bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanostructures and surface nanomechanical properties of polyacrylonitrile/graphene oxide composite nanofibers by electrospinning
Authors: Wang Qingqing , Du Yuanzhi , Feng Quan , Huang Fenglin , Lu Keyu , Liu Jingyan , Wei Qufu
Published: August 2012

In this work, polyacrylonitrile (PAN)/graphene oxide (GO) composite nanofibers were prepared by a facile compounding and electrospinning processes. A small amount of GO powders were first dispersed in N,N‐dimethylformamide by sonication, and then, PAN powders were added to prepare an electrospinning solution. The surface morphology was analyzed by atomic force microscopy and transmission electron microscopy, whereas the chemical properties of the PAN and PAN/GO composite nanofibers were compared by infrared (IR) spectroscopy. Also, lateral force microscopy and force–distance curves (FDC) were employed to investigate the surface properties, such as friction force and elasticity. The experimental results indicate that with increasing GO concentration, the surface friction force and adhesive force increased, so the nanofibers showed promise for applications as supports for enzyme immobilization. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Electrically conductive adhesive based on bismaleimide‐triazine resin filled with microcoiled carbon fibers
Authors: Wu Guanglei , Kou Kaichang , Li Ning , Shi Hailin , Chao Min
Published: August 2012

Electrically conductive adhesive (ECA) was prepared with cyanate ester resin and bismaleimide resin formed bismaleimide‐triazine resin as the matrix, a γ‐glycidoxy propyl trimethoxy silane (KH‐560) as the coupling agent, and the carbon microcoils (CMCs) as the conducting filler. CMCs were synthesized by the catalytic decomposition of acetylene using nickel sulfide particles as the catalyst, which prepared by solvothermal method. The morphology and microstructure of CMCs were examined by scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction. The electrical conductivity of the ECA increased to 3.16 × 10−2 S/cm. When the content of CMCs was 1.5 wt %, the shear strength between 25 and 200°C remained at a high value of 22.8 and 21.4 MPa, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Mechanical and morphological properties of waste Eurycoma longifolia fiber/montmorillonite reinforced poly(vinyl chloride) hybrid composites
Authors: Hamid Yasin , Bakar Aznizam Abu , Deirram Nayeleh
Published: August 2012

Hybrid composites are currently spearheading in polymer composites field with the promising ability in improving polymer properties. The influence of Eurycoma longifolia (EL)/montmorillonite (MMT) hybrid fillers loading on the mechanical properties of poly(vinyl chloride) (PVC) hybrid composites has been investigated. PVC resin and various additives were first dry‐blended using a laboratory blender before being milled into sheets using two‐roll mills at 165°C and hot pressed at 180°C and 120 kgm−2. The mechanical properties of PVC hybrid composites were determined using Izod impact, tensile, and flexural test. The incorporation of EL fiber into PVC matrix improved the flexural modulus, tensile modulus of PVC composites, whereas the tensile strength and impact strength decreased with increasing EL fiber content. The addition of MMT into EL‐filled PVC composites has significantly increased the flexural modulus, tensile modulus of PVC hybrid composite compared to PVC composites. However, MMT decreased the flexural strength and impact strength of PVC hybrid composites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis of hybrid polyaniline/carbon nanotubes nanocomposites in toluene by dynamic interfacial inverse emulsion polymerization under sonication
Authors: Suckeveriene R. Y. , Mechrez G. , Filiba O. Hachamo , Mosheev S. , Narkis M.
Published: August 2012

This work describes an empirical study of in situ interfacial dynamic inverse emulsion polymerization process under sonication of aniline in the presence of nine different types of carbon nanotubes (CNT) in toluene. The polymerization method described in this work is simple and very fast (5 min) compared to the other literature reports (3–12 h). During polymerization, CNT are coated with polyaniline (PANI) forming a core‐shell structure of nanowires as evidenced by transmission electron microscopy (TEM) and high‐resolution scanning microscopy (HRSEM). HRSEM images and surface resistivity imply that PANI coating of CNT leads to a remarkable improvement in separation and dispersion of CNT in toluene, which otherwise would have rapidly coagulate and settle. Two of the nine different CNT studied have shown the lowest surface resistivities. Films of uniform thickness were successfully produced (HRSEM of cross‐sections). The effect of film thickness on conductivity and optical properties is reported in the work. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Durability of polylactide‐based polymer blends for injection‐molded applications
Authors: Harris Angela M. , Lee Ellen C.
Published: August 2012

The durability of polylactide (PLA) blended with polycarbonate (PC) was assessed by exposure to conditions of elevated temperature and humidity over a period of several weeks. Mechanical performance, moisture absorption, chemical composition, and thermal properties were monitored as a function of continuous conditioning at 70°C and 90% relative humidity (RH). All PLA and PC/PLA blends showed significant moisture absorption and hydrolysis, resulting in degradation of properties. Furthermore, while the addition of PC was intended to improve the durability of the blend over neat PLA, it was found that the hydrolysis products of PLA accelerated the degradation of PC itself. This study shows for the first time the hydrolysis behavior of PC/PLA blends in an increasingly acid environment during heat and humidity conditioning. These injection‐molding grades of PLA‐based resins are currently not suitable for use in applications that require long‐term durability in environments subject to elevated temperature and humidity, such as automotive interiors. Further material formulation work is required before use in injection‐molded applications for automotive. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Copolymerizing behavior and processability of benzoxazine/epoxy systems and their applications for glass fiber composite laminates
Authors: Xu Mingzhen , Yang Xulin , Zhao Rui , Liu Xiaobo
Published: August 2012

