bluuebunny/crossref_metadata_2025 huggingface dataset:
Atlantoaxial stabilization with the use of C1–3 lateral mass screw fixation
Authors: Horn Eric M. , Hott Jonathan S. , Porter Randall W. , Theodore Nicholas , Papadopoulos Stephen M. , Sonntag Volker K. H.
Published: January 2008

✓ Atlantoaxial stabilization has evolved from simple posterior wiring to transarticular screw fixation. In some patients, however, the course of the vertebral artery (VA) through the axis varies, and therefore transarticular screw placement is not always feasible. For these patients, the authors have developed a novel method of atlantoaxial stabilization that does not require axial screws. In this paper, they describe the use of this technique in the first 10 cases.

Ten consecutive patients underwent the combined C1–3 lateral mass–sublaminar axis cable fixation technique. The mean age of the patients was 62.6 years (range 23–84 years). There were six men and four women. Eight patients were treated after traumatic atlantoaxial instability developed (four had remote trauma and previous nonunion), whereas in the other two atlantoaxial instability was caused by arthritic degeneration. All had VA anatomy unsuitable to traditional transarticular screw fixation.

There were no intraoperative complications in any of the patients. Postoperative computed tomography studies demonstrated excellent screw positioning in each patient. Nine patients were treated postoperatively with the aid of a rigid cervical orthosis. The remaining patient was treated using a halo fixation device. One patient died of respiratory failure 2 months after surgery. Follow-up data (mean follow-up duration 13.1 months) were available for seven of the remaining nine patients and demonstrated a stable construct with fusion in each patient.

The authors present an effective alternative method in which C1–3 lateral mass screw fixation is used to treat patients with unfavorable anatomy for atlantoaxial transarticular screw fixation. In this series of 10 patients, the method was a safe and effective way to provide stabilization in these anatomically difficult patients.
Intramedullary neuroma of the cervicomedullary junction
Authors: Santagata Sandro , Tuli Sagun , Wiese Don E. , Day Arthur , De Girolami Umberto
Published: January 2008

✓ Neuromas typically arise in the peripheral nervous system in response to traumatic injury at the site of partial or complete nerve transection as new axons from the proximal nerve stump sprout to reinnervate the distal segment. In rare cases neuromas have also been described as intramedullary spinal cord lesions. These lesions have been identified as incidental autopsy findings in association with prior trauma and cervical spondylosis, multiple sclerosis, spinal tumors, and syringomyelia.

The authors report the case of a 50-year-old man who had been involved in a motor vehicle accident, during which his car was struck from behind as it was stationary at an intersection, more than 5 years before presentation. A workup for syncopal and presyncopal episodes involved magnetic resonance imaging that revealed a 1.1-cm lesion at the cervicomedullary junction (CMJ). The imaging features of the lesion raised the question of an ependymoma or subependymoma. The lesion was excised, and examination of the tissue demonstrated a neuroma with haphazardly arranged interlacing bundles of axons ensheathed by Schwann cells with interfascicular regions of reactive glial cells and Rosenthal fibers, consistent with those present after traumatic injury. This case may represent the first true traumatic intramedullary neuroma of the CMJ diagnosed in a living patient and treated surgically.
Split–spinous process laminotomy and discectomy for degenerative lumbar spinal stenosis: a preliminary report
Authors: Cho Der-Yang , Lin Hung-Lin , Lee Wen-Yuan , Lee Han-Chung
Published: January 2008

Object

The authors evaluated a new minimally invasive spinal surgery technique to correct degenerative lumbar spinal stenosis involving a split–spinous process laminotomy and discectomy (also known as the “Marmot operation”).

Methods

This prospective study randomized 70 patients with lumbar stenosis to undergo either a Marmot operation (40 patients), or a conventional laminectomy (30 patients), with or without discectomy. Spinal anteroposteri-or diameter, cross-sectional area, lateral recess distance, spinal stability, postoperative back pain, functional outcomes, and muscular trauma were evaluated. The follow up ranged from 10 to 18 months, with a mean of 15.1 months for the Marmot operation group and 14.8 months for the conventional laminectomy group.

Compared with patients in the conventional laminectomy group, patients who received a Marmot operation had a shorter mean postoperative duration until ambulation without assistance, a reduced mean duration of hospital stay, a lower mean creatine phosphokinase–muscular-type isoenzyme level, a lower visual analog scale score for back pain at 1-year follow up, and a better recovery rate. These patients also had a longer mean duration of operative time and a greater mean blood loss compared with the conventional group. Satisfactory neurological decompression and symptom relief were achieved in 93% of these patients. Most of the patients (66%) in this group needed discectomy for decompression. The postoperative mean lateral recess width, spinal anteroposterior diameter, and cross-sectional area were all significantly increased. There was no evidence of spinal instability in any patient. One patient with insufficient lateral recess decompression and recurrent disc herniation needed additional conventional laminectomy and discectomy, and one patient with mild superficial wound infection was successfully treated with antibiotics and frequent dressing changes.

