bluuebunny/crossref_metadata_2025_split huggingface dataset:
Notably Enhanced Reactivity of the Fulleroid anti‐Bredt Double Bond in Diels–Alder Reactions
Authors: Ikuma Naohiko , Susami Yasunori , Oshima Takumi 
Published: September 2011

AbstractA kinetic study of Diels–Alder (DA) reactions of some fullerene dienophiles, i.e. C60, [R1, R2]‐substituted fulleroids 1 (a: [H, H], b: [H, CN], c: [H, CO2Et]; d: [H, Ph], e: [Ph, Ph]) and [H, H]‐substituted methanofullerene (2), with various dienes [cyclopentadiene (3a), 9‐methylanthracene (3b), 1,3‐cyclohexadiene (3c), 2,3‐dimethylbutadiene (3d) and 2‐methylbutadiene (3e)] has been carried out in toluene at 30 °C. Notably, the relative rate ratio k/k0 for each dienophile (vs. C60) was remarkably dependent on the diene used; the less hindered H/CN fulleroids 1a and 1b became 25–104 times more reactive than C60 with conformationally flexible dienes such as 3d and 3e. These fulleroids, however, showed similar or rather diminished reactivity with rigid 3a and 3b. In contrast, slightly hindered 1c exhibited a three to seven times reduced rate of reaction for 3d–e, and more hindered 1d–e and the 58‐π‐conjugated 2 displayed reduced reactivity with almost all the dienes. Based on product analysis, the enhanced reactivity was ascribed to the exclusive addition at the highly strained bridgehead double bond of the transannular [5,6] open ring orifice. It was concluded that the twisted anti‐Bredt double bond can perform a topologically suitable [π2s + π4s] orbital interaction with the less congested, labile dienes. Such an orbital interaction is inhibited for both the congested fulleroids and the rigid dienes, which displayed alternative addition at a less twisted double bond.
Bay Region Borylation of Perylene Bisimides
Authors: Dey Somnath , Efimov Alexander , Lemmetyinen Helge 
Published: September 2011

AbstractNovel bispinacolborane‐N,N′‐bis(octyl)‐3,4,9,10‐perylenetetracarboxylic acid bisimide (PBI) was synthesized in high yield. The title compound is a key intermediate in the preparation of PBI aryl derivatives through Suzuki cross‐coupling by using a large variety of easily accessible aryl halides. The benign effect of a nonpolar solvent, mild base, and high reaction temperature on the borylation reaction was studied, and the reaction conditions were optimized accordingly. To demonstrate the potential and flexibility of the proposed building block, two corresponding bisarylperylene bisimides were prepared in high yields.
Ultra Sensitive Quantification of Thiourea at Nanomolar Level by Catalytic‐Kinetic Differential Pulse Voltammetry
Authors: Abbasi S. , Khodarahmiyan K. , Farmany A. 
Published: September 2011

AbstractA new simple and highly selective and sensitive catalytic differential pulse voltammetry procedure for the determination of thiourea at nanomolar level is reported. Thiourea has a catalytic effect on the oxidation of Janus green by iodate in the hydrochloric acid medium. The potential was scanned in the negative direction and the differential pulse voltammograms were recorded. The variations of the peak current with hydrochloric acid concentration, oxidant, Janus green, pulse amplitude, pulse time and scan rate were optimized. Under the optimized conditions, the relationship between the peak current and concentration of thiourea was obtained. It is shown that the calibration curve is linear in the range of 0.01–6.00 µg/mL. The detection limit of the method was 0.005 µg/mL. The relative standard deviation for 6 replicate determinations of 0.01, 0.50 and 2.00 µg/mL is equal to 2.25%, 1.52% and 1.03%, respectively. The method was applied to the determination of thiourea in fruit juices with satisfactory results.
Electrochemical Sensor for Ultrasensitive Determination of Doxorubicin and Methotrexate Based on Cyclodextrin‐Graphene Hybrid Nanosheets
Authors: Guo Yujing , Chen Yihong , Zhao Qiang , Shuang Shaomin , Dong Chuan 
Published: September 2011