Copolymerizing behavior and processability of epoxy/benzoxazine containing cyano groups (EP/BA‐ph) systems were investigated by differential scanning calorimetry and dynamic rheological analysis. The results showed that EP/BA‐ph systems exhibited two characteristic peaks corresponding to ring‐opening of benzoxazine and ring‐formation of cyano groups, respectively. Compared with BA‐ph, EP/BA‐ph copolymer processability was improved and can be controlled by varying EP contents, processing temperature, and time. Then EP/BA‐ph copolymers were employed to prepare EP/BA‐ph/glass fiber (GF) composite laminates and their mechanical, morphological, and thermal properties were investigated. Compared with those of BA‐ph/GF composites, the flexural strength, and modulus of EP/BA‐ph/GF composites with 50 wt % EP content were increased by 13.5 and 20%, respectively. The enhancements in mechanical properties are mainly due to the strong interfacial adhesions between GF and matrices, which was confirmed by SEM observations. All EP/BA‐ph/GF composite laminates are stable up to 510°C in air. EP/BA‐ph/GF laminates will have potential applications in the areas where require of excellent mechanical properties and high temperature resistance. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
JAK inhibition with tofacitinib suppresses arthritic joint structural damage through decreased RANKL production
Authors: LaBranche Timothy P. , Jesson Michael I. , Radi Zaher A. , Storer Chad E. , Guzova Julia A. , Bonar Sheri L. , Thompson Janice M. , Happa Fernando A. , Stewart Zachary S. , Zhan Yutian , Bollinger Chris S. , Bansal Prashant N. , Wellen Jeremy W. , Wilkie Dean P. , Bailey Steven A. , Symanowicz Peter T. , Hegen Martin , Head Richard D. , Kishore Nandini , Mbalaviele Gabriel , Meyer Debra M.
Published: August 2012

Objective

The mechanistic link between Janus kinase (JAK) signaling and structural damage to arthritic joints in rheumatoid arthritis (RA) is poorly understood. This study was undertaken to investigate how selective inhibition of JAK with tofacitinib (CP‐690,550) affects osteoclast‐mediated bone resorption in a rat adjuvant‐induced arthritis (AIA) model, as well as human T lymphocyte RANKL production and human osteoclast differentiation and function.

Methods

Hind paw edema, inflammatory cell infiltration, and osteoclast‐mediated bone resorption in rat AIA were assessed using plethysmography, histopathologic analysis, and immunohistochemistry; plasma and hind paw tissue levels of cytokines and chemokines (including RANKL) were also assessed. In vitro RANKL production by activated human T lymphocytes was evaluated by immunoassay, while human osteoclast differentiation and function were assessed via quantitative tartrate‐resistant acid phosphatase staining and degradation of human bone collagen, respectively.

Results

Edema, inflammation, and osteoclast‐mediated bone resorption in rats with AIA were dramatically reduced after 7 days of treatment with the JAK inhibitor, which correlated with reduced numbers of CD68/ED‐1+, CD3+, and RANKL+ cells in the paws; interleukin‐6 (transcript and protein) levels were rapidly reduced in paw tissue within 4 hours of the first dose, whereas it took 4–7 days of therapy for RANKL levels to decrease. Tofacitinib did not impact human osteoclast differentiation or function, but did decrease human T lymphocyte RANKL production in a concentration‐dependent manner.

Conclusion

These results suggest that the JAK inhibitor tofacitinib suppresses osteoclast‐mediated structural damage to arthritic joints, and this effect is secondary to decreased RANKL production.
A novel patchwork model used in lecture and laboratory to teach the three‐dimensional organization of mesenteries
Authors: Noël Geoffroy P.J.C.
Published: August 2012

Anatomy teaching is seeing a decline in both lecture and laboratory hours across many medical schools in North America. New strategies are therefore needed to not only make anatomy teaching more clinically integrated, but also to implement new interactive teaching techniques to help students more efficiently grasp the complex organization of the human body. Among the difficult anatomical concepts that students struggle to understand, the anatomy of the peritoneal cavity with its complex projections of peritoneum could benefit strongly from new learning aids. In this report, an innovative teaching tool is presented to engage students during both lecture and laboratory, and help them build three‐dimensional (3D) mental maps of peritoneal cavity. The model consists of a patchwork of mesenteries and gut made from colored cloth stitched together onto a T‐shirt to denote the origin and outflow of each peritoneum projection. As the lecturer wears the life‐size model, the students can appreciate the 3D organization of the peritoneal cavity on a living body. In addition, the T‐shirt model can be used in parallel with dissection to ensure a strong reinforcement of the spatial understanding of the peritoneal cavity. Anat Sci Educ. © 2012 American Association of Anatomists.
Can intermediary‐based science standards crosswalking work? Some evidence from mining the standard alignment tool (SAT)
Authors: Reitsma René , Marshall Byron , Chart Trevor
Published: August 2012

We explore the feasibility of intermediary‐based crosswalking and alignment of K‐12 science education standards. With the increasing availability of K‐12 science, technology, engineering, and mathematics (STEM) digital library content, alignment of that content with educational standards is a significant and continuous challenge. Whereas direct, one‐to‐one alignment of standards is preferable but currently unsustainable in its resource demands, less resource‐intensive intermediary‐based alignment offers an interesting alternative. But will it work? We present the results from an experiment in which the machine‐based Standard Alignment Tool (SAT)—incorporated in the National Science Digital Library (NSDL)—was used to collect over half a million direct alignments between standards from different standard‐authoring bodies. These were then used to compute intermediary‐based alignments derived from the well‐known AAAS Project 2061 Benchmarks and NSES standards. The results show strong variation among authoring bodies in their success at crosswalking, with the best results for those who modeled their standards on the intermediaries. The results furthermore show a strong inverse relationship between recall and precision when both intermediates were involved in the crosswalking.
In vitro and in vivo evaluation of a primaquine prodrug without red blood cell membrane destabilization property
Authors: Davanço Marcelo Gomes , Campos Michel Leandro , Nogueira Marco Antonio , Campos Silvio Lopes , Marques Ricardo Vian , dos Santos Jean Leandro , Chin Chung Man , da Fonseca Luiz Marcos , Peccinini Rosângela Gonçalves
Published: August 2012

