bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanoparticulate Functional Materials
Authors: Goesmann Helmut , Feldmann Claus
Published: January 2010

Nanoparticulate functional materials offer manifold perspectives for the increasing miniaturization and complexity of technical developments. Nanoparticles also make a major contribution to utilization of materials that is sparing of natural resources. Besides these obvious aspects, however, the importance of nanoparticles is due to their fundamentally novel properties and functions. These include photonic crystals and efficient luminophors, single particles and thin films for electronic storage media and switching elements, magnetic fluids and highly selective catalysts, a wide variety of possibilities for surface treatments, novel materials and concepts for energy conversion and storage, contrast agents for molecular biology and medical diagnosis, and fundamentally novel forms and structures of materials, such as nanocontainers and supercrystals. Creating high‐quality nanoparticles requires that numerous parameters, involving the particle core and surface, colloidal properties, and particle deposition, are taken into consideration during synthesis of the material. An appropriate characterization and evaluation of the properties requires the incorporation of a wide range of expertise from widely differing areas. These circumstances are what challenges and appeals to the nanoscientist.
Studies on shrinkage, depth of cure, and cytotoxic behavior of novel organically modified ceramic based dental restorative resins
Authors: Lizymol P. P.
Published: January 2010

Polymerization shrinkage, depth of cure, and in vitro cytotoxic behavior of dental restorative composite based on inorganic–organic hybrid (organically modified ceramic) resins, containing alkoxides of silicone, calcium, and titanium with various polymeric methacrylate groups were evaluated in this study. Comparison was made between dimethacrylate and tetra methacrylate resins. Statistical evaluation using analysis of variance (single factor) showed that tetramethacrylate organically modified ceramic resin‐based composites showed better shrinkage properties. P < 0.05 was considered as statistically significant. Compared to dimethacrylates, tetramethacrylates based composites showed lower depth of cure value. Cytotoxicity characteristics of these composites were mainly depending on the nature of inorganic material incorporated rather than difference in dimethacrylate or tetramethacrylate structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of poly(methyl methacrylate) addition on the dielectric and energy storage properties of poly(vinylidene fluoride)
Authors: Meng Qingjie , Li Wenjing , Zheng Yuansuo , Zhang Zhicheng
Published: January 2010

Poly(methyl methacrylate) (PMMA) was introduced into poly(vinylidene fluoride) (PVDF) via a solution blending process, and a series of PVDF/PMMA blends were obtained in an effort to reduce the energy loss of pure PVDF. The effects of the composition and thermal treatment on the properties of the polymer blends were carefully studied. The results show that the introduction of PMMA led to a lower crystallinity and a smaller crystal size of PVDF for its dilution effect. As a result, the dielectric constant and energy storage density of the polymer blends were slightly reduced. Meanwhile, the phase transition of the PVDF crystals from the α phase to the β phase happened during the quenching of the blend melt to ice–water; this was also observed in the untreated or annealed blends with PMMA contents over 50 wt %. Compared with the α‐PVDF, the PVDF crystals in the β phase possessed a lower melting temperature, a higher dielectric constant, and a lower dielectric loss. The addition of PMMA reduced the energy loss of PVDF significantly, whereas the energy storage density decreased slightly. The optimized blend film with about 40 wt % PMMA and PVDF in the β phase showed a relative high energy storage density and the lowest energy loss. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and self‐assembly of polyaniline nanorods and their application as electroactive actuators
Authors: Kim Seong Hun , Oh Kyung Wha , Choi Ji Hyoung
Published: January 2010

To improve the performance of ion‐exchange polymer–metal composite (IPMC) actuators, an electrical pathway material for enhancing the surface adhesion between the membrane and the metal electrodes of the IPMC was studied. As an efficient electrical pathway material, polyaniline nanorods (PANI‐NRs) doped with p‐toluene sulfonic acid (TSA) were synthesized with a template‐free method. The factors affecting polyaniline morphology were studied with various dopant concentrations and oxidant feeding rates. Highly conductive PANI‐NRs were formed when they were synthesized with ammonium persulfate at a 5.0 mL/min oxidant feeding rate and doped with 0.125M TSA. The conductivity of the PANI‐NRs was 1.15 × 10−1 S/cm, and their diameters and lengths were 120–180 nm and 0.6–2 μm, respectively. To apply the membrane as an actuator, perfluorosulfonated ionomer (Nafion)/PANI‐NR blends were prepared by solution blending and casting. The actuating ability of the three‐layered membrane consisting of Nafion/PANI‐NR blends was then examined and compared with that of Nafion only. The actuating ability of the IPMC was improved when Nafion/PANI‐NRs were used as electrical pathways. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Gelatin‐g‐poly(methyl methacrylate)/silver nanoparticle hybrid films and the evaluation of their antibacterial activity
Authors: Liu Ying , Liu Xiaoheng , Wang Xin , Yang Jiazhi , Yang Xu‐Jie , Lu Lude
Published: January 2010

