bluuebunny/crossref_metadata_2025 huggingface dataset:
Polymer dose assessment using the streaming current detector
Authors: Abu‐Orf Mohammad M. , Dentel Steven K.
Published: October 2006

The streaming current detector(SCD) is an electrokinetic analyzer for characterizing charge properties of particles in aqueous suspension. Its use in water treatment is well established. This research evaluated its use for automatic monitoring of polymer dosage in three wastewater treatment facilities using centrifuges or belt filter presses for dewatering. Continuous SCD readings from the liquid stream (centrate or filtrate) and other process responses were recorded while imposing stepwise changes in the polymer dose. The polymer caused a transition from negative to positive charge in both the conditioned solids and the liquid stream. Near‐zero SCD readings coincided with optimal fullscale dewatering, as indicated by solids measurements and recoveries and by minima in filtrate turbidity, filtrate viscosity, conditioned solids filterability times, and (in some cases) capillary suction times. Thus, charge neutralization is a key mechanism in solids conditioning, and the SCD is suitable for monitoring of polymer dosage. For its use in automatic polymer dose control—evaluated in a subsequent phase of the study—modifications were required to provide more reliable continuous sampling.
Degradation of triethanolamine and chemical oxygen demand reduction in wastewater by photoactivated periodate
Authors: Weavers Linda K. , Hua Inez , Hoffmann Michael R.
Published: October 2006

The rapid reduction of chemical oxygen demand (COD) of industrial wastewater is achieved using a novel oxidant, periodate (IO4−), coupled with ultraviolet (UV) irradiation. The wastewater is characterized by a high COD, low total suspended solids, variable triethanolamine (TEA) concentrations, and low concentrations of iron and zinc. The use of periodate and UV irradiation with either aqueous TEA solutions or real wastewater is shown to be effective in reducing the COD to acceptable levels. The optimal pH for COD degradation is determined to be 7.6 because of the combined effects of pH on the speciation of TEA and IO4− Increasing the ratio of the initial concentrations of period ate to TEA, [IO4−]0/[TEA]0, increased the degradation rate up to an apparent saturation value. Irradiation with a 1 000‐W mercury‐xenon lamp increased the COD pseudo‐first‐order degradation rate constant by a factor of 5.5 for synthetic TEA solutions and 2.3 for industrial wastewater, compared to irradiation with a 1 000‐W xenon lamp.
Nitrification reactions in treatment of supernatant from dewatering of digested sludge
Authors: Mossakowska Agnes , Reinius Lars‐Gunnar , Hultman Bengt
Published: October 2006

Separate nitrification of the discarded water from dewatering of digested sludge has been studied at the Bromma wastewater treatment plant in Stockholm. Experimental studies were carried out in a sequencing batch reactor pilot plant. It was shown that a high nitrification rate could be obtained in the reactor, approximately 30 to 40 g NH4–N/kg mixed liquor volatile suspended solids·h. During the nitrification process, nitrite was accumulated until ammonium nitrogen was depleted in the reactor. When all ammonium had been oxidized, all nitrite could thereafter be completely oxidized to nitrate. By use of multivariate methodology, it was shown that nitrite accumulation was primarily caused by the initial concentration of ammonium and secondly by the oxygen concentration. The nitrification rate strongly depended on the oxygen concentration. The strong dependence of nitrification rates on oxygen concentration makes the process easy to control by using measurements of oxygen concentration, air flow, and pH.
Hydrogeochemical modeling of waters in Mogan and Eymir Lakes special environmental protection area, Ankara, Turkey
Authors: Camur M. Zeki , Yazicigil Hasan , Altinbilek Dogan H.
Published: October 2006

On the basis of water‐rock interactions, hydrogeochemical characteristics of spring, stream, wetland, and lake waters in the Mogan and Eymir Lakes special environmental protection area of Turkey were modeled using a reaction‐path simulation method. Geochemical characteristics of surface waters, mineralogical sources of ion concentrations in the springs, mixing, and evaporation/dilution relationships between the compositions of input flows and the lakes and between the compositions of inflows and wetlands were quantitatively determined. Major ion distributions in spring water reflect mineralogical characteristics of the lithologies that have been traversed by related springs before reaching the surface. Mixing and evaporation/dilution calculations show that approximately 41 to 83% of the ion concentrations in the Mogan Lake is provided by groundwater and the remaining is supplied by streams. In addition to the mixing, cation exchange and carbon dioxide (CO2) outgasing reactions are also required to obtain the observed lake composition. Chemistry of the wetland waters provided by Mogan Lake by way of groundwater and the regulator canal is primarily controlled by CO2 ingasing and exchange reactions. Small amounts of dilution by other sources are also required. The majority of ion concentrations in Eymir Lake water, on the other hand, is supplied by the wetland area. Ion concentration contributions of groundwater from other areas to the Eymir Lake are calculated to be approximately 8 to 59% of the total input. Silica precipitation, exchange, and evaporation are the effective processes in the production of Eymir Lake water concentrations. In general, the ranges of model results are consistent with those of hydrological data.
Environmental monitoring of the North Porto Alegre landfill, Brazil
Authors: Kuajara O. , Sanchez J.C.D. , Ballestrin R.A. , Teixeira E.C.
Published: October 2006

