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101.
Abdul Wajid Khan Saleem Jan Shaista Parveen Rahmat Ali Khan Asma Saeed Abdul Jabbar Tanveer Anwar Ali Shad 《Chemistry Central journal》2012,6(1):1-6
Background
Nickel ferrite, a kind of soft magnetic materials is one of the most attracting class of materials due to its interesting and important properties and has many technical applications, such as in catalysis, sensors and so on. In this paper the synthesis of NiFe2O4 nanoparticles by the hydrothermal method is reported and the inhibition of surfactant (Glycerol or Sodium dodecyl sulfate) on the particles growth is investigated.Methods
For investigation of the inhibition effect of surfactant on NiFe2O4 particles growth, the samples were prepared in presence of Glycerol and Sodium dodecyl sulfate. The X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM) and inductively coupled plasma atomic emission spectrometer (ICP-AES) techniques were used to characterize the samples.Results
The results of XRD and ICP-AES show that the products were pure NiFe2O4 and also nanoparticles grow with increasing the temperature, while surfactant prevents the particle growth under the same condition. The average particle size was determined from the Scherrer's equation and TEM micrographs and found to be in the range of 50-60 nm that decreased up to 10-15 nm in presence of surfactant. The FT-IR results show two absorption bands near to 603 and 490 cm-1 for the tetrahedral and octahedral sites respectively. Furthermore, the saturated magnetization and coercivity of NiFe2O4 nanoparticles were in the range of 39.60 emu/g and 15.67 Qe that decreased for samples prepared in presence of surfactant. As well as, the nanoparticles exhibited a superparamagnetic behavior at room temperature.Conclusions
Nanosized nickel ferrite particles were synthesized with and without surfactant assisted hydrothermal methods. The results show that with increasing of temperature, the crystallinity of nanoparticles is increased. In the presence of surfactants, the crystallinity of NiFe2O4 nanoparticles decreased in comparison with surfactant- free prepared samples. All of the nickel ferrite nanoparticles were superparamagnetic at room temperature.Graphical abstract
相似文献102.
Rakesh K. Sindhu Rishu Verma Twinkle Salgotra Md. Habibur Rahman Muddaser Shah Rokeya Akter Waheed Murad Sidra Mubin Parveen Bibi Safaa Qusti Eida M. Alshammari Gaber El-Saber Batiha Micha Tomczyk Hayder M. Al-kuraishy 《Molecules (Basel, Switzerland)》2021,26(17)
Breast cancer persists as a diffuse source of cancer despite persistent detection and treatment. Flavonoids, a type of polyphenol, appear to be a productive option in the treatment of breast cancer, because of their capacity to regulate the tumor related functions of class of compounds. Plant polyphenols are flavonoids that appear to exhibit properties which are beneficial for breast cancer therapy. Numerous epidemiologic studies have been performed on the dynamic effect of plant polyphenols in the prevention of breast cancer. There are also subclasses of flavonoids that have antioxidant and anticarcinogenic activity. These can regulate the scavenging activity of reactive oxygen species (ROS) which help in cell cycle arrest and suppress the uncontrolled division of cancer cells. Numerous studies have also been performed at the population level, one of which reported a connection between cancer risk and intake of dietary flavonoids. Breast cancer appears to show intertumoral heterogeneity with estrogen receptor positive and negative cells. This review describes breast cancer, its various factors, and the function of flavonoids in the prevention and treatment of breast cancer, namely, how flavonoids and their subtypes are used in treatment. This review proposes that cancer risk can be reduced, and that cancer can be even cured by improving dietary intake. A large number of studies also suggested that the intake of fruit and vegetables is associated with reduced breast cancer and paper also includes the role and the use of nanodelivery of flavonoids in the healing of breast cancer. In addition, the therapeutic potential of orally administered phyto-bioactive compounds (PBCs) is narrowed because of poor stability and oral bioavailability of compounds in the gastrointestinal tract (GIT), and solubility also affects bioavailability. In recent years, creative nanotechnology-based approaches have been advised to enhance the activity of PBCs. Nanotechnology also offers the potential to become aware of disease at earlier stages, such as the detection of hidden or unconcealed metastasis colonies in patients diagnosed with lung, colon, prostate, ovarian, and breast cancer. However, nanoformulation-related effects and safety must not be overlooked. This review gives a brief discussion of nanoformulations and the effect of nanotechnology on herbal drugs. 相似文献
103.
