bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple slip effects on MHD nanofluid flow over an inclined, radiative, and chemically reacting stretching sheet by means of FDM
Authors: Barik Ashok K. , Mishra Saumya K. , Mishra S. R. , Pattnaik P. K.
Published: November 2019

In the present study, the magnetohydrodynamic characteristics of an electrically conducting nanofluid flowing past an inclined stretching sheet have been studied numerically. The governing partial differential equations were transformed to nonlinear ordinary differential equations (ODEs) via suitable similarity variables. The wall suction/injection as well as Navier's first‐order slip has been considered for velocity, temperature, and concentration at the wall. The ODEs were solved in a finite difference framework via a computer program written in Engineering Equation Solver platform. The effect of different parameters on the velocity, temperature, and concentration field has also been presented. Multiple slip flow finds its application in many practical fields such as microelectromechanical systems, nanoelectromechanical systems, flow of micro‐organisms, rarefied gas flow, to name a few.
Liver haploinsufficiency of RuvBL1 causes hepatic insulin resistance and enhances hepatocellular carcinoma progression
Authors: Mello Tommaso , Materozzi Maria , Zanieri Francesca , Simeone Irene , Ceni Elisabetta , Bereshchenko Oxana , Polvani Simone , Tarocchi Mirko , Marroncini Giada , Nerlov Claus , Guasti Daniele , Bani Daniele , Pinzani Massimo , Galli Andrea
Published: November 2019

RuvBL1 is an AAA+ ATPase whose expression in hepatocellular carcinoma (HCC) correlates with a poor prognosis. In vitro models suggest that targeting RuvBL1 could be an effective strategy against HCC. However, the role of RuvBL1 in the onset and progression of HCC remains unknown. To address this question, we developed a RuvBL1hep+/− mouse model and evaluated the outcome of DEN‐induced liver carcinogenesis up to 12 months of progression. We found that RuvBL1 haploinsufficiency initially delayed the onset of liver cancer, due to a reduced hepatocyte turnover in RuvBL1hep+/− mice. However, RuvBL1hep+/−mice eventually developed HCC nodules that, with aging, grew larger than in the control mice. Moreover, RuvBL1hep+/− mice developed hepatic insulin resistance and impaired glucose homeostasis. We could determine that RuvBL1 regulates insulin signaling through the Akt/mTOR pathway in liver physiology in vivo as well as in normal hepatocytic and HCC cells in vitro. Whole transcriptome analysis of mice livers confirmed the major role of RuvBL1 in the regulation of hepatic glucose metabolism. Finally, RuvBL1 expression was found significantly correlated to glucose metabolism and mTOR signaling by bioinformatic analysis of human HCC sample from the publicly available TGCA database. These data uncover a role of RuvBL1 at the intersection of liver metabolism, hepatocyte proliferation and HCC development, providing a molecular rationale for its overexpression in liver cancer.
One‐dimensional and two‐dimensional synergized nanostructures for high‐performing energy storage and conversion
Authors: Li Xin , Wang John
Published: November 2019

To address the worldwide energy challenges, advanced energy storage and conversion systems with high comprehensive performances, as the promising technologies, are inevitably required on a timely basis. The performance of these energy systems is intimately dependent on the properties of their electrodes. In addition to the electrode materials selection and their compositional optimization, materials fabrication with the designed nanostructure also provides significant benefits for their performances. In the past decade, considerable efforts have been made to promote the search for multidimensional nanostructures containing both one‐dimensional (1D) and two‐dimensional (2D) nanostructures in synergy, namely, 1D‐2D synergized nanostructures. By developing the freestanding electrodes with such unique nanoarchitectures, the structural features and electroactivities of each component can be manifested, where the synergistic properties among them can be simultaneously obtained for further enhanced properties, such as the increased number of active sites, fast electronic/ionic transport, and so forth. This review overviews the state‐of‐the‐art on the 1D‐2D synergized nanostructures, which can be broadly divided into three groups, namely, core/shell, cactus‐like, and sandwich‐like nanostructures. For each category, we introduce them from the aspects of structural features, fabrication methodologies to their successful applications in different types of energy storage/conversion devices, including rechargeable batteries, supercapacitors, water splitting, and so forth. Finally, the main challenges faced by and perspectives on the 1D‐2D synergized nanostructures are discussed.

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Working Across Cultural Boundaries: The Many Faces of Diversity
Authors: Haskins Cecilia
Published: November 2019

Most professionals are familiar with the works of Geert Hofstede who developed a framework for cross‐cultural communications in 1980 based on a worldwide survey of employee values between 1967 and 1973, or, Richard D. Lewis and his book, When Cultures Collide, first issued in 1996 and now in its third edition featuring the Lewis model of cross‐cultural communication. Both are based on years of research into the personal attributes one might expect to find in the various countries and offer suggestions on how persons of different backgrounds might use those differences to build relationships and work together. The first person to coin the term culture was Sir Edward Burnett Tylor, an English anthropologist in the 18th century. In his words, culture is “that complex whole which includes knowledge, belief, art, morals, law, custom and any other capabilities and habits acquired by man as a member of society (Taylor 1871, 1).”

