bluuebunny/crossref_metadata_2025 huggingface dataset:
Squaraine Planar‐Heterojunction Solar Cells
Authors: Fan Bin , Maniglio Ylenia , Simeunovic Marina , Kuster Simon , Geiger Thomas , Hany Roland , Nüesch Frank
Published: August 2009

The photovoltaic performance of squaraine‐based organic solar cells is investigated. Two squaraine
derivatives with extraordinarily high extinction coefficients are used as electron donors in bilayer heterojunctions with fullerene C60 as electron acceptor. Due to the very strong squaraine absorption band in the red spectral domain, antibatic behavior due to light filtering is observed in the photocurrent spectrum for film thicknesses of 35 nm to 40 nm. At reduced film thicknesses of 20 nm, this filtering effect at maximum absorption can be alleviated and power conversion efficiencies under simulated AM 1.5 full sun irradiation of 0.59% and 1.01% are obtained for the two squaraine derivatives, respectively. The photovoltaic properties of these cells are investigated with respect to electrode materials and chemical doping.
Genipin Cross-Linked Polymeric Alginate-Chitosan Microcapsules for Oral Delivery: In-Vitro Analysis
Authors: Chen Hongmei , Ouyang Wei , Martoni Christopher , Prakash Satya
Published: August 2009

We have previously reported the preparation of the genipin cross-linked alginate-chitosan (GCAC) microcapsules composed of an alginate core with a genipin cross-linked chitosan membrane. This paper is the further investigation on their structural and physical characteristics. Results showed that the GCAC microcapsules had a smooth and dense surface and a networked interior. Cross-linking by genipin substantially reduced swelling and physical disintegration of microcapsules induced by nongelling ions and calcium sequestrants. Strong resistance to mechanical shear forces and enzymatic degradation was observed. Furthermore, the GCAC membranes were permeable to bovine serum albumin and maintained a molecular weight cutoff at 70 KD, analogous to the widely studied alginate-chitosan, and alginate-poly-L-lysine-alginate microcapsules. The release features and the tolerance of the GCAC microcapsules in the stimulated gastrointestinal environment were also investigated. This GCAC microcapsule formulation offers significant potential as a delivery vehicle for many biomedical applications.
Acylated 2‐(N‐arylaminomethylene)benzo[b]thiophene‐3(2H)‐Ones: Molecular Switches with Varying Migrants and Substituents
Authors: Dubonosov Alexander D. , Rybalkin Vladimir P. , Popova Lydia L. , Tsukanov Alexey V. , Revinsky Yurii V. , Bren Vladimir A. , Minkin Vladimir I.
Published: August 2009

Synthesis and properties of photochromic acylated 2‐(N‐arylaminomethylene)benzo[b]thiophene‐3(2H)‐ones are described. Their structure largely depends on the nature of acyl migrant and in a less degree on N‐aryl substituent.
Growth of GaN@InGaN Core‐Shell and Au‐GaN Hybrid Nanostructures for Energy Applications
Authors: Kuykendall Tevye , Aloni Shaul , Jen-La Plante Ilan , Mokari Taleb
Published: August 2009

We demonstrated a method to control the bandgap energy of GaN nanowires by forming GaN@InGaN core‐shell hybrid structures using metal organic chemical vapor deposition (MOCVD). Furthermore, we show the growth of Au nanoparticles on the surface of GaN nanowires in solution at room temperature. The work shown here is a first step toward engineering properties that are crucial for the rational design and synthesis of a new class of photocatalytic materials. The hybrid structures were characterized by various techniques, including photoluminescence (PL), energy dispersive x‐ray spectroscopy (EDS), transmission and scanning electron microscopy (TEM and SEM), and x‐ray diffraction (XRD).
Electronic and Lattice Dynamical Properties of the Iron-Based Superconductors LiFeAs and NaFeAs
Authors: Jishi R. A. , Alyahyaei H. M.
Published: August 2009

The electronic structure and lattice vibrational frequencies of the newly discovered superconductors, LiFeAs and NaFeAs, are calculated within density functional theory. We show that, in the vicinity of the Fermi energy, the density of states is dominated by contributions from Fe 3d states. We also calculate the electron-phonon coupling strength and show that it is too weak to account for the observed values of the superconducting transition temperatures. This seems to indicate that the iron-based superconductors are not of the conventional type.
Increased Neovascularization in Advanced Lipid-Rich Atherosclerotic Lesions Detected by Gadofluorine-M-Enhanced MRI
Authors: Sirol Marc , Moreno Pedro R. , Purushothaman K.-Raman , Vucic Esad , Amirbekian Vardan , Weinmann Hanns-Joachim , Muntner Paul , Fuster Valentin , Fayad Zahi A.
Published: August 2009

Background—

Inflammation and neovascularization may play a significant role in atherosclerotic plaque progression and rupture. We evaluated gadofluorine-M-enhanced MRI for detection of plaque inflammation and neovascularization in an animal model of atherosclerosis.

Methods and Results—

Sixteen rabbits with aortic plaque and 6 normal control rabbits underwent gadofluorine-M-enhanced MRI. Eight rabbits had advanced atherosclerotic lesions, whereas the remaining 8 had early lesions. Magnetic resonance atherosclerotic plaque enhancement was meticulously compared with plaque inflammation and neovessel density as assessed by histopathology. Advanced plaques and early atheroma were enhanced after gadofluorine-M injection. Control animals displayed no enhancement. After accounting for the within-animal correlation of observations, mean contrast-to-noise ratio was significantly higher in advanced plaques than compared with early atheroma (4.29�0.21 versus 3.00�0.32;
P
=0.004). Macrophage density was higher in advanced plaques in comparison to early atheroma (geometric mean=0.50 [95% CI, 0.19 to 1.03] versus 0.25 [0.07 to 0.42];
P
=0.05). Furthermore, higher neovessel density was observed in advanced plaques (1.83 [95% CI, 1.51 to 2.21] versus 1.29 [0.99 to 1.69];
P
=0.05). The plaque accumulation of gadofluorine-M correlated with increased neovessel density as shown by linear regression analysis (
r
=0.67;
P
<0.001). Confocal and fluorescence microscopy revealed colocalization of gadofluorine-M with plaque areas containing a high density of neovessels.

