bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent Progress in (Dynamic) Kinetic Resolution Catalyzed by N‐Heterocyclic Carbenes
Authors: Chen Shihao , Shi Yu‐Hua , Wang Ming
Published: July 2018

Catalytic kinetic resolution is often the “method of choice” for the preparation of optically enriched functionalized compounds and, over the past decade, kinetic resolutions and dynamic kinetic resolutions catalyzed by N‐heterocyclic carbenes (NHCs) have been employed for the synthesis of a variety of optically enriched functionalized molecules. Herein we provide an overview of reported NHC‐catalyzed kinetic resolutions in terms of the structure of the substrate, the reaction type, and the activation mode. This Focus Review is arranged according to the structure of the racemic compounds and includes the kinetic resolution of alcohols, amines, imines, and aldehydes, as well as dynamic kinetic resolution. In each section, the activation mode and reaction mechanism are discussed. We conclude with a summary of the current state‐of‐play in NHC‐catalyzed kinetic resolution and provide an outlook for the development of this field in the future.
SERS Signal Enhancement of Methylene Blue‐embedded Agglomerated Gold Nanorod@SiO2 Core@Shell Composites
Authors: Shim Kyu‐Dong , Jang Eue‐Soon
Published: July 2018

In medical science, Raman spectroscopy has received considerable attention as the next noninvasive diagnostic imaging technique. However, its clinical applications are limited by the weak signal intensities of Raman active molecules. Previously, we showed that a methylene‐blue‐loaded gold nanorod@silica (MB‐GNR@SiO2) core@shell nanostructure is promising for the development of a cancer theranostic agent due to its excellent surface‐enhanced Raman scattering (SERS) performance and synergistic cancer‐destroying efficacy. In this study, we successfully synthesized MB‐embedded agglomerated gold nanorod@SiO2 (MB‐A.GNR@SiO2) composites, in which the many interparticle junctions created by the agglomerated GNRs were able to enhance the SERS signal of the loaded MB by a factor of five compared to MB‐GNR@SiO2. This high SERS performance of the present MB‐A.GNR@SiO2 could provide us with an approach to explore a rapid and ultra‐sensitive SERS detection method for various biological molecules.
Sustainability management: research insights from social cognitive neuroscience
Authors: McDonald Paul
Published: July 2018

Research in the field of social cognitive neuroscience is advancing rapidly, accelerated by technological innovation in brain imaging. This research is producing novel insights as to how humans process information, make decisions and behave in response to the growing imperatives for sustainability management. Recent research findings have implications for the theoretical foundations of sustainability management as well as the practical challenges confronting managers. Neuroscientific evidence underscores the magnitude of the challenges. Physiological evidence of six neural processes, hardwired via synaptic connections and potentially antagonistic to enhanced sustainability management, establish the structure of the paper. These neural phenomena, which are reflexive and preconscious, include: amygdala intercept, in‐group/out‐group differentiation, loss aversion, implicit persuasion and priming effects – cognitive and cultural. Propositions are advanced linking neurological processes to sustainability management. The paper concludes with strategic considerations and practical implications for greater integration between social cognitive neuroscience and sustainability management research.
Acquiring startups in the energy sector: a study of firm value and environmental policy
Authors: Kwon Ohsung , Lim Sangmin , Lee Duk Hee
Published: July 2018

Mergers and acquisitions are important activities for the growth of firms. In the energy sector, acquiring firms can obtain eco‐friendly technology and premiums, as well as tangible assets, through the acquisition of energy firms. Among many energy firms, an acquired startup is more effective since the acquisition price is relatively inexpensive and the acquiring firm is also exposed to entrepreneurial culture. In this study, to test the acquisition effect, datasets from Worldscope and CrunchBase are used. It is observed that, despite the advantages of an acquisition, the effect of a startup acquisition is negative. However, firms in environmentally sensitive industries benefit from such acquisition activity. The acquisition price of energy startups is overestimated due to increasing demand for acquisitions. On the other hand, the eco‐premiums also help dirty firms make a profit.
Understanding Commonalities and Interplay Between Organotemplate‐Free Zeolite Synthesis, Hierarchical Structure Creation, and Interzeolite Transformation
Authors: Zhang Ke , Fernandez Sergio , Ostraat Michele L.
Published: July 2018

Zeolites are crystalline microporous materials that have been widely used in many applications related to industrial catalysis, ion‐exchange, and adsorption. In recent years, there has been a growing emphasis on the development of green chemistry toward more sustainable zeolite synthesis routes. Considerable efforts have been devoted to identifying alternative approaches in order to reduce the negative impacts of organic templates. This review will focus on the significant progress achieved during the past decade on the development of novel organotemplate‐free strategies through three distinctive topics, i. e. zeolite synthesis, hierarchical zeolite synthesis, and interzeolite transformation. The progress of each topic will be documented, followed by a summary of the intriguing commonalities and interplay among these approaches. The insights into the mechanism and interplay leading to different zeolite materials will enable us to understand the requirements for designing novel zeolite catalysts and catalyst supports in an organotemplate‐free environment that are likely to further enhance the industrial impact of these materials in the future. We conclude this article with a perspective and outlook focusing on current trends and future directions in this area.
Tissue‐Penetrating, Hypoxia‐Responsive Echogenic Polymersomes For Drug Delivery To Solid Tumors
Authors: Kulkarni Prajakta , Haldar Manas K. , Karandish Fataneh , Confeld Matthew , Hossain Rayat , Borowicz Pawel , Gange Kara , Xia Lang , Sarkar Kausik , Mallik Sanku
Published: July 2018

