bluuebunny/crossref_metadata_2025 huggingface dataset:
Genomic signatures of population bottleneck and recovery in Northwest Atlantic pinnipeds
Authors: Cammen Kristina M. , Schultz Thomas F. , Don Bowen W. , Hammill Michael O. , Puryear Wendy B. , Runstadler Jonathan , Wenzel Frederick W. , Wood Stephanie A. , Kinnison Michael
Published: June 2018

Population increases over the past several decades provide natural settings in which to study the evolutionary processes that occur during bottleneck, growth, and spatial expansion. We used parallel natural experiments of historical decline and subsequent recovery in two sympatric pinniped species in the Northwest Atlantic, the gray seal (Halichoerus grypus atlantica) and harbor seal (Phoca vitulina vitulina), to study the impact of recent demographic change in genomic diversity. Using restriction site‐associatedDNAsequencing, we assessed genomic diversity at over 8,700 polymorphic gray seal loci and 3,700 polymorphic harbor seal loci in samples from multiple cohorts collected throughout recovery over the past half‐century. Despite significant differences in the degree of genetic diversity assessed in the two species, we found signatures of historical bottlenecks in the contemporary genomes of both gray and harbor seals. We evaluated temporal trends in diversity across cohorts, as well as compared samples from sites at both the center and edge of a recent gray seal range expansion, but found no significant change in genomewide diversity following recovery. We did, however, find that the variance and degree of allele frequency change measured over the past several decades were significantly different from neutral expectations of drift under population growth. These two cases of well‐described demographic history provide opportunities for critical evaluation of current approaches to simulating and understanding the genetic effects of historical demographic change in natural populations.
SDS‐PAGE fractionation to increase metaproteomic insight into the taxonomic and functional composition of microbial communities for biogas plant samples
Authors: Wenzel Lisa , Heyer Robert , Schallert Kay , Löser Lucy , Wünschiers Röbbe , Reichl Udo , Benndorf Dirk
Published: June 2018

Metaproteomics represent an important tool for the taxonomic and functional investigation of microbial communities in humans, environment, and technical applications. Due to the high complexity of the microbial communities, protein, and peptide fractionation is applied to improve the characterization of taxonomic and functional composition of microbial communities. In order to target scientific questions regarding taxonomic and functional composition adequately, a tradeoff between the number of fractions analyzed and the required depth of information has to be found. Two samples of a biogas plant were analyzed by either single LC‐MS/MS measurement (1D) or LC‐MS/MS measurements of fractions obtained after SDS‐PAGE (2D) separation. Fractionation with SDS‐PAGE increased the number of identified spectra by 273%, the number of peptides by 95%, and the number of metaproteins by 59%. Rarefaction plots of species and metaproteins against identified spectra showed that 2D separation was sufficient to identify most microbial families but not all metaproteins. More reliable quantitative comparison could be achieved with 2D. 1D separation enabled high‐throughput analysis of samples, however, depth in functional descriptions and reliability of quantification were lost. Nevertheless, the proteotyping of multiple samples was still possible. 2D separations provided more reliable quantitative data combined with a deeper insight into the taxonomic and functional composition of the microbial communities. Regarding taxonomic and functional composition, metaproteomics based on 2D is just the tip of an iceberg.
Direct Growth of CoFe2 Alloy Strongly Coupling and Oxygen‐Vacancy‐Rich CoFe2O4 Porous Hollow Nanofibers: an Efficient Electrocatalyst for Oxygen Evolution Reaction
Authors: Wu Liang , Shi Lei , Zhou Shiming , Zhao Jiyin , Miao Xianbing , Guo Jianhui
Published: June 2018

Efficient electrocatalysts for the oxygen evolution reaction (OER) is crucial for improving the performance of metal−air batteries and water splitting. In this study, the CoFe2 alloy strongly coupling and oxygen‐vacancy‐rich CoFe2O4 (CoFe2 alloys/CoFe2O4) porous hollow complex nanofibers, as a highly efficient and stable electrocatalyst for OER, have been synthesized via a facile method of electrospinning combining with two‐step heat treatment. The obtained CoFe2 alloys/CoFe2O4 porous hollow complex nanofibers show high electrical conductivity with the smaller charge transfer resistance than that of the commercial RuO2, and even two orders of magnitude lower than that of the single CoFe2O4 porous hollow nanofibers. When used as an electrocatalyst for OER, it demonstrates a superior electrochemical performance with an over‐potential of 300 mV at the current density of 10 mA cm−2, which is comparable to that of the commercial RuO2 but obviously better than that of the single CoFe2O4 porous hollow nanofibers. Moreover, the CoFe2 alloys/CoFe2O4 porous hollow complex nanofibers exhibit remarkably stability with negligible potential increase of only 1.2 % at high current density of 100 mA cm−2 for 16 h. Meanwhile, the CoFe2 alloys/CoFe2O4 porous hollow complex nanofibers also show an excellent hydrogen evolution reaction (HER) activity, affording an over‐potential of 152 mV at the current density of 10 mA cm−2. When using for water splitting in 1 M KOH, the CoFe2 alloys/CoFe2O4 porous hollow complex nanofibers delivers a current density of 10 mA cm−2 at a cell voltage of 1.687 V. More important, the direct growth of CoFe2 alloys on the CoFe2O4 base of the porous hollow nanofibers can be an effective way to control the coupling of the CoFe2 alloys and CoFe2O4, the electronic conductivity and the active sites, and then the electrochemical performance of OER.
Transport of perfluorocarbon tracers in the Cranfield Geological Carbon Sequestration Project
Authors: Soltanian Mohamad Reza , Amooie Mohammad Amin , Cole David , Graham David , Pfiffner Susan , Phelps Tommy , Moortgat Joachim
Published: June 2018

