bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Austalides from the Sponge‐Associated Fungus Aspergillus sp.
Authors: Zhou Yaming , Mándi Attila , Debbab Abdessamad , Wray Victor , Schulz Barbara , Müller Werner E. G. , Lin WenHan , Proksch Peter , Kurtán Tibor , Aly Amal H. 
Published: August 2011

AbstractChromatographic separation of a crude extract obtained from the fungus Aspergillus sp., isolated from the Mediterranean sponge Tethya aurantium, yielded five new meroterpenoid metabolites, austalides M–Q (1–5), together with nine known compounds (6–13). The structures of the new compounds were unambiguously elucidated on the basis of extensive 1D and 2D NMR methods and by mass spectral analysis. Furthermore, the absolute configurations of 1 and 4 were determined by time‐dependent density functional theory electronic circular dichroism (TDDFT ECD) calculations, allowing the assignment of the absolute configuration of analogous compounds 2, 3, and 5. The calculations revealed that the conformation of the benzene‐fused phthalide chromophore, which is sensitive to even minor changes in its proximity, is decisive for the ECD parameters, rendering a simple ECD comparison of related homochiral austalides difficult. All compounds were evaluated for their cytotoxic activity against murine cancer cell line L5178Y by using the MTT method. Compounds 8 and 11 exhibited moderate to pronounced cytotoxicity, with IC50 values of 39.4 and 0.2 μM, respectively, whereas the remaining investigated compounds showed either weak or no activity in this assay.
Recent Developments in Synthesis and Applications of Triptycene and Pentiptycene Derivatives
Authors: Jiang Yi , Chen Chuan‐Feng 
Published: August 2011

AbstractIptycenes are a class of aromatic compounds with arene units fused to the [2.2.2]bicyclooctatriene bridgehead system. As a result of their unique structures, more and more iptycenes, especially triptycene and pentiptycene derivatives, have been efficiently synthesized. These compounds have wide applications in many research areas, including molecular machines, molecular balances, catalysis, materials chemistry, molecular assembly, host–guest chemistry, and so on. This microreview mainly describes the developments in the synthesis and applications of triptycene and pentiptycene derivatives during the last ten years. Particular attention is paid to the synthesis and applications of hosts derived from triptycene and pentiptycene systems in recent years.
Heterogeneous Bisoxazoline/Copper Complex: A Green Catalyst for the Enantioselective Reaction of Nitromethane with Substituted Benzaldehydes
Authors: Maggi Raimondo , Lanari Daniela , Oro Chiara , Sartori Giovanni , Vaccaro Luigi 
Published: August 2011

AbstractPolystyrene‐supported chiral 2,2′‐methylenebis[(4S)‐4‐tert‐butyl‐2‐oxazoline] is a promising heterogeneous catalyst for the enantioselective Henry reaction of nitromethane with substituted benzaldehydes. The process is carried out in ethanol as a green solvent, and the corresponding chiral β‐nitroalcohols are obtained in 56–95 % yield with 49–88 % ee.
Selective Synthesis of New Fluorinated Alicyclic β‐Amino Ester Stereoisomers (Eur. J. Org. Chem. 26/2011)
Authors: Kiss Loránd , Forró Enikő , Fustero Santos , Fülöp Ferenc 
Published: August 2011

AbstractThe cover picture shows a waterfall located in the Eastern Carpathians in Transylvania, near Bicaz Canyon. Although fluorinated organic compounds are nonexistent in nature, an increasing number of drugs (25 %) on the market contain at least one fluorine atom. Cyclic fluorinated β‐amino acid derivatives have been synthesized by selective hydroxylation and hydroxy?fluorine exchange. Details are discussed in the article by F. Fülöp et al. on p. 4993 ff.
Fast‐responding thermal‐death‐time tubes for the determination of thermal bacteria inactivation
Authors: Büchner Christin , Thomas Susann , Jaros Doris , Rohm Harald 
Published: August 2011

