bluuebunny/crossref_metadata_2025 huggingface dataset:
Process enhancement for maximization of methane production in codigestion biogas plants
Authors: Capodaglio Andrea G , Ranieri Ezio , Torretta Vincenzo
Published: March 2016

Purpose

– The purpose of this paper is to develop improvements in the efficiency of the codigestion process.

Design/methodology/approach

– Two pilot plants, fed by different compositions of manure and industrial organic waste, generating biogas by mesophilic and thermophilic anaerobic fermentation, respectively, were analysed.

Findings

– It was observed that these processes do not commonly operate at maximum theoretical efficiency.

Research limitations/implications

– The limiting factor in the process was found to be the hydrolysis of the digested material.

Practical implications

– A technical solution had been suggested: implementing a secondary (after) storage phase which has the purpose of exploiting, by promoting enhanced hydrolysis, the substrate potential that remains undigested after the traditional process.

Originality/value

– The proposed configuration opens to original variations in the anaerobic digestion schemes.
Chemometric modeling to predict aquatic toxicity of benzene derivatives in Pimephales Promelas
Authors: Ziani Nadia , Amirat Khadidja , Messadi Djelloul
Published: March 2016

Purpose

– The purpose of this paper is to predict the aquatic toxicity (LC50) of 92 substituted benzenes derivatives in Pimephales promelas.

Design/methodology/approach

– Quantitative structure-activity relationship analysis was performed on a series of 92 substituted benzenes derivatives using multiple linear regression (MLR), artificial neural network (ANN) and support vector machines (SVM) methods, which correlate aquatic toxicity (LC50) values of these chemicals to their structural descriptors. At first, the entire data set was split according to Kennard and Stone algorithm into a training set (74 chemicals) and a test set (18 chemical) for statistical external validation.

Findings

– Models with six descriptors were developed using as independent variables theoretical descriptors derived from Dragon software when applying genetic algorithm – variable subset selection procedure.

Originality/value

– The values of Q2 and RMSE in internal validation for MLR, SVM, and ANN model were: (0.8829; 0.225), (0.8882; 0.222); (0.8980; 0.214), respectively and also for external validation were: (0.9538; 0.141); (0.947; 0.146); (0.9564; 0.146). The statistical parameters obtained for the three approaches are very similar, which confirm that our six parameters model is stable, robust and significant.
A Mathematical Model for Self-Twist Yarn Spinning Process
Authors: Cui Hong , Yu Chongwen
Published: March 2016

A mathematical model is established for self-twist spinning process by applying laws of fluid mechanics (i.e. mass conservation and momentum conservation). The motion curve of the convergent point was determined and the convergence point was decided by densities and velocities of two fed-in strands and the resultant self-twist yarn, independent of their mechanical properties. The experimental verification proves that the motion trajectory of the convergence point reaches a better agreement with the theoretical trajectory. The results provide general way to study the self-twist yarn spinning process and optimize the process parameters.
Studies on the Influence of Seasonal and Regional Aspects on the Quality of Muga Silk
Authors: Padaki Naveen V , Bhattacharya Amal , Das Brojeswari , Choudhury Brajendra , Mishra SN , Singh BK
Published: March 2016

Muga is an exclusive naturally golden coloured wild silk obtained by the Antherea assamensis silkworm species grown in the north-eastern region of India. Although many research studies on Bombyx mori silk can be found, but studies that involve muga silk is uncommon. This article attempts to characterise the muga cocoon of two commercially available crops (Kotia and Jethua) in three prominent muga rearing regions. Reeling studies on these have also been conducted to assess the regional and seasonal influences on silk reelability performance. Kotia cocoons are found to possess better cocoon quality and reeling performance in comparison to Jethua muga cocoons.
Study on the Increase of Comfort in Ten Fashion Summer Tops Made of Four Kinds of Textiles
Authors: Chang Yi-Ching , Lee Kuei-Chi , Miao Mei-Fen , Yu Huei-Jen
Published: March 2016

In response to the increasing demands for energy saving and carbon reduction under current global trends, we apply 10 fashion summer tops from Paris and New York made of cotton and CVC fabrics, fabric that has moisture transferring and sweat expulsion abilities, and fabric with moisture transferring and sweat expulsion properties that also imparts a cooling sensation in this study. Furthermore, by analyzing the activity of sympathetic and parasympathetic nerves which are measured by a heartbeat variability analyzer, we have obtained the relative comfort results in both the dynamic and static modes while the tested subject is wearing garments made from the 4 types of fabrics. We have tried to bring out the relationship between summer fashion style, fabric type and comfort. The test results indicate that the fabric with moisture transferring and sweat expulsion abilities can greatly increase the comfort of the garment and the comfort will be further increased if the fabric adds nano mineral-powder that imparts a cooling sensation for further moisture transferring and sweat expulsion. Finally, less coverage and stress on the top part (neck, shoulders and upper back) of the human body can reduce induced pressure and increase the relative comfort.
Adoption of Information and Communication Technologies in Textile Virtual Collaboration
Authors: Fang Siyan , To Chester K.M. , Zhang Zhiming , Chang Jimmy M.T.
Published: March 2016

