bluuebunny/crossref_metadata_2025 huggingface dataset:
Effectiveness of periodontal therapies on the treatment of different aetiological factors induced gingival overgrowth in puberty
Authors: Kara C , Demir T , Tezel A
Published: October 2007

Abstract:  Objectives:  The aim of the present study was to compare oral improvement achieved by different periodontal therapies (surgical and non‐surgical) for different aetiological factors induced gingival overgrowth in 60 subjects (mean age ± SD = 12.33 ± 1.05 years; age range = 12–15 years).

Methods:  Subjects received oral hygiene instructions, scaling, surgical treatment (if necessary) and periodontal maintenance therapy. Clinical parameters were taken at baseline, after initial treatment and after periodontal surgery.

Results:  The decrease in the clinical index values after all treatments compared to the initial values is found to be statistically significant (P < 0.05). Although there was a statistically significant difference in all aspects of the clinical index values of the study groups after initial treatments, for drug‐induced gingival overgrowth subjects full improvement was seen only after periodontal surgery.

Conclusion:  Attention to plaque control and removal of local irritants is very important for the gingival health of the patients in puberty. In puberty, plaque‐induced gingival overgrowth can be treated with plaque removal. However, these approaches alone do not prevent drug‐induced gingival overgrowth and surgical therapy often becomes the treatment of choice.
The comparison of the effects of three types of piezoelectric ultrasonic tips and air polishing system on the filling materials: an in vitro study
Authors: Arabaci T , Çiçek Y , Özgöz M , Çanakçi V , Çanakçi CF , Eltas A
Published: October 2007

Abstract:  Aim:  The aim of this study was to evaluate the effect of air polishing and different ultrasonic scaler inserts on dental fillings, such as amalgam, composite and porcelain.

Materials and methods:  This study was performed on amalgam, composite and porcelain samples. The surfaces of the samples were exposed to different type of piezoelectric ultrasonic scaler inserts and air‐abrasive unit. The scaler inserts were Instrument A, Instrument PS and PI. The roughness of the surfaces of each sample were measured with a profilometer and observed by stereomicroscope.

Results:  The stereomicroscopic images and profilometric values showed that Instrument A and PS resulted in rough surfaces, such as chips, nicks and scratches on the amalgam, composite and porcelain surfaces. The Instrument PI roughened the amalgam surface, but it did not roughen the porcelain or composite surfaces. The profilometric measurements (Ra) showed that the roughness of the surfaces depending on air polishing was less than the ultrasonically scaled surfaces.

Conclusion:  The wrong tip applications during dental scaling procedure cause roughness, such as scratches, nicks or chips, not only on the teeth surfaces but also on the filling materials. Thus, dental scaling procedure on the restorations should be performed carefully and the roughness sites on the restorations have to be re‐polished after scaling to prevent plaque accumulation.
Interpreting neuropsychological impairment among adolescent inhalant users: two case reports
Authors: Takagi Michael J. , Lubman Dan I. , Yücel Murat
Published: October 2007

Objective:

To illustrate the need to carefully consider mental health, psychosocial and motivational factors when investigating cognitive and intellectual impairment among chronic inhalant users.

Methods:

Two adolescent chronic inhalant users with similar psychosocial disadvantages (eg unstable and dysfunctional families, state-based care, school absenteeism and forensic issues) and histories of comorbid drug use and mental health problems were assessed using a battery of paper and pencil and computerised neuropsychological tests.

Results:

Contrary to the expectations of her case manager, one participant performed within the normal range for her age in all domains of intellectual ability, while the other participant, in line with the expectations of her case manger, showed marked cognitive deficits and intellectual disability.

Conclusions:

The typically complex presentation of chronic inhalant users (ie disadvantaged psychosocial backgrounds, comorbid psychopathology and poor motivation/engagement) is rarely considered when investigating associated cognitive and intellectual functioning. Future research should more carefully consider the role of such factors, given the evidence suggesting that they can considerably alter (accentuate or diminish) the association between inhalant abuse and neuropsychological impairment.
Potentiation of Histamine Release by Microfungal (1→3)‐ and (1→6)‐β‐D‐Glucans
Authors: Holck Peter , Sletmoen Marit , Stokke Bjørn Torger , Permin Henrik , Norn Svend
Published: October 2007

Abstract:  (1→3)‐β‐D‐Glucans, a cell wall component in most microfungi, are suggested to play a role in the development of respiratory and general symptoms in organic dust‐related diseases. The mechanisms by which they induce these effects are, however, not clear. In the present study, mediator release and its potentiation by the (1→3)‐β‐D‐glucan as well as by the (1→6)‐β‐D‐glucan found in yeast and other fungi were therefore examined. Blood leucocytes from healthy volunteers and from patients allergic to house dust mite were incubated with (1→3)‐β‐D‐glucans with increasing 1,6‐branchings: curdlan [a linear (1→3)‐β‐D‐glucan], laminarin and scleroglucan, and furthermore with pustulan, a linear (1→6)‐β‐D‐glucan. Histamine release was not observed on exposure to the glucans only, but in the presence of anti‐immunoglobulin E (IgE) antibody or specific antigens, all the glucans investigated led to an enhancement of the IgE‐mediated histamine release. The glucans induced a significant potentiation of the mediator release when present at concentrations in the range of 2–5 × 10−5 M. These results suggest that (1→3)‐β‐D‐glucan as well as (1→6)‐β‐D‐glucan aggravates IgE‐mediated histamine release. Knowledge concerning the effects of glucans on immune responses may be of importance for understanding and treating inflammatory and allergic diseases.
Educating European (Junior) Doctors for Safe Prescribing
Authors: Maxwell Simon R. J. , Cascorbi Ingolf , Orme Michael , Webb David J. ,   On behalf of the Joint BPS/EACPT Working Group on Safe Prescribing
Published: October 2007

