bluuebunny/crossref_metadata_2025 huggingface dataset:
Medicinal Plants from Peru: A Review of Plants as Potential Agents Against Cancer
Authors: Gonzales Gustavo F. , Valerio Luis G.
Published: April 2008

Natural products have played a significant role in drug discovery and development especially for agents against cancer and infectious disease. An analysis of new and approved drugs for cancer by the United States Food and Drug Administration over the period of 1981-2002 showed that 62% of these cancer drugs were of natural origin. Natural compounds possess highly diverse and complex molecular structures compared to small molecule synthetic drugs and often provide highly specific biological activities likely derived from the rigidity and high number of chiral centers. Ethnotraditional use of plant-derived natural products has been a major source for discovery of potential medicinal agents. A number of native Andean and Amazonian medicines of plant origin are used as traditional medicine in Peru to treat different diseases. Of particular interest in this mini-review are three plant materials endemic to Peru with the common names of Cats claw (Uncaria tomentosa), Maca (Lepidium meyenii), and Dragons blood (Croton lechleri) each having been scientifically investigated for a wide range of therapeutic uses including as specific anti-cancer agents as originally discovered from the long history of traditional usage and anecdotal information by local population groups in South America. Against this background, we present an evidence-based analysis of the chemistry, biological properties, and anti-tumor activities for these three plant materials. In addition, this review will discuss areas requiring future study and the inherent limitations in their experimental use as anti-cancer agents.
New Generation of Liposomal Drugs for Cancer
Authors: Minko Tamara , Pakunlu Refika I. , Wang Yang , Khandare Jayant J. , Saad Maha
Published: April 2008

This review is focused on liposomes as a delivery system for anticancer agents and more specifically on the advantages of using liposomes as drug nanocarrier in cancer chemotherapy. The main advantages of liposomal drugs over the non-encapsulated drugs include: (1) improved pharmacokinetics and drug release, (2) enhanced intracellular penetration, (3) tumor targeting and preventing adverse side effects and (4) ability to include several active ingredients in one complex liposomal drug delivery system (DDS). The review also includes our recent data on advanced liposomal anticancer drug delivery systems. As a conclusion we propose a novel liposomal DDS which includes inhibitors of pump resistance combined in one liposomal drug delivery system with an inhibitor of antiapoptotic cellular defense, an apoptosis inducer (a traditional anticancer drug) and a targeting moiety. The proposed drug delivery system utilizes a novel three tier approach, simultaneously targeting three molecular targets: (1) extracellular receptors or antigen expressed on the surface of plasma membrane of cancer cells in order to direct the whole system specifically to the tumor, preventing adverse side effects on healthy tissues; (2) drug efflux pumps in order to inhibit them and enhance drug retention by cancer cells, increasing intracellular drug accumulation and thereby limiting the need for prescribed high drug doses that cause adverse drug side effects; and (3) intracellular controlling mechanisms of apoptosis in order to suppress cellular antiapoptotic defense.
Recent Developments in Polymeric Nanoparticle Engineering and Their Applications in Experimental and Clinical Oncology
Authors: Moein Moghimi S.
Published: April 2008

Promising results have come from attempts to direct drugs, nucleic acids and diagnostic agents to tumours by using polymeric nanoparticles. Such carriers are versatile; their encapsulation capacity, drug release profile, and biological performance vary with their chemical makeup, morphology, and size. Polymeric nanoparticles may therefore be engineered for therapeutic and diagnostic purposes in accordance with the type, developmental stage and location of the cancer as well as the required route of administration. This article examines recent developments in design and engineering of polymeric nanoparticles and related platforms to include supramolecular systems such as nanocapsules and nanoparticlebased hydrogels, and assesses their potential diagnostic and therapeutic applications in experimental and clinical oncology.
Photoactivatable Platinum Complexes
Authors: Bednarski Patrick J. , Mackay Fiona S. , Sadler Peter J.
Published: April 2008

The development of photoactivatable prodrugs of platinum-based antitumor agents is aimed at increasing the selectivity and hence lowering toxicity of this important class of antitumor drugs. These drugs could find use in treating localized tumors accessible to laser-based fiber-optic devices. PtIV complexes appeared attractive because these octahedral complexes are usually substitution inert and require reduction to the PtII species to become cytotoxic. Based on the knowledge of PtIV photochemistry, Pt IV analogs of cisplatin, [Pt(en)Cl2] and transplatin were designed, synthesized and investigated for their ability to be photoreduced to cytotoxic PtII species. Two classes of photoactivatable Pt complexes have been looked at thus far: diiodo-PtIV and diazido-Pt IV diam(m)ine complexes. The first generation, diiodo-PtIV complexes, represented by cis, trans-[Pt(en)(I)2(OAc)2], react to visible light by binding irreversibly to DNA and forming adducts with 5-GMP in the same manner as [Pt(en)Cl2]. Furthermore, the photolysis products are cytotoxic to human cancer cells in vitro. However, these complexes are too reactive towards biological thiols (i.e., glutathione), which rapidly reduced them to cytotoxic PtII species, thus making them unsuitable as drugs. The second generation, diazido-PtIV complexes, represented by cis, trans, cis-[Pt(N3)2(OH)2(NH3)2] and cis, trans-[Pt(en)(N3)2(OH)2], are also photosensitive, binding irreversibly to DNA and forming similar products with DNA and 5-GMP in the presence of light as the respective PtII complexes. However, they are stable to glutathione and thus show very low dark cytotoxicity. Light of lirr = 366 nm activates both complexes to cytotoxic species that effectively kill cancer cells by destroying their nuclei, leaving behind shrunken cell ghosts. Interestingly, the all-trans analog, trans, trans, trans-[Pt(N3)2(OH)2(NH3)2] is non-toxic to HaCaT keratinocytes in the dark, but as active as cisplatin in the light. These studies show that photoactivatable PtIV antitumor agents represent a promising area for new drug development.
Radionuclide Therapy of Cancer with Radiolabeled Antibodies
Authors: Oyen Wim J. , Postema E. J. , Corstens Frans H. , Boerman Otto C. , Koppe Manuel J.
Published: April 2008

