bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication and Characterization of Polysulfone-Dicalcium Silicate Composite Films
Authors: Cheng Wei , Chang Jiang
Published: March 2006

Polysulfone (PSU) composite films filled with β-dicalcium silicate (-Ca2SiO4) particles are prepared by the solvent casting-evaporation method. The surface morphologies and mechanical properties of the films are determined. The bioactivity of the composite films is evaluated by soaking them in simulated body fluid (SBF) and the results show that the composites are bioactive as they induce the formation of hydroxyapatite (HAp) on the surface of the composite films. The measurement of the water contact angles suggests that the incorporation of -Ca2SiO4 particles into PSU matrix can improve the hydrophilicity of the composite. PSU composite films filled with modified -dicalcium silicate (-mCa2SiO4) particles are also prepared after -Ca2SiO4 particles are treated with dodecyl alcohol through surface esterification reactions. The infrared spectra of the -mCa2SiO4 particles before and after aging in water indicate that the surface modification is reversible. The scanning electron microscope (SEM) images (micrographs) of both composites show that the dispersion of inorganic particles in the polymer matrix improves after surface modification. The PSU- -mCa2SiO4 composite is still bioactive and exhibits the same water contact angle after aging in water as compared to that of the PSU- -Ca2SiO4 composite. All these results suggest that the incorporation of -Ca2SiO4 particles is a useful method to prepare composites with improved bioactivity and hydrophilicity, and the surface modification of -Ca2SiO4 particles can improve the dispersion while retaining the bioactivity and hydrophilicity.
Influence of a Pre-blended Antibiotic (Gentamicin Sulfate Powder) on Various Mechanical, Thermal, and Physical Properties of Three Acrylic Bone Cements
Authors: Lewis Gladius , Bhattaram Anuradha
Published: March 2006

The aim of this work was to determine an array of mechanical, physical, and thermal properties of three pairs of commercially available acrylic bone cement brands, with the brands in each pair having the same compositions except that one contains 4.22 wt/wt% gentamicin sulfate blended with the powder by the manufacturer and the other one does not. The difference between the pairs was in the viscosity of the curing cement dough, with one pair of ‘low-viscosity’, one pair of ‘medium-viscosity’, and one pair of ‘high-viscosity’ brands being used. Thus, the brands studied cover the range of those used in anchoring some total joint replacements (TJRs). The properties determined were the strength, modulus, and work-to-fracture (all under four-point bending), plane-strain fracture toughness, Weibull mean fatigue life (fatigue conditions: 15 MPa; 2 Hz), activation energy and frequency factor for the cement polymerization process (both determined, using differential scanning calorimetry, at heating rates of 5, 10, 15, and 20 K min 1), and the diffusion coefficient for the absorption of phosphate-buffered saline at 37 C by the cured cement. For each property determined, there was no significant difference in the mean values for the brands in each of the pairs. These results indicate that over the range of cement brands that are widely used in the anchoring of cemented TJRs, the addition of gentamicin sulfate powder does not degrade the properties of the cement, and, hence, may not adversely affect the in vivo longevity of the replacement.
A Prospective Analysis of Juvenile Male Sex Offenders
Authors: Vandiver Donna M.
Published: March 2006

This research assesses the recidivism rates of a sample of 300 registered male sex offenders who were juveniles at the time of their initial arrest for a sex offense. This sample is followed for 3 to 6 years after they reached adulthood; recidivism rates are assessed during their adulthood only. The typical juvenile is a 15-year-old Caucasian male who was arrested for sexual assault or indecency with a child. The majority of the victims are females with an average age of 8. Although only 13 are rearrested during the follow-up period for a sex offense, more than half of the sample is arrested at least once for a nonsexual offense. The results of a Cox regression indicate that victim age, offender age, and victim sex are significant predictors of recidivism during adulthood.
Doing Democracy, Engaging the Material
Authors: Cheney George , Cloud Dana L.
Published: March 2006

This colloquy results froma series of discussions between the authors concerning issues of (a) the status of labor activity in organizational communication study, (b) the dimensions of and prospects for workplace democracy in practice, and (c) the need for the discipline of communication to attend more seriously to the material world. The authors write this essay using three voices: each of theirs plus a joint expression of interests. Above all, this conversation seeks to strengthen engagement of possibilities for robust democratic practices in the work of today's globalizing market economy and to challenge communication scholars to see economic and labor phenomena as more than can be perceived through the lens of unbridled discursive and symbolic constructionism. Although this essay ranges across questions of ontological status, epistemological choices, disciplinary mythos, and theoretical preferences, it is ultimately practical with a call for (organizational) communication scholars and activists to engage the misguided pursuits, injustices, and hopes surrounding contemporary corporate-consumer capitalism.
Evaluation of Entrepreneurial Risk-Taking using Magnitude of Loss Scale
Authors: Kamalanabhan T.J. , Sunder D.L. , Manshor Amat Taap
Published: March 2006

