bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Improvement of a Circular MCFC Through Optimal Design of the Fluid Distribution System
Authors: Sciacovelli Adriano , Verda Vittorio , Amelio Cristina , Repetto Carlo , Diaz Gustavo
Published: March 2012

In this paper, the prototype of a circular Molten Carbonate Fuel Cell (MCFC) built in the laboratories of FN SpA Nuove Tecnologie e Servizi Avanzati is analyzed using a tridimensional computational fluid dynamic (CFD) model. The prototype is the result of FN and Politecnico di Torino activities developed for the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) within the framework of Ministry of Economic Development, MSE-ENEA. This model considers heat, mass and current transfer as well as chemical and electrochemical reactions. The results show that some inhomogeneous distributions in the reactants, causing non-optimal use of the reactant surfaces. An effective way to improve the distribution in current density consists in tracing tree shaped channels on the surface onto the distribution porous medium. In this paper Y shaped channels are adopted to improve the distribution of gas within the fuel cell and consequently to enhance the performance of the original design of the fuel cell. In addition, the configuration of the outlet of the anodic compartment is also investigated in order to further increase the performance of the fuel cell. The geometrical parameter identifying the topology of distribution channels are chosen accordingly to the constructal theory. The results show that significant improvements can be achieved. Power density is increased of about 6% when the tree-shaped channel is adopted. If a double anodic inlet is also considered the enhancement in the power density is of about 11% with respect to the initial configuration.
Toward Carbon Foam Structures in a Microfluidic Fuel Cell
Authors: Fuerth D. , Bazylak A.
Published: March 2012

In this paper, the design and performance of a flow-through microfluidic fuel cell with carbon-based electrodes is presented. Our preliminary results include the use of Toray TGP-H-090 carbon paper as our porous carbon electrodes. The cell exhibited a maximum power density of 0.12 mW/cm2 and an open cell potential of 1.2 V, and a discussion of this performance is provided. The vanadium redox species is employed as fuel (V2+) and oxidant (VO2+) due to its ability to naturally react on bare carbon, eliminating the need for additional catalysts. Our future work will include the investigation of carbon foam electrodes with grades of 45, 80, and 100 pores per linear inch (PPI).
Hydrogen Generation Using Aluminum Powder for Fuel Cell Applications
Authors: Ahmad Faizan , Kahandawala Moshan , Krishnan Anupriya , Sidhu Sukh
Published: March 2012

One method of producing on-demand hydrogen for fuel cells is through the use of aluminum which reacts with water under certain conditions to produce hydrogen. This process can be used for applications as small as portable handheld devices, onboard generation for vehicles, or as large as a hydrogen refueling center. However, the utilization of aluminum for generating on-demand hydrogen is critically dependent on the control of the rate of hydrogen generation from the reaction. Experiments with micron and nano-sized aluminum powder are described in this work and the effects of particle size, reagent quantities, temperature and solution concentration on the hydrogen generation rate and total yield are analyzed and quantified. Regression models are developed and yield and rate predictions are confirmed. In general, aluminum nanoparticles are found to have poorer hydrogen yields, but marginally faster reaction rates as compared to micron particles.
Experimental and Theoretical Performance Analysis of a High Temperature PEM Fuel Cell Fed With LPG Using a Compact Steam Reformer
Authors: Zuliani Nicola , Taccani Rodolfo , Radu Robert
Published: March 2012

High temperature PEM (HTPEM) fuel cell based on polybenzimidazole polymer (PBI) and phosphoric acid, can be operated at temperature between 120°C and 180°C. Reactants humidification is not required and CO content up to 1% in fuel can be tolerated, affecting only marginally performance. This is what makes HTPEM fuel cells very attractive, as low quality reformed hydrogen can be used and water management problems are avoided. This paper aims to present the preliminary experimental results obtained on a HTPEM fuel cell fed with LPG using a compact steam reformer. The analysis focus on the reformer start up transient, on the influence of the steam to carbon ratio on reformate CO content and on the single fuel cell performance at different operating conditions. By analyzing the mass and energy balances of the fuel processor, fuel cell system, and balance-of-plant, a previously developed system simulation model has been used to provide critical assessment on the conversion efficiency for a 1 kWel system. The current study attempts to extend the previously published analyses of integrated HTPEM fuel cell systems.
Oxygen Transport Resistances Induced by Rib/Channel Geometry
Authors: Shiomi Takeshi , Fukuyama Yosuke , Miyazaki Shinichi , Tabuchi Yuichiro , Kubo Norio , Sakai Hiromasa
Published: March 2012

The influences of rib/channel geometries on the oxygen transport resistances in a polymer electrolyte fuel cell (PEFC) were investigated through experimental and numerical analyses. A limiting current method was used for evaluating the oxygen transport resistances, which could be separated into two parts. One was macro transport resistances, which were defined as pressure-dependent resistances and the other was micro transport resistances, which were defined as pressure-independent resistances. Both of resistances significantly increased with wider rib/channel widths. Also, the increase in micro transport resistances was more significant than that in macro transport resistances in the lower Platinum (Pt) loading. The numerical model implementing oxygen transport resistances near Pt surface was well correlated with experimental results. The validation results revealed that both in-plane and through-plane reaction distribution became inhomogeneous due to the oxygen concentration distribution induced by rib/channel geometry, resulting in the increase in both oxygen transport resistances. The through-plane reaction distribution also suggested that the micro transport resistances increased due to larger oxygen flux per Pt surface area under low Pt loading. Moreover, the model was applied to verify the impact of oxygen transport resistances on cell performance with lower Pt loading. It was found that the increase in oxygen transport resistances due to larger oxygen flux per Pt surface area lowered the cell performance under high current density operation.
Implementation of a Model-Based Methodology Aimed at Detecting Degradation and Faulty Operation in SOFC Systems
Authors: Marra Dario , Pianese Cesare , Sorrentino Marco
Published: March 2012

