bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitro activity of dermaseptin S1 derivatives against genital pathogens
Authors: SAVOIA DIANELLA , DONALISIO MANUELA , CIVRA ANDREA , SALVADORI SEVERO , GUERRINI REMO
Published: May 2010

Savoia D, Donalisio M, Civra A, Salvadori S, Guerrini R. In vitro activity of dermaseptin S1 derivatives against genital pathogens. APMIS 2010; 118: 674–80.

The aim of this study was to evaluate the biological activity of nine dermaseptin‐S1 (DRS‐S1) derivatives (synthesized by solid‐phase methods and purified) against different pathogens causing genital infections (Trichomonas vaginalis, Herpes simplex virus, Papillomavirus). The in vitro activity on T. vaginalis was determined by counting the protozoon in a hemocytometer after vital staining with trypan blue; antiviral activity of the compounds was tested on monolayers of Vero cells for Herpes simplex virus‐1 (GFP) and on 293TT cells for human papillomavirus (HPV‐16) pseudovirions (GFP). The cytotoxicity of the derivatives was assessed by evaluating both the hemolytic activity and the effect on Vero and 293TT cells. The DRS‐S1 longer peptides demonstrated a superior activity on T. vaginalis but also a certain cytopathic effect. The compounds with 29 amino acids exhibited activity against the two viruses tested at concentrations not toxic to cells. The results obtained show that some of the synthetic peptides assessed have inhibitory activity against the pathogens tested, indicating a potential for the development of new molecules for use as topical microbicides to prevent the sexual transmission of microorganisms.
Bioengineering strategies for regeneration of craniofacial bone: a review of emerging technologies
Authors: Ward BB , Brown SE , Krebsbach PH
Published: May 2010

Oral Diseases (2010) 16, 709–716

Although advances in surgical techniques and bone grafting have significantly improved the functional and cosmetic restoration of craniofacial structures lost because of trauma or disease, there are still significant limitations in our ability to regenerate these tissues. The regeneration of oral and craniofacial tissues presents a formidable challenge that requires synthesis of basic science, clinical science, and engineering technology. Tissue engineering is an interdisciplinary field of study that addresses this challenge by applying the principles of engineering to biology and medicine toward the development of biological substitutes that restore, maintain, and improve normal function. This review will explore the impact of biomaterials design, stem cell biology and gene therapy on craniofacial tissue engineering.
Polymorphisms inCYP2A13andUGT1A7genes and head and neck cancer susceptibility in North Indians
Authors: Sharma R , Ahuja M , Panda NK , Khullar M
Published: May 2010

Oral Diseases(2010)16, 760–768

Objectives: To examine role of genetic variants ofCYP2A13andUGT1A7genes, involved in activation and detoxification of tobacco carcinogens, with risk of head and neck cancer as well as to assess the potential modifying role of gene‐gene and gene‐environment interactions.

Methods: 203 head and neck cancer patients and 201 healthy controls were genotyped for functional polymorphisms ofCYP2A13andUGT1A7genes using polymerase chain reaction‐restriction fragment length polymorphism, denaturing high‐performance liquid chromatography and sequencing.

Results: We identified two novel polymorphisms T478C and T494C inCYP2A13gene which were associated with significantly reduced risk of cancer (OR 0.37; 95% CI 0.19–0.71;P < 0.05). ACYP2A13haplotype carrying variant alleles of T478C/T494C was found to be associated with reduced risk of head and neck cancer (OR 0.42; 95% CI 0.22–0.78;P = 0. 005). Mutant ‘T’ allele ofCYP2A13C578T polymorphism was found to be present in cancer patients only. A sevenfold increased risk of cancer was observed in smokers withUGT1A7low activity genotypes (OR 7.01; 95% CI 1.02–48.37;P < 0.05).UGT1A7haplotype carrying C allele (T622C) showed 10‐fold increased risk of cancer (OR 10.12; 95% CI 1.29–79.4;P < 0.05).

Conclusion: Interplay between genetic variants ofCYP2A13andUGT1A7genes and smoking may modulate susceptibility to head and neck cancer.
Icariin Inhibits Hydrogen Peroxide‐Mediated Cytotoxicity by Up‐regulating Sirtuin Type 1‐Dependent Catalase and Peroxiredoxin
Authors: Zhang Ling , Huang Siyuan , Chen Yanting , Wang Zhongyuan , Li Erguang , Xu Yun
Published: May 2010

Abstract:  Previous studies suggest that flavonol icariin protects against neuron injury after oxygen and glucose deprivation by increasing SIRT1. This study demonstrates that icariin can inhibit H2O2‐induced neurotoxicity. The neuroprotection of icariin enhances the antioxidant capacity through both a direct scavenging effect on over‐produced free radicals and an indirect stimulating effect on the expression and activity of cellular antioxidant enzymes including catalase (CAT) and peroxiredoxin 1 (Prx1). The mechanism may be partially involved in the up‐regulation of SIRT1. The SIRT1 antagonist can partly block this neuroprotection and the enhancement of CAT/Prx1 by icariin. These results indicate that the effect of icariin on H2O2‐induced neurotoxicity is dependent on increasing SIRT1 and provides a potentially novel pharmacological strategy for stroke prevention and/or treatment.
Factors Associated withSalmonellaPresence in Environmental Samples and Bulk Tank Milk from US Dairies
Authors: Ruzante J. M. , Lombard J. E. , Wagner B. , Fossler C. P. , Karns J. S. , Van Kessel J. A. S. , Gardner I. A.
Published: May 2010