The importance of risk-taking in business ventures has been emphasised by many. Attempts to distinguish entrepreneurs on their risk-taking propensity have produced conflicting results. Data on two measures of risk-taking propensity were collected from entrepreneurs, prospective entrepreneurs and non-entrepreneur others. While the groups did not differ significantly on risk-taking propensity as measured by the Choice Dilemma Questionnaire, entrepreneurs and prospective entrepreneurs differed significantly from others on the Magnitude of Loss Questionnaire. Similarly, entrepreneurial aspirants differed significantly from the nonentrepreneur group. These results highlight the significance of loss, an important aspect in risk-taking, which is often ignored in entrepreneurial and managerial studies. The riskiness in business ventures which has been the main stumbling block for many is not the low probability of success but the high stakes involved in entrepreneurship.
Characteristics of Entrepreneurs:
Authors: Nair K.R.G. , Pandey Anu
Published: March 2006

This paper examines the socio-economic and attitudinal characteristics of entrepreneurs on the basis of primary data for the state of Kerala. It does not appear that business acumen runs in families nor is there evidence that religion has an impact on entrepreneurship. The economic status of the family, age, technical education/training and work experience in a similar or related field seem to favour entrepreneurship. In comparison to the rest of the population, entrepreneurs tend to be more innovative in their attitude, but do not seem to have greater faith in the internal locus of control.
Comparative Methods for Studying Cultural Trait Evolution: A Simulation Study
Authors: Nunn Charles L. , Mulder Monique Borgerhoff , Langley Sasha
Published: March 2006

Anthropologists and archaeologists increasingly use phylogenetic methods to test hypotheses involving cross-cultural traits, but the appropriateness of applying tree-based methods to analyze cultural traits is unclear. The authors developed a spatially explicit computer simulation model to investigate trait evolution in relation to phylogeny and geography and used the simulation to assess the sensitivity of two comparative methods (independent contrasts and partial Mantel tests) to different degrees of horizontal transmission. Simulation results show that (a) the method of independent contrasts is sensitive to even small amounts of horizontal transmission in cultural data sets, (b) Mantel tests fail to cleanly discriminate between datasets characterized by different levels of horizontal and vertical trait transmission, and (c) partial Mantel tests do not produce markedly improved statistical performance when testing for associations among traits (as compared to independent contrasts). The results highlight the need for empirical estimates of horizontal transmission and extinction rates in cross-cultural datasets.
Do Living Wage Policies Diffuse?
Authors: Martin Isaac
Published: March 2006

This research note examines the conditions under which large U.S. cities pass living wage laws. It updates the only published article on the subject with new data and improved analytic methods. First, it shows that poverty, privatization, and the density of community organizations are associated with policy passage. Second, it provides new quantitative evidence that the living wage movement is, in part, a diffusion process associated with national community-organizing networks.
(Dis)similar Readings
Authors: Chitnis Ketan S. , Thombre Avinash , Rogers (late) Everett M. , Singhal Arvind , Sengupta Ami
Published: March 2006

The present article compares Indian and American audiences’ interpretations of the Hollywood sitcom Friends. The article is guided by Olson’s narrative transparency theory, which posits transparency as ‘the capability of certain texts to seem familiar regardless of their origin, to seem a part of one’s own culture, even though they have been crafted elsewhere’. Thirty-seven regular viewers of Friends in India and 35 from the US were interviewed personally and in focus groups. Indian viewers questioned the truth-value of the content to conclude that Friends portrayed a universal American culture that is completely different from an Indian standpoint. These interpretations made the media text opaque, and the Indian audience members rejected the safe sex message discussed in the episode studied. The American audience found Friends overly exaggerated, but safe sex and sexuality messages somewhat more culturally proximate.
Functions of Egyptian Journalists
Authors: Ramaprasad Jyotika , Hamdy Naila Nabil
Published: March 2006

This study reports on Egyptian journalists’ rating of various journalistic functions in terms of both importance and ability to perform these functions. The functions, rated for importance, coalesced into four factors, Sustain Democracy, Support Arabism/Values, Support Government and Provide Entertainment. Egyptian journalists gave prime importance to supporting Arabism/values and also performed this function most often. They considered democracy-sustaining functions second in importance, but were able to perform them least often, at about the average level. For all function factors, perceived importance was discrepant with actual amount of performance, with the latter always being lower. The study’s contribution lies in (1) the quantitative benchmarks it establishes for Egyptian journalism practice, (2) its inclusion of functions specific to Egyptian society and press as culled from the literature and (3) its finding of the prime placement by Egyptian journalists of the function support for the Palestinian cause in terms of both importance of the function and how often they performed it. This finding may be useful in creating an understanding in the non-western world of how critical this issue is to the press and possibly therefore to the Egyptian public.
Alexithymia: a relevant psychological variable in near-fatal asthma
Authors: Serrano J. , Plaza V. , Sureda B. , de Pablo J. , Picado C. , Bardagí S. , Lamela J. , Sanchis J.
Published: March 2006

Alexithymia is a psychological trait characterised by difficulty in perceiving and expressing emotions and body sensations. Failure to perceive dyspnoea could lead alexithymic asthmatics to underestimate the severity of an asthma exacerbation, and thereby increase the risk of developing a fatal or near-fatal asthma (NFA) attack. The objective of the present study was to determine the prevalence of alexithymia in NFA patients and to analyse their clinical characteristics.

Alexithymia was assessed using the Toronto Alexithymia Scale in this multicentric prospective observational study. From 33 Spanish hospitals, 179 NFA patients and 40 non-NFA patients, as a control group, were enrolled.