Hypoxia in solid tumors facilitates the progression of the disease, develops resistance to chemo and radiotherapy, and contributes to relapse. Due to the lack of tumor penetration, most of the reported drug carriers are unable to reach the hypoxic niches of the solid tumors. We have developed tissue‐penetrating, hypoxia‐responsive echogenic polymersomes to deliver anticancer drugs to solid tumors. The polymersomes are composed of a hypoxia‐responsive azobenzene conjugated and a tissue penetrating peptide functionalized polylactic acid‐polyethylene glycol polymer. The drug‐encapsulated, hypoxia‐responsive polymersomes substantially decreased the viability of pancreatic cancer cells in spheroidal cultures. Under normoxic conditions, polymersomes were echogenic at diagnostic ultrasound frequencies but lose the echogenicity under hypoxia. In‐vivo imaging studies with xenograft mouse model further confirmed the ability of the polymersomes to target, penetrate, and deliver the encapsulated contents in hypoxic pancreatic tumor tissues.
Heteroatom‐Doping Increases Cluster Nuclearity: From an [Ag20] to an [Au3Ag18] Core
Authors: Chang Wan‐Ting , Sharma Sachil , Liao Jian‐Hong , Kahlal Samia , Liu Yu‐Chiao , Chiang Ming‐Hsi , Saillard Jean‐Yves , Liu C. W.
Published: July 2018

A templated galvanic exchange performed on [Ag20{Se2P(OiPr)2}12] of C3 symmetry with three equiv AuI yields a mixture of [Au1+xAg20−x{Se2P(OiPr)2}12]+ (x=0–2) from which [Au@Ag20{Se2P(OiPr)2}12]+ and [Au@Au2Ag18{Se2P(OiPr)2}12]+ are successfully characterized to have T and C1 symmetry, respectively. Crystal structural analyses combined with DFT calculations on the model compounds explicitly demonstrate that the central Ag0 of Ag20 being oxidized by AuI migrates to the protecting atomic shell as a new capping AgI, and both second and third Au dopants prefer occupying non‐adjacent icosahedron vertices. The differences in symmetry, T and C1, are manifested in the spatial orientation of their protecting atomic shell composed of eight capping Ag atoms as well as re‐construction upon the replacement of Ag atoms on the vertices of AuAg12 icosahedral core with second and third Au dopants. As a result, a unique pathway for substitutional‐doped clusters with increased nuclearity is proposed.
A Strongly Luminescent Chromium(III) Complex Acid
Authors: Otto Sven , Förster Christoph , Wang Cui , Resch‐Genger Ute , Heinze Katja
Published: July 2018

The synthesis, structure, reactivity, and photophysical properties of a novel acidic, luminescent chromium(III) complex [Cr(H2tpda)2]3+ (23+) bearing the tridentate H2tpda (2,6‐bis(2‐pyridylamino)pyridine) ligand are presented. Excitation of 23+ at 442 nm results in strong, long‐lived NIR luminescence at 782 nm in water and in acetonitrile. X‐ray diffraction analysis and IR spectroscopy reveal hydrogen‐bonding interactions of the counter ions to the NH groups of 23+ in the solid state. Deprotonation of the NH groups of 23+ by using a non‐nucleophilic Schwesinger base in CH3CN switches off the luminescence. Re‐protonation by using HClO4 restores the emission. In water, the pKa value of 23+ amounts to 8.8, yet deprotonation is not reversible in the presence of hydroxide ions. Dioxygen quenches the emission of 23+, but to a weaker extent than expected. This is possibly due to the strong ion‐pairing properties of 23+ even in solution, reducing the energy transfer efficiency to O2. Deuteration of the NH groups of 23+ approximately doubles the quantum yield and lifetime in water, demonstrating the importance of multiphoton relaxation in these NIR emitters.
Atrial fibrillation in an African‐American cohort: The Jackson Heart Study
Authors: Austin Thomas R. , Wiggins Kerri L. , Blackshear Chad , Yang Yi , Benjamin Emelia J. , Curtis Lesley H. , Sotoodehnia Nona , Correa Adolfo , Heckbert Susan R.
Published: July 2018

Background

Atrial fibrillation (AF) is an important public health problem across race/ethnic groups. Data from US cohort studies initiated in the 1980s suggest a higher prevalence of AF risk factors among African‐Americans (AAs) than whites, but lower AF incidence. The Jackson Heart Study (JHS) is a community‐based study of 5306 AAs recruited starting in 2000.

Hypothesis

Demographic, anthropometric, cardiovascular, and/or electrocardiographic factors are associated with AF incidence in JHS.

Methods

Using baseline participant characteristics and incident AF identified through hospital surveillance, study electrocardiogram, and Medicare claims, we estimated age‐ and sex‐specific AF incidence rates, compared them with rates in AA participants in the Multi‐Ethnic Study of Atherosclerosis (MESA) and Cardiovascular Health Study (CHS), and examined associations of cardiovascular risk factors with AF.

Results

A total of 66 participants had prevalent AF at baseline. Over an average follow‐up of 8.5 years, 242 cases of incident AF were identified. Age‐ and sex‐specific AF incidence rates in JHS were similar to those among AAs in MESA and appeared slightly lower than those among AAs in CHS. In an age‐ and sex‐adjusted model, associations with incident AF were observed for modifiable risk factors: high body weight (HR = 1.23 per 15 kg, 95%CI 1.13‐1.35), systolic blood pressure (HR = 1.29 per 20 mmHg, 95%CI 1.13‐1.47), and current smoking (HR = 1.80, 95%CI 1.27‐2.55). Risk estimates associated with these risk factors were only slightly attenuated after multivariable adjustments.