A field‐scale carbon dioxide (CO2) injection pilot project was conducted by the Southeast Regional Carbon Sequestration Partnership (SECARB) at Cranfield, Mississippi. Two associated campaigns in 2009 and 2010 were carried out to co‐inject perfluorocarbon tracers (PFTs) and sulfur hexafluoride (SF6) with CO2. Tracers in gas samples from two observation wells were analyzed to construct breakthrough curves. In this work, we present the field data and numerical modeling of the flow and transport of CO2, brine, and tracers. A high‐resolution static model of the formation geology in the detailed area study (DAS) was used to capture the impact of connected flow pathways created by fluvial channels on breakthrough curves and breakthrough times of PFTs and SF6 tracers. We use the cubic‐plus‐association (CPA) equation of state, which takes into account the polar nature of water molecules, to describe the phase behavior of CO2–brine‐tracer mixtures. Our simulated results show good agreement for the 2009 tracer campaign in Cranfield, while a larger discrepancy emerges by 2010. The combination of multiple tracer injection pulses with detailed numerical simulations proves to be a powerful tool in constraining both formation properties and how complex flow paths develop over time. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.
Accreted seamounts in the South Tianshan Orogenic Belt, NW China
Authors: Yang Gaoxue , Li Yongjun , Li Sanzhong , Tong Lili , Wang Zuopeng , Wu Le
Published: June 2018

The South Tianshan Orogenic Belt (STOB) is situated in the southwest margin of the Central Asian Orogenic Belt and is characterized by thedistributionof ophiolitic mélanges and metamorphic rocks. In this study, we focus on 5 ophiolitic mélanges with ocean island basalt (OIB) and aim to discuss the tectonic evolution of the South Tianshan Ocean. The Kynda, Kainar, Uchkel, Heiyingshan, and Guluogou ophiolitic mélanges in STOB mainly consist of metamorphic peridotite, gabbros, basaltic lavas (pillows), abyssal radiolarian cherts, and limestones. The basaltic rocks mainly occur as tectonic blocks within the mélanges. These basaltic rocks are characterized by LREE enrichment and HREE depletion, very weak or no Eu anomalies, and no obvious Nb, Ta, and Ti negative anomalies, positive εNd(t) values, relatively high initial87Sr/86Sr ratios, and wide206Pb/204Pb ratios, showing the signature of OIB. The OIB‐type rocks from Kynda, Kainar, and Guluogou are likely to be derived from garnet lherzolite by relatively high degrees of melting (10% to 20%). But the basaltic rocks of Uchkel and Heiyingshan formed at significantly lower degrees of partial melting (1% to 5%) of spinel and/or garnet lherzolite. The OIB‐type rocks in these ophiolitic mélanges are considered as accreted seamount fragments and may represent mantle plume‐related magmatism within the South Tianshan Ocean. In combination with previous work, we suggest an updated model, which is bidirectional oceanic subduction with seamounts accretion and subduction system, is suitable for Palaeozoic tectonic evolution of the South Tianshan Ocean.
Association of antidiabetic medication use, cognitive decline, and risk of cognitive impairment in older people with type 2 diabetes: Results from the population‐based Mayo Clinic Study of Aging
Authors: Wennberg Alexandra M.V. , Hagen Clinton E. , Edwards Kelly , Roberts Rosebud O. , Machulda Mary M. , Knopman David S. , Petersen Ronald C. , Mielke Michelle M.
Published: June 2018

Objective

To determine the cross‐sectional and longitudinal associations between diabetes treatment type and cognitive outcomes among type II diabetics.

Methods

We examined the association between metformin use, as compared to other diabetic treatment (ie, insulin, other oral medications, and diet/exercise) and cognitive test performance and mild cognitive impairment (MCI) diagnosis among 508 cognitively unimpaired at baseline type II diabetics enrolled in the Mayo Clinic Study of Aging. We created propensity scores to adjust for treatment effects. We used multivariate linear and logistic regression models to investigate the cross‐sectional association between treatment type and cognitive test z scores, respectively. Mixed effects models and competing risk regression models were used to determine the longitudinal association between treatment type and change in cognitive test z scores and risk of developing incident MCI.

Results

In linear regression analyses adjusted for age, sex, education, body mass index, APOE ε4, insulin treatment, medical comorbidities, number of medications, duration of diabetes, and propensity score, we did not observe an association between metformin use and cognitive test performance. Additionally, we did not observe an association between metformin use and cognitive test performance over time (median = 3.7‐year follow‐up). Metformin was associated with an increased risk of MCI (subhazard ratio (SHR) = 2.75; 95% CI = 1.64, 4.63, P < .001). Similarly, other oral medications (SHR = 1.96; 95% CI = 1.19, 3.25; P = .009) and insulin (SHR = 3.17; 95% CI = 1.27, 7.92; P = .014) use were also associated with risk of MCI diagnosis.

