bluuebunny/crossref_metadata_2025 huggingface dataset:
COVID‐19 lockdowns, intimate partner violence and coercive control
Authors: Smyth Ciara , Cullen Patricia , Breckenridge Jan , Cortis Natasha , valentine kylie
Published: April 2021

2020 was a year like no other, with the COVID‐19 virus upending life as we know it. When governments around the world imposed lockdown measures to curb the spread of COVID‐19, advocates in the domestic and family violence (DFV) sector recognised that these measures were likely to result in increases in violence against women, particularly intimate partner violence (IPV). IPV can take many forms, including physical, emotional, psychological, financial, coercive controlling behaviours, surveillance and isolation tactics. Lockdown conditions provide fertile ground for the exercise of coercive control by encouraging people to stay at home, limiting social interactions to household members, reducing mobility and enabling perpetrators to closely monitor their partner's movements. However, media reports and awareness of IPV are generally dominated by a focus on physical violence and lethality, which are easily defined and measured. By contrast, coercive control as a concept is difficult to operationalise, measure and action in law, policy and frontline interventions. This paper discusses the challenges inherent in measuring coercive control and engages with current debates around the criminalisation of coercive control in NSW. Such reflection is timely as the conditions of COVID‐19 lockdowns are likely to lead to an increase in coercive controlling behaviours.
Identification of Kinetic and Spectroscopic Signatures of Copper Sites for Direct Oxidation of Methane to Methanol
Authors: Sushkevich Vitaly L. , Artsiusheuski Mikalai , Klose Daniel , Jeschke Gunnar , van Bokhoven Jeroen A.
Published: April 2021

Copper‐exchanged zeolites of different topologies possess high activity in the direct conversion of methane to methanol via the chemical looping approach. Despite a large number of studies, identification of the active sites, and especially their intrinsic kinetic characteristics remain incomplete and ambiguous. In the present work, we collate the kinetic behavior of different copper species with their spectroscopic identities and track the evolution of various copper motifs during the reaction. Using time‐resolved UV/Vis and in situ EPR, XAS, and FTIR spectroscopies, two types of copper monomers were identified, one of which is active in the reaction with methane, in addition to a copper dimeric species with the mono‐μ‐oxo structure. Kinetic measurements showed that the reaction rate of the copper monomers is somewhat slower than that of the dicopper mono‐μ‐oxo species, while the activation energy is two times lower.
Isoretikuläre Kristallisation von hochporösen kubischen kovalentorganischen Käfigverbindungen**
Authors: Ivanova Svetlana , Köster Eva , Holstein Julian J. , Keller Niklas , Clever Guido H. , Bein Thomas , Beuerle Florian
Published: April 2021

Modulare Netzwerke mit definierten Porenstrukturen in mikroskaligen Domänen ergeben maßgeschneiderte poröse Materialien. Für durchlässige molekulare Feststoffe lässt sich die Fernordnung nach einer Desolvatisierung jedoch nur schwer aufrechterhalten, da die Packung typischerweise nur von schwachen supramolekularen Wechselwirkungen geprägt wird. Hier stellen wir zwei Serien von Nanowürfeln vor, die durch Cokondensation von zwei verschiedenen Hexahydroxytribenzotriquinacenen (TBTQs) und Benzol‐1,4‐diboronsäuren (BDBAs) mit unterschiedlichen linearen Alkylketten in 2,5‐Position gebildet werden. n‐Butyl‐Gruppen an der apikalen Position der TBTQ‐Ecken führen zu löslichen Modellverbindungen, die durch Massenspektrometrie und NMR‐Spektroskopie analysiert wurden. Dagegen kristallisierten methylsubstituierte Käfige spontan als isostrukturelle und hochporöse Feststoffe mit BET‐Oberflächen bis zu 3426 m2 g−1und Porenvolumina bis zu 1.84 cm3 g−1. Röntgenbeugungsexperimente und Sorptionsmessungen offenbarten ein komplexes kubisches System alternierender Mikro‐ und Mesoporen von 0.97 bis 2.2 nm, deren Größen durch die Alkylsubstituenten am BDBA‐Linker genau einstellbar sind.
Stabilization of an Enantiopure Sub‐monolayer of Helicene Radical Cations on a Au(111) Surface through Noncovalent Interactions
Authors: Giaconi Niccolò , Sorrentino Andrea Luigi , Poggini Lorenzo , Lupi Michela , Polewczyk Vincent , Vinai Giovanni , Torelli Piero , Magnani Agnese , Sessoli Roberta , Menichetti Stefano , Sorace Lorenzo , Viglianisi Caterina , Mannini Matteo
Published: April 2021

In the past few years, the chirality and magnetism of molecules have received notable interest for the development of novel molecular devices. Chiral helicenes combine both these properties, and thus their nanostructuration is the first step toward developing new multifunctional devices. Here, we present a novel strategy to deposit a sub‐monolayer of enantiopure thia[4]helicene radical cations on a pre‐functionalized Au(111) substrate. This approach results in both the paramagnetic character and the chemical structure of these molecules being maintained at the nanoscale, as demonstrated by in‐house characterizations. Furthermore, synchrotron‐based X‐ray natural circular dichroism confirmed that the handedness of the thia[4]helicene is preserved on the surface.
Asymmetric Palladium‐Catalyzed Oxycarbonylation of Terminal Alkenes: Efficient Access to β‐Hydroxy Alkylcarboxylic Acids
Authors: Tian Bing , Li Xiang , Chen Pinhong , Liu Guosheng
Published: April 2021

