bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of the COVID‐19 pandemic on risk management practice: A report from the epicenter of the epicenter in New York City
Authors: Tolentino Victorio R. , Derevlany Louise , DeLaMothe Cassandra , Vick Suzanne , Chalyavski Luba 
Published: January 2021

AbstractHealth care organizations have had to respond to the Coronavirus disease 2019 (COVID‐19) pandemic in unprecedented ways. In the United States, where health risk management is an established profession, health care risk managers (HRMs) contributed to the response by supporting organizations and frontline workers. HRMs advised administrative and clinical leadership on decisions and policies aimed at addressing the medico legal, ethical, and operational dilemmas raised by this public health emergency. This article describes these challenges from the perspective of a New York City (NYC) public hospital located in the “epicenter within the epicenter” of the pandemic and aims to provide practical guidance for HRMs on the front lines of this crisis.
Experience with PlasmaJet™ in debulking surgery in 87 patients with advanced‐stage ovarian cancer
Authors: Volcke Alexander , Van Nieuwenhuysen Els , Han Sileny , Salihi Rawand , Van Gorp Toon , Vergote Ignace 
Published: January 2021

AbstractObjectiveThe aim was to evaluate the effectiveness and safety of PlasmaJet™ in cytoreductive surgery in patients with advanced‐stage ovarian cancer.MethodsAll patients between September 2013 and January 2018 undergoing surgical cytoreduction for advanced‐stage ovarian cancer with the help of PlasmaJet™ were identified and analyzed retrospectively.ResultsEighty‐seven patients diagnosed with advanced‐stage ovarian cancer underwent surgery with PlasmaJet™. Primary debulking surgery was performed in 15 cases. Fifty‐seven patients underwent interval debulking after neoadjuvant chemotherapy. Secondary and tertiary debulking was done in, respectively, 11 and three patients, and one patient underwent quaternary debulking using PlasmaJet™. In all 87 patients but one, complete resection of all macroscopic disease was obtained. PlasmaJet™ was used to remove carcinomatosis on the peritoneum, bowel serosa, intestinal mesentery, and lesions in the upper abdomen (diaphragm and liver surface). No damage to the bladder or ureter was noted in relation to the use of PlasmaJet™. Three patients developed a bowel leakage postoperatively. In one of these patients, PlasmaJet™ was used to treat tumoral implants in the affected region.ConclusionsOur series suggests that the use of PlasmaJet™ is efficient and safe in obtaining complete resection of all macroscopic tumoral lesions in advanced‐stage ovarian cancer.
Lung Ultrasound for Identification of Patients Requiring Invasive Mechanical Ventilation in COVID‐19
Authors: Seiler Claudia , Klingberg Cecilia , Hårdstedt Maria 
Published: January 2021

ObjectivesIndication for invasive mechanical ventilation in COVID‐19 pneumonia has been a major challenge. This study aimed to evaluate if lung ultrasound (LUS) can assist identification of requirement of invasive mechanical ventilation in moderate to severe COVID‐19 pneumonia.Materials and MethodsBetween April 23 and November 12, 2020, hospitalized patients with moderate to severe COVID‐19 (oxygen demand ≥4 L/min) were included consecutively. Lung ultrasound was performed daily until invasive mechanical ventilation (IMV‐group) or spontaneous recovery (non‐IMV‐group). Clinical parameters and lung ultrasound findings were compared between groups, at intubation (IMV‐group) and highest oxygen demand (non‐IMV‐group). A reference group with oxygen demand <4 L/min was examined at hospital admission.ResultsAltogether 72 patients were included: 50 study patients (IMV‐group, n = 23; non‐IMV‐group, n = 27) and 22 reference patients. LUS‐score correlated to oxygen demand (SpO2/FiO2‐ratio) (r = 0.728; p < .0001) and was higher in the IMV‐group compared to the non‐IMV‐group (20.0 versus 18.0; p = .026). Based on receiver operating characteristic analysis, a LUS‐score of 19.5 was identified as cut‐off for requirement of invasive mechanical ventilation (area under the curve 0.68; sensitivity 56%, specificity 74%). In 6 patients, LUS identified critical coexisting conditions. Respiratory rate and oxygenation index ((SpO2/FiO2)/respiratory rate) ≥4.88 identified no requirement of invasive mechanical ventilation with a positive predictive value of 87% and negative predictive value of 100%.ConclusionsLUS‐score had only a moderate diagnostic value for requirement of invasive mechanical ventilation in moderate to severe COVID‐19. However, LUS proved valuable as complement to respiratory parameters in guidance of disease severity and identifying critical coexisting conditions.
Impacts of nitrogen enrichment on vegetation growth dynamics are regulated by grassland degradation status
Authors: Xu Xiaotian , Hu Guozheng , Liu Xu , Lu Shaowei , Li Shaoning , Zhao Na 
Published: January 2021

