bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Investigation of the Location of Maximum Erosive Wear Damage in Elbows
Authors: Mazumder Quamrul H. , Shirazi Siamack A. , McLaury Brenton
Published: February 2008

Erosive wear damage of elbows due to solid particle impact has been recognized as a significant problem in several fluid handling industries. Solid particle erosion is a complex phenomenon due to different parameters causing material removal from the metal surface. The particle density, size, shape, velocity, concentration, impact angle, and impacting surface material properties are some of the major parameters. Among the various factors, the particle impact velocity has the greatest influence in erosion. The particle impact velocity and impact angles depend on the fluid velocity and fluid properties. The particle to particle, particle to fluid, and particle to wall interactions increase the complexity of the erosive wear behavior. In multiphase flow, the presence of different fluids and their corresponding spatial distribution of the phases, adds another dimension to the problem. Most of the previous investigations were focused on determination of erosion in terms of mass loss of the eroding surfaces without identifying the specific location of the maximum erosive wear. During this investigation, magnitude of erosion at different location of an elbow specimen was measured to determine the location of maximum erosion. Experimental investigation of erosion in single-phase and multiphase flows was conducted at different fluid velocities. Both mass loss and thickness loss measurements were taken to characterize erosion behavior and erosion patterns in an elbow. Experimental results showed different erosion behavior and location of maximum erosion damage in single-phase and multiphase flows. The locations of maximum wear due to erosion were also different for horizontal flow compared to vertical flow.
A Proposed Model for Creep Relaxation of Soft Gaskets in Bolted Joints at Room Temperature
Authors: Alkelani Ali A. , Housari Basil A. , Nassar Sayed A.
Published: February 2008

A mathematical model is proposed for predicting the residual clamp load during creep and∕or relaxation in gasketed joints. An experimental procedure is developed to verify the proposed model for predicting the gasket relaxation under a constant compression, gasket creep under a constant stress, and gasket creep relaxation. To study gasket creep relaxation, a single-bolt joint is used. The bolt is tightened to a target preload and the clamp load decay due to gasket creep relaxation is observed over time under various preload levels. Experimental and analytical results are presented and discussed. The proposed model provides an accurate prediction of the residual clamp load as a function of time, gasket material, and geometric properties of the gasket. A closed form solution is formulated to determine the initial clamp load level necessary to provide the desired level of a steady state residual clamp load in the joint, by taking the gasket creep relaxation into account.
Neutron Diffraction Evaluation of Residual Stress for Several Welding Arrangements and Comparison With Fitness-for-Purpose Assessments
Authors: Pardowska Anna M. , Price John W. H. , Ibrahim Raafat , Finlayson Trevor R.
Published: February 2008

In this research, the neutron diffraction technique was used to investigate and compare the residual stress characteristics in several weld arrangements. This research has focused on the effects on residual stress of restraint condition applied during welding, the start and end of the weld for a single bead, and increasing the number of passes. The measured residual stress distributions are normalized by the yield strength of the material and compared with distribution provided in fitness-for-purpose procedures. It is found that the current safety assessment procedure BS 7910 and R6 Level 1 significantly conservative for longitudinal stresses outside the weld and heat affected zone, and for transverse residual stress across the weldment for surface measurements. For a less conservative assessment, R6 Level 2 is recommended, however, even if this assessment is often conservative, in particular, for transverse residual stresses.
Magnetostrictive Microactuations and Modal Sensitivities of Thin Magnetoelastic Shells
Authors: Chai W. K. , Tzou H. S. , Arnold S. M. , Lee H.-J.
Published: February 2008

This study is to evaluate distributed microscopic actuation characteristics and control actions of segmented magnetostrictive actuator patches laminated on a flexible cylindrical shell panel. A mathematical model and its modal domain governing equations of the cylindrical shell panel laminated with distributed magnetostrictive actuator patches are presented first, followed by the formulation of distributed magnetostrictive control forces and microcontrol actions including circumferential membrane∕bending and longitudinal bending control components. Transverse mode shape functions with simply supported boundary conditions are used in the modal control force expressions and the microcontrol action analyses. Control effectives and spatial characteristics of distributed actuators depend on applied magnetic fields and on geometrical (e.g., spatial segmentation, location, and shape) and material (i.e., various actuator materials) properties. Spatially distributed magnetoelectromechanical actuation characteristics contributed by circumferential membrane∕bending and longitudinal bending control actions are investigated. Distributed control forces and microactuations of a magnetostrictive actuator patch at various locations are analyzed, and modal-dependent spatial control effectiveness is evaluated.
Plastic Collapse Assessment Procedure for Vessel With Local Thin Area Simultaneously Subjected to Internal Pressure and External Bending Moment
Authors: Konosu Shinji , Mukaimachi Norihiko
Published: February 2008

Assessment of the local thin area should be undertaken for both tension and compression bending. In this paper, simplified reference stresses for a flaw in a cylinder are proposed. By using these results, a newly developed p-M (internal pressure ratio and external bending moment ratio) diagram which can evaluate the collapse condition for pressure equipment such as vessels, piping, and storage tanks with a local thin area simultaneously subjected to internal pressure p and external bending moment M due to earthquake, etc., is proposed. The p-M line is verified by comparison with the finite element analysis results and the numerous results of experiment for a cylinder with a volumetric flaw obtained through the reference literatures. It was clarified that the differences in collapse limit between the p-M line and DNV guideline under both internal pressure and compression moment became evident where the outer diameter/wall thickness of a cylinder is large and the yield ratio of the material is small.
Perturbative and nonperturbative studies with the delta function potential
Authors: Bera Nabakumar , Bhattacharyya Kamal , Bhattacharjee Jayanta K.
Published: February 2008

