bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and Validation of a Dynamic Thermal Model for a Polymer Electrolyte Membrane Fuel Cell
Authors: Headley Alexander , Hadisujoto Budi , Chen Dongmei , Moon Tess J. 
Published: December 2013

The development and validation of a control-oriented dynamic thermal model for a polymer electrolyte membrane (PEM) fuel cell stack is presented. This model is based on the first law of thermodynamics within four defined control volumes in the fuel cell; the cathode channel, anode channel, coolant channel, and fuel cell stack body. Energy and mass conservation equations are developed for each control volume. Transient dynamics captured by this model include the electrochemical reaction, heat transfer and mass transport. Activation, ohmic, and concentration voltage losses are also modeled to improve the accuracy of the voltage model response. This allows the stack voltage and cell temperature to be modeled based on the inlet temperature, pressure, and species flow rate and the relative humidity level setting.
An experiment was conducted to give a baseline with which to tune the model. Tuning of the model parameters was performed and validation of these adjustments was then conducted through comparison to another experiment. The model predicts the dynamic thermal and electrical response of the fuel cell system with a good degree of accuracy in both cases.
Numerical Simulation of Liquid Water Behavior in Microchannel With a 90° Bend
Authors: Alrahmani Mosab , Chen Rui , Ibrahim Salah 
Published: December 2013

Water management is an effective way of improving Proton Exchange Membrane (PEM) fuel cell performance and durability. Changing the wettability of gas channel walls and gas diffusion layer (GDL) is one way of controlling the water management in a fuel cell for its influence on the liquid water dynamic behavior. The objective of this study is to investigate liquid water dynamic behavior in a microchannel with a 90° bend and different surface wettability combinations through 3D numerical simulation. Volume-of-fluid (VOF) method was employed to track the fluid-fluid interface in the multiphase flow.
The simulated microchannel has a square cross-section with a dimension of 0.25 mm and a total length of 1.5 mm. Water is introduced to the channel via two pores in the bottom surface representing a GDL while air flows from one end to another. The air and water velocities used are in the order of magnitude of a high current density fuel cell. Nine different combinations of wall/GDL wettability are investigated.
The results show that liquid water takes less time to leave the channel in a hydrophilic GDL compared to moderate and hydrophobic GDL regardless of wall wettability. Furthermore, the GDL wettability shows more significant impact on liquid water behavior compared to the wall wettability; however, wall wettability has a slight but considerable impact.
A Compact Versatile Microbial Fuel Cell From Paper
Authors: Wagner Luke T. , Hashemi Niloofar , Hashemi Nastaran 
Published: December 2013

Microbial fuel cells (MFCs) have been a potential green energy source for a long time but one of the problems is that either the technology must be used on a large scale or special equipment have been necessary to keep the fuel cells running such as syringe pumps. Paper-based microbial fuel cells do not need to have a syringe pump to run and can run entirely by themselves when placed in contact with the fluids that are necessary for it to run. Paper-based microbial fuel cells are also more compact than traditional MFCs since the device doesn’t need any external equipment to run.
The goal of this paper is to develop a microbial fuel cell that does not require a syringe pump to function. This is done by layering chromatography paper with wax design printed onto it. This restricts the fluids to a specific flow path allowing it to act like the tubes in a typical microbial fuel cell device by delivering the fluids to the chamber. The fluids are picked up by tabs that sit in the fluid and use capillary attraction to flow up the tab and into the device. The fluids are directed to the chambers where the chemical and biological processes take place. These flows are then directed out of the device so that they are taken to a waste container and out of the system.
Our microliter scale paper-based microbial fuel cell creates a significant current that is sustained for a period of time and can be repeated. A paper-based microbial fuel cell also has a fast response time. These results mean that it could be possible for a set of paper-based microbial fuel cells to create a power density capable of powering small, low power circuits when used in series or parallel.
In this paper, we discuss the fabrication and experimental results of our paper-based microbial fuel cell. Also there will be a discussion of how paper-based microbial fuels cells compare to the traditional microbial fuel cells and how they could be used in the future.
Degradation of Extracytoplasmic Catalysts for Protein Folding in Bacillus subtilis
Authors: Krishnappa Laxmi , Monteferrante Carmine G. , Neef Jolanda , Dreisbach Annette , van Dijl Jan Maarten 
Published: December 2013

