bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of electron donor, dissolved oxygen, and oxidation–reduction potential biodegradation of carbon tetrachloride by Escherichia coli K‐12
Authors: Jin Guang , Englande Andrew J.
Published: October 2006

Carbon tetrachloride (CT) is recalcitrant to spontaneous degradation. To achieve efficient biodegradation of CT, conditions favorable for dechlorination should be created. Oxidation–reduction potential (ORP) and dissolved oxygen (DO) were found to be important environmental factors in optimizing CT bioremediation. A desired oxidation‐reduction environment was obtained by controlling medium composition and/or adding external reducing agents. Environmental modification resulted in greater than 80% removal of CT by Escherichia coli K‐12 at a CT initial concentration of 300 μg/L within 300 hours under the conditions of this study. The degradation followed pseudo‐first‐order kinetics. A substantially improved overall substrate removal rate constant, K, hence a more efficient CT removal, are observed at −162 mV < ORP < −50 mV under the conditions of the study. The trend of decreasing K observed at ORP of approximately −160 mv is caused by inhibition of the reducing agent titanium (III) citrate on E. coli K‐12 at its higher concentrations. At trace DO levels, ORP was found to be a more reliable and feasible parameter for CT biodegradation correlation. Results obtained from this study yield higher and more consistent CT biodegradation rates than those reported in the literature for the same type culture of microorganisms. This underscores the significance of DO and ORP as conditions for optimizing CT biodegradation. These findings are important in terms of field application, which is commonly limited by site‐specific environmental conditions.
Laboratory studies on the temperature‐phased anaerobic digestion of domestic primary sludge
Authors: Han Vue , Dague Richard R.
Published: October 2006

The temperature‐phased anaerobic process involves a two‐stage reactor system with the first stage operated at a thermophilic temperature (typically 55°C) and the second stage operated at a mesophilic temperature (typically 35°C). The purpose of this laboratory study was to compare the performance of the temperature‐phased system with the conventional single‐stage mesophilic system for treating domestic wastewater sludge. Of particular interest in the research was a comparison of the two systems from the standpoint of coliform reduction, volatile solids destruction, and biogas production. The temperature‐phased system achieved almost complete destruction of total and fecal coliforms over a range of solids retention times (SRTs) from 10 to 15 days. The concentration of fecal coliforms in the effluent from the temperature‐phased system never exceeded 1 000 MPN/g total solids, which can meet the U.S. federal fecal coliform requirements for Class A biosolids. At SRTs ranging from 10 to 15 days, the temperature‐phased system achieved an 18% higher destruction of volatile solids and 16% more methane production than was possible with the single‐stage mesophilic process.
Formation of disinfection byproducts during chlorination of secondary effluent and renovated water
Authors: Rebhun Menahem , Heller‐Grossman Lilly , Manka Josepha
Published: October 2006

Disinfection byproduct (DBP) formation was studied in nonnitrified and nitrified secondary effluents from several treatment plants and renovated water following soil aquifer treatment. The wastewater was chlorinated using different concentrations of chlorine. The study included formation of trihalomethanes (THM), haloacetic acids (HAA), and total dissolved organic halogens (DOX). In ammonia‐containing effluents (nonnitrified), where stable chloramine is formed, applying a chlorine dose of 0.34 (weight ratio of Cl/C) produced an average ratio of DOX to dissolved organic carbon (DOC) of 8.5 μg Cl/mg C, and insignificant concentrations of THM and HAA. In nitrified‐effluents forming free chlorine residual, a Cl/C dose of 0.34 (weight ratio) yielded an average DOX/DOC of 49 μg Cl/mg C. The THM formation varied widely with the effluent source and HAA/DOC formation was 2 to 3 μg Cl/mg C. The DOX formation potential (DOXFP) per mg carbon averaged 28 μg Cl/mg C for ammonia‐containing effluents and 147 μg Cl/mg C for completely nitrified effluents. The THM formation potential (THMFP) constituted 13 to 56% and HAAFP constituted 10 to 17% of the DOXFP, respectively. The results indicated that high concentrations of DBP are formed during chlorination of effluents, posing a contamination problem. Reduction of DBP formation can be achieved by applying treatment processes producing low‐DOC effluents and leaving a small concentration of residual ammonia.
Use of a centrifugation-based, point-of-care device for production of canine autologous bone marrow and platelet concentrates
Authors: Thoesen Michael S. , Berg-Foels Wendy S. Vanden , Stokol Tracy , Rassnick Kenneth M. , Jacobson May S. , Kevy Sherwin V. , Todhunter Rory J.
Published: October 2006

Objective—To analyze a centrifugation-based, point-of-care device that concentrates canine platelets and bone marrow–derived cells.

Animals—19 adult sexually intact dogs.

Procedures—Anticoagulated peripheral blood (60 mL) and 60 mL of anticoagulated bone marrow aspirate (BMA) were concentrated by centrifugation with the centrifugation-based, point-of-care device to form a platelet and a bone marrow concentrate (BMC) from 11 dogs. Blood samples were analyzed on the basis of hemograms, platelet count, and PCV. The BMA and BMC were analyzed to determine PCV, total nucleated cell count, RBC count, and differential cell counts. The BMC stromal cells were cultured in an osteoinductive medium. Eight additional dogs were used to compare the BMC yield with that in which heparin was infused into the bone marrow before aspiration.

Results—The centrifugation-based, point-of-care device concentrated platelets by 6-fold over baseline (median recovery, 63.1%) with a median of 1,336 × 103 platelets/μL in the 7-mL concentrate. The nucleated cells in BMCs increased 7-fold (median recovery, 42.9%) with a median of 720 × 103 cells/μL in the 4-mL concentrate. The myeloid nucleated cells and mononuclear cells increased significantly in BMCs with a significant decrease in PCV, compared with that of BMAs. Stromal cell cultures expressed an osteoblastic phenotype in culture. Infusion of heparin into the bone marrow eliminated clot formation and created less variation in the yield (median recovery, 61.9%).