Conclusions

These findings suggest that metformin use, as compared to management of diabetes with other treatments, is not associated with cognitive test performance. However, metformin was associated with incident MCI diagnosis.
Noninferiority of three months versus six months of oxaliplatin‐based adjuvant chemotherapy for resected colon cancer. How should IDEA findings affect clinical practice?
Authors: Formica Vincenzo , Zaniboni Alberto , Loupakis Fotios , Roselli Mario
Published: June 2018

The eagerly awaited results of the multi‐continental International Duration Evaluation of Adjuvant Chemotherapy (IDEA) project have recently been presented at major oncological meetings. The 3‐year disease‐free survival (DFS) was presented for 12,834 Stage III colon cancer patients in a pooled analysis of 6 individual noninferiority phase III randomized trials, all investigating three versus six months of oxaliplatin‐based adjuvant therapy. Noninferiority (NI) could not be demonstrated for the whole population as the DFS hazard ratio (HR) of 1.07 with its 95% CI of 1.00–1.15 crossed the postulated NI boundary of 1.12. However, there was an expected reduction in the incidence of specific side effects with the three months treatment. NI could be demonstrated for the T3N1 subgroup (∼60% of patients, HR for DFS 1.01, 95% CI 0.90–1.12). Moreover, NI was also declared for the subgroup treated with the CAPOX regimen (capecitabine plus oxaliplatin, ∼40% of patients), but the CAPOX choice was physician‐based and not subject to randomization. Overall, the IDEA results indicate that three months of therapy might be adequate for most of Stage III tumors; however, a small subset of these patients still have high risk of recurrence and death with short treatment duration. Precise predictors of benefit need to be identified, nonetheless tumor‐intrinsic factors, such as tumor stage, might currently be considered as useful tools to inform the decision‐making process.
Feasibility, acceptability, and validity of crowdsourcing for collecting longitudinal alcohol use data
Authors: Strickland Justin C. , Stoops William W.
Published: June 2018

Challenges to conducting longitudinal research include financial, time, and geographic constraints. An emerging sampling method positioned to address these concerns is crowdsourcing. This study evaluated the feasibility, acceptability, and validity of collecting intensive longitudinal alcohol use data with the crowdsourcing platform, Amazon.com's Mechanical Turk (mTurk). Participants (N = 278) recruited from mTurk provided weekly recordings of daily alcohol and soda use over an 18‐week period. Construct and external validity was evaluated using generalized linear mixed models describing associations of between‐subject (e.g., alcohol use severity) and within‐subject (e.g., day of week) variables with prospectively collected alcohol and soda use. High response rates were observed across the 18‐week period demonstrating feasibility (64.1%‐86.8%). The design was acceptable with 94% of participants indicating they were satisfied with the procedures. Multilevel models supported construct and external validity by replicating expected associations, such as more frequent and heavier drinking by individuals with higher AUDIT scores and on weekends. These effects were specific to alcohol use and did not extend to soda consumption. These data support the feasibility, acceptability, and validity of using mTurk for intensive longitudinal data collection. Future studies may leverage this platform to generate large, geographically diverse samples for prospective behavioral analytic research.
An Easy Synthetic Approach to Construct Some Ebselen Analogues and Benzo[b]selenophene Derivatives: Their Antioxidant and Cytotoxic Assessment
Authors: Elsherbini Mohamed , Hamama Wafaa S. , Zoorob Hanafi H.
Published: June 2018

2‐(Chloroseleno)benzoyl chloride serves as a versatile building block for the synthesis of novel ebselen (2‐phenyl‐1,2‐benzisoselenazol‐3(2H)‐one) analogues and benzo[b]selenophen‐3(2H)‐one derivatives. The antioxidant activity and cytotoxic evaluation of the newly synthesized compounds were implemented. Among all the synthesized compounds, 1‐(3‐hydroxybenzo[b]selenophen‐2‐yl)ethanone oxime (9) was the most potent antioxidant and the most cytotoxic compound as well.
New Method for Synthesis of Multi‐substituted Imidazoles
Authors: Marzouk Adel A. , Mohamed Shaaban K. , Aljohani Enas T. , Abdelhamid Antar A.
Published: June 2018

Here, we reported two methods for the synthesis of multi‐substituted imidazoles, firstly via four‐component cyclocondensation reaction of benzil, aliphatic amines (allylamine or pentylamine), and aromatic aldehyde and ammonium acetate. Using an ionic liquid catalyst namely, diethyl ammonium hydrogen sulfate, and under solvent‐free conditions. Secondly, via the alkylation of synthesized NH imidazoles with alkyl halide (allyl bromide and pentyl bromide) gave 8a–c in high yield (average 90%), the products can be purified by a non‐chromatographic method, and these newly synthesized compounds have been characterized by spectral data: FTIR, IR, 1H, 13C nuclear magnetic resonance, the elemental analysis, and the X‐ray structure.
A variation of pigmentation in the glabrous skin of dogs
Authors: Elofsson Rolf , Kröger Ronald H. H.
Published: June 2018

The usual pigmentation pattern in mammalian skin consists of fixed melanocytes in the basal layer of the epidermis, supplying keratinocytes with melanosomes. We observed that the glabrous skin (rhinaria and footpads) of dogs deviates from this pattern. In dogs, melanocytes are found in both the dermis and epidermis. The epidermal melanocytes are situated in the intercellular spaces of the basal and spinous layers. They are characterized by a quantity of cytoplasm containing a centriole, also developing melanosomes, and in some cases annulate lamellae. There is a high frequency of closely apposed melanocytes in the epidermis. Melanosomes in different stages of formation are also abundant. The morphology of the glabrous skin of dogs suggests transport of melanocytes from the dermis into the epidermis and formation of melanosomes in the epidermis. A distributed and intense pigment formation may be necessary to achieve the black noses of many dog breeds and wild canids, as well as dark footpads despite heavy abrasion and rapid skin renewal.
Discovery of biomarkers to identify peri‐implant osteolysis before radiographic diagnosis
Authors: Ross Ryan D. , Deng Youping , Fang Rui , Frisch Nicholas B. , Jacobs Joshua J. , Sumner Dale R.
Published: June 2018

