bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural transition during thermal denaturation of collagen in the solution and film states
Authors: Shanmugam Ganesh , Polavarapu Prasad L. 
Published: August 2008

AbstractTemperature dependent vibrational circular dichroism (VCD) spectra of type I collagen, in solution and film states, have been measured. These spectra obtained for solution sample suggest that the thermal denaturation of collagen results in transition from poly‐L‐proline II (PPII) to unordered structure. The PPII structure of collagen is identified by the presence of negative VCD couplet in the amide I region, while the formation of unordered structure is indicated by the disappearance of VCD in the amide I region. The temperature dependent spectra obtained for the supported collagen film indicated a biphasic transition, which is believed to be the first vibrational spectroscopic report to support a biphasic transition during thermal denaturation of collagen film. The temperature dependent spectra of collagen films suggest that the thermal stability of collagen structure depends on its state and decreases in the order: supported film > free standing film > solution state. These observations are believed to be significant in the VCD spectroscopic analysis of secondary structures of proteins and peptides. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Stereo‐selective activity of menthol on GABAAreceptor
Authors: Corvalán Natalia A. , Zygadlo Julio A. , García Daniel A. 
Published: August 2008

AbstractMenthol is a naturally occurring compound, which has three chiral centers that define eight possible optically actives stereoisomers. Neuroactivity of menthol and related agents by affecting neuronal intracellular signaling or by modulation of neurotransmitter‐gated currents has been reported. Furthermore, stereo‐selectivity of menthol in its analgesic activity as well as in its sensory properties and other biological activities was also described. The present study is the first contribution to the description of stereo‐selectivity of GABAAreceptor against the most possible isomers of menthol, discussed in terms of their chirality. The results showed that only (+)‐menthol, among the five stereoisomers analyzed, was active, stimulating in a dose‐response manner the binding of an allosteric GABAAreceptor ligand. Taking into account these results, and comparing them with those of some active phenolic compounds, it is strongly suggested that the existence of a relative spatial location of its substituents with respect to the ring (equatorial position of all substituents and (1S,2R,5S)‐configuration) as well as the presence in the cyclic molecule of an aliphatic non polar group (isopropyl) with free rotation near to a polar group (hydroxyl) are crucial points to demonstrate activity on the receptor. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Gas chromatographic enantioseparation of unfunctionalized chiral alkanes: A challenge in separation science (overview, state of the art, and perspectives)
Authors: Sicoli Giuseppe , Kreidler Diana , Czesla Harri , Hopf Henning , Schurig Volker 
Published: August 2008

AbstractThe chromatographic enantioseparation of small unfunctionalized chiral alkanes C*HR1R2R3 (R = alkyl) represents a challenge in separation science. Because of the lack of any functional groups, enantiorecognition in the presence of a chiral selector is solely based upon weak enantioselective Van der Waals forces. Racemic alkanes containing seven and eight carbon atoms, i.e. 3‐methylhexane (C7), 2,3‐dimethylpentane (C7), 3‐methylheptane (C8), 3,4‐dimethylhexane (C8), 2,4‐dimethylhexane (C8), 2,3‐dimethylhexane (C8), and 2,2,3‐trimethylpentane (C8) have been gas chromatographically enantioseparated on different modified cyclodextrins. The substitution pattern and cavity size of the cyclodextrin selectors have a pronounced effect on the degree of enantiorecognition observed. Thermodynamic parameters of enantiorecognition between four chiral alkanes and octakis(6‐O‐methyl‐2,3‐di‐O‐pentyl)‐γ‐cyclodextrin (Lipodex G) have been determined. The possible role of molecular inclusion is indicated by the complete loss of enantioselectivity when the cyclodextrins are replaced by the corresponding linear dextrins (“acyclodextrins”). The enantioseparations of all seven chiral C7‐C8 alkanes, six of them simultaneously, has been achieved on mixed binary selector systems whereby two different modified cyclodextrins are present in one gas chromatographic column. The smallest chiral (nonisotopically labeled) allene, i.e., 2,3‐pentadiene, has been resolved gas chromatographically on a cyclodextrin selector. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Enantiomeric separation of chiral ruthenium(II) complexes using capillary electrophoresis
Authors: Jiang Chunxia , Tong Man‐Yung , Armstrong Daniel W. , Perera Sirantha , Bao Ye , MacDonnell Frederick M. 
Published: August 2008