Conclusions and Clinical Relevance—Bone marrow–derived cell and platelet-rich concentrates may form bone if delivered in an engineered graft, thus decreasing the need for cancellous bone grafts.
Cytoarchitecture, morphology, and lumbosacral spinal cord projections of the red nucleus in cattle
Authors: Chiocchetti Roberto , Bombardi Cristiano , Grandis Annamaria , Mazzuoli Gemma , Gentile Arcangelo , Pisoni Luciano , Joechler Monica , Lucchi Maria Luisa
Published: October 2006

Objective—To analyze the morphology, cytoarchitecture, and lumbosacral spinal cord projections of the red nucleus (RN) in cattle.

Animals—8 healthy Friesian male calves.

Procedures—Anesthetized calves underwent a dorsal laminectomy at L5. Eight bilateral injections (lateral to the midline) of the neuronal retrograde fluorescent tracer fast blue (FB) were administered into the exposed lumbosacral portion of the spinal cord. A postsurgical calf survival time of 38 to 55 days was used. Following euthanasia, the midbrain and the L5-S2 spinal cord segments were removed. Nissl's method of staining was applied on paraffin-embedded and frozen sections of the midbrain.

Results—The mean length of the RN from the caudal to cranial end ranged from 6,680 to 8,640 μm. The magnocellular and parvicellular components of the RN were intermixed throughout the nucleus, but the former predominate at the caudal portion of the nucleus and the latter at the cranial portion with a gradual transitional zone. The FB-labeled neurons were found along the entire craniocaudal extension of the nucleus, mainly in its ventrolateral part. The number of FB-labeled neurons was determined in 4 calves, ranging from 191 to 1,469 (mean, 465). The mean cross-sectional area of the FB-labeled neurons was approximately 1,680 μm2.

Conclusions and Clinical Relevance—In cattle, small, medium, and large RN neurons, located along the entire craniocaudal extension of the RN, contribute to the rubrospinal tract reaching the L6-S1 spinal cord segments. Thus, in cattle, as has been shown in cats, the RN parvicellular population also projects to the spinal cord.
Intraobserver and interobserver agreement, reproducibility, and accuracy of computed tomographic measurements of pituitary gland dimensions in healthy dogs
Authors: van der Vlugt-Meijer Roselinda H. , Meij Björn P. , Voorhout George
Published: October 2006

Objective—To determine the reproducibility and accuracy of computed tomographic (CT) measurements of pituitary gland dimensions in healthy dogs.

Animals—35 healthy sexually intact adult dogs.

Procedures—2 observers independently viewed CT images of the skull in 35 dogs twice. Pituitary gland height, width, length, and volume and pituitary gland height–to–brain area ratio (P:B ratio) were measured or calculated. Intraobserver and interobserver agreement indexes (AIs) were calculated for pituitary gland dimensions. Computed tomography was performed also on 5 phantoms, and both observers measured phantom dimensions twice. True-value AIs were calculated for the phantom study.

Results—The mean ± SD interobserver AI between observer 1 and 2 for pituitary gland height and the P:B ratio was 0.90 ± 0.07. The intraobserver AI for pituitary gland height and the P:B ratio was 0.97 ± 0.04 for observer 1 and 0.94 ± 0.04 for observer 2. The intraand interobserver AIs for the other dimensions were lower than those for pituitary gland height and the P:B ratio. All phantom dimensions on CT images were underestimated significantly, compared with their true values.

Conclusions and Clinical Relevance—The intra- and interobserver AIs for pituitary gland dimension measurements on CT images were high. However, the same observer preferably should perform serial measurements. Window settings influence pituitary gland dimension measurements, and predetermined window settings are recommended to make comparisons among dogs. Pituitary gland dimension measurements made from CT images in our study underestimated the true values.
Regulation by Jun N-terminal kinase/stress activated protein kinase of cytokine expression in Mycobacterium avium subsp paratuberculosis–infected bovine monocytes
Authors: Souza Cleverson D. , Evanson Oral A. , Weiss Douglas J.
Published: October 2006

Objective—To evaluate activation of Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) pathway in bovine monocytes after incubation with Mycobacterium avium subsp paratuberculosis (Mptb) organisms.

Sample Population—Bovine monocytes obtained from 4 healthy adult Holstein dairy cows.

Procedures—Bovine monocytes were incubated with Mptb organisms with or without a specific inhibitor of the JNK/SAPK pathway (SP600125) for 2, 6, 24, or 72 hours. Expression of interleukin (IL)-1β, IL-10, IL-12, IL-18; transforming growth factor-β (TGF-β); and tumor necrosis factor-α (TNF-α) and the capacity of Mptb-infected monocytes to acidify phagosomes and kill Mptb organisms were evaluated. Phosphorylation status of JNK/SAPK was evaluated at 10, 30, and 60 minutes after Mptb incubation.

Results—Compared with uninfected control monocytes, Mptb-infected monocytes had increased expression of IL-10 at 2 and 6 hours after incubation and had increased expression of TNF-α, IL-1β, IL-18, and TGF-β at 2, 4, and 6 hours. Additionally, Mptb-infected monocytes had increased expression of IL-12 at 6 and 24 hours. Addition of SP600125 (specific chemical inhibitor of JNK/SAPK) resulted in a decrease in TNF-α expression at 2, 6, and 24 hours, compared with untreated Mptb-infected cells. Addition of SP600125 resulted in a decrease in TGF-β expression at 24 hours and an increase in IL-18 expression at 6 hours. Addition of SP600125 failed to alter phagosome acidification but did enhance the capacity of monocytes to kill Mptb organisms.

Conclusions and Clinical Relevance—Activation of JNK/SAPK may be an important mechanism used by Mptb to regulate cytokine expression in bovine monocytes for survival and to alter inflammatory and immune responses.
Somatic alterations of the p53 tumor suppressor gene in vaccine-associated feline sarcoma
Authors: Banerji Nilanjana , Kanjilal Sagarika
Published: October 2006

Objective—To determine somatic alterations in p53 in vaccine-associated feline sarcoma (VAFS).

