bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulmonary Hypertension in Patients with Chronic Renal Failure
Authors: Havlucu Y. , Kursat S. , Ekmekci C. , Celik P. , Serter S. , Bayturan O. , Dinc G.
Published: May 2007

Background: Many etiologies causing pulmonary hypertension (PH) have been reported, and one of the background disease seen with patients with PH is chronic renal failure (CRF); however, the pathogenesis of PH in this group of patients is not explained satisfactorily. Objectives: The aims of this study were to evaluate the incidence of unexplained PH among patients with CRF and to suggest possible etiologic factors. Methods: Two hundred and eleven patients with CRF were evaluated and the ones who have comorbid conditions that cause PH were excluded. Pulmonary arterial pressure (PAP) and cardiac functions were evaluated by Doppler echocardiography. Arteriovenous fistula (AVF) flow was measured by Doppler sonography. The patients were followed for at least 6 months. Results: Forty-eight CRF patients (20 males, 28 females) were included: 23 were predialysis patients, and 25 patients received hemodialysis via AVF. Patients were followed for 7.5 ± 1.01 months. Systolic PAP >35 mm Hg was found in 56% (14/25) of patients receiving hemodialysis (36.8 ± 10.7 mm Hg) and in 39.1% (9/23) of predialysis patients (29.5 ± 9.5 mm Hg). The parathyroid hormone level, cardiac output values and CRF duration were found to be increased in patients with elevated systolic PAP (p < 0.05). AVF flow and AVF duration were positively correlated with systolic PAP in patients receiving hemodialysis (p < 0.05). There was a negative correlation between systolic PAP and residual urine volume (p < 0.05). AVF compression in hemodialysis patients decreased systolic PAP from 36.8 ± 10.7 to 32.8 ± 10.5 mm Hg. Systolic PAP values were increased at the end of the study in the predialysis group, whereas they were decreased at the end of the follow-up in the hemodialysis group (36.9 ± 10.5 and 32.04 ± 10.5 mm Hg, respectively). Conclusions: This study demonstrates a high incidence of PH among patients with CRF. CRF duration, AVF flow, parathyroid hormone level and cardiac output may be involved in the pathogenesis of PH. The effective hemodialysis and dry weight reduction decreased systolic PAP values.
New Apparatus for Spinal Cord Stereotaxis and its Use in the Microsurgery of Lumbar Enlargement
Authors: Nádvorník P. , Fröhlich J. , Ježek V. , Šramka M.
Published: May 2007

Our construction of the spinal cord stereotaxic apparatus is different from similar apparatus available. The base of the apparatus is attached directly to the arc of the vertebral body by means of a handle screw. The apparatus is light, easily demontable. Movement is possible in 3 perpendicular plains and carries one fine uni- or dipolar electrode. By means of this electrode the spinal cord potentials are recorded, the spinal cord structures can be stimulated and lesions are carried out by electrocoagulation. The target can be reached according to model maps of the spinal cord. The apparatus is used in order to influence the hyperspastic bladder and the spasticity of the lower limbs after interruption of the spinal cord. Results are encouraging us to use the stereotaxic method for the treatment of neurogenic bladder in the spinal cord segment S2.
Myoclonic Disease of Ramsey-Hunt Treated by Transtentorial Bilateral Dentatotomy from the Right Side
Authors: Šramka M. , Nádvorník P. , Lisý L.
Published: May 2007

The idea that lesion of the nucleus dentatus may stop the pathological mechanism of Ramsey-Hunt disease led us to perform a dentatotomy in a female patient aged 28, who suffered from myoclonic movements for 6 years. Surgery was carried out by transtentorial approach from a burr hole in the right temporo-occipital region. The coagulation electrode was introduced first into the right nucleus dentatus; after its coagulation, myoclonic movements in the right extremities disappeared. For this reason, the left nucleus dentatus was also destroyed by introducing the electrode into the left side from the same right side burr hole through the midline. All myoclonic movements stopped at least transitorily.
A non-sense mutation in the putative anti-mutator gene ada/alkA of Mycobacterium tuberculosis and M. bovis isolates suggests convergent evolution
Authors: Nouvel Laurent X , Vultos Tiago Dos , Kassa-Kelembho Eric , Rauzier Jean , Gicquel Brigitte
Published: May 2007

Background

Previous studies have suggested that variations in DNA repair genes of W-Beijing strains may have led to transient mutator phenotypes which in turn may have contributed to host adaptation of this strain family. Single nucleotide polymorphism (SNP) in the DNA repair gene mutT 1 was identified in MDR-prone strains from the Central African Republic. A Mycobacteriumtuberculosis H37Rv mutant inactivated in two DNA repair genes, namely ada/alkA and ogt, was shown to display a hypermutator phenotype. We then looked for polymorphisms in these genes in Central African Republic strains (CAR).

Results

In this study, 55 MDR and 194 non-MDR strains were analyzed. Variations in DNA repair genes ada/alkA and ogt were identified. Among them, by comparison to M. tuberculosis published sequences, we found a non-sense variation in ada/alkA gene which was also observed in M. bovis AF2122 strain. SNPs that are present in the adjacent regions to the amber variation are different in M. bovis and in M. tuberculosis strain.