This article investigates the connections between diversity in systems engineering teams, and quality, innovation, and competitive advantage. I look at the many faces of diversity from a cultural viewpoint and harvest some useful wisdom from the literature and my own experiences as an American living and working in Norway. I conclude that the path to successful appreciation of others comes from maintaining an open mind, alongside careful reflection of the viewpoints of colleagues and friends, and an open attitude toward the value of continuous learning and exploration of the “ologies.”
Towards a More Diverse INCOSE
Authors: Harding Alan , Pickard Andy
Published: November 2019

We often talk about the lack of women in the engineering workforce, and more broadly the need for diversity and inclusion (D&I) in our enterprises. Within INCOSE, the Empowering Women Leaders in Systems Engineering (EWLSE) initiative advocates both for women as leaders in systems engineering and for improved understanding and responses to the wider diversity issues.

Let us assume that INCOSE is not as diverse as we would hope in an ideal world. Let us agree that evidence‐based decisions on how to evolve INCOSE towards that idea are desirable. This paper will establish an understanding of INCOSE's current diversity based on available data, and in doing so will answer the following questions:

1) Why is it important for INCOSE to be diverse?

2) What do we mean by diversity with respect to INCOSE?

3) What do we know about INCOSE diversity today, and how does it compare to equivalent societies and the wider communities in which we operate?

4) Where are the gaps and what can we do to improve INCOSE diversity?
Overcoming the Male Leadership Culture
Authors: Dove Rick
Published: November 2019

Empowering women as leaders in systems engineering is a clarion call–a strong and emotional appeal to do something. But who is to do this empowering, why should it be done, and what stands in the way? This article speaks to both men and women, collectively and individually. For men that feel empathetic and supportive of gender equality, it will suggest why your empathy and support may not be what you think it is. For women who want to understand the nature of the inequality problem, it will show you key elements of what perpetuates it as a means to help address it. The principle goals of this article are to expose some key elements of the problem space, and to create an appreciation for the values of social sensitivity in working relationships and in leadership.
A step toward engineering thick tissues: Distributing microfibers within 3D printed frames
Authors: Molde Joseph , Steele Joseph A. M. , Pastino Alexandra K. , Mahat Anisha , Murthy N. Sanjeeva , Kohn Joachim
Published: November 2019

Microfiber mats for tissue engineering scaffolds support cell growth, but are limited by poor cell infiltration and nutrient transport. Three‐dimensional printing, specifically fused deposition modeling (FDM), can rapidly produce customized constructs, but macroscopic porosity resulting from low resolution reduces cell seeding efficiency and prevents the formation of continuous cell networks. Here we describe the fabrication of hierarchical scaffolds that integrate a fibrous microenvironment with the open macropore structure of FDM. Biodegradable tyrosine‐derived polycarbonate microfibers were airbrushed iteratively between layers of 3D printed support structure following optimization. Confocal imaging showed layers of airbrushed fiber mats supported human dermal fibroblast growth and extracellular matrix development throughout the scaffold. When implanted subcutaneously, hierarchical scaffolds facilitated greater cell infiltration and tissue formation than airbrushed fiber mats. Fibronectin matrix assembled in vitro throughout the hierarchical scaffold survived decellularization and provided a hybrid substrate for recellularization with mesenchymal stromal cells. These results demonstrate that by combining FDM and airbrushing techniques we can engineer customizable hierarchical scaffolds for thick tissues that support increased cell growth and infiltration.
Epidemiological investigation and antimicrobial susceptibility analysis of mycoplasma in patients with genital manifestations
Authors: Gu Xiaodong , Liu Sudong , Guo Xuemin , Weng Ruiqiang , Zhong Zhixiong
Published: November 2019

Background

The aim of this study was to investigate the infection and antimicrobial resistance of Ureaplasma urealyticum and Mycoplasma hominis in patients with genitourinary symptoms among Hakka population in Meizhou, China.

Methods

A total of 12 633 females and 3315 males who presented urogenital symptoms and were subjected to mycoplasma tests from 2014 to 2018 were enrolled in this study. The mycoplasma detection and antimicrobial susceptibility were tested using the Mycoplasma ID/AST kit.

Results

The total incidence of mycoplasma infection, as well as the incidence of U urealyticum in Hakka population was annually increasing from 2014 to 2018. The total incidences and U urealyticum infection were more prevalent in females than males. Higher positive rate of mycoplasmas infection was observed in women aged 16‐20 (50.9%) and men aged 26‐30 (25.4%). The occurrence of antimicrobial resistance of mycoplasma to antibacterial agents remained relatively similar in the past five years. Ureaplasma urealyticum infection, M hominis infection, and co‐infection of resistance to levofloxacin, erythromycin, ciprofloxacin, ofloxacin, roxithromycin, azithromycin, clarithromycin, and sparfloxacin were dramatically higher in females than in males.

Conclusion

Our findings indicate a high burden of mycoplasmas infection and antimicrobial resistance of mycoplasmas infection among females, and josamycin and minocycline may be recommended as the primary choice in clinical treatment of anti‐mycoplasmas.
Optimizing efficiency and skill utilization: Analysis of genetic counselors' attitudes regarding delegation in a clinical setting
Authors: Read Parker , Yashar Beverly M. , Robinson Linda , Marvin Monica
Published: November 2019

