bluuebunny/crossref_metadata_2025 huggingface dataset:
Cross‐sectional follow‐up of a flu‐like respiratory illness among fiberglass manufacturing employees: Endotoxin exposure associated with two distinct sequelae
Authors: Milton Donald K. , Amsel Jon , Reed Charles E. , Enright Paul L. , Brown L. R. , Aughenbaugh Gregory L. , Morey Philip R.
Published: April 2007

Over a period of 10 years, employees in a manufacturing plant experienced sporadic flu‐like episodes after work in a basement containing a recirculated washwater mist. We report a cross‐sectional study to define the flu‐like illness and bioaerosol exposures. High concentrations of gram‐negative bacteria (GNB) (>107 cfu/ml) and endotoxin (range 34‐46 μ/ml) were found in the water. Mist contained >103 cfu/m3 of GNB, and endotoxin up to 13,900 to 27,800 ng/m3. Few fungi and thermotolerant Bacillus species and no Actinomycetes, Legionella species, or amoeba were found in washwater. Airborne levels of fungi were of the same species and magnitudes as outdoor samples. Subjects volunteered (n = 28) because of a history of flu‐like symptoms or were randomly selected (n = 102) from workers with and without current exposure to the basement. No acute cases were examined. Cases did not fulfill criteria for hypersensitivity pneumonitis (HP) and high levels of IgG antibodies to water‐borne antigens were not observed. However, among 20 subjects indicating a history of severe flu‐like episodes (severe basement flu, SBF), diffusion capacity (DLCO) was significantly lower (p = 0.015) than among other workers. The prevalence of SBF was independent of smoking. Cases occurred in clusters, and SBF was more common among workers with intermittent exposure to the basement (19 cases) than with daily exposure (1 case). These findings suggest that SBF and associated chronically depressed DLCO resulted from toxic injury following high‐level endotoxin exposure. Asthma was prevalent in the study population, particularly among employees with daily, rather than intermittent, exposure to endotoxin‐containing mist (odds ratio 6.7, p = 0.02). Thus, endotoxin exposure in this study was associated with two distinct sequelae depending on the temporal pattern of exposure.
Asbestos bodies in lung tissue following exposure to crocidolite
Authors: Williams Vincent , de Klerk Nicholas H. , Whitaker Darrell , Musk A. William , Shilkin Keith B.
Published: April 2007

A series of 206 necropsies in Western Australia (WA) have had routine counts made of asbestos bodies in samples of lung tissue using conventional light microscopy. Thirty‐two cases had worked in the asbestos industry at Wittenoom, WA and (log) counts of asbestos bodies in their lung tissue correlated well with estimates of their (log) cumulative airborne exposure to crocidolite fibers (r = 0.60). There was no association between the number of asbestos bodies and time since exposure to asbestos ceased. In subjects without known exposure to asbestos, there was a weak but nonsignificant increase in number of asbestos bodies with increasing age, with 26% of cases having no asbestos bodies present. It is concluded that the relatively simple technique of light microscopy for counting of asbestos bodies in lung tissue provides a reliable indication of the level of past occupational exposure to crocidolite in subjects whose exposure has been only to crocidolite. This could be extremely useful in follow‐up studies of cohorts that lack reliable measures of airborne exposure to crocidolite asbestos.
Development of a questionnaire in spanish on neurotoxic symptoms
Authors: Rodezno Rafael Amador , Lundberg Ingvar , Escalona Evelin
Published: April 2007

A questionnaire in Spanish (with yes/no answers) was developed in order to study effects of neurotoxic agents in groups of workers in Nicaragua. Since many workers in Latin America are illiterate, the questions were read to the subjects. The questionnaire initially contained 34 questions, which were reduced to 16 after studying whether the questions were interpreted in the intended way by the subjects, whether the answers were reasonably reproducible over a 3‐week period, and whether the questions discriminated between groups exposed to different neurotoxic agents (mercury, lead, organic solvents, and organophosphate insecticides) and nonexposed groups. In total, 851 male workers in Nicaragua and Venezuela participated in the evaluation. The questionnaire is submitted for use in the monitoring of groups exposed to neurotoxic agents, particularly in Latin America. The authors welcome further evaluation.
Musculoskeletal problems among ontario dental hygienists
Authors: Liss Gary M. , Jesin Evie , Kusiak Robert A. , White Paul
Published: April 2007

Two U.S. surveys suggested that dental hygienists (DHs) may suffer from carpal tunnel syndrome (CTS), but these studies did not use validated questionnaires, adjust for confounders, or include external controls. We conducted a questionnaire survey of all 2,142 DHs belonging to the Ontario Dental Hygienists' Association, and a referent group of 305 dental assistants (DAs), who do not scale teeth. The Standardized Nordic Questionnaire was used as the basis for asking about muscuioskeletal symptoms. The response rates in the two groups were identical. Of the DHs, 7.0% had been told by a physician since starting work that they had CTS, but only 1 of 65 had received workers' compensation. Compared to the DAs, after adjusting for age the DHs were 5.2 times (95% confidence interval [CI] 0.9‐32) more likely to have been told they had CTS and 3.7 times (95% CI 1.1‐11.9) more likely to meet a CTS case definition. The DHs were also 2.5 (95% CI 1.6‐3.9), 2.8 (95% CI 1.8‐4.4), and 1.8 (95% CI 1.2‐2.7) times more likely to report hand/wrist, shoulder, and neck problems in the past 12 months, respectively, but were less likely to report low back trouble. In internal analyses among DHs using logistic regression models, the number of heavy calculus patients per day, “clock” position around the dental chair, and years in practice were significant predictors of CTS. Days worked per week (but not heavy calculus patients), time with the trunk rotated, and years of practice were significant predictors of reported shoulder trouble in the past 12 months. Given that there are more than 9,000 DHs in Canada and about 100,000 in the United States, these findings suggest an important public health problem. They highlight the need to inform DHs during training and continuing education about muscuioskeletal problems in general and CTS in particular. Attention should be directed to areas such as work station design, posture, treating patients with heavy calculus, and scheduling rest periods.
Inflammatory markers in nasal lavage fluid from industrial arts teachers
Authors: Åhman Mats , Holmström Mats , Ingelman‐Sundberg Henrik
Published: April 2007

