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排序方式: 共有202条查询结果,搜索用时 31 毫秒
191.
Andreas Mayr Muthialu Srisailas Qun Zhao Yuan Gao Heidi Hsieh Mahsa Hoshmand-Kochi Natalie St. Fleur 《Tetrahedron》2007,63(34):8206-8217
Oligo(phenyleneethynylene)s that are of variable length, contain a central arenediimide unit, either a pyromellitdiimide or a naphthalenediimide group, and are terminated by isocyanide groups have been prepared. The extended frameworks were assembled from appropriately functionalized arenediimide and areneformamide units whose lengths were adjusted by adding phenyleneethynylene units. Final transformation of the formamide groups into isocyanide groups gave the title compounds. Several isocyanide-terminated oligo(phenyleneethynylene)s without an arenediimide unit have also been prepared. 相似文献
192.
Mahsa Pourmirz Shahla Ebrahimnezh Ali Ramazani Aidin Bahrami Sholeh. Alaei Ali. Reza Dadrass 《无机化学学报》2019,35(2):344-350
通过2-溴-1-(对甲苯基)乙醛与三(对甲苯基)膦的反应制备α-磷配体:1-(对甲苯基)-2-(三对甲苯基-5-亚磷酰基)乙醛(L)。氯化镉和溴化汞与L分别反应,生成配合物[Cd(L)Cl2]2(C1)和[Hg(L)(μ2-Br)Br]2(C2)。用IR和NMR(1H,13C,31P)对配合物进行了表征。通过单晶X射线衍射测定了C2的结构,并在B3LYP/6-31G*水平对C2的结构进行了DFT计算研究,以揭示C2的复合反应位点与Schiff碱等亲核基团的相互作用。 相似文献
193.
Formaggio JA Yu J Adams T Alton A Avvakumov S de Barbaro L de Barbaro P Bernstein RH Bodek A Bolton T Brau J Buchholz D Budd H Bugel L Conrad JM Drucker RB Fleming BT Foster J Frey R Goldman J Goncharov M Harris DA Johnson RA Kim JH Koutsoliotas S Lamm MJ Marsh W Mason D McDonald J McFarland KS McNulty C Naples D Nienaber P Romosan A Sakumoto WK Schellman HM Shaevitz MH Spentzouris P Stern EG Suwonjandee N Vakili M Vaitaitis A Yang UK Zeller GP Zimmerman ED 《Physical review letters》2001,87(7):071803
The NuTeV experiment at Fermilab has used a sign-selected neutrino beam to perform a search for the lepton number violating process nu(mu)e(-)-->mu(-)nu(e), and to measure the cross section of the standard model inverse muon decay process nu(mu)e(-)-->mu(-)nu(e). NuTeV measures the inverse muon decay asymptotic cross-section slope sigma/E to be (13.8 +/- 1.2 +/- 1.4) x 10(-42) cm(2)/GeV. The experiment also observes no evidence for lepton number violation and places one of the most restrictive limits on the cross-section ratio sigma(nu(mu)e(-)-->mu(-)nu(e))/sigma(nu(mu)e(-)-->mu(-)nu(e)) < or = 1.7% at 90% C.L. for V-A couplings and < or = 0.6% for scalar couplings. 相似文献
194.