This study assessed genetic counselors' (GCs) perceptions of delegation as a tool to increase workforce efficiency and help meet the current gap between the number of genetic service providers and the number of patients. GCs were recruited to participate via an online survey that assessed activities (categorized as typical genetic counseling, administrative, or professional development) performed by a clinical genetic counselor. Respondents indicated which activities represent their largest time consumers, their willingness to delegate these activities, and barriers to and perceived outcomes of delegation. Overall, respondents indicated that they spend 25% of their time performing administrative activities that they would largely be willing to delegate; however, respondents were generally unwilling to delegate many typical genetic counseling and professional development activities, citing concerns regarding accuracy and liability, and highlighting the belief that these activities constitute the core role of a genetic counselor. Respondents indicated that delegation of time‐consuming administrative activities would increase access to genetic services and improve job satisfaction. Additionally, differences were identified among clinical specialties regarding which activities were selected as top time consumers, indicating that potential targets of re‐allocation of time or delegation may be variable. This research indicates a need to reduce the number of administrative tasks in which GCs are directly involved to re‐allocate time toward core responsibilities, direct patient care, and professional development, the result of which is more efficient use of the GC skill‐set.
Benzofuran‐isatin conjugates as potent VEGFR‐2 and cancer cell growth inhibitors
Authors: Zou Yulin
Published: November 2019

A series of benzofuran‐isatin conjugates 6a‐l and 7a,b tethered by various alkyl linkers were synthesized and evaluated for their VEGFR‐2 inhibitory activity and in vitro activity against a panel of cancer cell lines. Seven of them were comparable with or better than Sunitinib against all tested cancer cells, demonstrating benzofuran‐isatin conjugates were potential anticancer candidates. The mechanism study revealed that VEGFR‐2 was at least one of the targets for this kind of conjugates. The structure‐activity relationship demonstrated that the carbon spacer between benzofuran and isatin moieties, substituents on the C‐2 position of benzofuran moiety, and substituents on C‐3 as well as C‐5 position of isatin motif influenced the anticancer activity significantly, and the enriched structure‐activity relationship may provide an insight for rational design of more effective conjugates.
Immunolocalization of Wnts in the lizard blastema supports a key role of these signaling proteins for tail regeneration
Authors: Alibardi Lorenzo
Published: November 2019

A highly upregulated gene during tail regeneration in lizards isWnt2b, a gene broadly expressed during development. The present study examines the distribution of Wnt proteins, most likely wnt2b, by western blotting and immunofluorescence in the blastema‐cone of lizards using a specific antibody produced against a lizard Wnt2b protein. Immunopositive bands at 48–50 and 18 kDa are present in the regenerative blastema, the latter likely as a degradation product. Immunofluorescence is mainly observed in the wound epidermis, including in the Apical Epidermal Peg where the protein appears localized in intermediate and differentiating keratinocytes. Labeling is more intense along the perimeter of keratinocytes, possibly as a secretory product, and indicates that the high epidermal proliferation of the regenerating epidermis is sustained by Wnt proteins. The regenerating spinal cord forms an ependymal tube within the blastema and shows immunolabeling especially in the cytoplasm of ependymal cells contacting the central canal where some secretion might occur. Also, regenerating nerves and proximal spinal ganglia innervating the regenerating blastema contain this signaling protein. In contrast, the blastema mesenchyme, muscles and cartilage show weak immunolabeling that tends to disappear in tissues located in more proximal regions, close to the original tail. However, a distal to proximal gradient of Wnt proteins was not detected. The present study supports the hypothesis that Wnt proteins, in particular Wnt2b, are secreted by the apical epidermis covering the blastema and released into the mesenchyme where they stimulate cell multiplication.
Binding of aldehydes to myofibrillar proteins as affected by two‐step heat treatments
Authors: Xu Yongxia , Wang Rui , Zhao Honglei , Zhao Jiamei , Li Xuepeng , Yi Shumin , Li Jianrong , Sun Xiaotao
Published: November 2019

BACKGROUND

The present study investigated the effect of two‐step heat treatments on the structure of grass carp myofibrillar proteins (MPs) and their binding ability for selected aldehydes (hexanal, heptanal, octanal and nonanal).

RESULTS

Within 30 min of the first heating step at 40 °C and 5–10 min of the second heating step at 90 °C, the enhancement of the flavor‐binding ability was likely explained by the increases in surface hydrophobicity and total sulfhydryl content due to the unfolding of secondary structures of MPs through exposure of hydrophobic amino acids and sulfhydryl groups. Nevertheless, lengthy heating at 90 °C accelerated the aggregation of unfolded MPs and reduced the hydrophobic bonding sites, thus weakening the hydrophobic interactions and decreasing the resultant binding ability of MPs with aldehydes.

CONCLUSION

The binding ability of aldehydes to MPs was found to be strongly influenced by changes in protein structure and surface during the two‐step heating process. The results provided insight into improving the flavor characteristics of freshwater fish surimi products. © 2019 Society of Chemical Industry
Multifiber solid‐phase microextraction using different molecularly imprinted coatings for simultaneous selective extraction and sensitive determination of organophosphorus pesticides
Authors: Xiang Xiaozhe , Wang Yulong , Zhang Xiaowei , Huang Mingquan , Li Xiujuan , Pan Siyi
Published: November 2019

Three types of molecularly imprinted solid‐phase microextraction fibers were fabricated through sol‐gel method using diazinon, parathion‐methyl, and isocarbophos as templates, respectively, and assembled together to construct a multifiber for analysis of organophosphorus pesticides in complex matrices. The multifiber provided large extraction capacity and high imprinting factor up to 3.89. In contrast, the imprinting factor of a single fiber was around 1.6, and the multi‐template imprinted coating showed no selectivity. The multifiber was applied to analyze pesticides in fruits and vegetables. The limits of detection, which ranged from 0.0052 to 0.23 µg/kg, were lower than those obtained by a single molecularly imprinted fiber, and much lower than those reported by other methods. The recoveries of five analytes in spiked apple, cucumber, Chinese cabbage, and cherry tomato samples were 75.1–123.2%. The study shows that the molecularly imprinted multifiber could achieve simultaneous selective extraction and sensitive determination of multiple targets in complex matrices for high‐throughput analysis.
Patient‐Specific 3‐Dimensional Model for High‐Intensity Focused Ultrasound Treatment Through the Rib Cage
Authors: Cao Rui , Huang Zhihong , Nabi Ghulam , Melzer Andreas
Published: November 2019

Objectives

The purpose of this study was to develop a patient‐specific 3‐dimensional model for high‐intensity focused ultrasound (HIFU) treatment through the rib cage using patient data.