AbstractIn this work, an electrochemical sensor based on a cyclodextrin‐graphene hybrid nanosheets modified glassy carbon electrode (CD‐GNs/GCE) was proposed for the ultrasensitive determination of doxorubicin and methotrexate. The peak currents of doxorubicin and methotrexate on the CD‐GNs/GCE increased 26.5 and 23.7 fold, respectively, compared to the results obtained on the bare GCE. Under optimized conditions, the linear response ranges for doxorubicin and methotrexate are 10 nM–0.2 µM and 0.1 µM–1.0 µM, with detection limits of 0.1 nM and 20 nM, respectively. The sensor showed the advantages of simple preparation, low cost, high sensitivity, good stability and reproducibility. These properties make the prepared sensor a promising tool for the determination of trace amounts of doxorubicin and methotrexate in biological, clinical and pharmaceutical fields.
Amperometric Immunosensor for Chagas’ Disease Using Gold CD‐R Transducer
Authors: Vinicius Foguel Marcos , Pilon dos Santos Glauco , Aparecido Pupim Ferreira Antonio , Yamanaka Hideko , Vicente Benedetti Assis 
Published: September 2011

AbstractChagas’ disease has been spread mainly through blood transfusion or blood components, therefore the development of a device for neglected diseases with high specificity and sensitivity is important to public health. This work describes the development of an amperometric immunosensor for determination of Chagas’ disease through a gold‐based electrode obtained from a recordable compact disc modified with 4‐(methylmercapto)benzaldehyde for the immobilization of Tc85 protein of the Trypanosoma cruzi. The immunoassays were carried out using positive and negative sera from Chagas’disease patients and immunoglobulin conjugated with peroxidase enzyme. The immunosensor presented −0.949 µA as cut‐off value and was applied in sera samples.
Godavarin K: a New Limonoid with an Oxygen Bridge between C(1) and C(29) from the Godavari Mangrove Xylocarpus moluccensis
Authors: Li Jun , Li Min‐Yi , Satyanandamurty Tirumani , Wu Jun 
Published: September 2011

AbstractGodavarin K (1), a new limonoid with an oxygen bridge between C(1) and C(29), was obtained from seeds of an Indian mangrove, Xylocarpus moluccensis, together with a known tetranortriterpene, 6‐de(acetyloxy)‐7‐deacetylchisocheton compound E (=(5α,7α,13α,17α)‐7‐hydroxy‐4,4,8‐trimethyl‐3‐oxocarda‐1,14‐dienolide; 2). The structure of godavarin K was established on the basis of spectroscopic data. In addition, the confusion of 1H‐ and 13C‐NMR data for compound 2 in previous literature was clarified.
A Simple One‐Pot Synthesis of N‐Alkyl‐2,5‐diaryl‐1,3‐dioxol‐4‐amines
Authors: Bayat Mohammad , Nasri Shima 
Published: September 2011

AbstractAn efficient procedure for the synthesis of N‐alkyl‐2,5‐diaryl‐1,3‐dioxol‐4‐amines 3 via a one‐pot reaction of aromatic aldehydes 2 and alkyl isocyanides 1 at room temperature in good yields is described (Scheme 1, Table).
CuBr/FeCl3 Catalysis: a Novel and Efficient Method for the Preparation of New Aryl (Iminomethyl)propargyl Ether Derivatives via CH Activation of Aryl Propargyl Ethers
Authors: Kumar Gautham Santhosh , Kurumurthy Chavva , Rao Pillalamarri Sambasiva , Veeraswamy Banda , Rao Pamulaparthi Shanthan , Narsaiah Banda 
Published: September 2011