In 1990, the administration of Porto Alegre, Brazil, declared a state of public emergency because its large landfills were not fit for operation. Almost 1 000 tid of domestic, industrial, and hospital wastes were being sent to the Porto Alegre landfill. Potential hazards to the local water resources have resulted because the landfill, besides receiving these wastes indiscriminately, was not equipped with a drainage or leachate treatment system. In addition, the waste disposal was not conducted orderly, thus rendering monitoring of the area practically unfeasible. Because of the difficulties in finding new suitable sites for waste disposal, the city administration opted to recover its northern landfill using an accelerated solid waste stabilization technique. This work assesses the results from the monitoring during the first 3 years of implementation of this technique. Chemical oxygen demand (COD), biochemical oxygen demand (BOD5), dissolved oxygen (DO), pH, nitrogenous series, phosphate, conductivity, alkalinity, total residue, and heavy metals (Al, Ag, Ba, Cd, Cu, Cr, Fe, Hg, Mn, Ni, Pb, and Zn) were determined in the surface water, groundwater, and leachate. Biogas samples taken directly from the flares installed in the various cells were analyzed for CH4, CO2, CO, H2, O2, and N2.
Evaluation of safety and pharmacokinetics of vancomycin after intraosseous regional limb perfusion and comparison of results with those obtained after intravenous regional limb perfusion in horses
Authors: Rubio-Martínez Luis M. , López-Sanromán Javier , Cruz Antonio M. , Tendillo Francisco , Rioja Eva , Román Fidel San
Published: October 2006

Objective—To evaluate the clinical effects and pharmacokinetics of vancomycin in plasma and synovial fluid after intraosseous regional limb perfusion (IORLP) in horses and to compare results with those obtained after IV regional limb perfusion (IVRLP).

Animals—6 horses.

Procedures—1 forelimb of each horse received vancomycin hydrochloride (300 mg in 60 mL of saline [0.9% NaCl] solution) via IORLP; the contralateral limb received 60 mL of saline solution (control). Solutions were injected into the medullary cavity of the distal portion of the third metacarpal bone. Synovial fluid from the metacarpophalangeal (MTCP) and distal interphalangeal (DIP) joints and blood were collected prior to perfusion and 15, 30, 45, 65, and 90 minutes after beginning IORLP, and synovial fluid from the MTCP joint only and blood were collected 4, 8, 12, and 24 hours after beginning IORLP. Plasma urea and creatinine concentrations and clinical appearance of the MTCP joint region and infusion sites were determined daily for 7 days. Results were compared with those of a separate IVRLP study.

Results—Clinical complications were not observed after IORLP. Mean vancomycin concentration in the MTCP joint was 4 μg/mL for 24 hours after IORLP. Compared with IORLP, higher vancomycin concentrations were detected in the DIP joint after IVRLP. Compared with IVRLP, higher vancomycin concentrations were detected in the MTCP joint for a longer duration after IORLP.

Conclusions and Clinical Relevance—IORLP with 300 mg of vancomycin in a 0.5% solution was safe and may be clinically useful in horses. Intravenous and intraosseous routes may be better indicated for infectious processes in the DIP and MTCP joints, respectively.
Effects of thermal energy on chondrocyte viability
Authors: Voss Jessica R. , Lu Yan , Edwards Ryland B. , Bogdanske John J. , Markel Mark D.
Published: October 2006

Objective—To determine the critical temperature that reduces chondrocyte viability and evaluate the ability of chondrocytes to recover after exposure to the critical temperature.

Sample Population—Cartilage explants obtained from the humeral heads of 30 sheep.

Procedures—In a randomized block design, 318 full-thickness cartilage explants were collected from 30 humeral heads of sheep and cultured for up to 14 days. On the first day of culture (day 0), explants were subjected to temperatures of 37°, 45°, 50°, 55°, 60°, or 65°C for 5 minutes by heating culture tubes in a warming block. The ability for chondrocytes to recover after exposure to the critical temperature was determined by evaluating viability at days 0, 1, 3, 7, and 14 days after heating. Images were analyzed by use of confocal laser microscopy.

Results—Analysis of images revealed a significant decrease in live cells and a significant increase in dead cells as temperature increased. Additionally, the deepest layer of cartilage had a significantly lower percentage of live cells, compared with values for the 3 most superficial layers. Chondrocytes did have some ability to recover temporarily after the initial thermal insult.

Conclusions and Clinical Relevance—A strong relationship exists between increasing temperature and cell death, with a sharp increase in chondrocyte death between 50° and 55°C. Chondrocytes in the deepest cartilage layer are most susceptible to thermal injury. The threshold of chondrocyte recovery from thermal injury is much lower than temperatures reached during chondroplasty by use of most radiofrequency energy devices.
Histomorphometric analysis of articular cartilage, zone of calcified cartilage, and subchondral bone plate in femoral heads from clinically normal dogs and dogs with moderate or severe osteoarthritis
Authors: Daubs Brian M. , Markel Mark D. , Manley Paul A.
Published: October 2006

Objective—To quantify and compare the microscopic changes in articular cartilage (AC), zone of calcified cartilage (ZCC), and subchondral bone plate in femoral heads from clinically normal dogs and dogs with moderate or severe osteoarthritis.

Sample Population—Femoral heads from clinically normal dogs (n = 16) and dogs with moderate (24) or severe (14) osteoarthritis.

Procedures—Femoral heads were allocated to 3 categories (normal, moderate, or severe osteoarthritis) on the basis of radiographic findings, macroscopic findings, and histologic grade determined by use of a modified Mankin scale. Equally spaced 2-mm sections were cut in each femoral head in a coronal or transverse plane. Thickness of the AC, ZCC, and subchondral bone plate was recorded.

Results—Mean thickness of AC was significantly greater in samples with moderate and severe osteoarthritis than those considered normal. Mean thickness of the ZCC was significantly greater in samples with moderate and severe osteoarthritis than those considered normal. Mean thickness of the subchondral bone plate in samples with severe osteoarthritis was significantly greater than those with moderate osteoarthritis and those considered normal. A significant decrease in AC thickness was detected in the proximomedial area of femoral heads with severe osteoarthritis, compared with those considered normal.