Shaista Zeb A. Qayyum Mehboob Sadiq M. Shafiq A. Waheed M. Zakaullah 《Plasma Chemistry and Plasma Processing》2007,27(2):127-139
This paper reports the deposition of diamond-like carbon (DLC) films on Si <100>, using a low energy (1.45 kJ) dense plasma
focus assisted sputtering of graphite insert at the tip of the tapered anode. The substrates are placed in front of the anode
at different axial and angular positions and are exposed to multiple focus shots. The information regarding the DLC structure
is acquired by using Raman spectroscopy. The spectra are characterized by two broad bands known as “G-band” and “D-band”.
The results point towards the formation of DLC films with both sp3 (diamond like) and sp2 (graphite like) domains. In X-ray diffraction (XRD) pattern, no additional peak is observed except a peak at 2θ = 69° which corresponds to the silicon (Si) substrate. The intensity of Si peak is reduced after treatment indicating the
deposition of amorphous carbon. Scanning electron microscopy (SEM) results demonstrate that the smoothness of the film increases
with increasing the substrate angular positions with respect to the anode axis. Energy dispersive X-ray (EDX) analysis reveals
that the films deposited at lower axial and angular positions are thicker which is complemented by the cross-sectional views
of the films. 相似文献
104.
Dr. Mohd Waheed Dr. Meshari A. Alsharif Dr. Mohammed Issa Alahmdi Dr. Sayeed Mukhtar Dr. Humaira Parveen 《European journal of organic chemistry》2023,26(14):e202300136
An efficient, environmentally benign and one-pot approach for the synthesis of 2-arylimino-2H-chromenes from 2-hydroxybenzyl alcohols and β-ketothioamides at room temperature under visible light has been developed. The reported reaction conditions were favorable for a wide range of β-ketothioamides afforded good to excellent yields of the respective products. The low cost and air stable Knölker iron catalyst has been employed for the dehydrogenation of 2-hydroxybenzyl alcohols under photolysis that would usually require a higher temperature. 相似文献
105.
Elena Michel Fabian F. Grieser Alexandra V. Mackenroth Michael Schukin Petra Krämer Shaista Tahir Dr. Frank Rominger Dr. Matthias Rudolph Prof. Dr. A. Stephen K. Hashmi 《Angewandte Chemie (International ed. in English)》2023,62(42):e202309274
The chemistry of alkynyl triazenes is an emerging field for organic chemists and especially acid-induced nucleophilic functionalizations, either directly, or after a prior reaction towards aromatic triazenes under extrusion of nitrogen, paved the way for fruitful strategies. In contrast, the chemical behavior of alkynyl triazenes upon irradiation with light is still unknown. Herein we present the first photoactivation of alkynyl triazenes that triggers an uncommon reactivity pattern involving the cleavage of the N1−N2 bond of the triazene moiety resulting in a unique approach to cyanocarbenes from a readily available, stable, and insensitive precursor. This allows to access various nitrile compounds without the use of a toxic cyanating agent by exploiting the reactivity pattern of carbenes. By variation of the reaction conditions and light sources, different substitution patterns can be obtained selectively in good yields under mild and metal-free conditions, thus introducing the alkynyl triazene unit as a photo accessible methylene nitrile synthon. Using this synthon, subclasses like α-alkoxynitriles, α-aminonitriles and α-cyanohydrazones become easily available. These exhibit synthetically valuable substitution patterns for the synthesis of pharmaceuticals, intermediates for total synthesis and amino acid synthesis. 相似文献
106.
Khan Ihtisham Wali Naeem Abdul Farooq Muhammad Mahmood Tahira Saeed Tooba Parveen Fouzia Malik Tabassum 《Catalysis Surveys from Asia》2022,26(3):144-160
Catalysis Surveys from Asia - The over-consumption of petroleum fuel due to the progressive increase in population, transportation, industrialization, modernization as well as improvement in the... 相似文献
107.