Modern organizations face more and more challenges in today's globalizing markets. Many textile firms operate collaboratively as a globally-networked virtual team to sustain their competitiveness. How to select and utilize a diversity of information and communication technologies (ICTs) to facilitate collaboration among these textile virtual teams is a critical issue to these enterprises. This paper explores the criteria of ICT adoption in collaboration processes from both theoretical and practical perspectives. First, ICTs theories of telecommunications are reviewed to conclude background knowledge and examine contextual requirements for ICTs. We find that the conveyance of social cues, the ability of fostering member involvement and coordinating interruptions, and the user-friendly interface of communication technology are crucial to the remote collaboration among textile firms. Second, empirical in-depth interviews with 20 practitioners in textile and apparel companies are conducted. Then, combining the findings, we discuss the features of primary ICTs adopted in practice at present. We recommend six essential facets in ICTs adoption during textile virtual team communication (i.e. synchronicity, medium richness, connectedness, disruptiveness, ease of use, and cost). We also suggest how these ICTs can be deployed in line with organizational and individual factors to facilitate textile virtual collaboration.
Photochromic Textiles and Measurement of Their Temperature Sensitivity
Authors: Vikova Martina , Vik Michal
Published: March 2016

Our previous papers (Viková & Vik, 2005) described a unique device, now patented in the Czech Republic in the author's name, for photochromic measurement in a reflectance mode together with a methodology. This device allows photochromic sensors to test the colorimetric and spectral characteristics of photochromic textiles, and also fatigue tests for control of colour change stability. This concept of colorimetric and spectral parameters also finds the dependence of colour change on the intensity of UV irradiation and temperature. In this paper, we would like to describe the dependence of colour change on temperature for the photochromic Photopia AQ Ink system (Blue, Purple and Yellow) produced by Matsui Shikiso Chemical Co.Ltd.

It is known that the reversion of photochromic compounds from coloured to colourless is promoted thermally. The photochromic structure can achieve a lower level of saturated absorbance at higher temperatures when thermo reversible photochromic systems, such as spirooxazines and chromenes, increase the rate of thermal bleaching reaction and thus decrease light stimulated coloration.
Improvement on Hydrophobicity of Synthetic Textiles by Plasma Treatment – A Review
Authors: Kwong C.H. , Ng S.P. , Kan C.W.
Published: March 2016

Plasma treatment is becoming increasingly popular in enhancing the hydrophobicity of synthetic textiles. In recent years, the study of surface hydrophobisation by means of plasma treatment, under low or atmospheric pressure, has drawn a great deal of attention. A large amount of research has reported on the possibility of applying this technique with merits that include a dry process, reduced pollution, a single step treatment, etc. In this regard, this paper reviews recent approaches on enhancing the hydrophobicity of synthetic textiles by means of plasma treatment. The basic working principle of generating plasma to enhance hydrophobicity is explained. Both low and atmospheric plasma treatments are introduced. A higher cost is usually required for low pressure plasma because of the investment on a vacuum chamber. On the other hand, carrier gas is required for atmospheric plasma treatment, which is not the case for low pressure plasma. The experimental set up and the chemicals involved in the processes are discussed. In order to enhance surface hydrophobicity, fluorocarbons are always applied, such as perfluoroalkylacrylate, perfluorodecaline and tetrafluoroethylene.
Design solutions to Address Garment Industry Issues in Egypt
Authors: Abd El Megid Z.M. , Hamdi A.
Published: March 2016

This research aims to develop design solutions for all the obstacles that workers face during the sewing process, and these solutions are focused on the following: chair design, sewing table design and sewing machine pedal. The design of the workplace includes the order of the components of the work according to the ability of the human body to handle lighting, ventilation and noise. Both the university and research centre consider that the purpose of the research is to examine these obstacles and propose appropriate solutions that could eliminate these occupational diseases that result from the process of sewing, and increase the production rates and quality which will consequently stimulate the Egyptian economy.

The research originates from the work of an integrated regulatory framework of design tools and equipment used for the sewing process and the related work place in accordance with design ergonomic objectives that when achieved, will accelerate the performance and quality of production, and prevent occupational diseases resultant from poor design. The research has also developed a set of recommendations that deal with the deficiencies in the performance of the sewing process, in order to raise the competitiveness of the garment industry in Egypt.
BN‐9, a chimeric peptide with mixed opioid and neuropeptide FF receptor agonistic properties, produces nontolerance‐forming antinociception in mice
Authors: Li Ning , Han Zheng‐lan , Wang Zi‐long , Xing Yan‐hong , Sun Yu‐long , Li Xu‐hui , Song Jing‐jing , Zhang Ting , Zhang Run , Zhang Meng‐na , Xu Biao , Fang Quan , Wang Rui
Published: March 2016

Background and Purpose

Neuropeptide FF (NPFF) behaves as an endogenous opioid‐modulating peptide. In the present study, the opioid and NPFF pharmacophore‐containing chimeric peptide BN‐9 was synthesized and pharmacologically characterized.

Experimental Approach

Agonist activities of BN‐9 at opioid and NPFF receptors were characterized in in vitro cAMP assays. Antinociceptive activities of BN‐9 were evaluated in the mouse tail‐flick and formalin tests. Furthermore, its side effects were investigated in rotarod, antinociceptive tolerance, reward and gastrointestinal transit tests.