AbstractPlant phenological responses under global climate change is a hot topic in current ecological research. However, it also has comprehensive interactions with other anthropogenic environmental factors including nitrogen (N) enrichment owing to atmospheric deposition and fertilization, and grassland degradation, which attracts less attention. Continuous photographic techniques enabled us to monitor the plant cover dynamics and extract the phenophases (start, end, length and the peak cover position of growing season) in a field experimental platform with six N treatment levels on five grasslands along a degradation gradient indicated by a human disturbance index (HDI). The results showed that N addition significantly promoted seasonal plant covers of degraded grasslands, while mature grassland responding less sensitively. Moreover, increasing rates during spring green‐up and decreasing rates during autumn senescence were promoted by N addition, while those of grasslands with lower degradation levels showed non‐linear saturation patterns. Phenophases at the community level were generally insensitive to N addition, with the most degraded grassland (totally degraded grassland, TD) and mature grassland (MG) responding significantly. The length of growing season of TD was shortened by 8 days and that of MG lengthened by 15 days on average from N addition. The responses of extracted phenophases were regulated more by the proportions of three groups of degradation indicators (annuals, moderate grazing degradation indicator species, and climax species) than those of grasses and forbs. Our findings highlight the relationship between community phenology and grassland degradation, which can benefit the assessment and restoration of degraded grasslands in semiarid regions.
Identification of dissolved organic matter size components in freshwater and marine environments
Authors: Asmala Eero , Massicotte Philippe , Carstensen Jacob 
Published: January 2021

AbstractDissolved organic matter (DOM) in the transition zone from freshwater to marine systems was analyzed with a new approach for parameterizing the size distribution of organic compounds. We used size‐exclusion chromatography for molecular size analysis and quantified colored DOM (CDOM) on samples from two coastal environments in the Baltic Sea (Roskilde Fjord, Denmark and Gulf of Gdansk, Poland). We applied a Gaussian decomposition method to identify peaks from the chromatograms, providing information beyond bulk size properties. This approach complements methods where DOM is separated into size classes with pre‐defined filtering cutoffs, or methods where chromatograms are used only to infer average molecular weight. With this decomposition method, we extracted between three and five peaks from each chromatogram and clustered these into three size groups. To test the applicability of our method, we linked our decomposed peaks with salinity, a major environmental driver in the freshwater‐marine continuum. Our results show that when moving from freshwater to low‐salinity coastal waters, the observed steep decrease of apparent molecular weight is mostly due to loss of the high‐molecular‐weight fraction (HMW; >2 kDa) of CDOM. Furthermore, most of the CDOM absorbance in freshwater originates from HMW DOM, whereas the absorbing moieties are more equally distributed along the smaller size range (< 2 kDa) in marine samples.
Elemental Sulfur Mediated Novel Multicomponent Redox Polycondensation for the Synthesis of Alternating Copolymers Based on 2,4‐Thiophene/Arene Repeating Units
Authors: Mutlu Hatice , Döpping Daniel A. , Huber Birgit , Theato Patrick 
Published: January 2021

AbstractA sulfur‐based self‐condensation method is investigated as an efficient tool for the synthesis of polythiophene derivatives. The reaction proceeds through multicomponent redox polycondensation between readily available diketone compounds and elemental sulfur in the presence of a Brønsted acid/base pair. Six different diketone derivatives have been screened and the polymerization is generalized by the synthesis of so‐far‐unprecedented alternating copolymers based on 2,4‐thiophene/arene repeating units. By exploiting microwave heating the synthetic procedure is optimized, particularly for alternating copolymers containing aryl and thiophene units, such that a copolymer can be synthesized in only 24 h compared to the conventional process taking 6 d, yielding polymers within the same apparent weight average molar mass (Mw). All obtained copolymers are analyzed in detail using size exclusion chromatography (SEC), nuclear magnetic resonance (NMR), attenuated total reflectance infrared spectroscopy (ATR‐IR), thermal gravimetric analysis and differential scanning calorimetry (DSC).
Model‐Assisted Optimization of RAFT Polymerization in Micro‐Scale Reactors—A Fast Screening Approach
Authors: Kandelhard Felix , Schuldt Karina , Schymura Juliane , Georgopanos Prokopios , Abetz Volker 
Published: January 2021