The objective of this study was to evaluate herd characteristics and management practices associated with presence ofSalmonellain the farm environment and in bulk tank milk (BTM) in US dairy herds. Herd management data, environmental culture, BTM and in‐line milk filter polymerase chain reaction results forSalmonellafrom 260 US dairy herds surveyed during the National Animal Health Monitoring System Dairy 2007 study were analysed. Herd characteristics and management practices were screened by univariate analysis, and selected variables were used to construct a logistic regression model to identify factors associated with the presence ofSalmonellain environmental samples. To identify factors associated with the occurrence ofSalmonellain BTM and milk filters,a prioriselected variables that were related to milking procedures were analysed univariately and a logistic regression model was constructed. The presence ofSalmonellain the farm environment was associated with location of the operation in the East (OR = 4.8; CI: 1.9–11.6), not using a broadcast manure spreader (OR = 3.2; CI: 1.4–7.5), use of bovine somatotropin (BST) (OR = 2.7; CI: 1.5–5.0) and use of anionic salts (OR = 2.2; CI: 1.2–3.9). In the final multivariable model, herds with fewer than 100 cows were at decreased odds (OR = 0.3; CI: 0.1–0.7) of being culture positive forSalmonellaas were herds with between 100 and 499 cows (OR = 0.4; CI: 0.2–0.8) compared with herds having 500 or more cows. The presence of culture‐positive environmental samples and herd size were significantly associated withSalmonellaBTM contamination. The herd‐level factors identified in this study were in agreement with prior studies but also identified other potential factors that can be targeted inSalmonellacontrol programmes.
Expression of key ion channels in the rat cardiac conduction system by laser capture microdissection and quantitative real‐time PCR
Authors: Ou Yan , Niu Xiao‐lin , Ren Fu‐xian
Published: May 2010

The objective of this study was to investigate the molecular basis of the inferior nodal extension (INE) in the atrioventricular junctional area that accounts for arrhythmias. The INE was separated from the adult rat heart by laser capture microdissection. The mRNA expression of ion channels was detected by quantitative real‐time PCR. Hierarchical clustering was used to demonstrate clustering of expression of genes in sections. The mRNA expression of HCN4, Cav3.1 and Cav3.2 was high in the INE, atrioventricular node and sino‐atrial node, and that of Cav3.2 high in Purkinje fibres. Although the expression of HCN1 and Cav1.3 was low in the rat heart, it was relatively higher in the INE, atrioventricular node and sino‐atrial node than in right atrial and right ventricular (working) myocytes. Both HCN2 and Cav1.2 were expressed at higher levels in working myocytes than in nodal tissues and in the INE. Hierarchical clustering analysis demonstrated that the expression of the HCN and calcium channels in INE was similar to that in the slow‐response automatic cells and different from that in working myocytes and Purkinje fibres. The expression of HCN and calcium channels in the INE of the adult rat heart is similar to that of slow‐response automatic cells and provides a substrate for automatic phase 4 depolarization in cells.
Structural and Functional Characterization of Diffusible Signal Factor Family Quorum-Sensing Signals Produced by Members of the
Burkholderia cepacia
Complex
Authors: Deng Yinyue , Wu Ji'en , Eberl Leo , Zhang Lian-Hui
Published: May 2010

Previous work has shown that
Burkholderia cenocepacia
produces the diffusible signal factor (DSF) family signal
cis
-2-dodecenoic acid (C
12
:Δ
2
, also known as BDSF), which is involved in the regulation of virulence. In this study, we determined whether C
12
:Δ
2
production is conserved in other members of the
Burkholderia cepacia
complex (Bcc) by using a combination of high-performance liquid chromatography, mass spectrometry, and bioassays. Our results show that five Bcc species are capable of producing C
12
:Δ
2
as a sole DSF family signal, while four species produce not only C
12
:Δ
2
but also a new DSF family signal, which was identified as
cis
,
cis
-11-methyldodeca-2,5-dienoic acid (11-Me-C
12
:Δ
2,5
). In addition, we demonstrate that the quorum-sensing signal
cis
-11-methyl-2-dodecenoic acid (11-Me-C
12
:Δ
2
), which was originally identified in
Xanthomonas campestris
supernatants, is produced by
Burkholderia multivorans
. It is shown that, similar to 11-Me-C
12
:Δ
2
and C
12
:Δ
2
, the newly identified molecule 11-Me-C
12
:Δ
2,5
is a potent signal in the regulation of biofilm formation, the production of virulence factors, and the morphological transition of
Candida albicans
. These data provide evidence that DSF family molecules are highly conserved bacterial cell-cell communication signals that play key roles in the ecology of the organisms that produce them.
Engineering of
Clostridium phytofermentans
Endoglucanase Cel5A for Improved Thermostability
Authors: Liu Wenjin , Zhang Xiao-Zhou , Zhang Zuoming , Zhang Y.-H. Percival
Published: May 2010

A family 5 glycoside hydrolase from
Clostridium phytofermentans
was cloned and engineered through a cellulase cell surface display system in
Escherichia coli
. The presence of cell surface anchoring, a cellulose binding module, or a His tag greatly influenced the activities of wild-type and mutant enzymes on soluble and solid cellulosic substrates, suggesting the high complexity of cellulase engineering. The best mutant had 92%, 36%, and 46% longer half-lives at 60°C on carboxymethyl cellulose, regenerated amorphous cellulose, and Avicel, respectively.
Acinetobacter baylyi
Starvation-Induced Genes Identified through Incubation in Long-Term Stationary Phase
Authors: Lostroh C. Phoebe , Voyles Bruce A.
Published: May 2010

