bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluvial incision and coarse gravel redistribution across the modern Dead Sea shelf as a result of base‐level fall
Authors: Eyal Haggai , Dente Elad , Haviv Itai , Enzel Yehouda , Dunne Thomas , Lensky Nadav G.
Published: April 2019

Global eustatic lowstands can expose vast areas of continental shelves, and occasionally the shelf edge and the continental slope. The degree of fluvial connectivity to receding shores influences the redistribution of sediments across these emerging landscapes. Shelf and slope emergence in the Dead Sea since the middle of the 20th century, offers a rare opportunity to examine evolution of stream connectivity in response to continuous base‐level decline. We characterize the connectivity evolution of two streams, using high‐resolution time series of aerial imagery and elevation models, field mapping, and grain‐size analyses. Our rich spatiotemporal dataset of evolving channel geomorphology, sediment transport conditions, and sediment redistribution, allows calculating potential coarse sediment mobility in response to base level decline. Following shelf emergence, alluvial fans first prograded onto the low‐gradient shelf under unfavourable conditions for transporting coarse sediment to the regressing shoreline. Then, with shelf and slope emergence, the two adjacent streams evolved differently. The smaller, more arid watershed still maintains its highstand delta progradation on the shelf and is practically disconnected from the receding lake. The larger catchment, heading in wetter environments and having a narrower shelf, has incised the shelf and renewed and gradually intensified the sediment transport from the highstand to the lowstand delta. Sediment mobilization to lowstand shorelines is controlled by the evolution of the channel profile and by the average speed of gravel transport (10s‐100s m yr‐1). These findings from the Dead Sea are relevant to fluvial processes operating on continental shelves during glacial maxima. Streams would have commonly stored high proportions of their coarse sediment on the continental shelves rather than efficiently connecting with the lowstand level. Additionally, differences in sediment routing patterns should exist among nearby streams, primarily due to continental margin geometry and watershed hydrology. © 2019 John Wiley & Sons, Ltd.
Citizen Science and Gamification
Authors: Kreitmair Karola V. , Magnus David C.
Published: April 2019

According to the mainstream conception of research involving human participants, researchers have been trained scientists acting within institutions and have been the individuals doing the studying, while participants, who are nonscientist members of the public, have been the individuals being studied. The relationship between the public and scientists is evolving, however, giving rise to several new concepts, including crowdsourcing and citizen science. In addition, the practice of gamification has been applied to research protocols. The role of gamified, crowdsourced citizen scientist is new in the domain of scientific research and does not fit into the existing taxonomy of researchers and participants. We delineate and explicate this role and show that, while traditional roles are governed by well‐established norms and regulations, individuals engaged in gamified, crowdsourced citizen science—gamers—fall through the cracks of research protections and regulations. We consider the issues this raises, including exploitation and the absence of responsibility and accountability. Finally, we offer suggestions for how the current lack of appropriate norms may be rectified.
Impact of the spatial variability of daily precipitation on hydrological projections: A comparison of GCM‐ and RCM‐driven cases in the Han River basin, Korea
Authors: Lee Moon‐Hwan , Im Eun‐Soon , Bae Deg‐Hyo
Published: April 2019

In this study, we investigate the impact of the spatial variability of daily precipitation on hydrological projections based on a comparative assessment of streamflow simulations driven by a global climate model (GCM) and two regional climate models (RCMs). A total of 12 different climate input datasets, that is, the raw and bias‐corrected GCM and raw and bias‐corrected two RCMs for the reference and future periods, are fed to a semidistributed hydrological model to assess whether the bias correction using quantile mapping and dynamical downscaling using RCMs can improve streamflow simulation in the Han River basin, Korea. A statistical analysis of the daily precipitation demonstrates that the precipitation simulated by the GCM fails to capture the large variability of the observed daily precipitation, in which the spatial autocorrelation decreases sharply within a relatively short distance. However, the spatial variability of precipitation simulated by the two RCMs shows better agreement with the observations. After applying bias correction to the raw GCM and raw RCMs outputs, only a slight change is observed in the spatial variability, whereas an improvement is observed in the precipitation intensity. Intensified precipitation but with the same spatial variability of the raw output from the bias‐corrected GCM does not improve the heterogeneous runoff distributions, which in turn regulate unrealistically high peak downstream streamflow. GCM‐simulated precipitation with a large bias correction that is necessary to compensate for the poor performance in present climate simulation appears to distort streamflow patterns in the future projection, which leads to misleading projections of climate change impacts on hydrological extremes.
Bulk density optimization to determine subsurface hydraulic properties in Rocky Mountain catchments using the GEOtop model
Authors: Fullhart Andrew T. , Kelleners Thijs J. , Chandler Dave G. , McNamara James P. , Seyfried Mark S.
Published: April 2019

Integrated watershed models can be used to calculate streamflow generation in snow‐dominated mountainous catchments. Parameterization of water flow is often complicated by the lack of information on subsurface hydraulic properties. In this study, bulk density optimization was used to determine hydraulic parameters for the upper and lower regolith in the GEOtop model. The methodology was tested in two small catchments in the Dry Creek Watershed in Idaho and the Libby Creek Watershed in Wyoming. Modelling efficiencies for profile‐average soil–water content for the two catchments were between 0.52 and 0.64. Modelling efficiencies for stream discharge (cumulative stream discharge) were 0.45 (0.91) and 0.54 (0.94) for the Idaho and Wyoming catchments, respectively. The calculated hydraulic properties suggest that lateral flow across the upper–lower regolith interface is an important driver of streamflow in both the Idaho and Wyoming watersheds. The overall calibration procedure is computationally efficient because only two bulk density values are optimized. The two‐parameter calibration procedure was complicated by uncertainty in hydraulic conductivity anisotropy. Different upper regolith hydraulic conductivity anisotropy factors had to be tested in order to describe streamflow in both catchments.
Does the world need faunists? Based on rotifer (Rotifera) occurrence reflections on the role of faunistic research in ecology
Authors: Ejsmont‐Karabin Jolanta
Published: April 2019

Most faunistic studies of large‐scale patterns concern terrestrial vertebrates, whereas smaller organisms, and in particular, freshwater invertebrates like rotifers receive less attention. As a result, the “rotiferologists” effect”, that is sampling intensity, is among the most influential factors observed, globally or locally, on species richness.

