bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Intramolecular Iodine‐Catalyzed C(sp3)−H Oxidation as a Versatile Tool for the Synthesis of Tetrahydrofurans
Authors: Koch Vanessa , Bräse Stefan 
Published: June 2021

AbstractThe formation of ubiquitous occurring tetrahydrofuran patterns has been extensively investigated in the 1960s as it was one of the first examples of a non‐directed remote C−H activation. These approaches suffer from the use of toxic transition metals in overstoichiometric amounts. An attractive metal‐free solution for transforming carbon‐hydrogen bonds into carbon‐oxygen bonds lies in applying economically and ecologically favorable iodine reagents. The presented method involves an intertwined catalytic cycle of a radical chain reaction and an iodine(I/III) redox couple by selectively activating a remote C(sp3)−H bond under visible‐light irradiation. The reaction proceeds under mild reaction conditions, is operationally simple and tolerates many functional groups giving fast and easy access to different substituted tetrahydrofurans.
Pressure‐responsive AuNPs/Polyacrylamide Nanocomposite Hydrogel with Highly Stable and Tunable Electrochemiluminescence Performances
Authors: Xie Qunfang , Tao Yingzhou , Zhang Ying , Cui Haiyan , Lin Zhenyu 
Published: June 2021

AbstractSynergistically taking the advantage of distinctive porous matrix, luminophore and functional nanoparticles, we prepared functional nanocomposite hydrogel combining the hydrophilic three‐dimensional network of hydrogels as matrix for the adsorption of luminophore, Ru(bpy)32+, and in situ grown gold nanoparticles (AuNPs) as the conductive. Interestingly, the designed nanocomposite hydrogel shows external pressure resposnsive properties, which precisely tune the distance between the AuNPs becomes shorter, resulting in a remarkable amplification of electrochemiluminescence (ECL) signals. Additionally, differing from the poor stability of conventional ECL, uniform dispersion of the Ru(bpy)32+ over nanocomposite hydrogel significantly enhanced the long term stability of ECL.
Efficient co‐production of propionic acid and succinic acid by Propionibacterium acidipropionici using membrane separation coupled technology
Authors: Li Xiaolian , Wei Liquan , Wang Ziqiang , Wang Yunshan , Su Zhiguo 
Published: June 2021

AbstractTo improve the fermentation efficiency of Propionibacterium acidipropionici, a semi‐continuous coupled fermentation process was established to achieve co‐production of propionic acid (PA) and succinic acid (SA). First, the optimal proportion of glucose (Glc) and glycerol (Gl) as a mixed carbon source was determined, and the feeding procedure of Gl was optimized to make more energy flow in the direction of product synthesis. Then, ZGD630 anion exchange resin was used for efficient adsorption of PA, thereby eliminating the feedback inhibition effect of PA. Finally, an efficient, coupled fermentation process of P. acidipropionici characterized by membrane separation and chromatography technology was developed. The concentrations of PA and SA reached 62.22 ± 2.32 and 20.45 ± 1.34 g L−1, with corresponding productivity of 0.43 and 0.14 g L−1 h−1, increased by 65.38% and 48.54%, respectively. Membrane separation coupled fermentation of PA and SA could significantly improve the process economics of P. acidipropionici, and has good prospects for industrial application.
Comparative studies of metal‐organic decomposed GaxCeyOz and CeO2 based functional MOS capacitor
Authors: Tan Kar Yeow , Megat Abdul Hedei Puteri Haslinda , Mohd Zabidi Ainita Rozati , Ahmad Farah Hayati , Abdul Shekkeer Kammutty Musliyarakath , Lau Khai Shenn , Lim Way Foong , Hassan Zainuriah , Quah Hock Jin 
Published: June 2021

SummaryA comparison between metal‐organic decomposed GaxCeyOz and CeO2 passivation layers subjected to post‐deposition annealing at 800°C in oxygen ambient was presented. Mitigation in the formation of positively charged oxygen vacancies in GaxCeyOz layer was disclosed by the grazing incidence X‐ray diffraction characterization as well as the acquisition of a lower value of positive effective oxide charge (Qeff) than CeO2 layer. In addition, GaxCeyOz layer was able to sustain a higher electric breakdown field and a lower leakage current density due to the attainment of a lower interface trap density extracted using Terman's and high‐low methods, slow trap density, and Qeff when compared with CeO2 layer.
A milligram‐scale flame calorimeter pyrolyzer system used to emulate burning of nonthermally thin solid samples
Authors: De Beer Jacques A. , Raffan‐Montoya Fernando , Stoliarov Stanislav I. 
Published: June 2021