Conclusions

These findings underscore the potential additional benefits of interventions for weight management, control of hypertension, and smoking cessation for the prevention of AF among AAs.
Hydroxypyridonecarboxylic Acids as Inhibitors of Human Cytomegalovirus pUL89 Endonuclease
Authors: Kankanala Jayakanth , Wang Yan , Geraghty Robert J. , Wang Zhengqiang
Published: July 2018

Human cytomegalovirus (HCMV) infection poses a major health threat to immunocompromised individuals. Until recently, treatment of HCMV infection has relied solely on polymerase inhibitors that have safety and resistance issues. pUL89 provides the enzymatic functions for the HCMV terminase complex in viral DNA packaging and is an attractive target for developing a new class of HCMV drugs. However, inhibitors of the endonuclease activity of the C terminus of pUL89 (pUL89‐C) were unknown before our recently characterized hydroxypyridonecarboxylic acid (HPCA) hit 7 r (1‐(3‐chloro‐4‐fluorobenzyl)‐5‐hydroxy‐4‐oxo‐1,4‐dihydropyridine‐3‐carboxylic acid; numbered as 10 k in our previous publication: Y. Wang, L. Mao, J. Kankanala, Z. Wang, R. J. Geraghty, J. Virol. 2017, 91, e02152‐16). Herein, we explored the structure–activity relationship (SAR) of the HPCA chemotype mainly with regard to the N1 site through the synthesis of 35 analogues. The SAR studies, along with molecular modeling, identified a possible pharmacophore model minimally consisting of a chelating triad and a hydrophobic phenyl or biphenyl methyl substituent at N1. Lastly, our best compounds consistently inhibited pUL89‐C in the low micromolar range in biochemical assays and exhibited strong antiviral activity without cytotoxicity, laying a solid medicinal chemistry foundation for further HCMV drug discovery efforts targeting pUL89‐C.
Nasal surgery handled by CFD tools
Authors: Sanmiguel‐Rojas Enrique , Burgos Manuel Antonio , Esteban‐Ortega Francisco
Published: July 2018

Annually, hundreds of thousands of surgical interventions to correct nasal airway obstruction are performed throughout the world. Recent studies have noted that a significant number of patients have persistent symptoms of nasal obstruction postoperatively. In the present work, we introduce a new methodology that raises the success rate of nasal cavity surgery. In this procedure, the surgeon performs virtual surgery on a 3D nasal model of a patient prior to the real surgery. The main goal of the methodology is to guide the surgeon throughout the virtual operation using mathematical estimators based on CFD results. The virtual surgery intervention ends as soon as the estimators fall into a region of a Cartesian coordinate system with a high success probability. This region is defined according to a statistical analysis of estimators corresponding to sets of healthy and diseased cavities. As examples of this application, this study includes 2 surgical operations performed with this innovative methodology on patients with severe nasal obstruction. The patients underwent nasal surgery according to the final nasal geometry revealed by CFD‐guided virtual surgery. Currently, both subjects show high degrees of satisfaction.
Doping and Surface Effects of CuFeS2 Nanocrystals Used in Thermoelectric Nanocomposites
Authors: Vaure L. , Liu Y. , Cadavid D. , Agnese F. , Aldakov D. , Pouget S. , Cabot A. , Reiss P. , Chenevier P.
Published: July 2018

In the search for low‐cost thermoelectric materials operating near room temperature, the potential of chalcopyrite (CuFeS2) nanocrystals is explored. Their colloidal synthesis is optimized to achieve around 40 nm sized nanocrystals with the goal to effectively reduce thermal conductivity via phonon scattering while maintaining high electrical conductivity. EDX and XPS analyses reveal that the nanocrystals are intrinsically nanostructured with a radial compositional gradient. Three strategies are explored to optimize the thermoelectric properties: i) Intrinsic doping by varying the Cu : Fe ratio. However, the effect of this variation is overcompensated by a global sulfur deficiency, making the chalcopyrite nanocrystals n‐type. A high Seebeck coefficient, S, up to −380 μV/K is obtained, while the figure of merit remains comparably low (ZT=0.07 at 400 °C) because of low electrical conductivity σ. ii) Removal of the native, insulating ligands by exchange with potassium selenide. This results in a better trade‐off between S and σ and hence a strongly improved ZT (0.18 at 400 °C). iii) Extrinsic doping via intimate mixture of chalcopyrite nanocrystals with metal nanoparticles. Sn (3 wt %) or Ag (16 wt %) nanoparticles give the best results (ZT=0.16 at 400 °C), inducing the concomitant reduction of thermal conductivity κ and increase of σ.
Highly Efficient, Cost Effective, and Safe Sodiation Agent for High‐Performance Sodium‐Ion Batteries
Authors: Shanmukaraj Devaraj , Kretschmer Katja , Sahu Tuhin , Bao Weizhai , Rojo Teofilo , Wang Guoxiu , Armand Michel
Published: July 2018

The development of sodium‐ion batteries has been hindered so far by the large irreversible capacity of hard carbon anodes and other anode materials in the initial few cycles, as sodium ions coming from cathode materials is consumed in the formation of the solid–electrolyte interface (SEI) and irreversibly trapped in anodes. Herein, the successful synthesis of an environmentally benign and cost‐effective sodium salt (Na2C4O4) is reported that could be applied as additive in cathodes to solve the irreversible‐capacity issues of anodes in sodium‐ion batteries. When added to Na3(VO)2(PO4)2F cathode, the cathode delivered a highly stable capacity of 135 mAh g−1 and stable cycling performance. The water‐stable Na3(VO)2(PO4)2F cathode in combination with a water‐soluble sacrificial salt eliminates the need for using any toxic solvents for laminate preparation, thus paving way for greener electrode fabrication techniques. A 100 % increase in capacity of sodium cells (full‐cell configuration) has been observed when using the new sodium salt at a C‐rate of 2C. Regardless of the electrode fabrication technique, this new salt finds use in both aqueous and non‐aqueous cathode‐fabrication techniques for sodium‐ion batteries.
Dynamics of dissipative solitons developed in a closed traveling‐wave field‐effect transistor
Authors: Narahara Koichi
Published: July 2018