We designed and prepared novel hybrid films of nanoparticles consisting of gelatin‐g‐poly(methyl methacrylate) (PMMA)/silver (Ag) polymers with ordered nanoporous, higher antibacterial activities. First, the gelatin‐grafted PMMA microspheres were fabricated with the in situ copolymerization of gelatin and alkenes under radical initiation, which acted as a stabilizer and regulator for Ag nanoparticle growth. Then, silver nitrate was entrapped in a copolymerization system at 40°C for 30 min. Finally, the gelatin‐g‐PMMA/Ag polymer hybrid films were prepared by the reduction of Ag+ with hydrazine, followed by emulsion solidification. The antibacterial activities of the gelatin‐g‐PMMA/Ag polymer hybrid films against Escherichia coli and Staphylococcus aureus were found with the disc diffusion method and colony count assays to be clear and lasting. In this study, our work not only presented a good example of a nanoporous antibacterial film material but also provided a facile method for making use of gelatin and metal/inorganic self‐assemble properties in graft copolymerization to prepare functional polymer hybrids, such as antibacterial, antithrombogenic, and dot‐quantum effect materials. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Mechanical and functional properties of composites based on graphite and carboxylated acrylonitrile butadiene rubber
Authors: Yang Jian , Zhang Li‐Qun , Shi Jun‐Hong , Quan Yan‐Nan , Wang Lei‐Lei , Tian Ming
Published: January 2010

In this study, carboxylated acrylonitrile butadiene rubber (xNBR)/expanded graphite (EG) nanocomposites were prepared with a latex compounding technique by ultrasonic stirring. The dispersion of EG in the xNBR matrix was investigated with transmission electron microscopy, scanning electron microscopy, and X‐ray diffraction analysis. EG could be exfoliated into lots of nanosheets dispersing in the xNBR matrix. More EG loading resulted in the presence of a few incompletely exfoliated agglomerates. The mechanical properties (hardness, tensile modulus, and tensile strength) of the xNBR/EG composites were determined. Dynamic mechanical thermal analysis was also performed, and it showed that the nanosheets of EG somewhat immobilized the motion of rubber macromolecular chains and led to the shifting and broadening of the tan δ peak toward higher temperatures. Many other functional properties of EG‐filled xNBR composites were studied, and it was established that the composites had excellent electrical conductivity as well as gas‐barrier and wear properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Polyurethane/acrylate hybrids: Effects of the acrylic content and thermal treatment on the polymer properties
Authors: Peruzzo Pablo J. , Anbinder Pablo S. , Pardini Oscar R. , Costa Carlos A. , Leite Carlos A. , Galembeck Fernando , Amalvy Javier I.
Published: January 2010

Polyurethane (PU)/acrylate hybrids with different acrylic contents (10, 30, 50, 70, and 90 wt %) were prepared by the polymerization of acrylic monomers in the presence of preformed PU chains with polymerizable terminal vinyl groups. Films obtained by the casting of polymer dispersions before and after thermal annealing were characterized by dynamic light scattering, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), TEM electron energy‐loss spectroscopy, differential scanning calorimetry, and gel fraction determination. Small‐angle X‐ray scattering (SAXS), wide‐angle X‐ray scattering, mechanical properties testing, atomic force microscopy, water contact angle testing, Buchholz hardness testing, and roughness testing of the films were also performed. The effects of the acrylic content and thermal treatment on the structure and properties were determined. TEM showed that a core–shell morphology was formed during polymerization. When the acrylic content increased, smaller particles without core–shell morphologies were observed. TEM energy‐loss spectroscopy studies confirmed this observation. Systems with up to 50 wt % acrylic component were homogeneous, as determined by SAXS, before and after thermal annealing. An attempt to incorporate a higher amount of acrylic component led to phase‐separated materials with a different morphology and, therefore, different properties. The relationship between the acrylic content and properties did not follow linear behavior. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Characteristic rheological features of high concentration PVA solutions in water with different degrees of polymerization
Authors: Gao Hanwen , He Jiyu , Yang Rongjie , Yang Lei
Published: January 2010

This work aims to study the impact of the degree of polymerization (Pn) on the rheological behavior of PVA solutions (15 wt %) under steady and oscillatory shear conditions. The values of Pn range from 1300 to 2400. The results show that PVA‐13 solution exhibits almost Newtonian flow behavior, whereas high Pn PVA solutions exhibit shear thinning behavior, for which the complex viscosity increases with Pn. However, the shear viscosity of PVA‐24 is lower than that of PVA‐20 at low shear rate (<1 s−1). In addition, the storage modulus of PVA solutions increases with increasing degree of polymerization from 1300 to 2000. There is a sharp increase at degrees of polymerization higher than 1300. However, the storage modulus of PVA‐24 is lower than that of PVA‐17 and PVA‐20 at low shear rate (<1 rad/s). The viscoelastic exponent of the PVA solutions shows a minimum value at degree of polymerization 2000. Thixotropy is detected by a hysteresis loop of the flow curves. The creep response of PVA solutions has also been investigated, with PVA‐24 showing negligible compliance recovery. These facts indicate that increasing Pn produces a corresponding effect in varying the molecular structure and types of hydrogen bonding, including intra‐ and inter‐chain, and polymer–water hydrogen bonding. Rheological parameters (G′, n, tanδ, J, and so on) can be used to evaluate the change in the molecular structure and type of hydrogen bonding. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Relaxation behavior of conductive carbon black reinforced chlorosulfonated polyethylene composites
Authors: Nanda M. , Tripathy D. K.
Published: January 2010

