bluuebunny/crossref_metadata_2025 huggingface dataset:
Brucella Peptide Cross-Reactive Major Histocompatibility Complex Class I Presentation Activates SIINFEKL-Specific T Cell Receptor-Expressing T Cells
Authors: Harms Jerome S. , Khan Mike , Hall Cherisse , Splitter Gary A. , Homan E. Jane , Bremel Robert D. , Smith Judith A.
Published: May 2018

Brucellaspp. are intracellular pathogenic bacteria remarkable in their ability to escape immune surveillance and therefore inflict a state of chronic disease within the host. To enable further immune response studies,Brucellawas engineered to express the well-characterized chicken ovalbumin (OVA). Surprisingly, we found that CD8 T cells bearing T cell receptors (TCR) nominally specific for the OVA peptide SIINFEKL (OT-1) reacted to parentalBrucella-infected targets as well as OVA-expressingBrucellavariants in cytotoxicity assays. Furthermore, splenocytes fromBrucella-immunized mice produced gamma interferon (IFN-γ) and exhibited cytotoxicity in response to SIINFEKL-pulsed target cells.To determine if the SIINFEKL-reactive OT-1 TCR could be cross-reacting toBrucellapeptides, we searched theBrucellaproteome using an algorithm to generate a list of near-neighbor nonamer peptides that would bind to H2Kb. Selecting fiveBrucellapeptide candidates, along with controls, we verified that several of these peptides mimicked SIINFEKL, resulting in T cell activation through the “SIINFEKL-specific” TCR. Activation was dependent on peptide concentration as well as sequence. Our results underscore the complexity and ubiquity of cross-reactivity in T cell recognition. This cross-reactivity may enable microbes such asBrucellato escape immune surveillance by presenting peptides similar to those of the host and may also lead to the activation of autoreactive T cells.
Malleilactone Is a Burkholderia pseudomallei Virulence Factor Regulated by Antibiotics and Quorum Sensing
Authors: Klaus Jennifer R. , Deay Jacqueline , Neuenswander Benjamin , Hursh Wyatt , Gao Zhe , Bouddhara Tiffany , Williams Todd D. , Douglas Justin , Monize Kyle , Martins Patricia , Majerczyk Charlotte , Seyedsayamdost Mohammad R. , Peterson Blake R. , Rivera Mario , Chandler Josephine R.
Published: May 2018

Burkholderia pseudomallei
, the causative agent of melioidosis, encodes almost a dozen predicted polyketide (PK) biosynthetic gene clusters. Many of these are regulated by LuxR-I-type acyl-homoserine (AHL) quorum-sensing systems. One of the PK gene clusters, the
mal
gene cluster, is conserved in the close relative
Burkholderia thailandensis
. The
B. thailandensis mal
genes code for the cytotoxin malleilactone and are regulated by a genetically linked LuxR-type transcription factor, MalR. Although AHLs typically interact with LuxR-type proteins to modulate gene transcription, the
B. thailandensis
MalR does not appear to be an AHL receptor. Here, we characterize the
mal
genes and MalR in
B. pseudomallei
. We use chemical analyses to demonstrate that the
B. pseudomallei mal
genes code for malleilactone. Our results show that MalR and the
mal
genes contribute to the ability of
B. pseudomallei
to kill
Caenorhabditis elegans
. In
B. thailandensis
, antibiotics like trimethoprim can activate MalR by driving transcription of the
mal
genes, and we demonstrate that some of the same antibiotics induce expression of
B. pseudomallei malR
. We also demonstrate that
B. pseudomallei
MalR does not respond directly to AHLs. Our results suggest that MalR is indirectly repressed by AHLs, possibly through a repressor, ScmR. We further show that malleilactone is a
B. pseudomallei
virulence factor and provide the foundation for understanding how malleilactone contributes to the pathology of melioidosis infections.

IMPORTANCE
Many bacterially produced polyketides are cytotoxic to mammalian cells and are potentially important contributors to pathogenesis during infection. We are interested in the polyketide gene clusters present in
Burkholderia pseudomallei
, which causes the often-fatal human disease melioidosis. Using knowledge gained by studies in the close relative
Burkholderia thailandensis
, we show that one of the
B. pseudomallei
polyketide biosynthetic clusters produces a cytotoxic polyketide, malleilactone. Malleilactone contributes to
B. pseudomallei
virulence in a
Caenorhabditis elegans
infection model and is regulated by an orphan LuxR family quorum-sensing transcription factor, MalR. Our studies demonstrate that malleilactone biosynthesis or MalR could be new targets for developing therapeutics to treat melioidosis.
Evaluation of a Turbidimetric β-
d
-Glucan Test for Detection of Pneumocystis jirovecii Pneumonia
Authors: Dichtl Karl , Seybold Ulrich , Wagener Johannes
Published: May 2018