Ariandokht Vakili Amir Reza Jalilian Kamal Yavari Simindokht Shirvani-Arani Alireza Khanchi Ali Bahrami-Samani Bahram Salimi Alireza Khorrami-Moghadam 《Journal of Radioanalytical and Nuclear Chemistry》2013,296(3):1287-1294
Yttrium-90 is a useful radionuclide for radioimmunotherapy (RIT) and the anti-epidermal growth factor receptor (anti-EGFR) antibody cetuximab is clinicsally approved for the treatment of EGFR-expressing metastatic colorectal cancer and advanced head and neck cancer. Thus in this work radiolabeling of monoclonal anti-EGFR with 90Y for radioimmunotherapy (RIT) is targetted. Cetuximab was successively labeled with [90Y] chloride (74 MBq) 2 mCi after conjugation with macrocyclics bifunctional chelating agent, 1,4,7,10-tetraazacyclododecane-N,N′,N″,N″′-tetraacetic acid mono-(N-hydroxysuccinimidyl) ester (DOTA-NHS), purified and concentrated by centrifugation using an Amicon Ultra-15 filter (Millipore, MWCo, 30000). 90Y chloride was obtained by 90Sr/90Y generator. Radiolabeling was completed in 2 h by the addition of DOTA-cetuximab conjugate at 42 °C. The stability of radiolabeled was studied in human serum. Biodistribution studies in normal rats were carried out to determine the radioimmunoconjugate distribution up to 96 h. Radiochemical purity of 92 % (using ITLC) was obtained for final radioimmunoconjugate (Specific activity = 0.55 GBq/mg). Stability of radiolabeled protein in presence of human serum was tested at 37 °C for up to 24 h. Biodistribution studies demonstrated the highest ID/g % in the blood (2.62 ± 0.005 at 24 h) and the liver (2.19 ± 0.001). This study demonstrated that 90Y-DOTA-cetuximab is a potential compound for the treatment of EGFR-expressing cancers. 相似文献
195.
H. Ebadi-Dehaghani M. Reiszadeh A. Chavoshi M. Nazempour M. H. Vakili 《Journal of Macromolecular Science: Physics》2014,53(1):93-107
The thermal conductivity (TC) of compression-moulded polypropylene (PP) and PP filled with 5–15% zinc oxide (ZnO) or calcium carbonate (CaCO3) nanoparticles, prepared by extrusion, was studied using a thermal conductivity analyzer (TCA). The effect of nanoparticle content and crystallinity on the thermal conductivity was investigated using conventional methods, including SEM, XRD, and DSC. The incorporation of nanoparticles improved the crystallinity and thermal conductivity simultaneously. The experimental TC values of the PP nanocomposites with different level of nanoparticles concentration showed a linear increase with an increase in crystallinity. The TC improvement in PP/ZnO nanocomposite was greater than that of PP/calcium carbonate nanocomposites. This fact can be attributed to the intrinsic, better thermal conductivity of the ZnO nanoparticles. Several models were used for prediction of the TC in the nanocomposites. In the PP/ZnO nanocomposites the TC values correlated well with the values predicted by the Series, Maxwell, Lewis and Nielson, Bruggeman, and De Loor models up to 10 wt%. 相似文献
196.
A very sensitive and selective spectrofluorimetric method has been developed for nickel (ΙΙ) determination in environmental samples. The method is based on measuring the decrease in fluorescence intensity of murexide after nickel (ΙΙ) binding. The intensity of the fluorescence emission peak was measured at ex/em 345/431 nm in several solutions with pH interval 3.0–7.0. The fluorescence intensity decrease was found to be linear in the concentration range of 0.007 mg.L?1 to 0.1 mg.L?1 and 0.1 mg.L?1 to 20 mg.L?1 of nickel (ΙΙ) by using 10?4 M murexide at pH 3. The detection limit was found 0.004 mg.L?1. Relatively large excesses of over 20 cations and anions do not interfere. The method was successfully applied to the analysis of nickel (ΙΙ) in sea, rain and ground water. This method is very precise and accurate (R.S.D.?=?0.42 % for the determination of 0.05 mg.L?1 nickel in 10 replicates). 相似文献
197.
An efficient and green method for the synthesis of phthalide [isobenzofuran-1(3H)-one] fused pyrazoles via the catalyst-free condensation reaction of 2-formylbenzoic acid, hydrazine hydrate, and acetylenic esters in water is reported. Reaction of 2-formylbenzoic acid with 6-amino-uracils or cyclic 1,3-diketones resulted in the formation of phthalide-fused pyrimidine or cyclic 1,3-diketone derivatives. 相似文献
198.