Acinetobacter
species encounter cycles of feast and famine in nature. We show that populations of
A
cinetobacter
baylyi
strain ADP1 remain dynamic for 6 weeks in batch culture. We created a library of
lacZ
reporters inserted into SalI sites in the genome and then isolated 30 genes with
lacZ
insertions whose expression was induced by starvation during long-term stationary phase compared with their expression during exponential growth. The genes encode metabolic, gene expression, DNA maintenance, envelope, and conserved hypothetical proteins.
Neisseria gonorrhoeae
FA1090 Carries Genes Encoding Two Classes of Vsr Endonucleases
Authors: Kwiatek Agnieszka , Łuczkiewicz Maciej , Bandyra Katarzyna , Stein Daniel C. , Piekarowicz Andrzej
Published: May 2010

A very short patch repair system prevents mutations resulting from deamination of 5-methylcytosine to thymine. The Vsr endonuclease is the key enzyme of this system, providing sequence specificity. We identified two genes encoding Vsr endonucleases V.NgoAXIII and V.NgoAXIV from
Neisseria gonorrhoeae
FA1090 based on DNA sequence similarity to genes encoding Vsr endonucleases from other bacteria. After expression of the gonococcal genes in
Escherichia coli
, the proteins were biochemically characterized and the endonucleolytic activities and specificities of V.NgoAXIII and V.NgoAXIV were determined. V.NgoAXIII was found to be multispecific and to recognize T:G mismatches in every nucleotide context tested, whereas V.NgoAXIV recognized T:G mismatches in the following sequences: GTGG, CTGG, GTGC, ATGC, and CTGC. Alanine mutagenesis of conserved residues showed that Asp50 and His68 of V.NgoAXIII and Asp51 and His69 of V.NgoAXIV are essential for hydrolytic activity. Glu25, His64, and Asp97 of V.NgoAXIV and Glu24, Asp63, and Asp97 of V.NgoAXIII are important but not crucial for the activity of V.NgoAXIII and V.NgoAXIV. However, Glu24 and Asp63 are also important for the specificity of V.NgoAXIII. On the basis of our results concerning features of Vsr endonucleases expressed by
N. gonorrhoeae
FA1090, we postulate that at least two types of Vsr endonucleases can be distinguished.
Changes in DnaA-Dependent Gene Expression Contribute to the Transcriptional and Developmental Response ofBacillus subtilisto Manganese Limitation in Luria-Bertani Medium
Authors: Hoover Sharon E. , Xu Weihong , Xiao Wenzhong , Burkholder William F.
Published: May 2010

The SOS response to DNA damage in bacteria is a well-known component of the complex transcriptional responses to genotoxic environmental stresses such as exposure to reactive oxygen species, alkylating agents, and many of the antibiotics targeting DNA replication. However, bacteria such asBacillus subtilisalso respond to conditions that perturb DNA replication via a transcriptional response mediated by the replication initiation protein DnaA. In addition to regulating the initiation of DNA replication, DnaA directly regulates the transcription of specific genes. Conditions that perturb DNA replication can trigger the accumulation of active DnaA, activating or repressing the transcription of genes in the DnaA regulon. We report here that simply growingB. subtilisin LB medium altered DnaA-dependent gene expression in a manner consistent with the accumulation of active DnaA and that this was part of a general transcriptional response to manganese limitation. The SOS response to DNA damage was not induced under these conditions. One of the genes positively regulated by DnaA inBacillus subtilisencodes a protein that inhibits the initiation of sporulation, Sda. Sda expression was induced as cells entered stationary phase in LB medium but not in LB medium supplemented with manganese, and the induction of Sda inhibited sporulation-specific gene expression and the onset of spore morphogenesis. In the absence of Sda, manganese-limited cells initiated spore development but failed to form mature spores. These data highlight that DnaA-dependent gene expression may influence the response of bacteria to a range of environmental conditions, including conditions that are not obviously associated with genotoxic stress.
Imaging OmpR Binding to Native Chromosomal Loci in
Escherichia coli
Authors: Libby Elizabeth A. , Ekici Seda , Goulian Mark
Published: May 2010

Previously, an unexplained subcellular localization was reported for a functional fluorescent protein fusion to the response regulator OmpR in
Escherichia coli
. The pronounced regions of increased fluorescence, or foci, are dependent on OmpR phosphorylation and do not occupy fixed, easily identifiable positions, such as the poles or mid-cell. Here we show that the foci are due to OmpR-YFP (yellow fluorescent protein) fusion binding to specific sites in the chromosome. To identify positions of foci and quantify their fluorescence intensity, we used a simple system to tag virtually any chromosomal location with arrays of
lacO
or
tetO
. The brightest foci colocalize with the OmpR-regulated gene
ompF
, which is strongly expressed under our growth conditions. When we increased OmpR-YFP phosphorylation by stimulating the EnvZ/OmpR system with procaine, we observed a small increase in OmpR-YFP fluorescence at
ompF
and a significant increase at the OmpR-regulated gene
ompC
. This supports a model of hierarchical binding of OmpR to the
ompF
and
ompC
promoters. Our results explain the inhomogeneous distribution of OmpR-YFP fluorescence in cells and further demonstrate that for a transcription factor expressed at wild-type levels, binding to native sites in the chromosome can be imaged and quantified by fluorescence microscopy.
CTnDOT Integrase Interactions with Attachment Site DNA and Control of Directionality of the Recombination Reaction
Authors: Wood Margaret M. , DiChiara Jeanne M. , Yoneji Sumiko , Gardner Jeffrey F.
Published: May 2010

