bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding Ball Milling Mechanochemical Processes with DFT Calculations and Microkinetic Modeling
Authors: Pladevall Bruna S. , de Aguirre Adiran , Maseras Feliu 
Published: April 2021

AbstractMechanochemistry is an emerging field with many potential applications in sustainable chemistry. But despite the growing interest in the field, its underlying mechanistic foundations are not fully understood yet. This work presents the application of computational tools, such as DFT calculations in continuum and microkinetic modeling, to the analysis of mechanically activated procedures. Two reactions reported in previous experimental publications were studied: (i) a series of Diels‐Alder reactions and (ii) the synthesis of sulfonylguanidines. Calculations succeed in reproducing experimentally reported reaction times. The procedures were mostly standard, coupled with some sensitive choices in terms of starting concentrations and dielectric constant. This means that these particular reactions accelerated by ball milling followed the same mechanism as the equivalent reactions in solution. The implications of this result on the general picture of mechanochemical processes are discussed.
Rh(III)‐Catalyzed [3+2] Annulation and C−H Alkenylation of Indoles with 1,3‐Diynes by C−H Activation
Authors: Kumar Sanjeev , Nunewar Saiprasad , Usama Khan Mohammad , Kanchupalli Vinaykumar 
Published: April 2021

AbstractDescribed herein is the Rh(III)‐ catalyzed [3+2] annulations and C2‐alkenylations of indoles with 1,3‐diynes, which deliver the synthetically important 3H‐pyrrolo[1,2‐a]indol‐3‐ones and highly functionalized tetrasubstituted olefin derivatives. Importantly, in this methodology, the additive controlled selective formation of desired scaffolds. This synthetic strategy exhibits high efficiency and broad functional group compatibility. Furthermore, this protocol has been successfully extended to the synthesis of bis‐annulated and trisubstituted alkenes. The method is also smoothly applied for the synthesis of the core structure of protein kinase C inhibitor and melatonin analogues.
Melanoma of the lacrimal drainage system: A systematic review
Authors: Vinciguerra Alessandro , Rampi Andrea , Giordano Resti Antonio , Barbieri Diego , Bussi Mario , Trimarchi Matteo 
Published: April 2021

AbstractMelanoma of the lacrimal drainage system (LDSM) is a rare and subtle condition that is frequently misdiagnosed. In the present work, we conducted a systematic review investigating the clinical features, management, and prognosis of LDSM. A structured search, according to PRISMA criteria, was performed in April 2020 and updated in February 2021 on Pubmed, EMBASE, Cochrane, and SCOPUS. The articles found underwent a double‐reviewer selection and the main data were extracted. After complete screening, 30 articles reporting 38 cases were included. The time from the first symptom to medical contact ranged from 1 month to 4 years. Surgery was the treatment proposed to all patients, with a variable extension of resection. LDSM is a rare disease that is burdened by poor prognosis. Early diagnosis is crucial, even if difficult to achieve. Surgery and radiotherapy are standardized treatments, while targeted therapy and immunotherapy are attractive prospects.
Cost‐effectiveness of risk‐based breast cancer screening: A systematic review
Authors: Khan Shah Alam , Hernandez‐Villafuerte Karla Vanessa , Muchadeyi Muchandifunga Trust , Schlander Michael 
Published: April 2021