Conclusion

An Amber codon was found in the ada/alkA locus of clustered M. tuberculosis isolates and in M. bovis strain AF2122. This is likely due to convergent evolution because SNP differences between strains are incompatible with horizontal transfer of an entire gene. This suggests that such a variation may confer a selective advantage and be implicated in hypermutator phenotype expression, which in turn contributes to adaptation to environmental changes.
Random Variability in Congenital Hypothyroidism from Thyroid Dysgenesis over 16 Years in Québec
Authors: Deladoëy Johnny , Bélanger Nicole , Van Vliet Guy
Published: May 2007

Context: Research on the etiology of congenital hypothyroidism from thyroid dysgenesis (CHTD) (comprising mostly ectopy and agenesis) over the past decade has focused on genetic mechanisms. However, the possibility that environmental factors might be involved has been raised by studies showing a seasonal variability of the incidence of CHTD.

Objectives: The objective of this study was to assess the variability in incidence of CHTD in the province of Québec, Canada.

Design, Setting, Patients, and Main Outcome Measure: The Québec provincial newborn screening database was analyzed from January 1990 to December 2005. Only cases of permanent congenital hypothyroidism with thyroid ectopy or agenesis on scintigraphy were analyzed.

Results: During the study period, 1,303,341 children were screened, and 424 cases of permanent congenital hypothyroidism were diagnosed, giving an overall incidence of 1:3074. Of these, 306 had CHTD (overall incidence 1:4259) from either ectopy (n = 231) or agenesis (n = 75). Over the 16 yr of the study, this incidence remained stable (P = 0.57), and no significant variability in monthly incidence was found (P = 0.87).

Conclusions: The incidence of CHTD did not vary over the observation period, and its monthly variation was random. Therefore, environmental factors do not appear to play a significant role in the etiology of CHTD.
Engaging Globalization in Modern Arabic Literature: Appropriation and Resistance
Authors: al-Musawi Muhsin J.
Published: May 2007

Muhsin J. al-Musawi is professor of Arabic studies at Columbia University. His recent books include Anglo-Orient (2000), The Postcolonial Arabic Novel: Debating Ambivalence (2003), Arabic Poetry: Trajectories of Modernity and Tradition (2006), Reading Iraq: Culture and Power in Conflict (2006), an edition of The Arabian Nights (2007), and The Islamic Context of the Arabian Nights (2007). He is editor of Journal of Arabic Literature and has received many awards, including the Owais Award in literary criticism, the most prestigious nongovernmental award in the Arab world.
Wnt signals provide a timing mechanism for the FGF-retinoid differentiation switch during vertebrate body axis extension
Authors: Olivera-Martinez Isabel , Storey Kate G.
Published: May 2007

Differentiation onset in the vertebrate body axis is controlled by a conserved switch from fibroblast growth factor (FGF) to retinoid signalling,which is also apparent in the extending limb and aberrant in many cancer cell lines. FGF protects tail-end stem zone cells from precocious differentiation by inhibiting retinoid synthesis, whereas later-produced retinoic acid (RA)attenuates FGF signalling and drives differentiation. The timing of RA production is therefore crucial for the preservation of stem zone cells and the continued extension of the body axis. Here we show that canonical Wnt signalling mediates the transition from FGF to retinoid signalling in the newly generated chick body axis. FGF promotes Wnt8c expression, which persists in the neuroepithelium as FGF signalling declines. Wnt signals then act here to repress neuronal differentiation. Furthermore, although FGF inhibition of neuronal differentiation involves repression of the RA-responsive gene,retinoic acid receptor β (RARβ), Wnt signals are weaker repressors of neuron production and do not interfere with RA signal transduction. Strikingly, as FGF signals decline in the extending axis, Wnt signals now elicit RA synthesis in neighbouring presomitic mesoderm. This study identifies a directional signalling relay that leads from FGF to retinoid signalling and demonstrates that Wnt signals serve, as cells leave the stem zone, to permit and promote RA activity, providing a mechanism to control the timing of the FGF-RA differentiation switch.
Enabled plays key roles in embryonic epithelial morphogenesis inDrosophila
Authors: Gates Julie , Mahaffey James P. , Rogers Stephen L. , Emerson Mark , Rogers Edward M. , Sottile Stephanie L. , Van Vactor David , Gertler Frank B. , Peifer Mark
Published: May 2007

Studies in cultured cells and in vitro have identified many actin regulators and begun to define their mechanisms of action. Among these are Enabled (Ena)/VASP proteins, anti-Capping proteins that influence fibroblast migration, growth cone motility, and keratinocyte cell adhesion in vitro. However, partially redundant family members in mammals and maternal Ena contribution in Drosophila previously prevented assessment of the roles of Ena/VASP proteins in embryonic morphogenesis in flies or mammals. We used several approaches to remove maternal and zygotic Ena function, allowing us to address this question. We found that inactivating Ena does not disrupt cell adhesion or epithelial organization, suggesting its role in these processes is cell type-specific. However, Ena plays an important role in many morphogenetic events, including germband retraction, segmental groove retraction and head involution, whereas it is dispensable for other morphogenetic movements. We focused on dorsal closure, analyzing mechanisms by which Ena acts. Ena modulates filopodial number and length, thus influencing the speed of epithelial zippering and the ability of cells to match with correct neighbors. We also explored filopodial regulation in cultured Drosophila cells and embryos. These data provide new insights into developmental and mechanistic roles of this important actin regulator.
Client-Focused Research: New Directions in Outcome Assessment
Authors: Newnham Elizabeth A. , Page Andrew C.
Published: May 2007

