bluuebunny/crossref_metadata_2025 huggingface dataset:
Amphiphilic Poly(N‐propargylamide) with Galactose and Lauryloyl Groups: Synthesis and Properties
Authors: Suenaga Masakazu , Kaneko Yoshiro , Kadokawa Jun‐ichi , Nishikawa Takehiro , Mori Hidezo , Tabata Masayoshi
Published: November 2006

Summary: An amphiphilic poly(N‐propargylamide) with galactose and lauryloyl groups was synthesized by copolymerization of the corresponding N‐propargylamide monomers using a Rh catalyst. The obtained copolymer formed a one‐handed helical conformation and molecular aggregates in water. The observations by fluorescence microscopy in a cell culture experiment in the presence of dye‐labeled copolymer indicated that the copolymer was incorporated into the cells.

Localization of rhodamine B‐labeled copolymer 8 in human aortic endothelial cells (fluorescence image).

magnified image

Localization of rhodamine B‐labeled copolymer 8 in human aortic endothelial cells (fluorescence image).
Asymptotic behaviour of global classical solutions of diagonalizable quasilinear hyperbolic systems
Authors: Liu Jianli , Zhou Yi
Published: November 2006

This paper is concerned with the asymptotic behaviour of global classical solutions of diagonalizable quasilinear hyperbolic systems with linearly degenerate characteristic fields. Based on the existence results of global classical solutions, we prove that when t tends to infinity, the solution approaches a combination of C1 travelling wave solutions, provided that L1 ∩ L∞ norm of the initial data as well as its derivative are bounded. Application is given for the time‐like extremal surface in Minkowski space. Copyright © 2006 John Wiley & Sons, Ltd.
Right wing authoritarianism, social dominance orientation and the dimensions of generalized prejudice
Authors: Duckitt John , Sibley Chris G.
Published: November 2006

Prior research suggests that individuals' prejudiced attitudes form a single generalized dimension predicted by Right Wing Authoritarianism (RWA) and Social Dominance Orientation (SDO). A dual process approach, however, expects different domains of generalized prejudice that relate differentially to RWA and SDO. To test this, 212 participants rated attitudes to 24 typically disliked groups. Factor analysis revealed three distinct generalized prejudice dimensions. Hierarchical Linear Modelling indicated that attitudes towards a ‘dangerous’ groups domain was significantly related only with RWA, attitudes toward a second ‘derogated’ groups domain was related only to SDO, and attitudes toward a third, ‘dissident’ groups, domain was significantly related to both, but powerfully with RWA and weakly with SDO. These findings have implications for explaining and reducing prejudice. Copyright © 2006 John Wiley & Sons, Ltd.
A review of the biological and potential therapeutic actions of Harpagophytum procumbens
Authors: Grant L. , McBean D. E. , Fyfe L. , Warnock A. M.
Published: November 2006

Harpagophytum procumbens (Hp), commonly known as Devil's Claw is a perennial plant which thrives in arid conditions. For centuries, it has been used as a traditional treatment for a variety of illnesses, including fevers, skin complaints, arthritis and diseases of the digestive tract as well as an appetite stimulant. Since its introduction to Europe in the early twentieth century, it has become a popular antiinflammatory and analgesic preparation amongst herbalists for supportive or adjuvant treatment of degenerative joint diseases, tendonitis, headache, backache and menstrual pain. The validity of Hp as an effective antiinflammatory and analgesic preparation, particularly in the relief of arthritic symptoms, has been investigated in numerous animal, clinical and in vitro studies. Although some contradictory evidence exists, the majority of animal studies appear to indicate Hp as an effective antiinflammatory and analgesic preparation in the treatment of acute and subacute inflammation. Clinical trials support Hp as a beneficial treatment for the alleviation of pain and improvement of mobility in a variety of musculoskeletal conditions. Analysis of the in vitro and ex vivo studies that currently exist, indicate that Hp has significant effects on numerous proinflammatory markers. However, the exact mechanism(s) by which Hp may reduce inflammation remain to be elucidated. Copyright © 2006 John Wiley & Sons, Ltd.
Pterocarpus santalinus: an In Vitro study on its anti‐Helicobacter pylori effect
Authors: Narayan Shoba , Veeraraghavan Mani , Devi C. S. Shyamala
Published: November 2006

The anti‐H. pylori activity of Pterocarpus santalinus (PS), a traditional herb, has been assessed and compared with that of bismuth subcitrate, through in vitro studies employing rat gastric epithelial cell cultures and H. pylori isolates from gastric mucosal biopsy patients. The MIC of PS was found to be 20 µg/mL. H. pylori was co‐cultivated with rat gastric epithelial cells in the presence/absence of PS at its MIC. A reduction in the activity of urease, a normal appearance of the epithelial cells on electron microscopic examination, a decrease in lipid peroxidation and lactate dehydrogenase suggests the possible anti‐H. pylori activity of PS. Copyright © 2006 John Wiley & Sons, Ltd.
In Silico Classification of Solubility using Binary k‐Nearest Neighbor and Physicochemical Descriptors
Authors: Fredsted Berith , Brockhoff Per B. , Vind Christian , Padkjær Søren B. , Refsgaard Hanne HF.
Published: November 2006

