bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reassessment of hydrogen tolerance in Caldicellulosiruptor saccharolyticus
Authors: Willquist Karin , Pawar Sudhanshu S , Van Niel Ed WJ 
Published: December 2011

AbstractBackgroundCaldicellulosiruptor saccharolyticushas the ability to produce hydrogen (H2) at high yields from a wide spectrum of carbon sources, and has therefore gained industrial interest. For a cost-effective biohydrogen process, the ability of an organism to tolerate high partial pressures of H2(PH2) is a critical aspect to eliminate the need for continuous stripping of the produced H2from the bioreactor.ResultsHerein, we demonstrate that, under given conditions, growth and H2production inC. saccharolyticuscan be sustained atPH2up to 67 kPa in a chemostat. At thisPH2, 38% and 16% of the pyruvate flux was redirected to lactate and ethanol, respectively, to maintain a relatively low cytosolic NADH/NAD ratio (0.12 mol/mol). To investigate the effect of the redox ratio on the glycolytic flux, a kinetic model describing the activity of the key glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), was developed. Indeed, at NADH/NAD ratios of 0.12 mol/mol (Ki of NADH = 0.03 ± 0.01 mM) GAPDH activity was inhibited by only 50% allowing still a high glycolytic flux (3.2 ± 0.4 mM/h). Even at high NADH/NAD ratios up to 1 mol/mol the enzyme was not completely inhibited. During batch cultivations, hydrogen tolerance ofC. saccharolyticuswas dependent on the growth phase of the organism as well as the carbon and energy source used. The obtained results were analyzed, based on thermodynamic and enzyme kinetic considerations, to gain insight in the mechanism underlying the unique ability ofC. saccharolyticusto grow and produce H2under relatively highPH2.ConclusionC. saccharolyticusis able to grow and produce hydrogen at highPH2, hence eliminating the need of gas sparging in its cultures. Under this condition, it has a unique ability to fine tune its metabolism by maintaining the glycolytic flux through regulating GAPDH activity and redistribution of pyruvate flux. Concerning the later, xylose-rich feedstock should be preferred over the sucrose-rich one for better H2yield.
TLR4 dependent heparan sulphate-induced pancreatic inflammatory response is IRF3-mediated
Authors: Akbarshahi Hamid , Axelsson Jakob BF , Said Katarzyna , Malmström Anders , Fischer Hans , Andersson Roland 
Published: December 2011

Abstract

Background
Degraded extracellular matrix can stimulate the innate immune system via the Toll-Like Receptor-4 (TLR4). In the pancreas, syndecan-anchored heparan sulphate (HS) on the ductal epithelium can be cleaved off its protein cores by the proteases (trypsin and elastase) and potentially activate TLR4 signalling.

Methods
To investigate this signalling event, a low sulphated HS (500 μg/ml) was infused into the biliary-pancreatic duct of C57BL/6J wild-type mice. Phosphate buffered saline (PBS) and lipopolysaccharide (LPS) were used as negative and positive controls, respectively. Mice were sacrificed after 1, 3, 6, 9, and 48 hours and tissues were analysed for neutrophil and cytokine contents. In order to study the TLR4 signalling pathway of HS in the pancreas, genetically engineered mice lacking TLR4, Myeloid Differentiation primary response gene (88) (MyD88) or Interferon Regulatory Factor 3 (IRF3) were subjected to pancreatic infusion of HS.

Results
Neutrophil sequestration and corresponding myeloperoxidase (MPO) activity in the pancreas were increased 9 hours following HS challenge. In wild-type mice, the monocyte chemoattractant protein-1(MCP-1) increased at 3 hours after infusion, while RANTES increased after 9 hours.
TLR4, MyD88, and IRF3 knockout mice showed an abrogated neutrophil recruitment and myeloperoxidase activity in the HS group, while the LPS response was only abolished in TLR4 and MyD88 knockouts.