Methods

Experimental testing to derive parameters used in defining the amount of energy and alteration needed in treatment protocols for upper abdominal disorders under the rib cage was performed. Reconstructed rib cage models based on patient data, tissue‐mimicking material phantoms, and magnetic resonance imaging–guided HIFU using a multielement phased array transducer were used in the experiments. Changes in the focal temperature, acoustic power, and acoustic pressure distribution were investigated with and without the presence of the rib cage model. An ExAblate system (InSightec Ltd, Tirat Carmel, Israel) was used to sonicate phantoms by varying the target phantom or rib cage model location.

Results

The effect of the rib cage on the acoustic pressure distribution and acoustic power was closely related to the anatomic structures of the ribs. Thermometry revealed that heating at the focus could be controlled by changing either the power or duration of HIFU application to improve the focal temperature change. The focal temperature change was found to be related to the distance between the rib cage model and focus and the shadow area on the transducer elements covered by the rib cage model in the beam path.

Conclusions

Experimental results suggest that the rib cage model is a valuable and useful tool that can provide realistic human anatomic structures and properties for evaluating the effects of the rib cage on ultrasound propagation.
Tumor Volume Useful Beyond Classic Criteria in Selecting Larynx Cancers For Preservation Therapy
Authors: Sharrett Jonathan M. , Ward Matthew C. , Murray Eric , Scharpf Joseph , Lamarre Eric D. , Prendes Brandon L. , Lorenz Robert R. , Burkey Brian B. , Koyfman Shlomo A. , Woody Neil M. , Greskovich John F. , Adelstein David J. , Geiger Jessica L. , Joshi Nikhil P.
Published: November 2019

Objective

To investigate the association between tumor volume and locoregional failure (LRF) after concurrent chemoradiation (CCRT) for locally advanced larynx cancer (LC).

Methods

This is a retrospective cohort study from 2009 to 2014 identified from an institutional review board–approved registry. Fifty‐nine of 68 patients with locally advanced larynx cancer treated with definitive CCRT who had available imaging for review were identified. The main endpoint to be assessed was the association between gross tumor volumes (GTV; T = total, P = primary, N = nodal) and LRF. Receiver operative characteristic (ROC) curves were used to investigate diagnostic accuracy.

Results

Twenty LRFs were observed, resulting in a 2‐year LRF rate of 39% (95% CI, 23–52%). On UVA, the GTV‐T (P = .01), GTV‐P (P = .05), and GTV‐N (P = .04) were statistically significant predictors of LRF. Furthermore, age, smoking status, N‐stage, larynx subsite, and tracheostomy/feeding tube dependence were potentially associated with LRF (P < .3), whereas T‐stage (T3–4 vs. T2) was not (HR 1.05, 95% CI, 0.38–2.91, P = .92). In the multivariable model, GTV‐P (HR 1.022, 95% CI, 0.999–1.046, P = .07) and GTV‐N (HR 1.053, 95% CI, 1.0004–1.108, P = .05) were the two most impactful covariates on the model's R2. ROC analysis suggested an optimal cut point of 12 cc in the GTV‐T. The 2‐year LRF for GTV‐T > 12 cc was 64.2% and ≤ 12 cc was 16.4%, P = .006.

Conclusion

GTV is associated with LRF after definitive CCRT for LC. Patients with bulky primary and/or nodal tumors may be better served with upfront surgical resection regardless of T‐stage. Further investigation into the safety of larynx preservation for low‐volume T4 tumors can be considered.

Level of Evidence

4 Laryngoscope, 130:2372–2377, 2020
Corrosion behavior of GO‐reinforced TC4 nanocomposites manufactured by selective laser melting
Authors: Liu Xin , Wu Meiping , Lu Peipei , Ye Xiu , Miao Xiaojin
Published: November 2019

To improve the corrosion resistance of Ti–6Al–4V (TC4) matrix, the influence on the corrosion behavior, microhardness, and microstructure of graphene oxide (GO)‐reinforced TC4 nanocomposites manufactured by selective laser melting was systematically investigated in this study. Microhardness tester, profilometer, X‐ray diffractometer, scanning electron microscopy, and electrochemical workstation were used to characterize the association between microhardness, pore microstructures, hard phases, and corrosion resistance of GO/TC4 nanocomposites. It can be observed that the incorporation of GO promotes the in situ formation of hard phases, such as TiC, TiO2, Al2O3, and so forth, and it also changes the microstructure of the matrix as well as increases its porosity. Nevertheless, GO/TC4 nanocomposites perform the best corrosion resistance when the mixing content of GO is 0.5 wt%, and its microhardness is greatly improved with the addition of GO. All experimental results suggest the efficacy of added GO.
All Sugar Based Cellulose Derivatives Synthesized by Azide–Alkyne Click Chemistry
Authors: Koschella Andreas , Chien Chih‐Ying , Iwata Tadahisa , Thonhofer Martin S. , Wrodnigg Tanja M. , Heinze Thomas
Published: November 2019