SummaryA new Milligram‐scale Flame Calorimetry (MFC) pyrolyzer system was developed to approximate heating conditions experienced by material samples in gram‐scale tests, such as cone calorimetry. The main features of this pyrolyzer system are a miniature flat heating coil embedded into a platform supporting the sample crucible. The use of a constant power rather than a constant heating rate operation mode distinguished the new MFC from the other mg‐scale flammability test method—microscale combustion calorimetry (MCC). A series of tests was carried out using the new MFC, cone, and MCC on five synthetic polymers representing a wide range of flammability behavior. All methods produced similar solid residue yields. The MFC peak heat release rate (HRR) was found to correlate linearly with the cone peak HRR (R2 = 0.93). The MCC peak HRR did not exhibit a strong correlation with the corresponding cone data. The new MFC was found to produce heat of combustion (HOC) values nearly identical to those measured in cone calorimetry. The MCC had a tendency to produce higher heats of combustion. Both MFC and MCC measured sample ignition temperatures that showed some correlation with the square root of the time to ignition measured in a cone calorimeter. The MFC airborne particular yield was found to correlate well (linear R2 = 0.91) with the average specific extinction area measured in the cone tests. It was concluded that the newly designed MFC can deliver relatively accurate flammability measurements similar to cone calorimetry while using three orders of magnitude smaller samples.
Synthesis of [2.2]Paracyclophane‐Based Glycidic Amides Using Chiral Ammonium Ylides
Authors: Weinzierl David , Waser Mario 
Published: June 2021

AbstractAn ammonium ylide‐mediated stereoselective protocol for the synthesis of a series of novel [2.2]paracyclophane‐based epoxides starting from racemic 4‐formyl[2.2]paracyclophane has been developed. By using achiral ammonium salts as ylide precursors, the corresponding epoxide products were obtained in isolated yields up to 76 % and with diastereoselectivities up to d.r.=9 : 1. When carrying out the reaction with chiral ammonium salts instead, the products were accessible with e.r.>93.5 : 6.5 and d.r.>3 : 1, accompanied with a moderately enantioselective kinetic resolution of the racemic starting aldehyde (e.r.=75 : 25).
A Molecular Analogue of the C−H Activation Intermediate of the Silica‐Supported Ga(III) Single‐Site Propane Dehydrogenation Catalyst: Structure and XANES Signature
Authors: Rochlitz Lukas , Searles Keith , Nater Darryl F. , Docherty Scott R. , Gioffrè Domenico , Copéret Christophe 
Published: June 2021

AbstractPropane dehydrogenation is an important field of research due to an increasing world‐wide demand of propene while classical production routes through naphtha cracking are in decline. In that context, silica‐supported Ga(III) sites, synthesized from surface organometallic chemistry principles, show high selectivity and stability in the propane dehydrogenation reaction. This performance is in significant contrast to the reported fast deactivation and lower selectivity of most Ga2O3 and CrO3 based materials. The Ga‐catalyzed propane dehydrogenation reaction is proposed to proceed through the formation of Ga alkyl intermediates for which it would be desirable to have detailed structural and spectroscopic information. Here, we prepare a consistent series of Ga(III) molecular complexes with varying numbers of alkyl and siloxide ligands; they are characterized by single crystal X‐Ray diffraction and X‐Ray Absorption Near Edge Structure analysis, which is known to be highly sensitive to the Ga coordination environment. We report in particular the structure and the spectroscopic signatures of [Ga(iPr)(OSi(OtBu)3)2(HOSi(OtBu)3)], a molecular mimic of the key proposed reaction intermediates in the Ga‐catalyzed PDH reaction.
Unobserved components with stochastic volatility: Simulation‐based estimation and signal extraction
Authors: Li Mengheng , Koopman Siem Jan 
Published: June 2021

