bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation of L Amino Acids and D Sugars, and Amplification of their Enantioexcesses in Aqueous Solutions, Under Simulated Prebiotic Conditions
Authors: Breslow Ronald 
Published: May 2011

AbstractThe Murchison meteorite delivered five α‐methyl amino acids to Earth with small excesses of the L enantiomer; later, additional examples were found and such compounds were also found in other meteorites. I describe our work using them under prebiotic conditions to form normal proteinogenic amino acids with an excess of the L enantiomers, and to amplify such excesses to dominant concentration in solution. I also extend this work to show how D sugars, such as D‐ribose, can have been formed and amplified in solution. I also show the high concentration amplifications of D‐nucleosides that can be obtained under credible prebiotic conditions. The simple theory of such amplifications, and corrections resulting from solvation effects, are described along with modern ideas of the source of such α‐methyl amino acids in meteorites.
Hierarchical Chirality in Polycarbodiimides
Authors: Kennemur Justin G. , Novak Bruce M. 
Published: May 2011

AbstractNon‐linear or helical polycarbodiimides feature a nitrogen‐rich fully substituted guanidine‐like backbone repeat unit with two synthetically selective pendant groups. As a result of a complex ballet of bond rotations within steric proximity of the backbone, these polymers can adopt multiple tiers of asymmetry. Primary locales of chiral influence incorporated onto the polymer or on the catalyst during polymerization permit amplification to secondary levels of chirality through a backbone with an excess helical sense. In turn, the conformational chirality of the helix promotes hierarchical orders of tertiary chirality around this chiral scaffolding. These higher levels of asymmetry have shown static and dynamic attributes and can be obtained from monomers containing no predominant chirality. Tailoring these properties with the selection of spatially constricting pendant groups such as substituted arenes, polyarenes, and enantiopure configurationally chiral alkanes has exemplified this behavior. This manuscript will focus on some of the highlights of dynamic and static asymmetry observed for these polycarbodiimide systems.
Applicable Properties of Cucurbiturils
Authors: Parvari Galit , Reany Ofer , Keinan Ehud 
Published: May 2011

AbstractThis account highlights three significant fields of applications for cucurbiturils (CBs). The first relates to cucurbituril‐based devices and sensors involving spectral effects associated with the formation and dissociation of inclusion complexes. The second refers to the use of CBs as catalysts that control the rate and selectivity of chemical reactions. The third deals with the potential use of CBs for the assembly of mechanical devices and molecular motors. An example of the sensor application is based on the discovery that 4‐aminobipyridine derivatives form strong inclusion complexes with CB6, exhibiting remarkably large enhancements of fluorescence intensity and quantum yields. This reversible binding phenomenon can be used for the design of switchable beacons that can be incorporated into cascades of binding networks for various applications. The second application is exemplified by selective, enhanced photoaddition reactions as well as [3+2]cycloaddition and other reactions mediated by the CB cavity. The third application is based on the idea that low‐barrier molecular rotary motors having rotaxane architecture can be constructed using a cucurbituril host and a polyyne guest serving as stator and rotator, respectively. The “low friction” between these components is supported by molecular mechanics calculations with model systems and experimentally verified by X‐ray crystallography with several synthetic host–guest complexes, all suggesting that the diyne rod floats at the center of the macrocyclic host with no apparent van der Waals contacts between them.
Comparison of quantification methods illustrates reduced Pseudomonas aeruginosa activity on nanorough polyvinyl chloride
Authors: Seil Justin T. , Rubien Nathan M. , Webster Thomas J. , Tarquinio Keiko M. 
Published: May 2011

AbstractPatients on mechanical ventilators for extended periods of time are faced with a high probability of developing ventilator associated pneumonia. Although this has been mostly addressed through the re‐engineering of endotracheal tubes (ETTs) with antimicrobial materials, such material coatings may easily delaminate during use. However, the potential exists to apply nanotechnology to the ETT to avoid delamination but implement antibacterial properties. Selecting a protocol to evaluate in vitro material for anti‐infection is difficult, partially due to the existence of conflicting reported methods of analysis. In this study, the susceptibility of conventional and nanorough polymeric materials to bacterial biofilm growth were evaluated. After creating nanorough polyvinyl chloride (PVC) ETTs, Pseudomonas aeruginosa biofilms were then grown on sample surfaces during a 24‐h culture. Biofilms were then removed and assayed from sample surfaces using a variety of techniques. Comparisons between the different techniques used for biofilm removal indicated that vortexing provided adequate removal of the biofilm from sample surfaces. Most importantly, a protocol following the vortexing method of biofilm and bacteria removal provided an ∼40% lower yield of colony forming units from nanorough PVC compared to conventional PVC. This suggests that Pseudomonas aeruginosa are less adherent on nanorough PVC than conventional PVC. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
A novel alkali metals/strontium co‐substituted calcium polyphosphate scaffolds in bone tissue engineering
Authors: Song Wei , Wang Qiguang , Wan Changxiu , Shi Tong , Markel David , Blaiser Ralph , Ren Weiping 
Published: May 2011