AbstractCapillary zone electrophoresis (CZE) and micellar capillary electrophoresis (MCE) were applied for the enantiomeric separation of nine mononuclear tris(diimine)ruthenium(II) complexes as well as the separation of all stereoisomers of a dinuclear tris(diimine)ruthenium(II) complex. Nine cyclodextrin (CD) based chiral selectors were examined as run buffer additives to evaluate their effectiveness in the enantiomeric separation of tris(diimine)ruthenium(II) complexes. Seven showed enantioselectivity. Sulfated γ‐cyclodextrin (SGC), with four baseline and three partial separations, was found to be the most useful chiral selector. In CZE mode, the derivatized γ‐CDs were more effective than β‐CDs while sulfated CDs work better than carboxymethyl CDs. In MCE mode, hydroxypropyl β‐CD separated the greatest number of tris(diimine) ruthenium(II) complexes. The effects of chiral selector concentration, run buffer pH and concentration, the concentration ratio between chiral selector and other factors were investigated. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Visualization of Intrinsically Disordered Regions of Proteins by High‐Speed Atomic Force Microscopy
Authors: Miyagi Atsushi , Tsunaka Yasuo , Uchihashi Takayuki , Mayanagi Kouta , Hirose Susumu , Morikawa Kosuke , Ando Toshio 
Published: August 2008

AbstractIntrinsically disordered (ID) regions of proteins are recognized to be involved in biological processes such as transcription, translation, and cellular signal transduction. Despite the important roles of ID regions, effective methods to observe these thin and flexible structures directly were not available. Herein, we use high‐speed atomic force microscopy (AFM) to observe the heterodimeric FACT (facilitates chromatin transcription) protein, which is predicted to have large ID regions in each subunit. Successive AFM images of FACT on a mica surface, captured at rates of 5–17 frames per second, clearly reveal two distinct tail‐like segments that protrude from the main body of FACT and fluctuate in position. Using deletion mutants of FACT, we identify these tail segments as the two major ID regions predicted from the amino acid sequences. Their mechanical properties estimated from the AFM images suggest that they have more relaxed structures than random coils. These observations demonstrate that this state‐of‐the‐art microscopy method can be used to characterize unstructured protein segments that are difficult to visualize with other experimental techniques.
Intrusive images in grief: an exploratory study
Authors: Boelen Paul A. , Huntjens Rafaele J. C. 
Published: August 2008

AbstractThe relevance of intrusive mental imagery to the understanding and treatment of psychological disorders is increasingly acknowledged. Little research has been done on intrusive imagery in grief. Using a sample of 131 mourners, recruited from professional and lay mental health care workers, the current study examined the frequency and correlates of four specific intrusive images: (a) positive intrusive memories of the lost person; (b) intrusive images of the death event; (c) re‐enactment fantasies; and (d) negative images of the future. Findings revealed that these intrusions were common and that the occurrence of these intrusions hardly varied across subgroups of mourners. All four intrusions were correlated with the severity of complicated grief symptoms, and intrusions (b), (c) and (d) were also correlated with the severity of symptoms of depression and anxiety. Findings have potential theoretical and clinical implications and indicate that a more comprehensive study of intrusions among bereaved people is warranted. Copyright © 2008 John Wiley & Sons, Ltd.
Emotion regulation as mediator of treatment outcome in therapy for deliberate self‐harm
Authors: Slee Nadja , Spinhoven Philip , Garnefski Nadia , Arensman Ella 
Published: August 2008

AbstractThis study presents the outcomes of mediator analyses as part of a randomized controlled trial of Cognitive‐Behavioural Therapy (CBT) for young people who engage in deliberate self‐harm (DSH). The study involved 90 people, aged 15–35 years, who were randomly assigned to CBT in addition to treatment as usual or to treatment as usual only. The findings showed that changes in DSH were partially mediated by changes in emotion‐regulation difficulties, particularly difficulties with impulse control and goal‐directed behaviours. In addition, the potential mediating role of symptoms of depression, anxiety and suicidal cognitions was examined. Although the CBT intervention significantly reduced depression, anxiety and suicidal cognitions, these measures of symptom severity did not play a mediating role. These findings suggest that interventions for DSH should not primarily focus on mental disorders associated with DSH, but should be DSH‐specific and should target specific emotion‐regulation difficulties. Copyright © 2008 John Wiley & Sons, Ltd.
Is therapist alliance or whole group cohesion more influential in group psychotherapy outcomes?
Authors: Crowe Trevor P. , Grenyer Brin F. S. 
Published: August 2008

