bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observations on the recovering lumbar spinal cord of lizards show multiple origins of the cells forming the bridge region including immune cells
Authors: Alibardi Lorenzo 
Published: November 2019

AbstractAfter transection the lumbar spinal cord of lizards forms a bridge of connective and nervous tissues between the severed proximal and distal ends of the cord. The types of proliferating cells activated in the injured spinal cord have been analyzed using light and ultrastructural immunolabeling for 5BrdU and nestin from 11 to 34 days after injury, when recovery of some hindlimb movements has occurred. At 11–22 days post‐transection an intense proliferation of glial, immune and meningeal cells takes place. Nestin is almost absent in the normal spinal cord but becomes detectable at 11–34 days postinjury in ependymal and sparse glial cells located in the bridge region. At 11–22 days postinjury also numerous macrophages, lymphocytes, and some plasma cells appear proliferating during the intense inflammatory and antimicrobial phase. Phagocytosis within the injured spinal cord probably decreases inflammation and may indirectly promote axonal regeneration. Proliferating cells likely derive from precursor or stem elements of the reactive ependymal epithelium, but also from glial cells and meningeal fibroblasts. This is indicated by the presence of 5BrdU‐long retaining labeling cells of glial and fibroblast types located in the stumps of the spinal cord and in the bridge. The present observations suggest that meningeal, ependymal, and numerous glial cells are the precursors of those forming the bridge region. Among glial cells, sparse oligodendrocytes myelinating the few axons present at 34 day after the injury also appear capable to proliferate. The myelinated axons are probably involved in the limited but important functional recovery of limb movements observed after 30–90 days postinjury.
Development of pancreatic acini in embryos of the grass snake Natrix natrix (Lepidosauria, Serpentes)
Authors: Kowalska Magdalena , Rupik Weronika 
Published: November 2019

AbstractThis study report about the differentiation of pancreatic acinar tissue in grass snake, Natrix natrix, embryos using light microscopy, transmission electron microscopy, and immuno‐gold labeling. Differentiation of acinar cells in the embryonic pancreas of the grass snake is similar to that of other amniotes. Pancreatic acini occurred for the first time at Stage VIII, which is the midpoint of embryonic development. Two pattern of acinar cell differentiation were observed. The first involved formation of zymogen granules followed by cell migration from ducts. In the second, one zymogen granule was formed at the end of acinar cell differentiation. During embryonic development in the pancreatic acini of N. natrix, five types of zymogen granules were established, which correlated with the degree of their maturation and condensation. Within differentiating acini of the studied species, three types of cells were present: acinar, centroacinar, and endocrine cells. The origin of acinar cells as well as centroacinar cells in the pancreas of the studied species was the pancreatic ducts, which is similar as in other vertebrates. In the differentiating pancreatic acini of N. natrix, intermediate cells were not present. It may be related to the lack of transdifferentiation activity of acinar cells in the studied species. Amylase activity of exocrine pancreas was detected only at the end of embryonic development, which may be related to animal feeding after hatching from external sources that are rich in carbohydrates and presence of digestive enzymes in the egg yolk. Mitotic division of acinar cells was the main mechanism of expansion of acinar tissue during pancreas differentiation in the grass snake embryos.
Left ventricular pacing in patients with preexisting tricuspid valve disease
Authors: Li Tony Y. W. , Seow Swee Chong , Singh Devinder , Yeo Wee Tiong , Kojodjojo Pipin , Lim Toon Wei 
Published: November 2019