Conclusions and Clinical Relevance—A cause and effect association between thickening of subchondral structures and thinning and loss of the overlying AC was not detected. Changes in AC were associated with changes in the subchondral bone plate, which is compatible with the theory of adaptation in response to altered load distribution.
Effects of dobutamine, norepinephrine, and vasopressin on cardiovascular function in anesthetized neonatal foals with induced hypotension
Authors: Valverde Alexander , Giguère Steeve , Sanchez L. Chris , Shih Andre , Ryan Clare
Published: October 2006

Objective—To determine the effects of dobutamine, norepinephrine, and vasopressin on cardiovascular function and gastric mucosal perfusion in anesthetized foals during isoflurane-induced hypotension.

Animals—6 foals that were 1 to 5 days of age.

Procedures—6 foals received 3 vasoactive drugs with at least 24 hours between treatments. Treatments consisted of dobutamine (4 and 8 μg/kg/min), norepinephrine (0.3 and 1.0 μg/kg/min), and vasopressin (0.3 and 1.0 mU/kg/min) administered IV. Foals were maintained at a steady hypotensive state induced by a deep level of isoflurane anesthesia for 30 minutes, and baseline cardiorespiratory variables were recorded. Vasoactive drugs were administered at the low infusion rate for 15 minutes, and cardiorespiratory variables were recorded. Drugs were then administered at the high infusion rate for 15 minutes, and cardiorespiratory variables were recorded a third time. Gastric mucosal perfusion was measured by tonometry at the same time points.

Results—Dobutamine and norepinephrine administration improved cardiac index. Vascular resistance was increased by norepinephrine and vasopressin administration but decreased by dobutamine at the high infusion rate. Blood pressure was increased by all treatments but was significantly higher during the high infusion rate of norepinephrine. Oxygen delivery was significantly increased by norepinephrine and dobutamine administration; O2 consumption decreased with dobutamine. The O2 extraction ratio was decreased following norepinephrine and dobutamine treatments. The gastric to arterial CO2gap was significantly increased during administration of vasopressin at the high infusion rate.

Conclusion and Clinical Relevance—Norepinephrine and dobutamine are better alternatives than vasopressin for restoring cardiovascular function and maintaining splanchnic circulation during isofluraneinduced hypotension in neonatal foals.
Development of a fecal sample collection strategy for extraction and quantification of fecal immunoglobulin A in dogs
Authors: Tress Ursula , Suchodolski Jan S. , Williams David A. , Steiner Jörg M.
Published: October 2006

Objective—To develop a fecal sample collection strategy and quantification method for measurement of fecal IgA concentrations in dogs.

Sample Population—Fecal samples from 23 healthy pet dogs of various breeds.

Procedures——Immunoglobulin A was extracted from fecal samples. An ELISA for the measurement of fecal IgA concentrations was established and analytically validated. Intraindividual variation of fecal IgA was determined by calculation of coefficients of variation. A sample collection strategy was developed on the basis of results of intraindividual variation of fecal IgA concentrations. A reference range for fecal IgA concentrations was determined.

Results—The method for extraction and quantification of fecal IgA was determined to be sufficiently sensitive, reproducible, accurate, and precise. On the basis of the intraindividual variability of our results, the determined fecal sample collection strategy required analysis of a total of 4 fecal samples/dog, with each fecal sample collected on 2 consecutive days with 28 days between sample collection periods (ie, days 1 and 2 followed by days 28 and 29). Reference range values for fecal IgA concentration were 0.22 to 3.24 mg/g of feces.

Conclusions and Clinical Relevance— Methods of fecal IgA extraction and quantification used in our study allow for identification of dogs with consistently low fecal IgA concentrations. Use of these techniques will enable future investigations into possible associations between low fecal IgA concentrations and signs of gastrointestinal disease in dogs.
Duration of corneal anesthesia following topical administration of 0.5% proparacaine hydrochloride solution in clinically normal cats
Authors: Binder Daniel R. , Herring Ian P.
Published: October 2006

Objective—To determine duration of corneal anesthesia following topical administration of 0.5% proparacaine hydrochloride solution in domestic shorthair (DSH) cats.

Animals—20 clinically normal DSH cats.

Procedures—Baseline corneal touch threshold (CCT) was established by use of a Cochet-Bonnet aesthesiometer. Treatment consisted of a single 50-μL topical application of an ophthalmic preparation of 0.5% proparacaine solution to a randomly selected eye of each cat. The corneal touch threshold was assessed 1 and 5 minutes after application to the cornea and at 5- minute intervals thereafter for 60 minutes.

Results—Corneal sensitivity, as determined by Cochet-Bonnet aesthesiometry, was significantly reduced from baseline for 25 minutes following topical administration of ophthalmic proparacaine. Maximal anesthetic effect lasted 5 minutes.

Conclusions and Clinical Relevance—As determined by Cochet-Bonnet aesthesiometry, duration of anesthetic effects on the cornea induced by a single topical application of an ophthalmic preparation of 0.5% proparacaine solution in DSH cats is considerably shorter than the reported duration of corneal anesthesia in dogs.
In vitro fungistatic and fungicidal activities of silver sulfadiazine and natamycin on pathogenic fungi isolated from horses with keratomycosis
Authors: Betbeze Caroline M. , Wu Ching Ching , Krohne Sheryl G. , Stiles Jean
Published: October 2006

Objective—To evaluate the in vitro antifungal properties of silver sulfadiazine (SSD) and natamycin against filamentous fungi isolated from eyes of horses with keratomycosis.