The emergence of client-focused research has led to substantial change in the field of outcome assessment. Using the client's clinical characteristics to determine expected outcome, client monitoring assists clinicians in assessing the current treatment plan and client progress. The methodology has been shown to be effective in outpatient samples, by implementing change in real time for the benefit of the individual (Lambert, Harmon, Slade, Whipple, & Hawkins, 2005). Accordingly, the framework is an appropriate and important addition to the assessment of clinical practice.
The Dorsolateral Prefrontal Cortex Contributes to Successful Relational Memory Encoding
Authors: Murray Linda J. , Ranganath Charan
Published: May 2007

Results from neuroimaging studies of long-term memory (LTM) encoding have contributed to the view that the ventrolateral prefrontal cortex (VLPFC) contributes to successful LTM formation, whereas the dorsolateral prefrontal cortex (DLPFC) does not. We hypothesized that the DLPFC does contribute to LTM, but under specific circumstances. That is, the DLPFC may be critical for building relationships between items during on-line processing, and this may promote LTM for associations between items. We used event-related functional magnetic resonance imaging (fMRI) to test this hypothesis by examining brain activity during sequential encoding of unrelated word pairs. During presentation of the second (“target”) word in each pair, subjects either made a semantic judgment specific to the target word (“item-specific” trials), or a semantic judgment that involved a comparison between the target word and the first word in the pair (“relational” trials). Behaviorally, recognition memory for target words was equivalent between the two trial types but associative recognition of studied word pairs was significantly greater for relational trials. fMRI results showed that DLPFC activity was greater during relational compared with item-specific encoding and that DLPFC activity predicted successful memory for associations but not successful item memory. Activity in the VLPFC was also greater for relational compared with item-specific encoding, but VLPFC activation predicted successful memory for both associations and items. These results support the view that the DLPFC may contribute to LTM through its role in active processing of relationships during encoding, whereas the VLPFC may have a more general role in promoting successful LTM formation.
Inhibition Determines Membrane Potential Dynamics and Controls Action Potential Generation in Awake and Sleeping Cat Cortex
Authors: Rudolph Michelle , Pospischil Martin , Timofeev Igor , Destexhe Alain
Published: May 2007

Intracellular recordings of cortical neurons in awake cat and monkey show a depolarized state, sustained firing, and intense subthreshold synaptic activity. It is not known what conductance dynamics underlie such activity and how neurons process information in such highly stochastic states. Here, we combine intracellular recordings in awake and naturally sleeping cats with computational models to investigate subthreshold dynamics of conductances and how conductance dynamics determine spiking activity. We show that during both wakefulness and the “up-states” of natural slow-wave sleep, membrane-potential activity stems from a diversity of combinations of excitatory and inhibitory synaptic conductances, with dominant inhibition in most of the cases. Inhibition also provides the largest contribution to membrane potential fluctuations. Computational models predict that in such inhibition-dominant states, spikes are preferentially evoked by a drop of inhibitory conductance, and that its signature is a transient drop of membrane conductance before the spike. This pattern of conductance change is indeed observed in estimates of spike-triggered averages of synaptic conductances during wakefulness and slow-wave sleep up states. These results show that activated states are defined by diverse combinations of excitatory and inhibitory conductances with pronounced inhibition, and that the dynamics of inhibition is particularly effective on spiking, suggesting an important role for inhibitory processes in both conscious and unconscious cortical states.
Connecting TNF-α Signaling Pathways to iNOS Expression in a Mouse Model of Alzheimer's Disease: Relevance for the Behavioral and Synaptic Deficits Induced by Amyloid β Protein
Authors: Medeiros Rodrigo , Prediger Rui D. S. , Passos Giselle F. , Pandolfo Pablo , Duarte Filipe S. , Franco Jeferson L. , Dafre Alcir L. , Di Giunta Gabriella , Figueiredo Cláudia P. , Takahashi Reinaldo N. , Campos Maria M. , Calixto João B.
Published: May 2007

Increased brain deposition of amyloid β protein (Aβ) and cognitive deficits are classical signals of Alzheimer's disease (AD) that have been highly associated with inflammatory alterations. The present work was designed to determine the correlation between tumor necrosis factor-α (TNF-α)-related signaling pathways and inducible nitric oxide synthase (iNOS) expression in a mouse model of AD, by means of bothin vivoandin vitroapproaches. The intracerebroventricular injection of Aβ1–40in mice resulted in marked deficits of learning and memory, according to assessment in the water maze paradigm. This cognition impairment seems to be related to synapse dysfunction and glial cell activation. The pharmacological blockage of either TNF-α or iNOS reduced the cognitive deficit evoked by Aβ1–40in mice. Similar results were obtained in TNF-α receptor 1 and iNOS knock-out mice. Aβ1–40administration induced an increase in TNF-α expression and oxidative alterations in prefrontal cortex and hippocampus. Likewise, Aβ1–40led to activation of both JNK (c-Jun-NH2-terminal kinase)/c-Jun and nuclear factor-κB, resulting in iNOS upregulation in both brain structures. The anti-TNF-α antibody reduced all of the molecular and biochemical alterations promoted by Aβ1–40. These results provide new insights in mouse models of AD, revealing TNF-α and iNOS as central mediators of Aβ action. These pathways might be targeted for AD drug development.
Auf ein Neues: Ästhetik und Politik. Und dazwischen das Spiel. Angestoßen durch Jacques Rancière
Authors: Früchtl Josef
Published: May 2007