IntDOT is a tyrosine recombinase encoded by the conjugative transposon CTnDOT. The core binding (CB) and catalytic (CAT) domains of IntDOT interact with core-type sites adjacent to the regions of strand exchange, while the N-terminal arm binding (N) domain interacts with arm-type sites distal to the core. Previous footprinting experiments identified five arm-type sites, but how the arm-type sites participate in the integration and excision of CTnDOT was not known.
In vitro
integration assays with substrates containing arm-type site mutants demonstrated that
attDOT
sequences containing mutations in the L1 arm-type site or in the R1 and R2 or R1 and R2′ arm-type sites were dramatically defective in integration. Substrates containing mutations in the L1 and R1 arm-type sites showed a 10- to 20-fold decrease in detectable
in vitro
excision, but introduction of multiple arm-type site mutations in
attR
did not have an effect on the excision frequency. A sixth arm-type site, the R1′ site, was also identified and shown to be required for integration and important for efficient excision. These results suggest that intramolecular IntDOT interactions are required for integration, while the actions of accessory factors are more important for excision. Gel shift assays performed in the presence of core- and arm-type site DNAs showed that IntDOT affinity for the
attDOT
core was enhanced when IntDOT was simultaneously bound to arm-type site DNA.
Off-trial access to experimental cancer agents for the terminally ill: balancing the needs of individuals and society
Authors: Chahal Manik
Published: May 2010

The development of cancer therapies is a long and arduous process. Because it can take several years for a cancer agent to pass clinical testing and be approved for use, terminal cancer patients rarely have the time to see these experimental therapies become widely available. For most terminal cancer patients the only opportunity they have to access an experimental drug that could potentially improve their prognosis is by joining a clinical trial. Unfortunately, several aspects of clinical trial methodology that are set in place in order to optimise drug development for the benefit of future generations of cancer patients, pose significant limitations to current patient participation. Therefore, several terminal cancer patients believe that they should have the right to access experimental agents that have passed initial safety testing without having to participate in clinical trials. However, granting off-trial access to patients could be detrimental to the scientific process of drug development, and thus could pose significant risks to the health of future patients relying on sound research. Examining this matter through two divergent ethical lenses, rights-based ethics and communitarian ethics, may provide new insight into the issues surrounding the balance between the autonomous rights of current terminal cancer patients, and the needs of future patients and the values of society.
COUPLED FLUID FLOW AND GEOMECHANICS IN COALBED METHANE RECOVERY STUDY
Authors: WEI ZHIJIE , ZHANG DONGXIAO
Published: May 2010

In this paper, we present a coupled fluid flow and geomechanics model for simulating coalbed methane recovery. In the model, the fluid flow process is simulated with a triple porosity/dual permeability representation, and the coupling effects of effective stress and matrix swelling/shrinkage approach are simulated with a coupled fluid flow, geomechanics and gas adsorption/desorption model. The mathematical model is implemented with a fully implicit finite volume method and simulation is conducted to evaluate the effect of coupled fluid flow, geomechanics, and gas adsorption/desorption.
NUMERICAL STUDY OF HOLE SHAPE EFFECT ON BLADE COOLING EFFECTIVENESS
Authors: YAO JUN , SIAN SOHAN , YAO YUFENG , DAVIS TONY W.
Published: May 2010

Numerical study of hole shape effect on blade adiabatic cooling effectiveness has been carried out on four geometry models comprising a standard cylindrical hole, a cylindrical hole with an upstream ramp, a shaped diffuser, and a double console slot. In all the cases, the hole centerline has an inclination angle of 35 degree against the mainstream gas flow. Results of the cylindrical hole model are in good agreement with available experimental and other numerical data. For the other three hole geometry variants considered, it was found that the cooling effectiveness has been considerably enhanced by a max factor of 2, compared to that from the base model. The physical mechanism for this is mainly due to the weakening of coolant flow penetration in the vicinity of the hole exit, thus reducing the level of mixing and the entrainment with the surrounding hot gas flow.
AEROELASTIC ANALYSIS OF ROTOR BLADES USING CFD/CSD COUPLING IN HOVER MODE
Authors: CHEN LONG , WU YIZHAO , XIA JIAN
Published: May 2010

A computational fluid dynamics (CFD) is coupled with a computational structural dynamics (CSD) to simulate the unsteady rotor flow with aeroelasticity effects. An unstructured upwind Navier-Stokes solver was developed for this simulation, with 2nd order time-accurate dual-time stepping method for temporal discretization and low Mach number preconditioning method. For turbulent flows, both the Spalart-Allmaras and Menter's SST model are available. Mesh deformation is achieved through a fast dynamic grid method called Delaunay graph map method for unsteady flow simulation. The rotor blades are modeled as Hodges & Dowell's nonlinear beams coupled flap-lag-torsion. The rotorcraft computational structural dynamics code employs the 15-dof beam finite element formulation for modeling. The structure code was validated by comparing the natural frequencies of a rotor model with UMARC. The flow and structure codes are coupled tightly with information exchange several times at every time step. A rotor blade model's unsteady flow field in the hover mode is simulated using the coupling method. Effect of blade elasticity with aerodynamic loads was compared with rigid blade.
k-ε-BASED TURBULENCE MODELS FOR SIMULATION OF CLOUD CAVITATING FLOWS
Authors: WANG GUOYU , HUANG BIAO , ZHANG BO
Published: May 2010