Animals—27 domestic shorthair cats undergoing first surgical treatment for primary VAFS with no history of chemotherapy or γ radiation.

Procedures—Sequence analysis was performed on the genomic sequence of p53 (between exons 5 through 9) from tumor and blood samples obtained from the cats. Cats were monitored for 3 years and disease-free intervals and survival times calculated.

Results—Eight single nucleotide polymorphisms were detected within the genomic sequence of p53, with 20 of 27 cats (74%) having heterozygosity at ≥ 1 polymorphic site. Somatic loss of heterozygosity at p53 was detected in the primary tumors of 12 of these 20 (60%) cats. Such allelic deletion was significantly associated with rapid tumor recurrence and reduced overall survival. Point mutations were rare, occurring in 3 of 27 primary tumors. The finding of malignant cells in the surgical margins was significantly associated with disease recurrence, but clear margins (with no detectable malignant cells) were not predictive of positive outcome.

Conclusions and Clinical Relevance—p53 status is an indicator of postsurgical recurrence and overall survival in cats with VAFS. Careful follow-up is important in treating vaccine-site tumors containing allelic deletion of p53, whereas aggressive surgical treatment may be sufficient to control primary vaccination site tumors without the allelic loss.
Parenteral vaccination of domestic pigs with Brucella abortus strain RB51
Authors: Stoffregen William C. , Olsen Steven C. , Bricker Betsy J.
Published: October 2006

Objective—To determine the immunogenicity and efficacy of Brucella abortus strain RB51 (SRB51) as a vaccine in domestic pigs.

Animals—Sixty-eight 6-week-old crossbred domestic pigs and twenty-four 4-month-old gilts.

Procedures—In experiment 1, pigs were vaccinated IM (n = 51) with 2 × 1010 CFUs of SRB51 or sham inoculated (17). Periodic blood samples were obtained to perform blood cultures, serologic evaluations, and cell-mediated immunity assays. Necropsies were performed at selected times between weeks 1 and 23 after vaccination to determine vaccine clearance. In experiment 2, gilts were similarly vaccinated (n = 18) or sham inoculated (8) and similar samples were obtained after vaccination. Gilts were bred and challenged conjunctivally with 5.0 × 107 CFUs of virulent Brucella suis strain 3B. Necropsies were performed on gilts and on fetuses or neonates after abortion or parturition, respectively. Bacterial cultures and serologic evaluations were performed on samples obtained at necropsy to determine vaccine efficacy.

Results—Humoral and cell-mediated immune responses did not differ between vaccinates and controls. After vaccination, SRB51 was not isolated from blood cultures of either group and was isolated from lymphoid tissues of 3 pigs at 2 weeks (n = 2) and 4 weeks (1) after vaccination. No differences were found in isolation of B suis or in seroconversion between vaccinated and control gilts and between their neonates or aborted fetuses.

Conclusions and Clinical Relevance—Parenteral vaccination with SRB51 does not induce humoral or cell-mediated immune responses. Vaccination with SRB51 did not protect gilts or their neonates and fetuses from virulent challenge with B suis.
Acute hepatic failure and coagulopathy associated with xylitol ingestion in eight dogs
Authors: Dunayer Eric K. , Gwaltney-Brant Sharon M.
Published: October 2006

Case Description—8 adult dogs were evaluated for treatment of lethargy and vomiting after ingestion of xylitol, a sugar alcohol used as a sweetener in various products.

Clinical Findings—In addition to vomiting and lethargy, 5 of the dogs had widespread petechial, ecchymotic, or gastrointestinal tract hemorrhages. Common clinicopathologic findings included moderately to severely high serum activities of liver enzymes, hyperbilirubinemia, hypoglycemia, hyperphosphatemia, prolonged clotting times, and thrombocytopenia. Necropsies were performed on 3 dogs and severe hepatic necrosis was found in 2. In the third dog, histologic examination revealed severe hepatocyte loss or atrophy with lobular collapse.

Treatment and Outcome—Treatments varied among dogs and included IV administration of fluids; plasma transfusions; and, if indicated, administration of dextrose. Three dogs were euthanatized, 2 dogs died, 2 dogs made a complete recovery, and 1 dog was recovering but was lost to follow-up.

Clinical Relevance—Although xylitol causes hypoglycemia in dogs, hepatic failure after ingestion has not previously been reported. Because an increasing number of consumer products contain xylitol, clinicians should be aware that ingestion of xylitol can have serious, life-threatening effects.
Association of portovenographic findings with outcome in dogs receiving surgical treatment for single congenital portosystemic shunts: 45 cases (2000–2004)
Authors: Lee Karla C. L. , Lipscomb Victoria J. , Lamb Christopher R. , Gregory Susan P. , Guitian Javier , Brockman Daniel J.
Published: October 2006

Objective—To determine whether hepatic portal vascularity, as assessed by intraoperative mesenteric portovenography (IMP), is related to outcome in dogs undergoing attenuation of single congenital portosystemic shunts (CPSSs).

Design—Retrospective case series.

Animals—45 dogs, each with a single CPSS, in which IMP was performed before and after temporary complete occlusion of the shunting vessel and that underwent complete (17 dogs) or partial (28 dogs) CPSS attenuation (surgery 1).

Procedures—Medical records were reviewed for signalment, clinical history, and bile acids stimulation test results. Intrahepatic portal vessel (IPV) opacification in pre- and postocclusion portovenograms was graded to determine whether the degree of opacification was correlated with the degree of shunt attenuation, clinical or biochemical factors, or long-term clinical outcome. In 17 of 28 dogs that had partial CPSS attenuation, these procedures were subsequently repeated (surgery 2) to achieve complete (14 dogs) or further partial (3 dogs) CPSS attenuation.

