bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid Characterization of Ultrathin Layers of Chalcogenides on SiO2/Si Substrates
Authors: Late Dattatray J. , Liu Bin , Matte H. S. S. Ramakrishna , Rao C. N. R. , Dravid Vinayak P. 
Published: February 2012

AbstractThere has been emerging interest in exploring single‐sheet 2D layered structures other than graphene to explore potentially interesting properties and phenomena. The preparation, isolation and rapid unambiguous characterization of large size ultrathin layers of MoS2, GaS, and GaSe deposited onto SiO2/Si substrates is reported. Optical color contrast is identified using reflection optical microscopy for layers with various thicknesses. The optical contrast of these thin layers is correlated with atomic force microscopy (AFM) and Raman spectroscopy to determine the exact thickness and to calculate number of the atomic layers present in the thin flakes and sheets. Collectively, optical microscopy, AFM, and Raman spectroscopy combined with Raman imaging data are analyzed to determine the thickness (and thus, the number of unit layers) of the MoS2, GaS, and GaSe ultrathin flakes in a fast, non‐destructive, and unambiguous manner. These findings may enable experimental access to and unambiguous determination of layered chalcogenides for scientific exploration and potential technological applications.
A Strategy in The Design of Micellar Shape for Cancer Therapy
Authors: Chen Tao , Guo Xing , Liu Xian , Shi Shuai , Wang Jie , Shi Chunli , Qian Zhiyong , Zhou Shaobing 
Published: February 2012

AbstractFor cancer therapy, optimization of carrier features is necessary to effectively deliver the targeting agents to tumor sites. Biodegradable poly(ether‐anhydrides) micelles with filamentous, rod‐like, and spherical shapes are fabricated. Their size and morphology are characterized by AFM and TEM. The encapsulation of doxorubicin hydrochloride (DOX) into the micelles does not impact their shape. The effect of micellar shape on the drug loading capacity and encapsulation efficiency, as well as in vitro drug release, is investigated. The cellular uptakes are evaluated using fluorescence microscopy, confocal laser scanning microscopy and flow cytometry on co‐cultures of human hepatoblastoma cell line (HepG2), lung epithelial cancer cell line (A549), and human nasopharyngeal epidermoid carcinoma cells (KB) and fibroblast normal cells mixed with the different shapes of DOX‐loaded micelles. The results show that the spherical DOX‐loaded micelles are more readily taken up by all types of cells. The impact of micellar shape on in vivo antitumor function is also assessed from changes of tumor volume, body weight loss, and survival rate of 4T1‐bearing mice and the immunostaining of tumor sections for analysis of tumor cell proliferation. The results reveal that the filamentous DOX‐loaded micelles possess the highest safety to body and the best therapeutic effects to artificial solid tumors. Therefore, the filamentous shape is deemed the most suitable morphology for design and engineering of drug vehicles for cancer therapy.
Increased percentage of mast cells within sinonasal mucosa of chronic rhinosinusitis with nasal polyp patients independent of atopy
Authors: Shaw Joanne L. , Ashoori Faramarz , Fakhri Samer , Citardi Martin J. , Luong Amber 
Published: February 2012