Conclusion—

Gadofluorine-M-enhanced MRI is effective for in vivo detection of atherosclerotic plaque inflammation and neovascularization in an animal model of atherosclerosis. These findings suggest that gadofluorine-M enhancement reflects the presence of high-risk plaque features believed to be associated with plaque rupture. Gadofluorine-M plaque enhancement may therefore provide functional assessment of atherosclerotic plaque in vivo.
Air Temperature and the Occurrence of Myocardial Infarction in Augsburg, Germany
Authors: Wolf Kathrin , Schneider Alexandra , Breitner Susanne , von Klot Stephanie , Meisinger Christa , Cyrys Josef , Hymer Heiko , Wichmann H. -Erich , Peters Annette
Published: August 2009

Background—

Air temperature changes have been associated with cardiovascular mortality and morbidity. The objective of this study was to examine in detail the registry-based myocardial infarction (MI) rates and coronary deaths in relation to air temperature in the area of Augsburg, Germany.

Methods and Results—

Between 1995 and 2004, the Monitoring Trends and Determinants on Cardiovascular Diseases/Cooperative Health Research in the Region of Augsburg (MONICA/KORA) registry recorded 9801 cases of MI and coronary deaths. Over the same period, meteorological parameters and air pollutant concentrations were measured in the study region. Poisson regression analyses adjusting for time trend, relative humidity, season, and calendar effects were used to estimate immediate, delayed, and cumulative temperature effects on the occurrence of MIs. The daily rates of total MI, nonfatal and fatal events, and incident and recurrent events were analyzed. For the total MI cases, a 10°C decrease in 5-day average temperature was associated with a relative risk of 1.10 (95% confidence interval, 1.04 to 1.15). The effect of temperature on the occurrence of nonfatal events showed a delayed pattern, whereas the association with fatal MI was more immediate. No association could be observed for recurrent events. The effects of temperature decreases on total MI cases were more pronounced in years with higher average temperatures and were visible in summer.

Conclusions—

We observed an inverse relationship between temperature and MI occurrence not only during winter but also during summer. Thus, our results suggest not a pure “cold effect” but an influence of unusual temperature decreases.
Platelet Dense-Granule Secretion Plays a Critical Role in Thrombosis and Subsequent Vascular Remodeling in Atherosclerotic Mice
Authors: King Sarah M. , McNamee Rachel A. , Houng Aiilyan K. , Patel Rakesh , Brands Michael , Reed Guy L.
Published: August 2009

Background—

Platelet aggregation plays a critical role in myocardial infarction and stroke; however, the role of platelet secretion in atherosclerotic vascular disease is poorly understood. Therefore, we examined the hypothesis that platelet dense-granule secretion modulates thrombosis, inflammation, and atherosclerotic vascular remodeling after injury.

Methods and Results—

Functional deletion of the Hermansky-Pudlak syndrome 3 gene (HPS3
−/−
) markedly reduces platelet dense-granule secretion. HPS3
−/−
mice have normal platelet counts, platelet morphology, and α-granule number, as well as maximal secretion of the α-granule marker P-selectin; however, their capacity to form platelet-leukocyte aggregates is significantly reduced (
P
<0.05). To examine the role of platelet dense-granule secretion in these processes, atherosclerosis-prone mice with combined genetic deficiency of apolipoprotein E and HPS3 (ApoE
−/−
, HPS3
−/−
) were compared with congenic, atherosclerosis-prone mice with normal platelet secretion (ApoE
−/−
, HPS3
+/+
). After 16 to 18 weeks on a high-fat diet, both groups of mice had similar fasting cholesterol levels and body weight. Carotid arteries of ApoE
−/−
, HPS3
+/+
mice thrombosed rapidly after FeCl
3
injury, but ApoE
−/−
, HPS3
−/−
mice were completely resistant to thrombotic arterial occlusion (
P
<0.01). Three weeks after injury, neointimal hyperplasia (from α-smooth muscle actin–positive cells) was significantly less (
P
<0.001) in arteries from ApoE
−/−
, HPS3
−/−
mice. In ApoE
−/−
, HPS3
−/−
mice, there were also pronounced reductions in arterial inflammation, as indicated by a 74% decrease in CD45-positive leukocytes (
P
<0.01) and a 73% decrease in Mac-3–positive macrophages (
P
<0.05).

Conclusions—

In atherosclerotic mice, reduced platelet dense-granule secretion is associated with marked protection against the development of arterial thrombosis, inflammation, and neointimal hyperplasia after vascular injury.
Hypercoagulability Inhibits Monocyte Transendothelial Migration Through Protease-Activated Receptor-1-, Phospholipase-Cβ-, Phosphoinositide 3-Kinase-, and Nitric Oxide-Dependent Signaling in Monocytes and Promotes Plaque Stability
Authors: Seehaus Stefanie , Shahzad Khurrum , Kashif Muhammed , Vinnikov Ilya A. , Schiller Martin , Wang Hongjie , Madhusudhan Thati , Eckstein Volker , Bierhaus Angelika , Bea Florian , Blessing Erwin , Weiler Hartmut , Frommhold David , Nawroth Peter P. , Isermann Berend
Published: August 2009

Background—

Clinical studies failed to provide clear evidence for a proatherogenic role of hypercoagulability. This is in contrast to the well-established detrimental role of hypercoagulability and thrombin during acute atherosclerotic complications. These seemingly opposing data suggest that hypercoagulability might exert both proatherogenic and antiatherogenic effects. We therefore investigated whether hypercoagulability mediates a beneficial effect during de novo atherogenesis.