AbstractCuBr/FeCl3 Catalysis as a novel and efficient method has been developed for the preparation of new aryl propargyl imine ether derivatives via CH activation of aryl propargyl ethers, followed by reaction with imines generated from aldehydes and amines.
Two New Cytotoxic Alkaloids from Mappianthus iodoidesHand.‐Mazz.
Authors: Xiao Xi‐Bin , Lin Yue‐Xing , Xu Geng‐Bo , Gong Xu‐Bo , Gu Ying , Tong Jie‐Feng , Yang Jing 
Published: September 2011

AbstractTwo new alkaloids, mappine A (1) and mapposidic acid (2), together with eleven known compounds, were isolated from the stems of Mappianthus iodoides Hand.‐Mazz. Their structures were elucidated by means of spectroscopic and mass‐spectrometric analyses, particularly 1D‐ and 2D‐NMR spectroscopy. The cytotoxic activities of the two new alkaloids were also evaluated.
The utility of serum CA‐125 in predicting extra‐uterine disease in apparent early‐stage endometrial cancer
Authors: Nicklin James , Janda Monika , Gebski Val , Jobling Thomas , Land Russell , Manolitsas Tom , McCartney Anthony , Nascimento Marcelo , Perrin Lewis , Baker Jannah F. , Obermair Andreas ,   for the LACE Trial Investigators
Published: September 2011

AbstractSurgical staging in early‐stage uterine cancer is controversial. Preoperative serum CA‐125 may be of clinical value in predicting the presence of extra‐uterine disease in patients with apparent early‐stage endometrial cancer. Between October 6, 2005, and June 17, 2010, 760 patients were enrolled in an international, multicentre, prospective randomized trial (LACE) comparing laparotomy with laparoscopy in the management of endometrial cancer apparently confined to the uterus. Of these, 657 patients with endometrial adenocarcinoma had a preoperative serum CA‐125 value recorded. Multiple cross‐validation analysis was undertaken to correlate preoperative serum CA‐125 with stage of disease (Stage I vs. Stage II+) after surgery. Patients' median preoperative serum CA‐125 was 14 U/ml. A cutoff point of 30 U/ml was associated with the smallest misclassification error, and using this cutoff, 98 patients (14.9%) had elevated CA‐125 levels. Of those, 36 (36.7%) had evidence of extra‐uterine disease. Of the 116 patients (17.7%) with evidence of extra‐uterine disease, 31.0% had an elevated CA‐125 level. On univariate and multivariable logistic regression analysis, only preoperative CA‐125 level, but no other preoperative clinical characteristics were found to be associated with extra‐uterine spread of disease. Utilizing a cutoff point of 30 U/ml achieved a sensitivity, specificity, positive predictive value and negative predictive value of 31.0, 88.5, 36.7 and 85.7%, respectively. Elevated CA‐125 above 30 U/ml in patients with apparent early‐stage disease is a risk factor for the presence of extra‐uterine disease and may assist clinicians in the management of patients with clinical Stage I endometrial cancer.
Clinical SERS: are we there yet?
Authors: Kho Kiang Wei , Fu Chit Yaw , Dinish U. S. , Olivo Malini 
Published: September 2011

AbstractSurface Enhanced Raman Spectroscopy or SERS has witnessed many successes over the past 3 decades, owing particularly to its simplicity of use as well as its highly‐multiplexing capability. This article provides an overview of SERS and its applicability in the field of bio‐medicine. We will preview recent developments in SERS substrate designs, and the various sensing technologies that are based on the SERS phenomenon. An overview of the clinical applications of SERS is also included. Finally, we provide an opinion on the future trends of this unique spectroscopic technique. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical study on the gas‐phase reaction mechanism between palladium monoxide and methane
Authors: Yang Hua‐Qing , Hu Chang‐Wei , Gao Chao , Yang Meng‐Yao , Li Fang‐Ming , Li Cai‐Qin , Li Xiang‐Yuan 
Published: September 2011

