bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of halogen‐free amino‐functionalized polymethyl methacrylate by atom transfer radical polymerization (ATRP)
Authors: Sadhu Veera Bhadraiah , Pionteck Jürgen , Voigt Dieter , Komber Hartmut , Voit Brigitte
Published: May 2004

In order to obtain amino‐terminated polymethyl methacrylate (PMMA‐NH2) free of halogen we used the atom transfer radical polymerization (ATRP) to polymerize methyl methacrylate (MMA) in presence of an initiator containing an alkyl bromide unit and a protected amine functional group. The use of CuBr / N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine (PMDETA) as co‐catalyst system results in a polymer free of halogen due to hydrogen transfer from PMDETA to the growing polymer chain. However, side reactions occur affecting the typically “living” character of the ATRP. The measured molecular weights are consistently higher than the theoretical ones and the molecular weight distributions are relatively broad.
Monolayers of reactive cellulose derivatives
Authors: Wenz Gerhard , Liepold Petra , Bordeanu Nico
Published: May 2004

Functional cellulose derivatives are very versatile materials for the creation of mono‐ and multilayer systems. Hydrophobic alkyl and trimethylsilyl celluloses form highly ordered Langmuir‐Blodgett multilayers on hydrophobic substrates. Cellulose thiosulfates and methyl thio ethers were self‐assembled on gold and silver surfaces to form hydrophilic monolayers. Cellulose layer systems are capable for chemical transformations under conservation of the structural order. They are suitable platforms for the investigation of molecular recognition at surfaces and the construction of sensor devices. Both biological ligands, e.g. biotin, and enzymes, e.g. horse radish peroxidase, could be attached to cellulose under conservation of their biological function.
Reactive methacrylate systems for dental bioadhesives
Authors: Gibas Mirosław , Kupka Tomasz , Tanasiewicz Marta , Malec Witold
Published: May 2004

The procedure of restoring missing crown part of a human tooth with use of experimental materials, including new functional dimethacrylate monomers, is presented. The essential steps are precise evaluation of root canal cavities and providing a good adhesion of restorative materials to tooth structures. Magnetic resonance microscopy is considered to be a valuable supporting technique in restorative dentistry.
Polypropylene surface peroxidation with heterofunctional polyperoxides
Authors: Nosova Natalya , Roiter Yuri , Samaryk Volodymyr , Varvarenko Sergiy , Stetsyshyn Yuri , Minko Sergiy , Stamm Manfred , Voronov Stanislav
Published: May 2004

Method of polyolefin surface activation via covalent grafting of polyperoxide nanolayer by free radical mechanism has been presented. The features of such the nanolayer formation under the thermoprocessing conditions, i.e.: formation of 3D crosslinked network in polyperoxide bulk; and its grafting with complete coating of polyolefin surface, ‐‐ is considered. The method provides an availability of uniformly placed peroxide groups of one type over the polyolefin surface activated, which may further be utilized for the tailored modification of polymer surfaces using the “grafting to” and “grafting from” techniques in that time when it is necessary.
Application of sensitive hydrogels in chemical and pH sensors
Authors: Gerlach Gerald , Guenther Margarita , Suchaneck Gunnar , Sorber Joerg , Arndt Karl‐Friedrich , Richter Andreas
Published: May 2004

In the present work, pH‐sensitive poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) blends as well as hydrogels based on poly(N‐isopropylacrylamide) (PNIPAAm), which are sensitive to organic solvent concentration in aqueous solutions, were used in silicon micromachined sensors. A sensitivity of approximately 15 mV/pH was obtained for a pH sensor with a 50 μm thick PVA/PAA hydrogel layer in a pH range above the acid exponent of acrylic acid (pKa=4.7). The output voltage versus pH‐value characteristics and the long‐term signal stability of hydrogel‐based sensors were investigated and the measurement conditions necessary for high signal reproducibility were determined. The influence of the preparation conditions of the hydrogel films on the sensitivity and response time of the chemical and pH sensors is discussed.
Novel reactive thermosensitive polyethers – control of transition point
Authors: Dworak Andrzej , Trzebicka Barbara , Wałach Wojciech , Utrata Alicja , Tsvetanov Christo
Published: May 2004

A new class of thermosensitive polymers based on polyethers is discussed. Using living anionic polymerisation techniques a series of homo‐ and block copolymers of 2,3‐epoxypropanol‐1 (the glycidol), ethoxy ethyl glycidol ether, its hydrophobic derivative, and ethylene oxide of different molar masses and topology (linear and comb‐like) was obtained. By simple chemical modification of hydroxyl groups in polyglycidol segments hydrophobic elements were introduced into polymer chains, which allowed to control the transition point related to the lower critical solution temperature between 0 to 100°C. The relation between the transition temperature and the structure of obtained polymers is discussed.
Complexes of cellulose and trypsin
Authors: Kotelnikova Nina E. , Mikhailova Sofia A. , Vlasova Elena N.
Published: May 2004

Adsorption of trypsin to microcrystalline cellulose has been determined as functions of protein concentration and pH of the aqueous medium. The study of adsorption at several pH values indicates that interaction of trypsin to the microcrystalline cellulose interface is controlled by the electrostatic effect. The FTIR, desorption, and SEM data reveal that a part of trypsin is strongly bound to the microcrystalline cellulose matrix. Resulting complexes consist of microcrystalline cellulose, trypsin, and water.
Automatically and electronically controllable hydrogel based valves and microvalves – design and operating performance
Authors: Richter Andreas , Howitz Steffen , Kuckling Dirk , Kretschmer Katja , Arndt Karl‐Friedrich
Published: May 2004

