bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparison of Experimental Methods in Molecular Chronic Rhinosinusitis Research
Authors: Ramanathan Murugappan , Lane Andrew P.
Published: June 2007

Background

Research into the molecular pathogenesis of chronic rhinosinusitis (CRS) requires the collection and analysis of sinonasal tissue. Recent gene expression studies have used either surgical tissue specimens or isolated epithelial cell preparations. Here, we compare cultures of nasal epithelial cells, nasal brush biopsy, and whole ethmoid mucosa with respect to expression of innate immune genes.

Methods

Ethmoid mucosa was collected intraoperatively from 12 CRS and control patients. This tissue either was processed whole for mRNA extraction or was used to generate primary nasal epithelial cell cultures. After 6 weeks, epithelial cells in culture were assessed for multiple innate immune proteins by flow cytometry. In parallel, middle meatal brush biopsy specimens were obtained from the same patients and studied acutely in a similar fashion by flow cytometry. Expression of innate immune genes was determined in whole tissue samples by real-time polymerase chain reaction.

Results

Flow cytometry revealed that brush biopsy specimens contain 75% epithelial cells, whereas primary nasal epithelial cell cultures were pure. Epithelial cells derived from individual subjects expressed very similar levels of innate immune markers whether studied acutely or after 6 weeks in culture. Whole tissue mRNA levels were variable and not correlated to epithelial expression.

Conclusion

The choice of experimental methodology can greatly influence the results and interpretation of CRS research. Primary nasal epithelial cells maintain their innate immune receptor expression profile when grown in prolonged culture in vitro. These findings imply that alterations in innate immune gene expression in CRS may be intrinsic to the epithelial cells, even outside of their in vivo microenvironment.
Rehabilitation of Surgically Traumatized Paranasal Sinus Mucosa using Retinoic Acid
Authors: Leung Man-Kit , Hwang Peter H.
Published: June 2007

Background

Paranasal sinus mucosa that regenerates after surgical stripping is characterized by sparse, dysmorphic cilia. Although such dysfunctional mucosal changes are thought to be irreversible, the potential rehabilitation of deciliated mucosa by topical therapies has not been explored. This study evaluated the effect of topical retinoic acid (RA) in rehabilitating deciliated sinus mucosa that has regenerated after surgical stripping.

Methods

Twelve New Zealand rabbits underwent bilateral maxillary sinus mucosal stripping and were allowed to remucosalize for 10 days. In the first treatment arm (n = 6), 0.01% RA was applied to the regenerated mucosa of the left maxillary sinus and an aqueous control was placed contralaterally. In the second treatment arm, the regenerated mucosa was surgically restripped bilaterally before applying RA and control. After 14 additional days, mucosa was harvested and examined by scanning electron microscopy for ciliary density, orientation, and morphology.

Results

In the first treatment arm, no significant differences in ciliary density, orientation, or morphology were noted between RA-treated sinuses and controls. In the second arm, RA-treated sinuses showed improved ciliary density, morphology, and orientation compared with controls.

Conclusion

RA does not appear to significantly enhance ciliogenesis when applied after mucosal regeneration has occurred. However, if deciliated mucosa is restripped and allowed to regenerate in the presence of RA, ciliary ultrastructural features may be enhanced. RA may have therapeutic value in rehabilitating deciliated sinus mucosa when applied before mucociliary differentiation of regenerating mucosa.
The Impact of Septorhinoplasty and Anterior Turbinoplasty on Nasal Conditioning
Authors: Rozsasi Ajnacska , Leiacker Richard , Kühnemann Stephan , Lindemann Jörg , Kappe Thomas , Rettinger Gerhard , Keck Tilman
Published: June 2007

Background

Septorhinoplasty and turbinoplasty is a frequently performed operation in facial plastic surgery. The aim of this study was to investigate nasal conditioning after septorhinoplasty and inferior turbinoplasty in patients with internal and external nasal deformities and hypertrophy of the inferior turbinates and to determine its relation to nasal patency.

Methods

Ten patients and 10 volunteers as controls were enrolled into this study. Measurement of nasal conditioning and active anterior rhinomanometry were performed before and 4–6 months after functional-esthetic septorhinoplasty and inferior turbinoplasty.

Results

Nasal airflow was significantly higher postoperatively than preoperatively. The preoperative nasal temperature (TEMP) and heat increase (HI) was lower in the patients compared with the controls. The postoperative TEMP, HI, total water content, and water gradient were significantly higher than the preoperative values.

Conclusion

Based on this relatively small series, functional-esthetic septorhinoplasty in combination with inferior turbinoplasty may be associated with improved nasal conditioning.
The Expression of MUC5AC and MUC5B Mucin Genes in the Mucosa of Chronic Rhinosinusitis and Nasal Polyposis
Authors: Ding Guo Qiang , Zheng Chun Quan
Published: June 2007

Background

The aim of this study was to investigate the expression of MUC5AC and MUC5B messenger RNAs (mRNAs) and localization of these proteins in human sinus mucosa of chronic rhinosinusitis (CRS) and CRS with nasal polyposis (CRS/NP).

Methods

Maxillary sinus ostia mucosa was harvested from patients undergoing endoscopic sinus surgery for CRS, CRS/NP, and non-CRS pathologies (control). Then, sinus mucosa was analyzed using reverse-transcription polymerase chain reaction to detect mRNA of MUC5AC and MUC5B. Hematoxylin and eosin staining and immunofluorescent staining were used to localize MUC5AC and MUC5B proteins in the sinus mucosa.