The paper focuses on a model-based methodology aimed at developing suitable diagnostics strategies to detect degradation level and faulty operation in solid oxide fuel cell (SOFC) systems. The methodology is based on the “inverse” use of a 1-D SOFC stack model to estimate cell parameters from measured variables. Modeling features allow simulating both co- and counter-flow planar SOFC with a good compromise between accuracy and computational burden, thus enhancing final implementation in a variety of optimization procedures. Main objective is to identify those model parameters that are not directly measurable in the real SOFC system, e.g. electrolyte and electrode Ohmic resistance. The inputs are the real-system measurable variables, such as stack voltage and current, inlet mass flow and temperatures. Once unmeasurable variables are identified, they are compared to corresponding reference values to generate suitable residuals, depending on which SOFC stack faulty conditions can be eventually detected and isolated and the stack degradation state can be estimated. The proposed model-based algorithm is suitable in SOFC stack monitoring and diagnosis, thus offering a high potential tool for improving SOFC system safety and durability for on-field applications.
Toward the Development and Validation of a Comprehensive PEM Fuel Cell Model
Authors: Chen Ken S. , Carnes Brian , Hao Liang , Ji Yan , Luo Gang , Wang Chao-Yang , Wang Yun
Published: March 2012

In this paper, we report our ongoing team efforts (which are being funded by the US Department of Energy) toward the development and validation of a three-dimensional, two-phase, comprehensive PEM (polymer electrolyte membrane) fuel cell model. Specifically, we report our progress in following areas: i) a channel two-phase flow submodel to account for the presence of liquid water in flow channels and its effect; ii) an approximate but robust approach for taking MPL (microporous layer) effect into account; iii) an investigation into the effect of cell segmenting; and iv) an ongoing effort in model validation.
Design and Analysis of Hybrid Guideway Heating System for Morgantown Personal Rapid Transit
Authors: Vedam Anand , Sneckenberger John E.
Published: March 2012

The Morgantown Personal Rapid Transit (M-PRT) system is a comfortable conveyance for travel in Morgantown, WV. One of its operating concerns is the increasing cost of heat to the guideway during winter. As the vehicles cannot run safely during snow, the system includes a guideway heating system to melt the ice from the guideway. To reduce the use of expensive natural gas, an interest has been expressed to define a hybrid heating system using an alternate fuel supply. Solid Oxide Fuel Cell (SOFC) was incorporated in the hybrid heating system. This hybrid heating system was designed, and then a detailed analysis was performed to ascertain the performance parameters like heat produced, thermal efficiency, cost of the system and the emissions involved. This high temperature fuel cell releases large amounts of usable heat in the form of exhaust gases. The exhaust gases are deprived of any undesired emissions that pollute the atmosphere. A USDOE EPSCoR WV State Implementation Award conducted by Advance Power Electricity Research Center (APERC) at West Virginia University provided support for conducting this research.
A novel energy mapping approach for CT‐based attenuation correction in PET
Authors: Teimourian B. , Ay M. R. , Zafarghandi M. Shamsaie , Ghafarian P. , Ghadiri H. , Zaidi H.
Published: March 2012

Purpose:

Dual‐energy CT (DECT) is arguably the most accurate energy mapping technique in CT‐based attenuation correction (CTAC) implemented on hybrid PET/CT systems. However, this approach is not attractive for clinical use owing to increased patient dose. The authors propose a novel energy mapping approach referred to as virtual DECT (VDECT) taking advantage of the DECT formulation but using CT data acquired at a single energy (kVP). For this purpose, the CT image acquired at one energy is used to generate the CT image at a second energy using calculated kVP conversion curves derived from phantom studies.

Methods:

The attenuation map (μ‐map) at 511 keV was generated for the XCAT phantom and clinical studies using the bilinear, DECT, and VDECT techniques. The generated μ‐maps at 511 keV are compared to the reference derived from the XCAT phantom serving as ground truth. PET data generated from a predefined activity map for the XCAT phantom were then corrected for attenuation using μ‐maps generated using the different energy mapping approaches. In addition, the generated μ‐maps using the above described methods for a cylindrical polyethylene phantom containing different concentrations of K2HPO4 in water were compared to actual attenuation coefficients. Likewise, CT images of five clinical whole‐body studies were used to generate μ‐maps using the various energy‐mapping approaches were compared with μ‐maps acquired at 511 keV using 68Ge/68Ga rod sources for the clinical studies.

Results:

The results of phantom studies demonstrate that the proposed method is more accurate than the bilinear technique. All three μ‐maps yielded almost similar results for soft and lung tissues whereas for bone tissues, the DECT and the VDECT methods produced a much smaller mean relative difference (3.0% and 2.8%, respectively) than the bilinear approach (11.8%). Likewise, the comparison of PET images corrected for attenuation using the various methods showed that the proposed method provides better accuracy (6.5%) than the bilinear method (13.4%). Clinical studies further demonstrated that, compared to the bilinear method, the VDECT approach has better agreement for bony structures with the DECT technique (1.5% versus 8.9%) and transmission scanning (8.8% versus 17.7%).