AbstractOur purpose of this study is to develop potassium or sodium/strontium co‐substituted calcium polyphosphate (K/Sr‐CPP or Na/Sr‐CPP) bioceramics in application of bone repairing scaffold. The incorporation of K, Na, and Sr into CPP substrate via a calcining‐sintering process was confirmed by X‐ray diffractometry and inductively coupled plasma atomic emission spectroscopy. In vitro degradation study of co‐substituted CPP indicated the incorporation of alkali metal elements promoted the degradability of CPP, and the scanning electron microscope showed the apatite‐like minerals were precipitated on the surface of co‐substituted CPP. The compress resistant strength of co‐substituted CPP was elevated by dopants. The MTT assay and confocal laser‐scanning microscope on osteoblasts culturing with co‐substituted CPP showed no cytotoxicity. The cell proliferation on co‐substituted CPP was even better than others. Thus, this co‐substituted CPP bioceramics might have potential of applications in orthopedic field. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Preparation and characterization of novel poly(ε‐caprolactone)/biphasic calcium phosphate hybrid composite microspheres
Authors: Bao Trinh‐Quang , Franco Rose‐Ann , Lee Byong‐Taek 
Published: May 2011

AbstractDesirably porous biodegradable hybrid composite microspheres were fabricated for use in bone graft and bone substitute applications. In this study, novel poly(ε‐caprolactone)/biphasic calcium phosphate (70/30) composite microspheres (PCL/BCP MPs) were prepared using the emulsion solvent‐evaporation method. Throughout this process, the ammonium bicarbonate (NH4HCO3) content was changed to obtain the desired porous structure. However, to maintain the spherical shape, the NH4HCO3 content should not be higher than 5%. In the optical images of the PCL/BCP MPs, almost all the microparticles had a spherical shape, and the average diameter was about 600 μm. The scanning electron microscopy and cross‐sectional optical images showed that the pore density and pore diameter of PCL/BCP MPs increased with increasing initial NH4HCO3 concentrations. In the phase‐composition analysis of the PCL/BCP MPs, which was characterized by X‐ray diffraction and EDS, the two crystals BCP and PCL phases were shown to be miscible in PCL/BCP MPs. When the degradation of these microspheres was characterized, PCL/BCP MPs‐0, PCL/BCP MPs‐2, and PCL/BCP MPs‐5 were found to display a sustained biodegradability, and the rate of degradation increased at higher initial NH4HCO3 concentrations. Proliferation of cells on three different sample types was assessed and compared, and based on these results, the PCL/BCP MPs‐5 was chosen to study MG‐63 osteoblast‐cell adhesion, growth, and proliferation. Furthermore, confocal images indicated that the cells effectively adhered, spread, and proliferated on PCL/BCP MPs‐5 during a 5‐day culture period. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Germanium recovery using polyphenol microspheres prepared by horseradish peroxidase reaction
Authors: Nozoe Atsunori , Abe Minoru , Ohto Keisuke , Kawakita Hidetaka 
Published: May 2011

AbstractBACKGROUND: The formation of polyphenol microspheres by the polymerization of 3‐methylcatechol was performed in a methanol/phosphate buffer solution using horseradish peroxidase (HRP), without the use of a surfactant or a water/oil interface, to be used for germanium recovery.RESULTS: The polyphenol microspheres were of diameter 1 mm. The functional group density of phenol group in the polymer was approximately 15 mol kg−1 determined by the Folin‐Denis method. In batchwise experiments, the amount of germanium adsorbed was 0.23 mol kg−1.CONCLUSION: Because germanium is a rare metal, a system for its recovery is required. Using the proposed system, continuous recovery of germanium can be achieved using multilayered microspheres. Copyright © 2011 Society of Chemical Industry
Photocatalytic reactors for environmental remediation: a review
Authors: McCullagh Cathy , Skillen Nathan , Adams Morgan , Robertson Peter K.J. 
Published: May 2011