This paper describes automatically and electronically controlled valves and microvalves based on smart hydrogels. The operating performance of such devices will be discussed in dependence on various design parameters. Furthermore, it will be shown that hydrogel based valves are showing an outstanding possibility of miniaturization, a leakage free switching behavior up to a pressure drop of 8.4 bar, and a pronounced particle tolerance.
The sol‐gel approach towards thermo‐responsive poly(N‐isopropyl acrylamide) hydrogels with improved mechanical properties
Authors: Loos Wouter , Du Prez Filip
Published: May 2004

A new type of thermo‐responsive hydrogels based on the polymer poly(N‐isopropyl acrylamide) (PNIPAA) has been synthesized with the sol‐gel technology. For the preparation of this type of nano‐structured hydrogels, the inorganic silica phase was synthesized by the sol‐gel process in the presence of an aqueous solution of high molecular weight PNIPAA. This combination of the organic and inorganic phases forms hybrid hydrogels with a semi‐IPN morphology. The unique structure of these hydrogels improves the mechanical stability to a great extent as compared to conventional PNIPAA‐hydrogels. This was shown by stress‐strain experiments and the capability to absorb and desorb large amounts of water. The silica only slightly influences the transition temperature of the hydrogels but allows us to vary the thermo‐responsive properties of the materials to a great extent.
Encapsulation of living cells with polymeric systems
Authors: Schwinger Christian , Klemenz Albrecht , Busse Karsten , Kressler Jörg
Published: May 2004

Microencapsulation of cells producing recombinant proteins or hormones leads to immunoprotection and immobilization in culture or in vivo. We are investigating three different strategies for the production of calcium cross‐linked alginate beads of a small size with immobilized and immunoprotected mammalian cells: a) the AirJet technology (coaxial gas flow extrusion), b) the vibrating nozzle technology, and c) the JetCutter technology. A alginate/poly‐L‐lysine/alginate complexation was used as the polymeric system. All three methods may be used for production of homogeneous beads with a diameter of approximately 350 μm. While the vibrating nozzle technique was limited to an alginate viscosity of 0.2 Pa·s or less, the AirJet and JetCutter technology were less sensitive to higher viscosities. High frequency Scanning Acoustic Microscopy is used for mechanical characterization of the microspheres as well as for investigation of surface properties.
Electrical properties of σ‐conjugated polymers with additives and their applications in sensors
Authors: Nešpůrek Stanislav , Wang Geng , Böhm Stanislav , Kořínek Marek , Adler Hans‐J.
Published: May 2004

The charge carrier transport in poly[methyl(phenyl)silylene] (PMPSi) proceeds predominantly along the σ‐delocalized Si backbone with participation of interchain hopping and polaron formation. The charge carrier mobility increases with increasing electron affinity of acceptor dopands having zero dipole moments. On the other band, the hole drift mobility is influenced by the dipole moment of the dopand. The electrostatic charge‐dipole interactions cause a broadening of the energy distribution of transport states, which results in a decrease in the charge carrier mobility. An addition of organic salts leads, under the conditions of increased humidity, to an increase in electrical conductivity and capacitance. This is demonstrated on the layers PMPSi/1,5‐dimorpholino‐1,5‐diphenylpentamethinium perchlorate.
Fine‐tuning the prediction of sequences cleaved by signal peptidase II: A curated set of proven and predicted lipoproteins of Escherichia coli K‐12
Authors: Gonnet Pedro , Rudd Kenneth E. , Lisacek Frédérique
Published: May 2004

A curated set of 81 proven and 44 predicted lipoproteins of Escherichia coli K‐12 was defined with the combined use of a literature survey, a variety of predictive tools and human expertise. The well‐documented Gram‐negative proteome of E. coli K‐12 was chosen to assess how the different approaches complement each other and to ensure a stable definition of a consistent set of lipoproteins. The results of detailed analysis of such proteins at the level of a single proteome are presented, corroborated and rationalized.
Umbilical cord occlusion of the donor versus recipient fetus in twin–twin transfusion syndrome
Authors: Nakata M. , Chmait R. H. , Quintero R. A.
Published: May 2004

Objectives

To compare the technical characteristics and perinatal outcomes of selected twin–twin transfusion syndrome (TTTS) cases treated with primary umbilical cord occlusion (UCO) of the donor vs. recipient twin.

Methods

TTTS patients who underwent primary UCO via ultrasound endoscopic‐guided umbilical cord ligation (UCL) or endoscopic umbilical cord photocoagulation (UCP) were eligible for the study. Primary UCO was offered only if a discordant lethal anomaly was present or by patient choice in TTTS Stages III/IV on the cord of the fetus with abnormal Doppler studies or hydrops.

Results

Primary UCO was performed in 25 TTTS cases between July 1997 and June 2002. UCO was performed in six (24%) donor twins and 19 (76%) recipient twins. UCL was performed in 23 cases and UCP in two cases. Overall, 22 (88%) patients had liveborn infants. There were no differences in cotwin survival (100% vs. 84.2%), median gestational age at delivery (34.8 vs. 33.8 weeks) and preterm premature rupture of membranes rate (16.6% vs. 15.7%) whether the donor or recipient twin, respectively, was the subject of UCO. However, two‐trocar access (50% vs. 5.3%; P = 0.03) and amnioinfusion (83.3% vs. 0%; P < 0.001) were required more often in the UCO of the donor than of the recipient twin, respectively. Operating time (75 vs. 40 min) was significantly longer in UCO of the donor twin (P = 0.04). UCP was more likely to be used in occlusion of the donor's cord (33%) than of the recipient's cord (0%; P = 0.05).

