-specific feeding mechanisms including the bulk of the catalyst. We further show that oxygen intercalation readily occurs under as-grown h-BN during ambient air exposure, as is common in further processing, and that this negatively affects the stability of h-BN on the catalyst. For extended air exposure Cu oxidation is observed, and upon re-heating in vacuum an oxygen-mediated disintegration of the h-BN film via volatile boron oxides occurs. Importantly, this disintegration is catalyst mediated, i.e., occurs at the catalyst/h-BN interface and depends on the level of oxygen fed to this interface. In turn, however, deliberate feeding of oxygen during h-BN deposition can positively affect control over film morphology. We discuss the implications of these observations in the context of corrosion protection and relate them to challenges in process integration and heterostructure CVD.
BACKGROUND AND PURPOSESignal analysis of FLAIR sequences is gaining momentum for studying neurodevelopment and brain maturation, but FLAIR intensity varies across scanners and needs to be normalized. ...This study aimed to establish normative values for standardized FLAIR intensity in the pediatric brain. MATERIALS AND METHODSA new automated algorithm for signal normalization was used to standardize FLAIR intensity across scanners and subjects. Mean intensity was extracted from GM, WM, deep GM, and cortical GM regions. Regression curves were fitted across the pediatric age range, and ANOVA was used to investigate intensity differences across age groups. Correlations between intensity and regional volume were also examined. RESULTSWe analyzed 429 pediatric FLAIR sequences in children 2-19 years of age with a median age of 11.2 years, including 199 males and 230 females. WM intensity had a parabolic relationship with age, with significant differences between various age groups (P < .05). GM and cortical GM intensity increased over the pediatric age range, with significant differences between early childhood and adolescence (P < .05). There were no significant relationships between volume and intensity in early childhood, while there were significant positive and negative correlations (P < .05) in WM and GM, respectively, for increasing age groups. Only the oldest age group showed significant differences between males and females (P < .05). CONCLUSIONSThis work presents a FLAIR intensity standardization algorithm to normalize intensity across large data sets, which allows FLAIR intensity to be used to compare regions and individuals as a surrogate measure of the developing pediatric brain.
The development of equine immunity from the fetus to adulthood is complex. The foal's immune response and the immune mechanisms that they are equipped with, along with changes over the first months ...of life until the immune system becomes adult‐like, are only partially understood. While several innate immune responses seem to be fully functional from birth, the onset of adaptive immune response is delayed. For some adaptive immune parameters, such as immunoglobin (Ig)G1, IgG3, IgG5 and IgA antibodies, the immune response starts before or at birth and matures within 3 months of life. Other antibody responses, such as IgG4, IgG7 and IgE production, slowly develop within the first year of life until they reach adult levels. Similar differences have been observed for adaptive T cell responses. Interferon‐gamma (IFN‐γ) production by T helper 1 (Th1)‐cells and cytotoxic T cells starts shortly after birth with low level production that gradually increases during the first year of life. In contrast, interleukin‐4 (IL‐4) produced by Th2‐cells is almost undetectable in the first 3 months of life. These findings offer some explanation for the increased susceptibility of foals to certain pathogens such as Rhodococcus equi. The delay in Th‐cell development and in particular Th2 immunity during the first months of life also provides an explanation for the reduced responsiveness of young horses to most traditional vaccines. In summary, all immune components of adult horses seem to exist in foals but the orchestrating and regulation of the immune response in immature horses is strikingly different. Young foals are fully competent and can perform certain immune responses but many mechanisms have yet to mature. Additional work is needed to improve our understanding of immunity and immune regulation in young horses, to identify the preferred immune pathways that they are using and ultimately provide new preventive strategies to protect against infectious disease.
(
) status has important implications for prognosis and therapy of pediatric low-grade gliomas. Currently,
status classification relies on biopsy. Our aim was to train and validate a radiomics ...approach to predict
fusion and
V600E mutation.
In this bi-institutional retrospective study, FLAIR MR imaging datasets of 115 pediatric patients with low-grade gliomas from 2 children's hospitals acquired between January 2009 and January 2016 were included and analyzed. Radiomics features were extracted from tumor segmentations, and the predictive model was tested using independent training and testing datasets, with all available tumor types. The model was selected on the basis of a grid search on the number of trees, opting for the best split for a random forest. We used the area under the receiver operating characteristic curve to evaluate model performance.
The training cohort consisted of 94 pediatric patients with low-grade gliomas (mean age, 9.4 years; 45 boys), and the external validation cohort comprised 21 pediatric patients with low-grade gliomas (mean age, 8.37 years; 12 boys). A 4-fold cross-validation scheme predicted
status with an area under the curve of 0.75 (SD, 0.12) (95% confidence interval, 0.62-0.89) on the internal validation cohort. By means of the optimal hyperparameters determined by 4-fold cross-validation, the area under the curve for the external validation was 0.85. Age and tumor location were significant predictors of
status (
values = .04 and <.001, respectively). Sex was not a significant predictor (
value = .96).
Radiomics-based prediction of
status in pediatric low-grade gliomas appears feasible in this bi-institutional exploratory study.
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