AbstractThe gas‐phase reaction mechanism between palladium monoxide and methane has been theoretically investigated on the singlet and triplet state potential energy surfaces (PESs) at the CCSD(T)/AVTZ//B3LYP/6‐311+G(2d, 2p), SDD level. The major reaction channel leads to the products PdCH2 + H2O, whereas the minor channel results in the products Pd + CH3OH, CH2OPd + H2, and PdOH + CH3. The minimum energy reaction pathway for the formation of main products (PdCH2 + H2O), involving one spin inversion, prefers to start at the triplet state PES and afterward proceed along the singlet state PES, where both CH3PdOH and CH3Pd(O)H are the critical intermediates. Furthermore, the rate‐determining step is RS‐CH3PdOH → RS‐2‐TS1cb → RS‐CH2Pd(H)OH with the rate constant of k = 1.48 × 1012 exp(−93,930/RT). For the first CH bond cleavage, both the activation strain ΔE≠strain and the stabilizing interaction ΔE≠int affect the activation energy ΔE≠, with ΔE≠int in favor of the direct oxidative insertion. On the other hand, in the PdCH2 + H2O reaction, the main products are Pd + CH3OH, and CH3PdOH is the energetically preferred intermediate. In the CH2OPd + H2 reaction, the main products are Pd + CH3OH with the energetically preferred intermediate H2PdOCH2. In the Pd + CH3OH reaction, the main products are CH2OPd + H2, and H2PdOCH2 is the energetically predominant intermediate. The intermediates, PdCH2, H2PdCO, and t‐HPdCHO are energetically preferred in the PdC + H2, PdCO + H2, and H2Pd + CO reactions, respectively. Besides, PdO toward methane activation exhibits higher reaction efficiency than the atom Pd and its first‐row congener NiO. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Retrospective analysis of 55,769 HbA1c EQA results obtained from professional laboratories and medical offices participating in surveys organized by two European EQA centers over a nine‐year period
Authors: Morandi Pierre‐Alain , Deom André , Kesseler Dagmar , Cohen Richard 
Published: September 2011

AbstractExternal Quality Assessment (EQA) is an essential tool for laboratories to monitor the performances of their analyses. It also allows a comparison of methods and types of laboratories (professional laboratories vs. medical offices). We, therefore, compared 55,769 HbA1c EQA results obtained between 1999 and 2008 by laboratories participating in EQA schemes organized by two European centers, Switzerland (center 1) and France (center 2). We used simple, nonparametrical statistics suited to EQA results to calculate the yearly and global precision performances. All the results, including the outliers, were included in the calculations. The best global precision performances were obtained by professional laboratories and medical offices using DCA POCT devices, followed byprofessional laboratories with the Integra, Hitachi, Cobas Mira, and HPLC groups of devices, and finally by both types of laboratories with the NycoCard POCT devices. When considering yearly precision performances, an overall improvement over time was observed for almost all diagnostic devices of center 1, whereas the trend was less clear for center 2. The HbA1c EQA results collected and analyzed over a 9‐year period showed that the DCA POCT devices used either by professional laboratories or medical offices had better reproducibility than laboratory devices (other than POCT) and that a general improvement of yearly precision performances was observed, especially when frequent EQA schemes were organized. J. Clin. Lab. Anal. 25:337–343, 2011. © 2011 Wiley‐Liss, Inc.
Evaluation of a novel fusion protein antigen for rapid serodiagnosis of tuberculosis
Authors: Cheng Zhe , Zhao Jun‐Wei , Sun Zhan‐Qiang , Song Yan‐Zheng , Sun Qing‐Wen , Zhang Xiang‐Yan , Zhang Xue‐Lian , Wang Hong‐Hai , Guo Xiao‐Kui , Liu Yu‐Feng , Zhang Shu‐Lin 
Published: September 2011

