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661.
Input of missing trace elements in some IAEA/NBS biological certified reference materials using INAA
J. H. Zaidi I. H. Qureshi M. Arif I. Fatima 《Journal of Radioanalytical and Nuclear Chemistry》1995,196(1):125-133
IAEA and NBS biological certified reference materials have been analyzed by instrumental neutron activation analysis and concentration of 17 elements was determined. The elements determined were either completely missing or their certified values were not given in the original compilations. For quality assurance of our work, a comparison of data on missing trace elements in some of the CRMs has been presented. It seems that second round of analysis for the certification of these elements would be useful. 相似文献
662.
S. K. Durrani A. H. Qureshi S. Qayyum M. Arif 《Journal of Thermal Analysis and Calorimetry》2009,95(1):87-91
The effects of barium substitution for Bi or Sr sites on the growth of superconducting phases have been studied. The sol spray
process has been used to synthesis the Bi-Sr-Ca-Cu-O (BSCCO) and Ba-BSCCO homogeneous ceramic powders. Thermogravimetric (TG),
differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques were employed
to characterize the synthesized materials. The electrical resistance was measured by classical d.c. fourprobe technique. It
has been observed that sol spray process has affected the physico-chemical properties of the materials and also avoid the
use of chelating agent as in the case of sol gel process. In addition to the Bi2Sr2CaCu2O8 (2212) phase Ba doped specimens also contained Bi2Sr2Ca2Cu3O10 (2223), BaBiO3, BaCuO2 and CuO phases.
The results revealed that the specific effect of barium-doping on either sites (Bi or Sr) seems to avoid the formation of
higher volume fraction of the low T
c phase and promoting the formation of BiBaO3, BaCuO2 and CuO along with formation of a high T
c 2223 phase. The substitution of Ba on either sites (Bi or Sr) lower the sintering temperature for the formation of high T
c (small volume fraction) however, the Ba doped specimens also contained non-superconducting phases. 相似文献
663.
Siddiqi ZA Kumar S Khalid M Shahid M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,71(5):1845-1850
The dipodal ligands (Im) and (BIm) as well as complexes [FeLCl3] [L = Im (1) and BIm (2)] have been prepared and studied using spectroscopic techniques. The magnetic moment, IR, electronic (ligand field), FAB-mass and NMR spectral data indicate a hexa-coordinate geometry around high-spin state Fe3+ where the ligands coordinate as a tridentate [N,N,N] chelating agent. 57Fe-Mössbauer spectral data confirmed the presence of a ligand asymmetry around Fe3+ in a high-spin state electronic configuration (t2g3,eg2, S = 5/2) with nuclear transition Fe(±3/2 → ±1/2) exhibiting Kramer's double degeneracy. The molecular computations provided the optimum energy perspective plots for the molecular geometries giving the important structural data. 相似文献
664.
Suhaib Alam Mohammad Shaad Ansari Avishek Banik Rafat Ali Sandeep Verma Mohammad Qureshi 《化学:亚洲杂志》2019,14(24):4673-4680
Seedless growth of vertically aligned nanostructures, which can induce smoother transport and minimize Ohmic contact between substrate and semiconductor, can be fabricated by in situ growth utilizing modified hydrothermal methods. Such devices can be useful in designing non‐invasive ultrasensitive hand‐held sensors for diagnostic identification of volatile organic compounds (VOCs) in exhaled air, offering pain‐free and easier detection of long‐term diseases such as asthma. In the present work, WO3 nanoblocks, with a high surface area and porosity, have been grown directly over transparent conducting oxide to minimize Ohmic resistance, facilitating smoother electron transfer and enhanced current response. Further modification with porous alumina (γ‐Al2O3), by electrodeposition, resulted in the selective and ultrasensitive detection of NOX in simulated exhaled air. Crystal phase purity of as‐fabricated pristine as well modified samples is validated with X‐ray diffraction analysis. Morphological and microstructural analyses reveal the successful deposition of porous alumina over the surface of WO3. Improved surface area and porosity is presented by porous alumina in the modified WO3 device, suggesting more active sites for the gas molecules to get adsorbed and diffuse through the pores. Oxygen vacancies, which are detrimental in the transport phenomenon in the presented sensors, have been studied using X‐ray photoelectron spectroscopic (XPS) analysis. Gas sensing studies have been performed by fabricating chemiresistor devices based on bare WO3 and Al2O3‐modified WO3. The higher sensitivity for NOX gas in case of γ‐Al2O3‐modified WO3 based devices, as compared to bare WO3‐based devices, is attributed to the better surface area and charge transport kinetics. The presented device strategy offers crucial understanding in the design and development of non‐invasive, hand‐held devices for NO gas present in the human breath, with potential application in medical diagnostics. 相似文献
665.