Cavitating flows around a hydrofoil are simulated in this work by using a transport equation-based model. It is shown that the original Launder-Spalding k-ε model significantly over-predicts the viscosities. The viscosity-corrected models can simulate better the cavitation characteristics including the shedding process.
FRONTAL INSTABILITY OF LOCK-EXCHANGE GRAVITY CURRENTS
Authors: PENG MING , LEE C. B.
Published: May 2010

In this work we address the frontal instability of gravity currents. The planar laser-induced fluorescence (PLiF) flow visualization is utilized to analyze the detailed dynamics of the current, which are generated in a lock-exchange Perspex tank. We believe that two dominant modes of instability determine the complex structures at the head of the flow. The first one resembles Kelvin–Helmholtz instability, which results in Kelvin–Helmholtz billows rolling up in the shear zone above the head. The other, categorized as convective instability known as "lobes and clefts", which stems from ground friction as well as unstable inverse density stratification, and is considered to be the cause for the disruption of the span-wise symmetry of Kelvin–Helmholtz billows. Moreover, our observations indicate that the convective instability also contributes to a secondary instability associated with Kelvin–Helmholtz vortex breakdown. These instabilities not only play a central role in shaping the three-dimension characteristics of the currents, but also govern the mixing and entrainment mechanisms. Therefore, more precise measurement of the positions of the frontal instability and the flow structures, especially the turbulent structures is indeed necessary.
EXPERIMENTAL ANALYSIS OF POOL BOILING HEAT TRANSFER ON EXTENDED SURFACES AT NEAR VACUUM PRESSURES
Authors: NG KIM CHOON , YAP CHRISTOPHER R. , CHAN MARK AARON
Published: May 2010

This research paper presents a study of boiling heat transfer from longitudinal rectangular and square pin finned surfaces immersed in saturated water at low vapor pressures of 2 and 9 kPa. Conventional boiling analysis, which is based on the nominal surface area of the heater, was compared with a boiling analysis that considers the total "wetted" surface area.
APPLICATIONS OF SURFACE MODIFICATION TECHNIQUES IN ENHANCEMENT OF PHASE CHANGE HEAT TRANSFER
Authors: LEU TZONG-SHYNG , LIN HUNG-WEN , WU TSENG-HSIN
Published: May 2010

When saturated vapor passes over a colder substrate, liquid drops nucleate and grow by coalescence with surrounding drops. Typically speaking, nucleation and growth rates of water droplets are faster on a hydrophilic surface than on a hydrophobic surface. However, heat transfer efficiency degrades once surface becomes filmwise condensation. In this paper, vapor condensing on a gradient surface to prevent filmwise condensation is studied. New gradient surfaces are fabricated. It is demonstrated that 10% increase of condensation heat flux can be achieved on a silicon wafer with C = 1 mm gradient surface. The main mechanism for heat transfer enhancement is found to be that drops condensing on C = 1 mm gradient surface begin to move at a much smaller size compared with those on silicon wafer without modification.
EVOLUTION OF NEEDLE-FREE MICRO-INJECTION TO THE SOFT SOLID MATERIAL FOR MEDICAL DELIVERY
Authors: WANG MUH-RONG , CHIU CHUN-HSIEN , HUANG YANG-SHENG , HUANG CHIEN-CHIH , CHENG LI-JAY
Published: May 2010

The evolutions and mechanisms of micro-jet penetration into the solid soft material are described in this paper. The diameter of the micro injector is 300µm. We use the gelatin gel as the solid soft material and water as the injection fluid. Experimental results show that the penetration processes can be described by three phases. I. Induction phase: this phase covers the penetration process of the skin layer. This period lasts only a very short time depending on the power of the micro jet. II. Break phase: This phase covers the penetration process of the inner layer. The volume of jet penetration grows dramatically in this period. III. Saturation phase: The saturation condition was attained when the penetration depth was found to be fixed with time. It is also found that the penetration rate increased linearly with the injection power. It can be fitted in a line with slope of 0.04. It indicates that the stress work of the soft solid is proportional to the injection power. The characteristics can be used to determine the strength of the soft solid materials by jet injection. These data are useful in the needle-free injection for the drug delivery with the endoscope system.
EXPERIMENTAL INVESTIGATION OF SLENDERNESS EFFECT ON SIDE FORCE OF SLENDER BODY
Authors: LEU TZONG-SHYNG , CHANG JENG-REN , KUO CHUN-LIN
Published: May 2010

This study investigates side force of a slender body with slenderness from 4.4 to 8.0. The experimental results show that flow over a slender body experiences a significant side force at angle-of-attack (AOA) higher than 30°. The side force reaches its maximum at AOA ≈ 50°. The present study demonstrates that slenderness (L/D) produces obvious influence on sectional side force distribution at high AOA. To understand the mechanism, evolution of near-wall vortex structure is investigated via hot wire and surface pressure measurements. It was found that one strong vortex is situated close to body surface and the other weak vortex away from the body, inducing a significant side force. Because the weak vortex lifts off early, a new vortex forms in near-wall region. Formation and evolution of the new vortex is the major mechanism that causes local sectional side force distribution exhibiting a wavy form with an alternating sign along the body. Therefore, overall side force does not necessarily increase with increasing slenderness. Reducing overall side force by canceling the alternating vortex-induced forces over the body surface is found if the slenderness L/D > 6.8 at AOA > 40°.
STREAMWISE VORTICES AND REYNOLDS STRESSES OF WALL-BOUNDED TURBULENT SHEAR FLOWS
Authors: ZHOU MING-DE , ZHU HONG-YU , CHEN KAI , SHE ZHEN-SU
Published: May 2010

