julilili42/papers huggingface dataset:
Imaging Pulmonary Blood Flow Using Pseudocontinuous Arterial Spin Labeling (PCASL) With Balanced Steady‐State Free‐Precession (bSSFP) Readout at 1.5T
2020-07-05

Background Quantitative assessment of pulmonary blood flow and visualization of its temporal and spatial distribution without contrast media is of clinical significance. Purpose To assess the potential of electrocardiogram (ECG)‐triggered pseudocontinuous arterial spin labeling (PCASL) imaging with balanced steady‐state free‐precession (bSSFP) readout to measure lung perfusion under free‐breathing (FB) conditions and to study temporal and spatial characteristics of pulmonary blood flow. Study Type Prospective, observational. Subjects Fourteen volunteers; three patients with pulmonary embolism. Field Strength/Sequences 1.5T , PCASL‐bSSFP . Assessment The pulmonary trunk was labeled during systole. The following examinations were performed: 1) FB and timed breath‐hold (TBH) examinations with a postlabeling delay (PLD) of 1000 msec, and 2) TBH examinations with multiple PLDs (100–1500 msec). Scan–rescan measurements were performed in four volunteers and one patient. Images were registered and the perfusion was evaluated in large vessels, small vessels, and parenchyma. Mean structural similarity indices (MSSIM) was computed and time‐to‐peak (TTP) of parenchymal perfusion in multiple PLDs was evaluated. Image quality reading was performed with three independent blinded readers. Statistical Tests Wilcoxon test to compare MSSIM, perfusion, and Likert scores. Spearman's correlation to correlate TTP and cardiac cycle duration. The repeatability coefficient (RC) and within‐subject coefficient of variation (wCV) for scan–rescan measurements. Intraclass correlation coefficient (ICC) for interreader agreement. Results Image registration resulted in a significant ( P &lt; 0.05) increase of MSSIM. FB perfusion values were 6% higher than TBH (3.28 ± 1.09 vs. 3.10 ± 0.99 mL/min/mL). TTP was highly correlated with individuals' cardiac cycle duration (Spearman = 0.89, P &lt; 0.001). RC and wCV were better for TBH than FB (0.13–0.19 vs. 0.47–1.54 mL/min/mL; 6–7 vs. 19–60%). Image quality was rated very good, with ICCs 0.71–0.89. Data Conclusion ECG‐triggered PCASL‐bSSFP imaging of the lung at 1.5T can provide very good image quality and quantitative perfusion maps even under FB. The course of labeled blood through the lung shows a strong dependence on the individuals' cardiac cycle duration. Level of Evidence 2 Technical Efficacy Stage 2 J. MAGN. RESON. IMAGING 2020;52:1767–1782.
Hydration for health hypothesis: a narrative review of supporting evidence
2020-07-06

Abstract Purpose An increasing body of evidence suggests that excreting a generous volume of diluted urine is associated with short- and long-term beneficial health effects, especially for kidney and metabolic function. However, water intake and hydration remain under-investigated and optimal hydration is poorly and inconsistently defined. This review tests the hypothesis that optimal chronic water intake positively impacts various aspects of health and proposes an evidence-based definition of optimal hydration. Methods Search strategy included PubMed and Google Scholar using relevant keywords for each health outcome, complemented by manual search of article reference lists and the expertise of relevant practitioners for each area studied. Results The available literature suggest the effects of increased water intake on health may be direct, due to increased urine flow or urine dilution, or indirect, mediated by a reduction in osmotically -stimulated vasopressin (AVP). Urine flow affects the formation of kidney stones and recurrence of urinary tract infection, while increased circulating AVP is implicated in metabolic disease, chronic kidney disease, and autosomal dominant polycystic kidney disease. Conclusion In order to ensure optimal hydration, it is proposed that optimal total water intake should approach 2.5 to 3.5 L day −1 to allow for the daily excretion of 2 to 3 L of dilute (&lt; 500 mOsm kg −1 ) urine. Simple urinary markers of hydration such as urine color or void frequency may be used to monitor and adjust intake.
Human Prostate Cancer Is Characterized by an Increase in Urea Cycle Metabolites
2020-07-06

