Biofabrication of Ag nanoparticles using Moringa oleifera leaf extract and their antimicrobial activity

Objective:To formulate a simple rapid procedure for bioreduction of silver nanoparticles using aqueous leaves extract of Moringa oleifera(M.oleifera).Methods:10 mL of leaf extract was mixed to 90 mL of 1 mM aqueous of AgNO_3 and was heated at 60-80 ℃ for 20 min.A change from brown to reddish color was observed.Characterization using UV-Vis spectrophotometry, Transmission Electron Microscopy(TEM) was performed.Results:TEM showed the formation of silver nanoparticles with an average size of 57 nm.Conclusions:M.oleifera demonstrates strong potential for synthesis of silver nanoparticles by rapid reduction of silver ions(Ag^+ to Ag^0). Biological methods are good competents for the chemical procedures,which are eco-friendly and convenient.

Antimicrobial and antiproliferative prospective of kosinostatin-a secondary metabolite isolated from Streptomyces sp.

Cancer is a communal health hazard worldwide. The present investigation attempts to evaluate anti- microbial and anticancer potential of kosinostatin on mammary carcinoma cell line （MCF-7）. The anticancer and antiproliferative activities of kosinostatin were analyzed on MCF cell line by MTT assay and cytotoxicity assays like lactate dehydrogenase （LDH） and glutathione （GSH）. The secondary metabolite kosinostatin exhibited its apoptotic nature by expressing p53 protein. Collectively, the results acquired from this study promise that kosinostatin shows the potent anticancer activity.

Discrete Time-Frequency Signal Analysis and Processing Techniques for Non-Stationary Signals

This paper presents the methodology, properties and processing of the time-frequency techniques for non-stationary signals, which are frequently used in biomedical, communication and image processing fields. Two classes of time-frequency analysis techniques are chosen for this study. One is short-time Fourier Transform (STFT) technique from linear time-frequency analysis and the other is the Wigner-Ville Distribution (WVD) from Quadratic time-frequency analysis technique. Algorithms for both these techniques are developed and implemented on non-stationary signals for spectrum analysis. The results of this study revealed that the WVD and its classes are most suitable for time-frequency analysis.

Synthesis and Evaluation of Antituberculosis Activity of Substituted 2,7-Dimethylimidazo [1,2-a]Pyridine-3-Carboxamide Derivatives

A series of substituted 2,7-dimethylimidazo[1,2-a]pyridine-3-carboxamides derivatives 5a-5m were synthesized through multi-step reactions. To achieve the synthesis of the desired compounds monobromo and dibromo substituted 2-amino-γ-picoline was reacted with ethyl 2-chloroacetoacetate. The crude ethyl ester subjected to hydrolysis in presence of lithium hydroxide to get 2a and 2b, with imidazo[1,2-a]pyri- dine-3-carboxylic acid to get 3a-3b, on treatment with substituted amines 4a-4g to get desired product 5a-5m in presence of EDCI and HOBt. The substituted imidazo[1,2-a]pyridine-3-carboxamides are characterized by FTIR, 1H-NMR, 13C-NMR and mass spectra. These newly synthesized compounds were tested in vitro for their antimycobacterial activity. The preliminary results of antituberculosis study showed that most of the synthesized compounds 5a-5m demonstrated moderate to good antituberculosis activity. Among the tested compounds 5b, 5d and 5e were found to be the most active with minimum inhibitory concentration (MIC) of 12.5 μg/mL against Mycobacterium tuberculosis (H37 RV strain) ATCC No-27294.