Conclusions

A Marmot operation may provide effective spinal decompression. Although this method requires more operative time than a conventional method, it may involve only minimal muscular trauma, spinal stability maintenance, and early mobilization; shorten the duration of hospital stay; reduce postoperative back pain; and provide satisfactory neurological and functional outcomes.
Public Lifestyle in the Low‐Density City
Authors: Wall Alex
Published: January 2008

Much maligned, shopping centres have come to represent many of the negative aspects of low‐density areas. They are all too often associated with high car dependency and a paucity of cultural and public amenities. Alex Wall questions this preconception. Could the well‐conceived and designed shopping centre actually prove to be urban sprawl's redemption?. Copyright © 2008 John Wiley & Sons, Ltd.
In the Our Beautiful Future
Authors: Rosler Martha
Published: January 2008

Martha Rosler describes Oleanna, a collaborative project, manifested in part at the 2003 Venice Biennale, that joined together students and artists in imagining alternative publics to ‘rescue the utopian hopes of modernity’. Copyright © 2008 John Wiley & Sons, Ltd.
Ville‐Port, Saint‐Nazaire The Historic Periphery
Authors: de Solá‐Morales Manuel
Published: January 2008

The harbour town of Saint‐Nazaire on the Atlantic coast of Brittany in northern France remains divided both by its memories and its built environment. Manuel de Solá‐Morales describes how his Ville‐Port project seeks to address the structural, visual and mnemonic divisions that have grown up over time between a working port and seaside resort. Copyright © 2008 John Wiley & Sons, Ltd.
Architecture and Dispersal
Authors: Segal Rafi , Verbakel Els , Allen Stan , Smets Marcel , Whiting Sarah , Crawford Margaret
Published: January 2008

To close the issue, guest‐editors Rafi Segal and Els Verbakel curated a discussion with Stan Allen, Margaret Crawford, Marcel Smets and Sarah Whiting, and put some provocative questions to them: What constitutes public space in the contemporary city? Can the public sphere still exist in the urban context? Should public space be fought for by architects and urban designers? Or, as Allen proposes, is it the landscape architects alone who have been quick to realise the potential of the empty spaces in our cities as a ripe terrain for change? Copyright © 2008 John Wiley & Sons, Ltd.
Putting the ‘I’ back into Architecture
Authors: Spiller Neil
Published: January 2008

Neil Spiller gets personal in a bid to put the ‘I’ back into architecture. He celebrates the spatial experimentation of the work of Charlotte Erckrath. Creating a space of desire, she produces a subjective ‘synthesis of architect, body, space and view’. Copyright © 2008 John Wiley & Sons, Ltd.
Thermodynamics of salt lake system: Representation, experiments, and visualization
Authors: Kwok Kui S. , Ng Ka M. , Taboada Maria E. , Cisternas Luis A.
Published: January 2008

A coherent, systematic approach for the determination of solid–liquid phase behavior of a multi‐component salt lake system for use in the synthesis of crystallization process is presented. It centers on the thermodynamics of such a salt lake system and integrates three interrelated activities—representation of the system phase behavior as a phase diagram/thermodynamic model, experimental determination of the necessary data and visualization of the relevant crystallization regions. To illustrate this approach, the thermodynamics of a simplified salt lake system Li+, Na+, K+, Mg2+//Cl−, SO42− ‐H2O at 25°C and 1 atm was determined. The identification of process alternatives using the resulting phase diagram for recovering Li2SO4·H2O was also illustrated. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Electrochemical Alternatives for Drinking Water Disinfection
Authors: Martínez‐Huitle Carlos A. , Brillas Enric
Published: January 2008

Chlorination is the most common method worldwide for the disinfection of drinking water. However, the identification of potentially toxic products from this method has encouraged the development of alternative disinfection technologies. Among them, electrochemical disinfection has emerged as one of the more feasible alternatives to chlorination. This article reviews electrochemical systems that can contribute to drinking water disinfection and underscores the efficiency of recently developed diamond films in chlorine‐free electrochemical systems.
Assessing an author's influence using time series historiographic mapping: The oeuvre of conrad hal waddington (1905–1975)
Authors: McCain Katherine W.
Published: January 2008

A modified approach to algorithmic historiography is used to investigate the changing influence of the work of Conrad Hal Waddington over the period 1945–2004. Overall, Waddington's publications were cited by almost 5,500 source items in the Web of Science (Thomson Scientific, formerly Thomson ISI, Philadelphia, PA). Rather than simply analyzing the data set as a whole, older works by Waddington are incorporated into a series of historiographic maps (networks of highly cited documents), which show long‐term and short‐term research themes grounded in Waddington's work. Analysis by 10–20‐year periods and the use of social network analysis soft‐ ware reveals structures—thematic networks and subnetworks—that are hidden in a mapping of the entire 60‐year period. Two major Waddington‐related themes emerge—canalization/genetic assimilation and embryonic induction. The first persists over the 60 years studied while active, visible research in the second appears to have declined markedly between 1965 and 1984, only to reappear in conjunction with the emergence of a new research field—Evolutionary Developmental Biology.
4‐(Dimethylamino)pyridine N‐oxide (DMAPO): An Effective Nucleophilic Catalyst in the Peptide Coupling Reaction with 2‐Methyl‐6‐nitrobenzoic Anhydride
Authors: Shiina Isamu , Ushiyama Hisaya , Yamada Yo‐ko , Kawakita Yo‐ichi , Nakata Kenya
Published: January 2008

Various carboxamides or peptides were synthesized from the corresponding carboxylic acids and amines or α‐amino acids in high yields by the catalysis of 4‐(dimethylamino)pyridine N‐oxide (DMAPO) with 2‐methyl‐6‐nitrobenzoic anhydride (MNBA). Because the segment‐coupling reaction of α‐amino acids proceeds through the effective activation of the carboxylic acid moieties with DMAPO in the presence of tertiary amines under mild conditions, undesired racemization was hardly observed in the synthesis of oligopeptides such as Z‐Gly‐Phe‐Val‐OMe, Z‐Phe‐Val‐Ala‐OMe, and Bz‐Val‐Val‐OMe.
Using green and red fluorescent proteins to teach protein expression, purification, and crystallization
Authors: Wu Yifeng , Zhou Yangbin , Song Jiaping , Hu Xiaojian , Ding Yu , Zhang Zhihong
Published: January 2008

