bluuebunny/crossref_metadata_2025_split huggingface dataset:
A simple dosimetric approach to spatially fractionated GRID radiation therapy using the multileaf collimator for treatment of breast cancers in the prone position
Authors: Murphy Natasha L. , Philip Rino , Wozniak Matt , Lee Brian H. , Donnelly Eric D. , Zhang Hualin 
Published: October 2020

AbstractThe purpose of this study was to explore the treatment planning methods of spatially fractionated radiation therapy (SFRT), commonly referred to as GRID therapy, in the treatment of breast cancer patients using multileaf collimator (MLC) in the prone position. A total of 12 patients with either left or right breast cancer were retrospectively chosen. The computed tomography (CT) images taken for the whole breast external beam radiation therapy (WB‐EBRT) were used for GRID therapy planning. Each GRID plan was made by using two portals and each portal had two fields with 1‐cm aperture size. The dose prescription point was placed at the center of the target volume, and a dose of 20 Gy with 6‐MV beams was prescribed. Dose‐volume histogram (DVH) curves were generated to evaluate dosimetric properties. A modified linear‐quadratic (MLQ) radiobiological response model was used to assess the equivalent uniform doses (EUD) and therapeutic ratios (TRs) of all GRID plans. The DVH curves indicated that these MLC‐based GRID therapy plans can deliver heterogeneous dose distribution in the target volume as seen with the conventional cerrobend GRID block. The plans generated by the MLC technique also demonstrated the advantage for accommodating different target shapes, sparing normal structures, and reporting dose metrics to the targets and the organs at risks. All GRID plans showed to have similar dosimetric parameters, implying the plans can be made in a consistent quality regardless of the shape of the target and the size of volume. The mean dose of lung and heart were respectively below 0.6 and 0.7 Gy. When the size of aperture is increased from 1 to 2 cm, the EUD and TR became smaller, but the peak/valley dose ratio (PVDR) became greater. The dosimetric approach of this study was proven to be simple, practical and easy to be implemented in clinic.
Technical note: Generation of a Cerenkov scatter function convolution kernel for a primary proton beam
Authors: Thompson Steven A. 
Published: October 2020

AbstractPurposeTo generate a Cerenkov scatter function (CSF) for a primary proton beam and to study the dependence of the CSF on the irradiated medium.Materials and MethodsThe MCNP 6.2 code was used to generate the CSF. The CSF was calculated for light‐pigmented, medium‐pigmented, and dark‐pigmented stratified skin, as well as for a homogeneous optical phantom, which mimics the optical properties of human tissue. CSFs were generated by binning all of the Cerenkov photons which escape the back end (end opposite beam incidence) of a 20 × 20 × 20 cm phantom. A 4 × 4 cm, 500 × 500 bin grid was used to create a histogram of the Cerenkov photon flux on the simulated medium’s back surface (surface opposite beam incidence). A triple Gaussian was then used to fit the data.ResultsFrom the triple Gaussian fit, the coefficients of the CSF for the four phantom materials was generated. The individual CSF fit coefficient errors, with respect to the Gaussian representation, were found to be between 0.92% and 4.11%. The R2 value for the fit was calculated to be 0.99. The phantom material was found to have a significant effect (63% difference between materials) on the CSF amplitude and full width at half maximum (195% difference between materials). The difference in these parameters for the three skin pigments was found to be small.ConclusionsThe CSF was obtained for a proton beam using the MCNP 6.2 code for a phantom constructed of light, medium, and dark stratified human skin, as well as for an optical phantom. The CSFs were then fit with a triple‐Gaussian function. The coefficients can be used to generate a radially symmetric CSF, which can then be used to deconvolve a measured Cerenkov image to obtain the dose distribution.
Reconstructed Water Oxidation Electrocatalysts: The Impact of Surface Dynamics on Intrinsic Activities
Authors: Selvam N. Clament Sagaya , Du Lijie , Xia Bao Yu , Yoo Pil J. , You Bo 
Published: October 2020