Aliakbar Dehno Khalaji Mahsa Nikookar Debasis Das 《Journal of Thermal Analysis and Calorimetry》2014,115(1):409-417
Asymmetric bidentate Schiff base ligand (HL) and its cobalt(III), nickel(II), and copper(II) complexes have been synthesized (where L = 2-[(4-methoxy-2-nitrophenyl)iminomethyl]phenol). The ligand and its metal complexes have been characterized by elemental analyses (CHN) and FTIR spectroscopy. Thermogravimetric analyses of the compounds reveal their thermal stabilities along with their thermal decomposition pattern. In addition, the complexes have been used for the preparation of corresponding metal oxide nanoparticles by controlled aerobic thermal decomposed at 500 °C. The FTIR pattern of the obtained solids receals the formation of the metal oxides nanoparticles. 相似文献
199.
Preparation of a novel sorptive stir bar based on vinylpyrrolidone‐ethylene glycol dimethacrylate monolithic polymer for the simultaneous extraction of diazepam and nordazepam from human plasma 下载免费PDF全文
Mahsa Torabizadeh Zahra Talebpour Nuoshin Adib Hassan Y. Aboul‐Enein 《Journal of separation science》2016,39(7):1316-1325
A new monolithic coating based on vinylpyrrolidone‐ethylene glycol dimethacrylate polymer was introduced for stir bar sorptive extraction. The polymerization step was performed using different contents of monomer, cross‐linker and porogenic solvent, and the best formulation was selected. The quality of the prepared vinylpyrrolidone‐ethylene glycol dimethacrylate stir bars was satisfactory, demonstrating good repeatability within batch (relative standard deviation < 3.5%) and acceptable reproducibility between batches (relative standard deviation < 6.0%). The prepared stir bar was utilized in combination with ultrasound‐assisted liquid desorption, followed by high‐performance liquid chromatography with ultraviolet detection for the simultaneous determination of diazepam and nordazepam in human plasma samples. To optimize the extraction step, a three‐level, four‐factor, three‐block Box–Behnken design was applied. Under the optimum conditions, the analytical performance of the proposed method displayed excellent linear dynamic ranges for diazepam (36–1200 ng/mL) and nordazepam (25–1200 ng/mL), with correlation coefficients of 0.9986 and 0.9968 and detection limits of 12 and 10 ng/mL, respectively. The intra‐ and interday recovery ranged from 93 to 106%, and the relative standard deviations were less than 6%. Finally, the proposed method was successfully applied to the analysis of diazepam and nordazepam at their therapeutic levels in human plasma. The novelty of this study is the improved polarity of the stir bar coating and its application for the simultaneous extraction of diazepam and its active metabolite, nordazepam in human plasma sample. The method was more rapid than previously reported stir bar sorptive extraction techniques based on monolithic coatings, and exhibited lower detection limits in comparison with similar methods for the determination of diazepam and nordazepam in biological fluids. 相似文献
200.
The adsorption of two common organophosphorus pesticides, diethoxy-[(2-isopropyl-6-methyl-4-pyrimidinyl)oxy]-thioxophosphorane
(diazinon) and dimethoxy-(3-methyl-4-nitrophenoxy)-thioxophosphorane (fenitrothion), by MCM-41 and MCM-48 mesoporous silicas
at room temperature was investigated. UVvis and IR spectroscopy, small-angle X-ray diffraction, and the specific surface area
analysis (S
BET) were used to study the adsorption behavior of diazinon and fenitrothion. The results show that the MCM-41 and MCM-48 mesoporous
silicas adsorb diazinon more efficiently than fenitrothion. The extraction of adsorbed materials from the adsorbents with
polar solvents and subsequent analysis by 31P NMR showed that the adsorption of diazinon and fenitrothion on mesoporous silicas is destructive and non-destructive, respectively.
Nitrogen adsorption measurements showed that the specific surface area of both silicas decreases after the adsorption of pesticides,
and the larger effect is observed for diazinon. The article is published in the original. 相似文献