AbstractTo analyse published evidence on the economic evaluation of risk‐based screening (RBS), a full systematic literature review was conducted. After a quality appraisal, we compared the cost‐effectiveness of risk‐based strategies (low‐risk, medium‐risk and high‐risk) with no screening and age‐based screening. Studies were also analysed for modelling, risk stratification methods, input parameters, data sources and harms and benefits. The 10 modelling papers analysed were based on screening performance of film‐based mammography (FBM) (three); digital mammography (DM) and FBM (two); DM alone (three); DM, ultrasound (US) and magnetic resonance imaging (one) and DM and US (one). Seven studies did not include the cost of risk‐stratification, and one did not consider the cost of diagnosis. Disutility was incorporated in only six studies (one for screening and five for diagnosis). None of the studies reported disutility of risk‐stratification (being considered as high‐risk). Risk‐stratification methods varied from only breast density (BD) to the combination of familial risk, genetic susceptibility, lifestyle, previous biopsies, Jewish ancestry and reproductive history. Less or no screening in low‐risk women and more frequent mammography screening in high‐risk women was more cost‐effective compared to no screening and age‐based screening. High‐risk women screened annually yielded a higher mortality rate reduction and more quality‐adjusted life years at the expense of higher cost and false positives. RBS can be cost effective compared to the alternatives. However, heterogeneity among risk‐stratification methods, input parameters, and weaknesses in the methodologies hinder the derivation of robust conclusions. Therefore, further studies are warranted to assess newer technologies and innovative risk‐stratification methods.
Hepatoprotective potential of kirenol on ethanol‐induced liver toxicity in albino rats and acetaminophen‐induced oxidative stress‐mediated apoptosis in hepatic HepG2 cells
Authors: Sun Dongsheng , Li Ying , Cao Hui , Guo Hui , Alahmadi Tahani Awad , Alharbi Sulaiman Ali , Yu Jian 
Published: April 2021

AbstractLiver diseases are a major health issue in both men and women and cause significant mortality worldwide. The hepatoprotective effects of kirenol were evaluated in acetaminophen (APAP)‐induced toxicity in HepG2 cells and ethanol (EtOH)‐ induced hepatotoxicity in rats. The cytotoxicity of kirenol (IC50, 25 µM/ml) and APAP (20 µg/ml) with sylimarin (IC50, 15 µg/ml) was observed in HepG2 cells by 3‐(4,5‐dimethylthiazol‐2‐yl)−2,5‐diphenyltetrazolium bromide assay. Furthermore, reactive oxygen species formation, mitochondrial membrane potential, and oxidative stress markers such as thiobarbituric acid‐reactive substance, suproxide dismutase, and catalase were assayed. Rats were administered a different dose (10, 20, and 30 mg/kg/day) for a period of 4 weeks before a single dose of EtOH (40% vol/vol) 3 g/kg/day. EtOH administered rats appeared to have lower body weight gain, severe hepatic and kidney damage as proved by elevated aspartate transaminase, alanine transaminase, alkaline phosphatase, uric acid, increased malondialdehyde (MDA), and inflammatory markers, and reduced glutathione (GSH) levels. Results showed that the kirenol treatment enhanced the GSH and reduced MDA in the liver and renal tissues and restored TNF‐α and IL‐6. Histoanalysis proved the protective effects of kirenol. In conclusion, it was proved that the kirenol demonstrated a hepato‐protective effect in APAP‐ and EtOH‐induced liver toxicity in HepG2 cells and rats, respectively.
A strategy for proline and glycine mutations to proteins with alchemical free energy calculations
Authors: Hayes Ryan L. , Brooks Charles L. 
Published: April 2021

AbstractComputation of the thermodynamic consequences of protein mutations holds great promise in protein biophysics and design. Alchemical free energy methods can give improved estimates of mutational free energies, and are already widely used in calculations of relative and absolute binding free energies in small molecule design problems. In principle, alchemical methods can address any amino acid mutation with an appropriate alchemical pathway, but identifying a strategy that produces such a path for proline and glycine mutations is an ongoing challenge. Most current strategies perturb only side chain atoms, while proline and glycine mutations also alter the backbone parameters and backbone ring topology. Some strategies also perturb backbone parameters and enable glycine mutations. This work presents a strategy that enables both proline and glycine mutations and comprises two key elements: a dual backbone with restraints and scaling of bonded terms, facilitating backbone parameter changes, and a soft bond in the proline ring, enabling ring topology changes in proline mutations. These elements also have utility for core hopping and macrocycle studies in computer‐aided drug design. This new strategy shows slight improvements over an alternative side chain perturbation strategy for a set T4 lysozyme mutations lacking proline and glycine, and yields good agreement with experiment for a set of T4 lysozyme proline and glycine mutations not previously studied. To our knowledge this is the first report comparing alchemical predictions of proline mutations with experiment. With this strategy in hand, alchemical methods now have access to the full palette of amino acid mutations.
PP7080 expedites the proliferation and migration of lung adenocarcinoma cells via sponging miR‐670‐3p and regulating UHRF1BP1
Authors: Dan Weibin , Shi Lei , Wang Li , Wu Dahe , Huang Xiaofang , Zhong Yong 
Published: April 2021

