bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extensional flow of stiff‐chain polymer solutions in the semidilute regime
Authors: Romo‐Uribe Angel 
Published: September 2021

AbstractStiff‐chain polymers are preponderant in biology as structural components of tissue and living cells. Hence, understanding their solution behavior under different flow histories is fundamental. Here, the extensional flow under capillary breakup of isotropic semidilute solutions of stiff‐chain poly‐n‐butyl isocyanate (PBIC) and hydroxypropyl cellulose (HPC) has been studied. PBIC‐chloroform and HPC‐water were studied as the polymer‐solvent interaction tunes the molecular conformation (Romo‐Uribe, J. Appl. Polym. Sci. 2021, 138, e49712). PBIC in chloroform exhibits a rod‐like conformation, and capillary breakup at constant concentration and temperature initially showed an exponential decay of filament diameter D(t) followed by a sudden decrease of D, and finally slow filament thinning. Increasing the molecular weight by threefold increased the breakup time τb by twofold. HPC in water adopts a semiflexible conformation and the filament thinning also exhibited three stages, however the breakup time was shorter than PBIC. Hence, the extensional viscosity as a function of strain of PBIC and HPC solutions exhibited three regimes, where initial constant extensional viscosity ηE was followed by strain hardening and finally a sudden decrease of extensional viscosity as strain increased. It was found that the filament breakup time τb is a function of the radius of gyration Rg.
Rheology, dispersion, and cure kinetics of epoxy filled with amine‐ and non‐functionalized reduced graphene oxide for composite manufacturing
Authors: Ackermann Annika C. , Carosella Stefan , Rettenmayr Markus , Fox Bronwyn L. , Middendorf Peter 
Published: September 2021

AbstractThis study evaluates the effect of plasma surface functionalization of reduced graphene oxide particles on the processing characteristics and homogeneity of dispersion of a bisphenol A‐(epichlorhydrin) epoxy matrix and amine‐based hardener with varying weight fractions from 0.00 to 1.50 wt%. It was observed that amine‐functionalized reduced graphene oxide leads to a more drastic viscosity increase of up to 18‐fold of the uncured suspensions and that its presence influences the conversion rates of the curing reaction. Optical microscopy of thin sections and transmission electron microscopy analysis showed that a more homogeneous dispersion of the particles could be achieved especially at higher weight fractions by using an appropriate surface functionalization. This knowledge can be used to define suitable processing conditions for epoxies with amine‐based hardeners depending on the loading and functionalization of graphene‐related particles.
Mit einem Holzhybrid neue Höhen erreichen
Authors: Hegner‐van Rooden Clementine , Christen Jasmin 
Published: September 2021

AbstractFür das 60 m hohe Holz‐Beton‐Hybridhochhaus Arbo auf dem Suurstoffi‐Areal in Rotkreuz (CH) zeichneten als Holzbauingenieure die Pirmin Jung Schweiz AG verantwortlich. Sie entwickelten ein Stützen‐Decken‐Kern‐System, das einen klassischen Skelettbau bildet und einen hohen sichtbaren Holzanteil aufweist. Einzig der Kern und das Untergeschoss sind in Beton hergestellt. Weil Holz und Beton verschiedene Materialeigenschaften aufweisen, waren kritische Punkte zu lösen. Ebenso bedingt der Kräftefluss an der Schnittstelle von Holz und Beton komplexe Details – aus bauphysikalischen, statischen und brandschutzspezifischen Gründen –, denn neben dem unterschiedlichen Materialverhalten von Beton, Holz oder ihrem Verbund prallen mit den Gewerken auch unterschiedliche Umgangsformen, verschiedene Toleranzen und ein anderes Handling aufeinander. Arbo ist daher ein Lehrbeispiel, wie ein Holzhybridbau aktuell umsetzbar sein kann und das beispielhaft ist für nachfolgende Bauten in der Schweiz und in Europa. Auch solche in einer reinen Holzkonstruktion.
How does Lewis acid affect the reactivity of mononuclear high‐valent chromium–oxo species? A theoretical study
Authors: Choi Yunhee , Pandey Bhawana , Li Xiao‐Xi , Lee Yong‐Min , Cho Kyung‐Bin , Nam Wonwoo 
Published: September 2021