We have designed a laboratory curriculum using the green and red fluorescent proteins (GFP and RFP) to visualize the cloning, expression, chromatography purification, crystallization, and protease‐cleavage experiments of protein science. The EGFP and DsRed monomer (mDsRed)‐coding sequences were amplified by PCR and cloned into pMAL (MBP‐EGFP) or pT7His (His10‐mDsRed) prokaryotic expression vectors. Then the fluorescent proteins were expressed in Rosetta (DE3) pLysS by IPTG induction or autoinduction. We purified the fluorescent proteins by affinity chromatography (Amylose and metal ion‐chelating column), anion‐exchange chromatography (High Q column), size exclusive chromatography (Sephacryl S‐200 column), and hydrophobic interaction chromatography (Methyl HIC column) to exhibit the protein‐purification techniques. After purification, the fusion protein MBP‐EGFP was cleaved by TEV protease. The recombinant mDsRed protein was crystallized by hanging drop vapor diffusion technique to show students the basic operation of crystallization. The whole procedure can be monitored real time by naked eyes when using fluorescent proteins. The demonstration of expression, purification, crystallization, and protease cleavage became much more vivid and interesting, which greatly deepened the students' understanding of modern protein‐science techniques.
Actin immobilization on chitin for purifying myosin II
Authors: de Souza Marcelle Gomes , Grossi André Luiz , Pereira Elisângela Lima Bastos , da Cruz Carolina Oliveira , Mendes Fernanda Machado , Cameron Luiz Claudio , Paiva Carmen Lucia Antão
Published: January 2008

This article presents our experience on teaching biochemical sciences through an innovative approach that integrates concepts of molecular cell biology and protein chemistry. This original laboratory exercise is based on the preparation of an affinity chromatography column containing F‐actin molecules immobilized on chitin particles for purifying skeletal myosin II. It favors the active learning of protein extraction and purification, the learning of concepts such as muscle contraction, cytoskeleton structure, and its importance for the living cell. This laboratory exercise also promotes learning biotechnological applications of chitin and the applications of protein immobilization in different industrial fields. Furthermore, the activities target the development of laboratorial abilities, problem‐solving skills, and the ability to write a scientific report, following the model of a scientific article. The trials are mainly proposed for either an undergraduate project for advanced students in the life sciences or a postgraduate practical training course. In both the cases, the students must have had biochemistry as part of their regular curriculum. Alternatively, the affinity chromatography method can fit in any regular biochemistry course if active chitin, F‐actin, and a myosin II extract are provided. It is very important to mention that this laboratory exercise can be used even in places where a facility such as ultracentrifugation is lacking. For that, the steps of actin purification are skipped, and actin is commercially obtained. Therefore, it is an adequate approach for the active learning of biochemical and molecular cell biology principles and techniques even in poor countries.
ChemInform Abstract: Njaoamines G (Ia) and H (Ib), Two New Cytotoxic Polycyclic Alkaloids and a Tetrahydroquinolone (II) from the Marine Sponge Neopetrosia sp.
Authors: Sorek Hagit , Rudi Amira , Benayahu Yehuda , Kashman Yoel
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Simulation of Air Quality using an ISCST3 Dispersion Model
Authors: Sharma Sumit , Chandra Avinash
Published: January 2008

Urban air quality is an issue of major concern across many cities in India. In particular, high levels of particulate matter (both SPM and RSPM) are responsible for noncompliance to air quality standards. Air quality modeling is an effective tool to simulate the air quality of a region and to predict air quality concentrations under different scenarios. Kanpur city which is a top‐ten urban conglomerate in India (based on population) is chosen for the application of the ISCST3 model and simulation of air quality. Sectored emission loads are estimated for transport, industrial, power, and domestic sectors, which provide an estimate of the major contributors to air pollution with specific reference to particulate matter, which is a major pollutant of concern. A detailed scenario analysis is carried out to estimate the changes in emissions that would take place due to various interventions. Dispersion modeling is carried out using the ISCST3 model, to estimate the concentrations of SPM all over the city under different scenarios. Emission inventory and meteorological data served as input to the model, and the air quality is predicted for various seasons and intervention scenarios. The modeled values for the scenario without intervention results in an underestimation of 48%, which is due to unaccountable or unidentified sources, trans‐boundary movement of SPM, and model calibration errors. To overcome the error, the model is calibrated with the observed values and results are obtained for other scenarios using the calibration factor. The paper demonstrates only the research direction currently used to simulate air quality in Indian cities. However, further refinement and research is required before it could be used for more accurate predictions.
Fine Particles (PM2.5) in Residential Areas of Lucknow City and Factors Influencing the Concentration
Authors: Barman S. C. , Singh Ramesh , Negi M. P. S. , Bhargava S. K.
Published: January 2008

