bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stereoselective synthesis and characterization of monocyclic cis‐β‐lactams containing 5‐methyl‐1,3,4‐thiadiazole‐2‐thiol moiety
Authors: Singh Vedeshwar N. , Sharma Sitaram 
Published: July 2021

AbstractThis article describes the stereoselective synthesis of monocyclic cis‐β‐lactams. The 2‐(4‐chlorophenoxy)‐acetic acid or 2‐phenoxy‐acetic acid with a carboxylic acid activator 2‐ethoxy carbonyl DCPN generate ketene in situ, which reacts with imines derived from substituted tetralone carbaldehyde yielded monocyclic cis‐β‐lactams having 5‐methyl‐1,3,4‐thiadiazole‐2‐thiol moiety through [2+2] cyclo‐addition reaction (Staudinger reaction). All structures of cis‐β‐lactams were elucidated by a spectral technique like FT‐IR, 1H and 13C NMR spectra, HRMS, and single X‐ray crystallography. The cis configuration of the β‐lactams was determined based on coupling constant (J) value using 1H NMR for hydrogens H‐3 and H‐4 of the β‐lactams ring. This work presents the synthesis of β‐lactams more simply with high yields. The products were simply purified by crystallization technique.
Computed tomography validated right ventricular mid‐septal lead implantation using right ventricular angiography
Authors: Shenthar Jayaprakash , Rai Maneesh K. , Chakali Siva S. , Pillai Vivek , Delhaas Tammo 
Published: July 2021

AbstractBackgroundRight ventricular (RV) mid‐septal pacing has been proposed as an alternative to RV apical pacing. Fluoroscopic and electrocardiogram criteria are unreliable for predicting the RV mid‐septal lead position. This study aimed to define the optimal RV mid‐septal pacing site using RV angiography.MethodsWe randomized patients undergoing pacemaker implantation (PPM) to the RV angiography‐guided group (Group A) or conventional fluoroscopy‐guided group (Group F). In Group A, we performed an angiogram in right anterior oblique (RAO 30°), left anterior oblique (LAO 40°), and left lateral (LL) views. We made a 5‐segment grid in RAO 30° and LL views and a 3‐segment grid in LAO 40° on the angiographic silhouette to define the lead position. Computed tomography (CT) was used to validate the lead tip position in both groups.ResultsWe enrolled 53 patients (Group A: 26, Group F: 27) with a mean age of 55.9 ± 12.2 years. CT images validated the lead position in the mid‐septum (Group A, 23 [88.5%]; Group F, 11 [40.7%], P = .0003) and anteroseptal (Group A, 3 [11.5%]; Group F, 5 [18.5%], P = .24). In Group F, the lead was in the anterior wall in 9 patients (33.3%) and the right ventricular outflow tract in 2 (7.4%) patients and none in these two positions in Group A. The lead tip in segment one on the angiographic 5‐segment grid in RAO 30° and LL views indicated a mid‐septal lead position on CT.ConclusionsRV angiography is safe and may be used to confirm the mid‐septal lead position during PPM.
Catheter inversion during cavotricuspid isthmus catheter ablation: The new shaft visualization catheter reduces fluoroscopy use
Authors: Santoro Amato , Baiocchi Claudia , Sisti Nicolò , Zacà Valerio , Pondrelli Carlo Renato , Falciani Francesca , Lamberti Filippo 
Published: July 2021

