bluuebunny/crossref_metadata_2025 huggingface dataset:
The three bellies of the canine posterior cricoarytenoid muscle: Implications for understanding laryngeal function
Authors: Sanders Ira , Jacobs Ian , Wu Bei‐Lian , Biller Hugh E.
Published: October 2009

The posterior cricoarytenoid (PCA) muscle is known to be active during phonation and respiration. The presence of muscle compartments (bellies) that might subserve these functions was investigated in the canine PCA by anatomical dissection and muscle fiber histochemistry. Five PCA muscles were microdissected and the origins and insertions of all muscle bundles were recorded. An additional six PCA muscles were frozen, sectioned, and stained for adenosine triphosphatase (ATPase) activity. The total number of fast‐ and slow‐twitch fibers were counted and their proportion was determined for each region of the muscle.

The PCA muscle was found to contain three distinct neuromuscular compartments. The vertical compartment is oriented at 24 degrees from true vertical, inserts on the lateral aspect of the muscular process of the arytenoid, and is composed of 65% type 2 (fast) muscle fibers. The oblique is oriented at 44 degrees from vertical, inserts on the top of the muscular process of the arytenoid, and is composed of 77% type 2 muscle fibers. The horizontal is oriented at 63 degrees from vertical, inserts on the medial aspect of the muscular process of the arytenoid, and is composed of 59% type 2 muscle fibers.

The cricoarytenoid joint is capable of three arcs of motion and the physical arrangement of each compartment appears to correspond to each of these motions. Moreover, the histochemical profiles show that the activity of the three bellies is quite different. These results suggest that the different compartments of the PCA perform distinctive motions during phonation and inspiration.
Histologic correlation of the degenerating facial nerve with electroneurography
Authors: Halvorson David J. , Coker Newton J. , Wang‐Bennett Lolin T.
Published: October 2009

The myogenic compound action potential (CAP) measured by electroneurography (ENoG) is hypothesized to correlate directly with the number of viable motoneurons in the facial nerve. In an animal model (cat), two independent ENoG techniques, standardized recording lead placement (SRLP) and optimized recording lead placement (ORLP), were used to record CAPs evoked from nerves undergoing degeneration. Normal test‐retest variability simulated human studies. Peripheral counts of viable axons correlated with N1 amplitude (ORLP ENoG), peak‐to‐peak (absolute) amplitude (both ENoG techniques), and area under the negative phase of the diphasic CAP waveform (both ENoG techniques) recorded over the whisker pad. These results validate ENoG as a reliable indicator of neural integrity following traumatic lesions of the facial nerve.
Eosinophil cationic protein in the nasal secretions of patients with mite allergic rhinitis
Authors: Nishioka Keiko , Saito Chisato , Nagano Toshiaki , Okano Mitsuhiro , Masuda Yu , Kuriyama Toyomitsu
Published: October 2009

In 25 patients with mite nasal allergy and 13 healthy control subjects, levels of eosinophil cationic protein (ECP) and histamine in nasal secretions were examined before and after challenge with mite extract. The ECP level was found to be significantly higher in the washings taken 30 minutes after challenge compared with the washings taken before challenge (P<.05). ECP levels measured both before and after mite extract challenge were found to be significantly higher in the patients than in the controls (P <.01). These facts suggest that the ECP affects the nasal mucosa by causing injury to ciliated cells and by acceleration of the processes of modification and inhibition of the allergic reaction.
Fibrin binding, fibrinolytic and fibrinogenolytic activity of plasminogen activator derived from the paranasal mucous membrane of humans
Authors: Yamashiro Yutaka , Nakamura Mariko , Huang Guang‐Wu , Kosugi Tadayoshi
Published: October 2009

It is known that large amounts of plasminogen activator (PA) are contained in tissue extracts of the human paranasal mucous membrane (PMM) with chronic sinusitis. The present study was undertaken to isolate and purify the PA in tissue extracts of PMM. Furthermore, the purified PA was identified as to whether it was of the tissue type or urokinase (UK) type, and some of its fibrinolytic characteristics were determined in comparison with those of urokinase. As starting material, extracts of acetone powder of PMM with chronic sinusitis were used, and Zn‐imminodiacetate affinity chromatography, lysine‐Sepharose affinity chromatography, and ultrafiltration were carried out to separate and purify the PA from the PMM. The PA was purified to a 107‐fold increase in specific activity. The molecular weight of the PA was estimated to be 65, 000 to 70, 000 d by gel filtration using Sephacryl S‐200. The purified PA was stable in the range of pH 8.0. to 9.0. Using S‐2288, a synthetic substrate, the Michaelis constant (Km) of the purified PA was estimated to be 0.11 mmol. The binding of the purified PA to fibrin was stronger than that of UK, while the fibrinogenolytic activity of the purified PA was not stronger than that of UK. Based on these results, the purified PA was identified as a tissue‐type plasminogen activator (t‐PA). From the kinetic data, it was identified as being of the two‐chain variety. It is considered that, as a thrombolytic agent, t‐PA derived from the PMM could be more useful than UK.
Metabolic activity of the central auditory structures following prolonged deafferentation
Authors: El‐Kashlan Hussam K. , Noorily Alan D. , Niparko John K. , Miller Josef M.
Published: October 2009

The goal of this work was to evaluate, using autoradiographic techniques, the effects of variable periods of deafness on resting and evoked metabolic activity in central auditory structures elicited by direct electrical cochlear nucleus (CN) stimulation.