Primaquine is an important therapeutic resource for malaria treatment and it has wide activity against several pathogens. The haematotoxicity of primaquine is the major problem for its therapeutic application. This effect is aggravated by repeated use at high doses and by the wide fluctuation of plasma levels after administration. The primaquine prodrug (Phe‐Ala‐PQ) was planned in order to modify the pharmacokinetics and toxicity of primaquine. The in vitro conversion of Phe‐Ala‐PQ to primaquine, and the primaquine pharmacokinetics were evaluated in four groups of rats: two groups that received a single dose of Phe‐Ala‐PQ, one by intravenous and the other by gavage route, and two other groups that received primaquine diphosphate, by intravenous and gavage routes. In addition, the erythrocyte osmotic fragility was compared in two groups of rats that received multiple doses of primaquine diphosphate or Phe‐Ala‐PQ, as a parameter of haematotoxicity. The in vitro conversion of Phe‐Ala‐PQ to primaquine by plasma enzyme action was observed. The pharmacokinetic profile of primaquine from Phe‐Ala‐PQ was more favourable due to the lower fluctuation of plasma concentrations. Haematotoxicity was not evidenced in the prodrug administration. The results reinforce the need for further studies with this prodrug, promising an alternative in the therapeutic use of primaquine. Copyright © 2012 John Wiley & Sons, Ltd.
Active intestinal absorption of fluoroquinolone antibacterial agent ciprofloxacin by organic anion transporting polypeptide, Oatp1a5
Authors: Arakawa Hiroshi , Shirasaka Yoshiyuki , Haga Makoto , Nakanishi Takeo , Tamai Ikumi
Published: August 2012

Fluoroquinolone antimicrobial drugs are absorbed efficiently after oral administration despite of their hydrophilic nature, implying an involvement of carrier‐mediated transport in their membrane transport process. It has been that several fluoroquinolones are substrates of organic anion transporter polypeptides OATP1A2 expressed in human intestine derived Caco‐2 cells. In the present study, to clarify the involvement of OATP in intestinal absorption of ciprofloxacin, the contribution of Oatp1a5, which is expressed at the apical membranes of rat enterocytes, to intestinal absorption of ciprofloxacin was investigated in rats. The intestinal membrane permeability of ciprofloxacin was measured by in situ and the vascular perfused closed loop methods. The disappeared and absorbed amount of ciprofloxacin from the intestinal lumen were increased markedly in the presence of 7,8‐benzoflavone, a breast cancer resistance protein inhibitor, and ivermectin, a P‐glycoprotein inhibitor, while it was decreased significantly in the presence of these inhibitors in combination with naringin, an Oatp1a5 inhibitor. Furthermore, the Oatp1a5‐mediated uptake of ciprofloxacin was saturable with a Km value of 140 µm, and naringin inhibited the uptake with an IC50 value of 18 µm by Xenopus oocytes expressing Oatp1a5. Naringin reduced the permeation of ciprofloxacin from the mucosal‐to‐serosal side, with an IC50 value of 7.5 µm by the Ussing‐type chamber method. The estimated IC50 values were comparable to that of Oatp1a5. These data suggest that Oatp1a5 is partially responsible for the intestinal absorption of ciprofloxacin. In conclusion, the intestinal absorption of ciprofloxacin could be affected by influx transporters such as Oatp1a5 as well as the efflux transporters such as P‐gp and Bcrp. Copyright © 2012 John Wiley & Sons, Ltd.
Recovery of poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) from Ralstonia eutropha cultures with non‐halogenated solvents
Authors: Riedel Sebastian L. , Brigham Christopher J. , Budde Charles F. , Bader Johannes , Rha ChoKyun , Stahl Ulf , Sinskey Anthony J.
Published: August 2012

Reduced downstream costs, together with high purity recovery of polyhydroxyalkanoate (PHA), will accelerate the commercialization of high quality PHA‐based products. In this work, a process was designed for effective recovery of the copolymer poly(hydroxybutyrate‐co‐hydroxyhexanoate) (P(HB‐co‐HHx)) containing high levels of HHx (>15 mol%) from Ralstonia eutropha biomass using non‐halogenated solvents. Several non‐halogenated solvents (methyl isobutyl ketone, methyl ethyl ketone, and butyl acetate and ethyl acetate) were found to effectively dissolve the polymer. Isoamyl alcohol was found to be not suitable for extraction of polymer. All PHA extractions were performed from both dry and wet cells at volumes ranging from 2 mL to 3 L using a PHA to solvent ratio of 2% (w/v). Ethyl acetate showed both high recovery levels and high product purities (up to 99%) when using dry cells as starting material. Recovery from wet cells, however, eliminates a biomass drying step during the downstream process, potentially saving time and cost. When wet cells were used, methyl isobutyl ketone (MIBK) was shown to be the most favorable solvent for PHA recovery. Purities of up to 99% and total recovery yields of up to 84% from wet cells were reached. During polymer recovery with either MIBK or butyl acetate, fractionation of the extracted PHA occurred, based on the HHx content of the polymer. PHA with higher HHx content (17–30 mol%) remained completely in solution, while polymer with a lower HHx content (11–16 mol%) formed a gel‐like phase. All PHA in solution could be precipitated by addition of threefold volumes of n‐hexane or n‐heptane to unfiltered PHA solutions. Effective recycling of the solvents in this system is predicted due to the large differences in the boiling points between solvent and precipitant. Our findings show that two non‐halogenated solvents are good candidates to replace halogenated solvents like chloroform for recovery of high quality PHA. Biotechnol. Bioeng. 2013; 110: 461–470. © 2012 Wiley Periodicals, Inc.
Chemical Constituents of Saniculiphyllum guangxiense
Authors: Geng Chang‐An , Huang Xiao‐Yan , Lei Li‐Gong , Zhang Xue‐Mei , Chen Ji‐Jun
Published: August 2012