AbstractThis study examined the differential ability of early in treatment measures of therapeutic alliance (Working Alliance Inventory), group cohesion (California Psychotherapy Alliance Scale for Group) and group climate (Group Climate Questionnaire) to predict outcome in a 16‐session dynamic group psychotherapy for adults with major depression. Six successful therapy groups with 30 patients receiving psychodynamic group therapy were studied. Patient perceptions of the therapist alliance was not related to outcome, however, perceptions of levels of conflict and group members' ability to work actively and purposefully in treatment did predict outcome. Future research should further investigate how patients' perceptions of the whole group influence their clinical improvement. Copyright © 2008 John Wiley & Sons, Ltd.
A time‐dominated TCP congestion control over heterogeneous networks
Authors: Lee Jongmin , Cha Hojung , Ha Rhan 
Published: August 2008

AbstractThe traditional transmission control protocol (TCP) suffers from performance problems such as throughput bias against flows with longer packet roundtrip time (RTT), which leads to burst traffic flows producing high packet loss, long delays, and high delay jitter. This paper proposes a TCP congestion control mechanism, TD‐TCP, that the sender increases the congestion window according to time rather than receipt of acknowledgement. Since this mechanism spaces out data sent into the network, data are not sent in bursts. In addition, the proposed mechanism reduces throughput bias because all flows increase the congestion window at the same rate regardless of their packet RTT. The implementation of the mechanism affects only the protocol stack at the sender; hence, neither the receiver nor the routers need modifications. The mechanism has been implemented in the Linux platform and tested in conjunction with various TCP variants in real environments. The experimental result shows that the proposed mechanism improves transmission performance, especially in networks with congestion and/or high packet loss rates. Experiments in real commercial wireless networks have also been conducted to support the proposed mechanism's practical use. Copyright © 2008 John Wiley & Sons, Ltd.
The role of twist during palate development
Authors: Yu Wenli , Kamara Harold , Svoboda Kathy K. H. 
Published: August 2008

AbstractIn palatogenesis, the MEE (Medial Edge Epithelium) cells disappear when palates fuse. We hypothesize that the MEE cells undergo EMT (Epithelial‐Mesenchymal Transition) to achieve mesenchyme confluence. Twist has an important role in EMT for tumor metastasis. The purpose of this study was to analyze Twist function during palatal fusion. Twist protein was expressed in palatal shelves and MEE both in vivo and in vitro just prior to fusion. Twist mRNA increased in chicken palates 3 and 6 hr after TGFβ3 treatment. Palatal fusion was decreased when cultured palatal shelves were treated with 200 nM Twist siRNA and the subcellular localization of β‐catenin was altered. Twist mRNA decreased in palatal shelves treated with TGFβ3 neutralizing antibody or LY294002, a specific phosphatidylinositol‐3 kinase (PI‐3K) inhibitor. In summary, Twist is downstream of TGFβ3 and PI‐3K pathways during palatal fusion. However, decreasing Twist with siRNA did not completely block palate fusion, indicating that the function of Twist may be duplicated by other transcription factors. Developmental Dynamics 237:2716–2725, 2008. © 2008 Wiley‐Liss, Inc.
Cellular nonmuscle myosins NMHC‐IIA and NMHC‐IIB and vertebrate heart looping
Authors: Lu Wenge , Seeholzer Steven H. , Han Mingda , Arnold Anne‐Sophie , Serrano Maria , Garita Barbara , Philp Nancy J. , Farthing Cassandra , Steele Peter , Chen Jizhen , Linask Kersti K. 
Published: August 2008

AbstractFlectin, a protein previously described to be expressed in a left‐dominant manner in the embryonic chick heart during looping, is a member of the nonmuscle myosin II (NMHC‐II) protein class. During looping, both NMHC‐IIA and NMHC‐IIB are expressed in the mouse heart on embryonic day 9.5. The patterns of localization of NMHC‐IIB, rather than NMHC‐IIA in the mouse looping heart and in neural crest cells, are equivalent to what we reported previously for flectin. Expression of full‐length human NMHC‐IIA and ‐IIB in 10 T1/2 cells demonstrated that flectin antibody recognizes both isoforms. Electron microscopy revealed that flectin antibody localizes in short cardiomyocyte cell processes extending from the basal layer of the cardiomyocytes into the cardiac jelly. Flectin antibody also recognizes stress fibrils in the cardiac jelly in the mouse and chick heart; while NMHC‐IIB antibody does not. Abnormally looping hearts of the NodalΔ 600 homozygous mouse embryos show decreased NMHC‐IIB expression on both the mRNA and protein levels. These results document the characterization of flectin and extend the importance of NMHC‐II and the cytoskeletal actomyosin complex to the mammalian heart and cardiac looping. Developmental Dynamics 237:3577–3590, 2008. © 2008 Wiley‐Liss, Inc.
Man1, an inner nuclear membrane protein, regulates left–right axis formation by controlling nodal signaling in a node‐independent manner
Authors: Ishimura Akihiko , Chida Shinsuke , Osada Shin‐Ichi 
Published: August 2008