Conclusion

Primary UCO of the donor twin is technically more demanding than that of the recipient twin, but perinatal outcomes of the cotwins are comparable. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Congenital constriction band of the upper arm: the role of three‐dimensional ultrasound in diagnosis, counseling and multidisciplinary consultation
Authors: Paladini D. , Foglia S. , Sglavo G. , Martinelli P.
Published: May 2004

Constriction band syndrome represents a sporadic condition that may result in amputations, constrictions and other deformities of the fetal limbs and body. Prenatal diagnosis by two‐dimensional ultrasound has been reported. We present a case of constriction band involving the upper arm in which the assessment by three‐dimensional ultrasound significantly contributed to the diagnosis and the multidisciplinary counseling. In fact, multiplanar imaging and surface rendering allowed a clear depiction of the extent of the constriction, the club‐hand deformity and the relationship between the amniotic band, the cord and the fetal limb. This case represents a unique and effective application of three‐dimensional ultrasound in prenatal diagnosis. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Ultrasound dating at 12–14 or 15–20 weeks of gestation? A prospective cross‐validation of established dating formulae in a population of in‐vitro fertilized pregnancies randomized to early or late dating scan
Authors: Saltvedt S. , Almström H. , Kublickas M. , Reilly M. , Valentin L. , Grunewald C.
Published: May 2004

Objectives

To determine the accuracy of established ultrasound dating formulae when used at 12–14 and 15–20 gestational weeks.

Methods

A total of 363 singleton pregnancies conceived after in‐vitro fertilization (IVF) and randomized to a dating scan at 12–14 or 15–20 gestational weeks were studied. ‘True’ gestational age was calculated on the basis of the day of oocyte retrieval and was compared to gestational age calculated on the basis of seven dating formulae including the fetal biparietal diameter (BPD) and three dating formulae including BPD and fetal femur length (FL). The mean of the differences between estimated and true gestational age (systematic measurement error) and their SD (random measurement error) were calculated for each formula.

Results

Three formulae showed systematic errors of less than −0.7 days at both early and late scanning. Two formulae overestimated gestational age at both early and late scanning by 5.7 and 3.1 vs. 2.3 and 2.8 days, respectively, while five formulae manifested very different systematic errors at early and late scanning. The formulae used for clinical management underestimated gestational age by a mean of 3 days when dating was performed at 12–14 weeks, and by a mean of 0.8 days when dating was done at 15–20 weeks. The random error was on average 1 day less when the scan was carried out early (2 vs. 3 days; P < 0.0005). Mean true gestational age at delivery in IVF pregnancies with spontaneous start of labor was 279 days (SD 12.9); excluding preterm deliveries it was 281 days (SD 8.1).

Conclusions

Ultrasound dating formulae originally intended for use in the middle of the second trimester do not necessarily perform well when used for dating earlier in gestation. The systematic and random error of any dating formula must be assessed for the gestational age interval in which the formula is intended to be used. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Dynamic cervical change during real‐time ultrasound: prospective characterization and comparison in patients with and without symptoms of preterm labor
Authors: Kurtzman J. T. , Jenkins S. M. , Brewster W. R.
Published: May 2004

Objectives

To compare the incidence of dynamic cervical change (spontaneous real‐time cervical shortening) in singleton patients with and without symptoms of preterm labor (PTL).

Methods

A total of 109 patients between 23 and 34 weeks' gestation with and without PTL symptoms underwent cervical length ultrasound and contraction monitoring over a 10‐min period. Cervical length measurements were taken at 1‐min intervals. Exclusion criteria included ruptured membranes, dilation > 3 cm or cerclage. Following the examination, the sonographer made a subjective assessment as to whether noticeable dynamic cervical change had occurred. A measurement was then made during the application of fundal pressure. The initial cervical length, shortest length, maximum change in length and incidence of dynamic change were compared between patients with and without PTL symptoms. The shortest cervical length was compared to the presence and timing of uterine contractions and the measurement during the application of fundal pressure.

Results

A total of 43 asymptomatic patients and 66 symptomatic patients were studied. Compared to asymptomatic patients, patients with PTL symptoms had shorter initial lengths, nadir lengths and mean lengths over time as well as a greater amount of maximum change. Dynamic cervical change was more frequently seen in symptomatic patients (48% vs. 9%, P < 0.001) and was associated with uterine contractions (odds ratio 4.6, 95% CI 1.9–10.8). Fundal pressure was not able to reproduce the shortest cervical length that occurred spontaneously during the observation period.

