bluuebunny/crossref_metadata_2025 huggingface dataset:
JC virus in the pathogenesis of colorectal cancer, an etiological agent or another component in a multistep process?
Authors: Coelho Tatiana R , Almeida Luis , Lazo Pedro A
Published: February 2010

JCV infection occurs early in childhood and last throughout life. JCV has been associated to colorectal cancer and might contribute to the cancer phenotype by several mechanisms. Among JCV proteins, particularly two of them, large T-antigen and agnoprotein, can interfere with cell cycle control and genomic instability mechanisms, but other viral proteins might also contribute to the process. Part of viral DNA sequences are detected in carcinoma lesions, but less frequently in adenomas, and not in the normal surrounding tissue, suggesting they are integrated in the host cell genome and these integrations have been selected; in addition viral integration can cause a gene, or chromosomal damage. The inflammatory infiltration caused by a local chronic viral infection in the intestine can contribute to the selection and expansion of a tumor prone cell in a cytokine rich microenvironment. JCV may not be the cause of colorectal cancer, but it can be a relevant risk factor and able to facilitate progression at one or several stages in tumor progression. JCV transient effects might lead to selective expansion of tumor cells. Since there is not a direct cause and effect relationship, JCV infection may be an alternative to low frequency cancer predisposition genes.
Epigenetic histone modifications of human transposable elements: genome defense versus exaptation
Authors: Huda Ahsan , Mariño-Ramírez Leonardo , Jordan I King
Published: February 2010

Background

Transposition is disruptive in nature and, thus, it is imperative for host genomes to evolve mechanisms that suppress the activity of transposable elements (TEs). At the same time, transposition also provides diverse sequences that can be exapted by host genomes as functional elements. These notions form the basis of two competing hypotheses pertaining to the role of epigenetic modifications of TEs in eukaryotic genomes: the genome defense hypothesis and the exaptation hypothesis. To date, all available evidence points to the genome defense hypothesis as the best explanation for the biological role of TE epigenetic modifications.

Results

We evaluated several predictions generated by the genome defense hypothesis versus the exaptation hypothesis using recently characterized epigenetic histone modification data for the human genome. To this end, we mapped chromatin immunoprecipitation sequence tags from 38 histone modifications, characterized in CD4+ T cells, to the human genome and calculated their enrichment and depletion in all families of human TEs. We found that several of these families are significantly enriched or depleted for various histone modifications, both active and repressive. The enrichment of human TE families with active histone modifications is consistent with the exaptation hypothesis and stands in contrast to previous analyses that have found mammalian TEs to be exclusively repressively modified. Comparisons between TE families revealed that older families carry more histone modifications than younger ones, another observation consistent with the exaptation hypothesis. However, data from within family analyses on the relative ages of epigenetically modified elements are consistent with both the genome defense and exaptation hypotheses. Finally, TEs located proximal to genes carry more histone modifications than the ones that are distal to genes, as may be expected if epigenetically modified TEs help to regulate the expression of nearby host genes.

Conclusions

With a few exceptions, most of our findings support the exaptation hypothesis for the role of TE epigenetic modifications when vetted against the genome defense hypothesis. The recruitment of epigenetic modifications may represent an additional mechanism by which TEs can contribute to the regulatory functions of their host genomes.
Neoadjuvant Clinical Trial With Sorafenib for Patients With Stage II or Higher Renal Cell Carcinoma
Authors: Cowey C. Lance , Amin Chirag , Pruthi Raj S. , Wallen Eric M. , Nielsen Matthew E. , Grigson Gayle , Watkins Cathy , Nance Keith V. , Crane Jeffrey , Jalkut Mark , Moore Dominic T. , Kim William Y. , Godley Paul A. , Whang Young E. , Fielding Julia R. , Rathmell W. Kimryn
Published: February 2010

Purpose

The multitargeted tyrosine kinase inhibitor sorafenib is used for the treatment of advanced-stage renal cell carcinoma. However, the safety and efficacy of this agent have yet to be evaluated in the preoperative period, where there may be potential advantages including tumor downstaging. This prospective trial evaluates the safety and feasibility of sorafenib in the preoperative setting.

Patients and Methods

Thirty patients with clinical stage II or higher renal masses, selected based on their candidacy for nephrectomy, underwent preoperative treatment with sorafenib. Toxicities, surgical complications, and tumor responses were monitored.

Results

Of the thirty patients enrolled, 17 patients had localized disease and 13 had metastatic disease. After a course of sorafenib therapy (median duration, 33 days), a decrease in primary tumor size (median, 9.6%) and radiographic evidence of loss of intratumoral enhancement, quantified using a methodology similar to Choi criteria (median, 13%), was also observed. According to Response Evaluation Criteria in Solid Tumors, of the 28 patients evaluable for response, two patients had a partial response and 26 had stable disease, with no patients progressing on therapy. Toxicities from sorafenib were similar to that expected with this class of medication. All patients were able to proceed with nephrectomy and no surgical complications related to sorafenib administration were observed.