AbstractBackground:Initial attention on the pathophysiology of chronic rhinosinusitis (CRS) has focused on eosinophils. Other immune cells such as mast cells (MCs) have been identified and appear to be elevated in CRS with nasal polyp (NP) patients. MCs are commonly linked to immunoglobulin E (IgE)‐mediated inflammatory changes characterized by elevated T helper 2 cytokines. Although atopy is a common comorbid condition with CRS, the objective of this study was to determine if elevated MCs are linked primarily to atopic status in CRS patients and to understand the significance of MCs in the pathophysiology of CRS.Methods:Ethmoid sinonasal mucosa from patients undergoing endoscopic sinus surgery was harvested from 3 groups: healthy control (HC), CRS without NP (CRSsNP), and CRS with NP (CRSwNP) and analyzed by flow cytometry to quantify CD117+/CD203c+ MCs and CRTH2+ CD4+ T cells. Relative expression of prostaglandin D2 synthase in ethmoid mucosa was determined by quantitative real‐time polymerase chain reaction (PCR).Results:MCs were significantly elevated in CRSwNP patients as compared to CRSsNP patients and HCs. This elevation was not solely dependent on the presence of IgE‐mediated hypersensitivity. Relative expression of prostaglandin D2 synthase was also increased in CRSwNP patients along with an associated presence of a CRTH2+ memory CD4+ T cell population.Conclusion:Elevated percentages of MCs are found in the sinonasal mucosa of CRSwNP patients, regardless of atopic status. Secreted by MCs, elevated prostaglandin D2 may play a role in the recruitment of CRTH2+ cells to the inflamed mucosa of CRSwNP patients © 2012 ARS‐AAOA, LLC.
Effect of lumbar drain placement on recurrence of cerebrospinal rhinorrhea after endoscopic repair
Authors: Caballero Nadieska , Bhalla Vidur , Stankiewicz James A. , Welch Kevin C. 
Published: February 2012

AbstractBackground:Lumbar drain (LD) use in the management of cerebrospinal fluid (CSF) rhinorrhea remains controversial. We analyzed the relationship between LD placement and CSF leak recurrence after endoscopic repair.Methods:A retrospective case series was conducted. Patients who underwent CSF leak repair from 1999 to 2010 were identified. Data collected included demographics, body mass index (BMI), history of obstructive sleep apnea (OSA) or idiopathic intracranial hypertension (IIH), associated meningoencephalocele, etiology and site of leak, LD placement, fluorescein and antibiotic use, recurrence, and site of recurrence. Correlation between LD placement and leak recurrence was analyzed.Results:A total of 105 patients underwent CSF leak repair. A total of 68 patients had an LD. Of these 68 patients, 15 (22%) had a recurrent leak. Of the 105 patients, 37 did not have an LD, and 5 of the 37 (14%) recurred. Recurrence rates with and without LD were not significantly different (p = 0.15). Of the 105 patients, 40 (38%) had a spontaneous leak, 15 (14%) had a traumatic leak, and 50 (48%) had an iatrogenic leak. In the spontaneous group, 30 of 40 patients had an LD and 10 of 40 did not. Recurrence was not significant between these subgroups (p = 1.0). LD was used in 11 of 15 patients with traumatic leaks. Of these 15 patients, 4 did not have a drain. Recurrence was not significant between these subgroups (p = 1.0). In 27 of 50 patients with an iatrogenic leak, an LD was placed. Of 50 patients, 23 did not have an LD. There was no statistical significance when the recurrence rates for these subgroups were compared (p = 0.26).Conclusion:In our study, there was no association identified between LD placement and recurrence rates after endoscopic repair of CSF rhinorrhea. © 2012 ARS‐AAOA, LLC.
Robust Gyro‐free Attitude Estimation for a Small Fixed‐wing Unmanned Aerial Vehicle
Authors: Kallapur Abhijit G. , Petersen Ian R. , Anavatti Sreenatha G. 
Published: February 2012

AbstractThis paper proposes a backup attitude estimation scheme for small fixed‐wing unmanned aerial vehicles (UAVs) in the event of gyroscopic failure. The attitude is propagated in terms of 3 degrees‐of‐freedom (DoF) aircraft dynamics. The errors in attitude propagation are updated using indirect attitude information obtained from accelerations as sensed by onboard accelerometers and a global positioning system (GPS) receiver. In the event of gyroscopic failure, large uncertainties are introduced into the attitude propagation model. Such uncertainties in states and parameters are modeled as norm‐bound uncertainties and a discrete‐time robust extended Kalman filter (REKF) is implemented to estimate the attitude of the UAV.
Effect of temperature on the photoproperties of luminescent terbium sensors for homogeneous bioassays
Authors: Dong Zhi‐Ning , Wu Ying‐Song , Wang Zheng , He An , Li Ming , Chen Meijun , Du Hongyan , Ma Qiang , Liu Tiancai 
Published: February 2012