Because there are many more small, isolated patches of habitats available to the specialist species, greater specialization has occurred in those forms than in ubiquitous species. This rule also applies to rotifers. Results show that: (a) the total number of rotifer species observed in a lake depends on both the number of samples collected and the type and number of lake habitats involved; and (b) the originality (variability) of rotifer fauna in particular lakes is more pronounced with the more species found in a lake.

The important purpose of faunistic studies is the registration of indigenous species. The inflow of alien species is currently one of the greatest threats to the preservation of natural fauna. However, if we do not recognize the composition of natural communities, we will not be able to recognize the invaders. The second most important goal is to enable tracking of long‐term changes in species diversity of rotifer fauna. Rotifers seem to be sensitive enough to climate change and pollution of the aquatic environment. Thus, for the reasons described above, faunistics will be still necessary.
Isolation and characterization of a novel scFv antibody fragments specific for Hsp70 as a tumor biomarker
Authors: Vostakolaei Mehdi Asghari , Molavi Ommoleila , Hejazi Mohammad Saeid , Kordi Shirafkan , Rahmati Saman , Barzegari Abolfazl , Abdolalizadeh Jalal
Published: April 2019

Many studies have shown that more than 50% of tumors express heat shock protein 70 kDa (Hsp70) at the plasma membrane surface while not seen in normal cells, therefore it is a promising therapeutic target in human cancers. Hence, we used phage display technology to produce a single‐chain fragment variable (scFv) antibody against human Hsp70. For this, a target peptide from human Hsp70 was designed using bioinformatics studies and was chemically synthesized. Then, the selection was performed using four rounds of biopanning with a stepwise decreased amount of the target peptide. Fourteen positive scFv clones were selected using monoclonal phage enzyme‐linked immunosorbent assay screening, which was further characterized by means of the polymerase chain reaction and DNA sequencing. Among them, the G6 clone was selected to express scFv into the Escherichia coli. Expression and purification of the scFv shown by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and confirmed by Western blot analysis. In silico analysis confirmed specific binding of the scFv to Hsp70 in CDR regions. The specificity of the scFv measured by surface plasmon resonance and immunofluorescence of the A549 human lung carcinoma cell line confirmed the in vitro function of the scFv. Based upon these findings, we propose a novel anti‐human Hsp70 scFv as potential immunotherapy agents that may be translated into preclinical/clinical applications.
A noncoding RNA LINC00504 interacts with c‐Myc to regulate tumor metabolism in colon cancer
Authors: Feng Jinfeng , Ma Jun , Liu Shaoqun , Wang Jianfa , Chen Yi
Published: April 2019

Accumulating evidence has shown a critical role of long‐non‐coding RNAs (lncRNAs) during multiple tumor progression. However, the potential functions of LINC00504 in colon cancer as well as its mechanisms remain obscure. By lncRNA profiling, we identified LINC00504 as a novel oncogenic lncRNA in colon cancer. The lncRNA LINC00504 was markedly upregulated in colon cancer cell lines and specimens. LINC00504 increases viability and migration of colon cells in vitro. Furthermore, LINC00504 also enhances colon cancer xenograft tumors in vivo. We noted that LINC00504 regulates metabolism at a transcriptional level which influences multiple metabolic pathways, such as glucose metabolism, pentose phosphate pathway, and tricarboxylic acid cycle. Mechanistic study showed that LINC00504 could interact with c‐Myc to promote chromatin recruitment of c‐Myc and enhance its transactivation activity. Collectively, our results showed that LINC00504 serves as an important transcriptional regulator for c‐Myc in colon cancer cells. LINC00504 can reprogram central metabolism in colon cancer cells implying that LINC00504 may serve as a potential target for therapeutic intervention.
Generation of a nitric oxide signaling pathway in mesenchymal stem cells promotes endothelial lineage commitment
Authors: Bandara Nadeeka , Gurusinghe Saliya , Kong Anne , Mitchell Geraldine , Wang Le‐Xin , Lim Shiang Y. , Strappe Padraig
Published: April 2019