Key Results

BN‐9 acted as a novel multifunctional agonist at μ, δ, κ, NPFF1 and NPFF2 receptors in cAMP assays. In the tail‐flick test, BN‐9 produced dose‐related antinociception and was approximately equipotent to morphine; this antinociception was blocked by μ and κ receptor antagonists, but not by the δ receptor antagonist. In the formalin test, supraspinal administration of BN‐9 produced significant analgesia. Notably, repeated administration of BN‐9 produced analgesia without loss of potency over 8 days. In contrast, repeated i.c.v. co‐administration of BN‐9 with the NPFF receptor antagonist RF9 produced significant antinociceptive tolerance. Furthermore, i.c.v. BN‐9 induced conditioned place preference. When given by the same routes, BN‐9 had a more than eightfold higher ED50 value for gastrointestinal transit inhibition compared with the ED50 values for antinociception.

Conclusions and Implications

BN‐9 produced a robust, nontolerance‐forming analgesia with limited inhibition of gastrointestinal transit. As BN‐9 is able to activate both opioid and NPFF systems, this provides an interesting approach for the development of novel analgesics with minimal side effects.
Alleviation of renal mitochondrial dysfunction and apoptosis underlies the protective effect of sitagliptin in gentamicin-induced nephrotoxicity
Authors: Abuelezz Sally A , Hendawy Nevien , Abdel Gawad Sara
Published: March 2016

Objective

This study aimed to investigate the potential protective effect of sitagliptin on gentamicin-induced nephrotoxicity and to elucidate the underlying mechanism.

Methods

Wistar rats were allocated as follows: Gentamicin group: received gentamicin intraperitoneally (100 mg/kg/day); Gentamicin plus sitagliptin group: received simultaneous gentamicin and sitagliptin (30 mg/kg/day orally); Sitagliptin group: received only sitagliptin; and Control group: received saline. Blood urea nitrogen (BUN), serum creatinine, urine protein levels and histopathology of kidney tissues were evaluated. The activity of mitochondrial enzyme complexes reflects the mitochondrial function. Oxidative stress biomarkers and immunohistochemical studies for apoptotic markers caspase-3 and bax were evaluated.

Key findings

Gentamicin causes significant elevation of BUN, serum creatinine and urine proteins. Oxidative stress was revealed by decreased superoxide dismutase activity and catalase activity, glutathione depletion and increased malondialdehyde. Significant decrease in mitochondrial NADH dehydrogenase, succinate dehydrogenase, cytochrome c oxidase and mitochondrial redox activity indicates mitochondrial dysfunction, along with significant elevation in renal caspase-3 and bax. The aforementioned markers and the histological injury in renal tubules were significantly reversed upon sitagliptin treatment.

Conclusion

These findings suggest that sitagliptin treatment attenuates renal dysfunction and structural damage through the reduction of oxidative stress, mitochondrial dysfunction and apoptosis in the kidney.
Bioavailability enhancement and pharmacokinetic profile of an anticancer drug ibrutinib by self-nanoemulsifying drug delivery system
Authors: Shakeel Faiyaz , Iqbal Muzaffar , Ezzeldin Essam
Published: March 2016

Objective

The current studies were undertaken to enhance dissolution and bioavailability/pharmacokinetic profile of a newly approved anticancer drug ibrutinib (IBR) via encapsulation of drug into self-nanoemulsifying drug delivery system (SNEDDS).

Methods

Various SNEDDS formulations of IBR were developed by aqueous phase titration method using Capryol-PGMC (oil phase), Tween-20 (surfactant), Carbitol (cosurfactant) and water (aqueous phase). Developed SNEDDS of IBR was evaluated in vitro for various physicochemical properties and drug release profile.

Key findings

Based on lowest droplet size (28.7 ± 3.2 nm), least polydispersity (0.123), optimal values of zeta potential (−32.8 mV) and refractive index (1.336), highest % transmittance (98.7 ± 0.2%), highest drug release profile via dialysis membrane (98.9 ± 8.2% after 48 h) and the presence of lowest concentration of Capryol-PGMC (12% w/w), SNEDDS I1 was selected for in-vivo pharmacokinetic/bioavailability studies in female Wistar rats. In-vivo pharmacokinetic studies in rats showed that optimized SNEDDS I1 controlled the absorption of IBR compared with IBR suspension. The bioavailability of IBR from optimized SNEDDS I1 was enhanced around 2.64 times in comparison with IBR suspension.

Conclusion

These results indicated the potential of developed SNEDDS as an alternative drug delivery system for IBR to enhance its bioavailability and anticancer efficacy.
Quantitative proteomics links metabolic pathways to specific developmental stages of the plant‐pathogenic oomycete Phytophthora capsici
Authors: Pang Zhili , Srivastava Vaibhav , Liu Xili , Bulone Vincent
Published: March 2016

The oomycete Phytophthora capsici is a plant pathogen responsible for important losses to vegetable production worldwide. Its asexual reproduction plays an important role in the rapid propagation and spread of the disease in the field. A global proteomics study was conducted to compare two key asexual life stages of P. capsici, i.e. the mycelium and cysts, to identify stage‐specific biochemical processes. A total of 1200 proteins was identified using qualitative and quantitative proteomics. The transcript abundance of some of the enriched proteins was also analysed by quantitative real‐time polymerase chain reaction. Seventy‐three proteins exhibited different levels of abundance between the mycelium and cysts. The proteins enriched in the mycelium are mainly associated with glycolysis, the tricarboxylic acid (or citric acid) cycle and the pentose phosphate pathway, providing the energy required for the biosynthesis of cellular building blocks and hyphal growth. In contrast, the proteins that are predominant in cysts are essentially involved in fatty acid degradation, suggesting that the early infection stage of the pathogen relies primarily on fatty acid degradation for energy production. The data provide a better understanding of P. capsici biology and suggest potential metabolic targets at the two different developmental stages for disease control.
Deep sequencing leads to the identification of eukaryotic translation initiation factor 5A as a key element in Rsv1‐mediated lethal systemic hypersensitive response to Soybean mosaic virus infection in soybean
Authors: Chen Hui , Adam Arsovski Andrej , Yu Kangfu , Wang Aiming
Published: March 2016

