bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical Investigation on the Substituent Effect of Halogen Atom on the Ground‐State Double Proton Transfer in the 2‐Pyridone‐Solvent (Solvent: H2O, NH3) Complexes
Authors: Ni Mei , Fang Hua 
Published: January 2019

AbstractThe substituted effect on the dynamics of ground‐state proton transfer (GSPT) in 2‐pyridone (2PY) clusters mediated by water or ammonia was investigated at the M06‐2X/6‐311+G(d, p) level. The GSPT process via H‐bonded channel was affected by the bridging solvent. When the bridging molecule changes from one water to one ammonia, proton transfer occurs in a concerted pathway, but the reaction mechanism changes from a synchronous pattern to an asynchronously protolytic pattern, which was ascribed to the larger basicity of ammonia with comparison to water. When two water or two ammonia molecules mediated the GSPT process of 2PY, GSPT reaction in both 2PY clusters prefers a concerted but asynchronous protolytic pathway since the basicity of the H‐bonded chain consisting of water or ammonia dimer was accumulated. For the 6X2PY‐H2O (X=H, F, Cl, Br) complex, the replacement of halogen atom also changed the GSPT mechanism from concertedly synchronicity to concertedly asynchronicity. However, the GSPT mechanism of 6X2PY‐NH3 (X=H, F, Cl, Br) complex was not influenced by the substitutents, but the asynchronicity of GSPT was enlarged apparently. The substituted effect also affected the structural parameters and reduced the barrier heights of GSPT.
Synthesis of Pd‐rGO Nanocomposite for the Evaluation of In Vitro Anticancer and Antidiabetic Activities
Authors: Hazarika Moushumi , Boruah Purna K. , Pal Mintu , Das Manash R. , Tamuly Chandan 
Published: January 2019

AbstractBiosynthesis of Pd‐rGO nanocomposite using water extract of Zanthoxylum armatum C.DC is reported here. The nanocomposite was characterized using X‐Ray Diffraction (XRD), Fourier Transform Infrared (FT‐IR), Transmission Electron Microscope (TEM), Scanning Electron Microscope‐Energy Dispersive X‐ray Spectroscopy (SEM‐EDX), X‐ray Photoelectron Spectroscopy (XPS), Raman and Thermo‐gravimetric (TG) analysis. Similarly, the Ag‐rGO and Au‐rGO nanocomposite were synthesized using the water extract of Zanthoxylum armatum C.DC. A comparative study was done on α‐glucosidase inhibition activity and cytotoxicity effect for these nanocomposites. The α‐glucosidase inhibition assay revealed that the Pd‐rGO nanocomposite has excellent inhibitory potency compared to GO, Ag‐rGO and Au‐rGO nanocomposite respectively. In this study, the 50% inhibition concentration (IC50) value was observed at 0.0218 ± 0.01 and 1.051 ± 0.28 μg/ml for Pd‐rGO and GO respectively. Overall our novel findings showed that the cytotoxic effect of Pd‐rGO nanocomposite was higher than other M‐rGO (M=Ag, Au) and GO against prostate cancer DU145 cells compared to non‐tumorigenic prostate epithelial cells, RWPE‐1.
Synthesis of Novel Nanomagnetic Catalyst with Acetic Acid Tags: Application in the Synthesis of New Amidoalkyl Phenols under Solvent‐Free Condition
Authors: Afsar Javad , Khazaei Ardeshir , Zarei Mahmoud , Zolfigol Mohammad Ali 
Published: January 2019

AbstractIn this paper, [Fe3O4@SiO2@(CH2)3‐im‐CH2CO2H]Br was designed, synthesized and fully characterized by different techniques such as Fourier transform spectroscopy infrared (FT‐IR), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), elemental mapping, transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and thermal gravimetric analysis (TG). It was used as an efficient acidic nanomagnetic catalyst in the preparation of amidoalkyl phenols via multi‐component condensation of various amides (benzamide, acetamide and urea), phenolic compounds and aryl aldehydes or isatin under solvent‐free condition. High yield of products, easy work‐up and reusability of the catalyst can be mentioned as the advantages of described work.
New Pd‐Mediated Cascade Reactions for Synthesis of Novel Functionalized 1,3‐Oxazole‐Linked Quinoxaline Amines
Authors: Keivanloo Ali , Abbaspour Sima , Bakherad Mohammad , Notash Behrouz 
Published: January 2019