Shaista S. Khokhar Thomas Wirth 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4):1087-1098
Abstract Chiral selenium electrophiles can be employed in cyclization reactions for the stereoselective synthesis of different heterocyclic compounds which are of great interest. 1 The effect of counterions in selenenylations and the interactions of selenium electrophiles with nearby heteroatoms have been reported earlier, but these observations do not yet give a conclusive picture. We recently observed interesting effects of external nucleophiles on the course of selenenylation reactions. To investigate in which way different nucleophiles solvents and counterions affect selenocyclizations, we synthesised alkene 1, which contains two different functional groups, an alcohol group and a carboxylic acid function. Electrophilic 5- exo-cyclization of 1 can lead to either tetrahydrofurans 2 or to lactones 3, depending on the attacking nucleophile (Scheme 1). The relative stereochemistry could not be resolved by NOE due to overlapping signals of 2 and 3, which are both obtained as mixture of cis (2a, 3a) and trans isomers (2b, 3b). An X-ray crystallographic analysis of 3a (E = I) finally allowed an unambiguous assignment. We will discuss the behavior of solvents, interactions of nucleophiles, and counterions with selenium electrophiles, which strongly affect the course of cyclizations.
Control of Selenocyclisations
Published online:
01 February 2007 SCHEME 1 相似文献
108.
Mehtab Parveen Raza Murad Ghalib Mahboob Alam Monika Singh 《Journal of Saudi Chemical Society》2013,17(3):303-305
The phenanthren skeleton, named as Peltophorin was isolated from methanolic extraction of the leaves of Peltophorum vogelianum. The structure was elucidated on the basis of chemical and physical evidence (IR, UV, 1H NMR, 13C NMR) and further confirmed X-ray analysis. 相似文献
109.
Nadia Parveen Rabia Nazir Muhammad Mazhar 《Journal of Thermal Analysis and Calorimetry》2013,111(1):93-99
Tris(bipyridine)nickel(II) chloride (1) and bis(bipyridine)nickel(II) chloride (2) pyrolize at heating rate of 50 °C/min to a maximum of 450 °C for 24 h under an inert atmosphere of flowing argon gas, to yield size-controlled nickel nanoparticles. Thermogravimetric studies of the complexes (1) and (2) and GC–MS analysis of the trapped volatile matter evolved during thermal degradation of the complexes indicate their clean decomposition pathway to zero-valent nickel. Both heating rate and argon gas flow rate affect purity, particle size, and shape of the particles. X-ray powder diffractometry and atomic force microscopy showed the formation of face-centered cubic (fcc) structured nickel particles having particle size in the range of 3.5–5.0 nm. Magnetic susceptibility measurements suggest nickel nanoparticles to be ferromagnetic in nature characterized by particle size–dependent Curie temperature and high coercivity that is comparable to the bulk iron. 相似文献
110.
Shaista PARVEEN Saima KALSOOM Rifhat BIBI Ambreen ASGHAR Abdul HAMEED Waqar AHMED Abbas HASSAN 《Turkish Journal of Chemistry》2020,44(6):1610
The current investigation presents the synthesis, computational molecular-docking and biological activity studies of arylated thiazole coumarins. Aryl substituted thiazolyl coumarin derivatives were synthesized via Suzuki cross-coupling reaction. A detailed reaction condition optimization revealed that the Pd-PEPPSI-IPent precatalyst in only 2 mol% loading resulted in the desired product with high yield. The aim of this study was to examine the antimicrobial behavior of thiazole coumarin derivatives through in vitro and in silico studies. All the compounds showed activity against both antibacterial strains, Staphylococcus aureus and Escherichia coli, except 5d . Similarly, the compounds 5a , 5b , and 5d were found to be active against Trichoderma harzianum. The compound 5d of this series was found to have a higher activity with MIC 125 mg/ml against Trichoderma harzianum. Molecular studies showed the high activities of these compounds are due to the presence of strong H-bonding and π-π interaction with their respective targets. A good correlation was observed between computational and in vitro studies. 相似文献