bluuebunny/crossref_metadata_2025 huggingface dataset:
Substitution of Scarce Metals – A Way out of Resource Scarcities?
Authors: Ziemann S. , Schebek L.
Published: October 2010

Viele technische Anwendungen benötigen eine wachsende Zahl von Metallen, die meist zwar nur in äußerst geringen Mengen in den Produkten enthalten, aber durch ihre einzigartigen Werkstoffeigenschaften nahezu unentbehrlich sind. Eine nachhaltige Bewirtschaftung mineralischer Rohstoffe ist unerlässlich um die Rohstoffversorgung bedeutender Schlüsseltechnologien zu gewährleisten. Die Substitution knapper Metalle wird dabei als eine Erfolg versprechende Strategie angesehen.
Potential of Construction and Demolition Waste as Raw Material
Authors: Müller A. , Schnell A. , Rübner K.
Published: October 2010

Die Ressourcenverknappung und steigende Preise rücken nachhaltiges Wirtschaften und die Wiederverwertung von Abfällen in den Blickpunkt der Forschung. Bauabfälle sind in Deutschland – mit 72,4 Mio. t im Jahr 2004 – der größte Abfallstrom. Es wird ein Überblick über den Stand der Technik zur Aufarbeitung und Verwertung von Bauabfällen gegeben und die Anforderungen an Bauabfälle, die als Sekundärrohstoff eingesetzt werden sollen, diskutiert. Die Forschung im Baustoffrecycling bezieht sich sowohl auf neue Aufbereitungstechniken als auch auf die Charakterisierung der Recyclingmaterialien sowie auf deren Einfluss auf die Betonqualität. Die Eignung und Verwertung von Bauabfällen als Sekundärrohstoffe für Baustoffe wird anhand ihrer chemischen Zusammensetzungen mit Hilfe von ternären Diagrammen diskutiert.
A Theoretical Study on the Vibrational Spectra and Thermodynamic Properties for the Derivatives of 2,5‐Dipicryl‐1,3,4‐oxadiazole with –NO2, –NH2, –OH and –CH3 Groups
Authors: Wang Guixiang , Gong Xuedong , Liu Yan , Xu Xiaojuan , Xiao Heming
Published: September 2010

The derivatives of 2,5‐dipicryl‐1,3,4‐oxadiazole (DPO) with nitro, amino, hydroxy and methyl groups were optimized to obtain their molecular geometries and electronic structures at the DFT‐B3LYP/6‐31G* level. Their IR spectra were obtained and assigned by vibrational analysis. Compared with the experimental results, all the calculated IR data were found to be reliable. Based on the frequencies scaled by 0.96 and the principle of statistic thermodynamics, the thermodynamic properties were evaluated, which are respectively linearly related with the number of nitro, amino, hydroxy and methyl groups as well as the temperature, obviously showing good group additivity.
Photoinduced Electron Transfer within Porphyrin‐Anthra‐quinone Dyads Connected by Hamilton Hydrogen Bonding
Authors: Zhao Xin , Chen Jinping , Zeng Yi , Li Yingying , Han Yongbin , Li Yi
Published: September 2010

Porphyrin‐ or zinc‐porphyrin‐cyanuric acid conjugants (TPP‐CA or ZnTPP‐CA) and anthraquinone connected with the known "Hamilton receptor" (AQ‐H) were synthesized. The supramolecular dyads constructed via the AQ‐H and TPP‐CA/ZnTPP‐CA exhibit six hydrogen bonds, which provide the association constant KAPP approximately (2.8±0.3)×103 mol−1·L in toluene. Selective excitation of the porphyrin/zinc porphyrin chromophores results in an electron transfer between TPP‐CA/ZnTPP‐CA and AQ‐H within the supramolecular assemblies, leading to an efficient quenching of the TPP‐CA/ZnTPP‐CA fluorescence. The singlet electron transfer from porphyrin/ zinc‐porphyrin to anthraquinone proceeds mainly via a 'through space' mechanism with efficiencies of 43%, 58%, and rate constants of 7.6×107, 7.0×108 s−1, respectively.
Study on the Reactions of 3‐Bromo‐4‐ethoxy‐1,1,1‐trifluoro‐ 3‐buten‐2‐one with Benzenethiols Promoted by InCl3·4H2O
Authors: Zhao Jingwei , Song Tao , Jiang Huiling , Xu Liangzhong , Zhu Shizheng
Published: September 2010

In the presence of InCl3·4H2O, the reaction of 3‐bromo‐4‐ethoxy‐1,1,1‐trifluoro‐3‐buten‐2‐one 2 with a series of benzenethiols proceeds readily and gave both the addition‐elimination product 3‐bromo‐1,1,1‐trifluoro‐4‐thiophenyl‐but‐3‐en‐2‐one and substitution product 1,1,1‐trifluoro‐3,4‐bis‐thiophenyl‐but‐3‐en‐2‐one. The reactivity of benzenethiols is discussed in terms of their substituted group.
Synthesis of Oxindoles via Direct Photolysis of N‐(2‐Bromoaryl)alkanamides
Authors: Cao Lidong , Li Chaozhong
Published: September 2010

The direct photolysis of N‐(2‐bromoaryl)alkanamides in refluxing acetonitrile with NaHCO3 as the base afforded the corresponding oxindoles in moderate to high yields under transition‐metal‐free and radical‐initiator‐free conditions.
Identification of Angiotensin I‐Converting Enzyme Inhibitors in Peptides Mixture of Hydrolyzed Red Deer Plasma with Proteomic Approach
Authors: Liu Xiaoyan , Song Chunxia , Chen Rui , Jiang Xinning , Jin Yan , Zou Hanfa
Published: September 2010