The first phytochemical investigation on Saniculiphyllum guangxiense resulted in the isolation of two new triterpenoids, 16β‐hydroxybryodulcosigenin (3) and 3α‐O‐feruloylolean‐12‐en‐27‐oic acid (6), together with six known compounds, menisdaurin (1), purshianin (2), oleanolic acid (4), 3β‐hydroxyolean‐12‐en‐27‐oic acid (5), β‐sitosterol (7), and daucosterol (8), which were characterized by extensive spectroscopic analyses and in one case by X‐ray diffraction. According to this primary investigation, S. guangxiense is rich in nitrile glucosides and triterpenoids, of which menisdaurin (1; 0.06%) and purshianin (2; 0.015%) are the main constituents. Compounds 1–6 were assayed for their anti‐hepatitis B virus (HBV) activities against the secretion of HBsAg and HBeAg, as well as HBV DNA replication on Hep G 2.2.15 cell line in vitro. The most active compound, menisdaurin (1), inhibits HBV DNA replication with an IC50 value of 0.32 mM (SI>11.97).
Essential Oil of Azorella cryptantha Collected in Two Different Locations from San Juan Province, Argentina: Chemical Variability and Anti‐Insect and Antimicrobial Activities
Authors: López Sandra , Lima Beatriz , Aragón Liliana , Espinar Luis Ariza , Tapia Alejandro , Zacchino Susana , Zygadlo Julio , Feresin Gabriela Egly , López María Liza
Published: August 2012

The essential oils (EOs) of two populations of Azorella cryptantha (Clos) Reiche, a native species from San Juan Province, were obtained by hydrodistillation in a Clevenger‐type apparatus and characterized by GC‐FID and GC/MS analyses. The compounds identified amounted to 92.3 and 88.7% of the total oil composition for A. cryptantha from Bauchaceta (Ac‐BAU) and Agua Negra (Ac‐AN), respectively. The EO composition for the two populations was similar, although with differences in the identity and content of the main compounds and also in the identity of minor components. The main compounds of the Ac‐BAU EO were α‐pinene, α‐thujene, sabinene, δ‐cadinene, δ‐cadinol, trans‐β‐guaiene, and τ‐muurolol, while α‐pinene, α‐thujene, β‐pinene, γ‐cadinene, τ‐cadinol, δ‐cadinene, τ‐muurolol, and a not identified compound were the main constituents of the Ac‐AN EO, which also contained 3.0% of oxygenated monoterpenes. The repellent activity on Triatoma infestans nymphs was 100 and 92% for the Ac‐AN and Ac‐BAU EOs, respectively. Regarding the toxic effects on Ceratitis capitata, the EOs were very active with LD50 values lower than 11 μg/fly. The dermatophytes Microsporum gypseum, Trichophyton rubrum, and T. mentagrophytes and the bacterial strains Escherichia coli LM1, E. coli LM2, and Yersinia enterocolitica PI were more sensitive toward the Ac‐AN EO (MIC 125 μg/ml) than toward the Ac‐BAU EO. This is the first report on the composition of A. cryptantha EO and its anti‐insect and antimicrobial properties.
Chemical Properties and Antioxidant and Antimicrobial Activities of Slovenian Propolis
Authors: Mavri Ana , Abramovič Helena , Polak Tomaž , Bertoncelj Jasna , Jamnik Polona , Smole Možina Sonja , Jeršek Barbara
Published: August 2012

The chemical composition as well as the antioxidant and antimicrobial activities of two EtOH extracts of propolis (PEEs) from Slovenia were determined. EtOH was used as extracting solvent at 70 and 96%, providing the extracts PEE70 and PEE96, respectively. The extraction with 70% EtOH was more efficient than that with 96% EtOH, as the PEE70 was richer in total phenolic compounds than the PEE96. The Slovenian propolis was characterized by different phenolic acids and flavonoids. The PEE96 was slightly richer in three specific compounds, i.e., caffeic acid, ferulic acid, and luteolin, while all other substances detected showed higher contents in the PEE70. The PEE70 showed a stronger reducing power and ability to scavenge free radicals and metal ions than the PEE96. Both PEEs were in the main more effective against Gram‐positive bacteria than against fungi and Gram‐negative bacteria like Salmonella and Escherichia coli, with the exception of Campylobacter. The PEE96 decreased the intracellular oxidation in Saccharomyces cerevisiae in a dose‐dependent manner. The antimicrobial activities and antioxidant properties were related to the total phenolic contents. The two PEEs have the potential for use as natural antimicrobial and antioxidant additives in foods.
Essential Oils of Three Taxa of the Nepeta argolica Aggregate from Greece
Authors: Hanlidou Effie , Karousou Regina , Lazari Diamanto
Published: August 2012