Solubility is a key property that highly affects both the absorption and screening efficiency of drug candidates. Here, we present an in silico k‐nearest neighbor model applying ten physicochemical descriptors which classify solubility based on a diverse set of chemical drug candidates. Data used for modeling the solubility consisted of turbidimetric solubility values at pH 7.4 for 518 drug candidates. Data were divided into a training set and a test set of 389 and 129 compounds, respectively, which additionally were binned into two classes with respect to the solubility: insoluble class: solubility ≤0.02 mg/mL and soluble class: solubility >0.02 mg/mL. Furthermore, a structural fragment analysis of soluble versus insoluble compounds was performed, and structural fragments and functional groups for which we found statistical difference in frequency between the two solubility classes were presented. Of the ten descriptors used for modeling, clog D was found to be the descriptor that separated the two solubility classes most efficiently. When the test set was classified, 84% were predicted to the right class. Validated with 12 soluble marketed drugs, the model predicted 11 of the 12 compounds to the right class. We found that the solubility model could be used to flag molecules with low solubility in an early stage of discovery projects.
What Works and What Does Not: Lessons From Experience in a Pharmaceutical Company
Authors: Martin Yvonne Connolly
Published: November 2006

Computational chemists make two types of contributions in drug research. The traditional contribution is to develop models that predict molecular properties and so provide experimentalists with information that helps them rule out certain compounds before detailed investigation – for example, the investigation can be following up a high‐throughput screening hit or synthesizing a new molecule. Our experience suggests that such models are useful, but a corollary utility is the addition of alternative perspective of a computational chemist to the usual composition of a discovery team. This alternative perspective can lead the team to novel discoveries, independent of quantitative models. Although we, computational chemists, show the inadequacy of global models to predict octanol–water log P, pKa, permeability, and bioavailability, scientists continue to use these models. Apparently, they are accurate enough for practical purposes. Computational chemists make a second type of contribution when they devise expert systems that encode knowledge into a computer system. An example of the latter is our development of red and yellow structure alerts that suggest that a compound might be reactive or unstable (red alert) or contain unattractive functional groups (yellow alert). These expert systems are not derived from traditional quantitative modeling techniques, nor can they be. Nonetheless, our experience had been that scientists make heavy use of such computer programs and take a responsibility for suggesting improvements in the rules. Experience suggests that computational chemists make the largest impact when they focus on solving the specific problems faced by their experimentalist colleagues .
MAC and encapsulation efficiency of satellite DVB using fade mitigation techniques
Authors: Lücke Oliver , Jahn Axel , Werner Markus
Published: November 2006

The paper discusses cross‐layer issues of DVB‐S2 networks with adaptive coding and modulation (ACM) on the physical layer forward link. Also future return channel via satellite (RCS) systems employing adaptive schemes on the return link are analysed. Cross‐layer issues focus on medium access control (MAC) and encapsulation layer effects. Recent work of the S2 encapsulation over generic streams (GS) is described, and the effects on quality of service (QoS) scheduling for the forward link are analysed by means of simulation. A performance comparison between DVB‐S and S2, both for transport streams (TS) and GS shows a significant gain by new encapsulation and fragmentation protocols that allow fragmentation across BBFrames. Here, realistic traffic scenarios with a mix of several services as well as rain fading are taken into account. For the return link, an adaptive scheme is discussed, going beyond the current RCS standard. Several approaches for access burst structures are presented and their impact on link efficiency through padding and encapsulation overhead is simulated. Finally, burst segmentation impact on jitter is investigated. Copyright © 2006 John Wiley & Sons, Ltd.
Cross‐layer enhancement of error control techniques for adaptation layers of DVB satellites
Authors: Cantillo Juan , Lacan Jérôme , Buret Isabelle
Published: November 2006

This paper assesses the way error control is managed jointly by Forward Error Codes (FEC) and Cyclic Redundancy Checks (CRC) in the lower layers of today's Digital Video Broadcasting (DVB) satellites. Mathematical and simulation results clearly show that the outer block codes of the coding schemes used in DVB‐S and DVB‐S2 (Reed–Solomon and Bose–Chaudhuri–Hocquenghem, respectively) can provide very accurate error‐detection information to the receiver in addition to their basic correction task at virtually no cost, making an uncorrected error after decoding an extremely improbable event. For this reason, the workload of CRCs can be ensured safely by the FEC subsystem if a dedicated function allowing the physical layer to share its decoding information with the adaptation layer is set. This particular cross‐layer mechanism would allow freeing up the bandwidth currently used by CRCs—which adds up to 10% for more than 35% of the total number of IP packets—and pave the way for an enhanced transport of IP over DVB‐S2. Copyright © 2006 John Wiley & Sons, Ltd.
Impact of Etiologic Factors and APACHE II and POSSUM Scores in Management and Clinical Outcome of Acute Intestinal Ischemic Disorders after Surgical Treatment
Authors: Hsu Hui‐Ping , Shan Yan‐Shen , Hsieh Yu‐Hsiang , Sy Edgar D. , Lin Pin‐Wen
Published: November 2006

Background

Acute intestinal ischemic disorder (AIID) is an uncommon vascular disease with high mortality. According to etiology, it can be categorized into three groups: arterial occlusive mesenteric ischemia (AOMI), mesenteric venous thrombosis (MVT), and nonocclusive mesenteric ischemia (NOMI). This study analyzes the effect of classification on surgical outcome.

Patients and Methods

All AIID patients who underwent operative treatment at National Cheng Kung University Hospital between January 1989 and August 2003 were enrolled in this study. Preoperative information on these patients was compared to find predictors of outcome.