AbstractDensity functional theory calculations were performed to study the Lewis acid (Sc3+) effects on the reactivity of ultrahigh‐valent chromium‐oxo species toward both CH bond activation and sulfoxidation reactions. Calculations confirm that the oxidizing power of chromium‐oxo species is enhanced by binding Sc3+ ion. In sulfoxidation reactions, especially, binding Sc3+ ion enhances the redox potential of the chromium‐oxo species, whereby the activation barrier is decreased dramatically. The details of the reactions obtained by theory are disclosed in this work.
Fe3O4@THAM‐Pd as a highly efficient magnetically recoverable nanocatalyst for facile one‐pot assembly of substituted imidazoles under solvent‐free conditions
Authors: Sanchooli Tazeh Kazem , Heydari Reza , Fatahpour Maryam 
Published: September 2021

AbstractThe current work has been explored an expeditious tactic toward one‐pot multicomponent synthesis of 1,2,4,5‐tetrasubstituted and 2,4,5‐trisubstituted imidazoles using Fe3O4@THAM‐Pd MNPs as an effective catalyst. With readily accessible benzil, ammonium acetate, anilines, and aromatic aldehydes as the simple starting materials, the condensation is run under solvent‐free conditions to afford the target products in high yields. The other salient features of the present catalytic system are a simple work‐up process, shorter reaction times, ease of preparation and handling of the catalyst, and cleaner reaction profiles. In addition, the sustainability of the methodology was checked by the investigation of the stability and reusability of the catalyst using an external magnet. The results showed that Fe3O4 @THAM‐Pd MNPs can be reused for successive five runs without an appreciable decline in catalytic efficiency.
Does the interaction between the knowledge management process and sustainable development practices boost corporate green innovation?
Authors: Shahzad Mohsin , Qu Ying , Zafar Abaid Ullah , Appolloni Andrea 
Published: September 2021

AbstractGreen innovations are being deployed in manufacturing industries to promote organisational sustainability by embracing sustainable development practices (SDPs). However, little is known about how corporate green innovation (CGI) is influenced by the knowledge management process (KMP). To fill this gap, we have developed a multidimensional framework based on the resource‐based view (RBV) theory that provides a foundation for sculpturing the process by which KMP was observed to capture and sustain CGI through SDPs. Data were collected from 393 respondents of large‐ and medium‐sized manufacturing corporations in Pakistan and analysed using partial least squares structural equation modelling (SEM) and fuzzy set qualitative comparative analysis (fsQCA). This study provides several key findings. First, KMP dimensions (acquisition, dissemination and application) significantly improve the SDPs' dimensions (environment, economic and social). Second, SDP dimensions play a significant role in achieving CGI. Third, the implementation of SDPs partially mediates the relationship between the KMP and CGI. Furthermore, the fsQCA results signify the robustness of all integrated constructs. Our results demonstrate that investing in and adopting the latest technologies and sustainable practices are not only valuable for long‐term success but the soft concerns such as managing organisational knowledge are also vital in the current knowledge‐based economy. Finally, in light of our findings, theoretical and managerial implications, with propositions for future studies, have been provided at the end of the paper.
Quinoid‐Aromatic Resonance for Very Small Optical Energy Gaps in Small‐Molecule Organic Semiconductors: A Naphthodithiophenedione‐oligothiophene Triad System
Authors: Kawabata Kohsuke , Takimiya Kazuo 
Published: September 2021

AbstractOrganic semiconductors with very small optical energy gaps have attracted a lot of attention for near‐infrared‐active optoelectronic applications. Herein, we present a series of donor‐acceptor‐donor (D−A−D) organic semiconductors consisting of a highly electron‐deficient naphtho[1,2‐b:5,6‐b′]dithiophene‐2,7‐dione quinoidal acceptor and oligothiophene donors that show very small optical energy gaps of down to 0.72 eV in the solid state. Investigation of the physicochemical properties of the D−A−D molecules as well as theoretical calculations of their electronic structures revealed an efficient intramolecular interaction between the quinoidal acceptor and the aromatic oligothiophene donors in the D−A−D molecules; this significantly enhances the backbone resonance and thus reduces the bond length alternation along the π‐conjugated backbones. Despite the very small optical energy gaps, the D−A−D molecules have low‐lying frontier orbital energy levels that give rise to air‐stable ambipolar carrier transport properties with hole and electron mobilities of up to 0.026 and 0.043 cm2 V−1 s−1, respectively, in field‐effect transistors.
Association between right ventricular dysfunction and mortality in COVID‐19 patients: A systematic review and meta‐analysis
Authors: Diaz‐Arocutipa Carlos , Saucedo‐Chinchay Jose , Argulian Edgar 
Published: September 2021