A traveling‐wave field‐effect transistor (TWFET) balances not only nonlinearity and dispersion but also dissipation and amplification. It therefore supports dissipative solitons (DSs). By applying reduction theory to a model equation of the device, we found repulsive interaction between 2 relatively distant DSs, meaning that when 2 DSs rotate on a closed TWFET, they should separate evenly at the asymptotic limit. We then carried out several SPICE calculations on a closed TWFET and demonstrated that 2 DSs asymptotically rotate such that the one occupies the other's antipodal point. The SPICE calculations also admit a bound state, in which the 2 rotating pulses maintain a relatively small separation.
Hidden diversity in forest soils: Characterization and comparison of terrestrial flatworm’s communities in two national parks in Spain
Authors: Álvarez‐Presas Marta , Mateos Eduardo , Riutort Marta
Published: July 2018

Terrestrial flatworms (Platyhelminthes, Tricladida, and Geoplanidae) belong to what is known as cryptic soil fauna of humid forests and are animals not easily found or captured in traps. Nonetheless, they have been demonstrated to be good indicators of the conservation status of their habitat as well as a good model to reconstruct the recent and old events affecting biodiversity. This is mainly due to their delicate constitution, their dependence on the integrity of their habitat, and their very low dispersal capacity. At present, little is known about their communities, except for some studies performed in Brazil. In this work, we analyze for the first time in Europe terrestrial flatworm communities. We have selected two protected areas belonging to theRed Española de Parques Nacionales. Our aims include performing a first study of the species richness and community structure for European terrestrial planarian species at regional and local scale. We evaluate the effect of type of forests in the community composition and flatworms’ abundance, but also have into account the phylogenetic framework (never considered in previous studies) analyzed based on molecular data. We find differences in the species composition among parks, with an astonishingly high diversity of endemic species in theParque Nacional de Picos de Europaand an extremely low diversity of species in theParque Nacional de Ordesa y Monte Perdido. These divergent patterns cannot be attributed to differences in physical variables, and in addition, the analyses of their phylogenetic relationships and, for a few species, their genetic structure, point to a more probable historical explanation.
Association of arginine vasopressin with low atrial natriuretic peptide levels, left ventricular remodelling, and outcomes in adults with and without heart failure
Authors: Chirinos Julio A. , Sardana Mayank , Oldland Garrett , Ansari Bilal , Lee Jonathan , Hussain Anila , Mustafa Anique , Akers Scott R. , Wei Wen , Lakatta Edward G. , Fedorova Olga V.
Published: July 2018

Aims

The arginine vasopressin (AVP) pathway has been extensively studied in heart failure (HF) with reduced ejection fraction (HFrEF), but less is known about AVP in HF with preserved EF (HFpEF). Furthermore, the association between AVP and atrial natriuretic peptide (ANP, a well‐known inhibitor of AVP secretion) in HF is unknown.

Methods and results

We studied subjects with HFpEF (n = 28) and HFrEF (n = 25) and without HF (n = 71). Left ventricular (LV) mass and left atrial (LA) volumes were measured with cardiac magnetic resonance imaging. Arginine vasopressin and ANP were measured with enzyme‐linked immunosorbent assay. Arginine vasopressin levels were significantly greater in HFpEF [0.96 pg/mL; 95% confidence interval (CI) = 0.83–1.1 pg/mL] compared with subjects without HF (0.69 pg/mL; 95% CI = 0.6–0.77 pg/mL; P = 0.0002). Heart failure with preserved ejection fraction (but not HFrEF) was a significant predictor of higher AVP after adjustment for potential confounders. Arginine vasopressin levels were independently associated with a greater LA volume and also paradoxically, with lower ANP levels. Key independent correlates of higher AVP were the presence of HFpEF (standardized β = 0.32; 95% CI = 0.09–0.56; P = 0.0073) and the ANP/LA volume ratio (standardized β = −0.23; 95% CI = −0.42 to −0.04; P = 0.0196). Arginine vasopressin levels were independently associated with LV mass (β = 0.26; 95% CI = 0.09–0.43; P = 0.003) and with an increased risk of death or HF admissions during follow‐up (hazard ratio = 1.61; 95% CI = 1.13–2.29; P = 0.008).

Conclusions

Arginine vasopressin is increased in HFpEF and is associated with LV hypertrophy and poor outcomes. Higher AVP is associated with the combination of LA enlargement and paradoxically low ANP levels. These findings may indicate that a relative deficiency of ANP (an inhibitor of AVP secretion) in the setting of chronically increased LA pressure may contribute to AVP excess.
Experimental and Computational Studies on Stepwise [3+2]‐Cycloadditions of Diaryldiazomethanes with Electron‐Deficient Dimethyl (E)‐ and (Z)‐2,3‐Dicyanobutenedioates
Authors: Mlostoń Grzegorz , Celeda Małgorzata , Jasiński Radomir , Heimgartner Heinz
Published: July 2018