Results

Data from 77 patients (49 men and 28 women, median age 70 years) were analyzed. The etiology was AOMI in 30 patients, MVT in 19 patients, and NOMI in 28 patients. Median age was younger in MVT (54 years) than in AOMI (70 years) or NOMI (72 years). In addition, MVT usually involved the jejunum (74%, versus 31% in AOMI and 46% in NOMI), whereas both AOMI and NOMI involved ileum and colon. The patients with AOMI had shorter duration of symptoms and higher ratio of underlying hypertension than those with MVT. The overall mortality rate was 53.2% (41/77). The day 1 and day 30 mortality were 0% and 10.5% in MVT, 16.7% and 30% in AOMI, and 42.9% and 67.9% in NOMI, respectively (P < 0.05). Both the etiology and the APACHE II scores were significant risk factors for day 30 and long‐term mortality. The patients with NOMI had higher POSSUM physiologic scores than patients with MVT. The P‐POSSUM regression equation can accurately predict mortality.

Conclusions

Patients with MVT had a more favorable prognosis, whereas those with NOMI had the worst outlook. The APACHE II and POSSUM scoring systems are useful in predicting the clinical outcome. Early diagnosis and classification of AIID patients are useful for aggressive treatment to improve the clinical outcome.
A Review of Mucinous Cystic Neoplasms of the Pancreas Defined by Ovarian‐type Stroma: Clinicopathological Features of 344 Patients
Authors: Goh Brian K. P. , Tan Yu‐Meng , Chung Yaw‐Fui A. , Chow Pierce K. H. , Cheow Peng‐Chung , Wong Wai‐Keong , Ooi London L. P. J.
Published: November 2006

Introduction

Despite formal definitions of mucinous cystic neoplasms (MCNs) and intraductal papillary neoplasms (IPMNs) by the World Health Organization (WHO) and Armed Forces Institute of Pathology (AFIP), several controversies with regard to MCNs remain. The aim of this review was to determine the clinicopathological features of MCNs defined by ovarian‐type stroma (OS) as proposed by the WHO and AFIP and to compare them with MCNs defined by less stringent criteria.

Methods

A MEDLINE search was conducted to identify English‐language articles on pancreatic MCNs from 1996 to 2005. Twenty‐five studies were identified. The studies were divided into 2 groups: group A included 10 studies with 344 patients whereby the presence of OS was a criteria for the diagnosis of MCNs, and group B, included 15 studies comprising 761 patients whereby the presence of OS was not mandatory for the diagnosis of MCNs.

Results

Patients in group A (MCNs as defined by OS) were almost always female (99.7%), with a mean age of 47 (range, 18–95) years. MCNs were located predominantly in the body or tail of the pancreas (94.6%) and had a mean size of 8.7 cm (range, 0.6–35 cm); 76% were symptomatic, 6.8% demonstrated ductal communication, and 27% were malignant. At a mean follow‐up of 57.5 (range, 1–264) months and 43 (range, 2–257) months after surgery, 97.9% of benign and 61.9% of malignant neoplasms were disease free, respectively. Patients in group B were older and had a higher proportion of males. Neoplasms were more evenly distributed in the pancreas, were smaller, communicated more frequently with the pancreatic duct, and were composed of a higher proportion of malignant tumors compared with group A. Their clinicopathological features were intermediate between those of group A and patients with IPMN.

Conclusion

Pancreatic MCNs with OS have unique and distinct clinicopathological features. MCNs should be defined by the presence of OS, as it is the most reliable way of distinguishing MCNs from IPMN. Adoption of “looser” criteria will result in misclassification of some IPMNs as MCNs.
Hyperhomocysteinemia and thrombosis
Authors: Cattaneo Marco
Published: November 2006

Homocysteine (Hcy) is a sulfhydryl amino acid derived from the metabolic conversion of methionine, which is dependent on vitamins (folic acid, B12, and B6) as cofactors or cosubstrates. In 1969, McCully first reported the presence of severe atherosclerotic lesions in patients with severe hyperhomocysteinemia and hypothesized the existence of a pathogenic link between hyperhomocysteinemia and atherogenesis. Several case‐control and cross‐sectional studies were consistent with the initial hypothesis of McCully, showing that moderate hyperhomocysteinemia is also associated with heightened risk of occlusive arterial disease. Less consistent results have been reported by prospective cohort studies of subjects who were healthy at the time of their enrollment, whereas prospective cohort studies of patients with overt coronary artery disease or other conditions at risk consistently confirmed the association between moderate hyperhomocysteinemia and cardiovascular morbidity and mortality. More recently, an association between moderate hyperhomocysteinemia and heightened risk of venous thromboembolism has been documented, suggesting that hyperhomocysteinemia might be involved not only in atherogenesis, but also in thrombogenesis. The mechanisms by which hyperhomocysteinemia might contribute to atherogenesis and thrombogenesis are incompletely understood. The mainstay of treatment of hyperhomocysteinemia is folic acid, alone or in combination with vitamin B12 and vitamin B6. Although it is quite clear that vitamins effectively reduce the plasma levels of total homocysteine (tHcy), we do not yet know whether they will decrease the risk of vascular disease. The results of ongoing randomized, placebo‐controlled, double‐blind trials of the effects of vitamins on the thrombotic risk will help ir, defining whether the relationship between hyperhomocysteinemia and thrombosis is causal, and will potentially have a dramatic effect in the prevention of thromboembolic events.
The Hordaland Homocysteine Studies
Authors: Ueland Per Magne , Nygård Ottar , Vollset Stein Emil , Refsum Helga
Published: November 2006

