bluuebunny/crossref_metadata_2025 huggingface dataset:
How thinking hurts: Rumination, worry, and avoidance processes in adjustment to bereavement
Authors: Eisma Maarten C. , de Lang Thomas A. , Boelen Paul A.
Published: February 2020

Repetitive negative thought plays an important role in the maintenance of mental health problems following bereavement. To date, bereavement researchers have primarily focused on rumination (i.e., repetitive thought about negative events and/or negative emotions), yet the interest in worry (i.e., repetitive thought about uncertain future events) is increasing. Both cognitive processes potentially lead to poorer adaptation to bereavement by contributing to loss‐related avoidance and behavioural avoidance of activities. The current study aims to establish the differential associations of rumination and worry with symptoms of depression and prolonged grief and clarify if avoidance processes mediate the associations of rumination and worry with symptom levels. Four hundred seventy‐four recently bereaved adults (82% female) filled out questionnaires assessing rumination, worry, loss‐related and behavioural avoidance, and depression and prolonged grief symptoms. Rumination and worry were both uniquely associated with depression and prolonged grief symptoms. Compared with worry, rumination related more strongly to prolonged grief symptoms, whereas correlations of both cognitive styles with depression symptoms did not differ. Loss‐related avoidance and behavioural avoidance partially mediated the associations of rumination and worry with prolonged grief symptoms. Behavioural avoidance partially mediated the associations of rumination and worry with depression symptoms. Findings suggest that exposure and behavioural activation may be effective interventions to reduce repetitive thinking and psychopathology after bereavement.
Pivotal cytokines and their transcription factors are the targets of guluronic acid (G2013) for inhibiting the immunopathogenesis process of multiple sclerosis
Authors: Hossein‐khannazer Nikoo , Shabani Samira , Farokhfar Mohadeseh , Azizi Gholamreza , Asarzadegan Farhad , Safarpour Lima Behnam , Mirshafeiey Abbas
Published: February 2020

The α‐L‐guluronic acid (G2013), is a novel immunosuppressive drug (PCT/EP2017/067920). One of the most popular ideas in designing drugs for multiple sclerosis (MS) is to restrict the main inflammation‐related lymphocytes and cytokines. The foremost problems with conventional drugs are their side effects and low efficacy. In order to rectify these problems, we examined the effect of two doses of G2013 on the gene expression of IFN‐γ, IL‐17, IL‐22, T‐bet, RORC, and AHR, in MS patients PBMCs. RNA was extracted from peripheral blood mononuclear cell (PBMC) of 12 relapsing–remitting MS patients and 12 healthy volunteers and the effect of two doses of G2013 on the gene expression of IFN‐γ, IL‐17, IL‐22, T‐bet, RORC, and AHR, were assessed by real‐time PCR. Overall, the results show that G2013 is able to significantly reduce the gene expression of IL‐22, AHR, RORC, and T‐bet. Collectively, G2013 might be considered and studied as a new drug of possible use to MS patients due to its immunosuppressive property on some of the main inflammatory cytokine and transcription factors.
Effects of seed morphology and elaiosome chemical composition on attractiveness of five Trillium species to seed‐dispersing ants
Authors: Miller Chelsea N. , Whitehead Susan R. , Kwit Charles
Published: February 2020

Morphological and chemical attributes of diaspores in myrmecochorous plants have been shown to affect seed dispersal by ants, but the relative importance of these attributes in determining seed attractiveness and dispersal success is poorly understood. We explored whether differences in diaspore morphology, elaiosome fatty acids, or elaiosome phytochemical profiles explain the differential attractiveness of five species in the genus Trillium to eastern North American forest ants. Species were ranked from least to most attractive based on empirically‐derived seed dispersal probabilities in our study system, and we compared diaspore traits to test our hypotheses that more attractive species will have larger diaspores, greater concentrations of elaiosome fatty acids, and distinct elaiosome phytochemistry compared to the less attractive species. Diaspore length, width, mass, and elaiosome length were significantly greater in the more attractive species. Using gas chromatography–mass spectrometry, we found significantly higher concentrations of oleic, linoleic, hexadecenoic, stearic, palmitoleic, and total fatty acids in elaiosomes of the more attractive species. Multivariate assessments revealed that elaiosome phytochemical profiles, identified through liquid chromatography–mass spectrometry, were more homogeneous for the more attractive species. Random forest classification models (RFCM) identified several elaiosome phytochemicals that differed significantly among species. Random forest regression models revealed that some of the compounds identified by RFCM, including methylhistidine (α‐amino acid) and d‐glucarate (carbohydrate), were positively related to seed dispersal probabilities, while others, including salicylate (salicylic acid) and citrulline (L‐α‐amino acid), were negatively related. These results supported our hypotheses that the more attractive species of Trillium—which are geographically widespread compared to their less attractive, endemic congeners—are characterized by larger diaspores, greater concentrations of fatty acids, and distinct elaiosome phytochemistry. Further advances in our understanding of seed dispersal effectiveness in myrmecochorous systems will benefit from a portrayal of dispersal unit chemical and physical traits, and their combined responses to selection pressures.
Performance assessment of a novel design concentrated photovoltaic system coupled with self‐cleaning and cooling processes
Authors: Acar Bahadır , Gürel Ali Etem , Ergün Alper , Ceylan İlhan , Ağbulut Ümit , Can Ali
Published: February 2020