Abstract:  Evidence of poor prescribing is widespread including overuse of medicines, underuse of effective medicines, avoidable adverse drug reactions and medication errors. Junior doctors who have recently graduated are responsible for much of the prescribing that takes place in hospitals and are implicated in many of the adverse medication events. Analysis of such events suggests that lack of knowledge and training underlies many of them and it has been shown that dedicated training can increase prescribing performance. In the context of these problems, it is a matter of increasing concern that recent changes to undergraduate medical education may have reduced exposure to clinical pharmacology, a discipline dedicated to optimal practice in relation to medicines. For this reason, the European Association of Clinical Pharmacology and Therapeutics (EACPT) and British Pharmacological Society (BPS) jointly organized a meeting to explore (i) the state of undergraduate education in clinical pharmacology in Europe, (ii) the knowledge and competencies in relation to medicines that should be expected of a new graduate, (iii) assessments that might demonstrate that this minimum standard had been reached, (iv) a curriculum that might help medical students to achieve this standard and (v) how competence can be developed in the postgraduate phase. It was agreed that the lack of exposure to clinical pharmacology is a cause for concern at a time when the challenges facing junior prescribers have never been greater. The potential for undertaking further research was discussed.
U.S. Sourcing from Low‐Cost Countries: A Comparative Analysis of Supplier Performance
Authors: Ruamsook Kusumal , Russell Dawn , Thomchick Evelyn
Published: October 2007

Given the increase in sourcing from low‐cost countries (LCCs), it is important to assess relative supplier performance across these regions. This work investigates the comparative performance of LCC suppliers on 14 operational indicators of international sourcing and supply chain performance. Using survey methods, the study addresses these two questions: (1) How do the LCC regions of Asia, the Western Hemisphere and Europe compare in terms of the 14 operational indicators?; and (2) How do LCC nations within these three regions compare with regard to the 14 operational indicators? Perceived differences exist among the regions of Asia, the Western Hemisphere and Europe, as well as among the LCC nations of these three regions. However, no one region outperforms the others, and no one nation outperforms the others, on all 14 operational indicators investigated. Accordingly, this study also identifies the key areas of comparative advantage and disadvantage that each LCC region and each LCC nation presents in its relationship with U.S. buying firms.
E‐Reverse Auctions Revisited: An Analysis of Context, Buyer–Supplier Relations and Information Behavior
Authors: Lösch Andrea , Lambert J. Siân
Published: October 2007

This study investigates context, information behavior and buyer–supplier relationships in e‐reverse auctions (e‐RAs). Following a grounded theory approach, a comprehensive online questionnaire was developed and sent to both users and nonusers of e‐RAs. Usable responses were received from 89 buyers and 54 suppliers that were analyzed taking into account both the size and consistency of effects obtained from the Mann–Whitney U‐test and Kendall's tau (τ) statistic. The results not only show that e‐RAs have fewer negative effects on buyer–supplier relationships than currently assumed but also that the management of e‐RAs (particularly a high valuation of types and sources of information combined with a high quality of information exchange and communication) has a positive impact on the buyer–supplier relationship.
Combining Anticholinergic and Anti‐inflammatory Activities into a Single Moiety: A Novel Approach to Reduce Gastrointestinal Toxicity of Ibuprofen and Ketoprofen
Authors: Halen Parmeshwari K. , Chagti Kewal K. , Giridhar Rajani , Yadav Mange R.
Published: October 2007

With the aim of reducing the local gastric irritation associated with non‐steroidal anti‐inflammatory drugs, a series of N,N‐disubstituted aminoalcohol ester derivatives of ibuprofen and ketoprofen were synthesized and evaluated. The esters were specially designed to possess the anticholinergic activity in the intact form and exhibit the anti‐inflammatory action after hydrolysis to the respective parent drug. The rationale being that besides blocking the acidic carboxylic group of the parent drug, the existence of the anticholinergic effect in the intact molecule would further aid in reducing the gastrointestinal mucosal damage by decreasing the gastric secretions and motility. All the ester derivatives were found to be stable in acidic and basic buffers. The synthesized derivatives, with experimentally proven good anti‐inflammatory and anticholinergic activities, showed significant reduction of ulcerogenicty in the stomach. These results are attributed to the acquired anticholinergic activity with a simultaneous reduction of acidic character compared to the parent compounds. The study offers a new strategy for design and development of compounds with safer therapeutic profile for long‐term treatment of inflammation‐associated disorders.
Mapping the Specific Cytoprotective Interaction of Humanin with the Pro‐apoptotic Protein Bid
Authors: Choi Jungyuen , Zhai Dayong , Zhou Xin , Satterthwait Arnold , Reed John C. , Marassi Francesca M.
Published: October 2007