Conclusion

The administration of preoperative sorafenib therapy can impact the size and density of the primary tumor and appears safe and feasible. Further studies are required to determine if preoperative systemic therapy improves outcomes in patients undergoing nephrectomy for renal cell carcinoma.
Genomic Changes in Chromosomes 10, 16, and X in Malignant Peripheral Nerve Sheath Tumors Identify a High-Risk Patient Group
Authors: Brekke Helge R. , Ribeiro Franclim R. , Kolberg Matthias , Ågesen Trude H. , Lind Guro E. , Eknæs Mette , Hall Kirsten S. , Bjerkehagen Bodil , van den Berg Eva , Teixeira Manuel R. , Mandahl Nils , Smeland Sigbjørn , Mertens Fredrik , Skotheim Rolf I. , Lothe Ragnhild A.
Published: February 2010

Purpose

The purpose of this study was to identify genetic aberrations contributing to clinical aggressiveness of malignant peripheral nerve sheath tumors (MPNSTs).

Patients and Methods

Samples from 48 MPNSTs and 10 neurofibromas were collected from 51 patients with (n = 31) or without (n = 20) neurofibromatosis type 1 (NF1). Genome-wide DNA copy number changes were assessed by chromosomal and array-based comparative genomic hybridization (CGH) and examined for prognostic significance. For a subset of 20 samples, RNA microarray data were integrated with the genome data to identify potential target genes.

Results

Forty-four (92%) MPNSTs displayed DNA copy number changes (median, 18 changes per tumor; range, 2 to 35 changes). Known frequent chromosomal gains at chromosome arms 8q (69%), 17q (67%), and 7p (52%) and losses from 9p (50%), 11q (48%), and 17p (44%) were confirmed. Additionally, gains at 16p or losses from 10q or Xq identified a high-risk group with only 11% 10-year disease-specific survival (P = .00005). Multivariate analyses including NF1 status, tumor location, size, grade, sex, complete remission, and initial metastatic status showed that the genomic high-risk group was the most significant predictor of poor survival. Several genes whose expression was affected by the DNA copy number aberrations were identified.

Conclusion

The presence of specific genetic aberrations was strongly associated with poor survival independent of known clinical risk factors. Conversely, within the total patient cohort with 34% 10-year disease-specific survival, a low-risk group was identified: without changes at chromosomes 10q, 16p, or Xq in their MPNSTs, the patients had 74% 10-year survival.
Peroxisome Proliferator-Activated Receptor-γ Receptor Ligand Partially Prevents the Development of Endometrial Explants in Baboons: A Prospective, Randomized, Placebo-Controlled Study
Authors: Lebovic Dan I. , Mwenda Jason M. , Chai Daniel C. , Santi Alessandro , Xu Xiao , D'Hooghe Thomas
Published: February 2010

A prospective, randomized, placebo-controlled study was conducted in a baboon model to determine if a thiazolidinedione agonist of peroxisome proliferator-activated receptor-γ, pioglitazone, can impede the development of endometriosis. Endometriosis was induced using laparoscopic, intrapelvic injection of eutopic menstrual endometrium, previously incubated with placebo or pioglitazone for 30 min, in 12 female baboons with a normal pelvis that had undergone at least one menstrual cycle since the time of captivity. At this point, the 12 baboons were randomized into two groups and treated from the day of induction. They received either PBS tablets (n = 6, placebo control, placebo tablets once a day by mouth) or pioglitazone (n = 6, test drug, 7.5 mg by mouth each day). A second and final laparoscopy was performed in the baboons to record the extent of endometriotic lesions between 24 and 42 d after induction (no difference in length of treatment between the two groups, P = 0.38). A videolaparoscopy was performed to document the number and surface area of endometriotic lesions. The surface area and volume of endometriotic lesions were significantly lower in pioglitazone treated baboons than the placebo group (surface area, 48.6 vs. 159.0 mm2, respectively, P = 0.049; vol, 23.7 vs. 131.8 mm3, respectively, P = 0.041). The surface area (3.5 vs. 17.8 mm2, P = 0.017, pioglizatone vs. placebo) and overall number (1.5 vs. 9.5, P = 0.007, pioglizatone vs. placebo) of red lesions were lower in the pioglitazone group. A peroxisome proliferator-activated receptor-γ ligand, pioglitazone, effectively reduced the initiation of endometriotic disease in the baboon endometriosis model. Using this animal model, we have shown that thiazolidinedione is a promising drug for preventive treatment of endometriosis.
Calcium-Sensing Receptor (CASR) Mutations in Hypercalcemic States: Studies from a Single Endocrine Clinic Over Three Years
Authors: Guarnieri Vito , Canaff Lucie , Yun Francisco H. J. , Scillitani Alfredo , Battista Claudia , Muscarella Lucia A. , Wong Betty Y. L. , Notarangelo Angelantonio , D'Agruma Leonardo , Sacco Michele , Cole David E. C. , Hendy Geoffrey N.
Published: February 2010

Context: Inactivating mutations of the calcium-sensing receptor (CASR) are implicated in different hypercalcemic syndromes, including familial hypocalciuric hypercalcemia (FHH), primary hyperparathyroidism (PHPT), and familial isolated hyperparathyroidism (FIHP). However, molecular diagnostics applied to large nonselected hypercalcemic cohorts from a single center have not been reported.