There was a higher proportion of alexithymia in the NFA group than in the non-NFA group (36versus13%). Patients with NFA and alexithymia were older than the rest of the NFA group, and had a lower level of education, a higher level of psychiatric morbidity, a higher proportion of severe persistent asthma and a greater number of prior very severe asthma exacerbations (49versus27%). Alexithymia, severe persistent asthma and a low level of education were identified as independent variables related to repeated very severe asthma exacerbations.

The results show that alexithymia is more frequent in near-fatal asthma patients compared to the rest of asthmatics and is associated with recurrent very severe asthma exacerbations.
Cost-optimisation of screening for latent tuberculosis in close contacts
Authors: Diel R. , Nienhaus A. , Lange C. , Schaberg T.
Published: March 2006

The aim of the present study was to perform cost-minimisation analysis of contact investigation from a public health perspective using the tuberculin skin test (TST) and a new blood assay, QuantiFERON-TB Gold (QFT-G).

A decision-analysis model simulated the costs of investigating a cohort of adult close tuberculosis contacts by the public health service following the current German guidelines over a period of 2 yrs. The economic outcomes were compared with alternative screening strategies. These were: 1) QFT-G instead of TST; 2) TST followed by QFT-G; and 3) TST followed by QFT-G in vaccinated (bacille Calmette–Guérin (BCG)) subjects.

In a base-case analysis, the costs of TST-based screening were 91.06 Euros (EUR)·contact-1, assuming a 1% tuberculosis-case-finding incidence. The least expensive strategy was TST screening plus subsequent QFT-G testing (52.05 EUR), resulting in a 43% cost reduction. Using QFT-G alone in BCG-vaccinated subjects who tested positive in the TST led to a 39% cost reduction. The savings using QFT-G alone instead of TST amounted to 29.77 EUR·contact-1. The results depended on the acquisition costs assumed and the proportion of positive results in TST-based screening.

Screening for tuberculosis by combining tuberculin skin testing and QuantiFERON-TB Gold markedly reduces public health costs compared with tuberculin skin test screening alone.
Estimation of the bronchodilatory effect of deep inhalation after a free run in children
Authors: Schweitzer C. , Vu L. T. T. , Nguyen Y. T. , Choné C. , Demoulin B. , Marchal F.
Published: March 2006

The bronchomotor effects of a deep inhalation (DI) may provide relevant information about the mechanisms of exercise-induced airway obstruction in children and may be assessed by respiratory conductance (Grs) measured using the forced oscillation technique. The aims of the present study were to assess the effect of DI onGrsafter exercise in relationship to the lung function response to exercise.

Grsat 12 Hz using a head generator and spirometric data were measured in 62 children suspected of asthma before and 5 min after a 6-min free run.

After exercise,Grswas significantly increased by DI in 38 subjects, who also showed largerGrsand forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) responses to exercise than the 24 nonresponders. Stepwise regression indicated significant correlation between the response ofGrsto DI and bothGrsand FEV1/FVC responses to exercise.

The data are consistent with exercise-induced bronchoconstriction being reversed by deep inhalation.
Comparison of three auto-adjusting positive pressure devices in patients with sleep apnoea
Authors: Nolan G. M. , Ryan S. , O’Connor T. M. , McNicholas W. T.
Published: March 2006

Auto-adjustable continuous positive airway pressure (APAP) devices are an emerging treatment alternative to fixed-pressure continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea syndrome. They have been engineered to automatically adjust the pressure to the optimal level on a continuous basis. However, not all APAP technologies use the same algorithm. Three different APAP devices (Autoset Spirit, Breas PV 10i and RemStar Auto) were compared in a randomised crossover trial in patients already established on fixed-pressure CPAP therapy. The outcome measures were compliance, quality of life and side-effects.

Twenty-seven middle-aged patients (25 male) previously diagnosed with severe obstructive sleep apnoea syndrome (median (interquartile range) apnoea/hypopnoea index 48 (29–76)), established on CPAP therapy for >3 yrs, were randomised to each APAP device for 4 weeks.

Mean pressure and patient compliance were significantly lower on the Breas PV 10i than on the other APAP devices. The devices were similar in terms of quality of life, daytime sleepiness and upper airway side-effects, but patients evaluated them significantly differently in terms of device features, sleep quality and pressure comfort, with the Breas PV 10i being the least popular.

Auto-adjustable positive airway pressure devices differ in pressure delivery and patient compliance in obstructive sleep apnoea syndrome patients.
Regulation ofDictyosteliumprestalk-specific gene expression by a SHAQKY family MYB transcription factor
Authors: Fukuzawa Masashi , Zhukovskaya Natasha V. , Yamada Yoko , Araki Tsuyoshi , Williams Jeffrey G.
Published: March 2006