Exposure to wood dust can cause allergic and nonallergic rhinitis. Inflammatory markers [cells, albumin, tryptase, and eosinophil cationic protein (ECP)] were examined in nasal lavage fluid (NAL) sampled from 24 Industrial Arts (IA) teachers exposed to wood dust and other irritants and from 24 control subjects. The IA teachers had more nasal complaints but they did not differ significantly from the controls regarding ECP concentration (median 4.1 and 4.7 μg/L, respectively), albumin concentration (median 30.7 and 20.7 g/L), and percentage of neutrophils (median 56 and 34) in NAL. Tryptase was not detected. No marked inflammation was thus found, but the albumin concentration was higher in subjects reporting nasal stuffiness. In the IA teachers, a relationship between the percentage of neutrophils and the number of classes during the working week was found (Spearman's rank correlation coefficient 0.53, p<0.01) indicating a possibility of wood‐dust‐related inflammatory effects on the nasal mucosa.
Incidence of farm‐work–related acute injury in a defined population
Authors: Nordstrom David L. , Layde Peter M. , Olson Kurt A. , Stueland Dean , Brand Laura , Follen Marilyn A.
Published: April 2007

To determine occurrence and sources of farm‐work‐related injury, we conducted a population‐based, prospective study in a large clinic and hospital serving a defined rural area. The population at risk was identified through a unique demographic and medical records linkage system and a special agricultural census. Cases were 510 individuals who sought inpatient or outpatient care from May 1990 through April 1992 from a physician or chiropractor for harm resulting from acute exposure to energy. One per 31 farm residents was treated annually for a farm‐work‐related injury. Eight percent of these cases were hospitalized. Animals were the most frequent source of injury. Severity did not differ between cases associated with animals, machinery, falls, or chemicals. Thirty‐eight percent of farm‐work‐related injury cases occurred in nonfarm residents. Injury risk was 2.5 times greater among dairy farm residents than among nondairy farm residents, 352.0 vs. 141.0 cases per 10,000 person‐years, respectively. Adult male farm residents had 556.9 injuries per 10,000 person‐years and 21.3 injuries per million hours of farm work.
Farm‐work hazard prevention efforts by school‐based agricultural education instructors
Authors: Chapman Larry J. , Schuler Ronald T. , Wilkinson Terry L. , Skjolaas Cheryl A.
Published: April 2007

Objective: To assess current prevention efforts, we examined agricultural work‐related safety and health activities by school‐based agricultural education instructors in Wisconsin. Methods: Questionnaires were administered to 284 high school agricultural education instructors. Results: Instructors taught agricultural safety and health to 61.5 students during 20.4 hours during the previous year. Extension agents were used most often as resources during preparation and presentation of coursework. Only a minority of instructors (13.6%) agreed that modifying the work to eliminate hazards should be emphasized over training people to work safely around hazards. After issues of time pressures and lack of student interest, the most important problems the instructors felt they faced were the needs for materials and other resources. Conclusion: Safety education alone is unlikely to reduce injuries unless unsafe conditions are modified. Instructors need to emphasize teaching of skills in hazard recognition, identification, and control. Instructors felt they could be more effective with better materials and more time for injury and disease prevention.
Back pain among workers in the United States: National estimates and workers at high risk
Authors: Guo How‐Ran , Tanaka Shiro , Cameron Lorraine L. , Seligman Paul J. , Behrens Virginia J. , Ger Jiin , Wild Deanna K. , Putz‐Anderson Vern
Published: April 2007

Back pain accounts for about one fourth of workers' compensation claims in the United States. The Occupational Health Supplement to the 1988 National Health Interview Survey provided an opportunity to assess the scope of this problem. The 30,074 respondents who worked in the 12 months before the interview were defined as “workers”, and those with back pain every day for a week or more during that period were defined as “cases.” A weighting factor was applied to the answers to derive national estimates. In 1988, about 22.4 million back pain cases (prevalence 17.6%) were responsible for 149.1 million lost workdays; 65% of cases were attributable to occupational activities. For back pain attributed to activities at work, the risk was highest for construction laborers among males (prevalence 22.6%) and nursing aides among females (18.8%). Our analyses show that back pain is a major cause of morbidity and lost production for U.S. workers and identifies previously unrecognized high risk occupations, such as carpenters, automobile mechanics, maids, janitors, and hairdressers, for future research and prevention.
Silica exposure and autoimmune diseases
Authors: Steenland Kyle , Goldsmith David F.
Published: April 2007

There have long been case reports linking silica exposure to a variety of autoimmune diseases (systemic sclerosis, rheumatoid arthritis, lupus, chronic renal disease). Evidence of this association in larger epidemiologic studies has been increasing in the last decade. We summarize this evidence here, and present some plausible mechanisms which have been discussed in the literature. The link between silica exposure and autoimmune disease may have been missed in cohort mortality studies because autoimmune diseases are rarely underlying causes of death. Similarly, case‐control studies of autoimmune diseases have often failed to consider occupational exposure to silica. Further research is needed in occupationally exposed populations to verify this association. The link between respirable silica exposure and autoimmune disease may have some bearing on the possible association between silicone breast implants and autoimmune disease, although the nature of the silica involved is quite different in the two Situations.
Moderne Potentiometrie
Authors: Bakker Eric , Pretsch Ernö
Published: April 2007