Reynolds Equation is the most commonly used governing equation in turbulence. However, its application in wall-bounded turbulent shear flows may involve a defect. In general, Reynolds averaging should be ensemble averaging and Reynolds stresses are supposed to express all the actions of turbulence on the mean field. In statistically steady three-dimensional flows, Reynolds stresses are usually defined as correlations of temporal velocity fluctuations so that they cannot contain the influences of steady components of streamwise vortices. This is believed to be one of the reasons why many closure models in RANS meet problems in flows where streamwise vortices play significant roles. In this paper, Spatial-Temporal (S-T) averaged Reynolds stresses were defined, which separates the turbulence actions caused by temporal or spatial velocity fluctuations. DNS data for a fully developed channel flow were then used to check balancing of equations. Comparison showed that the balancing errors in the S-T averaged Reynolds equations were obviously smaller than those in the temporal averaged one, in particular, in the near wall region where the streamwise vortices located. Thus, a combination of traditional model with a supplemental model expressing influences of streamwise vortices might be a way out to improve the turbulence modeling.
NUMERICAL AND EXPERIMENTAL STUDY ON UNSTEADY SHEDDING OF PARTIAL CAVITATION
Authors: JI BIN , LUO XIANWU , WU YULIN , PENG XIAOXING , XU HONGYUAN
Published: May 2010

Periodically unsteady shedding of partial cavity and forming of cavitation cloud have a great influence on hydraulic performances and cavitation erosion for ship propellers and hydro machines. In the present study, the unsteady cavitating flow around a hydrofoil has been calculated by using the single fluid approach with a developed cavitation mass transfer expression based on the vaporization and condensation of the fluid. The numerical simulation depicted the unsteady shedding of partial cavity, such as the process of cavity developing, breaking off and collapsing in the downstream under the steady incoming flow condition. It is noted that good agreement between the numerical results and that of experiment conducted at a cavitation tunnel is achieved. The cavitating flow field indicates that the cavity shedding was mainly caused by the re-entrant jet near cavity trailing edge, which was also clearly recorded by high-speed photographing.
SCALING LAWS, TURBULENCE STRUCTURE AND SUBGRID-SCALE MODELS FOR LARGE EDDY SIMULATION
Authors: DING KEQI , XIAO ZUOLI , SHI YIPENG
Published: May 2010

Turbulence structures are classified by defining the structure parameters. It is verified that the probabilities of these structure classes keep invariant at different scales within the inertial range. It is also shown that this scale-invariant property of turbulence leads to the existence of scaling laws for a series of physical quantities. From them we deduce the variation principle and the physical constraints to optimize the subgrid-scale stress model coefficients for large eddy simulation.
RESPONSE OF METAL CORE PIEZOELECTRIC FIBERS TO UNSTEADY AIRFLOWS
Authors: QIU J. H. , JI H. L. , ZHU K. J. , PARK M. J.
Published: May 2010

In the previous study, possible applications of metal core piezoelectric fibers with a diameter of 200 to 250 µm as bionic airflow sensors mimicking the flow sensitive receptor hairs of crickets have been proposed. This study aims to investigate the dynamic responses of the metal core piezoelectric fibers to unsteady airflow. The metal core piezoelectric fiber is half coated on the outer surface and is used in the bending mode. Wind tunnel tests were carried out and the output voltage of the fiber under the excitation of the unsteady aerodynamic force during flow acceleration and deceleration was measured when the wind tunnel was suddenly closed or opened by a shutter. The relationship between the maximum voltage and the steady-state velocity and that between the voltage and the acceleration of flow were also obtained.
EFFECT OF STRATIFICATION ON STABILITY OF FLOW AND HEAT TRANSFER IN THE LIQUID FILM FLOWING DOWN AN INCLINED HEATED PLATE
Authors: CHENG YOULIANG , FAN XIAOCHAO , TIAN YING
Published: May 2010

The stability analysis in a stratified liquid film flowing down an inclined heated plate is investigated. The boundary value problem of the stability differential equation on small perturbation for general density distribution is derived. Then, the boundary value problem is solved and the solution to the problem is obtained for a special case. The result for non-stratified is agreement with the known one. And the effects of stratification and the other factors such as Re, Ma, We, Bi, Pr, the inclined angle β on the stability of the film are analyzed.
THE WING-BODY AEROELASTIC ANALYSES USING THE INVERSE DESIGN METHOD
Authors: LEE SEUNG JUN , IM DONG-KYUN , LEE IN , KWON JANG-HYUK
Published: May 2010

Flutter phenomenon is one of the most dangerous problems in aeroelasticity. When it occurs, the aircraft structure can fail in a few second. In recent aeroelastic research, computational fluid dynamics (CFD) techniques become important means to predict the aeroelastic unstable responses accurately. Among various flow equations like Navier-Stokes, Euler, full potential and so forth, the transonic small disturbance (TSD) theory is widely recognized as one of the most efficient theories. However, the small disturbance assumption limits the applicable range of the TSD theory to the thin wings. For a missile which usually has small aspect ratio wings, the influence of body aerodynamics on the wing surface may be significant. Thus, the flutter stability including the body effect should be verified. In this research an inverse design method is used to complement the aerodynamic deficiency derived from the fuselage. MGM (modified Garabedian-McFadden) inverse design method is used to optimize the aerodynamic field of a full aircraft model. Furthermore, the present TSD aeroelastic analyses do not require the grid regeneration process. The MGM inverse design method converges faster than other conventional aerodynamic theories. Consequently, the inverse designed aeroelastic analyses show that the flutter stability has been lowered by the body effect.
STEADY-STATE THERMAL ANALYSIS OF A PLATE FIN HEAT SINK USING GREEN'S FUNCTION
Authors: SU XIANGHUI , XU SHUO
Published: May 2010