Cellulose is functionalized with different monosaccharides by the azide–alkyne click chemistry approach. Either azide or alkyne moieties are attached to the cellulose backbone and allowed to react with sugar moieties bearing the opposite clickable groups. Between 16% and 100% of the reactive sites at the polymer can be functionalized with sugar molecules and a clear correlation between steric demand and DSSugar is observed. The polymers remain soluble in aprotic dipolar media like dimethyl sulfoxide. Products with a sufficient hydrophilicity dissolve in water as well. FTIR‐ and NMR spectroscopy reveal the triazole formation and indicate an incomplete conversion of the reactive sites as usually observed in the field of click chemistry with polymers.
The aryl hydrocarbon receptor (AhR) as a breast cancer drug target
Authors: Baker Jennifer R. , Sakoff Jennette A. , McCluskey Adam
Published: November 2019

Breast cancer is the most common cancer in women, with more than 1.7 million diagnoses worldwide per annum. Metastatic breast cancer remains incurable, and the presence of triple‐negative phenotypes makes targeted treatment impossible. The aryl hydrocarbon receptor (AhR), most commonly associated with the metabolism of xenobiotic ligands, has emerged as a promising biological target for the treatment of this deadly disease. Ligands for the AhR can be classed as exogenous or endogenous and may have agonistic or antagonistic activity. It has been well reported that agonistic ligands may have potent and selective growth inhibition activity in a number of oncogenic cell lines, and one (aminoflavone) has progressed to phase I clinical trials for breast cancer sufferers. In this study, we examine the current state of the literature in this area and elucidate the promising advances that are being made in hijacking the cytosolic‐to‐nuclear pathway of the AhR for the possible future treatment of breast cancer.
General decay for a coupled Lamé system of nonlinear viscoelastic equations
Authors: Boulaaras Salah , Ouchenane Djamel
Published: November 2019

In this paper, we consider a coupled Lamé system of nonlinear viscoelastic equations with general source terms. Under some suitable conditions on the initial data and the relaxation functions, we prove an asymptotic stability result of global solution taking into account that the kernel is not necessarily decreasing. This work generalizes and improves earlier results in the literature.
Non‐oxidized graphene/elastomer composite films for wearable strain and pressure sensors with ultra‐high flexibility and sensitivity
Authors: Meng Qingshi , Liu Zhiwen , Cai Rui , Han Sensen , Lu Shaowei , Liu Tianqing
Published: November 2019

It remains challenging to prepare wearable strain and pressure sensors with excellent mechanical properties, ultra‐high flexibility and sensitivity. Electrically conductive graphene platelets (GnPs) with high structural integrity are used in making a composite film fabricated using robust fabrication techniques. The gauge factor for the strain is up to 100 at 0%‐5% strain and 50 at 5%‐30% strain, and the sensitivity to pressure is 2.7×10‐2 kPa‐1 between 0 and 10 kPa and 1.5×10‐4 kPa‐1 between 300 and 1000 kPa. In addition, the flexible sensor demonstrates good repeatability and durability after 1000 cycles of tensile and compression tests. The flexible sensor has fast response ability and a wide operating temperature range, suggesting the excellent response to temperature. The flexible sensor is applied in monitoring several human motions as a wearable device with high accuracy. The ability to detect strain, pressure and temperature of the flexible sensor extends its applications to multifunctional wearable devices.
Investigation of the Effective Parameters on Preparation of the Gelled IRFNA
Authors: Saberimoghaddam Ali , Emamifard Zahra , Mahdi Bahri Rasht Abadi Mohammad , Meyghani Naeem
Published: November 2019

In the present work, the gelled IRFNA oxidizer was prepared and its quality was analyzed using several methods. Obtained results showed that fumed silica with mean particle size of 12 nm was appropriate gelling agent for preparing the gelled IRFNA. Moreover, mixing time of 30 min was sufficient for preparing the gel. Considering the effect of temperature (between −5 °C and 35
) on the quality of the prepared gel showed that preparing the gel was feasible in the temperature range between −4 °C and 35 °C, but temperature range between 25 °C and 35 °C was more appropriate than the total range. Time needed for developing the gel network was 24 h in which the gel viscosity increased up to 30 % compared to the viscosity of the gel immediately after its preparation. The quality analysis showed a good stability of the gel in temperature range between (−52
) and (+64
). The prepared gel retained its desirable rheological properties for at least 6 months. Mechanical stability test in acceleration of 500 g for 30 mins showed that the prepared gel had suitable mechanical stability. In addition, the prepared gel showed desirable rheological properties such as shear thinning, thixotropic and hysteresis. The viscometry results were in a good agreement with power law model. Flow behavior index (n) was increased from 0.2 to 0.3 by decreasing the gellant percentage from 4.5 to 3 % which show decreasing the shear thinning behavior of gel due to decrease in the gel gellant percentage.
Cross‐docking benchmark for automated pose and ranking prediction of ligand binding
Authors: Wierbowski Shayne D. , Wingert Bentley M. , Zheng Jim , Camacho Carlos J.
Published: November 2019