Objective: Our objective was to describe the prevalence, type, and potential pathogenicity of CASR mutations in a series of cases with FHH (n = 17), PHPT (n = 165), and FIHP (n = 3) and controls (n = 198) presenting at a single endocrine clinic.

Subjects: All were prospectively evaluated at the “Casa Sollievo della Sofferenza” Hospital in southern Italy over a 3-yr period.

Methods: CASR screening was conducted by denaturing HPLC. The variant CASRs were functionally characterized by transient transfection studies in kidney cells in vitro.

Results: A single novel missense variant was identified in one PHPT case. However, in FHH probands, mutations were found in eight of 17 (47%). With a hypercalcemic family member, mutation detection rate in FHH rose to seven of eight (87%), whereas only one of nine sporadic cases was positive, and none of the three FIHP cases had detectable CASR mutations. Five missense variant CASRs, identified in control subjects, performed as wild type in functional assays, whereas the missense mutant CASRs identified in the FHH patients, and in the one PHPT case, exhibited significant impairment. A novel intronic mutation (IVS4-19a→c) found in one FHH family, created an abnormally spliced product in an in vitro minigene assay.

Conclusion: CASR testing, with functional analysis, provides critical confirmatory evidence in the differential diagnosis of hypercalcemic states.
Prenatal Exposure to the Environmental Obesogen Tributyltin Predisposes Multipotent Stem Cells to Become Adipocytes
Authors: Kirchner Séverine , Kieu Tiffany , Chow Connie , Casey Stephanie , Blumberg Bruce
Published: February 2010

The environmental obesogen hypothesis proposes that pre- and postnatal exposure to environmental chemicals contributes to adipogenesis and the development of obesity. Tributyltin (TBT) is an agonist of both retinoid X receptor (RXR) and peroxisome proliferator-activated receptor γ (PPARγ). Activation of these receptors can elevate adipose mass in adult mice exposed to the chemical in utero. Here we show that TBT sensitizes human and mouse multipotent stromal stem cells derived from white adipose tissue [adipose-derived stromal stem cells (ADSCs)] to undergo adipogenesis. In vitro exposure to TBT, or the PPARγ activator rosiglitazone increases adipogenesis, cellular lipid content, and expression of adipogenic genes. The adipogenic effects of TBT and rosiglitazone were blocked by the addition of PPARγ antagonists, suggesting that activation of PPARγ mediates the effect of both compounds on adipogenesis. ADSCs from mice exposed to TBT in utero showed increased adipogenic capacity and reduced osteogenic capacity with enhanced lipid accumulation in response to adipogenic induction. ADSCs retrieved from animals exposed to TBT in utero showed increased expression of PPARγ target genes such as the early adipogenic differentiation gene marker fatty acid-binding protein 4 and hypomethylation of the promoter/enhancer region of the fatty acid-binding protein 4 locus. Hence, TBT alters the stem cell compartment by sensitizing multipotent stromal stem cells to differentiate into adipocytes, an effect that could likely increase adipose mass over time.
Prostaglandin F2α Represses IGF-I-Stimulated IRS1/Phosphatidylinositol-3-Kinase/AKT Signaling in the Corpus Luteum: Role of ERK and P70 Ribosomal S6 Kinase
Authors: Arvisais Edward , Hou Xiaoying , Wyatt Todd A. , Shirasuna Koumei , Bollwein Heinrich , Miyamoto Akio , Hansen Thomas R. , Rueda Bo R. , Davis John S.
Published: February 2010

Little is known about the early intracellular events that contribute to corpus luteum regression. Experiments were designed to determine the effects of prostaglandin F2α (PGF2α) on phosphatidylinositol-3-kinase (PI3K)/Akt signaling in the corpus luteum in vivo and in vitro. Treatment of midluteal-phase cows with a luteolytic dose of PGF2α resulted in a rapid increase in ERK and mammalian target of rapamycin (mTOR)/p70 ribosomal protein S6 kinase (p70S6K1) signaling and a rapid suppression of Akt phosphorylation in luteal tissue. In vitro treatment of primary cultures of luteal cells with PGF2α also resulted in an increase in ERK and mTOR/p70S6K1 signaling and a diminished capacity of IGF-I to stimulate PI3K, Akt, and protein kinase C ζ activation. Accounting for the reductions in PI3K and Akt activation observed in response to PGF2α treatment, we found that PGF2α promoted the phosphorylation of serine residues (307, 612, 636) in the insulin receptor substrate 1 (IRS1) peptide sequence in vivo and in vitro. Serine phosphorylation of IRS1 was associated with reduced formation of IGF-I-stimulated IRS1/PI3Kp85 complexes. Furthermore, treatment with inhibitors of the MAPK kinase 1/ERK or mTOR/p70S6K1 signaling pathways prevented PGF2α-induced serine phosphorylation of IRS1 and abrogated the inhibitory actions of PGF2α on Akt activation. Taken together, these experiments provide compelling evidence that PGF2α treatment stimulates IRS1 serine phosphorylation, which may contribute to a diminished capacity to respond to IGF-I. It seems likely that the rapid changes in phosphorylation events are among the early events that mediate PGF2α-induced corpus luteum regression.
An exosome-based secretion pathway is responsible for protein export fromLeishmaniaand communication with macrophages
Authors: Silverman Judith Maxwell , Clos Joachim , de'Oliveira Carolina Camargo , Shirvani Omid , Fang Yuan , Wang Christine , Foster Leonard J. , Reiner Neil E.
Published: February 2010