AbstractBackgroundConventional right ventricular (RV) pacing is increasingly recognised to cause tricuspid valve (TV) injury or dysfunction, in part due to the need to pass the lead through the valve. This may be especially problematic in patients with preexisting TV disease or prior TV surgery. An alternative in this situation is to implant a left ventricular (LV) lead instead of ventricular pacing.MethodsWe performed a single‐center retrospective analysis of 26 patients with tricuspid valve surgery/disease who received a LV pacing lead in the coronary veins to avoid crossing the tricuspid valve, with or without a right atrial lead. A matched control population was obtained from patients receiving conventional right ventricular pacing and outcomes were compared. Main outcomes of interest were lead stability, electrical lead parameters and change in echocardiographic parameters such as left ventricular ejection fraction (LVEF) during long‐term follow‐up.ResultsSuccessful left ventricular pacing was established in 25 out of the 26 cases with one case converted to a RV lead due to lead dislodgement. During the 2.96 ± 1.0 year follow‐up, 24 of 25 (96.0%) leads were functional with stable pacing and sensing parameters, and 1 of 25 (4.0%) was extracted for due to device infection following an episode of thrombophlebitis.ConclusionWe conclude that in patients with existing tricuspid valve disease or surgery, ventricular pacing via the coronary veins is a feasible, safe, and reliable alternative to right ventricular pacing.
Performance of CMIP5 wind speed from global climate models for the Bay of Bengal region
Authors: Krishnan Athira , Bhaskaran Prasad K. 
Published: November 2019

AbstractRealistic estimates of surface wind speed (WS) are an essential prerequisite for process‐based air–sea interaction studies and numerical modelling needs. In this context, historical and projected WS estimates obtained from global and regional climate models warrant proper assessment and necessary bias corrections before it can be optimally used for rigorous analysis and research needs. Adequate evaluation and bias correction of WS estimates are therefore crucial to understand the extremes. For example, they have direct implications on extreme wind‐wave characteristics that can influence the coastal zones. The present study performed a detailed evaluation of WS obtained from the Coupled Model Intercomparison Project Fifth Phase (CMIP5) products to assess their projections for the Bay of Bengal region. A suite of global climate models (GCMs) is employed to generate the CMIP5 projections under four Representative Concentrative Pathways (RCPs) of 2.6, 4.5, 6.0, and 8.5 and based on differential CO2 emission scenarios. The present study also used the Research Moored Array for African–Asian–Australian Monsoon Analysis and Prediction (RAMA) buoys located in the central Bay of Bengal in order to validate and skill assess the CMIP5 wind products under varying RCPs. Besides, an intercomparison exercise that was performed between RAMA buoys data and merged satellite altimeter data from the French Research Institute for Exploitation of the Sea/Laboratory of Oceanography from Space (IFREMER/CERSAT) provided the necessary confidence to ascertain the quality of CMIP5 WS products. The study signifies that a moderate positive correlation was noticed in the WS comparison between CMIP5 GCM products and the RAMA buoys (maximum correlation of .64), and the correlation factor varied between the suite of models used in CMIP5 experiments. This exercise would provide detailed know‐how on the performance of various GCMs and also provide a basis to select the best performing GCMs for the Bay of Bengal region. Analysis of the upper 10% (90th percentile) showed a maximum underestimation/overestimation of 2.5 and 1.5 m·s−1, respectively, for WS comparison between CMIP5 and RAMA buoys data. Probability density of WS data fitted to Weibull distribution showed an increase of moderate WS (6–8 m·s−1) during the period of study. Although the CMIP5 GCMs are not able to represent the contemporary WS climatology satisfactorily, the models such as HadGEM2‐ES, HadGEM2‐CC, CanESM2, and ACCESS‐1.3 showed the best performance concerning near‐surface WS for the Bay of Bengal region.
Direct and indirect luminescence dating of tephra: A review
Authors: Bösken Janina Johanna , Schmidt Christoph 
Published: November 2019

ABSTRACTIn Quaternary studies, tephras are widely used as marker horizons to correlate geological deposits. Therefore, accurate and precise dating is crucial. Among radiometric dating techniques, luminescence dating has the potential to date tephra directly using glass shards, volcanic minerals that formed during the eruption or mineral fragments that originate from the shattered country rock. Moreover, sediments that frame the tephra can be dated to attain an indirect age bracket. A review of numerous luminescence dating studies highlights the method's potential and challenges. While reliable direct dating of volcanic quartz and feldspar as a component in tephra is still methodically difficult mainly due to thermal and athermal signal instability, red thermoluminescence of volcanic quartz and the far‐red emission of volcanic feldspar have been used successfully. Furthermore, the dating of xenolithic quartz within tephra shows great potential. Numerous studies date tephra successfully indirectly. Dating surrounding sediments is generally straightforward as long as samples are not taken too close to the tephra horizons. Here, issues arise from the occurrence of glass shards within the sediments or unreliable determination of dose rates. This includes relocation of radioelements, mixing of tephra into the sediment and disregarding different dose rates of adjacent material.
Validity testing of a three‐dimensionally printed endoscopic sinonasal surgery simulator
Authors: Alwani Mohamedkazim M. , Svenstrup Thomas J. , Bandali Elhaam H. , Sharma Dhruv , Higgins Thomas S. , Wu Arthur W. , Shipchandler Taha Z. , Illing Elisa A. , Ting Jonathan Y. 
Published: November 2019