Results

mRNAs of MUC5AC and MUC5B in the sinus mucosa of CRS and CRS/NP were significantly increased compared with that in normal sinus mucosa (p < 0.01), and no significant difference was found between the mucosa of CRS and that of CRS/NP (p > 0.05). MUC5AC protein was expressed mainly in the goblet cells, and MUC5B expression was located in the submucosal glands cells and the epithelia of sinus mucosa. ARPC in staining of MUC5AC and MUC5B were found no different between the CRS group and the CRS/NP group (p > 0.05), whereas they were significantly lower in the normal group compared with the other two groups, respectively (p < 0.05).

Conclusion

This study showed that MUC5AC and MUC5B mucin genes were up-regulated in sinus mucosa of CRS and CRS/NP. MUC5AC and MUC5B may play an important role in the pathogenesis of CRS and NP.
Blood Flow Changes in the Trapezius Muscle and Overlying Skin Following Transcutaneous Electrical Nerve Stimulation
Authors: Sandberg Margareta L , Sandberg Matilda K , Dahl Johanna
Published: June 2007

Background and Purpose: Various researchers have studied the effects of transcutaneous electrical nerve stimulation (TENS) on hemodynamics. The purpose of this study was to examine the effects of TENS on local blood flow in the trapezius muscle and overlying skin.

Subjects: Thirty-three women who were healthy, aged 25 to 55 years, were randomly assigned to receive 1 of 3 different modes of TENS.

Methods: Skin and muscle blood flow were monitored noninvasively using a new application of photoplethysmography for 15 minutes of TENS applied at high frequency (80 Hz) and sensory-level intensity and at low frequency (2 Hz) and motor-level intensity and for 15 minutes after stimulation. Subliminal 80-Hz TENS was used as a control. Blood flow was monitored simultaneously on stimulated and nonstimulated shoulders.

Results: Blood flow in the trapezius muscle, but not skin blood flow, increased significantly with motor-level 2-Hz TENS, whereas no increase occurred with sensory-level 80-Hz TENS or subliminal 80-Hz TENS.

Discussion and Conclusion: Muscle contractions induced by motor-level 2-Hz TENS appear to be a prerequisite for increasing blood flow in the trapezius muscle. However, high stimulation intensity may prevent increased blood flow in the overlying skin.
Correcting a Significance Test for Clustering
Authors: Hedges Larry V.
Published: June 2007

A common mistake in analysis of cluster randomized trials is to ignore the effect of clustering and analyze the data as if each treatment group were a simple random sample. This typically leads to an overstatement of the precision of results and anticonservative conclusions about precision and statistical significance of treatment effects. This article gives a simple correction to the t statistic that would be computed if clustering were (incorrectly) ignored. The correction is a multiplicative factor depending on the total sample size, the cluster size, and the intraclass correlation ρ. The corrected t statistic has Student’s t distribution with reduced degrees of freedom. The corrected statistic reduces to the t statistic computed by ignoring clustering when ρ = 0. It reduces to the t statistic computed using cluster means when ρ = 1. If 0 < ρ < 1, it lies between these two, and the degrees of freedom are in between those corresponding to these two extremes.
Combining Correlation Matrices: Simulation Analysis of Improved Fixed-Effects Methods
Authors: Hafdahl Adam R.
Published: June 2007

The originally proposed multivariate meta-analysis approach for correlation matrices—analyze Pearson correlations, with each study’s observed correlations replacing their population counterparts in its conditional-covariance matrix—performs poorly. Two refinements are considered: Analyze Fisher Z-transformed correlations, and substitute better estimates of correlations in the conditional covariances. Fixed-effects methods with and without each refinement were examined in a Monte Carlo study; number of studies and the distribution of within-study sample sizes were varied. Both refinements improved element-wise point and interval estimates, as well as Type I error control for homogeneity tests, especially with many small studies. Practical recommendations and suggestions for future methodological work are offered. An appendix describes how to transform Fisher- Z (co)variances to the Pearson- r metric.
Traditional forest utilization practice by the Mro tribe in the Bandarban region, Bangladesh
Authors: Miah Md. Danesh , Chowdhury Mohammad Shaheed Hossain
Published: June 2007

The traditional utilization of forest products by theMro tribe was explored in the Bandarban region,Bangladesh. The dependence of the tribe on foods, fruits,energy, and timber derived from the neighbouring forests was determined in this study, which also focused on their cultural festivals based on forest plants. The results reveal an extreme dependence of the Mro tribe on forest products.
Zum Forschungsstand über Waldkindergärten | State of research on forest kindergartens
Authors: Kiener Sarah
Published: June 2007

Although forest kindergartens have existed in Scandinavian countries for over 60 years, empirical research on the consequences is still very scanty. Most diploma thesis and studies in this area concern themselves with describing projects and concepts of forest kindergartens or the school abilities of the «forest» children. As far as empirical research of the experience gained so far is concerned, it can be concluded that the effects are positive on the children's motorary skills and creative development and prepares them for school at least as well as children who visit a conventional kindergarten.
Utilisation of wild growing yams as supplementary nutrition and its impact on the dry forest ecosystem in north-western Madagascar
Authors: Ackermann Klaus
Published: June 2007

Wild growing yams (Dioscorea spp.) are an important supplementary food in Madagascar, especially during periods of rice shortage in the rainy season. Yams grow in dry forests and there is a particularly high occurrence of yam tubers in recently burned, open secondary forest formations. The study found that the uncontrolled harvest of yams can contribute to the degradation of dry forests due to the high quantity of wild yams harvested by the local population and the widespread practice of intentionally burning forests to increase yams production.
Gestion de la forêt tropicale en zone rurale: le transfert de technologies peut-il être le catalyseur de partenariats durables? | Management of tropical forests in rural areas: Can technology transfer really act as a catalyst for sustainable partnerships?
Authors: Pfund Jean-Laurent , Kistler Pierre , Guidese Stefano
Published: June 2007

This article discusses the necessary adaptation of improvement techniques to local rural requirements, based on two case studies on (i) a forest with high timber potential and (ii) a forest with high agricultural pressure. Results underline the importance of the exchange of information and communication networks as essential components of a dynamic development.