Methods and Results—

De novo atherogenesis was evaluated in 2 mouse models with hyperlipidemia and genetically imposed hypercoagulability (TM
Pro/Pro
ApoE
−/−
and FVL
Q/Q
ApoE
−/−
mice). In both mouse models, hypercoagulability resulted in larger plaques, but vascular stenosis was not enhanced secondary to positive vascular remodeling. Importantly, plaque stability was increased in hypercoagulable mice with less necrotic cores, more extracellular matrix, more smooth muscle cells, and fewer macrophages. Long-term anticoagulation reversed these changes. The reduced frequency of intraplaque macrophages in hypercoagulable mice is explained by an inhibitory role of thrombin and protease-activated receptor-1 on monocyte transendothelial migration in vitro. This is dependent on phospholipase-Cβ, phosphoinositide 3-kinase, and nitric oxide signaling in monocytes but not in endothelial cells.

Conclusions—

Here, we show a new function of the coagulation system, averting stenosis and plaque destabilization during de novo atherogenesis. The in vivo and in vitro data establish that thrombin-induced signaling via protease-activated receptor-1, phospholipase-Cβ, phosphoinositide 3-kinase, and nitric oxide in monocytes impairs monocyte transendothelial migration. This likely accounts for the reduced macrophage accumulation in plaques of hypercoagulable mice. Thus, in contrast to their role in unstable plaques or after vascular injury, hypercoagulability and thrombin convey a protective effect during de novo atherogenesis.
Protein Tyrosine Phosphatase 1B, a Major Regulator of Leptin-Mediated Control of Cardiovascular Function
Authors: Belin de Chantemèle Eric J. , Muta Kenjiro , Mintz James , Tremblay Michel L. , Marrero Mario B. , Fulton David J. , Stepp David W.
Published: August 2009

Background—

Obesity causes hypertension and sympathoactivation, a process proposed to be mediated by leptin. Protein tyrosine phosphatase 1B (PTP1B), a major new pharmaceutical target in the treatment of obesity and type II diabetes mellitus, constrains the metabolic actions of leptin, but the extent to which PTP1B regulates its cardiovascular effects is unclear. This study examined the hypothesis that PTP1B is a negative regulator of the cardiovascular effects of leptin.

Methods and Results—

PTP1B knockout mice had lower body fat but higher mean arterial pressure (116±5 versus 105±5 mm Hg,
P
<0.05) than controls. Leptin infusion produced a greater anorexic effect in PTP1B knockout mice and a marked increase in mean arterial pressure (135±5 mm Hg) in PTP1B knockout mice only. The decrease in mean arterial pressure in response to ganglionic blockade was higher in PTP1B knockout mice (−38±3% versus −29±3%,
P
<0.05), which suggests increased sympathetic tone. PTP1B deletion blunted mean arterial pressure responses to phenylephrine injection (55±10% versus 93±7%,
P
<0.05). Phenylephrine-induced aortic contraction was reduced in PTP1B knockout mice (57.7±9% versus 96.3±12% of KCl,
P
<0.05), consistent with desensitization to chronically elevated sympathetic tone. Furthermore, PTP1B deletion significantly reduced gene expression of 3 α
1
-adrenergic receptor subtypes, consistent with blunted constriction to phenylephrine.

Conclusions—

These data indicate that PTP1B is a key regulator of the cardiovascular effects of leptin and that reduced vascular adrenergic reactivity provides a compensatory limit to the effects of leptin on mean arterial pressure.
Increased Expression of Integrin-Linked Kinase Attenuates Left Ventricular Remodeling and Improves Cardiac Function After Myocardial Infarction
Authors: Ding Liang , Dong Li , Chen Xin , Zhang Lujie , Xu Xiaoyu , Ferro Albert , Xu Biao
Published: August 2009

Background—

Left ventricular (LV) remodeling is associated with the development of heart failure after myocardial infarction. Here we investigated whether integrin-linked kinase (ILK) may regulate LV remodeling and function after myocardial infarction.

Methods and Results—

Adenoviral vector expressing ILK (n=25) or empty adeno-null (n=25) was injected into rat peri-infarct myocardium after left anterior descending coronary artery ligation. ILK expression was confirmed by Western blotting and immunofluorescence. Echocardiographic and hemodynamic analyses demonstrated relatively preserved cardiac function in adeno-ILK animals. ILK treatment was associated with reduced infarct scar size, increased scar thinning ratio, and preserved LV diameter, wall thickness, cardiomyocyte size, and myofilament density. Enhanced angiogenesis and reduced fibrosis were observed in the adeno-ILK group, along with reduced apoptosis as demonstrated by terminal deoxynucleotidyl transferase–mediated dUTP nick-end labeling analysis. Moreover, increased cardiomyocyte proliferation was found in adeno-ILK animals, as measured by proliferating cell nuclear antigen, Ki-67, and phosphohistone-H3 staining. At long-term follow-up, most indices of cardiac function and hemodynamics showed no difference between adeno-ILK and control animals by 9 weeks, although LV end-systolic diameter and infarct scar size were reduced in the adeno-ILK group at this time point. Additionally, ILK overexpression was found to exert a rescue effect on remodeling when administered in a delayed fashion 1 week after coronary artery ligation.