SummaryThe unobserved components time series model with stochastic volatility has gained much interest in econometrics, especially for the purpose of modelling and forecasting inflation. We present a feasible simulated maximum likelihood method for parameter estimation from a classical perspective. The method can also be used for evaluating the marginal likelihood function in a Bayesian analysis. We show that our simulation‐based method is computationally feasible, for both univariate and multivariate models. We assess the performance of the method in a Monte Carlo study. In an empirical study, we analyse U.S. headline inflation using different univariate and multivariate model specifications.
P53 inhibitor pifithrin‐α inhibits ropivacaine‐induced neuronal apoptosis via the mitochondrial apoptosis pathway
Authors: Zeng Lian , Zhang Fuyu , Zhang Zhen , Xu Min , Xu Yang , Liu Ying , Xu Hongxia , Sun Xiaodong , Sang Ming , Luo Huiyu 
Published: June 2021

AbstractThe neurotoxicity of local anesthetics (LAs) has attracted more and more attention, However, they lack preventive and therapeutic measures. Many studies have shown that apoptosis plays an important role in the process of LA‐induced neurotoxicity. As an important signaling molecule to activate apoptosis, p53 has been proved to be involved in the neurotoxicity induced by LAs, but the mechanism is unclear. In this study, we explored the effect of pifithrin‐α (PFT‐α), a p53 inhibitor, on apoptosis by ropivacaine (Rop) in vivo and in vitro. Cell viability and apoptosis detected by CCK‐8 and a JC‐1 apoptosis detection kit, the changes of spinal cord structure observed after hematoxylin and eosin staining, apoptosis of the spinal cord measured by terminal deoxynucleotidyl transferase dUTP nick end labeling staining, behavioral assessment of the nerve Injury evaluated by the detection of sciatic nerve conduction velocity (SNCV) andmechanical withdrawal threshold (MWT), the expression of p53 and many apoptosis‐related genes included Bax, Bcl‐2, and caspase‐3 detected by quantitative real‐time polymerase chain reaction, Western blot analysis, immunofluorescence, and immunohistochemistry. Results showed that PC12 cell viability decreased because of Rop, but the pretreatment of PFT‐α could protect it. And PFT‐α reduced the injuries in the spinal cord by Rop included vacuoles or edema. The results of immunofluorescence and immunohistochemistry testing showed that PFT‐α inhibited the p53 protein upregulated by Rop. Apoptosis rate and many proapoptotic genes include p53, Bax, caspase‐3 messenger RNA, and proteins were increased by Rop, but PFT‐α could decrease it. In conclusion, PFT‐α inhibited cell apoptosis and spinal cord injuries induced by Rop.
Facile extraction and characterization of cellulose nanocrystals from agricultural waste sugarcane straw
Authors: Lu Shuyu , Ma Tao , Hu Xinna , Zhao Jing , Liao Xiaojun , Song Yi , Hu Xiaosong 
Published: June 2021

AbstractBACKGROUNDSugarcane straw is an available but largely ignored lignocellulosic biomass to obtain cellulose nanocrystals (CNCs) with highly crystalline, tunable surface chemistries and a wide‐ranging adaptability. Herein, we utilized sugarcane straw to obtain pure cellulose via purification processes, followed by subsequent preparation of CNCs via sulfuric acid hydrolysis. The properties of the purified fibers and obtained CNCs were assessed by their composition, morphology, chemical structure, crystallinity and thermal stability.RESULTSAfter the purification process, alkali‐treated fibers (ATFs) contained 886.33 ± 1.25 g kg−1 cellulose, and its morphological analysis revealed a smooth and slender fibrous structure. The CNCs obtained by treatment with 64 wt% sulfuric acid at 45 °C for 60 min were isolated in a yield of 21.8%, with a diameter and length of 6 to 10 nm and 160 to 200 nm, respectively. Moreover, crystallinity index of these CNCs reached 62.66%, and thermal stability underwent a two‐step degradation. Short‐term ultrasonication after hydrolysis was employed to enhance isolation of the CNC particles and improve the anionic charge with higher value −38.00 mV.CONCLUSIONOverall, isolation and characterization results indicated the potential for CNCs preparation using sugarcane straw, in addition to offering a fundamental understanding of this material and indicating potential applications. © 2021 Society of Chemical Industry.
Perioperative Challenges in Patients Transplanted with Livers from Extreme Obese Donors
Authors: Valvi Deepa , Villagomez Diego , Shah Malay B. , Mei Xiaonan , Gupta Meera , Ancheta Alexandre , Marti Francesc , Desai Siddharth , Benrajab Karim , Gedaly Roberto 
Published: June 2021