ABSTRACT

The general protein secretion pathway of
Bacillus subtilis
has a high capacity for protein export from the cytoplasm, which is exploited in the biotechnological production of a wide range of enzymes. These exported proteins pass the membrane in an unfolded state, and accordingly, they have to fold into their active and protease-resistant conformations once membrane passage is completed. The lipoprotein PrsA and the membrane proteins HtrA and HtrB facilitate the extracytoplasmic folding and quality control of exported proteins. Among the native exported proteins of
B. subtilis
are at least 10 proteases that have previously been implicated in the degradation of heterologous secreted proteins. Recently, we have shown that these proteases also degrade many native membrane proteins, lipoproteins, and secreted proteins. The present studies were therefore aimed at assessing to what extent these proteases also degrade extracytoplasmic catalysts for protein folding. To this end, we employed a collection of markerless protease mutant strains that lack up to 10 different extracytoplasmic proteases. The results show that PrsA, HtrA, and HtrB are indeed substrates of multiple extracytoplasmic proteases. Thus, improved protein secretion by multiple-protease-mutant strains may be related to both reduced proteolysis and improved posttranslocational protein folding and quality control.
Characterization of a Multiresistant Mosaic Plasmid from a Fish Farm Sediment Exiguobacterium sp. Isolate Reveals Aggregation of Functional Clinic-Associated Antibiotic Resistance Genes
Authors: Yang Jing , Wang Chao , Wu Jinyu , Liu Li , Zhang Gang , Feng Jie 
Published: December 2013

ABSTRACT

The genus
Exiguobacterium
can adapt readily to, and survive in, diverse environments. Our study demonstrated that
Exiguobacterium
sp. strain S3-2, isolated from marine sediment, is resistant to five antibiotics. The plasmid pMC1 in this strain carries seven putative resistance genes. We functionally characterized these resistance genes in
Escherichia coli
, and genes encoding dihydrofolate reductase and macrolide phosphotransferase were considered novel resistance genes based on their low similarities to known resistance genes. The plasmid G+C content distribution was highly heterogeneous. Only the G+C content of one block, which shared significant similarity with a plasmid from
Exiguobacterium arabatum
, fit well with the mean G+C content of the host. The remainder of the plasmid was composed of mobile elements with a markedly lower G+C ratio than the host. Interestingly, five mobile elements located on pMC1 showed significant similarities to sequences found in pathogens. Our data provided an example of the link between resistance genes in strains from the environment and the clinic and revealed the aggregation of antibiotic resistance genes in bacteria isolated from fish farms.
Listeria monocytogenes Associated with New Zealand Seafood Production and Clinical Cases: Unique Sequence Types, Truncated InlA, and Attenuated Invasiveness
Authors: Cruz Cristina D. , Pitman Andrew R. , Harrow Sally A. , Fletcher Graham C. 
Published: December 2013

ABSTRACT

Listeriosis is caused by the food-borne pathogen
Listeria monocytogenes
, which can be found in seafood and processing plants. To evaluate the risk to human health associated with seafood production in New Zealand, multi-virulence-locus sequence typing (MVLST) was used to define the sequence types (STs) of 31
L. monocytogenes
isolates collected from seafood-processing plants, 15 from processed foods, and 6 from human listeriosis cases. The STs of these isolates were then compared with those from a collection of seafood isolates and epidemic strains from overseas. A total of 17 STs from New Zealand clustered into two lineages: seafood-related isolates in lineages I and II and all human isolates in lineage II. None of the New Zealand STs matched previously described STs from other countries. Isolates (belonging to ST01-N and ST03-N) from mussels and their processing environments, however, were identical to those of sporadic listeriosis cases in New Zealand. ST03-N isolates (16 from mussel-processing environments, 2 from humans, and 1 from a mussel) contained an
inlA
premature stop codon (PMSC) mutation. Therefore, the levels of invasiveness of 22 isolates from ST03-N and the three other common STs were compared using human intestinal epithelial Caco-2 cell lines. STs carrying
inlA
PMSCs, including ST03-N isolates associated with clinical cases, had a low invasion phenotype. The close relatedness of some clinical and environmental strains, as revealed by identical MVLST profiles, suggests that local and persistent environmental strains in seafood-processing environments pose a potential health risk. Furthermore, a PMSC in
inlA
does not appear to give
L. monocytogenes
a noninvasive profile.
Disruption of Putrescine Biosynthesis in Shewanella oneidensis Enhances Biofilm Cohesiveness and Performance in Cr(VI) Immobilization
Authors: Ding Yuanzhao , Peng Ni , Du Yonghua , Ji Lianghui , Cao Bin 
Published: December 2013