Die meisten Chemiker verbinden Potentiometrie mithilfe ionenselektiver Elektroden (ISEs) in erster Linie mit pH‐Messungen mit einer Glaselektrode. Wer sich für die klinische Analytik interessiert, weiß außerdem, dass ISEs routinemäßig zur Bestimmung von Elektrolyten im Blut eingesetzt werden und einen Marktumfang erzielen, der dem von Glaselektroden nahekommt. Weniger bekannt ist, dass die Potentiometrie im Laufe des letzten Jahrzehnts eine stille Revolution durchlaufen hat. Die untere Nachweisgrenze und die Diskriminierung von Störionen (die Selektivitätskoeffizienten) wurden in vielen Fällen um Faktoren von bis zu 106 bzw. 1010 verbessert, sodass heute Anwendungen z. B. in der Umweltspurenanalyse und der potentiometrischen Biosensorik möglich sind. Eine weitere wichtige Anwendung, die ebenfalls Thema dieses Kurzaufsatzes ist, ist die Bestimmung von Komplexbildungskonstanten von Komplexen aus lipophilen Wirt‐ und ionischen Gastkomponenten.
Cover Picture: Surface Change of Ras Enabling Effector Binding Monitored in Real Time at Atomic Resolution (ChemBioChem 7/2007)
Authors: Kötting Carsten , Kallenbach Angela , Suveyzdis Yan , Eichholz Carolin , Gerwert Klaus
Published: April 2007

The cover picture shows the switch‐I movement that turns the Ras protein from the off‐signalling to the on‐signalling state (RasoffGTP (PDB ID: 1X1S) to RasonGTP (PDB ID: 5P21)). Time‐resolved FTIR spectroscopy monitors the switch‐I movement in real time with a rate constant of 5 s−1 at 260 K by using the carbonyl vibration of Thr35 as a marker. This absorption was assigned by means of isotopically labelled Ras. Laser flash photolysis of para‐hydroxyphenacyl‐caged GTP triggers the reaction within nanoseconds. Surprisingly, we identified a nonsignalling Ras state even when GTP is bound (RasoffGTP). A small molecule that is able to shift the equilibrium from RasonGTP to RasoffGTP in oncogenic mutations would prevent uncontrolled signalling. The IR difference spectrum can then be used as a spectroscopic fingerprint in a screening assay for such small molecules. For further information see the full paper by C. Kötting, K. Gewert, et al. on p. 781 ff.
Catalytic Transformations for Production of Fine Chemicals and Pharmaceuticals from Wood‐Derived Raw Materials
Authors: Murzin D. Y. , Mäki‐Arvela P. , Salmi T. , Holmbom B.
Published: April 2007

Wood is a valuable raw material for the production of fine chemicals. However, since wood extractives cannot be used directly, their chemical transformation is required. Catalytic processes, in particular, possess the advantages of being environmentally friendly and industrially attractive. The use of sugars for the production of sugar alcohols and terpene transformations, are well known examples. In contrast, catalytic processes for the utilization of fatty acids, phytosterols and lignans as raw materials are very rarely reported. The products obtained from these materials exhibit health promoting properties. The present mini‐review is focused on recent activities devoted to catalytic transformations of fatty acids, phytosterols and lignans derived from wood.
Dry SO2 Removal Process Using Calcium/Siliceous‐Based Sorbents: Deactivation Kinetics Based on Breakthrough Curves
Authors: Dahlan I. , Mohamed A. R. , Kamaruddin A. H. , Lee K. T.
Published: April 2007

The removal of sulfur dioxide (SO2) from simulated flue gas was investigated in a laboratory‐scale stainless steel fixed‐bed reactor using sorbents prepared from various siliceous materials, i.e., coal fly ash (CFA), oil palm ash (OPA) and rice husk ash (RHA) mixed with lime (CaO) by means of the water hydration method. Experiments were carried out with a flue gas flow rate of 150 mL/min, reaction temperature of 100 °C, and SO2 concentration of 1000 ppm. It was found that sorbents prepared from RHA have high BET surface areas and high SO2 sorption capacities, based on breakthrough curve analysis. In addition, the SO2 breakthrough curves were also described in terms of a simple first‐order deactivation model containing only two rate constants, one of which, ks, describes the surface reaction rate constant while the other, kd, describes the deactivation rate constant. The values of ks and kd obtained from the deactivation kinetics model were in good agreement with the experimental breakthrough curves and were also compared with those available in the literature.
Bed Expansion – Extending Correlations for Fluidized Beds with Inserts to Open Fluidized Beds
Authors: Leaper M. C. , Hilal N.
Published: April 2007

Bed expansion occurs during the operation of gas‐fluidized beds and is influenced by particle properties, gas properties and distributor characteristics. It has a significant bearing on heat and mass transfer phenomena within the bed. A method of predicting bed expansion behavior from other fluidizing parameters would be a useful tool in the design process, dispensing with the need for small‐scale trials. This study builds on previous work on fluidized beds with vertical inserts to produce a correlation that links a modified particle terminal velocity, minimum fluidizing velocity and distributor characteristics with bed voidage in the relationship with P as the pitch between holes in the perforated distributor plate.
Determination of bevantolol enantiomers in human plasma by coupled achiral–chiral high performance‐liquid chromatography
Authors: Oh Joung Weon , Trung Tran Quoc , Sin Kwan Seog , Kang Jong Seong , Kim Kyeong Ho
Published: April 2007