AbstractThe knowledge of thermal inactivation kinetics, usually expressed in terms of D‐ and z‐values, is of crucial importance for the design of sanitation and sterilization processes. In this study, we designed a simple, fast‐responding, and mechanically stable aluminum tube for inactivation measurements and compared these experiments with the successive‐sampling method at different temperatures. Up to 65°C, we determined a come‐up time of approximately 15 s for the tubes, which is lower than the corresponding values of other devices, presumably because of lower wall thickness, material properties, and a higher surface to volume ratio. D‐values of Escherichia coli calculated from tube inactivation experiments by first‐order kinetics were 370 s (56°C), 126 s (58°C), 53.2 s (60°C), 33.8 s (62°C), and 3.22 s (65°C), and the corresponding values determined with the successive‐sampling flask method were insignificantly different (417, 138, 48.6, and 29.1 s for 56, 58, 60, and 62°C, respectively). These data as well as those measured for Enterobacter cloacae, Pseudomonas putida, Serratia odorifera, and Yersinia rhodei were in close accordance with literature values.
Cytokine production using membrane adsorbers: Human basic fibroblast growth factor produced by Escherichia coli
Authors: Chen Ran , John Jinu , Lavrentieva Antonina , Müller Susann , Tomala Magda , Zhao Yangxi , Zweigerdt Robert , Beutel Sascha , Hitzmann Bernd , Kasper Cornelia , Martin Ulrich , Rinas Ursula , Stahl Frank , Scheper Thomas 
Published: August 2011

AbstractBasic fibroblast growth factor (FGF‐2) is a multifunctional cytokine that regulates various cellular processes both in vitro and in vivo. FGF‐2 is extensively used in embryonic stem cell cultures since it can maintain the cells in an undifferentiated state. However, the high price of FGF‐2 has limited its application in stem cell research. Here we present a fast and efficient process for the purification of FGF‐2 from recombinant Escherichia coli cultures using reusable membrane adsorbers. A high expression level of FGF‐2 (42 mg/g dry cell) was achieved by fed‐batch cultivation of E. coli BL21(DE3). A new combination of cation exchange membrane chromatography and heparin‐sepharose affinity chromatography was used for the purification of the protein. A novel anion exchange membrane chromatography was used in the polishing step to remove endotoxins and DNA. In this new process, about 200 mg soluble FGF‐2 was yielded from 1.9 L culture broth with a purity of 98%. The purified protein was identified to be endotoxin‐free and bioactive. It was successfully tested to keep primate embryonic stem cell and human‐induced pluripotent stem cell pluripotent. Our approach, in which a controlled cultivation process is combined with an optimized fast and versatile downstreaming process, is suitable for low‐cost preparation of bioactive FGF‐2 at bench‐scale and may be beneficial to the effective production of other cytokines.
Amphibians at risk? Susceptibility of terrestrial amphibian life stages to pesticides
Authors: Brühl Carsten A , Pieper Silvia , Weber Brigitte 
Published: August 2011

Abstract
Current pesticide risk assessment does not specifically consider amphibians. Amphibians in the aquatic environment (aquatic life stages or postmetamorphic aquatic amphibians) and terrestrial living juvenile or adult amphibians are assumed to be covered by the risk assessment for aquatic invertebrates and fish, or mammals and birds, respectively. This procedure has been evaluated as being sufficiently protective regarding the acute risk posed by a number of pesticides to aquatic amphibian life stages (eggs, larvae). However, it is unknown whether the exposure and sensitivity of terrestrial living amphibians are comparable to mammalian and avian exposure and sensitivity. We reviewed the literature on dermal pesticide absorption and toxicity studies for terrestrial life stages of amphibians, focusing on the dermal exposure pathway, that is, through treated soil or direct overspray. In vitro studies demonstrated that cutaneous absorption of chemicals is significant and that chemical percutaneous passage, P (cm/h), is higher in amphibians than in mammals. In vivo, the rapid and substantial uptake of the herbicide atrazine from treated soil by toads (Bufo americanus) has been described. Severe toxic effects on various amphibian species have been reported for field-relevant application rates of different pesticides. In general, exposure and toxicity studies for terrestrial amphibian life stages are scarce, and the reported data indicate the need for further research, especially in light of the global amphibian decline. Environ. Toxicol. Chem. 2011;30:2465–2472. © 2011 SETAC
Validation of a chronic dietary cadmium bioaccumulation and toxicity model for Hyalella azteca exposed to field-contaminated periphyton and lake water
Authors: Golding Lisa A , Borgmann Uwe , Dixon D. George 
Published: August 2011