AbstractBackgroundAn increasing body of evidence has revealed that long non‐coding RNAs play a significant part in a variety of human cancers, including lung adenocarcinoma (LUAD).MethodsThe expression of PP7080, miR‐670‐3p and UHRF1BP1 in LUAD cells and tissues was detected using a quantitative real‐time polymerase chain reaction. The role of PP7080 in LUAD cells was validated by CCK‐8, flow cytometry, colony formation, transwell and wound healing assays. The binding capacity between PP7080/UHRF1BP1 and miR‐670‐3p was confirmed by luciferase reporter assays. Moreover, the interactional mechanism among PP7080, miR‐670‐3p and UHRF1BP1 was determined by means of RNA immunoprecipitation and western blot assays.ResultsThe expression level of PP7080 is up‐regulated in LUAD cells and tissues compared to their matched controls. Down‐regulation of PP7080 restrained the proliferative and migratory abilities of LUAD cells, but induced cell apoptosis. PP7080 up‐regulation led to the opposite results. Moreover, the binding ability between miR‐670‐3p and PP7080/UHRF1BP1 in LUAD cells was confirmed. A rescue assay revealed that PP7080 contributes to LUAD development by modulating the miR‐670‐3p/UHRF1BP1 signaling pathway.ConclusionsPP7080 expedites the proliferation and migration of LUAD cell via sponging miR‐670‐3p and modulating UHRF1BP1.
Shape accuracy of fiber optic sensing for medical devices characterized in bench experiments
Authors: Megens Mischa , Leistikow Merel D. , van Dusschoten Anneke , van der Mark Martin B. , Horikx Jeroen J. L. , van Putten Elbert G. , Hooft Gert W. 't 
Published: April 2021

PurposeFiber Optic RealShape (FORS) is a new technology that visualizes the full three‐dimensional shape of medical devices, such as catheters and guidewires, using an optical fiber embedded in the device. This three‐dimensional shape provides guidance to clinicians during minimally invasive procedures, and enables intuitive navigation. The objective of this paper is to assess the accuracy of the FORS technology, as implemented in the current state‐of‐the‐art Philips FORS system. The FORS system provides the shape of the entire device, including tip location and orientation. We consider all three aspects.MethodsIn bench experiments, we determined the accuracy of the location and orientation of the tip by displacing and rotating the fiber end, while allowing the rest of the fiber to change shape freely. To test the accuracy of the full shape, we have placed the fiber in a groove, which was accurately machined in a thick, stiff metal “path plate.” We then compared the reconstructed shape with the known shape of the groove.ResultsThe tip location is found with submillimeter accuracy, and the orientation is sensed with milliradian accuracy. The shape of a fiber in the path plate faithfully follows the known shape of the groove, with typical deviation less than 0.5 mm in the plane of the plate. Out of plane accuracy, perhaps slightly less relevant clinically, is more challenging, due to the influence of twist; yet even out of the plane, the deviation is only submillimeter.ConclusionThe technology achieves submillimeter precision and provides full three‐dimensional shape, surpassing the reported precision of other navigation and tracking technologies, and therefore may potentially alleviate the need for fluoroscopy.
Characterization of a high‐resolution 2D transmission ion chamber for independent validation of proton pencil beam scanning of conventional and FLASH dose delivery
Authors: Zou Wei , Diffenderfer Eric S. , Ota Kan , Boisseau Paul , Kim Michele M. , Cai Yongliang , Avery Stephen M. , Carlson David J. , Wiersma Rodney D. , Lin Alexander , Koumenis Constantinos , Cengel Keith A. , Metz James M. , Dong Lei , Teo Boonkeng K. 
Published: April 2021