Nadiah Zafar Jean Pierre Valour Geraldine Agusti Hatem Fessi Abdelhamid Elaissari 《先进技术聚合物》2016,27(12):1637-1641
Functional, reactive and smart textiles are nowadays of great interest in the fields of both cosmetic and pharmaceutical industries. Textile functionalization according to demands of the consumers can only be achieved with better understanding of the properties of the textile surface as well as sound knowledge about the technique to be used to functionalize the textiles. The aim of this work was to investigate the zeta potential of polyamide textile and prepared sponge like particles as a function of pH and salinity of the electrolyte. Special attention has been dedicated to the electrokinetic properties of textile as a function of sponge like particles amount present during adsorption process. As a general tendency, streaming potential measurement showed the changes in surface charge density of textile because of the changes in pH, salinity and adsorbed particles amount. All presented results were discussed in terms of zeta potential. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
666.
Dr. Angel T. Garcia-Esparza Dr. Tatsuya Shinagawa Dr. Samy Ould-Chikh Muhammad Qureshi Dr. Xuyuan Peng Dr. Nini Wei Dr. Dalaver H. Anjum Dr. Alain Clo Dr. Tsu-Chien Weng Dr. Dennis Nordlund Dr. Dimosthenis Sokaras Prof. Jun Kubota Prof. Kazunari Domen Prof. Kazuhiro Takanabe 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(21):5874-5878
For overall water-splitting systems, it is essential to establish O2-insensitive cathodes that allow cogeneration of H2 and O2. An acid-tolerant electrocatalyst is described, which employs a Mo-coating on a metal surface to achieve selective H2 evolution in the presence of O2. In operando X-ray absorption spectroscopy identified reduced Pt covered with an amorphous molybdenum oxyhydroxide hydrate with a local structural order composed of polyanionic trimeric units of molybdenum(IV). The Mo layer likely hinders O2 gas permeation, impeding contact with active Pt. Photocatalytic overall water splitting proceeded using MoOx/Pt/SrTiO3 with inhibited water formation from H2 and O2, which is the prevailing back reaction on the bare Pt/SrTiO3 photocatalyst. The Mo coating was stable in acidic media for multiple hours of overall water splitting by membraneless electrolysis and photocatalysis. 相似文献
667.
Dr. Anna J. Parker Dr. Arnab Dey Mohammad Usman Qureshi Jakob M. Steiner Dr. John W. Blanchard Dr. Jochen Scheuer Nikolas Tomek Dr. Stephan Knecht Felix Josten Dr. Christoph Müller Dr. Patrick Hautle Dr. Ilai Schwartz Prof. Patrick Giraudeau Dr. Tim R. Eichhorn Dr. Jean-Nicolas Dumez 《Angewandte Chemie (International ed. in English)》2023,62(50):e202312302
The HYPNOESYS method (Hyperpolarized NOE System), which relies on the dissolution of optically polarized crystals, has recently emerged as a promising approach to enhance the sensitivity of NMR spectroscopy in the solution state. However, HYPNOESYS is a single-shot method that is not generally compatible with multidimensional NMR. Here we show that 2D NMR spectra can be obtained from HYPNOESYS-polarized samples, using single-scan acquisition methods. The approach is illustrated with a mixture of terpene molecules and a benchtop NMR spectrometer, paving the way to a sensitive, information-rich and affordable analytical method. 相似文献
668.