Dynamic mechanical analysis and dielectric relaxation spectra of conductive carbon black reinforced chlorosulfonated polyethylene (CSM) composites were used to study their relaxation behavior as a function of temperature and frequency, respectively. A marginal increase in glass transition temperature has been observed upto 30 phr carbon black filled polymer composite, beyond which it decreases, which has been explained on the basis of aggregation of filler particles in the polymer matrix. The strain dependent dynamical parameters were evaluated at dynamic strain amplitudes of 0.1–200%. The nonlinearity in storage modulus increases with increase in filler loading. It can be explained on the basis of filler–polymer interaction and aggregation of the filler particulates. The frequency dependent dynamical mechanical analysis has also been studied at frequency range of 0.1–100 Hz. The variation in real and complex part of impedance with frequency has been studied as a function of filler loading. The effect of filler loading on ac conductivity has been observed as a function of frequency. An increase in conductivity value has been observed with increase in filler loading. This can be explained on the basis of formation of conducting paths between filler particulates. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and Evaluation of Novel Indolylthiadiazinoazetidinones and Indolylthiadiazinothiazolidinones as Antimicrobial Agents
Authors: Kumar Vikas , Sharma Suneel Kumar , Singh Sheoraj , Kumar Ashok , Sharma Shalabh
Published: January 2010

Some new 5‐methoxy/ethoxy‐2,3‐[2′‐(3′′‐chloro‐2′′‐oxo‐4′′‐substituted‐aryl‐1′′‐azetidinyl)‐1′,3′,4′‐thiadiazino]indoles 13–20 and 5‐methoxy/ethoxy‐2,3‐[2′‐(2′′‐substituted‐aryl‐4′′‐oxo‐1′′,3′′‐thiazolidin‐3′′‐yl)‐1′,3′,4′‐thiadiazino]indoles 21–28 have been synthesized from 5‐methoxy/ethoxy‐2,3‐[2′‐(substituted‐benzylidinylimino)‐1′,3′,4′‐thiadiazino]indoles 5–12. These newly synthesized compounds were characterized by elemental and spectral analysis. Further, compounds 5–28 of the present series have been screened for their antibacterial and antifungal activities. Both minimal inhibitory concentration (MIC) and inhibition zones were determined in order to monitor the efficacy of the synthesized compounds. Compounds 14 and 16 were found to be the most potent members of the present series, they showed maximal antibacterial and antifungal properties much better than the standard drugs.
An empirical analysis of engineers' information behaviors
Authors: Robinson Mark A.
Published: January 2010

The importance of the acquisition and provision of information within knowledge work such as engineering is widely acknowledged. This article reports an extensive empirical study of such information behaviors in engineers, using a novel and effective work sampling method. Seventy‐eight design engineers each carried a portable handheld computer (PDA) for 20 working days. Once every hour, they were prompted to enter data concerning the task they were currently performing, including the information behaviors in which they were engaging. The resultant data represent a comprehensive picture of engineers' information behaviors and the percentage of their working time for which each of these behaviors accounts (55.75% in total). Specific hypotheses concerning the time spent engaged in these behaviors were also tested. Accordingly, it was found that participants spent substantially more time receiving information they had not requested than information they had, and this pattern was also reflected when they provided others with information. Furthermore, although there was no difference found between the time participants spent searching for information from other people compared with nonhuman sources, in the former case they spent relatively less time locating the information source and information within that source, and relatively more time engaged in problem solving and decision making. The results are discussed in terms of their implications for theory and organizational practice.
The modifying effects of green tea polyphenols on acute colitis and inflammation‐associated colon carcinogenesis in male ICR mice
Authors: Kim Mihye , Murakami Akira , Miyamoto Shingo , Tanaka Takuji , Ohigashi Hajime
Published: January 2010

Reactive oxygen species (ROS) have been implicated as mediators of intestinal inflammation and carcinogenesis. Although green tea polyphenols (GTP) have anticancer property as antioxidants they also generate ROS in vitro. In this study, we investigated the modifying effects of GTP on dextran sulfate sodium (DSS)‐induced acute colitis and on 1,2‐dimethylhydrazine (DMH) and DSS‐induced colon carcinogenesis in male ICR mice. At sacrifice after 6 days, the colon shortening induced by 2% DSS was unchanged by 0.1% and 0.25% GTP, but increased by 0.5% and 1% GTP‐containing diet. The expression of interleukin‐1β and macrophage‐migration inhibitory factor in the DSS + 0.1% GTP group were lower than the DSS alone group, whereas the expression levels were increased in the DSS + 0.5% GTP and DSS + 1% GTP groups when compared with the DSS alone group. In a subsequent experiment to determine the effects of 0.01–1% GTP on inflammation‐associated colon carcinogenesis induced by DMH/DSS, 0.5 and 1% doses of GTP failed to prevent the development of multiple colon tumors, rather, they tended to increase it. Our results thus indicate that the modifying effects of GTP on DSS‐induced acute colitis and DMH/DSS‐induced colon carcinogenesis depends upon its dosage and the expression of proinflammatory cytokines.
Present trends in vitamin E research
Authors: Galli Francesco , Azzi Angelo
Published: January 2010