Proteomics is a rapidly emerging set of key technologies that are of major importance for proteins and drug development process, especially when mass spectrometry (MS) is being used for high‐throughput characterization and identification of proteins. Since the safer and healthier angiotensin I‐converting enzyme (ACE) inhibitors are extremely concerned, many research groups have combed for novel ACE inhibitors from food components by different approaches. Here, shotgun proteomics technology aided with structure‐activity analysis was applied to screen ACE inhibitory peptides from hydrolyzed red deer plasma. The peptides were analysed by mass spectrometry after primary separation with Sephadex G‐25 chromatography. 36 peptides were identified by searching red deer database and 165 peptide sequences derived were identified in mammalian database. Amino acid sequences of peptide and bioactivity relationship have been developed as a faster and useful way to predict and screen new inhibitors. Depending on the relationship of peptide structure and ACE inhibitory activity, a nonapeptide, VYNEGLPAP, was predicted with ACE inhibitory activity. The activity was verified by synthesized VYNEGLPAP and the 50% inhibition concentration (IC50) was 3.1 µmol·L−1. VYNEGLPAP had good thermal stability, pH stability and strong enzyme‐resistant properties against gastrointestinal protease. Kinetic experiments demonstrated that inhibitory kinetic mechanism of this peptide was competitive. This study demonstrated the possibility of screening bioactive peptides from protein hydrolysates mixture based on shotgun proteomics technology, which will provide a potential convenient method to screening bioactive peptides from protein source.
Application of Tandem Mass Spectra for the Peaks of Isotope Pattern in the Elemental Composition Assignment of Product Ions
Authors: Leng Jiapeng , Wang Haoyang , Zhang Li , Zhang Jing , Guo Yinlong
Published: September 2010

For an ion of known formula, there are some ambiguous formulas with respect to its product ions in tandem mass spectrometry in many cases. Researchers determined them mainly by high resolution mass spectrometer combing database searching. Here, we presented an innovative method to enhance the assignment possibility of the elemental composition of the product ion by exploiting the tandem mass spectra of isotopic peaks from the precursor ion such as [M+H+1]+, [M+H+2]+ and [M+H+3]+. This approach involved a process of excluding low match formulas for product ion stepwise until the final formula with the highest match. It also facilitated the deduction of the fragmentation pathway for the precursor ion in tandem mass spectrometry. The isotopic proportions of product ions possessed a good repeatability. Additionally, this method could be performed fast and conveniently on variety of instruments, which offers an alternative determination tool for the elemental composition of product ion in tandem mass spectrometry.
Floating Potentials in Two‐Electron Temperature Plasma with Two Species of Positive Ions: Kinetic Model and PIC Simulation
Authors: Čerček M. , Fiipič G. , Gyergyek T. , Kovačič J.
Published: September 2010

Potential formation in a two electron temperature plasma with two species of positive ions has been studied analytically by a one‐dimensional, collision‐less fully kinetic model. The results have been verified in a PIC simulation. It has been found that addition of heavy ions and energetic electrons lowers the floating potential of an electrode in plasma. We have also shown that each ion species enters the sheath with the same velocity normalized to the corresponding ion acoustic velocity. Because of that the lighter ions hit the collector with higher velocity as compared to the case when they are the only ion species in the plasma (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐grade prostatic sarcoma seen in a catheterized urine specimen: Case report and differential diagnosis
Authors: Stoll Lisa Marie , Johnson Michael W. , Rosenthal Dorothy L.
Published: October 2010

Urine cytology has been effectively used in the diagnosis and management of epithelial bladder tumors, particularly high‐grade urothelial carcinoma. Indeed it is the gold standard for bladder cancer screening. Although urothelial carcinoma is the most frequently identified bladder tumor by urine cytology, metastatic carcinomas from the kidney, colon, and a variety of other regional organs have been detected. Stromal lesions such as inflammatory myofibroblastic tumor, gastrointestinal stromal tumor, and leiomyosarcoma are other much rarer entities occurring within the bladder. Few to no case reports exist documenting their identification within urine cytology specimens. Herein we report the detection of a high‐grade prostatic sarcoma within a catheterized urine specimen of a young male having a diffusely enlarged prostate. The specimen consisted of numerous fragments of relatively uniform spindle cells having ovoid nuclei with rounded ends and finely dispersed chromatin. Cytoplasmic borders were indistinct. No mitoses or significant atypia was present. The background consisted of numerous red blood cells, cellular debris, and a few clusters of unremarkable urothelial cells. Followup surgical biopsy of the patient's prostate revealed a high‐grade spindle‐cell sarcoma. Further immunohistochemical and molecular delineation of the tumor was not informative for a more definitive diagnosis. Although rare, sarcomas and other mesenchymal tumors involving the bladder are unique entities with a broad differential diagnosis. Diagn. Cytopathol. 2010. © 2010 Wiley‐Liss, Inc.
TLR‐mediated signaling pathways circumvent the requirement for DAP12 in mast cells for the induction of inflammatory mediator release
Authors: Smrž Daniel , Iwaki Shoko , McVicar Daniel W. , Metcalfe Dean D. , Gilfillan Alasdair M.
Published: September 2010

