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مرکز اطلاعات علمی SID1
اسکوپوس
مرکز اطلاعات علمی SID
ریسرچگیت
strs
اطلاعات دوره: 
  • سال: 

    2017
  • دوره: 

    7
  • شماره: 

    2
  • صفحات: 

    103-109
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    35514
  • دانلود: 

    18627
چکیده: 

An efficient four-component synthesis of benzopyranopyridines is described by one-pot condensation of salicylaldehydes, thiols and 2 equiv of malononitrile with nano-PbWO4 as a robust and reusable heterogeneous catalyst under ULTRASONIC IRRADIATION. Lead tungstate (PbWO4) nanostructures have been synthesized via a sonochemical method based on the reaction between lead (II) nitrate and sodium tungstate dihydrate in an aqueous solution. Some advantages of this protocol include use of simple and readily available starting materials, rapid assembly of medicinally privileged heterocyclic molecules, reusability of the catalyst, low amount of the catalyst and application of the sonochemical methodology as an efficient technique and innocuous means of activation in synthetic chemistry.

آمار یکساله:  

بازدید 35514

دانلود 18627 استناد 0 مرجع 0
اطلاعات دوره: 
  • سال: 

    2013
  • دوره: 

    0
  • شماره: 

    20
تعامل: 
  • بازدید: 

    76
  • دانلود: 

    28
کلیدواژه: 
چکیده: 

THIOUREA DERIVATIVES ARE WIDELY USED IN MANY FIELDS INCLUDING PHARMACEUTICAL INDUSTRY DUE TO THEIRBIOLOGICAL PROPERTIES SUCH AS ANTICANCER, ANTIMICROBIAL, ANTIBACTERIAL, ANTIFUNGAL, ANTIMALARIAL AND ANTITUBERCULOSIS. IT HAS ALSO BEEN FOUND AS INTERESTING ORGANIC INHIBITORS FOR CORROSION ACTIVITYBECAUSE OF THE PROTONATION OF SULPHUR ATOM THAT CAN OCCUR IN ACIDIC SOLUTION [1]...

آمار یکساله:  

بازدید 76

دانلود 28
نویسندگان: 

NAGHIBI SANAZ | Gharagozlou Mehrnaz | Vahed Shohreh

نشریه: 

JOURNAL OF NANOSTRUCTURES

اطلاعات دوره: 
  • سال: 

    2019
  • دوره: 

    9
  • شماره: 

    4
  • صفحات: 

    768-775
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    20913
  • دانلود: 

    9234
چکیده: 

Synthesis and characterization of Cd-TiO2/PEG/FA nanocomposite as a biomaterial is the main aim of this research. Cd-doped TiO2 nanoparticles (NPs) were synthesized by solvothermal assisted sol-gel method. Then, polyethylene glycol (PEG) was added to the as-synthesized NPs to modify their surface and to prevent agglomeration. In the next step, folic acid (FA) was conjugated to Cd-TiO2/PEG nanocomposite. Optimization of FA concentration and infl uence of ultraviolet (UV) radiation, visible light, or ULTRASONIC IRRADIATION on antibacterial activity of the synthesized nanocomposite were assessed. Results showed that the influence of FA on the antibacterial performance of the as-synthesized compounds is positive and dose-dependent. FA was used as bait for bacteria and led them to accumulate around the Cd-TiO2 NPs. The bactericidal response under UV or visible light IRRADIATION was maximized at 0. 6 weight ratio of FA to CdTiO2, whereas, this parameter under ULTRASONIC IRRADIATION was improved and then became approximately constant.

آمار یکساله:  

بازدید 20913

دانلود 9234 استناد 0 مرجع 0
گارگاه ها آموزشی
نویسندگان: 

Asadnezhad Hossein | SABERI ALI | Azimi Roshan Abbas

اطلاعات دوره: 
  • سال: 

    2019
  • دوره: 

    13
  • شماره: 

    2
  • صفحات: 

    81-88
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    43904
  • دانلود: 

    28510
چکیده: 

A highly efficient and convenient procedure for the enantioselective synthesis of (S)-Rivastigmine tartrate, a cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer’ s disease, is accomplished by the treatment of versatile, readily accessible N-Ethyl-N-methyl carbamoyl chloride with 3-hydroxyacetophenone under ULTRASONIC IRRADIATION in presence of nano-K2CO3were reported. This protocol provided a high yielding stereoselective and short synthesis of (S)-Rivastigmine tartrate with an overall isolated yield of 83%. All the starting reagents and catalyst are inexpensive and commercially available. Compared to conventional heating which provides thermal energy in the macro system, ultra sonification reduces reaction times, improves yields and minimizes side product formation by providing the activation energy in micro environment. As this technology involves energy conservation and minimal waste generation, it is widely accepted as a green chemistry approach. The reported strategy afforded under ULTRASONIC IRRADIATION and in presence of Nano-K2CO3 via four steps, which (to the best of our knowledge) depicts the shortest and the most rapid method to enantiopure Rivastigmine tartrate reported to date.