Ausgehend von Jacques Rancière lässt sich das Verhältnis von Ästhetik und Politik erneut, wie schon im deutschen Idealismus, als Einheit eines Widerspruchs begreifen. Rancière verknüpft dieses Verhältnis mit einem romantischen Begriff von Politik. Unabhängig davon aber rekonstruiert er es ‚historisch-apriorisch‘ unter dem genannten idealistischen Prinzip. Für das Konzept des Spiels hat das, über Rancière hinausgehend, ambivalente Konsequenzen. Seine Attraktivität wie Kalamität werden bestimmt durch die ‚Regime‘ der Moderne, die sich als ausdifferenzierte Formen des dialektischen Widerspruchsprinzips erweisen.
Ethisch-politischer Perfektionismus. Stanley Cavell und die praktische Philosophie
Authors: Saar Martin
Published: May 2007

Cavells originärer Beitrag zur praktischen Philosophie lässt sich nur durch eine Rekonstruktion des wichtigen Topos des ‘moralischen Perfektionismus’ angemessen verstehen. Er bezieht sich zum einen auf Cavells an Thoreau und Emerson orientierte dynamische Konzeption des Selbst, das sich erst in ständiger Auseinandersetzung bildet und weiterentwickelt. Er steht zum anderen für das Bild einer intern agonal verfassten Gemeinschaft, die sich nie mit dem erreichten Maß an Gerechtigkeit zufrieden gibt.
Ultrasound Surveillance in Pregnancy Complicated by Diabetes
Authors: Dupak Julie D.L. , Trujillo Angelina L.
Published: May 2007

This article evaluates the clinical relevance of ultrasonography during pregnancy complicated by diabetes for fetal surveillance, assessment of diabetes impact, guidance of diabetes treatment, and obstetric management. Although ultrasound has improved, its effect on reduction of perinatal morbidity and mortality remains to be proven, and its use to detect large-for-gestational-age fetuses is unreliable. Clinical decisions based on birth weight prediction by sonography are often in error. Measurement of the insulin-sensitive fetal fat layer and fetal abdominal circumference may better reflect the impact of diabetes on the fetus.
Insulin Analogs and Pregnancy
Authors: Trujillo Angelina L.
Published: May 2007

Diabetes during pregnancy is a major risk factor for poor fetal, neonatal,and maternal outcomes; however, the risk can be greatly reduced by early institution of medical nutritional therapy and insulin treatment. Maintaining maternal glycemia as near to normal as possible reduces the risk of congenital anomalies, macrosomia, neonatal hypoglycemia, and large-for-gestational-age infants. Achieving normoglycemia has usually been accomplished with human insulin. However, the newer rapid-acting insulin analogs lispro and aspart,when compared to regular human insulin, demonstrate both efficacy and safety for the treatment of diabetes during pregnancy. NPH insulin is the only basal insulin that has been studied in pregnancy. There are not yet any published controlled studies evaluating the long-acting insulin analogs for use in pregnancy.
Use of Movement System Diagnoses in the Management of Patients With Neuromuscular Conditions: A Multiple-Patient Case Report
Authors: Scheets Patricia L , Sahrmann Shirley A , Norton Barbara J
Published: May 2007

Background and Purpose

Medical diagnoses are not sufficient to guide physical therapy intervention. To provide a rational basis for treatment selection by physical therapists, we developed a set of diagnoses at the level of impairment that are relevant to the human movement system. The diagnoses describe the primary human movement system problem and provide a basis for matching a specific problem with appropriate treatment. The purposes of this 3-patient case report are to illustrate an updated version of the diagnostic system and to show how treatment decisions can be made relative to both the movement system diagnosis and the patient's prognosis.

Case Descriptions and Outcomes

We diagnosed 3 patients with hemiplegia due to stroke as having 3 different movement system problems: force production deficit, fractionated movement deficit, and perceptual deficit. Specific intervention and actual patient outcomes for each case are outlined.

Discussion

Use of movement system diagnoses may have multiple benefits for patient care. The possible benefits include decreasing the variability in management of patients with neuromuscular conditions, minimizing the trial-and-error approach to treatment selection, improving communication among health care professionals, and advancing research by enabling creation of homogenous patient groupings.
Disabling Our Diagnostic Dilemmas
Authors: Coffin-Zadai Cynthia A
Published: May 2007

The physical therapy profession's diagnostic dilemma results from its confused response to competing issues that affect the physical therapist's role as a diagnostician. The major components of the diagnostic dilemma are: (1) the competition among new ideas, (2) the complexity of the diagnostic process and language used to describe the outcome, (3) the profession's lack of consensus regarding the diagnostic classification construct to be embraced, and (4) the rapid evolution and impact of new knowledge. The interaction of these 4 components results in “diagnostic disablement.” Whether managing a patient, creating a curriculum to educate new physical therapy practitioners, or applying for research funding to study the science or practice of diagnostic classification, physical therapists face a real challenge in understanding and complying with all the current diagnostic requirements of the US health care system and the physical therapy profession. This article traces the 4 components and considers the strategies the profession can use to resolve its diagnostic dilemma. The first step would be to standardize the language that physical therapists use to describe or diagnose phenomena within their scope of practice.
The Potential of Gait Analysis to Contribute to Differential Diagnosis of Early Stage Dementia: Current Research and Future Directions
Authors: Morgan Debra , Funk Melanie , Crossley Margaret , Basran Jenny , Kirk Andrew , Bello-Haas Vanina Dal
Published: May 2007