In silico prediction of monovalent and chimeric tetravalent vaccines for prevention and treatment of dengue fever

Reverse vaccinology method was used to predict the monovalent peptide vaccine candidate to produce antibodies for therapeutic purpose and to predict tetravalent vaccine candidate to act as a common vaccine to cover all the dengue virus serotypes. Envelope（E）-proteins of DENV-1-4 serotypes were used for vaccine prediction using NCBI,Uniprot/Swissprot, Swiss-prot viewer, VaxiJen V2.0, TMHMM, BCPREDS, Propred-1, Propred and MHC Pred. Eproteins of DENV-1-4 serotypes were identified as antigen from which T cell epitopes, through B cell epitopes, were predicted to act as peptide vaccine candidates. Each selected T cell epitope of E-protein was confirmed to act as vaccine and to induce complementary antibody against particular serotype of dengue virus. Chimeric tetravalent vaccine was formed by the conjugation of four vaccines, each from four dengue serotypes to act as a common vaccine candidate for all the four dengue serotypes. It can be justifiably concluded that the monovalent 9-mer T cell epitope for each DENV serotype can be used to produce specific antibody against dengue virus and a chimeric common tetravalent vaccine candidate to yield a comparative vaccine to cover any of the four dengue virus serotype. This vaccine is expected to be highly immunogenic against dengue fever.

Hypoglycemic effect of Brassica juncea(seeds) on streptozotocin induced diabetic male albino rat

Objective:To evaluate the hypoglycemic effect of Brassica juncea(seeds) on streptozotocin induced diabetic male albino rats.Methods:Hypoglycemic activity of Brassica juncea(seeds)aqueous extract at a dose of 250,350 and 450 mg/kg body weight was evaluated.Adult male Swiss albino rats of six numbers in each group was undertaken for study and evaluated.Results:The serum insulin levels were recorded a significant depletion in all groups,short term as well as long term diabetic animals,when compared to that of normal animals.A significant dosage dependent augmenting effect of the seed extract on the serum insulin was recorded in both short term as well as long term groups.Conclusions:The aqueous seed extract of Brassica juncea has potent hypoglycemic activity in male albino rat.

Antibacterial activity of various leaf extracts of Merremia emarginata

Objective:To investigate the antibacterial activity and phytochemical screening of the aqueous.methanol and petroleum ether leaf extracts of Merremia emarginata(M.emarginata).Methods:The antibavterial activity of leaf extracts of M.emarginata were evaluated by agar well diffusion method against four selected bacterial species.Results:The presence of tannins,flavonoids,amino acids,starch,glycosides and carbohydrates in the different leaf extracts was established.The methanol extract was more effective against Baciilus cereus and Eseherkhia coli,whereas aqueous extract was more effective against Staphylococcus aureus and Pseudomonas aeruginosa.Condusions:The results in the present study suggest that M.emarginata leaf can be used in treating diseases caused by the tested organisms.

Catharanthus roseus:a natural source for the synthesis of silver nanoparticles

Objective:To develop a simple rapid procedure for bioreduction of silver nanoparticles(AgNPs)using aqueous leaves extracts of Catharanthus roseus(C.roseus).Methods:Characterization were determined by using UV-Vis spectrophotometry,scanning electron microscopy(SEM),energy dispersive X-ray and X-ray diffraction.Results:SEM showed the formation of silver nanoparticles with an average size of 67 nm to 48 nm.X-ray diffraction analysis showed that the particles were crystalline in nature with face centered cubic geometry.Conclusions:C.roseus demonstrates strong potential for synthesis of silver nanoparticles by rapid reduction of silver ions(Ag^+ to Ag^0).This study provides evidence for developing large scale commercial production of value-added products for biomedical/nanotechnology-based industries.

非晶态金属-磷酸铝催化正庚醛和苯甲醛羟醛缩合制茉莉醛(英文)

Amorphous aluminophosphate(AlP) and metal-aluminophosphates(MAlPs, where M = 2.5 mol%Cu, Zn, Cr, Fe, Ce, or Zr) were prepared by coprecipitation method. Their surface properties and catalytic activity for the synthesis of jasminaldehyde through the aldol condensation of nheptanal and benzaldehyde were investigated. The nitrogen adsorption-desorption isotherms showed that the microporosity exhibited by the aluminophosphate was changed to a mesoporous and macroporous structure which depended on the metal incorporated, with a concomitant change in the surface area. Temperature-programmed desorption of NHand COrevealed that the materials possessed both acidic and basic sites. The acidic strength of the material was either increased or decreased depending on the nature of the metal. The basicity was increased compared to AlP. All the materials were X-ray amorphous and powder X-ray diffraction studies indicated the absence of metal oxide phases. The Fourier transform infrared analysis confirmed the presence of phosphate groups and also the absence of any M-O moieties in the materials. The selected organic reaction occurred only in the presence of the AlP and MAlPs. The selectivity for the jasminaldehyde product was up to 75% with a yield of 65%. The best conversion of nheptanal with a high selectivity to jasminaldehyde was obtained with FeAlP as the catalyst, and this material was characterized to have less weak acid sites and more basic sites.