Thirty‐five pigmented guinea pigs, divided into five groups, underwent acute implantation of bipolar electrodes in the CN. One group was not deafened and served as hearing controls. The other four groups were deafened using an established protocol of sequential kanamycin/ethacrynic acid treatment and were tested at 4 weeks, 9 weeks, 16 weeks, and 15 months after deafening.

Threshold currents for eliciting evoked middle latency responses (EMLRs) with direct CN stimulation were not significantly different between hearing and deafened groups. Autoradiographic data showed progressive reduction of the evoked metabolic response with incremental periods of deafferentation. Nevertheless, central auditory structures remained responsive to direct electrical stimulation of the CN.

These data indicate that direct CN stimulation remains capable of activating the auditory tract despite prolonged periods of deafness.
Inhalation of platelet‐activating factor increases respiratory resistance in rats: Determination by means of an astograph under nonanesthetized conditions
Authors: Kosugi Tadayoshi , Saitoh Shigeru , Tamaki Noboru , Hanashiro Kazuhiko , Nakahodo Kazuhiro , Nakamura Mariko
Published: October 2009

Intratracheal administration of platelet‐activating factor (PAF) to dogs, baboons, and humans has been shown to induce hyperreactivity of the airways and contraction of the smooth muscle. However, it has not yet been reported whether intratracheal administration of PAF to rats induces hyperreactivity. In the present study, the authors estimated the respiratory resistance of rats during intratracheal administration of PAF in order to evaluate the reactivity of the airways to PAF. In both the nonsensitized group and the sensitized group of rats, intratracheal administration of PAF induced an increase in respiratory resistance. The results obtained clarify that responsiveness to PAF exists in the airways of rats.
Histopathologic changes in the aging human cricoarytenoid joint
Authors: Casiano Roy R. , Ruiz Phillip J. , Goldstein Warren
Published: October 2009

Detrimental effects of the natural aging process on the human cricoarytenoid joint have been hypothesized as a possible etiology for the voice changes seen in the aging population. Cellular events occurring at the histologic level, such as cricoarytenoid joint erosion or arthritis may lead to alterations in laryngeal structure which ultimately affect its function and performance. Seven normal human larynges of varying ages ranging from 29 to 69 years of age were examined histopathologically for changes in the cricoarytenoid joint. The synovium, joint space, periarticular muscle, and respiratory epithelium were evaluated for the presence of inflammatory changes or edema and degree of vascularity. The location and amount of ossification, elastin, and collagen formation were also noted.

There were no appreciable changes noted in the synovium or joint space itself with increasing age. No differences were observed in the degree of elastin or collagen formation. However, there was progressive cricoid and arytenoid ossification and periarticular muscular atrophy and fibrosis.

These findings suggest that other laryngeal changes may play a greater role in determining senescent vocal quality rather than changes within the cricoarytenoid joint itself.
Treatment of paranasal sinus cancer with cranial base surgery: Results
Authors: Janecka Ivo P. , Sen Chandranath , Sekhar Laligam , Curtin Hugh
Published: October 2009

Paranasal sinus cancer has been difficult to treat with surgery. A significant negative factor has been the high frequency of tumor‐positive surgical margins. The goal of this study was to evaluate the effectiveness of cranial base surgery in achieving higher tumor‐free resective margins and its impact on the disease control. Fifty patients with paranasal sinus cancer were treated with cranial base surgery and retrospectively evaluated. Surgery was performed for both primary and recurrent disease (“salvage”). with more than half of the surgeries being salvage procedures. The survival at 40 months of mean follow‐up is 74%, and 64% of the patients either have no evidence of disease (NED) or have died of other causes (DOC).

Cranial base surgery is an effective treatment of paranasal sinus cancer. The ability to achieve tumor‐free surgical margins (77% in squamous cell carcinoma [SCC]) is directly related to NED status (75% of NED patients had free margins).
The inverted schneiderian papilloma: A 25‐year study
Authors: Vrabec Donald P.
Published: October 2009

Inverted papillomas arising from the lateral nasal wall are controversial lesions which have been reported in the medical literature under a variety of titles. The designation “inverted Schneiderian papilloma” is recommended as an appropriate title to best convey the tumor's qualities of inversion, location, and distinctiveness of character. The etiology is uncertain. In the absence of a better explanation of its origin, the tumor should be considered a true epithelial neoplasm.

Clinical features in 101 cases seen at the Geisinger Medical Center during the past 25 years are presented. The most frequent presenting complaint was nasal obstruction. The site of origin was the lateral nasal wall in the region of the middle meatus. The most characteristic attributes of the tumor were its tendency to recur, its destructive capacity, and its propensity to be associated with malignancy. To illustrate the pernicious nature of the lesion, a detailed description is given of the extent of bone erosion, the extraordinary sites of tumor extension, and the perioperative complications encountered.

A philosophy of management has evolved based on the experiences gained from these 101 patients combined with a review of the experiences of others and study of the regional anatomy. A bold surgical approach is detailed using a lateral rhinotomy incision or a modified Weber‐Ferguson incision to expose the tumor adequately and remove it completely. The recurrence rate using this approach was 2%.