Rsv1, a single dominant resistance locus in soybean, confers extreme resistance to the majority of Soybean mosaic virus (SMV) strains, but is susceptible to the G7 strain. In Rsv1‐genotype soybean, G7 infection provokes a lethal systemic hypersensitive response (LSHR), a delayed host defence response. The Rsv1‐mediated LSHR signalling pathway remains largely unknown. In this study, we employed a genome‐wide investigation to gain an insight into the molecular interplay between SMV G7 and Rsv1‐genotype soybean. Small RNA (sRNA), degradome and transcriptome sequencing analyses were used to identify differentially expressed genes (DEGs) and microRNAs (DEMs) in response to G7 infection. A number of DEGs, DEMs and microRNA targets, and the interaction network of DEMs and their target mRNAs responsive to G7 infection, were identified. Knock‐down of one of the identified DEGs, the eukaryotic translation initiation factor 5A (eIF5A), diminished the LSHR and enhanced viral accumulation, suggesting the essential role of eIF5A in the G7‐induced, Rsv1‐mediated LSHR signalling pathway. This work provides an in‐depth genome‐wide analysis of high‐throughput sequencing data, and identifies multiple genes and microRNA signatures that are associated with the Rsv1‐mediated LSHR.
FACTORS INFLUENCES RESIDENTIAL LOCATION SELECTION PREFERENCES TOWARD FUTURE NEIGHBORHOOD
Authors: Sinniah Gobi Krishna , Shah Muhammad Zaly , Vigar Geoff
Published: March 2016

It is critical to study the travel behaviour of residents as it provides an understanding on what people do over space and how people use transportation within that space. The objective of this study is to identify the factors that determine residential location preferences towards future neighborhood selection. Current literature focuses on preferences in relation to physical and demographic aspects, such as ownership, income, land use, facilities as well as transportation services. However, this study suggests safety and cultural aspects which are likely to be significant in many contexts. In order to further investigate these suggestions, a case study has been carried out based on Iskandar Malaysia’s development region. A Structural Equation Modeling (SEM) is applied to 384 household heads on their housing selection preferences. The result shows that there are significant relationships between residential location preferences and travel behaviour.
LATERAL MOVEMENT OF VEHICLES UNDER WEAK-LANE DISCIPLINE HETEROGENEOUS TRAFFIC
Authors: Mahapatra Geetimukta , Maurya Akhilesh Kumar , Minhans Anil
Published: March 2016

Safe driving can be achieved by prevention of risky situations which requires the knowledge of the vehicle dynamics and road geometry. The Indian traffic condition is heterogeneous in nature and has weak lane discipline. Hence, vehicles interactions takes place laterally also along with their longitudinal interaction. Vehicles lateral movements (interactions) are quite high due to absence of lane discipline. Therefore, the lateral acceleration of vehicles are an important variable which characterizes the corresponding vehicle dynamics. Several studies have been done by various authors on lateral acceleration in curves, however, lateral movement study of vehicles on straight road section is also important to analyze vehicles’ maneuver in such traffic (i.e. traffic stream with weak lane discipline). Therefore, the present study is about the observation of lateral movements of vehicles over different types of roads in three metropolitan cities of India (Kolkata, Mumbai and Pune) under moderate traffic conditions. Lateral acceleration variation of five different types of vehicles (SUV cars, Sedan cars, Hutch Back cars, motorized three wheeler and two wheeler) have been recorded to investigate its relationship with vehicles longitudinal characteristics (i.e. longitudinal speed) in Indian heterogeneous and weak lane disciplined traffic. Lateral acceleration values quickly rises with initial increase in speed afterward lateral acceleration values reduces with further increase in vehicles longitudinal speed.  Impact of vehicle type and locations on the lateral maneuvering of vehicles have also been studied
Engineering Embryonic Stem Cell Microenvironments for Tailored Cellular Differentiation
Authors: Huang Chenyu , Melerzanov Alexander , Du Yanan
Published: March 2016

The rapid progress of embryonic stem cell (ESCs) research offers great promise for drug discovery, tissue engineering, and regenerative medicine. However, a major limitation in translation of ESCs technology to pharmaceutical and clinical applications is how to induce their differentiation into tailored lineage commitment with satisfactory efficiency. Many studies indicate that this lineage commitment is precisely controlled by the ESC microenvironment in vivo. Engineering and biomaterial-based approaches to recreate a biomimetic cellular microenvironment provide valuable strategies for directing ESCs differentiation to specific lineages in vitro. In this review, we summarize and examine the recent advances in application of engineering and biomaterial-based approaches to control ESC differentiation. We focus on physical strategies (e.g., geometrical constraint, mechanical stimulation, extracellular matrix (ECM) stiffness, and topography) and biochemical approaches (e.g., genetic engineering, soluble bioactive factors, coculture, and synthetic small molecules), and highlight the three-dimensional (3D) hydrogel-based microenvironment for directed ESC differentiation. Finally, future perspectives in ESCs engineering are provided for the subsequent advancement of this promising research direction.
Wave Propagation in Sandwich Structures With Multiresonators
Authors: Chen J. S. , Huang Y. J.
Published: March 2016