Conclusions
The results of this study show that HS is capable of initiating a TLR4-dependent innate immune response in the pancreas which is distinctly different from that induced by LPS. This inflammatory response was mediated predominantly through IRF3- dependent pathway. Release of HS into the pancreatic duct may be one important mediator in the pancreatic ductal defence.
Maximal and minimal point theorems and Caristi's fixed point theorem
Authors: Li Zhilong , Jiang Shujun 
Published: December 2011

AbstractThis study is concerned with the existence of fixed points of Caristi-type mappings motivated by a problem stated by Kirk. First, several existence theorems of maximal and minimal points are established. By using them, some generalized Caristi's fixed point theorems are proved, which improve Caristi's fixed point theorem and the results in the studies of Jachymski, Feng and Liu, Khamsi, and Li.MSC 2010: 06A06; 47H10.
Rapid detection of newly isolated Tembusu-related Flavivirus by reverse-transcription loop-mediated isothermal amplification assay
Authors: Wang Youling , Yuan Xiaoyuan , Li Yufeng , Yu Kexiang , Yang Jinxing , Xu Huaiying , Zhang Yuxia , Yu Kangzhen , Liao Ming , Qin Zhuoming 
Published: December 2011

Abstract

Background
From April 2010 to January 2011, a severe new viral disease had devastated most duck-farming regions in China. This disease affected not only laying ducks but also meat ducks, causing huge economic losses for the poultry industry. The objective of this study is to develop a one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of the new virus related to Tembusu-related Flavivirus.

Results
The RT-LAMP assay is very simple and rapid, and the amplification can be completed within 50 min under isothermal conditions at 63°C by a set of 6 primers targeting the E gene based on the sequences analysis of the newly isolated viruses and other closely related Flavivirus.The monitoring of gene amplification can also be visualized by using SYBR green I fluorescent dye. In addition, the RT-LAMP assay for newly isolated Tembusu-related Flavivirus showed higher sensitivity with an RNA detection-limit of 2 copies/μL compared with 190 copies/μL of the conventional RT-PCR method. The specificity was identified without cross reaction to other common avian pathogens. By screening a panel of clinical samples this method was more feasible in clinical settings and there was higher positive coincidence rate than conventional RT-PCR and virus isolation.

Conclusion
The RT-LAMP assay for newly isolated Tembusu-related Flavivirus is a valuable tool for the rapid and real-time detection not only in well-equipped laboratories but also in general conditions.
Application of in vivo micro-computed tomography in the temporal characterisation of subchondral bone architecture in a rat model of low-dose monosodium iodoacetate-induced osteoarthritis
Authors: Mohan Geetha , Perilli Egon , Kuliwaba Julia S , Humphries Julia M , Parkinson Ian H , Fazzalari Nicola L 
Published: December 2011

Abstract
Introduction
Osteoarthritis (OA) is a complex, multifactorial joint disease affecting both the cartilage and the subchondral bone. Animal models of OA aid in the understanding of the pathogenesis of OA and testing suitable drugs for OA treatment. In this study we characterized the temporal changes in the tibial subchondral bone architecture in a rat model of low-dose monosodium iodoacetate (MIA)-induced OA using in vivo micro-computed tomography (CT).

Methods
Male Wistar rats received a single intra-articular injection of low-dose MIA (0.2 mg) in the right knee joint and sterile saline in the left knee joint. The animals were scanned in vivo by micro-CT at two, six, and ten weeks post-injection, analogous to early, intermediate, and advanced stages of OA, to assess architectural changes in the tibial subchondral bone. The articular cartilage changes in the tibiae were assessed macroscopically and histologically at ten weeks post-injection.

Results
Interestingly, tibiae of the MIA-injected knees showed significant bone loss at two weeks, followed by increased trabecular thickness and separation at six and ten weeks. The trabecular number was decreased at all time points compared to control tibiae. The tibial subchondral plate thickness of the MIA-injected knee was increased at two and six weeks and the plate porosity was increased at all time points compared to control. At ten weeks, histology revealed loss of proteoglycans, chondrocyte necrosis, chondrocyte clusters, cartilage fibrillation, and delamination in the MIA-injected tibiae, whereas the control tibiae showed no changes. Micro-CT images and histology showed the presence of subchondral bone sclerosis, cysts, and osteophytes.