Significant efforts have been devoted in the last decade to improving molecular docking techniques to predict both accurate binding poses and ranking affinities. Some shortcomings in the field are the limited number of standard methods for measuring docking success and the availability of widely accepted standard data sets for use as benchmarks in comparing different docking algorithms throughout the field. In order to address these issues, we have created a Cross‐Docking Benchmark server. The server is a versatile cross‐docking data set containing 4,399 protein‐ligand complexes across 95 protein targets intended to serve as benchmark set and gold standard for state‐of‐the‐art pose and ranking prediction in easy, medium, hard, or very hard docking targets. The benchmark along with a customizable cross‐docking data set generation tool is available at http://disco.csb.pitt.edu. We further demonstrate the potential uses of the server in questions outside of basic benchmarking such as the selection of the ideal docking reference structure.
Surface Electronic Properties of Si‐Doped AlGaN and Thermionic Emission Characteristics with Adsorption of Alkali Metal Atoms
Authors: Kimura Shigeya , Yoshida Hisashi , Uchida Shota , Ogino Akihisa
Published: November 2019

A thermionic energy converter (TEC) is a heat engine with a high theoretical efficiency, but a reduction in operating temperature is required for practical applications. Herein, the experimentally determined thermionic conversion characteristics of Si‐doped GaN films with Cs adsorption at 600 °C are reported. Low‐temperature thermionic emission around 300 °C is also reported for Si‐doped AlGaN surfaces with Cs adsorption. This emission temperature is considerably lower than the operating temperatures of conventional systems with a metal emitter. The AlGaN thin films are grown on n‐type 6H‐SiC substrates, and it is confirmed by ultraviolet photoelectron spectroscopy that the work function decreases as the AlN mole fraction x in the AlGaN samples is increased. Threshold temperatures of thermionic emission decrease with increasing AlN mole fraction and a corresponding reduction in the work function.
Automaticity and Control: How Do Executive Functions and Reading Fluency Interact in Predicting Reading Comprehension?
Authors: Kieffer Michael J. , Christodoulou Joanna A.
Published: November 2019

The authors investigated the roles of reading fluency in mediating and moderating the relation between executive functions and reading comprehension. Linguistically diverse students (n = 106) were assessed on multiple measures of reading fluency at the passage and word levels, reading comprehension, and executive functions in grade 7 and again in grade 8. Path analyses using factor scores indicated that executive functions made indirect (mediated) contributions to reading comprehension via reading fluency, controlling for oral vocabulary and processing speed in both grades. Mediation was partial, with a statistically significant direct contribution of executive functions to reading comprehension remaining. Interaction analyses indicated that executive functions also statistically significantly interacted with reading fluency in predicting reading comprehension in both grades. Contrary to theoretical predictions, these interactions were positive, with executive functions predicting reading comprehension more strongly for students with higher reading fluency. Findings indicate that executive functions are implicated in reading fluency and that the contributions of executive functions and reading fluency to reading comprehension may be multiplicative rather than additive or compensatory.
RCM vs Oxacycloisomerization through Divergent Reactivity of Dienyl‐ or Ynenylcycloalkanols using Grubbs Catalyst: an Access to Carbobicycles and Fused Bicyclic Dihydrofurans
Authors: Taleb Assya , Lahrech Mokhtar , Hacini Salih , Thibonnet Jerome , Parrain Jean‐Luc
Published: November 2019

Starting from simple cyclic 1,3‐ketoesters, a three‐steps sequence including allylic or propargylic allylation, 1,2‐addition reaction of functional Grignard reagent and alkylidene ruthenium‐catalyzed cyclization yields to carbobicycles and/or bicyclic dihydrofurans depending on the nature of the insaturation (diene or enyne). If the classical ene‐ene ring closing metathesis is observed with dienyl substituents, similar enynes led to enyne ring closing metathesis or oxacycloisomerization products depending on the chain length. In the case of ene‐yne systems with appropriate longer carbon chains, under the same conditions, metathesis reations give access to bicyclic dihydrofurans through oxacycloisomerization, demonstrating that it is possible to orient the activity of the Grubbs reagent.
Computational Design and Electropolymerization of Molecularly Imprinted Poly(p‐Aminobenzoic‐Acid‐Co–Dapsone) Using Multivariate Optimization for Tetradifon Residue Analysis
Authors: Ganjeizadeh Rohani Fatemeh , Mohadesi Alireza , Ansari Mehdi
Published: November 2019

In this study, tetradifon as a non‐electroactive pesticide was measured by a new gold electrode modified with electropolymerized molecularly imprinted poly(para aminobenzoic acid‐co‐4,4‐diaminodiphenyl sulfone) (P‐pABA‐co‐DDS). The best available monomer was selected based on computational design and then the polymer was developed in optimized condition. Screening of various factors was performed by Plackett–Burman design (PBD) and central composite design (CCD) was utilized to select optimized condition. Under the optimized condition, calibration curve of tetradifon on MIP/gold electrode was constructed with a linear range of 0.05‐ 2.50 μM. The limit of detection (LOD) and limit of quantification (LOQ) was found to be 0.014 and 0.047 μM, respectively. The developed method showed good stability, repeatability, and reproducibility, sensitivity and selectivity for tetradifon. The developed method was applied to determine tetradifon in real water samples.
Adsorption of Lead and Arsenic Ions from Aqueous Solution by Activated Carbon Prepared from Tamarix Leaves
Authors: Koohzad Elnaz , Jafari Dariush , Esmaeili Hossein
Published: November 2019