ABSTRACTWe developed a luminescent terbium sensor (LTS) based on energy resonance transfer for homogeneous bioassays. The effect of temperature on photoluminescence and time‐resolved fluorescence of the LTS was investigated. When the temperature was increased from 277 K to 369 K, the photoluminescence quantum yield decreased by up to 25 %, time‐resolved fluorescence decreased by up to 54 %, and the lifetime shortened dramatically. Studies showed that both photoluminescence and time‐resolved fluorescence quantum yields were largely recovered after samples were heated from 298 to 310, 333 or 369 K and subsequently cooled to 298 K. These results indicate that the homogeneous bioassay with LTS is sensitive to temperature and should be conducted at a constant temperature to ensure the temperature effect does not influence data and to increase the accuracy of the results. The results of this study are important for LTS applications in homogeneous bioassays. Copyright © 2012 John Wiley & Sons, Ltd.
Validated LC‐MS/MS assay for the quantitative determination of clematichinenoside AR in rat plasma and its application to a pharmacokinetic study
Authors: Wang Dawei , Li Feng , Li Pei , Zhang Ji , Liu Li , Xu Ping , Zhou Lei , Liu Xiaodong 
Published: February 2012

ABSTRACTThis study aimed to develop and validate a liquid chromatography tandem mass spectrometry method for measuring clematichinenoside AR in rat plasma. Clematichinenoside AR was extracted by solid‐phase extraction and chromatographed on an XTerra MS C8 column. Pulchinenoside B4 was used as the internal standard. Elution was achieved using an isocratic mobile phase of acetonitrile with 0.1% acetic acid (21:79, v/v) at a flow‐rate of 0.2 mL/min. The detection was performed by multiple reaction monitoring mode via a negative electrospray ionization interface. Standard curves were linear, ranging from 2.5 to 500 ng/mL. The intra‐ and inter‐day precision values were <14.0% and the accuracy was within ±13%. Extraction recovery ranged from 93.2 to 93.9%. This proposed method was successfully applied to a pharmacokinetic study on clematichinenoside AR in rats after oral administration. Copyright © 2012 John Wiley & Sons, Ltd.
Liquid chromatography/tandem mass spectrometry method for quantification of trans‐stilbene glycoside in rat plasma and its pharmacokinetic application
Authors: Wang Jiankun , Zhu Xuanxuan , Peng Ying , Zha Weibin , Feng Dong , Zhu Yinci , Wan Ping , Qi Huanhuan , He Jichao , Zhou Jie , Sun Jianguo 
Published: February 2012

ABSTRACTA rapid and sensitive liquid chromatography/tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the quantification of trans‐stilbene glycoside (SG) in rat plasma. As trans‐SG can be rapidly isomerized under light exposure, trans‐SG plasma samples were prepared in the dark and assayed immediately. Trans‐SG and internal standard were extracted by protein precipitation. Chromatographic separation was achieved on a C18 column with a gradient elution program. The detection of analytes was performed by negative ion via multiple reaction monitoring mode. The precursor‐to‐product ions of m/z 405.1 → 242.9 for trans‐SG and m/z 389.1 → 226.9 for polydatin (internal standard) were monitored. No interference of endogenous components was observed for any plasma samples that we studied.The method was linear over the concentration range of 1.0–1000.0 ng/mL with a good correlation coefficient. The lower limit of quantification was 1.0 ng/mL for trans‐SG. The intra and inter‐batch accuracy for trans‐SG in stable rat plasma samples ranged from 93.3 to 102.7% and the variation was less than 8.1%. The extraction recoveries of trans‐SG in rat plasma were from 102.8 to 112.4% and the matrix effects were also acceptable. This method was successfully applied to pharmacokinetic study of trans‐SG in rats after intravenous administration. Copyright © 2012 John Wiley & Sons, Ltd.
A fast, sensitive and simple method for mirtazapine quantification in human plasma by HPLC‐ESI‐MS/MS. Application to a comparative bioavailability study
Authors: Borges Ney Carter , Barrientos‐Astigarraga Rafael Eliseo , Sverdloff Carlos Eduardo , Donato José Luiz , Moreno Patricia , Felix Leila , Galvinas Paulo Alexandre Rebelo , Moreno Ronilson Agnaldo 
Published: February 2012