A new sandwich beam with embedded multiresonators is presented. Two continuum Timoshenko beam models are adopted for modeling sandwich beams. Numerical results show that multiple resonators can lead to multiple resonant-type bandgaps with remarkable wave attenuation. The effective mass is found to become negative for frequencies in the bandgaps where the wave is greatly attenuated. With two identical resonators connected in parallel, only one single bandgap can be found. If two resonators with equal masses and springs are connected in series, the central frequency of the second bandgap is approximated twice of the central frequency of the first gap. For the beam with series-connected resonators, a simple two degrees-of-freedom system is proposed and used for predicting the initial frequencies of the bandgaps while for the beam with resonators in parallel, two separate single degree-of-freedom systems are introduced.
Enhanced Heat Transfer and Fouling Propensity of Diamond-Like Carbon Coated Smooth and Finned Tubes During External Nucleate Boiling
Authors: Reza Malayeri M. , Evangelidou M.
Published: March 2016

Smooth DLC (diamond-like carbon) coated surfaces can profoundly mitigate scaling during pool boiling of calcium sulphate solutions. Previous investigations though carried out mostly for the smooth surfaces rather than structured, i.e., finned tubes. This study compares experimental results of DLC coated smooth and finned tubes at clean and fouling conditions. Fouling runs were conducted during pool boiling of saturated CaSO4 solution of 1.6 g/L at 300 kW/m2. The substrate of the attempted tubes was stainless steel and finned tubes of 19 and 40 fins per inch were used. The DLC coated smooth tube showed an enhanced clean heat transfer up to 50% and reduced fouling resistance compared to the uncoated smooth tube. After a short operating time, though, the coated smooth tube reached an asymptotic fouling resistance of 0.00005 m2 K/W whereas for the uncoated smooth tube, it was 4.8 times higher. DLC coating of the finned tubes with the physical vapor deposition (PVD) technique implicated difficulties. The base surface of the finned tubes was defectively coated. The defectiveness of the coating was attributed to the limitation of the PVD for coating of structured surfaces.
Numerical Investigation of Heat Transfer Enhancement Using Hybrid Vortex Generator Arrays in Fin-and-Tube Heat Exchangers
Authors: Agarwal Shubham , Sharma R. P.
Published: March 2016

This is a novel study for assessing the heat transfer enhancement in a multi-row inline-tube heat exchanger using hybrid vortex generator (VG) arrays, i.e., rectangular winglet pairs (RWPs) with different geometrical configurations installed in coherence for enhanced heat transfer. The three-dimensional numerical study uses a full scale seven-tube inline heat exchanger model. The effect of roll of rectangular winglet VG on heat transfer enhancement is analyzed and optimized roll angle is determined for maximum heat transfer enhancement. Four different configurations are analyzed and compared in this regard: (a) single RWP (no roll); (b) 3RWP-inline array(alternating tube row with no roll of VGs); (c) single RWP (with optimized roll angle VGs); and (d) 3RWP-inline array(alternating tube row with all VGs having optimized roll angle). It was found that the inward roll of VGs increased the heat transfer from the immediately downstream tube but reduced heat transfer enhancement capability of other VG pairs downstream. Further, four different hybrid configurations of VGs were analyzed and the optimum configuration was obtained. For the optimized hybrid configuration at Re = 670, RWP with optimized roll angle increased heat transfer by 17.5% from the tube it was installed on and by 42% from the immediately downstream tube. Increase in j/ƒ of 36.7% is obtained by use of hybrid VGs in the optimized hybrid configuration. The deductions from the current study are supposed to well enhance the performance of heat exchangers with different design configurations.
Development of a mass spectrometer using two rotating electric fields
Authors: Nojima Masashi , Anai Yuki , Hotta Masanao , Kurumi Satoshi , Suzuki Kaoru , Adachi Tatsuya , Kusanagi Takashi , Moritani Kosuke
Published: March 2016

The authors propose a new principle for a mass analyzer involving a pair of rotating electric fields (REFs). Its design is reviewed from the perspectives of electronics, ion optics, and operating principle. The use of REFs to separate ions by mass was demonstrated by introducing a Ga focused-ion-beam column directly into the REFs optical system. By optimizing the system phase contrast, the 69Ga+ ions were made to converge to the central axis while the 71Ga+ formed an annular pattern. Asymmetries in annular patterns are caused by nonuniformity in the alternating current voltage of each REF electrode. By varying the frequency, the locations of the 69Ga+ and 71Ga+ projections can be exchanged between the center and exterior.
Structural analysis of negative ions by postsource decay in time-of-flight secondary ion mass spectrometry
Authors: Son Jin Gyeong , Shon Hyun Kyong , Park Jungdae , Moon Jeong Hee , Han Sang Woo , Lee Tae Geol
Published: March 2016