AbstractElectroreduction of small molecules such as H2O, CO2, and N2 for producing clean fuels or valuable chemicals provides a sustainable approach to meet the increasing global energy demands and to alleviate the concern on climate change resulting from fossil fuel consumption. On the path to implement this purpose, however, several scientific hurdles remain, one of which is the low energy efficiency due to the sluggish kinetics of the paired oxygen evolution reaction (OER). In response, it is highly desirable to synthesize high‐performance and cost‐effective OER electrocatalysts. Recent advances have witnessed surface reconstruction engineering as a salient tool to significantly improve the catalytic performance of OER electrocatalysts. In this review, recent progress on the reconstructed OER electrocatalysts and future opportunities are discussed. A brief introduction of the fundamentals of OER and the experimental approaches for generating and characterizing the reconstructed active sites in OER nanocatalysts are given first, followed by an expanded discussion of recent advances on the reconstructed OER electrocatalysts with improved activities, with a particular emphasis on understanding the correlation between surface dynamics and activities. Finally, a prospect for clean future energy communities harnessing surface reconstruction‐promoted electrochemical water oxidation will be provided.
Isotope Effect in the Magneto‐Optoelectronic Response of Organic Light‐Emitting Diodes Based on Donor–Acceptor Exciplexes
Authors: Liu Xiaojie , Popli Henna , Kwon Ohyun , Malissa Hans , Pan Xin , Park Bumwoo , Choi Byoungki , Kim Sunghan , Ehrenfreund Eitan , Boehme Christoph , Vardeny Z. Valy 
Published: October 2020

AbstractThe isotope effect is studied in the magneto‐electroluminescence (MEL) and pulsed electrically detected magnetic resonance of organic light‐emitting diodes based on thermally activated delayed fluorescence (TADF) from donor–acceptor exciplexes that are either protonated (H) or deuterated (D). It is found that at ambient temperature, the exchange of H to D has no effect on the spin‐dependent current and MEL responses in the devices. However, at cryogenic temperatures, where the reverse intersystem crossing (RISC) from triplet to singlet exciplex diminishes, a pronounced isotope effect is observed. These results show that the RISC process is not governed by the hyperfine interaction as thought previously, but proceeds through spin‐mixing in the triplet exciplex. The observations are corroborated by electrically detected transient spin nutation experiments that show relatively long dephasing time at ambient temperature, and interpreted in the context of a model that involves exchange and hyperfine interactions in the spin triplet exciplex. These findings deepen the understanding of the RISC process in TADF materials.
Hydrogen‐Bonding‐Assisted Cationic Aqua Palladium(II) Complex Enables Highly Efficient Asymmetric Reactions in Water
Authors: Kitanosono Taku , Hisada Tomoya , Yamashita Yasuhiro , Kobayashi Shū 
Published: October 2020

AbstractMetal‐bound water molecules have recently been recognized as a new facet of soft Lewis acid catalysis. Herein, a chiral palladium aqua complex was constructed that enables carbon–hydrogen bonds of indoles to be functionalized efficiently. We embraced a chiral 2,2′‐bipyridine as both ligand and hydrogen‐bond donor to configure a robust, yet highly Lewis acidic, chiral aqua complex in water. Whereas the enantioselectivity could not be controlled in organic solvents or under solvent‐free conditions, the use of aqueous environments allowed the σ‐indolylpalladium intermediates to react efficiently in a highly enantioselective manner. This work thus describes a potentially powerful new approach to the transformation of organometallic intermediates in a highly enantioselective manner under mild reaction conditions.
Structural Basis of the Modulation of the Voltage‐Gated Calcium Ion Channel Cav1.1 by Dihydropyridine Compounds**
Authors: Gao Shuai , Yan Nieng 
Published: October 2020

Abstract1,4‐Dihydropyridines (DHP), the most commonly used antihypertensives, function by inhibiting the L‐type voltage‐gated Ca2+ (Cav) channels. DHP compounds exhibit chirality‐specific antagonistic or agonistic effects. The structure of rabbit Cav1.1 bound to an achiral drug nifedipine reveals the general binding mode for DHP drugs, but the molecular basis for chiral specificity remained elusive. Herein, we report five cryo‐EM structures of nanodisc‐embedded Cav1.1 in the presence of the bestselling drug amlodipine, a DHP antagonist (R)‐(+)‐Bay K8644, and a titration of its agonistic enantiomer (S)‐(−)‐Bay K8644 at resolutions of 2.9–3.4 Å. The amlodipine‐bound structure reveals the molecular basis for the high efficacy of the drug. All structures with the addition of the Bay K8644 enantiomers exhibit similar inactivated conformations, suggesting that (S)‐(−)‐Bay K8644, when acting as an agonist, is insufficient to lock the activated state of the channel for a prolonged duration.
Investigating the effect of silver nanorods embedded in polydimethylsiloxane matrix using nanoindentation and its use for flexible electronics
Authors: Maithani Yogita , Mehta Bodh Raj , Singh Jitendra Pratap 
Published: October 2020