IntroductionUltra‐high dose rate (FLASH) radiotherapy has become a popular research topic with the potential to reduce normal tissue toxicities without losing the benefit of tumor control. The development of FLASH proton pencil beam scanning (PBS) delivery requires accurate dosimetry despite high beam currents with correspondingly high ionization densities in the monitoring chamber. In this study, we characterized a newly designed high‐resolution position sensing transmission ionization chamber with a purpose‐built multichannel electrometer for both conventional and FLASH dose rate proton radiotherapy.MethodsThe dosimetry and positioning accuracies of the ion chamber were fully characterized with a clinical scanning beam. On the FLASH proton beamline, the cyclotron output current reached up to 350 nA with a maximum energy of 226.2 MeV, with 210 ± 3 nA nozzle pencil beam current. The ion recombination effect was characterized under various bias voltages up to 1000 V and different beam intensities. The charge collected by the transmission ion chamber was compared with the measurements from a Faraday cup.ResultsCross‐calibrated with an Advanced Markus chamber (PTW, Freiburg, Germany) in a uniform PBS proton beam field at clinical beam setting, the ion chamber calibration was 38.0 and 36.7 GyE·mm2/nC at 100 and 226.2 MeV, respectively. The ion recombination effect increased with larger cyclotron current at lower bias voltage while remaining ≤0.5 ± 0.5% with ≥200 V of bias voltage. Above 200 V, the normalized ion chamber readings demonstrated good linearity with the mass stopping power in air for both clinical and FLASH beam intensities. The spot positioning accuracy was measured to be 0.10 ± 0.08 mm in two orthogonal directions.ConclusionWe characterized a transmission ion chamber system under both conventional and FLASH beam current densities and demonstrated its suitability for use as a proton pencil beam dose and spot position delivery monitor under FLASH dose rate conditions.
The antioxidant dieckol reduces damage of oxidative stress‐exposed porcine oocytes and enhances subsequent parthenotes embryo development
Authors: Pyeon Da‐Bin , Lee Seung‐Eun , Yoon Jae‐Wook , Park Hyo‐Jin , Park Chan‐Oh , Kim So‐Hee , Oh Seung‐Hwan , Lee Do‐Geon , Kim Eun‐Young , Park Se‐Pill 
Published: April 2021

AbstractThis study investigated the effect of the antioxidant dieckol, a component of Ecklonia cava, on maturation and developmental competence of porcine oocytes exposed to oxidative stress in vitro. Oocytes were matured in in vitro maturation (IVM) medium containing various concentrations of dieckol. The blastocyst formation rate was highest in the 0.5 μM dieckol‐treated (0.5 DEK) group. The reactive oxygen species level was decreased, and the level of glutathione and expression of antioxidant genes (NFE2L, SOD1, and SOD2) at metaphase II were increased in the 0.5 DEK group. Abnormal spindle organization and chromosome misalignment were prevented in the 0.5 DEK group. Expression of maternal markers (CCNB1 and MOS) and activity of p44/42 mitogen‐activated protein kinase were increased in the 0.5 DEK group. After parthenogenetic activation, the total number of cells per blastocyst was increased and the percentage of apoptotic cells was decreased in the 0.5 DEK group. Expression of development‐related genes (CX45, CDX2, POU5F1, and NANOG), antiapoptotic genes (BCL2L1 and BIRC5), and a proapoptotic gene (CASP3) were altered in the 0.5 DEK group. These results indicate that the antioxidant dieckol improves IVM and subsequent development of porcine oocytes and can be used to improve the quality of oocytes under peroxidation experimental conditions.
Cultural and linguistic adaptation of psychosocial measurements for latinx participants—Leveraging community‐engaged research methods
Authors: Nagy Gabriela A. , Solorzano Rosa , Stafford Allison M. , Mercado Emerson Maralis , Gonzalez‐Guarda Rosa 
Published: April 2021

AbstractPredominantly Spanish‐speaking Latinx individuals are underrepresented in research, and one primary barrier is the lack of infrastructure to effectively engage, among them, adequate cultural and linguistic adaptation of research measures. Capitalizing on existing recommendations for appropriate and ethical engagement of Latinx individuals in research, we present a comprehensive approach to cultural and linguistic adaptation, and describe the application of this approach in the context of an ongoing longitudinal, observational, community‐engaged study that follows a cohort of young adult Latinx immigrants (ages 18–44) in the Southeastern region of the United States who were predominantly Spanish‐speakers (N = 391). We describe barriers that researchers may face in their pursuit of cultural and linguistic adaptation and offset these challenges with tangible solutions. We discuss lessons learned through our application to a research study. This approach holds promise for reducing barriers to participation in research and health disparities in predominantly Spanish‐speaking Latinx individuals, who represent a population that is growing in size in the United States yet is still underrepresented as research participants and in the research workforce.
Synergistic effects of strontium carbonate on a novel intumescent flame‐retardant polypropylene system
Authors: Chen Kui , Cheng Jingwei , Wu Bin , Liu Chengjuan , Guo Jianing 
Published: April 2021