Enhancing differentiation of mesenchymal stem cells (MSCs) to endothelial cells may improve their ability to vascularize tissue and promote wound healing. This study describes a novel role for nitric oxide (NO) in reprogramming MSCs towards an endothelial lineage and highlights the role of Wnt signaling and epigenetic modification by NO. Rat MSCs were transduced with lentiviral vectors expressing endothelial nitric oxide synthase (pLV‐eNOS) and a mutated caveolin gene (pLV‐CAV‐1F92A) to enhance NO generation resulting in increased in vitro capillary tubule formation and endothelial marker gene expression. An exogenous source of NO could also stimulate CD31 expression in MSCs. NO was associated with an arterial‐specific endothelial gene expression profile of Notch1, Dll4, and Hey2 and significantly reduced expression of venous markers. Wnt signaling associated with NO was evident through increased gene expression of Wnt3a and β‐catenin protein, and expression of the endothelial marker Pecam‐1 could be significantly reduced by treatment with the Wnt signaling inhibitor Dkk‐1. The role of NO as an epigenetic modifier was evident with reduced gene expression of the methyltransferase, DNMT1, and bisulfite sequencing of the endothelial Flt1 promoter region in NO‐producing MSCs showed significant demethylation compared to control cells. Finally, subcutaneous implantation of NO‐producing MSCs seeded in a biomaterial scaffold (NovoSorb®) resulted in survival of transplanted cells and the formation of blood vessels. In summary, this study describes, NO as a potent endothelial programming factor which acts as an epigenetic modifier in MSCs and may provide a novel platform for vascular regenerative therapy.
Frontline Science: TLR3 activation inhibits food allergy in mice by inducing IFN-γ+ Foxp3+ regulatory T cells
Authors: Hong Jing-Yi , Li Shan-Shan , Hu Tian-Yong , Liu Zhi-Qiang , Yu Dian , Yu Hai-Qiong , Guan Li , Wu Gao-Hui , Zeng Hao-Tao , Liu Zhi-Gang , Yang Ping-Chang
Published: April 2019

The pathologic feature of food allergy (FA) is the aberrant Th2-biased immune response in the intestine. Regulatory T cells (Tregs) play an important role in the suppression of aberrant immune response. The activities of the TLRs regulate multiple cell functions. This study aims to investigate the role of TLR3 activation in the regulation of Th2-biased immune response in the intestine by the generation of inducible Tregs (iTregs). In this study, polyinosinic polycytidylic acid (polyI:C) was used as an activator of TLR3. An FA mouse model was developed to establish the Th2-biased inflammation in the intestine. The effects of TLR3 activation on the generation of iTreg were tested in the culture and in mice. We observed that exposure to polyI:C induced IFN-γ+ Foxp3+ iTregs in mouse intestine and in the culture. The IFN-γ+ Foxp3+ iTregs showed immune suppressive functions. Exposure to polyI:C increased T-bet levels in CD4+ T cells. The T-bet formed a complex with GATA3 to dissociate Foxp3 from GATA3/Foxp3 complex in CD4+ T cells. The Foxp3 thus gained the opportunity to move to TGF-β promoter to generate iTregs. Administration with polyI:C prevented the development of FA and inhibited existing FA. In conclusion, activation of TLR3 induces IFN-γ+ Foxp3+ Tregs, which can prevent FA development and inhibit existing FA in mice.
Top‐down mass spectrometry of intact phosphorylated β‐casein: Correlation between the precursor charge state and internal fragments
Authors: Chen Jianzhong , Shiyanov Pavel , Green Kari B.
Published: April 2019

Phosphorylated proteins play essential roles in many cellular processes, and identification and characterization of the relevant phosphoproteins can help to understand underlying mechanisms. Herein, we report a collision‐induced dissociation top‐down approach for characterizing phosphoproteins on a quadrupole time‐of‐flight mass spectrometer. β‐casein, a protein with two major isoforms and five phosphorylatable serine residues, was used as a model. Peaks corresponding to intact β‐casein ions with charged states up to 36+ were detected. Tandem mass spectrometry was performed on β‐casein ions of different charge states (12+, and 15+ to 28+) in order to determine the effects of charge state on dissociation of this protein. Most of the abundant fragments corresponded to y, b ions, and internal fragments caused by cleavage of the N‐terminal amide bond adjacent to proline residues (Xxx‐Pro). The abundance of internal fragments increased with the charge state of the protein precursor ion; these internal fragments predominantly arose from one or two Xxx‐Pro cleavage events and were difficult to accurately assign. The presence of abundant sodium adducts of β‐casein further complicated the spectra. Our results suggest that when interpreting top‐down mass spectra of phosphoproteins and other proteins, researchers should consider the potential formation of internal fragments and sodium adducts for reliable characterization.
Herpesviral infections and antimicrobial protection for Alzheimer's disease: Implications for prevention and treatment
Authors: Qin Qingsong , Li Yun
Published: April 2019

Accumulating evidence suggests that infections by herpesviruses might be closely linked to Alzheimer's disease (AD). Pathological hallmarks of AD brains include senile plaques induced by amyloid β peptide (Aβ) in the extracellular space and intracellular neurofibrillary tangles (NFTs) consisting of phosphorylated tau protein. The prevailing hypothesis for the mechanism of AD is amyloid cascade reaction. Recent studies revealed that infections by herpesviruses induce the similar pathological hallmarks of AD, including Aβ production, phosphorylation of tau (P‐tau), oxidative stress, neuroinflammation, etc. Aβ peptide is regarded as one of the antimicrobial peptides, which inhibits HSV‐1 replication. In the elderly, reactivation of herpesviruses might act as an initiator for amyloid cascade reaction in vulnerable individuals, triggering the neurofibrillary formation of phosphorylated tau and inducing oxidative stress and neuroinflammation, which can further contribute to the accumulation of Aβ and P‐tau by impairing mitochondria and autophagosome. Epidemiological studies have shown AD susceptibility genes, such as APOE‐ε4 allele, are highly linked to infections by herpesviruses. Interestingly, anti‐herpesviral therapy significantly reduced the risk of AD in a large population study. Given that herpesviruses are arguably the most prevalent opportunistic pathogens and often reactivate in the elderly, it is reasonable to argue reactivation of herpesviruses might be major culprits for initiating AD in individuals carrying AD susceptibility genes. In this review, we summarize epidemiological and molecular evidence that support for a hypothesis of herpesviral infections and antimicrobial protection in the development of AD, and discuss the implications for future prevention and treatment of the disease.
RW‐2018—Research Workshop: The Effect of Nutrition on Epigenetic Status, Growth, and Health
Authors: Skinner Michael , Lumey L. H. , Fleming Tom P. , Sapienza Carmen , Hoyo Cathrine , Aronica Lucia , Thompson Jeff , Nichol Peter F.
Published: April 2019