Electron‐deficient dimethyl (E)‐ and (Z)‐2,3‐dicyanobutenedioates (dimethyl dicyanofumarate and dicyanomaleate, respectively) react with diaryldiazomethanes at room temperature under spontaneous evolution of N2. The type of the products strongly depends on the structure of the diazo compound. Whereas diphenyldiazomethane and its bis(4‐methoxy) derivative yield cyclopropanes, sterically crowded 5‐diazo‐5H‐dibenzo[a,d]cycloheptane derivatives afford either the dimer of the carbene formed via N2 elimination or the adduct of the carbene onto the starting diazo compound. The course of the studied reactions is rationalized by stepwise mechanisms initiated by the formation of a C–N bond. A cascade of reactions leads to the corresponding cyclopropanes or to release of a carbene species. The formation of a pyrazole via [3+2]‐cycloaddition (32CA) is observed only in reactions with (trimethylsilyl)diazomethane, which behaves similar to the parent diazomethane. The proposed mechanisms were analyzed computationally using the DFT method.
Assessing models for estimation and methods for uncertainty quantification for spatial return levels
Authors: Cao Yi , Li Bo
Published: July 2018

The return level estimation is an essential topic in studying spatial extremes for environmental data. Recently, various models for spatial extremes have emerged, which generally yield different estimates for return levels, given the same data. In the meantime, several approaches that obtain confidence intervals (CIs) for return levels have arisen, and the results from different approaches can also largely disagree. These pose natural questions for assessing different return level estimation methods and different CI derivation approaches. In this article, we compare an array of popular models for spatial extremes in return level estimation, as well as three approaches in CI derivation, through extensive Monte Carlo simulations. Our results show that in general, max‐stable models yield return level estimates with similar mean squared error, and the spatial generalized extreme value model also provides comparable estimates. The bootstrap method is recommended for max‐stable models to compute the CI, and the profile likelihood CI works well for spatial generalized extreme value. We also evaluate the methods for return level interpolation at unknown spatial locations and find that kriging of marginal return level estimates performs as well as max‐stable models.
Breaking from the average: Why large grains matter in gravel‐bed streams
Authors: MacKenzie Lucy G. , Eaton Brett C. , Church Michael
Published: July 2018

While the influence of large grains on the morphodynamics of gravel‐bed rivers has long been recognized, nothing dominates our collective efforts to model such rivers like the bed surface D50, which turns up in virtually all the relevant equations. While researchers interested in flow resistance have recognized the relative importance of large grains and have modified flow resistance equations accordingly, there have been few attempts to quantify the effects of large grains on gravel‐bed river morphodynamics. However, there is little evidence that D50 exerts first‐order control over the physics occurring along the channel boundary, and its prevalence seems to be primarily based on the untested, a priori assumption that the best description of a distribution is the mean or median value. This commentary questions the long‐standing assumption that D50 is the best choice for characteristic grain size, and uses evidence from previous studies to show that mobilization of the largest grains in the bed likely controls morphological stability, and possibly sediment transport. © 2018 John Wiley & Sons, Ltd.
Petrography, geochemistry, and geochronology of Lower Jurassic sedimentary rocks from the Northern Tianshan (West Bogda area), Northwest China: Implications for provenance and tectonic evolution
Authors: Ji Hongjie , Tao Huifei , Wang Qi , Ma Dongxu , Hao Lewei
Published: July 2018

The Bogda Mountains, situated in the southern part of the Central Asian Orogenic Belt (CAOB), is an important intraplate orogenic belt for studying the Mesozoic tectonic evolution mechanism of the CAOB. The detailed palaeogeographic evolution process of the Bogda area during Early Jurassic times remains poorly understood. The sandstone petrography, sedimentary rock geochemistry, and detrital zircon U–Pb geochronology were integrated to research the provenance of the Lower Jurassic Badaowan and Sangonghe formations clastic rocks from the northern flank of the Bogda Mountains and further constrain the palaeogeographic evolution of Bogda Mountains. The petrological and geochemical data in this study indicate that the Lower Jurassic sediments were derived from a felsic source area. Compared with the Badaowan Formation, the source rocks for the Sangonghe Formation show more mafic characteristics. U–Pb age patterns of the Badaowan Formation have multiple age groups, and most of the zircon ages are concentrated in the Carboniferous and Late Permian–Early Triassic ages. The Late Permian–Early Triassic age group disappears in the U–Pb age spectrum of the Sangonghe Formation, and every peak age is 20–50 Ma younger than those of the Badaowan Formation. Combined with the compiled sedimentary facies and paleocurrent data, the felsic‐intermediate volcanic rocks and granitoid intrusions in the Harlik arc and the east of the Jueluotage belt were the predominant sources of the Badaowan Formation, and then the dominant source changed to the bimodal volcanic rocks in the Eastern Bogda Mountains during the Sangonghe Formation deposition period. Early Mesozoic palaeogeographic evolution of the Northern Tianshan belt is speculated: (1) the paleotopography of the Jueluotage belt had a differential uplift along its strike, transforming from high in the west during Triassic times to high in the east during early Early Jurassic times and (2) the Eastern Bogda Mountains initiated uplift during late Early Jurassic times.
Tafresh intrusive rocks within the Urumieh‐Dokhtar Magmatic Arc: Appraisal of Neo‐Tethys subduction
Authors: Mirnejad Hassan , Raeisi Davood , McFarlane Christopher , Sheibi Maryam
Published: July 2018

This paper presents UPb zircon dating and element compositions for Miocene intrusive rocks in NE Tafresh situated in the central Urumieh‐Dokhtar Magmatic Arc. These intrusive rocks, consisting of granodiorite and diorite, were emplaced during the Early Miocene (19.07–20.37 Ma), following extensive submarine volcanic activity in the Eocene. In normalized multi‐element diagrams, all the analysed rocks are characterized by enrichments in large ion lithophile elements (e.g., Ba, Rb, and Sr) and depletions in high field strength elements (e.g., Nb, Ta, and Hf) and display geochemical features typical of subduction‐related calc‐alkaline arc magmas. The enrichment of light rare earth elements and flat heavy rare earth elements patterns reflect amphibole fractionation from relatively hydrous, calc‐alkalic magmas. The geochemical features and ages of the Tafresh intrusive rocks suggest that the Neo‐Tethys Ocean did not close completely in the region until the Miocene and is consistent with a diachronous collision starting in the NW and closing later in the SE.
Geochronology and geochemistry of volcanic rocks from the Tanjianshan Group, NW China: Implications for the early Palaeozoic tectonic evolution of the North Qaidam Orogen
Authors: Sun Hua‐Shan , Li Huan , Algeo Thomas J. , Gabo‐Ratio Jillian Aira S. , Yang Hui , Wu Jing‐Hua , Wu Pan
Published: July 2018