Radioimmunotherapy (RIT) using radiolabeled monoclonal antibodies (MAbs) directed against tumor-associated antigens has evolved from an appealing concept to one of the standard treatment options for patients with non-Hodgkins lymphoma (NHL). Inefficient localization of radiolabeled MAbs to nonhematological cancers due to various tumor-related factors, however, limits the therapeutic efficacy of RIT in solid tumors. Still, small volume or minimal residual disease has been recognized as a potentially suitable target for radiolabeled antibodies. Several strategies are being explored aimed at improving the targeting of radiolabeled MAbs to solid tumors thus improving their therapeutic efficacy. In this review, various aspects of the application of radiolabeled MAbs as anti-cancer agents are discussed, and the clinical results of RIT in patients with hematological and various solid cancers (colorectal, ovarian, breast and renal carcinomas) are reviewed.
Factors Affecting the Sensitivity and Detection Limits of MRI, CT, and SPECT for Multimodal Diagnostic and Therapeutic Agents
Authors: Seevinck Peter R. , Seppenwoolde Jan-Henry , de Wit Tim C. , W. Nijsen Johannes F. , Beekman Freek J. , van het Schip Alfred D. , G. Bakker Chris J.
Published: April 2008

Noninvasive imaging techniques like magnetic resonance imaging (MRI), computed tomography (CT) and single photon emission computed tomography (SPECT) play an increasingly important role in the diagnostic workup and treatment of cancerous disease. In this context, a distinct trend can be observed towards the development of contrast agents and radiopharmaceuticals that open up perspectives on a multimodality imaging approach, involving all three aforementioned techniques. To promote insight into the potentialities of such an approach, we prepared an overview of the strengths and limitations of the various imaging techniques, in particular with regard to their capability to quantify the spatial distribution of a multimodal diagnostic agent. To accomplish this task, we used a two-step approach. In the first step, we examined the situation for a particular therapeutic anti-cancer agent with multimodal imaging opportunities, viz. holmium- loaded microspheres (HoMS). Physical phantom experiments were performed to enable a comparative evaluation of the three modalities assuming the use of standard equipment, standard clinical scan protocols, and signal-known-exactly conditions. These phantom data were then analyzed so as to obtain first order estimates of the sensitivity and detection limits of MRI, CT and SPECT for HoMS. In the second step, the results for HoMS were taken as a starting point for a discussion of the factors affecting the sensitivity and detection limits of MRI, CT and SPECT for multimodal agents in general. In this, emphasis was put on the factors that must be taken into account when extrapolating the findings for HoMS to other diagnostic tasks, other contrast agents, other experimental conditions, and other scan protocols.
Contrast Agents in X-Ray Computed Tomography and Its Applications in Oncology
Authors: Rutten Annemarieke , Prokop Mathias
Published: April 2008

Intravascular iodinated contrast agents are required for a large proportion of computed tomography (CT) studies. Contrast media are indispensable to more clearly differentiate anatomic structures and to detect and characterize abnormalities. Depending on the indication up to 200 ml of these agents are injected during CT. Despite these large amounts adverse effects are rare and have further decreased with the introduction of non-ionic substances. However, it took 10 to 20 years until these non-ionic agents replaced the older ionic agents in clinical practice. In recent years no new substance has been brought to the market. The introduction of rapid scanning using multislice CT technology, however, has led to the development of more sophisticated contrast injection techniques. Current research focuses on optimizing contrast application techniques and on further evaluating the safety profiles of the various substances. The amount of contrast enhancement obtained in individual patients for instance depends on the contrast agent characteristics, such as iodine concentration, and the parameters of the contrast injection protocol, such as iodine flux and iodine dose. Meanwhile, contrast agent characteristics such as osmolality and viscosity play a role in the safety profile of an agent. This paper provides a current overview of CT contrast media, CT contrast dynamics, and CT contrast applications with a special focus on oncological imaging.
The Bright Future of Radionuclides for Cancer Therapy
Authors: Franciscus Wilhelmus Nijsen Johannes , Cornelis Krijger Gerard , Dirk van het Schip Afred
Published: April 2008

Originally, nuclear medicine focused on radiopharmaceuticals trapped in organ structures, based on their function, and the presence of disease was seen by the absence of radioactivity. More recently, target-specific radiopharmaceuticals have been developed to visualize and/or treat oncological diseases. Since radiopharmaceuticals have historically a leading position in the search for “molecular imaging”, it would be a waste not to learn from the pitfalls and opportunities that have been and are found during the development of radiopharmaceuticals. This knowledge can be used in the improvement of contrast agents for other imaging modalities like MRI and CT. In this article the aspects that are needed for the use of current and future therapeutic and diagnostic radiopharmaceuticals are described. Especially the production and development of therapeutic and imageable radiopharmaceuticals are demonstrated. MRI or CT can sometimes also image stable isotopes of elements that contain useful radionuclides. This can result in real multimodality imaging. Combining imaging modalities and imaging agents will result in better patient care and can only be advantageous if all departments and institutes will collaborate on their research work. The combination of approaches together with the fast progress in developments in the medical imaging world will result in a bright future for imaging driven therapy of cancer.
Harnessing Telomerase in Cancer Therapeutics
Authors: Johans Fakhoury  , Graeme A.M. Nimmo  , Chantal Autexier
Published: April 2008