An associated malignancy was present in 8 patients. Four died of widespread metastases within a year of the diagnosis. The remaining 4 patients are long‐term survivors free of disease.
Investigation of a coaxial bipolar nerve stimulator for intraoperative motor nerve monitoring
Authors: Dankle Jon A. , Wiegand David A.
Published: October 2009

Intraoperative cranial motor nerve monitoring has improved the preservation of cranial nerve function during cerebellopontine angle and skull base surgery. Further improvements are needed to provide greater selectivity and sensitivity during intraoperative motor nerve stimulation. Use of bipolar stimulator probes has been recommended by previous investigators. The authors hypothesized that a coaxial bipolar stimulator design might provide important advantages over existing designs. This study compared the results of bipolar and monopolar stimulation using a coaxial stimulator probe in a rat model and during neurotologic procedures. The coaxial bipolar probe was superior in selectivity, thereby permitting useful multichannel monitoring. The coaxial design may also offer advantages over previous bipolar stimulator designs.
Nano‐imaging through tip‐enhanced Raman spectroscopy: Stepping beyond the classical limits
Authors: Verma P. , Ichimura T. , Yano T. , Saito Y. , Kawata S.
Published: October 2009

The spatial resolution in optical imaging is restricted by so‐called diffraction limit, which prevents it to be better than about half of the wavelength of the probing light. Tip‐enhanced Raman spectroscopy (TERS), which is based on the SPP‐induced plasmonic enhancement and confinement of light near a metallic nanostructure, can however, overcome this barrier and produce optical images far beyond the diffraction limit. Here in this article, the basic phenomenon involved in TERS is reviewed, and the high spatial resolution achieved in optical imaging through this technique is discussed. Further, it is shown that when TERS is combined with some other physical phenomena, the spatial resolution can be dramatically improved. Particularly, by including tip‐applied extremely localized pressure in TERS process, it has been demonstrated that a spatial resolution as high as 4 nm could be achieved.
Erosions‐Korrosions‐Untersuchungen an gradierten Multilayer‐Chromkarbidschichten
Authors: Durst O. , Ellermeier J. , Troßmann T. , Berger C.
Published: October 2009

PVD‐ und PECVD‐Schichten haben sich als Verschleißschutz vor allem auf Werkzeugen zur spanenden Bearbeitung bewährt. Je nach Art der Schicht ist hierbei nicht nur eine Verminderung des Verschleißes, sondern auch eine Reibwert‐Reduktion möglich, z. B. durch den Einbau wasserstoffhaltigen Kohlenstoffs in die Schicht. Solche kohlenstoffhaltigen Schichten verhalten sich außerdem auch in vielen Medien elektrochemisch inert, so dass sie selbst in wässrigen Medien nicht korrodieren. Da sie zusätzlich über eine sehr dichte Struktur verfügen, erscheint eine Anwendung als Korrosionsschutz‐Beschichtung Erfolg versprechend.

Für die durchzuführenden Untersuchungen wurde ein neuer Versuchsstand entwickelt, der eine erosiv‐korrosive Komplexbeanspruchung ermöglicht. In diesem werden beschichtete Proben betriebsnah einem strömenden feststoffbeladenen Medium ausgesetzt. Mittels der damit möglichen Versuche sollten neu entwickelte gradierte Multilayer‐Chromkarbidschichten auf ihre Erosions‐Korrosions‐Eigenschaften hin untersucht werden. Ziel war die Klärung der Schädigungsmechanismen zur Weiterentwicklung der Schichten und eine Beurteilung der Einsatzmöglichkeiten PVD/PECVD‐beschichteter niedriglegierter Stähle unter erosiv‐korrosiver Beanspruchung. Vergleichend wurden eine dem Stand der Technik entsprechende industrielle DLC‐Schicht sowie ein Duplex‐Stahl untersucht.

Für den Einsatz von PVD‐/PECVD‐beschichtetem niedriglegiertem Stahl in erosiv‐korrosiv beanspruchten Bereichen bedeuten die Ergebnisse der durchgeführten Untersuchungen, dass die untersuchten Schichten zur Verwendung in Bereichen mit starkem Prallverschleiß bislang noch nicht geeignet sind. Jedoch besitzt vor allem die gradierte Multilayer‐Chromkarbidschicht aufgrund ihrer dichten Struktur, die nur eine geringe Korrosion des Grundwerkstoffs zulässt, das Potenzial zum Schutz vor Erosions‐Korrosion.

Für meist eher spröde PVD‐ bzw. PECVD‐Schichten stellen Partikel, die in relativ großem Winkel auf die Oberfläche treffen und zu Prallverschleiß führen, eine besonders harte Beanspruchung dar. Es stellt sich daher die Frage, ob die entwickelten Schichten nicht unter abrasiv furchendem Verschleiß, wie er bei tangentialer, erosiver Strömung auftritt und auch in der Praxis vorkommt, bessere Eigenschaften besitzen. Dies soll in zukünftigen Versuchen genauer untersucht werden.
Densification and mechanical properties of liquid phase sintered tantalum
Authors: Filgueira M. , Pinatti D. G. , de Holanda J. N. F. , Gomes U. U.
Published: October 2009

This paper has as main objective to investigate the influence of nickel (Ni), iron (Fe) and copper (Cu) addition on the tantalum (Ta) powder processing, by promoting a liquid phase sintering (LPS). The role of these metals is to lower the Ta sintering temperature, maintaining good densification and mechanical properties.