The widely exposed Tanjianshan volcanic rocks in the North Qaidam Orogen (NW China) encode abundant information about early Palaeozoic magma origin and tectonic evolution. This research utilizes petrological, geochemical, and geochronological methods to investigate the last volcanic cycle (Formation d) of the Tangjianshan Group, aiming to reveal the tectonic evolutionary processes of the North Qaidam Orogen. Formation d can be further divided into two major volcanic sequences, that is, Formation d‐1/d‐4 and Formation d‐3. Formation d‐1/d‐4 is a set of intermediate–basic volcaniclastic rocks intercalated with volcanic lava and contemporary hypabyssal diabase–gabbro intrusive rocks. The rocks are characterized by high average concentrations of Al2O3, K2O, Na2O, and P2O5, pronounced differentiation of light (LREE) and heavy rare earth elements (HREE) and enrichment of LREEs and light‐ion lithophile elements (LILE), showing continental arc affiliation and enriched mid‐ocean‐ridge basalt (E‐MORB) characteristics. They have positive zircon εHf (t) values (7.5 to 16.1) and variable whole‐rock εNd (t) values (−2.7 to 7.0), with crustal Hf model ages (TDMC) and two‐stage Nd model ages (T2DM) ranging from 428 to 970 Ma and from 618 to 1,410 Ma, respectively. The magma may have originated from an enriched mantle source and experienced crustal contamination in a continental back‐arc basin. In contrast, Formation d‐3 is composed of volcaniclastic rocks intercalated with layered basaltic andesite and basalts. It has higher average concentrations of CaO, FeOT, and MgO, lower ΣREE and flatter REE patterns, lower average 87Sr/86Sr ratios (0.70557), higher average 143Nd/144Nd ratios (0.51285), and exclusively positive εNd (t) values (1.3 to 5.0), consistent with normal mid‐ocean‐ridge basalt (N‐MORB) influence. The magma may have been derived from a normal mantle source without significant modification, which probably formed in a rift‐related tectonic setting or even a mid‐ocean ridge that developed within a back‐arc basin. Magmatic zircons from Formation d‐1/d‐4 yield U–Pb ages mostly at 460–440 Ma, whereas zircons modified by continental exhumation‐related orogenic fluids are mainly dated at 430–420 Ma. Magmatic zircons from Formation d‐3 mainly have U–Pb ages of 440–430 Ma. Integrating the magma genesis and rock affiliation interpretations of this study with geological information for the study area and adjacent regions, a four‐stage tectonic evolutionary model is proposed for the early Palaeozoic North Qaidam Orogen: (a) oceanic subduction with arc magmatism (520–460 Ma), (b) continental collision with back‐arc magmatism (Formation d‐1/d‐4) (460–440 Ma), (c) mid‐ocean ridge extension with rift‐related magmatism (Formation d‐3) (440–430 Ma), and (d) continental exhumation with orogenic fluid modification (430–420 Ma).
Analysis of the convective heat transfer and flow behavior around two counter‐rotating side‐by‐side cylinders
Authors: Darvishyadegari Mohsen , Hassanzadeh Rahim
Published: July 2018

This study presents details of the heat and fluid flow around two counter‐rotating cylinders. For this goal, three different nondimensional gap spaces such as G/D = 1.5, 2.0, and 3.0 are examined in the constant Reynolds number of 200 and Prandtl number of 7.0. In addition, computations are carried out at various nondimensional rotating speeds (R.S) in the range from 0 to 4. The obtained results are validated against the available data in the open literature for stationary cases. The results showed that the flow structure, vortex shedding process, and exerted forces on the cylinders strongly depended on the R.S and G/D. Reductions of the drag coefficients are observed for both cylinders with increasing the R.S due to suppression of the wake downstream of the cylinders at low R.S and eliminating the vortex shedding process at high R.S. Finally, it is demonstrated that, regardless of the G/D value, increasing the R.S diminishes dramatically the convective heat exchange rate between the cylinders and fluid flow.
IS REFLECTIVE SUPERVISION ENOUGH? AN EXPLORATION OF WORKFORCE PERSPECTIVES
Authors: Eaves Simpson Tanika , Robinson Joann L. , Brown Edna
Published: July 2018

Infant mental health practice requires the performance of intense emotional labor. Professionals comprising the infant mental health (IMH) field are largely women at seminal points in adult life‐span development. The purpose of this article is to explore the day‐to‐day challenges faced by clinical infant mental health professionals and their perspectives on the supports available for effective job performance. We review reflective supervision as a long‐cherished professional support in the IMH field designed to hold the practitioner's fears, worries, and ambivalence, so that she may return to the work fortified to remain in therapeutic alliance with families despite unsolvable problems and an unknowable future (Weatherston, D., 2009). Yet, we propose that reflective supervision alone may not be an adequate protective measure for a workforce performing intensive emotional labor for extended periods and therefore at potentially increased risk for burnout and high turnover (Hochschild, A.R. ; C. Maslach, , C.M. Brotheridge & A.A. Grandey, 2009; A.S. Wharton, ). We suggest that structural factors concerning organizational culture, flexibility in scheduling, and professional growth and versatility bear deeper examination for their merits in supporting the IMH workforce. Finally, we contend that the overrepresentation of women in practitioner positions in IMH leaves an empirical gap where little is known about the experience of male IMH practitioners and the ramifications of their performance of emotional labor.
Social network analysis and ICT4D research: Principles, relevance, and practice
Authors: Renken Jaco , Heeks Richard
Published: July 2018