AbstractAimsCatheter ablation (CA) is the choice therapy of cavotricuspid isthmus (CTI) atrial flutter. The aim of this study was to describe our approach to improve the CTI ablation using a zero‐fluoroscopy (ZF). The procedural difficulties could be related to anatomical characteristics of the CTI.MethodsOne hundred eighty‐eight patients that performed CA of CTI were retrospectively and consecutively evaluated between 2017 and 2019. The studied population was divided into two groups. Eighty‐eight patients who were undergone CA using ablation catheter without shaft visualization catheter (NSV) were Group 1. One hundred patients were undergone CA using ablation catheter with a shaft visualization (SV); they were Group 2. The catheter was looped at the Eustachian ridge after 200 seconds of radiofrequencies (RF) without elimination of local electrogram.ResultsA conduction line block of CTI was obtained in all patients of Group 2 using a ZF approach. In 16 patients of Group 1, the catheter inversion was obtained using fluoroscopy to avoid damages during its loop. In Group 2, a complete CTI block was obtained with a catheter inversion approach in ten patients without fluoroscopy, visualizing the shaft and the tip of the ablation catheter on the electroanatomic (EAM) map. In the overall population studied the use of SV had a linear correlation with the ZF approach (r = .629; P < .001). The duration of RF was lower in Group 2 than in Group 1 (Group 1: 27.8 ± 6.3 vs Group 2: 15.6 ± 7.2 minutes; P < .01). The procedure time between two groups was lower in Group 2 than in Group 1 (Group 1: 58.4 ± 22.4 vs Group 2: 42.2 ± 15.7 minutes; P < .01). No differences between two groups were documented regarding success and complications.ConclusionsThe visualization of the shaft's catheter on the EAM permitted the catheter inversion safely in order to overcome some complex CTI anatomy and obtain bidirectional block. The SV reduced procedure time, RF applications and fluoroscopy exposition during CTI ablation.
An evaluation of CMIP5 and CMIP6 climate models in simulating summer rainfall in the Southeast Asian monsoon domain
Authors: Khadka Dibesh , Babel Mukand S. , Abatan Abayomi A. , Collins Matthew 
Published: July 2021

AbstractIn this study, 28 climate models from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) and 32 models from the sixth phase (CMIP6) have been evaluated for their ability to simulate large‐scale atmospheric circulations (using rainfall, wind fields, geopotential height, temperature, and moisture flux convergence) for the summer monsoon in Southeast Asia. Using a multi‐criteria decision making technique, models have been ranked based on 25 metrics which compare their performances with observation data. Results indicate a better representation of annual rainfall cycles as well as spatial pattern by CMIP6 models compared to CMIP5. Though majority of the models from both CMIPs show late onset and early retreat of the rainy season, CMIP6 GCMs simulate the onset, retreat, and the length of the rainy season closer to the observation. Large‐scale circulation patterns evaluated using spatial correlation and root mean square error (RMSE) show improvements in CMIP6 across all metrics, especially for the moisture flux convergence. Performances for large‐scale circulation are generally reflected in rainfall simulation; however, few models showed that better simulations of rainfall do not exclusively depend on their performance for large‐scale variables. Overall, CMIP6 models are found to be superior to CMIP5 models in simulating rainfall and large‐scale circulation, which is likely attributable to CMIP6 model's higher spatial resolutions, increased number of vertical levels, improved atmospheric and land surface parameterization, etc. Finally, subsets of optimal models from CMIP5 and CMIP6 that proved to be better at representing the summer monsoons in the study area are identified. These models are recommended to develop robust future projections that can be used for climate change impact and adaptation studies.
Future projections of precipitation, surface temperatures and drought events over the monsoon transitional zone in China from bias‐corrected CMIP6 models
Authors: Piao Jinling , Chen Wen , Wang Lin , Chen Shangfeng 
Published: July 2021

AbstractBias‐corrected monthly precipitation and surface temperature datasets are constructed for the monsoon transitional zone (MTZ) in China during 1965–2100 based on 21 coupled climate models from phase 6 of the Coupled Model Intercomparison Project (CMIP6) using the equi‐ratio and equidistant cumulative distribution function quantile‐based mapping methods (equi‐ratio cumulative distribution function [ERCDF] and equidistant cumulative distribution function [EDCDF]), respectively. The efficiencies of the two methods are verified via cross‐validation by the jack‐knife method, and the biases are remarkably reduced compared to those of the raw model outputs. Then, the bias‐corrected model outputs are applied to future projections of precipitation, surface temperatures and drought events under the medium (SSP2‐4.5) and high (SSP5‐8.5) shared socioeconomic pathway scenarios. The obtained results present pronounced increases in both the projected annual mean precipitation and temperature fields for the model ensemble mean. In accompany, the MTZ is predicted to become drier in the three future periods; this result was attributed to the dramatic increases in semiarid events and to the decreases in humid events. The drought tension showed more rapid development under SSP585 than under the other scenario, with comparable occurrence frequencies of relatively wet and dry events in the long‐term period, posing a serious threat to regional sustainable development.
A novel intramedullary nail to control interfragmentary motion in diaphyseal tibial fractures
Authors: Ziran Navid , McCarty Colin P. , Ho Nathan C. , Gilmartin Neda F. , Ebramzadeh Edward , Park Sang‐Hyun , Sangiorgio Sophia N. 
Published: July 2021