Currently, diagnosis of
Pneumocystis jirovecii
pneumonia (PJP) relies on analysis of lower respiratory specimens, either by microscopy or quantitative real-time PCR (qPCR). Thus, bronchoscopy is required, which is associated with increased risk of respiratory failure. We assessed the value of noninvasive serologic β-
d
-glucan (BDG) testing for laboratory diagnosis of PJP using a newly available turbidimetric assay. We identified 73 cases of PJP with positive qPCR results from lower respiratory specimens for
Pneumocystis
and serology samples dating from 1 week before to 4 weeks after qPCR. In addition, 25 sera from controls with suspected PJP but specimens negative for
Pneumocystis
by qPCR were identified. Sera were tested with a turbidimetric BDG assay (Fujifilm Wako Chemicals Europe GmbH, Neuss, Germany), using an 11-pg/ml cutoff. Sensitivity and specificity were calculated based on qPCR test results as a reference. The turbidimetric BDG assay identified 63/73 patients with positive or slightly positive qPCR tests for an overall sensitivity of 86%; after exclusion of cases with only slightly positive qPCR results, sensitivity was 91%. No correlation between serum BDG levels and respiratory specimen DNA levels was found. Serologic BDG testing was negative in 25/25 controls with negative qPCR for a specificity of 100% using the predefined cutoff. In 22/25 samples (88%), no BDG was detected. Serologic BDG testing using the turbidimetric assay showed high sensitivity and specificity compared to qPCR of lower respiratory specimens for the diagnosis of PJP. Both turnover time and test performance will allow clinicians to delay or in some cases forego bronchoscopy.
Why miltefosine—a life-saving drug for leishmaniasis—is unavailable to people who need it the most
Authors: Sunyoto Temmy , Potet Julien , Boelaert Marleen
Published: May 2018

Miltefosine, the only oral drug approved for the treatment of leishmaniasis—a parasitic disease transmitted by sandflies—is considered as a success story of research and development (R&D) by a public-private partnership (PPP). It epitomises the multiple market failures faced by a neglected disease drug: patients with low ability to pay, neglect by authorities and uncertain market size. Originally developed as an anticancer agent in the 1990s, the drug was registered in India in 2002 to treat the fatal visceral leishmaniasis. At the time, miltefosine was considered a breakthrough in the treatment, making it feasible to eliminate a regional disease. Today, access to miltefosine remains far from secure. The initial PPP agreement which includes access to the public sector is not enforced. The reality on the ground has been challenging: shortages due to inefficient supply chains, and use of a substandard product which led to a high number of treatment failures and deaths. Miltefosine received orphan drug status in the USA; when it was registered there in 2014, a priority review voucher (PRV) was awarded. The PRV, meant to facilitate drug development for neglected disease, was subsequently sold to another company for US$125 million without, to date, any apparent impact on drug access. At the heart of these concerns are questions on how to protect societal benefit of a drug developed with public investment, while clinicians worldwide struggle with its lack of affordability, limited availability and sustainability of access. This article analyses the reasons behind the postregistration access failure of miltefosine and provides the lessons learnt.
Sexual risk behaviour, sexual victimisation, substance use and other factors related to depression in men who have sex with men in Wenzhou, China: a cross-sectional study
Authors: Pan Xiaohong , Li Runhua , Ma Qiaoqin , Wang Hui , Jiang Tingting , He Lin , Zeng Shidian , Wang Dayong , Ye Zhenmiao , Zhu Haishen , Zhao Dongshe , Xia Shichang
Published: May 2018

Objectives

Men who have sex with men (MSM) are a marginalised population at high risk for a variety of mental health problems that may mutually facilitate HIV transmission. We assessed factors associated with depressive symptoms among MSM, which can provide some guidance for future mental health interventions with the MSM population for prevention of HIV infection and transmission.

Methods

A cross-sectional study was conducted in Wenzhou city, China using respondent-driven sampling (RDS) between December 2013 and June 2014. A face-to-face questionnaire survey was employed to collect information about mental and psychosocial health conditions and sexual behaviour characteristics among MSM. Bivariate and multivariable logistic regression analyses were used to identify factors associated with major depressive symptoms.

Results

Of the 454 participants in the study, prevalence of major depressive symptoms was 34.6%. During the past 6 months, 85% had anal sex with men, and rate of consistent condom use during anal intercourse was 45.1%. Of the respondents, 16.1% reported suicidal ideation, 62.6% had a history of smoking and 41.4% had a history of drinking alcohol, of which 46.3% reported that they were once drunk. Drug use was reported in 3.7% of the sample. Adult sexual violence from same-sex partners was 7.9%, and 5.1% reported childhood sexual abuse. ARDS-weighted multivariable analysis showed that major depressive symptoms among MSM were associated with inconsistent condom use during anal sex with men, multiple oral male sexual partners, suicidal ideation, adult sexual violence from male partners and being once drunk in the past year.

Conclusion

We found high levels of depressive symptoms, unprotected sex and suicidal ideation among MSM. Comprehensive intervention strategies that combine psychological, behavioural and social aspects are needed to address the mental health issues of MSM, with special attention given to suicidality and high-risk behaviours in mental health and HIV prevention interventions.
Association between high-fasting insulin levels and metabolic syndrome in non-diabetic middle-aged and elderly populations: a community-based study in Taiwan
Authors: Chen Yun-Hung , Lee Yu-Chien , Tsao Yu-Chung , Lu Mei-Chun , Chuang Hai-Hua , Yeh Wei-Chung , Tzeng I-Shiang , Chen Jau-Yuan
Published: May 2018

Objectives

We aimed to determine the association between fasting insulin (FI) levels and metabolic syndrome (MetS) in non-diabetic middle-aged and elderly adults in a community in Taiwan.