Specialized secretion systems are used by numerous bacterial pathogens to export virulence factors into host target cells. Leishmania and other eukaryotic intracellular pathogens also deliver effector proteins into host cells; however, the mechanisms involved have remained elusive. In this report, we identify exosome-based secretion as a general mechanism for protein secretion by Leishmania, and show that exosomes are involved in the delivery of proteins into host target cells. Comparative quantitative proteomics unambiguously identified 329 proteins in Leishmania exosomes, accounting for >52% of global protein secretion from these organisms. Our findings demonstrate that infection-like stressors (37°C ± pH 5.5) upregulated exosome release more than twofold and also modified exosome protein composition. Leishmania exosomes and exosomal proteins were detected in the cytosolic compartment of infected macrophages and incubation of macrophages with exosomes selectively induced secretion of IL-8, but not TNF-α. We thus provide evidence for an apparently broad-based mechanism of protein export by Leishmania. Moreover, we describe a mechanism for the direct delivery of Leishmania molecules into macrophages. These findings suggest that, like mammalian exosomes, Leishmania exosomes function in long-range communication and immune modulation.
Human dermal stem cells differentiate into functional epidermal melanocytes
Authors: Li Ling , Fukunaga-Kalabis Mizuho , Yu Hong , Xu Xiaowei , Kong Jun , Lee John T. , Herlyn Meenhard
Published: February 2010

Melanocytes sustain a lifelong proliferative potential, but a stem cell reservoir in glabrous skin has not yet been found. Here, we show that multipotent dermal stem cells isolated from human foreskins lacking hair follicles are able to home to the epidermis to differentiate into melanocytes. These dermal stem cells, grown as three-dimensional spheres, displayed a capacity for self-renewal and expressed NGFRp75, nestin and OCT4, but not melanocyte markers. In addition, cells derived from single-cell clones were able to differentiate into multiple lineages including melanocytes. In a three-dimensional skin equivalent model, sphere-forming cells differentiated into HMB45-positive melanocytes, which migrated from the dermis to the epidermis and aligned singly among the basal layer keratinocytes in a similar fashion to pigmented melanocytes isolated from the epidermis. The dermal stem cells were negative for E-cadherin and N-cadherin, whereas they acquired E-cadherin expression and lost NGFRp75 expression upon contact with epidermal keratinocytes. These results demonstrate that stem cells in the dermis of human skin with neural-crest-like characteristics can become mature epidermal melanocytes. This finding could significantly change our understanding of the etiological factors in melanocyte transformation and pigmentation disorders; specifically, that early epigenetic or genetic alterations leading to transformation may take place in the dermis rather than in the epidermis.
Dual regulation of a Dictyostelium STAT by cGMP and Ca2+ signalling
Authors: Araki Tsuyoshi , van Egmond Wouter N. , van Haastert Peter J. M. , Williams Jeffrey G.
Published: February 2010

When cells are exposed to hyperosmotic stress, the Dictyostelium STAT orthologue STATc is rapidly tyrosine phosphorylated. Previous observations suggest a non-paradigmatic mode of STAT activation, whereby stress-induced serine phosphorylation of the PTP3 protein tyrosine phosphatase inhibits its activity towards STATc. We show that two serine residues in PTP3, S448 and S747, are rapidly phosphorylated after osmotic stress. cGMP is a second messenger for hyperosmotic stress response and 8-bromo-cGMP, a membrane-permeable form of cGMP, is a known activator of STATc. GbpC, a cGMP-binding Ras guanine nucleotide exchange factor protein, is a founder member of a protein family that includes LRRK2, the gene commonly mutated in familial Parkinson's disease. Genetic ablation of gbpC prevents STATc activation by 8-bromo-cGMP. However, osmotic-stress-induced activation of STATc occurs normally in the gbpC null mutant. Moreover, 8-bromo-cGMP does not stimulate phosphorylation of S448 and S747 of PTP3 in a wild-type strain. These facts imply the occurrence of redundant activation pathways. We present evidence that intracellular Ca2+ is a parallel second messenger, by showing that agents that elevate intracellular Ca2+ levels are potent STATc activators that stimulate phosphorylation of S448 and S747. We propose that stress-induced cGMP signalling exerts its stimulatory effect by potentiating the activity of a semi-constitutive tyrosine kinase that phosphorylates STATc, whereas parallel, stress-induced Ca2+ signalling represses STATc dephosphorylation through its inhibitory effect on PTP3.
Evaluation criteria of the constitutive law formulation for the metal-cutting process
Authors: Shi B , Attia M H
Published: February 2010

Modelling of the cutting process is necessary to predict cutting forces, residual stresses, and burr formation. A major difficulty in this modelling process is the description of the material behaviour in the primary and the secondary deformation zones, which is characterized by severe plastic deformation at high temperatures and strain rates. The description of the material behaviour requires correct formulation of the constitutive law. Although a number of formulations have been proposed to capture the flow stress behaviour, the assessment of these formulations for the cutting process is still a very difficult task owing to the lack of direct measurements of the high strains, strain rates, and temperatures encountered in the cutting process.