Humanin is a short endogenous peptide, which can provide protection from cell death through its association with various receptors, including the pro‐apoptotic Bcl‐2 family proteins Bid, Bim, and Bax. By using NMR chemical shift mapping experiments, we demonstrate that the interaction between Humanin‐derived peptides and Bid is specific, and we localize the binding site to a region on the surface of Bid, which includes residues from the conserved helical BH3 domain of the protein. The BH3 domain mediates the association of Bid with other Bcl‐2 family members and is essential for the protein’s cytotoxic activity. The data suggest that Humanin exerts its cytoprotective activity by engaging the Bid BH3 domain; this would hinder the association of Bid with other Bcl‐2 family proteins, thereby mitigating its toxicity. The identification of a Humanin‐specific binding site on the surface of Bid reinforces its importance as a direct modulator of programmed cell death, and suggests a strategy for the design of cytoprotective peptide inhibitors of Bid.
QSAR of Aromatic Substances: Protein Tyrosine Kinase Inhibitory Activity of Flavonoid Analogues
Authors: Deeb Omar , Clare Brian W.
Published: October 2007

The flip regression procedure that we used earlier for handling xanthones (J Enzyme Inhib Med Chem;22:277, 2006) has been applied to flavonoid analogues. It is demonstrated that the electrostatic and quantum chemical descriptors for the interaction of flavonoids with the specific enzymatic active site plays an important role. In particular, the maximal total interaction for a C–O bond is the most important factor in the regression. In this contribution it is shown that the orientation of nodes in their occupied π orbitals, and also the energies of these orbitals explain a further large portion of the variance in their inhibitory activity.
Stability and Activity in Sputum of G10KHc, a Potent Anti‐Pseudomonas Antimicrobial Peptide
Authors: Eckert Randal , Mchardy Ian , Yarbrough Daniel K. , He Jian , Qi Fengxia , Anderson Maxwell H. , Shi Wenyuan
Published: October 2007

G10KHc, a specifically targeted antimicrobial peptide developed in our laboratory, has shown rapid and selective killing activity against Pseudomonas aeruginosa in culture medium. Because of the major role played by this pathogen in cystic fibrosis, we sought to evaluate the utility of G10KHc under more physiologic conditions in vitro. In the current study, we found that robust G10KHc activity could be maintained in expectorated sputum if serine protease‐dependant digestion associated with this fluid was inhibited, either by chemical antagonists or by the construction of a d‐amino acid enantiomer of G10KHc. Further investigations revealed that specifically targeted antimicrobial peptide activity in sputum could be further enhanced when samples were treated with a combination of peptide and recombinant human DNase. Our results illustrate the importance of investigating combination therapy to treat cystic fibrosis, especially if protease‐sensitive peptide‐based agents, such as G10KHc, are to be developed as alternatives to, or in conjunction with, conventional small‐molecule antibiotics.
Conservation rates: the best ‘new’ source of urban water during drought
Authors: Smith William James , Wang Young‐Doo
Published: October 2007

In the United States, water conservation‐oriented rates (WCOR) are an increasingly vital tool for promoting water conservation and mitigating urban drought. Our models prove that one type of WCOR, drought demand rates (DDR), can produce with minimal regulation the quadruple objectives of conservation rates: (1) improving efficiency; (2) providing revenue neutrality; (3) assuring distributional equity and (4) guaranteeing the conservation of water. We demonstrate that such rates can also reduce days that urban streams drop below ‘critical flow’ levels, providing a voice for nature. Our study is situated in northern New Castle County (NCC), Delaware (DE), USA, and the lessons garnered have relevance for industrialized communities seeking a ‘soft‐path’ to drought mitigation.
The Hebrew Bible and the Quran: The Problem of the Jewish ‘Influence’ on Islam
Authors: Pregill Michael E.
Published: October 2007

The biblical tradition is manifest in the Quran in many different ways. Similarly, scholars have adopted a number of different approaches to the phenomenon of the biblical ‘borrowings’ found in the Quran. Since the foundation of the modern discipline of Islamic studies in the nineteenth century until very recently, scholars have often seen the appearance of biblical stories in the Quran, often in significantly altered, distorted, or amplified form, as reflecting Muhammad's dependence upon Jewish teachers and thus an overarching Jewish influence on Islam. In point of fact, this approach to the biblical tradition in the Quran has significant roots in medieval Christian polemic against Islam. In recent years, a few scholars have sought to develop more constructive approaches to this material and to Quranic narrative in general; nevertheless, a full‐scale reconsideration of the basic problem is still lacking, and the legacy of medieval polemic in the early Orientalist tradition, as well as its modern implications, has yet to be widely recognized.
The Effect of Maternal Smoking and Drinking During Pregnancy Upon 3H‐Nicotine Receptor Brainstem Binding in Infants Dying of the Sudden Infant Death Syndrome: Initial Observations in a High Risk Population
Authors: Duncan Jhodie R. , Randall Leslie L. , Belliveau Richard A. , Trachtenberg Felicia L. , Randall Bradley , Habbe Donald , Mandell Federick , Welty Thomas K. , Iyasu Solomon , Kinney Hannah C
Published: October 2007