Abstract
A model previously developed in the laboratory to predict chronic bioaccumulation and toxicity of cadmium to Hyalella azteca from a diet of periphyton was validated by comparing predictions with measurements of Cd in two exposure scenarios: laboratory-cultured H. azteca exposed for 28 d to field-contaminated water and periphyton, and Cd measured in field-collected H. azteca. In both exposure scenarios, model predictions of bioaccumulation were shown to be robust; however, effects on Cd bioaccumulation from complexation with dissolved organic carbon (DOC) and inhibition of Cd bioaccumulation by Ca2+ must be incorporated into the model to permit its wider application. The model predicted that 80 to 84% of Cd in H. azteca came from periphyton when H. azteca were chronically exposed to dissolved Cd in lake water at 2.63 to 3.01 nmol/L and periphyton at 1,880 to 2,630 nmol/g ash-free dry mass. Dietary Cd contributed markedly to the model-predicted decrease in 28-d survival to 74% at environmental Cd concentrations in food and water. In reality, survival decreased to 10%. The lower than predicted survival likely was due to the higher nutritional quality of periphyton used to develop the model in the laboratory compared with the field-collected periphyton. Overall, this research demonstrated that Cd in a periphyton diet at environmental concentrations can contribute to chronic toxicity in H. azteca. Environ. Toxicol. Chem. 2011;30:2628–2638. © 2011 SETAC
Mesh adaptivity for the transport equation led by variational multiscale error estimators
Authors: Hauke Guillermo , Doweidar Mohamed H. , Fuentes Sergio 
Published: August 2011

SUMMARYRecently, we developed an explicit a posteriori error estimator especially suited for fluid dynamics problems solved with a stabilized method. The technology is based upon the theory that inspired stabilized methods, namely, the variational multiscale theory. The salient features of the formulation are that it can be readily implemented in existing codes, it is a very economical procedure, and it yields very accurate local error estimates uniformly from the diffusive to the advective regime.In this work, the variational multiscale error estimator is applied to develop adaptive strategies for the advection–diffusion‐reaction equation. The performance of L1 and L2 local error norms combined with three strategies to adapt the mesh is investigated. Emphasis is placed on flows with sharp boundary and interior layers but also attention is given to diffusion‐dominated flows. Computational results show that the method generates meshes with a smooth transition of the element size, which capture all the flow features. Copyright © 2011 John Wiley & Sons, Ltd.
Differential genotoxicity of chemical properties and particle size of rare metal and metal oxide nanoparticles
Authors: Hasegawa Go , Shimonaka Motoyuki , Ishihara Yoko 
Published: August 2011

ABSTRACTNanoparticles of rare metal compounds are used in various products. However, their carcinogenicity and genotoxicity have not been sufficiently evaluated. The tumor‐initiating and ‐promoting potentials of four rare metals, indium oxide (In2O3), dysprosium oxide (Dy2O3), tungsten oxide (WO3) and molybdenum (Mo), with a well‐defined particle diameter were evaluated. The mutagenicity of these rare metals was investigated by Ames test using five bacteria strains, and transformability of these rare metals was investigated by cell‐transformation assay using v‐Ha‐ras‐transfected BALB/c 3T3 cells (Bhas 42 cells). Nano‐sized Dy2O3 showed strong mutagenesis in all five bacteria strains tested with and without metabolic activation, while micro‐sized particles showed weak mutagenesis in two bacterial strains. Dy2O3 induced transformation colonies of Bhas 42 cell dose‐dependently, although there was no difference in the number of transformed foci between nano‐sized and micro‐sized particles. Nano‐sized In2O3 and WO3 showed positive mutagenic response in TA1537 and TA98, respectively, whereas the micro‐sized metal oxide particles showed no mutagenesis in the test bacterial strains. Both nano‐sized and micro‐sized In2O3 showed similar levels of transformability. However, nano‐sized and micro‐sized WO3 did not show any transformability. Both nano‐sized and micro‐sized Mo particles showed neither mutagenesis nor transformability. These results suggest that mutagenicity of rare metals depends on their particle size, although transformability depends on their chemical components but not on their particle size. Copyright © 2011 John Wiley & Sons, Ltd.
Beneficial effects of hydrocortisone or spironolactone coating on foreign body response to mesh biomaterial in a mouse model
Authors: Brandt Christopher J. , Kammer Daniel , Fiebeler Anette , Klinge Uwe 
Published: August 2011