The generation of electrical energy with photovoltaic modules is a highly useful and environmentally friendly method. For this reason, studies to increase the electrical energy production from photovoltaic (PV) modules have gained great importance. Concentrated PV systems constitute a significant part of these studies. The major problems with the concentrated PV systems are the risks of lowering the efficiency of the cells (i.e., concentration process increases PV cell temperature) and the thermal damage that can occur with sudden temperature increases. In order to avoid these risks, various applications are used to cool concentrated PV modules. In this study, an active system, which was developed for cleaning and cooling PV modules, was tested. The aim of the present study was to ensure that the surfaces were clean and free of external, contaminating factors such as dust and dirt, and that the PV cells were cooled. During the experiments, two different systems were compared: the system with the cleaning‐cooling processes and the one without these processes. Prior to starting experiments, a hydrophobic liquid onto the surfaces of the PV modules was applied to facilitate the cleaning process. The results of the experiments revealed that the temperature of the PV module was 50°C in the cleaning‐cooling process and 67°C in the system without the cleaning‐cooling process. On the other hand, it was observed that the proposed design increased the power output of PV module up to 40%.
Numerical homogenization‐based seismic assessment of an English‐bond masonry prototype: Structural level application
Authors: Silva Luís C. , Lourenço Paulo B. , Milani Gabriele
Published: February 2020

A multiscale strategy is evaluated at a structural level for the analysis of unreinforced masonry structures. The mechanical characterization of the masonry is deduced from homogenization‐based micro‐scale finite element (FE) models. The derived data are here employed at a structural level via a discrete FE model. The discrete FE model is composed of quadrilateral rigid plates interconnected through vertical and horizontal interfaces. On the interfaces, between adjoining discrete elements, a model that accounts for the in‐ and out‐of‐plane behavior of masonry, with damage and plasticity, is adopted. Such interfaces represent the material pre‐ and post‐peak regimes, its orthotropy, and, depending on the micro‐model assumed, account by three‐dimensional shear effects that are especially important for multi‐leaf walls and complex regular textures. The discrete model has been implemented in an advanced structural analysis software where powerful built‐in features as the arc‐length method, line‐search algorithm, and implicit or explicit solver schemes are available.

The multi‐scale model is applied for the dynamic study of a small English‐bond masonry house prototype subjected to a series of consecutive earthquake records. Detailed comparisons between the experimental and numerical data are presented, including the results obtained through a continuous total strain rotating crack model. Quasi‐static and dynamic analyses are conducted. Results demonstrate that when enough experimental information is available on the masonry components under tension, shear, and compression regimes, the approach predicts well the seismic structural response in terms of time‐history displacements, seismic capacity, and damage patterns. The required computational cost (CPU time) is very attractive.
Water Quality Impairments Due to Aquatic Life Pesticide Toxicity: Prevention and Mitigation in California, USA
Authors: Moran Kelly , Anderson Brian , Phillips Bryn , Luo Yuzhou , Singhasemanon Nan , Breuer Richard , Tadesse Dawit
Published: February 2020

The management of pesticides to protect water quality remains a significant global challenge. Historically, despite regulatory frameworks intended to prevent, minimize, and manage off-site movement of pesticides, multiple generations of pesticide active ingredients have created a seemingly unending cycle of pesticide water pollution in both agricultural and urban watersheds. In California, the most populous and most agricultural US state, pesticide and water quality regulators realized in the 1990s that working independently of each other was not an effective approach to address pesticide water pollution. Over the years, these California agencies have developed a joint vision and have continued to develop a unified approach that has the potential to minimize pesticide risks to aquatic life through a combination of prevention, monitoring, and management actions, while maintaining pesticide availability for effective pest control. Key elements of the current California pesticide/water quality effort include: 1) pesticide and toxicity monitoring, coupled with watershed modeling, to maximize information obtained from monitoring; 2) predictive fate and exposure modeling to identify potential risks to aquatic life for new pesticide products when used as allowed by the label or to identify effective mitigation measures; and 3) management approaches tailored to the different pesticide uses, discharge sources, physical environments, and regulatory environments that exist for agricultural runoff, urban runoff, and municipal wastewater. Lessons from this effort may inform pesticide management elsewhere in the world as well as other chemical regulatory programs, such as the recently reformed US Toxic Substances Control Act and California's Safer Consumer Products regulatory program. Environ Toxicol Chem 2020;39:953–966. © 2020 SETAC
Performance comparison of programming languages for Internet of Things middleware
Authors: Abbade Lucas R. , da Cruz Mauro A. A. , Rodrigues Joel J. P. C. , Lorenz Pascal , Rabelo Ricardo A. L. , Al‐Muhtadi Jalal
Published: February 2020

The rapid spread of Internet of Things (IoT) devices in recent years has driven the creation of a number of IoT middleware for enabling communication between devices using different standards and technologies. Such middleware facilitates the development of IoT solutions, allowing the developer to handle data and devices through middleware without the need to understand and communicate with each device individually. Although some studies present the performance of middleware solutions, they do not consider the effect of the underlying programming language in the overall performance of the solution. This paper replicates a common middleware use case in three different programming languages, evaluates their comparative performance, and discusses the results found. In the studied use case, Javascript presents better performance for small to medium applications, while, globally, Java demonstrates to be the most robust choice for IoT middleware.
Vitamin A prevents lipopolysaccharide‐induced injury on tight junctions in mice
Authors: He Caimei , Hu Xin , Xiao Di , Wu Jingtao , Zhou Sichun , Deng Jun , Xu Simeng , Huang Yanjun , Peng Mei , Yang Xiaoping
Published: February 2020