Sample Population—Filamentous fungal isolates obtained from eyes of keratomycosis-affected horses.

Procedures—Fungal culture of ocular samples yielded 6 Fusarium spp; 7 Aspergillus spp; and 1 isolate each of Curvularia, Scopulariopsis, Penicillium, and Chrysosporium. For each fungal isolate, minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of SSD and natamycin were determined.

Results—For all 17 fungal isolates, SSD MIC distribution ranged from ≤ 1 to > 64 μg/mL; MIC50 and MIC90 (MICs at which 50% and 90% of organisms were inhibited) were 4 and 32 μg/mL, respectively. The SSD MFC distribution for all isolates was ≤ 1 to > 64 μg/mL; MFC50 and MFC90 (MFCs at which 50% and 90% of organisms were killed) were 8 and > 64 μg/mL, respectively. For all fungal isolates, natamycin MIC distribution ranged from 256 to > 1,000 μg/mL; MIC50 and MIC90 were 512 and > 1,000 μg/mL, respectively. The natamycin MFC distribution for all isolates ranged from 512 to > 1,000 μg/mL; MFC50 and MFC90 were each > 1,000 μg/mL.

Conclusions and Clinical Relevance—These in vitro data suggest that SSD is fungicidal against the fungal isolates that were obtained from eyes of horses with keratomycosis and that natamycin is fungicidal against some of the isolates at the drug concentrations evaluated. Silver sulfadiazine may be a therapeutic option for equine keratomycosis.
Evaluation of ProMED-mail as an electronic early warning system for emerging animal diseases: 1996 to 2004
Authors: Cowen Peter , Garland Tam , Hugh-Jones Martin E. , Shimshony Arnon , Handysides Stuart , Kaye Donald , Madoff Lawrence C. , Pollack Marjorie P. , Woodall Jack
Published: October 2006

Objective—To identify emerging animal and zoonotic diseases and associated geographic distribution, disease agents, animal hosts, and seasonality of reporting in the Program for Monitoring Emerging Diseases (ProMED)-mail electronic early warning system.

Design—Retrospective study.

Sample Population—10,490 disease reports.

Procedures—Descriptive statistics were collated for all animal disease reports appearing on the ProMED-mail system from January 1, 1996, to December 31, 2004.

Results—Approximately 30% of reports concerned events in the United States; reports were next most common in the United Kingdom, Canada, Australia, Russia, and China. Rabies, bovine spongiform encephalopathy, and anthrax were reported consistently over the study period, whereas avian influenza, Ebola virus, and Hantavirus infection were reported frequently in approximately half of the study years. Reports concerning viral agents composed more than half of the postings. Humans affected by zoonotic disease accounted for a third of the subjects. Cattle were affected in 1,080 reports, and wildlife species were affected in 825 reports. For the 10,490 postings studied, there was a retraction rate of 0.01 and a correction rate of 0.02.

Conclusions and Clinical Relevance—ProMED-mail provided global coverage, but gaps in coverage for individual countries were detected. The value of a global electronic reporting system for monitoring emerging diseases over a 9-year period illustrated how new technologies can augment disease surveillance strategies. The number of animal and zoonotic diseases highlights the importance of animals in the study of emerging diseases.
Evaluation of epidural administration of morphine or morphine and bupivacaine for postoperative analgesia after premedication with an opioid analgesic and orthopedic surgery in dogs
Authors: Kona-Boun Jean-Jacques , Cuvelliez Sophie , Troncy Eric
Published: October 2006

Objective—To evaluate the analgesic efficacy of epidural administration of morphine or a morphine-bupivacaine combination administered before orthopedic surgery in dogs that received opioid premedication.

Design—Prospective, randomized, blinded, clinical study.

Animals—36 healthy adult dogs that underwent elective orthopedic surgery on a pelvic limb.

Procedures—Each dog received 1 of 3 epidural treatments before surgery. Anesthetic and supportive care protocols were standardized. Dogs under going different surgical procedures were randomly allocated among the 3 treatment groups. Respiratory and cardiovascular variables, end-tidal isoflurane concentration, and requirements for rescue analgesia were monitored. Postsurgical analgesia was evaluated with a multiparametric pain scoring system and by determination of rescue analgesia requirements and cortisolemia.

Results—The morphine-bupivacaine combination was associated with lower values than morphine or a saline solution for intraoperative arterial blood pressure; minimum and maximum isoflurane requirements; and postoperative pain scores, rescue analgesia requirements, and plasma cortisol concentrations. Values obtained after administration of morphine alone were not significantly different from those obtained after administration of saline solution for most variables.

Conclusions and Clinical Relevance—The preoperative epidurally administered morphine-bupivacaine combination induced better analgesia than morphine alone and should be considered for use in clinical patients. The degree of hemodynamic depression associated with the combination was considered acceptable for healthy patients undergoing elective surgery.
Using rhythms of relationships to understand e‐mail archives
Authors: Perer Adam , Shneiderman Ben , Oard Douglas W.
Published: October 2006

Due to e‐mail's ubiquitous nature, millions of users are intimate with the technology; however, most users are only familiar with managing their own e‐mail, which is an inherently different task from exploring an e‐mail archive. Historians and social scientists believe that e‐mail archives are important artifacts for understanding the individuals and communities they represent. To understand the conversations evidenced in an archive, context is needed. In this article, we present a new way to gain this necessary context: analyzing the temporal rhythms of social relationships. We provide methods for constructing meaningful rhythms from the e‐mail headers by identifying relationships and interpreting their attributes. With these visualization techniques, e‐mail archive explorers can uncover insights that may have been otherwise hidden in the archive. We apply our methods to an individual's 15‐year e‐mail archive, which consists of about 45,000 messages and over 4,000 relationships.
Web searching on the Vivisimo search engine
Authors: Koshman Sherry , Spink Amanda , Jansen Bernard J.
Published: October 2006