PstA and pstO cells are the two major populations in the prestalk region of the Dictyostelium slug and DIF-1 is a low molecular weight signalling molecule that selectively induces pstO cell-specific gene expression. The two cell types are defined by their differential use of spatially separated regions of the ecmA promoter. Additionally, there are anterior-like cells (ALCs) scattered throughout the rear, prespore region of the slug. They,like the pstO cells, use a cap-site distal ecmA promoter segment termed the ecmO region. When multimerised, a 22-nucleotide subsegment of the ecmO region directs expression in pstA cells, pstO cells and ALCs. It also directs DIF-inducible gene expression. The 22-nucleotide region was used to purify MybE, a protein with a single MYB DNA-binding domain of a type previously found only in a large family of plant transcription factors. Slugs of a mybE-null (mybE–) strain express an ecmAO:lacZfusion gene (i.e. a reporter construct containing the ecmA and ecmO promoter regions) in pstA cells but there is little or no expression in pstO cells and ALCs. The ecmA gene is not induced by DIF-1 in a mybE-strain. Thus,MybE is necessary for DIF-1 responsiveness and for the correct differentiation of pstO cells and ALCs.
XNF-ATc3 affects neural convergent extension
Authors: Borchers Annette , Fonar Yuri , Frank Dale , Baker Julie C.
Published: March 2006

Convergent extension is the primary driving force elongating the anteroposterior body axis. In Xenopus, convergent extension occurs in the dorsal mesoderm and posterior neural ectoderm, and is mediated by similar molecular pathways within these tissues. In this paper, we show that activation of NF-AT, a transcription factor known to modulate multiple signaling events, inhibits convergent extension in the dorsal mesoderm and in the posterior neural ectoderm. This is seen in whole embryos, mesodermal explants and posterior neural explants, solidly implicating a role of NF-AT in convergent extension. In the whole embryo, inhibition of NF-AT reveals a more selective function, affecting only convergent extension in the neural ectoderm. This specific activity was further teased apart using a variety of temporal and spatial approaches. Targeted injections of dominant-negative XNF-ATc3, or dosing over time with the calcineurin inhibitor cyclosporin in neural tube explants or in whole embryos, shows that inhibition of NF-AT signaling blocks neural convergent extension. Consistent with a function in neural convergent extension, we show that XNF-ATc3 is expressed and transcriptionally active within the neural tube. This work identifies XNF-ATc3 as a regulator of neural convergent extension in Xenopus and adds to a short list of molecules involved in this process.
Dishevelled genes mediate a conserved mammalian PCP pathway to regulate convergent extension during neurulation
Authors: Wang Jianbo , Hamblet Natasha S. , Mark Sharayne , Dickinson Mary E. , Brinkman Brendan C. , Segil Neil , Fraser Scott E. , Chen Ping , Wallingford John B. , Wynshaw-Boris Anthony
Published: March 2006

The planar cell polarity (PCP) pathway is conserved throughout evolution,but it mediates distinct developmental processes. In Drosophila,members of the PCP pathway localize in a polarized fashion to specify the cellular polarity within the plane of the epithelium, perpendicular to the apicobasal axis of the cell. In Xenopus and zebrafish, several homologs of the components of the fly PCP pathway control convergent extension. We have shown previously that mammalian PCP homologs regulate both cell polarity and polarized extension in the cochlea in the mouse. Here we show, using mice with null mutations in two mammalian Dishevelledhomologs, Dvl1 and Dvl2, that during neurulation a homologous mammalian PCP pathway regulates concomitant lengthening and narrowing of the neural plate, a morphogenetic process defined as convergent extension. Dvl2 genetically interacts with Loop-tail, a point mutation in the mammalian PCP gene Vangl2, during neurulation. By generating Dvl2 BAC (bacterial artificial chromosome) transgenes and introducing different domain deletions and a point mutation identical to the dsh1 allele in fly, we further demonstrated a high degree of conservation between Dvl function in mammalian convergent extension and the PCP pathway in fly. In the neuroepithelium of neurulating embryos, Dvl2 shows DEP domain-dependent membrane localization, a pre-requisite for its involvement in convergent extension. Intriguing, the Loop-tailmutation that disrupts both convergent extension in the neuroepithelium and PCP in the cochlea does not disrupt Dvl2 membrane distribution in the neuroepithelium, in contrast to its drastic effect on Dvl2 localization in the cochlea. These results are discussed in light of recent models on PCP and convergent extension.
Dual inhibition of the dactyl opener muscle in lobster
Authors: Worden Mary Kate , Camacho Joseph A.
Published: March 2006

The dactyl opener neuromuscular system of crayfish and lobster has long been a popular model system for studies of synaptic physiology and its modulation. Previous studies of its neural innervation in both species have reported that whereas the opener excitor axon (OE) and the specific opener inhibitor (OI) innervate the entire muscle, the common inhibitor (CI) is restricted to a small number of the most proximal muscle fibers and is the physiologically weaker of the two inhibitors. Here, we show in the lobster that, contrary to previous reports, CI innervates fibers along the entire extent of the dactyl opener muscle and thus shares the innervation targets of OE and OI. To characterize the physiological function of CI in the lobster dactyl opener system, we independently stimulated both OI and CI and compared their effects. The physiological impact of each inhibitor was similar:inhibitors elicit inhibitory junction potentials of similar sizes, both trigger muscle relaxations and both inhibit excitatory junction potentials and muscle contractions to a comparable extent. Thus, in the periphery, CI and OI appear to be equally powerful inhibitors with similar physiological roles,both in suppressing contractions triggered by the excitor OE and in directly relaxing muscle tension. In light of these observations, our understanding of the physiological roles of specific and common inhibitors in crustacean motor control requires reevaluation.
Forage fibre digestion, rates of feed passage and gut fill in juvenile and adult red kangaroosMacropus rufusDesmarest: why body size matters
Authors: Munn Adam J. , Dawson Terence J.
Published: March 2006