The essential‐oil composition of three not previously studied taxa belonging to the Nepeta argolica aggregate was examined. The oils of N. argolica ssp. malacotrichos and N. argolica ssp. vourinensis (both Greek endemics) are rich in 1,8‐cineole (30.9–55.6% of the total oil composition), while those of the Balkan endemic N. spruneri are rich in either sesquiterpenes (mainly caryophyllene oxide, 14.6–19.8%) or in 4aα,7α,7aβ‐ and 4aα,7α,7aα‐nepetalactones (total content 17.5–40.5%), accompanied by caryophyllene oxide (11.5–11.7%) and 1,8‐cineole (up to 16.5%). The comparison of our results with published information concerning the related taxa of the N. argolica aggregate showed that while oils with as main components nepetalactones or 1,8‐cineole are common, sesquiterpene‐rich oils are reported for the first time within the aggregate.
Isolation and Characterization of Two Novel Antibacterial Cyclic Hexapeptides from Streptomyces alboflavus 313
Authors: Ji Zhiqin , Qiao Gang , Wei Shaopeng , Fan Lixia , Wu Wenjun
Published: August 2012

Two novel cyclic hexapeptides, designated NW‐G08 (1) and NW‐G09 (2), were isolated from the fermentation broth of Streptomyces alboflavus 313. Their structures were elucidated on the basis of extensive spectroscopic analysis, MS experiments, and chemical analysis. Their antibacterial activities against several strains of bacteria were evaluated by micro‐broth dilution method. NW‐G08 (1) and NW‐G09 (2) were highly antibacterial against Gram‐positive but not active against Gram‐negative bactaria. The minimum inhibitory concentrations (MICs) of 1 against Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus were 6.25, 6.25, and 1.56 μg/ml, respectively. It is worth noting that 1 and 2 exhibited much higher activities against methicillin‐resistant Staphylococcus aureus (MRSA) than ampicillin, which implies that they might be potential candidates for the development of novel drugs against resistant pathogenic bacteria.
Studies on Chemical Structure Modification and StructureActivity Relationship of Derivatives of Gambogic Acid at C(39)
Authors: Sun Hao‐Peng , Liu Zong‐Liang , Xue Xin , Gao Yuan , Zhang Lei , Wang Jin‐Xin , Guo Qing‐Long , You Qi‐Dong
Published: August 2012

The natural product gambogic acid exhibits high potency in inhibiting cancer cell lines. Rational medicinal modifications on gambogic acid will improve its physicochemical properties and drug‐like characters. To investigate the structureactivity relationship of gambogic acid and also to find rational modification position on its chemical skeleton, we designed, synthesized, and characterized 16 derivatives of gambogic acid that were modified at C(39). The structureactivity relationships (SARs) were discussed. The anti‐proliferation data were accquired through MTT (=3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide) assays of A549, BGC823, U251, HepG2, and MDA‐MB‐231 cancer cell lines. Most of the synthesized compounds showed strong inhibitory effects. The SAR study revealed that derivatives with aliphatic amino moieties at C(39) were more potent than those with other substituents. The C(39) position can undergo different kinds of chemical modifications without leading to loss of activity. Compounds 4 and 6 can serve as potential lead compounds for further development of new anticancer drugs.
Fatty‐Acid Profile of Total and Polar Lipids in Cultured Rainbow Trout (Oncorhynchus mykiss) Raised in Freshwater and Seawater (Croatia) Determined by Transmethylation Method
Authors: Staver Mladenka Malenica , Jerković Igor , Giacometti Jasminka , Malenica Ante , Marijanović Zvonimir
Published: August 2012

Fatty acids from total lipids and polar lipids in cultured rainbow trout (Oncorhynchus mykiss) raised in seawater (SW) and freshwater (FW) were identified and quantified from the muscle samples in January, April, and July. The highest total lipid and polar lipid amounts were found in April. July contents of total lipids were low, but percent of the polyunsaturated fatty acids (PUFAs) was high in SW and FW environment (particularly n‐3 PUFAs). Variety of 17 fatty acids was identified by GC‐FID after transmethylation. The predominant fatty acids in rainbow trout from SW and FW were: docosahexaenoic acid among n‐3 PUFAs, palmitic acid among saturated fatty acids (SFAs), and oleic acid among monounsaturated fatty acids (MUFAs). Appreciably higher n‐3/n‐6 ratio was found in total lipids in April (6.40, FW fish) and in polar lipids in July (18.76; SW fish). High n‐3/n‐6 ratio in total lipids and polar lipids of rainbow trout from SW and FW, besides beneficial n‐3/n‐6 ratio in the commercial fish food, could be characteristic for the local environmental conditions (Croatia).
Melanogenesis‐Inhibitory and Cytotoxic Activities of Diarylheptanoids from Acer nikoense Bark and Their Derivatives
Authors: Akihisa Toshihiro , Takeda Ayano , Akazawa Hiroyuki , Kikuchi Takashi , Yokokawa Satoru , Ukiya Motohiko , Fukatsu Makoto , Watanabe Kensuke
Published: August 2012

Nine cyclic diarylheptanoids, 1–9, including two new compounds, i.e., 9‐oxoacerogenin A (8) and 9‐O‐β‐D‐glucopyranosylacerogenin K (9), along with three acyclic diarylheptanoids, 10–12, and four phenolic compounds, 13–16, were isolated from a MeOH extract of the bark of Acer nikoense (Aceraceae). Acid hydrolysis of 9 yielded acerogenin K (17) and D‐glucose. Two of the cyclic diarylheptanoids, acerogenin A (1) and (R)‐acerogenin B (5), were converted to their ether and ester derivatives, 18–24 and 27–33, respectively, and to the dehydrated derivatives, 25, 26, 34, and 35. Upon evaluation of compounds 1–16 and 18–35 for their inhibitory activities against melanogenesis in B16 melanoma cells, induced with α‐melanocyte‐stimulating hormone (α‐MSH), eight natural glycosides, i.e., six diarylheptanoid glycosides, 2–4, 6, 9, and 12, and two phenolic glycosides, 15 and 16, exhibited inhibitory activities with 24–61% reduction of melanin content at 100 μM concentration with no or almost no toxicity to the cells (88–106% of cell viability at 100 μM). In addition, when compounds 1–16 and 18–35 were evaluated for cytotoxic activity against human cancer cell lines, two natural acyclic diarylheptanoids, 10 and 11, ten ether and ester derivatives, 18–22 and 27–31, and two dehydrated derivatives, 34 and 35, exhibited potent cytotoxicities against HL60 human leukemia cell line (IC50 8.1–19.3 μM), and five compounds, 10, 11, 20, 29, and 30, against CRL1579 human melanoma cell line (IC50 10.1–18.4 μM).
Melanogenesis Inhibitory Activity of Monoterpene Glycosides from Gardeniae Fructus
Authors: Akihisa Toshihiro , Watanabe Kensuke , Yamamoto Ayako , Zhang Jie , Matsumoto Masahiro , Fukatsu Makoto
Published: August 2012