The application of clustering to Web search engine technology is a novel approach that offers structure to the information deluge often faced by Web searchers. Clustering methods have been well studied in research labs; however, real user searching with clustering systems in operational Web environments is not well understood. This article reports on results from a transaction log analysis of Vivisimo.com, which is a Web meta‐search engine that dynamically clusters users' search results. A transaction log analysis was conducted on 2‐week's worth of data collected from March 28 to April 4 and April 25 to May 2, 2004, representing 100% of site traffic during these periods and 2,029,734 queries overall. The results show that the highest percentage of queries contained two terms. The highest percentage of search sessions contained one query and was less than 1 minute in duration. Almost half of user interactions with clusters consisted of displaying a cluster's result set, and a small percentage of interactions showed cluster tree expansion. Findings show that 11.1% of search sessions were multitasking searches, and there are a broad variety of search topics in multitasking search sessions. Other searching interactions and statistics on repeat users of the search engine are reported. These results provide insights into search characteristics with a cluster‐based Web search engine and extend research into Web searching trends.
Improving high accuracy retrieval by eliminating the uneven correlation effect in data fusion
Authors: Wu Shengli , McClean Sally
Published: October 2006

The aim of this research is twofold. On the one hand, high accuracy retrieval has been a concern of the information retrieval community for some time. We aim to investigate this issue via data fusion. On the other hand, the correlation among component results has been proven harmful to data fusion, but it has not been taken into account in data fusion algorithms. In the hope of achieving better performance, we propose a group of algorithms to eliminate the effect of uneven correlation among component results by assigning different weights to all component results or their combinations. Then the linear combination method or a variation is used for fusion. Extensive experimentation is carried out to evaluate the performances of these algorithms with six groups of component results, which are the top 10 systems submitted to Text REtrieval Conference (TREC) 6, 7, 8, 9, 2001, and 2002. The experimental results show that all eight data fusion methods involved outperform the best component system on average. Therefore, we demonstrate that the data fusion technique in general is effective with accurate retrieval results. The experimental results also demonstrate that all six methods presented in this article are effective for eliminating the effect of uneven correlation among component results. All of them outperform CombSum and five of them outperform CombMNZ on average.
Wirtschaftlichkeitsuntersuchungen zu Tribünenplatten unter dynamischer Beanspruchung
Authors: Roeser W. , Kuhlmann D.
Published: October 2006

Im vorliegenden Beitrag wird das dynamische Verhalten von Tribünenplatten in Sportstadien untersucht. Dabei werden neue Meßergebnisse beschrieben und auf die Wirtschaftlichkeit verschiedener Stufen‐ und Plattentypen eingegangen.
Kombiniertes Verfahren zur wirklichkeitsnahen Berechnung schlanker Stahlbetonstabtragwerke
Authors: Starossek Uwe , Wallmichrath Ingmar , Löhning Thomas
Published: October 2006

Der wirklichkeitsnahen und damit nichtlinearen Berechnung von allgemeinen Stahlbetontragwerken kommt eine wachsende Bedeutung zu. Eine Kombination des allgemeinen Weggrößenverfahrens, des Übertragungsverfahrens und eines Querschnittsmoduls führt zu einem effektiven Berechnungsverfahren für allgemeine Stabtragwerke aus Stahl‐ und Spannbeton. Neben der stofflichen Nichtlinearität berücksichtigt das Verfahren auch geometrische Nichtlinearität mit großen Verformungen. Die übergeordnete Berechnung des Systems erfolgt inkrementell und iterativ mit dem allgemeinen Weggrößenverfahren. Auf Stabebene wird ein erweitertes Übertragungsverfahren zur Bestimmung der Stabendschnittgrößen und der Steifigkeitsmatrix eingesetzt. Die Formulierung des Übertragungsverfahrens erfolgt in einem rekursiven Schema für einen verformten Stab, der in Abhängigkeit vom Steifigkeitsgradienten in einzelne Abschnitte diskretisiert wird. Das nichtlineare Materialverhalten einschließlich Rißbildung, Entfestigung und Fließen der Bewehrung wird im Querschnittsmodul über eine Querschnittsintegration erfaßt.
Schutz und Instandsetzung von Betonbauteilen mit genormten Produkten nach EN 1504
Authors: Raupach M.
Published: October 2006