Conclusions—

ILK gene therapy improves cardiac remodeling and function in rats after myocardial infarction and is associated with increased angiogenesis, reduced apoptosis, and increased cardiomyocyte proliferation. This may represent a new approach to the treatment of postinfarct remodeling and subsequent heart failure.
Losartan Metabolite EXP3179 Blocks NADPH Oxidase-Mediated Superoxide Production by Inhibiting Protein Kinase C
Authors: Fortuño Ana , Bidegain Julen , Robador Pablo A. , Hermida José , López-Sagaseta Jacinto , Beloqui Oscar , Díez Javier , Zalba Guillermo
Published: August 2009

Oxidative stress plays a critical role in the pathogenesis of hypertension. The NADPH oxidase constitutes a major source of superoxide anion in phagocytic cells, and its activation is associated with matrix metalloproteinase (MMP)-9 secretion by these cells. We investigated the effects of the angiotensin II type 1 receptor antagonist losartan and its metabolites (EXP3174 and EXP3179) on NADPH oxidase activity and MMP-9 secretion in human phagocytic cells. EXP3179, but not losartan and EXP3174, dose-dependently inhibited (P<0.05) phorbol myristate acetate and insulin-stimulated NADPH oxidase activity. EXP3179 also inhibited phorbol myristate acetate–induced NADPH oxidase in endothelial cells. In addition, EXP3179 inhibited (P<0.05) both phorbol myristate acetate–stimulated p47phox translocation from cytosol to membranes and protein kinase C activity. Affinity experiments and enzymatic assays confirmed that EXP3179 inhibited several protein kinase C isoforms. EXP3179 also inhibited (P<0.05) phorbol myristate acetate–stimulated MMP-9 secretion. In a study performed in 153 hypertensive patients, phagocytic NADPH oxidase activity was lower (P<0.05) in losartan-treated compared with untreated patients and in patients treated with other angiotensin II type 1 receptor antagonists or with angiotensin-converting enzyme inhibitors. Plasma levels of MMP-9 were lower (P<0.05) in losartan-treated hypertensives compared with the other group of patients. Thus, EXP3179 acts as a blocker of the NADPH oxidase in phagocytic cells by a potential mechanism that targets the protein kinase C signaling pathway. This effect can be involved in reduced MMP-9 secretion by these cells. It is proposed that the EXP3179 metabolite may confer to losartan the specific capacity to reduce oxidative stress mediated by phagocytic cells in hypertensive patients.
Magnetic Resonance Imaging Left Ventricular Mass Reduction With Fixed-Dose Angiotensin-Converting Enzyme Inhibitor–Based Regimens in Patients With High-Risk Hypertension
Authors: Reichek Nathaniel , Devereux Richard B. , Rocha Ricardo A. , Hilkert Robert , Hall Donna , Purkayastha Das , Pitt Bertram
Published: August 2009

Left ventricular hypertrophy, a major cardiovascular risk factor for morbidity and mortality, is commonly caused by arterial hypertension. The renin-angiotensin-aldosterone system may contribute to the pathogenesis of left ventricular hypertrophy. The Assessment of Lotrel in Left Ventricular Hypertrophy and Hypertension Study compared a single-pill combination of amlodipine/benazepril at doses 5.0/20.0 mg, 5.0/40.0 mg, and 10.0/40.0 mg with hydrochlorothiazide/benazepril at doses 12.5/20.0 mg, 12.5/40.0 mg, and 25.0/40.0 mg on the reduction of left ventricular mass index measured by cardiac MRI in stage 2 hypertensive patients over 52 weeks of treatment in a randomized clinical trial. A total of 125 male and female patients, ≥55 years of age, with echocardiographic left ventricular hypertrophy and high-risk hypertension defined as blood pressure ≥160/100 mm Hg or current antihypertensive treatment were enrolled. After 52 weeks of treatment, left ventricular mass index was significantly reduced from baseline with amlodipine/benazepril (mean: 10.16 g/m
2
) or hydrochlorothiazide/benazepril (mean: 6.74 g/m
2
; both
P
<0.0001), with a mean difference between treatment groups of 3.36 g/m
2
(
P
=0.16). No significant treatment differences were observed in subgroups defined by age, male gender, race, diabetes status, or dose level. However, in female patients, left ventricular mass index reduction was greater with amlodipine/benazepril (
P
=0.02). Both treatments were well tolerated.
Quantitative Genetic Analysis of the Retinal Vascular Caliber
Authors: Sun Cong , Zhu Gu , Wong Tien Y. , Hewitt Alex W. , Ruddle Jonathan B. , Hodgson Lauren , Montgomery Grant W. , Young Terri L. , Hammond Christopher J. , Craig Jamie E. , Martin Nicholas G. , He Mingguang , Mackey David A.
Published: August 2009