Nearly after one century of research and thousands of publications, the physiological function(s) of vitamin E remain unclear. Available evidence suggests a role in cell homeostasis that occurs through the modulation of specific signaling pathways and genes involved in proliferative, metabolic, inflammatory, and antioxidant pathways. Vitamin E presence in the human body is under close metabolic control so that only α‐tocopherol and, to a lower extent, γ‐tocopherol are retained and delivered to tissues. Other vitamin E forms that are not retained in the body in significant amounts, exhibit responses in vitro that are different form those of α‐tocopherol and may include tumor cell specific toxicity and apoptosis. These responses provide a therapeutic potential for these minor forms, either as such or metabolically modified, to produce bioactive metabolites. These cellular effects go beyond the properties of lipophilic antioxidant attributed to α‐tocopherol particularly investigated for its alleged protective role in atherosclerosis or other oxidative stress conditions. Understanding signaling and gene expression effects of vitamin E could help assign a physiological role to this vitamin, which will be discussed in this review. Besides vitamin E signaling, attention will be given to tocotrienols as one of the emerging topics in vitamin E research and a critical re‐examination of the most recent clinical trials will be provided together with the potential use of vitamin E in disease prevention and therapy.
Garlic‐derived anticancer agents: Structure and biological activity of ajoene
Authors: Kaschula Catherine H. , Hunter Roger , Parker M. Iqbal
Published: January 2010

Garlic has been used throughout the centuries to treat infections, heart disease, and cancer. Ajoene is one of the main compounds formed from heating crushed garlic as a mixture of E‐ and Z‐isomers (E‐ and Z‐4,5,9‐trithiadodeca‐1,6,11‐triene 9‐oxide). Ajoene possesses a broad spectrum of biological activities that include anticancer activity. It's cytotoxicity towards cancer cells is postulated to occur via an apoptotic mechanism involving activation of the mitochondrial‐dependent caspase cascade. Structure‐activity studies on ajoene and ajoene analogues have revealed that the Z‐isomer is moderately more active than the E‐isomer at inhibiting in vitro tumor cell growth, suggesting that specific protein interactions may be important. Substitution of the terminal end allyl groups in ajoene for alkyl, aromatic, or heteroaromatic groups produces some analogs with superior in vitro anticancer activity to ajoene, opening up the way to developing ajoene‐based anticancer agents.
Biosynthesis of metal and oxide nanoparticles using Lactobacilli from yoghurt and probiotic spore tablets
Authors: Jha Anal K. , Prasad K.
Published: January 2010

Green, low‐cost, and reproducible Lactobacillus‐mediated biosynthesis of metal and oxide nanoparticles are reported. Silver and titanium dioxide nanoparticles are synthesized using Lactobacillus sp. procured from yoghurt and probiotic tablets. The synthesis is performed akin to room temperature in the laboratory ambience. X‐ray and transmission electron microscopy analyses are performed to ascertain the formation of metallic and oxide nanoparticles. Individual nanoparticles having the dimensions of 10–25 nm (n‐Ag) and 10–70 nm (n‐TiO2) are found. The mechanism involved for the synthesis of metallic and oxide nanoparticles has also been discussed.
Executive perceptions of adopting an environmental certification program
Authors: Michael Judd H. , Echols Ann E. , Bukowski Steve
Published: January 2010

Environmental certification is playing an increasingly important role in the strategies of many businesses. This is due in large part to consumer demand for environmentally friendly products. Little is known, however, about why executives adopt environmental certification for a product or process, or how they view the benefits and challenges of certification. This paper seeks to advance our knowledge in this area by exploring executives' perceptions of benefits and challenges associated with adopting an environmental certification program. We surveyed executives in the kitchen cabinet industry about a second party certification scheme initiated for producers in that industry. Results suggest that perceptions of the benefits and challenges of environmental certification differ significantly based on whether the company had or had not adopted the certification scheme in question. The paper considers the implications for companies considering adopting environmental certification as well as for organizations providing certification schemes. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Laparoscopic pelvic anatomy of nerve‐sparing radical hysterectomy
Authors: Park Nae Yoon , Cho Young Lae , Park Il Soo , Lee Yoon Soon
Published: January 2010

Many reports regarding nerve‐sparing radical hysterectomy have been published. However, most reports have been based on systematic descriptions via laparotomy or cadaver dissection. The aim of this work was to describe the pelvic anatomy of nerve‐sparing radical hysterectomy via laparoscopy, with specific focus on the inferior hypogastric plexus. This study is based on 125 patients with FIGO stage IB cervical cancer who had undergone laparoscopic nerve‐sparing radical hysterectomies since 1999. The inferior hypogastric plexus was demonstrated via laparoscopy and was comprised of afferent fibers from the sacral root (S2, S3, and S4), sacral sympathetic ganglion, and hypogastric nerve, and efferent fibers forming its vesical, uterovaginal, and rectal branches. During the dissection of the posterior leaf of the vesicouterine ligament, various vesical veins were identified. If the cut edge of an inferior vesical vein was pulled medially with upward traction, the vesical branches of the inferior hypogastric plexus were exposed and these were divided into medial and lateral branches. The magnified view of laparoscopy made it possible to dissect nerves and vessels meticulously and to secure a clear resection margin during the dissection of the deep part of the cardinal ligament, uterosacral ligament, and posterior leaf of the vesicouterine ligament. Clin. Anat. 23:186–191, 2010. © 2010 Wiley‐Liss, Inc.
Room‐Temperature Alkane Reactivity in Zeolites: An H/D Exchange Study
Authors: Sido Abdelkarim Sani Souna , Walspurger Stéphane , Barbiche Jérémy , Sommer Jean
Published: January 2010