Urban populations are exposed to a high level of fine and ultrafine particles from motor vehicle emissions which affect human health. To assess the hourly variation of fine particle (PM2.5) concentration and the influence of temperature and relative humidity (RH) on the ambient air of Lucknow city, monitoring of PM2.5 along with temperature and RH was carried out at two residential locations, namely Vikas Nagar and Alambagh, during November 2005. The 24 h mean PM2.5 concentration at Alambagh was 131.74 μg/m3 and showed an increase of 13.74%, which was significantly higher (p < 0.05) than the Vikas Nagar level. The 24 h mean PM2.5 on weekdays for both locations was found to be 142.74 μg/m3 (an increase of 66.23%) which was significantly higher (p < 0.01) than the weekend value, indicating that vehicular pollution is one of the important sources of PM2.5. The mean PM2.5 at night for all the monitoring days was 157.69 μg/m3 and was significantly higher (p < 0.01) than the daytime concentration (89.87 μg/m3). Correlation and multiple regressions showed that the independent variables, i. e., time, temperature, and RH together accounted for 54%, whereas RH alone accounted for 53% of total variations of PM2.5, suggesting that RH is the best influencing variable to predict the PM2.5 concentration in the urban area of Lucknow city. The 24 h mean PM2.5 for all the monitoring days was found to be higher than the NAAQS recommended by the US‐EPA (65 μg/m3) and can be considered to be an alarming indicator of adverse health effects for city dwellers.
Sedimentary Phosphorus Form Distribution and Cycling in the Littoral Subzones of a Eutrophic Lake
Authors: Liu Honglei , Yin Chengqing , Wang Hongjun , Wang Weidong , Shan Baoqing
Published: January 2008

Algae which bloom in open water and accumulate in the littoral zones may affect the biogeochemical cycle of phosphorus in eutrophic lakes. To determine such effects, a part of the lakeshore with little allochthonous nutrient input in Taihu Lake, China was selected for this field study. Distinct differences in sedimentary P forms were found among the different littoral subzones. The surface sedimentary total phosphorus (TP) content was 655 mg/kg in the eulittoral subzone and 631 to 641 mg/kg in the infralittoral subzone. Both were much higher than that in the profundal zone (410 mg/kg). Calcium‐bound P (Ca‐P) was significantly correlated to exchangeable P (Ex‐P), and they both had the highest contents in the infralittoral subzone and the lowest in the profundal zone. The aluminum‐ and iron‐bound P (Al‐P, Fe‐P) contents decreased from land to water along the ecotone section. Lower Fe/P ratios and higher Al‐P/Fe‐P ratios appeared in the infralittoral subzone, as compared with the profundal zone. This suggested that the accumulated algae could lead to a great deposit of P in the littoral zones. However, the active sedimentary P form transformation in the littoral zones would also result in a partial release of the accumulated P to the overlying water.
Nutrient Recovery from Human Urine Using Pretreated Zeolite and Struvite Precipitation in Combination with Freezing‐Thawing and Plant Availability Tests on Common Wheat
Authors: Ganrot Zsófia , Slivka Andreas , Dave Göran
Published: January 2008

The nutrient rich fractions in wastewater originating from human urine and can be recovered as solids for more efficient recycling, facilitated handling and storage for reuse in agriculture. Freezing and thawing can be used to concentrate the urine nutrients. Phosphorus (P) and nitrogen (N) can be precipitated as struvite [(Mg,Ca)(K,NH4)(PO4)·6H2O] by adding MgO and additional nitrogen can be recovered by using zeolites. The zeolite in this study was pretreated in two ways: (i) washed and (ii) washed and thermally treated. The P recovery was high (> 97%) and the N recovery was ca. 50 to 60%. There was no significant difference in the nitrogen recovery among the different pretreated zeolites or between the pretreated and the untreated zeolite. Freezing had a positive effect on the nutrient concentration. The acute toxicity of the supernatants was tested on Daphnia magna to evaluate the possibilities of discharging the remaining supernatants to a recipient. The supernatants from the frozen treatments and from the unfrozen and washed zeolites were much less toxic than those of the original urine. The minerals acted as slow‐release fertilizers in climate chamber tests on spring wheat.
Behavior of Steroid Hormones and Conjugates During Wastewater Treatment – A Comparison of Three Sewage Treatment Plants
Authors: Schlüsener Michael P. , Bester Kai
Published: January 2008

The fate of the steroid hormones 17 β‐estradiol, estrone, estriol, 16 α‐hydroxyestrone, and β‐estradiol 17‐acetate, the hormone‐conjugates β‐estradiol 3‐sulfate and estrone 3‐sulfate, and the oral contraceptives 17 α‐ethinylestradiol and mestranol were studied during wastewater treatment as wastewater treatment plants are the major source contamination of urban surface waters with steroid hormones. The elimination efficiencies of three different concepts of WWTPs, i. e., activated sludge versus trickling filter, were compared over four weeks at different weather conditions. While larger WWTPs operating on activated sludge eliminated hormones more constantly than smaller WWTPs, heavy rainfall events led to a collapse of the elimination efficiency. By using trickling filter techniques for the treatment of wastewater an elimination of the steroid hormones could not be observed. Additionally, mass flows on a per person basis are compared. In the three experiments, which ran continuously for four weeks each, it turned out that the concentrations of ethinylestradiol and mestranol were below 6 ng/L in all samples. The inflow concentrations were 70 to 82 ng/L (estrone), 17 to 44 ng/L (estradiol), 61 to 130 ng/L (hydroxyestrone), 189 to 255 ng/L (estriol), 10 to 17 ng/L (estrone‐3‐sulfate) and about 28 ng/L (estradiol‐3‐ sulfate). While in the activated sludge treatment plants the elimination of estrone was 90 and 50%, respectively, estrone was formed from precursors in the trickling filter plant. A similar situation occurred for 17β‐estradiol, estrone 3‐sulfate, and estradiol 3‐sulfate. Hydroxyestrone was eliminated with similar efficiencies in all wastewater treatment plants (64 to 82%), as well as estriol (34 to 69%). Accordingly, the emissions of the wastewater treatment plants differed largely and were not attributed to the size of the respective plant, only.
On decoupled time step/subcycling and iteration strategies for multiphysics problems
Authors: Valli A. M. P. , Carey G. F. , Coutinho A. L. G. A.
Published: January 2008