We show that the δ-function potential can be exploited along with perturbation theory to yield the result of certain infinite series. The idea is that any exactly soluble potential, if coupled with a δ function potential, remains exactly soluble. We use the strength of the δ function as an expansion parameter and express the second-order energy shift as an infinite sum in perturbation theory. The analytical solution is used to determine the second-order energy shift and hence the sum of an infinite series. By an appropriate choice of the unperturbed system, we can show the importance of the continuum in the energy shift of bound states.
Adventures in Friedmann cosmology: A detailed expansion of the cosmological Friedmann equations
Authors: Nemiroff Robert J. , Patla Bijunath
Published: February 2008

The general relativistic cosmological Friedmann equations, which describe how the scale factor of the universe evolves, are expanded explicitly to include energy forms not usually seen. The evolution of the universe as predicted by the Friedmann equations when dominated by a single, isotropic, stable, static, perfect-fluid energy form is discussed for different values of the gravitational pressure to density ratio w. These energy forms include phantom energy (w<−1), cosmological constant (w=−1), domain walls (w=−2∕3), cosmic strings (w=−1∕3), normal matter (w=0), radiation and relativistic matter (w=1∕3), and a previously little-discussed form of energy called “ultralight” (w>1∕3). A brief history and possible futures of Friedmann universes dominated by a single energy form are discussed.
Potassium Channel Phosphorylation in Excitable Cells: Providing Dynamic Functional Variability to a Diverse Family of Ion Channels
Authors: Park Kang-Sik , Yang Jae-Won , Seikel Edward , Trimmer James S.
Published: February 2008

Phosphorylation of potassium channels affects their function and plays a major role in regulating cell physiology. Here, we review previous studies of potassium channel phosphorylation, focusing first on studies employing site-directed mutagenesis of recombinant channels expressed in heterologous cells. We then discuss recent mass spectrometric-based approaches to identify and quantify phosphorylation at specific sites on native and recombinant potassium channels, and newly developed mass spectrometric-based techniques that may prove beneficial to future studies of potassium channel phosphorylation, its regulation, and its mechanism of channel modulation.
GATA-3 Expression in Breast Cancer Has a Strong Association with Estrogen Receptor but Lacks Independent Prognostic Value
Authors: Voduc David , Cheang Maggie , Nielsen Torsten
Published: February 2008

Background: GATA-3 is a transcription factor involved in human growth and differentiation. Gene expression profiling has shown that GATA-3 is highly expressed in the Luminal A subtype of breast cancer. A recent study found GATA-3 to be associated with favorable breast cancer pathologic features, including negative lymph node and positive estrogen receptor (ER) status. GATA-3 levels were also found to be an independent prognostic marker, with low expression predicting for breast cancer recurrence.

Materials and Methods: Our case series consists of 3,119 cases of invasive breast cancer in which GATA-3 expression was assessed by immunohistochemistry on tissue microarrays. We considered >5% nuclear staining to be a positive result for GATA-3.

Results: Thirty-two percent of cases were GATA-3 positive. GATA-3 is almost exclusively expressed in ER+ patients and is also associated with lower tumor grade, older age at diagnosis, and the absence of Her2 overexpression. In univariate analysis, the presence of GATA-3 is a marker of good prognosis and predicted for superior breast cancer–specific survival, relapse-free survival, and overall survival. However, in multivariate models including patient age, tumor size, histologic grade, nodal status, ER status, and Her2 status, GATA-3 was not independently prognostic for these same outcomes. In the subgroups of ER+ patients treated with or without tamoxifen, GATA-3 was again nonprognostic for all outcomes.

Discussion: GATA-3 is a molecular marker that is highly associated with ER expression, but it does not seem to have prognostic value independent of ER, nor does it predict for response to tamoxifen among ER-positive patients. (Cancer Epidemiol Biomarkers Prev 2008;17(2):365–73)
Apoptosis in Normal Rectal Mucosa, Baseline Adenoma Characteristics, and Risk of Future Adenomas
Authors: Keku Temitope O. , Amin Ahmad , Galanko Joseph , Martin Christopher , Schliebe Barbara , Sandler Robert S.
Published: February 2008

Low apoptosis in the normal rectal mucosa has been associated with colorectal adenomas in cross-sectional studies. It is unknown whether apoptosis can predict the occurrence of new adenomas. We evaluated whether apoptosis at baseline colonoscopy, as well as patient and adenoma characteristics, could predict future occurrence of adenomas. Study subjects were participants in the Diet and Health Study III, a cross-sectional study of adenoma risk factors between August 1998 and March 2000. At baseline, subjects underwent colonoscopy and provided normal rectal mucosal biopsies to evaluate apoptosis as well as information about diet and lifestyle. The present study includes 257 subjects who returned for follow-up colonoscopy between 2000 and 2005. Apoptosis, number of adenomas, size, and atypia at baseline colonoscopy were evaluated as predictors of new adenomas. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (95% CI). At baseline, low apoptosis was significantly associated with increased risk of adenomas (P = 0.0001). Compared with those in the lowest tertile, subjects with high apoptosis were less likely to have an adenoma at follow-up (crude OR, 0.25; 95% CI, 0.09-0.65; adjusted OR, 0.29; 95% CI, 0.08-1.06). Having three or more adenomas at baseline was associated with increased risk of new adenomas (crude OR, 2.46; 95% CI, 1.14-5.31; adjusted OR, 3.74; 95% CI, 1.01-13.83). This study suggests that lower apoptosis is associated with increased risk of future adenoma development. If confirmed in larger studies, apoptosis could potentially be used to identify patients at highest risk for developing new adenomas. (Cancer Epidemiol Biomarkers Prev 2008;17(2):306–10)
Use of Sun-Protective Clothing at Outdoor Leisure Settings from 1992 to 2002: Serial Cross-sectional Observation Survey
Authors: Dixon Helen G. , Lagerlund Magdalena , Spittal Matthew J. , Hill David J. , Dobbinson Suzanne J. , Wakefield Melanie A.
Published: February 2008