Peri‐implant osteolysis is commonly diagnosed after substantial bone loss has occurred, making revision surgery more challenging. The goal of the current study was to identify urinary biomarkers that differentiate total hip replacement patients who eventually develop osteolysis from patients who do not. We used a repository of 24‐h urine samples collected prior to surgery and annually thereafter in 26 patients, 16 who developed osteolysis, and 10 who did not. We examined the markers at radiographic diagnosis, annually for 6 years preceding diagnosis, at the first post‐operative sampling point, and pre‐operatively. Patients in the osteolysis and non‐osteolysis groups were matched according to time post‐surgery and did not differ in the male:female ratio or age at surgery. Seven candidate biomarkers were measured, including free deoxypyridinoline (DPD), cross‐linked N‐telopeptides (NTX), interleukin‐6 (IL‐6), interleukin‐8 (IL‐8), osteoprotegerin (OPG), α‐crosslaps (α‐CTX), and β‐crosslaps (β‐CTX). As an individual biomarker, DPD demonstrated the highest ability to predict osteolysis, with an area under the curve (AUC) in Receiver Operating Characteristic (ROC) analyses of 0.844 at 6 years prior to diagnosis. A panel of α‐CTX and IL‐6 was able to identify at‐risk patients with an AUC of 0.941 or greater at all post‐operative time points and an AUC of 1.000 pre‐operatively. The results demonstrate the potential of using non‐invasive biomarkers to identify patients at risk for peri‐implant osteolysis long before the emergence of radiographic signs. Further, the high accuracy of the pre‐operative biomarker levels demonstrates the potential importance of pre‐existing, patient‐specific factors driving subsequent osteolysis. Study Design © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2754–2761, 2018.
Immunohistopathologic evaluation of Drynaria fortunei rhizome extract in the management of Class II furcation defects in a canine model
Authors: Afifi Marwa M. , Kotry Gehan S. , El‐Kimary Gillan I. , Youssef Hayat A.
Published: June 2018

Background

Management of furcation defects is still a challenging subject in periodontal therapy. Drynaria fortunei (Df) is a common type of traditional Chinese herb in the area of orthopedics and traumatology. In vitro and tissue engineering studies have shown that Df induces osteoblastic proliferation and promotes the differentiation of human periodontal ligament cells. This study investigated the management of Class II furcation defects in dogs using guided tissue regeneration (GTR) and Df granules mixed with β‐tricalcium phosphate (β‐ TCP) alloplast.

Methods

Sixteen Class II critical‐sized furcation defects were surgically created in four mongrel dogs: Eight defects were treated with GTR and Df granules mixed with (β‐TCP) alloplast served as the experimental group, while the other eight were managed with GTR and alloplast, served as control. Dogs were sacrificed at 4 and 8 weeks and the premolars were processed for the evaluation of treatment outcome including; osteoblastic count (OC), cementum layer thickness (CLT), percentage of collagen in bone matrix (CBM), and alkaline phosphatase (ALP) immunoreaction.

Results

Experimental group treated with Df showed a significant increase (P < 0.001) in the values of OC, CLT, CBM, and ALP immunoreactivity when compared with control at 4 and 8 weeks after treatment.

Conclusion

Drynaria fortunei demonstrated increased regeneration and bone formation when used in the treatment of furcation defects in a canine model.
Simultaneous derivatization and lighter‐than‐water air‐assisted liquid–liquid microextraction using a homemade device for the extraction and preconcentration of some parabens in different samples
Authors: Farajzadeh Mir Ali , Bakhshizadeh Aghdam Mehri , Afshar Mogaddam Mohammad Reza , Alizadeh Nabil Ali Akbar
Published: June 2018

Simultaneous derivatization and air‐assisted liquid–liquid microextraction using an organic that is solvent lighter than water has been developed for the extraction of some parabens in different samples with the aid of a newly designed device for collecting the extractant. For this purpose, the sample solution is transferred into a glass test tube and a few microliters of acetic anhydride (as a derivatization agent) and p‐xylene (as an extraction solvent) are added to the solution. After performing the procedure, the homemade device consists of an inverse funnel with a capillary tube placed into the tube. In this step, the collected extraction solvent and a part of the aqueous solution are transferred into the device and the organic phase indwells in the capillary tube of the device. Under the optimal conditions, limits of detection and quantification for the analytes were obtained in the ranges of 0.90–2.7 and 3.0–6.1 ng/mL, respectively. The enrichment and enhancement factors were in the ranges of 370–430 and 489–660, respectively. The method precision, expressed as the relative standard deviation, was within the range of 4–6% (n = 6) and 4–9% (n = 4) for intra‐ and interday precisions, respectively. The proposed method was successfully used for the determination of methyl‐, ethyl‐, and propyl parabens in cosmetic, hygiene and food samples, and personal care products.
Monolith affinity chromatography for the rapid quantification of a single‐chain variable fragment immunotoxin
Authors: Satzer Peter , Sommer Ralf , Paulsson Johanna , Rodler Agnes , Zehetner Romana , Hofstädter Klaus , Klade Christoph , Jungbauer Alois
Published: June 2018