As evidenced by H/D exchange with acidic zeolites, isoalkanes react readily at room temperature whereas linear alkanes do not. The observed regioselectivity of the exchange process demonstrates that the main factor controlling the reaction is not the accessibility to the acid sites, but the intrinsic reactivity of the alkane. The mechanism is best rationalized by classic organic chemistry involving carbocationic intermediates including the Markovnikov rule.
Kombination von Biokatalyse und Kristallisation zur Darstellung enantiomerenreiner Mandelsäurederivate
Authors: Seidel‐Morgenstern A. , von Langermann J. , Tam L. M. , Lorenz H. , Seidel‐Morgenstern A.
Published: January 2010

Die biokatalytische Synthese enantiomerenreiner Cyanhydrine mittels Hydroxynitrillyasen erfolgt nur in wenigen Ausnahmen mit den benötigten Enantioselektivitäten von mehr als 99 %. Dementsprechend müssen für die nur enantiomerenangereicherten Cyanhydrine bzw. deren Folgeprodukte andere Aufreinigungsverfahren angewendet werden. Als äußerst leistungsfähiges Verfahren bietet sich an dieser Stelle die enantioselektive Kristallisation an, deren Kombination mit der Synthese der Derivate der Mandelsäure großes Potenzial besitzt.
Proposed adjustments to pathologic staging of epithelial malignant pleural mesothelioma based on analysis of 354 cases
Authors: Richards William G. , Godleski John J. , Yeap Beow Y. , Corson Joseph M. , Chirieac Lucian R. , Zellos Lambros , Mujoomdar Aneil , Jaklitsch Michael T. , Bueno Raphael , Sugarbaker David J.
Published: January 2010

BACKGROUND:

Several pathologic staging systems for malignant pleural mesothelioma (MPM) have been published, but none of them provide optimal survival stratification or stage distribution among patients treated with surgery. Interpretation of prior studies that correlate pathologic factors with outcome has been confounded by the inclusion of patients undergoing differing surgical procedures and with varied tumor histology.

METHODS:

We examined pathologic characteristics, previously included in published studies, and explored correlations with outcome among patients with epithelioid MPM who underwent extrapleural pneumonectomy (EPP) at Brigham and Women's Hospital (BWH). Comparisons of survival among patients with and without each tumor or lymph node feature guided adjustments to the American Joint Commission on Cancer (AJCC)/International Union Against Cancer (UICC) classification criteria. Proportional hazards modeling of TN combinations guided adjustments to stage groupings.

RESULTS:

Three hundred fifty‐four patients were resectable by EPP and had complete pathologic data. Overall median survival was 18 months from surgery. By AJCC/UICC criteria, 233 (66%) patients were stage III, whereas by BWH criteria, 194 (55%) patients were stage III. T classification criteria were adjusted based on prevalence and relation to survival. N status correlated significantly with survival. Regrouping of TN combinations based on relative hazard and Kaplan‐Meier survival analysis resulted in improved stage distribution (stage I‐IV: 8%, 43%, 33%, 16%, respectively) and survival stratification (51, 26, 15, 8 months, respectively).

CONCLUSIONS:

Proposed adjustments to TNM staging criteria improved outcome stratification of patients with epithelial tumor histology who received surgical therapy by EPP and complete pathologic assessment. Determining relevance to other treatment or staging modalities will require verification in additional cohorts. Cancer 2010. © 2010 American Cancer Society.
Phase 2 study of intrathecal, long‐acting liposomal cytarabine in the prophylaxis of lymphomatous meningitis in human immunodeficiency virus‐related non‐Hodgkin lymphoma
Authors: Spina Michele , Chimienti Emanuela , Martellotta Ferdinando , Vaccher Emanuela , Berretta Massimiliano , Zanet Ernesto , Lleshi Arben , Canzonieri Vincenzo , Bulian Pietro , Tirelli Umberto
Published: January 2010

BACKGROUND:

Patients with aggressive non‐Hodgkin lymphoma (NHL) develop central nervous system (CNS) progression or recurrence during the course of their disease. Patients with human immunodeficiency virus (HIV)‐NHL often develop CNS progression despite the use of prophylaxis. Liposomal cytarabine (DepoCyte) has shown activity in lymphomatous meningitis, but there are limited data for prophylaxis.

METHODS:

Between May 2006 and December 2008, a phase 2 study of intrathecal liposomal cytarabine was performed at the dose of 50 mg in 30 patients with HIV‐NHL, with the aim of evaluating feasibility and activity for prophylaxis.

RESULTS:

Liposomal cytarabine was well tolerated, with headache grade I to III being the most frequent side effect in 40% of patients. With a median follow‐up of 10.5 months, only 1 (3%) patient developed a combined systemic and meningeal recurrence. The use of liposomal cytarabine allowed significant reduction of the number of lumbar injections in comparison to the standard schedules (around 50%), improving the quality of life of patients and reducing the professional exposure risk.