AbstractA number of functionalized 1,3‐oxazoles‐linked amine‐substituted quinoxalines were synthesized via one‐pot Pd‐catalyzed reactions in high yields. The cascade reactions of benzoyl chlorides, proprgylamine, and 3‐chloroquinoxaline‐2‐amines catalyzed by Pd–Cu in the presence of Et3N afforded new 3‐(amine‐substituted)quinoxalin‐2‐yl)(2‐aryl‐1,3‐oxazol‐5‐yl)methanone derivatives at 70 °C. The reactions commenced with the production of N‐propargylamides from benzoyl chlorides and proprgylamine, and proceeded through the Sonogashira coupling reactions with 3‐chloroquinoxaline‐2‐amines followed by the in situ ring closure of the resulting intermediates to give the target products. The use of primary 3‐chloroquioxaline‐2‐amines revealed that the cyclization step was regioselective and that pyrrolo[2,3‐b]quinoxalines were not prepared in this process.
Crossed NiCo2S4 Nanowires Supported on Nickel Foam as a Bifunctional Catalyst for Efficient Overall Water Splitting
Authors: Gong Yaqiong , Lin Yu , Yang Zhi , Wang JinLei , Pan Hailong , Xu Zhoufeng , Liu Yaqing 
Published: January 2019

AbstractIncreasing demands for renewable clean fuel and environmental protection have attracted much research on energy production and conversion. Designing efficient and stable electrocatalysts, which has been recognized as one of the primary goals for anodic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), provides the most prospective route towards mass production of hydrogen from renewable sources. In this paper, 3D‐networked, ultrathin, and crossed nanowires NiCo2S4 grown on Ni foam (NF) was successfully synthesized by a simple hydrothermal method and worked as a unprecious metal‐based overall water splitting electrocatalyst. NiCo2S4/NF possess predominant catalytic activity with an overpotential of 251 mV to drive a current density of 40 mA cm−2 in alkaline media and 191 mV at 10 mA cm−2 for HER in 1.0 M KOH electrolyte. Moreover, NiCo2S4/NF||NiCo2S4/NF was constructed by employing NiCo2S4/NF as both the cathode and anode, the overall water splitting electrolyzer results revealed that only 1.59 V was required to reach the current density of 10 mA cm−2. Notably, NiCo2S4/NF ||NiCo2S4/NF also shows long‐term electrochemical durability with its activity being retained for over 12 h‐long. The newly developed cost‐effective high efficent electrocatalyst towards water splitting provides a novel approach for the design of earth‐abundant transition metal sulfide for high efficiency overall water splitting electrode.
A Green Route for Quick and Kilogram Production of Reduced Graphene Oxide and Their Applications at Low Loadings in Epoxy Resins
Authors: Tiwari Santosh K. , Nimbalkar Ajaysing S. , Hong Chang Kook , Ha Sung Kyu 
Published: January 2019

AbstractThis work reports a green and facile approach to produce bulk amount reduced Graphene Oxide using Graphene Oxide as precursor through Ball Milling in presence of Zinc (Zn) powder activated with NaOH (0.5 ml NaOH (1 M) for 2 g Zn powder). Compared to most of the reported reduction of GO by using hydrazine or any other means, the present route is quite simple, inexpensive and eco‐friendly. Since the proposed reduction for GO to rGO involves a solid‐state processing assisted with a friction and chemical reactions, no additional purification is required. Furthermore, the extent of reduction of GO (C/O ratio in rGO ∼8.8) in the present strategy is much higher than that in the different approaches using metallic Zinc and NaOH, indicating a cooperativity between friction generated during milling and chemical reactions. A probable mechanism for GO to rGO reduction is proposed and reduction strategy has been optimized in terms of milling time, rpm and amount of Zn powder used. To verify the applicability of as‐prepared rGO, we have examined the impact of rGO on the improvement of thermo‐mechanical and morphological properties of Epoxy nanocomposites. Here, few layered rGO based Epoxy nanocomposites were obtained via solution blending method and subsequent hot‐pressing. It was observed that rGO apparently filled in the interspaces of polymeric chains, which were helpful for the synchronously ∼10‐15% increment in thermo‐mechanical properties of fabricated nanocomposites even with an eminently low loading of rGO.
Nickel@Nitrogen‐Doped Carbon@MoS2 Nanosheets: An Efficient Electrocatalyst for Hydrogen Evolution Reaction
Authors: Shah Sayyar Ali , Shen Xiaoping , Xie Minghua , Zhu Guoxing , Ji Zhenyuan , Zhou Hongbo , Xu Keqiang , Yue Xiaoyang , Yuan Aihua , Zhu Jun , Chen Yao 
Published: January 2019

