bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature‐sensitive hydrogel microspheres formed by liquid–liquid phase transitions of aqueous solutions of poly(N,N‐dimethylacrylamide‐co‐allyl methacrylate)
Authors: Yin Xiangchun , Stöver Harald D. H. 
Published: March 2005

AbstractPoly(N,N‐dimethylacrylamide‐co‐allyl methacrylate) (DMA‐co‐AMA) copolymers were prepared by the copolymerization of N,N‐dimethylacrylamide with allyl methacrylate (AMA). The methacryloyl group of AMA reacted preferentially, and this resulted in pendant allyl groups along the copolymer chains. Aqueous solutions of these DMA‐co‐AMA copolymers were thermoresponsive and showed liquid–liquid phase transitions at temperatures that depended on the AMA content. Hydrogel microspheres were prepared from these thermally phase‐separated liquid microdroplets by the free‐radical crosslinking of the pendant allyl groups. The morphologies of the resulting thermoresponsive microspheres as a function of the reaction temperature and the amount of the initiator were examined. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1641–1648, 2005
Ultrafast synthesis of poly(methyl methacrylate)‐b‐poly(vinyl chloride)‐b‐poly(methyl methacrylate) block copolymers by the Cu(0)/tris(2‐dimethylaminoethyl)amine‐catalyzed living radical block copolymerization of methyl methacrylate initiated with α,ω‐di(iodo)poly(vinyl chloride) in the presence of dimethyl sulfoxide at 25 °C
Authors: Percec Virgil , Guliashvili Tamaz , Popov Anatoliy V. , Ramirez‐Castillo Ernesto , Hinojosa‐Falcon Luis A. 
Published: March 2005

Abstractα,ω‐Di(iodo)poly(vinyl chloride)s, with number‐average molecular weights ranging from 2100 to 29,500 and molecular weight distributions (weight‐average molecular weight/number‐average molecular weight) ranging from 1.74 to 2.16, were prepared by the previously reported single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization of vinyl chloride initiated with iodoform and catalyzed by sodium dithionite in water at 25–35 °C. These α,ω‐di(iodo)poly(vinyl chloride) macroinitiators were used for the synthesis of poly(methyl methacrylate)‐b‐poly(vinyl chloride)‐b‐poly(methyl methacrylate) (PMMA‐b‐PVC‐b‐PMMA) block copolymers via the metal‐catalyzed living radical block copolymerization of methyl methacrylate. In this article, we report the effects of various ligands on the rate of block copolymerization mediated by Cu(0) in dimethyl sulfoxide (DMSO). The block copolymerization catalyzed by Cu(0)/tris(2‐dimethylaminoethyl)amine in DMSO at 90 °C yielded block copolymers in less than 15 min, whereas at 25 °C, the reaction times ranged from 60 to 100 min. Therefore, this ultrafast synthetic method provided access to PMMA‐b‐PVC‐b‐PMMA, regardless of the reaction temperature, in the same range of reaction times as the induction period of the same reactions carried out at 90 °C in diphenyl ether and catalyzed by CuCl/2,2′‐bipyridine. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1660–1669, 2005
Oxidative coupling polymerization of 2,3‐dihydroxynaphthalene with dinuclear‐type copper(II) catalyst
Authors: Habaue Shigeki , Muraoka Ryo , Aikawa Akiko , Murakami Soichiro , Higashimura Hideyuki 
Published: March 2005

AbstractThe oxidative coupling polymerization of 2,3‐dihydroxynaphthalene with the novel dinuclear‐type copper(II) catalysts successfully produced poly(2,3‐dihydroxy‐1,4‐naphthylene). For example, the MeOH‐insoluble polymer with a number average molecular weight of 4.4 × 103 from the polymerization using the complex of CuCl2 and N,N′‐bis(2‐morpholinoethyl)‐p‐xylylenediamine (p‐1) at room temperature under an O2 atmosphere followed by acetylation of the hydroxyl groups was obtained in 63% yield. The structures of the tetraamine ligands and the counter anion of the copper(II) salts significantly influenced the catalyst activity. The polymerization of 2,2′‐dimethoxy‐1,1′‐binaphthalene‐3,3′‐diol with the 2CuCl2‐p‐1 catalyst, however, resulted in a lower yield. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1635–1640, 2005
A theoretical study of electronic and vibrational properties of neutral, cationic, and anionic B24 clusters
Authors: Lau Kah Chun , Deshpande Mrinalini , Pati Ranjit , Pandey Ravindra 
Published: March 2005