Vitamin A (VA) is one of the most widely used food supplements, but its molecular mechanisms largely remain elusive. Previously, we have demonstrated that VA inhibits the action of lipopolysaccharide (LPS) on intestinal epithelial barrier function and tight junction proteins using IPEC‐J2 cells, one of representative intestinal cell lines as a cellular model. These exciting findings stimulated us continue to determine the effects of VA on LPS‐induced damage of intestinal integrity in mice. Our results demonstrated that LPS treatment caused reductions of the mRNA levels of tight junction proteins including Zo‐1, Occludin, and Claudin‐1, well‐known biomarkers of intestinal integrity, and these reductions were reversed by VA pretreatment. Intestinal immunofluorescent results of Claudin‐1 revealed that LPS disrupted the structure of tight junction and reduced the expression of Claudin‐1 at protein level, which was reversed by VA pretreatment. These results suggest that VA may exert a profound role on preventing intestinal inflammation in vivo.
Effects of galvanic vestibular stimulation on resting state brain activity in patients with bilateral vestibulopathy
Authors: Helmchen Christoph , Machner Björn , Rother Matthias , Spliethoff Peer , Göttlich Martin , Sprenger Andreas
Published: February 2020

We examined the effect of galvanic vestibular stimulation (GVS) on resting state brain activity using fMRI (rs‐fMRI) in patients with bilateral vestibulopathy. Based on our previous findings, we hypothesized that GVS, which excites the vestibular nerve fibers, (a) increases functional connectivity in temporoparietal regions processing vestibular signals, and (b) alleviates abnormal visual–vestibular interaction. Rs‐fMRI of 26 patients and 26 age‐matched healthy control subjects was compared before and after GVS. The stimulation elicited a motion percept in all participants. Using different analyses (degree centrality, DC; fractional amplitude of low frequency fluctuations [fALFF] and seed‐based functional connectivity, FC), group comparisons revealed smaller rs‐fMRI in the right Rolandic operculum of patients. After GVS, rs‐fMRI increased in the right Rolandic operculum in both groups and in the patients' cerebellar Crus 1 which was related to vestibular hypofunction. GVS elicited a fALFF increase in the visual cortex of patients that was inversely correlated with the patients' rating of perceived dizziness. After GVS, FC between parietoinsular cortex and higher visual areas increased in healthy controls but not in patients. In conclusion, short‐term GVS is able to modulate rs‐fMRI in healthy controls and BV patients. GVS elicits an increase of the reduced rs‐fMRI in the patients' right Rolandic operculum, which may be an important contribution to restore the disturbed visual–vestibular interaction. The GVS‐induced changes in the cerebellum and the visual cortex were associated with lower dizziness‐related handicaps in patients, possibly reflecting beneficial neural plasticity that might subserve visual–vestibular compensation of deficient self‐motion perception.
ASSESSMENT OF SOCIO‐ECONOMIC FACTORS IMPACTING ON THE CROPPING INTENSITY OF AN IRRIGATION SCHEME IN DEVELOPING COUNTRIES
Authors: Kaini Santosh , Gardner Ted , Sharma Ashok K.
Published: February 2020

An increase of cropping intensity of irrigation schemes is required to address the challenge of global food security. Socio‐economic factors also have a significant impact on the cropping intensity within an irrigated area. This research is focused on understanding the impact of socio‐economic factors on cropping intensity in an irrigation scheme. To assess the socio‐economic factors and cropping intensity, a framework was developed, which we believe can be adopted in other irrigation schemes in developing countries. The framework was applied to an irrigation area in Nepal. An interview checklist and observation techniques were used as the primary data‐gathering method, which followed the concepts articulated in the developed framework. A census survey was also conducted in 72 farmer households. The results showed that farmers' socio‐economic status and their socio‐cultural practices affected cropping intensity. The research also highlighted that mechanization in agricultural practices, coordination between irrigation and agricultural district offices with farmers, market facilities for agricultural inputs and agricultural products, and land tenancy agreements all significantly influenced agricultural intensification. Based on the findings of this research, an approach to intensify cropping intensity by farm owners and farming tenants has been developed, which can be applied in irrigated areas in the developing world. © 2020 John Wiley & Sons, Ltd.
Omega‐3 PUFA and aspirin as adjuncts to periodontal debridement in patients with periodontitis and type 2 diabetes mellitus: Randomized clinical trial
Authors: Castro dos Santos Nidia C. , Andere Naira M. R. B. , Araujo Cássia F. , de Marco Andrea C. , Kantarci Alpdogan , Van Dyke Thomas E. , Santamaria Mauro P.
Published: February 2020

Background

Supplementation with omega‐3 polyunsaturated fatty acids (ω‐3 PUFA) and low‐dose aspirin (ASA) have been proposed as a host modulation regimen to control chronic inflammatory diseases. The aim of this study was to investigate the clinical and immunological impact of orally administered ω‐3 PUFA and ASA as adjuncts to periodontal debridement for the treatment of periodontitis in patients type 2 diabetes.

Methods

Seventy‐five patients (n = 25/group) were randomly assigned to receive placebo and periodontal debridement (CG), ω‐3 PUFA + ASA (3 g of fish oil/d + 100 mg ASA/d for 2 months) after periodontal debridement (test group [TG]1), or ω‐3 PUFA + ASA (3 g of fish oil/d + 100 mg ASA/d for 2 months) before periodontal debridement (TG2). Periodontal parameters and GCF were collected at baseline (t0), 3 months after periodontal debridement and ω‐3 PUFA + ASA or placebo for TG1 and CG (t1), after ω‐3 PUFA + ASA (before periodontal debridement) for TG2 (t1), and 6 months after periodontal debridement (all groups) (t2). GCF was analyzed for cytokine levels by multiplex ELISA.