This paper presents novel evaluation criteria to assess the degree of accuracy of the constitutive equation under machining conditions. Different existing constitutive laws are identified for Inconel 718, and then evaluated using the proposed criteria. To better describe the plastic behaviour of Inconel 718, new constitutive relationships are formulated and evaluated. From the evaluation results, an accurate description of the constitutive relationship for Inconel 718 is established. This constitutive law is further validated using high-speed split Hopkinson pressure bar (SHPB) tests and orthogonal cutting tests in conjunction with finite element simulations.
Preform design for forging and extrusion processes based on geometrical resemblance
Authors: Yang C , Ngaile G
Published: February 2010

Preform design in multi-stage forging processes is critical to ensure the production of defect-free parts. Moreover, owing to the geometry and material-flow complexities in forging processes, finding the optimal preform shapes could be difficult and time consuming. This paper proposes an efficient preform design methodology based on geometrical resemblance, which requires several finite element analysis simulation iterations to obtain a good preform shape. The initial and subsequent simulations are carried out by constructing a slightly larger part that geometrically resembles the desired part. Initial finite element analysis simulation of the larger part is performed with a reasonably guessed preform shape, whose forming defects or flash formation would be corrected in subsequent steps. Then a series of intermediate parts of similar shape and between the largest part and the desired part in size are constructed. The undeformed shape corresponding to an intermediate part can be obtained by backwards tracing of material flow from the simulation results of the larger part. This undeformed shape is then taken as the preform shape of the intermediate part. The procedure is repeated until the intermediate part is geometrically close to the desired part, which leads to the preform shape. In order to verify this preform-design methodology, several case studies on forging and extrusion processes have been carried out. The methodology has been shown to be computationally efficient, requiring as few as three finite element iterations to obtain a good preform shape.
Bi-performance optimization of electrochemical machining characteristics of Al/20%SiCp composites using NSGA-II
Authors: Senthilkumar C , Ganesan G , Karthikeyan R
Published: February 2010

Electrochemical machining (ECM) is one of the important non-traditional machining processes, which is used for machining of difficult-to-cut materials and intricate shapes. Being a complex process, it is very difficult to determine optimal parameters for improving cutting performance. The cutting parameters used for the experiments were electrolyte concentration, electrolyte flowrate, applied voltage, and tool feed rate. Experiments were carried out according to response surface methodology (RSM). Statistical models based on second-order polynomial equations were developed for the different responses. The non-dominated sorting genetic algorithm (NSGA-II) tool was used to optimize the ECM process parameters to maximize MRR and minimize Ra. A non-dominated solution set has been obtained and reported.
Using an electronic product code network to improve monitoring systems for continuous operating equipment — a thermal power plant example
Authors: Chang S-Y , Li D-C , Chen T-L
Published: February 2010

The term ‘continuous operating equipment’ refers to equipment that operates for long periods without any stoppage or power outages. Continuous monitoring and long-term surveillance systems are crucial in ensuring the reliability of such equipment. Continuous monitoring operations involve constantly monitoring and recording active information and static data, including information-processing tasks such as access, query, and implementation. With the aim of obtaining information continuously, accurately, and rapidly, this study proposes to use the electronic product code (EPC) network on outflow electricity and equipment to enable constant information management regarding power quality and equipment operations. The radio frequency identification (RFID)-based EPC network used functions principally for information transmission, real-time calculation, and production management to reduce the non-performing rate of the power system, thus preventing failures and safety risks. A thermal power plant in Taiwan is used to explain the structure of the proposed continuous operation monitoring system. The performance results of the approach reveal a significant reduction in operating cost (14 operators are reduced to four operators), fast real-time monitoring response, and low power system variation. RFID tags can increase the power factor of the transformer and save 7 357 898 kW h of electricity, as well as decreasing carbon dioxide emissions by approximately 4 751 338 kg.
Analysis of surface generation in ultra-precision machining with a fast tool servo
Authors: Kwok T C , Cheung C F , Kong L B , To S , Lee W B
Published: February 2010