TLR, expressed on the surface of mast cells, respond to a variety of bacterial and viral components to induce and enhance high‐affinity IgE receptor‐mediated cytokine production. Recent reports have indicated that specific TLR‐dependent responses in macrophages and dendritic cells are regulated by the ITAM‐containing molecule, DAP12. When phosphorylated, DAP12 recruits Syk, which is a critical molecule for mast cell activation. We therefore examined whether DAP12 similarly regulates TLR‐mediated responses in mast cells. DAP12 was confirmed to be expressed in both human and mouse mast cells and, upon phosphorylation, to recruit Syk. However, although TLR agonists induced cytokine production, and synergistically enhanced high‐affinity IgE receptor‐mediated cytokine production, surprisingly, they failed to increase DAP12 phosphorylation in mouse bone marrow‐derived mast cells (BMMC). Furthermore, normal TLR‐mediated responses were observed in DAP12−/− BMMC. However, DAP12 phosphorylation and subsequent Syk recruitment were observed in BMMC following Con A‐induced aggregation of mannose‐glycosylated receptors, and these responses, together with Con A‐induced degranulation, were substantially reduced in the DAP12−/− BMMC. These data demonstrate that TLR have differential requirements for DAP12 for their function in different cell types and that the inability of TLR to influence mast cell degranulation may be linked to their inability to utilize DAP12 to recruit Syk.
Enhanced Electrocatalytic Performance of Anthraquinonemonosulfonate‐Doped Polypyrrole Composite: Electroanalysis for the Specific Roles of Anthraquinone Derivative and Polypyrrole Layer on Oxygen Reduction Reaction
Authors: Zhao Sha , Zhang Guoquan , Fu Lei , Liu Lifen , Fang Xiaohong , Yang Fenglin
Published: September 2010

To analyze the specific roles of anthraquinone‐2‐sulfonate (AQS) and polypyrrole (PPy) layer on oxygen reduction reaction (ORR), the electrocatalytic reduction of oxygen was investigated on the AQS/PPy composite modified graphite electrode. Results show that the enhanced electrocatalytic performance is attributed to the excellent electrocatalytic activity of the immobilized AQS functional groups to mediate two‐electron reduction of O2 to H2O2. The PPy layer may not participate in ORR, but it can further catalyze the two‐electron reduction of H2O2 to produce H2O in the potential range more negative than that the two‐electron reduction of oxygen proceeds efficiently on the AQS sites.
Enhanced Direct Electron Transfer of a Multihemic Nitrite Reductase on Single‐walled Carbon Nanotube Modified Electrodes
Authors: Silveira Célia M. , Baur Jessica , Holzinger Michael , Moura José J. G. , Cosnier Serge , Almeida M. Gabriela
Published: September 2010

Single‐walled carbon nanotubes (SWCNTs) deposits on glassy carbon and pyrolytic graphite electrodes have dramatically enhanced the direct electron transfer of the multihemic nitrite reductase from Desulfovibrio desulfuricans ATCC 27774, enabling a 10‐fold increase in catalytic currents. At optimal conditions, the sensitivity to nitrite and the maximum current density were 2.4±0.1 A L mol−1 cm−2 and 1500 µA cm−2, respectively. Since the biosensor performance decreased over time, laponite clay and electropolymerized amphiphilic pyrrole were tested as protecting layers. Both coating materials increased substantially the bioelectrode stability, which kept about 90 % and 60 % of its initial sensitivity to nitrite after 20 and 248 days, respectively.
Landslides in Styria in 2009 /
Authors: Hornich Rudolf , Adelwöhrer Raimund
Published: October 2010

At the end of June 2009, a period of heavy rainfall set in the Austrian state of Steiermark (Styria), which in addition to widespread flooding on the scale of a disaster also caused an unusually large number of landslides. These mass movements affected southeast Styria worst. This was not only due to the concentration of precipitation in the area, but also the particular geological conditions, which are especially favourable for landslides. The landslides severely affected not only agricultural areas but also transport and utility infrastructure so that in the Feldbach district, located in the middle of this area, a state of emergency had to be declared and maintained for several weeks.

Ende Juni 2009 setzte in der Steiermark eine Starkregenperiode ein, die neben zahlreichen Hochwasserüberschwemmungen im Katastrophenausmaß auch eine außerordentlich große Anzahl von Hangrutschungen auslöste. Von diesen Massenbewegungen war hauptsächlich die Südoststeiermark betroffen. Dies lag nicht nur an der Konzentration der Niederschläge in diesem Bereich der Steiermark, sondern auch an den besonderen geologischen Verhältnissen, die Rutschungserscheinungen besonders begünstigen. Von diesen Hangrutschungen waren nicht nur landwirtschaftliche Kulturen, sondern auch Verkehrs‐ und Leitungsinfrastruktur schwer beeinträchtigt, sodass im Bezirk Feldbach, der im Zentrum dieses Bereiches liegt, der Katastrophenzustand ausgerufen werden musste und über mehrere Wochen aufrecht erhalten blieb.
Role of brittle fracture on swelling behaviour of weak rock tunnels: hypothesis and qualitative evidence /
Authors: Steiner Walter , Kaiser Peter K. , Spaun Georg
Published: October 2010

Underground construction in rock prone to swelling behaviour may result in long‐term problems, especially in the invert, if the structure cannot resist swelling pressures. Swelling phenomena are not only a consequence of ground conditions but are strongly influenced by excavation and construction procedures. Evidence of brittle failure observed in the field will be presented and analyzed to prove that brittle failure is the trigger effect of swelling phenomena in shale and clay‐anhydrite rocks. Brittle fractures have also been observed in laboratory swelling tests. Brittle failure can create cracks that form pathways for water, leading to changes in the stress‐state, and as a consequence trigger swelling phenomena. In clay‐anhydrite rock, the swelling pressure is caused by the crystallization pressure of gypsum. The excavation and construction procedures used for the tunnel are a decisive factor for controlling swelling behaviour.