A novel PdII‐catalyzed enantioselective oxycarbonylation of alkenes has been established. The ligand with an ethyl group at the C‐6 position of Pyox plays a significant role in the intermolecular oxypalladation process, leading to high reactivity and excellent enantioselective control. Compared to the conventional methods, the reaction itself features alkenes as easily prepared starting materials, mild and operationally simple reaction conditions, and insensitivities to air and water. Moreover, this method allows for broad alkene substrate scope, excellent regio‐ and enantioselectivities, scalabilities and a wide array of applications, and provides a useful route for the convenient and straightforward synthesis of chiral β‐hydroxy alkylcarboxylic acids/esters.
Porous Covalent Organic Polymers for Efficient Fluorocarbon‐Based Adsorption Cooling
Authors: Zheng Jian , Wahiduzzaman Mohammad , Barpaga Dushyant , Trump Benjamin A. , Gutiérrez Oliver Y. , Thallapally Praveen , Ma Shengqian , McGrail B. Peter , Maurin Guillaume , Motkuri Radha Kishan
Published: April 2021

Adsorption‐based cooling is an energy‐efficient renewable‐energy technology that can be driven using low‐grade industrial waste heat and/or solar heat. Here, we report the first exploration of fluorocarbon adsorption using porous covalent organic polymers (COPs) for this cooling application. High fluorocarbon R134a equilibrium capacities and unique overall linear‐shaped isotherms are revealed for the materials, namely COP‐2 and COP‐3. The key role of mesoporous defects on this unusual adsorption behavior was demonstrated by molecular simulations based on atomistic defect‐containing models built for both porous COPs. Analysis of simulated R134a adsorption isotherms for various defect‐containing atomistic models of the COPs shows a direct correlation between higher fluorocarbon adsorption capacities and increasing pore volumes induced by defects. Combined with their high porosities, excellent reversibility, fast kinetics, and large operating window, these defect‐containing porous COPs are promising for adsorption‐based cooling applications.
Accidental systemic administration of 1 litre of cardioplegia solution during paediatric cardiac surgery
Authors: Newington D. F. , Barker C. L.
Published: April 2021

Cardioplegia is used to induce cardiac arrest in order to facilitate cardiac surgery in patients supported by cardiopulmonary bypass. It is administered directly into the coronary vessels after the heart has been isolated from the systemic circulation. We describe the case of a 9‐year‐old boy who mistakenly received 1 l of high strength St Thomas’ Harefield cardioplegia solution delivered into the systemic circulation during cardiac surgery. Although the patient’s heart did not stop, the subsequent physiological derangements were severe. The presenting features were refractory hypotension and dilutional anaemia along with severe hyperkalaemia, hypermagnesaemia and hyperchloraemic metabolic acidosis. Local anaesthetic systemic toxicity from the procaine contained within the cardioplegia solution was also a concern. Treatment required vasopressor administration and an extended period of cardiopulmonary bypass while serum electrolyte concentrations were corrected by haemodiafiltration. The systemic administration of cardioplegia solution is a rare but important iatrogenic clinical emergency that anaesthetists working in cardiac centres should be aware of. This case demonstrates that full recovery is possible.
Ultrasound‐guided sacral multifidus plane block for analgesia following excision of sacrococcygeal teratoma in two neonates
Authors: Mahajan R. , Gulati S. , Gupta K. , Jain K. , Bloria S. , JItendra M.
Published: April 2021

Peri‐operative pain management in the neonate with a sacrococcygeal teratoma poses significant challenges to the anaesthetist. Involvement of the sacrococcygeal area by the tumour often prevents the use of conventional regional anaesthetic techniques such as caudal or epidural analgesia, with a subsequent reliance on intravenous opioids and paracetamol. Since opioids are associated with respiratory depression, constipation and urinary retention, there is high incidence of opiophobia with consequent inappropriate dosage prescription, particularly in the paediatric population. We describe the use of an ultrasound‐guided sacral multifidus plane block in two neonates undergoing surgical excision of sacrococcygeal teratoma. The block is technically easy to perform and also avoids traversing critical structures. Hence, it may be regarded as a promising analgesic technique for painful interventions in the sacrococcygeal area.
Design, synthesis, and catalytic evaluation of aluminum‐incorporated magnetic core–shell mesoporous microsphere catalyst NiFe2O4@SiO2@Al‐MS for the synthesis of functionalized indenopyrazolones
Authors: Mirheidari Mahnaz , Safaei‐Ghomi Javad
Published: April 2021

A core–shell structured magnetic metal‐mesoporous microsphere materials NiFe2O4@SiO2@Al‐MS in which magnetic particles of NiFe2O4 are core and ordered mesoporous silica are shell, incorporated with aluminum to modify acid‐catalyzed reactions. The catalyst was synthesized by Pluronic P123 as a first surfactant and a small quantity of cetrimonium bromide as a template for assistant in acidic medium to create a porous layer. The structural characterization of the catalyst was assessed by Fourier transform infrared (FT‐IR), scanning electron microscopy (SEM), X‐ray diffraction (XRD), energy‐dispersive X‐ray (EDX), vibrating‐sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET) analyses. The catalyst demonstrated considerable magnetic properties, a unique mesoporous structure with great surface area (370.36 m2 g−1), high‐value recovery, and reusability. The catalyst performance was evaluated for the synthesis of indenopyrazolones via the condensation of ninhydrin, phenylhydrazine, and various aldehydes. The mild conditions for the synthesis, easy workup, and short reaction time are the considerable benefits of the reaction in the presence of Nife2O4@SiO2@Al‐MS as a catalyst.
Detoxification of Asbestos and Recovery of Valuable Metals from Detoxified Asbestos
Authors: Hong Myung Hwan , Choi Hyeok Mok , Yoon Jin‐Ho , Kim Seok Chan
Published: April 2021

