bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alkyne Metatheses in Transition Metal Coordination Spheres: Convenient Tungsten‐ and Molybdenum‐Catalyzed Syntheses of Novel Metallamacrocycles
Authors: Bauer Eike B. , Hampel Frank , Gladysz J. A. 
Published: July 2004

AbstractReactions of (CO)5Re(Br), (η5‐C5H5)Ru(Cl)(PPh3)2, and [Pt(μ‐Cl)(C6F5)(S(CH2CH2‐)2)]2 with the alkyne‐containing phosphine Ph2P(CH2)6C≡CCH3 give the bis(phosphine) complexes fac‐(CO)3Re(Br)(Ph2P(CH2)6C≡CCH3)2 (5), (η5‐C5H5)Ru(Cl)(Ph2P(CH2)6C≡CCH3)2 (6), and trans‐(Cl)(C6F5)Pt(Ph2P(CH2)6C≡CCH3)2 (7). Alkyne metatheses with the catalyst (t‐BuO)3W(≡C‐t‐Bu) (10–15 mol %, chlorobenzene, 80 °C) give the seventeen‐membered metallamacrocycles fac‐(CO)3Re(Br)(Ph2P(CH2)6CC(CH2)6PPh2) (8), (η5‐C5H5)Ru(Cl)(Ph2P(CH2)6CC(CH2)6PPh2) (9), and trans‐(Cl)(C6F5)Pt(PPh2(CH2)6CC(CH2)6PPh2) (10). 31P NMR analyses show 90–75% conversions to 8–10 (59–47% isolated after chromatography). The identity of 8 was confirmed by a crystal structure, and 10 was hydrogenated over Pd/C to fac‐(CO)3Re(Br)(Ph2P(CH2)6CC(CH2)6PPh2) (12, 87%), which was crystallographically characterized earlier. A catalyst derived from Mo(CO)6/4‐chlorophenol effects a slower conversion of 7 to 10 at 140 °C. In the case of 5, a mer, trans isomer of 8 is isolated (11, 44%), as established by NMR and IR data. In 10–12, the diphosphines span trans positions. These results, together with previous examples involving group VIII metallocenes, establish the wide viability of the title reaction.
Optically Pure 1,2‐Bis[(o‐alkylphenyl)phenylphosphino]ethanes and Their Use in Rhodium‐Catalyzed Asymmetric Hydrogenations of α‐(Acylamino)acrylic Derivatives
Authors: Wada Yoshiyuki , Imamoto Tsuneo , Tsuruta Hideyuki , Yamaguchi Kentaro , Gridnev Ilya D. 
Published: July 2004

AbstractOptically pure (S,S)‐1,2‐bis[(o‐alkylphenyl)phenylphosphino]ethanes 1a–d were prepared in four steps from phenyldichlorophosphine via phosphine‐boranes as the intermediates. The rhodium complexes 5a–d of these diphosphines were used for the asymmetric hydrogenations of α‐(acylamino)acrylic derivatives including β‐disubstituted derivatives. Markedly high enantioselectivity (78–>99%) was observed for the reduction of β‐monosubstituted derivatives. β‐Disubstituted derivatives were also reduced in considerably high enantioselectivity (up to 90%). The single crystal X‐ray analysis of the rhodium complex 5c of (S,S)‐1,2‐bis[phenyl(5′,6′,7′,8′‐tetrahydronaphthyl)phosphino]ethane (1c) revealed its δ‐type structure with face orientation of the two tetrahydronaphthyl groups and edge orientation of the two phenyl groups. This conformation corresponds to that of the rhodium complex of 1,2‐bis[(o‐methoxyphenyl)phenylphosphino]ethane (DIPAMP); the rhodium complex of (R,R)‐DIPAMP, whose chirality at phosphorus is opposite that of 5c, exhibits a λ‐type structure with the face orientation of the two o‐methoxyphenyl groups and the edge orientation of the two phenyl groups. The conformational similarity of these rhodium complexes as well as the stereochemical outcome in the asymmetric hydrogenations means that the coordinative interaction of the methoxy group of DIPAMP with rhodium metal is not the main factor that affects asymmetric induction.
Allylation of Carbon Pronucleophiles with Alkynes in the Presence of Palladium/Acetic Acid Catalyst
Authors: Patil Nitin T. , Kadota Isao , Shibuya Akinori , Gyoung Young Soo , Yamamoto Yoshinori 
Published: July 2004