Conclusions:

It was concluded that the proposed method outperforms the bilinear method especially in bony structures. Further evaluation using a large clinical PET/CT database is underway to evaluate the potential of the technique in a clinical setting.
New perspective on the optical theorem of classical electrodynamics
Authors: Mansuripur Masud
Published: March 2012

A proof of the optical theorem (also known as the optical cross-section theorem) is presented, which reveals the intimate connection between the forward scattering amplitude and the absorption-plus-scattering of the incident wave within the scatterer. The oscillating charges and currents as well as the electric and magnetic dipoles of the scatterer, driven by an incident plane wave, extract energy from the incident beam. The same oscillators radiate electromagnetic energy into the far field, thus giving rise to well-defined scattering amplitudes along various directions. The essence of the proof presented here is that the extinction cross-section of an object can be related to its forward scattering amplitude using the induced oscillations within the object without knowledge of the form assumed by these oscillations.
Listeria monocytogenes Grown at 7°C Shows Reduced Acid Survival and an Altered Transcriptional Response to Acid Shock Compared to L. monocytogenes Grown at 37°C
Authors: Ivy R. A. , Wiedmann M. , Boor K. J.
Published: March 2012

Survival of the food-borne pathogenListeria monocytogenesin acidic environments (e.g., in the human stomach) is vital to its transmission. Refrigerated, ready-to-eat foods have been sources of listeriosis outbreaks. The purpose of this study was to determine whether growth at a low temperature (i.e., 7°C) affectsL. monocytogenessurvival or gene transcription after exposure to a simulated gastric environment (i.e., acid shock at 37°C).L. monocytogenescells grown at 7°C were less resistant to artificial gastric fluid (AGF) or acidified brain heart infusion broth (ABHI) than bacteria grown at higher temperatures (i.e., 30°C or 37°C). ForL. monocytogenesgrown at 7°C, stationary-phase cells were more resistant to ABHI than log-phase cells, indicating that both temperature and growth phase affect acid survival. Microarray transcriptomic analysis revealed that the number and functional categories of genes differentially expressed after acid shock differed according to both growth temperature and growth phase. The acid response ofL. monocytogenesgrown to log phase at 37°C involved stress-related transcriptional regulators (i.e., σB, σH, CtsR, and HrcA), some of which have been implicated in adaptation to the intracellular environment. In contrast, for bacteria grown at 7°C to stationary phase, acid exposure did not result in differential expression of the stress regulons examined. However, two large operons encoding bacteriophage-like proteins were induced, suggesting lysogenic prophage induction. The adaptive transcriptional response observed in 37°C-grown cells was largely absent in 7°C-grown cells, suggesting that temperatures commonly encountered during food storage and distribution affect the ability ofL. monocytogenesto survive gastric passage and ultimately cause disease.
Phospholipase A
2
Inhibitors Synthesized by Two Entomopathogenic Bacteria, Xenorhabdus nematophila and Photorhabdus temperata subsp. temperata
Authors: Seo Samyeol , Lee Sunghong , Hong Yongpyo , Kim Yonggyun
Published: March 2012

The entomopathogenic bacteria
Xenorhabdus nematophila
and
Photorhabdus temperata
subsp.
temperata
suppress insect immune responses by inhibiting the catalytic activity of phospholipase A
2
(PLA
2
), which results in preventing biosynthesis of immune-mediating eicosanoids. This study identified PLA
2
inhibitors derived from culture broths of these two bacteria. Both
X. nematophila
and
P. temperata
subsp.
temperata
culture broths possessed significant PLA
2
-inhibitory activities. Fractionation of these bacterial metabolites in the culture broths using organic solvent and subsequent chromatography purified seven potent PLA
2
inhibitors, three of which (benzylideneacetone [BZA], proline-tyrosine [PY], and acetylated phenylalanine-glycine-valine [FGV]) were reported in a previous study. Four other compounds (indole, oxindole,
cis
-cyclo-PY, and
p
-hydroxyphenyl propionic acid) were identified and shown to significantly inhibit PLA
2
.
X. nematophila
culture broth contained these seven compounds, while
P. temperata
subsp.
temperata
culture broth contained three compounds (BZA, acetylated FGV, and
cis
-cyclo-PY). BZA was detected in the largest amount among these PLA
2
compounds in both bacterial culture broths. All seven bacterial metabolites also showed significant inhibitory activities against immune responses, such as phenoloxidase activity and hemocytic nodulation; BZA was the most potent. Finally, this study characterized these seven compounds for their insecticidal activities against the diamondback moth,
Plutella xylostella
. Even though these compounds showed relatively low toxicities to larvae, they significantly enhanced the pathogenicity of
Bacillus thuringiensis
. This study reports bacterial-origin PLA
2
inhibitors, which would be applicable for developing novel insecticides.
Conserved Terminal Organelle Morphology and Function in Mycoplasma penetrans and Mycoplasma iowae
Authors: Jurkovic Dominika A. , Newman Jaime T. , Balish Mitchell F.
Published: March 2012