We developed a novel analytical method for concentration determination of tandem single‐chain antibody diphtheria toxin (immunotoxin). The method is based on polymethacrylate monoliths with Protein L ligands as the binding moiety. Different buffers were tested for elution of the Protein L‐bound immunotoxin and 4.5 M guanidinium hydrochloride performed best. We optimized the elution conditions and the method sequence resulting in a fast and robust method with a runtime <10 min. Fast determination of immunotoxin is critical if any process decisions rely on this data. We determined method performance and a lower limit of detection of 27 μg/mL and a lower limit of quantification of 90 μg/mL was achieved. The validity of the method in terms of residual analysis, precision, and repeatability was proven in a range from 100 to 375 μg/mL. The short runtime and ease of use of a high‐performance liquid chromatography method is especially useful for a process analytical tool approach. Bioprocesses related to immunotoxin where fermentation or other process parameters can be adjusted in accordance to the immunotoxin levels will be benefited from this method to achieve the highest possible purity and productivity.
An integrated demand and supply conceptual framework: Investigating agritourism services
Authors: Brandano Maria Giovanna , Osti Linda , Pulina Manuela
Published: June 2018

The present paper offers an integrated conceptual framework to jointly analyze demand and supply of agritourism firms and aims to identify motivations along with perceptions of externalities that influence the choice of a firm over another. On the supply side, a cluster analysis identifies homogenous groups of agritourism firms. On the demand side, a factor analysis is run on a set of motivations and environmental externalities and a probabilistic model estimates the determinants that influence the likelihood to choose 1 type of firm over the other. The results show that traditional and genuine food, culture, and authenticity are elements that determine the choice of 1 firm over another. A further contribution of this paper is the identification of environmental externalities as determinants of the attractiveness of a firm. From a marketing perspective, linking demand to supply is essential to determine product development strategies capable of satisfying actual and potential customers. Several strategies are proposed to different types of agritourism firms to attract and retain customers.
An experimental and theoretical study on the kinetics of the reaction between 4‐hydroxy‐3‐hexanone CH3CH2C(O)CH(OH)CH2CH3 and OH radicals
Authors: Dib Gisèle El , Aazaad Basheer , Lakshmipathi Senthilkumar , Laversin Hélène , Roth Estelle , Chakir Abdelkhaleq
Published: June 2018

Experimental and theoretical rate coefficients are determined for the first time for the reaction of 4‐hydroxy‐3‐hexanone (CH3CH2C(O)CH(OH)CH2CH3) with OH radicals as a function of temperature. Experimental studies were carried out using two techniques. Absolute rate coefficients were measured using a cryogenically cooled cell coupled to the pulsed laser photolysis‐laser‐induced fluorescence technique with temperature and pressure ranges of 280‐365 K and 5‐80 Torr, respectively. Relative values of the studied reaction were measured under atmospheric pressure in the range of 298‐354 K by using a simulation chamber coupled to a FT‐IR spectrometer. In addition, the reaction of 4H3H with OH radicals was studied theoretically by using the density functional theory method over the range of 278‐350 K. Results show that H‐atom abstraction occurs more favorably from the C–H bound adjacent to the hydroxyl group with small barrier height. Theoretical rate coefficients are in good agreement with the experimental data. A slight negative temperature dependence was observed in both theoretical and experimental works. Overall, the results are deliberated in terms of structure–reactivity relationship and atmospheric implications.
Quantum mechanics investigation on initial decomposition of ammonia borane in glyme
Authors: Chatterjee Tanusree , Thynell Stefan T.
Published: June 2018

The chemical kinetics of ammonia borane (AB) in glyme solution is studied using quantum mechanics (QM) based calculations along with experimental results available in the literature. The primary objective of this study is to propose a detailed reaction mechanism that explains the formation of species observed during AB decomposition for temperatures ranging from 323 to 368 K. The quantum mechanics investigation uses transition state theory to identify the relevant reaction pathways. Intrinsic reaction coordinate calculations use the identified transition‐state structure to link the reactants to the products. These calculations were performed using the Gaussian 09 program package, including the solvation model based on density (SMD) with acetonitrile as the solvent. Thermodynamic properties of species at equilibrium or at transition states were computed using the G4(MP2) compound method. Sensitivity analysis was performed using a species conservation model to identify reactions and species that play a critical role. This study confirms the previous experimental observation regarding the initiation of decomposition of AB in glyme. It also elucidates the role of DADB, ammonium borohydride salt ([BH4]−[NH4]+) and BH2NH2 in hydrogen release and intermediates formed during initial phase of AB decomposition. This work shows how QM calculations along with experimental results can contribute to our understanding of the complex chemical kinetics involved during AB dehydrogenation.
Knowledge sharing behavior in online discussion communities: Examining behavior motivation from social and individual perspectives
Authors: Kumi Richard , Sabherwal Rajiv
Published: June 2018

Background

Prior research has advanced several reasons, using various perspectives, to explain user participation in online discussion communities. Nonetheless, relatively few studies have explored personal and social factors together in the same study to explain knowledge seeking and sharing behaviors in online discussion communities; additionally, relatively few studies have examined the outcomes of these behaviors.

Research question

Using social identity and personal motivation theories, this study examines the following research questions. First, how do social identity and extrinsic and intrinsic motivations influence knowledge seeking and sharing behaviors in online discussion communities? Second, how do knowledge seeking and sharing behaviors affect satisfaction with a community?