In spite of fundamentally different forest management schemes, a number of analytical elements seem common in both cases studied (Congo Basin and Madagascar). According to these examples, one can see that the disabling factors arise,on the one hand, from classical problems of maladjustment to local conditions, and from deficiencies in the «tools» of information transmission and sustainability gaps, due to lack of support from the local population, on the other. Moreover, it is clear that a strategy needs to be adopted that grants the local system as much autonomy as possible. The strategy must satisfy the basic needs of the local population and also take the growing need for cash into account.

The article concludes that the transfer of technologies can indeed quickly become a catalyst of sustainable partnerships in favorable conditions of local development, provided that the local beneficiaries of the transfer are identified in an equitable manner. At the same time, preceding and normally complementary measures are necessary to improve local competences and organization. The setting up of lasting relations with partners and their organisations is the key to reaching a consensus on the definition of objectives, as well as to regular relations that allow for adjustments to the system should complications arise. Responsibility for the sustainability of the system remains with the State, which co-ordinates activities as a whole, while dynamic impulses come more from the economic sector. In addition to setting up long-term partnerships the central concerns of the system include local know-how, the capabilities of assimilation and negotiation between the principal local actors and sound financial analysis.
Processing Routes, Microstructure and Mechanical Properties of Metallic Glasses and their Composites
Authors: Eckert J. , Das J. , Pauly S. , Duhamel C.
Published: June 2007

Metallic glasses represent an interesting group of materials as they are superior in certain mechanical properties, i.e. they reach near theoretical strength, exhibit large elastic strain (2 %) and low elastic modulus compared to their crystalline counterparts. The discovery of new alloy compositions solidifying into bulk glassy samples allows for conventional mechanical characterization and raises the hope for possible applications as structural material. In order to improve and tailor the mechanical properties, composite materials have been developed that consist of a glassy matrix with second phase dispersions of different chemical compositions, morphology, and different length scale. This article reviews the different processing routes, the evolution of different microstructures and the resulting elastic and plastic properties of metallic glasses and their composites. Additionally, the recently reported monolithic ductile bulk metallic glasses will be discussed in terms of their structure, chemical composition and their unique “work hardening”‐like behavior.
Phase Diagrams and Glass Formation in Metallic Systems
Authors: Baricco M. , Palumbo M.
Published: June 2007

The basic thermodynamic aspects of glass‐formation in metallic systems are reviewed. In particular, the specific features of a phase diagram with respect to glass‐formation are evidenced. On the basis of the regular solution model, the effect of various thermodynamic quantities on the free energy difference between undercooled liquid and crystal phases are outlined. In order to describe the amorphous phase, a specific heat difference between liquid and solid phases in the undercooling regime is introduced in the CALPHAD assessment of various binary systems. The glass‐transition is described as a second order transition. Examples are given for different systems, including Fe‐B and Cu‐Mg. From the description of the free energy of various phases as a function of composition and temperature, the driving forces for nucleation of crystal phases and the T0 curves are estimated.
Characterization of dynamical emulsification process in concentrated conditions
Authors: Baravian Christophe , Mougel Julien , Caton François , Durand Alain
Published: June 2007

Emulsification at constant shear rate in concentrated conditions (50% in volume fraction) is investigated experimentally by measuring simultaneously the droplet size and the global shear stress using a specially designed rheo‐optical “Steady Light Transport” apparatus. The capillary number is varied by changing the continuous phase viscosity, corresponding to disperse to continuous phase viscosity ratios between 0.02 and 2. We show that when the capillary number is large enough (>0.35), emulsification occurs. At constant shear rate, this time‐dependant process can be separated into four steps: (1) flow start‐up, (2) premix formation, (3) a progressive reduction in droplet size, associated with an increase in shear stress, (4) changes in droplet size and shear stress stop at a well‐defined emulsification time. Step (3), called dynamical emulsification, is fully controlled by the critical capillary number and the mechanism of drop size reduction stops when viscous dissipation dominates the droplet elongation and break‐up mechanism. This approach accurately describes both the variation in shear stress with droplet size during Stage (3) and the final state of the emulsion in terms of droplet size and viscosity. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Is the 5‐HTTLPR polymorphism associated with bipolar disorder or with suicidal behavior of bipolar disorder patients?
Authors: Neves F.S. , Silveira G. , Romano‐Silva M.A. , Malloy‐Diniz L. , Ferreira A.A. , De Marco L. , Correa H.
Published: June 2007