Studies on detoxification of asbestos and recovery of valuable metals from detoxified asbestos were conducted. First, asbestos was detoxified by a microwave heat treatment that used silicon carbide balls, which are inorganic heating elements that absorb microwaves and release heat at room temperature. For efficient heat treatment, the asbestos containing waste (ACW) was powdered by crushing and grinding processes and then a detoxification heat treatment was performed. Microwave heat treatment temperature and time variables were adjusted to investigate the detoxification properties according to heat treatment conditions. After heat treatment, treated ACW was analyzed for detoxification properties through crystal structure and microstructure analysis using X‐ray diffraction (XRD) and scanning electron microscopy. Complete asbestos detoxification was confirmed when the microwave heat treatment was performed at 1200°C for over 60 min and at 1300°C for over 10 min. Second, recovery of valuable metals from detoxified asbestos was carried out. The main components, Si, Ca, and Mg, of detoxified asbestos‐containing waste (DACW) were separated and recovered in the form of SiO2, CaSO4, and Mg(OH)2. SiO2 was separated first after treatment of DACW with HCl. Ca in the form of sulfate, CaSO4, was recovered when subsequent treatment of remaining aqueous acid solution with H2SO4. The remaining Mg was recovered by precipitation as Mg(OH)2 form under strong basic conditions. Each separated component was confirmed by XRD and Inductively Coupled Plasma (ICP) analysis.
Integration of clinical anatomical sciences in medical education: Design, development and implementation strategies
Authors: Khalil Mohammed K. , Giannaris Eustathia Lela , Lee Vaughan , Baatar Dolgor , Richter Saskia , Johansen Krista S. , Mishall Priti L.
Published: April 2021

For the last 20 years, undergraduate medical education has seen a major curricular reform movement toward integration of basic and clinical sciences. The rationale for integrated medical school curricula focuses on the application of knowledge in a clinical context and the early ability to practice key skills such as critical thinking and clinical problem‐solving. The method and extent of discipline integration can vary widely from single sessions to entire programs. A challenge for integrated curricula is the design of appropriate assessments. The goal of this review is to provide a framework for clinical anatomy educators with definitions of integration, examples of existing integration models, strategies, and instructional methods that promote integration of basic and clinical sciences.
Risk factors for neonatal brachial plexus palsy attributed to anatomy, physiology, and evolution
Authors: Dunbar Donald C. , Vilensky Joel A. , Suárez‐Quian Carlos A. , Shen Peter Yi , Metaizeau Jean‐Paul , Supakul Nucharin
Published: April 2021

The inherent variable anatomy of the neonate and the uniquely‐shaped maternal birth canal that is associated with the evolution of human bipedalism constitute risk factors for neonatal brachial plexus palsy (NBPP). For example, those neonates with a prefixed brachial plexus (BP) are at greater risk of trauma due to lateral neck traction during delivery than those with a normal or postfixed BP. Compared to adults, neonates also have extremely large and heavy heads (high head: body ratio) set upon necks with muscles and ligaments that are weak and poorly developed. Accordingly, insufficient cranial stability can place large torques on the cervical spinal nerves. In addition, the pelvic changes necessary for habitual bipedal posture resulted in a uniquely‐shaped, obstruction‐filled, sinusoidal birth canal, requiring the human fetus to complete a complicated series of rotations to successfully traverse it. Furthermore, although there are many risk factors that are known to contribute to NBPP, the specific anatomy and physiology of the neonate, except for macrosomia, is not considered to be one of them. In fact, currently, the amount of lateral traction applied to the neck during delivery is the overwhelming legal factor that is used to evaluate whether a birth attendant is liable in cases of permanent NBPP. Here, we suggest that the specific anatomy and physiology of the neonate and mother, which are clearly not within the control of the birth attendant, should also be considered when assessing liability in cases of NBPP.
Affinity Selections of DNA‐Encoded Chemical Libraries on Carbonic Anhydrase IX‐Expressing Tumor Cells Reveal a Dependence on Ligand Valence
Authors: Oehler Sebastian , Catalano Marco , Scapozza Ilario , Bigatti Martina , Bassi Gabriele , Favalli Nicholas , Mortensen Michael R. , Samain Florent , Scheuermann Jörg , Neri Dario
Published: April 2021