The Hordaland Homocysteine Study is a population‐based screening of total plasma homocysteine (tHcy) in ∼18,000 men and women aged 40–67 yr that took place in 1992–1993 in the county of Hordaland in Western Norway. In this cohort, tHcy was associated with several physiologic and life‐style factors, including age and gender, blood pressure, serum cholesterol, smoking, alcohol and coffe consumption, physical activity, diet, and vitamin status. All associations with established cardiovascular risk factors were in the direction expected to confer increased risk. In a subset of 5,883 women aged 40–42 yr, tHcy was associated with previous pregnancy outcomes, including preeclampsia, placental abruption, and neural tube defects. This article reviews the published results from the Hordaland Homocysteine Study in the light of relevant literature. The Hordaland Homocysteine cohort will be used for future investigations of the stability of tHcy and vitamin status over time, and to investigate associations with mortality and morbidity including cancer incidence.
Marine n‐3 fatty acids: Basic features and background
Authors: Schmidt Erik Berg , Christensen Jeppe Hagstrup , Aardestrup Inge , Madsen Trine , Riahi Sam , Hansen Vibeke Ellegaard , Skou Helle Aarup
Published: November 2006

There is some evidence from epidemiology that intake of n‐3 polyunsaturated fatty acids (PUFA) from seafood may protect against coronary artery disease (CAD). This hypothesis is further supported from animal data showing a beneficial effect of n‐3 PUFA on thrombosis and atherosclerosis in animals fed fish oils in most, but not all, studies. There are several mechanisms by which an increased intake of marine n‐3 PUFA may protect against CAD; the most universal finding is a reduction of plasma triglycerides. It is puzzling, however, that a very low amount of n‐3 PUFA, with no known beneficial biochemical effects, seems to be cardioprotective. It has therefore been of paramount interest to perform clinical trials. Such evidence and trials are discussed in later chapters, and the results have been very encouraging.
n−3 polyunsaturated fatty acids and coronary thrombosis
Authors: Kristensen S. D. , Bach Iversen A. M. , Schmidt E. B.
Published: November 2006

Studies of Greenland Eskimos showed that a very high intake of marine n−3 fatty acids markedly inhibited platelet reactivity and suggested that intake of these fatty acids might prevent coronary thrombosis. Later studies with lower, more practical doses of n−3 fatty acids also have shown a platelet inhibitory effect of n−3 fatty acids, albeit fairly marginal. Furthermore, n−3 fatty acids have little effect on measures of blood coagulability and may slightly decrease fibrinolysis. In animal models, n−3 fatty acids often have been shown to inhibit thrombosis, but again the doses have tended to be very high. Finally, there has been little effect of (low‐dose) n−3 fatty acids in clinical trials in humans on the incidence of myocardial infarction. Overall, there is little evidence for a major antithrombotic effect of practical doses of n−3 fatty acids on coronary thrombosis. This does not exclude a beneficial effect of n−3 fatty acids on coronary heart disease as suggested from clinical trials, but the major effect may be antiarrhythmic rather than antithrombotic.
n−3 fatty acids and revascularization procedures
Authors: Arnesen Harald
Published: November 2006

Largely initiated by studies among Greenland Eskimos in the early 1970s, great attention has been given to the possible effects of the very long chain n−3 polyunsaturated fatty acids (PUFA) in a variety of cardiovascular disease states. A series of possibly positive effects on pathogenetic mechanisms in cardiovascular disease has evolved from laboratory studies in cell cultures and animals as well as in humans, focusing mainly on eicosanoid metabolism with reduced activities of platelets and leucocytes, reduced plasma triglycerides and, antiarrhythmic effects in the myocardium. A rationale for a positive effect of very long chain n−3 PUFA in the secondary prophylaxis after revascularization procedures obviously also exists. The positive clinical effects based on prospectively randomized trials are summarized as follows. After coronary artery bypass grafting (CABG), the SHOT study showed statistically significant reduction in angiographic vein graft occlusion in 610 patients after 1 yr with supplementation of 3.4 g/d of highly concentrated very long chain n−3 PUFA. The reduction in occlusion rates was significantly related to the change in the n−3 PUFA concentration in serum phospholipids during the study period with the occlusion rate in the upper quartile of such changes at only ∼50% of that in the lower quartile. These results were also clearly related to the presence of angina pectoris and occurrence of myocardial infarction after 1 yr. Several studies were conducted in patients after percutaneous transluminal coronary angioplasty (PTCA). By 1993, two meta‐analyses indicated a positive effect on the restenosis rate, a significant problem after otherwise successful PTCA. During the late 1990s, three large prospective randomized placebo‐controlled angiographic studies were conducted with very long n−3 PUFA 5.1–8.0 g/d, all with completely negative results. Today, therefore, very long chain n−3 PUFA supplementation cannot be recommended to reduce the incidence of restenosis after PTCA. All studies were performed without stenting of the coronary lesion. In the very special revascularization procedure of heart transplantation, evolving hypertension and accelerated atherosclerosis have been major clinical problems. In other studies, positive effects by supplementation with very long chain n−3 PUFA (3.4–5.7 g/d) were obtained on the surrogate end points coronary vasoreactivity to acetylcholine and hypertension, respectively. On the basis of the presently available literature from clinical studies, recommendations for supplementation with very long chain n−3 PUFA can be given to patients after venous CABG (up to 3.4 g/d), and after heart transplantation (3.4–5.7 g/d) but not to patients after traditional PTCA. In fact, data from substudies suggested the possibility that large doses (5.1 g/d) of very long chain n−3 PUFA might be contraindicated because they induce a proinflammatory state in patients under oxidative stress.
n−3 fatty acids, heart rate variability, and sudden cardiac death
Authors: Christensen Jeppe Hagstrup , Schmidt Erik Berg
Published: November 2006