AbstractThe equilibrium geometries, electronic and vibrational properties, and static polarizability of B24, B, and B clusters are reported here. First‐principles calculations based on density functional theory predict the staggered double‐ring configuration to be the ground state for B24, B, and B, in contrast to the quasi‐planar structure observed in small neutral and ionized Bn clusters with n ≤ 15. Furthermore, the (4 × B6) tubular structure is found to be relatively stable in comparison to the 3D cage structure. The presence of delocalized π and multicentered σ bonds appears to be the cause of the stability of the double‐ring and tubular isomers. For the ground state of B24, the lower and upper bound of the electron affinity is 2.67 and 2.81 eV, respectively, and the vertical ionization potential is 6.88 eV. Analysis of the frequency spectrum of the double‐ring and tubular isomers reveals the characteristic vibrational modes typically observed in carbon nanotubes. The corresponding IR spectrum also reflects the presence of some of these characteristic modes in the neutral and ionized B24, suggesting that double‐ring and tubular structures can be considered as the building blocks of boron nanotubes. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
A canonical sequence approach to the E ⊗ ε Jahn–Teller effect
Authors: Fessatidis Vassilios , Mancini Jay D. , Bowen Samuel P. , Massano William J. 
Published: March 2005

AbstractWe study the linear E ⊗ ε Jahn–Teller effect in which a doubly degenerate fermionic (electron) level is coupled to a pair of degenerate oscillators. Because of the relative simplicity of the model, and since a complete numerical solution has been known for a long time, theorists have had at their disposal an excellent proving ground for a variety of calculational efforts. Here we apply the recently developed canonical sequence method (CSM) of Šamaj et al. J Phys 1997, A30, 1741 to investigate the ground state of this system. Comparisons are then made with other calculation schemes. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Conditions and numerical simulation of dissipative structure formation in imperfect double‐component reaction‐diffusion systems
Authors: Krasilnikov Vladimir V. , Savotchenko Serge E. , Nemtsev Alexander N. 
Published: March 2005

AbstractImperfection of a reaction‐diffusion system is investigated. This imperfection causes modification of Fick's equation. We provide imperfection of diffusion fluxes on the basis of a chemical reaction model of unimolecular and bimolecular processes with two intermediate substances. We demonstrate that allowing for imperfection of diffusion processes leads to introducing the spatial derivatives of fourth order in the evolution equations for concentrations of intermediate substances. It is important that dissipative structures including oscillations can be formed in the system due to the availability of these derivatives in the evolution equations. It is proved that the necessary condition of forming the dissipative structures can appear due to imperfection of diffusion processes in the systems considered. It is shown by linear analysis that concentration of the intermediate substance near a stationary state can exhibit oscillatory behavior under certain conditions. Phase‐plane portrait peculiarities of a nonlinear system are investigated at different values of the initial parameters. It is shown by numerical simulation that dependence of concentrations of the intermediate substances has a quasi‐periodical character. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Improved matrix‐assisted laser desorption/ionisation sample preparation of a partially depolymerised cellulose derivative by continuous spray deposition and interfacing with size‐exclusion chromatography
Authors: Momcilovic Dane , Wahlund Karl‐Gustav , Wittgren Bengt , Brinkmalm Gunnar 
Published: March 2005

AbstractContinuous spray deposition (CSD) of aqueous solutions of partially depolymerised methyl cellulose was found to improve matrix‐assisted laser desorption/ionisation (MALDI) sample preparation. One feature was that the sensitivity in MALDI time‐of‐flight mass spectrometry increased up to an order of magnitude compared with the standard sample preparation method. Another feature was that CSD provided targets for MALDI with homogeneously distributed analyte. This resulted in a more even signal intensity and a higher reproducibility than in the standard method. High‐mass discrimination was more pronounced in CSD than in the standard method. Size‐exclusion chromatography with aqueous eluent was coupled online to CSD onto matrix‐precoated foils. The suitability for determination of the molar mass distribution of methyl cellulose was investigated. Copyright © 2005 John Wiley & Sons, Ltd.
Identification of oral antidiabetics and their metabolites in human urine by liquid chromatography/tandem mass spectrometry—a matter for doping control analysis
Authors: Thevis Mario , Geyer Hans , Schänzer Wilhelm 
Published: March 2005

