bluuebunny/crossref_metadata_2025_split huggingface dataset:
Promoting Effect and Mechanism of Alkali Na on Pd/SBA‐15 for Room Temperature Formaldehyde Catalytic Oxidation
Authors: Xiang Ning , Hou Yaqin , Han Xiaojin , Li Yulin , Guo Yaoping , Liu Yongjin , Huang Zhanggen 
Published: August 2019

AbstractRoom temperature HCHO catalytic oxidation over inert support loaded Pd catalysts remains a significant challenge. Herein, a series of alkali Na (1–4 wt.%) modified 1Pd/SBA‐15 catalysts were prepared by a co‐impregnation method and used for HCHO catalytic oxidation at room temperature. Results showed that alkali Na significantly improved the HCHO oxidation performance of 1Pd/SBA‐15 and the optimal Na loading was 2 wt.%. BET, XRD, STEM, XPS, H2‐TPR, O2‐TPD and in situ DRIFTS were performed to reveal the promotion role of alkali Na. As a consequence, alkali Na addition could stabilize well dispersed Pd particles which then facilitated the O2 activation and accelerated the decomposition of formate intermediates species, thus a superior HCHO catalytic oxidation performance was obtained. This study first clearly illustrated the promotion mechanism of alkali Na without the implication of active support and provides an efficient and facile way to achieve high dispersion of Pd particles on inert support and tremendously expands the selected range of supports for room temperature HCHO catalytic oxidation.
Multiple‐Porphyrin Functionalized Hexabenzocoronenes
Authors: Martin Max M. , Lungerich Dominik , Hampel Frank , Langer Jens , Ronson Tanya K. , Jux Norbert 
Published: August 2019

AbstractPorphyrin–hexabenzocoronene architectures serve as good model compounds to study light‐harvesting systems. Herein, the synthesis of porphyrin functionalized hexa‐peri‐hexabenzocoronenes (HBCs), in which one or more porphyrins are covalently linked to a central HBC core, is presented. A series of hexaphenylbenzenes (HPBs) was prepared and reacted under oxidative coupling conditions. The transformation to the respective HBC derivatives worked well with mono‐ and tri‐porphyrin‐substituted HPBs. However, if more porphyrins are attached to the HPB core, Scholl oxidations are hampered or completely suppressed. Hence, a change of the synthetic strategy was necessary to first preform the HBC core, followed by the introduction of the porphyrins. All products were fully characterized, including, if possible, single‐crystal XRD. UV/Vis absorption spectra of porphyrin‐HBCs showed, depending on the number of porphyrins as well as with respect to the substitution pattern, variations in their spectral features with strong distortions of the porphyrins’ B‐band.
Face‐Centered‐Cubic Ag Nanoclusters: Origins and Consequences of the High Structural Regularity Elucidated by Density Functional Theory Calculations
Authors: Lv Ying , Ma Xiangyu , Chai Jinsong , Yu Haizhu , Zhu Manzhou 
Published: August 2019

AbstractFace‐centered‐cubic (FCC) silver nanoclusters (NCs) adopting either cubic or half‐cubic growth modes have been recently reported, but the origin of these atomic assembly patterns and how they are achieved, which would inform our understanding of larger FCC silver nanomaterials, are both unknown. In this study, the cubic and half‐cubic growth modes have been unified based on common structural characteristics, and differentiated depending on the starting blocks (cubic vs. half cubic). In both categories, the silver atoms adopt octahedral Ag6, linear AgS2 (in projection drawing), or tetrahedral AgS3P binding modes, and the sulfur atoms adopt T‐shaped SAg3 and orthogonal SAg4 modes. An additional T‐shaped AgS3 mode is oriented on the surface edge in cubic NCs to complete the cubic framework. Density functional theory calculations indicated that the high structural regularity originates from the strong diffusing capacity of the Ag(5d) and S(3p) orbitals, and the angular momentum distribution of the formed superatomic orbitals. The equatorial orientation of μ4‐S or μ4‐Ag determines whether growth stops or continues. In particular, a density‐of‐states analysis indicated that the octahedral silver atoms are chemically more reactive than the silver atoms in the AgS3P motif, regardless of whether the parent NC functions as an electron donor or acceptor.
The Symbiotic Relationship Between Drug Discovery and Organic Chemistry
Authors: Grygorenko Oleksandr O. , Volochnyuk Dmitriy M. , Ryabukhin Sergey V. , Judd Duncan B. 
Published: August 2019

