bluuebunny/crossref_metadata_2025_split huggingface dataset:
Procedure for optimal implementation of automatic tube potential selection in pediatric CT to reduce radiation dose and improve workflow
Authors: Browne Jacinta E. , Bruesewitz Michael R. , Thomas Vrieze , Thomas Kristen B. , Hull Nathan C. , McCollough Cynthia H. , Yu Lifeng 
Published: December 2020

AbstractIt is important to employ radiation dose reduction techniques in pediatric computed tomography (CT) to reduce potential risks of radiation‐induced malignancy. Automatic tube potential (kV) selection tools have been developed and become available on many CT scanners, which select the optimum kV based on the patient size and clinical task to improve the radiation dose efficiency. However, its use in pediatric CT has been mostly empirical, following manufacturer’s default recommendation without solid demonstration for quality improvement. This study aimed to implement an automatic tube potential tool (CAREkV, Siemens Healthcare) into routine pediatric CT practice, using the “Plan‐Do‐Study‐Act” quality improvement process, in place of an existing kV/mAs technique chart. The design of this quality improvement project involved Plan‐Do‐Study‐Act stages. Plan and Do stages identified the criteria for optimal automatic kV selection; a range of phantoms representing typical pediatric groups were scanned on a dual‐source 128‐slice scanner using a fast‐pitch scanning mode. The identified CAREkV settings were implemented into the CT protocol and evaluated after a 6‐month period. In the Study stage, an objective evaluation of the image metrics and radiation dose for two similar patient cohorts using CAREkV and the technique‐chart, respectively, were compared. The kV selected, image quality and radiation dose determined by CAREkV were comparable to those obtained while using the technique‐chart. The CAREkV was successfully implemented into our pediatric abdominopelvic CT practice. By utilizing the “PDSA” process optimal image quality and radiation dose reduction were achieved with an automatic kV selection tool to improve CT workflow.
Clinical experience of MRI4D QUASAR motion phantom for latency measurements in 0.35T MR‐LINAC
Authors: Kim Taeho , Lewis Benjamin , Lotey Rajiv , Barberi Enzo , Green Olga 
Published: December 2020

AbstractPurposeIn MRgRT, accuracy of treatment depends on the gating latency, when real‐time targeting and gating is enabled. Gating latency is dependent on image acquisition, processing time, accuracy, efficacy of target tracking algorithms, and radiation beam delivery latency. In this report, clinical experience of the MRI4D QUASAR motion phantom for latency measurements on a 0.35‐T magnetic resonance‐linear accelerator (MR‐LINAC) with two imaging speeds and four tracking algorithms was studied.Materials/MethodsBeam‐control latency was measured on a 0.35‐T MR‐LINAC system with four target tracking algorithms and two real‐time cine imaging sequences [four and eight frames per second (FPS)]. Using an MR‐compatible motion phantom, the delays between phantom beam triggering signal and linac radiation beam control signal were evaluated for three motion periods with a rigid target. The gating point was set to be 8 mm above the full exhalation position. The beam‐off latency was measured for a total of 24 combinations of tracking algorithm, imaging FPS, and motion periods. The corresponding gating target margins were determined using the target motion speed multiplied by the beam‐off latency.ResultsThe largest measured beam‐off latency was 302 ± 20 ms with the Large Deforming Targets (LDT) algorithm and 4 s motion period imaged with 8‐FPS cine MRI. The corresponding gating uncertainty based on target motion speed was 3.0 mm. The range of the average beam‐off latency was 128–243 ms in 4‐FPS imaging and 47–302 ms in 8‐FPS imaging.ConclusionsThe gating latency was measured using an MRI4D QUASAR motion phantom in a 0.35‐T MR‐LINAC. The latency measurements include time delay related to MR imaging method, target tracking algorithm and system delay. The gating uncertainty was estimated based on the beam‐off latency measurements and the target motion.
Clinical and imaging characteristics of breast ductal carcinoma in situ with microinvasion
Authors: Han Sijia , Qiu Fang , Han Ye , Xu Yongqing , Yin Jianqiao , Xing Fei , Bian Xiaobo , He Guijin 
Published: December 2020