Using red kangaroos Macropus rufus Desmarest, a large (>20 kg)marsupial herbivore, we compared the digestive capabilities of juveniles with those of mature, non-lactating females on high-quality forage (chopped lucerne Medicago sativa hay) of 43±1% neutral-detergent fibre (NDF)and poorer quality, high-fibre forage (chopped oaten Avena sativahay) of 64±1% NDF. On chopped lucerne apparent dry matter (DM)digestibilities by young-at-foot (YAF) red kangaroos (an age that would normally be taking some milk from their mother), weaned juveniles and mature females were similar (55–59%). On chopped oaten hay apparent DM digestibility was lower in the YAF (35.9±2.3%) followed by weaned(43.4±2.8%) and mature females (44.6±1%). The digestion of NDF and its components (mainly cellulose and hemicellulose) was lowest among the YAF followed by weaned and then mature females. The YAF and weaned kangaroos could not sustain growth on the poor-quality diet, and appeared to be at or near maximal gut fill on both forages; the values being 114–122 g DM for YAF and 151–159 g DM for weaned kangaroos. Mean retention times (MRT) of particle and solute markers were significantly longer for the YAF and weaned kangaroos on oaten hay than on lucerne hay, and DM intake (g d–1) was ∼50% lower on the oaten hay. In contrast, solute and particle MRTs in the mature females were not significantly affected by diet; they maintained DM intakes by increasing DM gut fill from 264±24 g on chopped lucerne to 427±26 g DM on chopped oaten hay. Clearly, the mature female kangaroos did not maximise gut fill on the high-quality forage,presumably as a consequence of their proportionally lower energy requirements compared with still-growing juveniles. Overall, we have provided the first mechanistic link between the physiological constraints faced by juvenile red kangaroos in relation to their drought-related mortalities, rainfall and forage quality.
Ontogeny of osmoregulation in embryos of intertidal crabs(Hemigrapsus sexdentatusandH. crenulatus, Grapsidae,Brachyura): putative involvement of the embryonic dorsal organ
Authors: Seneviratna Deepani , Taylor H. H.
Published: March 2006

This study examined whether the existence of hyperosmotic internal fluids in embryos of euryhaline crabs (Hemigrapsus sexdentatus and H. crenulatus) in dilute seawater reflects osmotic isolation due to impermeability of the egg envelope, as proposed for other decapods, or active osmoregulation. When ovigerous crabs with eggs at gastrula stage were transferred from 100% seawater (osmolality 1000 mmol kg–1) to 50% seawater, embryogenesis and hatching of zoea were completed normally, but were delayed. Hatching failed if the transfer to 50% seawater occurred before gastrulation, and embryogenesis was abnormal in 25% seawater. In 100%seawater, embryos at all stages were internally hyperosmotic by 150–250 mmol kg–1. On transfer to 50% seawater, osmolality initially decreased but remained 200–350 mmol kg–1 hyperosmotic to the medium for several weeks until hatching. High efflux rates of tritium-labelled water (t1/2 16–75 min)and 22Na (t1/2 109–374 min) from H. crenulatus embryos were inconsistent with the osmotic isolation hypothesis. It is concluded that post-gastrula embryos were actively hyper-osmoregulating. The diffusional water permeability of the embryos decreased during development while the sodium efflux rate increased 10-fold. Very rapidly exchanging pools of water and sodium (t1/2 a few seconds to minutes) probably corresponded to peri-embryonic fluid and implied that the egg envelope was a negligible barrier to diffusion of water and salts. Higher Na+/K+-ATPase activities in late embryos of H. crenulatus incubated in 50% seawater than in embryos incubated in full strength seawater were consistent with an acclimation response. An area of the embryonic surface located over the yolk in the region of the embryonic dorsal organ stained with AgNO3. Staining appeared at gastrulation, persisted throughout development and was lost at hatching. Deposits of AgCl between the outer and inner membranes, identified by X-ray microanalysis, suggest that the dorsal organ was a site of chloride extrusion. A model for osmoregulation in post-gastrula embryos is proposed: osmotic uptake of water is balanced by excretion of water and salts via the dorsal organ and salt loss is balanced by active uptake over the general embryonic ectoderm.
From superphanes to beltenes
Authors: Gleiter Rolf , Hellbach Björn , Gath Silke , Schaller Rolf J.
Published: March 2006

This short review describes paths to superphanes with metal-stabilized cyclobutadiene and cyclopentadienone rings in a one-pot and stepwise fashion. The stepwise synthesis also led to a new class of belt-like systems with large rings composed of CpCo-stabilized cyclobutadiene rings connected with propane chains. Finally, our research yielded the first beltenes composed of alternating four- and eight-membered conjugated rings.
Ladder π-conjugated materials with main group elements
Authors: Yamaguchi Shigehiro , Xu Caihong , Okamoto Toshihiro
Published: March 2006

