bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microwave Synthesis of Water‐Soluble 2‐, 5‐ and 9‐Substituted Benzo[a]phenoxazinium Chlorides in Comparison with Conventional Heating
Authors: Firmino A. Daniela G. , Raju B. Rama , Gonçalves M. Sameiro T. 
Published: January 2013

AbstractMicrowave irradiation was used for the first time in an efficient synthesis of benzo[a]phenoxazinium chlorides. The main advantage of this protocol is the notable reduction in reaction times and good to excellent yields of the products in comparison to those obtained under classical heating conditions. These new series of compounds possess 5‐amine and/or 2‐hydroxyl substituents in the polycyclic system to improve their solubility in aqueous media, in addition to the functional groups as terminals in the side chains, allowing their further use in covalent labeling. Fundamental photophysical studies carried out in ethanol and water at physiological pH revealed that all cationic fluorophores absorbed and emitted at 610–628 and 630–652 nm, respectively, with relative fluorescent quantum yields of 0.16–0.96.
Coinage Metal Catalysts for the Addition of O–H to C=C Bonds
Authors: Barreiro Elena M. , Adrio Luis A. , (Mimi) Hii King Kuok , Brazier John B. 
Published: January 2013

AbstractThe direct addition of O–H bonds to C=C bonds is a very attractive way of synthesising alcohols, ethers and esters, due to the inherent atom‐ and step‐economy of the process. This microreview focuses on the development of group 11 metal catalysts in mediating these transformations. Brønsted acid catalysis has been shown to play a role in some of these processes, and this is highlighted where appropriate. The utility of these methods in organic synthesis is addressed through selected examples.
Catalytic Asymmetric Conjugate Addition of α‐Substituted Nitro Acetates to Nitro Olefins: Enantioselective Synthesis of Highly Substituted γ‐Lactams
Authors: Li Ying‐Zi , Li Fei , Tian Ping , Lin Guo‐Qiang 
Published: January 2013

AbstractBifunctional bis(demethyldihydroquinine)‐catalyzed asymmetric conjugate addition of α‐substituted nitro acetates to nitro olefins is described. These addition reactions proceed smoothly with a low catalyst loading (1.0 mol‐%) at 0 °C, giving excellent diastereo‐ (up to 99:1 dr) and enantioselectivities (up to 98 % ee). Furthermore, highly substituted and optically pure 1‐pyrazoline and γ‐lactam have been prepared to demonstrate the synthetic application of the addition products.
Alternative Motifs for Halogen Bonding
Authors: Troff Ralf W. , Mäkelä Toni , Topić Filip , Valkonen Arto , Raatikainen Kari , Rissanen Kari 
Published: January 2013

AbstractThe halogen‐bonding interaction is one of the rising stars in supramolecular chemistry. Although other weak interactions and their influence on the structure and chemistry of various molecules, complexes and materials have been investigated thoroughly, the field of halogen bonding is still quite unexplored and its impact on chemistry in general is yet to be fully revealed. In principle, every Y–X bond (Y = electron‐withdrawing atom or moiety, X = halogen atom) can act as a halogen‐bond donor when the halogen is polarized enough by Y. Perfluorohalocarbons are iconic halogen‐bond donor molecules in which Y is a perfluorinated aryl or alkyl moiety and X is either iodine or bromine. In this article, alternative halogen‐bond motifs such as X2···A and Ar–X···A [A = Lewis basic halogen‐bond‐accepting atom of a molecule or ion; Ar = neutral or charged (hetero)aromatic system] are reviewed. In addition, haloalkenes, haloalkynes, N‐haloamides and other non‐metallic halogen‐bond donors and their respective halogen‐bonded structures will also be described. Although purely organic halogen‐bonding motifs are very prominent, the role of metal complexes in halogen bonding is becoming increasingly evident as well, which is also reflected in this review. Finally, halogen bonding in solution is briefly highlighted. Contemporary research is proving that halogen bonding is more than a solid‐state phenomenon and is now a well‐recognized weak interaction in chemistry.
Potential effects of climate change on streambed scour and risks to salmonid survival in snow‐dominated mountain basins
Authors: Goode Jaime R. , Buffington John M. , Tonina Daniele , Isaak Daniel J. , Thurow Russell F. , Wenger Seth , Nagel David , Luce Charlie , Tetzlaff Doerthe , Soulsby Chris 
Published: January 2013