AbstractResearch in the field of photocatalytic reactors in the past three decades has been an area of extensive and diverse activity with an extensive range of suspended and fixed film photocatalyst configurations being reported. The key considerations for photocatalytic reactors, however, remain the same; effective mass transfer of pollutants to the photocatalyst surface and effective deployments and illumination of the photocatalyst. Photocatalytic reactors have the potential versatility to be applied to the remediation of a range of water and gaseous effluents. Furthermore they have also been applied to the treatment of potable waters. The scale‐up of photocatalytic reactors for waste and potable water treatment plants has also been demonstrated. Systems for the reduction of carbon dioxide to fuel products have also been reported. This paper considers the main photocatalytic reactor configurations that have been reported to date. Copyright © 2011 Society of Chemical Industry
Study on condensation of N‐aryl thioureas with 3‐bromo‐acetylacetone: Synthesis of aminothiazoles and iminodihydrothiazoles, and their in vitro antiproliferative activity on human cervical cancer cells
Authors: Shi Hai‐Bo , Zhang Shi‐Jie , Lin Yan‐Fang , Hu Wei‐Xiao , Cai Chao‐Ming 
Published: May 2011

AbstractThe condensation of N‐aryl thioureas with 3‐bromo‐acetylacetone in neutral solvent acetone not only led to 5‐acetyl‐4‐methyl‐2‐(substituted anilino) thiazoles 3 but also 2‐imino‐3‐(substituted phenyl)‐4‐methyl‐5‐acetyl‐2,3‐dihydrothiazoles 4. Further study found that different reaction solvents displayed an important role toward the ratio of aminothiazoles 3 and iminodihydrothiazoles 4, and the reaction scope was extended. A plausible mechanism involving solvent effect and in situ hydrobromic acid catalyzation was proposed. Some selected isomers exhibited moderate in vitro antiproliferative activity on human cervical cancer cell lines (Hela, Siha). J. Heterocyclic Chem., (2011).
One‐step synthesis of 2,4,5‐trisubstituted pyrimidines
Authors: Zhang Chuang‐Jun , Han Wen‐Yong , Gao Mi‐Xiang , Xu Fei‐Fei , Zhang Zun‐Ting 
Published: May 2011

AbstractA simple and straightforward methodology towards the synthesis of 2,4,5‐trisubstituted pyrimidines has been developed by one‐step reaction of isoflavones with thiourea or guanidine. Ten 2‐mercapto‐4,5‐diphenylpyrimidines and eight 2‐amino‐4,5‐diphenylpyrimidines were reported. All of them were characterized by FT‐IR, NMR, and elemental analysis. A variety of substrates can participate in the process with good yields and high purities, making this methodology suitable for library synthesis in drug discovery. J. Heterocyclic Chem., (2011).
Surface‐enhanced Raman scattering of molecules adsorbed on Co‐doped ZnO nanoparticles
Authors: Xue Xiangxin , Ruan Weidong , Yang Libin , Ji Wei , Xie Yunfei , Chen Lei , Song Wei , Zhao Bing , Lombardi John R. 
Published: May 2011

AbstractTransition‐metal‐doped semiconductor nanoparticles (NPs) have been well studied for their optical and catalytic properties but seldom studied by surface‐enhanced Raman scattering (SERS). In this paper, transition‐metal‐doped semiconductor NPs are investigated for their SERS property. Four groups of Co‐doped (0.5, 1, 3, and 5%) ZnO (CoZnO) NPs and pure ZnO NPs were synthesized and studied. When 4‐mercaptobenzoic acid was used as probing molecule, significant SERS signals were obtained on all the five samples. Moreover, it is very interesting to observe a relationship between the Co‐doping concentration and enhancement of the SERS signals. SERS intensities first increase with doping concentration (up to 1%), and then decrease with further increase in doping concentration (up to 5%). Charge transfer (CT) is considered to be the main contribution to this phenomenon. Different CT ratios from substrates to molecules seem to induce different intensities of the SERS signals. In our experiments, the crystalline defects of CoZnO NPs caused by the Co dopant affect the CT ratios. A possible mechanism of CT from the valance band of CoZnO NPs to the lower unoccupied molecular orbital of the molecules via energy of the surface states is suggested. X‐ray photoelectron spectra, UVvis spectra, and Raman spectra were used to characterize the structure and defects in CoZnO NPs. Copyright © 2011 John Wiley & Sons, Ltd.
State diagram of salmon (Salmo salar) gelatin films
Authors: Díaz Paulo , López Daniel , Matiacevich Silvia , Osorio Fernando , Enrione Javier 
Published: May 2011