A coupled achiral–chiral high performance liquid chromatographic method was developed and fully validated for the determination of bevantolol enantiomers, (−)‐(S)‐bevantolol and (+)‐(R)‐bevantolol, in human plasma. Plasma samples were prepared by solid phase extraction with Sep‐Pak Plus C18 cartridges followed by HPLC. Bevantolol enantiomers and (+)‐(R)‐Propranolol as internal standard (IS) were preseparated from interfering components in plasma on a Phenomenex silica column and bevantolol enantiomers and IS were resolved and determined on a Chiralcel OJ‐H chiral stationary phase. The two columns were connected by a switching valve equipped with silica precolumn. The Precolumn was used to concentrate bevantolol in the eluent from the achiral column before back flushing onto chiral phase. A detailed validation of the method was performed accordingly to FDA guidelines. For each enantiomer the assay was linear between 20 and 1600 ng/ml. The quantification limits of both bevantolol enantiomers were 20 ng/ml. The intraday variation was between 1.07 and 12.64% in relation to the measured concentration and the interday variation was 0.91 and 11.79%. The method has been applied to the determination of (−)‐(S)‐ and (+)‐(R)‐bevantolol in plasma from healthy volunteers dosed with racemic bevantolol hydrochloride. hydrochloride. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Application of liquid chromatography—Tandem mass spectrometry method for the analysis of new nonselective β‐adrenergic blocker 1‐(1‐H‐indol‐4‐yloxy)‐3‐{[2‐(2‐methoxy phenoxy)ethylo]amino}propan‐2‐ol (2F109) in rat plasma
Authors: Walczak Maria , Szafarz Malgorzata , Szymura‐Oleksiak Joanna , Groszek Grazyna , Bednarski Marek , Filipek Barbara
Published: April 2007

A sensitive and specific liquid chromatography electrospray ionization—tandem mass spectrometry method for the enantioselective determination of the novel β‐adrenolytic compound, 1‐(1‐H‐indol‐4‐yloxy)‐3‐{[2‐(2‐methoxyphenoxy)ethylo]amino} propan‐2‐ol, in rat plasma has been developed and validated. Chromatography was performed on a reversed‐phase Chiralcel OD‐RH analytical column (150 × 4.6 mm, 5 μm, Daicel Chemical Industries, Tokyo, Japan) with isocratic elution using a mobile phase containing acetonitrile and water with 0.01% formic acid. Detection was achieved by an Applied Biosystems MDS Sciex (Concord, Ontario, Canada) API 2000 triple quadrupole mass spectrometer. Electrospray ionization (ESI) was used for ion production. The limit of detection in the MRM mode was found to be 1.25 ng/ml. The limit of quantification of both enantiomers was 2.5 ng/ml. The precision and accuracy for both intra‐ and inter‐day determination of 2F109 enantiomers ranged from 2.6 to 12% and from 89.1 to 107.1%. This analytical method allowed us to carry out pharmacokinetic studies in rats. Our findings demonstrate that 2F109 shows stereoselective disposition in rat plasma after i.v. administration. The terminal half‐lives of (+)‐(R)‐2F109 and (−)‐(S)‐2F109 were 33.5 and 42.6 min, respectively. The AUC0–inf of (+)‐(R)‐2F109 exceeded that of (−)‐(S)‐2F109. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Measurement of 1H–1H Residual Dipolar Coupling Constants for Structural Studies of Medium Size Molecules
Authors: Jin Lan , Pham Tran N. , Uhrín Dušan
Published: April 2007

Residual dipolar coupling constants (RDCs) are being increasingly applied to elucidate the configuration and conformation of small organic molecules, peptides and oligosaccharides. In this paper we describe a set of robust 1D NMR methods for accurate and precise measurement of proton–proton RDCs of small and medium size molecules. The performance of these techniques is not impeded by the presence of overlapping and broad 1H multiplets that are typically observed for such molecules in weakly aligned media. The use of these techniques provides access to a large pool of proton–proton RDCs opening new avenues for the solution structure elucidation of medium size molecules by NMR. The techniques are illustrated on the determination of the alignment tensor of the reducing monosaccharide ring of cellobiose and the determination of the relative configuration of sodium cholate.
Reactions of 1,2,4‐Trithiolane, 1,2,5‐Trithiepane, 1,2,5‐Trithiocane and 1,2,6‐Trithionane with Nonacarbonyldiiron: Structural Determination and Electrochemical Investigation
Authors: Windhager Jochen , Rudolph Manfred , Bräutigam Silvio , Görls Helmar , Weigand Wolfgang
Published: April 2007

The reactions of 1,2,4‐trithiolane (1), 1,2,5‐trithiepane (6), 1,2,5‐trithiocane (12) and 1,2,6‐trithionane (10) with nonacarbonyldiiron (2) have been investigated. A novel diiron model complex, which can serve as a model complex of the active site of [Fe‐only]‐hydrogenase, was formed from the reaction with 1. In contrast, the reaction of 6 with 2 afforded the trinuclear iron cluster 7. Interestingly, the diiron compound 11 was obtained with 1,2,6‐trithionane (10), which can be attributed to the more flexible dithiolato ligand 10. Furthermore, the reaction with 1,2,5‐trithiocane (12) yielded the trinuclear cluster 13. X‐ray structure analyses were performed on compounds 3, 7, 10, 11 and 13. The reactions of the reduced iron species 3 with pivalic acid (HP) were studied electrochemically. The most significant features of the experimental cyclic voltammograms (CVs) could be reproduced by digital simulation on the basis of a reaction scheme that includes both the coordination of HP as well as the catalytic generation of hydrogen. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Asymmetric Synthesis of Aliphatic 2‐Hydroxy Ketones by Enzymatic Carboligation of Aldehydes
Authors: Domínguez de María Pablo , Pohl Martina , Gocke Dörte , Gröger Harald , Trauthwein Harald , Stillger Thomas , Walter Lydia , Müller Michael
Published: April 2007