Background: Previous population-based surveys to monitor sun protection behavior over time have relied on self-report, which can be subject to recall and misclassification bias and social desirability bias. The present study aimed to describe the prevalence and determinants of teenagers' and adults' observed sun protection behavior while engaged in outdoor leisure activities on summer weekends, over a decade of the SunSmart skin cancer prevention program, which involved public education and advocacy.

Method: Serial cross-sectional observational field surveys of teenagers and adults at leisure were undertaken during summer weekends between 11 a.m. and 3 p.m., from 1992 to 2002 (N = 46,810). The four types of setting for observation were parks and gardens, golf courses, tennis courts, and pools and beaches, located within a 25-km radius of Melbourne city center, Australia. The main outcome measure was a binary clothes cover index representing persons above or below the median level of body cover for each type of leisure setting. The index was based on the proportion of body surface covered by the type of hat, shirt, and leg cover garments worn.

Results: Body cover varied by environmental factors and the activity demands and demographic characteristics of individuals. After adjusting for covariates, significant improvements in the extent of body cover occurred over the decade, such that the odds of the proportion of people wearing clothes cover above the median level increased by 3% per year (95% confidence interval, 2-4%).

Conclusion: Results suggest that significant gains in sun-protective behavior have occurred, coincident with the conduct of an ongoing comprehensive skin cancer prevention program. (Cancer Epidemiol Biomarkers Prev 2008;17(2):428–34)
Relative Weight at Age 12 and Risk of Postmenopausal Breast Cancer
Authors: Bardia Aditya , Vachon Celine M. , Olson Janet E. , Vierkant Robert A. , Wang Alice H. , Hartmann Lynn C. , Sellers Thomas A. , Cerhan James R.
Published: February 2008

Background: Early adolescent weight may affect the risk of postmenopausal breast cancer, and this association may be modified by a family history of breast or ovarian cancer in a first-degree relative, and/or estrogen (ER) and progesterone (PR) receptor status of the disease.

Methods: Relative weight at age 12 years (above, below, or average weight compared with peers) and family history were ascertained using a mailed questionnaire in 1986, in the Iowa Women's Health Study, a prospective cohort study of postmenopausal women. Incident breast cancer cases (including ER and PR status) were identified using the Iowa Surveillance, Epidemiology, and End Results Cancer Registry. Relative risks (RR) and 95% confidence intervals (95% CI) were estimated using Cox proportional hazards regression, and were adjusted for breast cancer risk factors, including body mass index at age 18 years and body mass index at study baseline.

Results: Through 2003, 2,503 cases of postmenopausal breast cancer were identified among 35,941 women in the analytic cohort. Compared with women with average weight at age 12 years, there was no association of below average weight with risk of breast cancer (RR, 1.02; 95% CI, 0.92-1.13), whereas women with above average weight had a lower risk (RR, 0.85; 95% CI, 0.74-0.98). There was no evidence of an interaction between weight at age 12 years and family history (P = 0.44). The inverse association of above average weight with risk of breast cancer was strongest for PR− tumors (RR, 0.62; 95% CI, 0.43-0.89), intermediate for ER+ (RR, 0.80; 95% CI, 0.67-0.96) and ER− (RR, 0.77; 95% CI, 0.50-1.19) tumors, and weakest for PR+ tumors (RR, 0.90; 95% CI, 0.74-1.09). These associations were not modified by a family history (all P > 0.18). In a joint ER/PR analyses, the strongest inverse association with above average weight at age 12 years was seen for ER+/PR− (RR, 0.49; 95% CI, 0.29-0.85).

Conclusion: Above average weight at age 12 years was inversely associated with risk of postmenopausal breast cancer, and was not modified by a family history of the disease. The inverse association was strongest for ER+/PR− tumors. (Cancer Epidemiol Biomarkers Prev 2008;17(2):374–8)
Plasma Tea Polyphenols and Gastric Cancer Risk: A Case-Control Study Nested in a Large Population-Based Prospective Study in Japan
Authors: Sasazuki Shizuka , Inoue Manami , Miura Tsutomu , Iwasaki Motoki , Tsugane Shoichiro ,   for the Japan Public Health Center-based Prospective Study Group
Published: February 2008

Abundant in vitro and animal studies have shown a protective effect of green tea against various types of cancer, but the evidence from epidemiologic studies is inconclusive. In this nested case-control study, we used plasma biomarkers to directly investigate the effect of tea polyphenols on the risk of gastric cancer. Subjects were followed up from 1990 to 2004. Among 36,745 subjects who answered the baseline questionnaire and provided blood samples, 494 gastric cancer cases matched to 494 controls were used in the analysis. The validated method used high-performance liquid chromatography to analyze baseline plasma samples. For men, a high plasma level of (-)-epigallocatechin was associated with an increased risk of gastric cancer. For women, a high plasma level of (-)-epicatechin-3-gallate (ECG) was associated with a decreased risk of gastric cancer; the adjusted odds ratios (95% confidence intervals) for ECG levels 0.32 to 9.2 and 9.3+ ng/mL were 1.03 (0.41-2.59) and 0.25 (0.08-0.73), respectively, compared with those whose ECG level was under the detection limit (P for trend = 0.02). Cigarette smoking was suggested to play a role as an effect modifier, which explains in part the different patterns observed by gender. (Cancer Epidemiol Biomarkers Prev 2008;17(2):343–51)
Pancreatic Cancer and Factors Associated with the Insulin Resistance Syndrome in the Korean Cancer Prevention Study
Authors: Berrington de Gonzalez Amy , Yun Ji Eun , Lee Sang-Yi , Klein Alison P. , Jee Sun Ha
Published: February 2008

