Preparation & characterization of high purity Cu2 ZnSn(SxSe1-x)4 nanoparticles

Research in thin film solar cells applies novel techniques to synthesize cost effective and highly efficient absorber materials in order to generate electricity directly from solar energy. Of these materials, copper zinc tin sulfoselenide (Cu2ZnSn(SxSe1-x) 4) nanoparticles have shown great promise in solar cell applications due to optimal material properties as well as low cost & relative abundance of materials.1,2 Sulfoselenide nanoparticles have also a broader impact in other industries including electronics3, LED 4, and biomedical research5. Of the many routes of manufacturing these class of semiconductors, colloidal synthesis of Cu 2ZnSn(SxSe1-x)4 offers a scalable, low cost and high-throughput route for manufacturing high efficiency thin-film solar cells. Hydrazine processed Cu2ZnSn(SxSe1-x )4 devices have reached a record power conversion efficiency (PCE) of 12.6%, much higher than the 9.6% reported for physical vapor deposition (PVD) systems.6,7^ Despite high efficiencies, wet synthesis of nanoparticles, however, is made more complicated in multi-element, quaternary and quinary systems such as copper zinc tin sulfoselenide (CZTSSe) and copper indium gallium diselenide (CIGSe). One major disadvantage in these systems is growth of the desired quaternary or quinary phase in competition with unwanted binary and ternary phases with low energy of formation.8,9 Moreover, various reaction parameters such as reaction time, temperature, and choice of ligand also affect, chemical as well as physical properties of resulting nanoparticles.^ Understanding of the formation mechanisms of the particles is necessary in order to address some of these challenges in wet synthesis of CZTSSe nanoparticles. In this study, we investigate synthesis conditions & reaction parameters which yield high purity Cu2ZnSn(SxSe1-x) 4 nanoparticles as well as attempt to understand the growth mechanism of these nanoparticles. This was achieved by manipulating anion precursor preparation routes as well order in which precursors are introduced into a reaction system. We report a new solution based sulfoselenide preparation route which has been used to synthesize high purity Cu2ZnSn(S xSe1-x)4 nanoparticles. Uniform phase Cu 2ZnSn(SxSe1-x)4nanoparticles were successfully synthesized over a wide range of varying chalcogen ratios. It was found that anion precursor solution plays a key role in determining the morphology & phase purity of the final nanoparticles, as observed from X-ray Diffraction (XRD) and Raman spectroscopy. A uniform sulfoselenide solution is needed to produce high purity Cu2ZnSn(SxSe1-x )4nanoparticles with narrow phase distribution. Moreover, the relative reactivity of each anion must be balanced in order to yield uniform phase nanoparticles. The findings of this study as well as the reported mixed chalcogen precursor preparation route can be applied in various industries, including photovoltaics to produce uniform phase, solution processed sulfoselenide nanoparticles

Case report on postmortem fentanyl measurement after overdose with more than 67 fentanyl patches

PURPOSE: Fentanyl is an analgesic that is frequently prescribed, which resulted in non-intentional as well as intentional misuse and deaths. Here, we present a postmortem case of a patient who clearly died of a fentanyl overdose due to an extensive number of fentanyl patches combined with oral intake of fentanyl and cocaine. We aimed to show how postmortem analysis can be used to interpret postmortem fentanyl concentrations in unique cases like the one we present. CASE DESCRIPTION: A 23-year-old male was found dead in his bedroom with 67 non-prescribed patches of fentanyl on his body. In the room, there also were fentanyl tablets of 100 µg and cocaine powder, which had possibly also been taken by the deceased. To confirm the cause of death, urine and subclavian blood were retrieved to perform a standard postmortem toxicology screening. The toxicological screening revealed the presence of several drugs, including cocaine, fentanyl, lidocaine and paracetamol. Further analysis of the quantitative postmortem values of fentanyl with ultra-performance liquid chromatography-tandem mass spectrometry revealed a fentanyl concentration of 57.9 µg/L. Considering several issues around postmortem drug analyses, this value seemed to be in line with concentrations found in previously reported postmortem cases. CONCLUSION: We were able to confirm the expected cause of death with an extensive toxicological screening in combination with the circumstantial evidence. We identified fentanyl as most important cause for the fatal outcome in this specific case and simultaneously contributed to the limited availability of knowledge on postmortem fentanyl concentrations

Global hemostatic status in patients with acute-on-chronic liver failure and septics without underlying liver disease