AbstractThe detection of Mycobacterium tuberculosis‐specific antibodies in human sera has been a rapid and important diagnostic aid for tuberculosis (TB) control and prevention. However, any single antigen is not enough to be used to cover the antibody profiles of all TB patients. In this study, a novel fusion protein was constructed using gene splicing by overlap extension (SOEing), and then the antibody level against it in 171 TB patients and 86 controls was evaluated by enzyme‐linked immunosorbent assay. Compared with the three individual antigen (16 kDa: sensitivity 19.9%, specificity 96.5%; MPT64: sensitivity 75.4%, specificity34.9%; 38 kDa: sensitivity 33.3%, specificity 83.7%), the fusion protein antigen (sensitivity 42.1%, specificity 89.5%) gave the best diagnostic performance with the largest receiver operating characteristic curve area 0.656 (95% confidence interval [CI], 0.590–0.721; P<0.01). These results suggested that the novel fusion protein antigen successfully constructed by gene SOEing provided the improved diagnostic performance for TB, and other mycobacterial multiepitope fusion proteins may also be worthy of investigation for further enhancing the detection sensitivity. J. Clin. Lab. Anal. 25:344–349, 2011. © 2011 Wiley‐Liss, Inc.
Optimization of a two‐step permeabilization fluorescence in situ hybridization (FISH) assay for the detection of Staphylococcus aureus
Authors: Lawson Thomas S. , Connally Russell E. , Vemulpad Subramanyam , Piper James A. 
Published: September 2011

AbstractBackground: Aspects of the fluorescence in situ hybridization (FISH) method for the detection of clinically important bacteria, such as Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli, were investigated for optimization. Methods: Various approaches to optimizing the FISH procedure were taken and different methods were compared. To save time, hybridization and washing buffers were prepared beforehand and stored at −20°C and mixed to their final formamide and NaCl concentrations just before use. The use of 50‐ml tubes for hybridizationincubation reduced drying out, reagent wastage, and reaction times. Results: A two‐step permeabilization FISH assay was developed that used phosphate‐buffered saline as a buffer for lysostaphin. It could detect bacteria with DNA probes conjugated to fluorophores with a higher signal intensity and the less expensive biotinylated DNA probes with minimal cell lysis in 1 hr. Conclusions: The two‐step assay might be used when the FISH signal is weak, bacterial numbers are low or if there is a need to use other reporter molecules. J. Clin. Lab. Anal. 25:359–365, 2011. © 2011 Wiley‐Liss, Inc.
Study of correlation of nitrite levels with malonaldehyde and the prognosis of patients with sickle cell disease on hydroxyurea, Ceará—BRAZIL
Authors: Gonçalves Romélia Pinheiro , Elias Darcielle Bruna Dias , Magalhães Hemerson Iury Ferreira , de Souza Jacqueline Holanda 
Published: September 2011

AbstractHydroxyurea (HU) is the only drug approved for the induction of fetal hemoglobin. Besides this benefit, there are others such as the reduction of leukocyte and generation of nitric oxide (NO). Sickle cell anemia (SCA) is characterized by chronic hemolytic anemia and vaso‐occlusive phenomena. The aim of this study was to evaluate the correlation of parameters MDA and NO2 with the prognosis of patients with SCA as outpatients at Hospital Universitário Walter Cantídeo. In all, 65 patients with SCA—51 without the use of HU (group I) and 14 chronically treated with HU (group II)—were recruited. Nitrite and malonaldehyde were determined by biochemical methods. We found that in group II therewas a significant difference of serum MDA with clinical variables: two or more transfusions during the year (P<0.0469), the presence of malleolar ulcers (P<0.0400), and the occurrence of vaso‐occlusive episodes (P<0.0031), and Group I with the occurrence of three or more vaso‐occlusive episodes (P<0.0051). Correlating the malonaldehyde with clinical variables in groups I and II, we observed a statistically significant relationship with two or more transfusions during the year and the presence of malleolar ulcer. Our results demonstrate that MDA levels can be used as parameter for prognosis in SCA. J. Clin. Lab. Anal. 25:369–373, 2011. © 2011 Wiley‐Liss, Inc.
Gender segregation in gene expression and vulnerability to oxidative stress induced injury in ventral mesencephalic cultures of dopamine neurons
Authors: Tao Qingqing , Fan Xiaolan , Li Ting , Tang Yu , Yang Dehua , Le Weidong 
Published: September 2011