The serotonin transporter gene has a 44 bp insertion/deletion polymorphism within the promoter region (5‐HTTLPR) with two allelic forms, the long (L) and the short (S) variants. Association between the low‐activity S variant and bipolar disorder (BPD) has been shown but its replication has not been consistent. It has also been described as an association between the S allele and suicidal behavior. Since suicidal behavior is a rather frequent event in BPD, an important question is whether suicidality, instead of bipolarity itself, could be related to S allele. We assessed 351 subjects (167 bipolar inpatients and 184 healthy controls). Diagnosis was conducted by a psychiatrist using a structured interview (MINI‐PLUS), according to DSM‐IV criteria. Suicidal behavior was assessed using a semi‐structured instrument and a review of medical records. Genotyping of the 5‐HTTLPR was performed using PCR. There were 77 patients with a history of previous suicide attempts. Bipolar patients and healthy controls showed comparable genotypic and allelic frequencies. Patients carrying the S allele made violent suicide attempts more frequently (χ2 = 20.2; P = 0.0001) and made more suicide attempts (t = 2.6; P = 0.01). We were able to show an association between the S allele and suicidal behavior but not with BPD. Our data suggest that a phenotypic stratification, taking into account the suicidal behavior history, is of pivotal importance when performing association studies between BPD and 5‐HTTLPR genotypes, which could explain previous contradictory results. © 2007 Wiley‐Liss, Inc.
Testing for gene × environment interaction effects in attention deficit hyperactivity disorder and associated antisocial behavior
Authors: Langley K. , Turic D. , Rice F. , Holmans P. , van den Bree M.B.M. , Craddock N. , Kent L. , Owen M.J. , O'Donovan M.C. , Thapar A.
Published: June 2007

Gene × environment (G × E) interactions are increasingly thought to have substantial influence on the aetiology and clinical manifestations of complex disorders. In ADHD, although main effects of specific genetic variants and pre‐ or peri‐natal variables have been reported and replicated using pooled analyses, few studies have looked at possible interactions. In a clinical sample of 266 children with ADHD, we tested for interaction between gene variants (in DRD4, DAT1, DRD5, and 5HTT) found to be associated with ADHD in pooled analyses and maternal smoking, alcohol use during pregnancy and birth weight. First, G × E effects on a diagnosis of ADHD were tested using conditional logistic regression analyses. Second, possible modifying effects of G × E on symptoms of associated conduct disorder and oppositional defiant disorder (ODD) were investigated using linear regression analysis. The sample size associated with each of the analyses differed as not each variant had been genotyped for each individual. No effects of G × E on ADHD diagnosis were observed. The results suggest that lower birth weight and maternal smoking during pregnancy may interact with DRD5 and DAT1 (birth weight only) in influencing associated antisocial behavior symptoms (ODD and conduct disorder). These preliminary findings showed no evidence of interaction between previously implicated variants in ADHD and specific environmental risk factors, on diagnosis of the disorder. There may be evidence of G × E on associated antisocial behavior in ADHD, but further investigation is needed. © 2007 Wiley‐Liss, Inc.
Relationship between VNTR polymorphisms of the human dopamine transporter gene and expression in post‐mortem midbrain tissue
Authors: Brookes Keeley J. , Neale Benjamin M. , Sugden Karen , Khan Nadeem , Asherson Philip , D'Souza Ursula M.
Published: June 2007

Attention deficit hyperactivity disorder (ADHD) is currently one of the most prevalent childhood behavioral disorders. The disorder is found to be highly heritable, suggesting a large genetic component. Association studies have repeatedly implicated the dopamine transporter (DAT1) gene, and in particular the 10‐repeat allele of a variable number tandem repeat (VNTR) polymorphism located in the 3′UTR of the gene. Inconclusive data has been generated from several earlier studies on the functional effects of this polymorphism. Therefore, there is call for further investigation and thus the focus on data described here from TaqMan RT‐PCR assays. The expression levels of the DAT1 gene from post‐mortem midbrain tissue was measured in relation to the polymorphism present at the 3′UTR VNTR, together with a further VNTR marker located within intron 8 of the gene (Int8 VNTR). The findings suggest that the presence of the 10‐repeat allele of the 3′UTR VNTR, the 3‐repeat of the intron 8 VNTR and both VNTR markers are correlated with increased levels of the DAT1 transcript in midbrain post‐mortem tissue. Further work using linear regression (LR) shows agreement with the correlation analysis, and either nominal significance or a trend in that direction. Given the small sample size, bootstrapping‐derived confidence intervals were calculated for the LR. These empirical analyses suggest that the 3′UTR VNTR to show a significant main effect on relative DAT1 expression. Furthermore, a significant effect was found for the combined model (3′UTR and Int8 VNTR markers) on expression. These data provide further evidence on the plausible molecular mechanism underlying the aetiology of the disorder. © 2007 Wiley‐Liss, Inc.
Preliminary report of familial clustering of EEG measures in ADHD
Authors: Loo Sandra K. , Smalley Susan L.
Published: June 2007

The purpose of the present study is to examine the familiality of electroencephalographic (EEG) measures among affected sibling pairs with Attention‐Deficit Hyperactivity Disorder (ADHD). EEG was recorded during baseline (eyes open and eyes closed) and cognitive activation conditions on a sample of 58 children with ADHD (27 multiplex families), ages 6–18. EEG power in three frequency bands: theta (4–7 Hz), alpha (8–12 Hz) and beta (12–20 Hz) was tested for sibling correlation, familial co‐segregation and association with behavioral task performance on a sustained attention task. Sibling correlation for EEG measures was moderate during baseline conditions and significantly higher for the cognitive activation condition. Familial clustering of frontal and parietal alpha power was evident, but only during the cognitive activation condition. Theta and alpha power correlated significantly with CPT response variability and omission errors, respectively. Cognitive task performance did not exhibit familial clustering in our sample. EEG measures (i.e., alpha power) recorded during cognitive activation is a strongly familial trait in ADHD and may be a putative endophenotype for ADHD. © 2007 Wiley‐Liss, Inc.
Effects of selected process parameters on the morphology of poly(ethylene terephthalate) preforms and bottles
Authors: Hanley Tracey , Sutton David , Karatchevtseva Inna , Cookson David , Burford Robert , Knott Robert
Published: June 2007