Ni, Fe and Cu 1wt% additions to Ta powder were performed. Samples were cold pressed at 350 MPa. Sintering was carried out at 1300 to 2000 °C, for 1 hour, under a vacuum of 10‐6 Pa. Density, linear shrinkage and activation energy were measured and calculated. Hardness and compression tests were also conducted. Ni was the most promissing Ta LPS activator, once it enabled the best results of densification and mechanical properties.
A pilot study using nabilone for symptomatic treatment in Huntington's disease
Authors: Curtis Adrienne , Mitchell Ian , Patel Smitaa , Ives Natalie , Rickards Hugh
Published: October 2009

Pilot study of nabilone in Huntington's disease (HD). Double‐blind, placebo‐controlled, cross‐over study of nabilone versus placebo. Primary outcome, Unified Huntington's Disease Rating Scale (UHDRS) total motor score. Secondary measures: UHDRS subsections for chorea, cognition and behavior, and neuropsychiatric inventory (NPI). 44 randomized patients received either nabilone (1 or 2 mg) followed by placebo (n = 22), or placebo followed by nabilone (n = 22). Recruiting was straightforward. Nabilone safe and well tolerated, no psychotic episodes. Assessment of either dose of nabilone versus placebo showed a treatment difference of 0.86 (95% CI: −1.8 to 3.52) for total motor score; 1.68 (95% CI: 0.44 to 2.92) for chorea; 3.57 (95% CI: −3.41 to 10.55) for UHDRS cognition; 4.01 (95% CI: −0.11 to 8.13) for UHDRS behavior, and 6.43 (95% CI: 0.2 to 12.66) for the NPI. Larger longer RCT of nabilone in HD is feasible and warranted. © 2009 Movement Disorder Society
Neurological symptoms in patients with biopsy proven celiac disease
Authors: Bürk Katrin , Farecki Marie‐Louise , Lamprecht Georg , Roth Guenter , Decker Patrice , Weller Michael , Rammensee Hans‐Georg , Oertel Wolfang
Published: October 2009

In celiac disease (CD), the gut is the typical manifestation site but atypical neurological presentations are thought to occur in 6 to 10% with cerebellar ataxia being the most frequent symptom. Most studies in this field are focused on patients under primary neurological care. To exclude such an observation bias, patients with biopsy proven celiac disease were screened for neurological disease. A total of 72 patients with biopsy proven celiac disease (CD) (mean age 51 ± 15 years, mean disease duration 8 ± 11 years) were recruited through advertisements. All participants adhered to a gluten‐free diet. Patients were interviewed following a standard questionnaire and examined clinically for neurological symptoms. Medical history revealed neurological disorders such as migraine (28%), carpal tunnel syndrome (20%), vestibular dysfunction (8%), seizures (6%), and myelitis (3%). Interestingly, 35% of patients with CD reported of a history of psychiatric disease including depression, personality changes, or even psychosis. Physical examination yielded stance and gait problems in about one third of patients that could be attributed to afferent ataxia in 26%, vestibular dysfunction in 6%, and cerebellar ataxia in 6%. Other motor features such as basal ganglia symptoms, pyramidal tract signs, tics, and myoclonus were infrequent. 35% of patients with CD showed deep sensory loss and reduced ankle reflexes in 14%. Gait disturbances in CD do not only result from cerebellar ataxia but also from proprioceptive or vestibular impairment. Neurological problems may even develop despite strict adherence to a gluten‐free diet. © 2009 Movement Disorder Society
A validation exercise on the new consensus criteria for multiple system atrophy
Authors: Osaki Yasushi , Ben‐Shlomo Yoav , Lees Andrew J. , Wenning Gregor K. , Quinn Niall P.
Published: October 2009

The revised (new) consensus clinical diagnostic criteria for multiple system atrophy (MSA) were published in 2008. To validate these criteria, we utilized the same cohort that we reported previously, which included 59 patients with a clinical diagnosis of MSA that was confirmed neuropathologically in 51 of them at the Queen Square Brain Bank for Neurological Disorders. At the first clinic visit, sensitivity with new consensus possible category was higher, and PPV marginally higher, than for clinical diagnosis and old consensus possible category. New consensus probable category showed marginally higher sensitivity than, and the same PPV as, old consensus probable category. At the last clinic visit, new consensus possible category had exactly the same sensitivity and only marginally higher PPV compared with old consensus possible category. New consensus probable category showed the same sensitivity and PPV as old consensus probable category. Our data indicate that in this case material the new consensus criteria for possible MSA could improve diagnostic accuracy at first neurological evaluation compared with the old consensus criteria. Prospective clinicopathological validation studies of the new consensus criteria, particularly incorporating in vivo structural and functional imaging results, are required to extend the current findings. © 2009 Movement Disorder Society
The next ten stories on antiviral drug discovery (part E): advents, advances, and adventures
Authors: De Clercq Erik
Published: October 2009

This review article presents the fifth part (part E) in the series of stories on antiviral drug discovery. The ten stories belonging to this fifth part are dealing with (i) aurintricarboxylic acid; (ii) alkenyldiarylmethanes; (iii) human immunodeficiency virus (HIV) integrase inhibitors; (iv) lens epithelium‐derived growth factor as a potential target for HIV proviral DNA integration; (v) thestatus presensof neuraminidase inhibitors NAIs in the control of influenza virus infections; (vi) thestatus presenson respiratory syncytial virus inhibitors; (vii) tricyclic (1,N‐2‐ethenoguanine)‐based acyclovir and ganciclovir derivatives; (viii) glycopeptide antibiotics as antivirals targeted at viral entry; (ix) the potential (off‐label) use of cidofovir in the treatment of polyoma (JC and BK) virus infections; and (x) finally, thymidine phosphorylase as a target for both antiviral and anticancer agents. © 2009 Wiley Periodicals, Inc. Med Res Rev, 31, No. 1, 118–160, 2010
A network evolution model for the anisotropic Mullins effect
Authors: Dargazany Roozbeh , Itskov Mikhail
Published: October 2009