Despite it being the most common incident of cancer among men, the pathophysiological mechanisms contributing to prostate cancer (PCa) are still poorly understood. Altered mitochondrial metabolism is postulated to play a role in the development of PCa. To determine the key metabolites (which included mitochondrial oncometabolites), benign prostatic and cancer tissues of patients with PCa were analyzed using capillary electrophoresis and liquid chromatography coupled with mass spectrometry. Gene expression was studied using real-time PCR. In PCa tissues, we found reduced levels of early tricarboxylic acid cycle metabolites, whereas the contents of urea cycle metabolites including aspartate, argininosuccinate, arginine, proline, and the oncometabolite fumarate were higher than that in benign controls. Fumarate content correlated positively with the gene expression of oncogenic HIF1α and NFκB pathways, which were significantly higher in the PCa samples than in the benign controls. Furthermore, data from the TCGA database demonstrated that prostate cancer patients with activated NFκB pathway had a lower survival rate. In summary, our data showed that fumarate content was positively associated with carcinogenic genes.
Bent folded‐end dipole head array for ultrahigh‐field MRI turns “dielectric resonance” from an enemy to a friend
2020-07-06

Purpose To provide transmit whole‐brain coverage at 9.4 T using an array with only eight elements and improve the specific absorption rate (SAR) performance, a novel dipole array was developed, constructed, and tested. Methods The array consists of eight optimized bent folded‐end dipole antennas circumscribing a head. Due to the asymmetrical shape of the dipoles (bending and folding) and the presence of an RF shield near the folded portion, the array simultaneously excites two modes: a circular polarized mode of the array itself, and the TE mode (“dielectric resonance”) of the human head. Mode mixing can be controlled by changing the length of the folded portion. Due to this mixing, the new dipole array improves longitudinal coverage as compared with unfolded dipoles. By optimizing the length of the folded portion, we can also minimize the peak local SAR (pSAR) value and decouple adjacent dipole elements. Results The new array improves the SEE (&lt; &gt;/√pSAR) value by about 50%, as compared with the unfolded bent dipole array. It also provides better whole‐brain coverage compared with common single‐row eight‐element dipole arrays, or even to a more complex double‐row 16‐element surface loop array. Conclusion In general, we demonstrate that rather than compensating for the constructive interference effect using additional hardware, we can use the “dielectric resonance” to improve coverage, transmit field homogeneity, and SAR efficiency. Overall, this design approach not only improves the transmit performance in terms of the coverage and SAR, but substantially simplifies the common surface loop array design, making it more robust, and therefore safer.
Formation of massive stars under protostellar radiation feedback: very metal-poor stars
2020-07-06

ABSTRACT We study the formation of very metal-poor stars under protostellar radiative feedback effect. We use cosmological simulations to identify low-mass dark matter haloes and star-forming gas clouds within them. We then follow protostar formation and the subsequent long-term mass accretion phase of over one million years using two-dimensional radiation-hydrodynamics simulations. We show that the critical physical process that sets the final mass is the formation and expansion of a bipolar H ii region. The process is similar to the formation of massive primordial stars, but radiation pressure exerted on dust grains also contributes to halting the accretion flow in the low-metallicity case. We find that the net feedback effect in the case with metallicity Z = 10−2 Z⊙ is stronger than in the case with Z ∼ 1 Z⊙. With decreasing metallicity, the radiation-pressure effect becomes weaker, but photoionization heating of the circumstellar gas is more efficient owing to the reduced dust attenuation. In the case with Z = 10−2 Z⊙, the central star grows as massive as 200 solar masses, similarly to the case of primordial star formation. We conclude that metal-poor stars with a few hundred solar masses can be formed by gas accretion despite the strong radiative feedback.
Elevation change of Bhasan Char measured by persistent scatterer interferometry using Sentinel-1 data in a humanitarian context
2020-07-06