Benzaldehyde lyase (BAL) and benzoylformate decarboxylase (BFD) catalyse the asymmetric ligation of aliphatic aldehydes to afford enantiomerically enriched 2‐hydroxy ketones. Carboligation of linear aldehydes with both enzymes results in high levels of conversion and in enantioselectivities of up to 80 % ee. In cases involving branched aliphatic aldehydes, BAL enables the carboligation of 3‐methylbutanal with a high level of conversion and an enantioselectivity of 89 % ee.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Isotope distribution of dissolved carbonate species in southeastern coastal aquifers of Sicily (Italy)
Authors: Schiavo M. A. , Hauser S. , Povinec P. P.
Published: April 2007

Concentrations of major ions and the δ13C composition of dissolved inorganic carbon in groundwater and submarine groundwater discharges in the area between Siracusa and Ragusa provinces, southeastern Sicily, representing coastal carbonate aquifers, are presented and discussed. Most of groundwater analysed belongs to calcium bicarbonate type, in agreement with the geological nature of carbonate host rocks. Carbonate groundwater acquires, besides the dissolution of carbonate minerals, dissolved carbon (and the relative isotopic composition) from the atmosphere and from soil biological activity. In fact, δ13C values and total dissolved inorganic carbon contents show that both these sources contribute to carbon dissolved species in the waters studied. Finally, mixing with seawater in the second main factor of groundwater mineralization Copyright © 2007 John Wiley & Sons, Ltd.
God's will, God's punishment, or God's limitations? Religious coping strategies reported by young adults living with serious mental illness
Authors: Phillips Russell E. , Stein Catherine H.
Published: April 2007

Qualitative research has demonstrated that religious meaning‐making coping, defined as attributions of a stressful life event that involve the sacred, is particularly relevant to persons with serious mental illness. However, recent research advances in the study of religious coping have yet to be employed in clinical samples. This longitudinal study examines religious meaning‐making coping in a sample of 48 young adults diagnosed with schizophrenia or bipolar disorder over a one‐year period. Young adults with mental illness generally reported using religious meaning‐making coping in levels comparable to nonpsychiatric samples. Reports of benevolent religious reappraisals were associated with perceptions of positive mental health, whereas punishing God reappraisals and reappraisals of God's power were associated with self‐reported distress and personal loss. Religious coping variables accounted for variation in adults' reports of psychiatric symptoms and personal loss one year later over and above demographic and global religious variables. Implications of findings for clinical practice are discussed. © 2007 Wiley Periodicals, Inc. J Clin Psychol.
Occult hepatitis B virus infection in the setting of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) co‐infection: Clinically relevant or a diagnostic problem?
Authors: Rodríguez‐Torres M. , Gonzalez‐Garcia J. , Bräu N. , Solá R. , Moreno S. , Rockstroh J. , Smaill F. , Mendes‐Correa M.C. , DePamphilis J. , Torriani F.J. ,   for the APRICOT investigators
Published: April 2007

The clinical relevance of occult hepatitis B virus (HBV) infection, defined as detectable HBV DNA serum/liver, in the absence of hepatitis B surface antigen (HBsAg), is unclear. We determined the prevalence of serum occult HBV infection in HIV/HCV co‐infected patients enrolled in APRICOT, a randomized multinational trial that investigated the efficacy and safety of peginterferon alfa‐2a (40 kDa) plus ribavirin for treatment of HCV. We also examined the effect of prior HBV exposure to liver histology at baseline. Only HBsAg‐negative patients were eligible. At screening, serum HBV DNA was assessed by commercial assay (detection limit = 200 copies/mL). Patients were divided into four serological groups: anti‐HBs+/anti‐HBc+; anti‐HBs−/anti‐HBc+; anti‐HBs+/ anti‐HBc−; anti‐HBs−/anti‐HBc−. Baseline liver biopsy grade and stage were compared among groups. Serum HBV DNA was undetectable in all patients, (n = 866). Results of anti‐HBs and anti‐HBc was available for 176 patients: 60 (34.1%) anti‐HBs+/anti‐HBc+; 60 (34.1%) anti‐HBs−/anti‐HBc+; 11 (6.3%) anti‐HBs+/anti‐HBc−; 45 (25.6%) anti‐HBs−/anti‐HBc−. There were no differences among the groups in the histological grade or stage at baseline liver biopsies. Occult HBV infection in serum was not detected in this large immunocompetent cohort. Moreover, prior exposure to HBV did not appear to have any affect on baseline liver histology. J. Med. Virol. 79: 694–700, 2007. © 2007 Wiley‐Liss, Inc.
Enhanced poly(ADP‐ribose) polymerase‐1 activation contributes to recombinant tissue plasminogen activator‐induced aggravation of ischemic brain injury in vivo
Authors: Crome Olaf , Doeppner Thorsten R. , Schwarting Sönke , Müller Barbara , Bähr Mathias , Weise Jens
Published: April 2007