ABSTRACT

Although biofilm-based bioprocesses have been increasingly used in various applications, the long-term robust and efficient biofilm performance remains one of the main bottlenecks. In this study, we demonstrated that biofilm cohesiveness and performance of
Shewanella oneidensis
can be enhanced through disrupting putrescine biosynthesis. Through random transposon mutagenesis library screening, one hyperadherent mutant strain, CP2-1-S1, exhibiting an enhanced capability in biofilm formation, was obtained. Comparative analysis of the performance of biofilms formed by
S. oneidensis
MR-1 wild type (WT) and CP2-1-S1 in removing dichromate (Cr
2
O
7
2−
), i.e., Cr(VI), from the aqueous phase showed that, compared with the WT biofilms, CP2-1-S1 biofilms displayed a substantially lower rate of cell detachment upon exposure to Cr(VI), suggesting a higher cohesiveness of the mutant biofilms. In addition, the amount of Cr(III) immobilized by CP2-1-S1 biofilms was much larger, indicating an enhanced performance in Cr(VI) bioremediation. We further showed that
speF
, a putrescine biosynthesis gene, was disrupted in CP2-1-S1 and that the biofilm phenotypes could be restored by both genetic and chemical complementations. Our results also demonstrated an important role of putrescine in mediating matrix disassembly in
S. oneidensis
biofilms.
Effects of Growth Medium on Matrix-Assisted Laser Desorption–Ionization Time of Flight Mass Spectra: a Case Study of Acetic Acid Bacteria
Authors: Wieme Anneleen D. , Spitaels Freek , Aerts Maarten , De Bruyne Katrien , Van Landschoot Anita , Vandamme Peter 
Published: December 2013

ABSTRACT
The effect of the growth medium used on the matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectra generated and its consequences for species and strain level differentiation of acetic acid bacteria (AAB) were determined by using a set of 25 strains. The strains were grown on five different culture media that yielded a total of more than 600 mass spectra, including technical and biological replicates. The results demonstrate that the culture medium can have a profound effect on the mass spectra of AAB as observed in the presence and varying signal intensities of peak classes, in particular when culture media do not sustain optimal growth. The observed growth medium effects do not disturb species level differentiation but strongly affect the potential for strain level differentiation. The data prove that a well-constructed and robust MALDI-TOF mass spectrometry identification database should comprise mass spectra of multiple reference strains per species grown on different culture media to facilitate species and strain level differentiation.
PVv3, a New Shuttle Vector for Gene Expression in Vibrio vulnificus
Authors: Klevanskaa Karina , Bier Nadja , Stingl Kerstin , Strauch Eckhard , Hertwig Stefan 
Published: December 2013

ABSTRACT

An efficient electroporation procedure for
Vibrio vulnificus
was designed using the new cloning vector pVv3 (3,107 bp). Transformation efficiencies up to 2 × 10
6
transformants per μg DNA were achieved. The vector stably replicated in both
V. vulnificus
and
Escherichia coli
and was also successfully introduced into
Vibrio parahaemolyticus
and
Vibrio cholerae
. To demonstrate the suitability of the vector for molecular cloning, the green fluorescent protein (GFP) gene and the
vvhBA
hemolysin operon were inserted into the vector and functionally expressed in
Vibrio
and
E. coli
.
The Gastrointestinal Tract of the White-Throated Woodrat (Neotoma albigula) Harbors Distinct Consortia of Oxalate-Degrading Bacteria
Authors: Miller Aaron W. , Kohl Kevin D. , Dearing M. Denise 
Published: December 2013