AbstractThere is limited evidence about the prognostic utility of right ventricular dysfunction (RVD) in patients with coronavirus disease 2019 (COVID‐19). We assessed the association between RVD and mortality in COVID‐19 patients. We searched electronic databases from inception to February 15, 2021. RVD was defined based on the following echocardiographic variables: tricuspid annular plane systolic excursion (TAPSE), tricuspid S′ peak systolic velocity, fractional area change (FAC), and right ventricular free wall longitudinal strain (RVFWLS). All meta‐analyses were performed using a random‐effects model. Nineteen cohort studies involving 2307 patients were included. The mean age ranged from 59 to 72 years and 65% of patients were male. TAPSE (mean difference [MD], −3.13 mm; 95% confidence interval [CI], −4.08–−2.19), tricuspid S′ peak systolic velocity (MD, −0.88 cm/s; 95% CI, −1.68 to −0.08), FAC (MD, −3.47%; 95% CI, −6.21 to −0.72), and RVFWLS (MD, −5.83%; 95% CI, −7.47–−4.20) were significantly lower in nonsurvivors compared to survivors. Each 1 mm decrease in TAPSE (adjusted hazard ratio [aHR], 1.22; 95% CI, 1.08–1.37), 1% decrease in FAC (aHR, 1.09; 95% CI, 1.04–1.14), and 1% increase in RVFWLS (aHR, 1.33; 95% CI, 1.19–1.48) were independently associated with higher mortality. RVD was significantly associated with higher mortality using unadjusted risk ratio (2.05; 95% CI, 1.27–3.31), unadjusted hazard ratio (3.37; 95% CI, 1.72–6.62), and adjusted hazard ratio (aHR, 2.75; 95% CI, 1.52–4.96). Our study shows that echocardiographic parameters of RVD were associated with an increased risk of mortality in COVID‐19 patients.
Successful pregnancy with stage IB2 uterine cervical cancer: A case report
Authors: Nagasawa Saya , Kasahara Makiko , Aoki Yuji , Kusunoki Soshi , Sugimori Yayoi , Matsuoka Shozo , Ogura Kanako , Ogishima Daiki 
Published: September 2021

AbstractBackgroundAlthough cervical cancer is one of the most common malignancies in pregnancy, its management mainly follows the guidelines for nonpregnant disease state. Within the limited time, patients, and healthcare workers must make difficult decisions to either delay treatment until documented fetal maturity or start immediate treatment based on the disease stage.CaseThe patient was a 37‐year‐old woman: gravida 1, para 0. Her cervical cytology revealed a high‐grade squamous intraepithelial lesion at 8 weeks' gestation. Moreover, invasive squamous cell carcinoma was suspected based on the findings of uterine cervix biopsy. Cervical conization was performed at 11 weeks' gestation, confirming a histopathological diagnosis of squamous cell carcinoma, pT1b2. Cervical cytology findings continued to be negative for intraepithelial lesion or malignancy from 2 weeks after conization until 2 weeks before a cesarean section. In addition, we performed abdominal pelvic lymphadenectomy at 16 weeks' gestation to determine whether the patient could continue her pregnancy. No lymph node metastasis or local recurrence was observed. Finally, a cesarean section and modified radical hysterectomy were performed at 35 weeks' gestation. There was no carcinoma invasion or metastasis. A baby girl weighing 2056 g was delivered with 1‐ and 5‐min Apgar scores of 8 and 9, respectively. Five years postoperatively, there was no evidence of cancer recurrence.ConclusionManagement of cervical cancer during pregnancy by using a combination strategy of deep conization and pelvic lymphadenectomy could be an effective strategy for carefully and safely assessing risks of recurrence and metastasis.
Nearest neighbors algorithm and genetic‐based collaborative filtering
Authors: Houshmand Nanehkaran Farimah , Lajevardi Seyed Mohammadreza , Mahlouji Bidgholi Mahmoud 
Published: September 2021