AbstractWe have developed an efficient and eco‐chemical process for the allylation of carbon pronucleophiles with alkynes. The reaction of alkynes with various active methynes and methylenes in the presence of Pd(PPh3)4/acetic acid gave the corresponding allylated products in high yields and high regioselectivities. In the present catalytic system, the key is the use of carboxylic acid which dramatically enhances the rate of the reactions. One of the important features of this process is that neither a leaving group is liberated nor is a stoichiometric amount of base needed to generate the nucleophiles.
Enantiomerically Pure Cyclopropane Building Blocks: Synthesis and Transformations of 2‐Iodocyclopropylboronic Esters
Authors: Hohn Erwin , Pietruszka Jörg 
Published: July 2004

AbstractEnantiomerically pure 2‐iodocyclopropylboronic esters 6 and 8 have been synthesized from the readily available allylic alcohol 2 via an oxidation‐radical decarboxylation sequence. These unique building blocks have been demonstrated to be versatile intermediates for a consecutive Suzuki‐coupling with aryl‐, heteroaryl‐, alkenyl‐, and cyclopropylboron derivatives (1 example each).
Room Temperature Aerobic Copper–Catalysed Selective Oxidation of Primary Alcohols to Aldehydes
Authors: Gamez Patrick , Arends Isabel W. C. E. , Sheldon Roger A. , Reedijk Jan 
Published: July 2004

AbstractA novel and very mild method for the oxidation of primary alcohols to aldehydes with excellent conversions has been developed. The reaction is carried out under air at room temperature and is catalysed using a [copper(II)‐(N ligand)n] complex with TEMPO and a base as co‐catalysts. In this paper, the performance of a series of N‐containing ligands, as well as different copper(II) salt precursors in different solvents are reported. Best results are obtained in acetonitrile/water as solvent using a copper(II) catalyst generated in situ from a Cu(II) salt with weak or non‐coordinating anions and bipyridine ligands with electron‐donating substituents. A reaction mechanism is postulated which resembles that of galactose oxidase, and in which TEMPO seems to be involved as a hydrogen acceptor.
Phenoxaphosphino‐Modified Xantphos‐Type Ligands in the Rhodium‐Catalysed Hydroformylation of Internal and Terminal Alkenes
Authors: Bronger Raymond P. J. , Bermon Jochem P. , Herwig Jürgen , Kamer Paul C. J. , van Leeuwen Piet W. N. M. 
Published: July 2004

AbstractThe solubility of the modifying ligand is an important parameter for the efficiency of a rhodium‐catalysed hydroformylation system. A facile synthetic procedure for the preparation of well‐defined xanthene‐type ligands was developed in order to study the influence of alkyl substituents at the 2‐, and 7‐positions of the 9,9‐dimethylxanthene backbone and at the 2‐, and 8‐positions of the phenoxaphosphino moiety of ligands 1–16 on solubility in toluene and the influence of these substituents on the performance of the ligands in the rhodium‐catalysed hydroformylation. An increase in solubility from 2.3 mmol⋅L−1 to >495 mmol⋅L−1 was observed from the least soluble to the most soluble ligand. A solubility of at least 58 mmol⋅L−1 was estimated to be sufficient for a large‐scale application of these ligands in hydroformylation. Highly active and selective catalysts for the rhodium‐catalysed hydroformylation of 1‐octene and trans‐2‐octene to nonanal, and for the hydroformylation of 2‐pentene to hexanal were obtained by employing these ligands. Average rates of >1600 (mol aldehyde) × (mol Rh)−1×h−1 {conditions: p(CO/H2) = 20 bar, T = 353 K, [Rh] = 1 mM, [alkene] = 637 mM} and excellent regio‐selectivities of up to 99% toward the linear product were obtained when 1‐octene was used as substrate. For internal olefins average rates of >145 (mol aldehyde)×(mol Rh)−1×h−1 {p(CO/H2) = 3.6–10 bar, T = 393 K, [Rh] = 1 mM, [alkene] = 640–928 mM} and high regio‐selectivities up to 91% toward the linear product were obtained.
Second‐Generation Paracyclophane Imine Ligands for the Dialkylzinc Addition to Aldehydes. Optimization of the Branched Side Chain leads to Improvement for Aliphatic Aldehydes
Authors: Höfener Sebastian , Lauterwasser Frank , Bräse Stefan 
Published: July 2004