Early differential diagnosis of dementia is becoming increasingly important as new pharmacologic therapies are developed, as these treatments are not equally effective for all types of dementia. Early detection and differential diagnosis also facilitates informed family decision making and timely access to appropriate services. Information about gait characteristics is informative in the diagnostic process and may have important implications for discriminating among dementia subtypes. The aim of this review paper is to summarize existing research examining the relationships between gait and dementia, including gait classification systems and assessment tools, gait patterns characteristic of different dementias (Alzheimer's disease, vascular dementia, dementia with Lewy Bodies, and fronto-temporal dementia), and the utility of gait analysis in early-stage diagnosis. The paper concludes with implications for future research.
Constituting the Violence of Criminalized Women
Authors: Comack Elizabeth , Brickey Salena
Published: May 2007

Recent efforts to make sense of the Violent Woman have revolved around three different (yet not disconnected) constructs: “victim,” “mad,” and “bad.” One issue that has been missing in discussions of the Violent Woman, however, is how women who use violence constitute themselves. In this study, using in-depth interviews with 18 criminalized women, we aim to uncover the women's own discursive constructions and the discourses they draw from in their efforts at framing identity. How and where is violence situated in the women's accounts of their lives? How do the women constitute themselves? What discourses do they draw from (and resist)? Do the prevailing constructs of the Violent Woman as “victim,” “mad,” or “bad” have resonance for these women? In the process, we argue that each of these constructs, while having some resonance in the women's accounts, fails to capture the complexity of their lives. Because identity is fractured and multiple, violence in the lives of criminalized women (their own violence and that which is directed at them) cannot be rendered plausible by imposing a master status template. We conclude by considering the implications of this analysis for making sense of women's violence.
Standardized Screening and Assessment of Older Emergency Department Patients: A Survey of Implementation in Quebec
Authors: McCusker Jane , Verdon Josée , Veillette Nathalie , Berg Katherine , Emond Tina , Belzile Eric
Published: May 2007

Cost-effective methods have been developed to help busy emergency department (ED) staff cope with the growing number of older patients, including quick screening and assessment tools to identify those at high risk and note their specific needs. This survey, from a sample of key informants from all EDs (n=111) in the province of Quebec (participation rate of 88.2%), investigated the implementation of these tools and barriers to implementation. Questionnaires (administered either by telephone or by self-completion) included characteristics of the ED, characteristics of the respondent, use of tools, and method of implementation. Barriers to the implementation of these tools included lack of resources for screening and follow-up, misunderstandings of the difference between screening and assessment tools, and need for adaptation of the tools to the local context. Education of staff and pre-implementation adaptation and testing are needed for successful implementation.
Paracellular nutrient absorption in a gum‐feeding new world primate, the common marmoset Callithrix jacchus
Authors: Mcwhorter Todd J. , Karasov William H.
Published: May 2007

The common marmoset is one of the few callitrichid species that is not threatened or endangered in the wild, and is widely used in biomedical research, yet relatively little is understood about its digestive physiology. Dietary specialization on plant exudates has lead to relatively reduced small intestines, yet the common marmoset has exceptional dietary breadth, allowing it to successfully utilize a variety of habitats. We predicted that passive, paracellular nutrient absorption would be used by the common marmoset to a greater extent than in other non‐flying mammals. We measured the bioavailability and rates of absorption of two metabolically inert carbohydrates not transported by mediated pathways (L‐rhamnose and cellobiose, molecular masses of 164 and 342, respectively) to measure paracellular uptake, and of a non‐metabolized D‐glucose analog (3‐O‐methyl‐D‐glucose) to measure total uptake by both mediated and paracellular pathways. We found high bioavailability of 3‐O‐methyl‐D‐glucose (83±5%), and much higher bioavailability of the paracellular probes than in similarly sized non‐flying mammals (30±3% and 19±2% for L‐rhamnose and cellobiose, respectively). Passive, paracellular nutrient absorption accounts for around 30% of total glucose absorption in common marmosets and intestinal permeability is significantly higher than in humans, the only other species of primate measured to date. This may allow the common marmoset to maintain high digestive efficiency when feeding on higher quality foods (fruit, arthropods, gums with higher proportions of simple sugars), in spite of relatively reduced small intestines correlated with adaptations for fermentative digestion of plant gums. We find no evidence to support, in primates, the hypothesis that reliance on paracellular nutrient absorption should increase with body size in mammals, but suggest instead that it may be associated with small body size and/or taxon‐specific adaptations to diet. Am. J. Primatol. 69:1399–1411, 2007. © 2007 Wiley‐Liss, Inc.
Morphology, thermal, and mechanical properties of polypropylene/polyaniline coated short glass fiber composites
Authors: Cruz‐Silva Rodolfo , Romero‐García Jorge , Vazquez‐Rodriguez Sofía , Luis Angulo‐Sánchez Jose
Published: May 2007