AbstractNumerous animal and human studies have demonstrated the benefit of controlled interfragmentary motion on fracture healing. In this study, we quantified interfragmentary motion and load transfer in tibial fractures fixed using a novel intramedullary nail (IMN) that allows controlled axial motion. Fifty composite tibias with various fracture patterns were utilized. For all test conditions, two interlocking screws were used to fix the nail in the proximal metaphysis, and two interlocking screws through the distal metaphysis. The nail allowed either no motion (static mode) or 1 mm (dynamic mode) of cyclic axial motion between the two fracture fragments for every fracture pattern tested. As expected, strain shielding was more prominent under static nail conditions. In contrast, specimens tested under dynamic nail conditions transferred axial load between the fracture fragments such that strains near the fracture site were generally similar to those measured on an intact tibia. Maximum shear strains proximal to the fracture were significantly lower in specimens with oblique or butterfly fracture patterns (p < 0.01) compared to intact specimens. This decrease in shear strain indicates that strain shielding effects were likely present due to the implant. However, strain shielding appeared to be reduced in tensile and compressive principal strains. In summary, the novel IMN allowed controlled axial motion between the fragments in a variety of common diaphyseal tibial fracture patterns. Clinical Significance: The present in vitro biomechanical study investigated a novel intramedullary nail capable of controlled axial interfragmentary motion which may potentially enhance fracture healing.
Prognostic factors for survival in advanced thymomas: The role of the number of involved structures
Authors: Chiappetta Marco , Aprile Vittorio , Lococo Filippo , Zanfrini Edoardo , Nachira Dania , Meacci Elisa , Korasidis Stylianos , Ambrogi Marcello , Lucchi Marco , Margaritora Stefano 
Published: July 2021

AbstractBackground and ObjectivesThe Masoka‐Koga and tumor node metastases staging systems for thymoma are based on structures involved, but the prognostic role of the number of infiltrated/involved structures is still debated. We analyzed the prognostic role of involved structures and their combinations in locally advanced thymomas patients.MethodsData on 174 surgically treated locally advanced thymoma patients from 1/01/1990 to 31/12/2015 were reviewed. Clinical and pathological characteristic, involved structures, number of involved structures and different combinations were correlated to cancer specific survival (CSS) using Kaplan–Meier product‐limit method.ResultsFive and 10‐year CSS was 92% and 87%. Masaoka Stage 3 (p < 0.001), absence of pericardial involvement (p = 0.001), number of involved structures (p = 0.018), R0 (p < 0.001) and adjuvant radiotherapy (p = 0.008) were favorable prognostic CSS factors. A significant better prognosis was present in ≤2 involved structures vs >2 involved structures (5‐ and 10‐year CSS: 95% and 93% vs. 80% and 51%). Multivariable analysis confirmed as independent prognostic factor R0 (p = 0.033, hazard ratio [HR]: 0.093, 95% confidence interval [CI] 0.010–0.827) and number of involved structures (p = 0.046, HR: 0.187, 95% CI: 0.036–0.968). In Masaoka Stage 3, patients with ≤2 involved structures had a significant better CSS than patients with >2 (10‐year CSS: 98% vs. 73%, p = 0.008).ConclusionsThe number of involved structures and the concomitant involvement of the pericardium seems to be associated with a poor prognosis in surgically treated advanced thymoma patients.
Electrochemical behavior of AISI 302 austenitic stainless steel in coal chemical high‐salt wastewater
Authors: Yang Guangming , Wang Weibing , Ren Yongsheng , Ma Yulong 
Published: July 2021

AbstractIn this study, the effect of grain size and grain boundary characteristic distribution on the corrosion resistance of AISI 302 austenitic stainless steel in simulated coal chemical high‐salt wastewater was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization measurements. The grain size of the heat‐treated sample is significantly increased and contains a greater fraction of high‐angle grain boundaries (HAGBs) and twin content. As the heat treatment temperature and time increase, the passivation current density increases, which makes the passive film more susceptible to attack. The coarse‐grained microstructure has exhibited worse pitting resistance due to its higher fraction of the HAGBs.
Corrosion behavior of carbon steel coated with a zinc‐rich paint containing metallic compounds under wet and dry cyclic conditions
Authors: Takahashi Masamitsu , Deguchi Hiroshi , Hayashi Yasunori , Kimura Akihiko , Hanaki Koushu , Tsuchiya Hiroaki , Yamashita Masato , Fujimoto Shinji 
Published: July 2021