This work investigates partitioned iterative solution of coupled multiphysics systems including subcycling time‐stepping strategies for decoupled subsystems in conjunction with a proportional‐integral‐derivative feedback control algorithm for adaptive time‐step selection. Some basic algorithms are proposed and the total computational effort to integrate to steady state is compared for a representative coupled flow and heat transfer problem to illustrate the approach and assess performance efficiency. Copyright © 2008 John Wiley & Sons, Ltd.
Thermal and mechanical numerical modelling of electric discharge machining process
Authors: Salah Nizar Ben , Ghanem Farhat , Atig Kaïs Ben
Published: January 2008

In electric discharge machining (EDM), the heat gradients caused by the electric discharge create a non‐uniform local thermal expansion on the level of the surface layers of machined materials from where genesis of thermal stresses takes place. These thermal stresses, if exceeding yield stress, can remain and become residual after the cooling of the part. The modelling of these phenomena, during the heating by the electric discharge and the cooling by the dielectric liquid, requires a heat transfer model, the material behaviour identification, a thermo‐mechanical model for the thermal and the residual stress models.

This paper presents numerical results concerning the temperature distribution, the thermal and residual stresses of a stable steel material (AISI316L) machined by EDM. Comparison of numerical results with experimental data and numerical results from the literature shows good agreement and is hence quite satisfactory. Copyright © 2008 John Wiley & Sons, Ltd.
Electrochemical Determination of L‐Lactate Using Phenylboronic Acid Monolayer‐Modified Electrodes
Authors: Takahashi Shigehiro , Kurosawa Shiho , Anzai Jun‐ichi
Published: January 2008

The surface of a gold (Au) disk electrode was modified with a self‐assembled monomolecular layer of dithiobis(4‐butylamino‐m‐phenylboronic acid) (DTBA‐PBA) to prepare L‐lactate‐sensitive electrodes. The DTBA‐PBA‐modified electrodes exhibited an attenuated cyclic voltammogram (CV) for the Fe(CN)63− ion in the presence of L‐lactate, as a result of the formation of phenylboronate ester of L‐lactate accompanied with the addition of OH− ion to the boron atom. In other words, the negatively charged DTBA‐PBA monolayer blocked the electrode surface from the access of the Fe(CN)63−/4− ions. Thus, the DTBA‐PBA monolayer‐modified Au electrode can be used for determining L‐lactate on the basis of the change in redox current of Fe(CN)63−/4− ions. The calibration graph useful for determining 1–30 mM L‐lactate was obtained.
Voltammetry of Selenium(+4) in Atmospheric Precipitates
Authors: Zelić Marina
Published: January 2008

Using square‐wave cathodic stripping voltammetry on a hanging mercury drop electrode, selenium(+4) was measured in rainwater samples and snow melts. The ratio of peak currents, obtained from filtered and nonfiltered fractions of the same sample, could be even three, but standard addition method indicates the same initial concentration in both cases. The influence of filtration is explained in terms of decreased surfactant level. From one of the samples, double peaks of unknown origin were obtained. They reflect two irreversible processes which are not fully independent. Possible explanation includes two modifications of the same deposit, formed during accumulation step. The influence of surfactants and/or other organic compounds on the signal of interest could perhaps be useful in various studies of organic matter, dissolved in rainwater or snow melt.
A Facile Preparation of H2O2 Sensors Using Layer‐by‐Layer Deposited Thin Films Composed of Poly(ethyleneimine) and Carboxymethyl Cellulose as Matrices for Immobilizing Hemin
Authors: Wang Baozhen , Du Xiaoyan , Wang Maoqing , Gong Weilei , Anzai Jun‐ichi
Published: January 2008

A layer‐by‐layer (LbL) thin film composed of poly(ethyleneimine) (PEI) and carboxymethyl cellulose (CMC) was prepared on the surface of a gold (Au) disk electrode and the LbL layer was impregnated with hemin to fabricate amperometric hydrogen peroxide (H2O2) sensors. Hemin can be easily immobilized in the LbL layer by immersing the LbL film‐coated electrode in the hemin solution. The hemin‐modified electrode thus prepared exhibited an amperometric response to H2O2 on the basis of the electrochemical reduction catalyzed by hemin. The output current of the hemin‐modified electrode depended on the concentration of H2O2 over the range of 0.005–1.0 mM. Thus, the LbL film composed of PEI and CMC was found to be an excellent material for the facile preparation of hemin‐based H2O2 sensors.
Concentration polarization and nonequilibrium electroosmotic slip in hierarchical monolithic structures
Authors: Nischang Ivo , Höltzel Alexandra , Seidel‐Morgenstern Andreas , Tallarek Ulrich
Published: January 2008