Telomerase is an attractive target for anti-cancer therapeutics due to its requirement for cellular immortalization and expression in greater than 85% of human neoplasms. Though initially promising, strategies that inhibit telomerase with either small molecules or antisense oligonucleotides have a major limitation, namely the lag time required for telomere shortening before cellular effects are attained. As alternative approaches, immunotherapy and gene therapy have been tailored to exploit, rather than antagonize telomerase expression and/or activity. Immunotherapy requires the presence of the catalytic subunit of telomerase, hTERT, to elicit an immune response directed towards hTERT peptide-presenting cells. hTERT promoter-driven gene therapy and mutant telomerase RNA (hTR) gene therapy depend on the innate telomerase activity of cancer cells to drive the expression of pro-apoptotic genes and to synthesize mutated DNA sequences onto telomeres, respectively. In addition, we will discuss telomestatin, a G-quadruplex binding ligand that may exert anti-proliferative effects independently of telomere shortening. In this review, the progress, advantages, and limitations of these strategies in the ongoing effort to develop clinically relevant telomerase-based cancer therapeutics will be examined.
Dipeptidyl Peptidase-IV Inhibitors: Pharmacological Profile and Clinical Use
Authors: White John R.
Published: April 2008

IN BRIEF

Sitagliptin is the first agent in a new category of medications, the dipeptidyl peptidase-IV (DPP-IV) inhibitors. It was recently approved in the United States for the management of hyperglycemia in patients with type 2 diabetes; vildagliptin, a second agent in this class, is likely to join it on the U.S. market soon. These compounds accentuate the activity of endogenously produced antihyperglyemic incretin hormones and are generally well tolerated. This article provides an overview of the pharmacology and clinical use of the DPP-IV inhibitors.
EVALUATION OF INDOOR ENVIRONMENT CONDITIONS IN OFFICES LOCATED IN BUILDINGS WITH LARGE GLAZED AREAS
Authors: Šeduikytė Lina , Paukštys Valdas
Published: April 2008

The field study was carried out during the heating season in two Lithuanian office buildings with large glazed areas. The methodology was prepared for evaluating indoor microclimate parameters while using objective and subjective evaluation. The results show that the average temperature in all tested offices was in the range of optimal zones, but in some offices the average temperature was not in compliance with the recommended temperature for offices. During the subjective evaluation, respondents working in these offices identified complains because of too high temperatures, stuffy air and irritation in eyes. The average relative humidity measured in all tested offices was not in compliance with the optimal requirements. Such SBS symptoms as irritation in eyes, cough and dry skin of the hands were identified as the most frequent symptoms in the second tested building. Main indoor microclimate problems arising in buildings with large glazed areas were related to overheating indoor spaces because of the direct sun and improper ventilation. Santrauka Straipsnyje nagrinėjamos patalpų mikroklimato sąlygos pastatuose esančiuose biuruose, turinčiuose didelius įstiklintus plotus. Didelių skaidrių atitvarų plotų įrengimas pastatuose ne tik didina energijos sąnaudas pastatams šildyti, vėsinti ir orui kondicionuoti, bet ir sukuria mikroklimato sąlygas, kuriose dirbantys žmonės dažnai patiria šiluminį diskomfortą, nors aplinkos parametrai atitinka normų reikalavimus. Natūriniams patalpų mikroklimato tyrimams sukurta patalpų mikroklimato tyrimo metodika, kuri sieja objektyvius ir subjektyvius tyrimo metodus patalpų sąlygoms optimaliai įvertinti. Patalpų mikroklimato sąlygos tiksliausiai įvertinamos pagal patalpų mikroklimato parametrų matavimo, papildyto subjektyvaus mikroklimato sąlygų įvertinimu, apibendrintos analizės rezultatus.
MAST BEHAVIOUR ANALYSIS AND PECULIARITIES OF NUMERICAL MODELLING/STIEBŲ ELGSENOS ANALIZĖ IR SKAITINIO MODELIAVIMO YPATUMAI
Authors: Juozapaitis Algirdas , Kutas Remigijus , Jatulis Donatas
Published: April 2008

Paper is assigned to numerical analysis peculiarities of masts applying specialised computer‐aided design packages. Mast's deformable behaviour is described as non‐linear one. The test problem of mast is solved by two widely applied in Lithuania computational packages STAADpro and Robot Millennium and the specialised programme for mast design SUDM. A corrected analytical method for mast guy analysis, taking into account a force component, acting along the guy supports. A performed numerical experiment is aimed to clarify the possibilities of the above‐mentioned numerical analysis instruments for geometrical non‐linear modelling of structure. The accuracy errors when determining the mast stress and strain fields by numerical analysis packages comparing with the ones obtained by a corrected analytical method are indicated. Possibilities of employing the considered computer‐aided design programming packages for practical design of masts are discussed. Santrauka Straipsnyje aptariami stiebų kaip netiesiškai deformuojamų konstrukcinių sistemų skaičiavimo ypatumai naudojant kompiuterinio projektavimo specializuotus programinius paketus. Sprendžiamas stiebo elgsenos analizės ir skaičiavimo uždavinys pasitelkiant dvi plačiai Lietuvoje taikomas statybinių konstrukcijų kompiuterinio projektavimo programas STAADpro ir Robot Millennium bei specializuotą stiebų skaičiavimo programą SUDM. Straipsnyje pateikiama ir patikslinta analizinė stiebo atotampos skaičiavimo metodika, rodanti apkrovos komponentę, veikiančią išilgai atotampos atramų. Remiantis atliktu skaitiniu eksperimentu, yra sprendžiama apie minėtųjų kompiuterinio projektavimo programinių paketų galimybes modeliuoti geometriškai netiesinės sistemos elgseną. Nurodomos šių programinių paketų stiebų elementų įrąžų bei poslinkių apskaičiavimo lyginant su patikslinta analizine skaičiavimo metodika paklaidos, aptariamos minėtųjų kompiuterinio projektavimo programų praktinio taikymo stiebams skaičiuoti galimybės.
Use of FM1‐43 and Other Derivatives to Investigate Neuronal Function
Authors: Cousin Michael A.
Published: April 2008