The goal of the 2018 American Society for Parenteral and Enteral Nutrition (ASPEN) Research Workshop was to explore the influence of nutrition and dietary exposure to xenobiotics on the epigenome during critical periods in development and how these exposures influence both disease incidence and severity transgenerationally. A growing compendium of research indicates that the incidence and severity of common and costly human diseases may be influenced by dietary exposures and deficiencies that modify the epigenome. The greatest periods of vulnerability to these exposures are the periconception period and early childhood. Xenobiotics in the food chain, protein malnutrition, and methyl donor deficiencies could have a profound bearing on the risk of developing heart disease, diabetes, obesity, hypertension, and mental illness over multiple generations. The financial impact and the life burden of these diseases are enormous. These and other aspects of nutrition, epigenetics, and health are explored in this research workshop.
Genetic variants in the liver kinase B1‐AMP‐activated protein kinase pathway genes and pancreatic cancer risk
Authors: Xu Xinyuan , Qian Danwen , Liu Hongliang , Cruz Diana , Luo Sheng , Walsh Kyle M. , Abbruzzese James L. , Zhang Xuefeng , Wei Qingyi
Published: April 2019

The liver kinase B1‐AMP‐activated protein kinase (LKB1‐AMPK) pathway has been identified as a new target for cancer therapy, because it controls the glucose and lipid metabolism in response to alterations in nutrients and intracellular energy levels. In the present study, we aimed to identify genetic variants of the LKB1‐AMPK pathway genes and their associations with pancreatic cancer (PanC) risk using 15 418 participants of European ancestry from two previously published PanC genome‐wide association studies. We found that six novel tagging single‐nucleotide polymorphisms (SNPs) (i.e, MAP2 rs35075084 T > deletion, PRKAG2 rs2727572 C > T and rs34852782 A > deletion, TP53 rs9895829 A > G, and RPTOR rs62068300 G > A and rs3751936 G > C) were significantly associated with an increased PanC risk. The multivariate logistic regression model incorporating the number of unfavorable genotypes (NUGs) with adjustment for age and sex showed that carriers with five to six NUGs had an increased PanC risk (odds ratio = 1.24, 95% confidence interval = 1.16‐1.32 and P < 0.0001), compared to those with zero to four NUGs. Subsequent expression quantitative trait loci (eQTL) analysis further revealed that these SNPs were associated with significantly altered mRNA expression levels either in 373 normal lymphoblastoid cell lines (TP53 SNP rs9895829, P < 0.05) or in whole blood cells of 369 normal donors from the genotype‐tissue expression project (GTEx) database [RPTOR SNP rs60268947 and rs28434589, both in high linkage disequilibrium (r2 > 0.9) withRPTOR rs62068300, P < 0.001]. Collectively, our findings suggest that these novel SNPs in the LKB1‐AMPK pathway genes may modify susceptibility to PanC, possibly by influencing gene expression.
Optimising the tension of an autologous fascia pubovaginal sling to minimize retentive complications
Authors: Preece Patrick D. , Chan Garson , O'Connell Helen E. , Gani Johan
Published: April 2019

Aim

To determine the optimal degree of pubovaginal slings (PVS) tension, measured by lax sling dimensions to minimize the risk of urinary retention.

Methods

This prospective study analyzed female patients undergoing PVS for stress urinary incontinence (SUI) by two surgeons over 24 months from January 2016.

Intra‐operative measurements of lax sling dimensions tented over rectus fascia were recorded. Logistic regression was used to analyse the likelihood of urinary retention (more than 3 months of intermittent self‐catheterisation (ISC) or surgical revision) for given PVS dimensions. The secondary analysis assessed for an association between PVS measurements and persistent SUI.

Results

Fifty‐one patients were recruited with a median age of 53 (34‐78) and follow‐up of 11 (3‐20) months. All but one patient reported improvement of SUI. Ten (19.6%) patients developed postoperative urinary retention. Five (9.8%) resolved after a temporary period of ISC. The other five (9.8%) required ongoing ISC or sling division. A strong association existed between short sling height and prolonged urinary retention (P = 0.00). Receiver operating characteristic (ROC) curve analysis showed a sling height of 40 mm had a sensitivity of 100% and specificity of 51% for retentive complications (area under curve [AUC]  = 0.90). Lax sling height up to 60 mm was not associated with persistent SUI.

Conclusions

Stretching the sling suspension sutures at least 40 mm above the rectus fascia was associated with a lower risk of urinary retention than less than 40 mm. This simple technique would appear to be worth evaluating in a larger sample. A looser sling did not compromise the cure of SUI at a mean follow‐up of 11 months.
Mediterranean diet during pregnancy and childhood for asthma in children: A systematic review and meta‐analysis of observational studies
Authors: Zhang Yin , Lin Jilei , Fu Wenlong , Liu Sha , Gong Caihui , Dai Jihong
Published: April 2019

Objectives

To evaluate the relationship between high adherence to the Mediterranean diet in pregnancy and childhood and the risk of asthma and wheeze in children.