Research into the genetic effects and specific genes associated with retinal vascular caliber, a risk marker of cardiovascular diseases, may provide new insights into the genetic contribution of early microvascular disease. A combined 374 monozygotic and 536 dizygotic twin pairs and 322 siblings from the Twins Eye Study in Tasmania and the Brisbane Adolescent Twin Study underwent complete ophthalmic examinations, including retinal photography, and bilateral retinal vascular caliber was measured. Structural equation modeling was used to estimate the heritability. Genome-wide linkage analysis was conducted on 836 individuals from 381 Brisbane Adolescent Twin Study families, with adjustments for age, sex, and other covariates. The heritabilities for the retinal arteriolar caliber were 59.4% (95% CI: 53.2% to 64.7%) and 56.5% (95% CI: 50.1% to 61.9%) in the Twins Eye Study in Tasmania and the Brisbane Adolescent Twin Study, respectively, and for venular caliber they were 61.7% (95% CI: 55.6% to 67.0%) and 64.2% (95% CI: 58.7% to 68.8%), respectively, after adjusting for age, sex, and body mass index. Two multipoint peaks detected on chromosomes 3p12.3 and 8p23.1 for retinal arteriolar caliber had suggestive linkage, with the highest multipoint peak logarithm of odds score of 2.24 on chromosome 8p23.1 (genome-wide
P
=7.0×10
−4
). Two suggestive logarithm of odds scores for venular caliber were identified on chromosomes 2p14 and 9q21.13. The largest multipoint logarithm of odds score was 2.69 on chromosome 2p14 (genome-wide
P
=2.0×10
−4
). In this large twin population, genetic factors appear to play a significant role in the variation of retinal vascular caliber. Several putative loci were identified for the retinal vascular caliber.
Impact of Accessory Hepatic Veins on Adrenal Vein Sampling for Identification of Surgically Curable Primary Aldosteronism
Authors: Miotto Diego , De Toni Renzo , Pitter Gisella , Seccia Teresa Maria , Motta Raffaella , Vincenzi Matteo , Feltrin Gianpietro , Rossi Gian Paolo
Published: August 2009

Adrenal vein sampling is the gold standard for identification of surgically curable primary aldosteronism, but its accuracy might be hindered by blood dilution from accessory vein blood. We prospectively investigated the presence of accessory veins draining into adrenal veins and their effect on the selectivity index (SI) in 74 consecutive patients undergoing adrenal vein sampling. On the right side, the venous anatomic pattern could be conclusively determined in 91.8% of the cases: we detected hepatic accessory veins in 12.1%, no accessory veins in 42.4%, and renal capsular veins in 45.5%. On the left side there was a phrenico-adrenal trunk in 89.4% and renal capsular accessory veins in 10.6% of the cases. On both sides, renal capsular and phrenic accessory veins did not affect the SI. At variance, on the right side, hepatic accessory veins were associated with SI values ≈3-fold lower than that found when such accessory veins were absent (median: 3.10 [range: 0.80 to 84.2] versus median: 1.10 [range: 0.70 to 2.20];
P
=0.01). However, superselective adrenal catheterization resulted into higher SI values (median: 23.88; range: 4.80 to 84.20) in these cases. Thus, hepatic accessory veins sharing egress into the inferior vena cava with the right adrenal vein occurred in ≈12% of the patients and imply a low SI, likely because of adrenal blood dilution by hepatic blood carrying a low cortisol concentration. In the presence of this anatomic variation, superselective catheterization of the right adrenal vein should be undertaken to determine the lateralization of aldosterone secretion.
Contribution of Endothelin 1 to the Vascular Effects of Diesel Exhaust Inhalation in Humans
Authors: Langrish Jeremy P. , Lundbäck Magnus , Mills Nicholas L. , Johnston Neil R. , Webb David J. , Sandström Thomas , Blomberg Anders , Newby David E.
Published: August 2009

Diesel exhaust inhalation impairs vascular function, and, although the underlying mechanism remains unclear, endothelin (ET) 1 and NO are potential mediators. The aim of this study was to identify whether diesel exhaust inhalation affects the vascular actions of ET-1 in humans. In a randomized, double-blind crossover study, 13 healthy male volunteers were exposed to either filtered air or dilute diesel exhaust (331±13 μg/m
3
). Plasma concentrations of ET-1 and big-ET-1 were determined at baseline and throughout the 24-hour study period. Bilateral forearm blood flow was measured 2 hours after the exposure during infusion of either ET-1 (5 pmol/min) or the ET
A
receptor antagonist, BQ-123 (10 nmol/min) alone and in combination with the ET
B
receptor antagonist, BQ-788 (1 nmol/min). Diesel exhaust exposure had no effect on plasma ET-1 and big-ET-1 concentrations (
P
>0.05 for both) or 24-hour mean blood pressure or heart rate (
P
>0.05 for all). ET-1 infusion increased plasma ET-1 concentrations by 58% (
P
<0.01) but caused vasoconstriction only after diesel exhaust exposure (−17% versus 2% after air;
P
<0.001). In contrast, diesel exhaust exposure reduced vasodilatation to isolated BQ-123 infusion (20% versus 59% after air;
P
<0.001) but had no effect on vasodilatation to combined BQ-123 and BQ-788 administration (
P
>0.05). Diesel exhaust inhalation increases vascular sensitivity to ET-1 and reduces vasodilatation to ET
A
receptor antagonism despite unchanged plasma ET-1 concentrations. Given the tonic interaction between the ET and NO systems, we conclude that diesel exhaust inhalation alters vascular reactivity to ET-1 probably through its effects on NO bioavailability.
The Private Regulation of Global Corporate Conduct
Authors: Vogel David
Published: August 2009

The article assesses the achievements and limitations of the private regulation of global corporate conduct. Private regulation occurs through voluntary, private, nonstate industry and cross-industry codes that address labor practices, environmental performance, and human rights policies. The author argues that while private regulation has resulted in some substantive improvements in corporate behavior, it cannot be regarded as a substitute for the more effective exercise of state authority at both the national and international levels. Ultimately, private regulation must be integrated with and reinforced by more effective state-based and enforced regulatory policies at both the national and international levels.
Improving Extreme-Scale Problem Solving: Assessing Electronic Brainstorming Effectiveness in an Industrial Setting
Authors: Dornburg Courtney C. , Stevens Susan M. , Hendrickson Stacey M. L. , Davidson George S.
Published: August 2009