Design

Cross-sectional observational study.

Setting

Community-based investigation in Guishan township of northern Taiwan.

Participants

Our study included adults aged 50 years and above during community health examinations between January and October 2014. People with diabetes mellitus were excluded. A total of 321 people were enrolled.

Outcome measures

We divided participants according to tertiles of FI as low, medium and high levels. Pearson correlation was assessed between insulin level and each of the diagnostic components of metabolic syndrome (MetS-DCs) with adjustment of age. The prevalence of MetS-DCs based on tertiles of FI were studied and analysed by Cochran–Armitage trend test. The risk for prevalence of MetS in the middle and high insulin group as compared with the low insulin group were assessed by multivariate logistic regression with adjustments for age, gender, smoking, body mass index (BMI), hypertension and hyperlipidaemia. Youden Index was performed for the optimised cut-off value.

Results

Our results showed positive correlation of FI level with systolic blood pressure, waist circumference, fasting plasma glucose and triglyceride levels, while negative correlation was shown with high-density lipoprotein (P<0.001). The prevalence of each MetS-DCs increased as a trend while FI levels increased (P<0.001). OR (95% CI) of MetS was 5.04 (2.15 to 11.81) for high insulin groups compared with the low insulin group after adjusting confounders (P<0.001). Area under receiver operating characteristic curve (ROC) curve (AUC) was 0.78, and cut-off value 7.35 μU/mL for FI was obtained (sensitivity: 0.69; specificity: 0.77).

Conclusions

Middle-aged and elderly non-diabetic people with increased FI are associated with a higher prevalence of MetS in the community in Taiwan. Furthermore, FI is an independent risk factor of MetS in this study population.
‘Treading water but drowning slowly’: what are GPs’ experiences of living and working with mental illness and distress in England? A qualitative study
Authors: Riley Ruth , Spiers Johanna , Chew-Graham Carolyn A , Taylor Anna K , Thornton Gail A , Buszewicz Marta
Published: May 2018

Objectives

This paper provides an in-depth account of general practitioners’ (GPs) experiences of living and working with mental illness and distress, as part of a wider study reporting the barriers and facilitators to help-seeking for mental illness and burn-out, and sources of stress/distress for GP participants.

Design

Qualitative study using in-depth interviews with 47 GP participants. The interviews were audio recorded, transcribed, anonymised and imported into NVivo V.11 to facilitate data management. Data were analysed using a thematic analysis employing the constant comparative method.

Setting

England.

Participants

A purposive sample of GP participants who self-identified as: (1) currently living with mental distress, (2) returning to work following treatment, (3) off sick or retired early as a result of mental distress or (4) without experience of mental distress. Interviews were conducted face to face or over the telephone.

Results

The findings report GP participants’ in-depth experiences of distress and mental illness with many recollecting their distressing experiences and significant psychological and physical symptoms relating to chronic stress, anxiety, depression and/or burn-out, and a quarter articulating thoughts of suicide. Many talked about their shame, humiliation and embarrassment at their perceived inability to cope with the stresses of their job and/or their symptoms of mental illness.

Conclusions

These findings paint a concerning picture of the situation affecting primary care doctors, with participants’ accounts suggesting there is a considerable degree of mental ill health and reduced well-being among GPs. The solutions are complex and lie in prevention and provision. There needs to be greater recognition of the components and cumulative effect of occupational stressors for doctors, such as the increasing workload and the clinical and emotional demands of the job, as well as the need for a culture shift within medicine to more supportive and compassionate work environments.
Managing perioperative pain in dogs and cats
Authors: MacFarlane Paul
Published: May 2018

Effective pain management in the perioperative period is important morally for the welfare of the animal, and also because it is likely to improve clinical outcomes. Pain is an emotional experience with multiple underlying physiological components and factors beyond traditional concepts of analgesia affect its severity. This article considers the techniques available to provide perioperative analgesia and how to best deploy them.
Slipped disc and dyspnoea in a French bulldog
Authors: McLellan Laura
Published: May 2018

THIS series gives readers the opportunity to consider and contribute to discussion of some of the ethical dilemmas that can arise in veterinary practice. Each month, a case scenario is presented, followed by discussion of some of the issues involved.

In addition, a possible way forward is suggested; however, there is rarely a cut‐and‐ dried answer in such cases, and readers may wish to suggest an alternative approach. This month's dilemma, ‘Slipped disc and dyspnoea in a French bulldog’, was submitted and is discussed by Laura McLellan. Readers with comments to contribute are invited to send them as soon as possible, so that they can be considered for publication in the next issue.