Lead and arsenic are regarded as the significant heavy metal ions which have a great contribution in the pollution of industrial wastewaters. In this research, the adsorption of Pb (II) and As (III) ions from the aqueous solution was studied using activated carbon prepared from Tamarix leaves as a new adsorbent. The adsorbent was characterized by Brunauer, Emmett, and Teller (BET), X‐ray fluorescence spectrometer (XRF), scanning electron microscope (SEM), energy dispersive X‐ray and mapping (EDX/Map), X‐ray diffraction (XRD), and Raman techniques. Batch experiments were designed to investigate the significance of adsorption parameters including pH, adsorbent dosage, time, temperature, and initial concentration on Pb and As ions removal efficiencies. The experiments indicated that the highest adsorption efficiencies were 97.86% for lead and 96.18% for arsenic ions in pH values of 6 for Pb and 7 for As, adsorbent dosage of 3 g/L and initial concentration of 10 mg/L for both of them, and contact time of 60 min and 40 min for Pb and As ions, respectively. Additionally, the results of adsorption kinetics showed that the pseudo second‐order model was more effective for the description of adsorption mechanism of both metals compared to the pseudo first‐order model. The equilibrium behavior of arsenic and lead ions were described well by Langmuir and Freundlich models, respectively. In addition, thermodynamic studies showed that the current adsorption processes were exothermic and spontaneous. Based on the results, the prepared adsorbent can be considered as a good adsorbent for the removal of Pb and As ions from aqueous solutions.
A Facile Synthesis of Green‐Blue Carbon Dots from Artocarpus lakoocha Seeds and Their Application for the Detection of Iron (III) in Biological Fluids and Cellular Imaging
Authors: Yadav Pradeep Kumar , Singh Vikas Kumar , Kumar Chandan , Chandra Subhash , Jit Satyabrata , Singh Sushil Kumar , Talat Mahe , Hasan Syed Hadi
Published: November 2019

Herein, a facile, green and eco‐friendly approach has been applied for the synthesis of fluorescent green‐blue carbon dots (GB‐CDs) through the one‐pot hydrothermal treatment of Artocarpus lakoocha seeds for the first time and entirely characterized via a variety of instrumental techniques like fluorescent spectroscopy, Transmission Electron Microscopy (TEM), X‐Ray Photoelectron Spectra (XPS), X‐Ray diffraction (XRD) and Fourier Transform Infra‐red (FTIR) analysis. The as‐prepared GB‐CDs displayed high fluorescent quantum yield (QY) up to 38.5% and high photostability based on which GB‐CDs were successfully applied as a sensitive nanoprobe for the detection of Fe3+ ion. The sensing of Fe3+ shows a linear range from 2 to 6 μM and the limit of detection was found to be 0.62 μM. The sensing of Fe3+ was further investigated in the bona fide sample like river water and human blood serum. In addition, to explore the potential application, MTT assay was carried out on SH‐SY5Y neuroblastoma cells. The results showed negligible cytotoxicity as well as high cell viability, which revealed that GB‐CDs could be utilized as a fluorescent probe in living cells.
Preparation of ZIF‐8/natural Plant Fiber Composites via Biomimetic Mineralization for Highly Efficient Removal of Formaldehyde
Authors: Ren Lipei , Xiao Xingfang , Chen Yali , Yu Yan , Zhang Qian , Liu Ruina , Xu Weilin
Published: November 2019

Novel composites containing zeolitic imidazolate framework‐8 (ZIF‐8) nanocrystals and natural plant fibers (Juncus effusus (JE) fibers) are successfully synthesized. ZIF‐8 nanocrystals are coated onto hydrophilic JE fibers (H‐JE fibers) via biomimetic mineralization after only several seconds at room temperature (25 °C). The ZIF‐8/H‐JE fiber composite (stirring) and ZIF‐8‐BSA/H‐JE fiber composite (biomimetic mineralization) composite materials have excellent formaldehyde (HCHO) removal properties. ZIF‐8‐BSA/H‐JE fiber composites, in particular, are highly efficient HCHO adsorbents. Up to 99.79% HCHO removal at a high concentration (100 mg/m3) can be achieved within 90 min, and 100% removal can be achieved at a low concentration (10 mg/m3) within 17 min. This study provides an effective strategy for developing natural‐plant‐fiber‐based composite materials for environmental protection.
Recent Advances and Prospects of Organic Reactions “On Water”
Authors: Harry Nissy Ann , Radhika Sankaran , Neetha Mohan , Anilkumar Gopinathan
Published: November 2019

Organic reactions “On water” is a rapidly developing area over the past few years. Many important classes of reactions like cross‐coupling reactions, pericyclic reactions, C−H activations etc. were performed on water and have shown tremendous increase in the reaction rates due to the potential hydrogen bonding capacity of water. This review focuses on the recent trends and developments in the field of on water reactions applied to organic synthesis and covers literature from 2016–2019.
Ruthenium‐Catalyzed Hydrogenative Depolymerization of End‐of‐Life Poly(bisphenol A carbonate)
Authors: Alberti Christoph , Eckelt Sarah , Enthaler Stephan
Published: November 2019

The conversion of end‐of‐life products to useful chemicals (waste‐to‐chemicals) can afford a resource‐efficient economy. In this context, the depolymerization of end‐of‐life polymers to yield low molecular weight chemicals can be an interesting target. Based on that, the selective depolymerization of end‐of‐life poly(bisphenol A carbonate) via hydrogenation was studied. Applying hydrogen and a ruthenium(II) complex as catalyst (Milstein Catalyst) end‐of‐life poly(bisphenol A carbonate) was hydrogenated to bisphenol A and methanol. The bisphenol A can be reused for the production of fresh polycarbonates; therefore a recycling is possible. On the other hand methanol can be used as hydrogen carrier and can be subjected to the hydrogen economy.
Degradation Studies of Single Cell and Short Stack for High Temperature Proton Exchange Membrane Fuel Cells Based on PBI/H3PO4 Membrane
Authors: Sun Xuejing , Li Yinhua , Qi Fulai , Jing Fenning , Sun Hai , Sun Gongquan
Published: November 2019