AbstractSnowmelt‐dominated basins in northern latitudes provide critical habitat for salmonids. As such, these systems may be especially vulnerable to climate change because of potential shifts in the frequency, magnitude, and timing of flows that can scour incubating embryos. A general framework is presented to examine this issue, using a series of physical models that link climate change, streamflow, and channel morphology to predict the magnitude and spatial distribution of streambed scour and consequent risk to salmonid embryos at basin scales. The approach is demonstrated for a mountain catchment in the Northern Rocky Mountains, USA. Results show that risk of critical scour varies as a function of species and life history and is modulated by local variations in lithology and channel confinement. Embryos of smaller‐bodied fall spawners may be at greater risk because of shallow egg burial depths and increased rain‐on‐snow events during their incubation period. Scour risk for all species is reduced when changes in channel morphology (width, depth, and grain size) keep pace with climate‐driven changes in streamflow. Although climate change is predicted to increase scour magnitude, the frequency of scouring events relative to typical salmonid life cycles is relatively low, indicating that individual year classes may be impacted by critical scour, but extirpation of entire populations is not expected. Furthermore, refugia are predicted to occur in unconfined portions of the stream network, where scouring shear stresses are limited to bankfull stage because overbank flows spread across alluvial floodplains; conversely, confined valleys will likely exacerbate climate‐driven changes in flow and scour. Our approach can be used to prioritize management strategies according to relative risk to different species or spatial distributions of risk and can be used to predict temporal shifts in the spatial distribution of suitable spawning habitats. A critical unknown issue is whether biological adaptation can keep pace with rates of climate change and channel response. Copyright © 2013 John Wiley & Sons, Ltd.
The Effectiveness of an Attachment‐Based Intervention in Promoting Foster Mothers’ Sensitivity toward Foster Infants
Authors: Bick Johanna , Dozier Mary 
Published: January 2013

AbstractInfants in foster care need sensitive, responsive caregivers to promote their healthy outcomes. The current study examined the effectiveness of the Attachment and Biobehavioral Catch‐up Intervention, a short‐term, targeted, attachment‐based intervention program designed to promote sensitive caregiving behavior among foster mothers. Ninety‐six foster mother–infant dyads participated in this study; 44 dyads were assigned to the Attachment and Biobehavioral Catch‐up Intervention, and 52 dyads were assigned to a control intervention. Results of hierarchical linear modeling indicated that foster mothers who were assigned to the Attachment and Biobehavioral Catch‐up Intervention showed greater improvements in their sensitivity from pre‐ to postintervention assessment time points when compared with foster mothers who were assigned to the control intervention. We conclude that a short‐term, targeted, attachment‐based intervention is effective in changing foster mothers’ responsiveness to their foster infants, which is critical for foster infants’ healthy socioemotional adjustment.
In vitro study on newly designed biodegradable Fe‐X composites (X = W, CNT) prepared by spark plasma sintering
Authors: Cheng J. , Zheng Y.F. 
Published: January 2013

AbstractEarly in vivo animal test on pure iron coronary stent had proved that it is a promising candidate material as biodegradable metal, despite a faster degradation rate and uniform degradation mode is expected. In this work, Fe‐X (X= W, CNT) composites were prepared from powders of pure iron and the additive secondary phase X using the spark plasma sintering (SPS) method, aiming to obtain a higher corrosion rate and a more uniform corrosion mode in physiological environment. The microstructures, mechanical properties, corrosion behaviors, and in vitro biocompatibility of these Fe‐X composites were investigated. It was found that the additives were uniformly distributed in the iron matrix and relatively high dense Fe‐X composite bulk samples were obtained after sintering by SPS. Both the yield strength and ultimate compressive strength increased when compared with that of as‐cast pure iron. The corrosion mode of Fe‐X composites turned out to be uniform corrosion instead of localized corrosion. Electrochemical measurements and immersion tests indicated that the addition of W and CNT could increase the corrosion rate of the iron matrix. From the results of cytotoxicity evaluation, it was found that all the Fe‐X composites extracts induced no obvious cytotoxicity to L929 cells and ECV304 cells whereas significantly decreased cell viabilities of VSMC cells. The hemocompatibility tests showed that all the hemolysis percentage of Fe‐X composites were less than 5%, and no sign of thrombogenicity was observed. It might be concluded that Fe composited with suitable second phase can exhibit higher strength, faster degradation rate, and uniform degradation mode than those of pure iron and are promising candidates for future development of new degradable metallic stents. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Effects of different sterilization techniques and varying anodized TiO2 nanotube dimensions on bacteria growth
Authors: Kummer Kim M. , Taylor Erik N. , Durmas Naside G. , Tarquinio Keiko M. , Ercan Batur , Webster Thomas J. 
Published: January 2013