Conclusions
These findings demonstrate that the low-dose MIA rat model closely mimics the pathological features of progressive human OA. The low-dose MIA rat model is therefore suitable to study the effect of therapeutic drugs on cartilage and bone in a non-trauma model of OA. In vivo micro-CT is a non-destructive imaging technique that can track structural changes in the tibial subchondral bone in this animal model, and could also be used to track changes in bone in preclinical drug intervention studies for OA treatments.
Olfactomedin 4 defines a subset of human neutrophils
Authors: Clemmensen Stine N , Bohr Christina T , Rørvig Sara , Glenthøj Andreas , Mora-Jensen Helena , Cramer Elisabeth P , Jacobsen Lars C , Larsen Maria T , Cowland Jack B , Tanassi Julia T , Heegaard Niels H H , Wren Jonathan D , Silahtaroglu Asli N , Borregaard Niels 
Published: December 2011

ABSTRACT
OLFM4 was identified initially as a gene highly induced in myeloid stem cells by G-CSF treatment. A bioinformatics method using a global meta-analysis of microarray data predicted that OLFM4 would be associated with specific granules in human neutrophils. Subcellular fractionation of peripheral blood neutrophils demonstrated complete colocalization of OLFM4 with the specific granule protein NGAL, and stimulation of neutrophils with PMA resulted in corelease of NGAL and OLFM4, proving that OLFM4 is a genuine constituent of neutrophil-specific granules. In accordance with this, OLFM4 mRNA peaked at the MY/MM stage of maturation. OLFM4 was, however, present in only 20–25% of peripheral blood neutrophils, as determined by immunocytochemistry and flow cytometry, whereas mRNA for OLFM4 was present in all MY/MM, indicating post-transcriptional regulation as a basis for the heterogeneous expression of OLFM4 protein.
Mechanisms underlying rhythmic locomotion: interactions between activation, tension and body curvature waves
Authors: Chen Jun , Friesen W. Otto , Iwasaki Tetsuya 
Published: December 2011

SUMMARY
Undulatory animal locomotion arises from three closely related propagating waves that sweep rostrocaudally along the body: activation of segmental muscles by motoneurons (MNs), strain of the body wall, and muscle tension induced by activation and strain. Neuromechanical models that predict the relative propagation speeds of neural/muscle activation, muscle tension and body curvature can reveal crucial underlying control features of the central nervous system and the power-generating mechanisms of the muscle. We provide an analytical explanation of the relative speeds of these three waves based on a model of neuromuscular activation and a model of the body–fluid interactions for leech anguilliform-like swimming. First, we deduced the motoneuron spike frequencies that activate the muscle and the resulting muscle tension during swimming in intact leeches from muscle bending moments. Muscle bending moments were derived from our video-recorded kinematic motion data by our body–fluid interaction model. The phase relationships of neural activation and muscle tension in the strain cycle were then calculated. Our study predicts that the MN activation and body curvature waves have roughly the same speed (the ratio of curvature to MN activation speed ≈0.84), whereas the tension wave travels about twice as fast. The high speed of the tension wave resulting from slow MN activation is explained by the multiplicative effects of MN activation and muscle strain on tension development. That is, the product of two slower waves (activation and strain) with appropriate amplitude, bias and phase can generate a tension wave with twice the propagation speed of the factors. Our study predicts that (1) the bending moment required for swimming is achieved by minimal MN spike frequency, rather than by minimal muscle tension; (2) MN activity is greater in the mid-body than in the head and tail regions; (3) inhibitory MNs not only accelerate the muscle relaxation but also reduce the intrinsic tonus tension during one sector of the swim cycle; and (4) movements of the caudal end are passive during swimming. These predictions await verification or rejection through further experiments on swimming animals.
High-altitude diving in river otters: coping with combined hypoxic stresses
Authors: Crait Jamie R. , Prange Henry D. , Marshall Noah A. , Harlow Henry J. , Cotton Clark J. , Ben-David Merav 
Published: December 2011

SUMMARYRiver otters (Lontra canadensis) are highly active, semi-aquatic mammals indigenous to a range of elevations and represent an appropriate model for assessing the physiological responses to diving at altitude. In this study, we performed blood gas analyses and compared blood chemistry of river otters from a high-elevation (2357 m) population at Yellowstone Lake with a sea-level population along the Pacific coast. Comparisons of oxygen dissociation curves (ODC) revealed no significant difference in hemoglobin-oxygen (Hb-O2) binding affinity between the two populations - potentially because of demands for tissue oxygenation. Instead, high-elevation otters had greater Hb concentrations (18.7 g dl-1) than sea-level otters (15.6 g dl-1). Yellowstone otters displayed higher levels of the vasodilator nitric oxide (NO), and half the concentration of the serum protein albumin, possibly to compensate for increased blood viscosity. Despite compensation in several hematological and serological parameters, theoretical aerobic dive limits (ADL) were similar between high-elevation and sea-level otters because of the lower availability of O2 at altitude. Our results suggest that recent disruptions to the Yellowstone Lake food web could be detrimental to otters because at this high elevation, constraints on diving may limit their ability to switch to prey in a deep-water environment.
Muscular tissues of the squid Doryteuthis pealeii express identical myosin heavy chain isoforms: an alternative mechanism for tuning contractile speed
Authors: Shaffer Justin F. , Kier William M. 
Published: December 2011