Objectives/HypothesisTo assess the face, content, construct, and concurrent validity of the PHACON Sinonasal Surgery Simulator (SNSS).Study DesignProspective cohort study.MethodsA total of 12 otolaryngology residents were recruited to perform sinonasal surgery on the simulator followed by cadaveric heads. Resident performances were recorded and de‐identified. Face and content validities were evaluated based on 5‐point Likert scale questionnaires. The recordings were evaluated by extramural expert rhinologists based on a validated Global Rating Scale (GRS). These results were analyzed and compared to assess construct and concurrent validity.ResultsThe appearance of anatomic structures was rated as realistic by 75% of all participants, while only 30% and 41.7% rated the mucosal and bony tissues as realistic, respectively. A total of 91.7% of participants found the model useful for teaching anatomy, while 66.7% said it was useful for teaching operative technique. Construct validity was confirmed by showing significant differences in performance between the novice and experienced groups. Concurrent validity was confirmed by showing significant correlation between performance on the model and gold standard (i.e. cadaver head).ConclusionsThis study demonstrates the face, content, concurrent, and construct validity of a 3D‐printed SNSS. Although this model has the potential to be a valuable tool in endoscopic sinus surgery training for otolaryngology residents, improvements are required with respect to the quality of simulated mucosal tissue as well as the simulated anatomy of the fronto‐ethmoid compartmentLevel of Evidence: NALaryngoscope, 2019
Impact of primary tumor‐specific growth rate on treatment failure for nonoropharyngeal head and neck cancers
Authors: Roldan Claudia S. , Chen Jie Jane , Fareed M. Mohsin , Hameed M. Yahya , Churilla Thomas M. , Lango Miriam N. , Galloway Thomas J. 
Published: November 2019

ObjectivesTo investigate the prognostic impact of primary tumor‐specific growth rate (TSGR) on treatment outcomes after definitive radiation therapy (RT) for nonoropharyngeal squamous cell carcinoma (non‐OPSCC).MethodsThe diagnostic tumor and nodal volumes of 39 non‐OPSCC patients were contoured and compared to corresponding RT planning scan volumes to determine TSGR. Overall survival (OS), disease‐free survival (DFS), and local recurrence‐free survival were evaluated according to the Kaplan‐Meier method; and hazard ratios (HR) were estimated using Cox regression. Based on the 75th percentile TSGR of 2.18%, we stratified patients into a high TSGR group (≥ 2.18% per day) and low TSGR group (< 2.18% per day).ResultsThe median follow‐up was 22 months (range: 1–86 months) and median time between diagnostic and simulation computed tomography scans was 22 days (range: 7–170 days). Median RT dose was 70 Gy (range: 60–79.2 Gy). Based on the 75th percentile TSGR, OS at median follow‐up was 50.0% for the high TSGR group compared to 92.5% for the low TSGR group (HR [95% confidence interval (CI)] = 2.12[1.16–11.42], P = 0.018). There was a trend toward worse DFS at median follow‐up for the high versus low TSGR groups, at 55.6% and 82.3%, respectively (HR [95% CI] = 2.29[0.82–6.38], P = 0.103).ConclusionOur study contributes to growing literature on TSGR as a temporal biomarker in patients with non‐OPSCC. Patients with high TSGR ≥2.18% per day have significantly worse OS compared to those with TSGR below this threshold. Efforts to address treatment initiation delays may benefit patients with particularly aggressive and rapidly growing tumors.Level of Evidence4 Laryngoscope, 130:2378–2384, 2020
Biotic formation of methylmercury: A bio–physico–chemical conundrum
Authors: Bravo Andrea G. , Cosio Claudia 
Published: November 2019