The fluorescent dye FM1‐43 and its derivatives can be used to monitor the physiology of synaptic vesicle turnover in central nerve terminals. They do so by their ability to reversibly partition into membranes, a process that results in a huge increase in fluorescence in comparison to their quantum yield in solution. This unit provides protocols for quantifying total synaptic vesicle turnover, the kinetics and extent of synaptic vesicle exocytosis, and the kinetics and mode of synaptic vesicle endocytosis. Descriptions of other ways these protocols have been used to derive information about the life cycle of the synaptic vesicle are also provided. Curr. Protoc. Neurosci. 43:2.6.1‐2.6.12. © 2008 by John Wiley & Sons, Inc.
Ballistic Labeling with Fluorescent Dyes and Indicators
Authors: Morgan Joshua L. , Wong Rachel O.L.
Published: April 2008

Neuronal cell labeling is fundamental to investigations of the nervous system. Labeling of cells in live or fixed tissue with dyes or ion indicators using ballistic approaches has recently been developed for the study of neuronal architecture and function. In this approach, dye‐coated particles are propelled into cells by a pulse of pressurized helium. This unit provides step‐by‐step protocols for coating tungsten particles with fluorescent or indicator dyes and for delivering these particles into cells and tissue. The major advantage of the ballistic method of dye delivery is that large populations of neurons can be rapidly labeled within a piece of live or fixed tissue. Advantages and limitations of the approach are discussed and technical advice is provided. Curr. Protoc. Neurosci. 43:2.11.1‐2.11.10. © 2008 by John Wiley & Sons, Inc.
Growth and Manipulation of Yeast
Authors: Treco Douglas A. , Winston Fred
Published: April 2008

Yeast cultures can be grown, maintained, and stored in liquid media or on agar plates using techniques similar to those for bacterial cultures. This unit describes culture conditions for these basic techniques. Additional methods describe determination of yeast mating type, diploid construction, sporulation, tetrad dissection, and random spore analysis. Curr. Protoc. Mol. Biol. 82:13.2.1‐13.2.12. © 2008 by John Wiley & Sons, Inc.
In Situ Polymerase Chain Reaction and Hybridization to Detect Low‐Abundance Nucleic Acid Targets
Authors: Bagasra Omar
Published: April 2008

This unit provides detailed methods and material descriptions for in situ hybridization following in situ amplification of DNA or RNA by PCR. It includes all essential components of the techniques, including variations suitable for different kinds of tissue and cell preparations. Planning, controls, and critical parameters for the amplification steps are discussed. Curr. Protoc. Mol. Biol. 82:14.8.1‐14.8.28. © 2008 by John Wiley & Sons, Inc.
Laboratory Safety
Authors: Meisenhelder Jill , Bursik Steve , Lunn George , Strober Warren
Published: April 2008

The pursuit of scientific knowledge has been considerably advanced by the use of a wide variety of hazardous substances, including radioisotopes, hazardous chemicals, and biohazards. This appendix addresses each of these classes of hazards and primary safety precautions that need to be considered. Curr. Protoc. Hum. Genet. 57:A.2A.1‐A.2A.10. © 2008 by John Wiley & Sons, Inc.
Fabrication of Hairy Polymeric Films Inspired by Geckos: Wetting and High Adhesion Properties
Authors: Cho Woo Kyung , Choi Insung S.
Published: April 2008

In this paper, we report a facile and efficient method for fabricating gecko‐inspired, hairy hard poly(dimethylsiloxane) (h‐PDMS) structures, composed of nanopillars with controllable lengths. The structures are generated by utilizing an anodic aluminum oxide (AAO) membrane as a replication template. For easy handling of the replicated h‐PDMS films, the vinyl‐terminated glass substrate is used. The cross‐linking between the vinyl moieties on the glass surface and methylhydrosiloxanes, one of the h‐PDMS components, makes it easy to transfer the molded h‐PDMS layer from the AAO template to the glass. The resulting hairy h‐PDMS‐coated glass surface shows both the static water contact angle as high as 150.5° ± 0.4° (superhydrophobicity) and high adhesion to water. A water droplet placed on the h‐PDMS surface does not slide, even when the surface is tilted vertically or turned upside down. We believe that the densely packed h‐PDMS nanopillars (2.6 × 106 pillars mm−2) are the key contributor to the observed high adhesion, presumably by generating large van der Waals' forces from the large surface area in very close contact with water. The adhesion force of the surface is found to be strong enough to catch a water droplet that rolls down fast on a tilted self‐cleaning surface. In addition to water, the wetting and high adhesion properties of the molded nanopillar h‐PDMS films are also investigated with several organic liquids.
Initiated and Oxidative Chemical Vapor Deposition of Polymeric Thin Films: iCVD and oCVD
Authors: Tenhaeff Wyatt E. , Gleason Karen K.
Published: April 2008

The techniques of initiated chemical vapor deposition (iCVD) and oxidative chemical vapor deposition (oCVD) enable the fabrication of chemically well‐defined thin polymeric films on complex objects with micro‐ and nano‐scale features. By depositing polymers from the vapor phase, many wetting and solution effects are avoided, and conformal films can be created. In iCVD, a variant of hot filament CVD, the deposition rate is enhanced and chemical functionalities of the polymers' constituents are maintained by including a thermally labile initiator in the feed stream. Due to the low energy required when using an initiator, delicate substrates can be coated. In oCVD, infusible, electrically conductive films are formed directly on the substrate of interest as the oxidant and monomer are introduced into the reactor simultaneously. This Feature Article provides an overview of the work that has been done to develop iCVD and oCVD into platform technologies. Relevant background, fundamentals, and applications will be discussed.
β‐ and γ‐Disubstituted Olefins: Substrates for Copper‐Catalyzed Asymmetric Allylic Substitution
Authors: Falciola Caroline A. , Tissot‐Croset Karine , Reyneri Hugo , Alexakis Alexandre
Published: April 2008