The fast tool servo (FTS) is one of the emerging ultra-precision machining technologies for the fabrication of high-quality optical microstructural surfaces. The diamond tool is fixed on the FTS, which is activated back and forth by a stacked type piezoelectric actuator. Optical microstructures with sub-micrometre form accuracy and nanometric surface finish can be fabricated without the need for any subsequent post processing. However, current understanding of the cutting mechanics and the factors affecting the surface generation in FTS machining is still far from complete. Although there has been some research work conducted to fill the research gaps with respect to FTS machining, most of the previous studies have been focused on the design of FTS for better performance and modelling characteristic of FTS actuators. The study of the process factors affecting surface generation in FTS machining has received little attention. As a result, this paper aims to analyse the effects of process parameters on surface generation in FTS machining. The factors being studied include spindle speed, feed rate, and depth of cut. A series of cutting experiments was carried out under various cutting conditions and the surface quality of the workpiece in terms of the form error and form defects were studied. Based on the results of the investigation, some recommendations for optimizing surface quality in the FTS machining process are discussed.
The effect of a local stiffener in the structural—acoustic coupled system
Authors: Park S Y , Kim S H , Kang Y J
Published: February 2010

This article proposes an analytical method that can be used to obtain the vibro-acoustic modal and forced response characteristics of a three-dimensional structural—acoustic coupled system, where the coupled system is composed of an acoustic cavity with a rectangular plate that is stiffened by a local stiffener. Through the proposed method, the effect of the local stiffener on the natural frequencies, modes, and forced responses is identified for the plate—cavity coupled system with the local stiffener. The relationship between the thickness and the location of the local stiffener on the vibro-acoustic modal characteristics and forced responses is investigated through the structural—acoustic modal coupling coefficient. The high peak-noise due to the strong modal coupling between the plate and acoustic modes can be effectively reduced by properly designing the local stiffener in the coupled system. Finally, the modal characteristics and frequency responses obtained by the proposed method are compared with those of finite-element analysis. The results of this article provide useful information for suppressing the booming noise generated by the strong modal coupling between the plate and acoustic modes in the coupled system.
A novel analytical approach for the buckling analysis of moderately thick functionally graded rectangular plates with two simply-supported opposite edges
Authors: Mohammadi M , Saidi A R , Jomehzadeh E
Published: February 2010

In this article, a novel analytical method for decoupling the coupled stability equations of functionally graded (FG) rectangular plates is introduced. Based on the Mindlin plate theory, the governing stability equations that are coupled in terms of displacement components are derived. Introducing four new functions, the coupled stability equations are converted into two independent equations. The obtained equations have been solved for buckling analysis of rectangular plates with simply-supported two edges and arbitrary boundary conditions along the other edges (Levy boundary conditions). The critical buckling loads are presented for different loading conditions, various thickness to side and aspect ratios, some powers of FG materials, and various boundary conditions. The presented results for buckling of moderately thick FG plates with two simply-supported edges are reported for the first time.
Bending Analysis of Thick Laminated Rectangular Plates Using a Boundary Layer Function
Authors: Saidi A R , Atashipour S R , Keshavarzi H
Published: February 2010

In this article, the governing bending equations of thick laminated transversely isotropic rectangular plates are derived based on third-order shear deformation theory (TSDT). Using a new function, called the boundary layer function, the three coupled governing equations are converted to two decoupled equations. These equations are in terms of the deflection of the plate and the mentioned boundary layer function, which are written in invariant form. By solving the decoupled equations, a Levy-type analytical solution is presented for bending of a transversely isotropic plate. Finally, numerical results are presented for boundary layer phenomenon and its effects in TSDT. It is shown that all of the boundary layer effects in Mindlin—Reissner theory appear in this theory. However, it is shown that the intensity of the boundary layer effects in TSDT exceeds that of the Mindlin—Reissner theory.
Recent advances in the CoBRASurge robotic manipulator and dexterous miniature in vivo robotics for minimally invasive surgery
Authors: Lehman A C , Tiwari M M , Shah B C , Farritor S M , Nelson C A , Oleynikov D
Published: February 2010

Minimally invasive surgery (MIS) reduces trauma and improves patient recovery. Traditional laparoscopic procedures are performed using multiple long, thin tools that are inserted through small incisions in the abdominal wall. The advantages of these procedures are often restricted to less complicated procedures owing to imaging and tissue manipulation limitations. These limitations can be overcome using advanced surgical systems, such as da Vinci®, that provide the surgeon with enhanced visualization and improved tool dexterity. However, the da Vinci system is expensive and occupies significant space in the operating room. The compact bevel-geared robot for advanced surgery, CoBRASurge, is a compact robotic system that addresses the space and expense limitations of large external robotic systems. This system provides a stable platform for laparoscopic tool manoeuvring, while also allowing the surgical team improved access to the patient. New methods for performing MIS, including single incision and natural orifice access, are also being developed to further minimize invasiveness through reducing or eliminating external incisions. However, the instruments for these procedures are further limited by accessing the peritoneal cavity through a single insertion point. Dexterous miniature robots that are completely inserted into the peritoneal cavity are being developed that mitigate these limitations to provide improved triangulation.
A method for improving the wireless power transmission efficiency of an endoscopic capsule based on electromagnetic localization and synthesis of magnetic field vector
Authors: Li H , Yan G , Gao P
Published: February 2010