ABSTRACTIn the present study a simple, fast, sensitive and robust method to quantify mirtazapine in human plasma using quetiapine as the internal standard (IS) is described. The analyte and the IS were extracted from human plasma by a simple protein precipitation with methanol and were analyzed by high‐performance liquid chromatography coupled to an electrospray tandem triple quadrupole mass spectrometer (HPLC‐ESI‐MS/MS). Chromatography was performed isocratically on a C18, 5 µm analytical column and the run time was 1.8 min. The lower limit of quantitation was 0.5 ng/mL and a linear calibration curve over the range 0.5–150 ng/mL was obtained, showing acceptable accuracy and precision. This analytical method was applied in a relative bioavailability study in order to compare a test mirtazapine 30 mg single‐dose formulation vs a reference formulation in 31 volunteers of both sexes. The study was conducted in an open randomized two‐period crossover design and with a 14 day washout period. Since the 90% confidence interval for Cmax, AUClast and AUC0–inf were within the 80–125% interval proposed by the Food and Drug Administration and ANVISA (Brazilian Health Surveillance Agency), it was concluded that mirtazapine 30 mg/dose is bioequivalent to the reference formulation, according to both the rate and extent of absorption. Copyright © 2012 John Wiley & Sons, Ltd.
Determination of the Volatile Fraction of Polygonum bistorta L. at Different Growing Stages and Evaluation of Its Antimicrobial Activity against Two Major Honeybee (Apis mellifera) Pathogens
Authors: Cecotti Roberto , Carpana Emanuele , Falchero Luca , Paoletti Renato , Tava Aldo 
Published: February 2012

AbstractThe composition of the volatile fraction of Polygonum bistorta L. (also known as bistort or snakeroot) was investigated. Fresh aerial parts of this plant species were collected in the Western Italian Alps during the summer at three different phenological stages, namely vegetative, flowering, and fruiting, and steam‐distilled in a Clevenger‐type apparatus. The oils accounted for 0.004 to 0.010% of the fresh plant material, and their compositions were determined by GC/FID and GC/MS. The composition of the oils during the vegetative period varied both in quantity and quality; several classes of compounds were found with a predominance of alcohols in the vegetative phase, terpenes and linear‐chained saturated hydrocarbons in the flowering phase, while saturated aliphatic acids and their methyl esters were predominant in fruiting phase. The most abundant compounds were 3‐methylbut‐3‐en‐1‐ol in the vegetative phase, linalool in the flowering phase, and dodecanoic acid and its methyl ester in the fruiting phase. The obtained essential oils were then tested against two major bee pathogens, i.e., Paenibacillus larvae and Melissococcus plutonius, and against a reference bacterial species, Bacillus subtilis. Data were compared to those obtained with reference standards used against those pathogens such as the essential oils obtained from leaves and bark of Cinnamomum zeylanicum (cinnamon), and the antibiotic oxytetracyclin.
pH‐ and Redox‐Responsive Polysaccharide‐Based Microcapsules with Autofluorescence for Biomedical Applications
Authors: Gao Liang , Fei Jinbo , Zhao Jie , Cui Wei , Cui Yue , Li Junbai 
Published: February 2012

AbstractAutofluorescent microcapsules were assembled by covalent cross‐linking of polysaccharide alginate dialdehyde (ADA) derivative and cystamine dihydrochloride (CM) through a layer‐by‐layer (LBL) technique. The formulated Schiff base and disulfide bonds render capsules with pH‐ and redox‐responsive properties for pinpointed intracellular delivery based on the physiological difference between intracellular and extracellular environments. This simple and versatile method could be extended to other polysaccharide derivatives for the fabrication of autofluorescent nano‐ and micromaterials with dual stimuli response for biomedical applications.
ChemInform Abstract: Catalytic Oxidative Carbonylation of Arylamines to Ureas with W(CO)6/I2 as Catalyst.
Authors: Zhang Li , Darko Ampofo K. , Johns Jennifer I. , McElwee‐White Lisa 
Published: February 2012