Small‐angle X‐ray scattering (SAXS) studies and polarized optical microscopy were undertaken to explore possible morphological explanations for the poor mechanical strength in the petaloid bases of poly(ethylene terephthalate) bottles. With a standard commercial production line, one set of injection‐molded preforms was overpacked by 1.1 wt % to investigate the effect on the molecular morphology with respect to a set of control samples. Both sets of preforms showed highly crystalline and oriented areas corresponding to the injection gate region. The main body of the control preform was amorphous, and although the overpacked preform was essentially amorphous, there was some evidence for weak crystallinity. The SAXS patterns of the bottle petaloid base blown from the corresponding preforms produced similar SAXS patterns for overpacked and control bottle bases, indicating that the commercial process is robust at least to this degree of overpacking. Optical microscopy showed detailed crystalline features around the gate region and thin crystalline layers sandwiched between a quenched skin layer in direct contact with the cold mold walls and the main flow of material into the mold. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Morphology and thermal properties of poly(L‐lactic acid)/organoclay nanocomposites
Authors: Lin Li‐Huei , Liu Hsin‐Jiant , Yu Neng‐Kai
Published: June 2007

A modified clay was used to prepare poly(L‐lactic acid)/clay nanocomposite dispersions. X‐ray diffraction and transmission electron microscopy experiments revealed that poly(L‐lactic acid) was able to intercalate the clay galleries. IR spectra of the poly(L‐lactic acid)/clay nanocomposites showed the presence of interactions between the exfoliated clay platelets and the poly(L‐lactic acid). Thermogravimetric analysis and differential scanning calorimetry were performed to study the thermal behavior of the prepared composites. The properties of the poly(L‐lactic acid)/clay nanocomposites were also examined as functions of the organoclay content. The exfoliated organoclay layers acted as nucleating agents, and as the organoclay content increased, the crystallization temperature increased. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Improving MCM‐41 as a Nitrosamines Trap through a One‐Pot Synthesis
Authors: Xu Jia Hui , Zhuang Ting Ting , Cao Yi , Yang Jing , Wen Jing Jia , Wu Zheng Ying , Zhou Chun Fang , Huang Li , Wang Ying , Yue Ming Bo , Zhu Jian Hua
Published: June 2007

Copper oxide was incorporated into MCM‐41 by a one‐pot synthesis under acidic conditions to prepare a new mesoporous nitrosamines trap for protection of the environment. The resulting composites were characterized by XRD, N2 adsorption–desorption, and H2 temperature‐programmed reduction techniques, and their adsorption capabilities were assessed in the gaseous adsorption of N‐nitrosopyrrolidine (NPYR). The adsorption isotherms were consistent with the Freundlich equation. The copper salt was deposited onto MCM‐41 during the evaporation stage and was fixed on the host in the calcination process that followed. MCM‐41 was able to capture NPYR in air below 373 K but not at 453 K. Loading of copper oxide on MCM‐41 greatly improved its adsorption capability at elevated temperatures. The influence of the incorporation of copper into MCM‐41 samples and the adsorption behavior of these samples are discussed in detail.
Sugar‐Alcohol Complexes of Palladium(II): On the Variable Rigidity of Open‐Chain Carbohydrate Ligands
Authors: Allscher Thorsten , Kästele Xaver , Kettenbach Gerhard , Klüfers Peter , Kunte Thomas
Published: June 2007

The C4, C5, and C6 sugar alcohols erythritol (Eryt), D‐threitol (D‐Thre), D‐arabitol (D‐Arab), ribitol (Ribt), xylitol (Xylt), dulcitol (Dulc), and D‐mannitol (D‐Mann) form chelate complexes upon dissolution in Pd‐en, an aqueous solution of [PdII(en)(OH)2]. Stability rules are derived from the proportion of a respective species in the solution equilibrium. Crystal‐structure analysis supports the NMR spectroscopic results for a series of binuclear compounds that contain the sugar alcohols as tetraanionic polyolato ligands: [Pd2(en)2(ErytH−4)]⋅ 10H2O, [Pd2(en)2(D‐Arab1,2;3,4H−4)]⋅ 7H2O, [Pd2(en)2(Xylt1,2;3,4H−4)]⋅4H2O, [Pd2(en)2(D‐Mann1,2;3,4H−4)]⋅5H2O, and [Pd2(en)2(Dulc2,3;4,5H−4)]⋅6H2O. In the case of the pentitols and hexitols, the metalated tetraanions are stabilized by intramolecular hydrogen bonds. The hydrogen bonds uniformly connect an alkoxide acceptor to the hydroxy donor group located at the δ carbon atom. As a consequence of hydrogen bonding, the open‐chain carbohydrate ligands become rigid. Crystal‐structure analysis provides information on the configurational requirements for rigidity. According to these rules, the hydrogen‐bond‐supported Dulc2,3;4,5H−4 tetraanion provides a geometrically persistent ligating pattern. Intramolecular hydrogen bonding seems to be the most‐competitive variable to metalation of a polyol. [Pd2(tm‐2,1:3,2‐tet)(OH)3]OH (tm‐2,1:3,2‐tet=1,3‐bis(2′‐dimethylaminoethyl)hexahydropyrimidine) is a metallizing agent that can force full metalation even in a case as intractable as that of dulcitol. Accordingly, [Pd4(tm‐2,1:3,2‐tet)2‐(DulcH−6)]Cl2⋅16H2O contains the fully deprotonated hexitol as the ligand.
Preliminary results on the fundamental parameters of the eclipsing binary V398 Lacertae
Authors: Çakırlı Ö. , Frasca A. , İbanoǧlu C. , Soydugan F. , Deǧirmenci Ö.
Published: June 2007