DNA‐encoded chemical libraries are typically screened against purified protein targets. Recently, cell‐based selections with encoded chemical libraries have been described, commonly revealing suboptimal performance due to insufficient recovery of binding molecules. We used carbonic anhydrase IX (CAIX)‐expressing tumor cells as a model system to optimize selection procedures with code‐specific quantitative polymerase chain reaction (qPCR) as selection readout. Salt concentration and performing PCR on cell suspension had the biggest impact on selection performance, leading to 15‐fold enrichment factors for high‐affinity monovalent CAIX binders (acetazolamide; KD=8.7 nM). Surprisingly, the homobivalent display of acetazolamide at the extremities of both complementary DNA strands led to a substantial improvement of both ligand recovery and enrichment factors (above 100‐fold). The optimized procedures were used for selections with a DNA‐encoded chemical library comprising 1 million members against tumor cell lines expressing CAIX, leading to a preferential recovery of known and new ligands against this validated tumor‐associated target. This work may facilitate future affinity selections on cells against target proteins which might be difficult to express otherwise.
First Total Synthesis of Phytoprostanes with Prostaglandin‐Like Configuration, Evidence for Their Formation in Edible Vegetable Oils and Orienting Study of Their Biological Activity
Authors: Smrček Jakub , Hájek Miroslav , Hodek Ondřej , Čížek Karel , Pohl Radek , Jahn Emanuela , Galano Jean‐Marie , Oger Camille , Durand Thierry , Cvačka Josef , Jahn Ullrich
Published: April 2021

Phytoprostanes (PhytoP) are natural products, which form in plants under oxidative stress conditions from α‐linolenic acid. However, their epimers with relative prostaglandin configuration termed phytoglandins (PhytoG) have never been detected in Nature, likely because of the lack of synthetic reference material. Here, the first asymmetric total synthesis of such compounds, namely of PhytoGF1α (9‐epi‐16‐F1t‐PhytoP) and its diastereomer ent‐16‐epi‐PhytoGF1α (ent‐9,16‐diepi‐16‐F1t‐PhytoP), has been accomplished. The synthetic strategy is based on radical anion oxidative cyclization, copper(I)‐mediated alkyl‐alkyl coupling and enantioselective reduction reactions. A UHPLC‐MS/MS study using the synthesized compounds as standards indicates PhytoG formation at significant levels during autoxidation of α‐linolenic acid in edible vegetable oils. Initial testing of synthetic PhytoGs together with F1‐PhytoP and 15‐F2t‐IsoP derivatives for potential interactions with the PGF2α (FP) receptor did not reveal significant activity. The notion that PUFA‐derived oxidatively formed cyclic metabolites with prostaglandin configuration do not form to a significant extent in biological or food matrices has to be corrected. Strong evidence is provided that oxidatively formed PhytoG metabolites may be ingested with plant‐derived food, which necessitates further investigation of their biological profile.
Organofunktionelle Silane als Haftvermittler
Authors: Wolf Andreas T.
Published: April 2021

Haftvermittler dienen zur Verbesserung der Adhäsion von flüssig applizierten, polymeren Werkstoffen zu Füllstoffen und Untergründen. Diese Aufgabe bewältigen sie, indem sie die Grenzfläche durch eine graduelle Übergangsphase ersetzen. Organofunktionelle Silane und oligomere Siloxane sind eine technisch besonders wichtige Klasse von Haftvermittlern. Der erste Teil dieser zweiteiligen Artikelserie befasst sich mit der Funktion und der Struktur, dem Chemismus und den Struktur‐Eigenschafts‐Beziehungen der organisch funktionalisierten Silanhaftvermittler. Insbesondere werden die bei der Anbindung eines organofunktionellen Alkoxysilans ablaufenden Teilreaktionen von Hydrolyse, intermolekulare Eigenkondensation (Oligomerisierung), Wasserstoffbrückenbildung und Kondensation mit Substrat oder Füllstoff sowie Reaktion mit dem organischen Polymer diskutiert.
Quantum computing: A measurement and analysis review
Authors: Gupta Mayank , Nene Manisha J.
Published: April 2021

Computing methodologies with rapid proliferation and need for greater concurrency have evolved over the years from parallel and distributed computing to latest technologies like cloud computing. A paradigm shift in computing methodologies has been witnessed in the form of exponential speed up, optimization of problem solutions, and solvability of few classically unsolvable problems with emergence of quantum computing. The study in this article presents observations on executing basic quantum operations that play a vital role in quantum computing. The results and analysis demonstrate how parameters of time, deviation, and shots have a significant effect on outcomes of quantum circuits executed which can be a reference point for the community in general engaged in designing of quantum circuits, protocols, algorithms, and quantum hardware to leverage quantum characteristics and properties. The study by means of experimental use cases provides a rigorous review of qubit behavior, standard, and entangled qubit measurement with practical results over a simulator and real quantum hardware for variable qubit configurations using a selected platform of IBM Q Experience. With the paradigm shift from classical to quantum computing, this article provides basic but very vital observations which can be brought to use by anyone intending to build quantum applications.
Structure Formation and Coupling Reactions of Hexaphenylbenzene and Its Brominated Analog
Authors: Teeter Jacob D. , Costa Paulo S. , Dobner Christoph , Sarker Mamun , Sinitskii Alexander , Enders Axel
Published: April 2021

The on‐surface coupling of the prototypical precursor molecule for graphene nanoribbon synthesis, 6,11‐dibromo‐1,2,3,4‐tetraphenyltriphenylene (C42Br2H26, TPTP), and its non‐brominated analog hexaphenylbenzene (C42H30, HPB), was investigated on coinage metal substrates as a function of thermal treatment. For HPB, which forms non‐covalent 2D monolayers at room temperature, a thermally induced transition of the monolayer's structure could be achieved by moderate annealing, which is likely driven by π‐bond formation. It is found that the dibrominated carbon positions of TPTP do not guide the coupling if the growth occurs on a substrate at temperatures that are sufficient to initiate C−H bond activation. Instead, similar one‐dimensional molecular structures are obtained for both types of precursors, HPB and TPTP.
Analysis of intra‐observer and inter‐observer variability of pathologists for non‐benign thyroid fine needle aspiration cytology according to Bethesda system categories
Authors: Kuzan Taha Yusuf , Güzelbey Burcu , Turan Güzel Nalan , Kuzan Beyza Nur , Çakır Mehmet Semih , Canbey Ceren
Published: April 2021

Aim

To examine the intra‐ and inter‐observer variability for non‐benign thyroid cytological subcategories according to the Bethesda classification system after the second review.