This paper presents a method for thermal simulation of a plate fin heat sink using an analytical solution of the three-dimensional heat equation resulting from an appropriate plate fin heat sink thermal model. The steady-state temperature map on the surface of the plate fin heat sink is computed analytically employing the Green's function method. The entire solution methodology is illustrated for the particular examples of the plate fin heat sink subjected to non-uniform heat density on the surfaces. The simulation results are validated with experimental measurements.
SYMBOLIC DYNAMICAL MODEL OF AVERAGE QUEUE SIZE OF RANDOM EARLY DETECTION ALGORITHM
Authors: HO CHARLOTTE YUK-FAN , LING BINGO WING-KUEN , IU HERBERT H. C.
Published: May 2010

In this paper, a symbolic dynamical model of the average queue size of the random early detection (RED) algorithm is proposed. The conditions for both the system parameters and the initial conditions that the average queue size of the RED algorithm would converge to a fixed point are derived. These results are useful for network engineers to design both the system parameters and the initial conditions so that internet networks can achieve a good performance.
Long-term exercise training does not alter brachial and femoral artery vasomotor function and endothelial phenotype in healthy pigs
Authors: Padilla Jaume , Newcomer Sean C. , Simmons Grant H. , Kreutzer Kurt V. , Laughlin M. Harold
Published: May 2010

Although the beneficial effects of exercise training on conduit artery endothelial function are well-established in animals and humans with compromised basal function, whether exercise exerts favorable effects on a healthy endothelium is inconclusive. We sought to determine whether long-term exercise training enhances endothelial function in peripheral conduit arteries of healthy pigs. Using a retrospective analysis of data collected in our laboratory ( n = 127), we compared in vitro brachial and femoral artery endothelium-dependent and -independent relaxation between a group of pigs that exercise-trained for 16–20 wk and a group that remained sedentary. No differences in vasomotor function were found between the 2 groups ( P > 0.05). Additionally, in a subset of pigs ( n = 16), expression levels of 18 proteins that are typically associated with the atherosclerotic process were measured by immunoblot analysis of endothelial cell scrapes obtained from the brachial and femoral arteries. We found no differences ( P > 0.05) in endothelial gene expression between these exercise-trained and sedentary healthy pigs. These results indicate that pigs exhibiting the classic training-induced adaptations do not demonstrate enhanced endothelium-dependent dilation nor reveal a more atheroprotected endothelial cell phenotype in their brachial and femoral arteries than their sedentary but otherwise healthy counterparts.
Elevated systemic TGF-β impairs aortic vasomotor function through activation of NADPH oxidase-driven superoxide production and leads to hypertension, myocardial remodeling, and increased plaque formation in apoE−/−mice
Authors: Buday Anna , Őrsy Petra , Godó Mária , Mózes Miklós , Kökény Gábor , Lacza Zsombor , Koller Ákos , Ungvári Zoltán , Gross Marie-Luise , Benyó Zoltán , Hamar Péter
Published: May 2010

The role of circulating, systemic TGF-β levels in endothelial function is not clear. TGF-β1may cause endothelial dysfunction in apolipoprotein E-deficient (apoE−/−) mice via stimulation of reactive oxygen species (ROS) production by the NADPH oxidase (NOX) system and aggravate aortic and heart remodeling and hypertension. Thoracic aorta (TA) were isolated from 4-mo-old control (C57Bl/6), apoE−/−, TGF-β1-overexpressing (TGFβ1), and crossbred apoE−/−× TGFβ1mice. Endothelium-dependent relaxation was measured before and after incubation with apocynin (NOX inhibitor) or superoxide dismutase (SOD; ROS scavenger). Superoxide production within the vessel wall was determined by dihydroethidine staining under confocal microscope. In 8-mo-old mice, aortic and myocardial morphometric changes, plaque formation by en face fat staining, and blood pressure were determined. Serum TGF-β1levels (ELISA) were elevated in TGFβ1mice without downregulation of TGF-β-I receptor (immunohistochemistry). In the aortic wall, superoxide production was enhanced and NO-dependent relaxation diminished in apoE−/−× TGFβ1mice but improved significantly after apocynin or SOD. Myocardial capillary density was reduced, fibrocyte density increased, aortic wall was thicker, combined lesion area was greater, and blood pressure was higher in the apoE−/−× TGFβ vs. C57Bl/6 mice. Our results demonstrate that elevated circulating TGF-β1causes endothelial dysfunction through NOX activation-induced oxidative stress, accelerating atherosclerosis and hypertension in apoE−/−mice. These findings may provide a mechanism explaining accelerated atherosclerosis in patients with elevated plasma TGFβ1.
Glutathione peroxidase-1 protects against cigarette smoke-induced lung inflammation in mice
Authors: Duong Chi , Seow Huei Jiunn , Bozinovski Steven , Crack Peter J. , Anderson Gary P. , Vlahos Ross
Published: May 2010