AbstractIn this work, the combination of different modeling approaches with in‐line proton nuclear magnetic resonance (1H‐NMR) spectroscopy is used to assist the transfer of a reversible addition‐fragmentation chain transfer (RAFT) polymerization of methyl methacrylate to a micro‐scale reactor. This approach is then applied to find the optimal process parameters like temperature or residence time as well as the best composition of the reaction mixture in order to optimize the conversion and molecular characteristics of the synthesized polymer. A kinetic model based on ordinary differential equations implemented in the program Predici is first validated based on experimental data of reactions performed at various temperatures. Further on, two glass chip reactors and a coil reactor are used and combined in different ways to investigate the influence of the reactor geometry on the polymerization process. This optimization step is assisted by multiphysics modeling that focuses on the heat transfer properties of specific areas inside the reactors. This experimental setup is used successfully to carry out a stationary polymerization. This study shows that instationary experiments in a micro‐fluidic reactor system equipped with in‐line analytics allow for the fast development of a kinetic model for RAFT polymerizations.
Physicochemical properties and antimicrobial activity of nanocomposite films based on carboxymethylcellulose and silver nanoparticles
Authors: Yunusov Khaydar Ergashovich , Sarymsakov Abdushkur Abdukhalilovich , Jalilov Javlon Zafar o`g`li , Аtakhanov Abdumutallib Abdupatto o`g`li 
Published: January 2021

AbstractSilver nanoparticles (AgNPs) stabilized by sodium carboxymethylcellulose (Na‐CMC) with degree of substitution (DS) 0.65‐0.90 and degree of polymerization (DP) 200‐600 were synthesized by photochemical method. The structural, physico‐chemical, and physico‐mechanical properties as well as antimicrobial activity of polymer films containing the Na‐CMC and AgNPs were studied. The shape, quantity, and size of the AgNPs embedded into the Na‐CMC films were determined by UV‐Vis spectroscopy, ZETASIZER Nano ZS, atomic force microscopy and transmission electron microscopy. It was found that the increase of silver nitrate concentration in solution of Na‐CMC followed by photoirradiation leads to the change of size and shape of AgNPs. The AgNPs in the range of size from 5 to 35 nm were found to enhance the microbicidal activities of the Na‐CMC films.
Schiff‐base‐functionalized polymeric hydrogel with high stretchability and multifunction
Authors: Liao Shanshan , Tang Liuyan , Qu Jinqing 
Published: January 2021

AbstractHere we report a novel salicylaldehyde‐based Schiff‐base‐functionalized polymeric hydrogel (SSb‐hydrogel) with excellent stretchability, temperature responsiveness, self‐healing property, and adjustable fluorescence intensity. The SSb‐hydrogel was obtained by a one‐pot micellar copolymerization of acrylamide (AAm), N‐isopropylacrylamide (NIPAM), and a hydrophobic cross‐linking agent (AVIMP). The three‐dimensional network of SSb‐hydrogel was formed by the chemical cross‐linking of AVIMP and the hydrophobic interaction between AVIMP molecules. The SSb‐hydrogel was able to stretch up to 1900% of its original length without fracture, and its transparency was adjustable by temperature. This hydrogel also had tunable fluorescence controlled by Zn2+/EDTA, and its fluorescence increased by 640% with 0.1 M Zn2+. Its fluorescence property enabled us to write on its surface repeatedly. This highly stretchable and multifunctional SSb‐hydrogel has potential applications in temperature‐sensitive materials, information transmission, and soft sensors.
The effect of poly(acrylic acid) on temperature‐dependent behaviors and structural evolution of poloxamer 407
Authors: Hirun Namon , Tantishaiyakul Vimon , Sangfai Tanatchaporn , Boonlai Wannisa , Soontaranon Siriwat , Rugmai Supagorn 
Published: January 2021