Within the genus
Mycoplasma
are species whose cells have terminal organelles, polarized structures associated with cytadherence and gliding motility.
Mycoplasma penetrans
, found mostly in HIV-infected patients, and
Mycoplasma iowae
, an economically significant poultry pathogen, are members of the
Mycoplasma muris
phylogenetic cluster. Both species have terminal organelles that interact with host cells, yet the structures in these species, or any in the
M. muris
cluster, remain uncharacterized. Time-lapse microcinematography of two strains of
M. penetrans
, GTU-54-6A1 and HF-2, and two serovars of
M. iowae
, K and N, show that the terminal organelles of both species play a role in gliding motility, with differences in speed within and between the two species. The strains and serovars also differed in their hemadsorption abilities that positively correlated with differences in motility speeds. No morphological differences were observed between
M. penetrans
and
M. iowae
by scanning electron microscopy (SEM). SEM and light microscopy of
M. penetrans
and
M. iowae
showed the presence of membranous filaments connecting pairs of dividing cells. Breaking of this filament during cell division was observed for
M. penetrans
by microcinematography, and this suggests a role for motility during division. The Triton X-100-insoluble fractions of
M. penetrans
and
M. iowae
consisted of similar structures that were unique compared to those identified in other mycoplasma species. Like other polarized mycoplasmas,
M. penetrans
and
M. iowae
have terminal organelles with cytadherence and gliding functions. The difference in function and morphology of the terminal organelles suggests that mycoplasmas have evolved terminal organelles independently of one another.
Molecular Structure of Isolated MvspI, a Variable Surface Protein of the Fish Pathogen Mycoplasma mobile
Authors: Adan-Kubo Jun , Yoshii Shu-hei , Kono Hidetoshi , Miyata Makoto
Published: March 2012

Mycoplasma mobile
is a parasitic bacterium that causes necrosis in the gills of freshwater fishes. This study examines the molecular structure of its variable surface protein, MvspI, whose open reading frame encodes 2,002 amino acids. MvspI was isolated from mycoplasma cells by a biochemical procedure to 92% homogeneity. Gel filtration and analytical ultracentrifugation suggested that this protein is a cylinder-shaped monomer with axes of 66 and 2.7 nm. Rotary shadowing transmission electron microscopy of MvspI showed that the molecule is composed of two rods 30 and 45 nm long; the latter rod occasionally features a bulge. Immuno-electron microscopy and epitope mapping showed that the bulge end of the molecular image corresponds to the C terminus of the amino acid sequence. Partial digestion by various proteases suggested that the N-terminal part, comprised of 697 amino acids, is flexible. Analysis of the predicted amino acid sequence showed that the molecule features a lipoprotein and 16 repeats of about 90 residues; 15 positions exist between residues 88 and 1479, and the other position is between residues 1725 and 1807. The amino acid sequence of MvspI was mapped onto a molecular image obtained by electron microscopy. The present study is the first to elucidate the molecular shape of a variable surface protein of mycoplasma.
The prognostic value of Ki-67 expression in penile squamous cell carcinoma
Authors: Stankiewicz Elzbieta , Ng Mansum , Cuzick Jack , Mesher David , Watkin Nick , Lam Wayne , Corbishley Cathy , Berney Daniel M
Published: March 2012

Aims

To determine whether Ki-67 immunoexpression in penile squamous cell carcinoma (PSCC) has a prognostic value and correlates with lymph node metastasis, human papillomavirus (HPV) infection and patient survival.

Methods

148 formalin-fixed paraffin-embedded PSCC samples were tissue-microarrayed, including 97 usual-type SCCs, 17 basaloid, 15 pure verrucous carcinomas, 2 warty and 17 mixed-type tumours. All samples were immunostained for Ki-67 protein. HPV DNA was detected with INNO-LiPA assay. Follow-up data were available for 134 patients.

Results

Ki-67 was strongly expressed in 57/148 (38.5%) of PSCCs. Different cancer subtypes showed significant difference in Ki-67 expression (p<0.0001) with highest positivity in basaloid, 16/17 (94%), followed by usual type, 38/97 (39%) and lack of Ki-67 positive cases within verrucous tumours, 0/15. Ki-67 positively correlated with high-risk HPV (p<0.0001) and showed good specificity (84%) but low sensitivity (61%) for high-risk HPV detection. Ki-67 protein strongly positively correlated with tumour grade (p<0.0001) but not with stage (p=0.2193), or lymph node status (p=0.7366). Ki-67 showed no prognostic value for cancer-specific survival (HR=1.00, 95%, CI 0.99 to 1.02, p=0.54) or overall survival (HR=1.00, 95%, CI 0.99 to 1.02, p=0.45). High tumour stage, lymph node metastasis, high tumour grade and age at diagnosis were all independent prognostic factors for cancer-specific survival and overall survival.

Conclusions

Ki-67 is only a moderate surrogate marker for HPV infection in PSCC. It does not show prognostic value for cancer-specific survival and overall survival in PSCC.
Comparison of the RNA-based EndoPredict multigene test between core biopsies and corresponding surgical breast cancer sections
Authors: Müller Berit Maria , Brase Jan C , Haufe Franziska , Weber Karsten E , Budzies Jan , Petry Christoph , Prinzler Judith , Kronenwett Ralf , Dietel Manfred , Denkert Carsten
Published: March 2012

Aim

This study compared the perfomance of the RNA-based EndoPredict multigene test on core biopsies and surgical breast cancer specimens and analysed the influence of biopsy-induced tissue injuries on the test result.

Methods

80 formalin-fixed paraffin-embedded samples comprising paired biopsies and surgical specimens from 40 ER-positive, HER2-negative patients were evaluated. Total RNA was extracted and the EndoPredict score was determined.

Results

RNA yield was considerably lower in core biopsies, but sufficient to measure the assay in all samples. The EndoPredict score was highly correlated between paired samples (Pearson r=0.92), with an excellent concordance of classification into a low or high risk of metastasis (overall agreement 95%).