Objective: An experiment was conducted to compare the effectiveness of individual versus group electronic brainstorming to address difficult, real-world challenges. Background: Although industrial reliance on electronic communications has become ubiquitous, empirical and theoretical understanding of the bounds of its effectiveness have been limited. Previous research using short-term laboratory experiments have engaged small groups of students in answering questions irrelevant to an industrial setting. The present experiment extends current findings beyond the laboratory to larger groups of real-world employees addressing organization-relevant challenges during the course of 4 days. Methods: Employees and contractors at a national laboratory participated, either in a group setting or individually, in an electronic brainstorm to pose solutions to a real-world problem. Results: The data demonstrate that (for this design) individuals perform at least as well as groups in producing quantity of electronic ideas, regardless of brainstorming duration. However, when judged with respect to quality along three dimensions (originality, feasibility, and effectiveness), the individuals significantly ( p < .05) outperformed the group. Conclusion: When quality is used to benchmark success, these data indicate that work-relevant challenges are better solved by aggregating electronic individual responses rather than by electronically convening a group. Application: This research suggests that industrial reliance on electronic problem-solving groups should be tempered, and large nominal groups may be more appropriate corporate problem-solving vehicles.
Dispersion of Nano CaCO3 on PVC and its Influence on Mechanical and Thermal Properties
Authors: Shimpi N.G. , Verma J. , Mishra S.
Published: August 2009

PVC/nano CaCO3 composites were prepared on Brabender Plasticorder. For comparison purposes, commercial CaCO3 composites were also prepared. Characterization of the nano CaCO3 and nanocomposites were done using scanning electron microscope (SEM) and transmission electron microscope (TEM). Their mechanical and thermal properties were also studied. Exfoliation was observed with the addition of different sizes of nano CaCO 3 filled in PVC composites. Best properties were observed with 9 nm CaCO3 PVC composites. Tensile strength and modulus improved significantly even though the amount of addition of nano filler is low. Thermal properties of PVC/nanocomposites were found to be better compared to that of commercial filled CaCO3 in PVC composites.
Failure Load Prediction by Damage Zone Method for Single-lap Bonded Joints of Carbon Composite and Aluminum
Authors: Nguyen Khanh-Hung , Kweon Jin-Hwe , Choi Jin-Ho
Published: August 2009

A damage zone method based on 3D finite element analysis was proposed to predict the failure loads of single-lap bonded joints with dissimilar composite-aluminum materials. To simulate delamination failure, interply resin layers between any two adjacent orthotropic laminas of composite adherend were assumed with a thickness of one-tenth of a composite lamina. Geometrically nonlinear effects due to the large rotation of the single-lap joint were included in the analysis. Analysis also considered the material nonlinearity of the aluminum adherend due to the stress exceeding yield level. Based on the experimental observation that the failure modes of the specimens were dominated by delamination and debonding, the Ye-criterion was applied to account for the out-of-plane failure of composite adherend and the Von Mises strain criterion was applied for the adhesive layer. The failure indices were multiplied to the predicted damage zone as a weight factor and the calculated damage zones were divided by an area or volume considering the joint geometry. Predicted failure loads show deviation within 18% from experimental results for nine different bonding lengths or adherend thicknesses.
Influence of Hyperbranched Polyamine-ester Modified Carbon Nanotubes on Properties of Epoxy Nanocomposites
Authors: Zheng Ya-Ping , Zhang Jiao-Xia , Yu Pei-Ying , Liu Li-Li , Gao Yuan
Published: August 2009

Surface modification of the acidified multi-walled carbon nanotubes (MWNTs) was conducted by hyperbranched polyamine-ester (HBP). The sample was characterized with the Raman spectra, X-ray diffraction, and transmission electron microscopy. Nanocomposites with MWNTs/epoxy matrix were prepared by compounding the modified MWNTs and epoxy resin. As a result, the MWNTs-capped organic molecules formed core/shell structure. The grafted organic molecules solve the dispersion of the MWNTs in the epoxy resin-based nanocomposites and then enhancing the antifriction and dielectric property of such nanocomposites.
Synthesis and Swelling Properties of Guar Gum-g-poly(sodium acrylate)/ Na-montmorillonite Superabsorbent Nanocomposite
Authors: Wang Wenbo , Wang Aiqin
Published: August 2009

Novel guar gum-g-poly(sodium acrylate)/Na-montmorillonite (GG-g-PNaA/MMT) superabsorbent nanocomposites were synthesized by grafted copolymerization among natural guar gum (GG), partially neutralized acrylic acid (NaA) and Na-montmorillonite (MMT) in the aqueous solution using ammonium persulfate as initiator and N,N′-methylenebisacrylamide (MBA) as crosslinker. Fourier transform infrared spectroscopy confirmed that NaA had been grafted onto GG and the -OH groups of MMT participated in the reaction. X-ray diffraction and scanning electron microscopy analyses revealed that MMT was exfoliated and equably dispersed in GG-g-PNaA matrix. The effects of MMT and MBA on water absorbency were investigated. The results show that introducing MMT into the GG-g-PNaA network improved the swelling capability and the swelling rate of the superabsorbent nanocomposite. The nanocomposites keep water absorbency high, within a wide pH range from 4 to 11 and exhibit better reswelling capability.
Analysis of In-plane and Out-of-plane Thermo-mechanical Stresses in Un-symmetric Cross-ply Curved Laminated Strips
Authors: Vargas G. , Arrese A. , Carbajal N. , Mujika F.
Published: August 2009

