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Pemerhatian arus ionosfera semasa suar suria kuat menggunakan data magnetometer dasar

Hamid N, Annadurai N, Yoshikawa A

Sains Malaysiana, 2018;47:595-601.

Suar suria merujuk kepada aktiviti matahari yang ditafsirkan sebagai cahaya terang yang meletus secara tiba-tiba
dari permukaan matahari. Ia mampu menjejaskan sistem ionosfera bumi justeru mengganggu mana-mana arus yang
mengalir di lapisan tersebut. Kejadian ini dapat diperhatikan melalui pemerhatian data magnetometer yang dicerap
di bumi. Kesan umum suar suria adalah peningkatan kekonduksian ionosfera seterusnya meningkatkan keamatan arus
namun didapati terdapat beberapa suar suria mampu memberikan kesan sebaliknya. Terdapat kajian yang melaporkan
bahawa satu suar suria mampu meningkatkan keamatan arus di sesetengah kawasan dan pengurangan keamatan
pada kawasan yang lain. Kajian lepas pula lebih tertumpu kepada kesan suar suria pada kawasan sektor tertentu atau
setempat. Walau bagaimanapun, kajian ini mengambil pendekatan untuk menganalisis sifat suar suria dan kesannya
menggunakan taburan data yang lebih meluas iaitu melibatkan stesen magnetometer yang dipasang di lima sektor. Data
yang digunakan adalah daripada jaringan Magnetic Data Acquisition System/Circum Pan Magnetometer Network Pacific
(MAGDAS/CPMN) dan suar suria dikenal pasti melalui data fluks sinar-X yang dicerap daripada satelit Geostationary
Operational Environmental Satellite 15 (GOES 15). Keputusan kajian menunjukkan kesan suar suria yang tidak pernah
ditemui sebelum ini iaitu pengurangan keamatan arus pada semua data cerapan di khatulistiwa magnetik dan punca
yang dicadangkan adalah kewujudan arus elektrojet berlawanan. Selain itu, keputusan kajian turut mendapati bahawa
suar suria tersebut berlaku pada fasa pemulihan ribut geomagnet semasa soltis Jun dalam fasa suria menaik.

Matched MeSH terms: Triiodobenzoic Acids
Evaluation of 2-indolcarbohydrazones as potent α-glucosidase inhibitors, in silico studies and DFT based stereochemical predictions

Taha M, Ismail NH, Javaid K, Imran S, Anouar el H, Wadood A, et al.

Bioorg Chem, 2015 Dec;63:24-35.
PMID: 26398141 DOI: 10.1016/j.bioorg.2015.09.001

2-Indolcarbohydrazones 1-28 were synthesized and evaluated for their α-glucosidase inhibitory potential. A varying degree of inhibitory potential with IC50 values in the range of 2.3±0.11-226.4±6.8μM was observed while comparing these outcomes with the standard acarbose (IC50=906.0±6.3μM). The stereochemistry of ten (10) randomly selected compounds (1, 3, 6, 8, 12, 18, 19, 23, 25 and 28) was predicted by Density Functional Theory (DFT). The stability of E isomer was deduced by comparing the calculated and experimental vibration modes of νCO, νNC and νCH (CH in NCH-R). It was observed that except compound 18, all other compounds were deduced to have E configuration while molecular modeling studies revealed the key interactions between enzyme and synthesized compounds.

Matched MeSH terms: Triiodobenzoic Acids
Synthesis, in vitro evaluation and molecular docking studies of biscoumarin thiourea as a new inhibitor of α-glucosidases

Zawawi NK, Taha M, Ahmat N, Ismail NH, Wadood A, Rahim F, et al.

Bioorg Chem, 2015 Dec;63:36-44.
PMID: 26432614 DOI: 10.1016/j.bioorg.2015.09.004

Biscoumarin analogs 1-18 have been synthesized, characterized by EI-MS and (1)H NMR and evaluated for α-glucosidase inhibitory potential. All compounds showed variety of α-glucosidase inhibitory potential ranging in between 13.5±0.39 and 104.62±0.3μM when compared with standard acarbose having IC50 value 774.5±1.94μM. The binding interactions of the most active analogs were confirmed through molecular docking. The compounds showed very good interactions with enzyme. All synthesized compounds 1-18 are new. Our synthesized compounds can further be studied to developed lead compounds.

Matched MeSH terms: Triiodobenzoic Acids
Fulltext Reverse pharmacophore mapping and molecular docking studies for discovery of GTPase HRas as promising drug target for bis-pyrimidine derivatives

Kumar S, Singh J, Narasimhan B, Shah SAA, Lim SM, Ramasamy K, et al.

Chem Cent J, 2018 Oct 22;12(1):106.
PMID: 30345469 DOI: 10.1186/s13065-018-0475-5

BACKGROUND: Pyrimidine is an important pharmacophore in the field of medicinal chemistry and exhibit a broad spectrum of biological potentials. A study was carried out to identify the target protein of potent bis-pyrimidine derivatives using reverse docking program. PharmMapper, a robust online tool was used for identifying the target proteins based on reverse pharmacophore mapping. The murine macrophage (RAW 264.7) and human embryonic kidney (HEK-293) cancer cell line used for selectivity and safety study.
METHODS: An open web server PharmMapper was used to identify the possible target of the developed compounds through reverse pharmacophore mapping. The results were analyzed and validated through docking with Schrodinger v9.6 using 10 protein GTPase HRas selected as possible target. The docking studies with Schrödinger validated the binding behavior of bis-pyrimidine compounds within GTP binding pocket. MTT and sulforhodamine assay were used as antiproliferative activity.
RESULTS AND DISCUSSION: The protein was found one of the top scored targets of the compound 18, hence, the GTPase HRas protein was found crucial to be targeted for competing cancer. Toxicity study demonstrated the significant selectivity of most active compounds, 12, 16 and 18 showed negligible cell toxicity at their IC50 concentration.
CONCLUSION: From the results, we may conclude that GTPase HRas as a possible target of studied bis-pyrimidine derivatives where the retrieved information may be quite useful for rational drug designing.

Matched MeSH terms: Triiodobenzoic Acids