Methods

We conducted searches of PubMed, EMBASE, and Cochrane Central Register of Controlled Trials from inception to 30 October 2018. Observational studies providing risk estimates and corresponding confidence intervals on the association of high adherence to the Mediterranean diet in pregnancy or childhood and the risk of asthma or wheeze in childhood were included. The methodological quality of all included studies was assessed. Summary odds ratios (OR) were calculated using a random‐effects model.

Results

Eighteen observational studies were included in this review. All studies were of moderate to high quality. The pooled data suggested high adherence to the Mediterranean diet during pregnancy was associated with a reduced incidence of wheeze in the first 12 months (OR, 0.92; 95% confidence interval [CI], 0.88‐0.95; P < 0.001), and there was an inverse association between the Mediterranean diet during childhood and the incidence of wheeze in the history (OR, 0.51; 95% CI, 0.37‐0.70; P = 0.001) and current wheeze (OR, 0.97; 95% CI, 0.95‐0.99; P = 0.013). However, there was no significant association between high adherence of the Mediterranean diet in pregnancy and childhood and any of the other meta‐analysis end points including diagnosed asthma.

Conclusion

High adherence to the Mediterranean diet during pregnancy and childhood may have short‐term effects on wheeze in children in early life. However, these findings should be interpreted with caution owing to the heterogeneity of the studies.
Network meta‐analysis of rare events using the Mantel‐Haenszel method
Authors: Efthimiou Orestis , Rücker Gerta , Schwarzer Guido , Higgins Julian P.T. , Egger Matthias , Salanti Georgia
Published: April 2019

The Mantel‐Haenszel (MH) method has been used for decades to synthesize data obtained from studies that compare two interventions with respect to a binary outcome. It has been shown to perform better than the inverse‐variance method or Peto's odds ratio when data is sparse. Network meta‐analysis (NMA) is increasingly used to compare the safety of medical interventions, synthesizing, eg, data on mortality or serious adverse events. In this setting, sparse data occur often and yet there is to‐date, no extension of the MH method for the case of NMA. In this paper, we fill this gap by presenting a MH‐NMA method for odds ratios. Similarly to the pairwise MH method, we assume common treatment effects. We implement our approach in R, and we provide freely available easy‐to‐use routines. We illustrate our approach using data from two previously published networks. We compare our results to those obtained from three other approaches to NMA, namely, NMA with noncentral hypergeometric likelihood, an inverse‐variance NMA, and a Bayesian NMA with a binomial likelihood. We also perform simulations to assess the performance of our method and compare it with alternative methods. We conclude that our MH‐NMA method offers a reliable approach to the NMA of binary outcomes, especially in the case or sparse data, and when the assumption of methodological and clinical homogeneity is justifiable.
A Novel Ni/NiF2‐AlF3 Catalyst with Mild‐Strength Lewis Acid Sites for Dehydrofluorination of 1, 1, 1, 2‐Tetrafluoroethane to Synthesize Trifluoroethylene
Authors: Xi Zhiwen , Liu Xing , Li Junhui , Yuan Juanjuan , Jia Wenzhi , Liu Xinhua , Liu Min , Zhu Zhirong
Published: April 2019

A novel Ni/NiF2‐AlF3 catalyst was prepared by impregnation and following vapor hydrofluorination, and it was used to dehydrofluorination of tetrafluoroethane to trifluoroethylene. BET, SEM, XRD, XPS, NH3‐TPD and Py‐IR techniques were employed to characterize the Ni/NiF2‐AlF3 catalysts. Based on the NH3‐TPD results, it was interestingly found that the strong acidic sites of Ni/NiF2‐AlF3 catalyst transformed into the mid‐strength acidic sites with the increase of Ni loading, attributing to the roles of Ni on the catalyst surface. Compared with the NiF2‐AlF3 catalyst, the added Ni particles can improve the catalyst activity and stability for dehydrofluorination of 1, 1, 1, 2‐tetrafluoroethane. The best performance was obtained at Al/Ni=2 over the Ni/NiF2‐AlF3 catalyst, with high trifluoroethylene selectivity(99%) and CF3CFH2 conversion of 21.3%, after the reaction for 20 h on‐time stream at 500 °C, which showed the better application possibility as a heterogeneous dehydrofluorination catalyst. It was suggested that catalytic performance was related with the mid‐strength Lewis acidity on the catalyst surface. And the Ni/NiF2‐AlF3 catalyst (Al/Ni=2) possessed the good catalytic stability due to the mild‐strength Lewis acid sites.
First Report on 3‐(3‐oxoaryl) Indole Derivatives as Anticancer Agents: Microwave Assisted Synthesis, In Vitro Screening and Molecular Docking Studies
Authors: Patel Tarun , Gaikwad Ruchi , Jain Kavita , Ganesh Routholla , Bobde Yamini , Ghosh Balaram , Das Kalpataru , Gayen Shovanlal
Published: April 2019

In this study ZrCl4 was identified as an efficient Lewis acid catalyst for the synthesis of 3‐(3‐oxoaryl) indole derivatives via microwave assisted Michael addition of 2‐phenylindole with chalcones under solvent‐free condition. The reaction proceeds smoothly with high efficiency under green reaction condition to afford a range of 3‐(3‐oxoaryl) indole derivatives exclusively within a short period of time in excellent yields. The synthesized compounds have shown promising in vitro anticancer activity against murine melanoma (B16F10) and human breast cancer (MCF7) cell lines. Molecular docking analysis showed that this type of indole derivatives may act as anticancer agents through the inhibition of tubulin polymerization.
Biomass‐Derived Lignocellulosic Graphene Composite: Novel Approach for Removal of Oil and Organic Solvent
Authors: Kulal Dnyaneshwar K. , Khose Rahul V. , Pethsangave Dattatray A. , Wadekar Pravin H. , Some Surajit
Published: April 2019