Results—Compared with preattenuation findings, IPV opacification increased significantly after partial or complete CPSS attenuation. The degree of IPV opacification before and after CPSS occlusion (surgery 1) was greater in dogs that tolerated complete versus partial CPSS attenuation and was correlated positively with age. The degree of IPV opacification following CPSS occlusion (surgery 1) was maximal in all dogs without encephalopathy and was correlated negatively with follow-up preprandial serum bile acids concentrations and positively with clinical improvement.

Conclusions and Clinical Relevance—Data suggest that IMP can be used to assess changes in IPV blood flow and help predict outcome following attenuation of single CPSSs in dogs.
Diagnostic value of cytologic examination of gastrointestinal tract tumors in dogs and cats: 83 cases (2001–2004)
Authors: Bonfanti Ugo , Bertazzolo Walter , Bottero Enrico , De Lorenzi Davide , Marconato Laura , Masserdotti Carlo , Zatelli Andrea , Zini Eric
Published: October 2006

Objective—To determine results of cytologic examination of fine-needle aspirates and impression smears of gastrointestinal tract tumors in dogs and cats.

Design—Retrospective case series.

Animals—38 dogs and 44 cats with histologically confirmed gastrointestinal tract tumors.

Procedures—Results of cytologic examination of fine-needle aspirates (n = 67) or impression smears (31) were compared with the histologic diagnosis, and extent of agreement was classified as complete, partial, none, or undetermined.

Results—For 48 of the 67 (72%) fine-needle aspirates, there was complete or partial agreement between the cytologic and histologic diagnoses. For 12 (18%) aspirates, the extent of agreement could not be determined because the cytologic specimen was considered unsatisfactory. For 29 of the 31 (94%) impression smears, there was complete agreement between the cytologic and histologic diagnoses, and for 2 (6%), there was partial agreement. None of the impression smears were considered unsatisfactory. Proportion of samples with complete agreement and proportion of samples with complete or partial agreement were significantly higher for impression smears than for fine-needle aspirates.

Conclusions and Clinical Relevance—Results suggest that there was moderate agreement between results of cytologic examination of fine-needle aspirates from dogs and cats with gastrointestinal tract neoplasia and the definitive histologic diagnosis. The agreement between results of cytologic examination of impression smears and the histologic diagnosis appeared to be higher.
Seasonal pasture myopathy in horses in the midwestern United States: 14 cases (1998–2005)
Authors: Finno Carrie J. , Valberg Stephanie J. , Wünschmann Arno , Murphy Michael J.
Published: October 2006

Objective—To determine clinical signs, diagnostic findings, tissue tremetone concentrations, and clinical outcome or postmortem findings in horses evaluated for acute severe nonexertional rhabdomyolysis initially attributed to white snakeroot toxicosis.

Design—Retrospective case series.

Animals—14 horses.

Procedures—Records of the University of Minnesota Veterinary Medical Center or Diagnostic Laboratory were searched from 1998 to 2005. Inclusion criteria included serum creatine kinase (CK) activity > 45,000 U/L, severe nonexertional myonecrosis of proximal postural muscles at necropsy, or signs of weakness without palpably firm muscles on physical examination. Vitamin E and selenium concentrations were measured in 6 horses; tremetone concentration was measured in 7.

Results—Clinical signs occurred during unfavorable weather conditions. Clinical signs of generalized weakness (n = 11 horses), muscle fasciculations (10), lethargy (6), and prolonged recumbency (4) were common. Serum CK activity ranged from 46,487 to 959,499 U/L (reference range, 82 to 449 U/L), and aspartate transaminase activity was > 1,500 U/L (reference range, 162 to 316 U/L). Two horses survived with aggressive antioxidant and fluid treatment. Postmortem examination revealed acute severe myonecrosis with lipid accumulation primarily in neck, proximal forelimb and hind limb, intercostal, and diaphragm muscles. Histopathologic signs of myocardial necrosis were detected in 7 horses. Vitamin E and selenium concentrations were within reference limits. Tremetone was not detected in liver or urine samples.

Conclusions and Clinical Relevance—Cases of rhabdomyolysis have been attributed to white snakeroot toxicosis; however, tremetone was not detected in any horses. Similarities exist between cases of seasonal pasture myopathy and cases of atypical myopathy in Europe.
Thirty‐five years in bioelectromagnetics research
Authors: Chou C‐K.
Published: October 2006

For 35 years, I have been involved in various bioelectromagnetics research projects including acute and long‐term radiofrequency (RF) bioeffects studies, dosimetry, exposure systems, MRI safety, cancer studies involving hyperthermia and electrochemical treatment, development of RF exposure and measurement standards, and product compliance. My first study demonstrated that effects on isolated nerve and muscle preparations were due to thermal effects of RF exposure. The recording of cochlear microphonics in animals shows the mechanical nature of the microwave auditory effect. In 1992, we published the results of a large‐scale lifetime study in which 100 rats were sham‐exposed and 100 rats were exposed for 21 h/day for 25 months to a pulsed RF signal. In dosimetry studies, human models were employed as well as many animal species including mice, rats, rabbits, monkeys, and birds of many sizes. Cancer hyperthermia studies demonstrated that knowledge of temperature distribution was crucial for successful treatment. Research on electrochemical treatment of tumors with direct current involved cellular, animal, and clinical studies. Over the past few decades, there has been rather extensive investigation of the public health impact of RF exposure. In my opinion, future research in bioelectromagnetics should place greater emphasis on medical applications. Bioelectromagnetics © 2006 Wiley‐Liss, Inc.
Besonderheiten beim Entwurf semi‐integraler Spannbetonbrücken: Eine Alternative im Brückenbau mit zunehmender Bedeutung – aufgezeigt am Beispiel der Fahrbachtalbrücke im Zuge der BAB A3 bei Aschaffenburg
Authors: Schiefer Stefan , Fuchs Michael , Brandt Bernd , Maggauer Gerhard , Egerer Andreas
Published: October 2006