AbstractSince 1999, insulin belongs to the list of prohibited substances of the International Olympic Committee and the World Anti‐Doping Agency. Except for patients suffering from insulin‐dependent diabetes mellitus, the administration of insulin is not allowed. Therapeutics developed to treat non‐insulin‐dependent diabetes mellitus act as releasing factors of endogenously produced insulin or improve its efficiency mediating the glucose uptake into insulin‐dependent tissues. Hence, these compounds are also relevant for sports drug testing, and a fast, robust, and sensitive assay was developed to identify 12 oral antidiabetic agents or respective hydroxylated metabolites in human urine. Urine specimens are enzymatically hydrolyzed; target analytes are extracted by liquid‐liquid extraction and identified by means of liquid chromatography interfaced to tandem mass spectrometry by electrospray ionization. Detection limits of respective drugs ranged between 10 and 30 ng/mL, metabolites of therapeutics were characterized by diagnostic fragmentation pathways upon collisionally activated dissociation of protonated molecules, and general fragmentation routes were proposed. Copyright © 2005 John Wiley & Sons, Ltd.
Prenatal screening for congenital heart disease using real‐time three‐dimensional echocardiography and a novel ‘sweep volume’ acquisition technique
Authors: Sklansky M. , Miller D. , Devore G. , Kung G. , Pretorius D. , Wong P. , Chang R.‐K. 
Published: March 2005

AbstractObjectivesConventional prenatal screening for congenital heart disease (CHD) involves a time‐consuming and highly operator‐dependent acquisition of the four‐chamber view and outflow tracts. By acquiring the entire fetal heart instantaneously as a single volume, real‐time three‐dimensional echocardiography (RT3DE) may facilitate fetal cardiac screening.MethodsFour reviewers, each experienced with fetal cardiac imaging, blindly and independently evaluated a single cardiac volume from each of 18 fetuses (11 normal, seven with CHD). Two‐dimensional echocardiography served as the gold standard. Three‐dimensional evaluation of each fetus included a series of volume acquisitions lasting 2–6 s each. A ‘sweep volume’ technique was developed to fit larger hearts into a single non‐gated volume.ResultsRT3DE had a high sensitivity for detecting CHD (93%), with only a single case being missed by two observers. Specificity for CHD was low (45%), with a high rate of ‘cannot determine’ responses and false positive artifacts.ConclusionsThese preliminary results suggest that RT3DE has the potential to function as a screening tool for fetal heart disease. However, artifacts must be recognized and minimized, resolution must improve, and substantial training will be necessary prior to widespread clinical use. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
The use of Ligasure Vessel Sealing System in thyroid surgery
Authors: Lachanas Vassilios A. , Prokopakis Emmanuel P. , Mpenakis Antonios A. , Karatzanis Alexander D. , Velegrakis George A. 
Published: March 2005

OBJECTIVESTo evaluate the role of Ligasure Vessel Sealing System (LVSS) (Valleylab, Boulder, CO) in thyroid surgery, with emphasis given to the duration of the procedure, as well as potential relevant postoperative complications.STUDY DESIGN AND SETTINGSA prospective study was conducted from November 1, 2002 to October 31, 2003, on patients undergoing thyroid surgery with the use of LVSS device as the primary means of ligation. All patients' records were placed in a database. Efficacy of hemostasis, operation time, and postoperative complications were assessed. Results were compared with previous surgical procedures done by our team when the LVSS was not available.RESULTSLVSS proved effective in providing ligation and hemostasis during thyroid surgery in 72 consecutive patients. There was a mean reduction in operating time of 23 minutes compared with previous surgical thyroid procedures. Transient hypocalcaemia occurred in 4 subjects (5.55%); one incidence of transient paresis of the recurrent laryngeal nerve was also observed.CONCLUSIONLVSS proved quite a reliable and safe device in thyroid surgery; it provided sufficient hemostasis and reducing operative time.
Is the middle fossa approach the treatment of choice for intracanalicular vestibular schwannoma?
Authors: Colletti Vittorio , Fiorino Francesco 
Published: March 2005