AbstractTwo novel diastereomeric [2.2]paracyclophane ketimine ligands (SP,S)‐2 and (RP,S)‐2, which unite a planar chiral element and a central chiral element, were used towards the enantioselective diethylzinc addition onto aliphatic aldehydes. These improved second‐generation ligands, which are stable in air and water and are easy to obtain, showed significant improvements with respect to the ligands that were previously used.
Smoking is an occupational hazard
Authors: Howard John 
Published: July 2004

AbstractBackgroundEven though the prevalence of tobacco smoking has declined in the general population and among white‐collar workers, the prevalence of tobacco smoking among blue‐collar workers remains unacceptably high. Blue‐collar workers experience greater exposure to workplace toxins which can add to, or even multiply, their risk of adverse health effects from tobacco smoking. Among blue‐collar workers, workers in the restaurant, bar, and gaming industries are exposed to much higher levels of environmental tobacco smoke (ETS) than are office workers, and are at increased risk of cancer and cardiovascular diseases even if they are non‐smokers themselves.MethodsThe literature on health risks, and the disparity between white and blue collar workers in smoking prevalence, and the literature on various tobacco control strategies provide the sources on which this review is based.ConclusionsOver the past 20 years, the accumulating scientific evidence about smoking as an occupational hazard has prompted the implementation of various educational, economic, and legal tobacco control strategies. Am. J. Ind. Med. 46:161–169, 2004. Published 2004 Wiley‐Liss, Inc.
Efficacy of tobacco dependence treatment in the context of a “smoke‐free grounds” worksite policy: A case study
Authors: Osinubi Omowunmi Y.O. , Sinha Sharmila , Rovner Elisheva , Perez‐Lugo Marla , Jain Neetu J. , Demissie Kitaw , Goldman Maurice 
Published: July 2004

AbstractBackgroundSmoking restrictions provide opportunities to modify smoking behavior. A large insurance company implemented a smoke‐free grounds policy at two of their office complexes in January, 2000.MethodsThis cohort study evaluated the impact of the smoke‐free grounds policy on abstinence among 128 employees who participated in a tobacco dependence treatment program.ResultsThe overall quit rate at 6 months was 44.5%. The larger complex showed a trend for higher quit rates compared to the smaller complex (46.5 vs. 28.6%). Post‐ban participants had higher quit rates than pre‐ban participants (52.4 vs. 43.0%). The probability of abstinence at 6 months follow‐up was higher for post‐ban compared to pre‐ban participants (P = 0.03). Post‐ban participants were 80% less likely to relapse than pre‐ban participants. Non‐quitters decreased their consumption by 6.6 cigarettes/day (39.1% decrease).ConclusionsA “smoke‐free grounds” policy encourages abstinence and may play a significant role in harm reduction among continuing tobacco users. Am. J. Ind. Med. 46:180–187, 2004. © 2004 Wiley‐Liss, Inc.
Evaluation of the reliability and validity of the University of South Florida Environmental Assessment Questionnaire
Authors: Haight Robert R. , Vuskovich Matthew A. , Brooks Stuart M. , Berish Thomas S. 
Published: July 2004