The application of information and communication technologies to socio‐economic development (ICT4D) is a complex sociotechnical phenomenon. That complexity has led to repeated calls for diversification in the theories, methodologies, and methods used in this field. This paper investigates one potential diversification: the use of social network analysis (SNA) as an approach for ICT4D research. Very few studies in the field have used SNA to date that led us, in the first instance, to provide an overview of core SNA concepts, network research design considerations, and analytic approaches. Based on the distinct principles underpinning SNA, we then outline 3 arguments for the relevance thereof in ICT4D: (1) conceptual relevance to ICT4D practice, (2) methodological and epistemological relevance to the present and future state of ICT4D research, and (3) instrumental relevance to the future ICT4D research agenda. The paper concludes with an illustrative example, demonstrating network research design and a few SNA procedures utilised in exploring the relationship‐ and resource‐orientations of an ICT4D champion. By introducing and illustrating SNA, we hope to help other ICT4D researchers determine whether and how SNA might be of relevance to their work.
MicroRNA‐760 Inhibits Doxorubicin Resistance in Hepatocellular Carcinoma through Regulating Notch1/Hes1‐PTEN/Akt Signaling Pathway
Authors: Tian Tao , Fu Xiao , Lu Jun , Ruan Zhiping , Nan Kejun , Yao Yu , Yang Yujuan
Published: July 2018

Accumulating studies have suggested that microRNA‐760 (miR‐760) plays an important role in chemoresistance of various cancer cells. However, whether miR‐760 regulates the chemoresistance of hepatocellular carcinoma (HCC) remains unclear. In this study, we found that miR‐760 was decreased in HCC cell lines, and doxorubicin (Dox) treatment significantly decreased miR‐760 expression in HCC cells. Overexpression of miR‐760 sensitized HCC cells to Dox‐induced cytotoxicity and apoptosis, whereas miR‐760 inhibition showed the opposite effects. Notch1 was predicted as a target gene of miR‐760. miR‐760 negatively regulated Notch1 expression and Notch1/Hes1 signaling. Overexpression of miR‐760 increased PTEN expression and decreased the phosphorylation of Akt. Activation of Notch signaling significantly reversed the inhibitory effect of miR‐760 on Dox‐resistance and abrogated the effect of miR‐760 on the PTEN/Akt signaling pathway in HCC cells. Overall, our results demonstrate that miR‐760 inhibits Dox‐resistance in HCC cells through inhibiting Notch1 and promoting PTEN expression.
Investigation of the kinetics and optimization of photocatalytic degradation of methylene blue
Authors: Farouq Rania
Published: July 2018

Studying and optimizing the photocatalytic degradation of methylene blue dye in a tubular reactor using different types of titanium dioxide are the main concerns of the present research. Subsequent experiments using a heterogeneous process (UV/H2O2/TiO2) were conducted to investigate the effects of the changing amounts of catalyst dosing, pH values, time, and the initial dye concentration on the process performance. Response‐surface methodology (RSM) experiment based on a mixture‐analysis experiment was applied. The results show that an initial dye concentration of 20 ppm at pH = 2 with the addition of H2O2 (0.2 mL) to the pollutant stream represents the best conditions of the photocatalytic process with 97.6% of dye degradation when using 1.5 g TiO2/L of the pollutant solution. All the experimental data showed good agreement with the predicted results obtained from statistical analysis.
Stereoselective Synthesis of γ‐Butyrolactones Subunit of Polycavernoside A
Authors: Kadari Sudhakar , Yerrabelly Hemasri , Gogula Thirupathi , Erukala Yadaiah Goud , Yerrabelly Jayaprakash Rao , Begari Prem Kumar
Published: July 2018

An efficient and versatile linear synthesis of γ‐butyrolactone subunit of polycavernolide A has been reported in 14.2% overall yield with 10 linear steps by employing Sharpless asymmetric epoxidation, ring‐closing metathesis, and diastereoface selective hydrogenation.
Effect of dispersant on nano‐PTFE: Striking the balance between stability and tribo‐performance
Authors: Dubey Mukesh Kumar , Bijwe Jayashree , Ramakumar S.S.V.
Published: July 2018

Nanoparticles (NPs) of PTFE (polytetrafluoroethylene) in suspension form were reported as very efficient extreme pressure (EP) additive in 150 N API Group II oil in our earlier work. The less stability of a nanosuspension due to agglomeration of NPs beyond 3 wt%, however, was a major issue, which needed to be addressed for its possible industrial exploitation in lubricants. Using another additive, eg polyisobutylene succinimide (PIBSI), as a dispersant appeared to be a plausible solution. Its inclusion (1 wt%) increased the stability of the oil by a factor of 4. It was necessary to investigate, however, whether it influenced other properties synergistically or antagonistically. The present paper highlights the positive and negative aspects of inclusion of PIBSI on the tribo‐performance (EP and anti‐wear) of the nano‐PTFE‐based oils.