AbstractProsthetic reinforcements markedly reduce the risk of hernia recurrence. However, the implantation of meshes is related to an inflammatory foreign body reaction (FBR) with serious complications (i.e., persistent seroma, wound infection, mesh migration, entrapment, chronic pain). Adrenal hormones profoundly modify inflammatory response. Their effects on FBR however, remain ill defined. We therefore studied the FBR to polyvinylidenfluoride (PVDF) mesh material that was coated with four different substances: hydrocortisone (COR) or mifepristone (MIF), which respectively stimulate and block the glucocorticoid receptor, and aldosterone (ALD) or spironolactone (SPI), which respectively stimulate and block the mineralocorticoid receptor. The coated substances were released from the meshes within 24 h. Seven, 21, and 90 days after implantation, the specimen was evaluated for collagen formation, granuloma size, inflammatory activity, and angiogenesis. COR and SPI coating protected from inflammatory response, while ALD and MIF coating showed little difference to the control group. The COR and SPI groups showed smaller granuloma sizes at all time points, as well as a reduced number of inflammatory cells (p < 0.001) at day 90, and decreased collagen formation starting after 21 days (p < 0.05). There was a negative correlation for angiogenesis with inflammation around foreign body structures. In summary, these results suggest that early and temporary stimulation of the glucocorticoid receptor or blockade of the mineralocorticoid receptor have beneficial effects on FBR in the long term. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 99A:335–335, 2011.
In vitroanalysis and mechanical properties of twin screw extruded single‐layered and coextruded multilayered poly(caprolactone) scaffolds seeded with human fetal osteoblasts for bone tissue engineering
Authors: Ergun Asli , Yu Xiaojun , Valdevit Antonio , Ritter Arthur , Kalyon Dilhan M. 
Published: August 2011

AbstractIn vitroculturing and mechanical properties of three types of three‐dimensional poly(caprolactone) scaffolds with interconnecting open‐foam networks are reported. The scaffolds targeted bone tissue regeneration and were fabricated using twin screw extrusion and coextrusion techniques, for continuous mixing/shaping and formation of single or multilayers with distinct and tailorable porosities and pore sizes. Human fetal preosteoblastic cells, hFOB, were cultured on the extruded and coextruded scaffolds under osteogenic supplements and the samples of the resulting tissue constructs were removed and characterized for cell viability and proliferation using the MTS assay, differentiation, and mineralized matrix synthesis via the alkaline phosphatase, ALP, activity and Alizarin Red staining and cell migration using confocal microscopy and scanning electron microscopy. The hFOB cells formed a confluent lining on scaffold surfaces, migrated to the interior and generated abundant extracellular matrix after 2 weeks of culturing, indicative of the promise of such scaffolds for utilization in tissue engineering. The scaffolds and tissue constructs exhibited compressive fatigue behavior that was similar to that of cancellous bone, suggesting the suitability of their use as bone graft substitutes especially for repair of critical‐sized defects or nonunion fractures. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Potential antiosteoporosis effect of biodegradable magnesium implanted in STZ‐induced diabetic rats
Authors: Yang Weili , Zhang Yu , Yang Jianhong , Tan Lili , Yang Ke 
Published: August 2011

AbstractPure magnesium (Mg) was implanted intramedullary into the femur of streptozotocin (STZ)‐induced diabetic rats to investigate its effect on bone growth after 6 weeks degradation. The experimental results showed that the femoral BMD in diabetic rats was significantly lower than that in controls (p < 0.01) but restored notably by Mg implantation. The contents of calcium (Ca), phosphorus (P), Mg, zinc (Zn), potassium (K), strontium (Sr), and sulfur (S) in bone of diabetic group were significantly lower than those in controls but remarkably increased with implantation of Mg. The residual weight calculation showed that 29.41% of Mg was degraded in vivo. The energy dispersive X‐ray spectroscopy (EDS) analysis showed that the reaction layer on the surface of the Mg implant mainly consisted of C, Ca, O, P, and Mg. Besides, serum Mg level was significantly decreased in diabetic group compared with the control group but increased by Mg treatment. Also, there were no significant differences in body weight and blood glucose, as well as blood glycosylated hemoglobin (HbAIc%), serum Ca, alanine aminitransperase (ALT), aspartate aminotransferase (AST), uric acid (UA), nonesterified fatty acid (NEFA), cholinesterase (CHE), and creatinine (CR) levels between diabetic and Mg‐implanted rats. The study indicated that Mg implant had no obvious toxicity in STZ‐induced diabetic rats and may act as a potential agent to treat osteoporosis. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
A human‐like collagen/chitosan electrospun nanofibrous scaffold from aqueous solution: Electrospun mechanism and biocompatibility
Authors: Chen Lan , Zhu Chenhui , Fan Daidi , Liu Bowen , Ma Xiaoxuan , Duan Zhiguang , Zhou Yang 
Published: August 2011