Short glass fiber Type E was coated with electrically conducting polyaniline (PAn) by in situ chemical polymerization. The resulting PAn coated glass fiber, with surface conductivity of 3.3 × 10−1 S/cm, was melt‐compounded with isotactic polypropylene (iPP). Polypropylene grafted with maleic anhydride was investigated as an adhesion promoter for these composites. Differential scanning calorimeter and polarized light microscopy indicates that the PAn coated glass fiber has a strong nucleating activity towards iPP. Scanning electron microscopy showed the improvement in the wetting and dispersion of the fibers when the adhesion promoter was added, although this also led to fiber encapsulation and lowering the electrical conductivity of the composites. The adhesion promoter greatly improved the Young's modulus of the composites, and a reaction between the maleic anhydride groups of the adhesion promoter and the PAn was proposed. Composites with an electrical conductivity greater than 10−9 S/cm were achieved using a 30 wt % of PAn coated glass fiber. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Cure characteristics and physical properties of ground‐rubber‐filled natural rubber vulcanizates: Effects of the curing systems of the ground rubber and rubber matrix
Authors: Kim S. W. , Park H. Y. , Lim J. C. , Jeon I. R. , Seo K. H.
Published: May 2007

Recycling discarded rubber is important for both environmental and economic reasons. One of the most attractive methods of recycling rubber waste is to use ground rubber (GR) as a compounding ingredient or as a replacement for raw polymers. In this study, ground natural rubber was prepared with different curing systems and compounded into the parent compounds. The cure behaviors and physical properties of the GR‐filled vulcanizates were investigated, and they were largely affected by the curing systems of the rubber matrix and GR. GR‐filled vulcanizates with GR and the rubber matrix, having a conventional curing system, showed the largest changes in the cure characteristics. The greatest decrease in the physical properties was observed for peroxide‐cured‐GR‐filled vulcanizates. The addition of GR decreased the crosslink density of the GR‐filled vulcanizates. This was thought to be the main reason for the reduction of the mechanical properties of the GR‐filled vulcanizates. However, the adhesion between the GR and rubber matrix may also have caused the differences in the physical properties of the GR‐filled vulcanizates with respect to the curing systems of the rubber matrix and GR. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Effect of zinc oxide nanoparticles as cure activator on the properties of natural rubber and nitrile rubber
Authors: Sahoo Suchismita , Maiti Madhuchhanda , Ganguly Anirban , Jacob George Jinu , Bhowmick Anil K.
Published: May 2007

Zinc oxide (ZnO) nanoparticles were synthesized by homogeneous precipitation and calcination method and were then characterized by transmission electron microscopy and X‐ray diffraction analysis. Synthesized ZnO was found to have no impurity and had a dimension ranging from 30–70 nm with an average of 50 nm. The effect of these ZnO nanoparticles as cure activator was studied for the first time in natural rubber (NR) and nitrile rubber (NBR) and compared with conventional rubber grade ZnO with special reference to mechanical and dynamic mechanical properties. From the rheograph, the maximum torque value was found to increase for both NR and NBR compounds containing ZnO nanoparticles. ZnO nanoparticles were found to be more uniformly dispersed in the rubber matrix in comparison with the conventional rubber grade ZnO as evident from scanning electron microscopy/X‐ray dot mapping analysis. The tensile strength was observed to improve by 80% for NR when ZnO nanoparticles were used as cure activator instead of conventional rubber grade ZnO. An improvement of 70% was observed in the case of NBR. The glass transition temperature (Tg) showed a positive shift by 6°C for both NR and NBR nanocomposites, which indicated an increase in crosslinking density. The swelling ratio was found to decrease in the case of both NR and NBR, and volume fraction of rubber in swollen gel was observed to increase, which supported the improvement in mechanical and dynamic mechanical properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Retracted: Preparation of PMR+PAN resin matrix and its studies on carbon fiber reinforced composite: Hydraulic, chemical, and temperature stability
Authors: Gupta Anand Kumar , Patel P. R. , Kurmvanshi S. K. , Bajpai R. , Keller J. M. , Nema S. K.
Published: May 2007

This article has been retracted because it was submitted without the knowledge of all of the authors and major portions have been plagiarized.
Effect of assisted ion energy on properties of silicon oxide thin film deposited by dual ion‐beam sputtering
Authors: Seong Jin‐Wook , Choi Daiwon
Published: May 2007

A silicon oxide thin film barrier was prepared with different oxygen ion energies, and its chemical composition, surface morphology, optical, and barrier property related to the deposition condition were characterized and discussed. Our study showed that in O2‐assisted process the stoichiometric silicon oxide thin film was obtained at a critical deposition condition of 100 eV oxygen ion energy. The thin film deposited at the critical condition showed the lowest surface roughness giving similar or higher optical transmittance than that of pure polycarbonate substrate. The boiling and tensile tests performed on the thin film deposited using assisted ions prior to the deposition process showed improvement in the adhesion between the oxide barrier layer and the polymer substrate. In addition, interface domination for improving the barrier properties of silicon oxide thin film was achieved through introduction of dual ion‐beam sputtering without pretreatment. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
The rheological behavior and dynamic mechanical properties of syndiotactic 1,2‐polybutadiene
Authors: He Xiaofeng , Sun Guangping , Li Jing , Wang Biao , Li Min , Liu Jingjiang , Bi Jifu , Jiang Liansheng , Zhang Xuequan
Published: May 2007