AbstractMercury (Hg) is a natural and widespread trace metal, but is considered a priority pollutant, particularly its organic form methylmercury (MMHg), because of human's exposure to MMHg through fish consumption. Pioneering studies showed the methylation of divalent Hg (HgII) to MMHg to occur under oxygen‐limited conditions and to depend on the activity of anaerobic microorganisms. Recent studies identified the hgcAB gene cluster in microorganisms with the capacity to methylate HgII and unveiled a much wider range of species and environmental conditions producing MMHg than previously expected. Here, we review the recent knowledge and approaches used to understand HgII‐methylation, microbial biodiversity and activity involved in these processes, and we highlight the current limits for predicting MMHg concentrations in the environment. The available data unveil the fact that HgII methylation is a bio‐physico‐chemical conundrum in which the efficiency of biological HgII methylation appears to depend chiefly on HgII and nutrients availability, the abundance of electron acceptors such as sulfate or iron, the abundance and composition of organic matter as well as the activity and structure of the microbial community. An increased knowledge of the relationship between microbial community composition, physico‐chemical conditions, MMHg production, and demethylation is necessary to predict variability in MMHg concentrations across environments.
Microbial community composition and functional potential in Bothnian Sea sediments is linked to Fe and S dynamics and the quality of organic matter
Authors: Rasigraf Olivia , van Helmond Niels A. G. M. , Frank Jeroen , Lenstra Wytze K. , Egger Matthias , Slomp Caroline P. , Jetten Mike S. M. 
Published: November 2019

AbstractThe Bothnian Sea is an oligotrophic brackish basin characterized by low salinity and high concentrations of reactive iron, methane, and ammonium in its sediments, enabling the activity and interactions of many microbial guilds. Here, we studied the microbial network in these sediments by analyzing geochemical and microbial community depth profiles at one offshore and two near coastal sites. Analysis of 16S rRNA gene amplicons revealed a distinct depth stratification of both archaeal and bacterial taxa. The microbial communities at the two near coastal sites were more similar to each other than the offshore site, which is likely due to differences in the quality and rate of organic matter degradation. The abundance of methanotrophic archaea of the ANME‐2a clade was shown to be related to the presence of methane and varied with sediment iron content. Metagenomic sequencing of sediment‐derived DNA from below the sulfate–methane transition zone revealed a broad potential for respiratory sulfur metabolism via partially reduced sulfur species. The potential for nitrogen cycling was dominated by reductive processes via a truncated denitrification pathway encoded exclusively by bacterial lineages. Gene‐centric fermentative metabolism analysis indicated a potential importance for acetate, formate, alcohol, and hydrogen metabolism. Methanogenic/‐trophic pathways were dominated by Methanosaetaceae, Methanosarcinaceae, Methanomassiliicoccaceae, Methanoregulaceae, and ANME‐2 archaea. Our results indicated flexible metabolic capabilities of core microbial community taxa, which could adapt to changing redox conditions, and with a spatial and depth distribution that is likely governed by the quality and input of available organic substrates and, for ANME‐2, of iron oxides.
Corneal Damage Effects Induced by a 770–2,500 nm Supercontinuum Light Source
Authors: Jiao Luguang , Fan Yan , Wang Jiarui , Yang Zaifu 
Published: November 2019

Background and ObjectivesWidespread applications of supercontinuum (SC) source lead to the possibility of ocular damages. However, the corneal damage effects induced by SC have not been explored before. The objectives of this study are to determine the rabbit corneal injury threshold for SC radiation and to examine whether the existing safety guidelines and standards are suitable for the hazard evaluation of this new kind of light source.Study Design/Materials and MethodsA series of experiments was conducted in the New Zealand white rabbit model to determine the corneal damage thresholds induced by a 770–2,500 nm SC source, with a corneal 1/e beam diameter of 0.37 mm. Through slit‐lamp biomicroscope, optical coherence tomography (OCT), and histopathology the corneal damage characteristics at the threshold level were revealed. By employing the action spectra determined through the analysis of safety guidelines and standards, the damage thresholds for SC source could be compared with the corresponding exposure limits.ResultsThe determined damage thresholds given in terms of the peak radiant exposure for exposure durations of 2.0 and 10.0 seconds were 2.1 × 103 and 7.4 × 103 J/cm2, respectively. At threshold level, corneal damages involved the epithelium and the shallower stroma, and no obvious changes could be found in the deep stroma, Descemet's membrane, and endothelium.ConclusionsThe exposure limits for the anterior parts of the eye in the wavelength range of 700–1,200 nm are overly conservative. The obtained results contribute to the knowledge base for the hazard evaluation of SC source. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.
Innovative 1064‐nm Nd:YAG Laser Significantly Improves Keratosis Pilaris, A Randomized, Double‐Blind, Sham‐Irradiation‐Controlled Trial
Authors: Maitriwong Praewvanid , Tangkijngamvong Natsinee , Asawanonda Pravit 
Published: November 2019