There is increasing evidence that type 2 diabetes mellitus and glucose intolerance are a cause, not just a consequence, of pancreatic cancer. We examined whether other factors that characterize the insulin resistance syndrome are also risk factors for pancreatic cancer in a prospective cohort study of 631,172 men and women (ages 45+ years) who received health insurance from the Korean Medical Insurance Corporation. The biennial medical evaluations from 1992 to 1995 provided the baseline information for this study. Relative risks (RR) were estimated using proportional hazards models adjusted for age, sex, smoking, and fasting serum glucose (after excluding the first 2 years of follow-up). There were 2,194 incident cases of pancreatic cancer diagnosed in the cohort over a median follow-up of 12 years. There was no evidence that pancreatic cancer risk was associated with total cholesterol, systolic blood pressure, WBC count, or body mass index. Abnormal levels of aspartate aminotransferase and alanine aminotransferase were both associated with a moderately increased risk of developing the disease (40+ versus <20; RR, 1.33; 95% CI, 1.14-1.55; Ptrend = 0.05 and RR, 1.34; 95% CI, 1.16-1.56; Ptrend = 0.02, respectively). Excluding 6 years of follow-up reduced this RR (95% CI) for aspartate aminotransferase to 1.22 (1.01-1.49), but even after excluding 10 years follow-up the RR (95% CI) for alanine aminotransferase was unchanged [1.36 (1.01-1.83)]. Although fasting serum glucose has been found previously to be associated with pancreatic cancer risk in this cohort, most other factors that characterize insulin resistance syndrome were not associated with pancreatic cancer risk. The association with elevated liver enzyme levels is a novel finding that warrants further investigation. (Cancer Epidemiol Biomarkers Prev 2008;17(2):359–64)
Association of Single Nucleotide Polymorphisms in Glycosylation Genes with Risk of Epithelial Ovarian Cancer
Authors: Sellers Thomas A. , Huang Yifan , Cunningham Julie , Goode Ellen L. , Sutphen Rebecca , Vierkant Robert A. , Kelemen Linda E. , Fredericksen Zachary S. , Liebow Mark , Pankratz V. Shane , Hartmann Lynn C. , Myer Jeff , Iversen Edwin S. , Schildkraut Joellen M. , Phelan Catherine
Published: February 2008

Studies suggest that underglycosylation of the cell membrane mucin MUC1 may be associated with epithelial ovarian cancer. We identified 26 genes involved in glycosylation and examined 93 single nucleotide polymorphisms (SNP) with a minor allele frequency of ≥0.05 in relation to incident ovarian cancer. Cases were ascertained at the Mayo Clinic, Rochester, MN (n = 396) or a 48-county region in North Carolina (Duke University; n = 534). Ovarian cancer–free controls (n = 1,037) were frequency matched to the cases on age, race, and residence. Subjects were interviewed to obtain data on risk factors and a sample of blood for DNA and genotyped using the Illumina GoldenGate assay. We excluded subjects and individual SNPs with genotype call rates of <90%. Data were analyzed using logistic regression, with adjustment for age and residence. We fitted dominant, log additive, and recessive genetic models. Among Caucasians, nine SNPs in eight genes were associated with risk at P < 0.05 under at least one genetic model before adjusting for multiple testing. A SNP in GALNT1 (rs17647532) was the only one that remained statistically significant after Bonferroni adjustment for multiple testing but was not statistically significant in Hardy-Weinberg equilibrium among controls. Haplotype analyses revealed a global association of GALNT1 with risk (P = 0.038, under a recessive genetic model), which largely reflected a decreased risk of one haplotype (0.10 frequency; odds ratio, 0.07; P = 0.01) compared with the most common haplotype (0.39 frequency). These results suggest that genetic polymorphisms in the glycoslyation process may be novel risk factors for ovarian cancer. (Cancer Epidemiol Biomarkers Prev 2008;17(2):397–404)
Meat Intake, Heterocyclic Amine Exposure, and Metabolizing Enzyme Polymorphisms in Relation to Colorectal Polyp Risk
Authors: Shin Aesun , Shrubsole Martha J. , Rice Jeffrey M. , Cai Qiuyin , Doll Mark A. , Long Jirong , Smalley Walter E. , Shyr Yu , Sinha Rashmi , Ness Reid M. , Hein David W. , Zheng Wei
Published: February 2008