Die integrale Bauweise bietet für Betonbrücken kleiner und zunehmend auch mittlerer Bauwerkslänge in vielen Fällen die optimale Lösung. Die fugen‐ und lagerlose Konstruktion ermöglicht wartungsarme, robuste und ästhetisch ansprechende Bauwerke. Bei der statischen Berechnung und konstruktiven Durchbildung integraler Bauwerke sind die Interaktionen zwischen Überbau, Unterbauten und Baugrund im Rahmen einer Optimierungsaufgabe zu lösen. Zum Nachweis der Ausführbarkeit einer semi‐integralen Konstruktion werden am Beispiel der in Bau befindlichen Fahrbachtalbrücke grundsätzliche Betrachtungen angestellt und deren Relevanz für die Entwurfs‐ und Ausführungsplanung untersucht. Daraus leiten sich Empfehlungen, Bemessungshilfen und einzuhaltende Randbedingungen für die Bearbeitung semi‐integraler Brücken ab. Insbesondere die Gründung hat einen wesentlichen Einfluß auf die Bemessung und das Verformungsverhalten des Gesamtsystems. Während die Beanspruchungen infolge der äußeren Einwirkungen (Eigengewicht und Verkehrslasten etc.) eine möglichst steife Gründung fordern, werden im Gegensatz dazu die Zwangsbeanspruchungen (Temperatur und unterschiedliche Stützensetzungen etc.) mit einer zunehmenden Nachgiebigkeit der Gründung abgebaut. Für die statischen Nachweise ist daher eine realistische Beschreibung der Bodenkennwerte des Baugrundes durch die Berücksichtigung von unteren und oberen Grenzwerten erforderlich.
Innovative Konstruktionsmöglichkeiten mit Stahlfaserbeton: Optimierter Stahlfaserbeton zum Nachweis der Rißbreitenbegrenzung eines kombinationsbewehrten Regenrückhaltebeckens
Authors: Nell Wilhelm , Greiff Manfred
Published: October 2006

Zur Optimierung der Leistungsfähigkeit von Stahlfaserbeton, in Kombination mit konventionellem Stahlbeton ist es erforderlich, ausgewählte Stahldrahtfasern in einem entsprechend konfektionierten Beton zu prüfen. Die Optimierung der Stahldrahtfaser und des Betons ist die Voraussetzung innovative, technisch anspruchsvolle Lösungen und wirtschaftliche Vorteile zu erzielen. Bei einem stark bewehrten Regenrückhaltebecken werden die Vorteile deutlich. Die Stabstahlbewehrung wird reduziert und die Dauerhaftigkeit gesteigert.
Instandsetzung von Beton und Stahlbeton im Wasserbau mit Spritzbeton
Authors: Kubens Christian
Published: October 2006

Nachdem die europäischen und deutschen Regelwerke für Beton und Stahlbeton ab 2005 in ihren Neufassungen anzuwenden waren, wurden für den Spritzbeton die beiden Normen DIN 18551 und DIN 18314 gleichfalls überarbeitet. Für die Instandsetzung von Betonbauwerken im Wasserbau wurde zeitgleich von einer Arbeitsgruppe unter Mitarbeit des Autors sowie unter Leitung der Bundesanstalt für Wasserbau ein darauf aufbauendes technisches und bauvertragliches Regelwerk, die ZTV‐W LB 219 entwickelt. Im Mittelpunkt des vorliegenden Beitrages steht dort die neu geregelte Instandsetzung mit Spritzbeton, 10 bis 15 cm dick, der bewehrt und auf Altbeton jeder Festigkeit dauerhaft rückverankert werden kann.
Investigating the M‐FAST: psychometric properties and utility to detect diagnostic specific malingering
Authors: Guy Laura S. , Kwartner Phylissa P. , Miller Holly A.
Published: October 2006

This study examined the ability of the M‐FAST to differentiate a group of undergraduate students simulating one of four DSM‐IV diagnoses (n = 190; schizophrenia, major depressive disorder, bipolar disorder, and posttraumatic stress disorder) and a clinical comparison sample drawn from previous M‐FAST studies comprising individuals with the same diagnosis (n = 142). Across all diagnostic conditions, the simulators obtained higher M‐FAST total scores than the clinical comparisons, and the rare combinations scale was equal or superior to the total score at differentiating the groups. The M‐FAST was most efficient at distinguishing feigned from bona fide schizophrenia. Although the internal consistency of the total score was high (α = 0.88), inter‐item correlations were lower than values reported in previous research. Lastly, given the importance of base rate considerations in the evaluation of diagnostic instruments, it was notable that the M‐FAST was able to identify malingerers even at relatively low base rates. Copyright © 2006 John Wiley & Sons, Ltd.
Structures and Vibrational Spectra of the Sulfur‐Rich Oxides SnO (n= 4–9): The Importance of π*–π* Interactions
Authors: Wong Ming Wah , Steudel Yana , Steudel Ralf
Published: October 2006

The structures of a large number of isomers of the sulfur oxides SnO withn= 4–9 have been calculated at the G3X(MP2) level of theory. In most cases, homocyclic molecules with exocyclic oxygen atoms in an axial position are the global minimum structures. Perfect agreement is obtained with experimentally determined structures of S7O and S8O. The most stable S4O isomer as well as some less stable isomers of S5O and S6O are characterized by a strong π*–π* interaction between SO and SS groups, which results in relatively long SS bonds with internuclear distances of 244–262 pm. Heterocyclic isomers are less stable than the global minimum structures, and this energy difference approximately increases with the ring size: 17 (S4O), 40 (S5O), 32 (S6O), 28 (S7O), 45 (S8O), and 54 kJ mol−1(S9O). Owing to a favorable π*–π* interaction, preference for an axial (orendo) conformation is calculated for the global energy minima of S7O, S8O, and S9O. Vapor‐phase decomposition of SnO molecules to SO2and S8is strongly exothermic, whereas the formation of S2O and S8is exothermic ifn<7, but slightly endothermic for S7O, S8O, and S9O. The calculated vibrational spectra of the most stable isomers of S6O, S7O, and S8O are in excellent agreement with the observed data.
Layer‐by‐Layer Deposition of Rhenium‐Containing Hyperbranched Polymers and Fabrication of Photovoltaic Cells
Authors: Tse Chui Wan , Man Ka Yan Kitty , Cheng Kai Wing , Mak Chris S. K. , Chan Wai Kin , Yip Cho Tung , Liu Zheng Tong , Djurišić Aleksandra B.
Published: October 2006