Results

Ten patients (40%) in TG1 and nine patients (36%) in TG2 achieved the clinical endpoint for treatment (less than or equal to four sites with probing depth ≥ 5 mm), as opposed to four (16%) in CG. There was clinical attachment gain in moderate and deep pockets for TG1. IFN‐γ and interleukin (IL)‐8 levels decreased over time for both test groups. IL‐6 levels were lower for TG1. HbA1c levels reduced for TG1.

Conclusion

Adjunctive ω‐3 and ASA after periodontal debridement provides clinical and immunological benefits to the treatment of periodontitis in patients with type 2 diabetes.
An Examination of Idiographic Networks of Posttraumatic Stress Disorder Symptoms
Authors: Reeves Jonathan W. , Fisher Aaron J.
Published: February 2020

Although the application of network theory to posttraumatic stress disorder (PTSD) has yielded promising insights, the lack of equivalence between inter‐ and intraindividual variation limits the generalizability of these findings to any one individual with PTSD. Instead, a better understanding of how PTSD symptoms occur and vary over time within an individual requires exploring the idiographic network structure of PTSD. To do so, the present study used an intensive repeated‐measures design to estimate intraindividual networks of PTSD symptoms on a person‐by‐person basis. Participants were 20 individuals who met criteria for PTSD and completed daily surveys assessing PTSD symptoms; surveys were completed four times per day for approximately 30 days. Employing a recently validated method provided by Fisher, Reeves, Lawyer, Medaglia, and Rubel (2017), we used these data to estimate a contemporaneous and temporal network of PTSD symptoms for individuals on a person‐by‐person basis. We then calculated centrality metrics to determine the relative importance of each symptom in each idiographic network. Across all contemporaneous networks, negative trauma‐related cognitions and emotions were most commonly the most central symptoms. Further, across all temporal networks, (a) negative trauma‐related emotions were the most common driver of variation in other symptoms over time and (b) distressing trauma‐related dreams and sleep disturbance were the most common downstream consequences of variation in other PTSD symptoms over time. We also reviewed data from two randomly selected participants to illustrate how this approach could be used to identify maintenance factors of PTSD for each individual and guide individual treatment planning.
Proteomic analysis of Aspergillus niger 3.316 under heat stress
Authors: Deng Xiangyu , Du Bin , Zhu Fengmei , Gao Yanan , Li Jun
Published: February 2020

β‐Glucosidase production by Aspergillus niger is accompanied by an inevitable temperature increase in the industrial fermentation environment. Hence, the synthetic process of β‐glucosidase is negatively affected. However, our understanding of the heat stress response (HSR) mechanism in A. niger is still incomplete. The current study explored the intracellular proteome profile of A. niger 3.316 in group T (50°C stress) and group C (30°C control) using two proteomic approaches (isobaric tags for relative and absolute quantitation [iTRAQ] and label‐free) and examined the expression of four proteins using a parallel reaction monitoring (PRM) approach. Based on the result of the iTRAQ proteomic analysis, 1,025 proteins were differentially expressed in group T compared to group C. Using the label‐free approach, we only focused on 77 proteins with significant changes in their protein expression levels. In addition, we performed bioinformatics analysis on all these proteins and obtained detailed gene ontology (GO) enrichment and Kyoto encyclopedia of genes and genomes (KEGG) pathway results. Under heat stress conditions, the relative expression levels of proteins with protection and repair functions were upregulated in A. niger 3.316. These proteins were involved in metabolic pathways, oxidative phosphorylation, porphyrin and chlorophyll metabolism, pyruvate metabolism, and the citrate cycle (TCA cycle). The insights obtained from the presented proteomics and bioinformatics analyses can be used to further explore the HSR mechanism of A. niger.
Procyanidin C1 Inhibits Melanoma Cell Growth by Activating 67‐kDa Laminin Receptor Signaling
Authors: Bae Jaehoon , Kumazoe Motofumi , Murata Kyosuke , Fujimura Yoshinori , Tachibana Hirofumi
Published: February 2020

Scope

Procyanidin C1 (PC1) is an epicatechin trimer found mainly in grapes that is reported to provide several health benefits. However, little is known about the molecular mechanisms underlying these benefits. The aim of this study is to demonstrate the molecular mechanisms by which PC1 operates.

Methods and results

A 67‐kDa laminin receptor (67LR) is identified as a cell surface receptor of PC1, with a Kd value of 2.8 µm. PC1 induces an inhibitory effect on growth, accompanied by dephosphorylation of the C‐kinase potentiated protein phosphatase‐1 inhibitor protein of 17 kDa (CPI17) and myosin regulatory light chain (MRLC) proteins, followed by actin cytoskeleton remodeling in melanoma cells. These actions are mediated by protein kinase A (PKA) and protein phosphatase 2A (PP2A) activation once PC1 is bound to 67LR.

Conclusion

It is demonstrated that PC1 elicits melanoma cell growth inhibition by activating the 67LR/PKA/PP2A/CPI17/MRLC pathway.
Monitoring the Salt Stability of Layer‐by‐Layer Self‐Assembled Films From Polyelectrolyte Blends by Quartz Crystal Microbalance‐Dissipation and Their Ion Separation Performances
Authors: Ergün Ayça , Tümer Eda Hazal , Cengiz Hacer Yeşim , Deligöz Hüseyin
Published: February 2020