Background Even the sickest patients with chronic liver disease (CLD), such as those with acute-on-chronic liver failure (ACLF) remain in hemostatic balance due to a concomitant decline in pro- and antihemostatic factors. Objectives We aimed to study whether the hemostatic status in ACLF is merely an exaggeration from the status in patients with compensated and acutely decompensated cirrhosis, or whether sepsis-associated hemostatic changes contribute. Methods We performed extensive hemostatic profiling in 31 adult patients with ACLF, 20 patients with sepsis without underlying CLD, and 40 healthy controls. Results We found similarly elevated plasma levels of the platelet adhesive protein von Willebrand factor (VWF) and decreased levels of the VWF-regulating protease ADAMTS13 in both groups compared to healthy controls. In vivo markers of activation of coagulation (thrombin-antithrombin III, D-dimer) were similarly elevated in both groups compared to controls, but ex vivo thrombin-generating capacity was similar between patients and controls, despite a much more profound international normalized ratio elevation in ACLF. Plasma fibrinogen levels were much higher in septics, which was accompanied by a decreased ex vivo clot permeability and an increase in ex vivo resistance to clot lysis. All hemostatic parameters were remarkably stable over the first 10 days after admission. Conclusions We have found hemostatic changes in ACLF to partially overlap with that of patients with sepsis, and evidence of preserved hemostatic capacity in both patient groups. The notable difference was a profound hyperfibrinogenemia, associated with a thrombogenic clot structure and a marked ex vivo resistance to fibrinolysis in patients with sepsis

BOLD Coupling between Lesioned and Healthy Brain Is Associated with Glioma Patients’ Recovery

Predicting functional outcomes after surgery and early adjuvant treatment is difficult due to the complex, extended, interlocking brain networks that underpin cognition. The aim of this study was to test glioma functional interactions with the rest of the brain, thereby identifying the risk factors of cognitive recovery or deterioration. Seventeen patients with diffuse non-enhancing glioma (aged 22–56 years) were longitudinally MRI scanned and cognitively assessed before and after surgery and during a 12-month recovery period (55 MRI scans in total after exclusions). We initially found, and then replicated in an independent dataset, that the spatial correlation pattern between regional and global BOLD signals (also known as global signal topography) was associated with tumour occurrence. We then estimated the coupling between the BOLD signal from within the tumour and the signal extracted from different brain tissues. We observed that the normative global signal topography is reorganised in glioma patients during the recovery period. Moreover, we found that the BOLD signal within the tumour and lesioned brain was coupled with the global signal and that this coupling was associated with cognitive recovery. Nevertheless, patients did not show any apparent disruption of functional connectivity within canonical functional networks. Understanding how tumour infiltration and coupling are related to patients’ recovery represents a major step forward in prognostic development.Consejeria de Economia, Innovacion, Ciencia y Empleo.Junta de Andalucia CV20-45250; A-TIC-080-UGR18; B-TIC-586-UGR20; P20-0052

Dynamic instabilities induced by asymmetric influence: Prisoners' dilemma game on small-world networks

A two-dimensional small-world type network, subject to spatial prisoners' dilemma dynamics and containing an influential node defined as a special node with a finite density of directed random links to the other nodes in the network, is numerically investigated. It is shown that the degree of cooperation does not remain at a steady state level but displays a punctuated equilibrium type behavior manifested by the existence of sudden breakdowns of cooperation. The breakdown of cooperation is linked to an imitation of a successful selfish strategy of the influential node. It is also found that while the breakdown of cooperation occurs suddenly, the recovery of it requires longer time. This recovery time may, depending on the degree of steady state cooperation, either increase or decrease with an increasing number of long range connections.Comment: 5 pages, 6 figure

Demographic Inference and Representative Population Estimates from Multilingual Social Media Data

Social media provide access to behavioural data at an unprecedented scale and granularity. However, using these data to understand phenomena in a broader population is difficult due to their non-representativeness and the bias of statistical inference tools towards dominant languages and groups. While demographic attribute inference could be used to mitigate such bias, current techniques are almost entirely monolingual and fail to work in a global environment. We address these challenges by combining multilingual demographic inference with post-stratification to create a more representative population sample. To learn demographic attributes, we create a new multimodal deep neural architecture for joint classification of age, gender, and organization-status of social media users that operates in 32 languages. This method substantially outperforms current state of the art while also reducing algorithmic bias. To correct for sampling biases, we propose fully interpretable multilevel regression methods that estimate inclusion probabilities from inferred joint population counts and ground-truth population counts. In a large experiment over multilingual heterogeneous European regions, we show that our demographic inference and bias correction together allow for more accurate estimates of populations and make a significant step towards representative social sensing in downstream applications with multilingual social media.Comment: 12 pages, 10 figures, Proceedings of the 2019 World Wide Web Conference (WWW '19

Brain charts for the human lifespan

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data (http://www.brainchart.io/). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes

BOLD Coupling between Lesioned and Healthy Brain Is Associated with Glioma Patients’ Recovery