Most colorectal cancers arise from adenomatous polyps or certain hyperplastic polyps. Only a few studies have investigated potential genetic modifiers of the associations between meat intake and polyp risk, and results are inconsistent. Using data from the Tennessee Colorectal Polyp Study, a large colonoscopy-based study, including 1,002 polyp cases (557 adenoma only, 250 hyperplastic polyp only, 195 both polyps) and 1,493 polyp-free patients, we evaluated the association of colorectal polyp risk with carcinogen exposure from meat and genetic polymorphisms in enzymes involved in heterocyclic amine (HCA) metabolism, including N-acetyltransferase 1 (NAT1) and N-acetyltransferase 2 (NAT2), cytochrome P450 1A2 (CYP1A2), and aryl hydrocarbon receptor (AhR). Data on intake levels of meats by preparation methods, doneness preferences, and other lifestyle factors were obtained. Fourteen single nucleotide polymorphisms in the AhR, CYP1A2, NAT1, and NAT2 genes were evaluated. No clear association was found for any polymorphisms with polyp risk. However, apparent interactions were found for intake of meat and HCAs with AhR, NAT1, and NAT2 genotypes, and the interactions were statistically significant for the group with both adenomatous and hyperplastic polyps. Dose-response relationships with meat or HCA intake were found only among those with the AhR GA/AA (rs2066853) genotype, NAT1 rapid, or NAT2 rapid/intermediate acetylators but not among those with other genotypes of these genes. This dose-response relationship was more evident among those with both AhR GA/AA and the NAT1 rapid acetylator than those without this genotype combination. These results provide strong evidence for a modifying effect of metabolizing genes on the association of meat intake and HCA exposure with colorectal polyp risk. (Cancer Epidemiol Biomarkers Prev 2008;17(2):320–9)
Circulating Concentrations of Folate and Vitamin B12 in Relation to Prostate Cancer Risk: Results from the European Prospective Investigation into Cancer and Nutrition Study
Authors: Johansson Mattias , Appleby Paul N. , Allen Naomi E. , Travis Ruth C. , Roddam Andrew W. , Egevad Lars , Jenab Mazda , Rinaldi Sabina , Kiemeney Lambertus A. , Bueno-de-Mesquita H. Bas , Vollset Stein Emil , Ueland Per M. , Sánchez Maria-José , Quirós J. Ramón , González Carlos A. , Larrañaga Nerea , Chirlaque María Dolores , Ardanaz Eva , Sieri Sabina , Palli Domenico , Vineis Paolo , Tumino Rosario , Linseisen Jakob , Kaaks Rudolf , Boeing Heiner , Pischon Tobias , Psaltopoulou Theodora , Trichopoulou Antonia , Trichopoulos Dimitrios , Khaw Kay-Tee , Bingham Sheila , Hallmans Göran , Riboli Elio , Stattin Pär , Key Timothy J.
Published: February 2008

Background: Determinants of one-carbon metabolism, such as folate and vitamin B12, have been implicated in cancer development. Previous studies have not provided conclusive evidence for the importance of circulating concentrations of folate and vitamin B12 in prostate cancer etiology. The aim of the present study was to investigate the relationship between prostate cancer risk and circulating concentrations of folate and vitamin B12 in a large prospective cohort.

Methods: We analyzed circulating concentrations of folate and vitamin B12 in 869 cases and 1,174 controls, individually matched on center, age, and date of recruitment, nested within the European Prospective Investigation into Cancer and Nutrition cohort. Relative risks (RR) for prostate cancer were estimated using conditional logistic regression models.

Results: Overall, no significant associations were observed for circulating concentrations of folate (Ptrend = 0.62) or vitamin B12 (Ptrend = 0.21) with prostate cancer risk. RRs for a doubling in folate and vitamin B12 concentrations were 1.03 [95% confidence interval (95% CI), 0.92-1.16] and 1.12 (95% CI, 0.94-1.35), respectively. In the subgroup of cases diagnosed with advanced stage prostate cancer, elevated concentrations of vitamin B12 were associated with increased risk (RR for a doubling in concentration, 1.69; 95% CI, 1.05-2.72, Ptrend = 0.03). No other subgroup analyses resulted in a statistically significant association.

Conclusion: This study does not provide strong support for an association between prostate cancer risk and circulating concentrations of folate or vitamin B12. Elevated concentrations of vitamin B12 may be associated with an increased risk for advanced stage prostate cancer, but this association requires examination in other large prospective studies. (Cancer Epidemiol Biomarkers Prev 2007;17(2):279–85)
Assessment of Interactions between PAH Exposure and Genetic Polymorphisms on PAH-DNA Adducts in African American, Dominican, and Caucasian Mothers and Newborns
Authors: Wang Shuang , Chanock Stephen , Tang Deliang , Li Zhigang , Jedrychowski Wieslaw , Perera Frederica P.
Published: February 2008

Polycyclic aromatic hydrocarbons (PAH) are widespread pollutants commonly found in air, food, and drinking water. Benzo[a]pyrene is a well-studied representative PAH found in air from fossil fuel combustion and a transplacental carcinogen experimentally. PAHs bind covalently to DNA to form DNA adducts, an indicator of DNA damage, and an informative biomarker of potential cancer risk. Associations between PAH-DNA adduct levels and both cancer risk and developmental deficits have been seen in previous experimental and epidemiologic studies. Several genes have been shown to play an important role in the metabolic activation or detoxification of PAHs, including the cytochrome P450 genes CYP1A1 and CYP1B1 and the glutathione S-transferase (GST) genes GSTM1, and GSTT2. Genetic variation in these genes could influence susceptibility to adverse effects of PAHs in polluted air. Here, we have explored interactions between prenatal PAH exposure and 17 polymorphisms in these genes (rs2198843, rs1456432, rs4646903, rs4646421, rs2606345, rs7495708, rs2472299, rs162549, rs1056837, rs1056836, rs162560, rs10012, rs2617266, rs2719, rs1622002, rs140194, and gene deletion GSTM1-02) and haplotypes on PAH-DNA adducts in cord blood of 547 newborns and in maternal blood of 806 mothers from three different self-described ethnic groups: African Americans, Dominicans, and Caucasians. PAHs were measured by personal air monitoring of mothers during pregnancy. Significant interactions (p < 0.05) were observed between certain genetic polymorphisms and CYP1A1 haplotype and PAHs in mothers and their newborns in the three ethnic groups. However, with our limited sample size, the current findings are suggestive only, warranting further study. (Cancer Epidemiol Biomarkers Prev 2008;17(2):405–13)
Plasma Insulin-Like Growth Factor I Is Inversely Associated with Colorectal Adenoma Recurrence: A Novel Hypothesis
Authors: Jacobs Elizabeth T. , Martínez María Elena , Alberts David S. , Ashbeck Erin L. , Gapstur Susan M. , Lance Peter , Thompson Patricia A.
Published: February 2008