Our study is concerned with the development of a novel type of layer‐by‐layer (LbL) self‐assembled membrane from a single cationic polyelectrolyte (PE) and blended anionic PEs. Their synthetic seawater stability is investigated as a function of PE type and blend ratios using quartz crystal microbalance‐dissipation (QCM‐D). These materials adsorbed into multilayers with significant viscoelasticity. Poly(allylamine hydrochloride) (PAH) and poly(vinylamine hydrochloride) (PVA) based LbL blend films did not show any multilayer decomposition with the addition of synthetic seawater regardless of blend ratio while chitosan based multilayers disintegrated. The flux of PVA based blend membrane to water with 1,000 ppm NaCl was found to be 6.7 L/m2.h at 40 bar and the flux properties of the membranes were highly dependent on both the thickness and hydrophilicity of multilayers. Ion rejection can be controlled with the charge of the top layer consistent with a Donnan exclusion approach. Sodium ion rejection of 60.5 layered LbL blend membrane was 98.4% at 40 bar and it was determined that sodium ion rejection improved 110.7% compared to a commercial nanofiltration membrane. POLYM. ENG. SCI., 60:1006–1018, 2020. © 2020 Society of Plastics Engineers
Advanced Cell Mapping Visualizations for Single Cell Functional Proteomics Enabling Patient Stratification
Authors: Bowman Nick , Liu Dong , Paczkowski Patrick , Chen Jon , Rossi John , Mackay Sean , Bot Adrian , Zhou Jing
Published: February 2020

Highly multiplexed single‐cell functional proteomics has emerged as one of the next‐generation toolkits for a deeper understanding of functional heterogeneity in cell. Different from the conventional population‐based bulk and single‐cell RNA‐Seq assays, the microchip‐based proteomics at the single‐cell resolution enables a unique identification of highly polyfunctional cell subsets that co‐secrete many proteins from live single cells and most importantly correlate with patient response to a therapy. The 32‐plex IsoCode chip technology has defined a polyfunctional strength index (PSI) of pre‐infusion anti‐CD19 chimeric antigen receptor (CAR)‐T products, that is significantly associated with patient response to the CAR‐T cell therapy. To complement the clinical relevance of the PSI, a comprehensive visualization toolkit of 3D uniform manifold approximation and projection (UMAP) and t‐distributed stochastic neighbor embedding (t‐SNE) in a proteomic analysis pipeline is developed, providing more advanced analytical algorithms for more intuitive data visualizations. The UMAP and t‐SNE of anti‐CD19 CAR‐T products reveal distinct cytokine profiles between nonresponders and responders and demonstrate a marked upregulation of antitumor‐associated cytokine signatures in CAR‐T cells from responding patients. Using this powerful while user‐friendly analytical tool, the multi‐dimensional single‐cell data can be dissected from complex immune responses and uncover underlying mechanisms, which can promote correlative biomarker discovery, improved bioprocessing, and personalized treatment development.
The Effects of Aniline Stabilizers on Nitrocellulose Based on Isothermal Thermal Decomposition
Authors: Luo Liqiong , Jin Bo , Chai Zuohu , Huang Qiong , Chu Shijin , Peng Rufang
Published: February 2020

The effects of various aniline stabilizers on the thermal stability of nitrocellulose (NC) were investigated via isothermal thermal decomposition dynamics. The pressure‐time curves of NC/stabilizer composites were found to have a distinct inflection point, which was not observed on the pressure‐time curves of NC. The effects of stabilizers on the isothermal thermal decomposition kinetics of NC were evaluated using Arrhenius equation and model‐fitting method, and the effect of stabilizers on the storage time of NC was estimated using Berthelot equation. Results showed that the activation energy of NC/MNA, NC/ENA, NC/i‐PNA, and NC/n‐BNA before the inflection point were 162.9, 153.3, 147.4, and 150.6 kJ mol−1, respectively, which were significantly increased compared with that of pure NC (144.7 kJ mol−1). Furthermore, the time required for the decomposition extent of NC/MNA, NC/ENA, NC/i‐PNA, and NC/n‐BNA to reach 0.1 % were 24.9, 11.2, 16.7, and 11.2 years, respectively, at 298.15 K, which was longer than that required of NC (10.6 years). UV‐vis revealed that the stabilizers were almost consumed when the NC/stabilizer thermal decomposition pressure‐time curve reached the inflection point. Based on the above results, the stability order was MNA>i‐PNA>ENA>n‐BNA as the criterion for time of the inflection point.
Analyses of protein cores reveal fundamental differences between solution and crystal structures
Authors: Mei Zhe , Treado John D. , Grigas Alex T. , Levine Zachary A. , Regan Lynne , O'Hern Corey S.
Published: February 2020

There have been several studies suggesting that protein structures solved by NMR spectroscopy and X‐ray crystallography show significant differences. To understand the origin of these differences, we assembled a database of high‐quality protein structures solved by both methods. We also find significant differences between NMR and crystal structures—in the root‐mean‐square deviations of the C
α atomic positions, identities of core amino acids, backbone, and side‐chain dihedral angles, and packing fraction of core residues. In contrast to prior studies, we identify the physical basis for these differences by modeling protein cores as jammed packings of amino acid‐shaped particles. We find that we can tune the jammed packing fraction by varying the degree of thermalization used to generate the packings. For an athermal protocol, we find that the average jammed packing fraction is identical to that observed in the cores of protein structures solved by X‐ray crystallography. In contrast, highly thermalized packing‐generation protocols yield jammed packing fractions that are even higher than those observed in NMR structures. These results indicate that thermalized systems can pack more densely than athermal systems, which suggests a physical basis for the structural differences between protein structures solved by NMR and X‐ray crystallography.
Multi‐targets localization and elliptical circumnavigation by multi‐agents using bearing‐only measurements in two‐dimensional space
Authors: Chun Shaoheng , Tian Yu‐Ping
Published: February 2020