Sudden cardiac death (SCD) is a major cause of mortality in Western countries. Furthermore, SCD is often the first manifestation of coronary artery disease, making it difficult to prevent. Heart rate variability (HRV), which can be determined by extended recording of the heart rate by 24‐h Holter monitoring, has been shown to be one of the best predictors of the risk of SCD. There is increasing evidence from animal experiments and clinical trials in humans that n−3 fatty acids reduce the risk of SCD. We have studied the effect of n−3 fatty acids on HRV and present data clearly showing that n−3 fatty acids increase HRV. This adds further to the hypothesis that an increased intake of n−3 fatty acids may reduce the risk of SCD.
Effects of carp and tuna oils on 5‐fluorouracil‐induced antitumor activity and side effects in sarcoma 180‐bearing mice
Authors: Kimura Yoshiyuki , Takaku Takeshi , Nakajima Shigeru , Okuda Hiromichi
Published: November 2006

In this study, we examined the effects of fish oils on 5‐fluorouracil (5‐FU)‐induced antitumor activity in mice. First, we examined the antitumor activity of the oral administration of two fish oils (carp oil and tuna oil) in sarcoma 180‐bearing mice. Carp oil (0.2 and 0.4 mL/mouse) and tuna oil (0.2 and 0.4 mL/mouse) had no effects on tumor growth. Next, we examined the combined effects of 5‐FU plus two fish oils (carp oil and tuna oil) on the antitumor activity and side effects compared to the effects of 5‐FU alone (12.5 mg/kg/d). We found that carp oil (0.4 mL/mouse) or tuna oil (0.2 or 0.4 mL/mouse) enhanced the ability of 5‐FU (12.5 mg/kg/d) to prevent tumor growth, without increasing side effects such as myelotoxicity and immunocompetent organ toxicity. Tuna oil (0.2 mL/mouse) slightly reduced body weight as compared to the effects of 5‐FU alone and water alone (control). The area under the curve (AUC) (0–120 min) of blood 5‐FU levels was reduced by the oral co‐administration of 5‐FU with carp oil or tuna oil. Apparent Tmax was shortened by the oral co‐administration of 5‐FU with carp oil or tuna oil. On the other hand, AUC (0–4 h) of 5‐FU incorporation into tumor RNA fraction was not affected by the oral co‐administration of 5‐FU with carp oil or tuna oil.
Energy value and digestibility of dietary oil containing mainly 1,3‐diacylglycerol are similar to those of triacylglycerol
Authors: Taguchi Hiroyuki , Nagao Tomonori , Watanabe Hiroyuki , Onizawa Kouji , Matsuo Noboru , Tokimitsu Ichiro , Itakura Hiroshige
Published: November 2006

Diacylglycerol (DAG) is a component of various vegetable oils. Approximately 70% of the DAG in edible oils are in the configuration of 1,3‐DAG. We recently showed that long‐term ingestion of dietary oil containing mainly 1,3‐DAG reduces body fat accumulation in humans as compared to triacylglycerol (TAG) oil with a similar fatty acid composition. As the first step to elucidate the mechanism for this result, we examined the difference in the bioavailabilities of both oils by measuring food energy values and digestibilities in rats. Energy values of the DAG oil and the TAG oil, measured by bomb calorimeter, were 38.9 and 39.6 kJ/g, respectively. Apparent digestibility expressed according to the formula: (absorbed) x (ingested)−1x100=(ingested—excreted in feces)x(ingested)−1x100 for the DAG oil and the TAG oil were 96.3±0.4 and 96.3±0.3% (mean±SEM), respectively. The similarity in the bioavailabilities of both oils supports the hypothesis that the reduced fat accumulation by dietary DAG is caused by the different metabolic fates after the absorption into the gastrointestinal epithelial cells.
Water‐soluble organosulfur compounds of garlic inhibit fatty acid and triglyceride syntheses in cultured rat hepatocytes
Authors: Liu Lijuan , Yeh Yu‐Yan
Published: November 2006