The insulin-like growth factor I (IGF-I) axis has been proposed to be a significant factor in the development of certain cancers, including colorectal. However, results from epidemiologic studies suggest modest effects on colorectal cancer risk. Using cross-sectional and prospective study designs within the same cohort of men who had at least one adenoma at baseline, we investigated whether plasma IGF-I, IGF-I binding protein 1, and IGF-I binding protein 3 were associated with colorectal adenoma characteristics at baseline and whether their levels were related to odds for adenoma recurrence. Plasma levels of each marker were measured at baseline in 299 male participants in the Wheat Bran Fiber Trial, who were followed prospectively for recurrence of their adenomatous lesions. In cross-sectional analyses, plasma IGF-I was significantly positively associated with the presence of adenomas with any villous features (P = 0.04). In contrast, IGF-I levels were inversely associated with odds of colorectal adenoma recurrence, with adjusted odds ratios (95% confidence interval) of 0.55 (0.29-1.01) and 0.49 (0.26-0.91) for the second and third tertiles of IGF-I, respectively, compared with the first tertile (Ptrend = 0.02). The inverse association was stronger for advanced adenoma recurrence (Ptrend = 0.02) than for nonadvanced recurrence (Ptrend = 0.10). These results suggest that, once an adenoma is removed, higher IGF-I levels reduce the odds of the formation of new lesions in the colorectum. (Cancer Epidemiol Biomarkers Prev 2008;17(2):300–5)
Physical Activity and Survival after Diagnosis of Invasive Breast Cancer
Authors: Holick Crystal N. , Newcomb Polly A. , Trentham-Dietz Amy , Titus-Ernstoff Linda , Bersch Andrew J. , Stampfer Meir J. , Baron John A. , Egan Kathleen M. , Willett Walter C.
Published: February 2008

Previous studies suggest that increased physical activity may lower the risk of breast cancer incidence, but less is known about whether levels of physical activity after breast cancer diagnosis can influence survival. We prospectively examined the relation between postdiagnosis recreational physical activity and risk of breast cancer death in women who had a previous invasive breast cancer diagnosed between 1988 and 2001 (at ages 20-79 years). All women completed a questionnaire on recent postdiagnosis physical activity and other lifestyle factors. Among 4,482 women without history of recurrence at the time of completing the questionnaire, 109 died from breast cancer within 6 years of enrollment. Physical activity was expressed as metabolic equivalent task-hours per week (MET-h/wk); hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated using Cox proportional hazards regression. After adjusting for age at diagnosis, stage of disease, state of residence, interval between diagnosis and physical activity assessment, body mass index, menopausal status, hormone therapy use, energy intake, education, family history of breast cancer, and treatment modality compared with women expending <2.8 MET-h/wk in physical activity, women who engaged in greater levels of activity had a significantly lower risk of dying from breast cancer (HR, 0.65; 95% CI, 0.39-1.08 for 2.8-7.9 MET-h/wk; HR, 0.59; 95% CI, 0.35-1.01 for 8.0-20.9 MET-h/wk; and HR, 0.51; 95% CI, 0.29-0.89 for ≥21.0 MET-h/wk; P for trend = 0.05). Results were similar for overall survival (HR, 0.44; 95% CI, 0.32-0.60 for ≥21.0 versus <2.8 MET-h/wk; P for trend <0.001) and were similar regardless of a woman’s age, stage of disease, and body mass index. This study provides support for reduced overall mortality and mortality from breast cancer among women who engage in physical activity after breast cancer diagnosis. (Cancer Epidemiol Biomarkers Prev 2008;17(2):379–86)
Comprehensive Evaluation of ESR2 Variation and Ovarian Cancer Risk
Authors: Leigh Pearce Celeste , Near Aimee M. , Butler Johannah L. , Van Den Berg David , Bretsky Philip , Conti David V. , Stram Daniel O. , Pike Malcolm C. , Hirschhorn Joel N. , Wu Anna H.
Published: February 2008

Studies indicate that estrogen receptor β, encoded by the ESR2 gene on chromosome 14q, may play a role in ovarian carcinogenesis. Using the genetic structure data generated by the Breast and Prostate Cohort Consortium (BPC3), we have comprehensively characterized the role of haplotype diversity in ESR2 and risk of ovarian cancer. Five haplotypes with a frequency of ≥5% were observed in White subjects and five haplotype tagging SNPs (htSNP) were selected to capture the locus diversity with a minimum Rh2 of 0.81. The htSNPs were genotyped in 574 White controls, 417 White invasive ovarian cancer cases, and 123 White borderline ovarian cancer cases from case-control studies carried out in Los Angeles County from 1994 through 2004. No statistically significant association was observed between the five htSNPs and related haplotypes and risk of ovarian cancer overall. Haplotype D was associated with a nonstatistically significant increased risk of invasive ovarian cancer overall (odds ratio, 1.38; 95% confidence interval, 0.93-2.02; P = 0.11) relative to the most common haplotype and a statistically significant increased risk of invasive clear cell ovarian cancer (odds ratio, 3.88; 95% confidence interval, 1.28-11.73; P = 0.016). Haplotype D was also reported by the BPC3 to be associated with increased risk of breast cancer. This haplotype warrants further investigation to rule out any effect with invasive ovarian cancer risk. (Cancer Epidemiol Biomarkers Prev 2008;17(2):393–6)
The Effect of Multiple Mailings on Recruitment: The Multiethnic Cohort
Authors: Steffen Alana D. , Kolonel Laurence N. , Nomura Abraham M. , Nagamine Faye S. , Monroe Kristine R. , Wilkens Lynne R.
Published: February 2008