The Hipparcos Space Astrometry Mission photometric observations of V398 Lac, led to the discovery of its variability, allowing to classify it as an eclipsing binary with an orbital period of about 5.4 days. This prompted us to acquire highresolution échelle spectra with the aim of performing accurate radial velocity measurements and to determine the main physical parameters of the system's components. We present, for the first time, a double‐lined radial velocity curve and determine the orbital and physical parameters of the two components, that can be classified both as late B‐type stars. In particular, we obtained an orbital inclination i ∼ 85°. With this value of the inclination, we deduced masses M1 = 3.83±0.35 M⊙ andM2 = 3.29±0.32 M⊙, and radii R1 = 4.89±0.18 R⊙ and R2 = 2.45±0.11 R⊙ for the more massive and less massive components, respectively. Both components are well inside their own Roche lobes. The mass ratio is M2/M1 ∼ 0.86. We derived also the projected rotational velocities as v1 sin i = 79±2 km s–1 and v2 sin i = 19±2 km s–1. Our measurements indicate that the rotation of the primary star is essentially pseudo‐synchronized with the orbital velocity at the periastron, while the secondary appears to rotate very slowly and has not yet attained synchronization. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low‐mass visual binaries in the solar neighbourhood: The case of HD 141272
Authors: Eisenbeiss T. , Seifahrt A. , Mugrauer M. , Schmidt T. O. B. , Neuhäuser R. , Roell T.
Published: June 2007

We search for stellar and substellar companions of young nearby stars to investigate stellar multiplicity and formation of stellar and substellar companions. We detect common proper‐motion companions of stars via multi‐epoch imaging. Their companionship is finally confirmed with photometry and spectroscopy. Here we report the discovery of a new co‐moving (13 σ) stellar companion ∼17.8 arcsec (350AU in projected separation) north of the nearby star HD141272 (21 pc).With EMMI/NTT optical spectroscopy we determined the spectral type of the companion to be M3±0.5V. The derived spectral type as well as the near infrared photometry of the companion are both fully consistent with a $ 0.26^{+0.07}_{-0.06} $ M⊙ dwarf located at the distance of HD141272 (21 pc). Furthermore the photometry data rules out the pre‐main sequence status, since the system is consistent with the ZAMS of the Pleiades. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Competence assessment of senior vascular trainees using a carotid endarterectomy bench model
Authors: Black S A , Harrison R H , Horrocks E J , Pandey V A , Wolfe J H N
Published: June 2007

Background

Competency-based assessment is being introduced to surgical training. The value of bench-top technical skills assessment using a synthetic carotid endarterectomy (CEA) model was evaluated in vascular trainees and consultants.

Methods

Forty-one surgeons (13 junior trainees, 15 senior trainees and 13 experienced consultants with experience of more than 50 CEAs) performed a three-throw knot-tying exercise on a jig and a CEA on the bench model. A composite score for knot-tying was calculated, incorporating electromagnetic motion analysis. CEA technical skill was assessed using validated rating scales by blinded video analysis.

Results

Senior trainees performed better than junior trainees in knot-tying (P = 0·025) as well as generic (P < 0·001) and procedural (P < 0·001) skills on CEA model assessment. There was no difference between senior trainees and consultants on any of these measures. The CEA model interobserver reliability was high for all rating scales (generic α = 0·974, procedural α = 0·952, end-product α = 0·976).

Conclusion

Senior trainees achieved the same score as consultants, suggesting a similar level of basic technical skill and knowledge required to perform CEA, and were significantly better than junior trainees. Performance on the bench model could provide an early assessment for suitability to proceed to operative training in a competency-based training and assessment programme.
Chemoenzymatic Synthesis of Prenylated Indole Derivatives by Using a 4‐Dimethylallyltryptophan Synthase from Aspergillus fumigatus
Authors: Steffan Nicola , Unsöld Inge A. , Li Shu‐Ming
Published: June 2007