The effect of a synergistic flame‐retardant system with epoxy resin microcapsule modified ammonium polyphosphate (MAPP) as the primary flame retardant, and strontium carbonate (SrCO3) as the synergistic agent on the flame retardancy of polypropylene (PP) were studied. The flame‐retardant performance of the prepared PP composite samples was analyzed by vertical combustion test (UL94), limiting oxygen index (LOI) test, cone calorimeter test, infrared chromatography (FT‐IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and other technical means. The results showed that when the addition amount of SrCO3 was 1.5 wt%, the LOI reached 36.1%, and the UL‐94 test reached V‐0. Compared with no SrCO3 added sample, the peak heat release rate (PHRR) dropped from 395 to 378 kW/m2. The SEM data showed that the addition of SrCO3 enabled the flame‐retardant system to form a firmer char layer. The TGA data showed that SrCO3 catalyzes the MAPP reaction to form a cross‐linked structure and forms a bridge bond between the two phosphate groups to promote a stable carbon layer. Compared with no SrCO3 added sample, PP composite's tensile strength was increased from 26.78 to 29.42 MPa. Thus, a suitable amount of SrCO3 had a synergistic effect on the flame retardancy of the PP composite and had improved the system's mechanical properties.
Preparation of phytic acid‐based green intumescent flame retardant and its application in PLA nonwovens
Authors: Yang Yufan , Wang Xingguo , Fei Bin , Li Hongfei , Gu Xiaoyu , Sun Jun , Zhang Sheng 
Published: April 2021

AbstractAs a bio‐based and biodegradable textile, poly (lactic acid) (PLA) nonwovens are an important supplement for nature cotton, flax, and silk. This work concentrated on improving the flame retardancy of PLA nonwovens by introducing a novel eco‐friendly flame retardant (TPA), which was synthesized from phytic acid and tris(hydroxymethyl)methyl aminomethane. The structure, composition, and properties of TPA were fully characterized, and the results showed that TPA owned excellent thermal expansion performance. The flame retardancy of PLA nonwovens was efficiently improved by the presence of TPA. For PLA/23%TPA sample, the molten droplet was inhibited and the damaged area was decreased by 71.8%. The LOI value was increased from 18.0% of control PLA to 26.5%, and the peak heat release rate (pHRR) and total heat release rate (THR) were decreased by 30.2% and 29.0%, respectively. Besides, TG analysis confirmed a great char‐forming capability of the treated fabrics with the residue amount increasing from 1.8 to 11.6 wt% at 800°C. TPA released vapor, phosphorus radicals into the gas phase, and also promoted to form a compact char barrier in the condensed phase, which enhanced the carbonization and flame retardancy of PLA nonwovens. To our best knowledge, our work is one of the few studies focused on the flame retardancy of bio‐based PLA nonwovens.
On the kinetic theory of fracture based on thermomechanical properties for fatigue life prediction of filament wound carbon fiber/epoxy composite cylindrical shell
Authors: Nikpourian Hediyeh , Bahramian Ahmad Reza , Molaee Morteza 
Published: April 2021

AbstractThis work presents a model of kinetic theory of fracture for predicting the fatigue life of carbon fiber/epoxy composite ring from a combination of thermogravimetric analyses and Fourier transform infrared spectroscopy of mechanical tests under different loading strains and investigates the effect of environmental exposure on the surface morphology, thermal, and fatigue properties of the composite ring. Three kinetic parameters of the model are first calibrated by means of experimental data. Then, the model is capable of predicting the fatigue life of the composite ring under ambient condition. Eventually, the influence of material constant on the fatigue life of the composite ring is studied. The main result of this work is the arrangement of theory and tests to fatigue life prediction, and it is found that the acetone solution has more devastating effect on reduction in the fatigue strength and thermal degradation of the composite ring in comparison to KMnO4 solution.