AbstractTitle carbonylation reaction of a wide variety of aromatic amines (I) with carbon monoxide is smoothly achieved in the system iodine—DMAP—W(CO)6 to give symmetrical diarylurea derivatives (III).
Probing Thermal Interactions of Ionic Liquids with Dimethyl Sulfoxide
Authors: Rai Gitanjali , Kumar Anil 
Published: February 2012

AbstractInteractions between ionic liquids and dimethyl sulfoxide (DMSO) are probed by isothermal titration calorimetry. The excess partial molar enthalpies of ionic liquids ${H_{{\rm{IL}}}^{\rm{E}} }$ in DMSO are discussed in terms of solute–solvent interactions. The specific interaction theory originally developed by Pitzer is used to analyze the apparent molar enthalpy ϕL of ionic liquids in DMSO with the help of ion‐interaction parameters. Furthermore, quantitative information on solvent reorganization and clathrate formation is obtained and interpreted.
Molecular‐Simulation‐Assisted Immobilization and Catalytic Performance of CC Hydrolase MfphA on SBA‐15 Mesoporous Silica
Authors: Zhou Hao , Qu Yuanyuan , Bu Yibin , Li Xinliang , Kong Chunlei , Ma Qiao , Zhang Qiang , Zhang Xuwang , Zhou Jiti 
Published: February 2012

AbstractA molecular simulation strategy based on homology modeling and electrostatic potential calculations has been proposed to assist the immobilization process of a CC hydrolase MfphA onto mesoporous SBA‐15. The size of the enzyme, pH‐dependence of the immobilization process, and possible orientation of MfphA onto mesoporous materials (MPs) were predicted by molecular simulation. The adsorption of MfphA onto SBA‐15 reached equilibrium in 1.5 hours at pH 7.0 and the maximum loading capacity was 34 mg g−1. Meanwhile at pH 9.0, no obvious adsorption was observed after 12 hours which corresponded to the molecular simulation prediction. It was also shown that, after immobilization, the catalytic activity of immobilized MfphA decreased to some extent, but the thermal stability was significantly improved. Guanidinium chloride (GdmCl) exhibited similar activity attenuation for both immobilized and free enzyme. By contrast, the immobilized MfphA was more resistant to urea at high concentration than was the free enzyme. Meanwhile, recycling experiments showed that the immobilized enzyme retained 30 % of its initial activity after ten reaction cycles.
Total Synthesis of (–)‐Neovibsanin G and (–)‐14‐epi‐Neovibsanin G: Towards the Synthesis of 15‐O‐Methylneovibsanin F and 14‐epi‐15‐O‐Methylneovibsanin F
Authors: Mak Jeffrey Y. W. , Williams Craig M. 
Published: February 2012

AbstractThe total synthesis of (–)‐neovibsanin G and (–)‐14‐epi‐neovibsanin G has been accomplished, establishing the absolute configurations of these caged diterpenes as 11S, and confirming Fukuyama's postulated biosynthesis of the neovibsanins. Synthetic studies towards 15‐O‐methylneovibsanin F and 14‐epi‐15‐O‐methylneovibsanin F were undertaken based on the hypothesis that these methoxy substituted caged neovibsanins were artifacts of isolation, formed by the addition of methanol to the terminal alkenes of neovibsanin G and 14‐epi‐neovibsanin G. The results strongly suggest, however, that the methoxy caged neovibsanins are true natural products.
A New Diterpenoid Alkaloid from the Roots of a White‐Flowering Aconitum orientale Sample
Authors: Meriçli Ali H. , Çağal‐Yurdusever Nil , Özçelik Hasan , Zapp Josef , Kiemer Alexandra K. 
Published: February 2012