Phospholipids (PLs) are membrane lipids of living cells whose considerable role in biological membranes include protein sorting and regulation of biophysical properties and signaling pathways. PLs are classified by their head groups into phosphatidic acid, phosphatidylcholine (PC), phosphatidylglycerol, phosphatidylinositol (PI), phosphatidylserine (PS), and cardiolipin. Since PLs have varying ionization efficiencies, depending on their electron affinity, they can be detected at positive or negative ion modes so that PC and PS are generally detected as positive ions, and phosphatidylethanolamine and PI as negative ions. As a result, metabolite analyses in time-of-flight secondary ion mass spectrometry (ToF-SIMS) should be carried out by performing tandem mass spectrometry measurements at both ion modes to identify unknown PLs. For tandem mass spectrometry measurements in ToF-SIMS, a postsource decay (PSD)-like method was successfully applied to identify several lipids by using cholesterol as a model molecule at the positive ion mode. In our study, the authors adapted 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphor-rac-(1-glycerol) ammonium salt with well-known fragmentation pathways as a model molecule at the negative ion mode to identify PI lipids. By using the PSD-like method at both ion modes, the authors successfully identified PC and PI from MDA-MB-231 breast cancer cell lysates to show that our PSD-like method would be useful in the process of identifying unknown lipids from biological samples in ToF-SIMS.
Compressive acoustic sound speed profile estimation
Authors: Bianco Michael , Gerstoft Peter
Published: March 2016

Ocean acoustic  sound speed   profile (SSP) estimation requires the inversion of acoustic fields using limited observations. Compressive sensing (CS) asserts that certain underdetermined problems can be solved in high resolution, provided their solutions are sparse. Here, CS is used to estimate SSPs in a range-independent shallow ocean by inverting a non-linear acoustic propagation model. It is shown that SSPs can be estimated using CS to resolve fine-scale structure.
Pharmacokinetics of Posaconazole Suspension in Lung Transplant Patients with and without Cystic Fibrosis
Authors: Zhang Hongfei , Nguyen M. Hong , Clancy Cornelius J. , Joshi Rujuta , Zhao Wenchen , Ensor Chris , Venkataramanan Raman , Shields Ryan K.
Published: March 2016

Invasive fungal infections (IFIs) are common among lung transplant recipients (LTRs). Posaconazole is an important antifungal agent for both prophylaxis and treatment of IFIs; however, detailed pharmacokinetic data are limited among LTRs, particularly those with cystic fibrosis (CF). Our objective was to conduct a pharmacokinetic study of posaconazole oral suspension among LTRs, with particular attention to patients with CF. We enrolled 20 LTRs, 7 with CF and 13 with other underlying lung diseases. Average daily doses in CF and non-CF patients were 829 and 862 mg, respectively. After ≥5 days of treatment, only 4 patients had average plasma concentrations of >0.7 μg/ml. Average steady-state plasma concentrations were 61% lower in CF patients (0.233 μg/ml) than in non-CF LTRs (0.594 μg/ml;
P
= 0.03). The average dose-normalized plasma area-under-the-curve (AUC) values were also lower in CF (0.007 h·μg/ml) than in non-CF LTRs (0.02 h·μg/ml;
P
= 0.02). The weight-normalized apparent oral clearance values were 2.51 and 0.74 liters/h/kg among CF and non-CF LTRs, respectively (
P
= 0.005). Despite significant interpatient variability, plasma trough concentrations were strongly correlated with posaconazole AUC across all LTRs (
r
2
= 0.95,
P
< 0.0001). Taken together, our study highlights a critical need to incorporate new formulations of posaconazole into prophylaxis and treatment strategies for LTRs, particularly those with CF. Future pharmacokinetic studies of both tablet and intravenous formulations must consider LTR-specific factors and incorporate a therapeutic drug monitoring plan in this patient population.
Pilot Study of the Pharmacokinetics of Cefotaxime in Critically Ill Patients with Acute Kidney Injury Treated with Continuous Renal Replacement Therapy
Authors: Koedijk Joost B. , Valk-Swinkels Corinne G. H. , Rijpstra Tom A. , Touw Daan J. , Mulder Paul G. H. , van der Voort Peter H. J. , van 't Veer Nils E. , van der Meer Nardo J. M.
Published: March 2016

The objective of this study was to describe the pharmacokinetics of cefotaxime (CTX) in critically ill patients with acute kidney injury (AKI) when treated with continuous renal replacement therapy (CRRT) in the intensive care unit (ICU). This single-center prospective observational pilot study was performed among ICU-patients with AKI receiving ≥48 h concomitant CRRT and CTX. CTX was administered intravenously 1,000 mg (bolus) every 6 h for 4 days. CRRT was performed as continuous venovenous hemofiltration (CVVH). Plasma concentrations of CTX and its active metabolite desacetylcefotaxime (DAC) were measured during CVVH treatment. CTX plasma levels and patient data were used to construct concentration-time curves. By using this data, the duration of plasma levels above 4 mg/liter (four times the MIC) was calculated and analyzed. Twenty-seven patients were included. The median CTX peak level was 55 mg/liter (range, 19 to 98 mg/liter), the median CTX trough level was 12 mg/liter (range, 0.8 to 37 mg/liter), and the median DAC plasma level was 15 mg/liter (range, 1.5 to 48 mg/liter). Five patients (19%) had CTX plasma levels below 4 mg/liter at certain time points during treatment. In at least 83% of the time any patient was treated with CTX, the CTX plasma level stayed above 4 mg/liter. A dosing regimen of 1,000 mg of CTX given four times daily is likely to achieve adequate plasma levels in patients with AKI treated with CVVH. Dose reduction might be a risk for suboptimal treatment.
Hepatitis C Virus Genotype 1 to 6 Protease Inhibitor Escape Variants:
In Vitro
Selection, Fitness, and Resistance Patterns in the Context of the Infectious Viral Life Cycle
Authors: Serre Stéphanie B. N. , Jensen Sanne B. , Ghanem Lubna , Humes Daryl G. , Ramirez Santseharay , Li Yi-Ping , Krarup Henrik , Bukh Jens , Gottwein Judith M.
Published: March 2016