AbstractDeveloping cheap, abundant, and easily available electrocatalysts to drive the hydrogen evolution reaction (HER) at small overpotentials is an urgent demand of hydrogen production from water splitting. Molybdenum disulfide (MoS2) based composites have emerged as competitive electrocatalysts for HER in recent years. Herein, nickel@nitrogen‐doped carbon@MoS2 nanosheets (Ni@NC@MoS2) hybrid sub‐microspheres are presented as HER catalyst. MoS2 nanosheets with expanded interlayer spacings are vertically grown on nickel@nitrogen‐doped carbon (Ni@NC) substrate to form Ni@NC@MoS2 hierarchical sub‐microspheres by a simple hydrothermal process. The formed Ni@NC@MoS2 composites display excellent electrocatalytic activity for HER with an onset overpotential of 18 mV, a low overpotential of 82 mV at 10 mA cm−2, a small Tafel slope of 47.5 mV dec−1, and high durability in 0.5 H2SO4 solution. The outstanding HER performance of the Ni@NC@MoS2 catalyst can be ascribed to the synergistic effect of dense catalytic sites on MoS2 nanosheets with exposed edges and expanded interlayer spacings, and the rapid electron transfer from Ni@NC substrate to MoS2 nanosheets. The excellent Ni@NC@MoS2 electrocatalyst promises potential application in practical hydrogen production, and the strategy reported here can also be extended to grow MoS2 on other nitrogen‐doped carbon encapsulated metal species for various applications.
Optimization of headspace for GC‐MS analysis of fragrance allergens in wooden children's products using response surface methodology
Authors: Li Meiping , Li Rong , Wang Zhijuan , Zhang Qing , Bai Hua , Lv Qing 
Published: January 2019

AbstractResidual chemicals in wooden children's products may threaten children's health, but few studies have paid attention to it so far. In this study, a simple and green method was developed for the determination of volatile chemicals, especially the 48 fragrance allergens in wooden children's products using static headspace coupled with gas chromatography and mass spectrometry. Minimal amounts of sample (20 mg) and acetone solvent (40 μL) were used, and no additional sample pretreatment was performed except for freezing and grinding. Three factors (incubating temperature, equilibration time, pressing pressure) affecting headspace extraction were optimized by response surface methodology to obtain scientific results considering of the interactions among variables. Under the optimum detection conditions, this method was successfully validated for the analysis of fragrances. The proposed method showed limits of quantification within the range of 0.2–20 mg/kg. Recoveries ranged from 79.8 to 115.2%, and the relative standard deviation (n = 5) varied from 0.6 to 9.9%. Moreover, interferences caused by different sample matrices were investigated. The method was further applied to the analysis of 30 commercial wooden samples. Results demonstrated the existence of fragrances in wooden children's products. Benzyl alcohol, trans‐2‐heptenal, eugenol, and isoeugenol were the compounds with high detection rate.
Optimal placement of metallic dampers for seismic upgrading of multistory buildings based on a cost‐effectiveness criterion using genetic algorithm
Authors: Li Zongjing , Shu Ganping 
Published: January 2019

SummaryIn this paper, an optimal placement methodology for metallic dampers is proposed to upgrade the seismic performance of multistory buildings. Most previous studies on optimal damper placement (ODP) problems have been focused on minimizing the seismic responses, whereas the present study aims to utilize the minimum total cost of dampers to achieve a prescribed level of seismic response. To this end, the optimization objective is constructed based on a cost‐effectiveness criterion, and the optimization constraint is defined based on a desired level of seismic response. An improved integer‐coded genetic algorithm is presented for solving the ODP problem. A 16‐story shear building is illustrated to verify the proposed optimal placement methodology. It is shown that the proposed methodology can be used to achieve the predetermined performance level while minimizing the retrofitting cost. Moreover, different algorithms, objective functions, and levels of accuracy on the optimization are also compared. Finally, a two‐step optimization approach is proposed for achieving better placement schemes with less computational efforts.
Synthesis of π‐Conjugated Benzocyclotrimers
Authors: Guo Changding , Xia Debin , Yang Yulin , Zuo Xia 
Published: January 2019

AbstractPolycyclic aromatic hydrocarbons (PAHs), especially three branchphene benzocyclotrimers represent a series of molecules with intriguing physical and chemical properties. Benzocyclotrimers are also important precursors to construct fullerenes and graphenes. In this article, we review the recent progress in the preparation methods of π‐conjugated benzocyclotrimers. In particular, cyclotrimerization reactions to construct varying shaped and edged benzocyclotrimers are illustrated. Various typical characterization methods for these materials, such as variable‐temperature 1H‐NMR, single crystal X‐ray analysis, density functional theory (DFT) calculations and atomic force microscope (AFM) measurements are included for discussion.
Fate of antibiotic resistance genes and antibiotic‐resistant bacteria in water resource recovery facilities
Authors: Li Renjie , Jay Jennifer A. , Stenstrom Michael K. 
Published: January 2019