AbstractFrom the roots of a white‐flowering Aconitum orientale Miller sample, collected in Artvin‐Şavşat, Turkey, a new diterpenoid alkaloid named aconitorientaline (1) was isolated, along with the known diterpenoid alkaloids septentiriodine, lappaconitine, finaconitine, ranaconitine, puberanidine and delstaphinine (Fig.). The structure of 1 was established on the basis of 1H‐ and 13C‐NMR, DEPT, 1H,1H‐COSY, NOESY, HSQC, and HMBC studies. All the known compounds were identified by comparison of their 1H‐ and 13C‐NMR data and co‐TLC behavior with those of authentic samples.
Trinuclear Non‐Heme Iron Complexes Based on 4‐Substituted 2,6‐Diacylpyridine Ligands as Catalysts in Aerobic Allylic Oxidations
Authors: Rabe Volker , Frey Wolfgang , Baro Angelika , Laschat Sabine 
Published: February 2012

AbstractTaking the regio‐ and chemoselectivities of our iron complex precursors with pyridine core in aerobic oxidations into account, we envisioned a more effective influence on catalytic properties by the introduction of different substituents in 4‐position of the pyridine moiety. The synthesis of these novel 4‐substituted (pyridine‐2,6‐diyl)dipropanoic acids 4 is described. Analogously to the unsubstituted derivative, ligands 4 reacted with Fe(ClO4)3 to form trinuclear Fe3(μ3‐O) complexes 3, which were tested in the aerobic Gif‐type oxidation of α‐pinene to myrtenol, verbenone, myrtenal, and pinene oxide. The electronic nature of the substituents was found to slightly effect the ratio of allylic oxidation/epoxidation, whereas its influence on the oxidation preference of secondary to primary CH bonds is negligible as compared to the unsubstituted complex.
Identification of Three New Flavonoids from the Peels of Citrus unshiu
Authors: Shin Hyun Ji , Nam Joo‐Won , Yoon Ui Joong , Han Ah‐Reum , Seo Eun‐Kyoung 
Published: February 2012

AbstractThree new flavonoids, 5,6,7,8,3′,4′‐hexamethoxyhomoflavone (1), 5,6,7,8,4′‐pentamethoxyhomoflavone (2) and 3,6,7,8,2′,5′‐hexamethoxyflavone (3) were isolated from the peels of mature fruits of Citrus unshiu Marcow (Rutaceae), together with the three known compounds 6,7,8,4′‐tetramethoxyflavone (=6,7,8‐trimethoxy‐2‐(4‐methoxyphenyl)‐4H‐1‐benzopyran‐4‐one), 3,5,7,8,2′,5′‐hexamethoxyflavone (=2‐(2,5‐dimethoxyphenyl)‐3,5,7,8‐tetramethoxy‐4H‐1‐benzopyran‐4‐one), and scopoletin (=7‐hydroxy‐6‐methoxy‐2H‐1‐benzopyran‐2‐one) of which the former two have never been isolated from natural resources, although they have been reported as synthetic compounds. The structures of 1–3 were elucidated on the basis of spectroscopic evidence, including 1D‐ and 2D‐NMR analysis.
One‐Pot Synthesis of 4‐Substituted 3,4‐Dihydro‐3‐methoxyisocoumarins via Carboxylation of α‐Substituted 2‐Lithio‐β‐methoxystyrenes with Carbon Dioxide
Authors: Kobayashi Kazuhiro , Nagaoka Toshiyuki , Shirai Yuu , Miyatani Wataru , Yokoi Yuki , Konishi Hisatoshi 
Published: February 2012

AbstractA new type of isocoumarins (=1H‐isochromen‐1‐ones=1H‐2‐benzopyran‐1‐ones), 4‐substituted 3,4‐dihydro‐3‐methoxyisocoumarins 2, can be obtained by a one‐pot process from α‐substituted 2‐bromo‐β‐methoxystyrenes 1. Thus, lithium 2‐(1‐aryl(or methyl)‐2‐methoxyethenyl)benzoates are conveniently generated via the Br/Li exchange between 1 and BuLi, followed by the action of CO2 on the resulting α‐substituted 2‐lithio‐β‐methoxystyrenes. Upon treating with concentrated HCl at room temperature, these lithium benzoates undergo lactonization to provide the desired 3,4‐dihydroisocoumarins 2 in relatively good yields.