AbstractConventional recommender systems often utilize similarity formulas to identify similarities between active users and others to predict the rating of the unseen items. Existing optimization algorithms seek to find the weights and coefficients affecting these similarities. Our proposed method, implemented in R in the GACFF package, shifts away from this view and directly uses the continuous genetic algorithm to find optimal similarities in big data (e.g., Movielens 1M and Netflix datasets) to improve the performance of user‐based collaborative filtering recommendation systems. First, by identifying the users who are the nearest neighbors along with their number, the number of genes in a chromosome is determined. Each gene represents the similarity between a neighboring user and an active user. This genetic algorithm is independent of the size of the data. Our method provides optimal solutions more quickly by estimating the starting points. Moreover, the genetic metric provides better results and recommendations than previous ones in terms of runtime and quality measures (i.e., mean absolute error, coverage, precision, and recall).
Synthesis of N4‐Methylcytidine (m4C) and N4,N4‐Dimethylcytidine (m42C) Modified RNA
Authors: Zheng Ya Ying , Mao Song , Sheng Jia 
Published: September 2021

AbstractThis article summarizes the protocols for phosphoramidite chemistry and solid phase synthesis of RNA oligonucleotides containing N4‐methylcytidine (m4C) and N4,N4‐dimethylcytidine (m42C) residues for base‐pairing, structural, and enzymatic activity studies. The two key m4C and m42C phosphoramidite building blocks can be synthesized starting from the partially protected cytidine nucleosides, followed by solid‐phase synthesis and HPLC purification of the modified target RNA oligonucleotides. These modified RNA strands are then prepared for base pairing stability, specificity, and structural studies using UV‐melting temperature (Tm) measurements and X‐ray crystallography. Functional studies are performed by reverse transcription assays in primer extension reactions employing different enzymes. © 2021 Wiley Periodicals LLC.Basic Protocol 1: Chemical synthesis of m4C phosphoramiditeBasic Protocol 2: Synthesis of m42C phosphoramiditeBasic Protocol 3: Synthesis and purification of m4C and m42C containing RNA oligonucleotides
Stimulated Raman Scattering (SRS) in α‐AlOOH (Diaspore)
Authors: Bohatý Ladislav , Lux Oliver , Eichler Hans‐Joachim , Rhee Hanjo , Kaminskii Alexander A. , Becker Petra 
Published: September 2021

AbstractIn single crystals of orthorhombic α‐AlOOH, known also as mineral diaspore, χ(3)‐nonlinear lasing by stimulated Raman scattering (SRS) and Raman‐induced four‐wave mixing (RFWM) is investigated. Picosecond pumping at 1.064 µm wavelength produces a broadband Stokes and anti‐Stokes frequency comb with up to 25 SRS‐ and RFWM‐generated emission lines. All observed Stokes and anti‐Stokes lasing components in the visible and near‐IR are identified and attributed to a single SRS‐promoting vibration mode with ωSRS ≈ 445 cm−1. The first Stokes steady‐state Raman gain coefficient in the visible spectral range is estimated to a value not less than 0.36 cm GW−1.
Risk factors and prediction models for incident heart failure with reduced and preserved ejection fraction
Authors: Gaziano Liam , Cho Kelly , Djousse Luc , Schubert Petra , Galloway Ashley , Ho Yuk‐Lam , Kurgansky Katherine , Gagnon David R. , Russo John P. , Di Angelantonio Emanuele , Wood Angela M. , Danesh John , Gaziano John Michael , Butterworth Adam S. , Wilson Peter W.F. , Joseph Jacob 
Published: September 2021

AbstractAimsThis study aims to develop the first race‐specific and sex‐specific risk prediction models for heart failure with preserved (HFpEF) and reduced ejection fraction (HFrEF).Methods and resultsWe created a cohort of 1.8 million individuals who had an outpatient clinic visit between 2002 and 2007 within the Veterans Affairs (VA) Healthcare System and obtained information on HFpEF, HFrEF, and several risk factors from electronic health records (EHR). Variables were selected for the risk prediction models in a ‘derivation cohort’ that consisted of individuals with baseline date in 2002, 2003, or 2004 using a forward stepwise selection based on a change in C‐index threshold. Discrimination and calibration were assessed in the remaining participants (internal ‘validation cohort’). A total of 66 831 individuals developed HFpEF, and 92 233 developed HFrEF (52 679 and 71 463 in the derivation cohort) over a median of 11.1 years of follow‐up. The HFpEF risk prediction model included age, diabetes, BMI, COPD, previous MI, antihypertensive treatment, SBP, smoking status, atrial fibrillation, and estimated glomerular filtration rate (eGFR), while the HFrEF model additionally included previous CAD. For the HFpEF model, C‐indices were 0.74 (SE = 0.002) for white men, 0.76 (0.005) for black men, 0.79 (0.015) for white women, and 0.77 (0.026) for black women, compared with 0.72 (0.002), 0.72 (0.004), 0.77 (0.017), and 0.75 (0.028), respectively, for the HFrEF model. These risk prediction models were generally well calibrated in each race‐specific and sex‐specific stratum of the validation cohort.ConclusionsOur race‐specific and sex‐specific risk prediction models, which used easily obtainable clinical variables, can be a useful tool to implement preventive strategies or subtype‐specific prevention trials in the nine million users of the VA healthcare system and the general population after external validation.
Quantification of the Lewis Basicities and Nucleophilicities of 1,3,5‐Tris(dialkylamino)benzenes
Authors: Micheletti Gabriele , Mayer Robert J. , Cino Silvia , Boga Carla , Mazzanti Andrea , Ofial Armin R. , Mayr Herbert 
Published: September 2021