The method of wireless power transmission is an important method in powering wireless medical devices in vivo, but the efficiency is still low, especially when the devices move freely in random positions and orientations. Aiming at powering an endoscopic capsule, a method for improving efficiency of wireless power transmission is proposed, which is based on electromagnetic localization and synthesis of magnetic field vector. By analysing the model and experimenting in vitro, the proposed method is verified, which can improve the efficiency of the wireless power transmission because of accurate localization of the capsule and synthesis of magnetic field vector.
On the Zeros of the Transfer Function of Flexible Link Manipulators and Their Non-Minimum Phase Behaviour
Authors: Vakil M , Fotouhi R , Nikiforuk P N
Published: February 2010

In this article, a study of the zeros of the transfer function, between the base torque and the end-effector displacement, for flexible link manipulators is performed. The analysis is carried out on a single flexible link manipulator with the initial part of the link being rigid. This type of manipulator is referred to as a slewing single rigid—flexible link manipulator (SRFLM). A new method for finding the zeros of the transfer function of an SRFLM without using the corresponding transfer function is introduced. The changes of the locations of the zeros of an SRFLM owing to the changes in all the physical parameters (PPs) are investigated.

It is shown that there are PPs where the increase in their values moves the zeros further from the imaginary axis; while by increasing the values of some other PPs the zeros become closer to the imaginary axis. Finally, there are PPs where the locations of the zeros are independent of their values. These findings will be beneficial in the design as well as control of flexible link manipulators and are among the main contributions of this work.
Numerical Simulation of Flow over a Thin Aerofoil at a High Reynolds Number Using a Transition Model
Authors: Genç M S
Published: February 2010

In this study, a prediction of the transition and stall characteristics of an NACA64A006 thin-aerofoil was numerically simulated by FLUENT using k— kL—ω and k—ω shear-stress transport (SST) transition models, recently developed, and k—ω SST and k—ε turbulence models. Subsonic flow with free stream Mach number ( M∞) of 0.17 and the high Reynolds number ( Re) of 5.8×106 was considered at an angle of attack varying from 2° to 11°. However, the computed results were compared with the experiments of McCollough and Gault. Lift and pressure curves were accurately predicted using the k— kL—ω transition model, while the k—ω SST transition model and the k—ω SST and k—ε turbulence models did not have a good agreement with the experimental results. The k— kL—ω transition model showed that the laminar separation and turbulent reattachment occurred near the leading edge of the NACA64A006 thin aerofoil, which caused the formation of the laminar separation bubble on the suction surface as in the experiments. Consequently, the transition and stalling characteristics of this aerofoil were successfully predicted using FLUENT with the k— kL—ω transition model at high Re number flow.
Sound quality evaluation of the impact noise induced by road courses having an impact bar and speed bumps in a passenger car
Authors: Kim H-W , Lee S-K , Na E-W
Published: February 2010

Sound quality indices for impact noise are developed by using sound metrics and a subjective evaluation. A new sound metric for impact sound is developed on the basis of a continuous wavelet transform, which is a useful tool for the analysis of non-stationary signals such as impact noise. Two other conventional sound metrics related to sound modulation and fluctuation are also considered. In all, three sound metrics are employed to develop impact sound quality indices for several specific impact courses on the road. The indices are verified by comparing the correlation between the index output and results of a subjective evaluation based on a test. These indices are successfully applied to an objective evaluation for improvement in the impact sound quality for cases where some parts of the suspension system of the test car are modified.
Simple method to predict balloon shape
Authors: Wen P H , Dorrington G E
Published: February 2010

A numerical scheme to predict the shape of large scientific balloons is described. The method ignores elastic deformation and asymmetric folding. Results are presented for geometries where all the tension in the balloon fabric is carried meridionally and the circumferential stresses are assumed to be zero, during ascent, as well as at the design float altitude. Some results with envelopes with non-zero circumferential stresses and with caps fitted are also given. Brief comparison with the results of more complex numerical models, reported by other workers, suggests that the method yields nearly identical geometric solutions.
Nanostructured materials for the construction of asymmetrical supercapacitors
Authors: Chae J H , Ng K C , Chen G Z
Published: February 2010

Mechanically robust power devices of high energy efficiency are one of the keys towards overcoming the challenges from the daunting climate change and the depletion of fossil fuels on the earth. The importance of mechanical engineering has been long recognized in physical type power devices, but less so in those based on electrochemical processes, such as batteries, fuel cells, and electrochemical capacitors (ECs). Particularly, ECs, which are also known as supercapacitors, bridge the crucial performance disparity between fuel cells or batteries with high energy capacities and the traditional capacitors capable of outputting pulsed high power. New materials and advanced configurations are the two essential elements for ECs to cope with mechanical engineering issues at both macro and micro levels. This review describes the design and characteristics of ECs and the emerging asymmetrical construction utilizing nanostructured composites that enable energy storage through both ion adsorptions (interfacial capacitance) and fast and reversible redox reactions (pseudo-capacitance). It is specially intended to rouse interest towards newly reported high-energy and high-power aqueous ECs with nanocomposites of transition metal oxides, nitrides or conducting polymers, and carbon nanotubes or activated carbons. Current collector materials and structures are also examined as important mechanical engineering elements in ECs. The chemical, material, and mechanical issues reviewed here call for more joined efforts among scientists, engineers, and industries to further advance ECs as a promising new energy technology.
Bath-related deaths in Kagoshima, the southwest part of Japan
Authors: Hayashi Takahito , Ago Kazutoshi , Ago Mihoko , Ogata Mamoru
Published: February 2010