Quellvorgänge in Tongesteinen und Ton‐Anhydritgesteinen führen oft zu langfristigen Problemen in Untertagebauten, insbesondere wenn der Ausbauwiderstand der Tragkonstruktion langfristig zu gering ist. Die Quellvorgänge, die besonders im Sohlbereich auftreten, sind nicht bloß eine Folge der Gesteinseigenschaften, sondern werden auch von den gewählten Bauvorgängen und der Tragkonstruktion beeinflusst. Sprödbruchvorgänge wurden in vielen Untertagbauten in Felsgesteinen mit geringer Festigkeit beobachtet. Deren Ursachen werden mit numerischen Modellen analysiert. Sprödbrüche wurden aber auch in Laborquellversuchen in Ton‐Anhydritgesteinen, wo sich Gips bildete, beobachtet. Die unterschiedlichen Beobachtungen werden in einen gemeinsamen Rahmen zusammengefügt. Sprödbrüche führen zur Bildung von Rissen und damit von Wasserwegen. Weiter ergeben sich wesentlichen Änderungen des Spannungszustands um die unterirdische Öffnung, und als Folge dieser Vorgänge werden Quellerscheinungen ausgelöst. In Ton‐Anhydritgesteinen wird der höhere Quelldruck durch den Kristallisationsdruck von Gips verursacht. Der gewählte Bauvorgang muss Sprödbruchvorgänge möglichst vermeiden und ist ein wesentlicher Faktor des aufzunehmenden Quelldrucks und der Quellerscheinungen.
Religious participation and risky health behaviors among adolescents
Authors: Mellor Jennifer M. , Freeborn Beth A.
Published: September 2010

Previous studies have shown that adolescent religious participation is negatively associated with risky health behaviors such as cigarette smoking, alcohol consumption, and illicit drug use. One explanation for these findings is that religion directly reduces risky behaviors because churches provide youths with moral guidance or with strong social networks that reinforce social norms. An alternative explanation is that both religious participation and risky health behaviors are driven by some common unobserved individual trait. We use data from the National Longitudinal Study of Adolescent Health and implement an instrumental variables approach to identify the effect of religious participation on smoking, binge drinking, and marijuana use. Following Gruber (2005), we use a county‐level measure of religious market density as an instrument. We find that religious market density has a strong positive association with adolescent religious participation, but not with secular measures of social capital. Upon accounting for unobserved heterogeneity, we find that religious participation continues to have a significant negative effect on illicit drug use. On the contrary, the estimated effects of attendance in instrumental variables models of binge drinking and smoking are statistically imprecise. Copyright © 2010 John Wiley & Sons, Ltd.
Do alcohol warning labels influence men's and women's attempts to deter others from driving when intoxicated?
Authors: Tam Tammy W. , Greenfield Thomas K.
Published: October 2010

Research on the federally mandated alcohol warning label has found mixed results, but some findings are consistent with a modest influence on precautionary behaviors to reduce drinkers' self‐reported drunk driving. We hypothesized that warnings would also influence the likelihood of intervening to deter others' driving after drinking. Using data from 1,376 adult drinkers in a U.S. national survey, a conceptual model reflecting effects of exposure to the label's drunk driving message on taking actions to avert another's driving under the influence was tested in a structural equation modeling framework. For men and women, in structural models with drinking and handling of alcoholic beverages potentially affecting both message recall and intervening, the predicted relationships were found between message recall and actions to deter another's drinking driving. This finding suggests that an important preventive effect of the alcohol warning label may be to legitimate collateral attempts to avert another's drunk driving. © 2010 Wiley Periodicals, Inc.
DNA‐Functionalized Carbon Nanotubes: Synthesis, Self‐Assembly, and Applications
Authors: Santiago‐Rodríguez Lenibel , Sánchez‐Pomales Germarie , Cabrera Carlos R.
Published: October 2010

Carbon nanotubes (CNTs) possess outstanding structural, mechanical, and electronic properties. Nevertheless, to achieve the full potential of CNTs, researchers must develop new purification methodologies or improvements in the existing purification and separation protocols, design and study novel functionalization chemistries that result in increased solubility of the CNTs without altering their properties, and devise a straightforward methodology for the attachment of aligned CNTs on solid substrates. To address these challenges, our group has studied the chemical functionalization of CNTs with deoxyribonucleic acid (DNA)—by covalent and non‐covalent approaches—in combination with the self‐assembling technique. In this short review, we will present an overview of DNA‐functionalized CNTs, focusing on the main findings of our group, and the application of the DNA‐CNT complexes as electrochemical biosensors.
Similarity analysis of DNA sequences based on the weighted pseudo‐entropy
Authors: Li Chun , Ma Hong , Zhou Yang , Wang Xiaolei , Zheng Xiaoqi
Published: October 2010

A DNA primary sequence is a string consisting of letters on an alphabet Ω = {a, c, g, t}. Based on all of the 2‐combinations of the set Ω, here the repetition is allowed, we transform a DNA primary sequence into a special sequence over a set with cardinality 10. With the 10‐letter sequence, we associate 10 nonnegative numerical sequences and then derive a 10‐component vector by means of a weighted pseudo‐entropy, which can reflect the information on elements of a sequence and, especially, the order relation among them. The new quantitative characterization of DNA sequences is sensitive to substitution of the string elements. The examination of the relationship among β‐globin genes of 15 species illustrates the utility of the proposed approach. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
Deletion of the p53 tumor suppressor gene improves neuromotor function but does not attenuate regional neuronal cell loss following experimental brain trauma in mice
Authors: Tomasevic Gregor , Raghupathi Ramesh , Scherbel Uwe , Wieloch Tadeusz , McIntosh Tracy K.
Published: October 2010