Recombinant tissue plasminogen activator (rt‐PA) treatment improves functional outcome after acute ischemic stroke, inducing reperfusion by its thrombolytic activity. Conversely, there is evidence that rt‐PA can mediate neuronal damage after ischemic brain injury in vivo. In addition to other mechanisms, enhancement of N‐methyl‐D‐aspartate (NMDA) receptor signalling has been proposed to underlie rt‐PA‐mediated neurotoxicity. However, the role of poly(ADP‐ribose) polymerase‐1 (PARP‐1) activation, which mediates postischemic excitotoxic cell death, in rt‐PA‐mediated aggravation of ischemic brain injury has not been established and was therefore addressed in this study. After permanent focal cerebral ischemia, intravenous rt‐PA application significantly increased early postischemic PARP‐1 activation within ischemic hemispheres and infarct volumes compared with control mice without affecting cerebral blood flow. Rt‐PA induced increase in PARP‐1 activation, and infarct volumes could be blocked by the PARP inhibitor 3‐aminobenzamide. Moreover, the rt‐PA‐induced increase in PARP‐1 activation was also prevented by the NMDA antagonist MK‐801. In summary, we demonstrate that rt‐PA treatment enhances postischemic PARP‐1 activation, which contributes to rt‐PA induced aggravation of ischemic brain injury in vivo. Furthermore, we provide evidence that NMDA receptor activation is required for rt‐PA‐mediated effects on postischemic PARP‐1 activation. © 2007 Wiley‐Liss, Inc.
Mechanics of oriented electrospun nanofibrous scaffolds for annulus fibrosus tissue engineering
Authors: Nerurkar Nandan L. , Elliott Dawn M. , Mauck Robert L.
Published: April 2007

Engineering a functional replacement for the annulus fibrosus (AF) of the intervertebral disc is contingent upon recapitulation of AF structure, composition, and mechanical properties. In this study, we propose a new paradigm for AF tissue engineering that focuses on the reconstitution of anatomic fiber architecture and uses constitutive modeling to evaluate construct function. A modified electrospinning technique was utilized to generate aligned nanofibrous polymer scaffolds for engineering the basic functional unit of the AF, a single lamella. Scaffolds were tested in uniaxial tension at multiple fiber orientations, demonstrating a nonlinear dependence of modulus on fiber angle that mimicked the nonlinearity and anisotropy of native AF. A homogenization model previously applied to native AF successfully described scaffold mechanical response, and parametric studies demonstrated that nonfibrillar matrix, along with fiber connectivity, are key contributors to tensile mechanics for engineered AF. We demonstrated that AF cells orient themselves along the aligned scaffolds and deposit matrix that contributes to construct mechanics under loading conditions relevant to the in vivo environment. The homogenization model was applied to cell‐seeded constructs and provided quantitative measures for the evolution of matrix and interfibrillar interactions. Finally, the model demonstrated that at fiber angles of the AF (28°–44°), engineered material behaved much like native tissue, suggesting that engineered constructs replicate the physiologic behavior of the single AF lamella. Constitutive modeling provides a powerful tool for analysis of engineered AF neo‐tissue and native AF tissue alike, highlighting key mechanical design criteria for functional AF tissue engineering. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1018–1028, 2007
Measurement of varus–valgus and internal–external rotational knee laxities in vivo—part i: assessment of measurement reliability and bilateral asymmetry
Authors: Shultz Sandra J. , Shimokochi Yohei , Nguyen Anh‐Dung , Schmitz Randy J. , Beynnon Bruce D. , Perrin David H.
Published: April 2007

We examined the capabilities of the Vermont Knee Laxity Device (VKLD) in measuring varus (VR)–valgus (VL) and internal (INT)–external (EXT) rotational laxities by quantifying measurement consistency and absolute measurement error (N = 10). Based on the expected measurement error, we then examined side‐to‐side differences (N = 20). For all measures, the knee was flexed 20°, the thigh securely fixed, and counterweights applied to the thigh and shank to create an initial zero shear and compressive load across the tibiofemoral joint. A 10‐Nm torque was applied to the knee for VL and VR during non‐weight‐bearing, and a 5‐Nm torque was applied for INT and EXT during non‐weight‐bearing and weight‐bearing conditions. Position sensors measured angular displacements (deg). Except for INT during weight bearing, measurement consistency was good to excellent (range, 0.68–0.96), with absolute measurement errors generally less than 2° for VR–VL and 3–4° for INT–EXT. Although side‐to‐side differences were observed, they did not exceed absolute measurement errors. The VKLD yields reliable measures of VR–VL and INT–EXT laxities, with sufficient measurement precision to yield clinically relevant differences. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:981–988, 2007
A comparison of mass removal, thermal injury, and crater morphology of cortical bone ablation using wavelengths 2.79, 2.9, 6.1, and 6.45 µm
Authors: Youn Jong‐In , Sweet Paula , Peavy George M.
Published: April 2007

Background and Objective

Previous investigations have reported evidence of wavelength dependence on cortical bone ablation. This study used mid‐infrared laser wavelengths generated by a free electron laser (FEL) and mass removal measurements to further examine the ablation efficiency of a wavelength (2.79 µm) not previously reported and three wavelengths (2.9, 6.1, and 6.45 µm) previously demonstrated by crater morphology alone to be efficient for cortical bone removal.

Study Design/Materials and Methods

The wavelengths examined were provided by an FEL emitting 4 microseconds macropulses consisting of 1–2 picoseconds duration micropulses delivered at 350 picoseconds intervals. The mass removal measurements were conducted by a microbalance, and the collateral thermal injury and crater morphology of cortical bone were examined by light microscopy following standard histologic processing.