In Japan, sudden death in the bathroom (what we call ‘bath-related death’) has been reported to occur particularly in the elderly population in the winter. This investigation aimed to obtain a better understanding of the factors associated with bath-related deaths. For this purpose, a retrospective review of the inquest records in Kagoshima Prefecture, the southwest part of Japan, during 2006–2007 was performed. There were 338 cases of bath-related death, which corresponds to a crude mortality rate of 9.7 per 100,000 persons per year. The occurrence of bath-related death was similar to that of other prefectures in Japan, despite the warm environment in Kagoshima. The victims' ages ranged from 37 to 101 years (mean 76.6 years) and 88.8% of patients were over 65 years. The associated factors included winter season (56.2%) and a medical history of hypertension (37.3%). These demographic and circumstantial factors correlated with previous studies in Japan. These results suggest that the Japanese method of bathing, in addition to cold bathrooms in winter, contributes to the high rate of bath-related death in Japan. In addition, the mortality rate of people who lived alone was significantly higher than that of those who lived with their families. Most cases occurred in the home bathroom (84.9%) at the time when elderly people usually bathe (48.7%). Our results indicate that bath-related death occurs most often during the normal daily life of the aged. Protective activities of the Japanese government and society should aim to reduce the number of these tragic deaths in the bathroom. Further, no autopsies were performed on the cases in this study. Therefore, the rate of autopsies in bath-related death should be increased in order to accumulate data based on objective evidence.
Cadaver procurement for anatomy teaching: legislative challenges in a transition-related environment
Authors: Stimec Bojan V , Draskic Marija , Fasel Jean H D
Published: February 2010

Background

Human gross anatomy is one of the cornerstones of a medical curriculum and cannot be performed without adequate cadaver procurement, which is a particular challenge for medical schools with a large student enrolment. The authors present the situation in a country with a low public awareness for willed body donor programmes and the prior absence of adequate legislation.

Aim

Against this background, a comprehensive proposition of a whole-body procurement procedure was elaborated in the health-care law.

Resolving the problem

The main goals of the proposition were: (a) identification of options for cadaver procurement (body bequeathal programme, unclaimed bodies and body donated with the permission of the next-of-kin); (b) defining the chain of order and responsibility of institutions in informing the medical school of the possible candidate for body procurement; (c) body storage and related procedures; (e) confidentiality of the deceased's personal data; (f) burial procedure of the deceased's remains.

Conclusions

The authors are convinced that the willed programme for whole-body donation is a definite aim of such a legislation. However, we suggest that the acquisition of unclaimed bodies is maintained as a temporary solution, until a satisfactory level of public awareness of the problem has been reached.
Study of suicides reported to the Coroner in Colombo, Sri Lanka
Authors: Fernando Ravindra , Hewagama Medhani , Priyangika W D D , Range Sonali , Karunaratne Shashi
Published: February 2010

Introduction

Deaths from suicide reached a peak in Sri Lanka in 1995. Several interventions reduced the suicide rate of 48.7 per 100,000 in 1995 to 23 per 100,000 in 2006, though it is still a major socioeconomic problem. All suicides have to be reported to the Inquirer of Sudden Death (ISD) or ‘Coroner’, according to the Criminal Procedure Code.

Method

All deaths where a verdict of ‘suicide’ was given after an inquest at the Coroner's Court, Colombo, in 2006 were studied. Close relations or friends who attended the inquest were interviewed by medically qualified research assistants. Age, sex, marital and occupational status, level of education, living circumstances and method and reasons for the suicide were studied.

Results

During 2006, 151 deaths from suicide were documented, of which 93 (62%) were men. The majority (47%) were aged between 20 and 29 years. One-third of the victims was unemployed. At the time of committing suicide, 75% were living with family; 89 (59%) were married and 46 (31%) were single. Poisoning was the cause of death in 66 (44%), 48 (70%) of which were due to pesticides. Burns caused 51 (34%) deaths. Other common causes of death included hanging (11%), jumping in front of a train (7%) and drowning (3%). The commonest reason for suicide was dispute with the spouse/marital disharmony (30%). Other reasons were dispute with parents (8%), financial matters (7%), organic diseases (7%), alcoholism (7%), psychiatric illnesses (6%) and disputes in love affairs (5%). In 29 cases (19%), no definite reason for the suicide was evident.

Discussion

Self-poisoning and self-immolation were the commonest methods used to commit suicide. Marital disharmony was the main reason (30%). Psychiatric illnesses were responsible for only 6%. Future interventional activities should include secure access and restriction of the availability of pesticides and drugs, empowering people to manage anger and conflicts, and recognition and treatment of alcoholism and psychiatric illnesses. The success story of the reduction in the incidence of suicides in Sri Lanka should be a lesson to many developing countries where suicide is a major socioeconomic and health issue.