AbstractBACKGROUND: A state diagram presents different physical states of a biomaterial as a function of solid content and temperature. Despite their technological interest, little information is available on protein systems such as gelatin/water mixtures. The objective of this work was to develop state diagrams of salmon gelatin (SG) and bovine gelatin (BG) in order to determine maximal freeze concentration parameters (T′g, T′m and Xs′) and to relate possible differences to their biochemical characteristics.RESULTS: Biochemical characterisation of SG showed lower molecular weight and iminoacid concentration compared with BG. Likewise, the glass transition temperature (Tg) was lower for SG at Xs > 0.8, which was associated with its lower molecular weight. Unexpectedly, the depression of freezing temperature (Tf) was greater for SG at Xs > 0.1, which was associated with its higher ash content. Isothermal annealing produced effective values of T′g ≈ − 52 °C, T′m ≈ − 46 °C and X′s ≈ 0.6 for both gelatins. Interestingly, the enthalpy change associated with T′m (ΔH) was significantly higher for SG than for BG after annealing, indicating a higher proportion of ice present at about − 50 °C.CONCLUSION: Maximal freeze concentration parameters were similar between the two gelatins, though differences in biochemical properties were evident. The results show that there are likely different ways of interaction of SG and BG with water. Copyright © 2011 Society of Chemical Industry
Disaster survivors in their third decade: Trajectories of initial stress responses and long‐term course of mental health
Authors: Holgersen Katrine Høyer , Klöckner Christian A. , Jakob Boe Hans , Weisæth Lars , Holen Are 
Published: May 2011

AbstractThis study analyzed trajectories of initial stress and long‐term mental health after the 1980 North Sea oil rig disaster. A growth‐mixture model of the survivors' stress manifestations in the first 8 weeks (Posttraumatic Stress Scale, [PTSS‐10]) and general mental health in 1980, 1981, 1985, and 2007 (General Health Questionnaire, [GHQ‐20]) was estimated. Survivors' GHQ‐scores in 1985 and 2007 were contrasted to those of a comparison group. Four trajectories were identified among survivors. The resilient (n = 43) displayed initially moderate stress that rapidly declined. The recovery (n = 10), chronic (n = 8), and relapse (n = 9) showed initially stable high stress scores, but the long‐term mental health differed. Early screening may identify those at long‐term risk.
A pilot randomized controlled trial assessing secondary prevention of traumatic stress integrated into pediatric trauma care
Authors: Kassam‐Adams Nancy , Felipe García‐España J. , Marsac Meghan L. , Kohser Kristen L. , Baxt Chiara , Nance Michael , Winston Flaura 
Published: May 2011

AbstractMedical settings provide opportunities for secondary prevention of traumatic stress and other sequelae of pediatric injury. This pilot randomized trial evaluated the delivery and effectiveness of a targeted preventive intervention based on best practice recommendations and integrated within acute medical care. Hospitalized injured children were screened for risk of developing posttraumatic stress disorder (PTSD). Those at risk (N = 85) were randomized to the intervention (n = 46) or usual care (n = 39). The preventive intervention did not reduce PTSD or depression severity or increase health‐related quality of life, compared to usual care. Both groups improved over time, but 6 months postinjury approximately 10% of each group still met criteria for PTSD, suggesting room for improvement in comprehensive pediatric injury care.
Comparing the diagnosis of PTSD when assessing worst versus multiple traumatic events in a chronically mentally ill sample
Authors: Simpson Tracy L. , Anne Comtois Katherine , Moore Sally A. , Kaysen Debra 
Published: May 2011