AbstractBackgroundThe National Institute for Occupational Safety and Health's (NIOSH) National Occupational Research Agenda (NORA), identified “exposure assessment methods” as a priority area for research in occupational medicine.MethodsThe University of South Florida Environmental Assessment Questionnaire (EAQ) describes exposures from the workers point of view. The questionnaire was distributed to a sample of workers drawn from a population of over 3,000 workers employed by a Florida food processing plant. The analysis of the validity was based on 211 subjects and the analysis of the reliability was based on 44 subjects.ResultsFor the category scores, the sensitivities ranged from 0.67 to 1.0, the specificities ranged from 0.52 to 0.83, the positive predictive values ranged from 0.60 to 1.0, and the negative predictive values ranged from 0.55 to 1.0. All of the weighted kappas for the subcategories were above zero. The Spearman rank‐order coefficients were above 0.5 for all of the exposure categories except the mold, plant, and animal exposure category which was 0.49. The correlation coefficient for the questionnaire as a whole was 0.85.ConclusionsThis study showed the EAQ as a whole to be reliable and valid. Gathering valid occupational exposure information with this method was both feasible and economical. Am. J. Ind. Med. 46:142–150, 2004. © 2004 Wiley‐Liss, Inc.
Reducing occupation‐based disparities related to tobacco: Roles for occupational health and organized labor
Authors: Barbeau Elizabeth M. , McLellan Deborah , Levenstein Charles , DeLaurier Gregory F. , Kelder Graham , Sorensen Glorian 
Published: July 2004

AbstractBackgroundPersistent and growing occupation‐based disparities related to tobacco pose a serious public health challenge. Tobacco exacts a disproportionate toll on individuals employed in working class occupations, due to higher prevalence of smoking and exposure to secondhand smoke among these workers compared to others.MethodsWe provide an overview of recent advances that may help to reduce these disparities, including research findings on a successful social contextual intervention model that integrates smoking cessation and occupational health and safety, and a new national effort to link labor unions and tobacco control organizations around their shared interest in reducing tobacco's threat to workers' health.ConclusionsImplications of these efforts for future research and action are discussed. Am. J. Ind. Med. 46:170–179, 2004. © 2004 Wiley‐Liss, Inc.
The New York City Smoke‐Free Air Act: Second‐hand smoke as a worker health and safety issue
Authors: Chang Christina , Leighton Jessica , Mostashari Farzad , McCord Colin , Frieden Thomas R. 
Published: July 2004

AbstractBackgroundDespite the provisions of a Smoke‐Free Air Act (SFAA) enacted in 1995, more than 415,000 non‐smoking New York City workers reported exposure to second‐hand smoke in the workplace all or most of the time in 2002. Continued exposure to second‐hand smoke in New York City prompted a renewed debate about a broader smoke‐free air law.MethodsThe approach taken by the New York City Department of Health and Mental Hygiene to make the case for workplace protection from second‐hand smoke, counter the opposition's arguments, and ultimately win the support of policymakers and the public for comprehensive smoke‐free workplace legislation is described.ResultsOn December 30, 2002, New York City's Mayor signed the SFAA of 2002 into law, making virtually all workplaces, including restaurants and bars, smoke‐free.ConclusionsProponents for a stronger law prevailed by defining greater protection from second‐hand smoke as a matter of worker health and safety. Efforts to enact smoke‐free workplace laws will inevitably encounter strong opposition, with the most common argument being that smoke‐free measures will harm businesses. These challenges, however, can be effectively countered and public support for these measures is likely to increase over time by focusing the debate on worker protection from second‐hand smoke exposure on the job. Am. J. Ind. Med. 46:188–195, 2004. © 2004 Wiley‐Liss, Inc.
Predictors of smoke‐free workplaces by employee characteristics: Who is left unprotected?
Authors: Delnevo Cristine D. , Hrywna Mary , Jane Lewis M. 
Published: July 2004

AbstractBackgroundOver the last decade, there has been steady progress in the adoption of workplace smoking policies in the United States. However, the benefits of a smoke‐free workplace are not distributed equally among the workforce.MethodsData from 44,357 adults who reported that they work indoors were derived from an optional tobacco module on the 2001 Behavioral Risk Factor Surveillance System (BRFSS), administered by 25 states. Logistic regression was utilized to examine factors associated with the absence of a smoke‐free workplace policy.ResultsOverall, 70.9% of respondents reported working under a smoke‐free workplace policy. The likelihood of being protected by a smoke‐free workplace policy was significantly lower among workers who were younger, male, non‐white, engaged in heavy labor, earned less than $50,000 annually, had a high school education or less, smoked everyday, or worked in the South or Midwest.ConclusionsThere remain considerable gaps in smoke‐free workplace policy coverage. Am. J. Ind. Med. 46:196–202, 2004. © 2004 Wiley‐Liss, Inc.
Airflow obstruction attributable to work in industry and occupation among U.S. race/ethnic groups: A study of NHANES III data
Authors: Hnizdo Eva , Sullivan Patricia A. , Bang Ki Moon , Wagner Gregory 
Published: July 2004