آمار یکساله:  

بازدید 43904

دانلود 28510 استناد 0 مرجع 0
نویسندگان: 

RANJBAR KARIMI R. | AZIZI H.

اطلاعات دوره: 
  • سال: 

    2017
  • دوره: 

    3
  • شماره: 

    2
  • صفحات: 

    132-138
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    36876
  • دانلود: 

    19915
چکیده: 

Some aryl and heteroaryl azido compounds were synthesized from the reaction of the corresponding fluoro and chloro compounds with sodium azide in DMF as solvent and under various reaction conditions especially ULTRASONIC IRRADIATION. Reaction of aromatic and heteroaromatic azido compound with thioacetic acid in the presence of sodium hydrogen carbonate and in methanol as solvent led to the different products. Further intermolecular nucleophilic aromatic substitution reaction ofN - (perfluoropyridin4-yl) acetamid allow the regioselective synthesis of 2, 6, 7-trifluoro-2-methyloxazolo [4, 5-c] pyridine. The structures of all compounds were confirmed by IR, 1H NMR and 13C NMR spectroscopy as well as elemental analysis.

آمار یکساله:  

بازدید 36876

دانلود 19915 استناد 0 مرجع 0
نویسندگان: 

KHATAMIFAR M. | RASHIDI RANJBAR Z. | FATEMI S.J.

اطلاعات دوره: 
  • سال: 

    2015
  • دوره: 

    6
  • شماره: 

    4
  • صفحات: 

    363-369
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    74669
  • دانلود: 

    22657
چکیده: 

This work reports a facile sonochemical route in the synthesis of nano particle of deferasirox for the first time. One application of nanotechnology is in improvement of available treatments for various diseases. Deferasirox (ICL670 or Exjade) is a tridentate chelating agent for removing transfusion overload iron in thalassemia patients. In the present work, deferasirox was prepared in nano size by using of ultrasound waves. The effects of amount and reaction time on the size of deferasirox were investigated. These parameters were optimized at various amounts and different reaction times. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) studies show that the deferasirox in nature structure does not change during the reaction. The results show that the finest particle is related to the following conditions: 45min, time reaction and 0.1g, amount of deferasirox. Therefore, the ULTRASONIC bath method has a fundamental role in the preparation of deferasirox in nano scale. This method is simple, relatively fast and low cost.

آمار یکساله:  

بازدید 74669

دانلود 22657 استناد 0 مرجع 0
strs
نویسندگان: 

NIE MIN | XIA HESHENG | WU JINKUI

اطلاعات دوره: 
  • سال: 

    2013
  • دوره: 

    22
  • شماره: 

    6
  • صفحات: 

    409-416
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    41439
  • دانلود: 

    19766
کلیدواژه: 
چکیده: 

Polymeric composite materials filled with single-walled carbon nanotubes (SWNTs) have attracted much attention, but successful applications of such composites require uniform dispersion of SWNTs in the polymeric matrix and the strong SWNTs-polymer interface interaction. In this paper, chemical modification combined with ULTRASONICally initiated in situ polymerization was successfully employed to prepare poly(styrene-co-butyl acrylate)/single-walled carbon nanotubes composites [P(St-BA)/SWNTs]. The whole procedure contained two steps: in the first step, 3-(trimethoxy)-propylmethacrylate-silane (silane-coupling agent, KH570), a kind of polymerizable vinyl monomer, was grafted onto the surface of SWNTs, forming KH570-g-SWNTs by reacting KH570 with hydroxyl groups on the surface of SWNTs, which was proved by combination of FTIR and XPS results. Due to the presence of polymerizable KH570 on the surface of SWNTs, this provides a basis for the next stage of polymerization to prepare polymer-encapsulated SWNTs composites. In the second step, an ULTRASONICally initiated in situ emulsion polymerization of monomer styrene (St) and n-butyl acrylate (BA) proceeded in the presence of KH570-g-SWNTs. Consequently, P(St-BA)/SWNTs composite emulsion was obtained. TEM confirmed that SWNTs were coated with the obtained polymer. FTIR and XPS further showed that even after 72 h of soxhlet extraction with boiling toluene, there were still unextracted polymers in P(St-BA)/SWNTs composite, indicating strong interaction between the polymer and carbon nanotubes. Finally, a mechanism for formation of polymer-encapsulated SWNTs through ULTRASONICally initiated in situ emulsion polymerization was proposed. This study could provide a new way to resolve the problems of the dispersion, stabilization, and compositing of SWNTs with polymer matrix and prepare polymer/SWNTs composites.