AbstractEquilibrium constants for the formation of Wheland complexes from 1,3,5‐tris(dialkylamino)benzenes and benzhydrylium ions (Ar2CH+) have been determined photometrically in dichloromethane solution at 20 °C. The Lewis basicity of the ring carbons increases in the series trimorpholinobenzene<tripiperidinobenzene<tripyrrolidinobenzene. Wheland complexes, which are formed with equilibrium constants 102<K/M−1<106 in the reactions of triaminobenzenes with carbenium ions, show temperature‐dependent dynamic 1H NMR spectra, due to rapid reverse reactions and recombination at different positions of the triaminobenzenes. Since the rates of the formation of the Wheland complexes are too high to be measured directly, they were calculated as the product of photometrically determined equilibrium constants and the rate constants for the reverse reactions, which were derived from the dynamic 1H NMR spectra. The experimentally determined equilibrium and rate constants were in good agreement with the results of DFT calculations using the SMD solvent model. The calculations show that in all cases the Wheland complexes are thermodynamically more stable than the ammonium ions formed by attack of the benzhydrylium ions at the amino group of the title compounds, which explains the exclusive formation of Wheland complexes in thermodynamically controlled reactions. With nucleophilicity parameters in the range 10<N<15 the triaminobenzenes have comparable nucleophilic reactivities as enamines, silyl ketene acetals as well as stabilized phosphonium and sulfonium ylides.
B(C6F5)3‐Catalyzed Hydroarylation of Aryl Alkynes for the Synthesis of 1,1‐Diaryl and Triaryl Substituted Alkenes
Authors: Chen Hui , Gao Liuzhou , Liu Xueting , Wang Guoqiang , Li Shuhua 
Published: September 2021

AbstractA new strategy for the synthesis of 1,1‐diaryl and triarylsubstituted alkenes has been developed utilizing B(C6F5)3‐catalyzed hydroarylation of alkynes with phenols. The method provides a direct route to ortho‐alkenylated phenols with both terminal and internal alkynes. The reactions show excellent regioselectivity, and good stereoselectivity was observed for the hydroarylation of internal alkynes. Computational and experimental studies suggest that for the reaction of internal alkynes and phenols, an acid‐catalyzed isomerization mechanism involving two tertiary carbonium ion intermediates is responsible for the formation of Z‐triaryl substituted alkenes.
Recent biopharmaceutical applications of capillary electrophoresis methods on recombinant DNA technology‐based products
Authors: Kaya S. Irem , Cetinkaya Ahmet , Caglayan Mehmet G. , Ozkan Sibel A. 
Published: September 2021

AbstractBiopharmaceuticals (recombinant technology‐based products, vaccines, whole blood and blood components, gene therapy, cells, tissues, etc.,) are described as biological medical products produced from various living sources such as human, microbial, animal, and so on by manufacturing, extraction, or semi‐synthesis. They are complex molecules having high molecular weights. For their safety and efficacy, their structural, clinical, physicochemical, and chemical features must be carefully controlled, and they must be well characterized by analytical techniques before the approval of the final product. Capillary electrophoresis (CE) having versatile modes can provide valuable safety and efficacy information, such as amino acid sequence, size variants (low and high molecular weight variants), charged variants (acidic and basic impurities), aggregates, N‐linked glycosylation, and O‐linked glycosylation. There are numerous applications of CE in the literature. In this review, the most significant and recent studies on the analysis of recombinant DNA technology‐based products using different CE modes in the last ten years have been overviewed. It was seen that the researches mostly focus on the analysis of mAbs and IgG. In addition, in recent years, researchers have started to prefer CE combined mass spectrometry (MS) techniques to provide a more detailed characterization for protein and peptide fragments.