AbstractAll pharmaceutical products contain organic molecules; the source may be a natural product or a fully synthetic molecule, or a combination of both. Thus, it follows that organic chemistry underpins both existing and upcoming pharmaceutical products. The reverse relationship has also affected organic synthesis, changing its landscape towards increasingly complex targets. This Review article sets out to give a concise appraisal of this symbiotic relationship between organic chemistry and drug discovery, along with a discussion of the design concepts and highlighting key milestones along the journey. In particular, criteria for a high‐quality compound library design enabling efficient virtual navigation of chemical space, as well as rise and fall of concepts for its synthetic exploration (such as combinatorial chemistry; diversity‐, biology‐, lead‐, or fragment‐oriented syntheses; and DNA‐encoded libraries) are critically surveyed.
B−B Cleavage and Ring‐Expansion of a 1,4,2,3‐Diazadiborinine with N‐Heterocyclic Carbenes
Authors: Thiess Torsten , Mellerup Soren K. , Braunschweig Holger 
Published: August 2019

AbstractA 1,4,2,3‐diazadiborinine derivative was found to form Lewis adducts with strong two‐electron donors such as N‐heterocyclic and cyclic (alkyl)(amino)carbenes. Depending on the donor, some of these Lewis pairs are thermally unstable, converting to sole B,N‐embedded products upon gentle heating. The products of these reactions, which have been fully characterized by NMR spectroscopy, elemental analysis, and single‐crystal X‐ray diffraction, were identified as B,N‐heterocycles with fused 1,5,2,4‐diazadiborepine and 1,4,2‐diazaborinine rings. Computational modelling of the reaction mechanism provides insight into the formation of these unique structures, suggesting that a series of B−H, C−N, and B−B bond activation steps are responsible for these “intercalation” reactions between the 1,4,2,3‐diazadiborinine and NHCs.
A facile synthesis of nontoxic luminescent carbon dots for detection of chromium and iron in real water sample and bio‐imaging
Authors: Sinha Rupam , Bidkar Anil P. , Rajasekhar Ravula , Ghosh Siddhartha S. , Mandal Tapas K. 
Published: August 2019

AbstractIn this study, we have reported the synthesis of luminescent carbon dots (CDs) from indigenous potato sources by simple heating reactions. The as‐synthesized CDs exhibited an average size of ~ 5.97 nm with a quantum yield (QY) of 6.08%. Furthermore, the CDs possessed high water‐solubility, possibly due to the presence of ─COOH and ─OH groups on their surfaces. The quenching of luminescence of the CDs specifically by Cr6+ and Fe3+ ions was used to detect chromium and iron in the water sample. The minimum limit of detection (LOD) for Cr6+ and Fe3+ ions was found to be 0.012 μM and 0.000549 μM, respectively, in a linear range of 0.5 μM‐100 μM and 0.5 μM‐5 μM for Cr6+ and Fe3+, respectively, which was well below the concentration specified by WHO. We used our sensing system to detect the metal ions in water from the Brahmaputra River as well as in tannery water. In addition, the MTT‐based cell viability experiments showed that the CDs were nontoxic within 200 μg/mL. High quantum yield and the easy uptake of CDs enabled the quick labelling of cytoplasm of the HeLa cells, which can be further attributed to bioimaging applications.
A comparative study of the population genetics of wild and cultivated populations of Paris polyphylla var. yunnanensis based on amplified fragment length polymorphism markers
Authors: Huang Yu , Zhou Nong , Yang Min , Shen Yuxiang , Zhang Dequan 
Published: August 2019