Methodology

To address these two research questions, we collected data from 144 users from two online communities and analyze the data using seemingly unrelated regression.

Results

The results indicate that intrinsic and extrinsic motivations have different impacts on knowledge seeking and sharing behaviors. Only one of the dimensions of social identity, affective social identity, has a significant impact on knowledge seeking and sharing behaviors.

Conclusions

Knowledge sharing and seeking behaviors are not driven by the same personal motivations. We discuss practical implications on online discussion communities, including insights into motivations, behaviors, and outcomes.
Metallothionein 1 family profiling identifies MT1X as a tumor suppressor involved in the progression and metastastatic capacity of hepatocellular carcinoma
Authors: Liu Zhikun , Ye Qianwei , Wu Lingjiao , Gao Feng , Xie Haiyang , Zhou Lin , Zheng Shusen , Xu Xiao
Published: June 2018

Metallothionein 1 (MT1s) is a family of cysteine‐rich proteins with diverse functions such as metal homeostasis, oxidative stress, and carcinogenesis. However, its involvement in hepatocellular carcinoma (HCC) remains not fully understood. We aimed to explore the contribution of the individual member of MT1s to HCC. Its member mRNA levels were determined in cohort 1 of normal (n = 30), cirrhotic (n = 30), peritumoral (n = 135), and HCC (n = 135). In cohort 1, seven of eight members were down‐regulated during the transition from normal liver to HCC, and only MT1G and MT1X were correlated with tumor features and outcomes. The MT1X was selected to be further stained in cohort 2 consisting of a series of liver nodules (15 normal livers, 33 cirrhotic livers, 12 dysplastic nodules, 31 HCC, and 9 HCC metastasis), and in cohort 3 (HCC, n = 85). In cohort 2, MT1X immunoreactivity was reduced in HCC and lost in metastatic HCC and showed good diagnostic performance for HCC (AUC = 0.754, 95%IC = 0.659‐0.849). In cohort 3, MT1X expression in peritumoral tissues was independent predictor for HCC (recurrence free survival: HR = 0.34, 95%CI = 0.17‐0.66; overall survival: HR = 0.32, 95%CI = 0.16‐0.60). Moreover, we found that ectopic overexpression of MT1X delayed G1/S progression of cell cycle and promoted apoptosis in HCC cells in vitro, and suppressed tumor growth and lung metastasis in nude mice in vivo. We further demonstrated that MT1X induces cell cycle arrest and apoptosis by inactivating NF‐κB signaling in HCC. In conclusion, MT1X may serve as a candidate of prognostic indicator and inhibits the progression and metastasis of HCC.
Interplay between Riccati, Ermakov, and Schrödinger equations to produce complex‐valued potentials with real energy spectrum
Authors: Blanco‐Garcia Zurika , Rosas‐Ortiz Oscar , Zelaya Kevin
Published: June 2018

Nonlinear Riccati and Ermakov equations are combined to pair the energy spectrum of 2 different quantum systems via the Darboux method. One of the systems is assumed Hermitian, exactly solvable, with discrete energies in its spectrum. The other system is characterized by a complex‐valued potential that inherits all the energies of the former one and includes an additional real eigenvalue in its discrete spectrum. If such eigenvalue coincides with any discrete energy (or it is located between 2 discrete energies) of the initial system, its presence produces no singularities in the complex‐valued potential. Non‐Hermitian systems with spectrum that includes all the energies of either Morse or trigonometric Pöschl‐Teller potentials are introduced as concrete examples.
Multilinear and multiparameter spectral multipliers on stratified groups
Authors: Fang Jingxuan , Zhao Jiman
Published: June 2018

As far as we know, the study of multilinear spectral multipliers on nilpotent Lie groups is a very new research work. There is even no study of Hörmander‐type multiplier theorem for multilinear and multiparameter spectral multipliers on nilpotent Lie groups. In this paper, on product spaces of stratified groups G = G1 × ⋯ × GM, we prove Hörmander‐type multiplier theorems for multilinear and multiparameter spectral multipliers from
to Lr(G) with
, from
to
with
, and from
to Lr(·)(G) with
or
for all ℓ = 1,…,N.
Global stability of an SIS epidemic model with delays
Authors: Fushimi Kei , Enatsu Yoichi , Ishiwata Emiko
Published: June 2018

In this paper, we consider the global dynamics of the S(E)IS model with delays denoting an incubation time. By constructing a Lyapunov functional, we prove stability of a disease‐free equilibrium E0 under a condition different from that in the recent paper. Then we claim that R0≤1 is a necessary and sufficient condition under which E0 is globally asymptotically stable. We also propose a discrete model preserving positivity and global stability of the same equilibria as the continuous model with distributed delays, by means of discrete analogs of the Lyapunov functional.
B‐spline spectral method for constrained fractional optimal control problems
Authors: Ejlali Nastaran , Hosseini Seyed Mohammad , Yousefi Sohrab Ali
Published: June 2018

In this paper, we present a direct B‐spline spectral collocation method to approximate the solutions of fractional optimal control problems with inequality constraints. We use the location of the maximum of B‐spline functions as collocation points, which leads to sparse and nonsingular matrix B whose entries are the values of B‐spline functions at the collocation points. In this method, both the control and Caputo fractional derivative of the state are approximated by B‐spline functions. The fractional integral of these functions is computed by the Cox‐de Boor recursion formula. The convergence of the method is investigated. Several numerical examples are considered to indicate the efficiency of the method.
Inverse problems for first‐order differential systems with periodic 2 × 2 matrix potentials and quasi‐periodic boundary conditions
Authors: Currie Sonja , Roth Thomas T. , Watson Bruce A.
Published: June 2018