AbstractThe corrosion behavior of carbon steel coated with a zinc‐rich paint containing two metallic compounds, Al2(SO4)3 and CaO, as anticorrosive additives was examined under wet and dry cyclic corrosion test conditions. The zinc‐rich paint coating without the two metallic compounds formed a white corrosion product and red iron rust on the surface after the corrosion test, whereas the coating with the metallic compounds showed reduced surface corrosion products. The corrosion current density of the painted steel substrate decreased drastically due to the incorporation of metallic compounds in the paint. The zinc‐rich paint coating modified with the metallic compounds contained dispersed simonkolleite (Zn5(OH)8Cl2·H2O) phase and possibly very fine CaSO4 particles, which remarkably improved the protectiveness of the zinc‐rich paint coating.
Correlation between microstructure and corrosion behavior in an AISI 316L steel pipeline exposed for 100,700 h at 640°C in a petrochemical plant
Authors: Calderón‐Hernández José W. , Alves  Sandro F. , de Moraes Flavio P. , de Melo Hercílio G. , Padilha Angelo F. 
Published: July 2021

AbstractThe microstructure and electrochemical properties of 316L stainless steel were investigated after two conditions: aged at 640°C for 100,700 h and solution annealed at 1050°C for 2 h. While the aged samples were obtained from a pipe of a petrochemical reactor plant that was in service, the solution annealing was carried out in a conventional laboratory furnace. After aging, the precipitates present in decreasing order of quantity were sigma, Laves phase, and M23C6. After solution annealing, the microstructure was full austenitic. These results were in agreement with equilibria phase simulation with Thermo‐Calc software. Intergranular corrosion susceptibility, evaluated by means of the single loop electrochemical potentiokinetic reactivation technique and Practice A of ASTM 262, indicated a preponderant role for the sigma precipitate. The pitting potential (Epit) was evaluated through potentiodynamic polarization curves in 0.6 M NaCl and electrochemical impedance spectroscopy was performed at the corrosion potential to complement the information about the corrosion resistance.
Movement Disorders Associated with Hypogonadism
Authors: Gonzalez‐Latapi Paulina , Sousa Mario , Lang Anthony E. 
Published: July 2021

ABSTRACTA variety of movement disorders can be associated with hypogonadism. Identification of this association may aid in guiding workup and reaching an accurate diagnosis. We conducted a comprehensive and structured search to identify the most common movement disorders associated with hypogonadism. Only Case Reports and Case Series articles were included. Ataxia was the most common movement disorder associated with hypogonadism, including entities such as Gordon‐Holmes syndrome, Boucher‐Neuhäuser, Marinesco‐Sjögren and Perrault syndrome. Tremor was also commonly described, particularly with aneuploidies such as Klinefelter syndrome and Jacob's syndrome. Other rare conditions including mitochondrial disorders and Woodhouse‐Sakati syndrome are associated with dystonia and parkinsonism and either hypo or hypergonadotropic hypogonadism. We also highlight those entities where a combination of movement disorders is present. Hypogonadism may be more commonly associated with movement disorders than previously appreciated. It is important for the clinician to be aware of this association, as well as accompanying symptoms in order to reach a precise diagnosis.
Multi‐source observations and high‐resolution numerical model applied on the analysis of a severe convective weather affecting the airport
Authors: Wan Ziwei , Liu Xinhua , Xu Chenlu 
Published: July 2021

AbstractIn order to explore the application of multi‐source data from different observational systems (including meteorological stations, radar, and airport observational reports) and high‐resolution numerical model results in the analysis of severe convective weather affecting airports, a local severe convective weather event that affected Beijing Capital International Airport (ZBAA) on 26 June 2018 was studied in this work. Although there was no significant triggering of synoptic systems, the process produced a violent thunderstorm with strong wind gusts, poor prevailing visibility, and hail in just a 30‐min period, resulting in severe impacts on the airport operations. In addition to the routine analysis of weather using observations from meteorological stations and radar, high spatial and temporal resolution data from instruments at the airport were used to reveal the fine‐scale characteristics of the development and evolution of various associated meteorological parameters, which demonstrably served as a useful auxiliary dataset for the analysis of this event. Furthermore, the reliability of the high‐resolution numerical (Weather Research and Forecasting) model simulation was evaluated by using these 1‐min‐scale airport observations. Based on what was judged to be a reliable simulation of the meteorological variables by the model, the trigger and strengthening mechanisms of the storm formed in this region of complex topography, as well as the interaction with another cell, were explored. The model results suggested that convections were initially triggered by the interaction of southerly flow from the plain and northwesterly flow from the mountains, in conjunction with the effect of orographic uplift. The outflow of the cold pool from the former cell prevented the later cell (affecting ZBAA) from moving east. Due to the strong vertical wind shear in the lower levels, the echo tilted to a certain extent and formed an inner secondary circulation, contributing to the maintenance and strengthening for the storm.
ODE‐based double‐preconditioning for solving linear systems Aαx=b and f(A)x=b
Authors: Antoine Xavier , Lorin Emmanuel 
Published: July 2021