آمار یکساله:  

بازدید 41439

دانلود 19766 استناد 0 مرجع 0
نشریه: 

لیزر در پزشکی

اطلاعات دوره: 
  • سال: 

    1390
  • دوره: 

    8
  • شماره: 

    3 (پی در پی 41)
  • صفحات: 

    28-33
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    518
  • دانلود: 

    245
چکیده: 

مقدمه: پاک سازی و شکل دهی کامل فضای کانال ریشه بخش مهمی از درمان های اندودانتیک است که با اعمال مکانیکی و شیمیایی انجام می شود. حذف بافت پالپی، دبری های آلی و غیر آلی، میکروارگانیسم ها و محصولات آن ها با استفاده از وسایل و شستشودهنده های داخل کانال، یکی از اهداف این فاز درمان است. هدف از انجام این مطالعه ارزیابی Ex vivo میزان حذف لایه اسمیر در دو روش Passive ULTRASONIC Irrigation، Laser Activated Irrigation با لیزر Nd:YAG در مقایسه با روش های مرسوم بالینی بود.روش بررسی: این مطالعه بر روی مجموعا 54 دندان قدامی تک کانال مندیبل انجام شد. پس از آماده سازی نمونه ها، آن ها به 3 گروه Conventional Irrigation + Smear Experimental layer، Passive ULTRASONIC Irrigation و Laser Activated Irrigation تقسیم شدند. پس از برش طولی نمونه ها از بعد مزیودیستال، میزان حذف لایه اسمیر به وسیله SEM با بزرگ نمایی 1500 X بررسی شد.یافته ها: میزان حذف لایه اسمیر در یک سوم کرونالی و میانی و آپیکالی کانال در گروه Conventional Irrigation + Smear layer بیشتر از دو گروه دیگر بود.نتیجه کیری: با توجه به حذف بهتر، لایه اسمیر در گروه CI+Smear layer removal به عنوان گروه Gold standard در نظر گرفته می شود و گروه های مذکور نمی توانند جانشینی برای آن محسوب شوند. 

آمار یکساله:  

بازدید 518

دانلود 245 استناد 0 مرجع 0
نویسندگان: 

نشریه: 

PROCEDIA ENGINEERING

اطلاعات دوره: 
  • سال: 

    2017
  • دوره: 

    170
  • شماره: 

    -
  • صفحات: 

    55-59
تعامل: 
  • استنادات: 

    383
  • بازدید: 

    6405
  • دانلود: 

    15214
کلیدواژه: 
چکیده: 

آمار یکساله:  

بازدید 6405

دانلود 15214 استناد 383 مرجع 0
نویسندگان: 

Sharifi Z. | Asgari G. | Seid mohammadi A.

اطلاعات دوره: 
  • سال: 

    2020
  • دوره: 

    33
  • شماره: 

    6 (TRANSACTIONS C: Aspects)
  • صفحات: 

    1060-1069
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    24100
  • دانلود: 

    9624
چکیده: 

In this study, nanoscale zero-valent copper (nZVC) as catalyst activated persulfate (PS) was used for the degradation of p-chlorophenol (p-CP) under ULTRASONIC (US) IRRADIATION in aqueous solution. The effect of different operational parameters such as solution pH (3. 5-10. 5), PS concentration (1-7. 5 mm/L), nZVC dosage (5-35 mg/L) and initial p-CP concentration (10-100 mg/L) were evaluated at different contact time. Results indicated that US/PS/nZVC system achieve higher efficiency in p-CP degradation than US/PS, US/nZVC and PS/nZVC systems. The optimal p-CP removal efficiency (98%) was achieved within 40 min with 5 mm/L PS and 30mg/L nanocatalyst at 25 mg/L initial p-CP concentration. It was also observed that the p-CP degradation rate depends on initial p-CP concentrations. To clarify the mineralization of p-CP, TOC and COD were analyzed at optimum conditions. COD and TOC removal rate obtained from the US/PS/nZVC system with contact time of 60 min were 61and 75%, respectively. Through the use of methanol (MA) and tert-butyl alcohol (TBA) as radical scavengers, SO4° − was identified as the main radical species that are generated during processes. The removal process of p-CP could be described by the pseudo-first-order kinetics. The apparent degradation rate constant (k) was 0. 076 min-1 in US/PS/nZVC system at optimal conditions.

آمار یکساله:  

بازدید 24100

دانلود 9624 استناد 0 مرجع 0
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