AbstractBackgroundWe analyzed the clinical and imaging characteristics of patients with breast ductal carcinoma in situ with microinvasion (DCISM) and breast ductal carcinoma in situ (DCIS).MethodsWe analyzed the records of 40 patients diagnosed with DCISM and 61 patients with DCIS who were hospitalized at Shengjing Hospital (Shenyang, China) from January 2009 to June 2016. The size, hardness, and degree of calcification of tumors were determined by mammography and ultrasonography.ResultsIn all, 37 DCISM patients and 45 DCIS patients showed clinical palpable masses (92.5% vs 73.77%, P = 0.018). Mammography showed that the mean size of tumor was larger in DCISM patients than that of DCIS patients (3.13 ± 1.51 vs 2.68 ± 1.77, P = 0.030). Ultrasound examination revealed calcification shadows in the solid tumor mass in 17 DCISM cases and 11 DCIS patients (42.5 vs 18.03%, P = 0.007). Furthermore, estrogen receptor positivity and progesterone receptor positivity were more common in DCIS patients (32.5% vs 54.10%, P = 0.033; 22.5% vs 45.90%, P = 0.017), and the percentage of menopausal patients were higher in DCISM patients than that of DCIS patients (70.00% vs 47.54%, P = 0.026).ConclusionClinically palpable and calcified tumor masses on sonography are more commonly encountered in DCISM lesions.
Biodegradable Zwitterionic Cream Gel for Effective Prevention of Postoperative Adhesion
Authors: Zhang Ershuai , Yang Jianhai , Wang Ke , Song Boyi , Zhu Hui , Han Xiangfei , Shi Yuanjie , Yang Chengbiao , Zeng Zhipeng , Cao Zhiqiang 
Published: December 2020

AbstractPostoperative peritoneal adhesions are frequent complications for almost any type of abdominal and pelvic surgery. This leads to numerous medical problems and a huge financial burden to the patients. Current anti‐adhesion strategies focus mostly on physical barriers including films and hydrogels. However, they can only alleviate or reduce adhesions to a certain level and their applying processes are far from ideal. This work reported the development of a biodegradable zwitterionic cream gel presenting a series of characters for an ideal anti‐adhesion material, including unique injectable yet malleable and self‐supporting properties, which enables an instant topical application, no curing, waiting, or suturing, no hemostasis requirement, protein/cell resistance, and biodegradability. The cream gel shows a major advancement in anti‐adhesion efficacy by completely and reliably preventing a primary and more severe recurrent adhesion in rat models.
Nanocellulose‐Reinforced Hydroxyapatite Nanobelt Membrane as a Stem Cell Multi‐Lineage Differentiation Platform for Biomimetic Construction of Bioactive 3D Osteoid Tissue In Vitro
Authors: Liu Feng , Wei Benjie , Xu Xiaoying , Ma Baojin , Zhang Shan , Duan Jiazhi , Kong Ying , Yang Hongru , Sang Yuanhua , Wang Shuhua , Tang Wei , Liu Chao , Liu Hong 
Published: December 2020

AbstractSevere bone defects, especially accompanied by vascular and peripheral nerve injuries, remain a massive challenge. Most studies related to bone tissue engineering have focused on osteogenic differentiation of mesenchymal stem cells (MSCs), and ignored the formation of blood vessels and nerves in the newly generated bone owing to the lack of proper materials and methodology for tuning stem cells differentiated into osteogenic, neuronal, and endothelial cells (ECs) in the same scaffold system. Herein, a nanocellulose‐reinforced hybrid membrane with good mechanical properties and control over biodegradation by assembling ultralong hydroxyapatite nanobelts in a bacterial nanocellulose hydrogel is designed and synthesized. Osteogenic, neuronal cells are successfully differentiated on this hybrid membrane. Based on the multi‐lineage differentiation property of the membrane, a bioactive 3D osteoid tissue (osteogenic, neural, and ECs) is mimetically constructed in vitro using layer‐by‐layer culture and integration. The bone regeneration ability of the as‐prepared bioactive osteoid tissue is assessed in vivo via heterotopic osteogenesis experiments for eight weeks. The rapid new bone growth and formation of blood capillaries and nerve fibers prove that the hybrid membrane can be universally applied as a stem cell multi‐lineage differentiation platform, which has significant applications in bone tissue engineering.
Anharmonicity‐Driven Rashba Cohelical Excitons Break Quantum Efficiency Limitation
Authors: Myung Chang Woo , Kim Kwang S. 
Published: December 2020