AbstractThis article is devoted to the computation of the solution to fractional linear algebraic systems using a differential‐based strategy to evaluate matrix–vector products , with . More specifically, we propose ODE‐based preconditioners for efficiently solving fractional linear systems in combination with traditional sparse linear system preconditioners. Different types of preconditioners are derived (Jacobi, incomplete LU, Padé) and numerically compared. The extension to systems is finally considered.
Synthesis and Characterization of Ligand‐Linked Pt Nanoparticles: Tunable, Three‐Dimensional, Porous Networks for Catalytic Hydrogen Sensing
Authors: Loof Daniel , Thüringer Oliver , Schowalter Marco , Mahr Christoph , Pranti Anmona Shabnam , Lang Walter , Rosenauer Andreas , Zielasek Volkmar , Kunz Sebastian , Bäumer Marcus 
Published: July 2021

AbstractPorous networks of Pt nanoparticles interlinked by bifunctional organic ligands have shown high potential as catalysts in micro‐machined hydrogen gas sensors. By varying the ligand among p‐phenylenediamine, benzidine, 4,4‘‘‐diamino‐p‐terphenyl, 1,5‐diaminonaphthalene, and trans‐1,4‐diaminocyclohexane, new variants of such networks were synthesized. Inter‐particle distances within the networks, determined via transmission electron microscopy tomography, varied from 0.8 to 1.4 nm in accordance with the nominal length of the respective ligand. While stable structures with intact and coordinatively bonded diamines were formed with all ligands, aromatic diamines showed superior thermal stability. The networks exhibited mesoporous structures depending on ligand and synthesis strategy and performed well as catalysts in hydrogen gas microsensors. They demonstrate the possibility of deliberately tuning micro‐ and mesoporosity and thereby transport properties and steric demands by choice of the right ligand also for other applications in heterogeneous catalysis.
Fabrication of the amphiphilic hyperbranched poly(ether amine)@graphene (hPEA‐AN@G) hybrid assemblies by ball milling
Authors: Li Jin , Ma Xiaodong , Su Zhilong , Yin Jie , Jiang Xuesong 
Published: July 2021

AbstractOrganic–inorganic hybrid assembly is a very attractive means for constructing complex functional materials. Here, a simple method for the preparation of amphiphilic hybrid graphene nanosheets (hPEA‐AN@G) is developed via the in situ hybrid assembly of anthracene‐ended hyperbranched poly(ether amine) (hPEA‐AN) and graphene by ball milling graphite in aqueous solution with hPEA‐AN. The amphiphilic hPEA‐AN, consisting of hydrophilic hPEA chains and electron‐rich π‐conjugated aromatic AN capped on the periphery, not only interacts strongly with graphene nanosheets and water molecules but also endows the hybrid hPEA‐AN@G assemblies with hydrophilic surfaces and functional groups. The concentration of the resulting few‐layered hPEA‐AN@G is as high as 3.5 mg mL–1. Moreover, the total interaction energy (VT) of hPEA‐AN@G is VT,max = 4.2 meV nm–2 calculated according to the classical Derjaguin–Landau–Verwey–Overbeek theory, as high as 16 800 eV for a 2 μm × 2 μm graphene flake, suggesting a high stability of the hPEA‐AN@G assemblies. The as‐prepared hPEA‐AN@G can be redispersed well in several organic solvents including N,N‐dimethylformamide, 1,4‐dioxane, acetone and ethanol for more than 3 months. The superior performance and convenient fabrication make this method very promising for the production of graphene nanosheets on a large scale in both aqueous and organic solution. © 2021 Society of Industrial Chemistry.