The series is being coordinated by Dr Steven McCulloch, acting director of the Centre for Animal Welfare, University of Winchester. It aims to provide a framework that will help practising veterinarians find solutions when facing similar dilemmas.
Obtaining good quality samples for cytology
Authors: Powell Roger
Published: May 2018

Cytology, or cytopathology, often requires the use of fine (less than 20 gauge) needle sampling to obtain cells to identify a pathological process. Alternatively, cells can be harvested via a direct impressed iatrogenic material or fluid preparation(s), via lavage or in‐vivo exfoliation into an effusion. Diagnosis of any pathology can be done with very few cells, but the more cells available, the more likely the correct diagnosis is made. To maximise chances of a correct diagnosis, cytology requires good quality samples, with detailed knowledge of normal and pathological cell features to examine the preparations. This article focuses on obtaining good quality samples with the principles being applicable to all veterinary species.
Marketing IQOS in a dark market
Authors: Mathers Annalise , Schwartz Robert , O’Connor Shawn , Fung Michael , Diemert Lori
Published: May 2018

Introduction

Phillip Morris International (PMI) is pushing hard to promote IQOS heat-not-burn cigarettes in Ontario, Canada. Canada regulates IQOS as a tobacco product so that the robust tobacco marketing ban creates challenges to its promotion.

Methods

We collected data on IQOS promotion in 49 retail outlets, and through interviews with clerks and observations outside an IQOS store.

Results

The dominant marketing channel is the visible availability of IQOS in a large number of tobacco retail outlets—1029 across Ontario. Several stores display the price of ‘heated tobacco’ on one of three price signs which are permitted despite Ontario’s total display ban. IQOS boutique stores are the locus of aggressive promotion including exchanging a pack of cigarettes or lighter for an IQOS device, launch parties, ‘meet and greet’ lunches and after-hour events. Outside the store, promotion includes a prominent IQOS sign, a sandwich board sign reading ‘Building a Smoke-Free Future’ and sales representatives regularly smoking IQOS. Membership services: Upon acquiring an IQOS device one can register to access the IQOS website store5 and receive customer support services, a map of retail locations and a product catalogue. Members receive regular email invitations to complete surveys with opportunities to win prizes.

Conclusions

These promotion activities have undoubtedly made substantial numbers of Ontarians aware of IQOS. Yet, the government has not provided guidance as to absolute and relative potential harms. Our observations of tactics to promote a new tobacco product in a dark market may inform government regulatory policy and non-governmental organisation efforts wherever heat-not-burn products are introduced.
Study of bilateral trading platform competition in consideration of suppliers’ spatial network
Authors: Xu Yan , Tao Xiaobo , Sun Yongbo
Published: May 2018

The bilateral trading platform is an intermediary system which serves both consumers and suppliers. To make this happen, platforms must attract users on board from both sides and make them trade with each other. Spatial distribution of suppliers has the significant impact on consumers platform adoption decision, but how does the supplier’s network affect the platform competition has rarely been studied. In this paper, the supplier’s spatial network is added to bilateral trading platform network effect model, and influences of the supplier’s network structure on the platform competition are discussed. Simulation results show that, compared with the central network, the decentralized network is more conducive to the platform competition. When suppliers on two competitive platforms follow the same network structure, the reinforcement effect of the first-mover advantage on platforms will vanish. This result is robust in different spatial network patterns. Conversely, when one of the platforms has a superior network structure of suppliers, its first-mover advantage will get strengthened, and it will achieve a better competition result; otherwise, its first-mover advantage will get weakened. These results provide an insight into the platform competition mechanism and will help platforms to make corresponding competitive strategies.
Research on the exponential growth effect on network topology: Theoretical and empirical analysis
Authors: Li Shouwei , You Zongjun
Published: May 2018

Integrated circuit (IC) industry network has been built in Yangtze River Delta with the constant expansion of IC industry. The IC industry network grows exponentially with the establishment of new companies and the establishment of contacts with old firms. Based on preferential attachment and exponential growth, the paper presents the analytical results in which the vertices degree of scale-free network follows power-law distribution [Formula: see text] ([Formula: see text]) and parameter [Formula: see text] satisfies [Formula: see text]. At the same time, we find that the preferential attachment takes place in a dynamic local world and the size of the dynamic local world is in direct proportion to the size of whole networks. The paper also gives the analytical results of no-preferential attachment and exponential growth on random networks. The computer simulated results of the model illustrate these analytical results. Through some investigations on the enterprises, this paper at first presents the distribution of IC industry, composition of industrial chain and service chain firstly. Then, the correlative network and its analysis of industrial chain and service chain are presented. The correlative analysis of the whole IC industry is also presented at the same time. Based on the theory of complex network, the analysis and comparison of industrial chain network and service chain network in Yangtze River Delta are provided in the paper.
Study of car-sharing diffusion criticality conditions based on human traveling network
Authors: Xu Yan , Ji Xuehong
Published: May 2018

Car-sharing program, like Car2go, is an innovative urban transportation mode where the car-sharing company provides a car fleet to offer people with the short-term access of car traveling. As a new traveling service, car-sharing platforms have been struggling hard to trigger initial users and speed up their diffusion process. Unlike new product spreading via geographical proximity people, car-sharing users usually drive sharing cars to different destinations and influence people there, and potential user decision also depends on previous user activity at all their destinations. Car-sharing user connections are mainly affected by their traveling behaviors. The influence of user traveling network on new service/product spreading process has been rarely studied before. Here, we find that the infective rate between users with the same destination is critical to the minimum user base of car-sharing diffusion. Moreover, a city with central user network is more appropriate for car-sharing. It leads to a small critical infective rate for diffusion, and a large stable market size of car-sharing service. Our study can impact car-sharing market strategies ranging from market expansion in one city to optimal market selection among different cities.
Thermal performance of nanofluid saturated porous medium on cooling electronics contained in an inclined hemispherical enclosure
Authors: Baïri A. , Laraqi N.
Published: May 2018