AbstractUnderstanding temperature‐dependent behaviors and structural evolution plays an essential role in the development of thermosensitive hydrogels. In this work, thermosensitive hydrogels composed of poly(acrylic acid) (PAA) and poloxamer 407 (PX) were investigated. The effect of PAA on the thermosensitive micellization, gelation and structural evolution of 20% PX (20PX) was studied by means of differential scanning calorimetry (DSC), rheology and small angle X‐ray scattering. In addition, the structural and amplitude‐dependent rheological characteristics of mixtures of 20PX and various concentrations of PAA (PAA/PX) gels at body temperature were also examined. The DSC thermograms of the PAA/PX mixtures revealed overlapping double endothermic peaks, reflecting the micellization of PX micelles with attached PAA and pure PX micelles. The formation of PX micelles with attached PAA increased when PAA concentration was increased. The intermicellar packing of PX micelles might be interfered by the attached PAA; the presence of PAA modulated the gelation temperature. All thermosensitive systems showed disorder‐to‐order structural evolution upon heating. Although the micelles in the plain 20PX gel arranged into a face‐centered cubic (FCC) geometry, a body‐centered cubic (BCC) phase emerged in the PAA/PX mixtures and became predominant with increasing PAA concentration. The presence of PAA chains tailored the ordered structure of the gels and favored the BCC arrangement.The rheological and ordered structural properties of the PAA/PX gels at body temperature can be modulated by varying the concentration of PAA. © 2021 Society of Chemical Industry
Dynamic model and control for a cable‐driven continuum manipulator used for minimally invasive surgery
Authors: Qi Fei , Chen Bai , Gao Shuyuan , She Shigang 
Published: January 2021

AbstractBackgroundDue to its unique flexible and dexterity, continuum robot has been widely used in small constrained environment. However, those advantages also bring that motion modelling and accurate control for the continuum robot is more complicated and tedious. A dynamic model and control strategy is presented for improving its control performance.MethodsThe kinematics and velocity model of the robot are derived. The inertial force, elastic force, gravity and actuation force applied to the continuum robot are analysed. Meanwhile, the friction in drive system is investigated, and dynamic model is established by the Kane's method. Finally, a motion control strategy is proposed based on this model to verify the dynamic model.ResultsResults of the simulation and experiment of a prototype verify the proposed model and its control method.ConclusionsThe proposed model and control strategy can be used to achieve the bending deformation of the robot.
Towards the Synthesis of Imidazopyridine Derivatives: Characterization, Single Crystal XRD, Hirshfeld Analysis, and Biological Evaluation
Authors: Kuthyala Sharanya , Sheikh Sareen , Nagaraja G. K. , Kannika B. R. , Madan Kumar S. , Chandra Nayak S. , Lokanath N. K. 
Published: January 2021

AbstractThis study explores the synthesis of different imidazopyridine derivatives, their characterization, single crystal x‐ray diffraction, molecular Hirshfeld surface analysis along with their anticancer and other supportive biological evaluations. X‐ray crystallography study resolved the crystal structure of 2,7‐dimethyl‐N‐(1,3‐dioxoisoindolin‐2‐yl)H‐imidazo[1,2‐a]pyridine‐3‐carboxamide (2 a) as monoclinic crystal system (space group P21/n). Graphical tool, Hirshfeld surface analysis quantified the major contribution of H⋅⋅⋅H, O⋅⋅⋅H, and C⋅⋅⋅H interactions towards the HS. Among the synthesized compounds, 2‐(4‐(4‐fluorophenyl)‐5‐(2,8‐dimethylH‐imidazo[1,2‐a]pyridin‐3‐yl)‐4H‐1,2,4‐triazol‐3‐ylthio)‐N‐(4‐fluorophenyl)acetamide (5 a) exhibited the highest cytotoxicity against lung adenocarcinoma with IC50 value of 43.04 μM. Selective action of 5 a was assured by cell death analysis using AO‐EB assay. In addition, the study was also supported by molecular docking studies. Together the study revealed, the compound 5 a, to be a likely candidate for further exploratory study in cancer treatment.
Recent Progress in Iodine‐Catalysed C−O/C−N Bond Formation of 1,3‐Oxazoles: A Comprehensive Review
Authors: Dhawan Sanjeev , Kumar Vishal , Girase Pankaj S. , Mokoena Sithabile , Karpoormath Rajshekhar 
Published: January 2021

AbstractOver the last few decades, iodine has been a stellar catalyst for numerous organic transformations such as C−H activation, hetero‐annulation and coupling reactions. In heterocyclic chemistry, iodine is primarily an economical and eco‐friendly catalyst that fascinates the construction of C−O/C−N bonds via oxidative, radical, and electrophilic pathways. Several novel Iodine‐catalyzed methodologies have been reported, presenting advances in heterocyclic synthesis with regioselectivity, wide substrate scope and excellent yields. Furthermore, feasible protocols implemented to get oxazole annulation in literature have an enormous impact on new synthetic applications. Therefore, this literature analysis comprises advancements in the field of iodine‐mediated 1,3‐oxazole synthesis since 1998. For the ease of the readers, the reported methodologies have been categorised based on iodine functioning in reactions with insight into the reaction mechanisms and highlights.
Chan−Lam Arylation of Benzimidazole and its Derivatives in the Presence of Copper‐Containing Minerals
Authors: Györke Gábor , Dancsó András , Volk Balázs , Milen Mátyás 
Published: January 2021