ABSTRACT

The microbiota inhabiting the mammalian gut is a functional organ that provides a number of services for the host. One factor that may regulate the composition and function of gut microbial communities is dietary toxins. Oxalate is a toxic plant secondary compound (PSC) produced in all major taxa of vascular plants and is consumed by a variety of animals. The mammalian herbivore
Neotoma albigula
is capable of consuming and degrading large quantities of dietary oxalate. We isolated and characterized oxalate-degrading bacteria from the gut contents of wild-caught animals and used high-throughput sequencing to determine the distribution of potential oxalate-degrading taxa along the gastrointestinal tract. Isolates spanned three genera:
Lactobacillus
,
Clostridium
, and
Enterococcus
. Over half of the isolates exhibited significant oxalate degradation
in vitro
, and all
Lactobacillus
isolates contained the
oxc
gene, one of the genes responsible for oxalate degradation. Although diverse potential oxalate-degrading genera were distributed throughout the gastrointestinal tract, they were most concentrated in the foregut, where dietary oxalate first enters the gastrointestinal tract. We hypothesize that unique environmental conditions present in each gut region provide diverse niches that select for particular functional taxa and communities.
Genetic Evidence for the Involvement of the S-Layer Protein Gene
sap
and the Sporulation Genes
spo0A
,
spo0B
, and
spo0F
in Phage AP50c Infection of Bacillus anthracis
Authors: Plaut Roger D. , Beaber John W. , Zemansky Jason , Kaur Ajinder P. , George Matroner , Biswas Biswajit , Henry Matthew , Bishop-Lilly Kimberly A. , Mokashi Vishwesh , Hannah Ryan M. , Pope Robert K. , Read Timothy D. , Stibitz Scott , Calendar Richard , Sozhamannan Shanmuga 
Published: December 2013

ABSTRACT

In order to better characterize the
Bacillus anthracis
typing phage AP50c, we designed a genetic screen to identify its bacterial receptor. Insertions of the transposon
mariner
or targeted deletions of the structural gene for the S-layer protein Sap and the sporulation genes
spo0A
,
spo0B
, and
spo0F
in
B. anthracis
Sterne resulted in phage resistance with concomitant defects in phage adsorption and infectivity. Electron microscopy of bacteria incubated with AP50c revealed phage particles associated with the surface of bacilli of the Sterne strain but not with the surfaces of Δ
sap
, Δ
spo0A
, Δ
spo0B
, or Δ
spo0F
mutants. The amount of Sap in the S layer of each of the
spo0
mutant strains was substantially reduced compared to that of the parent strain, and incubation of AP50c with purified recombinant Sap led to a substantial reduction in phage activity. Phylogenetic analysis based on whole-genome sequences of
B. cereus sensu lato
strains revealed several closely related
B. cereus
and
B. thuringiensis
strains that carry
sap
genes with very high similarities to the
sap
gene of
B. anthracis
. Complementation of the Δ
sap
mutant in
trans
with the wild-type
B. anthracis
sap
or the
sap
gene from either of two different
B. cereus
strains that are sensitive to AP50c infection restored phage sensitivity, and electron microscopy confirmed attachment of phage particles to the surface of each of the complemented strains. Based on these data, we postulate that Sap is involved in AP50c infectivity, most likely acting as the phage receptor, and that the
spo0
genes may regulate synthesis of Sap and/or formation of the S layer.
The chronic kidney disease Water Intake Trial (WIT): results from the pilot randomised controlled trial
Authors: Clark William F , Sontrop Jessica M , Huang Shih-Han , Gallo Kerri , Moist Louise , House Andrew A , Weir Matthew A , Garg Amit X 
Published: December 2013

Background and objectivesIncreased water intake may benefit kidney function. Prior to initiating a larger randomised controlled trial (RCT), we examined the safety and feasibility of asking adults with chronic kidney disease (CKD) to increase their water intake.Design, setting, participants and measurementsBeginning in October 2012, we randomly assigned 29 adults with stage 3 CKD (estimated glomerular filtration rate (eGFR) 30–60 mL/min/1.73 m2and albuminuria) to one of the two groups of water intake: hydration (n=18) or standard (n=11). We asked the hydration group to increase their water intake by 1.0–1.5 L/day (in addition to usual intake, depending on sex and weight) for 6 weeks, while the control group carried on with their usual intake. Participants collected a 24 h urine sample at baseline and at 2 and 6 weeks after randomisation. Our primary outcome was the between-group difference in change in 24 h urine volume from baseline to 6 weeks.Results(63%)of participants were men, 81% were Caucasians and the average age was 61 years (SD 14 years). The average baseline eGFR was 40 mL/min/1.73 m2(SD 11 mL/min/1.73 m2); the median albumin to creatinine ratio was 19 mg/mmol (IQR 6–74 mg/mmol). Between baseline and 6-week follow-up, the hydration group's average 24 h urine volume increased by 0.7 L/day (from 2.3 to 3.0 L/day) and the control group's 24 h urine decreased by 0.3 L/day (from 2.0 to 1.7 L/day; between-group difference in change: 0.9 L/day (95% CI 0.4 to 1.5; p=0.002)). We found no significant changes in urine, serum osmolality or electrolyte concentrations, or eGFR. No serious adverse events or changes in quality of life were reported.ConclusionsA pilot RCT indicates adults with stage 3 CKD can successfully and safely increase water intake by up to 0.7 L/day in addition to usual fluid intake.Trial registration Registered with Clinical Trials—government identifierNCT01753466.
Inflammation Amplifier, a New Paradigm in Cancer Biology
Authors: Atsumi Toru , Singh Rajeev , Sabharwal Lavannya , Bando Hidenori , Meng Jie , Arima Yasunobu , Yamada Moe , Harada Masaya , Jiang Jing-Jing , Kamimura Daisuke , Ogura Hideki , Hirano Toshio , Murakami Masaaki 
Published: December 2013