The copper‐catalyzed asymmetric allylic alkylation has shown through many examples that it is a powerful means to generate stereogenic centers with mono β‐ and γ‐substituted olefinic substrates. However, little has been reported about more substituted olefinic patterns, such as β‐disubstituted allylic electrophiles. In this paper, we show that a simple procedure using easily accessible Grignard reagents and as low as 3 mol% of copper/ligand can promote high to nearly perfect enantioselectivities (up to >99% ee) with very good γ‐selectivities on a wide panel of aliphatic or aromatic β‐disubstituted substrates.
Population balance modeling of bubbly flows considering the hydrodynamics and thermomechanical processes
Authors: Cheung Sherman C. P. , Yeoh G. H. , Tu J. Y.
Published: April 2008

Three‐dimensional two‐fluid model and population balance equation is presented to treat the complex hydrodynamics and thermomechanical processes under various bubbly flow conditions. The class method, realized by the MUSIG model, alongside with suitable bubble coalescence and bubble breakage kernels is adopted. Homogeneous MUSIG model predictions have shown to yield good agreement against isothermal bubbly flow measurements. Subcooled boiling flow is further modeled through the use of class method with an improved wall heat partition model. Against experimental data, numerical results also showed good agreement for the local Sauter mean bubble diameter, void fraction, and interfacial area concentration profiles. Inhomogeneous MUSIG model is applied to investigate transition bubbly‐to‐slug flow. Better prediction of bubble diameter is accomplished, especially capturing separation of small and large bubbles. Weakness exists nonetheless in the interfacial forces model. Work is in progress through the consideration of swarm and cluster bubbles instead of isolated spherical bubble calibration. © 2008 American Institute of Chemical Engineers AIChE J, 2008
PRNP mutations in a series of apparently sporadic neurodegenerative dementias in China
Authors: Zheng Liu , Longfei Jia , Jing Ye , Xinqing Zhang , Haiqing Song , Haiyan Lv , Fen Wang , Xiumin Dong , Jianping Jia
Published: April 2008

Mutations in prion protein gene (PRNP) may lead to genetic prion disease, which usually has a broad range of phenotypic presentations that overlap with other neurodegenerative dementias. In this study, we screened the PRNP gene to evaluate the frequency of PRNP mutations and their correlations with clinical phenotype in 185 sporadic neurodegenerative dementia cases and 310 control subjects. Samples of DNA from each subject underwent polymerase chain reaction (PCR) amplification and direct sequencing of PRNP. The clinical characteristics of patients carrying PRNP mutations were detailed. We identified five different PRNP mutations in five patients, of which three were novel (S97N, F198V, and R208C) and two were known (D178N‐129M and M232R). The rate of PRNP mutation was 2.70% in our sample. Though future studies confirming the correlation between PRNP mutations and clinical phenotype need to be undertaken, PRNP genotyping may be a valuable tool to differentiate between prion disease and other neurodegenerative dementias. Am. J. Med. Genet. © 2008 Wiley‐Liss, Inc.
Epoxy‐clay nanocomposites: Influence of the clay surface modification on structure
Authors: Rýznarová B. , Zelenka J. , Lednický F. , Baldrian J.
Published: April 2008

In this article, the effect of four different clay surface modifiers on the structure of epoxy‐clay nanocomposites was studied. Various organoclays were prepared via cation exchange reaction between inorganic cations naturally occuring in the clay gallery and different alkylammonium ions. Epoxy‐clay nanocomposites were prepared by in situ intercalative polymerization using a hardener of polyoxypropylenediamine type. It was found that various clay surface modifiers exhibit different catalytic effect on curing of epoxy inside the clay gallery as observed by measuring of the gel time with dynamic mechanical analysis. This was confirmed by monitoring the change in the d‐spacing by wide angle X‐ray scattering performed in situ during curing. Morphology of the cured systems was probed by transmission electron microscopy (TEM) and wide angle X‐ray scattering (WAXS). The degree of dispersion observed by TEM and WAXS corresponds with achieved mechanical properties of cured composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Porous honeycomb films prepared from poly (phthalazionone ether sulfone ketone) (PPESK) by self‐organization method
Authors: Zhang Youquan , Tian Ye , Wang Lihua
Published: April 2008

Preparation of honeycomb‐patterned films from Poly (phthalazionone ether sulfone ketone) (PPESK), one of the thermally stable polymers, in a humid atmosphere was reported in this article. The mechanism of forming honeycomb structure was discussed. Some influences, such as the effect of PPESK concentration and the atmosphere humidity were tested. Furthermore, the thermal stability of honeycomb‐patterned films was also investigated, and it was shown that the honeycomb structures could be stable existed at 300°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Maghnite‐H+, a solid catalyst for the cationic polymerization of α‐methylstyrene
Authors: Moulkheir Ayat , Harrane Amine , Belbachir Mohamed
Published: April 2008