AbstractMan1, an inner nuclear membrane protein, regulates transforming growth factor β signaling by interacting with receptor‐associated Smads. In Man1‐deficient (Man1Δ/Δ) embryos, vascular remodeling is perturbed by misregulation of Smad activity. Here, we show that Man1Δ/Δ embryos exhibit abnormal heart morphogenesis including the looping abnormality. We searched for the molecular basis underlying the heart abnormalities and found that the left side‐specific genes responsible for left–right (LR) asymmetry, Nodal, Lefty2, and Pitx2, were expressed bilaterally in the lateral plate mesoderm and that their expression was enhanced significantly in mutants. Notably, Lefty1, a marker for the midline barrier, was maintained in Man1Δ/Δ mutants. Crossing Man1Δ/+ with Nodal hypomorphs (Nodalneo/+), in which Nodal signaling in the node is disrupted, to generate double homozygous embryos (Man1Δ/Δ; Nodalneo/neo) revealed that the bilateral Nodal was retained in Man1Δ/Δ; Nodalneo/neo embryos. These results suggest that Man1 regulates LR asymmetry by controlling Nodal signaling in a node‐independent manner. Developmental Dynamics 237:3565–3576, 2008. © 2008 Wiley‐Liss, Inc.
1‐(Pyridin‐2‐yl)methanamine‐Based Ruthenium Catalysts for Fast Transfer Hydrogenation of Carbonyl Compounds in 2‐Propanol
Authors: Baratta Walter , Rigo Pierluigi 
Published: August 2008

AbstractThis Microreview focuses on the development of novel ruthenium complexes displaying high performance in the catalytic asymmetric transfer hydrogenation of ketones with 2‐propanol, providing this procedure alternative to the hydrogenation with dihydrogen. The key role is played by 1‐(pyridin‐2‐yl)methanamine (Pyme) type ligands which in combination with appropriate phosphanes afforded ruthenium systems of unprecedented high catalytic activity and productivity for the reduction of ketones and aldehydes. For the pincer CNN complexes a mixed inner‐outer sphere mechanism involving Ru‐hydride and Ru‐alkoxide species is proposed. The excellent properties of these complexes are expected to have implications for the design of a new generation of catalysts.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Improved Preparation of 4,6,6‐Trimethyl‐1,3,2‐dioxaborinane and Its Use in a Simple [PdCl2(TPP)2]‐Catalyzed Borylation of Aryl Bromides and Iodides
Authors: PraveenGanesh Nageswaran , Chavant Pierre Yves 
Published: August 2008

AbstractWe describe a convenient preparation of 4,6,6‐trimethyl‐1,3,2‐dioxaborinane (MethylPentaneDiolBorane, MPBH) and demonstrate that it is an excellent reagent for the [PdCl2(PPh3)2]‐catalyzed borylation of aryl bromides and iodides. The corresponding boronic esters undergo rapid Suzuki coupling reactions in the presence of cesium fluoride. Thus, MPBH is an excellent alternative to pinacolborane for Pd‐catalyzed borylation and cross‐coupling reactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A numerical model of infiltration processes for hysteretic flow coupled with mass conservation
Authors: Tan Yih‐Chi , Ma Kuo‐Chen , Chen Chu‐Hui , Ke Kai‐Yuan , Wang Ming‐Tsan 
Published: August 2008