Background and ObjectiveKeratosis pilaris (KP) is a common follicular disorder for which various topical agents and energy‐based devices have been used with some efficacy. To evaluate the efficacy of a novel 1064‐nm Nd:YAG laser for the reduction of skin roughness, erythema, and hyperpigmentation in KP subjects.Study Design/Materials and MethodsTwenty‐three subjects with untreated KP on the upper outer arms participated in a randomized, single‐blind fashion. One arm of each subject was divided into upper and lower parts. One part was randomized to be treated with an innovative 1064‐nm Nd:YAG laser, while the other part received sham irradiation. Subjects received four consecutive treatments at 4‐week intervals. Antera3D was used to measure skin roughness, erythema, and hyperpigmentation at baseline and 4 weeks after the last treatment. Moreover, clinical outcomes were also evaluated by subjects' Global Improvement Score (GIS) and subjects' satisfaction grading scores.ResultsTwenty‐three subjects completed the study. There was statistically significant reduction of skin roughness measured by Antera3D compared with control group (P < 0.001). There were statistically significant improvements of skin roughness, erythema, hyperpigmentation, and overall appearances graded by subjects' Global Improvement Score (P < 0.001 all). Subjects' satisfaction scores were graded significantly better in treatment parts (P < 0.001). No adverse events including burning, bulla, erosion, post‐inflammatory hyper/hypopigmentation, and scar formation developed in any subjects throughout the study period.ConclusionThis innovative 1064‐nm Nd:YAG laser has proved to significantly and safely reduce skin roughness in Thai KP subjects compared with control after four sessions. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.
Liver Transplantation in Children With Propionic Acidemia: Medium‐Term Outcomes
Authors: Curnock Richard , Heaton Nigel D. , Vilca‐Melendez Hector , Dhawan Anil , Hadzic Nedim , Vara Roshni 
Published: November 2019

Liver transplantation (LT) for patients with propionic acidemia (PA) is an emerging therapeutic option. We present a retrospective review of patients with PA who underwent LT at a tertiary liver center between 1995 and 2015. A total of 14 children were identified (8 males) with median age at initial presentation of 3 days (range, 0‐77 days). Pretransplant median protein restriction was 1 g/kg/day (range, 0.63‐1.75 g/kg/day), 71% required supportive feeding, and 86% had developmental delay. Frequent metabolic decompensations (MDs) were the main indication for LT with a median age at transplantation of 2.4 years (range, 0.8‐7.1 years). Only 1 graft was from a living donor, and 13 were from deceased donors (4 auxiliary). The 2‐year patient survival was 86%, and overall study and graft survival was 79% and 69%, respectively. Three patients died after LT: at 43 days (biliary peritonitis), 225 days (acute‐on‐chronic rejection with multiorgan failure), and 13.5 years (posttransplant lymphoproliferative disease). Plasma glycine and propionylcarnitine remained elevated but reduced after transplant. Of 11 survivors, 5 had at least 1 episode of acute cellular rejection, 2 sustained a metabolic stroke (with full recovery), and 3 developed mild cardiomyopathy after LT. All have liberalized protein intake, and 9 had no further MDs: median episodes before transplant, 4 (range, 1‐30); and median episodes after transplant, 0 (range, 0‐5). All survivors made some developmental progress after LT, and none worsened at a median follow‐up of 5.8 years (range, 2‐23 years). LT in PA significantly reduces the frequency of MDs, can liberalize protein intake and improve quality of life, and should continue to be considered in selected cases.