AbstractNovel human‐like collagen (HLC)/chitosan blended with poly(ethylene oxide) (PEO) nanofibrous meshes of different ratios were fabricated by electrospinning from aqueous solutions. Through studying the effects of the three composition on the solution rheological properties and the morphology of electrospun meshes, the mechanism of electrospinning was explored at the molecular level, and the ratio of PEO/(HLC & chitosan) (w/w) should be controlled below 1/4 as a plasticizer and HLC/chitosan maintained 4/3 w/w. Obtained meshes were treated by 0.2% glutaraldehyde solution (95% ethanol) for crosslinking and 0.2 M glycine solution for blocking unreacted aldehyde groups and became insoluble with fiber diameters of 151 ± 33 to 278 ± 46 nm, PEO was leached out after crosslinking and rinsing. HLC/chitosan scaffolds (4/3, w/w) could mimic native ECM in both chemical component and structure and support cellular in‐growth in vivo while exhibited proper degradation rate in vivo. Bone marrow stromal cells adopted a flattened shape with filopodia‐ and lamellipodia‐like extensions in the scaffolds and grew as a confluent layer after 7 days of culture in vitro. This study indicated the feasibility of electrospun nanofabrious HLC/chitosan scaffold from aqueous solution for tissue engineering application. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Microstructure and characteristics of the metal–ceramic composite (MgCa‐HA/TCP) fabricated by liquid metal infiltration
Authors: Gu X. N. , Wang X. , Li N. , Li L. , Zheng Y. F. , Miao Xigeng 
Published: August 2011

AbstractIn this article, a novel MgCa alloy‐hydroxyapatite‐tricalcium phosphate (HA/TCP) composite was fabricated using the liquid alloy infiltration technique. The feasibility of the composite for biomedical applications was studied through mechanical testing, electrochemical testing, immersion testing, and cell culture evaluation. It was shown that the composite had a strength about 200‐fold higher than that of the original porous HA/TCP scaffold but retained half of the strength of the bulk MgCa alloy. The corrosion test indicated that the resulting composite exhibited an average corrosion rate of 0.029 mL cm−2 h−1 in the Hank's solution at 37°C, which was slower than that of the bulk MgCa alloy alone. The indirect cytotoxicity evaluation revealed that 100% concentrated (i.e., undiluted or as‐collected) extract of the MgCa‐HA/TCP composite showed significant toxicity to L‐929 and MG63 cells (p < 0.05). In contrast, the diluted extracts with 50 and 10% concentrations of the MgCa‐HA/TCP composite exhibited a similar degree of cell viability (p > 0.05), equivalent to the grade I cytotoxicity of the standard ISO 10993‐5: 1999. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Lineage-committed osteoclast precursors circulate in blood and settle down into bone
Authors: Muto Akinori , Mizoguchi Toshihide , Udagawa Nobuyuki , Ito Susumu , Kawahara Ichiro , Abiko Yoshimitsu , Arai Atsushi , Harada Suguru , Kobayashi Yasuhiro , Nakamichi Yuko , Penninger Josef M , Noguchi Toshihide , Takahashi Naoyuki 
Published: August 2011

Abstract
Osteoclasts are derived from the monocyte/macrophage lineage, but little is known about osteoclast precursors in circulation. We previously showed that cell cycle–arrested quiescent osteoclast precursors (QOPs) were detected along bone surfaces as direct osteoclast precursors. Here we show that receptor activator of NF-κB (RANK)-positive cells isolated from bone marrow and peripheral blood possess characteristics of QOPs in mice. RANK-positive cells expressed c-Fms (receptors of macrophage colony-stimulating factor) at various levels, but scarcely expressed other monocyte/granulocyte markers. RANK-positive cells failed to exert phagocytic and proliferating activities, and differentiated into osteoclasts but not into dendritic cells. To identify circulating QOPs, collagen disks containing bone morphogenetic protein-2 (BMP disks) were implanted into mice, which were administered bromodeoxyuridine daily. Most nuclei of osteoclasts detected in BMP-2–induced ectopic bone were bromodeoxyuridine-negative. RANK-positive cells in peripheral blood proliferated more slowly and had a much longer lifespan than F4/80 (a macrophage marker)-positive macrophages. When BMP disks and control disks were implanted in RANK ligand-deficient mice, RANK-positive cells were observed in the BMP disks but not in the controls. F4/80-positive cells were distributed in both disks. Administration of FYT720, a sphingosine 1-phosphate agonist, promoted the egress of RANK-positive cells from hematopoietic tissues into bloodstream. These results suggest that lineage-determined QOPs circulate in the blood and settle in the bone. © 2011 American Society for Bone and Mineral Research