The polymerization of α‐methylstyrene (AMS) catalyzed by Maghnite‐H+(Mag‐H) was investigated. Mag‐H is a montmorillonite sheet silicate clay, exchanged with protons. It was found that the cationic polymerization of AMS is initiated by Mag‐H at ambient temperature in bulk and in solution. The effect of the amount of Mag‐H, the temperature, and the solvent was studied. The polymerization rate increased with increase in the temperature and the proportion of catalyst, and it was larger in nonpolar solvents. These results indicated the cationic nature of the polymerization. It may be suggested that the polymerization is initiated by proton addition to monomer from Mag‐H. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of emulsion polymerized mixed matrix aluminum silicate/poly(2,6‐dimethyl 1,4‐phenylene oxide) films
Authors: Sadeghi F. , Tremblay A. Y. , Kruczek B.
Published: April 2008

A series of poly (2,6‐dimethyl‐1,4‐phenylene oxide) (PPO)‐based organic/inorganic films for the potential application in membrane gas separation were prepared by employing a method in which aluminum hydroxonitrate contained in a stable water‐in‐oil (W/O) emulsion, the oil phase being a solution of PPO in trichloroethylene, was mixed with a homogeneous solution of PPO in trichloroethylene containing tetraethyl orthosilicate (TEOS). Inorganic polymerization occurred in or at the surface of the aqueous droplets of the W/O emulsion. Subsequently, thin films were prepared by a spin coating technique, and they were referred to as emulsion polymerized mixed matrix (EPMM) films. Scanning electron micrographs taken from a film cross section indicated the presence of particles in the PPO matrix, and energy dispersive X‐ray measurements showed that the embedded particles contained Al and Si elements. Differential scanning calorimetry analysis showed a decrease in the glass transition of the EPMM films with increase of TEOS loading. The compatibility between aluminum silicate nanoparticles and PPO in the EPMM films was confirmed by air separation tests. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Cellular Uptake, Cytotoxicity, and Metabolic Profiling of Human Cancer Cells Treated with Ruthenium(II) Polypyridyl Complexes [Ru(bpy)2(NN)]Cl2 with NN=bpy, phen, dpq, dppz, and dppn
Authors: Schatzschneider Ulrich , Niesel Johanna , Ott Ingo , Gust Ronald , Alborzinia Hamed , Wölfl Stefan
Published: April 2008

A series of five ruthenium(II) polypyridyl complexes [Ru(bpy)2(NN)]Cl2 was tested against human HT‐29 and MCF‐7 cancer cell lines. Cellular uptake efficiency and cytotoxicity were found to increase with the size of the aromatic surface area of the NN ligand. The most active compound carrying the dppn ligand exhibits a low micromolar IC50 value against both cell lines comparable to that of cisplatin under similar conditions. Continuous measurement of oxygen consumption, extracellular acidification rate, and impedance of the cell layer with a chip‐based sensor system upon exposure to the complexes showed only small changes for the first two parameters throughout the series. A significant and irreversible decrease in impedance was, however, found for the dppn compound. This suggests that its biological activity is related to modifications in cell morphology or cell–cell and cell–matrix contacts.
Structural remodeling of nucleus ambiguus projections to cardiac ganglia following chronic intermittent hypoxia in C57BL/6J mice
Authors: Lin Min , Ai Jing , Li Lihua , Huang Chenghui , Chapleau Mark W. , Liu Rugao , Gozal David , Wead William B. , Wurster Robert D. , Cheng Zixi (Jack)
Published: April 2008

The baroreflex control of heart rate (HR) is reduced following chronic intermittent hypoxia (CIH). Since the nucleus ambiguus (NA) plays a key role in baroreflex control of HR, we examined whether CIH remodels vagal efferent projections to cardiac ganglia. C57BL/6J mice (3–4 months of age) were exposed to either room air (RA) or CIH for 3 months. Confocal microscopy was used to examine NA axons and terminals in cardiac ganglia following Fluoro‐Gold (FG) injections to label cardiac ganglia, and microinjections of tracer DiI into the left NA to anterogradely label vagal efferents. We found that: 1) Cardiac ganglia were widely distributed on the dorsal surface of the atria. Although the total number of cardiac ganglia did not differ between RA and CIH mice, the size of ganglia and the somatic area of cardiac principal neurons (PNs) were significantly decreased (P < 0.01), and the size of the PN nuclei was increased following CIH (P < 0.01). 2) NA axons entered cardiac ganglia and innervated PNs with dense basket endings in both RA and CIH mice, and the percentage of innervated PNs was similar (RA: 50 ± 1.0%; CIH: 49 ± 1.0%; P > 0.10). In CIH mice, however, swollen cardiac axons and terminals without close contacts to PNs were found. Furthermore, varicose endings around PNs appeared swollen and the axonal varicose area around PNs was almost doubled in size (CIH: 163.1 ± 6.4 μm2; RA: 88 ± 3.9 μm2, P < 0.01). Thus, CIH significantly altered the structure of cardiac ganglia and resulted in reorganized vagal efferent projections to cardiac ganglia. Such remodeling of cardiac ganglia and vagal efferent projections provides new insight into the effects of CIH on the brain–heart circuitry of C57BL/6J mice. J. Comp. Neurol. 509:103–117, 2008. © 2008 Wiley‐Liss, Inc.
Immunolocalization of NMDA receptor subunit NR3B in selected structures in the rat forebrain, cerebellum, and lumbar spinal cord
Authors: Wee Karen S.‐L. , Zhang Yibin , Khanna Sanjay , Low Chian‐Ming
Published: April 2008