Conclusions

The measurements are comparable between core biopsies and surgical sections, which suggest that the EndoPredict assay can be performed on core biopsy tissue. Inflammatory changes induced by presurgical biopsies had no significant effect on the RNA-based risk assessment in surgical specimens.
Roles of sarcoplasmic reticulum Ca2+ cycling and Na+/Ca2+ exchanger in sinoatrial node pacemaking: Insights from bifurcation analysis of mathematical models
Authors: Kurata Yasutaka , Hisatome Ichiro , Shibamoto Toshishige
Published: March 2012

To elucidate the roles of sarcoplasmic reticulum (SR) Ca2+ cycling and Na+/Ca2+ exchanger (NCX) in sinoatrial node (SAN) pacemaking, we have applied stability and bifurcation analyses to a coupled-clock system model developed by Maltsev and Lakatta ( Am J Physiol Heart Circ Physiol 296: H594-H615, 2009). Equilibrium point (EP) at which the system is stationary (i.e., the oscillatory system fails to function), periodic orbit (limit cycle), and their stability were determined as functions of model parameters. The stability analysis to detect bifurcation points confirmed crucial importance of SR Ca2+ pumping rate constant ( Pup), NCX density ( kNCX), and L-type Ca2+ channel conductance for the system function reported in previous parameter-dependent numerical simulations. We showed, however, that the model cell does not exhibit self-sustained automaticity of SR Ca2+ release at any clamped voltage and therefore needs further tuning to reproduce oscillatory local Ca2+ release and net membrane current reported experimentally at −10 mV. Our further extended bifurcation analyses revealed important novel features of the pacemaker system that go beyond prior numerical simulations in relation to the roles of SR Ca2+ cycling and NCX in SAN pacemaking. Specifically, we found that 1) NCX contributes to EP instability and enhancement of robustness in the full system during normal spontaneous action potential firings, while stabilizing EPs to prevent sustained Ca2+ oscillations under voltage clamping; 2) SR requires relatively large kNCX and subsarcolemmal Ca2+ diffusion barrier (i.e., subspace) to contribute to EP destabilization and enhancement of robustness; and 3) decrementing Pup or kNCX decreased the full system robustness against hyperpolarizing loads because EP stabilization and cessation of pacemaking were observed at the lower critical amplitude of hyperpolarizing bias currents, suggesting that SR Ca2+ cycling contributes to enhancement of the full system robustness by modulating NCX currents and promoting EP destabilization.
Adenoviral short hairpin RNA therapy targeting phosphodiesterase 5a relieves cardiac remodeling and dysfunction following myocardial infarction
Authors: Li Longhu , Haider Husnain Kh. , Wang Linlin , Lu Gang , Ashraf Muhammad
Published: March 2012

We previously showed that treatment with tadalafil, a long-acting phosphodiesterase-5a (PDE5a) inhibitor, effectively prevented adverse left ventricular (LV) remodeling of the infarcted heart. We hypothesized that short-hairpin RNA (shRNA) therapy targeting PDE5a would simulate the effects of pharmacological intervention for treatment of postinfarction LV remodeling and dysfunction. Experimental model of myocardial infarction was developed in female mice by permanent ligation of left coronary artery. Immediately after that, an adenoviral vector encoding for shRNA sequence targeting PDE5a (Ad-shPDE5a) was injected intramyocardially, which specifically inhibited PDE5a in the heart. Four weeks later, Ad-shPDE5a treated mice showed significant mitigation of the left ventricle (LV) dilatation and dysfunction as indicated by smaller LV cavity and more preserved ejection fraction and fractional shortening. Infarction size and fibrosis were significantly reduced in Ad-shPDE5a-treated mice. Additionally, more salvaged cardiomyocytes, significantly reduced collagen contents, and higher blood vessel density were observed in Ad-shPDE5a-treated mice. The cytoprotective effects of Ad-shPDE5a were demonstrated in vitro in Ad-shPDE5a transfected cardiomyocytes cultured under oxygen glucose deprivation. Among downstream mediators of PDE5a signaling, cyclic GMP (cGMP) and cGMP-dependent protein kinase G (PKG) were activated with concomitant reduction in caspase-3 activity. However, no significant change in PKA and cAMP activities were observed in Ad-shPDE5a-treated hearts. Inhibition with shRNA improved cardiac remodeling and dysfunction by reducing infarction size and cardiac fibrosis and increased cGMP and PKG activity. These findings suggest that PDE5 inhibition with Ad-shPDE5a is a novel approach for treatment of myocardial infarction.
Forecast-Based Decision Support for San Francisco International Airport: A NextGen Prototype System That Improves Operations during Summer Stratus Season
Authors: Reynolds David W. , Clark David A. , Wilson F. Wesley , Cook Lara
Published: March 2012