A new approach for determining in-plane and out-of-plane stresses due to thermal and mechanical loading, in un-symmetric [0n/90 m] cross-ply curved laminated strips is presented in this work. This approach can also be applicable to bi-modulus curved laminated strips. Predictions of curvatures, displacements, and stresses based on the superposition principle are carried out. In-plane stresses are calculated considering classical beam theory. In addition, out-of-plane stresses are predicted by using the Airy’s stress function in polar coordinates. The new approach satisfies the continuity conditions at the interface between 0° and 90° layers. Results show that in-plane and out-of-plane stresses are particularly sensitive to the thickness ratio and to geometric conditions. Finally, thermo-mechanical predictions have revealed that out-of-plane stresses are much lesser than in-plane stresses for initially flat laminates. For laminates with high imposed curvatures out-of-plane stresses are high, leading to delamination failure.
Development of Low Moisture Absorbing SMC
Authors: Kia Hamid G.
Published: August 2009

In this work, the role of SMC constituent components in controlling the moisture absorption of the final molded panels is discussed. A variety of polyester resins, low profile additives, and fillers were exposed to high humidity, defined as 90% relative humidity at 40°C, for extended hours. It was concluded that calcium carbonate, which is the most common filler for SMC, at a 0.12 wt% moisture absorption level, is the second lowest in moisture absorption. The comparison of the calculated and measured moisture absorption numbers indicated that rule of mixtures can be used to accurately predict the behavior of SMC based on the polymeric matrix. However, the polymeric matrix moisture uptake has to be measured experimentally and cannot be predicted using the mixing rule for its constituent ingredients due to the complexity of the interactions in the mixture. It was also identified that MgO, which is the most commonly used thickening agent, has a significant impact on moisture uptake of SMC. Based on the generated information, two low moisture absorbing SMC formulations were developed and their properties were measured.
Democracy, Foreign Policy, and Terrorism
Authors: Savun Burcu , Phillips Brian J.
Published: August 2009

This article takes a closer look at the relationship between democracy and transnational terrorism. It investigates what it is about democracies that make them particularly vulnerable to terrorism from abroad. The authors suggest that states that exhibit a certain type of foreign policy behavior, regardless of their regime type, are likely to attract transnational terrorism. States that are actively involved in international politics are likely to create resentment abroad and hence more likely to be the target of transnational terrorism than are states that pursue a more isolationist foreign policy. Democratic states are more likely to be targeted by transnational terrorist groups not because of their regime type per se but because of the type of foreign policy they tend to pursue. The empirical analysis provides support for the argument.
Item Parameter Estimation for the MIRT Model
Authors: Finch Holmes
Published: August 2009

The accuracy of item parameter estimates in the multidimensional item response theory (MIRT) model context is one that has not been researched in great detail. This study examines the ability of two confirmatory factor analysis models specifically for dichotomous data to properly estimate item parameters using common formulae for converting factor loadings and thresholds to discrimination and difficulty indices. The two MIRT estimation methods included in this research, unweighted least squares (ULS) and robust weighted least squares (RWLS), and the unidimensional estimation approach used are accessible in the widely distributed software packages NOHARM, Mplus, and BILOGMG, respectively. These techniques have been assessed in terms of the overall accuracy, bias, and standard error of item parameter estimates under a variety of sample sizes, test lengths, intertrait correlations, pseudo-guessing, and latent trait distribution conditions. Results indicate that there exists a complex relationship between these manipulated factors and the estimation accuracy of these methods. Recommendations for practice in light of these results are provided.
In the Eye of the Beholder
Authors: Camparo James , Camparo Lorinda B. , Wagner Judith T.
Published: August 2009

Peer nominations are used widely in psychological and sociological research to examine intergroup dynamics, even though this assessment tool suffers from thorny methodological problems: Gender, ethnic, age, and trait compositions vary across subsamples, subjects differ in the number of nominations they make, and the issue of sampling without replacement is often ignored. To overcome these problems, the authors have developed a differential index for the peer nominations procedure, with the number of individuals chosen above or below chance as the unit of measure. The index is specifically designed for use with individuals (as opposed to subgroups like classrooms), so that group means, confidence intervals, and standard deviations are readily determined, opening the door to research designs that go beyond null hypothesis testing. Here, we introduce the index and illustrate its unique capabilities in a study examining preference and bias reciprocity among fourth-grade students.
Blackness beyond witness
Authors: Havis Devonya N.
Published: August 2009

The article posits that philosophy’s visual bias has limited exploration of the ways in which sound, and the awareness of sound, offers an alternative framework for social change. It moves from sight to sound and from visual witnessing to sound-based wit(h)ness to illustrate the implications of sound as a form of political resistance. Combining insights from the work of Michel Foucault and Emmanuel Levinas with elements of the Black Vernacular tradition, it articulates the ways in which the blues, jazz and work songs evoke distinctive sound-based wit(h)ness to perform philosophical interventions by destabilizing the status quo, offering a nonphenotypical account of black solidarity, and transforming what counts as work.
Locke and toleration
Authors: Tate John William
Published: August 2009

This article challenges the claim that John Locke’s arguments for toleration are fundamentally at odds with any we might now associate with the liberal tradition. By showing how this perspective fundamentally misreads Locke on toleration, it seeks to defend Locke’s own status as one of the founding fathers of the liberal tradition.
Multitude against Empire
Authors: McDaniel Ian K.
Published: August 2009