AbstractThe stretchable electrodes with excellent flexibility, electrical conductivity, and mechanical durability are the most fundamental components in the emerging and exciting field of flexible electronics. This article proposes a method for fabrication of such a stretchable electrode by embedding silver nanorods (AgNRs) into a polydimethylsiloxane (PDMS) matrix that is grown by a unique glancing angle deposition technique. The surface, mechanical, and electrical properties of PDMS are significantly changed after embedding the AgNRs in it. The results show that surface roughness and polarity increase after AgNRs are embedded in the PDMS matrix. Elastic modulus (E) and hardness (H) decrease with an increase in the indentation load as a result of the indentation depth effect. Due to strong interfacial adhesion of AgNRs embedded in the PDMS matrix, the E and H of nanocomposite are increased by 167.6 and 93.3% compared with PDMS film, respectively. Furthermore, the AgNRs‐PDMS film has an electrical resistivity value in the order of 10−7 Ωm. It remains conductive during various mechanical strains such as bending, twisting, and stretching, which is demonstrated using a light‐emitting diode circuit. Simultaneously, the antimicrobial activity of silver could make it a promising candidate for wearable electronics.
Quaternized poly (2,6‐dimethyl‐1,4‐phenylene oxide) crosslinked by tertiary amine and siloxane for anion exchange membranes
Authors: Ding Ao , Zhou Jinyue , Cheng Xiangze , Shen Chunhui , Gao Shanjun 
Published: October 2020

AbstractA series of tertiary amine and siloxane crosslinked composite anion exchange membranes were prepared by incorporating 2‐(3,4‐epoxycyclohexyl) ethyltrimethoxysilane (EHTMS) and N,N,N′,N′‐Tetramethyl‐1,6‐hexanediamine (TMHDA) into N‐Methyldiethanolamine (MDEA)‐functionalized poly (2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) backbone via sol‐gel process. The resultant membranes named as AEM‐X (X = 1, 2, 3, 4), which own a three‐dimensional (3D) cross‐linking structure, exhibit superior swelling resistance, mechanical properties, even the thermal stability is up to 220°C. Compared with AEM‐1 (contains no crosslinker), the swelling ratio of AEM‐2 obviously decreases by 10.2% at 80°C, while the OH− conductivity of AEM‐2 has a merely 1.9% decline (20.6 mS cm−1) at 80°C and can maintain 67% of its initial value in a 2 M aqueous NaOH at 80°C for 240 h. The simultaneous introduction of inorganic siloxane and organic linear crosslinker provides a new idea for the preparation of anion exchange membranes with largely improvement in dimensional stability and alkali resistance while the ionic conductivity is kept at comparatively high level.
An efficient protocol for functional studies of apple transcription factors using a glucocorticoid receptor fusion system
Authors: Estevan Joan , Gómez‐Jiménez Sara , Falavigna Vítor da Silveira , Camuel Alicia , Planel Lisa , Costes Evelyne , Andrés Fernando 
Published: October 2020

PremiseWe report a protocol for studying the function of apple (Malus ×domestica) transcription factors based on the glucocorticoid receptor (GR) system, which allows the dexamethasone (DEX)‐mediated activation of plant transcription factors to monitor the expression levels of their potential target genes.Methods and ResultsApple leaves are transformed with a vector that allows the expression of the studied transcription factor (i.e., FLOWERING LOCUS C [MdFLC]) fused to GR. Calli derived from the transformed leaves are treated with DEX and cycloheximide, a protein synthesis inhibitor. Compared with other methods, combining the GR system with cycloheximide treatments enables the differentiation between direct and indirect transcription factor target genes. Finally, the expression levels of putative MdFLC target genes are quantified using quantitative reverse transcription PCR.ConclusionsWe demonstrate the efficiency of our GR system to study the function of apple transcription factors. This method is accessible to any laboratory familiar with basic molecular cloning procedures and the apple leaf–mediated agro‐transformation technique.
Topographical and structural characterization of the V1–V2 transition zone in the visual cortex of the long‐finned pilot whale Globicephala melas (Traill, 1809)
Authors: Graïc Jean‐Marie , Peruffo Antonella , Grandis Annamaria , Cozzi Bruno 
Published: October 2020