During summer, marine stratus encroaches into the approach to San Francisco International Airport (SFO) bringing low ceilings. Low ceilings restrict landings and result in a high number of arrival delays, thus impacting the National Air Space (NAS). These delays are managed by implementation of ground delay programs (GDPs), which hold traffic on the ground at origination airports in anticipation of insufficient arrival capacity at SFO. In an effort to reduce delays and improve both airport and NAS efficiency, the Federal Aviation Administration (FAA) funded a research effort begun in 1995 to develop an objective decision support system to aid forecasters in the prediction of stratus clearing times. By improving forecasts at this major airport, the scope and duration of ground and airborne holds can be reduced. The Marine Stratus Forecast System (MSFS) issues forecasts both deterministically and probabilistically. Following transition to NWS operations in 2004, the system continued to provide reliable forecasts but showed no significant improvement in delay reduction. Changes to the FAA GDP issuance procedures in 2008 allowed them to utilize the improved forecasts, leading to quantifiable reductions in ground and airborne holds for SFO equating to dollars saved. To further reduce delays, a refined statistically based model, the Ground Delay Parameters Selection Model (GPSM) for selecting an optimal ground delay strategy has been developed, utilizing the available archive of objective MSFS probabilistic forecasts and accompanying traffic flow data. This effort represents one of the first systematic attempts to integrate objective probabilistic weather information into the air traffic flow decision process, which is a cornerstone element of the FAA's visionary NextGen program.
Risk Factors for Vagal Palsy following Cerebellopontine Angle Surgery
Authors: Best Simon R. , Starmer Heather M. , Agrawal Yuri , Ward Bryan K. , Hillel Alexander T. , Chien Wade W. , Francis Howard W. , Tamargo Rafael J. , Akst Lee M.
Published: March 2012

Objective

Describe the incidence, risk factors, and outcomes of postoperative vagal palsy in patients undergoing surgical excision of cerebellopontine angle (CPA) tumors.

Study Design

Case series with chart review.

Setting

Academic tertiary care center.

Subjects and Methods

One hundred eighty‐one consecutive patients undergoing surgical excision of CPA pathology from January 1, 2008, to December 31, 2010, at Johns Hopkins Hospital. Postoperative unilateral vagal palsy was identified by laryngoscopy or videofluoroscopy, and clinical variables were collected from medical records.

Results

Postoperative unilateral vagal palsy was identified in 19 of 181 (10%) patients. Vocal fold motion impairment (VFMI) in combination with pharyngeal palsy was more common than VFMI or pharyngeal palsy alone. Those with vagal palsy had a larger mean tumor size (30 mm) than those without vagal palsy (20 mm, P =. 0002) and a significantly longer mean hospital stay (9 vs 5 days, P <. 0001). Vagal palsy was not associated with tumor pathology, prior treatment (stereotactic radiation or prior surgery), or surgical approach (suboccipital craniotomy vs translabyrinthine approach). Significant rates of aspiration were observed in patients with vagal palsy (67%).

Conclusion

Voice and swallowing function can be affected by surgical excision of pathology of the CPA. Tumor size is an independent risk factor for postoperative vagal palsy, which in turn has important consequences for prolonged hospital stay, aspiration, and voice and swallowing impairment.
Inhibition of Bcl-2 antiapoptotic members by obatoclax potently enhances sorafenib-induced apoptosis in human myeloid leukemia cells through a Bim-dependent process
Authors: Rahmani Mohamed , Aust Mandy Mayo , Attkisson Elisa , Williams David C. , Ferreira-Gonzalez Andrea , Grant Steven
Published: March 2012

Interactions between the multikinase inhibitor sorafenib and the BH3-mimetic obatoclax (GX15-070) were examined in human acute myeloid leukemia (AML) cells. Treatment with sorafenib/obatoclax induced pronounced apoptosis in and reduced the clonogenic growth of multiple AML lines and primary AML cells but not normal CD34+ cells. Sorafenib triggered rapid and pronounced Mcl-1 down-regulation accompanied by enhanced binding of Bim to Bcl-2 and Bcl-xL, effects that were abolished by obatoclax coadministration. Notably, shRNA knockdown of Bim, Bak, or Bax, but not Noxa, significantly attenuated obatoclax/sorafenib lethality, whereas ectopic expression of Mcl-1 exerted a protective effect. Furthermore, exposure of leukemia cells to sorafenib and obatoclax markedly induced autophagy, reflected by rapid and pronounced LC3 processing and LC3–green fluorescent protein (GFP) punctate formation. Multiple autophagy inhibitors or VPS34 knockdown, significantly potentiated sorafenib/obatoclax lethality, indicating a cytoprotective role for autophagy in this setting. Finally, studies in a xenograft mouse model revealed that combined sorafenib/obatoclax treatment markedly reduced tumor growth and significantly prolonged survival in association with Mcl-1 down-regulation and apoptosis induction, whereas agents administered individually had only modest effects. These findings suggest that combining sorafenib with agents that inhibit Mcl-1 and Bcl-2/Bcl-xL such as obatoclax may represent a novel and potentially effective strategy in AML.
Cyclic intensive light exposure induces retinal lesions similar to age-related macular degeneration in APPswe/PS1 bigenic mice
Authors: Dong Zhizhang , Li Juan , Leng Yunxia , Sun Xuerong , Hu Huiling , He Yuan , Tan Zhiqun , Ge Jian
Published: March 2012

Background

Intensive light exposure and beta-amyloid (Aβ) aggregates have been known as a risk factor for macular degeneration and an important component in the pathologic drusen structure involved in this disorder, respectively. However, it is unknown whether Aβ deposition mediates or exacerbates light exposure-induced pathogenesis of macular degeneration. Several studies including the one from us already showed accumulation of Aβ deposits in the retina in Alzheimer's transgenic mice. Using histopathological analysis combined with electroretinographic functional assessment, we investigated the effects of cyclic intensive light exposure (CILE) on the architecture of retina and related function in the APPswe/PS1bigenic mouse.