This article illustrates the appearance and electrohydrodynamic consequences of concentration polarization (CP) in hierarchically structured monolithic fixed beds used as stationary phases in CEC and related electrical‐field‐assisted separation techniques. Subject of the investigation are silica‐based monoliths in capillary format with a bimodal pore size distribution. Ion‐permselectivity in the intraskeleton pore space together with diffusive and electrokinetic transport induces depleted and enriched CP zones at the anodic and cathodic interfaces, respectively, of the cation‐selective mesoporous skeleton. The extent of electrical‐field‐induced CP is shown to be governed by the fluid phase ionic strength, which tunes the ion‐permselectivity of the mesoporous monolith skeleton via local electrical double layer overlap, and by the applied electrical field strength, which determines local transport. The analysis of quantitative confocal laser scanning microscopy data, resolving CP on the local skeleton scale, indicates that at sufficiently high field strength a transition from intraskeleton to interskeleton boundary‐layer‐dominated transport of charged species occurs. This transition is correlated to the onset of macroscopically measured, nonlinear EOF velocities, whose occurrence is explained in the framework of a nonequilibrium electroosmotic slip. It is shown that the onset of nonlinear electrokinetics in the system can be tuned by properties of the BGE, particularly buffer pH, which modulates the pH‐dependent surface charge density and consequently the ion‐permselective skeleton's charge selectivity. Finally, the CP dynamics of monolithic and particulate fixed beds are compared, and the observed differences are related to the specific morphologies of the two hierarchical fixed bed structures.
CD161 expression on hepatitis C virus–specific CD8+ T cells suggests a distinct pathway of T cell differentiation
Authors: Northfield John W. , Kasprowicz Victoria , Lucas Michaela , Kersting Nadine , Bengsh Bertram , Kim Arthur , Phillips Rodney E. , Walker Bruce D. , Thimme Robert , Lauer Georg , Klenerman Paul
Published: January 2008

Hepatitis C virus (HCV) causes chronic infection accompanied by a high risk of liver failure and hepatocellular carcinoma. CD8+ T cell responses are important in the control of viremia. However, the T cell response in chronic infection is weak both in absolute numbers and in the range of epitopes targeted. In order to explore the biology of this response further, we analyzed expression of a panel of natural killer cell markers in HCV compared with other virus-specific T cell populations as defined by major histocompatibility complex class I tetramers. We found that CD161 was significantly expressed on HCV-specific cells (median 16.8%) but not on CD8+ T cells specific for human immunodeficiency virus (3.3%), cytomegalovirus (3.4%), or influenza (3.4%). Expression was seen in acute, chronic, and resolved disease and was greatest on intrahepatic HCV-specific T cells (median 57.6%;

P

< 0.05). Expression of CD161 was also found on hepatitis B virus–specific CD8+ T cells. In general, CD161+CD8+ T cells were found to be CCR7− “effector memory” T cells that could produce proinflammatory cytokines (interferon-γ and tumor necrosis factor-α) but contained scanty amounts of cytolytic molecules (granzyme B and perforin) and proliferated poorly in vitro. Expression of CD161 on CD8+ T cells was tightly linked to that of CXCR6, a chemokine with a major role in liver homing.

Conclusion:

We propose that expression of CD161 indicates a unique pattern of T cell differentiation that might help elucidate the mechanisms of HCV immunity and pathogenesis. (Hepatology 2008;47:396–406.)
Further Highly Oxygenated Guaiane Lactones from the South China Sea Gorgonian Menella sp.
Authors: Li Liang , Wang Chang‐Yun , Huang Hui , Mollo Ernesto , Cimino Guido , Guo Yue‐Wei
Published: January 2008

Four new highly oxygenated guaiane lactones, 1‐epimenverin B (1), menverin F (2), 1‐deoxymenverin F (3), and menverin G (4), together with the two known related analogues menverins B (5) and C (6), were isolated from the South China Sea gorgonian Menella sp. Their structures and relative configuration were elucidated by analysis of spectroscopic data and by comparison with those of known related compounds.
Three Novel Compounds from the Flowers of Bombax malabaricum
Authors: Wu Jun , Zhang Xiao‐Hui , Zhang Shu‐Wei , Xuan Li‐Jiang
Published: January 2008

Two unusual 9′‐norneolignans, bombasin (1) and bombasin 4‐O‐β‐glucoside (2), and a novel D‐gulono‐γ‐lactone derivative, bombalin (3), were isolated from the flowers of Bombax malabaricum, together with the three known compounds dihydrodehydrodiconiferyl alcohol 4‐O‐β‐D‐glucopyranoside (4), trans‐3‐(p‐coumaroyl)quinic acid (5), and neochlorogenic acid (6). Their structures were elucidated by extensive spectroscopic methods as well as chemical transformation. Compounds 1–3 were evaluated against the HGC‐27 gastrointestinal and Hela cervical human cancer cell lines, but all were inactive in both lines (IC50>50 μM).
Synthesis of 4‐(Isothiazol‐3‐yl)morpholines and 1‐(Isothiazol‐3‐yl)piperazines, and Their Inhibitory Activity towards Acetylcholinesterase
Authors: Wolf Janine , Tanarro Camino M. González , Gütschow Michael , Sieler Joachim , Schulze Bärbel
Published: January 2008

The synthesis of novel triaryl‐substituted 4‐(isothiazol‐3‐yl)morpholines 7 and 8, and 1‐(isothiazol‐3‐yl)piperazines 9–13 by reaction of the corresponding isothiazolium salts 5 and 6 with secondary amines in the presence of t‐BuOK in absolute THF is described. Some representatives of the isothiazoles were evaluated as inhibitors of acetylcholinesterase from Electrophorus electricus.
A One‐Pot Synthesis of 1,3‐Dihydro‐1,3,3‐tris(perfluoroalkyl)isobenzofuran‐1‐olates and Their Complete NMR Spectroscopic Analysis on the Basis of 1D and 2D Experiments
Authors: Tyrra Wieland , Scherer Harald , Babadzhanova Lesya A. , Kirij Natalya V. , Yagupolskii Yurii L. , Naumann Dieter , Pantenburg Ingo
Published: January 2008