AbstractDespite interest in the nature of the traumatic event required to meet Criterion A for posttraumatic stress disorder (PTSD) as defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV; American Psychiatric Association, 1994), little attention has been paid to the diagnostic ramifications of linking PTSD symptoms to a single traumatic event in the context of multiple trauma exposures. In this study, 67 dually diagnosed clients with at least 2 potential Criterion A traumatic events completed the Posttraumatic Stress Diagnostic Scale twice, in counterbalanced order: once regarding their worst event and once regarding all events. When responding regarding their worst trauma, 53.7% met probable PTSD criteria. This rose to 67.2% when considering all traumas. Although preliminary, these results suggest that linking PTSD symptoms to a single traumatic event excludes a meaningful number of cases who are otherwise indistinguishable based on symptom profile.
Manubrial resection and anterior mediastinal tracheostomy: Friend or Foe?
Authors: Chan Yu Wai , Yu Chow Velda Ling , Lun Liu Lawrence Hin , Ignace Wei William 
Published: May 2011

AbstractObjectives/Hypothesis:To review our experience with manubrial resection and anterior mediastinal tracheostomy and formulate operative guidelines to improve the surgical outcome.Study Design:Retrospective study.Methods:Between January 1980 and June 2010, we performed 38 manubrial resections. The indications of the procedure, reconstructive methods, and operative outcomes were analyzed.Results:Fourteen patients had tumors of the hypopharynx/cervical esophagus, eight had parastomal recurrences of laryngeal tumor, four had recurrent esophageal tumors, four had postirradiation sarcoma, four suffered from subglottic/upper tracheal tumors, three had thyroid malignancy, and the remaining patient had tumor recurrence at the previous tracheostomy site. The hospital mortality rate was 5.3% due to bleeding from major vessel erosion. The mean length of the tracheal stump was 5.4 cm, of which 81.6% required relocation inferior to the innominate artery for construction of the mediastinal tracheostomy. Among the different reconstructive methods for the pharyngoesophageal defects, the anastomotic leakage rate was 17.6%, the majority of which required exteriorization followed by second stage reconstruction. The long‐term tracheostomy stenosis rate was 47.4%, the risk of which was significantly increased by anastomotic leakage and necrosis of distal trachea. The use of a pectoralis major flap was shown to protect against this complication. The overall survival was 80.6% at 1 year and 55.6% at 5 years after surgery.Conclusions:With attention to operative details, manubrial resection and anterior mediastinal tracheostomy is a safe procedure with acceptable outcome. It should be performed when indicated to facilitate tumor resection in the cervicothoracic region.
FPipTB, a benzimidazole derivative, induces chondrosarcoma cell apoptosis via endoplasmic reticulum stress and apoptosis signal‐regulating kinase 1
Authors: Liu Ju‐Fang , Chang Chih‐Shiang , Fong Yi‐Chin , Kuo Sheng‐Chu , Tang Chih‐Hsin 
Published: May 2011

AbstractChondrosarcoma is the second most common primary bone tumor and it responds poorly to both chemotherapy and radiation treatment. In this study, we investigated the anticancer effects of a new benzimidazole derivative, 2‐(furanyl)‐5‐(piperidinyl)‐ (3,4,5‐trimethoxybenzyl) benzimidazole (FPipTB) in human chondrosarcoma cells. FPipTB‐induced apoptosis in human chondrosarcoma cell lines (JJ012 and SW1353) but not in primary chondrocytes. Furthermore, it triggered endoplasmic reticulum (ER) stress, which was characterized by changes in cytosolic calcium levels. Treatment of chondrosarcoma cells with FPipTB was associated with increased intracellular levels of ASK1, p38, p53, and Bax, followed by release of cytochrome c from mitochondria and activation of caspases. It is also known that ER stress activates apoptosis signal‐regulating kinase 1 (ASK1), which mediates activation of JNK and p38 pathways. We also found that FPipTB‐induced p38 and p53 phosphorylation and upregulated Bax expression. To study the mechanism of Bax upregulation, we determined that Bax promoter activity was increased in FPipTB‐treated cells, leading to an increase in intracellular levels of Bax. In addition, cell treated with Ca2+ chelator or p38 inhibitor showed reduced transcriptional activity. The results further suggest that FPipTB triggered ER stress, as indicated by changes in cytosolic calcium levels and activated the ASK1‐MKK3/6‐p38‐p53‐Bax pathway, causing chondrosarcoma cell death. Importantly, animal studies revealed a dramatic 40% reduction in tumor volume after 21 d of treatment. Thus, FPipTB may be a novel anticancer agent for the treatment of chondrosarcoma. © 2011 Wiley Periodicals, Inc.