Results

Histopathological analysis has found significant loss of outer nuclear layer/photoreceptor outer segment and outer plexiform layer along with abnormal hypo- and hyper-pigmentation in the retinal pigment epithelium (RPE), remarkable choroidal neovascularization (CNV), and exaggerated neuroinflammatory responses in the outer retina of APPswe/PS1 bigenic mice following cyclic intensive light exposure (CILE), whereas controls remained little change contrasted with age-matched non-transgenic littermates. CILE-induced degenerative changes in RPE are further confirmed by transmission electron microcopy and manifest as formation of basal laminar deposits, irregular thickening of Bruch's membrane (BrM), deposition of outer collagenous layer (OCL) in the subretinal space, and vacuolation in the RPE. Immunofluorescence microscopy reveals drusenoid Aβ deposits in RPE as well as neovessels attached which are associated with disruption of RPE integrity and provoked neuroinflammatory response as indicated by markedly increased retinal infiltration of microglia. Moreover, both immunohistochemistry and Western blots detect an induction of vascular endothelial growth factor (VEGF) in RPE, which corroborates increased CNV in the outer retina in the bigenic mice challenged by CILE.

Conclusions

Our findings demonstrate that degenerative changes in the outer retina in the APPswe/PS1 bigenic mouse induced by CILE are consistent with these in AMD. These results suggest that an Alzheimer's transgenic animal model with accumulation of Aβ deposits might be an alternative animal model for AMD, if combined with other confounding factors such as intensive light exposure for AMD.
Factors associated with discharge destination from acute care after acquired brain injury in Ontario, Canada
Authors: Chen Amy Y , Zagorski Brandon , Parsons Daria , Vander Laan Rika , Chan Vincy , Colantonio Angela
Published: March 2012

Background

The aim of this paper is to examine factors associated with discharge destination after acquired brain injury in a publicly insured population using the Anderson Behavioral Model as a framework.

Methods

We utilized a retrospective cohort design. Inpatient data from provincial acute care records from fiscal years 2003/4 to 2006/7 with a diagnostic code of traumatic brain injury (TBI) and non-traumatic brain injury (nTBI) in Ontario, Canada were obtained for the study. Using multinomial logistic regression models, we examined predisposing, need and enabling factors from inpatient records in relation to major discharge outcomes such as discharge to home, inpatient rehabilitation and other institutionalized care.

Results

Multinomial logistic regression revealed that need factors were strongly correlated with discharge destinations overall. Higher scores on the Charlson Comorbidity Index were associated with discharge to other institutionalized care in the nTBI population. Length of stay and special care days were identified as markers for severity and were both strongly positively correlated with discharge to other institutionalized care and inpatient rehabilitation, compared to discharge home, in both nTBI and TBI populations. Injury by motor vehicle collisions was found to be positively correlated with discharge to inpatient rehabilitation and other institutionalized care for patients with TBI. Controlling for need factors, rural location was associated with discharge to home versus inpatient rehabilitation.

Conclusions

These findings show that need factors (Charlson Comorbidity Index, length of stay, and number of special care days) are most significant in terms of discharge destination. However, there is evidence that other factors such as rural location and access to supplemental insurance (e.g., through motor vehicle insurance) may influence discharge destination outcomes as well. These findings should be considered in creating more equitable access to healthcare services across the continuum of care.
Petrological and Geochemical Investigations of Rajpardi Lignite Deposit, Gujarat, India
Authors: Singh Prakash K , Singh M.P. , Singh Alok K , Naik A.S. , Singh Vikas K , Singh Vijay K , Rajak P.K.
Published: March 2012

The present paper entails the petrographic and chemical characteristics of the lignite samples drawn from the Rajpardi lignite deposit of Bharuch district, Gujarat. This lignite contains a high concentration of huminite which is dominated by telohuminite, followed by detrohuminite. Liptinite and inertinite macerals are very low in concentration. The dominant microlithotype is humite. Its elevated volatile matter and high hydrogen content depicts its perhydrous nature. The study reveals that this lignite originated in a limno-telmatic to telmatic condition. The paleomire is further characterized as a wet moor having moderate to high flooding with good tissue preservation and increasing bacterial activity.
Hydrocarbon-Generation in Cambrian-Silurian High- to Over- Mature Source Rocks, Middle and Upper Yangtze Region, China
Authors: Tao Shu , Wang Yanbin , Tang Dazhen , Xu Hao
Published: March 2012

Two main Cambrian-Silurian high- to over-mature hydrocarbon source rocks occur in the Middle and Upper Yangtze region: the Lower Cambrian Niutitang Formation (mostly shale), and the Lower Silurian Longmaxi and Upper Ordovician Wufeng formations (mostly graptolite shale). Due to several complicated tectonic events occurred in the study area, the source rocks experienced inhomogeneous uplift, deformation, and burial, resulting in discontinuous and episodic hydrocarbon generation evolution. Based on a detailed study of the tectonic burial history and an analysis of the current degree of thermal evolution of the source rocks, this paper studied the burial history, the thermal history, and the hydrocarbon-generation history of the Cambrian-Silurian source rocks. It used basin modeling technology and thermal simulation tests on source rocks to reveal the process and the regional regularity of the hydrocarbon-generation evolution, and to expound the tectonic phases and the time-spatial distribution of hydrocarbon generation. It shows that the region from western Hubei to eastern Chongqing is the major source area of Lower Cambrian rocks, and the region from southeastern Sichuan to central Guizhou is the major source area of Lower Silurian rocks. Reconstruction of hydrocarbon-generation history allows simulated estimation of the remaining hydrocarbon-generation potential of the high-over mature marine source rocks.
Vertical Diversity of Coalbed Methane Content and its Geological Controls in the Qingshan Syncline, Western Guizhou Province, China
Authors: Lei Bo , Qin Yong , Gao Di , Fu Xuehai , Wang Geoff G.X. , Zou Mingjun , Shen Jian
Published: March 2012