Ladder-type π-conjugated skeletons are promising building units for new materials for organic electronics, wherein their annelated coplanar structures enhance the π-conjugation, leading to a set of desirable properties such as intense fluorescence and high carrier mobility. As a new entry into this class of skeletons, we now disclose two series of ladder molecules, i.e., silicon- and carbon-bridged oligo(p-phenylenevinylene)s and thiophene- and selenophene-based heteroacenes. The former ladder molecules contain the silole substructure in which the silicon bridges affect the electronic structure and thus photophysical properties through the σ*-π* conjugation. The latter heteroacenes can be recognized as the heteroatom analogs of acenes and may be promising materials for organic thin film transistors. These two series of molecules have been synthesized based on newly developed intramolecular cyclizations of acetylenic compounds.
Double elimination protocol for aryleneethynylenes
Authors: Otera Junzo
Published: March 2006

A variety of aryleneethynylenes are synthesized by double elimination reaction of β-substituted sulfones. The acetylenic bond is formed from readily available aromatic aldehydes and benzylic sulfones. A sequence of aldol reaction, trapping of the aldolates with a leaving group, and eliminations proceeds in one pot. The utility of this protocol is exemplified by synthesis of dihalo diphenylacetylenes, 5,6,11,12-tetradehydrodibenzo[a,e]cyclooctene, and double-helical aromatic acetylenes.
Functionalized aromatics aligned with the three Cartesian axes: Extension of centropolyindane chemistry
Authors: Kuck Dietmar
Published: March 2006

The unique geometrical features and structural potential of the centropolyindanes, a complete family of novel, 3D polycyclic aromatic hydrocarbons, are discussed with respect to the inherent orthogonality of their arene units. Thus, the largest member of the family, centrohexaindane, a topologically nonplanar hydrocarbon, is presented as a "Cartesian hexabenzene", because each of its six benzene units is stretched into one of the six directions of the Cartesian space. This feature is discussed on the basis of the X-ray crystal structures of centrohexaindane and two lower members of the centropolyindane family, viz. the parent tribenzotriquinacenes. Recent progress in multiple functionalization and extension of the indane wings of selected centropolyindanes is reported, including several highly efficient six- and eight-fold C-C cross-coupling reactions. Some particular centropolyindane derivatives are presented, such as the first twelve-fold functionalized centrohexaindane and a tribenzotriquinacene bearing three mutually orthogonal phenanthroline groupings at its molecular periphery. Challenges to further extend the arene peripheries of the tribenzotriquinacenes and fenestrindanes to give, eventually, graphite cuttings bearing a central bowl- or saddle-shaped center are outlined, as is the hypothetical generation of a "giant" nanocube consisting of eight covalently bound tribenzotriquinacene units. Along these lines, our recent discovery of a related, solid-state supramolecular cube, containing eight molecules of a particular tribromotrinitrotribenzotriquinacene of the same absolute configuration, is presented for the first time.
Development of quadrupolar engaging auxiliaries as novel gearing elements for macrocyclization
Authors: Collins Shawn K. , El-Azizi Yassir
Published: March 2006

The formation of various macrocyclic cyclophanes via ring-closing olefin metathesis is possible through the use of a pendant pentafluorobenzyl ester group. A quadrupolar interaction between the cyclophane core and the auxiliary is proposed to act as a gearing element facilitating cyclization. The development of these noncovalent interactions as gearing elements as well as the investigation of the effect of the site of metathesis upon the macrocyclization process is described.
Complexation of carbon nanorings with fullerenes
Authors: Kawase Takeshi , Oda Masaji
Published: March 2006

To explore the supramolecular properties of the hollow space of carbon nanotubes, the belt-shaped conjugated systems with sizable and deep cavities are intriguing molecules. Recently, we found that the "carbon nanorings", cyclic [6]paraphenyleneacetylene ([6]CPPA), and the related compounds involving two naphthylene rings, form stable inclusion complexes with fullerenes in solution as well as in the solid state. The stability of these complexes correlates well with the van der Waals (VDW) contact between the host and guest. Thus, carbon nanorings having a deep cavity should form considerably stable complexes with fullerenes. In this context, we have designed a new carbon nanoring, cyclic [6](1,4)naphthyleneacetylene. The host forms considerably stable inclusion complexes with fullerenes and can act as the best fluorescence sensor for fullerenes among all the known hosts. The NMR spectra reveal the formation of two major conformational isomers, in which five or six naphthylene rings surround a guest molecule to gain wide contact area. The high affinity between C60 and naphthylene rings similar to an ion-dipolar interaction plays an important role in the novel guest-induced conformation fixation.
Fullerene peroxides in cage-opening reactions
Authors: Gan Liangbing
Published: March 2006

Fullerene-mixed peroxides C60(O)(OOtBu)4 and C60(OOtBu)6 are effective precursors for cage-opened fullerene derivatives. Lewis acids induce the heterolysis of peroxo O-O bond in C60(O)(OOtBu)4. Subsequent Hock-type rearrangement affords both [5,6]- and [6,6]-fullerene hemiketals - oxahomofullerene. Photolysis of C60(OOtBu)6 results in the homolysis of O-O and C-O bonds, affording fullerene diketone as the major product. Spectroscopic data and single-crystal analysis confirmed the cage-opening reactions.
Molecular assembly of 1,3,5-tris(cyanomethyl) and 1,4-bis(cyanomethyl)arenes with silver triflate
Authors: Kilway Kathleen V. , Deng Shiping , Bowser Sean , Mudd Joseph , Washington Laronda , Ho Douglas M.
Published: March 2006