In this contribution, a micro‐mechanical constitutive model for filled rubberlike materials is proposed. Rubber network is decomposed into two parts, elastic rubber network and polymer‐filler network. As a consequence of filler contribution, the last one is subjected to damage. A non‐Gaussian strain energy function for a single chain with a constant valence angle has been postulated. Damage in different directions is governed by the corresponding maximal micro‐stretch and is considered as a result of network evolution. Directional network rearrangement as a consequence of network evolution has been employed in order to describe induced anisotropy and permanent set. The model shows good agreement with experimental data on uniaxial tension tests in two orthogonal directions. (© 2008 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of interfacial adhesion on the structural and mechanical behavior of PP‐banana/glass hybrid composites
Authors: Nayak Sanjay K. , Mohanty Smita , Samal Sushanta K.
Published: October 2009

Hybrid composites of polypropylene (PP), reinforced with short banana and glass fibers were fabricated using Haake torque rheocord followed by compression molding with and without the presence maleic anhydride grafted polypropylene (MAPP) as a coupling agent. Incorporation of both fibers into PP matrix resulted in increase of tensile strength, flexural strength, and impact strength upto 30 wt% with an optimum strength observed at 2 wt% MAPP treated 15 wt% banana and 15 wt% glass fiber. The rate of water absorption for the hybrid composites was decreased due to the presence of glass fiber and coupling agent. The effect of fiber loading in presence of coupling agent on the dynamic mechanical properties has been analyzed to investigate the interfacial properties. An increase in storage modulus (E′) of the treated‐composite indicates higher stiffness. The loss tangent (tan δ) spectra confirms a strong influence of fiber loading and coupling agent concentration on the α and β relaxation process of PP. The nature of fiber matrix adhesion was examined through scanning electron microscopy (SEM) of the tensile fractured specimen. Thermal measurements were carried out through differential scanning calorimetry (DSC) and the thermogravimetric analysis (TGA), indicated an increase in the crystallization temperature and thermal stability of PP with the incorporation of MAPP‐treated banana and glass fiber. POLYM. COMPOS., 31:1247–1257, 2010. © 2009 Society of Plastics Engineers
Triboelectrification electrostatic potential of graphite/monomer casting nylon composites under dry sliding: Correlation with electrical resistivity and wear mechanisms
Authors: Jian Lingqi , Ning Liping , Yang Shengrong , Wang Jianmin , Hua Minqi
Published: October 2009

The variations of triboelectrification electrostatic potential of graphite (GP)/monomer casting (MC) nylon composites under plane contact dry sliding were investigated and the correlation with electrical resistivity and wear mechanisms were studied. MC nylon could be modified as excellent anti‐triboelectrification materials by a proper addition of GP, although unfilled MC nylon was inclined to generate higher triboelectrification electrostatic potential after friction due to the high electrical resistivity. The triboelectrification electrostatic potential and electrical resistivity of composites can be predicted by the content control of GP. The incorporation of GP filler made considerable contributions, which not only reduced and stabilized the triboelectrification electrostatic potential of composites but also enhanced their lubricating properties and the friction heat dissipation. The influences of PV‐values on the triboelectrification electrostatic potential of composites were less than that of electrical resistivity. Although the severe wear and the formation of transfer films resulted in triboelectrification electrostatic potential of unfilled MC nylon abruptly dropping shortly after the beginning of friction under the high PV‐values, it was conductive property, particle shape and size, distribution and dispersion of GP fillers, and density of conductive network built by GP flakes that played the dominant role in deciding triboelectrification electrostatic potential of composites under various PV‐values. POLYM. COMPOS., 31:1369–1377, 2010. © 2009 Society of Plastics Engineers
Kinetics and thermodynamics of isothermal curing reaction of epoxy‐4, 4′‐diaminoazobenzene reinforced with nanosilica and nanoclay particles
Authors: Barghamadi M.
Published: October 2009

The kinetics of the cure reaction for a system of bisphenol‐A epoxy resin (DGEBA), with 4, 4′‐diaminoazobenzene (DAAB), reinforced with nanosilica (NS), and nanoclay (NC) by means of isothermal technique of differential scanning calorimetry were studied. The Kamal autocatalytic‐like kinetic model was used to estimate the reaction orders (m, n), rate constants (k1, k2), and also active energies (Ea) and pre‐exponential factors (A) of the curing reaction. However, the existence of NS and NC with hydroxyl groups in the structure improves the cure reaction and influence the rate of reaction and therefore kinetics parameters. The Ea of cure reaction of DGEBA/DAAB system showed a decrease when nanoparticles were present and therefore the rate of the reaction was increased. Using the rate constants from the kinetic analysis and transition state theory, thermodynamic parameters such as enthalpy (ΔH#), entropy (ΔS#), and Gibbs free energy (ΔG#) changes were also calculated. The thermodynamic functions were shown to be very sensitive parameters for evaluation of the cure reaction. POLYM. COMPOS., 31:1442–1448, 2010. © 2009 Society of Plastics Engineers
Noninvasive prenatal diagnosis of early onset primary dystonia I in maternal plasma
Authors: Meaney Cathy , Norbury G.
Published: October 2009

Objective

The genetic trait of a fetus may be determined early on in pregnancy using cell‐free fetal DNA extracted from the plasma of pregnant women. The challenges for noninvasive diagnosis include the variable but still low amount of cell‐free fetal DNA in the first trimester (57–761 gE/mL) and the competing high background of maternal DNA in the plasma (∼90%). Prenatal detection of a paternally inherited dystonia 3 bp deletion mutation was undertaken using cell‐free DNA (cfDNA) from the plasma of two at‐risk pregnancies. The predicted fetal genotype was subsequently confirmed in each fetus.