Reactive oxygen species (ROS) produced from cigarette smoke cause oxidative lung damage including protein denaturation, lipid peroxidation, and DNA damage. Glutathione peroxidase-1 (gpx-1) is a detoxifying enzyme that may protect lungs from such damage. The aim of this study was to determine whether gpx-1 protects the lung against oxidative stress-induced lung inflammation in vivo. Male wild-type (WT) or gpx-1−/−mice were exposed to cigarette smoke generated from nine cigarettes per day for 4 days to induce oxidative stress and lung inflammation. The effect of the gpx mimetic ebselen on cigarette smoke-induced lung inflammation was evaluated when given prophylactically and therapeutically, i.e., during established inflammation. Mice were killed, and the lungs were lavaged with PBS and then harvested for genomic and proteomic analysis. Gpx-1−/−mice exposed to cigarette smoke had enhanced BALF neutrophils, macrophages, proteolytic burden, whole lung IL-17A, and MIP1α mRNA compared with WT mice. The gpx mimetic ebselen (10 and 100 μM) inhibited cigarette smoke extract-induced oxidation of MH-S cells in vitro and inhibited cigarette smoke-induced increases in BALF macrophages, neutrophils, proteolytic burden, and macrophage and neutrophil chemotactic factor gene expression when administered prophylactically. In addition, ebselen inhibited established BALF inflammation when administered therapeutically. These data show that gpx-1 protects against cigarette smoke-induced lung inflammation, and agents that mimic the actions of gpx-1 may have therapeutic utility in inflammatory lung diseases where cigarette smoke plays a role.
Human Lipoxygenase Pathway Gene Variation and Association with Markers of Subclinical Atherosclerosis in the Diabetes Heart Study
Authors: Burdon Kathryn P. , Rudock Megan E. , Lehtinen Allison B. , Langefeld Carl D. , Bowden Donald W. , Register Thomas C. , Liu Yongmei , Freedman Barry I. , Carr J. Jeffrey , Hedrick Catherine C. , Rich Stephen S.
Published: May 2010

Aims. Genes of the 5-lipoxygenase pathway are compelling candidates for atherosclerosis. We hypothesize that polymorphisms inALOX12, ALOX15, ALOX5, andALOX5APgenes are associated with subclinical atherosclerosis in multiple vascular beds.Methods. Families with two or more siblings with type 2 diabetes and their nondiabetic siblings were studied as part of the Diabetes Heart Study (DHS). European American diabetic (n=828) and nondiabetic (n=170) siblings were genotyped for SNPs in theALOX12, ALOX15, ALOX5, andALOX5APgenes. Subclinical measures of atherosclerosis (IMT, coronary (CorCP), carotid (CarCP) and aortic (AorCP) calcified plaque) were obtained.Results. Associations were observed betweenALOX12with CorCP,ALOX5with CorCP, AorCP, and IMT, andALOX5APwith CorCP and CarCP, independent of known epidemiologic risk factors. Further, lipoxygenase pathway SNPs that were associated with measures of atherosclerosis were associated with markers of inflammation (CRP, ICAM-1) and calcification (MGP).Conclusions. Polymorphisms withinALOX12, ALOX5, andALOX5APare genetically associated with subclinical atherosclerosis and with biomarkers of disease in families with type 2 diabetes. These results suggest that variants in lipoxygenase pathway genes may have pleiotropic effects on multiple components that determine risk of cardiovascular disease.
The Immune‐Modulatory Role of Apolipoprotein E with Emphasis on Multiple Sclerosis and Experimental Autoimmune Encephalomyelitis
Authors: Zhang Hong-Liang , Wu Jiang , Zhu Jie
Published: May 2010

Apolipoprotein E (apoE) is a 34.2 kDa glycoprotein characterized by its wide tissue distribution and multiple functions. The nonlipid‐related properties of apoE include modulating inflammation and oxidation, suppressing T cell proliferation, regulating macrophage functions, and facilitating lipid antigen presentation by CD1 molecules to natural killer T (NKT) cells, and so forth. Increasing studies have revealed that APOE ε allele might be associated with multiple sclerosis (MS), although evidence is still not sufficient enough. In this review, we summarized the current progress of the immunomodulatory functions of apoE, with special focus on the association of APOE ε allele with the clinical features of MS and of its animal model experimental autoimmune encephalomyelitis (EAE).
Cavernous Hemangioma of the Rib: A Rare Diagnosis
Authors: Gourgiotis Stavros , Piyis Anastasios , Panagiotopoulos Nikolaos , Panayotopoulos Panayotis , Salemis Nikolaos S.
Published: May 2010

Hemangioma of the rib is an uncommon benign vascular tumour. A case of rib hemangioma in a 29-year-old woman is presented. Chest roentgenogram and computed tomography revealed a mass along the inner surface of the 7th left rib with bone destruction. She underwent resection of the 7th rib. The pathologic diagnosis was cavernous hemangioma. Hemangiomas of the rib are rare tumours but should be kept in mind in the differential diagnosis of rib tumours.
Transformation of a Cutaneous Follicle Center Lymphoma to a Diffuse Large B-Cell Lymphoma—An Unusual Presentation
Authors: Dias Coelho J. , Diamantino F. , Costa I. , Farinha P. , Gameiro P. , Sebastião M. , Baptista J.
Published: May 2010

Primary cutaneous follicle center lymphoma (PCFCL) is characterized by a proliferation of follicle center cells in the skin. A definitive diagnosis is frequently delayed because of difficulties in interpretation of the histopathologic findings. It has an excellent prognosis with a 5-year survival over 95% and its risk of transformation has not been established. We describe a case report of man with a gastric diffuse large B-cell lymphoma (DLBCL) referred to our clinic because of nodules in the back that had gradually developed over a period of 10 years. A biopsy performed 3 years before was interpreted as reactive follicular hyperplasia. A new skin biopsy revealed a diffuse large B-cell lymphoma and immunoglobulin heavy chain gene rearrangements from the initial skin biopsy (PCBCL) and the DLBCL gastric biopsy were studied by polymerase chain reaction and an identical clonal rearrangement was detected which was highly suggestive of a transformation lymphoma.