Methods

Between November 2018 and May 2019, thyroid fine needle aspiration biopsies of 381 nodules were retrospectively evaluated. Among them, 74 non‐benign (category III‐VI) thyroid biopsies, analyzed according to the Bethesda system (pathologist 1:40 vs pathologist 2:34) by two independent pathologists, were reassessed by the same pathologists and by a cytopathologist. In this observer‐blinded study, weighted Cohen's kappa was used to assess the intra‐observer agreement, and Krippendorff's alpha was used to assess the inter‐observer agreement.

Results

At the first and second evaluations of pathologists 1 and 2, the percentage agreement was 62.5% for pathologist 1 and 58.8% for pathologist 2. The intra‐observer agreement was substantial (κ = 0.705) for pathologist 1, and moderate (κ = 0.447) for pathologist 2. In the second evaluation of pathologist 1 and 2, which was compared with the cytopathologist, the agreement percentage of pathologist 1 with the cytopathologist was 50.0%, and that of pathologist 2 was 56.8%. The inter‐observer agreement was below the lowest acceptable limit for an overall agreement (α = 0.634) among the three raters. The inter‐observer agreement was only acceptable between the cytopathologist and the second pathologist, while it was low between the other raters. In the evaluation of the non‐benign nodules, the mean category score of the cytopathologist was 3.22 and lower than both pathologists (3.73 and 3.58, respectively).

Conclusions

The intra‐observer agreement of pathologists was moderate‐to‐substantial in the evaluation of non‐benign thyroid biopsies according to the Bethesda reporting system. However, the inter‐observer agreement was below the lowest acceptable limit when the cytopathologist was taken as a reference.
Development Strategies in Transition Metal Borides for Electrochemical Water Splitting
Authors: Yao Yihang , Zhang Zhaoyuan , Jiao Lifang
Published: April 2021

Electrochemical water splitting is a feasible method for producing environmental benignity energy of hydrogen, while high price and low availability on the earth of noble electrocatalysts constrain their global‐scale application. Transition metal borides (TMBs) have displayed unique metalloid characteristic and outstanding performance for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in the last few decades. Herein, recent developments of the TMBs for HER and OER are summarized. Initially, the impact factors and relevant evaluation of electrocatalytic performance are described, that is, overpotential, Tafel slope and exchange current density, stability, faradaic efficiency, turnover frequency, mass and specific activities. Moreover, the optimization strategies of borides are emphasized, which principally include coupling with effective substrates, elemental doping, phase modification, interfacial engineering, and morphology control. Finally, in order to reach the goal of application, the remaining challenges and perspectives are given to point out a direction for enhancing the performance of borides.
Proportioning of self‐centering energy dissipative braces
Authors: Xiao Yi , Eberhard Marc O. , Zhou Ying , Stanton John F.
Published: April 2021

Self‐centering energy dissipative (SCED) braces are designed to limit the maximum story drifts in buildings during earthquakes and to nearly eliminate residual drifts. The key properties of conventional braces (eg, strength, stiffness) can be determined with current seismic design procedures, but additional criteria are needed to select the hysteretic properties of SCED braces (eg, prestressing level, fuse activating deformation). Past investigations of the seismic performance of the SCED braced frames selected brace characteristics to match the hysteretic characteristics of buckling restrained braces (BRB). However, those characteristics may not be achieved because the performance of the SCED system is constrained by the elongation capacity of the post‐tensioned tendons. To develop recommendations for proportioning SCED braces, the researchers conducted a parametric study on the properties of two typical SCED systems, using a nine‐story steel braced frame office building. The seismic performances of the SCED systems were then compared with that of a BRB system including an analysis without property uncertainty and an analysis with uncertainty using Monte Carlo simulation. Based on the cost and seismic performances of SCED systems designed using various characteristics, recommendations are proposed for proportioning the SCED systems. Besides having much smaller residual drifts, the SCED systems had a smaller likelihood of exceeding a maximum story drift of 3% and less drift concentration compared with the BRB system, though they generated larger floor accelerations and forces in connections and adjacent members. The property uncertainty increased the residual drift of the SCED systems.
Effect of a plasma synthesized polypyrrole coverage on polylactic acid/hydroxyapatite scaffolds for bone tissue engineering
Authors: Flores‐Sánchez María G. , Islas‐Arteaga Nancy C. , Raya‐Rivera Atlántida M. , Esquiliano‐Rendon Diego R. , Morales‐Corona Juan , Uribe‐Juarez Omar E. , Vivar‐Velázquez Flor I. , Ortiz‐Vázquez Greta P. , Olayo Roberto
Published: April 2021