Conclusions

Dynamic cervical change (real‐time cervical shortening) is common in patients with PTL symptoms and is associated with uterine contractions. Whether this finding enhances the ability to predict preterm delivery remains to be elucidated. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Thromboembolic Prophylaxis as a Risk Factor for Postoperative Complications after Breast Cancer Surgery
Authors: Friis Esbern , Hørby John , Sørensen Lars Tue , Pilsgaard Bo , Wille‐Jørgensen Peer , Johansen Lars , Jørgensen Torben
Published: May 2004

Hematoma and bruising (sugillation) are frequent problems after operations for primary breast cancer. In the present study we evaluated the influence of various methods of perioperative thromboembolic prophylaxis on the postoperative incidence of hematoma and suggilation. From June 1994 through August 1996, a series of 425 patients consecutively operated on for primary breast cancer were included. Thromboembolic prophylaxis was low‐molecular‐weight heparin (LMWH) in 310 patients and thigh‐long graded compression (TED) stockings in 102 patients. Postoperative complications including deep vein thrombosis, pulmonary embolism, wound hematoma, and sugillation were recorded, and 17 variables with a potential influence on complications were analyzed by logistic regression analysis. Heparin prophylaxis compared to prophylaxis with TED stockings was significantly and independently associated with postoperative hematoma [odds ratio (OR) 3, 13; 95% confidence interval (CI) 1.38–7.13] or sugillation (OR 3.34; 95% CI 1.93–5.78). No clinically overt thromboembolic complications were diagnosed. After operations for breast cancer we found that LMWH was significantly associated with postoperative hematoma and sugillation compared to TED stockings for perioperative thromboembolic prophylaxis.
The ‘real’ woman with heart failure. Impact of sex on current in‐hospital management of heart failure by cardiologists and internists
Authors: Opasich C. , De Feo S. , Ambrosio G.A. , Bellis P. , Di Lenarda A. , Di Tano G. , Fico D. , Gonzini L. , Lavecchia R. , Tomasi C. , Maggioni Aldo P.
Published: May 2004

Aim:

To identify differences between sexes in the clinical profile, use of resources, management and outcome in a large population of ‘real world’ patients with heart failure (HF).

Methods:

A prospective cross‐sectional survey was conducted on 2127 consecutive patients (47% women) admitted with HF to 167 cardiology and 250 internal medicine departments between February 14 and 25, 2000.

Results:

Women were older, had a higher prevalence of atrial fibrillation, and more frequently a hypertensive or valvular aetiology. Females were admitted more frequently in Medical than in Cardiology Departments. The rate of invasive and non‐invasive procedures was lower in women than in men, slightly higher if managed by cardiologists. Women were less frequently prescribed ACE‐inhibitors, amiodarone, and spironolactone, and more frequently prescribed digoxin. In‐hospital mortality was similar, without difference between health‐care providers. A 6‐month follow‐up was performed in 56.4% of the cases in both setting, but less frequently in women. Event rates were similar with nearly half of patients re‐hospitalised at least once.

Conclusion:

The ‘real’ HF woman has generally a more severe disease; she is an old lady who is more frequently hospitalised in a medical unit, receives few diagnostic, and cardiovascular procedures and pharmacological therapy, has a relatively low probability of dying in hospital, but a high likelihood of requiring readmission.
Acute hypoxic hepatitis (‘liver shock’): still a frequently overlooked cardiological diagnosis
Authors: Denis Caroline , de Kerguennec Caroline , Bernuau Jacques , Beauvais Florence , Solal Alain Cohen
Published: May 2004

The diagnosis of acute hypoxic hepatitis remains problematic. We describe a series of 14 patients who were initially hospitalized in an hepatic care unit with a diagnosis of fulminant hepatitis, and were subsequently found to have acute hypoxic hepatitis (‘liver shock’) secondary to heart failure. A diagnostic algorithm is proposed.
Effect of carvedilol on diastolic function in patients with diastolic heart failure and preserved systolic function. Results of the Swedish Doppler‐echocardiographic study (SWEDIC)
Authors: Bergström A. , Andersson B. , Edner M. , Nylander E. , Persson H. , Dahlström U.
Published: May 2004

Aim:

The purpose of this study was to investigate the effects of carvedilol on diastolic function (DF) in heart failure patients with preserved left ventricular (LV) systolic function and abnormal DF.

Patients and Methods:

We randomised 113 patients with diastolic heart failure (DHF) (symptomatic, with normal systolic LV function and abnormal DF) into a double blind multi‐centre study. The patients received either carvedilol or matching placebo in addition to conventional treatment. After uptitration, treatment was continued for 6 months. Two‐dimensional and Doppler echocardiography were used for quantification of LV function at baseline and at follow‐up. Four different DF variables were evaluated by Doppler echocardiography: mitral flow E:A ratio, deceleration time (DT), isovolumic relaxation time (IVRT) and the ratio of systolic/diastolic pulmonary venous flow velocity (pv‐S/D). Primary endpoint was change in the integrated quantitative assessment of all four variables during the study.

Results:

Ninety‐seven patients completed the study. A mitral flow pattern reflecting a relaxation abnormality was recorded in 95 patients. There was no effect on the primary endpoint, although a trend towards a better effect in carvedilol treated patients was noticed in patients with heart rates above 71 beats per minute. At the end of the study, there was a statistically significant improvement in E:A ratio in patients treated with carvedilol (0.72 to 0.83) vs. placebo (0.71 to 0.76), P<0.05.