The high rate of the sudden infant death syndrome (SIDS) in American Indians in the Northern Plains (3.5/1000) may reflect the high incidence of cigarette smoking and alcohol consumption during pregnancy. Nicotine, a neurotoxic component of cigarettes, and alcohol adversely affect nicotinic receptor binding and subsequent cholinergic development in animals. We measured 3H‐nicotine receptor binding in 16 brainstem nuclei in American Indian SIDS (n = 27) and controls (n = 6). In five nuclei related to cardiorespiratory control, 3H‐nicotinic binding decreased with increasing number of drinks (P < 0.03). There were no differences in binding in SIDS compared with controls, except upon stratification of prenatal exposures. In three mesopontine nuclei critical for arousal there were reductions (P < 0.04) in binding in controls exposed to cigarette smoke compared with controls without exposure; there was no difference between SIDS cases with or without exposure. This study suggests that maternal smoking and alcohol affects 3H‐nicotinic binding in the infant brainstem irrespective of the cause of death. It also suggests that SIDS cases are unable to respond to maternal smoking with the “normal” reduction seen in controls. Future studies are needed to establish the role of adverse prenatal exposures in altered brainstem neurochemistry in SIDS.
Environmental Enrichment Counteracts Alzheimer’s Neurovascular Dysfunction in TgCRND8 Mice
Authors: Herring Arne , Yasin Hamzah , Ambrée Oliver , Sachser Norbert , Paulus Werner , Keyvani Kathy
Published: October 2007

We and others have recently demonstrated that cognitive and physical stimulation in form of environmental enrichment reduces cerebral β‐amyloid (Aβ) deposition in transgenic mouse models of Alzheimer’s disease. This effect was independent from amyloid precursor protein (APP) expression or processing and rather a consequence of enhanced clearance of Aβ. However, the detailed mechanisms remain unclear. In the present study, we show that environmental enrichment in TgCRND8 mice (carrying human APPSwedish+Indiana) affect the neurovascular unit by increased angiogenesis and differential regulation of Aβ receptor/transporter molecules, namely up‐regulation of LRP1, ApoE and A2M as well as down‐regulation of RAGE so that brain to blood Aβ clearance is facilitated. These results suggest a hitherto unknown effect of environmental enrichment counteracting the vascular dysfunction in Alzheimer diseased brain.
Vascular Endothelial Growth Factor and Nitric Oxide Production in Response to Hypoxia in the Choroid Plexus in Neonatal Brain
Authors: Sivakumar Viswanathan , Lu Jia , Ling Eng Ang , Kaur Charanjit
Published: October 2007

Damage to the choroid plexus in 1‐day‐old Wistar rats subjected to hypoxia was investigated. The mRNA and protein expression of hypoxia‐inducible factor‐1α (HIF‐1α), endothelial, neuronal, inducible nitric oxide synthase (eNOS, nNOS, iNOS), and vascular endothelial growth factor (VEGF) along with nitric oxide (NO) production and VEGF concentration was up‐regulated significantly in hypoxic rats. Ultrastructurally, the choroid plexus epithelial cells showed massive accumulation of glycogen. A striking feature was the extrusion of cytoplasmic fragments from the apical cell surfaces into the ventricular lumen following the hypoxic insult. Intraventricular macrophages showed increased expression of complement type 3 receptors, major histocompatibility complex class I and II antigens, and ED1 antigens. Following an intravenous injection of horseradish peroxidase (HRP), a large number of intraventricular macrophages were labeled suggesting enhanced leakage of the tracer from the blood vessels in the choroid plexus connective tissue stroma into the ventricular lumen. We suggest that increased production of NO in hypoxia is linked to the structural alteration of the choroid plexus, and along with VEGF, may lead to increased vascular permeability. Melatonin treatment reduced VEGF and NO levels as well as leakage of HRP suggesting its potential value in ameliorating damage in choroid plexus pathologies.
Retention and Distribution of Polyphenols after Pan‐Frying of French Fries in Oils Enriched with Olive Leaf Extract
Authors: Chiou A. , Salta F.N. , Kalogeropoulos N. , Mylona A. , Ntalla I. , Andrikopoulos N.K.
Published: October 2007

ABSTRACT:  Palm oil, olive oil, and sunflower oil were supplemented with an extract rich in polyphenols obtained from olive tree (Olea europaea) leaves at levels of 120 and 240 mg total polyphenols per kilogram of oil. Pan‐frying of potatoes was performed in both the enriched and the nonsupplemented oils under domestic frying conditions. Total polyphenol content was estimated by the Folin–Ciocalteau assay, oleuropein was determined by HPLC analysis, while other individual polyphenols by GC/MS analysis. Fourteen polyphenol species were identified in the olive leaf extract, among which oleuropein predominated (1.25 g/kg olive leaves). All the enriched oils contained oleuropein before and after frying. Oleuropein as well as other polyphenol species were detected in all French fries cooked in enriched oils. Polyphenol intake by consuming French fries pan‐fried in the enriched oils was calculated to be 6 to 31 times higher than that in the case of French fries fried in commercial oils, being dependent on the frying oil type.
Optimization of β‐Carotene Production by Rhodotorula glutinis Using High Hydrostatic Pressure and Response Surface Methodology
Authors: Wang S.‐L. , Sun J.‐S. , Han B.‐Z. , Wu X.‐Z.
Published: October 2007

ABSTRACT:  Rhodotorula glutinis RG6 was treated by high hydrostatic pressure (HHP) of 300 MPa for 15 min for improving its ability of β‐carotene production. After the treatments of 5 repeated cycles, the mutant strain RG6p was obtained, β‐carotene production of which reached 10.01 mg/L, increased by 57.89% compared with 6.34 mg/L from parent strain RG6. To optimize the medium for β‐carotene fermentation by mutant RG6p, a response surface methodology (RSM) approach was used in conjunction with a factorial design and a central composite design, and the maximum yield of β‐carotene (13.43 mg/L), an increase of 34.17% compared to the control, was obtained at a pH 6.7 with an optimum medium (40 mL/250 mL) of yeast extract (4.23 g/L), glucose (12.11 g/L), inoculum (30 mL/L), tomato extract (2.5 mL/L), peanut oil (0.5 mL/L), and (NH4)2SO4 (5 g/L).
Effect of γ‐Ray Irradiation on Modeling Equilibrium Moisture Content of Wheat
Authors: Yu Y. , Wang J.
Published: October 2007