A generalisation is given of the inverse problem considered in S. Currie, B.A. Watson, and T.T. Roth. First‐order systems in
on
with periodic matrix potentials and vanishing instability intervals, Math. Meth. Appl. Sci.38 (2015), 4435‐4447. In particular, the self‐adjoint first‐order system, JY ′ + QY = λY, with integrable, real, symmetric, and π‐periodic, 2 × 2 matrix potential Q is considered, where
. It is shown that all eigenvalues to the above equation with boundary conditions Y(π) = ±R(θ)Y(0), where R(θ) is the rotation matrix
, are double eigenvalues if and only if Q = rI for some real scalar valued integrable function r.
Clinicians have several therapeutic relationships and patients only one: The effect on their assessments of relationships
Authors: Greenberg Lauren , Bremner Stephen , Carr Catherine , Priebe Stefan
Published: June 2018

Objectives

Little attention has been given to the common assessment problem that clinicians assess outcomes of several patients and may rate them in comparison to one another, whereas patients assess only their own outcomes without any comparison. We explored empirically whether this would lead to a greater variability of clinician ratings as compared to patient ratings.

Methods

Data from two independent samples in which clinicians and patients, using consistent instruments, rated their therapeutic relationships. We present descriptive statistics of variability and intracluster correlation coefficients.

Results

The Helping Alliance Scale was completed at baseline and follow‐up by 20 clinicians and 103 patients in an observational study and by 88 clinicians and 431 patients in a trial. Patients tended to rate their relationship 5–10% more highly than their clinicians, but with 50–100% more variability. Intraclinician Helping Alliance Scale ratings were more correlated than those by patients (intracluster correlation coefficients 0.3–0.7 vs. 0.0–0.2).

Conclusion

Contrary to our assumption, clinicians' ratings of therapeutic relationships were in both samples less variable than those of their patients. When clinicians rate outcomes of several patients, a cluster effect of ratings may have to be considered in the design and analysis.
A flexible natural coordinates formulation (FNCF) for the efficient simulation of small‐deformation multibody systems
Authors: Vermaut Martijn , Naets Frank , Desmet Wim
Published: June 2018

This paper introduces the novel flexible natural coordinates formulation to model small‐deformation multibody dynamics. The main contribution of this work is its resulting constant mass matrix and quadratic constraint equations devoid of any other nonlinearities. These properties are similar to those of a natural coordinates formulation for rigid multibody systems with the addition of constant damping and stiffness matrices to model the flexibility under the assumption of small deformations. As such, it is a straightforward extension to natural coordinates while maintaining its beneficial properties. The main concept of the current approach is to introduce ample redundancy in the set of generalized coordinates to simplify the kinematics ensuring the aforementioned properties and the similarity to a natural coordinates approach. This is not achievable by standard techniques that introduce redundancy. Not only does this offer a very simple equation structure but also interesting properties toward the development of system‐level model order reduction techniques for flexible multibody systems as well as a straightforward parameter gradient extraction. The formulation accuracy is validated with a floating frame of reference implementation.
Intrinsic Dynamic Nature of Neutral Hydrogen Bonds Elucidated with QTAIM Dual Functional Analysis: Role of the Compliance Force Constants and QTAIM‐DFA Parameters in Stability
Authors: Nishide Taro , Hayashi Satoko , Nakanishi Waro
Published: June 2018

The dynamic and static nature of various neutral hydrogen bonds (nHBs) is elucidated with quantum theory of atoms‐in‐molecules dual functional analysis (QTAIM‐DFA). The perturbed structures generated by using the coordinates derived from the compliance force constants (Cij) of internal vibrations are employed for QTAIM‐DFA. The method is called CIV. The dynamic nature of CIV is described as the “intrinsic dynamic nature”, as the coordinates are invariant to the choice of the coordinate system. nHBs are, for example, predicted to be van der Waals (H2Se−✶−HSeH; ✶=bond critical point),t‐HBnc(typical‐HBs with no covalency: HI−✶−HI),t‐HBwc(t‐HBs with covalency: H2C=O−✶−HI), CT‐MC [molecular complex formation through charge transfer (CT): H2C=O−✶−HF], and CT‐TBP (trigonal bipyramidal adduct formation through CT: H3N−✶−HI) in nature. The results with CIV were the same as those with POM in the calculation errors, for which the perturbed structures were generated by partial optimization, and the interaction distances in question were fixed suitably in POM. The highly excellent applicability of CIV for QTAIM‐DFA was demonstrated for the various nHBs, as well as for the standard interactions previously reported. The stability of the HBs, evaluated by ΔE, is well correlated withCij(ΔE×Cij=constant value of −165.64), and the QTAIM parameters, although a few deviations were detected.
Fibroblast growth factor 2 decreases bleomycin‐induced pulmonary fibrosis and inhibits fibroblast collagen production and myofibroblast differentiation
Authors: Koo Hyun Young , El‐Baz Lamis MF , House StaceyL , Cilvik Sarah N , Dorry Samuel J , Shoukry Nahla M , Salem Mohamed L , Hafez Hani S , Dulin Nickolai O , Ornitz David M , Guzy Robert D
Published: June 2018