Method

Cell‐free fetal DNA was extracted from the plasma of two pregnancies between 8 and 9 weeks' gestation as determined by fetal ultrasound scan. Analysis was by PCR amplification with size separation using polyacrylamide gel electrophoresis and detection by ethidium bromide staining.

Results

In both pregnancies the c.904_906delGAG DYT1 mutation was detected in the maternal plasma and then confirmed in the subsequent fetal tissue verifying that the fetus had inherited the paternal mutation.

Conclusion

The detection of a paternally inherited DYT1 mutation in maternal plasma was undertaken using simple, rapid, and inexpensive techniques with minimal risk of contamination. Further developments in the enrichment for fetal cfDNA will enhance the detection of point mutations in monogenic disorders. Copyright © 2009 John Wiley & Sons, Ltd.
Validation of diagnostic codes for outpatient‐originating sudden cardiac death and ventricular arrhythmia in Medicaid and Medicare claims data
Authors: Hennessy Sean , Leonard Charles E. , Freeman Cristin P. , Deo Rajat , Newcomb Craig , Kimmel Stephen E. , Strom Brian L. , Bilker Warren B.
Published: October 2009

Purpose

Sudden cardiac death (SD) and ventricular arrhythmias (VAs) caused by medications have arisen as an important public health concern in recent years. The validity of diagnostic codes in identifying SD/VA events originating in the ambulatory setting is not well known. This study examined the positive predictive value (PPV) of hospitalization and emergency department encounter diagnoses in identifying SD/VA events originating in the outpatient setting.

Methods

We selected random samples of hospitalizations and emergency department claims with principal or first‐listed discharge diagnosis codes indicative of SD/VA in individuals contributing at least 6 months of baseline time within 1999–2002 Medicaid and Medicare data from five large states. We then obtained and reviewed medical records corresponding to these events to serve as the reference standard.

Results

We identified 5239 inpatient and 29 135 emergency department events, randomly selected 100 of each, and obtained 119 medical records, 116 of which were for the requested courses of care. The PPVs for an outpatient‐originating SD/VA precipitating hospitalization or emergency department treatment were 85.3% (95% confidence interval [CI] = 77.6–91.2) overall, 79.7% (95%CI = 68.3–88.4) for hospitalization claims, and 93.6% (95%CI = 82.5–98.7) for emergency department claims.

Conclusions

First‐listed SD/VA diagnostic codes identified in inpatient or emergency department encounters had very good agreement with clinical diagnoses and functioned well to identify outpatient‐originating events. Researchers using such codes can be confident of the PPV when conducting studies of SD/VA originating in the outpatient setting. Copyright © 2009 John Wiley & Sons, Ltd.
Two‐dimensional crystals of carboxysome shell proteins recapitulate the hexagonal packing of three‐dimensional crystals
Authors: Dryden Kelly A. , Crowley Christopher S. , Tanaka Shiho , Yeates Todd O. , Yeager Mark
Published: October 2009

Bacterial microcompartments (BMCs) are large intracellular bodies that serve as simple organelles in many bacteria. They are proteinaceous structures composed of key enzymes encapsulated by a polyhedral protein shell. In previous studies, the organization of these large shells has been inferred from the conserved packing of the component shell proteins in two‐dimensional (2D) layers within the context of three‐dimensional (3D) crystals. Here, we show that well‐ordered, 2D crystals of carboxysome shell proteins assemble spontaneously when His‐tagged proteins bind to a monolayer of nickelated lipid molecules at an air–water interface. The molecular packing within the 2D crystals recapitulates the layered hexagonal sheets observed in 3D crystals. The results reinforce current models for the molecular design of BMC shells.
Dissection of a β‐barrel motif leads to a functional dimer: The case of the intestinal fatty acid binding protein
Authors: Franchini Gisela R. , Curto Lucrecia M. , Caramelo Julio J. , María Delfino José
Published: October 2009

A lingering issue in the area of protein engineering is the optimal design of β motifs. In this regard, the framework provided by intestinal fatty acid binding protein (IFABP) was successfully chosen to explore the consequences on structure and function of the redesign of natural motifs. A truncated form of IFABP (Δ98Δ) served to illustrate the nonintuitive notion that the integrity of the β‐barrel can indeed be compromised with no effect on the ability to attain a native‐like fold. This is most likely the outcome of the key role played by the preservation of essential core residues. In the search for the minimal structural determinants of this fold, Δ98Δ offered room for further intervention. A dissection of this protein leads to a new abridged variant, Δ78Δ, containing 60% of the amino acids of IFABP. Spectroscopic analyses indicate that Δ78Δ retains substantial β‐sheet content and preserves tertiary interactions, displaying cooperative unfolding and binding activity. Most strikingly, this construct adopts a remarkably stable dimeric structure in solution. This phenomenon takes advantage of the inherent structural plasticity of this motif, likely profitting from edge‐to‐edge interactions between β‐sheets, whereas avoiding the most commonly occurring outcome represented by aggregation.
Structural and functional characterization of a triple mutant form of S100A7 defective for Jab1 binding
Authors: West Nathan R. , Farnell Benjamin , Murray Jill I. , Hof Fraser , Watson Peter H. , Boulanger Martin J.
Published: October 2009