AbstractInfection of titanium (Ti)‐based orthopedic implants is a growing problem due to the ability of bacteria to develop a resistance to today's antibiotics. As an attempt to develop a new strategy to combat bacteria functions, Ti was anodized in the present study to possess different diameters of nanotubes. It is reported here for the first time that Ti anodized to possess 20 nm tubes then followed by heat treatment to remove fluorine deposited from the HF anodization electrolyte solution significantly reduced both S. aureus and S. epidermidis growth compared to unanodized Ti controls. It was further found that the sterilization method used for both anodized nanotubular Ti and conventional Ti played an important role in the degree of bacteria growth on these substrates. Overall, UV light and ethanol sterilized samples decreased bacteria growth, while autoclaving resulted in the highest amount of bacteria growth. In summary, this study indicated that through a simple and inexpensive process, Ti can be anodized to possess 20 nm tubes that no matter how sterilized (UV light, ethanol soaking, or autoclaving) reduces bacteria growth and, thus, shows great promise as an antibacterial implant material. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part 2013.
Novel pluronic‐chitosan micelle as an ocular delivery system
Authors: Lin Hong‐Ru , Chang Pei‐Csang 
Published: January 2013

AbstractPluronic micelles were prepared for ophthalmic delivery by incorporation of ethyl acetate as a dispersion agent and their surfaces were modified by chitosan to improve their bioavailability. The micelles disperse well in the solution and have a core‐shell like structure with a particle size ranging from 93 to 181 nm for drug unloaded, 123–232 nm for drug‐loaded, and a zeta potential between 6.1 and 9.2 mV, indicating very suitable use as ophthalmic carrier. The in vitro serum stability tests indicate the particle size of the micelles was very stable during the serum absorption. The turbidity test reveals that the prepared micelles were very stable under phosphate buffered saline environment, which can prevent the blurred vision. The loading efficiency of metipranolol in micelles can be as high as 83%. Finally, the in vitro and in vivo studies indicate the pluronic micelles modified by chitosan have sustained release behavior and good pharmacological response. As the results, the pluroic‐chitosan micelles system provides a potential opportunity in decreasing frequency of administration and improving patient compliance for ocular drug delivery. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Cell viabilities and biodegradation rates of DNA/protamine complexes with two different molecular weights of DNA
Authors: Mori Nana , Ohno Jun , Sakagami Ryuji , Hayakawa Tohru , Fukushima Tadao 
Published: January 2013

AbstractTwo types of DNA/protamine complexes were prepared from protamine sulfate and 7000 base pair (bp) DNA or original DNA to investigate the effect of the molecular weight of DNA on zeta potential, cell viability, flowability, soft tissue response, and biodegradation rate. The 7000 bp DNA/protamine complex had a negative charge while the original DNA/protamine complex had a positive charge. The cell viabilities (90.4–106.8%) of these complexes were close to each other. The 7000 bp DNA/protamine complex became a softer dough than that of the original DNA/complex when both were kneaded with water. In vivo, the original DNA/protamine complex showed a milder tissue response. The original DNA/protamine complex almost disappeared 30 days after implantation. The 7000 bp DNA/complex disappeared approximately 2 weeks after implantation and areas where samples were implanted became empty. Thereafter, the empty space was gradually replaced by new soft tissues. The original DNA/protamine complex showed low intercalation and groove binding ratios of daunorubicin hydrochloride. Results indicate that high DNA condensation by cationic protamine protected the penetration of degradation enzymes into these complexes. It was found that a high molecular weight of DNA reduced the biodegradation rate and flowability. This study suggests that DNA/protamine complexes could be candidates for biomaterials that control biodegradation rates and flowability. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Biocompatibility studies and characterization of poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate)/polycaprolactone blends
Authors: Lim Jing , Chong Mark Seow Khoon , Teo Erin Yiling , Chen Guo‐Qiang , Chan Jerry K. Y. , Teoh Swee‐Hin 
Published: January 2013