In the final section of their work Empire, Hardt and Negri discuss the coming into being of the multitude, the unified force that overthrows the system of ‘Empire’. Absent from the account of this unification of the multitude is the influence of religion. I endeavor to show that contrary to Hardt’s and Negri’s assumption, religion is not dissipating among the multitude and that its impact will be contrary to the creation of a unified multitude. Thus the creation of the unified multitude requires an absence of religion, but the creation of the multitude under the system of Empire entails a creation of more theists, leading to a seeming contradiction in the process of creating a unified multitude. In order for the creation of the multitude envisioned by Hardt and Negri to be complete, the issue of religion must be addressed, it cannot simply be assumed away as unimportant or non-existent.
Rawls and Kant on the public use of reason
Authors: Koukouzelis Kostas
Published: August 2009

The article addresses the debate that has arisen in the wake of John Rawls’ political theory, in particular his concept of the ‘use of public reason’. Such a concept is crucial because it involves all his fundamental presuppositions about reason, publicity, legitimacy and the liberal subject that sustain his theory of justice. In this article we will mainly doubt Rawls’ Kantian origins in favour of Kant’s own thinking about reason and publicity. Initially then, we will critically present an account of Rawls’ conception of (public) reason, and then turn to Kant in order to argue for a non-constructivist reading. This will be based on the importance of reason’s non-empirical need [ Bedürfnis ], instead of Rawls’ empirical conception of it. Such a thing would constitute the basis for Kant’s non-instrumental conception of publicity as an a priori condition of our freedom, which would also have room for a positive role for dissent rather than mere consent (built into Rawls’ principle of liberal legitimacy). According to Kant, there is a juridical right based on reason’s need. In the end, it is concluded that the two thinkers have differing views on both the nature of human reason, and the nature of publicity at the basis of modern societies, a fact that might also be the beginning for the strengthening of Kant’s modern republicanism rather than liberalism.
Femoral Tunnel Placement During Anterior Cruciate Ligament Reconstruction
Authors: Abebe Ermias S. , Moorman C. T. , Dziedzic T. Scott , Spritzer Charles E. , Cothran R. Lee , Taylor Dean C. , Garrett William E. , DeFrate Louis E.
Published: August 2009

Background

Recent studies have questioned the ability of the transtibial technique to place the anterior cruciate ligament graft within the footprint of the anterior cruciate ligament on the femur. There are limited data directly comparing the abilities of transtibial and tibial tunnel—independent techniques to place the graft anatomically at the femoral attachment site of the anterior cruciate ligament in patients.

Hypothesis

Because placement with the tibial tunnel–independent technique is unconstrained by the tibial tunnel, it would allow for more anatomic tunnel placement compared with the transtibial technique.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

High-resolution, multiplanar magnetic resonance imaging and advanced 3-dimensional modeling techniques were used to measure in vivo femoral tunnel placement in 8 patients with the transtibial technique and 8 patients with a tibial tunnel–independent technique. Femoral tunnel placement in 3 dimensions was measured relative to the center of the native anterior cruciate ligament attachment on the intact contralateral knee.

Results

The tibial tunnel–independent technique placed the graft closer to the center of the native anterior cruciate ligament attachment compared with the transtibial technique. The transtibial technique placed the tunnel center an average of 9 mm from the center of the anterior cruciate ligament attachment, compared with 3 mm for the tibial tunnel–independent technique. The transtibial technique resulted in a more anterior and superior placement of the tunnel compared with the tibial tunnel– independent technique.

Conclusion

The tibial tunnel–independent technique allowed for more anatomic femoral tunnel placement compared with the transtibial technique.
Radiologic Evaluation of the Insertion Sites of the 2 Functional Bundles of the Anterior Cruciate Ligament Using 3-dimensional Computed Tomography
Authors: Lorenz Stephan , Elser Florian , Mitterer Martin , Obst Tobias , Imhoff Andreas B.
Published: August 2009

Background

Anterior cruciate ligament reconstruction with a double-bundle technique requires exact tunnel positioning. Reference values for the anatomic insertions are necessary for radiographic intra- and postoperative control and fluoroscopy-based navigation.

Hypothesis

The femoral and tibial insertions of the anteromedial bundle (AMB) and posterolateral bundle (PLB) of the anterior cruciate ligament can be described using standardized computed tomography scans.

Study Design

Descriptive laboratory study.

Methods

The insertion sites of the AMB and PLB were macroscopically identified and tagged by copper wire in 12 specimens. Computed tomography scans with predefined reconstructions were performed. Femorally, the geometric center of the insertions were determined in the sagittal view and described in a deep-high 10 × 10 grid. Tibially, the insertions were described as the ratio between the geometric center of the insertion sites with respect to the mediolateral and sagittal diameter of the tibia in frontal and sagittal reconstruction, respectively. The tibial insertions were described using a 10 × 10 grid in axial orientation.

Results

The geometric midpoints of the insertion areas at the femur of the AMB and PLB were located on the reticule at x = 21% ± 3% and y = 22% ± 2% for the AMB and x = 27% ± 3% and y = 45% ± 3% for the PLB. In the sagittal plane, the center of the tibial insertion was located at 41% ± 3% and 52% ± 3% of the tibial diameter from the anterior border for the AMB and PLB, respectively. The geometric centers of the tibial insertions in axial view were x = 52% ± 2% and y = 37% ± 3% for the AMB and x = 50% ± 2% and y = 48% ± 3% for the PLB.

Conclusion

The insertion site characteristics of the AMB and PLB can be evaluated by predefined reconstructions of computed tomography scans.

Clinical relevance

These results can serve as orientation landmarks for intra- and postoperative radiographic control and fluoroscopic-based navigation.