A convenient synthesis of the 1,3‐dihydro‐1,3,3‐tris(perfluoroalkyl)isobenzofuran‐1‐ols 3a,b was elaborated starting from commercially available phthaloyl dichloride and trimethyl(perfluoroalkyl)silanes (Me3SiRf) 1a,b (Rf=CF3, C2F5) in the presence of a fluoride source (Schemes 1 and 3). In a reaction analogous to alkyl Grignard reagents, double chloride substitution by two perfluoroalkyl groups and subsequent addition of one perfluoroalkyl group with concomitant ring closure led to this new class of compounds (Scheme 2). The syntheses of the alcohols and some alcoholates, as well as of the corresponding trimethylsilyl ethers are described. A combination of special 1D and 2D NMR experiments allowed the assignment of all atoms of the new compounds. The solid‐state structure of 1,3‐dihydro‐1,3,3‐tris(trifluoromethyl)isobenzofuran‐1‐ol (3a) was elucidated by X‐ray diffraction methods.
Age‐related and zonal anatomical changes of apparent diffusion coefficient values in normal human prostatic tissues
Authors: Tamada Tsutomu , Sone Teruki , Toshimitsu Shinya , Imai Shigeki , Jo Yoshimasa , Yoshida Koji , Yamamoto Akira , Yamashita Takenori , Egashira Naoto , Nagai Kiyohisa , Fukunaga Masao
Published: January 2008

Purpose

To identify age‐related changes and differences in the diffusion of water molecules within the prostate, through diffusion‐weighted imaging (DWI) of the prostate gland in healthy adult Japanese men.

Materials and Methods

A total of 114 healthy male volunteers (mean age, 55 years; range, 24–81 years) underwent DWI of the prostate with a single‐shot echo‐planar imaging (EPI) sequence using b‐factors of 0 and 1000 seconds/mm2. Apparent diffusion coefficient (ADC) values of six locations in the peripheral zone (PZ) and two locations in the central gland (CG) were measured and correlations between region and age were examined.

Results

ADC values measured within both PZ and CG regions of the prostate showed a uniform distribution, and no significant differences were found between evaluated regions. However, mean ADC values were 1.64 ± 0.27 ×10−3 mm2/second for PZ and 1.26 ± 0.12 ×10−3 mm2/second for CG, representing a significant difference. In addition, significant positive correlations were identified between ADC values for both PZ and CG regions and subject age (r = 0.526, P < 0.0001; r = 0.190, P = 0.0431, respectively).

Conclusion

ADC values within both PZ and CG regions of the prostate increase with age, and this must be taken into consideration when using DWI in the diagnosis of prostate cancer. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
Comparison of parallel acquisition techniques generalized autocalibrating partially parallel acquisitions (GRAPPA) and modified sensitivity encoding (mSENSE) in functional MRI (fMRI) at 3T
Authors: Preibisch Christine , Wallenhorst Tim , Heidemann Robin , Zanella Friedhelm E. , Lanfermann Heinrich
Published: January 2008

Purpose

To evaluate the parallel acquisition techniques, generalized autocalibrating partially parallel acquisitions (GRAPPA) and modified sensitivity encoding (mSENSE), and determine imaging parameters maximizing sensitivity toward functional activation at 3T.

Materials and Methods

A total of eight imaging protocols with different parallel imaging techniques (GRAPPA and mSENSE) and reduction factors (R = 1, 2, 3) were compared at different matrix sizes (64 and 128) with respect to temporal noise characteristics, artifact behavior, and sensitivity toward functional activation.

Results

Echo planar imaging (EPI) with GRAPPA and a reduction factor of 2 revealed similar image quality and sensitivity than full k‐space EPI. A higher incidence of artifacts and a marked sensitivity loss occurred at R = 3. Even though the same eight‐channel head coil was used for signal detection in all experiments, GRAPPA generally showed more benign patterns of spatially‐varying noise amplification, and mSENSE was also more susceptible to residual unfolding artifacts than GRAPPA.

Conclusion

At 3T and a reduction factor of 2, parallel imaging can be used with only little penalty with regard to sensitivity. With our implementation and coil setup the performance of GRAPPA was clearly superior to mSENSE. Thus, it seems advisable to pay special attention to the employed parallel imaging method and its implementation. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
MRI‐guided interventions of the breast
Authors: Kaiser Werner A. , Pfleiderer Stefan O.R. , Baltzer Pascal A.T.
Published: January 2008

MRI has proven to be a very reliable diagnostic tool in the detection and differential diagnosis of breast lesions. Some lesions are, even in retrospect, not detectable in x‐ray or ultrasound images but MRI is able to detect lesions at a much smaller size than the average size of lesions depicted by x‐ray and ultrasound. The aim in the future is to develop combined procedures where imaging, biopsy, and interventional therapies are combined in a single outpatient procedure. As a step toward this goal different interventional procedures are useful that include interstitial laser therapy (ILT), radiofrequency ablation (RFA), high‐intensity focused ultrasound (HIFU), microwave ablation therapy, and cryotherapy. In this overview the main features and initial results of these procedures are described and discussed. J. Magn. Reson. Imaging 2008;27:347–355. © 2008 Wiley‐Liss, Inc.
E protein dosage influences brain development more than family member identity
Authors: Ravanpay Ali C. , Olson James M.
Published: January 2008