CONCLUSIONS:

In this first study on prophylaxis of lymphomatous meningitis in HIV‐NHL, liposomal cytarabine seems safe and active; it reduces by approximately 50% the number of lumbar punctures, and exposure risk for health staff as well. Cancer 2010. © 2010 American Cancer Society.
Ethylglucuronide as a potential marker for alcohol‐induced elevation of urinary testosterone/epitestosterone ratios
Authors: Große Joachim , Anielski Patricia , Sachs Hans , Thieme Detlef
Published: January 2010

The potential influence of alcohol consumption on endogenous steroids has already been described in the literature. In those studies the ethanol level after ingestion was monitored using its concentration in blood, urine or saliva. Corresponding methods are not commonly used in anti‐doping laboratories. Ethylglucuronide (EtG), which can be easily detected by liquid chromatography coupled to tandem mass spectrometry (LC‐MS/MS), appears to be a more suitable parameter for this purpose. It is slowly excreted into the urine and indicates alcohol intake for a much longer period than blood or urinary alcohol and it is therefore routinely used for legal purposes as an alcohol consumption marker. In pharmacokinetic studies that aimed to establish calculation models after ethanol intake, the formation of EtG was observed to coincide with elevated urinary testosterone/epitestosterone (T/E) ratios. Similarly, large amounts of EtG were correlated with abnormal steroid profiles found in routine doping samples. In this pilot study, several cases with significantly elevated T/E ratios were associated with urinary EtG concentrations higher than 50 µg/mL. These findings confirmed recent intake of ethanol in considerable amounts and suggest a connection to changes in specific steroid profile parameters. Owing to the ease with which procedures to determine EtG can be carried out, and the potential for such procedures to be introduced into screening schemes, the inclusion of this marker in the final evaluation of suspicious outliers in T/E ratio longitudinal studies would seem to be very useful. Copyright © 2010 John Wiley & Sons, Ltd.
Reiterative use of the notch signal during zebrafish intrahepatic biliary development
Authors: Lorent Kristin , Moore John C. , Siekmann Arndt F. , Lawson Nathan , Pack Michael
Published: January 2010

The Notch signaling pathway regulates specification of zebrafish liver progenitor cells towards a biliary cell fate. Here, using staged administration of a pharmacological inhibitor of Notch receptor processing, we show that activation of the Notch pathway is also important for growth and expansion of the intrahepatic biliary network in zebrafish larvae. Biliary expansion is accompanied by extensive cell proliferation and active remodeling of the nascent ductal network, as revealed by time lapse imaging of living zebrafish larvae that express a Notch responsive fluorescent reporter transgene. Together, these data support a model in which the Notch signal functions reiteratively during biliary development; first to specific biliary cells and then to direct remodeling of the nascent biliary network. As the Notch pathway plays a comparable role during mammalian biliary development, including humans, these studies also indicate broad conservation of the molecular mechanisms directing biliary development in vertebrates. Developmental Dynamics 239:855–864, 2010. © 2010 Wiley‐Liss, Inc.
Cell fate specification in the C. elegans embryo
Authors: Maduro Morris F.
Published: January 2010

Cell specification requires that particular subsets of cells adopt unique expression patterns that ultimately define the fates of their descendants. In C. elegans, cell fate specification involves the combinatorial action of multiple signals that produce activation of a small number of “blastomere specification” factors. These initiate expression of gene regulatory networks that drive development forward, leading to activation of “tissue specification” factors. In this review, the C. elegans embryo is considered as a model system for studies of cell specification. The techniques used to study cell fate in this species, and the themes that have emerged, are described. Developmental Dynamics 239:1315–1329, 2010. © 2010 Wiley‐Liss, Inc.
2′‐Linking of Lipids and Other Functions to Uridine through 1,2,3‐Triazoles and Membrane Anchoring of the Amphiphilic Products
Authors: Kaczmarek Oliver , Scheidt Holger A. , Bunge Andreas , Föse David , Karsten Sebastian , Arbuzova Anna , Huster Daniel , Liebscher Jürgen
Published: January 2010

A straightforward synthesis of 2′‐functionalized uridines was developed based on a Cu‐catalyzed cycloaddition of 2′‐azido‐2′‐deoxyuridine and functionalized alkynes. The functions comprise biochemically important groups such as lipids, a fluorescent marker (Cy5 analogue), pentaacetylglucose, lysine and biotin, and are linked to the 2′‐position of uridine by a 1,2,3‐triazole ring. A number of NMR spectroscopic investigations revealed that the lipidated 2′‐triazolyl‐2′‐deoxyuridines anchor themselves in the phospholipid membranes without affecting the molecular order in the double layers; the polar moieties – uracil, ribose and triazole – are located in the lipid/water interface of the membrane.
Fluorous‐Assisted One‐Pot Oligosaccharide Synthesis
Authors: Yang Bo , Jing Yuqing , Huang Xuefei
Published: January 2010