The putative hypolipidemic effect of garlic remains controversial. To gain further insight into the effect of garlic on lipid metabolism, the present study determined the inhibitory effects of water‐soluble organosulfur compounds present in garlic on triglyceride (TG) and fatty acid synthesis in cultured rat hepatocytes. When incubated at 0.05 to 4.0 mmol/L with cultured hepatocytes, S‐allyl cysteine (SAC) and S‐propyl cysteine (SPC) decreased [2‐14C]acetate incorporation into triglyceride in a concentration‐dependent fashion achieving a maximal inhibition at 4.0 mmol/L of 43 and 51%, respectively. The rate of [2‐14C]acetate incorporation into phosphlipids was depressed to a similar extent by SAC and SPC. SPC, SAC, S‐ethyl cysteine (SEC), and γ‐glutamyl‐S‐methyl cysteine decreased [2‐14C]acetate incorporation into fatty acid synthesis by 81, 59, 35, and 40%, respectively, at 2.0–4.0 mmol/L concentrations. Alliin, γ‐glutamyl‐S‐allyl cysteine, γ‐glutamyl‐S‐propyl cysteine S‐allyl‐N‐acetyl cysteine, S‐allylsulfonyl alanine, and S‐methyl cysteine had no effect on fatty acid synthesis. The activities of lipogenic enzymes, fatty acid synthase (FAS), and glucose‐6‐phosphate dehydrogenase (G6PDH) were measured in cultured hepatocytes treated with the inhibitors. The activity of FAS in cells treated with 4.0 mmol/L SAC and SPC, respectively, was 32 and 27% lower than that of non‐treated cells. Neither SAC nor SPC affected G6PDH activity. The results indicate that SAC, SEC, and SPC inhibit lipid biosynthesis in cultured rat hepatocytes, and further suggest that these S‐alk(en)yl cysteines of garlic impair triglyceride synthesis in part due to decreased de novo fatty acid synthesis resulting from inhibition on FAS. Whether tissue concentrations of active garlic components can achieve levels required to inhibit TG synthesis in vivo warrants further investigation.
Regioisomers of octanoic acid‐containing structured triacylglycerols analyzed by tandem mass spectrometry using ammonia negative ion chemical ionization
Authors: Kurvinen J. ‐P. , Mu H. , Kallio H. , Xu X. , Høy C. E.
Published: November 2006

Tandem mass spectrometry based on ammonia negative ion chemical ionization and sample introduction via direct exposure probe was applied to analysis of regioisomeric structures of octanoic acid containing structured triacylglycerols (TAG) of type MML, MLM, MLL, and LML (M, medium‐chain fatty acid; L, long‐chain fatty acid). Collision‐induced dissociation of deprotonated parent TAG with argon was used to produce daughter ion spectra with appropriate fragmentation patterns for structure determination. Fatty acids constituting the TAG molecule were identified according to [RCO2]− ions in the daughter ion spectra. With the standard curve for ratios of [M‐H‐RCO2H‐100]− ions corresponding to each [RCO2]− ion, determined with known mixtures of sn‐1/3 and sn‐2 regioisomers of structured TAG, it was possible to determine the proportions of different regioisomers in unknown samples. The method enabled quantification of MML‐ and MLM‐type structured TAG. In the case of MLL‐ and LML‐type TAG, it was possible to determine the most abundant regioisomer in the unknown mixture and estimate the proportions of regioisomers when there were more than 50% MLL‐type isomers in the mixture.
Reconstruction of circumferential pharyngolaryngectomy using a ‘horseshoe-shaped’ pectoralis major myocutaneous flap
Authors: Jegoux F , Ferron C , Malard O , Espitalier F , de montreuil C Beauvillain
Published: November 2006

Eighteen patients underwent a circumferential pharyngolaryngectomy reconstruction post pharyngolaryngectomy. All tumours showed pharyngo-oesophageal junction invasion or circular involvement of the hypopharynx, requiring total, circumferential pharyngolaryngectomy. A pectoralis major myocutaneous flap was directly sutured to the pre-vertebral fascia. A Montgomery® salivary bypass tube was introduced into the oesophagus, and a nasogastric tube was placed within it. No post-operative complications occurred for 14 patients and only minor ones for the other four. Average post-operative stay was 12 days. For 15 patients, feeding returned to normal throughout the follow-up period. No fistulae were noted and neopharyngeal stenosis occurred in three patients (16 per cent). Thirteen had complete resection with normal margins. Thirteen were still alive after one to three years of follow up. The local recurrence rate was 16 per cent.

The use of a pectoralis major myocutaneous flap with Spriano's technique provides a simple, reliable method for circumferential hypopharyngeal resection. It has been applied to a wide range of patients, especially elderly ones and those with poor general status, as well as to cases in which widespread involvement was detected during surgery.
Presentation of first branchial cleft anomalies: the Sheffield experience
Authors: Del Pero M Martinez , Majumdar S , Bateman N , Bull P D
Published: November 2006

Abnormalities of the first branchial cleft are rare. They may present with a cutaneous defect in the neck, parotid region, external auditory meatus or peri-auricular area, or with inflammatory or infective lesions at these sites.

A retrospective case note review of the patients treated by the senior author is presented. This group consisted of 18 patients and represents the largest published UK series to date. Eleven patients (65 per cent) had undergone incomplete surgery prior to referral.

Over half the patients had a clinically apparent lesion in relation to the external auditory meatus. There was a variable relationship between the tract and the facial nerve, which was identified at surgery in 15 cases.

These findings are consistent with those of previously published series. Clinicians should keep this diagnosis in mind when assessing patients with infected lesions in the neck and parotid area. Surgeons should be familiar with parotid surgery, in children where appropriate, and be prepared to expose the facial nerve before embarking on the surgical management of these lesions.
Mediterranean oceanic response to the interannual variability of a high‐resolution atmospheric forcing: A focus on the Aegean Sea
Authors: Bozec A. , Bouruet‐Aubertot P. , Béranger K. , Crépon M.
Published: November 2006