In order to enable the multi‐agents to elliptically circumnavigate the multi‐targets in more complex environment, we propose a geometric center estimator and an elliptical circumnavigation controller in two‐dimensional space by only employing bearing measurements without knowing the target's position and velocity. The stability of the algorithm is proved for both stationary targets and dynamic targets. Finally, a series of numerical simulations is presented to verify the correctness of the algorithm both in ideal networks and in networks with communication delays.
A primer on strong vs weak control of familywise error rate
Authors: Proschan Michael A. , Brittain Erica H.
Published: February 2020

Multiple comparison adjustments have a long history, yet confusion remains about which procedures control type 1 error rate in a strong sense and how to show this. Part of the confusion stems from a powerful technique called the closed testing principle, whose statement is deceptively simple, but is sometimes misinterpreted. This primer presents a straightforward way to think about multiplicity adjustment.
Carbon Quantum Dot Incorporated Nickel Pyrophosphate as Alternate Cathode for Supercapacitors
Authors: Priyadharshini Matheswaran , Pazhanivel Thangavelu , Bharathi Ganapathi
Published: February 2020

In spite of its large theoretical capacitance, the crystal structure of transition metal pyrophosphates frequently endures sluggish charge transfer and volume expansion leading to severe structural instability which may be ascribed to low power density and constant intercalation and deintercalation of ions in the matrix. Due to the stated facts, it resulted in quick capacity degradation and limited the overall performance of the energy device. To overcome the stated facts, we report the electrochemical charge storage performances of Nickel pyrophosphate/Carbon quantum dot (Ni2P2O7/CQD) nanocomposites. Here, we adopted a facile technique to prepare biowaste derived CQD and composited it with transition metal (Nickel) pyrophosphate. Incorporation of carbon quantum dots not only increased the specific capacitance than bare, besides, it also provides a long‐run cyclability. The addition of CQDs to the matrix favors rapid charge transfer and buffered the mechanical stress of nanocomposite. Using power law, the capacitance contribution from diffusion‐controlled and capacitive type mechanisms to the total specific capacitance was also elucidated. Hence the cost‐effective, facile synthesis method and favorable redox reaction empowered with voltage would have a potential application in high energy devices.
Preparation of rod‐like MgO by simple precipitation method for CO2 capture at ambient temperature
Authors: Tuan Vu Anh , Lee Chang Ha
Published: February 2020

Rod‐like MgO was prepared by the simple precipitation method and subsequently evaluated for CO2 capture efficiency under ambient‐temperature adsorption and intermediate‐temperature regeneration. The MgO precursor was analyzed by thermogravimetric analysis (TGA) and X‐ray power diffraction (XRD), it was decomposed completely at 500°C to form MgO. The as‐synthesized MgO samples were characterized by XRD, BET and FE‐SEM. The MgO samples were comprised of grains with an approximate length of 4‐6 μm and diameter of 0.5 μm. The BET surface area of MgO was 330.5 m2/g, which was much higher than that of commercial MgO (CM‐MgO, 103.2 m2/g). The CO2 uptake on MgO samples were evaluated by TGA. As‐synthesized MgO had the high CO2 sorption capacity compared to CM‐MgO. The effect of temperature on CO2 sorption capacity was also investigated. In addition, the stability of sample was evaluated by cyclic experiment.
Flavonoids from the leaves of Aralia dasyphylla Miq. (Araliaceae)
Authors: Thu Hien Nguyen Thi , Dieu Thuan Nguyen Thi , Van Huyen Pham , Anh Hong Truong Thi , Toan Phan Nguyen Huu
Published: February 2020

From the methanol extract of leaves of Aralia dasyphylla Miq. collected in Da Lat, Lam Dong province, seven known compounds including kaempferol (1), quercetin (2), hispidulin (3), eupafolin (4), kaempferol‐7‐O‐α‐L‐rhamnoside (5), kaempferol 3,7‐O‐α‐L‐dirhamnopyranoside (6), kaempferol3‐O‐β‐D‐glucopyranoside‐7‐O‐α‐L‐rhamnoside (7) have been isolated for the first time from this plant by various chromatographic techniques. Structural elucidation of the metabolites was carried out by analysis of their spectroscopic data and comparison with those reported in the literature.
High‐purity amorphous silica from rice husk: Preparation and characterization
Authors: Ngoc Nguyen Nguyen , Thanh Le Xuan , Vinh La The , Van Anh Bui Thi
Published: February 2020

Amorphous silica has a wide range of applications in chemical, biological and environmental sectors. In this work, we studied the preparation of amorphous silica from rice husk, an abundant silica‐rich agricultural waste in Vietnam. We investigated and compared two methods of preparation: (1) via selective removal of alkaline and alkaline‐earth oxides from rice husk ash to yield amorphous silica; and (2) via selective precipitation of silica from aqueous solutions which had been prepared by dissolving rice husk ask in NaOH solutions. The obtained silica was characterized by using XRD, EDX, SEM and BET techniques. The results show that the best obtained silica is a white amorphous and porous powder with high purity of SiO2, in the form of aggregates of 50 nm‐sized primary particles, and a specific surface area of 186 m2/g. The SiO2 recovery is around 8.3 (g) per 100 (g) rice husk. Moreover, in the context of the present work, method (1) can be a more straightforward route for the preparation of amorphous silica in terms of silica's purity, porousity and amorphousness. In contrast, method (2) is shown for a lower grade of silica purity which could be due to strong adsorption of ions from the solution onto the amorphous SiO2 precipitate during precipitation process. The obtained silica has promising applications as adsorbents, fillers and fertilizers.
Synthesis of reduced graphene oxide for high‐performance supercapacitor
Authors: Nam Pham Thi , Van Khanh Nguyen , Thom Nguyen Thi , Phuong Nguyen Thu , Van Trang Nguyen , Xuyen Nguyen Thi , Thai Vu Quoc , Tuan Vu Anh , Mai Thanh Dinh Thi
Published: February 2020