Conclusions:

Treatment with carvedilol resulted in a significant improvement in E:A ratio in patients with heart failure due to a LV relaxation abnormality. E:A ratio was found to be the most useful variable to identify diastolic dysfunction in this patient population. This effect was observed particularly in patients with higher heart rates at baseline.
Neurological soft signs and dermatoglyphic anomalies in twins with schizophrenia
Authors: Kelly Brendan D. , Cotter David , Denihan Cian , Larkin Deirdre , Murphy Peter , Kinsella Anthony , Walsh Dermot , Waddington John , Larkin Conall , O’Callaghan Eadbhard , Lane Abbie
Published: May 2004

Schizophrenia is associated with altered neural development. We assessed neurological soft signs (NSS) and dermatoglyphic anomalies (total a–b ridge count (TABRC) and total finger ridge count) in 15 pairs of twins concordant and discordant for schizophrenia. Within-pair differences in both NSS and TABRC scores were significantly greater in discordant compared to concordant monozygotic pairs. There was no significant difference in NSS and TABRC scores between subjects with schizophrenia and their co-twins without the illness. However, monozygotic discordant twins with schizophrenia had higher ABRCs on their right hands compared to their co-twins without the illness. These findings suggest that an unidentified environmental event acting between weeks 6 and 15 of gestation affects the development of monozygotic twins who go on to develop schizophrenia but does not have a corresponding effect on their co-twins who do not develop the illness. The effect of such an event on dermatoglyphic profiles appears lateralised to the right hand in affected twins.
Causation or covariation: an empirical re‐examination of the link between TQM and financial performance
Authors: York Kenneth M , Miree Cynthia E
Published: May 2004

Total Quality Management (TQM) is an integrated management system designed to focus an organization’s resources on increasing the quality of a firm’s products/services, satisfying customer needs and improving the efficiency of the processes that produce the firm’s products/services. Advocates of TQM have suggested that there should be a positive relationship between implementing TQM practices and financial performance measures. The empirical evidence supporting this assertion, however, is limited at best. Most of the research has been limited to surveys of managers’ perceptions of the effect of TQM on financial performance. A few empirical studies using financial performance measures have been done, and have shown that TQM firms have better financial performance than other firms. However, better performing companies may be more likely to adopt TQM, so that rather than being a path to improved financial success (causation), TQM merely “comes along for the ride” (covariation). This study examined the relationship between TQM and financial performance, using a sample of Baldrige Award winners and replicated with a second sample of state quality award winning companies, and three different sets of financial performance measures. Both Baldrige and state quality award winners generally had better financial performance than their peers after winning a quality award, and before.
Intense summer Si‐recycling in the surface Southern Ocean
Authors: Beucher Charlotte , Tréguer Paul , Hapette Ana‐Maria , Corvaisier Rudolph , Metzl Nicolas , Pichon Jean‐Jacques
Published: May 2004

Si‐cycle in surface waters was investigated in summer 2003 during a transect conducted from south‐Australia to Antarctica. Diatoms dominated the microphytoplankton. Silicic acid was depleted up to 60°S; a subsurface maximum of biogenic silica (= biosilica) was observed in the Permanent Open Ocean Zone. In the 100–0.01% light zone, the ratio of depth‐integrated biosilica dissolution rate (D) to depth‐integrated biosilica production rate (P) ranged between 0 to 3.1, being >1 for 5 of our 6 stations. The biosilica dissolution was related to the percentage of dead diatoms but not to the temperature and might be, at least partially, under bacteria mediation. This study shows that during summer the Southern Ocean silicate pump can be much less efficient than usually expected. Existence of scenarios with intense surface Si‐recycling in the Southern Ocean has major consequences both for modelers and paleoceanographers.
Neutral polar wind
Authors: Gardner Larry C. , Schunk Robert W.
Published: May 2004

The classical polar wind is an ambipolar outflow of ions from high latitudes along open geomagnetic field lines. The polar wind consists of light thermal ions (H+, He+) and energetic light and heavy ions (H+, He+, O+). The characteristics of these ions have been studied quite extensively since the 1960s. In just the last 20 years, however, energetic neutral atoms (ENAs) that are produced in charge exchange reactions between the singly ionized polar wind ions and the surrounding neutral atoms have been used as a means to remotely probe plasma populations. Recent estimates for neutral outflow integrated fluxes from the LENA instrument on the IMAGE spacecraft have shown values of 1–4 × 109 cm−2 s−1, with a considerable diurnal variation. A theoretical model has been used in this study that is similar to the high‐latitude hydrodynamic polar wind model developed at Utah State University, but it has been expanded to include the effects of neutral stream particles so that the characteristics of the neutral polar wind can be elucidated. The neutral polar wind model results show a high neutral hydrogen outflow flux on the order of 109 cm−2 s−1.
Pathologic changes of glial cells in murine model of Niemann–Pick disease type C: Immunohistochemical, lectin‐histochemical and ultrastructural observations
Authors: SUZUKI HIROYOSHI , SAKIYAMA TAKESHI , HARADA NAOKO , ABE MISTUBUMI , TADOKORO MAMORU
Published: May 2004

Abstract

Background
: In recent years, morbid states of glial cells have been reported in several neurodegenerative diseases. We studied neuropathologically the glial cells in a murine model of Niemann–Pick disease type C (NPC) to clarify involvement of glias, the most important supportive cells in the central nervous system, by the disease.

Methods
: The brains of sphingomyelinosis mice (spm/spm), aged from 5 to 13 weeks, and 15 of their age‐matched normal siblings were studied histopathologically, immunohistochemically and electron micro‐scopically.

Results
: Accumulation of ubiquitin‐positive materials was found in the cytoplasm of foam cells and ballooned neurons immunohistochemically. In addition to the morphologically abnormal cells, double immunostaining of ubiquitin and glial fibrillary acidic protein (GFAP) revealed the deposition of ubiquitinated substances in the cytoplasm of astrocytes. Ultrastructurally, numerous concentric lamellar inclusions, so‐called ‘myelin figures’, appeared in the neurons and phagocytotic cells. Some oligodendrocytes also contained ‘myelin figure’ inclusions and multivesicular inclusions. Astrocytes contained abnormal irregularily‐shaped electron dense materials.