OBJECTIVESTo compare the 2 surgical techniques most commonly used during vestibular schwannoma (VS) surgery, i.e., the middle fossa (MF) and the retrosigmoid‐transmeatal (RS‐TM) routes, when hearing preservation is attempted.STUDY DESIGNA longitudinal study of a series of consecutive patients operated on with the 2 techniques by the same surgeon was conducted. Selection criteria included tumor confined to the internal auditory canal (IAC) with a length ranging from 4 to 12 mm and hearing class A or B. Patients were alternately assigned to 1 of the 2 groups regardless of auditory class and distance of the tumor from the IAC fundus. Thirty‐five subjects were operated on with the RS‐TM technique and 35 via the MF route.RESULTSNo significant differences in auditory and facial nerve function results between the 2 techniques were observed. The RS‐TM approach, however, showed better facial nerve results at discharge. VS size, IAC enlargement, and, particularly, the distance from the IAC fundus were found to influence the postoperative results more than the type of approach itself.CONCLUSIONSThe MF approach has been described as being the better technique for VS surgery in terms of auditory results. However, this claim lacks statistical substantiation because no prospective studies are to be found in the literature. The present longitudinal investigation shows that the MF approach does not afford any particular advantages over the RS‐TM route in terms of auditory results in intracanalicular VS, with the exception of tumors reaching the IAC fundus.
Surgical complications after thyroid surgery performed in a cancer hospital
Authors: Filho JoäO Gonçalves , Kowalski Luiz Paulo 
Published: March 2005

OBJECTIVEThis study evaluates the incidence and risk factors of complications in patients submitted to thyroidectomy in a cancer hospital with residency training.STUDY DESIGNA retrospective chart and complications review of 1020 patients (1990–2000) underwent to thyroidectomy.RESULTSAt our cancer hospital, 1020 patients underwent thyroidectomy. The main postoperative complications consisted of transient hypocalcemia in 134 (13.1%) patients, permanent hypocalcemia in 26 (2.5%) patients, transient vocal cord palsy in 14 (1.4%) patients, and permanent vocal cord palsy in 4 (0.4%) patients. The type of thyroidectomy, neck dissection, and paratracheal lymph node dissection were significantly associated with transitory and permanent hypocalcemia.CONCLUSIONThyroid surgery can be performed safely in a surgical residency training program under direct supervision of an experienced surgeon with little morbidity to the patients. Hypocalcemia is the most significant complication. Neck and para‐tracheal lymph node dissections were the most significant predictors of hypocalcemia in patients who underwent total thyroidectomy.
Reading performance in children with otitis media
Authors: Golz Avishay , Netzer Aviram , Westerman S. Thomas , Westerman Liane M. , Gilbert David A. , Joachims Henry Z. , Goldenberg David 
Published: March 2005

OBJECTIVETo examine whether middle ear diseases and the associated hearing loss in early childhood affect reading performance later at school.STUDY DESIGN AND SETTINGOne hundred and sixty children, 6.5 to 8 years of age, were enrolled in this study: 80 children with a history of recurrent infections and/or prolonged periods of effusions of the middle ear before the age of 5 years, and 80 healthy children without any history of middle ear disease. Data were collected from the medical records of the children. Every child underwent a complete otological and audiological evaluation, followed by special reading tests.RESULTSThe study group performed more poorly, in all reading tests, as compared to the controls (P < 0.001).CONCLUSIONChildren with recurrent or prolonged middle ear diseases during the first five years of life tend to be at greater risk for delayed reading than aged‐matched controls with no previous middle ear diseases.
Incidence, age at onset, and potential reasons of malignant transformation in recurrent respiratory papillomatosis patients: 20 years experience
Authors: Gerein Valentin , Rastorguev Eugen , Gerein Johann , Draf Wolfgang , Schirren Joachim 
Published: March 2005

Forty‐two patients with recurrent respiratory papillomatosis (RRP) were accepted into a multicenter prospective study in 1983 to 1990, treated with alfa‐IFN 3 MU/m2 3 times a week and then followed‐up until August 1, 2003. All the patients who had disease progression with pulmonary spread were characterized by insufficient response to IFN‐therapy and detection of HPV type 11. Five patients (4/5 smokers) presented malignant transformation in lungs or nasopharynx (mean RRP duration was 27.2 ± 8 years from RRP onset and 14.6 ± 6.3 years from pulmonary spread until malignant transformation) with persistent RRP in larynx. The results of long‐term follow‐up in RRP patients with HPV 11 underline the necessity of reanalyzing the current therapy.
Surgical management of parapharyngeal space tumors: A 10‐year review
Authors: Khafif AVI , Segev Yoram , Kaplan Daniel M. , Gil ZIV , Fliss Dan M. 
Published: March 2005