Hepatitis C virus (HCV) NS3 protease inhibitors (PIs) are important components of novel HCV therapy regimens. Studies of PI resistance initially focused on genotype 1. Therefore, knowledge about the determinants of PI resistance for the highly prevalent genotypes 2 to 6 remains limited. Using Huh7.5 cell culture-infectious HCV recombinants with genotype 1 to 6 NS3 protease, we identified protease positions 54, 155, and 156 as hot spots for the selection of resistance substitutions under treatment with the first licensed PIs, telaprevir and boceprevir. Treatment of a genotype 2 isolate with the newer PIs vaniprevir, faldaprevir, simeprevir, grazoprevir, paritaprevir, and deldeprevir identified positions 156 and 168 as hot spots for resistance; the Y56H substitution emerged for three newer PIs. Substitution selection also depended on the specific recombinant. The substitutions identified conferred cross-resistance to several PIs; however, most substitutions selected under telaprevir or boceprevir treatment conferred less resistance to certain newer PIs. In a single-cycle production assay, across genotypes, PI treatment primarily decreased viral replication, which was rescued by PI resistance substitutions. The substitutions identified resulted in differential effects on viral fitness, depending on the original recombinant and the substitution. Across genotypes, fitness impairment induced by resistance substitutions was due primarily to decreased replication. Most combinations of substitutions that were identified increased resistance or fitness. Combinations of resistance substitutions with fitness-compensating substitutions either rescued replication or compensated for decreased replication by increasing assembly. This comprehensive study provides insight into the selection patterns and effects of PI resistance substitutions for HCV genotypes 1 to 6 in the context of the infectious viral life cycle, which is of interest for clinical and virological HCV research.
Hepatitis C Virus RNA-Dependent RNA Polymerase Interacts with the Akt/PKB Kinase and Induces Its Subcellular Relocalization
Authors: Valero María Llanos , Sabariegos Rosario , Cimas Francisco J. , Perales Celia , Domingo Esteban , Sánchez-Prieto Ricardo , Mas Antonio
Published: March 2016

Hepatitis C virus (HCV) interacts with cellular components and modulates their activities for its own benefit. These interactions have been postulated as a target for antiviral treatment, and some candidate molecules are currently in clinical trials. The multifunctional cellular kinase Akt/protein kinase B (PKB) must be activated to increase the efficacy of HCV entry but is rapidly inactivated as the viral replication cycle progresses. Viral components have been postulated to be responsible for Akt/PKB inactivation, but the underlying mechanism remained elusive. In this study, we show that HCV polymerase NS5B interacts with Akt/PKB. In the presence of transiently expressed NS5B or in replicon- or virus-infected cells, NS5B changes the cellular localization of Akt/PKB from the cytoplasm to the perinuclear region. Sequestration of Akt/PKB by NS5B could explain its exclusion from its participation in early Akt/PKB inactivation. The NS5B-Akt/PKB interaction represents a new regulatory step in the HCV infection cycle, opening possibilities for new therapeutic options.
Coxiella burnetii Infects Primary Bovine Macrophages and Limits Their Host Cell Response
Authors: Sobotta Katharina , Hillarius Kirstin , Mager Marvin , Kerner Katharina , Heydel Carsten , Menge Christian
Published: March 2016

Although domestic ruminants have long been recognized as the main source of human Q fever, little is known about the lifestyle that the obligate intracellular Gram-negative bacteriumCoxiella burnetiiadopts in its animal host. Because macrophages are considered natural target cells of the pathogen, we established primary bovine monocyte-derived macrophages (MDM) as anin vitroinfection model to study reservoir host-pathogen interactions at the cellular level. In addition, bovine alveolar macrophages were included to take cell type peculiarities at a host entry site into account. Cell cultures were inoculated with the virulent strain Nine Mile I (NMI; phase I) or the avirulent strain Nine Mile II (NMII; phase II). Macrophages from both sources internalized NMI and NMII. MDM were particularly permissive for NMI internalization, but NMI and NMII replicated with similar kinetics in these cells. MDM responded to inoculation with a general upregulation of Th1-related cytokines such as interleukin-1β (IL-1β), IL-12, and tumor necrosis factor alpha (TNF-α) early on (3 h postinfection). However, inflammatory responses rapidly declined whenC. burnetiireplication started.C. burnetiiinfection inhibited translation and release of IL-1β and vastly failed to stimulate increased expression of activation markers, such as CD40, CD80, CD86, and major histocompatibility complex (MHC) molecules. Such capability of limiting proinflammatory responses may helpCoxiellato protect itself from clearance by the host immune system. The findings provide the first detailed insight intoC. burnetii-macrophage interactions in ruminants and may serve as a basis for assessing the virulence and the host adaptation ofC. burnetiistrains.
Borrelia burgdorferi CheD Promotes Various Functions in Chemotaxis and the Pathogenic Life Cycle of the Spirochete
Authors: Moon Ki Hwan , Hobbs Gerry , Motaleb M. A.
Published: March 2016