AbstractClosed‐shell light‐emitting diodes (LEDs) suffer from the internal quantum efficiency (IQE) limitation imposed by optically inactive triplet excitons. Here, an unrevealed emission mechanism of lead halide perovskites (LHPs) APbX3 (A = Cs/CN2H5; X = Cl/Br/I) that circumvents the efficiency limit of closed‐shell LEDs is explored. Though efficient emission is prohibited by optically inactive J = 0 in inversion symmetric LHPs, the anharmonicity arising from stereochemistry of Pb and resonant orbital‐bonding network along the imaginary A+…X−(T1u) transverse optical (TO) modes, breaks inversion symmetry, introducing disorder and Rashba–Dresselhaus spin‐orbit coupling (RD‐SOC). This results in bright cohelical and dark antihelical excitons. Many‐body theory and first‐principles calculations show that the optically active cohelical exciton is the lowest excited state in organic/inorganic LHPs. Thus, RD‐SOC can drive to achieve the ideal 50% IQE by utilizing anharmonicity, much over the 25% IQE limitation for closed‐shell LEDs.
Water‐Surface Drag Coating: A New Route Toward High‐Quality Conjugated Small‐Molecule Thin Films with Enhanced Charge Transport Properties
Authors: Deng Wei , Xiao Yanling , Lu Bei , Zhang Liang , Xia Yujian , Zhu Chenhui , Zhang Xiujuan , Guo Jinghua , Zhang Xiaohong , Jie Jiansheng 
Published: December 2020

AbstractElectronic properties of organic semiconductor (OSC) thin films are largely determined by their morphologies and crystallinities. However, solution‐processed conjugated small‐molecule OSC thin films usually exhibit abundant grain boundaries and impure grain orientations because of complex fluid dynamics during solution coating. Here, a novel methodology, water‐surface drag coating, is demonstrated to fabricate high‐quality OSC thin films with greatly enhanced charge transport properties. This method utilizes the water surface to alter the evaporation dynamics of solution to enlarge the grain size, and a unique drag‐coating process to achieve the unidirectional growth of organic crystals. Using 2,8‐difluoro‐5,11‐bis(triethylsilylethynyl)anthradithiophene (Dif‐TES‐ADT) as an example, thin films with millimeter‐sized single‐crystal domains and pure crystallographic orientations are achieved, revealing a significant enhancement (4.7 times) of carrier mobility. More importantly, the resulting film can be directly transferred onto any desired flexible substrates, and flexible transistors based on the Dif‐TES‐ADT thin films show a mobility as high as 16.1 cm2 V−1 s−1, which represents the highest mobility value for the flexible transistors reported thus far. The method is general for the growth of various high‐quality OSC thin films, thus opening up opportunities for high‐performance organic flexible electronics.
Assessing the Applicability of Gravity Separation for Recycling of Non‐Metal Fraction from Waste Printed Circuit Boards
Authors: Kumar Amit , Holuszko Maria E. , Janke Travis 
Published: December 2020

AbstractPrinted circuit boards (PCB) are one of the most studied electronic waste streams due to the presence of high‐value metals. The rejects from waste PCB recycling, also known as a non‐metal fraction (NMF), are usually sent to landfill. This work explores the applicability of gravity separation, widely used in the mineral processing industry, to separate organic and inorganic components in the NMF. The float‐sink test is conducted to understand the gravity separation performance, and the results show that a 47% yield at 86% organic content with 70% combustible recovery can be obtained using dense media separation. The washability behavior of NMF is assessed using different washability indices standard in the coal industry; and the material is classified as difficult‐to‐clean. The float‐sink products show the concentration of organic stream in −1.8 g cm−3 range, fiberglass in +2.0–2.5 g cm−3 range, and metals in +2.5 g cm−3 range. The recovery of these components will facilitate the concept of the circular economy and promote sustainability.
Alloying Nickel with Molybdenum Significantly Accelerates Alkaline Hydrogen Electrocatalysis
Authors: Wang Miao , Yang Hao , Shi Jinan , Chen Yufeng , Zhou Yuan , Wang Liguang , Di Sijia , Zhao Xuan , Zhong Jun , Cheng Tao , Zhou Wu , Li Yanguang 
Published: December 2020