Jasmeet Kaur Md. Khalid Anwer Ali Sartaj Bibhu Prasad Panda Abuzer Ali Ameeduzzafar Zafar Vinay Kumar Sadaf Jamal Gilani Chandra Kala Mohamad Taleuzzaman 《Molecules (Basel, Switzerland)》2022,27(4)
The objective of the current research is to develop ZnO-Manjistha extract (ZnO-MJE) nanoparticles (NPs) and to investigate their transdermal delivery as well as antimicrobial and antioxidant activity. The optimized formulation was further evaluated based on different parameters. The ZnO-MJE-NPs were prepared by mixing 10 mM ZnSO4·7H2O and 0.8% w/v NaOH in distilled water. To the above, a solution of 10 mL MJE (10 mg) in 50 mL of zinc sulfate was added. Box–Behnken design (Design-Expert software 12.0.1.0) was used for the optimization of ZnO-MJE-NP formulations. The ZnO-MJE-NPs were evaluated for their physicochemical characterization, in vitro release activity, ex vivo permeation across rat skin, antimicrobial activity using sterilized agar media, and antioxidant activity by the DPPH free radical method. The optimized ZnO-MJE-NP formulation (F13) showed a particle size of 257.1 ± 0.76 nm, PDI value of 0.289 ± 0.003, and entrapment efficiency of 79 ± 0.33%. Drug release kinetic models showed that the formulation followed the Korsmeyer–Peppas model with a drug release of 34.50 ± 2.56 at pH 7.4 in 24 h. In ex vivo studies ZnO-MJE-NPs-opt permeation was 63.26%. The antibacterial activity was found to be enhanced in ZnO-MJE-NPs-opt and antioxidant activity was found to be highest (93.14 ± 4.05%) at 100 µg/mL concentrations. The ZnO-MJE-NPs-opt formulation showed prolonged release of the MJE and intensified permeation. Moreover, the formulation was found to show significantly (p < 0.05) better antimicrobial and antioxidant activity as compared to conventional suspension formulations. 相似文献
669.
Sharma Vishal Sharma Rajeev Kamal Razak R. K. Abdul Thakur Deepak Said Zafar Alwetaishi Mamdooh Saleel C Ahamed Afzal Asif 《Journal of Thermal Analysis and Calorimetry》2022,147(22):12595-12615
Journal of Thermal Analysis and Calorimetry - Coniferous forest residue, such as pine needles, has enormous potential in Himalayan territories and could play a significant role in energy supply.... 相似文献
670.
Sana Yaqoob Nourina Nasim Rahila Khanam Yan Wang Almas Jabeen Urooj Qureshi Zaheer Ul-Haq Hesham R. El-Seedi Zi-Hua Jiang Farooq-Ahmad Khan 《Molecules (Basel, Switzerland)》2021,26(5)
In search of anti-inflammatory compounds, novel scaffolds containing isonicotinoyl motif were synthesized via an efficient strategy. The compounds were screened for their in vitro anti-inflammatory activity. Remarkably high activities were observed for isonicotinates 5–6 and 8a–8b. The compound 5 exhibits an exceptional IC50 value (1.42 ± 0.1 µg/mL) with 95.9% inhibition at 25 µg/mL, which is eight folds better than the standard drug ibuprofen (11.2 ± 1.9 µg/mL). To gain an insight into the mode of action of anti-inflammatory compounds, molecular docking studies were also performed. Decisively, further development and fine tuning of these isonicotinates based scaffolds for the treatment of various aberrations is still a wide-open field of research. 相似文献