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991.
992.
Dr. Vladimir Ya. Lee Haruka Sugasawa Dr. Olga A. Gapurenko Prof. Dr. Ruslan M. Minyaev Prof. Dr. Vladimir I. Minkin Prof. Dr. Heinz Gornitzka Prof. Dr. Akira Sekiguchi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(49):17585-17589
Pyramidanes C[C4R4] constitute a novel class of highly strained and reactive polyhedral clusters that attracted a great deal of attention of both theoreticians and experimentalists. Although well‐studied from the theoretical viewpoint, pyramidanes were synthetically inaccessible, and only very recently their very first isolable representatives have been described. In this Communication, we report on the synthesis and structural studies of the cationic pyramidane with the Group 15 element at the apex, namely, phosphapyramidane, an isoelectronic analogue of the neutral pyramidanes of the Group 14 elements. 相似文献
993.
Mohd Noor Hidayat Adenan Latifah Saiful Yazan Annie Christianus Nur Fariesha Md Hashim Suzita Mohd Noor Shuhaimi Shamsudin Farah Jehan Ahmad Bahri Khairuddin Abdul Rahim 《Molecules (Basel, Switzerland)》2021,26(6)
Large doses of ionizing radiation can damage human tissues. Therefore, there is a need to investigate the radiation effects as well as identify effective and non-toxic radioprotectors. This study evaluated the radioprotective effects of Kelulut honey (KH) from stingless bee (Trigona sp.) on zebrafish (Danio rerio) embryos. Viable zebrafish embryos at 24 hpf were dechorionated and divided into four groups, namely untreated and non-irradiated, untreated and irradiated, KH pre-treatment and amifostine pre-treatment. The embryos were first treated with KH (8 mg/mL) or amifostine (4 mM) before irradiation at doses of 11 Gy to 20 Gy using gamma ray source, caesium-137 (137Cs). Lethality and abnormality analysis were performed on all of the embryos in the study. Immunohistochemistry assay was also performed using selected proteins, namely γ-H2AX and caspase-3, to investigate DNA damages and incidences of apoptosis. KH was found to reduce coagulation effects at up to 20 Gy in the lethality analysis. The embryos developed combinations of abnormality, namely microphthalmia (M), body curvature and microphthalmia (BM), body curvature with microphthalmia and microcephaly (BMC), microphthalmia and pericardial oedema (MO), pericardial oedema (O), microphthalmia with microcephaly and pericardial oedema (MCO) and all of the abnormalities (AA). There were more abnormalities developed from 24 to 72 h (h) post-irradiation in all groups. At 96 h post-irradiation, KH was identified to reduce body curvature effect in the irradiated embryos (up to 16 Gy). γ-H2AX and caspase-3 intensities in the embryos pre-treated with KH were also found to be lower than the untreated group at gamma irradiation doses of 11 Gy to 20 Gy and 11 Gy to 19 Gy, respectively. KH was proven to increase the survival rate of zebrafish embryos and exhibited protection against organ-specific abnormality. KH was also found to possess cellular protective mechanism by reducing DNA damage and apoptosis proteins expression. 相似文献
994.
Wan Muhammad Ikram Wan Mohd Zamri Fridelina Sjahrir Nor Suhaila Yaacob Noor Fazreen Dzulkafli Mohd Fadzli Ahmad Hasdianty Abdullah Maegala Nallapan Maniyam Emi Fazlina Hashim Nobuyuki Kawasaki Kazuhiro Komatsu Victor S. Kuwahara 《Molecules (Basel, Switzerland)》2021,26(9)
The assessment of water-extractable organic matter using an autoclave can provide useful information on physical, chemical, and biological changes within the soil. The present study used virgin forest soils from Chini Forest Reserve, Langkawi Island, and Kenyir Forest Reserve (Malaysia), extracted using different extraction methods. The dissolved organic carbon (DOC), total dissolved nitrogen (TDN), total dissolved phosphorus (TDP), and ammonium-nitrate content were higher in the autoclave treatments, up to 3.0, 1.3, 1.2, and 1.4 times more than by natural extraction (extracted for 24 h at room temperature). Overall, the highest extractable DOC, TDN, TDP, ammonium and nitrate could be seen under autoclaved conditions 121 °C 2×, up to 146.74 mg C/L, 8.97 mg N/L, 0.23 mg P/L, 5.43 mg N mg/L and 3.47 N mg/L, respectively. The soil extracts became slightly acidic with a higher temperature and longer duration. Similar trends were observed in the humic and nonhumic substances, where different types of soil extract treatments influenced the concentrations of the fractions. Different soil extraction methods can provide further details, thus widening the application of soil extracts, especially in microbes. 相似文献
995.