AbstractCopper catalysis plays a remarkable role in synthetic organic chemistry. The catalytic activity of copper‐containing minerals is not sufficiently presented in the literature, even though the economical value of such procedures is rather high. With the direct usage of these readily available ores, the highly polluting industrial copper production can be avoided. In the present work, the copper‐containing mineral catalyzed Chan−Lam reaction of benzimidazole, substituted benzimidazoles or imidazole with various phenylboronic acids is described. A total of nine readily available ores were tested in our model reaction with bornite (Cu5FeS4) and chalcocite (Cu2S) being the best among them. The in situ formed catalytic system of Cu5FeS4/TMEDA was able to produce the desired products in up to 98 % yields and it was reusable making this process even more economical and environmentally friendly.
Synthesis and Properties of a New Chitosan‐Based Shape Memory Polymer and its Composites
Authors: Antony Gnanadickam Jerald Maria , Poulose Priya , Aruna Singanahalli ThippaReddy , Shanuja Shailaja Kesavan , Gnanamani Arumugam , Suneetha Yalachigere Kempaiah , Raja Samikkannu 
Published: January 2021

AbstractIn the present study, a new thermo‐responsive shape memory polymer (SMP) based on biopolymers such as chitosan (CH), cellulose acetate (CA), and polyvinyl acetate (PVAc) is fabricated, and the probable structure is elucidated based on proton nuclear magnetic resonance spectroscopy. CH based biopolymer composites are prepared by incorporating fillers like polyethylene glycol methacrylate grafted hydroxyapatite (g‐HAp) and turmeric (TUR) powders. The morphology of g‐HAp and TUR particles are investigated by scanning electron microscopy. The mechanical properties of SMP composites are evaluated at room temperature and above the glass transition temperature (Tg). The obtained SMP exhibits a Tg of 75 °C and the Tg of the composites did not alter after incorporation of fillers. The developed SMP shows the shape memory effect due to the presence of PVAc. The addition of TUR and g‐HAp fillers enhanced the mechanical properties and biocompatibility of SMP. The Young‘s modulus (max. 27 MPa) obtained for the SMP composite in this study is higher than the reported values of 2–4 MPa for CH composite containing bioactive glass nanoparticles. The developed CH‐SMPs may find application in wound healing and bone implants.
Unearthing a lectotype for Polytrichum commune Hedw. (Bryophyta, Polytrichaceae)
Authors: Kariyawasam Isuru U. , Price Michelle J. , Bell Neil E. , Long David G. , Mill Robert R. , Hyvönen Jaakko 
Published: January 2021

AbstractThe name Polytrichum commune, validated in Hedwig's Species muscorum frondosorum of 1801, was based on earlier entities that can be traced back to the pre‐Linnaean literature of the early 16th century. More than 200 years after its valid publication it remains to be typified. The single herbarium sheet for P. commune in the Hedwig‐Schwägrichen Herbarium in G contains nine specimens from different continents that represent four different species (P. commune, P. juniperinum, P. perigoniale, P. subpilosum). After careful study of the origins and taxonomic affinities of the specimens on this sheet, a lectotype is designated.
Non‐Covalent Interaction‐Directed Coordination‐Driven Self‐Assembly of Non‐Trivial Supramolecular Topologies
Authors: Singh Jatinder , Kim Hyunuk , Chi Ki‐Whan 
Published: January 2021

AbstractThe design of molecules with non‐trivial topologies is an essential step in the development of methods to mimic biological transformation in artificial systems. However, the generation of supramolecular topologies of increasing complexity, such as [n]catenanes, rotaxanes, knots and links, is relatively rare and challenging. Primarily, selective and quantitative synthesis of supramolecular topologies is a formidable challenge. Template‐free, non‐covalent interaction‐directed coordination‐driven self‐assembly provides an alternative approach for constructing non‐trivial topologies in selective and quantitative manner. This review briefly summarizes and provides a comprehensive insight into non‐trivial topologies obtained via template‐free, coordination and non‐covalent interaction‐driven self‐assembly.