A 4‐dimethylallyltryptophan synthase, FgaPT2, has been identified in the genome of Aspergillus fumigatus. In a previous study, FgaPT2 was overexpressed in Saccharomyces cerevisiae and characterized biochemically. A higher protein yield (up to 100‐fold higher than that for S. cerevisiae) has now been achieved by overexpression in E. coli; this has permitted investigation into substrate specificity with alternative substances. FgaPT2 accepted 17 of 37 commercially available indole derivatives as substrates. Tryptophan derivatives that carry methyl groups at the indole ring showed a different acceptance from those with methyl groups on the side chain. 5‐Hydroxytryptophan was well accepted by FgaPT2, while the halogenated derivatives were not accepted. Decarboxylation, deamination, or oxidative deamination of tryptophan, as well as replacement of the NH2 group by OH, or of the COOH group by CH2COOH or CONHOH resulted in decreased but still significant enzymatic activity. None of the tested tryptophan‐containing dipeptides was accepted by FgaPT2. Structural elucidation of isolated enzymatic products by NMR and MS analyses proved unequivocally that the prenylation was regioselective at position C4 of the indole ring in the presence of dimethylallyl diphosphate. Determination of the kinetic parameters revealed that L‐tryptophan was accepted as the best substrate by the enzyme, followed by 5‐,6‐,7‐methyltryptophan and L‐abrine. The enzymatic rate constant (kcat Km−1) of nine selected substrates were found to be about 1.0 to 6.5 % of that for L‐tryptophan. Overnight incubation with eight substances showed that the conversion ratio to their prenylated derivatives was in the range 32.5 to 99.7 %. This provides evidence that 4‐dimethylallylated indole derivatives can be produced by chemoenzymatic synthesis with FgaPT2.
Redox Chemistry of Copper–Amyloid‐β: The Generation of Hydroxyl Radical in the Presence of Ascorbate is Linked to Redox‐Potentials and Aggregation State
Authors: Guilloreau Luc , Combalbert Sarah , Sournia‐Saquet Alix , Mazarguil Honoré , Faller Peter
Published: June 2007

Aggregation of the β‐amyloid peptide (Aβ) to amyloid plaques is a key event in Alzheimer's disease. According to the amyloid‐cascade hypothesis, Aβ aggregates are toxic to neurons through the production of reactive oxygen species (ROS). Copper ions play an important role, because they are able to bind to Aβ and influence its aggregation properties. Moreover, Cu–Aβ is supposed to be directly involved in ROS production. To get a better understanding of these reactions, we measured the production of HO. and the redox potential of Cu–Aβ. The results were compared to other biological copper–peptide complexes in order to get an insight into the biological relevance. Cu–Aβ produced more HO. than the complex of copper with Asp‐Ala‐His‐Lys (Cu–DAHK), but less than with Gly‐His‐Lys (Cu–GHK). Cyclic voltammetry revealed that the order for reduction potential is Cu–GHK>Cu–Aβ>Cu–DAHK, but for the oxidation potential the order is reversed. Thus, easier copper redox cycling correlated to higher HO. production. The copper complex of the form Aβ1–42 showed a HO. production five‐times higher than that of the form Aβ1–40. Time‐dependence and aggregation studies suggest that an aggregation intermediate is responsible for this increased HO. production.
Community college international education: Looking back to forecast the future
Authors: Raby Rosalind Latiner , Valeau Edward J.
Published: June 2007

This chapter traces the historical foundations on which today's community college international programs are based and concludes with strategies for strengthening and expanding the internationalization of community colleges.
The role of globalization in technical and occupational programs
Authors: Dellow Donald A.
Published: June 2007

This chapter describes how globalism is changing the U.S. economy and the job market for community college students. Special emphasis is given to the changes required of technical and occupational programs in order to internationalize their curricula and the roles that administrative leadership and faculty play in the process of internationalization.
In union there is strength: The role of state global education consortia in expanding community college involvement in global education
Authors: Korbel Linda A.
Published: June 2007

This chapter profiles state and regional global education consortia, the successes they have enjoyed, and the challenges they face. It concludes with recommendations for strengthening these associations and ensuring their continued existence and effectiveness.
Internationalizing the curriculum: On‐ and off‐campus strategies
Authors: Raby Rosalind Latiner
Published: June 2007

This chapter explores how community colleges internationalize curricula by examining both on‐ and off‐campus strategies.
International faculty in U.S. community colleges
Authors: Wells Ryan
Published: June 2007

This chapter profiles international faculty in U.S. community colleges, compares them to noninternational faculty, and calls for greater emphasis on this often‐overlooked group in future policies and research.
Percutaneous coronary intervention for chronic total occlusions: Improved survival for patients with successful revascularization compared to a failed procedure
Authors: Aziz Shahid , Stables Rodney H. , Grayson Antony D. , Perry Raphael A. , Ramsdale David R.
Published: June 2007

Background:

There are limited data on the impact of successful chronic total occlusion (CTO) revascularization by percutaneous coronary intervention (PCI) on survival. We performed a retrospective study comparing the survival between patients with a successful and a failed CTO revascularization by PCI.

Methods:

Between January 1, 2000 and June 30, 2004, 543 of 5803 (9.4%) patients underwent PCI for a CTO at our center. A CTO was defined as an occlusion of the artery present for at least 3 months with Thrombolysis in Myocardial Infarction flow grade 0 or 1. Patient records were linked to a national database to monitor all deaths during follow up. Propensity matching was used to balance out case mix differences.

Results:

Technical success for CTO was 377 of 543 (69.4%). In‐hospital mortality was 0.3% and 1.2% for the CTO success and CTO failure patients, respectively. During a mean (SD) follow up of 1.7 (0.5) years, the mortality rate was 2.5% in the CTO success patients and 7.3% in the CTO failure patients. The crude hazard ratio for death with CTO failure was 3.92 (95% confidence intervals 1.56–10.07; P = 0.004). The rates of coronary artery bypass were 3.2% vs. 21.7% (P < 0.001) for the CTO success and CTO failure patients, respectively. Our propensity matched 157 CTO success to CTO failure patients and the associated hazard ratio for death with CTO failure was 4.63 (95% confidence interval 1.01–12.61; P = 0.049). Multivariate analysis showed that CTO failure was an independent predictor of death.