AbstractPoly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBHHx) is a biocompatible and bioresorbable copolymer that has generated research interest as a bone scaffold material. However, its brittleness and degradation characteristics can be improved upon. We hypothesized that blending with medical‐grade polycaprolactone (PCL) can improve degradation and mechanical characteristics. Here, we report the development of solvent‐blended PHBHHx/PCL for application as a potential biomaterial for tissue engineering. Enhanced yield strength, yield strain and Young's modulus occurred at 30/70 blend when compared with PHBHHx and PCL. Polarized light microscopy demonstrated PHBHHx and PCL to exist as morphologically and optically distinct phases and, together with thermal analyses, revealed immiscibility. Hydrophilicity improved with the addition of PCL. Accelerated hydrolytic studies suggested predictable behavior of PHBHHx/PCL. Notably, 30/70 blend exhibited similar degradation behavior to PCL in terms of changes in crystallinity, molecular weight, morphology, and mass loss. Finally, human fetal mesenchymal stem cells (hfMSCs) were evaluated on PHBHHx/PCL using live/dead assay and results suggested encouraging hfMSC adhesion and proliferative capacity, with near‐confluence occurring in PHBHHx and 30/70 blend after 5 days. Taken together, these are encouraging results for the further development of PHBHHx/PCL as a potential biomaterial for tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Transplantation of inbred adipose‐derived stromal cells in rats with plasma gel containing fragmin/protamine microparticles and FGF‐2
Authors: Sumi Yuki , Ishihara Masayuki , Kishimoto Satoko , Takikawa Megumi , Doumoto Takashi , Azuma Ryuichi , Nakamura Shingo , Hattori Hidemi , Fujita Masanori , Kiyosawa Tomoharu 
Published: January 2013

AbstractFragmin/protamine microparticles (F/P MPs) have been used as a cell carrier for adipose‐derived stromal cells (IR‐ASCs) in inbred male Fisher 344 rats, and for preservation and controlled‐release of fibroblast growth factor (FGF)‐2 and various cytokines in inbred rat plasma (IRP)‐DMEM (Dulbecco's modified Eagle's medium) gel. In this study, we investigated the capability of an IRP‐DMEM gel containing F/P MPs and/or FGF‐2, as a three‐dimensional (3D)‐culture, to expand IR‐ASCs. We found that IR‐ASCs grow faster under 3D‐culture conditions in low IRP (3%)‐DMEM gel containing F/P MPs and FGF‐2 without any animal serum than those under 2D‐culture in low inbred rat serum (3%)‐DMEM with F/P MPs and FGF‐2. About 0.3 mL of IR‐ASCs (about 4,000,000 cells mL−1) grown in IRP (6%)‐DMEM gel containing F/P MPs and FGF‐2 disappeared 8 days after subcutaneous injection in rats, suggesting that they are rapidly biodegradable. The number of large (diameter ≥200 μm or containing ≥100 erythrocytes), medium (diameter = 20–200 μm or containing 10–100 erythrocytes) and small (diameter ≤20 μm or containing 1–10 erythrocytes) capillaries after injection with IR‐ASCs in an IRP‐DMEM gel containing both F/P MPs and FGF‐2, as well as the thickness of tissue granulation per microphotograph at the injected site, was significantly higher than those after injection with IR‐ASCs in an IRP‐DMEM gel containing either FGF‐2 or F/P MPs. Thus, IRP‐DMEM gel containing F/P MPs and FGF‐2 are useful and safe IR‐ASC carriers that facilitate cell proliferation, vascularization, and tissue granulation locally at injection sites. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Swimming Capability and Swimming Behavior of Juvenile Acipenser schrenckii
Authors: Cai Lu , Taupier Rachel , Johnson David , Tu Zhiying , Liu Guoyong , Huang Yingping 
Published: January 2013