Deletion of the tumor suppressor gene p53 has been shown to improve the outcome in experimental models of focal cerebral ischemia and kainate‐induced seizures. To evaluate the potential role of p53 in traumatic brain injury, genetically modified mice lacking a functional p53 gene (p53–/–, n = 9) and their wild‐type littermates (p53+/+, n = 9) were anesthetized and subjected to controlled cortical impact (CCI) experimental brain trauma. After brain injury, neuromotor function was assessed by using composite neuroscore and rotarod tests. By 7 days posttrauma, p53–/– mice exhibited significantly improved neuromotor function, in the composite neuroscore (P = 0.002) as well as in two of three individual tests, when compared with brain‐injured p53+/+ animals. CCI resulted in the formation of a cortical cavity (mean volume = 6.1 mm3) 7 days postinjury in p53+/+ as well as p53–/– mice. No difference in lesion volume was detected between the two genotypes (P = 0.95). Although significant cell loss was detected in the ipsilateral hippocampus and thalamus of brain‐injured animals, no differences between p53+/+ and p53–/– mice were detected. Although our results suggest that lack of the p53 gene results in augmented recovery of neuromotor function following experimental brain trauma, they do not support a role for p53 acting as a mediator of neuronal death in this context, underscoring the complexity of its role in the injured brain. © 2010 Wiley‐Liss, Inc.
A time‐lapse and quantitative modelling analysis of neural stem cell motion in the absence of directional cues and in electric fields
Authors: Arocena Miguel , Zhao Min , Collinson Jon Martin , Song Bing
Published: October 2010

Neural stem cell (NSC) migration is an important component of their developmental function and therapeutic potential. Understanding their mode of migration and their response to guidance cues can contribute to improved therapies for CNS repair, in which appropriate homing to sites of injury is essential. Using time‐lapse imaging, we have analyzed the NSC mode of migration in vitro, both in the absence of directional cues and in the presence of applied electric fields (EFs), previously shown to constitute a strong directional signal for these cells. Without EFs, NSCs displayed an amoeboid motion, characterized by small lamellipodial‐like protrusions with changing orientations, leading to highly tortuous migration. In EFs, tortuosity diminished as electrotaxis toward the cathode occurred. EFs suppressed the formation of protrusions oriented toward the anode, suggesting that restriction of protrusions with opposing orientation could underlie the change from tortuous motion to directed migration. Treatment with LY294002, a phosphatidylinositol‐3‐OH kinase (Pi3K) inhibitor, reduced the cathodal bias of protrusions in EFs and the frequency of changes in direction. We generated a model of NSC migration with only two key parameters, which could accurately reproduce experimental migration patterns, and we used it to show that both effects of LY294002 contribute to impair electrotaxis, although decreased protrusion bias is the most important. Our results show that control of protrusion orientation by EFs is an important component of the electrotactic response. A simple modelling approach might be useful in understanding how diverse pharmacological treatments or genetic deletions affect different kinds of directional cell migration. © 2010 Wiley‐Liss, Inc.
Efficient four‐drug cocktail therapy targeting amyloid‐β peptide for Alzheimer's disease
Authors: Asai Masashi , Iwata Nobuhisa , Tomita Taisuke , Iwatsubo Takeshi , Ishiura Shoichi , Saido Takaomi C. , Maruyama Kei
Published: October 2010

Cocktail treatment is an effective multidrug medication therapy for some diseases, such as cancer and AIDS, because of the additive or synergistic effect of each medicine and relief from adverse effects. Amyloid‐β peptide (Aβ), which is now recognized as central to the development of Alzheimer's disease (AD), is derived from the sequential proteolysis of amyloid precursor protein (APP) by β‐ and γ‐secretases. Secretase inhibitors are one of most attractive targets for therapeutic intervention in AD. However, because β‐ and γ‐secretases cleave not only APP but also other substrate proteins, strong inhibition of these secretases leads to severe adverse effects. Some nonsteroidal antiinflammatory drugs (NSAIDs) and cholesterol‐lowering drugs (statins) can modify the production of Aβ. Here, we report that a cocktail treatment with four drugs (NSAID, statin, and β‐ and γ‐secretase inhibitors) had additive effects on the reduction of Aβ levels in cultured cells without competing with each other. Moreover, the four‐drug cocktail treatment caused no changes in processing of the γ‐secretase substrate Notch. This is suggests that this cocktail treatment could be a new therapeutic approach for AD. © 2010 Wiley‐Liss, Inc.
Knockdown of growth‐arrest‐specific gene 7b (gas7b) using short‐hairpin RNA desensitizes neuroblastoma cells to cisplatin: Implications for preventing apoptosis of neurons
Authors: Hung Feng‐Chun , Chao Chuck C.‐K.
Published: October 2010

Efficient control of cell survival and cell proliferation is critical for the development of neuron cells. Earlier, we observed that growth arrest‐specific gene 7 (Gas7) plays a role in controlling neuritogenesis in mammals. In the present study, we report that the Gas7b isoform is involved in controlling growth arrest and apoptosis of neuroblastoma cells in response to various stimuli. Accordingly, knockdown of Gas7b using small‐hairpin RNA (shRNA) was shown to reduce apoptosis induced either by serum starvation or by the antineoplastic agents cisplatin and nocodazole in human neuroblastoma SH‐SY5Y cells. Gas7b knockdown also enhanced the ability of the treated cells to form clones in response to cisplatin. On the other hand, forced expression of Gas7a or Gas7b isoform in mouse neuroblastoma Neuro2A cells, which express a defective Gas7 gene, rendered the cells proapoptotic and vulnerable to cisplatin‐induced apoptosis. In addition, Neuro2A cells that overexpressed Gas7 showed a reduced ability to form clones. Overexpression of Gas7 produced similar but less extensive effects in nonneuronal HEK293 cells. Taken together, our observations suggest that Gas7b is involved not only in neuritogenesis but also in the regulation of neuronal cell death. © 2010 Wiley‐Liss, Inc.
Intra‐articular injection of hyaluronan restores the aberrant expression of matrix metalloproteinase‐13 in osteoarthritic subchondral bone
Authors: Hiraoka Nobuyuki , Takahashi Kenji A. , Arai Yuji , Sakao Kei , Mazda Osam , Kishida Tsunao , Honjo Kuniaki , Tanaka Sakae , Kubo Toshikazu
Published: September 2010