A nanofluid saturated porous medium is used for cooling purposes of a plane electronic device contained in the base of a hemispherical cavity. According to the intended application in embarked electronics, the base could be tilted with respect to the horizontal plane by an angle ranging from 0[Formula: see text] to 180[Formula: see text] (horizontal disc with cupola facing upwards and downwards, respectively). The volume fraction of the considered monophasic water-based ZnO nanofluid varies between 0% (pure water) and 10%, while the Rayleigh number based on the radius of the cavity ranges from [Formula: see text] to [Formula: see text]. The ratio between the thermal conductivity of the porous medium solid matrix and that of the base fluid varies between 0 and 70. Influence of these four parameters on the average temperature of the active electronic device is presented and commented. The work shows that the saturated porous medium has a significant effect on the thermal state of the electronic device. A correlation is proposed to easily calculate this temperature for any combination of these parameters, which allows thermal sizing for optimal cooling of this assembly used in electronics engineering.
Interacting Hidden Markov Models for Video Understanding
Authors: Narayana Pradyumna , Beveridge J. Ross , Draper Bruce A.
Published: May 2018

People, cars and other moving objects in videos generate time series data that can be labeled in many ways. For example, classifiers can label motion tracks according to the object type, the action being performed, or the trajectory of the motion. These labels can be generated for every frame as long as the object stays in view, so object tracks can be modeled as Markov processes with multiple noisy observation streams. A challenge in video recognition is to recover the true state of the track (i.e. its class, action and trajectory) using Markov models without (a) counter-factually assuming that the streams are independent or (b) creating a fully coupled Hidden Markov Model (FCHMM) with an infeasibly large state space. This paper introduces a new method for labeling sequences of hidden states. The method exploits external consistency constraints among streams without modeling complex joint distributions between them. For example, common sense semantics suggest that trees cannot walk. This is an example of an external constraint between an object label (“tree”) and an action label (“walk”). The key to exploiting external constraints is a new variation of the Viterbi algorithm which we call the Viterbi–Segre (VS) algorithm. VS restricts the solution spaces of factorized HMMs to marginal distributions that are compatible with joint distributions satisfying sets of external constraints. Experiments on synthetic data show that VS does a better job of estimating true states with the given observations than the traditional Viterbi algorithm applied to (a) factorized HMMs, (b) FCHMMs, or (c) partially-coupled HMMs that model pairwise dependencies. We then show that VS outperforms factorized and pairwise HMMs on real video data sets for which FCHMMs cannot feasibly be trained.
Granularity Approach for Multi-Criteria Decision Making About Hybrid Evaluation Information
Authors: Liu Shihu , Yu Fusheng , Wang Patrick S. P.
Published: May 2018

In this study, a new version of TOPSIS method is reconstructed to deal with the problem of multi-criteria decision making. Here, the data representation of all alternatives is varied according to different criteria, such as real number, interval-valued number, set-valued number and intuitionistic fuzzy-valued number, etc. Because the distinguishing ability of each criterion can be reflected by its knowledge granularity, naturally, a knowledge granularity method is constructed to measure the criteria weights. Besides, the approach of how to select the ideal solution is redefined, especially for the case that the content of criterion according to all alternatives is not a totally ordered set anymore. What is more, the decision maker’s personal preference is considered, and the concrete indicator value can be calculated by the convex combination of the distance from possible alternatives to ideal solutions. Finally, the validity of the proposed decision-making algorithm is illustrated by a synthetic example.
Absorption of zero-mass planar waves by dirty black holes
Authors: Macedo Caio F. B. , Leite Luiz C. S. , Crispino Luís C. B.
Published: May 2018

Astrophysical black holes are often with companions, including other gravitating objects, accretion disks, electromagnetic fields, and others. Because of the nonlinear nature of general relativity, it is difficult to account for the gravitational effects of these companions, which can only be investigated analytically for very few cases. In this paper, we consider black holes with surrounding matter — often called dirty black holes — and analyze the absorption cross section of massless scalar fields. We start by laying out the generic setup for spherically symmetric scenarios and then specify for a simple model. We consider planar massless scalar waves impinging upon a Schwarzschild black hole surrounded by a thin spherical shell, and compute the absorption cross section. We present a selection of numerical results complementary to those presented in [C. F. B. Macedo, L. C. S. Leite and L. C. B. Crispino, Phys. Rev. D 93 (2016) 024027, arXiv:1511.08781 [gr-qc]] for arbitrary frequencies, considering different values of the shell position as well as its mass.
STRUCTURE OF A PHTHALOCYANINE DYE ON ZnO
Authors: ZHENG HAO , XU YONG , DONG GUO-CAI , KRÖGER JÖRG , BERNDT RICHARD
Published: May 2018