Multilayer thin films were prepared by the layer‐by‐layer (LBL) deposition method using a rhenium‐containing hyperbranched polymer and poly[2‐(3‐thienyl)ethoxy‐4‐butylsulfonate] (PTEBS). The radii of gyration of the hyperbranched polymer in solutions with different salt concentrations were measured by laser light scattering. A significant decrease in molecular size was observed when sodium trifluoromethanesulfonate was used as the electrolyte. The conditions of preparing the multilayer thin films by LBL deposition were studied. The growth of the multilayer films was monitored by absorption spectroscopy and spectroscopic ellipsometry, and the surface morphologies of the resulting films were studied by atomic force microscopy. When the pH of a PTEBS solution was kept at 6 and in the presence of salt, polymer films with maximum thickness were obtained. The multilayer films were also fabricated into photovoltaic cells and their photocurrent responses were measured upon irradiation with simulated air mass (AM) 1.5 solar light. The open‐circuit voltage, short‐circuit current, fill factor, and power conversion efficiency of the devices were 1.2 V, 27.1 μ A cm−2, 0.19, and 6.1×10−3 %, respectively. The high open‐circuit voltage was attributed to the difference in the HOMO level of the PTEBS donor and the LUMO level of the hyperbranched polymer acceptor. A plot of incident photon‐to‐electron conversion efficiency versus wavelength also suggests that the PTEBS/hyperbranched polymer junction is involved in the photosensitization process, in which a maximum was observed at approximately 420 nm. The relatively high capacitance, determined from the measured photocurrent rise and decay profiles, can be attributed to the presence of large counter anions in the polymer film.
What a Role did Histidine Residue Play in Arylamine N‐Acetyltransferase 2 Acetylation? A Quantum Chemistry Study
Authors: Qiao Qing‐An , Cai Zheng‐Ting , Yang Chuan‐Lu , Wang Mei‐Shan
Published: October 2006

Arylamine N‐acetyltransferases (NATs, EC 2.3.1.5) catalyze an acetyl group transfer from acetyl coenzyme A (AcCoA) to primary arylamines and play a very important role in the metabolism and bioactivation of drugs and carcinogens. Experiments revealed that His‐107 was likely the residues responsible for mediating acetyl transfer. The full catalytic mechanism of acetylation process has been examined by density functional theory. The results indicate that, if the acetyl group is directly transferred from the donor, p‐nitrophenyl acetate, to the acceptor, cysteine, the high activation energy will be a great hindrance. These energies have dropped in a little range of 20–25 kJ/mol when His‐107 assisted the transfer process. However, when protonated His‐107 mediated the reaction, the activation energies have been dropped about 73–85 kJ/mol. Our calculations strongly supported an enzyme acetylation mechanism that experiences a thiolate‐imidazolium pair, and verified the presumption from experiments.
Preparation of Mesoporous Molecular Sieves Al‐MSU‐S Using Ionic Liquids as Template
Authors: Yu Xin‐Yu , Liu Cai‐Hua , Yang Jian‐Guo , Wu Hai‐Hong , Wu Peng , He Ming‐Yuan
Published: October 2006

Mesoporous molecular sieves Al‐MSU‐S has been prepared from the precursor of zeolite Y using ionic liquids 1‐hexadecane‐3‐methylimidazolium bromide (CMIMB) as a template in basic medium, which exhibited larger pore diameter, pore volume and surface area than that synthesized using cetyl trimethyl ammonium bromide (CTAB) template.
Investigation of Antibacterial Activity of Two Kinds of Novel Schiff Bases on Escherichia coli by Microcalorimetry
Authors: Zhu Jun‐Cheng , Liu Yi , Wong Wai‐Kwok , Zhou Bo , Yin Jun
Published: October 2006

The microcalorimetric method was used to study the antibacterial activity of two newly synthesized Schiff base compounds (H2L3′ and H2L3) on Escherichia coli, trying to obtain the action on both of multiplying bacteria and non‐multiplying bacteria at one experiment. The metabolic power‐time curves of the bacteria treated with the compounds were obtained, and the thermokinetic parameters were analyzed, from which the antibacterial activities of these compounds were evaluated. The results showed that both of the two compounds have good activity on aerobic multiplying metabolism of E. coli, with the value of IC50 75.8 and 168.8 mg/L respectively, but have not effective action on fermentation metabolism of E. coli. The action of the compounds on the non‐multiplying metabolism was investigated by taking the heat output of E. coli in the stationary phase as the guideline of the activity. The value of MSC50 (minimum stationary‐cidal concentration 50) of them is 118 and 187.5 mg/L, respectively. So, H2L3′ has stronger antibacterial action on E. coli than H2L3 either for multiplying bacteria or non‐multiplying bacteria, and their activity on the aerobic multiplying bacteria of E. coli is mainly shown. It does strongly suggest that the calorimetric method should play an important role in the fight against the drug‐resistant bacteria.
Thermodynamic Properties of the Azeotropic Mixture of Acetone, Cyclohexane and Methanol
Authors: Wang Xiu‐Rong , Nan Zhao‐Dong , Tan Zhi‐Cheng
Published: October 2006