Die Europäische Normenreihe EN 1504 für Schutz und Instandsetzung von Betonbauteilen steht unmittelbar vor ihrer Fertigstellung. Sie besteht aus 10 Hauptnormen und 62 zugehörigen Europäischen Prüfnormen. Die Hauptnormen EN 1504‐2 bis 7 regeln die Produktgruppen Oberflächenschutzsysteme, Mörtel, Klebstoffe für Verstärkungen, Riß‐ und Hohlraumfüllstoffe, Ankermörtel sowie die Stahlbeschichtungen. Die Prinzipien für den Gebrauch der Produkte sowie die Anwendung der Produkte auf der Baustelle mit zugehöriger Qualitätssicherung sind in den Teilen 9 und 10 enthalten. Ferner ist die Qualitätssicherung der Produkte in Teil 8 geregelt. Somit liegt in Kürze ein umfassendes Normenwerk für Schutz und Instandsetzung von Betonbauteilen vor. Derzeit wird beraten, wie dieses Normenwerk in Deutschland eingeführt wird. Aus verschiedenen Gründen wurde beschlossen, daß die Teile für Planung und Anwendung in Deutschland nicht eingeführt werden, weil mit den bestehenden Richtlinien des DAfStb “Schutz und Instandsetzung von Betonbauwerken” sowie der ZTV‐ING langjährig bewehrte Regelwerke vorliegen. Um die Europäisch zukünftig mit CE‐Zeichen markierten Produkte für Schutz und Instandsetzung von Betonbauwerken verwenden zu können, wurden für den Oberflächenschutz, die Mörtel, Rißfüllstoffe und die Stahlbeschichtungen inzwischen entsprechende Restnormen (DIN V 18026 bis 18028) erarbeitet, während die Kleber und Ankermörtel wie bisher in Zulassungen geregelt werden. In diesem Beitrag wird beschrieben wie zukünftig in Deutschland Schutz und Instandsetzung von Betonbauteilen mit genormten Produkten nach EN 1504 erfolgen soll.
Living donor versus deceased donor liver transplantation for early irresectable hepatocellular carcinoma
Authors: Lo C M , Fan S T , Liu C L , Chan S C , Ng I O-L , Wong J
Published: October 2006

Background

Hypothetical studies that favour living donor liver transplantation (LDLT) for early hepatocellular carcinoma (HCC) assumed a comparable outcome after LDLT and deceased donor liver transplantation (DDLT). The aim of this study was to compare the outcome after LDLT with that after DDLT, and to identify factors that might account for any differences.

Methods

The study included 60 patients who met the radiological Milan or University of California at San Francisco (UCSF) criteria and underwent LDLT (43 patients) or DDLT (17).

Results

The LDLT group had fewer incidental tumours and a lower rate of pretransplant transarterial chemoembolization but a higher rate of salvage transplantation. Waiting time was shorter and graft weight to standard liver weight (GW : SLW) ratio was lower in this group. The perioperative course, and histopathological tumour size, number, grade and stage were comparable. Median follow-up was 33 (range 4–120) months. The cumulative 5-year recurrence rate was 29 per cent in the LDLT group and 0 per cent in the DDLT group (P = 0·029). A GW : SLW ratio of 0·6 or less, salvage transplantation, three or more tumour nodules, microscopic vascular invasion, and pathological stage beyond the Milan or UCSF criteria were significant confounding risk factors. Multivariable analysis identified salvage transplantation (relative risk 5·16 (95 per cent confidence interval (c.i.) 1·48 to 18·02); P = 0·010) and pathological stage beyond the UCSF criteria (relative risk 4·10 (95 per cent c.i. 1·02 to 16·48); P = 0·047) as independent predictors of recurrence.

Conclusion

Despite standard radiological selection criteria based on number and size, patients who underwent LDLT for HCC had more recurrence because of selection bias for other clinical characteristics.
Damages and rewards: assessment of malingered disorders in compensation cases
Authors: Rogers Richard , Payne Joshua W.
Published: October 2006

The assessment of malingering poses unique challenges to forensic practitioners in compensation cases and disability determinations. Beyond malingering itself, false claims can be presented regarding both the source of genuine symptoms and their injurious effects on work and social functioning. The article examines how contextually based psychological factors can affect clients' presentation in compensation cases. Important distinctions between different types of response style (e.g. malingering, feigning, and secondary gain) are presented. In addition, empirically validated detection strategies provide a clinical framework for the assessment of feigned disorders. With an emphasis on compensation cases and clinically relevant disorders, the effectiveness of these detection strategies is considered for specific psychological measures. Copyright © 2006 John Wiley & Sons, Ltd.
Enyne Metathesis–Oxidation Sequence for the Synthesis of 2‐Phosphono Pyrroles: Proof of the “Yne‐then‐Ene” Pathway
Authors: Dieltiens Nicolai , Moonen Kristof , Stevens Christian V.
Published: October 2006

A new tandem reaction sequence has been developed for the synthesis of 2‐phosphono pyrroles. The sequence consists of ring‐closing enyne metathesis of a substituted aminophosphonate, containing a terminal alkyne and an internal alkene, in combination with in situ oxidation of the produced 3‐pyrrolines using tetrachloroquinone. By analyzing the formation of the end and certain byproducts, taking into account the difference in reactivity of different substrates and carefully studying spectroscopic data, it was found that the reaction proceeds by means of the “yne‐then‐ene” pathway. During the initiation phase, a new ruthenium carbene is formed which continues the propagation cycle.
Organocatalyzed Highly Enantioselective Direct Aldol Reactions of Aldehydes with Hydroxyacetone and Fluoroacetone in Aqueous Media: The Use of Water To Control Regioselectivity
Authors: Chen Xiao‐Hua , Luo Shi‐Wei , Tang Zhuo , Cun Lin‐Feng , Mi Ai‐Qiao , Jiang Yao‐Zhong , Gong Liu‐Zhu
Published: October 2006