A new iridoid glycoside, 10‐O‐(4″‐O‐methylsuccinoyl)geniposide (7), and two new pyronane glycosides, jasminosides Q and R (13 and 14, resp.), along with nine known iridoid glycosides, 1–6 and 8–10, and two known pyronane glycosides, 11 and 12, were isolated from a MeOH extract of Gardeniae Fructus, the dried ripe fruit of Gardenia jasminoides (Rubiaceae). The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses and comparison with literature. Upon evaluation of compounds 1–14 on the melanogenesis in B16 melanoma cells induced with α‐melanocyte‐stimulating hormone (α‐MSH), three compounds, i.e., 6‐O‐p‐coumaroylgeniposide (3), 7, and 6′‐O‐sinapoyljasminoside (12), exhibited inhibitory effects with 21.6–41.0 and 37.5–47.7% reduction of melanin content at 30 and 50 μM, respectively, with almost no toxicity to the cells (83.7–106.1% of cell viability at 50 μM).
Diversity of Unavailable Polysaccharides and Dietary Fiber in Domesticated Nopalito and Cactus Pear Fruit (Opuntia spp.)
Authors: Peña‐Valdivia Cecilia Beatriz , Trejo Carlos , Arroyo‐Peña V. Baruch , Sánchez Urdaneta Adriana Beatriz , Balois Morales Rosendo
Published: August 2012

The aim of this study was to quantify mucilages, pectins, hemicelluloses, and cellulose of nopalitos (edible, as vegetable, young cladodes of flat‐stemmed spiny cacti) of most consumed Mexican cultivars, and sweet and acid cactus pear fruits of Opuntia spp. The hypothesis is that, regardless of their unavailable polysaccharides diversity, nopalitos and cactus pear fruits are rich sources of soluble and insoluble dietary fiber. Twelve cultivars of Opuntia spp. were used. Nopalitos had a significant variation in structural polysaccharides among the cultivars: mucilages (from 3.8 to 8.6% dry matter (DM)) averaged near a half of pectins content (from 6.1 to 14.2% DM) and tightly bound hemicelluloses (from 2.2 to 4.7% DM), which were the less abundant polysaccharides, amounted 50% of the loosely bound hemicelluloses (from 4.3 to 10.7% DM). Acid fruits (or ‘xoconostle’) had significantly higher unavailable polysaccharides content than sweet fruit, and contain similar proportions than nopalitos. Unavailable polysaccharides represent a high proportion of dry tissues of nopalitos and cactus pear fruits, composition of both of these soluble and insoluble polysaccharides (total dietary fiber) widely vary among cultivars without an evident pattern. Nopalitos and cactus pear fruit can be considered an excellent source of dietary fiber.
Malonylated Glycerolipids from the Glandular Trichome Exudate of Ceratotheca triloba
Authors: Ohkawa Akiko , Sakai Takaomi , Ohyama Kiyoshi , Fujimoto Yoshinori
Published: August 2012

Chemical investigation of the glandular trichome exudate from Ceratotheca triloba (Pedaliaceae) led to the identification of nine 1‐O‐acetyl‐2‐O‐[(R)‐3‐acetyloxy‐fatty acyl]‐3‐O‐malonylglycerols. Among these, 1‐O‐acetyl‐2‐O‐[(R)‐3‐acetyloxyicosanoyl]‐3‐O‐malonylglycerol (7) was the most abundant constituent (41%), followed by 1‐O‐acetyl‐2‐O‐[(R)‐(3‐acetyloxyoctadecanoyl)‐3‐O‐malonylglycerol (2; 21%). Compounds having iso‐ and anteiso‐type structures in the 3‐acetyloxy‐fatty acyl groups in the fatty acyl moiety were also characterized as minor constituents. This is the first report of the isolation of malonylated glycerolipids as natural products.
On CO Egress from, and Re‐Uptake by, the Enzyme MauG, as a Mimic of the Acquisition of Oxidizing Agents by the pre‐MADH_MauG System. A Molecular Mechanics Approach
Authors: Pietra Francesco
Published: August 2012

In this work, by applying a non‐deterministic, randomly‐oriented minimal force to the dissociated CO ligand of the MauG‐CO system, the molecular‐dynamics (MD) behavior of this system could be quickly unraveled. It turned out that CO has no marked directional egress from the high‐spin c‐heme iron distal pocket. Rather, CO is able to exploit all interstices created during the protein fluctuations. Nonetheless, no steady route toward the surrounding solvent was ever observed: CO jumped first into other binding pockets before being able to escape the protein. In a few cases, on hitting the surrounding H2O molecules, CO was observed to reverse direction, re‐entering the protein. A contention that conformational inversion of the P107 ring provides a gate to the iron ion is not supported by the present simulations.
“Procedural trauma risks longitudinal shortening of the promus element™ stent platform”
Authors: Shannon Joanne , Latib Azeem , Takagi Kensuke , Chieffo Alaide , Figini Filippo , Sacco Francesco , Ferrarello Santo , Montorfano Matteo , Colombo Antonio
Published: August 2012