Molar heat capacities of the pure samples of acetone, methanol and the azeotropic mixture composed of acetone, cyclohexane and methanol were measured by an adiabatic calorimeter from 78 to 320 K. The solid‐solid and solid‐liquid phase transitions of the pure samples and the mixture were determined based on the curve of the heat capacity with respect to temperature. The phase transitions took place at (126.16±0.68) and (178.96±1.47) K for the sample of acetone, (157.79±0.95) and (175.93±0.95) K for methanol, which were corresponding to the solid‐solid and the solid‐liquid phase transitions of the acetone and the methanol, respectively. And the phase transitions occurred in the temperature ranges of 120 to 190 K and 278 to 280 K corresponding to the solid‐solid and the solid‐liquid phase transitions of mixture of acetone, cyclohexane and methanol, respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to standard temperature of 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.
Investigation of Surface Tensions for Pure Fluids outside and inside the Critical Region
Authors: Fu Dong
Published: October 2006

An equation of state (EOS) applicable for both the uniform and non‐uniform fluids was established by using the density‐gradient expansion, in which the influence parameter κ[ρ(r),T] was obtained by the use of direct correlation function. The density functional theory (DFT) provides a framework under which both the phase equilibria and interfacial properties can be investigated within a single set of molecular parameters. The phase equilibria inside the critical region can be improved by the renormalization group theory (RGT). However, the correction of interfacial properties by DFT and RGT is computationally difficult. In the present work, the density gradient theory (DGT) in which κ[ρ(r),T] is treated as a constant is used to combine with the RGT for interfacial properties inside the critical region.
Many‐body Expanded Analytical Potential Energy Function for Ground State PuOH Molecule
Authors: Li Yue‐Xun , Gao Tao , Zhu Zheng‐He
Published: October 2006

Using the density functional method B3LYP with relativistic effective core potential (RECP) for Pu atom, the low‐lying excited states (4Σ+, 6Σ+, 8Σ+) for three structures of PuOH molecule were optimized. The results show that the ground state is X6Σ+of the linear Pu‐O‐H (C∞v), its corresponding equilibrium geometry and dissociation energy are RPu–O=0.20595 nm, RO–H=0.09581 nm and −8.68 eV, respectively. At the same time, two other metastable structures [PuOH (Cs) and H‐Pu‐O (C∞v)] were found. The analytical potential energy function has also been derived for whole range using the many‐body expansion method. This potential energy function represents the considerable topographical features of PuOH molecule in detail, which is adequately accurate in the whole potential surface and can be used for the molecular reaction dynamics research.
Evaluation of Intrinsic Ionization and Complexation Constants of TiO2 and Mg‐Fe Hydrotalcite‐like Compounds
Authors: Hou Wan‐Guo , Ren Carolyn
Published: October 2006

The intrinsic surface reaction constants, pKinta1, pKinta2, p*KintC and p*KintA, were evaluated by a modified double extrapolation (MDE) for TiO2 without structural charge and Mg‐Fe hydrotalcite‐like compounds (HTlc) with structural charge, respectively. The results of intrinsic surface reaction constants for TiO2 were compared with those obtained by class double extrapolation (CDE) in literature. Furthermore, the values of intrinsic surface reaction constants obtained by MDE were used to simulate the charging behaviors of the materials. The following conclusions were obtained. For TiO2 without structural charge, the pKinta1 and pKinta2 evaluated by MDE are equal to those by CDE, however the p*KintC and p*KintA evaluated by MDE are much different from those by CDE. In principle, the results of the p*KintC and p*KintA evaluated by MDE are more accurate than those by CDE. The values of intrinsic surface reaction constants obtained by MDE can excellently simulate the charging curves for TiO2 with the triple layer model (TLM). For HTlc with positive structural charge, the results of *KintC=0 and *KintA→∞ were obtained by MDE, which means the inert electrolyte chemical binding does not exist; the point of zero net charge (PZNC) of c‐independence also exist as the same as solid without structural charge, and the pHPZNC obtained by the acid‐base titration can excellently be simulated and the surface charging tendency can be simulated to a great extent using the pKinta1 and pKinta2 evaluated by MDE and the diffuse layer model (DLM).
Preparation of LLDPE/MgAl‐LDH Exfoliation Nanocomposites with Enhanced Thermal Properties by Melt Intercalation
Authors: Du Long‐Chao , Qu Bao‐Jun
Published: October 2006

The interlayer surface of MgAl layered double hydroxide (MgAl‐LDH) was modified by exchanging about half of the interlayer nitrate anions by dodecyl sulfate anions (DS) to get MgAl(H‐DS) LDH, and then the MgAl(H‐DS) was melt intercalated by LLDPE to get the LLDPE/MgAl‐LDH exfoliation nanocomposites. The samples were characterized by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), ion chromatography, transmission electron microscopy (TEM), and thermogravimetry analysis (TGA). The nanoscale dispersion of MgAl‐LDH layers in the LLDPE matrix was verified by the disappearance of (00l) XRD reflection of the modified MgAl‐LDH and by the TEM observation. The TGA profiles of LLDPE/MgAl‐LDH nanocomposites show a faster charring process between 210 and 370 °C and a higher thermal stability above 370 °C than LLDPE. The decomposition temperature of the nanocomposites with 10 wt% MgAl(H‐DS) can be 42 °C higher than that of LLDPE at 40% weight loss.
Determination of Active Ingredients of Hawthorn by Capillary Electrophoresis with Electrochemical Detection
Authors: Tang Zhu‐Xing , Zeng Yi‐Kun , Zhou Yun , Zang Shu‐Liang , He Pin‐Gang , Fang Yu‐Zhi
Published: October 2006

A method based on capillary electrophoresis with electrochemical detection has been developed for the separation and determination of epicatechin, kaempferol, chlorogenic acid, 4‐hydroxybenzoic acid, quercetin and protocatechuic acid in hawthorn for the first time. The effects of working electrode potential, pH and concentration of running buffer, separation voltage and injection time on CE‐ED were investigated. Under the optimum conditions, the analytes could be separated in a 60 mmol·L−1 borate buffer (pH 8.7) within 21 min. A 300 μm diameter carbon disk electrode has a good response at +0.95 V (vs. SCE) for all analytes. The response was linear over three orders of magnitude with detection limits (S/N=3) ranging from 3×10−8 to 2×10−7 g·mL−1 for the analytes. The method has been successfully applied to the analysis of real sample, with satisfactory results.
Sensitive Method for Enantioseparation of Rivastigmine with Highly Sulfated Cyclodextrin as Chiral Selector by Capillary Electrophoresis
Authors: Wang Zhao‐Yan , Xu Xing‐Xiang , Hu Zhi‐De , Kang Jing‐Wu
Published: October 2006