Room temperature scanning tunneling microscopy was used to investigate the adsorption of a dye molecule, iron-phthalocyanine (FePc), on ZnO(0001). Submolecular resolution reveals the orientation of molecules with respect to crystallographic directions of the surface. Upon adsorption, the molecular symmetry is reduced. First-principles calculations trace these observations to a strong molecule-substrate bond, which induces deformations of the molecule.
Molecular dynamics simulation of N-octyl-N-quaternized chitosan derivatives as a drug carrier
Authors: Tayyem Muna T. , Zughul Mohammad B. , Almatarneh Mansour H.
Published: May 2018

The dynamic amphiphilic behavior of N-octyl-N-quaternized chitosan derivatives in aqueous solution is investigated using molecular dynamics (MD) simulations. It is found that quaternization decreases the intra-chain hydrogen bond formation which leads to reduced rigidity of the chitosan backbone. The effect of octyl substitution is much less pronounced. Analysis of hydrogen bonding reveals the presence of a hydrogen bond within the quaternized glucosamine unit, which causes the distortion of the usual chair conformation. Also, H-bond formation with the solvent water molecules was found to stabilize the intra-chain HO3-O5 hydrogen bond. Additionally, an aqueous solution containing the 10%-N-octyl-50%-N-quaternized chitosan derivative (1O5QCS) and the anti-cancer drug 10-hydroxycamptothecin (10-HCPT) was also investigated using MD simulations. It was found that van der Waals and electrostatic forces have virtually equal contributions to the nonbonded interactions responsible for complexation. Furthermore, H-bond formation between drug and drug carrier contributes to lactone ring stability and subsequent bioavailability.
Proposing drug fragments for dengue virus NS5 protein
Authors: Alhossary Amr , Awuni Yaw , Kwoh Chee Keong , Mu Yuguang
Published: May 2018

Dengue fever is a febrile illness caused by Dengue Virus, which belongs to the Flaviviridae family. Among its proteome, the nonstructural protein 5 (NS5) is the biggest and most conserved. It has a primer-independent RNA-dependent RNA polymerase (RdRp) domain at its C-Terminus. Zou et al. studied the biological relevance of the two conserved cavities (named A and B) within the NS5 proteins of dengue virus (DENV) and West Nile Virus (WNV) using mutagenesis and revertant analysis and found four mutations located at cavity B having effects on viral replication. They recommended Cavity B, but not Cavity A as a potential target for drugs against flavivirus RdRp. In this study, we virtually screened the MayBridge drug fragments dataset for potential small molecule binders of cavity B using both AutoDock Vina, the standard docking tool, and QuickVina 2, our previously developed tool. We selected 16 fragments that appeared in the top 100 docking results of each of the representative structures of NS5. Visual inspection suggests that they have reasonable binding poses. The 16 predicted fragments are plausible drug candidates and should be considered for further validation, optimization, and linking to come up with a suitable inhibitor of dengue virus.
Modeling the probability distribution of the bacterial burst size via a game-theoretic approach
Authors: Malekpour Seyed Amir , Pakzad Parsa , Foroughmand-Araabi Mohammad-Hadi , Goliaei Sama , Tusserkani Ruzbeh , Goliaei Bahram , Sadeghi Mehdi
Published: May 2018

Based on previous studies, empirical distribution of the bacterial burst size varies even in a population of isogenic bacteria. Since bacteriophage progenies increase linearly with time, it is the lysis time variation that results in the bacterial burst size variations.

Here, the burst size variation is computationally modeled by considering the lysis time decisions as a game. Each player in the game is a bacteriophage that has initially infected and lysed its host bacterium. Also, the payoff of each burst size strategy is the average number of bacteria that are solely infected by the bacteriophage progenies after lysis. For calculating the payoffs, a new version of ball and bin model with time dependent occupation probabilities (TDOP) is proposed.

We show that Nash equilibrium occurs for a range of mixed burst size strategies that are chosen and played by bacteriophages, stochastically. Moreover, it is concluded that the burst size variations arise from choosing mixed lysis strategies by each player. By choosing the lysis time and also the burst size stochastically, the released bacteriophage progenies infect a portion of host bacteria in environment and avoid extinction. The probability distribution of the mixed burst size strategies is also identified.
Energy conditions in higher derivative f(R,□R,T) gravity
Authors: Yousaf Z. , Sharif M. , Ilyas M. , Zaeem-ul-Haq Bhatti M.
Published: May 2018

In this paper, we examined the viability bounds of a higher derivative [Formula: see text] theory through analyzing energy conditions (where [Formula: see text] and [Formula: see text] are the Ricci scalar, d’Alemberts operator and trace of energy–momentum tensor, respectively). We take flat Friedmann–Lemaître–Robertson–Walker spacetime coupled with ideal configurations of matter content. We consider three different realistic models of this gravity, that could be utilized to understand the stability of cosmological solutions. After constructing certain bounds mediated by energy conditions, more specifically the weak energy condition, we discuss viable zones of the under considered modified models in an environment of recent estimated numerical choices of the cosmic parameters.
Dynamic Mechanical Responses of Ultrafine-Grained IF Steel Over a Wide Range of Temperatures
Authors: Liu Jiejian , Suo Tao , Fan Yuqing , Li Jianguo , Zhou Fenghua , Li Yulong
Published: May 2018