The rheological behavior and the dynamic mechanical properties of syndiotactic 1,2‐polybutadiene (sPB) were investigated by a rotational rheometer (MCR‐300) and a dynamic mechanical analyzer (DMA‐242C). Rheological behavior of sPB‐830, a sPB with crystalline degree of 20.1% and syndiotactic content of 65.1%, showed that storage modulus (G′) and loss modulus (G″) decreased, and the zero shear viscosity (η0) decreased slightly with increasing temperature when measuring temperatures were lower than 160°C. However, G′ and G″ increased at the end region of relaxation curves with increasing temperature and η0 increased with increasing temperature as the measuring temperatures were higher than 160°C. Furthermore, critical crosslinked reaction temperature was detected at about 160°C for sPB‐830. The crosslinked reaction was not detected when test temperature was lower than 150°C for measuring the dynamic mechanical properties of sample. The relationship between processing temperature and crosslinked reaction was proposed for the sPB‐830 sample. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
A new business model for sustainable development: an exploratory study using the theory of constraints in Nordic organizations
Authors: Birkin Frank , Polesie Thomas , Lewis Linda
Published: May 2007

The business model in use by many large companies has changed significantly from that of a decade ago and has incorporated environmental and social aspects of performance. However, given these achievements, are there unavoidable inhibitions in the contemporary business model that mean that even exemplar corporations cannot become sustainable?

A key issue is consumption without limits, but can businesses do anything about this? The UK Government's Sustainable Development Commission identifies this as an issue. There is a need for an open‐minded consideration of business fundamentals to consider this issue as part of an identification of criteria for a sustainable business model.

This is an account of an exploratory study undertaken to identify a new business model for sustainable development. The theory of constraints was adapted to provide the project's methodology that made use of semi‐structured interviews and secondary material. The cloverleaf account of sustainable development was used to structure and analyse sustainable development information. The organizations studied are all located in Nordic countries, since these countries are globally recognized for sustainable development achievements. Conclusions of the study acknowledge that, whilst specific new management tools and approaches of Nordic organizations do help sustainable development, it is the social context in which these organizations function that is a critical factor. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Model‐based conformational clustering of ring molecules
Authors: Kessler Mathieu , Bueso María C. , Pérez José
Published: May 2007

In this paper we address the problem of classifying the conformations of m‐membered rings using experimental observations obtained by crystal structure analysis. After formulating a model for the data generation mechanism that is based on a multidimensional mixture model and takes into account the symmetry of the data, we suggest an algorithm, based on the mclust algorithm introduced by Raftery et al. to perform the conformational classification of the crystal structures. The method is illustrated on a simulated data set and on real data corresponding to cyclooctane and related structures. Copyright © 2007 John Wiley & Sons, Ltd.
Substituent electronic descriptors for fast QSAR/QSPR
Authors: Hemmateenejad Bahram , Sanchooli Mahmood
Published: May 2007

Substituent electronic descriptors (SED), calculated by ab initio quantum chemical methods for radical substituents, were proposed as an efficient and simple to use descriptors for use in Quantitative structure‐activity/property relationships (QSPR/QSAR) studies. Twenty five SED parameters were calculated for a set of simple substituents using orbital energies, local charges, and dipole moments. Calculation of these parameters for a substituent takes much lower time comparing with that for parent molecule. Different chemical and biological data were analyzed by the SED parameters and it was found that in addition to the simplicity and speed of calculations, models obtained by SED parameters have better or comparable efficiency in relative to existing models. Copyright © 2007 John Wiley & Sons, Ltd.
Quantum‐chemical calculations on the electronic circular dichroism of (−)‐dibromophakellin and (−)‐dibromophakell‐statin
Authors: Atodiresei Iuliana , Zöllinger Michael , Lindel Thomas , Fleischhauer Jörg , Raabe Gerhard
Published: May 2007

The CD spectra of the pyrrole‐imidazole alkaloids, (−)‐dibromophakellin and (−)‐dibromophakellstatin, have been calculated employing the quantum‐chemical time‐dependent density functional theory. Comparison of calculated and measured spectra showed that this well‐established method is also a useful tool to elucidate the absolute stereochemistry of this class of compounds. The computational results have further been used to analyze the spectra measured in methanol and to explain the remarkable red shift of one CD band when trifluoroethanol is used as a solvent instead of methanol. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Stereoselective hexobarbital 3′‐hydroxylation by CYP2C19 expressed in yeast cells and the roles of amino acid residues at positions 300 and 476
Authors: Saito Keita , Dan Hikari , Masuda Kazufumi , Katsu Takashi , Hanioka Nobumitsu , Yamamoto Shigeo , Miyano Kazuko , Yamano Shigeru , Narimatsu Shizuo
Published: May 2007

We examined the enzymatic function of recombinant CYP2C19 in enantiomeric hexobarbital (HB) 3′‐hydroxylation, and searched the roles of amino acid residues, such as Phe‐100, Phe‐114, Asp‐293, Glu‐300, and Phe‐476 of CYP2C19 in the stereoselective HB 3′‐hydroxylation, using a yeast cell expression system and site‐directed mutagenesis method. CYP2C19 wild‐type exerted substrate enantioselectivity of (R)‐HB ≫ (S)‐HB and metabolite diastereoselectivity of 3′(R) < 3′(S) in 3′‐hydroxylation of HB enantiomers. The substitution of Asp‐293 by alanine failed to yield an observable peak at 450 nm in its reduced carbon monoxide‐difference spectrum. CYP2C19‐E300A and CYP2C19‐E300V with alanine and valine, respectively, in place of Glu‐300 exerted total HB 3′‐hydroxylation activities of 45 and 108%, respectively, that of the wild‐type. Interestingly, these two mutants showed substrate enantioselectivity of (R)‐HB < (S)‐HB, which is opposite to that of the wild‐type, while metabolite diasteroselectivity remained unchanged. The replacement of Phe‐476 by alanine increased total HB 3′‐hydroxylation activity to approximately 3‐fold that of the wild‐type. Particularly, 3′(S)‐OH‐(S)‐HB‐forming activity elevated to 7‐fold that of the wild‐type, resulting in the reversal of the substrate enantioselectivity. In contrast, the substitution of phenylalanine at positions 100 and 114 by alanine did not produce a remarkable change in the total activity or the substrate enantioselectivity. These results indicate that Glu‐300 and Phe‐476 are important in stereoselective oxidation of HB enantiomers by CYP2C19. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Hepatic steatosis is associated with increased frequency of hepatocellular carcinoma in patients with hepatitis C‐related cirrhosis
Authors: Pekow Joel R. , Bhan Atul K. , Zheng Hui , Chung Raymond T.
Published: May 2007