The combination of rising rates of obesity and the shortage of deceased donor livers have forced the consideration of marginal liver donors in terms of body mass index (BMI) for liver transplantation (LT). To date, there are still conflicting data on the impact of donor obesity on post‐LT outcomes. We analyzed all patients undergoing LT alone in the United States (US) from October 2005 through December 2019 using the United Network of Organ Sharing (UNOS) data set. We categorized donor BMI >40 kg/m2 as extremely obese (EO). Primary endpoints included 30‐day perioperative mortality and early graft loss (EGL) within 7 days. A subgroup analysis was performed for the EO donor group to assess how macrovesicular steatosis (MaS) >30% affects 30‐day mortality and EGL within 7 days. A total of 72,616 patients underwent LT during the study period. The 30‐day perioperative mortality was significantly higher in the EO donor group (P = 0.02). On multivariate analysis, recipients undergoing LT with EO donors had a 38% higher 30‐day mortality risk (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.21‐1.69) and 53% increased risk of EGL (OR, 1.53; 95% CI, 1.22‐1.90). MaS >30% was independently associated with a 2‐fold increased risk of 30‐day mortality (P = 0.003) and 3.5‐fold increased risk of EGL within 7 days (P < 0.001). The impact of MaS >30% in EGL was 2‐fold for all patients transplanted during the study period compared with 3.5‐fold in the EO donor group. There is an increased risk of EGL and 30‐day perioperative mortality in recipients transplanted with EO donors. Future studies are warranted in morbid and super obese donors to assess the possible effect of obesity‐related proinflammatory factors in EGL.
Chemical isotope labeling for quantitative proteomics
Authors: Tian Xiaobo , Permentier Hjalmar P. , Bischoff Rainer 
Published: June 2021

AbstractAdvancements in liquid chromatography and mass spectrometry over the last decades have led to a significant development in mass spectrometry‐based proteome quantification approaches. An increasingly attractive strategy is multiplex isotope labeling, which significantly improves the accuracy, precision and throughput of quantitative proteomics in the data‐dependent acquisition mode. Isotope labeling‐based approaches can be classified into MS1‐based and MS2‐based quantification. In this review, we give an overview of approaches based on chemical isotope labeling and discuss their principles, benefits, and limitations with the goal to give insights into fundamental questions and provide a useful reference for choosing a method for quantitative proteomics. As a perspective, we discuss the current possibilities and limitations of multiplex, isotope labeling approaches for the data‐independent acquisition mode, which is increasing in popularity.
DiSpect: Displacement spectrum imaging of flow and tissue perfusion using spin‐labeling and stimulated echoes
Authors: Zhang Zhiyong , Karasan Ekin , Gopalan Karthik , Liu Chunlei , Lustig Michael 
Published: June 2021

PurposeWe propose a new method, displacement spectrum (DiSpect) imaging, for probing in vivo complex tissue dynamics such as motion, flow, diffusion, and perfusion. Based on stimulated echoes and image phase, our flexible approach enables observations of the spin dynamics over short (milliseconds) to long (seconds) evolution times.MethodsThe DiSpect method is a Fourier‐encoded variant of displacement encoding with stimulated echoes, which encodes bulk displacement of spins that occurs between tagging and imaging in the image phase. However, this method fails to capture partial volume effects as well as blood flow. The DiSpect variant mitigates this by performing multiple scans with increasing displacement‐encoding steps. Fourier analysis can then resolve the multidimensional spectrum of displacements that spins exhibit over the mixing time. In addition, repeated imaging following tagging can capture dynamic displacement spectra with increasing mixing times.ResultsWe demonstrate properties of DiSpect MRI using flow phantom experiments as well as in vivo brain scans. Specifically, the ability of DiSpect to perform retrospective vessel‐selective perfusion imaging at multiple mixing times is highlighted.ConclusionThe DiSpect variant is a new tool in the arsenal of MRI techniques for probing complex tissue dynamics. The flexibility and the rich information it provides open the possibility of alternative ways to quantitatively measure numerous complex spin dynamics, such as flow and perfusion within a single exam.
A longitudinal study of educational needs among patients with inflammatory arthritis
Authors: Grønning Kjersti , Lim Siriwan , Bratås Ola 
Published: June 2021