ABSTRACT:  The experimental research found that gamma irradiation dose affected the equilibrium moisture content of wheat at the same relative humidity and temperature of ambient. Values of the equilibrium moisture content decreased with an increasing dose of γ‐ray irradiation during both adsorption and desorption. These were due to the changes of wheat starch granules and their water bound ability caused by different irradiation doses. Factor of irradiation dose was added in 3 widely used models for modeling the equilibrium moisture content of irradiated wheat, and the parameters in models were estimated based on the experimental data. Based on the study of correlation coefficient, mean relative error, and standard error the modified Chung–Pfost equation and the modified Henderson equation were found to fit the desorption and adsorption isotherms for wheat, respectively, in the range of experiment at conditions studied.
Changes of Glucosinolates in Mixed Fresh‐Cut Broccoli and Cauliflower Florets in Modified Atmosphere Packaging
Authors: Schreiner M. , Peters P. , Krumbein A.
Published: October 2007

ABSTRACT:  Glucosinolates of broccoli and cauliflower florets were assessed to determine the effect of modified‐atmosphere packaging on postharvest glucosinolate dynamics in mixed florets of Brassica vegetables. Mixed‐packaged broccoli and cauliflower florets stored in food trays sealed with 2 different microperforated biaxial‐oriented polypropylene films for up to 7 d at 8 °C were analyzed. Both applied modified atmospheres (1% O2+ 21% CO2; 8% O2+ 14% CO2) maintained aliphatic glucosinolates in cauliflower florets, whereas in broccoli florets, the aliphatic glucosinolate concentration decreased slightly in each modified atmosphere. In addition, total indole glucosinolate concentration for both broccoli and cauliflower florets was maintained, and even increased in cauliflower florets at 1% O2+ 21% CO2 due to rising neoglucobrassicin concentration. Thus, to simultaneously maintain glucosinolates and external appearance as well as to prevent off‐odor, a modified atmosphere of 1% O2+ 21% CO2 provides a suitable environment for storage of this Brassica floret medley for up to 7 d at 8°C.
Advanced Glycosylation End Products and Nutrition—A Possible Relation with Diabetic Atherosclerosis and How to Prevent It
Authors: Xanthis A. , Hatzitolios A. , Koliakos G. , Tatola V.
Published: October 2007

ABSTRACT:  Advanced glycosylation end product (AGE) levels are elevated in diabetic patients and may contribute to the excessive cardiovascular disease in this population, promoting oxidant stress and chronic vascular inflammation. AGEs in people with diabetes mellitus are formed mainly by protein and lipid glucosylation in an environment of chronic hyperglycemia and also by prolonged thermal food processing (diet derived AGEs). This brief review summarizes current literature about food derived AGEs and their relationship with diabetic vascular disease and supports the importance of low AGE diet as an essential preventive or therapeutic intervention against atheromatosis progress.
Experimental Determination of the Dynamics of Vacuum Impregnation of Apples
Authors: Laurindo J.B. , Stringari G.B. , Paes S.S. , Carciofi B.A.M.
Published: October 2007

ABSTRACT:  Vacuum impregnation (VI) is a food processing method by which air and native solution are removed from porous spaces within a food and replaced by an external solution. In this study, an experimental device based on a previous design was built, including some modifications, in order to investigate the dynamics of the VI process. The device measured the net force exerted by a food sample submitted to the VI process using a load cell. The influence of the vacuum level and sample geometry was well quantified by the experimental procedure and the modified equipment using apple samples (Fuji var.) as a food model. The results indicated that the experimental device proposed in this study, together with the suggested procedure, is a useful tool to investigate the dynamics of VI processes. It is robust and versatile, and has the advantage of not requiring the determination of the water evaporated during the VI process in a separate experiment, which represents an increase in the accuracy of the results.
Simulation as a Social Process in Organizations
Authors: Hoffman Steve G.
Published: October 2007

An emergent research literature is starting to cohere on simulation as a sociological process within organizations. This paper shines a spotlight on this scholarship, and offers new ways to think about the dizzying array of simulation we encounter in our organizational, institutional, and everyday lives. I define simulation as an empirical social process and show how they vary in consequence by their experiential modality, their referential frame, and their perceived realism. I then document three conceptual trends in the literature: (i) treating simulation as an organizational technique for risk management; (ii) a focus on virtual reality, video games, and moral ambiguity; and (iii) studies of the impact of computer simulation on scientific knowledge production and the reorganization of some technical fields, such as weapons research, artificial intelligence, and meteorology. Organizational uncertainty tends to coalesce around disputes about the appropriate qualities and functions of a given simulation technique or technology. I conclude the paper by identifying how the sociology of simulation can connect with more established areas of contemporary research within organizations, work and occupations, and institutional sociology.
Effect of MG132 on proteasome activity and prooxidant/antioxidant status of rat liver subjected to ischemia/reperfusion injury
Authors: Alexandrova Albena , Petrov Lubomir , Georgieva Almira , Kessiova Mila , Tzvetanova Elina , Kirkova Margarita , Kukan Marian
Published: October 2007

Aim: Previous studies have shown that proteasome inhibitors exerted protective effects against ischemia/reperfusion injury (IRI) of brain, heart, kidney and intestine. The aim of the present study was to investigate: (i) whether the proteasome inhibitor MG132 protects rat liver against IRI; and (ii) whether MG132 modulates prooxidant/antioxidant status of rat liver subjected to warm IRI.