Subchondral bone is a candidate for treatment of osteoarthritis (OA). We investigated the effects of intra‐articular injection of hyaluronan (IAI‐HA) on subchondral bone in rabbit OA model. OA was induced by anterior cruciate ligament transection, with some rabbits receiving IAI‐HA. OA was graded morphologically, and expression of mRNA was assessed by real‐time RT‐PCR. Tissue sections were stained with hyaluronan‐binding protein, and penetration of fluorescent hyaluronan was assessed. The in vitro inhibitory effect of hyaluronan on MMP‐13 was analyzed in human osteoarthritic subchondral bone osteoblasts (OA Ob) by real‐time RT‐PCR and ELISA. Binding of hyaluronan to OA Ob via CD44 was assessed by immunofluorescence cytochemistry. Expression of MMP‐13 and IL‐6 mRNA in cartilage and subchondral bone, and morphological OA grade, increased over time. IAI‐HA ameliorated the OA grade and selectively suppressed MMP‐13 mRNA in subchondral bone. IAI‐HA enhanced the hyaluronan staining of subchondral bone marrow cells and osteocyte lacunae. Fluorescence was observed in the subchondral bone marrow space. In OA Ob, hyaluronan reduced the expression and production of MMP‐13, and anti‐CD44 antibody blocked hyaluronan binding to OA Ob. These findings indicate that regulation of MMP‐13 in subchondral bone may be a critical mechanism during IAI‐HA. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:354–360, 2011
Comparison of joint mechanics of both lower limbs of tha patients with healthy participants during stair ascent and descent
Authors: Lamontagne Mario , Beaulieu Mélanie L. , Beaulé Paul E.
Published: September 2010

Total hip arthroplasty (THA) is a common surgical procedure for patients suffering from osteoarthritis to relieve their pain and to attempt to restore their normal locomotion patterns. Although this procedure does not restore normal mobility during activities of daily living, it remains unclear how it affects the joint mechanics of both lower limbs during stair negotiation tasks. Hence, we compared the 3D joint mechanics of both lower limbs of THA patients with matched healthy controls during stair ascent and stair descent. 3D kinematics and kinetics of both lower limbs were recorded for 20 patients having undergone unilateral THA and 20 healthy, age and body mass index matched control participants. The THA patients generated limited power at the operated hip joint, and thus compensated with larger power generation at the contralateral ankle to lift the body weight to the next step. This stair ambulation strategy, as well as others, adopted by the THA patients implied decreased activation of the lower limb musculature, which may be indicative of a muscle strength deficiency or a post‐operatively adopted protective mechanism to unload the prosthesis. These asymmetric power production patterns should be addressed in rehabilitation programs pre‐ and post‐operatively. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:305–311, 2011
Significance of lymphangiogenesis in primary tumor and draining lymph nodes during lymphatic metastasis of pancreatic head cancer
Authors: Kurahara Hiroshi , Takao Sonshin , Shinchi Hiroyuki , Maemura Kousei , Mataki Yuko , Sakoda Masahiko , Hayashi Tomomi , Kuwahata Taisaku , Minami Koji , Ueno Shinichi , Natsugoe Shoji
Published: September 2010

Background and Objectives

The aim of this study was to investigate the significance of lymphangiogenesis in primary pancreatic tumors and in draining lymph nodes during lymphatic metastasis of pancreatic head cancers.

Methods

Specimens were obtained from 70 patients. To evaluate lymphangiogenesis, we measured lymphatic vessel density (LVD) using D2‐40 antibody in the primary tumors and in the draining lymph nodes. AE1/AE3 antibody was used to detect tiny, histologically negative metastases in lymph nodes.

Results

Patients with high LVD of primary tumors had significantly higher incidence of node metastasis (P = 0.0006) and lower postoperative survival rate (P = 0.0066) than those with low LVD. Intranodal LVDs increased with increasing size of the intranodal metastases. The LVDs of non‐metastatic nodes in patients with node metastasis were also significantly higher than those of non‐metastatic nodes in patients without node metastasis (P < 0.0001). The LVDs of peripancreatic nodes in patients with paraaortic node metastases were significantly higher than those in patients without paraaortic metastasis (P < 0.0001).

Conclusions

Lymphangiogenesis in primary tumors and draining lymph nodes is essential for efficient spread of tumor cells through the lymphatic system. Thus, inhibition of lymphangiogenesis could limit lymphatic dissemination of tumor cells. J. Surg. Oncol. 2010;102:809–815. © 2010 Wiley‐Liss, Inc.
The “dimer nucleophile mechanism” for reactions with rate‐determining first step: Derivation of the whole kinetic law and further treatment of kinetic results
Authors: Alvaro Cecilia E. Silvana , Nudelman Norma Sbarbati
Published: October 2010