Composite biomaterials are solids that contain two or more different materials, combining the properties of their components to restore or improve the function of tissues. In this study, we report the generation of electrospun matrices with osteoconductive properties and porosity using the combination of a biodegradable polyester, polylactic acid (PLA), and hydroxyapatite (HA). Additionally, we report the effects of modifying these matrices through plasma polymerization of pyrrole on the growth and osteogenic differentiation of rabbit bone marrow stem cells. Cells were isolated, seeded and cultured on biomaterials for periods between 7 and 28 days. The matrices we obtained were formed by nano and microfibers containing up to 35.7 wt% HA, presenting a variety of apparent pore sizes to allow for the passage of nutrients to bone cells. Scanning electron microscopy showed that the fibers were coated with polypyrrole doped with iodine, and MTT assay demonstrated this increased cell proliferation and significantly improved cell viability due to the adhesive properties of the polymer. Our results show that PLA/HA/Pyrrole/Iodine matrices are favorable for bone tissue engineering.
Efficacy and safety of infrahepatic inferior vena cava clamping under controlled central venous pressure for reducing blood loss during hepatectomy: A randomized controlled trial
Authors: Junrungsee Sunhawit , Suwannikom Karnpichamonch , Tiyaprasertkul Worakamol , Lapisatepun Worakitti , Chotirosniramit Anon , Sandhu Trichak , Chandacham Kamtone , Jirapongcharoenlap Tidarat , Lapisatepun Warangkana , Ko‐iam Wasana
Published: April 2021

Background

The purpose of this study was to evaluate the effectiveness and safety of inferior vena cava (IVC) clamping for reducing blood loss during hepatectomy.

Methods

In total, 120 elective hepatectomy patients who underwent surgery from May 2016 to October 2017 were enrolled and randomized into the IVC clamping group or nonclamping group. Both groups were managed by anesthesiological techniques for CVP reduction. Blood loss and clinical parameters were analyzed for 30 days after surgery.

Results

Fifty‐nine patients were assigned to the IVC clamping group and 61 to the non‐IVC clamping group. There was a significant difference in the total blood loss between both groups, with less blood loss observed in the IVC clamping group [500 vs 600 mL, P = .006]. The transection blood loss in the IVC clamping group was also significantly lower than that in the non‐IVC clamping group [300 vs 500 mL, P < .001]. However, CVP was not associated with blood loss volume. Postoperative outcomes were not significant in either group.

Conclusions

IVC clamping is beneficial for reducing blood loss during hepatectomy and is safe when combined with anesthesiological techniques. If feasible, this technique should be used regardless of the CVP value.
Low‐cost surrogate modeling of antennas using two‐level Gaussian process regression method
Authors: Zhang Zhen , Jiang Fan , Jiao Yaxi , Cheng Qingsha S.
Published: April 2021

In order to improve the accuracy of the surrogate model for antennas, a novel two‐level Gaussian process regression (GPR) modeling method is proposed in this paper. A heuristic hypercube sampling method is proposed using the K‐means clustering method to generate the training dataset with high uniformity. Based on the training dataset, the first‐level GPR model is established between the design parameters and the full‐wave electromagnetic (EM) simulation responses. The second‐level GPR model is established using the design parameters and the residuals between the first‐level GPR model and the EM simulation model. The sum of the two surrogate models is the two‐level GPR model. The performance of the proposed modeling method is verified by two antenna examples including an ultra‐wideband antenna and a circularly polarized dielectric antenna. Numerical results show that the proposed two‐level GPR method achieves higher accuracy of antenna models than the conventional methods (GPR method and neural networks) with no additional cost. The overall time saving of the proposed method compared to the conventional methods is more than 50% for the majority of our tests.
Targeting SARS‐CoV‐2 Spike Protein/ACE2 Protein‐Protein Interactions: a Computational Study
Authors: Pirolli Davide , Righino Benedetta , De Rosa Maria Cristina
Published: April 2021

The spike glycoprotein (S) of the SARS‐CoV‐2 virus surface plays a key role in receptor binding and virus entry. The S protein uses the angiotensin converting enzyme (ACE2) for entry into the host cell and binding to ACE2 occurs at the receptor binding domain (RBD) of the S protein. Therefore, the protein‐protein interactions (PPIs) between the SARS‐CoV‐2 RBD and human ACE2, could be attractive therapeutic targets for drug discovery approaches designed to inhibit the entry of SARS‐CoV‐2 into the host cells. Herein, with the support of machine learning approaches, we report structure‐based virtual screening as an effective strategy to discover PPIs inhibitors from ZINC database. The proposed computational protocol led to the identification of a promising scaffold which was selected for subsequent binding mode analysis and that can represent a useful starting point for the development of new treatments of the SARS‐CoV‐2 infection.
Automatic clinical target volume delineation for cervical cancer in CT images using deep learning
Authors: Shi Jialin , Ding Xiaofeng , Liu Xien , Li Yan , Liang Wei , Wu Ji
Published: April 2021

Purpose

Accurately delineating clinical target volumes (CTV) is essential for completing radiotherapy plans but is time‐consuming, labor‐intensive, and prone to inter‐observer variation. Automating CTV delineation has the benefits of both speeding up contouring process and improving the quality of contours. Recently, auto‐segmentation approaches based on deep learning have achieved some improvements. However, unlike organ segmentation, the CTV contains potential tumor spread tissues or subclinical disease tissues, resulting in poorly defined margin interface and irregular shape. It is not reasonable to directly apply the deep learning segmentation algorithms to CTV tasks without considering the unique characteristics of shape and margin. In this work, we propose a novel automatic CTV delineation algorithm based on deep learning addressing the unique shape and margin challenges.