This article belongs to the Special Issue Perioperative Imaging and Mapping Methods in Glioma Patients.[Simple Summary] Glioma, a type of brain tumour, affects not only the function of immediately adjacent brain tissue but also that in more distant areas, potentially impacting cognitive function after its surgical removal. Here, 17 patients with glioma had brain scans and tests of cognitive function during treatment and recovery. We investigated the effects of glioma on the brain, and what happens during recovery, using the brain’s “global signal” detected with magnetic resonance imaging (MRI). We found that the signal from gliomas was synchronised with the global signal in all patients and that this synchronisation was associated with the recovery of cognition after surgery. Specifically, patients with a greater reduction in glioma–global signal synchronisation following surgery were more likely to have a larger number of newly acquired cognitive difficulties. Together, these results suggest that the interaction between gliomas and the brain can predict how patients recover their cognitive abilities, which is important for their quality of life.[Abstract] Predicting functional outcomes after surgery and early adjuvant treatment is difficult due to the complex, extended, interlocking brain networks that underpin cognition. The aim of this study was to test glioma functional interactions with the rest of the brain, thereby identifying the risk factors of cognitive recovery or deterioration. Seventeen patients with diffuse non-enhancing glioma (aged 22–56 years) were longitudinally MRI scanned and cognitively assessed before and after surgery and during a 12-month recovery period (55 MRI scans in total after exclusions). We initially found, and then replicated in an independent dataset, that the spatial correlation pattern between regional and global BOLD signals (also known as global signal topography) was associated with tumour occurrence. We then estimated the coupling between the BOLD signal from within the tumour and the signal extracted from different brain tissues. We observed that the normative global signal topography is reorganised in glioma patients during the recovery period. Moreover, we found that the BOLD signal within the tumour and lesioned brain was coupled with the global signal and that this coupling was associated with cognitive recovery. Nevertheless, patients did not show any apparent disruption of functional connectivity within canonical functional networks. Understanding how tumour infiltration and coupling are related to patients’ recovery represents a major step forward in prognostic development.This research was supported by the Guarantors of Brain, Cancer Research UK Cambridge Centre, The Brain Tumour Charity and the EMERGIA Junta de Andalucia program. Y.E. is funded by a Royal Society Dorothy Hodgkin Research Fellowship (DHF130100). JMG is funded by the Ministerio de Ciencia e Innovación (España)/FEDER under the RTI2018-098913-B100 project, by the Consejería de Economía, Innovación, Ciencia y Empleo (Junta de Andalucía) and FEDER under CV20-45250, A-TIC-080-UGR18, B-TIC-586-UGR20 and P20-00525 projects. MA was funded by a Cambridge Trust—Yousef Jameel Scholarship. This research was also supported by the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014). SJP (NIHR Career Development Fellowship, CDF-2018-11-ST2-003) is funded by the National Institute for Health Research (NIHR) for this research project

Bold coupling between lesioned and healthy brain is associated with glioma patients’ recovery

Predicting functional outcomes after surgery and early adjuvant treatment is difficult due to the complex, extended, interlocking brain networks that underpin cognition. The aim of this study was to test glioma functional interactions with the rest of the brain, thereby identifying the risk factors of cognitive recovery or deterioration. Seventeen patients with diffuse non-enhancing glioma (aged 22–56 years) were longitudinally MRI scanned and cognitively assessed before and after surgery and during a 12-month recovery period (55 MRI scans in total after exclusions). We initially found, and then replicated in an independent dataset, that the spatial correlation pattern between regional and global BOLD signals (also known as global signal topography) was associated with tumour occurrence. We then estimated the coupling between the BOLD signal from within the tumour and the signal extracted from different brain tissues. We observed that the normative global signal topography is reorganised in glioma patients during the recovery period. Moreover, we found that the BOLD signal within the tumour and lesioned brain was coupled with the global signal and that this coupling was associated with cognitive recovery. Nevertheless, patients did not show any apparent disruption of functional connectivity within canonical functional networks. Understanding how tumour infiltration and coupling are related to patients’ recovery represents a major step forward in prognostic development.</p

Large-scale associations between the leukocyte transcriptome and BOLD responses to speech differ in autism early language outcome subtypes.

Heterogeneity in early language development in autism spectrum disorder (ASD) is clinically important and may reflect neurobiologically distinct subtypes. Here, we identified a large-scale association between multiple coordinated blood leukocyte gene coexpression modules and the multivariate functional neuroimaging (fMRI) response to speech. Gene coexpression modules associated with the multivariate fMRI response to speech were different for all pairwise comparisons between typically developing toddlers and toddlers with ASD and poor versus good early language outcome. Associated coexpression modules were enriched in genes that are broadly expressed in the brain and many other tissues. These coexpression modules were also enriched in ASD-associated, prenatal, human-specific, and language-relevant genes. This work highlights distinctive neurobiology in ASD subtypes with different early language outcomes that is present well before such outcomes are known. Associations between neuroimaging measures and gene expression levels in blood leukocytes may offer a unique in vivo window into identifying brain-relevant molecular mechanisms in ASD