S100A7 (psoriasin) is a calcium‐ and zinc‐binding protein implicated in breast cancer. We have shown previously that S100A7 enhances survival mechanisms in breast cells through an interaction with c‐jun activation domain binding protein 1 (Jab1), and an engineered S100A7 triple mutant (Asp56Gly, Leu78Met, and Gln88Lys—S100A73) ablates Jab1 binding. We extend these results to include defined breast cancer cell lines and demonstrate a disrupted S100A73/Jab1 phenotype is maintained. To establish the basis for the abrogated Jab1 binding, we have recombinantly produced S100A73, demonstrated that it retains the ability to form an exceptionally thermostable dimer, and solved the three dimensional crystal structure to 1.6 Å. Despite being positioned at the dimer interface, the Leu78Met mutation is easily accommodated and contributes to a methionine‐rich pocket formed by Met12, Met15, and Met34. In addition to altering the surface charge, the Gln88Lys mutation results in a nearby rotameric shift in Tyr85, leading to a substantially reorganized surface cavity and may influence zinc binding. The final mutation of Asp56 to Gly results in the largest structural perturbation shortening helix IV by one full turn. It is noteworthy that position 56 lies in one of two divergent clusters between S100A7 and the functionally distinct yet highly homologous S100A15. The structure of S100A73 provides a unique perspective from which to characterize the S100A7‐Jab1 interaction and better understand the distinct functions between S100A7, and it is closely related paralog S100A15.
Probing exciton propagation and quenching in carbon nanotubes with near‐field optical microscopy
Authors: Georgi Carsten , Böhmler Miriam , Qian Huihong , Novotny Lukas , Hartschuh Achim
Published: October 2009

We report on near‐field optical imaging of single‐walled carbon nanotubes (SWNTs), observing photoluminescence (PL) quenching at nanotube ends and defects. The extension of reduced PL reflects the exciton diffusion length of about 100 nm, which can be directly visualized with our technique. Additionally, we model the complete imaging process, including exciton diffusion and tip‐induced rate enhancement, for a deeper understanding of the experimental data and the determination of, e.g. diffusion length and tip enhancement from near‐field PL images.
Raman spectroscopy study of Ar+ bombardment in highly oriented pyrolytic graphite
Authors: Jorio Ado , Lucchese Marcia M. , Stavale Fernando , Achete Carlos A.
Published: October 2009

In this work, we discuss the effect of low energy Ar+ ion bombardment on highly oriented pyrolytic graphite (HOPG). The evolution of the G and D peak intensities are analyzed as a function of ion dose, as well as the evolution of a broad density‐of‐states (DOS)‐like background. For low ion doses, a small D band is observed. It increases and finally gives place to the broad DOS‐like feature. The ID/IG analysis clearly shows three distinct regimes. No frequency shifts are observed, indicating sp2 bondings are mostly preserved. Comparison between preliminary work on single‐layer graphene and HOPG shows the effect observed in HOPG is limited to the top surface.
Toward a consistent reanalysis of the upper stratosphere based on radiance measurements from SSU and AMSU‐A
Authors: Kobayashi Shinya , Matricardi Marco , Dee Dick , Uppala Sakari
Published: October 2009

Radiance measurements from the Stratospheric Sounding Unit (SSU) and the Advanced Microwave Sounding Unit (AMSU‐A) are the primary source of information for stratospheric temperature in reanalyses of the satellite era. To improve the time consistency of the reanalyses, radiance biases need to be properly understood and accounted for in the assimilation system. The investigation of intersatellite differences between SSU and AMSU‐A radiance observations shows that these differences are not accurately reproduced by the operational version of the radiative transfer model for the TIROS Operational Vertical Sounder (RTTOV‐8). We found that this deficiency in RTTOV was mainly due to the treatment of the Zeeman effect (splitting of the oxygen absorption lines at 60 GHz) and to changes in the spectral response function of the SSU instrument that are not represented in RTTOV. On this basis we present a revised version of RTTOV that can reproduce SSU and AMSU‐A intersatellite radiance differences more accurately.

Assimilation experiments performed with the revised version of RTTOV in a four‐dimensional variational analysis system (4D‐Var) show some improvements in the stratospheric temperature analysis. However, significant jumps in the stratospheric temperature analysis still occur when switching satellites, which is due to the fact that systematic errors in the forecast model are only partially constrained by observations. Using a one‐dimensional retrieval equation, we show that both the extent and vertical structure of the partial bias corrections must inevitably change when the nature of the radiance measurement changes with the transition from SSU to AMSU‐A. Copyright © 2009 Royal Meteorological Society
Scaffold Diversity Analysis of Compound Data Sets Using an Entropy‐Based Measure
Authors: Medina‐Franco Jose L. , Martínez‐Mayorga Karina , Bender Andreas , Scior Thomas
Published: October 2009

Scaffold diversity analysis of compound databases has multiple applications in medicinal chemistry and drug discovery including library design, compounds acquisition, virtual screening and assessment of structure‐activity‐relationships. The scaffold diversity is commonly measured based on frequency counts. Further information can be obtained by considering the specific distribution of the molecules in those scaffolds. To this end, we introduce in this work the use of an entropy‐based information metric to assess the scaffold diversity of compound data sets. As a test case we analyzed the scaffold diversity of 16 data sets of active compounds comparable in size targeting five protein classes of interest in drug design. The diversity was also assessed in terms of frequency counts and scaffold retrieval curves. The entropy‐based information metric takes into account the frequency distribution of the different scaffolds and is a complementary measure of scaffold diversity enabling a more comprehensive analysis.
Screening strategy for the rapid detection ofin vitrogenerated glutathione conjugates using high‐performance liquid chromatography and low‐resolution mass spectrometry in combination with LightSight® software for data processing
Authors: Ramírez‐Molina César , Burton Lucy
Published: October 2009