AbstractObjectivesTo estimate the fraction of airflow obstruction attributable to workplace exposure by U.S. race/ethnic group.MethodsU.S. population‐based third National Health and Nutrition Examination Survey (NHANES III) data on 4,086 Caucasians, 2,774 African‐Americans, and 2,568 Mexican‐Americans, aged 30–75, were studied. Airflow obstruction was defined as FEV1/FVC<75% and FEV1<80% predicted. Weighted prevalence, and prevalence odds ratios (OR) adjusted for the effect of age, smoking status, pack‐years, body mass index, education, and socio‐economic status were estimated using SUDAAN software.ResultsIndustries with the most cases of airflow obstruction attributable to workplace exposure include: armed forces; rubber, plastics, and leather manufacturing; utilities; textile mill manufacturing; health care; food products manufacturing; sales; construction; and agriculture. The fraction of cases with airflow obstruction associated with work in industry varied by race/ethnic group and was estimated as 22.2% (95% CI 9.1–33.4) among Caucasians, 23.4% (95% CI 2.2–40.0) among African‐Americans, and 49.6% (32.1–62.6) among Mexican‐Americans.ConclusionsThis study found differences in the fraction of airflow obstruction cases associated with employment pattern among major U.S. race/ethnic population groups. Am. J. Ind. Med. 46:126–135, 2004. Published 2004 Wiley‐Liss, Inc.
Lack of modulating influence of GSTM1 and GSTT1 polymorphisms on urinary biomonitoring markers in coke‐oven workers
Authors: Wu Ming‐Tsang , Pan Chih‐Hong , Chen Ching‐Yi , Chen Chiou‐Jong , Huang Li‐Hung , Tsai Li‐Yu , Huang Chia‐Tsuan , Ho Chi‐Kung 
Published: July 2004

AbstractBackgroundCoke‐oven workers (COWs) are occupationally exposed to high concentrations of polycyclic aromatic hydrocarbons (PAHs). Urinary 8‐hydroxy‐2‐deoxyguanosine (8‐OH‐dG) and 1‐hydroxypyrene (1‐OHP) are biological markers of oxidative DNA damage and PAHs metabolism, respectively. In this study, we investigated whether polymorphisms of glutathione S‐transferase (GSTM1 and GSTT1) can modulate the relationship between urinary 8‐OH‐dG and 1‐OHP concentrations among the COWs.MethodsThis was a cross‐sectional study. Between February and November of 2001, 53 topside‐oven and 130 side‐oven workers with the presence of GSTM1 and GSTT1 genotypes were investigated.ResultsUrinary 1‐OHP and 8‐OH‐dG concentrations (mean ± SD) in the topside‐oven workers with the presence of GSTM1 were 107.2 ± 107.9 and 15.3 ± 9.7 ng/ml, respectively, which were not significantly different from those in the absence of GSTM1 (84.1 ± 104.5 and 12.8 ± 14.1 ng/ml). The similar insignificant results were also noted in the sideoven workers. For GSTT1 polymorphism, the results remained insignificant. In contrast, individual excretion of urinary 8‐OH‐dG and 1‐OHP concentrations were still highly correlated (Spearman correlation coefficients: r = 0.43, P < 0.0001, n = 183).ConclusionsGST may not play a role in the regulation of metabolism of urinary biological markers in COWs. Am. J. Ind. Med. 46:112–119, 2004. © 2004 Wiley‐Liss, Inc.
Impairment of cell and plasma redox state in subjects professionally exposed to chromium
Authors: Mattia Giancarlo De , Bravi Maria Cristina , Laurenti Oriana , Luca Orietta De , Palmeri Alessandro , Sabatucci Antonio , Mendico Gino , Ghiselli Andrea 
Published: July 2004