Reduced graphene oxide (rGO) were prepared by thermal reduction technique from graphene oxide (GO) in N2 gas atmosphere at 600°C for 1 h. The results shown that rGO possessed a multiple layer structure and a specific surface area BET of 389.9 m2/g. The electrochemical properties of the rGO materials have been investigated for supercapacitors. Electrochemical measurements show that rGO exhibit a specific capacitance of 85.3 F/g at 1 A/g, and still kept 85 % capacitance after 1000 cycles at 1 A/g, indicating rGO could be a promising candidate for high‐performance supercapacitor applications.
Theoretical investigation of the mechanism of indirect decomposition of nitrous oxide (N2O) by hydrogen (H2) on Cu7 cluster
Authors: Thuy Phan Thi , Thao Linh Dao Thi , Giang Vu Thi Huong , Cuong Ngo Tuan , Minh Hue Nguyen Thi
Published: February 2020

Mechanism of the decomposition reaction between N2O and H2 molecules on the Cu7 cluster was studied using density functional theory (DFT) with the BP86 functional in combination with the Aug‐cc‐pVDZ basis sets for N, O and H atoms, and the cc‐pVDZ‐PP basis set for Cu atom. The results show that the reaction undergoes via two successive steps. The first step involves adsorption of N2O on the Cu7 surface, followed by the decomposition of N2O with an energy barrier of barely ~3 kcal/mol, producing an O atom, which subsequently binds to the cluster and a N2 molecule. In the second step, the adsorped O atom couples with the H2 molecule bound to a different Cu atom of the cluster leading to a release of H2O molecule via two different pathways. The pathway corresponding to an adsorption of a N2O molecule onto the most positively charged site of Cu7 as turns out that the most energetically favorable with an energy barrier of ~22 kcal/mol, which is much lower than the barrier of 42 kcal/mol for the reaction without a catalyst.
Effect of calcination temperature on phase evolution and photoluminescent properties of GdPO4:Eu3+ nanoparticle phosphors synthesized by combustion method
Authors: Dieu Hien Thai Thi , Roan Pham Duc , Thanh Nguyen Trong , Tien Dinh Manh , Vu Nguyen
Published: February 2020

Eu3+ ‐doped GdPO4 nanoparticles were synthesized by a straightforward combustion method using urea as fuel and metal nitrates as precursors. Structures, morphologies and photoluminescent properties of the synthesized samples were studied by X‐ray diffraction, scanning electron microscopy and photoluminescent spectroscopy. There are two types of crystal structures formed during the annealing process: hexagonal GdPO4.H2O and monoclinic GdPO4. The former can be found at low annealing temperatures (300‐500°C) while the latter can be obtained at higher annealing temperatures (700‐900°C). The average diameters for nanoparticles are 20‐30 nm. Under the excitation at 273 nm, both GdPO4.H2O:Eu3+ and GdPO4:Eu3+ powders showed red emission bands originating from the 5D0 ‐ 7FJ (J = 1, 2, 3 and 4) transitions of Eu3+. Their PL intensity and crystal structures exhibit a similar behavior as a function of the annealing temperature.
Influence of ammonia on properties of TiO2‐MgFe2O4 as high visible‐light active photocatalysts for the degradation of Rhodamine B
Authors: Nha Khanh Dang Nguyen , Lin Hoang Ngoc , Mai Tho Nguyen Thi , Nhat Ha Ho Nguyen , Huy Vu Quang , Phuong Dieu Nguyen Thi , Huy Do Manh , Dat Duong Phuoc , Kim Phuong Nguyen Thi
Published: February 2020

The influence of ammonia on TiO2‐MgFe2O4 catalysts synthesized via a hydrolysis and co‐precipitation, followed by calcination at 500°C, was studied. Two different catalysts, TiO2‐MgFe2O4 (Am) and TiO2‐MgFe2O4 (W), were prepared using Ti‐precursors, which were synthesized by the hydrolysis of Ti‐butoxide with and without ammonia. The resulting TiO2‐MgFe2O4 catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), specific surface area measurements, X‐ray diffraction, and UV‐vis diffuse reflectance techniques. It was revealed that strong electronic coupling exists between the TiO2 and MgFe2O4 components within the TiO2‐MgFe2O4 catalysts. Photocatalytic activity toward Rhodamine B (RhB) was investigated in aqueous solution under visible light irradiation. TiO2‐MgFe2O4 (W) was found to be an effective catalyst and had several advantages over TiO2‐MgFe2O4 (Am). These results clearly highlight that ammonia had a significant influence on the photocatalytic activity of the TiO2‐MgFe2O4 catalysts. Therefore, the results reported herein indicate that TiO2‐MgFe2O4 is a green, low‐cost, and highly efficient photocatalyst for environmental remediation.
Study on water soluble constituentsfrom Gomphrena celoisiodes
Authors: Trang Do Thi , Tai Bui Huu , Yen Pham Hai , Yen Duong Thi Hai , Nhiem Nguyen Xuan , Kiem Phan Van
Published: February 2020