Novel approach to develop a biomass derived lignin‐cellulose based, ultra‐light, hydrophobic graphene supported spongy composite was synthesized to absorb oil and organic solvents from wastewater. Spongy composite was synthesized by a facile and highly efficient one‐pot hydrothermal method from the natural precursor. Lignin‐cellulose functionalized graphene (LCG) sponge was synthesized from graphene oxide (GO) and sugarcane waste powder (SCwP) in presence of natural latex. LCG successfully demonstrated separation of oil from oil‐water mixture. LCG has high oil sorption capacity in the range of 25–50 g of oil per gram of sorbent. This material showed high efficiency as a sorbent to separate organic chemicals from wastewater. The absorption capacity of LCG sponge was enhanced thrice in comparison with SCwP and could be reused up to 10 cycles. The continuous oil water separation process was demonstrated using LCG sponge from the oil‐water mixture, which can be applied for large scale oil recovery from the waste stream.
Synthesis of Anatase TiO2 Nanocrystals with Defined Morphologies from Exfoliated Nanoribbons: Photocatalytic Performance and Application in Dye‐sensitized Solar Cell
Authors: Du Yi‐en , Niu Xianjun , Bai Yang , Qi Hongxue , Guo Yanqing , Chen Yongqiang , Wang Pengfei , Yang Xiaojing , Feng Qi
Published: April 2019

Rutile/anatase TiO2 nanocrystals with various morphologies and exposed crystal facets, have been successfully synthesized by a facile hydrothermal strategy in the absence of fluorine and organic capping surfactants. The samples were characterized by X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and high‐resolution transmission electron microscopy (HRTEM). Furthermore, the transformation mechanism, photocatalytic performances, adsorption properties, and photovoltaic performances of the anatase TiO2 nanocrystals with different morphologies and crystal facets were also investigated systematically and discussed, and compared to the Degussa P25 TiO2 nanocrystals. The results indicated that the anatase TiO2 nanospindles (pH 7.0‐T180) with dominantly exposed {010} facets exhibited the highest photocatalytic activity, adsorption property, and photovoltaic performance.
Development of Highly Efficient Dual Sensor Based on Carbon Dots for Direct Estimation of Iron and Fluoride Ions in Drinking Water
Authors: Sarkar Probir Kumar , Kar Prasenjit , Halder Animesh , Lemmens Peter , Pal Samir Kumar
Published: April 2019

The fluorescent nanomaterial carbon dots (CDs) have attracted tremendous attention in the recent times because of their unique physico‐chemical characteristics. Highly fluorescent CDs were prepared through a simple and nontoxic one‐step hydrothermal carbonization of polyvinylpyrrolidone (PVP). The as‐synthesised CDs, without any pre‐treatments or post‐treatments, show high stability over a broad pH range and have an excellent potential in chemical sensing applications. The as‐prepared CDs have been demonstrated to be an excellent nano probe for Fe3+ ions sensing in aqueous media based on the fluorescence quenching with high sensitivity (lower limit of detection ∼ 1 μM) and selectivity towards Fe3+ ions. “Turn off” fluorescence arises due to the formation of CDs‐Fe3+ nanocomposite complex in the solution. The nanocomposite complex forms by the attachment of Fe3+ ions to the surface emissive site of the CDs, resulting in an obvious fluorescence quenching. Here, CDs itself act as a promising nano carrier for loading of Fe3+ ions to form the CDs‐Fe3+ nanocomposite complex in the solution. In addition to all, in this study we are intensely focused to explore the application of CDs‐Fe3+ nanocomposite complex. We have used the CDs‐Fe3+ nanocomposite complex as a novel sensor probe for the detection of F‐ ions in aqueous media based on “Turn on” fluorescence mechanism. “Turn on” fluorescence occurs due to the formation of thermodynamically highly stable [FeF6]3‐ complex and bare CDs in the solution. The developed sensor has high sensitivity (lower limit of detection ∼ 1 μM) and selectivity towards F‐ ions over a wide‐ranging other competing anions. Finally, we successfully demonstrate the real life application of the developed sensor by estimating the trace F‐ ions in the real world drinking water samples.
Molecular Structure, DFT, Vibrational Spectra with Fluorescence Effect, Hirshfeld Surface, Docking Simulation and Antioxidant Activity of Thiazole Derivative
Authors: Khamees Hussien A. , Mohammed Yasser H. E. , Swamynayaka Ananda , Al‐Ostoot Fares H. , Sert Yusuf , Alghamdi Saad , Khanum Shaukath A. , Madegowda Mahendra
Published: April 2019

2‐(4‐methylphenoxy)‐N‐(4‐(4‐bromophenyl) thiazol‐2‐yl) acetamide compound was obtained via a multistep synthesis sequence processes, which is characterized by 1H NMR, 13C NMR and its three‐dimensional structure has been confirmed by single crystal X‐ray diffraction method. The supramolecular structure of the molecule revealed the stability of crystal packing with diverse intermolecular interactions. Density functional theory calculations (DFT) at B3LYP 6–311++G(d,p) level has been used to predict the molecular geometry and were in good agreement with the experimental data. Moreover, the theoretical calculations were carried out to appraise the electronic structure, vibrational spectra, natural bond orbital analysis, molecular electrostatic potential, frontier molecular orbitals and global reactivity descriptors. Raman spectra with fluorescence effect was examined with visible and near IR excitation wavelengths. Hirshfeld surface and energy framework analysis revealed the important intermolecular contacts and interaction energies. The antioxidant activity of this synthesized compound was predicted by in silico docking study on human peroxiredoxin 5 protein. The potential antioxidant activity was investigated by 1,1‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical screening and compared with standard drug ascorbic acid.
Preparation of 3D nanostructured MnCo2S4 as a robust electrocatalyst for overall water splitting
Authors: Hou Bin , Fu Jianpeng , Su Hui , Du Xiaoqiang
Published: April 2019