One‐Pot ‘On‐solvent’ Multicomponent Protocol for the Synthesis of Medicinally Relevant 4H‐Pyrano[3,2‐c]quinoline Scaffold
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Anatoly N. Vereshchagin Michail N. Elinson Ruslan F. Nasybullin Fedor V. Ryzhkov Sergey I. Bobrovsky Ivan S. Bushmarinov Mikhail P. Egorov 《Helvetica chimica acta》2015,98(8):1104-1114
‘One‐pot’ AcONa‐catalyzed transformation of salicylaldehydes, malononitrile and 4‐hydroxy‐1‐methylquinolin‐2(1H)‐one in the presence of a minimal quantity of EtOH results in fast (3 min) and efficient formation of unknown 2‐amino‐4‐(2‐hydroxyaryl)‐6‐methyl‐5‐oxo‐5,6‐dihydro‐4H‐pyrano[3,2‐c]quinoline‐3‐carbonitriles in 85–98% yields, which are potential pharmaceutical agents for treating disorders responsive to the induction of apoptosis, antiproliferation, or vascular disruption. This efficient ‘on‐solvent’ approach to the 4H‐pyrano[3,2‐c]quinoline scaffold represents a novel synthetic concept for multicomponent reaction (MCR) strategy and allows to combine the synthetic virtues of conventional MCR with ecological benefits and convenience of facile ‘on‐solvent’ procedure. 相似文献
996.
Vladimir Ya. Lee Olga A. Gapurenko Shogo Miyazaki Akira Sekiguchi Ruslan M. Minyaev Vladimir I. Minkin Heinz Gornitzka 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(47):14324-14328
Compact and highly reactive bicyclo[1.1.0]butanes constitute one of the most fascinating classes of organic compounds. Furthermore, interplay of bicyclo[1.1.0]butanes with their valence isomers, such as buta‐1,3‐dienes and cyclobutenes, is among the fundamental pericyclic transformations in organic chemistry. Herein we report the back‐and‐forth interconversion between the cyclotrisilenes and thiatrisilabicyclo[1.1.0]butanes, allowing for the synthesis of novel representatives of such classes of highly reactive organometallics. The peculiar structural and bonding features of the newly synthesized compounds, as well as the mechanism of their isomerization, were verified both experimentally and computationally. 相似文献
997.
How does hybrid bridging core modification enhance the nonlinear optical properties in donor‐π‐acceptor configuration? A case study of dinitrophenol derivatives
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Shabbir Muhammad Ahmad Irfan Mohd Shkir Aijaz R. Chaudhry Abul Kalam Salem AlFaify Abdullah G. Al‐Sehemi A. E. Al‐Salami I. S. Yahia Hong‐Liang Xu Zhong‐Min Su 《Journal of computational chemistry》2015,36(2):118-128
This study spotlights the fundamental insights about the structure and static first hyperpolarizability (β) of a series of 2,4‐dinitrophenol derivatives (1–5), which are designed by novel bridging core modifications. The central bridging core modifications show noteworthy effects to modulate the optical and nonlinear optical properties in these derivatives. The derivative systems show significantly large amplitudes of first hyperpolarizability as compared to parent system 1 , which are 4, 46, 66, and 90% larger for systems 2, 3, 4 , and 5 , respectively, at Moller–Plesset (MP2)/6‐31G* level of theory. The static first hyperpolarizability and frequency dependent coupled‐perturbed Kohn–Sham first hyperpolarizability are calculated by means of MP2 and density functional theory methods and compared with respective experimental values wherever possible. Using two‐level model with full‐set of parameters dependence of transition energy (ΔΕ), transition dipole moment (μ0) as well as change in dipole moment from ground to excited state (Δμ), the origin of increase in β amplitudes is traced from the change in dipole moment from ground to excited state. The causes of change in dipole moments are further discovered through sum of Mulliken atomic charges and intermolecular charge transfer spotted in frontier molecular orbitals analysis. Additionally, analysis of conformational isomers and UV‐Visible spectra has been also performed for all designed derivatives. Thus, our present investigation provides novel and explanatory insights on the chemical nature and origin of intrinsic nonlinear optical (NLO) properties of 2,4‐dinitrophenol derivatives. © 2014 Wiley Periodicals, Inc. 相似文献
998.
Research on Chemical Intermediates - The influence of different chemical elicitors was evaluated for increased andrographolide production using adventitious root cultures of Andrographis... 相似文献
999.
Al-Maqtari Helmi Mohammed Jamalis Joazaizulfazli Hadda Taibi Ben Sankaranarayanan Murugesan Chander Subhash Ahmad Noor Aisyah Mohd Sirat Hasnah Althagafi Ismail I. Mabkhot Yahia Naseer 《Research on Chemical Intermediates》2017,43(3):1893-1907
Research on Chemical Intermediates - A series of heterocyclic chalcone derivatives (4a–h) were synthesized and characterized by IR, 1H and 13C NMR as well as MS. All the synthesized compounds... 相似文献
1000.
We continue the study of homeomorphisms preserving integrally controlled weighted p-module of the ring domains. It was established earlier that under appropriate growth condition for the spherical mean of the weight such mappings are locally Hölder continuous with respect to logarithms of the distances. In this paper, we consider much more general growth conditions and derive the differentiability almost everywhere, local Lipschitz and Hölder continuity. The sharpness of these results is illustrated by several examples. The distortion estimates for measures under such mappings are also established. 相似文献