We investigated the interannual variability of the Mediterranean Sea thermohaline circulation under present climate conditions using an oceanic model of 1/8° resolution. Two numerical simulations of 50 year duration were performed. In a control simulation the model was forced by a perpetual year forcing inferred from the climatology of the ECMWF fields, while in a random simulation the 6 years of the ECMWF fields were randomly applied. In this way we were able to test the sensitivity of the thermohaline circulation under an atmospheric interannual variability. In particular, during the last 10 years of the random simulation a succession of cold winters led to anomalous deep water formation in the Aegean Sea. We focused our analysis on this event. This anomalously dense water mostly forms in the Central and Southern Aegean subbasins with a formation rate of about 0.6 Sv. This led to strong modifications in water mass budgets and circulation with intensified exchanges between these two subbasins. The export of those dense waters to the Levantine basin remains weak except for a few particular years. Thus the impact of this event is localized as opposed to the Eastern Mediterranean Transient. These results show the possibility for transient events to reoccur in the Eastern basin in the forthcoming years.
Development of a snowfall retrieval algorithm at high microwave frequencies
Authors: Noh Yoo‐Jeong , Liu Guosheng , Seo Eun‐Kyoung , Wang James R. , Aonashi Kazumasa
Published: November 2006

A snowfall retrieval algorithm based on Bayes' theorem is developed using high‐frequency microwave satellite data. In this algorithm, observational data from both airborne and surface‐based radars are used to construct an a priori database of snowfall profiles. These profiles are then used as input to a forward radiative transfer model to obtain brightness temperatures at high microwave frequencies. In the radiative transfer calculations, two size distributions for snowflakes and ten observed atmospheric sounding profiles are used with snowfall profiles from observations. In addition, the scattering properties of the snowflakes are calculated on the basis of realistic nonspherical shapes using discrete dipole approximation. The algorithm is first verified by airborne microwave and radar observations and then applied to the Advanced Microwave Sounding Unit‐B (AMSU‐B) satellite data. The retrieved snowfall rates using AMSU‐B data from three snowfall cases in the vicinity of Japan show reasonable agreement with surface radar observations with correlation coefficients of about 0.8, 0.6, and 0.96 for the three cases, respectively. The comparison results also suggest the algorithm performs better for dry and heavy snow cases, but is less accurate for wet and weak snow cases.
Fracture toughness of dry snow slab avalanches from field measurements
Authors: McClung D. M. , Schweizer Jürg
Published: November 2006

Dry snow slab avalanches release by propagating fractures. The first fracture occurs in shear within a thin weak layer underneath a planar slab which eventually fails in tension perpendicular to the weak layer at some distance up‐slope. Thus fracture properties of both the weak layer (in shear) and the slab (in tension) are important for determining the character of the slab avalanche including its volume and, hence, destructive potential. In this paper, the fundamental fracture properties relevant during slab avalanche release are evaluated for both weak layer shear and slab tensile fracture from field measurements. Data from nearly 300 slab avalanches are used to estimate tensile and shear fracture toughness. Two important practical results come from the analysis. The first is that, on average, slab tensile toughness is about 5–7 times the weak layer shear toughness with a range of about 2–15. This is of immense practical importance since it allows estimates of slab dimensions (length) and width from measured estimates of the slab depth, D. The second important result is that a length scale is provided for a highly stressed (tensile stress) boundary layer of about 20 cm from the weak layer up through the body of the slab over which the tensile crack should first form. This estimate gives an important scale for field evaluation of snow slab instability for measurements from snow profiles. For example, it gives a guideline for estimating important hardness changes between the weak layer and the slab which have been shown from field data to be associated with human triggering of snow slabs. We expect that our results will provide a framework for analysis of rock avalanches and flake‐type landslides which fail on weak interfaces under slabs.
Three‐dimensional unsaturated flow modeling using cellular automata
Authors: Mendicino Giuseppe , Senatore Alfonso , Spezzano Giandomenico , Straface Salvatore
Published: November 2006

The parabolic partial differential equation describing fluid flow in partially saturated porous media, Richards' equation, is highly nonlinear due to pressure head dependencies in the specific soil moisture capacity and relative hydraulic conductivity terms. In order to solve Richards' equation several numerical techniques have been developed, which, starting from the discretization of the partial differential equation, produced even more accurate models, leading to complex and computationally expensive simulations for large‐scale systems. A three‐dimensional unsaturated flow modeling developed through a simulation environment based on cellular automata (CA) is described in this paper. The proposed model represents an extension of the original computational paradigm of cellular automata, because it uses a macroscopic CA approach where local laws with a clear physical meaning govern interactions among automata. This CA structure, aimed at simulating a large‐scale system, is based on functionalities capable of increasing its computational capacity, both in terms of working environment and in terms of the optimal number of processors available for parallel computing. The model has been validated with reference multidimensional solutions taken from benchmarks in literature, showing a good agreement even in the cases where nonlinearity is very marked. Furthermore, some analyses have been carried out considering quantization techniques aimed at transforming the CA model into an asynchronous structure. The use of these techniques in a three‐dimensional benchmark allowed a considerable reduction in the number of local interactions among adjacent automata without changing the efficiency of the model, especially when simulations are characterized by scarce mass exchanges. Finally, from a computational point of view the higher efficiency values were achieved running the model on a parallel architecture, obtaining a high speedup very close to the optimal with the maximum number of processors available.
Modeling mass transfer processes using random walk particle tracking
Authors: Salamon P. , Fernàndez‐Garcia D. , Gómez‐Hernández J. J.
Published: November 2006