The knowledge of drug metabolism in the early phases of the drug discovery process is vital for minimising compound failure at later stages. As chemically reactive metabolites may cause adverse drug reactions, it is generally accepted that avoiding formation of reactive metabolites increases the chances of success of a molecule. In order to generate this important information, a screening strategy for the rapid detection ofinvitrogenerated reactive metabolites trapped by glutathione has been developed. The bioassay incorporated the use of native glutathione and its close analogue the glutathione ethyl ester. The generic conditions for detecting glutathione conjugates that undergo constant neutral loss of 129 Da were optimised using a glutathione‐based test mix of four compounds. The final liquid chromatography/tandem mass spectrometry constant neutral loss method used low‐resolution settings and a scanning window of 200 amu. Data mining was rapidly and efficiently performed using LightSight® software. Unambiguous identification of the glutathione conjugates was significantly facilitated by the analytical characteristics of the conjugate pairs formed with glutathione and glutathione ethyl ester, i.e. by chromatographic retention time and mass differences. The reliability and robustness of the screening strategy was tested using a number of compounds known to form reactive metabolites. Overall, the developed screening strategy provided comprehensive and reliable identification of glutathione conjugates and is well suited for rapid routine detection of trapped reactive metabolites. This new approach allowed the identification of a previously unreported diclofenac glutathione conjugate. Copyright © 2009 John Wiley & Sons, Ltd.
Compound‐specific δ18O analyses of neutral sugars in soils using gas chromatography–pyrolysis–isotope ratio mass spectrometry: problems, possible solutions and a first application
Authors: Zech Michael , Glaser Bruno
Published: October 2009

Although gas chromatography–pyrolysis–isotope ratio mass spectrometry (GC‐Py‐IRMS) has allowed us to make online compound‐specific δ18O measurements for about the last ten years, this technique has hardly been applied. We tested different pyrolysis reactor designs using standards (vanillin, ethylvanillin, a fatty acid methyl ester and alkanes) in order to optimize the GC‐Py‐IRMS δ18O measurements. The method was then applied to methylboronic acid (MBA) sugar derivatives (pentoses, 6‐deoxyhexoses and hexoses). Plant‐ and microbial‐derived monosaccharides were extracted hydrolytically from litter and topsoils before derivatization. The measured δ18O values of samples and co‐analyzed reference material were first drift‐corrected by use of regularly discharged pulses of CO reference gas. Secondly, they were corrected for the amount dependence of the δ18O values. Thirdly, the δ18O values were calibrated using the reference material (principle of ‘Identical Treatment’), and, finally, a correction was applied by taking the hydrolytically introduced and water‐exchangeable oxygen atoms into account. Our results suggest that the δ18O values of plant‐derived monosaccharides in litter reflect the climatic conditions of the last year, whereas δ18O values of the respective topsoils reflect the averaged climate signal of the last decades or even centuries. This demonstrates the high potential of the method for palaeoclimate reconstructions. Copyright © 2009 John Wiley & Sons, Ltd.
Determination of K‐Ar ages in milligram samples using an infrared laser for argon extraction
Authors: Solé Jesús
Published: October 2009

The K‐Ar dating method has been used for decades to decipher the ages of terrestrial and extraterrestrial minerals and rocks. The natural radioactive decay of a metal to a rare gas is an advantage that allows the determination of very small amounts of argon by mass spectrometry. Although the Ar‐Ar method has superseded K‐Ar, the latter is still used and it has room for improvement. One of these is the reduction of the analyzed sample mass, adesideratumof any current analytical technique. I report here our experience in K‐Ar geochronology of milligram‐sized samples using laser heating and melting for gas extraction. This modification of the classical K‐Ar technique has not been, to my knowledge, used in any other laboratory in the world and deserves a detailed description of its advantages and limitations. Copyright © 2009 John Wiley & Sons, Ltd.
Peptide‐binding specificity of the prosurfactant protein C Brichos domain analyzed by electrospray ionization mass spectrometry
Authors: Fitzen Michael , Alvelius Gunvor , Nordling Kerstin , Jörnvall Hans , Bergman Tomas , Johansson Jan
Published: October 2009

The C‐terminal domain of lung surfactant protein C (CTC) precursor (proSP‐C) is involved in folding of the transmembrane segment of proSP‐C. CTC includes a Brichos domain with homologs in cancer‐ and dementia‐associated proteins. Mutations in the Brichos domain cause misfolding of proSP‐C and hence amyloid fibril formation in interstitial lung disease. Electrospray ionization mass spectrometry (ESI‐MS) with collision‐induced dissociation (CID) experiments was applied to study non‐covalent interactions between human recombinant CTC or its Brichos domain, and SP‐C analogs, homotripeptides and peptides designed to model amyloid fibril formation. The results show that the Brichos domain contains the peptide‐binding function of CTC. In titration experiments, apparent dissociation constants (KD) were in the micromolar range where triple‐valine showed the lowest KD and triple‐tyrosine the highest. Non‐hydrophobic peptides failed to form complexes with Brichos. CID revealed that complexes with aromatic peptide ligands are more stable in the gas phase than complexes with non‐aromatic ligands. The Brichos domain was also shown to bind fibril‐forming peptides containing aromatic/hydrophobic residues. Copyright © 2009 John Wiley & Sons, Ltd.