Dicyano- and tricyano-substituted aromatic angular building blocks were systematically complexed with silver triflate, and their structures were determined by means of single-crystal X-ray diffraction. The molecular assembly of 1,3,5-tris(cyanomethyl)-2,4,6-triethylbenzene with silver triflate from benzene resulted in a layered structure with distorted square pyramidal silver sites. The structure resulting from the complexation of 1,3,5-tris(cyanomethyl)-2,4,6-trimethylbenzene with silver triflate is dependent on the solvent of crystallization. From benzene or toluene, reaction of 1,3,5-tris(cyanomethyl)-2,4,6-trimethylbenzene with silver triflate yielded a porous, channel-containing, solvated structure, but from acetone the resulting material was a network solid containing no solvent. Complexation of 1,4-bis(cyanomethyl)-2,3,5,6-tetraethylbenzene and 1,4-bis(cyanomethyl)-2,3,5,6-tetramethylbenzene with silver triflate resulted in network solids where the triflate anions were strongly coordinated to the silver.
Conjugated shape-persistent macrocycles via Schiff-base condensation: New motifs for supramolecular chemistry
Authors: MacLachlan Mark J.
Published: March 2006

Shape-persistent conjugated macrocycles are challenging synthetic targets with interesting properties and potential for a number of applications. In contrast to the standard kinetic approaches to macrocycles, reversible Schiff-base condensation offers a one-step, thermodynamic route to large macrocycles. These macrocycles, which feature "salen"-type coordination environments and an interior that resembles a crown-ether have interesting properties themselves and are novel substrates for supramolecular chemistry. This short review article places conjugated [3+3] Schiff-base macrocycles in the context of shape-persistent macrocycles and discusses their synthesis. In addition, specific examples of supramolecular chemistry with these macrocycles highlight their unique behavior when compared to conjugated carbon-based macrocycles and flexible crown-ethers.
Evaluation Procedures of Nonmetallic Inclusions in Steel for Highly Reliable Bearings
Authors: Unigame Y , Hiraoka K , Takasu I , Kato Y
Published: March 2006

The improvement in rolling contact fatigue life is a key subject to increase the reliability of bearings. It has been well known that the fatigue properties are significantly affected by nonmetallic inclusions in steel. The rolling contact fatigue life may be divided into two types, according to the type of reliability requirements. One is “L10 life,” which represents general bearing performance. The other is “accidental short life,” where a bearing prematurely fails in its service period and its calculated life is hardly met. Since the probabilities of these failures are significantly different, the distribution densities of the corresponding life-limiting inclusions are also expected to be widely different. When nonmetallic inclusions are evaluated as an index of fatigue life, therefore, testing volume should be appropriately determined according to the concerned type of life. From this point of view, it is effective for the reliability assessment of bearing steel to combine the evaluations of large microscopic inclusions by statistics of extreme value and macroscopic inclusions in larger volume by a high-frequency ultrasonic test. It was found that the L10 life determined by thrust-type rolling-contact fatigue tests was well correlated with maximum micro-inclusion diameter predicted by the statistics of extreme value, where both oxide and sulfide played as life-limiting inclusions. Fifteen MHz ultrasonic testing was employed to evaluate the macroscopic inclusions. The combination of these two procedures was able to demonstrate the difference in reliability clearly, even when other cleanliness indices could not characterize the concerned materials.
Outcomes of Drug and Alcohol Treatment Programs Among American Indians in California
Authors: Evans Elizabeth , Spear Suzanne E. , Huang Yu-Chang , Hser Yih-Ing
Published: March 2006

Objectives. We examined differences in substance abuse treatment outcomes between American Indians and their non–American Indian counterparts in California, during 2000 to 2002.

Methods. A total of 368 American Indians and a matched sample of 368 non–American Indians from 39 substance abuse treatment programs in 13 California counties were assessed at multiple time points. Records on arrests, driving while under the influence of alcohol or drugs, and mental health care were obtained 1 year before and 1 year after treatment entry. Differences in pretreatment characteristics, services received, treatment satisfaction, treatment completion and retention, and outcomes were examined.

Results. Pretreatment problems were similarly severe among American Indians and non–American Indians. About half in both groups either completed treatment or stayed in treatment more than 90 days; American Indians in residential care had significantly shorter treatment retention. American Indians received fewer individual sessions and out-of-program services, especially for alcohol abuse, but were nevertheless generally satisfied with their treatment. Both groups improved after treatment, with American Indians demonstrating greater reductions in arrests than non–American Indians.

Conclusion. American Indians benefit from substance abuse treatment programs, although the type and intensity of services offered could be improved.
Fostering International Collaboration in Birth Defects Research and Prevention: A Perspective From the International Clearinghouse for Birth Defects Surveillance and Research
Authors: Botto Lorenzo D. , Robert-Gnansia Elisabeth , Siffel Csaba , Harris John , Borman Barry , Mastroiacovo Pierpaolo
Published: March 2006

The International Clearing-house for Birth Defects Surveillance and Research, formerly known as International Clearinghouse of Birth Defects Monitoring Systems, consists of 40 registries worldwide that collaborate in monitoring 40 types of birth defects. Clearinghouse activities include the sharing and joint monitoring of birth defect data, epidemiologic and public health research, and capacity building, with the goal of reducing disease and promoting healthy birth outcomes through primary prevention.