The exploitation and use of efficient and inexpensive electrochemical catalysts accelerate overall water splitting, which rapidly produces oxygen and hydrogen. In this work, MnCo2S4 is grown on nickel foam by a two‐step method, hydrothermal and sulfuration method. Experiments have shown that the resulting MnCo2S4/NF exhibits a low overpotential of 310 mV to achieve a current density of 50 mA cm−2 in 1.0 M potassium hydroxide for oxygen evolution reaction (OER). In addition, the MnCo2S4/NF exhibits a low overpotential of only 167 mV at 10 mA cm−2 for hydrogen evolution reaction (HER). Furthermore, MnCo2S4/NF is acted as a bifunctional water splitting catalyst, and in 1.0 M potassium hydroxide, in order to maintain a current of 10 mA cm−2, a low battery voltage of 1.61 V is required. The nanostructure, which provides a large specific surface area, which in turn increases the reactive sites, facilitates contact of large areas of water with the catalyst, and rapid transfer of electrons. At the same time, through a series of characterization (XRD, SEM and XPS), it is proved that the catalyst is efficient and stable under alkaline condition.
Synthesis of Ferrocene Tethered Heteroaromatic Compounds Using Solid Supported Reaction Method, their Cytotoxic Evaluation and Fluorescence Behavior.
Authors: Dewangan Smriti , Mishra Sasmita , Mawatwal Shradha , Dhiman Rohan , Parida Rakesh , Giri Santanab , Wölper Christoph , Chatterjee Saurav
Published: April 2019

Synthesis of ferrocene conjugated heterocyclic molecular systems involving three different heterocyclic moieties like indole, quinoline and pyrazine was carried out in high yields using redmud as solid support.Their cytotoxic properties against RAW 264.7 cancer cell lines shows excellent inhibitory activity for indole and quinoline based molecular system, while significant antibacterial activity was shown by the pyrazinyl‐ferrocene conjugate.Compound 2 was structurally characterized using single crystal X‐ray diffraction study and shows the presence of chiral conformation forming a racemate within the asymmetric unit.The fluorescence response of 1–3 was investigated and their unique quenching behavior upon ferrocenyl oxidation was studied for application related to bio‐signaling and sensor based properties.The quenching behavior of 1 and 2 was supported by DFT calculation which revealed some interesting features related to electron transfer processes.
Precise Surface Engineering of Cathode Materials for Improved Stability of Lithium‐Ion Batteries
Authors: Liu Yuan , Lin Xi‐Jie , Sun Yong‐Gang , Xu Yan‐Song , Chang Bao‐Bao , Liu Chun‐Tai , Cao An‐Min , Wan Li‐Jun
Published: April 2019

As lithium‐ion batteries continue to climb to even higher energy density, they meanwhile cause serious concerns on their stability and reliability during operation. To make sure the electrode materials, particularly cathode materials, are stable upon extended cycles, surface modification becomes indispensable to minimize the undesirable side reaction at the electrolyte–cathode interface, which is known as a critical factor to jeopardizing the electrode performance. This Review is targeted at a precise surface control of cathode materials with focus on the synthetic strategies suitable for a maximized surface protection ensured by a uniform and conformal surface coating. Detailed discussions are taken on the formation mechanism of the designated surface species achieved by either wet‐chemistry routes or instrumental ones, with attention to the optimized electrochemical performance as a result of the surface control, accordingly drawing a clear image to describe the synthesis–structure–performance relationship to facilitate further understanding of functional electrode materials. Finally, perspectives regarding the most promising and/or most urgent developments for the surface control of high‐energy cathode materials are provided.
Characteristics of aerosol pollution in the vicinity of an oil refinery near Rijeka, Croatia
Authors: Čargonja Marija , Mekterović Darko , Mance Diana , Žauhar Gordana , Bogdanović Radović Iva , Zamboni Ivana
Published: April 2019

Fine aerosol pollution is one of the most important factors in air pollution monitoring. Industrial production often represents significant source of aerosol pollution in surrounding areas, and therefore, it is important to understand its impact on air quality. In order to investigate contribution coming from the oil refinery to air pollution, PM2.5 (particulate matter with aerodynamic diameter smaller than 2.5 μm) samples were collected in the vicinity of an oil refinery during the 1‐year period. At the same time, PM2.5 was sampled in the city of Rijeka, Croatia, at the distance that is about 10 km far from the refinery. This site was used for comparison. The sampling was performed with two cyclone samplers on thin polytetrafluoroethylene filters. PM2.5 was sampled for 24 h every other day, simultaneously at both locations. In total, 306 samples were collected. The samples were analysed using X‐ray fluorescence and particle‐induced X‐ray emission to obtain concentrations of 17 elements from Na to Pb. Additionally, concentrations of black carbon were determined using laser‐integrated plate method. It was found that concentrations of S, V, and Ni, elements characteristic for oil burning, were substantially higher at the refinery sampling site comparing to the reference location. Obtained concentrations were statistically evaluated by performing positive matrix factorization to identify oil refinery as one of the pollution sources in the vicinity of such a facility. The same method was also performed at the urban site where the contribution from oil refinery was not separated from other similar sources.
b→sμ+μ− anomalies and related phenomenology in $$ \mathrm{U}{(1)}_{{\mathrm{B}}_3-{\mathrm{x}}_{\mu }{\mathrm{L}}_{\mu }-{\mathrm{x}}_{\tau }{\mathrm{L}}_{\tau }} $$ flavor gauge models
Authors: Ko P. , Nomura Takaaki , Yu Chaehyun
Published: April 2019