Abstract
Tumor-associated inflammation can induce various molecules expressed from the tumors themselves or surrounding cells to create a microenvironment that potentially promotes cancer development. Inflammation, particularly chronic inflammation, is often linked to cancer development, even though its evolutionary role should impair nonself objects including tumors. The inflammation amplifier, a hyperinducer of chemokines in nonimmune cells, is the principal machinery for inflammation and is activated by the simultaneous stimulation of NF-κB and STAT3. We have redefined inflammation as local activation of the inflammation amplifier, which causes an accumulation of various immune cells followed by dysregulation of local homeostasis. Genes related to the inflammation amplifier have been genetically associated with various human inflammatory diseases. Here, we describe how cancer-associated genes, including interleukin (IL)-6, Ptgs2, ErbB1, Gas1, Serpine1, cMyc, and Vegf-α, are strongly enriched in genes related to the amplifier. The inflammation amplifier is activated by the stimulation of cytokines, such as TNF-α, IL-17, and IL-6, resulting in the subsequent expression of various target genes for chemokines and tumor-related genes like BCL2L11, CPNE7, FAS, HIF1-α, IL-1RAP, and SOD2. Thus, we conclude that inflammation does indeed associate with the development of cancer. The identified genes associated with the inflammation amplifier may thus make potential therapeutic targets of cancers. Cancer Res; 74(1); 8–14. ©2013 AACR.
The Fatty Acid Synthase Inhibitor Orlistat Reduces the Growth and Metastasis of Orthotopic Tongue Oral Squamous Cell Carcinomas
Authors: Agostini Michelle , Almeida Luciana Y. , Bastos Débora C. , Ortega Rose M. , Moreira Fernanda S. , Seguin Fabiana , Zecchin Karina G. , Raposo Helena F. , Oliveira Helena C.F. , Amoêdo Nivea D. , Salo Tuula , Coletta Ricardo D. , Graner Edgard 
Published: December 2013

Abstract
Fatty acid synthase (FASN) is the biosynthetic enzyme responsible for the endogenous synthesis of fatty acids. It is downregulated in most normal cells, except in lipogenic tissues such as liver, lactating breast, fetal lung, and adipose tissue. Conversely, several human cancers, including head and neck squamous cell carcinomas (HNSCC), overexpress FASN, which has been associated with poor prognosis and recently suggested as a metabolic oncoprotein. Orlistat is an irreversible inhibitor of FASN activity with cytotoxic properties on several cancer cell lines that inhibits tumor progression and metastasis in prostate cancer xenografts and experimental melanomas, respectively. To explore whether the inhibition of FASN could impact oral tongue squamous cell carcinoma (OTSCC) metastatic spread, an orthotopic model was developed by the implantation of SCC-9 ZsGreen LN-1 cells into the tongue of BALB/c nude mice. These cells were isolated through in vivo selection, show a more invasive behavior in vitro than the parental cells, and generate orthotopic tumors that spontaneously metastasize to cervical lymph nodes in 10 to 15 days only. SCC-9 ZsGreen LN-1 cells also exhibit enhanced production of MMP-2, ERBB2, and CDH2. The treatment with orlistat reduced proliferation and migration, promoted apoptosis, and stimulated the secretion of VEGFA165b by SCC-9 ZsGreen LN-1 cells. In vivo, the drug was able to decrease both the volume and proliferation indexes of the tongue orthotopic tumors and, importantly, reduced the number of metastatic cervical lymph nodes by 43%. These results suggest that FASN is a potential molecular target for the chemotherapy of patients with OTSCC. Mol Cancer Ther; 13(3); 585–95. ©2013 AACR.