Background: The current study considers potential nonresponse bias and data quality issues in the Multiethnic Cohort, a prospective study of lifestyle-cancer associations among adults ages 45 to 75 years from five ethnic groups in Hawaii and California.

Methods: We examined determinants of early versus later response to the baseline questionnaire using logistic regression with response wave regressed on measures of demographics, history of illness, health behaviors, medication, and supplement use.

Results: Participants who were more health conscious tended to respond earlier. Female sex, more education, personal experience with cancer, more physical activity, and regular use of aspirin were associated with early response. Race other than white and current smoking were associated with later response. Of note, African-Americans and Latinos, with lower response rates, and Japanese, with the highest response rate overall, were more likely to respond to a later mailing. Results were generally consistent across sex, age groups (under 65, 65+), and ethnic groups and over time. Although repeated mailings increased the proportion responding and the diversity of participants, the percent of missing item responses increased somewhat with response wave.

Conclusion: Multiple mailings are recommended for recruiting ethnic minority groups but the tradeoff may be more missing data among later respondents. (Cancer Epidemiol Biomarkers Prev 2008;17(2):447–54)
DNA Methyltransferase and Alcohol Dehydrogenase: Gene-Nutrient Interactions in Relation to Risk of Colorectal Polyps
Authors: Jung Audrey Y. , Poole Elizabeth M. , Bigler Jeanette , Whitton John , Potter John D. , Ulrich Cornelia M.
Published: February 2008

Disturbances in DNA methylation are a characteristic of colorectal carcinogenesis. Folate-mediated one-carbon metabolism is essential for providing one-carbon groups for DNA methylation via DNA methyltransferases (DNMTs). Alcohol, a folate antagonist, could adversely affect one-carbon metabolism. In a case-control study of colorectal polyps, we evaluated three single nucleotide polymorphisms (−149C>T, −283T>C, −579G>T) in the promoter region of the DNMT3b gene, and a functional polymorphism in the coding region of the alcohol dehydrogenase ADH1C gene, ADH1C *2. Cases had a first diagnosis of colorectal adenomatous (n = 530) or hyperplastic (n = 202) polyps at the time of colonoscopy, whereas controls were polyp-free (n = 649). Multivariate logistic regression analysis was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI). There were no significant main associations between the DNMT3b or ADH1C polymorphisms and polyp risk. However, DNMT3b −149TT was associated with an increase in adenoma risk among individuals with low folate and methionine intake (OR, 2.00; 95% CI, 1.06-3.78, P interaction = 0.10). The ADH1C *2/*2 genotype was associated with a possibly elevated risk for adenomatous polyps among individuals who consumed >26 g of alcohol/d (OR, 1.95; 95% CI, 0.60-6.30), whereas individuals who were wild-type for ADH1C were not at increased risk of adenoma (P interaction = 0.01). These gene-diet interactions suggest that polymorphisms relevant to DNA methylation or alcohol metabolism may play a role in colorectal carcinogenesis in conjunction with a high-risk diet. (Cancer Epidemiol Biomarkers Prev 2008;17(2):330–8)
The Study of Cold War International History in China: A Review of the Last Twenty Years
Authors: Xia Yafeng
Published: February 2008

The study of Cold War international history in China has made major strides in the past two decades. By using newly available Chinese sources, augmented by sources from American, British, Russian, and East European archives, Chinese scholars have produced important works on Cold War history. As the latest publications in China show, Chinese scholars have been gradually adopting a more evenhanded approach in their writings about the Cold War. They have also expanded international cooperation by conducting joint research projects and engaging in meaningful academic dialogues with foreign scholars. This article offers a review of the field, including a survey of new Chinese sources, the leading Chinese scholars, and their main research interests and contributions. The article also points out the challenges, obstacles, and opportunities of the field in China.
Functionalization of Ordered Iron-Based Nanoparticles Deposited on Mesoporous Films
Authors: Marchi M. Claudia , Figueroa Carlos A. , Alvarez Fernando
Published: February 2008

Mesoporous films obtained by dip-coating, combining polycondensation of silicate species and organization of amphiphilic mesophases, were decorated with iron-based nanoparticles from iron aqueous solution. High-resolution transmission electron microscopy (HR-TEM) images and energy dispersive
X-rays spectroscopy (EDS) analysis show that the nanoparticles have diameters between 5 to 10 nm and they are deposited in an ordered sequence exclusively on top of the mesoporous structure. Afterward, by irradiating the material with a hydrogen ion beam, the iron-based compound is functionalized,
i.e., its physical-chemical properties are modified. X-ray photoelectron spectroscopy (XPS) showed that the iron oxides and hydroxides are reduced to metallic iron. The deposition of organized iron-based nanoparticles and further ion beam functionalization might open perspectives on the study
and fabrication of complex new materials.
A Technique to Produce Thin Cucurbit[6]uril Films
Authors: Demets Grégoire Jean-François , Schneider Beatriz Vivian Skalee , Correia Henrique Dias , Gonçalves Rogéria Rocha , Nobre Thatyane Morimoto , Darbello Zaniquelli Maria Elisabete
Published: February 2008