AbstractMany important diseases are showing resistance to commonly used antibiotics, and the resistance is potentially caused by widespread use of antibiotics for maintaining human health and improving food production. Antibiotic resistance genes (ARGs) and antibiotic‐resistant bacteria (ARB) are associated with this increase, and their fate in water resource recovery facilities is an important, emerging area of research. This literature review summarizes current findings of worldwide research on the fate of ARB and ARGs in various types of treatment plants. Twenty‐five published studies were reviewed which contained 215 observations in activated sludge, membrane bioreactors, anaerobic digestion, constructed wetlands, coagulation–filtration, and three types of disinfection. We found 70% decreased observations, 18% increased observations, and 12% unchanged observations of all observations in all treatment processes. Resistance genes to tetracycline were most often observed, but more studies are needed in other antibiotic resistance genes. The causes for increased abundance of ARGs and ARB are not well understood, and further studies are warranted.Practitioner points

Antibiotic resistance is increasing with concern that treatment plants may acclimate bacteria to antibiotics.

A literature survey found 215 resistance observations with 70% decreased, 18% increased, 12% unchanged after treatment.

The type of treatment process is important with activated sludge showing the greatest reductions.
Chiral rings for surface operators in 4d and 5d SQCD
Authors: Baek Jong-Hyun 
Published: January 2019

AbstractChiral rings of two-dimensional (2,2) theories coupled to 4d$$ \mathcal{N} $$N= 2 theories with matter hypermultiplets are studied. Specifically, the vacua of the twisted superpotential of the 2d theories with vanishing sum of matter charges are computed by considering the resolvent of the bulk theory. The solutions to the chiral ring equations are also obtained from the instanton partition function via Higgsing for simple surface operators and via the orbifold description for full surface operators. These 2d/4d coupled theories are lifted to 3d/5d theories and vacua are found similarly in two different methods: by solving the 3d chiral ring equations taking into account the effect of 5d resolvent and by computing the 5d instanton partition function in the presence of a surface operator. We also check the Seiberg-like duality for both 2d/4d and 3d/5d coupled systems with a specific Chern-Simons coefficient for the latter.
A theory of R(D*, D) anomaly with right-handed currents
Authors: Babu K. S. , Dutta Bhaskar , Mohapatra Rabindra N. 
Published: January 2019

AbstractWe present an ultraviolet complete theory for theR(D*) andR(D) anomaly in terms of a low massWR±gauge boson of a class of left-right symmetric models. These models, which are based on the gauge symmetry SU(3)c× SU(2)L× SU(2)R× U(1)B−L, utilize vector-like fermions to generate quark and lepton masses via a universal seesaw mechanism. A parity symmetric version as well as an asymmetric version are studied. A light sterile neutrino emerges naturally in this setup, which allows for new decay modes ofB-meson via right-handed currents. We show that these models can explainR(D*) andR(D) anomaly while being consistent with LHC and LEP data as well as low energy flavor constraints arising from$$ {K}_L-{K}_S,\kern0.5em {B}_{d,s}-{\overline{B}}_{d,s},\kern0.5em D-\overline{D} $$KL−KS,Bd,s−B¯d,s,D−D¯mixing, etc., but only for a limited range of theWRmass: 1.2 (1.8) TeV ≤$$ {M}_{W_R} $$MWR≤ 3 TeV for parity asymmetric (symmetric) Yukawa sectors. The ratioR(D)/R(D*) is predicted to be ≃ 1.16, which is the same as in the Standard Model. The light sterile neutrinos predicted by the model may be relevant for explaining the MiniBoone and LSND neutrino oscillation results. The parity symmetric version of the model provides a simple solution to the strong CP problem without relying on the axion. It also predicts an isospin singlet top partner with a massMT= (1.5 − 2.5) TeV.
Surgical Procedures Performed by Emergency Medical Teams in Sudden‐Onset Disasters: A Systematic Review
Authors: Coventry Charles A. , Vaska Ashish I. , Holland Andrew J. A. , Read David J. , Ivers Rebecca Q. 
Published: January 2019