BACKGROUND.

Chronic hepatitis C can result in fatty changes in the liver. Previous studies have suggested that hepatic steatosis is a risk factor for hepatocellular carcinoma in patients with hepatitis C virus (HCV) infection. The authors sought to determine whether hepatic steatosis is associated with hepatocellular carcinoma (HCC) in a cohort of patients with hepatitis C‐related cirrhosis.

METHODS.

The authors retrospectively identified 94 consecutive patients with hepatitis C cirrhosis who underwent liver transplantation from 1992 to 2005 and had pathology available for review. Of these, 32 had evidence of HCC, and 62 had no HCC on explant histology. All explant specimens were graded again for steatosis by a single, blinded pathologist. Steatosis, age, sex, body mass index, HCV RNA, HCV genotype, Model for End‐Stage Liver Disease (MELD) score, chronic alcohol use, and diabetes were examined in univariate and multivariate analyses for association with HCC.

RESULTS.

In total, 69% of patients in the HCC group and 50% of patients in the control group had evidence of steatosis (1+) on histology. Odds ratios for the development of HCC for each grade of steatosis compared with grade 0 were as follows: grade 1 (1.61 [0.6–4.3]), grade 2 (3.68 [1.1–12.8]), and grade 3 or 4 (8.02 [0.6–108.3]) (P = .03 for the trend). In univariate analysis, there was a significant association between increasing steatosis grade (P = .03), older age (56 years vs 49 years; P < .02), higher aspartate aminotransferase (122.5 U/L vs 91.5 U/L; P = .005), higher alanine aminotransferase (95.8 U/L vs 57.2 U/L; P = .002), higher alpha‐fetoprotein (113.5 ng/mL vs 17.8 ng/mL; P < .001), lower median HCV RNA (239,000 IU/mL vs 496,500 IU/mL; P = .02), higher biologic MELD score (21.8 vs 20.3; P = .03), and risk of HCC. In multivariate analysis, age (P = .02), AFP (P = .007), and steatosis (P = .045) were significantly associated with HCC.

CONCLUSIONS.

In patients with HCV‐related cirrhosis, the presence of hepatic steatosis is independently associated with the development of hepatocellular carcinoma. These findings suggest that steatosis poses an additional risk for HCC and that increased vigilance should be practiced in surveillance of persons with both HCV and steatosis. Cancer 2007. © 2007 American Cancer Society.
Redefining pT3 renal cell carcinoma in the modern era
Authors: Margulis Vitaly , Tamboli Pheroze , Matin Surena F. , Meisner Matthew , Swanson David A. , Wood Christopher G.
Published: May 2007

BACKGROUND.

The 2002 American Joint Committee on Cancer (AJCC) tumor classification for renal cell carcinoma (RCC) does not take into account concomitant venous invasion and extrarenal tumor extension (ERE). In the current study, the authors evaluated the prognostic significance of venous tumor thrombus (VTT) and its extent, the presence and location of ERE, and a combination of both features on survival after the surgical management of patients with pathologic T3 (pT3) RCC.

METHODS.

With Institutional Review Board approval, the institutional nephrectomy database of 3470 patients treated at the University of Texas M. D. Anderson Cancer Center from 1990 to 2006 was searched for pT3 RCC patients who were treated with partial or radical nephrectomy. Patients with nonmetastatic, lymph node‐negative RCC and a minimum follow‐up of 6 months were included in the analysis.

RESULTS.

A total of 419 patients with pT3N0/NxM0 RCC and a mean follow‐up of 40.8 months met the study inclusion criteria. In multivariate Cox regression analyses, the 2002 AJCC primary tumor classification was not found to be an independent predictor of cancer‐specific mortality. A total of 211 patients with ERE only (50.4%) and 72 patients with VTT only (17.2%) were found to have a similar risk of death from RCC (hazards ratio [HR] of 1.018; P = .957), whereas 136 patients harboring both features (32.5%) were found to be significantly more likely to die from RCC (HR of 2.660; P < .001). The authors proposed a new primary tumor classification in which they grouped patients with both ERE and VTT (which was found to be an independent predictor of cancer‐specific survival) into a separate staging category, and demonstrated improved prognostic ability when compared with the 2002 AJCC classification (c indexes of 0.625 vs 0.580, respectively).

CONCLUSIONS.

The prognostic accuracy of the 2002 AJCC pT3 tumor classification can be improved by subclassifying patients with ERE only and those with VTT only into a prognostic category that is separate from patients with both ERE and VTT. Cancer 2007. © 2007 American Cancer Society.