Abstract

We propose a generation dependent lepton/baryon gauge symmetry,

$$ \mathrm{U}{(1)}_{B_3-{x}_{\mu }{L}_{\mu }-{x}_{\tau }{L}_{\tau }}\equiv \mathrm{U}{(1)}_X $$

U

1

B
3

−

x
μ

L
μ

−

x
τ

L
τ

≡
U

1

X

(with x

μ
+ x

τ
= 1 for anomaly cancellation), as a possible solution for the b → sμ
+
μ
− anomalies. By introducing two Higgs doublet fields, we can reproduce the observed CKM matrix, and generate flavor changing Z
′ interactions in the quark sector. Thus one can explain observed anomalies in b → sℓ
+
ℓ
− decay with the lepton non-universal U(1)
X
charge assignments. We show the minimal setup explaining b→sℓ
+
ℓ
− anomalies, neutrino masses and mixings and dark matter candidate, taking into account experimental constraints of flavor physics such as charged lepton flavor violations and the

$$ {B}_s-{\overline{B}}_s $$

B
s

−

B
¯

s

mixing. Finally we discuss collider physics focusing on Z
′ production at the Large Hadron Collider and relic density of our dark matter candidate.
Effect of wind turbine nacelle on turbine wake dynamics in large wind farms
Authors: Foti Daniel , Yang Xiaolei , Shen Lian , Sotiropoulos Fotis
Published: April 2019

Wake meandering, a phenomenon of large-scale lateral oscillation of the wake, has significant effects on the velocity deficit and turbulence intensities in wind turbine wakes. Previous studies of a single turbine (Kang et al., J. Fluid. Mech., vol. 774, 2014, pp. 374–403; Foti et al., Phys. Rev. Fluids, vol. 1 (4), 2016, 044407) have shown that the turbine nacelle induces large-scale coherent structures in the near field that can have a significant effect on wake meandering. However, whether nacelle-induced coherent structures at the turbine scale impact the emergent turbine wake dynamics at the wind farm scale is still an open question of both fundamental and practical significance. We take on this question by carrying out large-eddy simulation of atmospheric turbulent flow over the Horns Rev wind farm using actuator surface parameterisations of the turbines without and with the turbine nacelle taken into account. While the computed mean turbine power output and the mean velocity field away from the nacelle wake are similar for both cases, considerable differences are found in the turbine power fluctuations and turbulence intensities. Furthermore, wake meandering amplitude and area defined by wake meanders, which indicates the turbine wake unsteadiness, are larger for the simulations with the turbine nacelle. The wake influenced area computed from the velocity deficit profiles, which describes the spanwise extent of the turbine wakes, and the spanwise growth rate, on the other hand, are smaller for some rows in the simulation with the nacelle model. Our work shows that incorporating the nacelle model in wind farm scale simulations is critical for accurate predictions of quantities that affect the wind farm levelised cost of energy, such as the dynamics of wake meandering and the dynamic loads on downwind turbines.
Non-periodic phase-space trajectories of roughness-driven secondary flows in high- boundary layers and channels
Authors: Anderson W.
Published: April 2019

Turbulent flows respond to bounding walls with a predominant spanwise heterogeneity – that is, a heterogeneity parallel to the prevailing transport direction – with formation of Reynolds-averaged turbulent secondary flows. Prior experimental and numerical work has determined that these secondary rolls occur in a variety of arrangements, contingent only upon the existence of a spanwise heterogeneity (i.e. from complex, multiscale roughness with a predominant spanwise heterogeneity, to canonical step changes, to different roughness elements). These secondary rolls are known to be a manifestation of Prandtl’s secondary flow of the second kind: driven and sustained by the existence of spatial heterogeneities in the Reynolds (turbulent) stresses, all of which vanish in the absence of spanwise heterogeneity. Herein, we show results from a suite of large-eddy simulations and complementary experimental measurements of flow over spanwise-heterogeneous surfaces. Although the resultant secondary cell location is clearly correlated with the surface characteristics, which ultimately dictates the Reynolds-averaged flow patterns, we show the potential for instantaneous sign reversals in the rotational sense of the secondary cells. This is accomplished with probability density functions and conditional sampling. In order to address this further, a base flow representing the streamwise rolls is introduced. The base flow intensity – based on a leading-order Galerkin projection – is allowed to vary in time through the introduction of time-dependent parameters. Upon substitution of the base flow into the streamwise momentum and streamwise vorticity transport equations, and via use of a vortex forcing model, we are able to assess the phase-space evolution (orbit) of the resulting system of ordinary differential equations. The system resembles the Lorenz system, but the forcing conditions differ intrinsically. Nevertheless, the system reveals that chaotic, non-periodic trajectories are possible for sufficient inertial conditions. Poincaré projection is used to assess the conditions needed for chaos, and to estimate the fractal dimension of the attractor. Its simplicity notwithstanding, the propensity for chaotic, non-periodic trajectories in the base flow model suggests similar dynamics is responsible for the large-scale reversals observed in the numerical and experimental datasets.