Loss‐of‐function studies have revealed the role of many basic helix‐loop‐helix (bHLH) transcription factors at specific points during development; however, the role of E proteins in the development of the nervous system has not been experimentally addressed. E proteins have been speculated to interact selectively with class II bHLH factors to form different neurogenic complexes. In this study, using coimmunoprecipitation in a culture model of neurogenesis (P19 cells), we show that E proteins E12, HEB, and E2‐2 interact with neuroD2. Using electrophoretic mobility shift assay and P19 cell culture, we show that these heterodimers bind a neuroD2 preferred E box and induce neurogenesis equally well. We examine the mRNA levels of the three E proteins at 10 time points during brain development and show that E protein gene expression is regulated such that at certain times during development selective interaction between neuroD2 and a single E protein (HEB) is a possibility. This led us to study the brains of HEB and E2A knockout mice, which manifest no gross neuroanatomical, cellular, or behavioral deficits. These findings, together with homology in the primary peptide sequence of E proteins, suggest functional compensation among E proteins during development of the nervous system. © 2008 Wiley‐Liss, Inc.
Hydroclimatic variability across the Susquehanna River Basin, USA, since the 17th century
Authors: Leathers Daniel J. , Malin Melissa L. , Kluver Daria B. , Henderson Gina R. , Bogart Tianna A.
Published: January 2008

The Susquehanna River Basin (SRB) is an extensive river drainage network that covers a total of 71 228 km2 in portions of New York, Pennsylvania, and Maryland, with more than 4 million inhabitants. It is the major source of fresh water to the USA's largest estuary, the Chesapeake Bay. Therefore, the hydroclimatic conditions within the SRB affect a large human population in addition to the ecological health of one of the world's most complicated and important estuarine environments.

This research project seeks to document the hydroclimatic history of the SRB and to understand the relationships between global‐scale forcing mechanisms and the climatic variability of the Basin. Hydroclimatic variability since 1680 is documented through the reconstruction of temperature, precipitation, streamflow and a drought index using proxy and observational data. Results indicate that the hydroclimatic history of the SRB is very complex. Prior to the advent of European settlement, the SRB seems to have responded in concert with other landmasses within the North Atlantic Sector evidencing a regional manifestation of both the Medieval Warm Period and the Little Ice Age. Since the beginning of European settlement, the hydroclimate of the SRB has varied greatly on both inter‐annual and decadal time scales. The climatic variability of the SRB is found to be only weakly associated with large‐scale forcing mechanisms that are commonly assumed to influence the eastern USA. A notable exception is a strong temperature response associated with volcanic activity. Thus, regional forcings and land cover variations may play an important role in the hydroclimatic variability of this important river system. Copyright © 2008 Royal Meteorological Society
Using electrophoretic mobility and bead modeling to characterize the charge and secondary structure of peptides
Authors: Pei Hongxia , Xin Yao , Allison Stuart A.
Published: January 2008

Using a modeling methodology developed in our laboratory previously, the free solution electrophoretic mobilities of several peptides are examined to see what they can tell us about: (i) the pKas of specific side groups, and (ii) possible secondary structure. Modeling is first applied to mobility versus pH data of several small peptides (Messana, I. et al., J. Chromatogr. B 1997, 699, 149) where the only adjustable parameter associated with the charge state of the peptide is the pKa of the C‐terminal. In addition to examining this parameter, the question of possible secondary structure is addressed. For two of the peptides considered, GGNA and GGQA, it is possible to account for the observed mobilities using “random” models with little restriction on the allowed range of Phi–Psi angles. For GGRA and RPPGF, “compact” models (possibly involving an I‐turn) must be used to match modeling mobilities with experiment. Finally, three more complicated peptides ranging in size from 15 to 20 amino acids are also examined and characterized (Sitaram, B. R. et al., J. Chromatogr. A 1999, 857, 263). Here also, we find evidence of I‐turns or some other “compact” structure in two of the three peptides examined.
Prozess zur Anodisierung von Aluminiumbändern mit hoher elektrischer Durchschlagsspannung
Authors: Alisch G. , Wielage B. , Steinhäuser S. , Lampke Th. , Podlesak H. , Nickel D.
Published: January 2008

Die Forschungsarbeiten hatten das Ziel, einen Prozess zu entwickeln, der die Erzeugung einer hohen elektrischen Durchschlagsfestigkeit in kürzester Prozesszeit auf Aluminiumbändern ermöglicht. Um in den Versuchen die Prozessparameter in einem breiten Bereich zu variieren, wurde gemeinsam mit der Fa. Steinert Elektromagnetbau GmbH Köln eine flexible diskontinuierliche Laboranlage konzipiert. Durch die Anwendung des Flüssigleiterprinzips ließ sich in diesem Equipment die in kontinuierlichen Anlagen praktizierte festkontaktfreie Anodisierung von Aluminiumbändern nachempfinden. Die Entwicklungsarbeiten konzentrierten sich auf die Gestaltung der Stromform. Anhand der Ergebnisse wird deutlich, dass es durch geeignete elektrische Parameter (Stromformen) in Verbindung mit einer entsprechenden Nachbehandlung möglich ist, höchste Durchschlagsspannungen in kürzester Prozesszeit zu erreichen. Die nach der neuen Technologie (Stromform TUCAL) erzeugten Schichten weisen zudem eine höhere Porendichte als die konventionell hergestellten auf, was sich in einer höheren Duktilität (geringeren Rissanfälligkeit) niederschlägt.