A new method for oligosaccharide assembly that combines the advantages of one‐pot synthesis and fluorous separation is described. After one‐pot glycosylations are completed, a fluorous tag is introduced into the reaction mixture to selectively “catch” the desired oligosaccharide, which is rapidly separated from non‐fluorous impurities by fluorous solid‐phase extraction (F‐SPE). Subsequent “release” of the fluorous tag and F‐SPE achieved the purification of the desired oligosaccharide without the use of time‐ and solvent‐consuming silica gel chromatography. Linear and branched oligosaccharides have been synthesized with this approach in just a few hours (for the overall oligosaccharide assembly and purification process).
Rapid and sensitive DNA target detection using enzyme amplified electrochemical detection based on microchip
Authors: Cao Wei , Su Mingming , Zhang Shusheng
Published: January 2010

A rapid and sensitive DNA targets detection using enzyme amplified electrochemical detection (ED) based on microchip was described. We employed a biotin‐modified DNA, which reacted with avidin‐conjugated horseradish peroxidase (avidin–HRP) to obtain the HRP‐labeled DNA probe and hybridized with its complementary target. After hybridization, the mixture containing dsDNA‐HRP, excess ssDNA‐HRP, and remaining avidin–HRP was separated by MCE. The separations were performed at a separation voltage of +1.6 kV and were completed in less than 100 s. The HRP was used as catalytic labels to catalyze H2O2/o‐aminophenol reaction. Target DNA could be detected by the HRP‐catalyzed reduction with ED. With this protocol, the limits of quantification for the hybridization assay of 21‐ and 39‐mer DNA fragments were of 8×10−12 M and 1.2×10−11 M, respectively. The proposed method has been applied satisfactorily in the analysis of Escherichia coli genomic DNA. We selected the detection of PCR amplifications from the gene of E. coli to test the real applicability of our method. By using an asymmetric PCR protocol, we obtained ssDNA targets of 148 bp that could be directly hybridized by the single‐stranded probe and detected with ED.
Stabilizing labile DNA–protein complexes in polyacrylamide gels
Authors: Sidorova Nina Y. , Hung Stevephen , Rau Donald C.
Published: January 2010

The electrophoretic mobility‐shift assay (EMSA) is one of the most popular tools in molecular biology for measuring DNA–protein interactions. EMSA, as standardly practiced today, works well for complexes with association binding constants Ka>109 M−1 under normal conditions of salt and pH. Many DNA–protein complexes are not stable enough so that they dissociate while moving through the gel matrix giving smeared bands that are difficult to quantitate reliably. In this work we demonstrate that the addition of the osmolyte triethylene glycol to polyacrylamide gels dramatically stabilizes labile restriction endonuclease EcoRI complexes with nonspecific DNA sequences enabling quantitation of binding using EMSA. The significant improvement of the technique resulting from the addition of osmolytes to the gel matrix greatly extends the range of binding constants of protein–DNA complexes that can be investigated using this widely used assay. Extension of this approach to other techniques used for separating bound and free components such as gel chromatography and CE is straightforward.
Efficient sampling and data reduction techniques for probabilistic seismic lifeline risk assessment
Authors: Jayaram Nirmal , Baker Jack W.
Published: January 2010

Probabilistic seismic risk assessment for spatially distributed lifelines is less straightforward than for individual structures. While procedures such as the ‘PEER framework’ have been developed for risk assessment of individual structures, these are not easily applicable to distributed lifeline systems, due to difficulties in describing ground‐motion intensity (e.g. spectral acceleration) over a region (in contrast to ground‐motion intensity at a single site, which is easily quantified using Probabilistic Seismic Hazard Analysis), and since the link between the ground‐motion intensities and lifeline performance is usually not available in closed form. As a result, Monte Carlo simulation (MCS) and its variants are well suited for characterizing ground motions and computing resulting losses to lifelines. This paper proposes a simulation‐based framework for developing a small but stochastically representative catalog of earthquake ground‐motion intensity maps that can be used for lifeline risk assessment. In this framework, Importance Sampling is used to preferentially sample ‘important’ ground‐motion intensity maps, and K‐Means Clustering is used to identify and combine redundant maps in order to obtain a small catalog. The effects of sampling and clustering are accounted for through a weighting on each remaining map, so that the resulting catalog is still a probabilistically correct representation. The feasibility of the proposed simulation framework is illustrated by using it to assess the seismic risk of a simplified model of the San Francisco Bay Area transportation network. A catalog of just 150 intensity maps is generated to represent hazard at 1038 sites from 10 regional fault segments causing earthquakes with magnitudes between five and eight. The risk estimates obtained using these maps are consistent with those obtained using conventional MCS utilizing many orders of magnitudes more ground‐motion intensity maps. Therefore, the proposed technique can be used to drastically reduce the computational expense of a simulation‐based risk assessment, without compromising the accuracy of the risk estimates. This will facilitate computationally intensive risk analysis of systems such as transportation networks. Finally, the study shows that the uncertainties in the ground‐motion intensities and the spatial correlations between ground‐motion intensities at various sites must be modeled in order to obtain unbiased estimates of lifeline risk. Copyright © 2010 John Wiley & Sons, Ltd.
Delivery horizon and grain market volatility
Authors: Karali Berna , Dorfman Jeffrey H. , Thurman Walter N.
Published: January 2010