AbstractParkinson's disease (PD) is a progressive neurodegenerative disorder characterized by loss of dopamine (DA) neurons in the substantia nigra pars compacta (SNC). Most epidemiologic studies have demonstrated that PD has a higher prevalence in males than in females. Both hormones and genetic factors have been considered to be contributors to this phenomenon. In the present study, we used primary cultures of ventral mesencephalic (VM) neurons from E13.5 Balb/C mice to investigate whether there were any gender differences in gene expression and cell sensitivity to oxidative stress in sex segregated cultures. We also investigated the role of SRY, the sex‐determining region on the Y chromosome, and the female hormone estrogen in the gender dimorphism. We measured the expression levels of genes that previously were thought to be related to PD or DA neuron development and functions by real‐time PCR, and found six of them, ATP13A2, ERβ, MAO‐A, D2, DAT, and Pitx3, showing significantly differential expression between males and females in the normal physiological state or under stress conditions. Furthermore, we demonstrated that male VM neurons are more vulnerable than female neurons to rotenone‐induced cytotoxicity and that 17β‐estrogen has a moderate protective effect in both male and female VM neurons. Moreover, we document that SRY can upregulate monoamine oxidase A and downregulate estrogen receptor‐β, and SRY‐overexpressing N2A cells enhance the resistance to oxidative stress‐induced cell injury. Our results suggest that gender indeed influences several PD‐related gene expressions in VM neurons, and SRY and estrogen are involved in the different responses to oxidative stress in culture. © 2011 Wiley Periodicals, Inc.
Neuron–glia interactions in glutamatergic neurotransmission: Roles of oxidative and glycolytic adenosine triphosphate as energy source
Authors: Schousboe A. , Sickmann H.M. , Bak L.K. , Schousboe I. , Jajo F.S. , Faek S.A.A. , Waagepetersen H.S. 
Published: September 2011

AbstractGlutamatergic neurotransmission accounts for a considerable part of energy consumption related to signaling in the brain. Chemical energy is provided by adenosine triphosphate (ATP) formed in glycolysis and tricarboxylic acid (TCA) cycle combined with oxidative phosphorylation. It is not clear whether ATP generated in these pathways is equivalent in relation to fueling of the energy‐requiring processes, i.e., vesicle filling, transport, and enzymatic processing in the glutamatergic tripartite synapse (the astrocyte and pre‐ and postsynapse). The role of astrocytic glycogenolysis in maintaining theses processes also has not been fully elucidated. Cultured astrocytes and neurons were utilized to monitor these processes related to glutamatergic neurotransmission. Inhibitors of glycolysis and TCA cycle in combination with pathway‐selective substrates were used to study glutamate uptake and release monitored with D‐aspartate. Western blotting of glyceraldehyde‐3‐P dehydrogenase (GAPDH) and phosphoglycerate kinase (PGK) was performed to determine whether these enzymes are associated with the cell membrane. We show that ATP formed in glycolysis is superior to that generated by oxidative phosphorylation in providing energy for glutamate uptake both in astrocytes and in neurons. The neuronal vesicular glutamate release was less dependent on glycolytic ATP. Dependence of glutamate uptake on glycolytic ATP may be at least partially explained by a close association in the membrane of GAPDH and PGK and the glutamate transporters. It may be suggested that these enzymes form a complex with the transporters and the Na+/K+‐ATPase, the latter providing the sodium gradient required for the transport process. © 2011 Wiley‐Liss, Inc.