Results

The study demonstrated that the highest mass removal was achieved at λ = 6.1 µm followed by, in order, λ = 2.9, 6.45, and 2.79 µm. The zones of thermal injury and crater morphology created in cortical bone at the selected wavelengths were examined at the radiant exposure of 28.3 J/cm2. Ablation using λ = 6.1 µm provided the largest crater size and the least collateral thermal injury. The greatest amount of collateral thermal injury was produced by λ = 2.79 µm at both the sides and base of the ablation crater.

Conclusions

The mass removal of cortical bone produced by FEL ablation at selected mid‐IR wavelengths was measured as a function of incident radiant exposure. The ablation efficiency was found to be dependent upon wavelength. The λ = 2.79 µm did not offer any improvement over the other wavelengths evaluated, suggesting that a potential shift in the dynamic optical properties of water during tissue irradiance with the FEL does not present an advantage to the cutting of cortical bone. The λ = 6.1 µm provided the highest ablation efficiency with deepest crater and the least amount of collateral thermal injury. Lasers Surg. Med. 39: 332–340, 2007. © 2007 Wiley‐Liss, Inc.
Novel Organic Activators for Single Site Iron Catalysts
Authors: Tudella Joana , Ribeiro Maria Rosário , Cramail Henri , Deffieux Alain
Published: April 2007

The synthesis of new organo‐aluminum derivatives based on the reaction of carboxylic acids with trialkylaluminum and their use as co‐catalysts for ethylene polymerization, in the presence of iron catalyst is described. These co‐catalysts were obtained through the reaction of acetic acid, benzoic acid, or benzoic acid derivatives with different trialkylaluminums. The most promising co‐catalyst was obtained from the reaction of benzene tricarboxylic acid (BTCA) with trimethylaluminum (TMA). The influence of alkylaluminum/BTCA ratio, reaction time, and temperature on the ethylene polymerization activity was investigated. 1H NMR spectra of some of the most active co‐catalysts confirm the formation of alumoxane‐type species.

Polymerization activities of the same order or even higher to those found using “pure” trialkylaluminums or methylaluminoxane (MAO) co‐catalysts were obtained.

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Zur Differentialgeometrie singulärer RIEMANNscher Räume
Authors: Dautcourt G.
Published: April 2007

Singuläre RIEMANNsche Räume V mit einem metrischen Tensor gμv vom Matrixrang n — d (wobei 0 < d ≦ n) sind in mehrfacher Hinsicht in der allgemeinen Relativitätstheorie von Bedeutung. In die indefinite Raum‐Zeit eingebettet können sie im Falle n = 3, d = 1 als Ausbreitungsfronten ruhmasseloser Strahlung, als Welthorizonte usw. auftreten. Weniger geklärt ist ihre Rolle als spezielle, von den EINTEINschen Feldgleichungen erlaubte Typen von Singularitäten der Raum‐Zeit. Die hier gegebene differentialgeometrische Behandlung singulärer Räume beruht auf dem Umstand, daß ihre isotropen Richtungen ausgezeichnete Kurvenkongruenzen definieren. Mit ihnen läßt sich eine Klasse affiner Zusammenhänge angeben, die eine geeignete Verallgemeinerung des Lemmas von RICCI erfüllen. Lokale geometrische Eigenschaften sind dann mit Hilfe der zugehörigen RICCIschen Rotationskoeffizienten der Kurvenkongruenzen ausdrückbar, wie Reduzibilität bzw. totale Reduzibilität, die explizite Gestalt von Differentialinvarianten usw.
Surface Phase Separation and Morphology of Stimuli Responsive Complex Micelles
Authors: Ma Rujiang , Wang Beilei , Xu Yanling , An Yingli , Zhang Wangqing , Li Guiying , Shi Linqi
Published: April 2007

Complex micelles with a P4VP core surrounded by a mixed PNIPAM/PEG shell were prepared by comicellization of PNIPAM93‐b‐P4VP58 and PEG114‐b‐P4VP58 in aqueous solutions. Increasing the temperature above the LCST of the PNIPAM induced a phase separation of the mixed shell due to the collapse of the PNIPAM block. The morphology of the collapsed PNIPAM was dependent on the composition of the mixed shell; a lower content of the PNIPAM resulted in separately distributed domains on the surface of the P4VP core, while a higher content of the PNIPAM led to the formation of continuous membrane around the P4VP core. When the continuous membrane was formed, the hydrophilic PEG block could connect the inner P4VP core and the outer milieu to form channels across the PNIPAM membrane for water and other small molecules to pass through.

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Reversible Thermally Responsive and Luminescent Coil–Rod–Coil Triblock Copolymers
Authors: Xiao Xing , Fu Ya‐qin , Zhou Jian‐jun , Bo Zhi‐shan , Li Lin , Chan Chi‐Ming
Published: April 2007

A functional coil–rod–coil triblock copolymer containing a terfluorene unit as the rigid segment and poly(N‐isopropylacrylamide) (PNIPAAm) as the flexible block was successfully synthesized via reversible addition–fragmentation chain‐transfer (RAFT) polymerization using terfluorene‐based dithioester as the RAFT agent. The temperature‐responsive optical properties were investigated with the aid of dynamic light scattering and fluorescence techniques. Additionally, the relationship between the optical properties and the reversible phase transition of the doping system formed by blending the copolymer with tetraphenylporphine tetrasulfonic acid was studied. Above the lower critical solution temperature, the energy transfer efficiency decreased as a result of the globule–to–coil transition from PNIPAAm segments. The result indicates that these copolymers have a potential to be used as responsive fluorescent probes in facile detection of dye‐labeled biopolymers.