AbstractIntroductionPatient education is important in the follow‐up and disease management for patients with chronic inflammatory arthritis. Patients’ needs for education and information varies, and it is important that the education is tailored to the individual patient. Hence, the aim of this study is to investigate whether patients’ educational needs change over time, and which demographic, disease‐related or self‐management characteristics that are associated with patients’ educational needs.MethodsThe Mann–Whitney U‐test was used to study patients’ longitudinal educational needs and whether their needs change over time, while multivariable linear regression analyses were used to investigate associations between patients’ educational needs and demographic variables, disease‐related and self‐management characteristics.ResultsThere were no changes in patients’ educational needs in the domains of managing pain, movement, feelings, arthritis process and treatment from health professionals during the study period of seven years. A small decrease in educational needs in the domains self‐help measures (p‐value 0.047) and support from others (p‐value 0.010) was detected. The regression analyses showed that higher educational needs were associated with being female, lower educational level, shorter disease duration, and a lower level of patient activation.ConclusionsPatients with chronic inflammatory arthritis have continual needs for patient education throughout their disease trajectory. Nurses and health care professionals must therefore ask their patients what kind of education they need at every follow‐up throughout the disease course.
A stabilized computational nonlocal poromechanics model for dynamic analysis of saturated porous media
Authors: Menon Shashank , Song Xiaoyu 
Published: June 2021

AbstractIn this article we formulate a stable computational nonlocal poromechanics model for dynamic analysis of saturated porous media. As a novelty, the stabilization formulation eliminates zero‐energy modes associated with the original multiphase correspondence constitutive models in the coupled nonlocal poromechanics model. The two‐phase stabilization scheme is formulated based on an energy method that incorporates inhomogeneous solid deformation and fluid flow. In this method, the nonlocal formulations of skeleton strain energy and fluid flow dissipation energy equate to their local formulations. The stable coupled nonlocal poromechanics model is solved for dynamic analysis by an implicit time integration scheme. As a new contribution, we validate the coupled stabilization formulation by comparing numerical results with analytical and finite element solutions for one‐dimensional and two‐dimensional dynamic problems in saturated porous media. Numerical examples of dynamic strain localization in saturated porous media are presented to demonstrate the efficacy of the stable coupled poromechanics framework for localized failure under dynamic loads.
Single-Center Analysis of Characteristics and Outcomes of De Novo, Concurrent, and Transformed Diffuse Large B-Cell Lymphoma
Authors: Desai Sanjal , Chaturvedi Mansi , Hameed Rumaisa , Baez-sosa Valentina , Shenoy Aarthi G. 
Published: June 2021

Abstract
Outcomes of diffuse large B-cell lymphoma (DLBCL), either concurrent with or transformed from indolent lymphoma, treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone are described in retrospective studies. The efficacy of other regimens in transformed or concurrent DLBCL is largely unknown. In this single-center retrospective study, we present characteristics of concurrent and transformed DLBCL and outcomes after dose-adjusted etoposide, vincristine, cyclophosphamide, prednisone, and doxorubicin with rituximab (DA-EPOCH-R) comparative with de novo DLBCL. Of 170 patients with DLBCL, 136 were de novo, 17 were concurrent, and 17 were transformed. Transformed DLBCL had significantly lower complete response rates and progression-free survival (PFS) but similar overall survival (OS) compared with de novo counterpart. There was no significant difference between de novo and concurrent DLBCL regarding response rates, PFS, and OS. DA-EPOCH-R was associated with inferior OS. Thus, intensified treatment with DA-EPOCH-R might not improve outcomes of transformed DLBCL.