The ultrafine-grained interstitial free (UFG-IF) steel was fabricated using the equal channel angular pressing (ECAP) method. Transmission electronic microscope (TEM) observations showed that the grains were refined to sub-micrometer scale and the average grain size was several hundred nanometers (nm). Uniaxial compression tests were conducted over a wide range of strain rates (up to 6000/s) and temperatures (from −196[Formula: see text]C to 300[Formula: see text]C) to understand the dependence of mechanical behaviors on the strain rate and temperature. It is found that the UFG-IF steel showed a weak strain rate sensitivity and displayed a strong temperature sensitivity only within a very narrow temperature range. Microstructural observations on the specimens deformed dynamically at temperatures below −20[Formula: see text]C via scanning electronic microscopy (SEM) and TEM indicated the occurrence of adiabatic shear localization. In order to explain the reason why adiabatic shear localization formed at the low temperatures and high strain rates, the susceptibility factor to adiabatic shear band (ASB) was estimated. It is proposed that more heat generated during the adiabatic plastic deformation process due to the enhanced flow stress of the UFG-IF steel at lower temperatures may play a dominant role in the formation of ASB. Meanwhile, the experimental results also provide strong evidence that for the UFG-IF steel the dynamic recrystallization which results from the severe plastic deformation and high temperature rise only occurs at the later stage of ASB evolution. With regard to the formation of ASB in the UFG IF steel, the localized plastic flow at a lower stress level indicates that localized deformation happens firstly and the temperature rise in the localized shearing zone leads to the final plastic instability.
The effect of temperature on morphology and electrochemical properties of NiCo2S4 by hydrothermal synthesis
Authors: Sui Yanwei , Hu Haihua , Zhang Yuanming , Tang Bin , Qi Jiqiu , Ren Yaojian , Wei Fuxiang , He Yezeng , Meng Qingkun , Sun Zhi
Published: May 2018

The hydrothermal method, using the template is a conspicuous way to change the morphology of the product, so it is used widely in many reports. The effect of temperature on morphology of NiCo2S4 by hydrothermal synthesis and its electrochemical properties is distinct as high-performance electrode materials for supercapacitors. With the help of the template (carbon sphere), different morphologies of NiCo2S4 under 90[Formula: see text]C, 120[Formula: see text]C and 180[Formula: see text]C were obtained. They have different properties after electrochemical analysis. In order to build a hierarchical multi-level structure, two-step vulcanization was carried out at each temperature, resulting in the difference in the morphology and performance of the six sample of electrodes. The obtained NiCo2S4 electrodes exhibit 1000[Formula: see text]F[Formula: see text]g[Formula: see text] at the current density of 1[Formula: see text]A[Formula: see text]g[Formula: see text] in the second-step of the hydrothermal process under 120[Formula: see text]C, which is superior to the microblocks NiCo2S4 electrode (90[Formula: see text]C, 888[Formula: see text]F[Formula: see text]g[Formula: see text] at the current density of 1[Formula: see text]A[Formula: see text]g[Formula: see text]) and microparticles NiCo2S4 electrode (180[Formula: see text]C, 574[Formula: see text]F[Formula: see text]g[Formula: see text] at the same current density) in the second-step hydrothermal, which shows a high-rate capability (640[Formula: see text]F[Formula: see text]g[Formula: see text] at 20[Formula: see text]A[Formula: see text]g[Formula: see text]). The obtained nanoparticles NiCo2S4 under 180[Formula: see text]C in the first-step hydrothermal electrode had an excellent cycle retention rate (89.7%), although its specific capacitance was lower. At the same time, the specific capacitance of these sample electrodes obtained in the second-step hydrothermal process is superior to those from the first-step. It was mainly attributed to the fact that temperature can influence the morphology by controlling ion exchange. And our experiment aims to use the hydrothermal method and the template method to find a more suitable temperature range to provide more ideas.
Successful Pregnancy following Mixed Double Embryo Transfer in a Patient with Variable Window of Implantation
Authors: Stamenov Georgi Stamenov , Parvanov Dimitar Angelov , Chaushev Todor Angelov
Published: May 2018

The process of embryo implantation is carried out during the receptive stage of the endometrium in the midluteal phase of the menstrual cycle, known as window of implantation (WOI). It has been assumed that the WOI is not a constant variable in all women and the determination of its displacement is of crucial importance, especially for patients with recurrent implantation failure (RIF). Furthermore, in rare cases it could have different duration and position in the menstrual cycle even in the same woman but during different periods. Here, we report a 37-year-old woman with RIF, who was previously classified as idiopathic but has now been diagnosed as having a variable WOI. This interpretation was done after the performance of immunohistochemical and histomorphological analyses of endometrial biopsies taken in the midluteal phase during three sequential menstrual cycles. In order to solve the problem with pinpointing a variable WOI, a specific type of embryo transfer, called mixed double embryo transfer (MDET), was done where one Day 3 and one Day 5 good quality embryos were transferred simultaneously 7 days after ovulation. A viable single pregnancy was confirmed by ultrasound scan and a healthy girl was born. This case showed a unique approach in overcoming the problem in RIF patients with variable WOI.
On the Solutions of a System of Third-Order Rational Difference Equations
Authors: Alotaibi A. M. , Noorani M. S. M. , El-Moneam M. A.
Published: May 2018