AbstractBifunctional hydrogen electrocatalysis (hydrogen‐oxidation and hydrogen‐evolution reactions) in alkaline solution is desirable but challenging. Among all available electrocatalysts, Ni‐based materials are the only non‐precious‐metal‐based candidates for alkaline hydrogen oxidation, but they generally suffer from low activity. Here, we demonstrate that properly alloying Ni with Mo could significantly promote its electrocatalytic performance. Ni4Mo alloy nanoparticles are prepared from the reduction of molybdate‐intercalated Ni(OH)2 nanosheets. The final product exhibits an apparent hydrogen‐oxidation activity exceeding that of the Pt benchmark and a record‐high mass‐specific kinetic current of 79 A g−1 at an overpotential of 50 mV. A superior hydrogen‐evolution performance is also measured in alkaline solution. These experimental data are rationalized by our theoretical simulations, which show that alloying Ni with Mo significantly weakens its hydrogen adsorption, improves the hydroxyl adsorption and decreases the reaction barrier for water formation.
Synthesis and Reactivity of Multinuclear Gold Complexes with (Diphenylphosphanyl)ferrocene and Oxygen Ligands
Authors: Schulz Jiří , Císařová Ivana , Gyepes Róbert , Štěpnička Petr 
Published: December 2020

AbstractAuI complexes combining hard oxygen and soft (diphenylphosphanyl)ferrocene (L) ligands in their molecules were synthesized, viz. the gold hydroxides [Au(OH)(L‐κP)] (5) and [{Au(L‐κP)}2(μ‐OH)][BF4] (4), and the oxonium cluster [{Au(L‐κP)}3(μ3‐O)][BF4] (1). In‐situ auration of 1 produced [{Au(L‐κP)}4(μ4‐O)][BF4]2 (2), which spontaneously converted into a dimeric tetragold complex featuring bridging phosphanylferrocenyl groups geminally diaurated in position 2 of the ferrocene scaffold. The same complex and its isomer incorporating ferrocene‐1,1′‐diyl bridges resulted similarly from 4. Upon crystallization, compound 5 underwent a redox reaction, producing a structurally unique, crown‐like, mixed‐valent Au0/AuI cluster, [Au7(L‐κP)6]OH. Compounds 1 and 5 were used to prepare the analogous, N‐bridged complexes, [{Au(L‐κP)}3(μ3‐NFc)][BF4] (Fc=ferrocenyl) and [{Au(L‐κP)}4(μ4‐N)][BF4]. The compounds were structurally characterized and further studied by DFT calculations.
Photochemical Electrocyclization of Poly(phenylacetylene)s: Unwinding Helices to Elucidate their 3D Structure in Solution
Authors: Rey‐Tarrío Francisco , Rodríguez Rafael , Quiñoá Emilio , Riguera Ricardo , Freire Félix 
Published: December 2020

AbstractPhotochemical electrocyclization of poly(phenylacetylene)s (PPAs) is used for the structural elucidation of a polyene backbone. This method not only allows classification of PPAs in cis‐cisoidal (ω1<90°) or cis‐transoidal structures (ω1>90°), but also approximating ω1. A PPA solution is illuminated with visible light and monitoring the photochemical electrocyclization of the PPA helix by measuring the ECD spectra at different times. PPAs with a cis‐cisoidal structure show a reduction of the ECD signal of at least 50 % before 30 min of irradiation, while cis‐transoidal helices need much longer time because the transoidal bond must be isomerized. The different cis‐cisoidal and cis‐transoidal helices require different times to decrease their ECD signal by 50 % (t1/2), depending on the degree of compression or stretching of the helix, establishing a relationship between the secondary structure adopted by PPA (ω1) and the time required to lose the ECD vinylic signal by light irradiation.
Multimodal Imaging of Autofluorescent Sites Reveals Varied Chemical Speciation in SSZ‐13 Crystals
Authors: Omori Naomi , Candeo Alessia , Mosca Sara , Lezcano‐Gonzalez Ines , Robinson Ian K. , Li Luxi , Greenaway Alex G. , Collier Paul , Beale Andrew M. 
Published: December 2020

AbstractA multimodal imaging study of chabazite is used to show the distribution of and discriminate between different emissive deposits arising as a result of the detemplation process. Confocal imaging, 3D fluorescence lifetime imaging, 3D multispectral fluorescence imaging, and Raman mapping are used to show three different types of emissive behaviours each characterised by different spatial distributions, trends in lifetime, spectral signals, and Raman signatures. A notable difference is seen in the morphology of agglomerated surface deposits and larger subsurface deposits, which experience lifetime augmentation due to spatial confinement. The distribution of organic residue throughout the crystal volume is comparable to XRF mapping that shows Si enrichment on the outer edges and higher Al content through the centre, demonstrating that a fluorescence‐based technique can also be used to indirectly comment on the compositional chemistry of the inorganic framework.
Long‐Range Exciton Migration in Coassemblies: Achieving High Photostability without Disrupting the Electron Donation of Fluorene Oligomers
Authors: Cheng Chuanqin , Gong Yanjun , Guo Yongxian , Cui Linfeng , Ji Hongwei , Yuan Hong , Jiang Lang , Zhao Jincai , Che Yanke 
Published: December 2020