Overwhelming evidence has been previously reported for the existence of the so‐called “dimer nucleophile mechanism” in aromatic nucleophilic substitutions by amines in aprotic solvents, for which the most prominent feature is the fourth‐order kinetics (third order in amine) that has been observed with many different substrate–nucleophile systems, especially those in which departure of the nucleofuge is the rate‐determining step. The mechanism has been confirmed by several other features, although other alternative mechanisms were suggested to explain the fourth‐order kinetics, no one has been able to explain the other above‐mentioned features. The present paper affords additional experimental evidence and derivation of the kinetic expressions for reactions with good nucleofugues, where the first step is rate determining. The work involves studies of the reactions of 2,4‐dinitrofluorobenzene and 2,4‐dinitrochlorobenzene with aniline and with alkyldiamines in toluene. The novelty of this work lies in the selection of substrate–nucleophile systems exhibiting kinetic behavior that allows estimations of the different k's involved. The satisfactory agreement between the quotients of k's calculated from sets of data obtained under different reaction conditions hereby reported indicates that the assumptions made are correct and that the whole treatment applied to the kinetic data is justified. All together, the results fit well with the reaction scheme involving the dimer nucleophile mechanism, adding new evidence to this mechanism that it is well established in the current literature. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 735–742, 2010
Cytochrome P450 17 (CYP17) is involved in endometrial cancinogenesis through apoptosis and invasion pathways
Authors: Chen Yi , Saini Sharanjot , Zaman Mohd Saif , Hirata Hiroshi , Shahryari Varahram , Deng Guoren , Dahiya Rajvir
Published: September 2010

Cytochrome P450 17 (CYP17) encodes cytochrome P450c17α, an enzyme with 17α‐hydroxylase and 17, 20‐lyase activities involved in estradiol biosynthesis. Here we examine the role of CYP17 gene in endometrial carcinogenesis. Immunohistochemistry staining of endometrial carcinoma and corresponding uninvolved tissues showed that CYP17 is upregulated in endometrial cancers (15 of 24, 62.5%). To understand the functional significance of this upregulation, we silenced CYP17 gene by introduction of siRNA into endometrial cancer cell line KLE followed by functional studies. Further, to understand the molecular basis of the role of CYP17, we profiled the expression of key pathway‐specific genes and identified several components of the apoptosis and invasion pathways that are potentially regulated by CYP17. Silencing of CYP17 caused decreased cell proliferation and induced apoptosis. Significantly, CYP17 depletion leads to downregulation of anti‐apoptotic genes B cell lymphoma 2 (Bcl‐2) and telomerase reverse transcriptase (TERT), indicating induced apoptosis. Also, attenuation of CYP17 decreased the cellular invasion ability and regulated expression of several invasion pathway components such as melanoma cell adhesion molecule (MCAM), matrix metallopeptidase 2 and 9 (MMP‐2 and MMP‐9), and tissue inhibitor of metalloproteinase 3 (TIMP3). In conclusion, this is the first report documenting that upregulation of CYP17 in endometrial cancers play a crucial role in endometrial carcinogenesis by targeting multiple components of apoptosis and invasion pathways. Further studies are required to understand the detailed mechanisms underlying CYP17‐mediated regulation of these components. Mol. Carcinog. © 2010 Wiley‐Liss, Inc.
Intracellular cathepsin B activity is inversely correlated with the quality and developmental competence of bovine preimplantation embryos
Authors: Balboula A.Z. , Yamanaka K. , Sakatani M. , Hegab A.O. , Zaabel S.M. , Takahashi M.
Published: October 2010

Recently, the activity of cathepsins B was found to be correlated inversely with the developmental competence of bovine oocytes. In this study, we investigated (1) the role of intracellular cathepsin B expression and developmental competence as well as the quality of bovine preimplantation embryos, and (2) the effect of cathepsin B inhibitor (E‐64) during in vitro culture (IVC) on the development and quality of bovine embryos. After in vitro fertilization (IVF) followed by IVC for 7 days, good and poor quality embryos classified by morphology and developmental rate on days 2, 4, and 7 were assessed for cathepsin B expression and activity. To investigate the effect of cathepsin B inhibition on embryonic development, putative zygotes were cultured with or without E‐64, followed by evaluation of cleavage and blastocyst rates on days 2 and 7, respectively. Embryonic quality was evaluated by both TUNEL staining and total cell number in day‐7 blastocysts. In each developmental stage, cathepsin B expression and activity were significantly higher in poor quality embryos than good quality ones. Moreover, addition of E‐64 during IVC significantly increased both the blastocyst rate and the total cell number. TUNEL staining revealed that inhibition of cathepsin B significantly decreased the number of apoptotic nuclei in day‐7 blastocysts. These results indicate that cathepsin B activity can be useful as a marker for inferior quality embryos. Moreover, inhibition of cathepsin B greatly improves the developmental competence of preimplantation embryos and increases the number of good quality embryos. Mol. Reprod. Dev. 77:1031–1039, 2010. © 2010 Wiley‐Liss, Inc.
Magnetic field threshold for accurate electrocardiography in the MRI environment
Authors: Jekic Mihaela , Ding Yu , Dzwonczyk Roger , Burns Patrick , Raman Subha V. , Simonetti Orlando P.
Published: October 2010

Although the electrocardiogram is known to be nondiagnostic within the bore of any high‐field magnet due to the magnetohydrodynamic effect, there are an increasing number of applications that require accurate electrocardiogram monitoring of a patient inside the MRI room but outside of the magnet bore. Magnetohydrodynamic effects on the ST segment of the electrocardiogram waveform were investigated in six subjects at magnetic field strengths ranging from 6.4 mT to 652 mT at the aortic midarch, and the electrocardiogram was found to be accurate at magnetic fields below 70 mT. This corresponds to a distance of 160 cm from the isocenter and 80 cm from the bore entrance for the 1.5‐T MRI system used in this study. These results can be translated to any MRI system, with knowledge of the fringe field. Accurate electrocardiogram monitoring is feasible in close proximity to the MRI magnet, such as during and after pharmacologic or exercise stress, or interventional or surgical procedures performed in the MRI room. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Stability analysis of an embankment resting upon a column‐reinforced soil
Authors: Jellali B. , Bouassida M. , de Buhan P.
Published: October 2010