This case series raises further awareness of the potential for longitudinal shortening with the Promus Element™ (Boston Scientific, MN) drug‐eluting stent (DES) platform. With safety at the forefront of DES development, newer generation systems are utilizing thinner platforms with little or no polymer. Although these contemporary, ultrathin platforms also improve conformability and deliverability, specific design characteristics might inadvertently reduce longitudinal strength. To date, there are no randomized data addressing this issue in vivo for any stent platform, with opinion based on individual experience and bench testing. We report five cases of longitudinal shortening with the Promus Element stent occurring in our institution over a 15‐month period. During the same period, we experienced only isolated cases with other second generation DES platforms. Our experience supports recently published bench‐top data correlating the two‐link design of this platform with the risk of compression. © 2012 Wiley Periodicals, Inc.
Influence of the antiscatter grid on dose and image quality in pediatric interventional cardiology X‐ray systems
Authors: Ubeda Carlos , Vano Eliseo , Gonzalez Luciano , Miranda Patricia
Published: August 2012

Objective

To present a methodology and experimental results to assess the influence, in terms of dose and image quality, of the antiscatter grid (AG) in a pediatric cardiology X‐ray system.

Method

Entrance surface air kerma and image quality, using a test object and different added thicknesses of polymethyl methacrylate (PMMA), for three different acquisition protocols, were measured with and without the AG, for fluoroscopy and cine modes. The image quality parameters, signal‐to‐noise ratio (SNR), high‐contrast spatial resolution (HCSR) and two figures of merit (FOM) were evaluated.

Results

The average bucky factor values measured during this experiment were 1.99, 2.49, 2.85, and 3.30, respectively for 4, 8, 12, and 16 cm of PMMA. SNR variations do not appear to be relevant when removing the AG. However, the use of AG improves HCSR significantly. Imaging the test object with 4 cm of PMMA seems appropriate without the AG, but for 8 cm (equivalent to chest thicknesses of 12 cm) and greater thicknesses, a good image quality would require the use of AG.

Conclusions

The AG should not be used for neonates and very young children with chest thicknesses equal to or less than 6 cm and weight less that 6 kg. © 2013 Wiley Periodicals, Inc.
Differential long‐term outcomes of zotarolimus‐eluting stents compared with sirolimus‐eluting and paclitaxel‐eluting stents in diabetic and nondiabetic patients: Two‐year subgroup analysis of the ZEST randomized trial
Authors: Jang Sun‐Joo , Park Duk‐Woo , Kim Won‐Jang , Kim Young‐Hak , Yun Sung‐Cheol , Kang Soo‐Jin , Lee Seung‐Whan , Lee Cheol Whan , Park Seong‐Wook , Park Seung‐Jung
Published: August 2012

Objectives

To evaluate the differential treatment effects of zotarolimus‐eluting stents (ZES), sirolimus‐eluting stents (SES), and paclitaxel‐eluting stents (PES) according to diabetic status.

Background

Diabetic patients have a higher risk of ischemic complications after stenting than nondiabetic patients.

Methods

Using data from the ZEST randomized trial, comparing ZES with SES and PES, we evaluated relative outcomes among stents in diabetic and nondiabetic patients. The primary outcome was a major adverse cardiac event (MACE), defined as a composite of death, myocardial infarction, or ischemia‐driven target‐vessel revascularization.

Results

Of the 2,645 patients enrolled in the ZEST trial, 760 (29%) had diabetes mellitus. Baseline clinical and angiographic characteristics were similar in the three stent groups, regardless of diabetic status. In diabetic patients, ZES showed similar rates of MACE as compared to PES (13.8% vs. 15.3%, P = 0.58), but higher rates of MACE than SES (13.8% vs. 7.7%, P = 0.05). In nondiabetic patients, ZES showed similar rates of MACE as compared to SES (10.3% vs. 10.8%, P = 0.72), whereas significantly lower rates of MACE compared to PES (10.3% vs. 15.3%, P = 0.01). In comparing the ZES and SES groups, there was a substantial interaction between diabetic status and stent types on MACE occurrence (Interaction P = 0.07). However, in comparison of ZES and PES, there were no significant interactions between diabetes and stent type on MACE (Interaction P = 0.25).

Conclusions

In diabetic patients, SES showed the lowest rate of MACE compared with ZES and PES. But, in nondiabetic patients, SES and ZES showed significantly lower rates of MACE than PES. ZES shows a diabetes‐related interaction on MACE compared with SES, but not with PES. © 2012 Wiley Periodicals, Inc.
Fractional flow reserve for the assessment of complex multivessel disease in a patient after hybrid coronary revascularization
Authors: Corban Michel T. , Eshtehardi Parham , Samady Habib
Published: August 2012

We present a case of a 43‐year‐old woman with history of hybrid coronary revascularization [endoscopic atraumatic coronary artery bypass (ACAB)] of left internal mammary artery (LIMA) to the left anterior descending artery (LAD) and stent implantation in right coronary artery (RCA), who presented 6 years later with recurrent atypical angina. Coronary angiography revealed patent LIMA to LAD and RCA stent, with a new lesion in an obtuse marginal artery and significant progression of disease in the proximal/mid LAD proximal to LIMA touchdown. To further evaluate the hemodynamic significance of these new disease segments, the patient underwent fractional flow reserve (FFR) assessment of the left coronary system with subsequent stent implantation in the proximal/mid LAD. This case illustrates (1) the critical value of FFR assessment in determining the ischemia provoking lesions in this post ACAB patient with complex multivessel coronary artery disease; and (2) the accelerated progression of atherosclerosis in bypassed segments as compared to segments proximal to stents. © 2012 Wiley Periodicals, Inc.
Transradial retrograde approach rescuing iatrogenic long spiral dissection during chronic total occlusion intervention
Authors: Abdou Sayed M. , Yip Hon Kan , Wu Chiung‐Jen
Published: August 2012