This study investigates the elevation changes for the island of Bhasan Char, located in the Bay of Bengal, which was selected for the relocation of around 100,000 refugees of the Rohingya minority which were forced to leave their homes in Myanmar. Eighty-nine Sentinel-1 products were analysed using persistent scatterer interferometry (PSI) beginning August 2016 through September 2019, divided into three periods of one year to reduce the impact of temporal decorrelation. The findings indicate that the island is a recent landform which underlies naturally induced surface changes with velocities of up to ±20 mm per year. Additional displacement is probably caused by heavy construction loads since early 2018, although we found no statistical evidence for this. The main built-up area shows stable behaviour during the analysed period, but there are significant changes along the coasts and artificial embankments of the island, and within one separate settlement in the north. The moist surface conditions and strong monsoonal rains complicated the proper retrieval of stable trends, but the sum of findings supports the assumption that the island underlies strong morphologic dynamics which put the people to be relocated at additional risk. Its suitability for construction has to be investigated in further studies.
MEG reveals preference specific increases of sexual-image-evoked responses in paedophilic sexual offenders and healthy controls
2020-07-06

Objectives Paedophilic disorder is characterised by sexual attraction towards children. Classification of a counterpart as sexually attractive likely occurs rapidly, and involves both conscious and unconscious attentional and cognitive processes. Magnetoencephalography (MEG) is an imaging method especially well-suited to examine visual and attentional processes triggered by sexual images within the range of milliseconds.Methods We investigated brain responses to sexual images depicting adults (frequent) and children (infrequent stimulus) in seventeen paedophilic patients with a history of child sexual offending (P + CSO) and twenty healthy controls (HC) during a passive visual oddball paradigm. Event-related fields (ERF) were measured to extract the magnetic visual mismatch negativity (vMMNm), and how it relates to the processing of different classes of sexual stimuli.Results P + CSO exhibited significantly longer vMMNm latencies (100–180 ms post-stimulus) than HC. Moreover, P + CSO showed widespread increased amplitudes in response to child images starting from P3a and P3b components and lasting up to 400 ms post-stimulus presentation localised in frontal and temporal brain regions.Conclusions This study uncovers the first MEG differences in automatic change detection between P + CSO and HC during the presentation of subliminal sexual images of adults and children, contributing towards a better understanding of the neurobiological processes of P + CSO.
Genome sequencing analysis identifies new loci associated with Lewy body dementia and provides insights into the complex genetic architecture
2020-07-06

Abstract The genetic basis of Lewy body dementia (LBD) is not well understood. Here, we performed whole-genome sequencing in large cohorts of LBD cases and neurologically healthy controls to study the genetic architecture of this understudied form of dementia and to generate a resource for the scientific community. Genome-wide association analysis identified five independent risk loci, whereas genome-wide gene-aggregation tests implicated mutations in the gene GBA . Genetic risk scores demonstrate that LBD shares risk profiles and pathways with Alzheimer’s and Parkinson’s disease, providing a deeper molecular understanding of the complex genetic architecture of this age-related neurodegenerative condition.
Influence of Biopsy Technique on Molecular Genetic Tumor Characterization in Non-Small Cell Lung Cancer—The Prospective, Randomized, Single-Blinded, Multicenter PROFILER Study Protocol
2020-07-06

The detection of molecular alterations is crucial for the individualized treatment of advanced non-small cell lung cancer (NSCLC). Missing targetable alterations may have a major impact on patient’s progression free and overall survival. Although laboratory testing for molecular alterations has continued to improve; little is known about how biopsy technique affects the detection rate of different mutations. In the retrospective study detection rate of epidermal growth factor (EGFR) mutations in tissue extracted by bronchoscopic cryobiopsy (CB was significantly higher compared to other standard biopsy techniques. This prospective, randomized, multicenter, single blinded study evaluates the accuracy of molecular genetic characterization of NSCLC for different cell sampling techniques. Key inclusion criteria are suspected lung cancer or the suspected relapse of known NSCLC that is bronchoscopically visible. Patients will be randomized, either to have a CB or a bronchoscopic forceps biopsy (FB). If indicated, a transbronchial needle aspiration (TBNA) of suspect lymph nodes will be performed. Blood liquid biopsy will be taken before tissue biopsy. The primary endpoint is the detection rate of molecular genetic alterations in NSCLC, using CB and FB. Secondary endpoints are differences in the combined detection of molecular genetic alterations between FB and CB, TBNA and liquid biopsy. This trial plans to recruit 540 patients, with 178 evaluable patients per study cohort. A histopathological and molecular genetic evaluation will be performed by the affiliated pathology departments of the national network for genomic medicine in lung cancer (nNGM), Germany. We will compare the diagnostic value of solid tumor tissue, lymph node cells and liquid biopsy for the molecular genetic characterization of NSCLC. This reflects a real world clinical setting, with potential direct impact on both treatment and survival.
An analytical solution for wind deficit decay behind a wind energy converter using momentum flux conservation validated by UAS data
2020-07-06