A sensitive method for enantioseparation of a basic drug rivastigmine and determination of its optical impurity by capillary electrophoresis with highly sulfated β‐cyclodextrin (HS‐β‐CD) as the chiral selector is described. In general, enantioseparation of basic chiral compounds is carried out in acidic condition (pH 2.5) to prevent analytes from adsorption on the capillary wall. However, in the case of rivastigmine, the detection sensitivity was too limited to determine the optical impurity of S‐rivastigmine lower than 1% when buffer pH was 2.5. It was found that the detection sensitivity was improved 1.6 times just by raising the buffer pH value from 2.5 to 5.8. The poor column efficiency due to the adsorption of the analytes on the capillary wall was resolved by using dynamical coating of the capillary wall with the linear polyacrylamide solution. The experimental parameters such as the concentration of HS‐β‐CD, buffer pH and buffer ionic strength were optimized, respectively. The method was validated in terms of repeatability, linearity, limit of detection (LOD) and limit of quantitation (LOQ). Using the present method, the optical purity of nonracemic rivastigmine with the enantiomeric excess (ee) value of 99.14% was determined.
An Efficient Method for Catalytic Asymmetric Reduction of Diketones and Application of Synthesis to Chiral 2,5‐Diphenylpyrrolidine and 2,5‐Diphenylthiolane
Authors: Li Xiang , Zhao Gang , Cao Wei‐Guo
Published: October 2006

Asymmetric reduction of diketones with borane reagents generated in situ using cheap and available NaBH4 and SnCl2 in the presence of (S)‐(−)‐α,α‐diphenyl‐2‐pyrrolidinemethanol was successfully achieved to yield the corresponding chiral diols with excellent stereoselectivity and enantioselectivity. And the chiral diol was transformed into optically pure C2‐symmetricl chiral amine or thioether.
Synthesis of Fluoroalkylated Heterocycles via the Reaction of 3‐(1‐Hydropolyfluoroalkenyl)‐1‐oxo‐2,4,1‐benzoxazines with Dinucleophilic Reagents
Authors: Yang Xian‐Jin , Liu Jin‐Tao
Published: October 2006

The reaction of 3‐(1‐hydropolyfluoroalkenyl)‐1‐oxo‐2,4,1‐benzoxazines 1 with some dinucleophiles was investigated. 7‐Fluoroalkyl‐2,3‐dihydro‐1,4‐diazepine[1,2‐d]quinazolin‐11‐ones 2, 2‐fluoroalkylisoxazolo[3,2‐b]quin‐azolin‐9‐ones 3 and 2‐fluoroalkylbenzoimidazoles 4 were obtained from the reaction of 1 with 1,2‐diaminoethane, hydroxylamine hydrochloride and 1,2‐diaminobenzene respectively.
Synthesis of an Ursolic Acid Saponin with N‐Acetylglucosamine‐containing Trisaccharide Residue
Authors: Wang Peng , Li Chun‐Xia , Wang Guang‐Fa , Li Ying‐Xia
Published: October 2006

The focus of this work is the synthesis of an ursolic acid saponin with an N‐acetylglucosamine‐containing trisaccharide residue. Therefore, ursolic acid 3‐yl α‐L‐arabinopyranosyl‐(1→2)‐α‐L‐arabinopyranosyl‐(1→6)‐2‐acetamido‐2‐deoxy‐β‐D‐glucopyranoside (1) was concisely synthesized in convergent synthesis with 48.0% overall yield. The structure of saponin 1 was confirmed by 1H NMR, 13C NMR and mass spectra.
One‐pot Synthesis of 3‐Aryl‐1,5‐bis(2‐hydroxyaryl)pentane‐1,5‐diones
Authors: Wang Can , Jiang Wen‐Qing , Zou Jian‐Ping , Zeng Run‐Sheng
Published: October 2006

A simple method for the synthesis of 3‐aryl‐1,5‐bis(2‐hydroxyaryl)pentane‐1,5‐diones is developed by one‐pot reaction involving 2‐hydroxyacetophenone and arylaldehyde in aqueous potassium hydroxide.
Asymmetric Allyltributylstannane Addition to Ketones Catalyzed by Chiral Indium(III)‐PYBOX Complex
Authors: Lu Jun , Ji Shun‐Jun
Published: October 2006

An indium complex of chiral pyridine bis(oxazoline) (PYBOX) has been applied to the catalytic asymmetric allylation of ketones. It has been found that this chiral indium complex is strong enough to promote the reaction of ketones with allyltributylstannane smoothly. The products were obtained in moderate yields with low to moderate enantioselectivities.
A New Route to Z‐5‐Fluoro‐2‐methyl‐1‐(p‐methylsulfinylbenzylidene)‐3‐indenylacetic Acid and Its X‐ray Diffraction Analysis
Authors: Zeng Zhuo , Chen Chao‐Sen , Jin Gui‐Fang , Zhao Jing‐Wei , Zhu Shi‐Zheng
Published: October 2006

The title compound (Sulindac) was prepared from the corresponding sulfinyl compound p‐methylsulfinylbenzyl bromide by four‐step reaction. The sole product (Z)‐5‐fuoror‐2‐methyl‐1‐(p‐methylsulfinylbenzylidene)‐3‐indenyl acetic acid (Sulindac) was obtained and the E isomer of it was not found. X‐ray single crystal diffraction analysis showed that the strong intermolecular hydrogen bonding and weak intermolecular hydrogen bonding coexisted in Sulindac.