We discuss 3 of these activities: the collaborative assessment of the potential teratogenicity of first-trimester use of medications (the MADRE project), an example of the intersection of surveillance and research; the international databases of people with orofacial clefts, an example of the evolution from surveillance to outcome research; and the study of genetic polymorphisms, an example of collaboration in public health genetics.
Telephone Coverage and Health Survey Estimates: Evaluating the Need for Concern About Wireless Substitution
Authors: Blumberg Stephen J. , Luke Julian V. , Cynamon Marcie L.
Published: March 2006

Objectives. We sought to determine whether the exclusion of adults without landline telephones may bias estimates derived from health-related telephone surveys.

Methods. We took data from the 2004 and 2005 National Health Interview Survey and used logistic regression to compare the odds of behavioral risk factors and health care service use for adults with landline telephones to those for adults with only wireless telephones and adults without any telephone service.

Results. When interviewed, 7.2% of adults, including those who did and did not have wireless telephones, did not have landline telephones. Relative to adults with landline telephones, adults without landline telephones had greater odds of smoking and being uninsured, and they had lower odds of having diabetes, having a usual place for medical care, and having received an influenza vaccination in the past year.

Conclusions. As people substitute wireless telephones for landline telephones, the percentage of adults without landline telephones has increased significantly but is still low, which minimizes the bias resulting from their exclusion from telephone surveys. Bias greater than 1 percentage point is expected only for estimates of health insurance, smoking, binge drinking, having a usual place for care, and receiving an influenza vaccination.
Work Activity in Pregnancy, Preventive Measures, and the Risk of Delivering a Small-for-Gestational-Age Infant
Authors: Croteau Agathe , Marcoux Sylvie , Brisson Chantal
Published: March 2006

Objectives. We undertook a case–control study to evaluate whether some occupational conditions during pregnancy increase the risk of delivering a small-for-gestational-age (SGA) infant and whether taking measures to eliminate these conditions decreases that risk.

Methods. The 1536 cases and 4441 controls were selected from 43898 women who had single live births between January 1997 and March 1999 in Québec, Canada. The women were interviewed by telephone after delivery.

Results. The risk of having an SGA infant increased with an irregular or shift-work schedule alone and with a cumulative index of the following occupational conditions: night hours, irregular or shift-work schedule, standing, lifting loads, noise, and high psychological demand combined with low social support. When the conditions were not eliminated, the risk increased with the number of conditions (Ptrend =.004; odds ratios=1.00, 1.08, 1.28, 1.43, and 2.29 for 0, 1, 2, 3, and 4–6 conditions, respectively). Elimination of the conditions before 24 weeks of pregnancy brought the risks close to those of unexposed women.

Conclusions. Certain occupational conditions experienced by pregnant women can increase their risk of having an SGA infant, but preventive measures can reduce the risk.
Reproductive Health Care and Family Planning Needs Among Incarcerated Women
Authors: Clarke Jennifer G. , Hebert Megan R. , Rosengard Cynthia , Rose Jennifer S. , DaSilva Kristen M. , Stein Michael D.
Published: March 2006

Objectives. Women in correctional institutions have substantial reproductive health problems, yet they are underserved in receipt of reproductive health care. We assessed the level of risk for sexually transmitted diseases (STDs) and the reproductive health needs of 484 incarcerated women in Rhode Island to plan an intervention for women returning to the community.

Methods. We used a 45-minute survey to assess medical histories, pregnancy and birth control use histories, current pregnancy intentions, substance use during the past 3 months, histories of childhood sexual abuse, and health attitudes and behaviors.

Results. Participants had extremely high risks for STDs and pregnancy, which was characterized by inconsistent birth control (66.5%) and condom use (80.4%), multiple partners (38%), and a high prevalence of unplanned pregnancies (83.6%) and STDs (49%). Only 15.4% said it was not likely that they would have sexual relations with a man within 6 months after release.

Conclusion. Reproductive health services must be offered to incarcerated women. Such interventions will benefit the women, the criminal justice systems, and the communities to which the women will return.
Trends in Smokeless Tobacco Use Among Adults and Adolescents in the United States
Authors: Nelson David E. , Mowery Paul , Tomar Scott , Marcus Stephen , Giovino Gary , Zhao Luhua
Published: March 2006

Objectives. Smokeless tobacco has many adverse health effects. We analyzed long-term national trends in smokeless tobacco use.

Methods. We used 1987 to 2000 National Health Interview Survey data for adults aged 18 years and older, 1986 to 2003 data from Monitoring the Future surveys of adolescents, and 1991 to 2003 data from the Youth Risk Behavior Survey for 9th- to 12th-grade students to examine overall and demographic-specific trends.

Results. Smokeless tobacco use among adult and adolescent females was low and showed little change. Smokeless tobacco use among men declined slowly (relative decline=26%), with the largest declines among those aged 18 to 24 years or 65 years and older, Blacks, residents of the South, and persons in more rural areas. Overall and demographic-specific data for adolescent boys indicate that smokeless tobacco use increased for 12th-grade students from 1986 until the early 1990s, but has subsequently declined rapidly in all grades since then (range of relative overall declines=43% to 48%).

Conclusions. Smokeless tobacco use has declined sharply, especially among adolescent boys. Ongoing prevention and cessation efforts are needed to continue this trend.