Abstract. The wind deficit behind a wind energy converter (WEC) results from a complex interaction of forces. Kinetic energy is removed from the atmosphere, but coherent turbulent structures prevent a swift compensation of momentum within the wake behind the WEC. A detailed description of the wake is beneficial in meso-scale weather forecast (e.g. WRF models) and numerical simulations of wind wake deficits. Especially in the near to intermediate wake (0.5–5 rotor diameter D), the dominating processes characterising the wake formation change along the wake. The conservation equation of momentum is used as a starting point to map the most important processes assuming the WEC operates at maximum efficiency in a neutral stratified boundary layer. The wake is divided into three different regions to accommodate the changing impact of atmospheric turbulence and the shear created by the WEC onto the wake. A differential equation that depicts the variable momentum transport into the wind deficit along the wake is derived and solved analytically. Additionally, a numerical solution (Euler method) of the simplified momentum conservation equation is shown to provide a quality control and error estimate to the analytical model. The analytical solution is compared to in-situ wake measurements behind an Enercon E-112 converter, located in the Jade Wind Park near the North Sea coast in Germany, captured by the MASC-3 UAS (unmanned aircraft system) of the University of Tübingen. The obtained UAS data cover the distance from 0.5–5 D at hub height behind the nacelle. The analytical and numerical model are found to be in good agreement with the data of the three measurement flights behind the WEC.
'We always support each other – no matter what': a qualitative analysis of work-related psychosocial demands, stressors and resources in general practice teams
2020-07-06

Abstract Background Work-related stress has been associated with poor psychological and physical outcomes. A better understanding of work-related psychosocial demands, risks and resources can therefore contribute to the prevention of work-related stress. Compared to the general population, medical staff have reported a higher prevalence of chronic stress. Using general practices as an example for small enterprises, this study aims to gain a deeper understanding of work-related psychosocial demands, stressors and resources in the primary care setting. Methods We applied an ethnographic design, comprising a combination of participating observations, individual interviews with physicians (N = 6) and focus group discussion with practice assistants and administrative staff (N = 19) in five general practices in Germany. Access to the practice teams was established via a university general practice network. A grounded theory approach was applied to analyze all data. Results Our results identified specific psychosocial demands, stressors and resources exemplified mainly along two typical tasks in GP practices: the issuing of medical prescriptions and blood sampling. Main psychosocial risks included factors related to work content and tasks (e.g. incompleteness of task), organization of work (e.g. frequent interruptions), and the working environment (e.g. noise). Work-related resources comprised staff’s influence on aspects related to work organization (e.g. scope for action) and social support (e.g. positively perceived teamwork). These factors did not occur in isolation but were closely interrelated with each other. Conclusion Although work processes in general practices are complex and required to comply with legal regulations, the specific organization of work processes is the responsibility of the general practitioner. Therefore, there are opportunities for practice owners and practice teams to establish working procedures in ways that reduce psychosocial risks and strengthen work-related resources.
Psychological burden of healthcare professionals in Germany during the acute phase of the COVID-19 pandemic: differences and similarities in the international context
2020-07-07