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) is one of the greatest challenges in coronary interventions. A retrograde approach via the collateral channel has been recently proposed to improve the success rate of PCI in CTO lesions of the coronary arteries. We describe an accidental complication encountered during transradial PCI to recanalize right coronary artery CTO in a patient with unstable angina. A long spiral dissection has been created by antegrade wiring and extended from the ostium all the way down to mid RCA segment. Subsequent attempts with antegrade wiring into the true lumen were unsuccessful. Ad‐hoc retrograde recanalization has been employed to rescue the vessel via septal collateral from left anterior descending artery. Retrograde wiring and dilatation were performed followed by successful antegrade wiring into the true lumen under IVUS guidance, which revealed significant intramural hematoma extending distally to the posterolateral branch. Bailout stenting was achieved with sealing of the multiple entry and exit sites created by the spiral dissection and complete coverage of the intramural hematoma. This report highlights the role of the retrograde approach as a rescue option in the setting of complicated antegrade approach and to improve the success rate of CTO‐PCI. Moreover, IVUS was a valuable tool to confirm the true lumen course of the successful wire and to guide the stenting procedure. © 2012 Wiley Periodicals, Inc.
Use of the melody™ transcatheter pulmonary valve as a “Covered stent” to repair conduit perforation during pulmonary valve implantation
Authors: Mahgerefteh Joseph , Sutton Nicole J. , Pass Robert H.
Published: August 2012

Right ventricular to pulmonary artery conduit tear after balloon dilation is a recognized potential complication, which can, in theory, be treated with a covered stent. We describe use of the Melody™ valve as a so‐called “covered” stent for containment of bleeding from RV‐PA conduit tear. © 2013 Wiley Periodicals, Inc.
Reading of Protein Surfaces in the Native State at Micromolar Concentrations by a Chirogenetic Porphyrin Probe
Authors: Mineo Placido , Micali Norberto , Villari Valentina , Donato Maria Grazia , Scamporrino Emilio
Published: August 2012

The recognition of some globular proteins was carried out in aqueous solution, at micromolar concentrations, by using an uncharged symmetrical cobalt–porphyrin (Co–P). By means of UV/Vis, induced circular dichroism, and fluorescence spectroscopy techniques, it was ascertained that the interactions between specific amino acid residues and Co–P occurred on the protein surface. In particular, spectroscopic evidence showed the formation of supramolecular complexes without disruption of the native structure of the proteins and, furthermore, that signal changes were characteristic of each Co–P/protein system, so that they could be used as a highly sensitive analytical tool for protein recognition. The relative association constants were proportional to the protein molecular masses (and then to the number of amino acid residues).
Anticancer Activity of Hydrogen‐Bond‐Stabilized Half‐Sandwich RuII Complexes with Heterocycles
Authors: Mitra Raja , Das Sangeeta , Shinde Sridevi V. , Sinha Sarika , Somasundaram Kumaravel , Samuelson Ashoka G.
Published: August 2012

Neutral half‐sandwich organometallic ruthenium(II) complexes of the type [(η6‐cymene)RuCl2(L)] (H1–H10), where L represents a heterocyclic ligand, have been synthesized and characterized spectroscopically. The structures of five complexes were also established by single‐crystal X‐ray diffraction confirming a piano‐stool geometry with η6 coordination of the arene ligand. Hydrogen bonding between the NH group of the heterocycle and a chlorine atom attached to Ru stabilizes the metal–ligand interaction. Complexes coordinated to a mercaptobenzothiazole framework (H1) or mercaptobenzoxazole (H6) showed high cytotoxicity against several cancer cells but not against normal cells. In vitro studies have shown that the inhibition of cancer cell growth involves primarily G1‐phase arrest as well as the generation of reactive oxygen species (ROS). The complexes are found to bind DNA in a non‐intercalative fashion and cause unwinding of plasmid DNA in a cell‐free medium. Surprisingly, the cytotoxic complexes H1 and H6 differ in their interaction with DNA, as observed by biophysical studies, they either cause a biphasic melting of the DNA or the inhibition of topoisomerase IIα activity, respectively. Substitution of the aromatic ring of the heterocycle or adding a second hydrogen‐bond donor on the heterocycle reduces the cytotoxicity.
Identification and characterization of a novel myosin Ic isoform that localizes to the nucleus
Authors: Ihnatovych Ivanna , Migocka‐Patrzalek Marta , Dukh Mykhaylo , Hofmann Wilma A.
Published: August 2012

In vertebrates, two myosin Ic isoforms that localize to the cytoplasm and to the nucleus have been characterized. The isoform that predominantly localizes to the nucleus is called nuclear myosin I (NMI). NMI has been identified as a key factor involved in nuclear processes such as transcription by RNA polymerases I and II and intranuclear transport processes. We report here the identification of a previously uncharacterized third MYOIC gene product that is called isoform A. Similar to NMI, this isoform contains a unique N‐terminal peptide sequence, localizes to the nucleus and colocalizes with RNA polymerase II. However, unlike NMI, upon exposure to inhibitors of RNA polymerase II transcription the newly identified isoform translocates to nuclear speckles. Furthermore, in contrast to NMI, this new isoform is absent from nucleoli and does not colocalize with RNA polymerase I. Our results suggest an unexpected diversity among nuclear myosin Ic isoforms in respect to their intranuclear localization and interaction with nuclear binding partners that could provide new insights into the regulation of myosin‐dependent nuclear processes. © 2012 Wiley Periodicals, Inc.