AbstractBackgroundChromium (Cr) is widely used in chemical, tannery, building, and metal industries. More recently, it has been demonstrated that Cr induces oxidative stress in mouse brain. Nevertheless very few data exist on in vivo oxidative damage in humans exposed to Cr.MethodsChanges in antioxidant parameters both in plasma (acid ascorbic redox state and total antioxidant capacity) and in red blood cells (glutathione (GSH) redox state) of 40 subjects (age 37.65 ± 7.46; M/F 20/20) professionally exposed to Cr who were recruited from metal, chemistry, and building industries were evaluated. We also evaluated the levels of lipoperoxidation (thiobarbituric acid‐reactive material, TBA‐RM) and thiol levels in plasma to assess the extent of oxidative stress state. To evaluate Cr exposure rate, we measured urinary‐chromium (U‐Cr) by an electrothermic atomization‐atomic absorption spectrometry (ETA‐AAS) method.ResultsIn this study, we found that Cr exposure induced a decrease both in GSH (P < 0.0005) and GSH/oxidized glutathione (GSSG) ratio (P < 0.0001) in red blood cells from workers with respect to control subjects. Furthermore, we also demonstrated a significant decrease of plasma acid ascorbic levels (45.7 ± 14.9 vs. 53.5 ± 16.5 μmol/L; P < 0.05) and in total plasma antioxidant capacity (1,126.3 ± 212.2 vs. 1,266.9 ± 207.8 μmol/L; P < 0.05) in subjects exposed to Cr. No difference was found with regard to TBA‐RM and thiol levels.ConclusionsThis study demonstrated that in humans, an oxidative stress occurs for Cr exposures as low as those considered safe. This oxidative stress appears to be able to affect intracellular and plasmatic antioxidant defense. Am. J. Ind. Med. 46:120–125, 2004. © 2004 Wiley‐Liss, Inc.
The association between HLA‐DPB1Glu69 and chronic beryllium disease and beryllium sensitization
Authors: McCanlies Erin C. , Ensey James S. , Schuler Christine R. , Kreiss Kathleen , Weston Ainsley 
Published: July 2004

AbstractBackgroundSeveral case‐control studies have found an association between chronic beryllium disease (CBD) and HLA‐DPB1 gene variants. However, the relationship between HLA‐DPB1 and beryllium sensitization, and whether the presence of one or two HLA‐DPB1Glu69 alleles is differentially associated with CBD and beryllium sensitization have not been completely resolved.MethodsRestriction fragment length polymorphism (RFLP) analysis was used to address these questions in a large population‐based cohort consisting of 884 beryllium workers (90 with CBD, 64 beryllium sensitized).ResultsHLA‐DPB1Glu69 was associated with both CBD (OR = 9.4; 95% CI = 5.4, 16.6) and sensitization (OR = 3.3, 95% CI = 1.9, 5.9). Further, workers with CBD and sensitization were more likely to be homozygous HLA‐DPB1Glu69 compared to workers without disease or sensitization (P < 0.001).ConclusionsFollow‐up of this cohort, scrutiny of HLA‐DPB1 haplotypes, and evaluation of gene–environment and gene–gene interactions will be important for fully understanding the immunogenetic nature of this occupational disease. Am. J. Ind. Med. 46:95–103, 2004. Published 2004 Wiley‐Liss, Inc.
Self‐reported dermatitis and skin cancer in California farm operators
Authors: Susitaival Päivikki , Beckman Robin , Samuels Steven J. , Schenker Marc B. 
Published: July 2004

AbstractBackgroundHigh rates of skin diseases and higher non‐melanoma skin cancer rates have been reported in farmers.MethodsSelf‐report of dermatitis and skin cancer was among the information collected from 1947 California farm operators, mostly men, in a telephone survey. The majority of the farmers cultivated fruits, nuts, or other field crops.ResultsDermatitis was reported by 8.9% of men and 15.8% of women during the previous 12 months. In a logistic regression model, female gender (OR 2.0, 95% confidence interval 1.3–3.0) and respiratory atopy (OR 1.4, 1.01–1.90) were the only significant independent risk factors for reported dermatosis. There was significantly less reporting of skin cancer among field farmers when compared to others. Regular sunscreen use was reported significantly more often by women (42%) as compared to men (11%).ConclusionsMore in‐depth studies are needed to get information on the role of agrochemicals as risk factors for dermatitis and skin cancer. Am. J. Ind. Med. 46:136–141, 2004. © 2004 Wiley‐Liss, Inc.