A series of nano‐PTFE oils (1%‐6%) stabilised with PIBSI (1%) were developed and evaluated for EP and anti‐wear performance. The PIBSI‐PTFE combination clearly showed antagonistic behaviour due to competition for film formation on the surfaces. However, with an increase in concentration of NPs, the film formation mechanism was dominated by them. Scanning electron microscopy, atomic force microscopy, and X‐ray photoelectron spectroscopy were used for the examination of the topography and surface chemistry of the protective films formed on the steel specimens.
Prolate and Temperature‐Responsive Self‐Assemblies of Amphiphilic Random Copolymers with Perfluoroalkyl and Polyoxyethylene Side Chains in Solution
Authors: Martinelli Elisa , Guazzelli Elisa , Galli Giancarlo , Telling Mark T. F. , Poggetto Giovanni Dal , Immirzi Barbara , Domenici Fabio , Paradossi Gaio
Published: July 2018

Two amphiphilic random copolymers, PEGMAx‐co‐FAy (x = 90 and 70 mol%), are synthesized by ATRP and their solutions are investigated as a function of solvent, concentration, and temperature by DLS and SANS analyses. Both copolymers self‐assemble in nanostructures by single‐chain folding in water solutions over a wide range of temperatures. The values of the DLS hydrodynamic radius and the SANS radius of gyration are found to be ≈4 nm and ≈3.4–3.7 nm, respectively. Moreover, SANS shows the self‐folded nanoassemblies to be prolated spheroids with a ratio of polar/equatorial axes of ≈5:1 for PEGMA90‐co‐FA10 and ≈2:1 for PEGMA70‐co‐FA30. On heating above a critical temperatureTc, multichain microassemblies are formed that revert back to nanoassemblies on cooling belowTc. This temperature‐responsive transition is fully and sharply reversible.
Ionic Gels and Their Applications in Stretchable Electronics
Authors: Wang Haifei , Wang Ziya , Yang Jian , Xu Chen , Zhang Qi , Peng Zhengchun
Published: July 2018

Ionic gels represent a novel class of stretchable materials where ionic conducting liquid is immobilized in a polymer matrix. This review focuses on the design of ionic gel materials and device fabrication of ionic‐gel‐based stretchable electronics. In particular, recent progress in ionic‐gel‐based electronic skin (pressure/strain sensors, electric double‐layer transistors, etc.), flexible displays, energy storage devices, and soft actuators are summarized, followed by a discussion of challenges in developing ionic‐gel‐based electronics and suggestions for future research directions that might overcome those challenges.
Polymerization‐Induced Self‐Assembly of Functionalized Block Copolymer Nanoparticles and Their Application in Drug Delivery
Authors: Zhang Wen‐Jian , Hong Chun‐Yan , Pan Cai‐Yuan
Published: July 2018

Drug delivery systems (DDS) based on functionalized polymeric nanoparticles have attracted considerable attention. Although great advances have been reported in the past decades, the fabrication efficiency and reproducibility of polymeric nanoparticles are barely satisfactory due to the intrinsic limitations of the traditional self‐assembly method, which severely prevent further applications of the intelligent DDS. In the last decade, a new self‐assembly method, which is usually called polymerization‐induced self‐assembly (PISA), has become a powerful strategy for the fabrication of the polymeric nanoparticles with bespoke morphology. The PISA strategy efficiently simplifies the fabrication of polymeric nanoparticles (combination of the polymerization and self‐assembly in one pot) and allows the fabrication of polymeric nanoparticles at a relatively high concentration (up to 50 wt%), making it realistic for large‐scale production of polymeric nanoparticles. In this review, the developments of PISA‐based polymeric nanoparticles for drug delivery are discussed.
Kinetic‐fluid derivation and mathematical analysis of the cross‐diffusion–Brinkman system
Authors: Bendahmane Mostafa , Karami Fahd , Zagour Mohamed
Published: July 2018

In this paper, we propose a new nonlinear model describing the dynamical interaction of two species within a viscous flow. The proposed model is a cross‐diffusion system coupled with the Brinkman problem written in terms of velocity fluid, vorticity, and pressure and describing the flow patterns driven by an external source depending on the distribution of species. In the first part, we derive macroscopic models from the kinetic‐fluid equations by using the micro‐macro decomposition method. On the basis of the Schauder fixed‐point theory, we prove the existence of weak solutions for the derived model in the second part. The last part is devoted to developing a one‐dimensional finite volume approximation for the kinetic‐fluid model, which is uniformly stable along the transition from kinetic to macroscopic regimes. Our computation method is validated with various numerical tests.
Cutaneous melanoma in adolescents and young adults
Authors: Indini Alice , Brecht Ines , Del Vecchio Michele , Sultan Iyad , Signoroni Stefano , Ferrari Andrea
Published: July 2018

Cutaneous melanoma is rare in children, but has greater incidence in adolescents and young adults (AYAs). Diagnosis may be challenging due to its rarity in these age groups. Few studies have specifically addressed the topic of AYA melanoma. Though young‐age melanoma may have particular biological characteristics, available data suggest that its clinical history is similar to that of adults. However, advances in treatment of adult melanoma have not been reflected in the treatment of AYAs. There is no standard treatment, and access to clinical trials is difficult for AYAs. Further efforts are needed to overcome these issues by improving cooperation with experts on adult melanoma.
Convergent evolution of 11p allelic loss in multifocal Wilms tumors arising in WT1 mutation carriers
Authors: Valind Anders , Wessman Sandra , Pal Niklas , Karlsson Jenny , Jonson Tord , Sandstedt Bengt , Gisselsson David
Published: July 2018

Wilms tumors in patients with constitutional WT1 mutations are examples of Knudson's tumor suppressor paradigm, with somatic inactivation of the second allele occurring through 11p loss of heterozygosity. The time point of this second hit has remained unknown. We analyzed seven Wilms tumors from two patients with constitutional WT1 mutations by whole exome sequencing and genomic array. All tumors exhibited wild type WT1 loss through uniparental isodisomy. Each tumor had a unique genomic breakpoint in 11p, typically accompanied by a private activating mutation of CTNNB1. Hence, convergent evolution rather than field carcinogenesis underlies multifocal tumors in WT1 mutation carriers.