Methods: The left lateral and medial lobes (approximately 70% of the total liver volume) of livers of male Wistar rats were subjected to 30‐min ischemia followed by 60‐min reperfusion. Lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels were measured in the plasma. Proteasome chymotryptic‐like (ChT‐L) activity, levels of thiobarbituric acid‐reactive substances (TBARS), protein carbonyls (PC) and glutathione (GSH), as well as superoxidase dismutase (SOD), catalase (CAT), glutathionine peroxidase and glutathionine reductase activities were measured in liver fractions.

Results: Thirty‐min ischemia followed by 60‐min reperfusion increased liver TBARS and PC, CAT and SOD activities, but decreased GSH level. Ischemia/reperfusion‐induced oxidative stress was exacerbated in mitochondria, indicating that these organelles are the preferential target of IRI. Plasma LDH and AST levels were decreased by MG132 during both ischemia and reperfusion, while ALT values were decreased only after 30 min of reperfusion. MG132 did not significantly affect liver TBARS and GSH levels, but it increased PC and decreased ChT‐L activity; the activities of CAT and SOD were also decreased.

Conclusions: MG132 exerts a protective effect during the early phase of reperfusion and it modulates prooxidant/antioxidant status of rat liver subjected to warm IRI.
Accordion Index: A new tool for the prediction of the efficacy of peg‐interferon‐α‐2b and ribavirin combination therapy for chronic hepatitis C
Authors: Satoh Takeaki , Masumoto Akihide
Published: October 2007

Aim:  An optimal treatment regimen based on individual virological response is essential to maximize the efficiency of interferon (IFN) therapy for chronic hepatitis C.

Methods:  Using indicators of the virological response and the treatment intensity, we developed the Accordion Index as a new tool for the efficacy prediction of peg‐IFN and ribavirin (RBV) combination therapy. For the Accordion Index, the IFN‐AC ratio and RBV‐AC ratio were defined as follows: IFN‐AC ratio = (total IFN dose given during the entire treatment period)/(total IFN dose required to achieve hepatitis C virus [HCV]–RNA negativity), RBV‐AC ratio = (total RBV dose given during the entire treatment period)/(total RBV dose required to achieve HCV–RNA negativity).

Results:  The analysis of the association between the Accordion Index and the sustained virological response (SVR)revealed that of 25 patients who had HCV–RNA negativity during treatment, all 10 patients with an IFN‐AC ratio and RBV‐AC ratio of at least 4.0 achieved SVR, while only four of 15 patients with an IFN‐AC ratio or RBV‐AC ratio of less than 4.0 achieved SVR. With the cut‐off value for both the IFN‐AC ratio and RBV‐AC ratio at 4.0 or higher, the quality of SVR prediction was as follows: the positive predictive value was 100%, the negative predictive value was 73.3%, and accuracy was 84.0%.

Conclusion:  The Accordion Index will thus be a useful tool for planning optimal treatment regimens for individual patients.
Increased Ca2+ influx through Na+/Ca2+ exchanger during long‐term facilitation at crayfish neuromuscular junctions
Authors: Minami Akira , Xia Yan‐fang , Zucker Robert S.
Published: October 2007

Intense motor neuron activity induces a long‐term facilitation (LTF) of synaptic transmission at crayfish neuromuscular junctions (NMJs) that is accompanied by an increase in the accumulation of presynaptic Ca2+ ions during a test train of action potentials. It is natural to assume that the increased Ca2+ influx during action potentials is directly responsible for the increased transmitter release in LTF, especially as the magnitudes of LTF and increased Ca2+ influx are positively correlated. However, our results indicate that the elevated Ca2+ entry occurs through the reverse mode operation of presynaptic Na+/Ca2+ exchangers that are activated by an LTF‐inducing tetanus. Inhibition of Na+/Ca2+ exchange blocks this additional Ca2+ influx without affecting LTF, showing that LTF is not a consequence of the regulation of these transporters and is not directly related to the increase in [Ca2+]i reached during a train of action potentials. Their correlation is probably due to both being induced independently by the strong [Ca2+]i elevation accompanying LTF‐inducing stimuli. Our results reveal a new form of regulation of neuronal Na+/Ca2+ exchange that does not directly alter the strength of synaptic transmission.
Prototype of Middle-Temperature Solar Receiver/Reactor With Parabolic Trough Concentrator
Authors: Jin Hongguang , Sui Jun , Hong Hui , Wang Zhifeng , Zheng Danxing , Hou Zhi
Published: October 2007

This paper manufactured an original middle-temperature solar receiver/reactor prototype, positioned along the focal line of one-axis parabolic trough concentrator, representing the development of a new kind of solar thermochemical technology. A 5kW prototype solar reactor at around 200–300°C, which is combined with a linear receiver, was originally manufactured. A basic principle of the design of the middle-temperature solar reactor is identified and described. A representative experiment of solar-driven methanol decomposition was carried out. Experimental tests were conducted from 200°C to 300°C under mean solar flux of 300–800W∕m2 and at a given methanol feeding rate of 2.1L∕h. The conversion of methanol decomposition yielded up to 50–95%, and the efficiency of solar thermal energy conversion to chemical energy reached 30–60%. The experimental results obtained here prove that the novel solar receiver/reactor prototype introduced in this paper can provide a promising approach to effectively utilize middle-temperature solar thermal energy by means of solar thermochemical processes.
A Novel 50kW 11,000 suns High-Flux Solar Simulator Based on an Array of Xenon Arc Lamps
Authors: Petrasch Jörg , Coray Patrick , Meier Anton , Brack Max , Häberling Peter , Wuillemin Daniel , Steinfeld Aldo
Published: October 2007