We report a methodology to obtain thin films of cucurbit[6]uril, starting from ammoniacal solutions. This technique is very useful for the obtention of modified electrodes or other substrates for sensor purposes. Cucurbit[6]uril is insoluble in most media, and film formation was impossible
until now.
Chemical Synthesis of Anisotropic Nanocrystalline Sb2Te3 and Low Thermal Conductivity of the Compacted Dense Bulk
Authors: Wang Wenzhong , Yan Xiao , Poudel Bed , Ma Yi , Hao Qing , Yang Jian , Chen Gang , Ren Zhifeng
Published: February 2008

We describe a one-step, one-pot non-aqueous route for the synthesis of Sb2Te3 nanocrystals with hexagonal shape and highly anisotropic nanostructures. The as-prepared nanostructures were characterized by XRD, TEM and HRTEM. The effect of the stabilizers on the
nanocrystal morphology has been discussed in detail. We have studied the thermal conductivity of the compacted bulk from the Sb2 Te3 nanostructures. The results indicated that a very low thermal conductivity of about 1 W/mK at 300 K, comparing to 4.7 W/mK of the polycrystalline
bulk, was achieved. The results indicated that nanostructured Sb2 Te3 is potentially a good candidate for engineered nanocomposites that can lead to high thermoelectric figure-of-merit.
SiGe Nanowire Field Effect Transistors
Authors: Qi Cheng , Rangineni Yaswanth , Goncher Gary , Solanki Raj , Langworthy Kurt , Jordan Jay
Published: February 2008

Si0.5Ge0.5 nanowires have been utilized to fabricate source-drain channels of p-type field effect transistors (p-FETs). These transistors were fabricated using two methods, focused ion beam (FIB) and electron beam lithography (EBL). The electrical
analyses of these devices show field effect transistor characteristics. The boron-doped SiGe p-FETs with a high-k (HfO2) insulator and Pt electrodes, made via FIB produced devices with effective hole mobilities of about 50 cm2V−1s−1.
Similar transistors with Ti/Au electrodes made via EBL had effective hole mobilities of about 350 cm2V−1s−1.
Detecting Mechanical Resonance in Carbon Nanotubes via Inter-Tube Electrical Transport Measurements
Authors: Singh Jitendra Pratap , Teki Ranganath , Ci Lijie , Ajayan Pulickel , Koratkar Nikhil
Published: February 2008

Detecting the mechanical resonance frequency of carbon nanotubes has strong potential applications that range from nano-scale balances to detect very small mass changes to ultra-sensitive bio-sensors. Detection of nanotube resonance requires elaborate and time-consuming techniques such
as in-situ TEM, which limits the practical utility of this concept. In this paper we report a simple and accurate technique for detection of nanotube resonance by monitoring inter-tube electrical transport in a vibrating array of aligned multiwalled carbon nanotubes. The conductivity
measurements are performed using a four-point probe in a direction perpendicular to the nanotube axis. We observe a dramatic decrease in the dc electrical resistance of the nanotube array at the mechanical resonance condition. We believe this is due to inter-tube impacts at resonance, which
leads to an increase in the nanotube local temperature and hence increases the electron hopping rate. The impacting of the tubes could also enable localized tunneling of electrons through the nanotube array along with the hopping.
Nickel Nanorods Produced by Annealing Composite Oxide Films
Authors: Jou Shyankay , Yeh Dong-Yu , Tseng Ampere A.
Published: February 2008

Nickel nanorods have been produced by annealing a dense composite film. The nanorods of 45–140 nm in lateral dimensions and 230–1400 nm in longitudinal dimensions were obtained by annealing NiO-YSZ composite films in H2 at 800 °C for one hour. The axis of
the nanorods at the 220 direction was observed. The dense NiO-YSZ composite film was originally created by co-sputtering Ni and Zr-Y-Ce targets in Ar and O2 environment at 350 °C. Reduction of NiOx to Ni nuclei takes place on the surface of the film. The low crystallinity
of the original composite film is believed to facilitate the NiO to grow into Ni nanorods on the discrete Ni seeds by diffusion.
Electronic Properties of Semiconductor Nanowires
Authors: Voon L. C. Lew Yan , Zhang Yong , Lassen B. , Willatzen M. , Xiong Qihua , Eklund P. C.
Published: February 2008

This paper provides a review of the state-of-the-art electronic-structure calculations of semiconductor nanowires. Results obtained using empirical k · p, empirical tight-binding, semi-empirical pseudopotential, and with ab initio methods are compared. For conciseness,
we will restrict our detailed discussions to free-standing plain and modulated nanowires. Connections to relevant experimental data, particularly band gaps and polarization anisotropy, will be made since these results depend crucially on the electronic properties. For completeness, a brief
review on the synthesis of nanowires is included.
Recombination Dynamics of Surface-Related Excitonic States in Single ZnO Nanowires
Authors: Voss Tobias , Wischmeier Lars
Published: February 2008

With decreasing diameter the influence of surface-related effects becomes increasingly important for an understanding of the optical properties of semiconductor nanowires. We present time integrated and time resolved photoluminescence studies of single zincoxide nanowires with different
diameters. We analyze the changes in the optical spectra for wires with different surface-to-volume ratios, present optical spectra of single wires at different excitation densities, and study the time-resolved dynamics of the surface related and donor-bound exciton related emission lines
for a single nanowire at low temperatures.