Conclusion
: In the murine model of NPC, astrocytes and oligodendrocytes are also involved in the morbid processes. Thus, it might be relevant to investigate the glial dysfunction to understand the pathological processes of the disease and to prepare an adjunct therapeutic strategy to manage the patients with NPC.
Therapeutic effect of spiramycin in brucellosis
Authors: GEYIK MEHMET FARUK , DIKICI BUNYAMIN , KOKOGLU OMER FARUK , BOSNAK MEHMET , CELEN MUSTAFA KEMAL , HOSOGLU SALIH , AYAZ CELAL
Published: May 2004

Abstract

Objective
: This study was undertaken to investigate the usefulness of spiramycin in treatment for brucellosis in an animal model.

Methods
: Eighty‐four Sprague‐Dawley rats were infected by intraperitoneal injection of Brucella melitensis suspension. Seven days after inoculation, four rats were selected randomly, killed and spleen cultures and Brucella standard tube agglutination test were carried out. All four rats were found to be infected. Eighty adult rats were randomly divided into four groups of 20 rats each. Tap water was given to the first group. Rifampicin 50 mg/kg per day and doxycycline 40 mg/kg per day were given to the second group, spiramycin 50 mg/kg per day orally was given to the third group, and a combination of spiramycin and rifampicin at the same dose and period was given to the fourth group. Duration of therapy regimens in all groups was 21 days. The spleens of all 80 rats were removed aseptically, homogenized, and placed onto Brucella agar plates to determine if viable bacteria were present.

Results
: Bacterial growth occurred in all of the rats’ spleens in the first group and in two rats’ spleens in the spiramycin group. Mean colony forming unit (c.f.u.) values were at the highest in the first group. The effectivities of spiramycin and rifampicin‐spiramycin were similar to rifampicin‐doxycycline. There were no differences in the treatment results between the three groups that received combined rifampicin‐doxycycline, rifampicin‐spiramycin and only spiramycin (P>0.05).

Conclusion
: The results show that spiramycin cures experimental rat brucellosis and may be an effective alternative in the therapy of human brucellosis.
Pharmacokinetics of etoposide with intravenous drug administration in children and adolescents
Authors: KATO YASUHIRO , NISHIMURA SHIN‐ICHIRO , SAKURA NOBUO , UEDA KAZUHIRO
Published: May 2004

Abstract

Background
: Pharmacokinetics of etoposide in Japanese children and adolescents has not been investigated. The objectives of the present study were (i) to document the pharmacokinetics of etoposide in Japanese children; (ii) to determine the intra‐ and interpatient variability in systemic etoposide exposure and (iii) to obtain insights into the age–pharmacokinetic parameter relationship.

Methods
: Pharmacokinetic studies of etoposide, given at doses of 60–200 mg/m2 by intravenous (i.v.) route of administration, were conducted in 18 children and adolescents (aged <19 years) with malignant diseases. High performance liquid chromatography was used to measure the blood etoposide levels.

Results
: Pharmacokinetic parameters (mean~SD) of the 14 patients (24 courses) who received etoposide 100 mg/m2 were as follows: peak serum concentration (Cmax), 18.5~6.4 μg/mL; trough serum concentration, 0.2~0.1 μg/mL; biological half‐life (T1/2), 3.6~0.7 h; volume of distribution (Vd), 6.3~3.4 L/m2; area under the etoposide serum concentration‐time curve (AUC), 129~38 hr•μg/mL; systemic clearance, 21.1~10.8 mL/min per m2. The T1/2, Vd, and AUC were not associated with age. An increase in etoposide dose per body surface area (BSA) was associated with increase in its Cmax and area under the time‐concentration curve (AUC). Wide interpatient variability in these parameters was demonstrated.

Conclusion
: The present study demonstrated that: (i) Pharmacokinetics of etoposide in Japanese children and adolescents were similar to those in Caucasians. (ii) Increased exposure to etoposide was associated with the Cmax. A clear correlation between Cmax and AUC was also found. (iii) Selecting the dose of etoposide according to body surface area (BSA) might give an acceptable range of exposure for children more than 1 year of age.
Screening for glucose‐6‐phosphate dehydrogenase deficiency using a modified formazan method: A pilot study on Filipino male newborns
Authors: PADILLA CARMENCITA , NISHIYAMA KAORU , SHIRAKAWA TAKU , MATSUO MASAFUMI ,   FOR THE NEWBORN SCREENING STUDY GROUP
Published: May 2004

Abstract

Background
: Glucose‐6‐phosphate dehydrogenase (G6PD) deficiency has increased prevalence rates in tropical Africa, tropical and subtropical Asia and some parts of the Mediterranean. Earlier studies on G6PD deficiency in the Philippines have shown prevalence rates of 4.5% to 25.7%.

Methods
: In the present study, 3278 male newborns were screened for G6PD deficiency using the modified formazan method, a simple screening procedure affordable in the setting of a developing country. Subjects with positive screening results were recalled for confirmatory testing using a commercial assay kit for quantitative enzyme determination.

Results
: Of the 3278 boys studied, 186 revealed positive screening results. Of the 186, 65 boys had confirmatory testing. Of these 65 boys, 45 were confirmed to have G6PD deficiency and 20 had normal results. This study reveals an incidence of G6PD deficiency of 3.9% among male Filipinos.