A novel high-flux solar simulator, capable of delivering over 50kW of radiative power at peak radiative fluxes exceeding 11,000 suns, is operational at the Paul Scherner Institute. It comprises an array of ten Xe arcs, each close-coupled with ellipsoidal specular reflectors of common focus. Its optical design, main engineering features, and operating performance are described. The Monte Carlo ray-tracing technique is applied to optimize the geometrical configuration for maximum source-to-target transfer efficiency of radiative power. Calorimeter measurements indicated an average flux of 6800kW∕m2 over a 60-mm-diameter circular target, which corresponds to stagnation temperatures above 3300K. This research facility simulates the radiation characteristics of highly concentrating solar systems and serves as an experimental platform for investigating the thermochemical processing of solar fuels and for testing advanced high-temperature materials.
Advances in Gas-Fired Thermophotovoltaic Systems
Authors: Durisch W. , von Roth F. , Tobler W. J.
Published: October 2007

In a first and completely new approach, a vacuum plasma-spray coating technique was used to deposit selective emitting rare-earth oxide films of ytterbia (Yb2O3) on porous silicon-infiltrated silicon carbide foams (Si–SiC). The plasma-spray coating technique offers a new and promising way to produce selective emitting coatings on different refractory substrates with complex geometries. The adhesion and thermal shock stability were tested until a film thickness of 130μm was achieved; the selective emittance of the oxide coating has been found to be dependent on the film thickness. The material combination Si–SiC and Yb2O3, however, needs some major improvement regarding high-temperature stability and high thermal cycling loads. In a different approach, the advantage of low emitting Al2O3 fibers and good thermal matching was combined with Yb2O3 slurry coating of flexible alumina (Al2O3) fiber bundles, formed into a cylindrical shape. The thin fiber structure tried to imitate the famous incandescent mantle emitters of Auer von Welsbach, but with a more rugged structure. Even though the fibers of the woven emitter were thin, the low thermal conductivity of Al2O3 led to a distinct reduction of the surface temperature and emittance, and a shielding effect of the radiation emanating from the hot inner walls by the cooler outer grid structure was inevitable. Optical filters consisting of a water film and of transparent conducting oxides (TCO) have been developed and tested to protect the photocells against overheating and to reflect nonconvertible off-band radiation back to the emitter. The water film led to a significant reduction of the cell temperature and increased cell performance, whereas with the TCO filters only a reduction of the cell temperature was observed.
PV-Trombe Wall Design for Buildings in Composite Climates
Authors: Ji Jie , Yi Hua , He Wei , Pei Gang
Published: October 2007

The design of the novel PV-Trombe wall in Hefei is theoretically processed in this paper. The area of winter air vents and width of PV-Trombe wall are determined, the effects of two improvements (thermal insulation and shading curtain) are investigated, and the different operating results for winter heating and summer cooling are also obtained. Results show that if compared to the original PV-Trombe wall, after thermal insulating, the indoor temperature increases by 2.36°C in winter and decreases by 2.47°C in summer and the electrical efficiency decreases by <2%. After curtain shading, the indoor temperature decreases by 2.00°C in summer and the electrical efficiency increases by ∼1%. It is recommended that thermal insulation in both winter and summer and appending a shading curtain in summer are adopted for PV-Trombe wall, especially for the diurnally used PV-Trombe wall.
Comparison of the Performance of a Forced-Air and a Radiant Floor Residential Heating System Connected to Solar Collectors
Authors: Haddad Kamel , Purdy Julia , Laouadi Aziz
Published: October 2007

A detailed building energy analysis tool is used to model the performance of a forced-air system and a radiant floor system. These two systems use a low-temperature tank to store solar energy from a solar collector array. An electrically heated tank at a higher temperature is used to provide any additional heat needed to meet the space heating load. The simulation models developed are then used to compare the performance of the forced-air and radiant floor systems based on maintaining the same operative temperature inside the space. It is found that the portion of the heating load that comes from solar energy is higher in the case of the radiant system. This portion from solar energy increases even further when the operating temperature of the radiant floor is lowered. The results also show that the energy performance of the radiant floor relative to the forced-air system improves for houses with higher envelope R-values and infiltration rates. Given the many different interacting factors that influence the performance of the solar-assisted systems studied, it is very important to use detailed simulation models to help assess which system is more energy efficient for a particular application.
On the Effectiveness of Baffles in Indirect Solar Storage Systems
Authors: Kulacki F. A. , Davidson Jane H. , Hebert M.
Published: October 2007

Parameters that control heat transfer and mixing in energy extraction from indirect solar storage tanks that employ an immersed heat exchanger with a straight baffle beneath are identified and estimated. The analysis of flow in the baffle is based on boundary layer theory and provides insight into the effectiveness of a baffle in controlling growth of the thermal plume from the heat exchanger. The important physical mechanisms are the restricted entrainment and heat transfer to the storage fluid. For an adiabatic baffle as a base case, key design factors are the point of attachment of the plume on the baffle and the width of the baffle relative to that of the heat exchanger.
Development of Optimal Design of Solar Water Heating System by Using Evolutionary Algorithm
Authors: Fong K. F. , Chow T. T. , Hanby V. I.
Published: October 2007