AbstractThe visual system of cetaceans is at best poorly understood. With a handful of electrophysiological studies and a limited number of histological preparations from well‐preserved specimen, the investigation of the principles underlying the cortical organization in cetaceans remains a challenge. In the course of our current investigation, we identified the transition from V2 to V1 in the long‐finned pilot whale Globicephala melas, only recognizable through immunocytochemistry, and a similar if not homologue transition in the sheep Ovis aries. Our results emphasize the importance of differential pattern recognition in which the application of different markers uncovers a diversity in a delphinid’s cortex, formerly widely considered as uniform and archetypal. In fact, the evidence that we present suggests the existence of relatively unacknowledged areas beyond the well‐known sensory territories in cetaceans.
Non‐minimal state space model predictive control using Laguerre functions for reference tracking
Authors: Liu Meng , Wu Hao , Wang Jun , Wang Changlin 
Published: October 2020

AbstractThis paper presents a new design of model predictive control which combines non‐minimal state space (NMSS) and Laguerre functions. The utilization of NMSS omits the observer design process and brings convenience to multi‐input, multi‐output systems with time delay. But the dimensions of NMSS are high, which is harmful to online computation. The use of Laguerre functions helps reduce the data required in the optimization algorithm and makes up for the deficiency of NMSS. A modified solution for the optimal tracking problem using NMSS and Laguerre functions is proposed. Although the choice of the parameters in Laguerre functions needs experiments and experience, the method presented in this paper brings convenience to MPC design. Simulation results show that this approach not only reduces the computing effort without sacrificing the control performance significantly, but also has a good robustness to interference when tracking.
Pharmacokinetics and tissue distribution study of obtusifolin in rats by liquid chromatography–tandem mass spectrometry
Authors: Huang Zhu , Sun Qiao , Hao Wenwen , Zhao Junyu 
Published: October 2020

AbstractThis paper reports the validation of an assay for obtusifolin based on liquid chromatography–tandem mass spectrometry (LC–MS/MS) and its application to a preclinical pharmacokinetic study in rats. After sample preparation of plasma and tissue homogenates by protein precipitation, the analyte and internal standard (IS) were separated by a reversed‐phase chromatographic system in a run time of 5.0 min and detected by negative ion electrospray ionization followed by selected reaction monitoring of the precursor‐to‐product ion transitions at m/z 283.0–268.1 for obtusifolin and m/z 329.0–314.1 for IS. The assay was linear in the concentration range 1.0–500 ng/ml with the LLOQ of 1.0 ng/ml. In the pharmacokinetic study of an intragastric administration of 1.3 mg/kg obtusifolin, the maximum plasma concentration of obtusifolin was 152.5 ± 62.3 ng/ml, reached at 0.39 ± 0.17 h. The AUC0–t and AUC0–∞ were 491.8 ± 256.7 and 501.7 ± 256.7 ng × h/ml, respectively, with an elimination half‐life of 3.1 ± 0.7 h. Obtusifolin was rapidly distributed into tissues, with the highest distribution in the liver and less in the brain. These results will give some insights for further pharmacological investigation of obtusifolin.
Plasma amino acid metabolomic pattern in heart failure patients with either preserved or reduced ejection fraction: The relation to established risk variables and prognosis
Authors: Saleem Tahia H. , Algowhary Magdy , Kamel Fatma Elzahraa M , El‐Mahdy Reham I 
Published: October 2020

AbstractCommunication between amino acids (AAs) and heart failure (HF) is unclear. We evaluate the plasma metabolomic profile of AAs in HF and its subgroups and association with clinical features. This is a case–control study in which 90 patients with HF, 63 with reduced ejection fraction (HFrEF) and 27 with preserved ejection fraction (HFpEF), were compared with 60 controls. The quantitative measurement of plasma concentrations of AA metabolites was performed using an AA analyzer. Compared with controls, HF patients had significantly higher levels of nine AAs and significantly lower levels of seven AAs. Leu, phenylalanine (Phe), and methionine (Met) were the independent predictors of HF that remained significant after adjustment for confounding factors in multivariate analysis. There was a significant difference in 10 AAs and some clinical features between HFpEF and HFrEF. The plasma levels of six AAs were significantly increased across the different New York Heart Association (NYHA) classes, (class II, class III, class IV) but they were not predictor of reduced EF and NYHA in multivariate regression analysis. There were significant associations between Leu, Phe, and Met with cardiovascular risk variables and prognosis. In conclusion, plasma Leu, Phe, and Met provide early prediction and prognostic values of HF. The plasma AAs could have significant impact on the risk‐stratifying HFrEF and HFpEF and NYHA functional class but do not predict them.
Comparative pharmacokinetics of seven bioactive components in normal, sham‐operated, and myocardial ischemia–reperfusion injury rats after oral administration of the Salvia Miltiorrhiza–Moutan Cortex herb pair
Authors: Yang Haotian , Qiu Bo , Xue Chaojun , Guo Caihui , Dong Zhanjun 
Published: October 2020