N‐methyl‐D‐aspartate (NMDA) receptors have been implicated in many neurological disorders. Although NMDA receptors are best known for their high calcium permeability, the recently discovered NR3 subunits, NR3A and NR3B, have been shown to reduce the calcium permeability of the NMDA receptor. Thus, NR3 subunits may be important players in modulating synaptic plasticity in neurons. Although NR3B expression in the rodent and human brain has been studied, little is known about its distribution in different cell types. Here we used immunolabeling with a specific NR3B antibody together with antibodies against established neurochemical markers to determine the cellular and subcellular localization of NR3B. The nucleus was concurrently stained with NR3B immunolabeling to show that NR3B is widely expressed by many cells in each brain region. Our findings indicate that NR3B is widely expressed in the structures examined in the rat forebrain (hippocampus, cerebral cortex, caudoputamen, and nucleus accumbens), cerebellum, and lumbar sections of the spinal cord. Within these regions NR3B was found to be expressed in all the substructures of the hippocampus (CA1, CA3, dentate gyrus), the various layers of the cerebral cortex, projection neurons and interneurons of the striatum, different cell types of the cerebellum, and motor neurons of the spinal cord. Furthermore, when stained with NR1—the obligatory subunit responsible for forming functional NMDA receptors—the distribution of NR3B appears to be as ubiquitous as NR1. Taken together, our data suggest that there may be a population of NR3B‐containing NMDA receptors conferring new functional roles in the mammalian central nervous system. J. Comp. Neurol. 509:118–135, 2008. © 2008 Wiley‐Liss, Inc.
Single crystal growth and properties of semiorganic nonlinear optical L‐arginine hydrochloride monohydrate crystals
Authors: Kalaiselvi D. , Kumar R. Mohan , Jayavel R.
Published: April 2008

L‐arginine hydrochloride monohydrate (LAHCl.H2O) has been synthesized and single crystals have been grown from its aqueous solution by slow evaporation and slow cooling methods. The solubility of the material was measured at various temperatures and bulk crystals of size 26×13×11 mm3 have been grown by optimizing the growth parameters. The grown crystals have been subjected to single crystal XRD studies to confirm the structure and to estimate the lattice parameters. FTIR analysis indicate the mode of vibrations of different molecular groups present in LAHCl and confirm the protonation of guanidyl, amino groups and deprotonation of COO‐ groups. UV‐Vis transmission spectrum revealed the linear optical properties of the grown crystals with a transparency of 65% over the entire visible range upto 300 nm. Thermal behavior of the grown crystal was investigated from DTA and TGA measurements. Dielectric studies have been carried out on the grown crystals. Kurtz and Perry powder SHG technique confirms the NLO property of the grown crystal. The SHG efficiency of LAHCl was found to be 0.38 with respect to KDP. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of the crystal shape and its influence on the anti‐tumor activity of tumor necrosis factor‐related apoptosis‐inducing ligand (Apo2L/TRAIL)
Authors: Yin Ji‐Cheng , Zhou Jin‐Song , Sun Jing , Qiu Yi , Wei Dong‐Zhi , Shen Ya‐Ling
Published: April 2008

This paper describes a method about the crystal shape control improving the anti‐tumor activity of tumor necrosis factor‐related apoptosis‐inducing ligand (Apo2L/TRAIL) in a batch cooling suspension crystallization by selecting pH values as a controllable variable. Three shaped TRAIL crystals could be obtained under different pH conditions, among which the hexagonal plate crystals had the highest specific activities against tumor cell line. The relationship among pH values, trimer contents and the specific activities of crystals and the purified TRAIL solutions were investigated. The results showed that different trimer contents resulted from pH altering in crystals and protein solutions is a main reason for their different specific activities. The studies may supply a new method to improve the bioactivity of TRAIL agent during its production and storage. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Controlled growth of ZnO torch‐like nanostructure arrays
Authors: Xiao Jing , Zhang Wei , Wu Yue , Sun Hui
Published: April 2008

Single‐crystal ZnO torch‐like nanostructure arrays were synthesized using a simple two‐step pressure controlled thermal evaporation method without any catalyst. The nanostructures had a hierarchical morphology, with well‐hexagonal faceted holders and needle‐like flames on them. The diameter of each single flame was about 20–40nm at the base and 10nm at the tip. Both the holders and flames were found to grow along the [0001] direction. The morphology of the structures could be effectively controlled by varying the growth temperature and vacuum pressure. The experimental results and analysis provided easy strategies to control the morphology of nanostructures and also enhanced the understanding of the growth mechanism. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Processing Conditions for the Formation of Spider Silk Microspheres
Authors: Lammel Andreas , Schwab Martin , Slotta Ute , Winter Gerhard , Scheibel Thomas
Published: April 2008

Spider silk is a material consisting of very large (>200 kDa) proteins and has a high potential for biomedical applications as a result of its biocompatibility and biodegradability. We report on the influence of physicochemical factors on structure formation of the engineered spider silk protein eADF4(C16), which mimics the known sequence of the dragline protein ADF4 from the spider Araneus diadematus. Under certain experimental conditions, eADF4(C16) forms stable microspheres that have been analyzed with respect to sphere size, size distribution, and surface inertness upon different preparation methods (dialysis, pipette and micromixing). As a result of their material strength, biocompatibility, and the possibility of functionalization, spider silk microspheres have a high potential for the development of targeted drug‐delivery systems.
An Exceptionally DMSO‐Tolerant Alcohol Dehydrogenase for the Stereoselective Reduction of Ketones
Authors: Lavandera Iván , Kern Alexander , Schaffenberger Martina , Gross Johannes , Glieder Anton , de Wildeman Stefaan , Kroutil Wolfgang
Published: April 2008

A novel short‐chain alcohol dehydrogenase from Paracoccus pantotrophus DSM 11072, which is applicable for hydrogen transfer, has been identified, cloned, and overexpressed in E. coli. The enzyme stereoselectively reduces several ketones in a sustainable substrate‐coupled approach using 2‐propanol (5 % v/v) as hydrogen donor. The enzyme maintained its activity in organic co‐solvents in biphasic as well as monophasic systems and was even active in micro‐aqueous media (1 % v/v aqueous buffer). In general, a higher conversion was observed at higher log P values of the solvent, however, DMSO, which exhibits the lowest log P value of all solvents investigated, was not only tolerated but led to a higher conversion and relative activity (110–210 %). For example, the conversion after 24 h in 15 % v/v DMSO was double that for the reaction performed in buffer. This tolerance to DMSO may be attributed to the ability of the wild‐type strain to adapt and grow in media with high sulfur content.
Bewertung und Zertifizierung der Nachhaltigkeit von Gebäuden
Authors: Graubner Carl‐Alexander , Lützkendorf Thomas
Published: April 2008