OBJECTIVEThe purpose of this article is to describe the diagnostic evaluation and surgical approaches to parapharyngeal space tumors in a tertiary referral center.STUDY DESIGN AND SETTINGThe study is a retrospective review of 47 patients diagnosed with tumors of the parapharyngeal space (12 with malignant diseases and 35 with benign lesions) and surgically treated during a 10‐year period. The transcervical (40%) and the transcervical‐transparotid approaches (46%) were the most commonly performed surgical procedures followed by the orbitozygomatic‐middle fossa approach (12%) and the transmandibular approach (2%).RESULTSThe surgical procedures were uneventful and there were no postoperative mortalities. Complications were rare; the most common was transient facial nerve paralysis (5 patients). After an average follow‐up of 35 months, only 1 of 35 patients with benign diseases had a recurrence 5 years following transcervical resection of a pleomorphic adenoma. Of 12 patients with malignant tumors, 5 (42%) are alive with no evidence of disease. The sensitivity of preoperative fine needle aspiration biopsy (n = 23 patients) was 87% for detection of malignant disease and specificity was 100%.CONCLUSIONSMost benign parapharyngeal space tumors can be removed surgically with a low rate of complications and recurrence. Malignant neoplasms, however, carry an ominous prognosis and a low rate of disease‐free survival. Fine needle aspiration may be helpful in preoperative diagnostic evaluation of patients with parapharyngeal space tumors.
Otolaryngologic presentations of amyotrophic lateral sclerosis
Authors: Chen Anton , Garrett C. Gaelyn 
Published: March 2005

OBJECTIVES/HYPOTHESISTo determine the incidence of voice disturbance as a presenting symptom of amyotrophic lateral sclerosis (ALS) and describe laryngologic features of ALS.STUDY DESIGNRetrospective review.METHODSRecords of patients with voice disturbance at a voice center and ALS patients at a neurology clinic were reviewed from January 1998 to March 2003.RESULTS15 of 1759 patients with voice disturbance were later diagnosed with ALS. Of 220 ALS patients presenting to neurology clinic, 44 had bulbar symptoms and 19 had initially presented to an otolaryngologist. Dysarthria, dysphagia, tongue fasciculation, and incomplete vocal fold closure were common findings. Neuromuscular disease was missed in 8 of 19 ALS patients seen by an otolaryngologist.CONCLUSIONSAlthough otolaryngologists rarely encounter undiagnosed ALS patients, a significant portion of bulbar ALS patients are initially evaluated by otolaryngologists.SIGNIFICANCEVigilance for neuromuscular abnormalities on otolaryngologic exam is important in patients who present with dysarthria, dysphonia, or dysphagia. EBM rating: C.
In vitro assessment of image‐guided otologic surgery: Submillimeter accuracy within the region of the temporal bone
Authors: Labadie Robert F. , Shah Rohan J. , Harris Steve S. , Cetinkaya Ebru , Haynes David S. , Fenlon Michael R. , Juszczyk Andrzej S. , Galloway Robert L. , Fitzpatrick J. Michael 
Published: March 2005

OBJECTIVESApplication of image‐guided surgery to otology has been limited by the need for sub‐millimeter accuracy via a fiducial system that is easily usable (noninvasive and nonobstructive). METHODS: A dental bite‐block was fitted with a rigid frame with 7 fiducial markers surrounding each external ear. The temporal bones of 3 cadaveric skulls were removed and replaced with surgical targets arranged in a bull's‐eye pattern about the centroid of each temporal bone. The surgical targets were identified both within CT scans and in physical space using an infrared optical tracking system. The difference between positions in CT space versus physical space was calculated as target registration error.RESULTSA total of 234 independent target registration errors were calculated. Mean ± standard deviation = 0.73 mm ± 0.25 mm.CONCLUSIONSThese findings show that image‐guided otologic surgery with submillimeter accuracy is achievable with a minimally invasive fiducial frame.SIGNIFICANCEIn vivo validation of the system is ongoing. With such validation, this system may facilitate clinically applicable image‐guided otologic surgery. EBM rating: A.