AbstractAcipenser schrenckii, the Amur Sturgeon, was a commercially valuable fish species inhabiting the Amur (Heilongjiang) River but populations have rapidly declined in recent years. Dams impede A. schrenckii spawning migration and wild populations were critically endangered. Building fishways helped maintain fish populations but data on swimming performance and behavior was crucial for fishway design. To obtain such data on A. schrenckii, a laboratory study of juvenile A. schrenckii (n = 18, body mass = 32.7 ± 1.2 g, body length = 18.8 ± 0.3 cm) was conducted using a stepped velocity test carried out in a fish respirometer equipped with a high‐speed video camera at 20°C. Results indicate: (1) The counter‐current swimming capability of A. schrenckii was low with critical swimming speed of 1.96 ± 0.10 BL/sec. (2) When a linear function was fitted to the data, oxygen consumption, as a function of swimming speed, was determined to be MO2 = 337.29 + 128.10U (R2 = 0.971, P < 0.001) and the power value (1.0) of U indicated high swimming efficiency. (3) Excess post‐exercise oxygen cost was 48.44 mgO2/kg and indicated excellent fatigue recovery. (4) Cost of transport decreased slowly with increased swimming speed. (5) Increased swimming speed led to increases in the tail beat frequency and stride length. This investigation contributed to the basic science of fish swimming behavior and provided data required for the design of fishways. Innovative methods have allowed cultivation of the species in the Yangtze River and, if effective fishways could be incorporated into the design of future hydropower projects on the Amur River, it would contribute to conservation of wild populations of A. schrenckii. The information provided here contributes to the international effort to save this critically endangered species. J. Exp. Zool. 319A:149–155, 2013. © 2013 Wiley Periodicals, Inc.
β‐Endorphin‐induced Inhibition of Vitellogenic Follicular Growth in the Fish Oreochromis mossambicus: Evidence for Opioidergic Mediation of Ovarian Stress Response
Authors: CHABBI AMBARISHA , GANESH C.B. 
Published: January 2013

AbstractThe opioid peptide β‐endorphin (β‐EP) is known to play modulatory role in vertebrate reproduction. The objective of the present study was to determine the influence of β‐EP and the opioid receptor antagonist naltrexone (NALT) on follicular development in normal, and stressed female tilapia Oreochromis mossambicus. Administration of 4 µg β‐EP, but not 0.5 or 1.5 µg β‐EP daily for 22 days caused a significant reduction in the mean GSI, HSI, and number of Stage IV (vitellogenic) follicles compared to experimental controls during the prespawning phase of the ovarian cycle. Furthermore, the Stage V (vitellogenic) follicles were completely absent during the prespawning phase concomitant with the significantly lower serum levels of estradiol and cortisol in 4 µg β‐EP treated fish compared to experimental controls. On the other hand, exposure of the fish to mild acute stressors for 22 days caused changes in the ovary similar to that of high dose of β‐EP, whereas administration of NALT attenuated these effects. The results reveal that β‐EP exerts inhibitory effect on the vitellogenic follicular growth through the suppression of ovarian steroidogenesis. The study provides evidence for the opioidergic mediation of the ovarian stress response for the first time in fish. J. Exp. Zool. 319A:156–165, 2013. © 2013 Wiley Periodicals, Inc.
Osteoarthritic versus osteoporotic bone and intra‐skeletal variations in normal bone: Evaluation with µCT and bone histomorphometry
Authors: Zupan Janja , van't Hof Rob J. , Vindišar Franci , Haring Gregor , Trebše Rihard , Komadina Radko , Marc Janja 
Published: January 2013

AbstractSeveral studies have shown that in contrast to osteoporosis (OP), osteoarthritis (OA) is characterized by high bone mineral density (BMD). Bone strength not only depends on mineral content as determined by dual X‐ray absorptiometry (DXA), but also on bone microarchitecture. We studied intertrochanteric bone from normal controls and OA and OP patients by bone histomorphometry (BHM) and microcomputed tomography (µCT) as well as DXA in order to first, test the differences between OA and OP comparing both groups to healthy controls, second, to assess variations between three different skeletal sites in controls and third, to determine the level of agreement between µCT, BHM, and DXA. Analysis was performed on 115 samples from OA and OP patients, and controls. We found significant differences between OA and OP samples in structural parameters and in the osteoid fraction (p < 0.05). The majority of the intra‐skeletal differences were shown between lumbar spine and femoral head samples (p < 0.05). Significant agreements were found between µCT and BHM and DXA (r = 0.32–0.45, p < 0.05). Our findings suggest differences in intertrochanteric bone between OA and OP, the age‐related intra‐skeletal variations and a correlation between microscopic and macroscopic bone evaluation methods. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1059–1066, 2013