SUMMARY
The speed of muscle contraction is largely controlled at the sarcomere level by the ATPase activity of the motor protein myosin. Differences in amino acid sequence in catalytically important regions of myosin yield different myosin isoforms with varying ATPase activities and resulting differences in cross-bridge cycling rates and interfilamentary sliding velocities. Modulation of whole-muscle performance by changes in myosin isoform ATPase activity is regarded as a universal mechanism to tune contractile properties, especially in vertebrate muscles. Invertebrates such as squid, however, may exhibit an alternative mechanism to tune contractile properties that is based on differences in muscle ultrastructure, including variable myofilament and sarcomere lengths. To determine definitively whether contractile properties of squid muscles are regulated via different myosin isoforms (i.e. different ATPase activities), the nucleotide and amino acid sequences of the myosin heavy chain from the squid Doryteuthis pealeii were determined from the mantle, arm, tentacle, fin and funnel retractor musculature. We identified three myosin heavy chain isoforms in squid muscular tissues, with differences arising at surface loop 1 and the carboxy terminus. All three isoforms were detected in all five tissues studied. These results suggest that the muscular tissues of D. pealeii express identical myosin isoforms, and it is likely that differences in muscle ultrastructure, not myosin ATPase activity, represent the most important mechanism for tuning contractile speeds.
Mechanisms of colour adaptation in the prawn Penaeus monodon
Authors: Wade Nicholas M. , Anderson Mike , Sellars Melony J. , Tume Ron K. , Preston Nigel P. , Glencross Brett D. 
Published: December 2011

SUMMARY
Exposure of prawns to dark- or light-coloured substrates is known to trigger a strong colour adaptation response through expansion or contraction of the colouration structures in the prawn hypodermis. Despite the difference in colour triggered by this adaptive response, total levels of the predominant carotenoid pigment, astaxanthin, are not modified, suggesting that another mechanism is regulating this phenomenon. Astaxanthin binds to a specific protein called crustacyanin (CRCN), and it is the interaction between the quantities of each of these compounds that produces the diverse range of colours seen in crustacean shells. In this study, we investigated the protein changes and genetic regulatory processes that occur in prawn hypodermal tissues during adaptation to black or white substrates. The amount of free astaxanthin was higher in animals adapted to dark substrate compared with those adapted to light substrate, and this difference was matched by a strong elevation of CRCN protein. However, there was no difference in the expression of CRCN genes either across the moult cycle or in response to background substrate colour. These results indicate that exposure to a dark-coloured substrate causes an accumulation of CRCN protein, bound with free astaxanthin, in the prawn hypodermis without modification of CRCN gene expression. On light-coloured substrates, levels of CRCN protein in the hypodermis are reduced, but the carotenoid is retained, undispersed in the hypodermal tissue, in an esterified form. Therefore, the abundance of CRCN protein affects the distribution of pigment in prawn hypodermal tissues, and is a crucial regulator of the colour adaptation response in prawns.
Intravenous Ketamine for Treatment-Resistant Major Depressive Disorder
Authors: Covvey Jordan R , Crawford Alexis Noble , Lowe Denise K 
Published: December 2011