Conclusion
: This study recommends the inclusion of G6PD deficiency in the panel of disorders for newborn screening among Filipino newborns.
RNA surveillance down-regulates expression of nonfunctional κ alleles and detects premature termination within the last κ exon
Authors: Delpy Laurent , Sirac Christophe , Magnoux Emmanuelle , Duchez Sophie , Cogné Michel
Published: May 2004

Random V(D)J junctions would generate nonfunctional and/or out-of-frame sequences in about two-thirds of cases and result in abundant transcripts encoding truncated proteins. Although allelic exclusion at the DNA recombination level ensures that a single allele is functional, the frequent biallelic rearrangements need additional mechanisms to down-regulate aberrant transcripts in those cells with both a functionally and a nonfunctionally rearranged allele. The process of nonsense-mediated decay targets aberrantly rearranged Ig heavy-chain transcripts, but the situation of light-chain mRNAs is more complex, because they do not meet the usual requirements for nonsense-mediated decay and most often lack a spliceable intron downstream of the premature termination. We studied immunoglobulin heavy-chain -/- pro-B cells in which light chain genes get rearranged and expressed in the absence of any selection for the assembly of a functional B cell receptor. Using this model, we show that the whole κ locus is accessible in pro-B cells and allows the assembly of a broad spectrum of VκJκ segments, most of which are out-of-frame. This model provides an evaluation of thein vivoefficiency of RNA surveillance toward aberrant κ mRNAs produced in pro-B cells. Our data show that nonfunctional κ transcripts are excluded from the mature mRNA pool not only by detecting termination in an upstream exon but also by detecting changes in the position of termination within the last exon. Similar mechanisms efficiently down-regulate nonfunctional κ transcripts arising in normal mature B cells due to the biallelic transcription of rearranged κ genes.
Helicobacter pylori
interacts with the human single-domain trefoil protein TFF1
Authors: Clyne Marguerite , Dillon Paul , Daly Stephen , O'Kennedy Richard , May Felicity E. B. , Westley Bruce R. , Drumm Brendan
Published: May 2004

Why
Helicobacter pylori
colonizes only gastric tissue is unknown. It is found on gastric mucus-secreting cells and in the overlying gastric mucus but not deep in gastric glands. This localization mirrors the expression of trefoil factor 1, TFF1. We hypothesized that
H. pylori
interacting with TFF1 could explain the tropism of this bacteria for gastric tissue. Recombinant human TFF1 expressed in
Escherichia coli
was purified by affinity chromatography, ion-exchange chromatography, and gel filtration. Binding of
H. pylori
was assessed by using flow cytometry and the BIAcore system, which allows real-time monitoring of molecular interactions. In flow cytometry,
H. pylori
bound to the TFF1 dimer, but
Campylobacter jejuni
strains and the laboratory strain of
E. coli
, HB101, did not bind. When the BIAcore system was used,
H. pylori
bound strongly to TFF1-coated dextran chips compared with uncoated chips. Binding was inhibited by a TFF1 monoclonal antibody and by soluble TFF1.
H. pylori
bound to porcine gastric mucin only if it was pretreated with TFF1. In conclusion,
H. pylori
interacts avidly with the dimeric form of TFF1, and this interaction enables binding to gastric mucin, suggesting that TFF1 may act as a receptor for the organism
in vivo
. This interaction may underline the previously unexplained tropism of this organism for gastric tissue and its colocalization with the gastric mucin MUC5AC.
Urinary concentrating defect in mice with selective deletion of phloretin-sensitive urea transporters in the renal collecting duct
Authors: Fenton Robert A. , Chou Chung-Lin , Stewart Gavin S. , Smith Craig P. , Knepper Mark A.
Published: May 2004

To investigate the role of inner medullary collecting duct (IMCD) urea transporters in the renal concentrating mechanism, we deleted 3 kb of the UT-A urea transporter gene containing a single 140-bp exon (exon 10). Deletion of this segment selectively disrupted expression of the two known IMCD isoforms of UT-A, namely UT-A1 and UT-A3, producing
UT-A1/3
-/-
mice. In isolated perfused IMCDs from
UT-A1/3
-/-
mice, there was a complete absence of phloretin-sensitive or vasopressin-stimulated urea transport. On a normal protein intake (20% protein diet),
UT-A1/3
-/-
mice had significantly greater fluid consumption and urine flow and a reduced maximal urinary osmolality relative to wild-type controls. These differences in urinary concentrating capacity were nearly eliminated when urea excretion was decreased by dietary protein restriction (4% by weight), consistent with the 1958 Berliner hypothesis stating that the chief role of IMCD urea transport in the concentrating mechanism is the prevention of urea-induced osmotic diuresis. Analysis of inner medullary tissue after water restriction revealed marked depletion of urea in
UT-A1/3
-/-
mice, confirming the concept that phloretin-sensitive IMCD urea transporters play a central role in medullary urea accumulation. However, there were no significant differences in mean inner medullary Na
+
or Cl
-
concentrations between
UT-A1/3
-/-
mice and wild-type controls, indicating that the processes that concentrate NaCl were intact. Thus, these results do not corroborate the predictions of passive medullary concentrating models stating that NaCl accumulation in the inner medulla depends on rapid vasopressin-regulated urea transport across the IMCD epithelium.
The structure of a thermophilic archaeal virus shows a double-stranded DNA viral capsid type that spans all domains of life
Authors: Rice George , Tang Liang , Stedman Kenneth , Roberto Francisco , Spuhler Josh , Gillitzer Eric , Johnson John E. , Douglas Trevor , Young Mark
Published: May 2004