AbstractParis polyphylla var. yunnanensis is one of the original plants used to make the traditional medicine Paridis Rhizoma. Wild individuals have been excessively collected in recent decades, and thus, it has become increasingly endangered. Cultivation is a major method for the conservation and sustainable utilization of its wild resources. In this study, amplified fragment length polymorphism markers were used in the genetic analysis of 15 wild and 17 cultivated populations of P. polyphylla var. yunnanensis. This study revealed that cultivated populations possessed higher genetic diversity than wild ones at the species level (H = 0.2636 vs. 0.2616, respectively). However, most of the genetic variation was found within populations for both of these groups (ΦST = 18.83% vs. 19.39%). In the dendrogram produced using UPGMA, the 32 populations were divided into three groups (I, II, and III). In group II, both wild and cultivated populations were included, but remained in distinct clusters within this group, which showed the significant separation between the cultivated and wild populations. Furthermore, wild populations were also clustered into three subgroups (W‐I, W‐II, and W‐III), with an obvious geographic structure. In contrast, although cultivated populations were similarly placed in three subgroups (C‐I, C‐II, and C‐III), the latter two of these were not separated based on geography. Finally, the wild populations in Guizhou, China (W‐I), possessed higher genetic diversity than those in Yunnan (W‐II and W‐III). As P. polyphylla var. yunnanensis is an endangered medicinal plant, the fact that it showed richer genetic diversity in its wild populations in Guizhou means that these should be regarded as priority areas for protection and used for provenance selection. Moreover, cultivated populations also showed high genetic variation, which might be attributed to them having originated from mixed provenances, indicating that screening for superior provenances should be carried out as soon as possible.
Evaluation of aDcp processing options for secondary flow identification at river junctions
Authors: Moradi Gelare , Vermeulen Bart , Rennie Colin D. , Cardot Romain , Lane Stuart N. 
Published: August 2019

AbstractSecondary circulation in river confluences results in a spatial and temporal variation of fluid motion and a relatively high level of morphodynamic change. Acoustic Doppler current profiler (aDcp) vessel‐mounted flow measurements are now commonly used to quantify such circulation in shallow water fluvial environments. It is well established that such quantification using vessel‐mounted aDcps requires repeated survey of the same cross‐section. However, less attention has been given to how to process these data. Most aDcp data processing techniques make the assumption of homogeneity between the measured radial components of velocity. As acoustic beams diverge with distance from the aDcp probe, the volume of the flow that must be assumed to be homogeneous between the beams increases. In the presence of secondary circulation cells, and where there are strong rates of shear in the flow, the homogeneity assumption may not apply, especially deeper in the water column and close to the bed. To reduce dependence on this assumption, we apply a newly‐established method to aDcp data obtained for two medium‐sized (~60–80 m wide) gravel‐bed river confluences and compare the results with those from more conventional data processing approaches. The comparison confirms that in the presence of strong shear our method produces different results to more conventional approaches. In the absence of a third set of fully independent data, we cannot demonstrate conclusively which method is best, but our method involves less averaging and so in the presence of strong shear is likely to be more reliable. We conclude that it is wise to apply both our method and more conventional methods to identify where data analysis might be impacted upon by strong shear and where inferences of secondary circulation may need to be made more cautiously. © 2019 John Wiley & Sons, Ltd.
Impact of fluid property shift and capillarity on the recovery mechanisms of CO2injection in tight oil reservoirs
Authors: Wu Shouya , Li Zhaomin , Sarma Hemanta K. , Zhang Chao , Lv Guangzhong 
Published: August 2019

AbstractThe phase equilibria with the confinement effect could shift in nano‐pores, which could have a great impact on the recovery mechanisms of CO2injection in tight oil reservoirs; this has not been systematically studied. In this paper, the confinement effect with property shift and capillarity effect is introduced into the flash calculation of confined fluids. The Soave modification of the Redlich–Kwong equation of state is extended by the molecular‐wall collision parameter to describe the shifted pressure–volume–temperature properties of confined fluid, and the Young–Laplace equation is applied to evaluate the capillary pressure. This developed model could effectively be applied for phase equilibrium calculation in tight porous media because of the verification of experimental results. A binary mixture is investigated to study the different effect of capillary pressure and property shift on phase equilibria. Subsequently, a typical hydrocarbon fluid from Middle Bakken tight oil reservoirs is studied with CO2injection. Results illustrate that the confinement effect could play an increasingly important part in the phase equilibrium state. The CO2solubility and mass transfer driving force in tiny pores would be greater than those in large pores under the same conditions. The gas phase saturation would be smaller with the same compositions, which could extend the single‐phase region of fluid flow in porous media. Furthermore, bubble‐point pressure, the minimum miscible pressure of CO2/hydrocarbon, and the viscosity of tight oil dissolved with CO2both decrease with the pore size, which has a good influence on tight oil recovery. In general, the confinement effect could effectively reinforce the recovery mechanisms of CO2injection, which is conducive to the enhancement of tight oil recovery. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.
A surgical approach to schwannomas originating from the esophageal branch of the recurrent laryngeal nerve: Pictorial essay
Authors: Kobayashi Kenya , Matsumoto Yoshihumi , Matsumoto Fumihiko , Sato Tetsufumi , Mori Taisuke , Tsuchida Takaaki , Omura Go , Matsumura Satoko , Ikeda Atsuo , Sakai Azusa , Eguchi Kotaro , Yoshimoto Seiichi 
Published: August 2019