Using combined chromatographic methods, eight glycoside compounds including two flavones: isorhamnetin 3‐O‐α‐L‐rhamnopyranosyl‐(1→6)‐β‐D‐glucopyranoside (1), kaempferol 3‐O‐β‐D‐glucopyranoside (2), three phenyls: 2‐phenylethyl β‐rutinoside (3), 2‐phenylethyl β‐primeveroside (4), hydrangeifolin I (5); two lignans: tortoside A (6), pinoresinol‐4′′‐O‐β‐D‐glucopyranoside (7), and a megastigmaneicariside B2 (8) were isolated from the methanol extract of the aerial part of Gomphrena celoisiodes. Their structures were identified on the basis of spectroscopic evidence and in comparison with those reported in the literature. All these compounds were isolated from G. celoisiodes for the first time.
Synthesis of mesoporous SiO2 from rice husk for removal of organic dyes in aqueous solution
Authors: Thu Hoang Thi , Dat Le Tien , Tuan Vu Anh
Published: February 2020

Mesoporous SiO2 was prepared from rice husk for removal of methylene blue (MB) from aqueous solution. As‐prepared SiO2 was characterized by FE‐SEM, TEM, XRD, FT‐IR and N2 adsorption/desorption isotherm. The effects of SiO2 dosage and contact time on adsorption of dye were investigated. The optimal dosage of SiO2 for removing methylene blue was 0.05 g and the removal efficiency of methylene blue reached to 91.9 % after 50 min of adsorption. The adsorption kinetic of methylene blue was studied to understand the mechanism of adsorption process. The kinetic data was analyzed by pseudo‐first‐order, pseudo‐second‐order, and intra‐particle diffusion models. The results showed that rate of adsorption dye followed pseudo‐second‐model with a good regression correlation (R2 = 0.999), the value of rate constant for adsorption process was calculated as 0.017 (g.mg‐1.min‐1) and film diffusion was the rate limiting step. In addition, the cyclic test for as‐prepared SiO2 was investigated and the removal efficiency was remained at 80.2% at 3rd cyclic experiment.
The chemical constituents and biological activity of some sponges in Northern Vietnam: A review
Authors: Van Kiem Phan , Van Minh Chau , Nhiem Nguyen Xuan , Tai Bui Huu , Yen Pham Hai , Hang Dan Thi Thuy , Dung Duong Thi , Cuc Nguyen Thi , Trang Do Thi , Yen Duong Thi Hai , Van Doan Vu , Hoang Nguyen Huy , Huong Phan Thi Thanh , Nam Nguyen Hoai , Cuong Nguyen Xuan
Published: February 2020

Chemical composition and biological activity of sponges have been studied by the authors since 2006. So far, the authors have studied about 30 species of sponges, mainly collected cross in the sea of Northern Vietnam. Over 250 compounds have been isolated and elucidated their chemical structures. Among them, there are more than 50 compounds with new chemical structures. In addition to NMR and HRMS spectra, many compounds with an unequal chemical structure are also determined by Circular Dichroism spectrometry. Some isolated compounds exhibited outstanding potential for cancer cytotoxicity and anti‐inflammatory effects.
1H‐Indole‐3‐acetonitrile glycoside, phenolic and other compounds from Stixis suaveolens
Authors: Anh Ngo Quoc , Yen Tran Thi , Hang Nguyen Thuy , Anh Duong Hong , Viet Pham Hung , Van Doan Vu , Van Kiem Phan
Published: February 2020

From the methanol extract of the Stixis suaveolensleaves, 1H‐Indole‐3‐acetonitrile4‐O‐β‐D‐glucopyranoside (1), α‐adenosine (2), β‐adenosine (3), 1‐O‐syrinoyl‐β‐D‐glucopyranoside (4), 2,6‐dimethoxy‐p‐hydroquinone 1‐O‐β‐D‐glucopyranoside(5), icariside B5 (6) were isolated by various chromatographic methods. The chemical structures of these compounds were elucidated by HRESI‐MS, 1D and 2D NMR spectra and by comparison with data reported in the literature. This is the first report of these compounds from Stixis suaveolens.
Isolation and characterization of six flavonoids from the leaves of Sterculia foetida Linn.
Authors: Cuong Doan Tran Duy , Dat Ha Tuan , Duan Nguyen Trung , Thuong Pham Dinh , Phat Nguyen Tan , Tri Mai Dinh , Van Son Dang , Hoa Nguyen Thi , Tuyen Pham Nguyen Kim , Phung Nguyen Kim Phi
Published: February 2020

Six flavonoids, including one flavan‐3‐ol epicatechin (1), one flavone glycoside apigenin 7‐O‐β‐D‐glucopyranoside (2), three flavones namely dimethylchrysin (3), trimethylapigenin (4) and luteolin (5) and one flavonol quercetin (6) were isolated from the hexane and chloroform extracts of the leaves of Sterculia foetida Linn. collected in Binh Thuan Province by using various chromatographic methods. Their chemical structures were identified by comparing their spectroscopic data as well as physical properties with those in literature. Compounds 1‐4 were obtained for the first time in Sterculia genus.
Kinetic analysis and chemical bond breakage of bagasse pyrolysis process
Authors: Van Nam Huynh , Viet Dinh Quoc , Tam Truong Thanh , Tho Van Dinh Son
Published: February 2020

In the present study, thermogravimetric analysis was used for investigation a bagasse pyrolysis. Multi‐period models were applied for evaluation of kinetics parameter based on the TG curve. The decomposition bagasse process was undergone four periods via the breakdown of each different chemical component in a sample. The dehydration occurred below 170°C; hemicellulose primarily and cellulose partially decomposed in a range of 170 to 318°C and cellulose continuously decomposed from 318 to 400°C. The temperature range of 400‐700°C for the last period showed the evidence of lignin decomposition. The study also identified activation energy constant (Ea), the pre‐exponential factor (A) and reaction order (n) for each period of pyrolysis process. The dependence of the breakdown of the specific chemical bond on the pyrolysis temperature was also proven by FTIR spectrum analysis.