The distribution of methane content in the coalbed is complex in the Qinshan Syncline of western Guizhou Province. Analyses of factors controlling on the distribution of gas content are made in this paper. Coal ranks and geo-structure in the region showed strong controls on the gas distribution. Coals with higher degree of metamorphism or located in syncline most likely have higher gas content. With the concept of coalbed methane content unite thickness (CBMCUT), those factors such as coal seam buried depth and coal structure present positive relations with gas content. Results indicated that the variation of CBMCUT is not fixed in different research areas or in different coal structures. Namely, the variation follows “v-shaped” correlation with the increasing coal buried depth in the region of Qinshan Syncline. However, the trend is smooth for the coals in the Panzhuang mining area. Usually, the critical value for primary-texture coal and mylonitized is different based on the analysis of the relationship between coal structure and CBMCUT in those two areas described above. The value is commonly higher in mylonitized coal and lower in those mainly primary-texture and fragmented coals.
Bulk Pyrolysis and Chemical Kinetic Characteristics of OM Related to the Occurrence of Immature-Low Mature Oils
Authors: Wang Min , Lu Shuangfang , Xue Haitao , Guo Xiaobo , Chen Guohui , Tian Shansi , Wang Weiming , Zhang Lei
Published: March 2012

Organic matters, such as resinite, suberinite, OM (organic matter) reworked by bacteria, sulphur-rich OM, which have close relationship to the occurrence and accumulation of immature-low mature oils, were pyrolyzed by the GHM and PY-GC for studying the hydrocarbon generation characteristics and the relationship between the special types of OMs and the occurrence of immature-low mature oil. Meantime, some reference OMs are studied in the same way. The experimental results indicate that the OMs related to the occurrence of immature-low mature oil can start to generate hydrocarbon obviously under a relative lower thermal stress, while the temperature required for hydrocarbon generation of reference OMs is relatively high. Furthermore, it shows that the generation of immature-low mature oil may be mostly a chemical reaction process. The chemical kinetic analyse shows that the OMs related to immature-low mature oils have lower activation energies than that of conventional OMs, although the occurrence and accumulation of immature oil are related to various geological conditions and factors. The preliminary application of the chemical kinetic model shows that the representative OMs related to the immature oils do start to generate a certain number of hydrocarbons in a shallower depth than that of hydrocarbon generation threshold for the conventional OMs.
Distribution Characteristics and Significance of Hydrocarbon Shows to Petroleum Geology in Kalpin Area, NW Tarim Basin
Authors: Gao Ping , Lü Xiuxiang , Zhang Jinhui , Hou Guo , Liu Rui , Yan Huan , Li Taotao
Published: March 2012

Abundant hydrocarbon shows are distributed in five different regions in the Kalpin area, northwestern Tarim Basin: Aksu hydrocarbon shows region, Subashi hydrocarbon shows region, Sanchakou hydrocarbon shows region, Piqiang hydrocarbon shows region, and Sickl hydrocarbon shows region, totaling 27 hydrocarbon show points. From the statistical analysis of all hydrocarbon shows in the study area, the paper summarizes the distribution characteristics. Combined with field investigation, previous documents of Kalpin area and oil-source correlation of hydrocarbon shows, the authors indicate that large multilayered oil-bearing paleo-reservoirs existed in the geological process in the Kalpin area, such as Aksu paleo-reservoirs and Piqiang paleo-reservoirs. Despite destruction by several periods of tectonic events after the formation of paleo-reservoirs, many reservoirs may still be left undamaged. Giant gas fields below the Middle Cambrian gypsum-salt bed could be preserved in the Kalpin area. In addition, the Middle-Lower Permian Balikelike formation, with good oil generating condition is an important exploration target in the Kalpin area.
Mechanism of the Removal of AuCl−4 Ions from Aqueous Solution by Means of Peat Soil Humin
Authors: Santosa Sri Juari , Sudiono Sri , Siswanta Dwi , Kunarti Eko Sri , Dewi Shinta Rosalia
Published: March 2012

Peat soil humin, obtained after the removal of fulvic and humic acid fractions according to the recommended procedure of the International Humic Substances Society (IHSS), has the ability to remove AuCl−4 ions from aqueous solution. The removal was greatest at medium acidity, which was equivalent to pH 2.0, and it was governed by two different processes, i.e. attachment onto un-ionized –COOH groups through hydrogen bonding and reduction to Au metal by the action of the –OH group. Purification of humin through repeated immersion and shaking in a mixed solution consisting of 0.1 M HCl and 0.05 M HF led to the abrupt increase in the –COOH contents from 386 mmol/kg to 2510 mmol/kg, while the content of total –OH functional groups remained relatively constant at values slightly higher than 3000 mmol/kg. The increase in –COOH content improved the removal of AuCl−4 ions from 23 mg/g to 27 mg/g, but it was unfortunately accompanied by a diminished reduction ability to Au metal. Hence, the role of the –COOH functional group in removing AuCl−4 ions through hydrogen bonding was more significant for the purified humin, while that of the –OH group in removing AuCl−4 ions through reduction to Au metal was better for the crude (unpurified) humin.