AbstractBackgroundSchwannoma originating from the esophageal branch of the recurrent laryngeal nerve is clinically rare event. The best approach to preoperative pathological diagnosis, surgery, and airway management for this submucosal tumor in the tracheal membranous portion remains controversial.Methods and ResultsA 69‐year‐old man had developed dyspnea for 6 months. Transnasal endoscopy revealed a submucosal tumor in the tracheal membranous portion, obstructing the airway. CT revealed that the tumor was located between the trachea and esophagus. Needle biopsy using ultrasonic bronchoscope diagnosed the submucosal tumor as schwannoma. Intercapsular resection was performed by a transtracheal approach under local anesthesia. The tumor was completely resected and the patient's symptoms completely improved.ConclusionsWe report the treatment of a rare schwannoma originating from the esophageal branch of the recurrent laryngeal nerve. A needle biopsy using an ultrasonic bronchoscope was successfully used for diagnosis. Intercapsular resection by a transtracheal approach was effective.
Social support and turnover among entry‐level service employees: Differentiating type, source, and basis of attachment
Authors: Tews Michael J. , Michel John W. , Stafford Kathryn 
Published: August 2019

AbstractPrevious research on social support and turnover has yielded mixed results. To advance research in a more comprehensive manner, the present study examined how turnover is influenced by type of support (emotional or instrumental), source of support (coworker or supervisor), and basis of attachment (affective commitment and constituent attachment as mediators). In the context of entry‐level service employees, these relationships were examined with a sample of restaurant servers company‐wide from a casual dining restaurant chain in the USA. Coworker emotional support was directly and negatively related to turnover, and coworker instrumental support was directly and positively related to turnover. Furthermore, supervisor emotional support and instrumental support were indirectly related to turnover through affective commitment. When the mediators were considered independently, coworker and supervisor emotional support were both indirectly related to turnover through constituent attachment.
Short‐term hypoxia promotes vascularization in co‐culture system consisting of primary human osteoblasts and outgrowth endothelial cells
Authors: Ma Bin , Li Ming , Fuchs Sabine , Bischoff Iris , Hofmann Alexander , Unger Ronald E. , Kirkpatrick Charles J. 
Published: August 2019

AbstractPrevascularization of tissue constructs before implantation has been developed as a novel and promising concept for successful implantation. Since hypoxia might induce angiogenesis, we have investigated the effects of hypoxic treatment on vascularization by using co‐cultures of primary human osteoblasts (POBs) and outgrowth endothelial cells. Our results show that: (a) repeated short‐term hypoxia (2% O2 for 8 hr), not long‐term hypoxia (2% O2 for 24 hr), over 1 or 2 weeks, significantly enhances microvessel formation in co‐cultures; (b) sustained hypoxia, not short‐term or long‐term hypoxia, causes cytotoxicity in mono‐ and co‐cultures; (c) the expression of some angiogenic and inflammatory factors such as vascular endothelial growth factor, platelet‐derived growth factor subunit B, insulin‐like growth factor 1, interleukin‐8, and early growth response protein 1 increases significantly in hypoxia‐treated POB monoculture and co‐cultures after single or multiple 8‐ or 24‐hr hypoxic treatments; (d) long‐term (24 hr) hypoxic treatment induces more angiogenic inhibitors compared with short‐term hypoxic treatment. Our findings suggest that hypoxia‐induced vascularization/angiogenesis is regulated by a complex balance of angiogenic/antiangiogenic factors, and that repeated short‐term hypoxia, but not repeated long‐term hypoxia, promotes the vascularization and tissue regeneration of bone tissue constructs.
Factors affecting bowel preparation adequacy and procedural time
Authors: Zad Mohammadali , Do Cuong N , Heffernan Aaron , Johnston Lucy , Al‐Ansari Mohammed 
Published: August 2019