Fibroblast growth factor (FGF) signaling has been implicated in the pathogenesis of pulmonary fibrosis. Mice lacking FGF2 have increased mortality and impaired epithelial recovery after bleomycin exposure, supporting a protective or reparative function following lung injury. To determine whether FGF2 overexpression reduces bleomycin‐induced injury, we developed an inducible genetic system to express FGF2 in type II pneumocytes. Double‐transgenic (DTG) mice with doxycycline‐inducible overexpression of human FGF2 (SPC‐rtTA;TRE‐hFGF2) or single‐transgenic controls were administered intratracheal bleomycin and fed doxycycline chow, starting at either day 0 or day 7. In addition, wild‐type mice received intratracheal or intravenous recombinant FGF2, starting at the time of bleomycin treatment. Compared to controls, doxycycline‐induced DTG mice had decreased pulmonary fibrosis 21 days after bleomycin, as assessed by gene expression and histology. This beneficial effect was seen when FGF2 overexpression was induced at day 0 or day 7 after bleomycin. FGF2 overexpression did not alter epithelial gene expression, bronchoalveolar lavage cellularity or total protein. In vitro studies using primary mouse and human lung fibroblasts showed that FGF2 strongly inhibited baseline and TGFβ1‐induced expression of alpha smooth muscle actin (αSMA), collagen, and connective tissue growth factor. While FGF2 did not suppress phosphorylation of Smad2 or Smad‐dependent gene expression, FGF2 inhibited TGFβ1‐induced stress fiber formation and serum response factor‐dependent gene expression. FGF2 inhibition of stress fiber formation and αSMA requires FGF receptor 1 (FGFR1) and downstream MEK/ERK, but not AKT signaling. In summary, overexpression of FGF2 protects against bleomycin‐induced pulmonary fibrosis in vivo and reverses TGFβ1‐induced collagen and αSMA expression and stress fiber formation in lung fibroblasts in vitro, without affecting either inflammation or epithelial gene expression. Our results suggest that in the lung, FGF2 is antifibrotic in part through decreased collagen expression and fibroblast to myofibroblast differentiation. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The safety, tolerability, and pharmacokinetic profile of GSK2838232, a novel 2nd generation HIV maturation inhibitor, as assessed in healthy subjects
Authors: Johnson Mark , Jewell Roxanne C. , Peppercorn Amanda , Gould Elizabeth , Xu Jianfeng , Lou Yu , Davies Matthew , Baldwin Sandra , Tenorio Allan R. , Burke Matthew , Jeffrey Jerry , Johns Brian A.
Published: June 2018

This work aimed to assess the safety, tolerability, pharmacokinetics (PK), and relative bioavailability of GSK2838232, an investigational HIV maturation inhibitor. GSK2838232 was administered over four dose‐escalation studies in healthy subjects which assessed single oral doses (5‐250 mg) and repeat doses (up to 200 mg once or twice daily) ±100 mg ritonavir (RTV) once daily. GSK2838232 administration (up to 250 mg) to 124 subjects across four studies resulted in few mild adverse events (AEs) with similar frequencies to placebo. There were no clearly identified drug‐related AEs. GSK2838232 tested fasted was quickly absorbed with a tmax of 2‐3 hours. With food, the absorption was delayed and more variable, with ~60% increase in AUC and Cmax. Overall, following single doses GSK2838232 AUC and Cmax generally exhibited proportional PK from 50 to 100 mg dose without RTV and from 50 to 250 mg with RTV and following repeated doses of 20‐200 mg with RTV. In relative bioavailability studies, a micronized formulation was found to be suitable for development. At steady state, RTV increased GSK2838232 AUC and Cmax by 10‐ and 3‐fold, respectively. Half‐life was prolonged from ~17 hours nonboosted to ~34 hours with RTV. This boosting effect was also seen in repeat‐dose GSK2838232 studies, which achieved the targeted plasma exposure with GSK2838232 as a once‐daily regimen of up to 200 mg with RTV. The results of these studies demonstrated a favorable safety and PK profile for GSK2838232 and support its investigation for the treatment of HIV infection.
Evaluation of matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry for differentiation of Pichia kluyveri strains isolated from traditional fermentation processes
Authors: De la Torre González Francisco Javier , Avendaño Daniel Oswaldo Gutiérrez , Mathis Anne Christine Gschaedler , Kirchmayr Manuel Reinhart
Published: June 2018

Rationale

Non‐Saccharomyces yeasts are widespread microorganisms that nowadays have gained importance for their ability to produce volatile compounds which in alcoholic beverages improve aromatic complexity and therefore the overall quality. Their rapid identification and differentiation in fermentation processes is vital for timely decision making.

Methods

A total of 19 strains of Pichia kluyveri isolated from mezcal, tejuino and cacao fermentations were analyzed with rep‐PCR fingerprinting using the primer (GTG)5 and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) on a Microflex LT mass spectrometer using Biotyper 3.1 software (Bruker Daltonics).

Results

The comparative analysis between MS spectra and rep‐PCR patterns obtained from these strains showed a high similarity between both methods. However, minimal differences between the obtained rep‐PCR and MALDI‐TOF MS clusters could be observed, especially by the presence and/or absence of one or more discriminating peaks even when they have similarities in their main spectra projection, observing that isolates from the same fermentative process were grouped into the same sub‐cluster based on their MALDI‐TOF MS profiles.

Conclusions

The data shown suggests that MALDI‐TOF MS is a promising alternative technique for rapid, reliable and cost‐effective differentiation of native yeast strains isolated from different traditional fermented foods and beverages.