The design against failure of an embankment resting upon a soft soil improved by a group of columns is investigated with the help of the yield design homogenization approach. Assuming that both constituents of the reinforced ground are purely cohesive materials (‘lime column’ technique), an upper bound estimate for the macroscopic strength condition of the reinforced soil as a homogenized medium is first obtained, providing definite evidence of a shear strength anisotropy associated with the reinforcement preferential orientation. The kinematic method of yield design is then performed on the basis of such a criterion, making use of rotational failure mechanisms involving slip circles in the reinforced ground. Upper bound estimates are finally obtained for the embankment stability factor, as functions of the degree of reinforcement and relative thickness of the soil layer. These results are compared with those derived from a simplified analysis, where the reinforced soil is assumed to exhibit an averaged isotropic cohesion. This comparison clearly indicates that the latter simplified analysis may produce quite unsafe estimates for the embankment stability, which can be attributed to the fact that it fails to capture the inherent strength anisotropy of the reinforced soil. Copyright © 2010 John Wiley & Sons, Ltd.
Generalized plasticity state parameter‐based model for saturated and unsaturated soils. Part 1: Saturated state
Authors: Manzanal Diego , Fernández Merodo José Antonio , Pastor Manuel
Published: October 2010

The behavior of granular materials is known to depend on its loose or dense nature, which in turns depends both on density and confining pressure. Many models developed in the past require the use of different sets of constitutive parameters for the same material under different confining pressures. The purpose of this paper is to extend a basic generalized plasticity model for sands proposed by Pastor, Zienkiewicz and Chan by modifying the main ingredients of the model flow—rule, loading–unloading discriminating direction and plastic modulus—to include a dependency on the state parameter. The proposed model is tested against the available experimental data on three different sands, using for each of them a single set of material parameters, finding a reasonably good agreement between experiments and predictions. Copyright © 2010 John Wiley & Sons, Ltd.
Numerical zoom for advection diffusion problems with localized multiscales
Authors: Lozinski Alexei , Pironneau Olivier
Published: October 2010

We investigate the Schwarz'domain decomposition algorithm for numerical zooms. Error estimates are given for nonmatching meshes for elliptic and parabolic partial differential equations. The method is applied to the security assessment of the burial of nuclear waste which is a typical multiscale problem for porous media flow. © 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2010
Deciphering the role of the thermodynamic and kinetic stabilities of SH3 domains on their aggregation inside bacteria
Authors: Castillo Virginia , Espargaró Alba , Gordo Veronica , Vendrell Josep , Ventura Salvador
Published: September 2010

The formation of insoluble deposits by globular proteins underlies the onset of many human diseases. Recent studies suggest a relationship between the thermodynamic stability of proteins and their in vivo aggregation. However, it has been argued that, in the cell, the occurrence of irreversible aggregation might shift the system from equilibrium, in such a way that it could be the rate of unfolding and associated kinetic stability instead of the conformational stability that controls protein deposition. This is an important but difficult to decipher question, because kinetic and thermodynamic stabilities appear usually correlated. Here we address this issue by comparing the in vitro folding kinetics and stability features of a set of non‐natural SH3 domains with their aggregation properties when expressed in bacteria. In addition, we compare the in vitro stability of the isolated domains with their effective stability in conditions that mimic the cytosolic environment. Overall, the data argue in favor of a thermodynamic rather than a kinetic control of the intracellular aggregation propensities of small globular proteins in which folding and unfolding velocities largely exceed aggregation rates. These results have implications regarding the evolution of proteins.
Microwave‐assisted synthesis of star‐shaped poly(ε‐caprolactone)‐block‐poly(L‐lactide) copolymers and the crystalline morphologies
Authors: Zhang Zhonghai , Ren Jie , Feng Yue , Li Jianbo , Yuan Weizhong
Published: October 2010

A monomode microwave reactor was used for the synthesis of designed star‐shaped polymers, which were based on dipentaerythritol with six crystallizable arms of poly(ε‐caprolactone)‐b‐poly(L‐lactide) (PCL‐b‐PLLA) copolymer via a two‐step ring‐opening polymerization (ROP). The effects of irradiation conditions on the molecular weight were studied. Microwave heating accelerated the ROP of CL and LLA, compared with the conventional heating method. The resultant hexa‐armed polymers were fully characterized by means of FTIR, 1H NMR spectrum, and GPC. The investigation of thermal properties and crystalline behaviors indicated that the crystalline behaviors of polymers were largely depended on the macromolecular architecture and the length of the block chains. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Accelerating effects of N‐aryl‐N′,N′‐dialkyl ureas on epoxy‐dicyandiamide curing system
Authors: Liu Xiang Dong , Kimura Mika , Sudo Atsushi , Endo Takeshi
Published: October 2010

This report focuses on epoxy‐dicyandiamide (DICY) curing system accelerated by N‐aryl‐N′,N′‐dialkyl urea, aiming at clarifying the accelerating mechanism and the relationship between accelerating effect and molecular structure of the accelerators. Nine N‐aryl‐N′,N′‐dialkyl ureas were synthesized and investigated with measurements of differential scanning calorimetry, thermo gravimetric/differential thermal analysis and NMR spectroscopy. The results revealed that the ureas released the corresponding secondary amines by the thermal dissociation in the presence of epoxide, which led to the formation of tertiary amines that catalyze the addition reaction of DICY to epoxide. Moreover, a tendency that the ureas able to release more compact amines exhibited higher acceleration effects was discovered. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010