AbstractIn this work, photostable coassemblies from a nonphotostable fluorene oligomer (the energy donor) and a photostable oligomer (the energy acceptor) are fabricated. Long‐range exciton migration over a net distance of about 370 energy‐donor molecules to energy acceptors is demonstrated in such coassemblies. The fast and long energy migration allows harvesting of the excitation energy of energy donors by embedding a small number of energy acceptors for photostability enhancement. Importantly, embedding a small number of energy acceptors in coassemblies causes a negligible negative influence on the electron donation of energy donors that are desired in practical applications. The advantages of the coassemblies fabricated, that is, high photostability without disrupting the electron donation of energy donors, are well illustrated in fluorescence detection of trace explosives where prolonged working life and improved detection capacity are achieved.
Convergent Total Synthesis of Yaku'amide A
Authors: Cai Yu , Ma Zhiwei , Jiang Jintao , Lo Concordia C. L. , Luo Shi , Jalan Ankur , Cardon Joseph M. , Ramos Alexander , Moyá Diego A. , Joaquin Daniel , Castle Steven L. 
Published: December 2020

AbstractTotal synthesis of the anticancer peptide natural product yaku'amide A is reported. Its β‐tert‐hydroxy amino acids were prepared by regioselective aminohydroxylation involving a chiral mesyloxycarbamate reagent. Stereospecific construction of the E‐ and Z‐ΔIle residues was accomplished through a one‐pot reaction featuring anti dehydration, azide reduction, and O→N acyl transfer. Alkene isomerization was negligible during this process. These methods enabled a highly convergent and efficient synthetic route to the natural product.
Current Trends in Metal–Organic and Covalent Organic Framework Membrane Materials
Authors: Hosseini Monjezi Bahram , Kutonova Ksenia , Tsotsalas Manuel , Henke Sebastian , Knebel Alexander 
Published: December 2020

AbstractMetal–organic frameworks (MOFs) and covalent organic frameworks (COFs) have been thoroughly investigated with regards to applications in gas separation membranes in the past years. More recently, new preparation methods for MOFs and COFs as particles and thin‐film membranes, as well as for mixed‐matrix membranes (MMMs) have been developed. We will highlight novel processes and highly functional materials: Zeolitic imidazolate frameworks (ZIFs) can be transformed into glasses and we will give an insight into their use for membranes. In addition, liquids with permanent porosity offer solution processability for the manufacture of extremely potent MMMs. Also, MOF materials influenced by external stimuli give new directions for the enhancement of performance by in situ techniques. Presently, COFs with their large pores are useful in quantum sieving applications, and by exploiting the stacking behavior also molecular sieving COF membranes are possible. Similarly, porous polymers can be constructed using MOF templates, which then find use in gas separation membranes.
Cooperative Stapling of Native Peptides at Lysine and Tyrosine or Arginine with Formaldehyde
Authors: Li Bo , Tang Hong , Turlik Aneta , Wan Zhao , Xue Xiao‐Song , Li Li , Yang Xiaoxiao , Li Jiuyuan , He Gang , Houk Kendall N. , Chen Gong 
Published: December 2020

AbstractStapling of peptides by intramolecular crosslinking of two neighboring amino acid side chains offers an important tool to modulate the structure and properties of peptides. In comparison to the stapling of artificially engineered peptide substrates, methods for stapling native peptides are more desirable for easier accessibility and genetic encodability. However, the existing strategy for selectivity control in the stapling of native peptides is relatively limited: the site of anchoring is often dominated by Cys, and the means for achieving the position selectivity among the same type of residues at different locations is lacking. We have developed a simple and powerful strategy for stapling native peptides at lysine residues with formaldehyde by the cooperation of nearby tyrosine or arginine residues. The stapling reactions can proceed with high efficiency and residue selectivity under mild conditions, and generate linchpins with distinct physiochemical properties. The new method for peptide stapling enables unique control of position‐selectivity for substrates bearing multiple reaction sites by reactivity that can be readily built in the peptide sequence.