Durability is a premise of extensive application for high‐temperature proton exchange membrane fuel cells (HT‐PEMFCs) based on H3PO4 doped polybenzimidazole membrane, but is far unsatisfactory. In this work, using our home‐made electrodes, a single cell with a start‐stop operation for 1900 h and a short stack with a continuous operation for 1344 h are separately conducted at 0.2 A cm−2 with hydrogen‐air feed. After 1900 h operation, an average degradation rate of 59.5 μV h−1 is obtained. Combined scanning electron microscope with energy dispersive spectrometer, transmission electron microscope, and electrochemical methods, the start‐stop operation cause more serious H3PO4 loss, cobalt element leaching, and platinum particles agglomeration, which produces a decreased ion conductivity and a big active polarization loss. In short stack test, we find electrode consistency is more important. An inferior cell enables a rapid failure due to almost complete acid loss in the membrane. The bigger polarization loss and more joule heat at the inferior electrode from a lower ionic and electrical conductivity further make acid loss aggravated, and it is a vicious circle. Despite a big gaps with life requirement, we believe our work will give a guidance for the design of high stable HT‐PEMFCs.
Singlet Oxygen Formation during the Oxygen Reduction Reaction in DMSO LiTFSI on Lithium Air Battery Carbon Electrodes
Authors: Córdoba Daniel , Rodríguez Hernán B. , Calvo Ernesto J.
Published: November 2019

Formation of singlet oxygen,1O2, during the O2 electroreduction reaction (ORR) on carbon electrode in Lithium bis‐(tri‐fluoromethylsulfonyl)imide (LiTFSI) dimethyl sulfoxide (DMSO) electrolyte has been detected “in‐operando” by fluorescence quenching of 9,10‐dimethylanthracene, DMA. Furthermore, the formation of 1O2 during ORR requires Li+ ions, while in the presence of the efficient physical 1O2 quencher, sodium azide, DMA fluorescence quenching is negligible. Addition of Li+ ions to superoxide solution in DMSO formed by ORR enhances DMA quenching, which is a proof that 1O2 results from superoxide bimolecular disproportionation.
Loss of Vimentin Enhances Cell Motility through Small Confining Spaces
Authors: Patteson Alison E. , Pogoda Katarzyna , Byfield Fitzroy J. , Mandal Kalpana , Ostrowska‐Podhorodecka Zofia , Charrier Elisabeth E. , Galie Peter A. , Deptuła Piotr , Bucki Robert , McCulloch Christopher A. , Janmey Paul A.
Published: November 2019

The migration of cells through constricting spaces or along fibrous tracks in tissues is important for many biological processes and depends on the mechanical properties of a cytoskeleton made up of three different filaments: F‐actin, microtubules, and intermediate filaments. The signaling pathways and cytoskeletal structures that control cell motility on 2D are often very different from those that control motility in 3D. Previous studies have shown that intermediate filaments can promote actin‐driven protrusions at the cell edge, but have little effect on overall motility of cells on flat surfaces. They are however important for cells to maintain resistance to repeated compressive stresses that are expected to occur in vivo. Using mouse embryonic fibroblasts derived from wild‐type and vimentin‐null mice, it is found that loss of vimentin increases motility in 3D microchannels even though on flat surfaces it has the opposite effect. Atomic force microscopy and traction force microscopy experiments reveal that vimentin enhances perinuclear cell stiffness while maintaining the same level of acto‐myosin contractility in cells. A minimal model in which a perinuclear vimentin cage constricts along with the nucleus during motility through confining spaces, providing mechanical resistance against large strains that could damage the structural integrity of cells, is proposed.
Poly(Sarcosine) Surface Modification Imparts Stealth‐Like Properties to Liposomes
Authors: Bleher Stefan , Buck Jonas , Muhl Christian , Sieber Sandro , Barnert Sabine , Witzigmann Dominik , Huwyler Jörg , Barz Matthias , Süss Regine
Published: November 2019

Circulation lifetime is a crucial parameter for a successful therapy with nanoparticles. Reduction and alteration of opsonization profiles by surface modification of nanoparticles is the main strategy to achieve this objective. In clinical settings, PEGylation is the most relevant strategy to enhance blood circulation, yet it has drawbacks, including hypersensitivity reactions in some patients treated with PEGylated nanoparticles, which fuel the search for alternative strategies. In this work, lipopolysarcosine derivatives (BA‐pSar, bisalkyl polysarcosine) with precise chain lengths and low polydispersity indices are synthesized, characterized, and incorporated into the bilayer of preformed liposomes via a post insertion technique. Successful incorporation of BA‐pSar can be realized in a clinically relevant liposomal formulation. Furthermore, BA‐pSar provides excellent surface charge shielding potential for charged liposomes and renders their surface neutral. Pharmacokinetic investigations in a zebrafish model show enhanced circulation properties and reduction in macrophage recognition, matching the behavior of PEGylated liposomes. Moreover, complement activation, which is a key factor in hypersensitivity reactions caused by PEGylated liposomes, can be reduced by modifying the surface of liposomes with an acetylated BA‐pSar derivative. Hence, this study presents an alternative surface modification strategy with similar benefits as the established PEGylation of nanoparticles, but with the potential of reducing its drawbacks.