There are growing initiatives to promote renewable energy in Hong Kong, particularly for solar energy. In order to encourage wider application of centralized solar water heating system for high-rise residential buildings, it is important to pursue an optimal design to get significant energy-savings potential. In this regard, system optimization would be useful because it can relate to a number of design variables of the solar water heating system. The objective function is to maximize the year-round energy savings by using the solar heating against the conventional domestic electric heating. For the methodology of optimization, evolutionary programming, one of the paradigms of the evolutionary algorithm, was applied. From the optimization results, it is suggested that the solar collectors can be installed onto the external shading devices as an integrated architectural feature, since the optimal tilt angle is 21 deg and relatively flat. The optimal surface azimuth is southwest 16 deg, instead of due south. For the engineering design, both the optimal values of calorifier storage capacity and pump flow rate show that the calculations from normal design practice may not achieve an optimal performance.
Multizone Porous Medium Model of Thermal/Fluid Processes During Discharge of an Inclined Rectangular Storage Vessel Via an Immersed Heat Exchanger
Authors: Su Yan , Davidson Jane H.
Published: October 2007

The transient natural convective thermal/fluid processes during discharge of an inclined rectangular solar storage tank via an immersed heat exchanger are modeled and compared to prior experimental data. The model treats the heat exchanger as a porous medium within the storage fluid and is applicable to a wide range of tank/heat exchanger configurations. In the present study, a two-dimensional model is applied to discharge of a 126l storage tank inclined at 30deg with respect to the horizontal and with a height to width ratio of 9:1. The heat exchanger has 240 tubes arranged in parallel and is located near the top of the tank. Transient temperature distributions and flow streamlines demonstrate the complexity of the flow field and the extent of mixing during discharge. The predicted results compare favorably to prior measurements of heat transfer and temperature distribution.
DLAs AND GALAXY FORMATION
Authors: NAGAMINE KENTARO
Published: October 2007

Damped Lyman-α systems (DLAs) are useful probes of star formation and galaxy formation at high-redshift (hereafter high-z). We study the physical properties of DLAs and their relationship to Lyman break galaxies (LBGs) using cosmological hydrodynamic simulations based on the concordance Λ cold dark matter model. Fundamental statistics such as global neutral hydrogen (H I) mass density, H I column density distribution function, DLA rate-of-incidence and mean halo mass of DLAs are reproduced reasonably well by the simulations, but with some deviations that need to be understood better in the future. We discuss the feedback effects by supernovae and galactic winds on the DLA distribution. We also compute the [C II] emission from neutral gas in high-z galaxies, and make predictions for the future observations by the Atacama Large Millimeter Array (ALMA) and Space Infrared Telescope for Cosmology and Astrophysics (SPICA). Agreement and disagreement between simulations and observations are discussed, as well as the future directions of our DLA research.
CHARGED PARTICLE TUNNELS FROM THE EINSTEIN–MAXWELL–DILATON–AXION BLACK HOLE
Authors: CHEN DEYOU , YANG SHUZHENG
Published: October 2007

Considering the self-gravitation interaction and the unfixed background space–time, we study the Hawking radiation of the Einstein–Maxwell–Dilaton–Axion (EMDA) black hole by the radial geodesic method and the Hamilton–Jacobi method. Both sets of results agree with Parikh and Wilczek's and show that the actual radiation spectrum deviates from the purely thermal one and the tunneling probability is related to the change of Bekenstein–Hawking entropy, which satisfies an underlying unitary theory.
LKB1 and the regulation of malonyl-CoA and fatty acid oxidation in muscle
Authors: Thomson D. M. , Brown J. D. , Fillmore N. , Condon B. M. , Kim H-J. , Barrow J. R. , Winder W. W.
Published: October 2007

5′-AMP-activated protein kinase (AMPK), by way of its inhibition of acetyl-CoA carboxylase (ACC), plays an important role in regulating malonyl-CoA levels and the rate of fatty acid oxidation in skeletal and cardiac muscle. In these tissues, LKB1 is the major AMPK kinase and is therefore critical for AMPK activation. The purpose of this study was to determine how the lack of muscle LKB1 would affect malonyl-CoA levels and/or fatty-acid oxidation. Comparing wild-type (WT) and skeletal/cardiac muscle-specific LKB1 knockout (KO) mice, we found that the 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR)-stimulated decrease in malonyl-CoA levels in WT heart and quadriceps muscles was entirely dependent on the presence of LKB1, as was the AICAR-induced increase in fatty-acid oxidation in EDL muscles in vitro, since these responses were not observed in KO mice. Likewise, the decrease in malonyl-CoA levels after muscle contraction was attenuated in KO gastrocnemius muscles, suggesting that LKB1 plays an important role in promoting the inhibition of ACC, likely by activation of AMPK. However, since ACC phosphorylation still increased and malonyl-CoA levels decreased in KO muscles (albeit not to the levels observed in WT mice), whereas AMPK phosphorylation was entirely unresponsive, LKB1/AMPK signaling cannot be considered the sole mechanism for inhibiting ACC during and after muscle activity. Regardless, our results suggest that LKB1 is an important regulator of malonyl-CoA levels and fatty acid oxidation in skeletal muscle.