Background and AimPoor bowel preparation results in difficult colonoscopies, missed lesions, and repeat procedures. Identifying patient risk factors for poor bowel preparation, such as prolonged runway time and prolonged cecal intubation, will aid in interventions prior to a procedure.MethodsThis was a retrospective, single‐center analysis of 3 295 colonoscopies performed between May 2012 and November 2014. Indications for colonoscopy included gastrointestinal bleed and anemia, change in bowel habits, for screening, and others (including planning re‐anastomoses, abdominal distension, family history and angioectasias). Data were collected from medical charts and endoscopy reports. Comparisons between patient factors and runway time were made with adequacy of bowel preparation as the primary outcomes.ResultsMale and diabetic patients had statistically higher rates of inadequate bowel preparation and prolonged cecal intubation times. A previous history of abdominal surgery also demonstrated prolonged cecal intubation. A runway time of ≤7.63 h was associated with higher rates of adequate bowel preparation by multivariate analysis. The optimal time frame is 3–6 h for the highest success rates.ConclusionPatient risk factors for inadequate bowel preparation or prolonged cecal intubation should signal clinicians to intervene prior to colonoscopy. A runway time between 3 and 6 h is optimal for adequate bowel preparation. This may involve further patient education, along with work flow optimization, to facilitate ideal runway times. Future studies should explore how to avoid repeat endoscopies using protocols enforcing this timeframe.
Soluble E‐cadherin is associated with oxidative stress in patients with chronic HBV infection
Authors: Yang Jun , Xiong Yuan , Zhou Lijing , Huang Yong , Chen Weixian , Wang Bo 
Published: August 2019

AbstractMounting evidence indicates that serum soluble E‐cadherin (sE‐cadherin) serves as an important player in various physiological and pathological processes. However, the crosstalk between serum sE‐cadherin and oxidative stress in chronic hepatitis B (CHB) remains to be illustrated. The main purpose of this study is to explore the molecular mechanisms underlying the function of sE‐cadherin in CHB virus infection. Levels of serum sE‐cadherin, total antioxidant capacity (TAC), glutathione (GSH), superoxide dismutase (SOD), total oxidant activity (TOA), NADPH oxidase 2 (NOX2), and malondialdehyde (MDA), from 51 patients with hepatitis B envelope antigen (HBeAg)‐negative CHB, 54 patients with HBeAg‐positive CHB, and 109 healthy individuals were detected by enzyme‐linked immunosorbent assay. In our study, patients with CHB showed significantly higher serum sE‐cadherin levels than healthy individuals (P < .01). Furthermore, we also found that the serum sE‐cadherin levels were significantly negatively correlated with TAC, antioxidant enzymes (GSH and SOD) in patients with CHB, and that serum sE‐cadherin concentrations were significantly positively correlated with liver enzyme markers (alanine transaminase and aspartate aminotransferase) and oxidative markers (TOA, NOX2, and MDA) in patients with CHB. Therefore, serum sE‐cadherin may act as a new candidate biomarker for reflecting inflammation and oxidative stress status in the development and progression of hepatitis B virus infection.
Hydrological and temperature variations between 1900 and 2016 in the Catskill Mountains, New York, USA
Authors: Kelly‐Voicu Petra , Frei Allan 
Published: August 2019

AbstractThe Catskill Mountains and surrounding counties in south‐central New York State are home to almost 400,000 residents, and supply drinking water to over 9 million people in New York City and other municipalities. In this study, we identify a set of stations in this region that are appropriate for climatological analysis, and examine variations in precipitation, streamflow, and temperature between 1900 and 2016, extending the time domain of previous studies of the climatology of this region during both the early and recent portions of the record. Temperatures have increased since the mid‐20th century, in particular daily minimum temperatures, at rates that vary with season and elevation. As a result, diurnal temperature ranges have tended to decrease, particularly during the warm season at lower elevations. The most significant hydrological events include the cold drought of the 1960s (a year‐round phenomenon), and the wet period beginning in the late 1990s (primarily a warm season phenomenon). We also find evidence of a particularly wet period at the start of the 20th century. Cyclic behaviour is found in both hydrological and temperature records, with the most prominent cycle in cold season precipitation and streamflow peaking at 28 years.