AbstractBackgroundEmergency medical teams (EMTs) frequently provide surgical care after sudden‐onset disasters (SODs) in low‐ and middle‐income countries. The purpose of this review is to describe the types of surgical procedures performed by EMTs with general surgical capability in order to aid the recruitment and training of surgeons for these teams.MethodsA search of electronic databases (PubMed, MEDLINE, and EMBASE) was carried out to identify articles published between 1990 and 2018 that describe the type of surgical procedures performed by EMTs in the impact and post‐impact phases of a SOD. Further relevant articles were obtained by hand searching reference lists.ResultsA total of 16 articles met the inclusion criteria. Articles reporting on EMTs from a number of different countries and responding to a variety of SODs were included. There was a high prevalence of procedures for extremity soft tissue injuries (46.8%) and fractures (28.3%), although a number of abdominal and genitourinary/obstetric procedures were also reported.ConclusionsBased upon this review, deployment of surgeons or teams with experience in the management of soft tissue wounds, orthopaedic trauma, abdominal surgery, and obstetrics is recommended.
Does Primary Hyperparathyroidism Have an Association with Thyroid Papillary Cancer? A Retrospective Cohort Study
Authors: Çetin Kenan , Sıkar Hasan E. , Temizkan Şule , Ofluoğlu Cem B. , Özderya Ayşenur , Aydın Kadriye , Gül Aylin E. , Küçük Hasan F. 
Published: January 2019

AbstractBackgroundTo investigate the relationship between primary hyperparathyroidism (pHPT) and papillary thyroid cancer (PTC).MethodsThe perioperative findings of 275 patients with pHPT who underwent surgery between January 2014 and December 2017 were retrospectively reviewed. Thirty‐one patients were diagnosed with pHPT and PTC concurrently. Pathology results and demographic findings of these patients were compared with 186 patients who underwent thyroidectomy and diagnosed with PTC at the same time interval.ResultsThe co‐occurrence of pHPT and PTC was 11.3% (31/275). The median ages of the pHPT, pHPT + PTC, and PTC groups were 55, 57, and 50 years old, respectively (p < 0.001). The diameter of tumor was smaller in the pHPT + PTC group [median 7 mm (range 0.5–25 mm) vs. 15 mm (range 1–100 mm)], with higher rates of microcarcinomas (p < 0.001), than the patients in the PTC group. Examination of tumor morphology showed higher rates of tumor capsule invasion and multicentricity in the pHPT + PTC group than those in the isolated PTC group (p = 0.02, p = 0.04, respectively).ConclusionThe pHPT + PTC group had significantly smaller tumor diameter than the PTC group. This result may support the idea that pHPT leads to overdiagnosis of PTC. However, observation of high rates of tumor capsule invasion and multicentricity in the pHPT + PTC group may suggest an associative etiology with more aggressive PTC.
Toward a global picture of bacterial secondary metabolism
Authors: Seyedsayamdost Mohammad R 
Published: January 2019

Abstract
Bacterial metabolism is comprised of primary metabolites, the intracellular molecules of life that enable growth and proliferation, and secondary metabolites, predominantly extracellular molecules that facilitate a microbe’s interaction with its environment. While our knowledge of primary metabolism and its web of interconnected intermediates is quantitative and holistic, significant knowledge gaps remain in our understanding of the secondary metabolomes of bacteria. In this Perspective, I discuss the main challenges involved in obtaining a global, comprehensive picture of bacterial secondary metabolomes, specifically in biosynthetically “gifted” microbes. Recent methodological advances that can meet these challenges will be reviewed. Applications of these methods combined with ongoing innovations will enable a detailed picture of global secondary metabolomes, which will in turn shed light onto the biology, chemistry, and enzymology underlying natural products and simultaneously aid drug discovery.
Otolith-Based Chronology of Brazilian Shellmounds
Authors: Carvalho Carla , Oliveira Fabiana , Macario Kita , Lima Tania , Chanca Ingrid , Alves Eduardo Q , Bertucci Thayse , Aguilera Orangel 
Published: January 2019

ABSTRACTThe radiocarbon (14C) chronology of hunter-fisher-gatherers’ archaeological settlements along the Brazilian coast is usually based on mollusk shells, charcoal from hearths, and eventually human bones. However, fish otoliths are found in several archaeological contexts and may represent a reliable option as a chronological record. In this work, we compare the 14C dates of whitemouth croakers (Micropogonias furnieri) otoliths with dates obtained from other materials (shell and charcoal), collected from shellmounds on the coast of Rio de Janeiro, with the aim of improving the accuracy in the 14C dating of Brazilian shellmounds, strengthening the comprehension of the native populations’ occupational trends and the coeval palaeoceanographic context. Based on x-ray diffraction results for archaeological otoliths, their geochemical composition indicates minimal diagenesis effect over time even under burial conditions in the studied sites. The comparison between otolith dates and dates obtained from other proxies revealed similar results but with decreased deviations in otolith dates in all of the studied sites.