Of the three domains of life (Eukarya, Bacteria, and Archaea), the least understood is Archaea and its associated viruses. Many Archaea are extremophiles, with species that are capable of growth at some of the highest temperatures and extremes of pH of all known organisms. Phylogenetic rRNA-encoding DNA analysis places many of the hyperthermophilic Archaea (species with an optimum growth ≳80°C) at the base of the universal tree of life, suggesting that thermophiles were among the first forms of life on earth. Very few viruses have been identified from Archaea as compared to Bacteria and Eukarya. We report here the structure of a hyperthermophilic virus isolated from an archaeal host found in hot springs in Yellowstone National Park. The sequence of the circular double-stranded DNA viral genome shows that it shares little similarity to other known genes in viruses or other organisms. By comparing the tertiary and quaternary structures of the coat protein of this virus with those of a bacterial and an animal virus, we find conformational relationships among all three, suggesting that some viruses may have a common ancestor that precedes the division into three domains of life >3 billion years ago.
A parieto-frontal network for visual numerical information in the monkey
Authors: Nieder Andreas , Miller Earl K.
Published: May 2004

Recent electrophysiological studies in monkeys have implicated the prefrontal cortex (PFC) and posterior parietal cortex (PPC) in numerical judgments. The functional organization and respective contributions of these (and other) cortical areas, however, are unknown; their neural activity during numerical judgments has not been directly compared. We surveyed activity in the PPC and the anterior inferior temporal cortex while monkeys performed a visual numerosity judgment task and compared it with a population of PFC neurons. In the PPC, the proportion of numerosity-selective neurons was highest in the fundus of the intraparietal sulcus; only few numerosity-selective neurons were found in other PPC areas or the anterior inferior temporal cortex. Further, neurons in the fundus of the intraparietal sulcus responded and conveyed numerosity earlier than PFC neurons, suggesting that numerosity information flows from the PPC to the lateral PFC. This finding suggests a parieto-frontal network for numerosity in monkeys and establishes homologies between the monkey and human brain.
The Effect of Group‐level Influences on Pupils' Progress in Reading
Authors: HUTCHISON DOUGAL
Published: May 2004

This article investigates the existence or otherwise of group‐level effects on progress in reading. ‘Administrative’ data, i.e. data already produced by a local education authority (LEA) for its own purposes, was combined to give two primary‐age cohorts, each of the order of 2500 pupils, in one medium‐sized LEA in the south‐east of England. After allowing for pupil and global school‐level effects, a wide variety of possible aggregated group‐level effects (AGLEs) was investigated. Different functions of pupil score were investigated. Mean score and pupil turnover, especially the latter, were the most important AGLEs on attainment, and these had greater effects for older pupils.
Do OFSTED Inspections of Secondary Schools Make a Difference to GCSE Results?
Authors: SHAW I. , NEWTON D. P. , AITKIN M. , DARNELL R.
Published: May 2004

The Office for Standards in Education (OFSTED) aims to improve school performance through inspection. A government indicator of a secondary school's performance in England and Wales is the students' success in examinations. The examination results of over 3000 OFSTED inspected secondary schools offering students for General Certificate of Secondary Education (GCSE) examination during the 1992 to 1997 inspection cycle were modelled statistically. For kinds of schools where achievement was already much higher or lower than the average (e.g. selective schools), inspection was associated with slight improvements in achievement. For county, local education authority maintained, comprehensive schools (the largest single group), inspection did not improve examination achievement. Some implications for school improvement are discussed.
An Evaluation of the Use of Accredited Baseline Assessment Schemes in England
Authors: LINDSAY GEOFF , LEWIS ANN
Published: May 2004

Baseline assessment (accredited through the Qualifications and Curriculum Authority [QCA]) became a statutory requirement from September 1998 for all main tained primary schools in England. Since that date, schools have been required to implement baseline assessment with all children within seven weeks of starting school (i.e. at about 4‐5 years of age) unless a comparable recent assessment has been made. A survey of baseline assessment in local education authorities (LEAs), covering both providers of schemes and LEAs using ‘bought in’ schemes, was carried out in summer 2000. This was followed by a parallel survey of a random sample of schools and case studies of the operation of baseline assessment in 16 LEAs. Baseline assessment was generally viewed positively and regarded as working effectively by school and, in particular, by LEA personnel. Areas of concern focused on lack of training in the use to be made of the data by schools, weaknesses concerning validity and reliability, lack of parental involvement or understanding of the process, and confusion of purposes. This study extends discussion and evidence concerning earlier phases of baseline assessment. It raises significant issues about the potential use of baseline assessment for performance management of individual teachers and, more broadly, sets the scene for the revision of statutory baseline assessment to take effect from 2002/2003.
On Flying, Writing Poetry and Doing Educational Research
Authors: SAUNDERS LESLEY
Published: May 2004

This article is written in a personal capacity; it is based on a presentation entitled ‘If the child is father to the man, can the researcher be mother to the poet?’ given as part of the ECER symposium, ‘Telling stories: truth and fiction in educational research’ hosted by David Bridges, at the European Conference on Educational Research, University of Edinburgh, 23 September 2000. It is meant as a stimulus to discussion about the relationship between poetry as a species of ‘creative’ writing, and research writing—how and why they might be complementarities as well as opposites. Rather than attempting a theoretical paper, the author uses excerpts from her own poetry—and those of the prize‐winning poet, Jane Draycott, with whom she recently co‐authored a book, and whose ideas have contributed to this article—to explore these ideas.