An organocatalyst prepared from (2R,3R)‐diethyl 2‐amino‐3‐hydroxysuccinate and L‐proline exhibited high regio‐ and enantioselectivities for the direct aldol reactions of hydroxyacetone and fluoroacetone with aldehydes in aqueous media. It was found that water could be used to control the regioselectivity. The presence of 20–30 mol % of the catalyst afforded the direct aldol reactions of a wide range of aldehydes with hydroxyacetone to give the otherwise disfavored products with excellent enantioselectivities, ranging from 91 to 99 % ee, and high regioselectivities. Aldolizations of fluoroacetone with aldehydes mediated by 30 mol % of the organocatalyst in aqueous media preferentially occurred at the methyl group, yielding products with high enantioselectivities (up to 91 % ee); however, these additions took place dominantly at the fluoromethyl group in THF. Optically active 3,5‐disubstituted tetrahydrofurans and (2S,4R)‐dihydroxy‐4‐biphenylbutyric acid were prepared by starting from the aldol reaction of hydroxyacetone. Theoretical studies on the role of water in controlling the regioselectivity revealed that the hydrogen bonds formed between the amide oxygen of proline amide, the hydroxy of hydroxyacetone, and water are responsible for the regioselectivity by microsolvation with explicit one water molecule as a hydrogen‐bond donor and/or an acceptor.
Enantioselective Addition of Phenylacetylene to Ketones Catalyzed by Chiral Amino Alcohols
Authors: Ding Juan , Shen Zong‐Xuan , Luo Xiao‐Qing , Chen Wei‐Yi , Zhang Ya‐Wen
Published: October 2006

(S)‐(1‐Benzylpyrrolidin‐2‐yl)diphenylmethanol and cinchonine were evaluated as promotors in the asymmetric additions of phenylacetylene to ketones, in order to prepare chiral propargylic alcohols. Good yields (up to 89%) and moderate enantioselectivities (up to 77.9% ee) were achieved. Addition of Ti(OPr‐i)4 can significantly improve the enantioselectivity of the reaction.
Laser Flash Photolysis Studies on Gallic Acid
Authors: Zhu Hong‐Ping , Zhao Hong‐Wei , Zhang Zhao‐Xia , Wang Wen‐Feng , Yao Si‐De
Published: October 2006

The transient species of gallic acid (GA) have been studied by 266 nm nanosecond laser flash photolysis in aqueous solution and acetonitrile. The intermediate with absorption at 320 nm was identified as excited triplet state (3GA*), the decay rates of which were obtained in aqueous solution and acetonitrile respectively. Energy transfer from 3GA* to β‐carotene was observed and the energy transfer rate constant kent was determined to be 2.2×109mol−1·L·s−1. GA underwent photoionization during photolysis and the quantum yield of photoionization was determined to be 0.12 at room temperature with KI as a reference.
One Novel Vanadium‐Phosphate Cluster [PV2.5O8.5]·3.83{H2O} with Three‐Dimensional Architecture
Authors: Liu Ying , Zhang Xian‐Xi , Dou Jian‐Min , Wang Da‐Qi , Xu Feng , Zhou Lei , Su Huai‐Jing
Published: October 2006

A novel vanadium‐phosphate compound [PV2.5O8.5]·3.83{H2O} (1) was obtained from the hydrothermal reaction and structurally characterized by elemental analysis and single‐crystal X‐ray diffraction, which exhibited that the title complex crystallized in cubic space group I‐43m with crystal data: a=1.6115(1) nm, V=4.1848(1) nm3,Z=12, Dc=1.783 g/cm3, F(000)=2278, R1=0.0528, and wR2=0.1329 [I>2σ(I)] (all data). The basic unit of {PV2.5O8.5} symmetrically extended to closed sphere‐like structure of {P4V10O34}, which was further linked to interleaving three‐dimensional network via sharing four phosphate through μ3‐oxygen atoms around the closed sphere‐like structures.
Design and Synthesis of Photoaffinity Probe Candidates for the GABA‐gated Chloride Channel
Authors: Liu Shang‐Zhong , Li Qing‐X.
Published: October 2006

In order to characterize binding sites of insecticidal compounds on GABA gated chloride channel, new photoaffinity probe candidates based on 5e‐t‐butyl‐2e‐[4‐(substituted‐propynyl)phenyl]‐1,3‐dithiane for the noncompetitive blocker (NCB) site of the γ‐aminobutyric acid (GABA)‐gated chloride channel were designed and synthesized, and their potency as an inhibitor on NCB was measured by 4′‐ethynyl‐4‐n‐[2,3‐3H2]‐propylbicycloorthobenzoate (3H EBOB) assay. The synthesized compounds showed high inhibition activities with half maximum inhibition concentrations (IC50) of lower than 35 nmol/L and were very stable in binding conditions as well photoreacted quickly at 300 nm light. These new compounds are expected to be good photoaffinity labeling probes if radioisotope iodine is incorporated.
Electron Effect of p‐Substituent on Iron(II) and Cobalt(II) Pyridinebisimine Catalyst for Ethylene Polymerization
Authors: Liu Jing‐Yu , Zheng Yi , Hu Ning‐Hai , Li Yue‐Sheng
Published: October 2006

A series of 2,6‐bis(imino)pyridyl iron and cobalt complexes bearing p‐substituent [2,6‐(ArN=CMe)2C5H3N]‐
MCl2 (Ar=2,6‐Me2C6H3, 2,4,6‐Me3C6H2, 2,6‐Me2‐4‐BrC6H2, 2,6‐Me2‐4‐ClC6H2, 2,4‐Me2‐6‐BrC6H2, 2,4‐Me2‐6‐ClC6H2, while M=Fe, Co) have been synthesized and investigated as catalysts for ethylene polymerization in the presence of modified methylaluminoxane as a cocatalyst. The electron effect and positions of the substituent of pyridinebisimine ligands were observed to affect considerably catalyst activity and polymer property.
Immunoregulatory function of mesenchymal stem cells
Authors: Uccelli Antonio , Moretta Lorenzo , Pistoia Vito
Published: October 2006