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STAT3: A critical transcription activator in angiogenesis
Authors: Chen Zhong , Han Zhong Chao
Published: April 2007

Angiogenesis, the formation of new blood vessels from the pre‐existing vasculature, is a complex multistage process regulated by a number of signal transduction pathways. Accumulating evidence suggests that signal transducer and activator of transcription (STATs), mainly STAT3, play an important role in angiogenesis under both physiological and pathological conditions in addition to cell survival, proliferation, differentiation, and oncogenesis. STAT3, as a critical multifunctional mediator, regulates many aspects of angiogenesis at the transcriptional level. This review will highlight the pivotal role of STAT3 in well‐studied tumorous angiogenesis and cardiac angiogenesis, and summarize various potential mechanisms utilized by STAT3 to regulate the transcriptional activation of VEGF. © 2007 Wiley Periodicals, Inc. Med Res Rev, 28, No. 2, 185–200, 2008
Improving k‐t SENSE by adaptive regularization
Authors: Xu Dan , King Kevin F. , Liang Zhi‐Pei
Published: April 2007

The recently proposed method known as k‐t sensitivity encoding (SENSE) has emerged as an effective means of improving imaging speed for several dynamic imaging applications. However, k‐t SENSE uses temporally averaged data as a regularization term for image reconstruction. This may not only compromise temporal resolution, it may also make some of the temporal frequency components irrecoverable. To address that issue, we present a new method called spatiotemporal domain‐based unaliasing employing sensitivity encoding and adaptive regularization (SPEAR). Specifically, SPEAR provides an improvement over k‐t SENSE by generating adaptive regularization images. It also uses a variable‐density (VD), sequentially interleaved k‐t space sampling pattern with reference frames for data acquisition. Simulations based on experimental data were performed to compare SPEAR, k‐t SENSE, and several other related methods, and the results showed that SPEAR can provide higher temporal resolution with significantly reduced image artifacts. Ungated 3D cardiac imaging experiments were also carried out to test the effectiveness of SPEAR, and real‐time 3D short‐axis images of the human heart were produced at 5.5 frames/s temporal resolution and 2.4 × 1.2 × 8 mm3 spatial resolution with eight slices. Magn Reson Med 57:918–930, 2007. © 2007 Wiley‐Liss, Inc.
Wear of Tools Coated with Various PVD Films: Correlation with Impact Test Results by Means of FEM Simulations
Authors: Bouzakis Konstantinos‐Dionysios , Mirisidis Ioannis , Michailidis Nikolaos , Lili Eleftheria , Sampris Anastasios , Erkens Georg , Cremer Rainer
Published: April 2007

The use of appropriate cutting conditions and coatings is an issue of pivotal significance since it affects the overall tool performance in manufacturing processes. This paper introduces a quick and innovative procedure for characterizing the coating cutting performance based on the film impact resistance. A correlation between coating impact resistance and cutting performance under various conditions is established. Depending on the coated tool and the workpiece parameters, there are concrete cutting speed and feed rate regions, which can be effectively detected considering the previously mentioned correlation, leading to an enhanced cutting performance.

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Antimicrobial films for food applications: a quantitative analysis of their effectiveness
Authors: Joerger Rolf D.
Published: April 2007

A tremendous effort has been made over the last decade to develop and test films with antimicrobial properties to improve food safety and shelf life. This review catalogues and analyses the outcome of these research efforts. The bacteriocin nisin was the antimicrobial most commonly incorporated into films, followed by food‐grade acids and salts, chitosan, plant extracts, and the enzymes lysozyme and lactoperoxidase. The methodologies for measuring antimicrobial activity of both edible and inedible films varied considerably among the studies. Results, defined as the difference in the log10 colony‐forming unit (CFU) of a test organism exposed to a control film and the log10 CFU of the organism exposed to the antimicrobial film, ranged from 0 to 9 for many of the antimicrobials tested. Even for antimicrobials such as nisin, chitosan or antimicrobial acids with a ‘long’ history of studying their incorporation into antimicrobial films, the majority of results centred around 2 log10 reductions. The results suggest that antimicrobial films still face limitations and are perhaps still best viewed as part of a hurdle strategy to provide safe foods. Copyright © 2007 John Wiley & Sons, Ltd.
Calibrated phase II clinical trials in oncology
Authors: Herson Jay , Carter Stephen K.
Published: April 2007

This paper proposes the use of calibrated designs in phase II oncological clinical trials and evaluates their statistical properties in terms of power recovery and cost. A calibrated phase II design for a new cancer treatment for a specific tumour, e.g. colo‐rectal, consists of random allocation of patients to receive either the investigational treatment or a standard treatment known to have activity at a certain level in phase II trials (e.g. 5 FU, expected response proportion = 0.20). Patients assigned to the standard treatment form the calibration group. The calibration group is not a control group in the traditional sense and one does not conduct a formal efficacy comparison between the investigational treatment group and the calibration group. Instead, one uses the calibration group to evaluate whether the sample of patients who receive the investigational treatment has the capability of showing a response. If the data do not support the hypothesis that the expected response proportion prevails in the calibration group, one declares the investigational group results suspect and recommends a second trial. Assuming acceptable results of the second trial, we use binomial calculations to find the effect of the calibration design on power recovery and relative cost. We show that when an unrepresentative sample occurs, calibration designs generally recover 90 per cent or more of nominal power at a cost of three to fivefold increase in sample size. We recommend for calibrated phase II trials a ‘master protocol’ approach in which several investigational treatment arms share one concurrent calibration group.
Age, period and cohort models: The use of individual records
Authors: Robertson Chris , Boyle Peter
Published: April 2007

Problems with the interpretation of age‐period‐cohort models are dlscussed. If individual records are available as for cancer incidence in Scotland, then a solution is obtainable. An example using incidence data for cancers of the lung and larynx in Scotland is presented to illustrate the models.