Conclusion:

Patients with a successful revascularization of a CTO by PCI have an increased survival rate compared to patients with a failed CTO procedure. © 2007 Wiley‐Liss, Inc.
Managing patient dose in interventional cardiology
Authors: Balter Stephen , Moses Jeffrey
Published: June 2007

This paper introduces a methodology for managing the radiation delivered to individual patients, incidental to their fluoroscopically guided interventional procedures. Because rare, but devastating skin injuries have occurred, radiation should be monitored and managed as well as drugs or radiographic contrast media. Dose metrics such as the total dose delivered to a reference point (reference point dose) should be used for this purpose. Fluoroscopy time is a poor independent predictor of skin dose in an individual patient. The concept of a “significant dose” is introduced. This is a predetermined action level of the selected dose metric. The numerical value is set based on classes of patient and procedural factors. Exceeding this value triggers processes for clinical justification of radiation usage and patient follow‐up. Slightly exceeding the significant dose threshold during a procedure should be highly unlikely to cause skin injury. © 2007 Wiley‐Liss, Inc.
Diboryl and Diboranyl Porphyrin Complexes: Synthesis, Structural Motifs, and Redox Chemistry: Diborenyl Porphyrin or Diboranyl Isophlorin?
Authors: Weiss Andre , Hodgson Michael C. , Boyd Peter D. W. , Siebert Walter , Brothers Penelope J.
Published: June 2007

The syntheses of diboryl porphyrin complexes [(BX2)2(ttp)] (ttp: dianion of tetra‐p‐tolylporphyrin) and the BB single‐bond diboranyl complexes [(BX)2(ttp)] (X=F, Cl, Br, I) are given. The former are prepared from the reactions of BX3 (X=F, Cl) with [Li2(ttp)] and the latter from B2Cl4 (X=Cl), the reaction of SbF3 with [(BCl)2(ttp)] (for X=F), and, in the cases of X=Br or I, in a remarkable reductive coupling reaction resulting directly from the reaction of BBr3 or BI3 with [Li2(ttp)]. Density functional theory (DFT) calculations on the thermochemical parameters for the reductive coupling reactions (and those calculated for related dipyrromethene complexes) indicate that a combination of the reducing ability of bromide and iodide ions combined with the constrained environment of the porphyrin ligand contribute to the driving force. The reductive coupling is also observed in the reaction of [(BCl2)2(ttp)] with nBuLi to give [(BnBu)2(ttp)], which was characterised crystallographically. The reaction of [(BCl)2(ttp)] with catechol gives a boron catecholato porphyrin complex, [B2(O2C6H4)(ttp)]. Chloride abstraction from [(BCl)2(ttp)] gives the planar dication [B2(ttp)]2+, whereas chemical reduction of [(BCl)2(ttp)] by using magnesium anthracenide gives a neutral complex, [B2(ttp)], in which the TTP ligand has been reduced by two electrons to give an unusual example of an isophlorin complex. The cationic and neutral complexes [B2(ttp)]2+ and [B2(ttp)] were characterised through a combination of spectroscopic data that is supported by DFT calculations on the porphine analogues.
Fully Fluorinated Imidodiphosphinate Shells for Visible‐ and NIR‐Emitting Lanthanides: Hitherto Unexpected Effects of Sensitizer Fluorination on Lanthanide Emission Properties
Authors: Glover Peter B. , Bassett Andrew P. , Nockemann Peter , Kariuki Benson M. , Van Deun Rik , Pikramenou Zoe
Published: June 2007

In this paper we demonstrate that the effect of aromatic CF substitution in ligands does not always abide by conventional wisdom for ligand design to enhance sensitisation for visible lanthanide emission, in contrast with NIR emission for which the same effect coupled with shell formation leads to unprecedented long luminescence lifetimes. We have chosen an imidodiphosphinate ligand, N‐{P,P‐di(pentafluorophinoyl)}‐P,P‐dipentafluorophenylphosphinimidic acid (HF20tpip), to form ideal fluorinated shells about all visible‐ and NIR‐emitting lanthanides. The shell, formed by three ligands, comprises twelve fully fluorinated aryl sensitiser groups, yet no‐high energy XH vibrations that quench lanthanide emission. The synthesis, full characterisation including X‐ray and NMR analysis as well as the photophysical properties of the emissive complexes [Ln(F20tpip)3], in which Ln=Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb, Y, Gd, are reported. The photophysical results contrast previous studies, in which fluorination of alkyl chains tends to lead to more emissive lanthanide complexes for both visible and NIR emission. Analysis of the fluorescence properties of the HF20tpip and [Gd(F20tpip)3] reveals that there is a low‐lying state at around 715 nm that is responsible for partially quenching of the signal of the visible emitting lanthanides and we attribute it to a π–σ* state. However, all visible emitting lanthanides have long lifetimes and unexpectedly the [Dy(F20tpip)3] complex shows a lifetime of 0.3 ms, indicating that the elimination of high‐energy vibrations from the ligand framework is particularly favourable for Dy. The NIR emitting lanthanides show strong emission signals in powder and solution with unprecedented lifetimes. The luminescence lifetimes of [Nd(F20tpip)3], [Er(F20tpip)3] and [Yb(F20tpip)3] in deuteurated acetonitrile are 44, 741 and 1111 μs. The highest value observed for the [Yb(F20tpip)3] complex is more than half the value of the Yb ion radiative lifetime.