OBJECTIVE: To evaluate the literature regarding the efficacy and safety of intravenous ketamine for treatment-resistant major depressive disorder (MDD). DATA SOURCES: A MEDLINE search (1966-September 2011) was performed using the terms treatment-resistant depression and ketamine. The search was restricted to articles published in English and reporting on use of ketamine in humans. STUDY SELECTION AND DATA EXTRACTION: All English-language articles identified from the data search were evaluated. Data were eligible for inclusion if they were primary literature and evaluated the efficacy of ketamine for depressive symptoms in treatment-resistant MDD. One case report, 3 case series, 3 open-label trials, and 1 randomized crossover trial were included. DATA SYNTHESIS: Several medications are available for treatment-resistant MDD; however, they are often limited by a slow onset of therapeutic effect and tolerability. It has been suggested that ketamine, a rapid-acting, N-methyl-D-aspartate glutamate receptor antagonist, may have antidepressant effects. Case reports, case series, and select trials evaluating ketamine use for depressive symptoms in treatment-resistant MDD have demonstrated a rapid effect for reductions of scores on a number of depression scales; however, its sustainability effect remains unknown. Several studies reported a large or moderate to large effect size for ketamine. Additionally, these studies showed that ketamine use in this patient population is associated with relatively well-tolerated adverse effects. CONCLUSIONS: Ketamine for treatment-resistant MDD requires further evaluation before it can be considered a viable treatment option.
Mixtures of Ionic Liquids as Possible Electrolytes for Lithium Ion Batteries
Authors: Taige Maria , Hilbert Diana , Schubert Thomas J. S. 
Published: December 2011

Abstract
Mixtures of Ionic Liquids as Possible Electrolytes for Lithium Ion Batteries
Due to their unique properties like incombustibility, low vapor pressure, large electrochemical stability, wide liquid range and high thermal stability, ionic liquids have a great potential as components of electrolytes for lithium ion batteries. Lithium ion batteries with electrolytes on the basis of ionic liquids are safer than those with conventional electrolytes. Unfortunately, ionic liquids normally possess a higher viscosity and lower conductivities than conventional electrolytes. In order to decrease the viscosity and increase the conductivity of electrolytes based on ionic liquids, we prepared mixtures of ionic liquids. We could show that the viscosity of ionic liquids can be significantly reduced by using eutectic mixtures. Therefore, the conductivities of some mixtures were significantly higher than those of the pure ionic liquids. In addition, we could increase the conductivity by introducing functional groups in the side chain of the ionic liquids.
Theoretical Investigation of the Reaction of Yttrium Cation with Acetone
Authors: Dai Guo-Liang , Wang Yong , Wu Jun-Yong , Wang Chuan-Feng , Zhou Qi-Zhong 
Published: December 2011

Abstract
The reaction mechanism of Y
+
with CH3COCH3 has been investigated with a DFT method. All the stationary points are determined at the UB3LYP/ECP/6-311++G** level of the theory. Both the ground and the excited state potential energy surfaces are investigated in detail. The present results show that the title reaction starts with the formation of an O-attached complex (IM0) followed by C–O, C–H and C–C activation. The minimum energy reaction path is found to involve the spin inversion in the initial reaction step. The potential energy curve-crossing dramatically affects reaction exothermic. The present results may be helpful in understanding the mechanism of the title reaction and further experimental investigation of the reaction.
Tolerance of Old World Climbing Fern (Lygodium microphyllum) Spores to Herbicides
Authors: Hutchinson Jeffrey T. , Langeland Kenneth A. 
Published: December 2011

AbstractOld World climbing fern (OWCF) is a highly invasive fern that disrupts natural communities in central and southern Florida. OCWF produces copious, wind-blown spores that have propelled its rapid invasion of Florida's natural areas over the last few decades. Current management of OWCF is limited to herbicides and natural resource managers in Florida have questioned if herbicides inhibit spore germination. This study compared spore germination rates of OWCF exposed to six herbicides and a surfactant from 1 to 24 h under laboratory conditions. Spores of OWCF were highly susceptible to metsulfuron, but exhibited tolerance to imazapyr, glyphosate, fluroxypyr, asulam, and triclopyr. Spore germination rates were 0.4% for spores exposed to 0.1 g ai L−1 of metsulfuron, but 0% for rates greater than or equal to 0.2 g ai L−1 at 30 d after treatment (DAT). Reduction in spore germination was observed with all other concentrations of herbicides tested, ranging from 10.4% with triclopyr (40 g ai L−1) to 42.6% with asulam (4.2 g ai L−1) compared to 47.9% germination for untreated checks 30 DAT. Spores were highly sensitive to metsulfuron with herbicide concentrations required for 50 and 95% inhibition of spore germination (I50 and I95) measuring 0.014 and 0.063 g ai L−1, respectively; spores were greater than 1,000-fold more sensitive to metsulfuron compared to I95 concentrations of any other herbicide tested. These results indicate that metsulfuron exhibits potential to control OWCF spore germination but spores are tolerant to the five other herbicides tested.