Mesenchymal stem cells (MSC) are a rare subset of stem cells residing in the bone marrow where they closely interact with hematopoietic stem cells and support their growth and differentiation. MSC can differentiate into multiple mesenchymal and non‐mesenchymal lineages, providing a promising tool for tissue repair. In addition, MSC suppress many T cell, B cell and NK cell functions and may affect also dendritic cell activities. Due to their limited immunogenicity, MSC are poorly recognized by HLA‐incompatible hosts. Based on these unique properties, MSC are currently under investigation for their possible use to treat immuno‐mediated diseases. However, both their condition of immunoprivilege and their immunosuppressive function have recently been challenged when analyzed under particular experimental conditions. Thus, it is likely that MSC effects on the immune system may be deeply influenced not only by cell‐to‐cell interactions, but also by environmental factors shaping their phenotype and functions.
C70[NR2]2O: The First C70 Intramolecular Ethers Bearing Two Amine Groups
Authors: Troshina Olesya A. , Troshin Pavel A. , Peregudov Alexander S. , Kozlovski Viacheslav I. , Lyubovskaya Rimma N.
Published: October 2006

Photochemical reactions between [70]fullerene and N‐substituted piperazines yield C70[NR2]2O, the first isolated and characterized C70‐based aminofullerenes. Spectroscopic characterization revealed the presence of intramolecular ether moieties in the structures of these compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
First Synthesis of Argadin: A Nanomolar Inhibitor of Family‐18 Chitinases
Authors: Dixon Mark J. , Andersen Ole A. , van Aalten Daan M. F. , Eggleston Ian M.
Published: October 2006

The first synthesis of the cyclic peptide natural product, argadin is reported. Use of a solid‐phase approach featuring side‐chain resin attachment through histidine and a novel protecting group strategy allows rapid and efficient access to the argadin backbone, whereupon the unusual 3‐amino‐5‐hydroxy‐2‐pyrrolidone moiety of the peptide is introduced by oxidative cyclisation of a homoserine residue. Argadin is shown to exist as a 5:1 mixture of diastereoisomers at the 5‐hydroxy centre of the pyrrolidone ring, and inhibits a representative family‐18 chitinase (ChiB1 from Aspergillus fumigatus) with Ki = 33 nM. The high‐resolution X‐ray crystal structure of synthetic argadin in complex with the same enzyme shows the binding of a single diastereoisomer as previously observed with the authentic natural product. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Double‐functional characteristics of a surface molecular imprinted adsorbent with immobilization of nano‐TiO2
Authors: Su Haijia , Li Qiang , Tan Tianwei
Published: October 2006

A new chitosan molecular imprinted adsorbent obtained by immobilization of nano‐TiO2 on the adsorbent surface (surface‐imprinted adsorbent with nano‐TiO2) was prepared. Based on photocatalytic reaction and the surface molecular imprinting technology, this new kind of surface‐imprinted adsorbent with immobilization of nano‐TiO2 can not only adsorb template metal ions but can also degrade organic pollutants. The results showed that, after the nano‐TiO2 was immobilized on the adsorbent surface, the adsorption ability for the imprinted ion (Ni2+) of this new imprinted adsorbent immobilized with nano‐TiO2 was not affected, but the degradation ability for p‐nitrophenol (PNP) of the surface‐imprinted adsorbent with nano‐TiO2 increased three‐fold compared with that of the surface‐imprinted adsorbent without nano‐TiO2, from 23.8 to 76.1% (at an initial PNP concentration of 20 mg·dm−3). The optimal TiO2 concentration in the adsorbent preparation was 0.025 g·TiO2 g−1 adsorbent. The removal capacity for PNP reached 60.25 mg·g−1 (at 400 mg·dm−3 initial PNP concentration) under UV irradiation. The surface‐imprinted adsorbent with nano‐TiO2 can be reused for at least five cycles without decreasing the removal ability for PNP and the imprinted ion (Ni2+). Copyright © 2006 Society of Chemical Industry
The use of evolutionary biology concepts for genome annotation
Authors: Danchin Etienne G.J. , Levasseur Anthony , Lopez Rascol Virginie , Gouret Philippe , Pontarotti Pierre
Published: October 2006

The past decade has seen the completion of numerous whole‐genome sequencing projects, began with bacterial genomes and continued with eukaryotic species from different phyla: fungi, plants and animals. Besides, more biological information are produced and are shared thanks to information exchange systems, and more biological concepts, as well as more bioinformatics tools, are available. In this article, we will describe how the evolutionary biology concepts, as well as computer science, are useful for a better understanding of biology in general and genome annotation in particular. The genome annotation process consists of taking the raw DNA produced, for example, by the genome sequencing projects, adding the layers of analysis and interpretation necessary to extract its biological significance and placing it in the context of our understanding of biological processes. Genome annotation is a multistep process falling into two broad categories: structural and functional annotation. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2006 Wiley‐Liss, Inc
Laser‐assisted microdissection (LAM) in developmental biology
Authors: Chimge Nyam‐Osor , Ruddle Frank , Bayarsaihan Dashzeveg
Published: October 2006

The analysis of gene expression in developing organs is a valuable tool for the assessment of genetic fingerprints during the various stages of differentiation. Complex processes in developing tissues are particularly difficult to understand in terms of biochemical phenomena. Laser‐assisted microdissection (LAM) allows the efficient and precise capture of cells or groups of cells from developing tissues in sufficient quantities and within the context of time and space to permit the subsequent molecular characterization of the targeted tissue. The technique development has dramatically increased the ease of isolating specific cells which, together with progress in tissue preparation and microextraction protocols, allows for broad‐range down‐stream applications in the fields of genomics, transcriptomics and proteomics. This review gives an overview of the LAM technology and its application in developmental biology. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2006 Wiley‐Liss, Inc.