The structure of the solutions for the system nonlinear difference equations xn+1=ynyn-2/(xn-1+yn-2), yn+1=xnxn-2/(±yn-1±xn-2), n=0,1,…, is clarified in which the initial conditions x-2, x-1, x0, y-2, y-1, y0 are considered as arbitrary positive real numbers. To exemplify the theoretical discussion, some numerical examples are presented.
Coulomb Planar Periodic Motion of n Equal Charges in the Field of n Equal Positive Charges Fixed at a Line and Constant Magnetic Field
Authors: Skrypnik W. I.
Published: May 2018

We consider a neutral Coulomb planar system of n equal negative charges in a constant magnetic field and a field of n equal fixed positive charges and construct a periodic solution of the equation of motion such that each negative charge is close to its own positive fixed charge.
Gestational Tubal Choriocarcinoma Presenting as a Pregnancy of Unknown Location following Ovarian Induction
Authors: Lin Lawrence Hsu , Fushida Koji , Hase Eliane Azeka , Schultz Regina , Tenorio Laysa Manatta , Madia Fabricia Andrea Rosa , Zanardo Evelin Aline , Kulikowski Leslie Domenici , Francisco Rossana Pulcineli Vieira
Published: May 2018

The management of pregnancy of unknown location (PUL) can be a challenging situation, since it can present as several different conditions. Here we describe a rare case of gestational choriocarcinoma arising in the fallopian tube after ovarian induction in an infertile patient. The patient received clomiphene for ovarian induction and had rising levels of human chorionic gonadotropin (hCG) over nine months without sign of pregnancy. After referral to our center, the patient was diagnosed with a paraovarian tumor, which revealed a gestational choriocarcinoma arising in the fallopian tube; the final diagnosis was supported by pathological and cytogenomic analysis. Malignancies, such as gestational trophoblastic disease, should be in the differential diagnosis of PUL; the early recognition of these conditions is key for the proper treatment and favorable outcome.
Melittin Constrains the Expression of Identified Key Genes Associated with Bladder Cancer
Authors: Jin Zidan , Yao Jie , Xie Nianlin , Cai Libo , Qi Shuai , Zhang Zhan , Li Bai
Published: May 2018

This work is aimed at investigating the effect of melittin on identified key genes in bladder cancer (BC) and further providing a theoretical basis for BC treatment. GSE35014 downloaded from the Gene Expression Omnibus (GEO) database was used to screen differentially expressed genes (DEGs) in BC cells and control. Results showed that a total of 389 upregulated and 169 downregulated genes were identified. Subsequently, GO analysis, KEGG pathway enrichment analysis, and PPI network analysis were employed to disclose the crucial genes and signaling pathways involved in BC. Fifteen module-related DEGs and their associated signaling pathways were obtained according to the PPI network and modular analyses. Based on the analysis of articles retrieved in the PubMed database, we found that melittin could induce apoptosis and constrain the progression of tumor cells as a result of regulating critical cancer-related signaling pathways, such as PI3K-Akt and TNF signaling pathways. Furthermore, PI3K-Akt and TNF signaling pathways were also found to be associated with module-related DEGs according to biological analyses. At last, qRT-PCR analysis demonstrated that melittin could constrain the expression of module-related DEGs (LPAR1, COL5A1, COL6A2, CXCL1, CXCL2, and CXCL3) associated with PI3K-Akt and TNF signaling pathways in BC cells. Functional assays revealed that melittin could constrain the proliferative and migrated abilities of BC cells. Conjointly, these findings provide a theoretical basis for these six genes as drug-sensitive markers of melittin in BC treatment.
Hybrid Aspect of Context-Aware Middleware for Pervasive Smart Environment: A Review
Authors: Madhusudanan J. , Geetha S. , Prasanna Venkatesan V. , Vignesh U. , Iyappan P.
Published: May 2018

Pervasive computing has made almost every device we see today to be communicated and function in collaboration with one another. Since the portable devices have become a part of our everyday life, people are more involved in a pervasive computing environment. They engage with many computational devices simultaneously without knowing the availability of their existence. The current world is being filled with more and more smart environments. These smart environments make them to be attracted towards the new technological emergence in the field of pervasive computing. Various researches are being carried out to improve the smart environment and their applications. Middleware plays a vital role in building the pervasive applications. The pervasive devices act based on the context of the situation, that is, they do their actions according to the environment of the application. They react to the situations smartly as they can take their own decisions based on the context developed for that specific application. Most of the pervasive applications were using its own middleware that is specific towards their need. As today, most of the applications are using their own middleware with their specific requirement, which leads us to unearth out their common features and their scope of using it. In this paper, a survey on the various hybrid aspects of the different context-aware middleware has been done. This middleware is classified based on service, context, and device aspects. Merits and demerits are identified from the existing smart environments, and future perspective of their development such as generic context-aware middleware need has been discussed.