Abstract Background Healthcare professionals (HPs) are the key figures to keep up the healthcare system during the COVID-19 pandemic and thus are one of the most vulnerable groups in this. To this point, the extent of this psychological burden, especially in Europe and Germany, remains unclear. This is the first study investigating German HPs after the COVID-19 outbreak. Methods We performed an online-based cross-sectional study after the COVID-19 outbreak in Germany (10–31 March 2020). In total, 2224 HPs (physicians n = 492, nursing staff n = 1511, paramedics n = 221) and 10 639 non-healthcare professionals (nHPs) were assessed including generalized anxiety (Generalized Anxiety Disorder-7), depression (Patient Health Questionnaire-2), current health status (EQ-5D-3L), COVID-19-related fear, subjective level of information regarding COVID-19. Results HPs showed less generalized anxiety, depression and COVID-19-related fear and higher health status and subjective level of information regarding COVID-19 than the nHPs. Within the HP groups, nursing staff were the most psychologically burdened. Subjective levels of information regarding COVID-19 correlated negatively with generalized anxiety levels across all groups. Among HPs, nursing staff showed the highest and paramedics the lowest generalized anxiety levels. Conclusions In the context of COVID-19, German HPs seem to be less psychological burdened than nHPs, and also less burdened compared with existing international data.
C-Type Lectin Receptors in Host Defense Against Bacterial Pathogens
2020-07-07

Antigen-presenting cells (APCs) are present throughout the human body-in tissues, at barrier sites and in the circulation. They are critical for processing external signals to instruct both local and systemic responses toward immune tolerance or immune defense. APCs express an extensive repertoire of pattern-recognition receptors (PRRs) to detect and transduce these signals. C-type lectin receptors (CLRs) comprise a subfamily of PRRs dedicated to sensing glycans, including those expressed by commensal and pathogenic bacteria. This review summarizes recent findings on the recognition of and responses to bacteria by membrane-expressed CLRs on different APC subsets, which are discussed according to the primary site of infection. Many CLR-bacterial interactions promote bacterial clearance, whereas other interactions are exploited by bacteria to enhance their pathogenic potential. The discrimination between protective and virulence-enhancing interactions is essential to understand which interactions to target with new prophylactic or treatment strategies. CLRs are also densely concentrated at APC dendrites that sample the environment across intact barrier sites. This suggests an-as yet-underappreciated role for CLR-mediated recognition of microbiota-produced glycans in maintaining tolerance at barrier sites. In addition to providing a concise overview of identified CLR-bacteria interactions, we discuss the main challenges and potential solutions for the identification of new CLR-bacterial interactions, including those with commensal bacteria, and for in-depth structure-function studies on CLR-bacterial glycan interactions. Finally, we highlight the necessity for more relevant tissue-specific <i>in vitro, in vivo</i> and <i>ex vivo</i> models to develop therapeutic applications in this area.
Effect of Natural Organic Matter on the Fate of Cadmium During Microbial Ferrihydrite Reduction
2020-07-07

Natural organic matter (NOM) is known to affect the microbial reduction and transformation of ferrihydrite, but its implication toward cadmium (Cd) associated with ferrihydrite is not well-known. Here, we investigated how Cd is redistributed when ferrihydrite undergoes microbial reduction in the presence of NOM. Incubation with <i>Geobacter sulfurreducens</i> showed that both the rate and the extent of reduction of Cd-loaded ferrihydrite were enhanced by increasing concentrations of NOM (i.e., C/Fe ratio). Without NOM, only 3-4% of Fe(III) was reduced, but around 61% of preadsorbed Cd was released into solution due to ferrihydrite transformation to lepidocrocite. At high C/Fe ratio (1.6), more than 35% of Fe(III) was reduced, as NOM can facilitate bioreduction by working as an electron shuttle and decreased aggregate size, but only a negligible amount of Cd was released into solution, thus decreasing Cd toxicity and prolonging microbial Fe(III) reduction. No ferrihydrite transformation was observed at high C/Fe ratios using Mössbauer spectroscopy and X-ray diffraction, and X-ray absorption spectroscopy indicated the proportion of Cd-OM bond increased after microbial reduction. This study shows that the presence of NOM leads to less mobilization of Cd under reducing condition possibly by inhibiting ferrihydrite transformation and recapturing Cd through Cd-OM bond.