AbstractRecently the Salvia Miltiorrhiza–Moutan Cortex (SM‐MC) herb pair is considered as a promising Chinese medicinal mixture exhibiting a range of pharmacological activities, including treating cardiovascular disease due to its unique composition. In this study, we conducted the comparative pharmacokinetic analysis of seven main bioactive components of SM‐MC in a different model rat. A straightforward ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) strategy that could simultaneously evaluate the levels of seven compounds was used to ensure the reliability of these pharmacokinetic analyses in rat plasma. The rat plasma samples were collected from normal, sham‐operated, and myocardial ischemia–reperfusion injury (MIRI) groups at predetermined time points after the administration of SM‐MC. The main pharmacokinetic parameters were detected and calculated. We successfully assessed the maximum concentration (Cmax), time to Cmax (Tmax), the elimination rate constant (λz), total half‐life (t1/2), total body clearance (CL), and the area under the concentration–time curve from 0 to last sampling time (AUC0–t) and extrapolated to infinity (AUC0–∞). To sum up, an optimized UPLC‐MS/MS approach that could be used to rapidly, simultaneously, and sensitively detect seven bioactive compounds derived from SM‐MC extract preparations was successfully developed, which may offer a pharmacokinetic basis for preclinical and clinical studies of SM‐MC herb pair for treating MIRI.
Verbascum nigrum: Cytotoxicity Evaluation in A431 Epidermoid Carcinoma Cells and Untargeted LC‐HR‐MS/MS Metabolite Profiling
Authors: Iliescu Iolanda Alca , Peter Samuel , Albert Ina , Skalicka‐Woźniak Krystyna , Miron Anca , Luca Simon Vlad , Wolfram Evelyn 
Published: October 2020

AbstractThe crude methanolic extract obtained from Verbascum nigrum aerial parts (VNE) and its six fractions (VNF1–VNF6) were initially screened regarding their effects on the viability of immortalized HaCaT keratinocytes and A431 epidermoid carcinoma cells (MTT assay, 24 h). None of the tested samples affected the viability of HaCaT cells in a concentration range of 25–150 μg/mL. VNE and VNF4 exhibited significant cytotoxic effects in A431 cells, with IC50 values of 81.92 and 12.27 μg/mL, respectively; the selectivity index was higher than 10 for VNF4. The untargeted LC/HR‐MS/MS metabolite profiling led to the tentative annotation of a total number of 23 compounds. Of these, VNE comprised mainly iridoid glycosides (harpagoside, laterioside, acylated aucubin derivatives), whereas VNF4 showed a high abundance of triterpene saponin glycosides (ilwensisaponins A and C, songarosaponins A and B), constituents known for their selective cytotoxic potential.
Highly Active and Stable Palladium Catalysts Supported on Surface‐modified Ceria Nanowires for Lean Methane Combustion
Authors: Wu Mingwei , Li Wenzhi , Ogunbiyi Ajibola T. , Guo Ge , Xue Fengyang , Chen Kun , Zhang Baikai 
Published: October 2020

AbstractAn efficient strategy was presented to synthesize highly active palladium catalyst supported on ceria nanowires modified by organosilanes (abbreviated as Pd/CeO2NWs@SiO2) for lean methane combustion. It is found that such a surface‐modified strategy can significantly improve the dispersion of surface palladium species and strengthen the concentration of active surface‐adsorbed oxygen species via reconstructing the surface microenvironment, invoking an efficient performance for methane oxidation. Under the space velocity of 60,000 mLg−1h−1, 0.5 wt% Pd/CeO2NWs@SiO2 displayed extraordinary catalytic activity with 90 % conversion rate at a temperature of around 327 °C, far lower than that of pristine Pd/CeO2NWs (378 °C) under the same conditions. What's more, unexpected stability was observed under high temperature and the presence of water vapor conditions owing to the intense metal support interaction of Pd/CeO2NWs@SiO2 catalyst. The possible reaction mechanism of lean methane oxidation was probed by in situ DRIFT spectra. It is observed that the pivotal intermediate products (carbonate and carbon oxygenates) generated on Pd/CeO2NWs@SiO2 surface are more readily decomposed into CO2. Importantly, the silicon hydroxyl groups (Si−OH) formed during the reaction can efficiently restrict the generation of the stable Pd(OH)x phase and release more active sites to facilitate the catalytic performance. This study provides a convenient method to design the highly reactive and durable palladium‐based catalyst for methane combustion.