We study the difference in the volatility dynamics of CBOT corn, soybeans, and oats futures prices across different delivery horizons via a smoothed Bayesian estimator. We find that futures price volatilities in these markets are affected by inventories, time to delivery, and the crop progress period and that there are important differences in the effects across delivery horizons. We also find that price volatility is higher before the harvest starts in most cases compared to the volatility during the planting period. These results have implications for hedging, options pricing, and the setting of margin requirements. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark 30:846–873, 2010
the Incidence and Risk Factors of Hepatocellular Carcinoma in Patients With Nonalcoholic Steatohepatitis
Authors: Ascha Mustafa S. , Hanouneh Ibrahim A. , Lopez Rocio , Tamimi Tarek Abu-Rajab , Feldstein Ariel F. , Zein Nizar N.
Published: January 2010

Nonalcoholic steatohepatitis (NASH) is a well-recognized cause of cirrhosis and has been increasingly associated with the development of hepatocellular carcinoma (HCC). The aims of this study were to (1) estimate the incidence of HCC in patients with NASH-related cirrhosis, (2) compare incidence in NASH-related cirrhosis with hepatitis C virus (HCV)-related cirrhosis, and (3) identify risk factors of HCC in patients with NASH-related cirrhosis compared with HCV-related cirrhosis. Adult patients with cirrhosis secondary to chronic HCV (n = 315) or NASH (n = 195) were evaluated at our hepatobiliary clinic between 2003 and 2007. To assess for HCC development, all patients were monitored using serial abdominal computed tomography and serum alpha-fetoprotein every 6 months. Kaplan-Meier analysis was performed to estimate the cumulative incidence of HCC. Descriptive statistics were computed for all factors. Univariate and multivariate Cox regression analysis were used to assess associations between HCC and factors of interest. The median follow-up was 3.2 years (25th percentile [P25], 75th percentile [P75]: 1.7, 5.7) during which 25/195 (12.8%) of NASH-cirrhotic and 64/315 (20.3 %) of HCV-cirrhotic patients developed HCC (

P

= 0.03). Yearly cumulative incidence of HCC was found to be 2.6% in patients with NASH-cirrhosis, compared with 4.0% in patients with HCV cirrhosis (

P

= 0.09). Multivariate regression analysis revealed that older age (

P

= 0.006) and alcohol consumption (

P

= 0.002) were independent variables associated with development of HCC in patients with NASH-cirrhosis. Compared with nondrinkers, patients who reported any regular alcohol consumption were at greater risk for HCC development (hazard ratio: 3.6; P25, P75: 1.5, 8.3).

Conclusion:

Patients with NASH cirrhosis have a greatly increased risk of liver cancer. Alcohol consumption, a modifiable risk factor, appears to be the most significant factor associated with risk of HCC development in our study population. (Hepatology 2010;)
Rapidly induced gene networks following induction of long‐term potentiation at perforant path synapses in vivo
Authors: Ryan Margaret M. , Mason‐Parker Sara E. , Tate Warren P. , Abraham Wickliffe C. , Williams Joanna M.
Published: January 2010

The canonical view of the maintenance of long‐term potentiation (LTP), a widely accepted experimental model for memory processes, is that new gene transcription contributes to its consolidation; however, the gene networks involved are unknown. To address this issue, we have used high‐density Rat 230.2 Affymetrix arrays to establish a set of genes induced 20‐min post‐LTP, and using Ingenuity Pathway network analysis tools we have investigated how these early responding genes are interrelated. This analysis identified LTP‐induced regulatory networks in which the transcription factors (TFs) nuclear factor‐KB and serum response factor, which, to date, have not been widely recognized as coordinating the early gene response, play a key role alongside the more well‐known TFs cyclic AMP response element‐binding protein, and early growth response 1. Analysis of gene‐regulatory promoter sites and chromosomal locations of the genes within the dataset reinforced the importance of these molecules in the early gene response and predicted that the coordinated action might arise from gene clustering on particular chromosomes. We have also identified a transcription‐based response that affects mitogen‐activated protein kinase signaling pathways and protein synthesis during the stabilization of the LTP response. Furthermore, evidence from biological function, networks, and regulatory analyses showed convergence on genes related to development, proliferation, and neurogenesis, suggesting that these functions are regulated early following LTP induction. This raises the interesting possibility that LTP‐related gene expression plays a role in both synaptic reorganization and neurogenesis. © 2010 Wiley‐Liss, Inc.
McGrath v Riddell: A flexible approach to the insolvency distribution rules?
Authors: Mamutse Blanca
Published: January 2010

The rules relating to the division of the insolvent estate assume considerable importance in the field of international insolvencies, where different legal systems interact. International instruments including the European insolvency regulation and the UNCITRAL Model Law on Cross‐Border Insolvency have provided a framework which governs the relationship between local and foreign distribution schemes. For English lawyers, questions remain however regarding the future role of the courts' statutory power to cooperate with the courts of ‘relevant’ countries or territories, and of the common law principle of universalism. An important issue connected to the determination of such questions is the established judicial approach to the pari passu rule, in the application of domestic law. This paper examines the manifestation of this tension in the litigation arising from the collapse of the HIH Casualty & General Insurance group of companies. It notes the scope which remains for continued resort to the statutory power of cooperation, and the potential for the Cross‐Border Insolvency Regulations 2006 to encourage a more flexible approach to resolving differences between distribution schemes. Copyright © 2010 John Wiley & Sons, Ltd.