Borrelia burgdorferi
possesses a sophisticated chemotaxis signaling system; however, the roles of the majority of the chemotaxis proteins in the infectious life cycle have not yet been demonstrated. Specifically, the role of CheD during host colonization has not been demonstrated in any bacterium. Here, we systematically characterized the
B. burgdorferi
CheD homolog using genetics and biochemical and mouse-tick-mouse infection cycle studies.
Bacillus subtilis
CheD plays an important role in chemotaxis by deamidation of methyl-accepting chemotaxis protein receptors (MCPs) and by increasing the receptor kinase activity or enhancing CheC phosphatase activity, thereby regulating the levels of the CheY response regulator. Our biochemical analysis indicates that
B. burgdorferi
CheD significantly enhances CheX phosphatase activity by specifically interacting with the phosphatase. Moreover, CheD specifically binds two of the six MCPs, indicating that CheD may also modulate the receptor proteins. Although the motility of the
cheD
mutant cells was indistinguishable from that of the wild-type cells, the mutant did exhibit reduced chemotaxis. Importantly, the mutant showed significantly reduced infectivity in C3H/HeN mice via needle inoculation. Mouse-tick-mouse infection assays indicated that CheD is dispensable for acquisition or transmission of spirochetes; however, the viability of
cheD
mutants in ticks is marginally reduced compared to that of the wild-type or complemented
cheD
spirochetes. These data suggest that CheD plays an important role in the chemotaxis and pathogenesis of
B. burgdorferi
. We propose potential connections between CheD, CheX, and MCPs and discuss how these interactions play critical roles during the infectious life cycle of the spirochete.
Enterococcal Sex Pheromones: Evolutionary Pathways to Complex, Two-Signal Systems
Authors: Dunny Gary M. , Berntsson Ronnie Per-Arne
Published: March 2016

Gram-positive bacteria carry out intercellular communication using secreted peptides. Important examples of this type of communication are the enterococcal sex pheromone systems, in which the transfer of conjugative plasmids is controlled by intercellular signaling among populations of donors and recipients. This review focuses on the pheromone response system of the conjugative plasmid pCF10. The peptide pheromones regulating pCF10 transfer act by modulating the ability of the PrgX transcription factor to repress the transcription of an operon encoding conjugation functions. Many Gram-positive bacteria regulate important processes, including the production of virulence factors, biofilm formation, sporulation, and genetic exchange using peptide-mediated signaling systems. The key master regulators of these systems comprise the RRNPP (
R
gg
R
ap/
N
prR/
P
lcR/
P
rgX) family of intracellular peptide receptors; these regulators show conserved structures. While many RRNPP systems include a core module of two linked genes encoding the regulatory protein and its cognate signaling peptide, the enterococcal sex pheromone plasmids have evolved to a complex system that also recognizes a second host-encoded signaling peptide. Additional regulatory genes not found in most RRNPP systems also modulate signal production and signal import in the enterococcal pheromone plasmids. This review summarizes several structural studies that cumulatively demonstrate that the ability of three pCF10 regulatory proteins to recognize the same 7-amino-acid pheromone peptide arose by convergent evolution of unrelated proteins from different families. We also focus on the selective pressures and structure/function constraints that have driven the evolution of pCF10 from a simple, single-peptide system resembling current RRNPPs in other bacteria to the current complex inducible plasmid transfer system.
Regulation by ToxR-Like Proteins Converges on
vttR
B
Expression To Control Type 3 Secretion System-Dependent Caco2-BBE Cytotoxicity in Vibrio cholerae
Authors: Miller Kelly A. , Sofia Madeline K. , Weaver Jacob W. A. , Seward Christopher H. , Dziejman Michelle
Published: March 2016

Genes carried on the type 3 secretion system (T3SS) pathogenicity island of
Vibrio cholerae
non-O1/non-O139 serogroup strain AM-19226 must be precisely regulated in order for bacteria to cause disease. Previously reported results showed that both T3SS function and the presence of bile are required to cause Caco2-BBE cell cytotoxicity during coculture with strain AM-19226. We therefore investigated additional parameters affecting
in vitro
cell death, including bacterial load and the role of three transmembrane transcriptional regulatory proteins, VttR
A
, VttR
B
, and ToxR. VttR
A
and VttR
B
are encoded on the horizontally acquired T3SS genomic island, whereas ToxR is encoded on the ancestral chromosome. While strains carrying deletions in any one of the three transcriptional regulatory genes are unable to cause eukaryotic cell death, the results of complementation studies point to a hierarchy of regulatory control that converges on
vttR
B
expression. The data suggest both that ToxR and VttR
A
act upstream of VttR
B
and that modifying the level of either
vttR
A
or
vttR
B
expression can strongly influence T3SS gene expression. We therefore propose a model whereby T3SS activity and, hence,
in vitro
cytotoxicity are ultimately regulated by
vttR
B
expression.

IMPORTANCE
In contrast to O1 and O139 serogroup
V. cholerae
strains that cause cholera using two main virulence factors (toxin-coregulated pilus [TCP] and cholera toxin [CT]), O39 serogroup strain AM-19226 uses a type 3 secretion system as its principal virulence mechanism. Although the regulatory network governing TCP and CT expression is well understood, the factors influencing T3SS-associated virulence are not. Using an
in vitro
mammalian cell model to investigate the role of three ToxR-like transmembrane transcriptional activators in causing T3SS-dependent cytotoxicity, we found that expression levels and a hierarchical organization were important for promoting T3SS gene expression. Furthermore, our results suggest that horizontally acquired, ToxR-like proteins act in concert with the ancestral ToxR protein to orchestrate T3SS-mediated pathogenicity.