AbstractThe study presents a numerical infiltration model of a hysteretic flow coupled with general mass conservation for practical application to unsaturated soil. In unsaturated soil, hysteresis is an important phenomenon in the complicated hydrological processes, and it is usually ignored when simulating the relationship of soil water content. The governing equation of unsaturated flow is the Richards equation, and it is difficult to obtain the analytic solutions because of the variation of temporal boundary conditions and the dynamics of change of soil water content in the vadose zone. The numerical solution is solved by the finite difference method technique with the Picard iteration scheme combined with the hysteresis model derived by Huang et al. (2005) and the mass conservation control within simulation domain. The results showed that the mixed form had better mass conservation. The present numerical solutions with the hysteresis model were verified by Gillham's experimental data of 1979. The results of the present mixed form numerical approximations with hysteresis effect are better than without hysteresis. In order to raise the accuracy of the soil water relationship numerical model, hysteresis and mass conservation are important factors in infiltration processes. Copyright © 2008 John Wiley & Sons, Ltd.
Hypoxia and oxidation levels of DNA and lipids in humans and animal experimental models
Authors: Møller Peter , Risom Lotte , Lundby Carsten , Mikkelsen Lone , Loft Steffen 
Published: August 2008

AbstractThe objective of this review was to evaluate the association between hypoxia and oxidative damage to DNA and lipids. Evaluation criteria encompassed specificity and validation status of the biomarkers, study design, strength of the association, dose‐response relationship, biological plausibility, analogous exposures, and effect modification by intervention. The collective interpretation indicates persuasive evidence from the studies in humans for an association between hypoxia and elevated levels of oxidative damage to DNA and lipids. The levels of oxidatively generated DNA lesions and lipid peroxidation products depend on both the duration and severity of the exposure to hypoxia. Largest effects are observed with exposure to hypoxia at high altitude, but other factors, including ultraviolet light, exercise, exertion, and low intake of antioxidants, might contribute to the effect observed in subjects at high altitude. Most of the animal experimental models should be interpreted with caution because the assays for assessment of lipid peroxidation products have suboptimal validity. © 2008 IUBMB IUBMB Life, 60(11): 707–723, 2008
Biomaterial and antibiotic strategies for peri‐implantitis: A review
Authors: Norowski P. Andrew , Bumgardner Joel D. 
Published: August 2008

AbstractDental implants have 89% plus survival rates at 10–15 years, but peri‐implantitis or dental implant infections may be as high as 14%. Peri‐implantitis can limit clinical success and impose health and financial burdens to patients and health providers. The pathogenic species associated with periodontitis (e.g., Fusobacterium ssp, A. actinomycetemcomitans, P. gingivalis) are also associated with peri‐implantitis. Incidence of peri‐implantitis is highest within the first 12 months after implantation, and is higher in patients who smoke or have poor oral health as well as with calcium‐phosphate‐coated or surface‐roughened implants. Biomaterial therapies using fibers, gels, and beads to deliver antibiotics have been used in the treatment of Peri‐implantitis though clinical efficacy is not well documented. Guided tissue regeneration membranes (e.g., collagen, poly‐lactic/glycolic acid, chitosan, ePTFE) loaded with antimicrobials have shown success in reosseointegrating infected implants in animal models but have not been proven in humans. Experimental approaches include the development of anti‐bioadhesion coatings, coating surfaces with antimicrobial agents (e.g., vancomycin, Ag, Zn) or antimicrobial releasing coatings (e.g., calcium phosphate, polylactic acid, chitosan). Future strategies include the development of surfaces that become antibacterial in response to infection, and improvements in the permucosal seal. Research is still needed to identify strategies to prevent bacterial attachment and enhance normal cell/tissue attachment to implant surfaces. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Multinozzle low‐temperature deposition system for construction of gradient tissue engineering scaffolds
Authors: Liu Li , Xiong Zhuo , Yan Yongnian , Zhang Renji , Wang Xiaohong , Jin Le 
Published: August 2008

AbstractTissue engineering is a technology that enables us to construct complicated hominine organs composed of many different types of cells. One of the key points to achieve this goal is to control the material composition and porous structure of the scaffold accurately. A disposable syringe based volume‐driven injecting (VDI) nozzle was proposed and designed to extrude both natural derived and synthetic polymers. A multinozzle low‐temperature deposition and manufacturing (M‐LDM) system is proposed to fabricate scaffolds with heterogeneous materials and gradient hierarchical porous structures. PLGA, collagen, gelatin, chitosan can be extruded without leaking to form hierarchical porous scaffolds for primary study. Composite scaffolds with two kinds of materials were fabricated via two different nozzles to get both hydrophilic and mechanical properties. The results from scanning electron microscopy (SEM) demonstrated that the natural‐derived biomaterials were strongly absorbed onto the synthetic biomaterials to form a stable network. Several gradient PLGA/TCP scaffolds were also fabricated to supply several samples. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009