Methods

Our deep learning method, called RA‐CTVNet, segments the CTV from cervical cancer CT images. RA‐CTVNet denotes our automatic CTV delineation algorithm based on deep learning with Area‐aware reweight strategy and Recursive refinement strategy. (1) In order to process the whole‐volume CT images and delineate all CTVs in one shot, our method is built upon the popular 3D Unet architecture. We further extend it with robust residual learning and squeeze‐and‐excitation blocks for better feature representation. (2) We propose area‐aware reweight strategy which assigns different weights for different slices. The core is adjusting model’s attention to each slice. (3) In terms of the trade‐off between providing performance improvements and meeting the limitations of GPU memory, we exploit a new recursive refinement strategy to address margin challenge.

Results

This retrospective study included 462 patients diagnosed with cervical cancer who received radiotherapy from June 2017 to May 2019. Extensive experiments were conducted to evaluate performance of RA‐CTVNet. First, compared to different network architectures, RA‐CTVNet achieved improvements in Dice similarity coefficient (DSC). Second, we conducted ablation study. The results showed that compared to the backbone, area‐aware reweight strategy increased DSC by 3.3% on average and recursive refinement strategy further increased DSC by 1.6% on average. Then, we compared our method with three human experts. Our RA‐CTVNet performed better than two experts while comparably to the third expert. Finally, a multicenter evaluation was conducted to verify the accuracy and generalizability.

Conclusions

Our findings show that deep learning is able to offer an efficient framework for automatic CTV delineation. The tailored RA‐CTVNet can improve the quality of CTV contours, which has great potential for reducing the burden of experts and increasing the accuracy of delineation. In the future, if with more training data, further improvements are possible, bringing this approach closer to real clinical practice.
Free‐breathing abdominal T1 mapping using an optimized MR fingerprinting sequence
Authors: van Riel Max H. C. , Yu Zidan , Hodono Shota , Xia Ding , Chandarana Hersh , Fujimoto Koji , Cloos Martijn A.
Published: April 2021

In this work, we propose a free‐breathing magnetic resonance fingerprinting (MRF) method that can be used to obtain B1+‐robust quantitative T1 maps of the abdomen in a clinically acceptable time. A three‐dimensional MRF sequence with a radial stack‐of‐stars trajectory was implemented, and its k‐space acquisition ordering was adjusted to improve motion‐robustness in the context of MRF. The flip angle pattern was optimized using the Cramér–Rao Lower Bound, and the encoding efficiency of sequences with 300, 600, 900 and 1800 flip angles was evaluated. To validate the sequence, a movable multicompartment phantom was developed. Reference multiparametric maps were acquired under stationary conditions using a previously validated MRF method. Periodic motion of the phantom was used to investigate the motion‐robustness of the proposed sequence. The best performing sequence length (600 flip angles) was used to image the abdomen during a free‐breathing volunteer scan. When using a series of 600 or more flip angles, the estimated T1 values in the stationary phantom showed good agreement with the reference scan. Phantom experiments revealed that motion‐related artifacts can appear in the quantitative maps and confirmed that a motion‐robust k‐space ordering is essential. The in vivo scan demonstrated that the proposed sequence can produce clean parameter maps while the subject breathes freely. Using this sequence, it is possible to generate B1+‐robust quantitative maps of T1 and B1+ next to M0‐weighted images under free‐breathing conditions at a clinically usable resolution within 5 min.
Scaling‐Up Stage 4 Pediatric Obesity Clinics: Identifying Barriers and Future Directions Using Implementation Science
Authors: Newsome Faith A. , Dilip Abhaya , Armstrong Sarah C. , Salloum Ramzi G. , Cardel Michelle I.
Published: April 2021

Nearly one‐fifth of the pediatric population in the United States has obesity. Comprehensive behavioral interventions, with at least 26 contact hours, are the recommended treatment for pediatric obesity; however, there are various barriers to implementing treatment. This Perspective applies the Exploration, Preparation, Implementation, and Sustainment (EPIS) framework to address barriers to implementing multidisciplinary pediatric weight management clinics and identify potential solutions and areas for additional research. Lack of insurance coverage and reimbursement, high operating costs, and limited access to stage 4 care clinics with sufficient capacity were among the main barriers identified. Clinicians, researchers, and patient advocates are encouraged to facilitate conversations with insurance companies and hospital and clinic administrators, increase telehealth adoption, request training to improve competency and self‐efficacy discussing and implementing obesity care, and advocate for more stage 4 clinics.
Predictor‐based H∞ leader‐following consensus of stochastic multi‐agent systems with random input delay
Authors: Li Ke , Mu Xiaowu
Published: April 2021

In this paper, we investigate H∞ leader‐following consensus of multi‐agent systems with state multiplicative noise governed by stochastic differential equations and random time‐varying input delays which satisfy a certain probability. A new predictor‐based controller is designed based on the reduction approach to guarantee H∞ leader‐following consensus is achieved in mean square sense. By designing a Lyapunov function and using stochastic techniques, sufficient conditions are obtained in a form of linear matrix inequalities. Finally, a simulation is given to demonstrate the effectiveness of the obtained theoretical results.
Benzoxazole phenoxide ligand supported group IV catalysts and their application for the ring‐opening polymerization of rac‐lactide and ε‐caprolactone
Authors: Pappuru Sreenath , Ramkumar Venkatachalam , Chakraborty Debashis
Published: April 2021