In Deutschland hat das Thema Nachhaltigkeit seit längerem auch in das Bauwesen Einzug gehalten. Damit einhergehend zeichnet sich in der Baubranche seit kurzem ein wachsender Bedarf nach einer Zertifizierung von “nachhaltigen” Gebäuden ab. Diesem Bedarf kommt das nationale System zur Beschreibung, Bewertung und Zertifizierung des Beitrags von Einzelbauwerken zu einer nachhaltigen Entwicklung entgegen, das im Auftrag des Bundesministeriums für Verkehr, Bau und Stadtentwicklung (BMVBS) entwickelt wurde. Das System wurde zunächst für den Neubau von Büro‐ und Verwaltungsgebäuden ausgestaltet, ist jedoch künftig auch für verschiedene Gebäude‐ und Nutzungsarten sowie Bestandsgebäude anwendbar. Zur Gewährleistung der Glaubwürdigkeit und Objektivität beruht die Nachhaltigkeitsbewertung weitestgehend auf quantifizierbaren Kernkriterien, die den vier Kategorien “ökologische Qualität”, “ökonomische Qualität”, “soziale und funktionale Qualität” sowie “technische Qualität” angehören. Die Nachhaltigkeit der untersuchten Objekte wird anhand eines speziell konzipierten Zertifikates dargestellt, welches durch ein Label ergänzt wird. Die Urkunde soll neben der erreichten Note auch gesondert ausgewiesene Informationen zu charakteristischen Gebäudeeigenschaften, der Qualität der Planungs‐, Bau‐ und Betriebsprozesse und der Standortqualität enthalten. Organisation und Durchführung der Gebäudezertifizierung werden derzeit zwischen dem Bund und verschiedenen privatwirtschaftlichen Organisationen diskutiert.
Theoretische und praktische Untersuchungen zur Bestimmung der Druckfestigkeit von Mauerwerk‐pfeilern aus Kalksand‐ und Porenbeton‐Vollsteinen
Authors: Brameshuber Wolfgang , Graubohm Markus
Published: April 2008

Nach dem heutigen Erkenntnisstand hängt die Druckfestigkeit von Mauerwerk von einer Vielzahl von Einflüssen ab. So wird das Tragverhalten von vertikal auf Druck beanspruchtem Mauerwerk u.a. durch die voneinander abweichenden Materialeigenschaften seiner Bestandteile, insbesondere durch die horizontalen Formänderungsunterschiede von Mauerstein und Mauermörtel, deutlich beeinflusst.

Eine rein theoretisch begründete und abgesicherte Lösung zur Berechnung der Mauerwerkdruckfestigkeit unter Berücksichtigung der wesentlichen Einflussparameter liegt trotz zahlreicher Untersuchungen zu dieser Thematik bislang nicht vor. Die Druckfestigkeit von Mauerwerk kann deshalb derzeit nur in grober Näherung auf Grundlage von Versuchsergebnissen in Abhängigkeit von den Kenngrößen Mauerstein‐ und Mörteldruckfestigkeit bestimmt werden.

Ziel einer am Institut für Bauforschung der RWTH Aachen (ibac) durchgeführten Forschungsarbeit ist es, eine theoretisch basierte Berechnungsmethode zur zutreffenden Vorherbestimmung der Mauerwerkdruckfestigkeit mit Hilfe von FE‐Methoden zu erarbeiten. In diesem Beitrag werden erste Ergebnisse dieser umfangreichen theoretischen und experimentellen Untersuchungen zur Bestimmung der Druckfestigkeit von Mauerwerk‐pfeilern aus Kalksand‐ und Porenbeton‐Vollsteinen vorgestellt.
Neue Herausforderungen für Nachhaltigkeit und Energieeffizienz – Vom Energieausweis der EnEV 2007 zum Zertifikat für nachhaltiges Bauen
Authors: Hegner Hans‐Dieter
Published: April 2008

Mit der Umsetzung der EG‐Richtlinie 2002/91/EG über die Ge‐samtenergieeffizienz von Gebäuden in nationales Recht wurde in Deutschland das Energieeinsparrecht (Energieeinspargesetz, Energieeinsparverordnung) umfassend novelliert. Das Zweite Gesetz zur Änderung des Energieeinspargesetzes ist am 08. 09. 2005 in Kraft getreten. Auf dieser Grundlage hat die Bundesregierung die Energieeinsparverordnung 2007 (EnEV 2007) am 24. 07. 2007 endgültig beschlossen. Sie ist am 1. Oktober 2007 in Kraft treten.

Die damit verbundene schrittweise Einführung von Energieausweisen für den gesamten Gebäudebestand wird die Sichtweisen von Mietern und Immobilienerwerbern langfristig verändern.

Die Energiepreise in Deutschland haben sich seit zehn Jahren etwa verdoppelt. Das betrifft insbesondere die privaten Haushalte, die im Gegensatz zur Industrie stärker belastet werden. Während bei vermieteten Wohnungen in den letzten sieben Jahren die Nettokaltmiete um 7 % gestiegen ist, stiegen die warmen Betriebskosten (Heizung und Warmwasser) um rd. 48%. Niedrige Betriebskosten werden noch stärker zu einem Verkaufs‐ oder Mietargument. Die Märkte werden darauf zunehmend reagieren.