The complexity of mass transfer processes often complicates solute transport simulations. We present a new approach for the implementation of the multirate mass transfer model into random walk particle tracking. This novel method allows for a spatially heterogeneous distribution of mass transfer coefficients as well as hydrodynamic parameters in three dimensions, and it is well suited for avoiding numerical dispersion and solving computationally demanding transport simulations. For this purpose the normalized zeroth spatial moments of the multirate transport equations are derived and used as phase transition probabilities. Performing a simple Bernoulli trial on the appropriate phase transition probabilities the particle distribution between the mobile domain and any immobile domain can be determined. The approach is compared satisfactorily to analytical and semianalytical solutions for one‐dimensional, advective‐dispersive transport with different types of mass transfer. Aspects of the numerical implementation of this approach are presented, and it is demonstrated that two restrictive criteria for the time step size have to be considered. By adjusting the time step size for each grid cell on the basis of the cell specific velocity field and mass transfer rate a correct simulation of solute transport is assured, while at the same time computational efficiency is preserved. Finally, an example is presented evaluating the effect of a heterogeneous intraparticle pore diffusion in a synthetic aquifer. The results demonstrate that for this specific case the heterogeneous distribution of mass transfer rates does not have a significant influence on mean solute transport behavior but that at low concentration ranges, differences between the different mass transfer models become visible.
The supramolecular architecture of junctional microdomains in native lens membranes
Authors: Buzhynskyy Nikolay , Hite Richard K , Walz Thomas , Scheuring Simon
Published: November 2006

Gap junctions formed by connexons and thin junctions formed by lens‐specific aquaporin 0 (AQP0) mediate the tight packing of fibre cells necessary for lens transparency. Gap junctions conduct water, ions and metabolites between cells, whereas junctional AQP0 seems to be involved in cell adhesion. High‐resolution atomic force microscopy (AFM) showed the supramolecular organization of these proteins in native lens core membranes, in which AQP0 forms two‐dimensional arrays that are surrounded by densely packed gap junction channels. These junctional microdomains simultaneously provide adhesion and communication between fibre cells. The AFM topographs also showed that the extracellular loops of AQP0 in junctional microdomains adopt a conformation that closely resembles the structure of junctional AQP0, in which the water pore is thought to be closed. Finally, time‐lapse AFM imaging provided insights into AQP0 array formation. This first high‐resolution view of a multicomponent eukaryotic membrane shows how membrane proteins self‐assemble into functional microdomains.
Snail genes at the crossroads of symmetric and asymmetric processes in the developing mesoderm
Authors: Morales Aixa V , Acloque Hervé , Ocaña Oscar H , de Frutos Cristina A , Gold Veronica , Nieto M Angela
Published: November 2006

Retinoic acid (RA) signalling ensures that vertebrate mesoderm segmentation is bilaterally synchronized, and corrects transient interferences from asymmetric left–right (L–R) signals involved in organ lateralization. Snail genes participate in both these processes and, although they are expressed symmetrically in the presomitic mesoderm (PSM), Snail1 transcripts are asymmetrically distributed in the L–R lateral mesoderm. We show that the alteration of the symmetric Snail expression in the PSM induces asynchronous somite formation. Furthermore, in the absence of RA signalling, normal asymmetric Snail1 expression in the lateral mesoderm is extended to the PSM, desynchronizing somitogenesis. Thus, Snail1 is the first cue corrected by RA in the PSM to ensure synchronized bilateral segmentation.
Influences on Small-Firm Compliance-Related Behaviour: The Case of Workplace Health and Safety
Authors: Baldock Robert , James Philip , Smallbone David , Vickers Ian
Published: November 2006

The authors investigate the relative roles of a number of influences on workplace health and safety in small firms and, more specifically, the adoption of compliance-related improvement measures. From findings drawn from a survey of over a thousand British small enterprises, marked variations in firm behaviour with respect to health and safety were found, underlining the heterogeneity of small firms in this respect, and the way such behaviour reflects their varied contexts. Factors identified as being particularly associated with a propensity to make compliance-related improvements were: regulatory enforcement activity, use of external assistance with respect to health and safety issues, enterprise size and growth performance, management training and experience, and membership of trade or business associations. Although, as a group, ethnic-minority businesses were found to be neither more or less likely to make improvements of this type compared with their white-owned counterparts, detailed analysis revealed that such variations did exist between individual ethnic groupings; variations that are themselves seen to reflect a number of factors, particularly the employment size and sectoral context. Primarily the authors conclude that inspections on the part of regulatory officials are the most important influence, although there is some scope for more innovative approaches to encouraging compliance-related improvements.
Making Policy Choices in Nonfinancial Business Support: An International Comparison
Authors: Mole Kevin F , Bramley George
Published: November 2006

The paper reports an international literature review of advisory business support. Most industrialised countries provide a degree of business support to small and medium-sized firms, such as information and advice. It is normal for programmes to be justified using arguments about market failure and programme designers tend to weight different aspects of market failure leading to different policy choices. The paper was based upon a literature review of business support in OECD countries conducted in 2004. A visual analogue scale was developed based on the choices made by policy makers across OECD countries which developed a taxonomy of business support choices to enable both a more systematic comparison of, and to differentiate, programmes. There are a considerable number of choices that can be made regarding how a programme is designed and delivered for a specific set of market failures. The key result of the research is to suggest a hierarchy of policy choices. At the top are four choices: Who delivers? What ‘type’ of support? How is it rationed? And how is it funded? At a point in time when there are significant institutional changes in English business support the paper has the opportunity to contribute by making more explicit the policy choices in the area of business advice to small firms.