Monomeric titanium [C48H62N2O6Ti] (1) and zirconium [C48H62N2O6Zr] (2) complexes were synthesized by combining the monoanionic salicylbenzoxazole pro‐ligand 2‐(5‐X‐benzoxazol‐2‐yl)‐6‐R1‐4‐R2‐phenol, LH (R1, R2, X = tBu, tBu, H, respectively) with Ti(OiPr)4 or Zr(OiPr)4∙(iPrOH) in a 2:1 stoichiometric ratio. Controlled hydrolysis of the monomeric Ti complex with deionized water yielded a new unusual hexanuclear titanium complex [C126H144N6O21Ti6] (3). In addition, the cage formed in this complex 3 was surrounded by all‐oxygen and penta‐coordinated Ti(IV) atoms, which leads to an hexanuclear drum‐shaped Ti complex 3 with a trigonal‐bipyramidal geometry at the metal center. The catalytic activity of these complexes toward ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL) and rac‐lactide (rac‐LA) was studied. All these complexes showed moderate to good catalytic activity without using any co‐catalyst additives. Single‐site zirconium alkoxide 2 showed the best catalytic activity and was able to convert 400 units of ε‐CL or rac‐LA into the polymer product in high yield (≥90%) within 1 hour under solvent‐free conditions. The obtained polymers showed good control in molecular weight (Mn = 46.2–6.3 kg/mol) and molecular weight distributions (MWD's = 1.37–1.15). The polymerization of rac‐LA by 2 yielded iso‐enriched polylactide (Pm = 0.60).
Preparation and properties of bacterial cellulose/graphene oxide composite films using dyeing method
Authors: Kiangkitiwan Nopparut , Srikulkit Kawee
Published: April 2021

In this study, bacterial cellulose (BC) hydrogels were cultured from a kombucha SCOBY starter. The scanning electron microscopy (SEM) results indicated that the dried BC exhibited an interpenetrating fibrous mat. The BC films harvested for 5, 10, and 15 days were 15–19, 14.4–24, and 30–31 μm thick, respectively. Then, BC/graphene oxide (GO) composite films were prepared via the exhaust dyeing method. GO sheets penetrated the BC matrix, resulting in the formation of a BC/GO composite, as revealed by the SEM analysis results. The mechanical properties of the composite films were investigated. Compared with virgin BC, the tensile strength of the composite films was higher, while the %E at break was lower, resulting in a significant increase in the Young's modulus. The X‐ray diffraction results indicated that an increase in the dyeing time (0.5–2 h) gradually induced cellulose crystalline conformation, which in turn affected the swelling ability, mechanical properties, and electrical properties of the BC/GO composite films. After the reduction of GO to reduced GO (rGO), flexible conductive BC/rGO films were obtained, as confirmed by their resistivity values. Thus, flexible conductive composite films with excellent mechanical properties were successfully fabricated.
Protection by ginseng saponins against cyclophosphamide‐induced liver injuries in rats by induction of cytochrome P450 expression and mediation of the l‐arginine/nitric oxide pathway based on metabolomics
Authors: Chen Jianbo , Li Zhiman , Hua Mei , Sun Yinshi
Published: April 2021

Ginseng saponins (GS) are the main active compounds in Panax ginseng and have been proven to be highly effective in attenuating the side effects of chemotherapy. However, there have been no reports on the mechanism of action of GS. Treatment with GS has certain benefits, including decreasing the toxicity levels in the liver [alanine aminotransferase (ALT), albumin (ALB), alkaline phosphatase (ALP), aspartate transaminase (AST)], reducing oxidative stress [malondialdehyde (MDA), nitric oxide (NO)], diminishing inflammatory factors [interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α) levels], and augmenting the levels of glutathione (GSH) and superoxide dismutase (SOD). The pharmacokinetics study showed that the area under the curve from 0 to 24 hr (AUC 0–24 hr) of 4‐ketocyclophosphamide (4‐KetoCTX) and carboxyphosphamide (CPM) was significantly increased after GS treatment. This study found that GS treatment can reduce chloroacetaldehyde (CAA) production by affecting CYP3A4, CYP2B6, and CYP2C9 protein expression in the liver. For the metabolomics study, GS attenuated the abnormalities of amino acid metabolic pathways in CP‐induced liver injuries of rats and significantly enhanced the l‐arginine level while reducing the serum nitric oxide (NO) level. This outcome was confirmed by the inhibition of the activities of NO synthase in the liver of rats.
Corrosion Behavior of Lightweight MgO in High Basicity Tundish Slag
Authors: Tan Chong , Liu Yu , Li Guangqiang , Yuan Cheng , Tian Yufeng , Zou Yongshun , Huang Ao
Published: April 2021

Demand for energy saving in steelmaking process, lightweight refractories have attracted great attentions for the excellent thermal insulation. Herein, the corrosion behavior of the lightweight magnesia in the high basicity tundish slag is explored, and compared with that of fused magnesia. The results show that the impurities in the fused magnesia cause more dissolution of magnesia into slag after 60 min. Different from fused magnesia, the penetration layer is found in the lightweight magnesia, where the intercrystalline CaZrO3–ZrO2 phases are dissolved by the slag. The micropores in the lightweight magnesia provide passages for slag infiltration, but also accelerate the supersaturation of slag in refractory and impede the mass transfer. Furthermore, the residual CaZrO3–ZrO2 phases in transition layer hinder the further slag infiltration. After 60 min holding, the MgO content in molten slag contacted with lightweight magnesia is lower, implying that the lightweight magnesia is the promising refractory for tundish lining.