Solution for fractional potential KdV and Benjamin equations using the novel technique

In this paper,we find the solutions for fractional potential Korteweg-de Vries(p-KdV)and Benjamin equations using q-homotopy analysis transform method(q-HATM).The considered method is the mixture of q-homotopy analysis method and Laplace transform,and the Caputo fractional operator is considered in the present investigation.The projected solution procedure manipulates and controls the obtained results in a large admissible domain.Further,it offers a simple algorithm to adjust the convergence province of the obtained solution.To validate the q-HATM is accurate and reliable,the numerical simulations have been conducted for both equations and the outcomes are revealed through the plots and tables.Comparison between the obtained solutions with the exact solutions exhibits that,the considered method is efficient and effective in solving nonlinear problems associated with science and technology.

Synthesis and characterization of organomodified Na-MMT using cation and anion surfactants

The Sodium Montmorillonite(Na-MMT)is not susceptible to polymer due to its organophilic character and low basal spacing.The primary objective of this study was to improve Na-MMT platelets separation by organically modifying it with cation and anion exchanges using Cetyl trimethyl ammonium bromide(CTAB)and Sodium dodecyl sulfate(SDS)respectively.Basal spacing,presence of functional groups,Zetapotential with particle size analysis and thermal stability of the Organomodified Na-MMT(OMMT)were characterized using XRD,FTIR,zeta-potential analyzer and TGA respectively.The basal spacing of CTAB modified OMMTincreased to 19.5Åfrom 11.0Åwhich corresponds to the basal spacing of Na-MMT.The SDS modified OMMT did not show any increase in the basal spacing.FTIR spectra of CTAB modified Na-MMT illustrated the attachment of CTAB functional groups to Na-MMT,while the same was absent in the case of SDS modified Na-MMT.The zeta-potential of Na-MMT shifted from–24.88 mV to 15.66 mV in the case of CTAB modified Na-MMTand 12.49 mV for SDS modified Na-MMT,indicating a greater surface potential of the modified nanoclay.The TGA showed greater weight loss for CTAB modified Na-MMT than that for Na-MMT,indicating the effective Na+ion exchange with alkyl amines.

Biosorption of heavy metals from aqueous solution by Gracilaria corticata varcartecala and Grateloupia lithophila

Objective:To study the biosorption of heavy metals viz.,Cr(VI),Cr(III),Hg(II),Pb(II)and Cd(II)using Gracilaria corticata varcartecala(G.corticata varcartecala)and Grateloupia lithophila(G.lithophila)biomass.Methods:Batch biosorption and acid digestion methods were used.Different physical and chemical parameters were optimized for biosorption.Results:Both seaweeds absorb Hg(II)upto 99.9%and 98.2%in batch biosorption method;whereas in acid digestion method,Cr(III)absorbed upto 96.49%by G.corticata varcartecala and Pb(II)absorbed upto 93.71%by G.lithophila.FT-IR analysis was used to know the involvement of different functional groups in the biosorption process.Scanning electron microscopy was carried out to study the morphological cell surface changes due to biosorption.Conclusions:It can be concluded that G.corticata varcartecala and G.lithophila are potential algal species for effective removal of heavy metals namely Cr(VI),Cr(III),Hg(II),Pb(II)and Cd(II)from environmental sources.

Geographic variation in cypermethrin insecticide resistance and morphometry in Spodoptera litura(Fabricius)(Lepidoptera:Noctuidae)

Objective:To find out the most resistant strain of Spodoptera litura(S.litura)from Tamil Nadu,Kerala and Karnataka by synthetic insecticide treatment.Methods:Using leaf disc no-choice method,the insects were tested with different doses for pesticides.The LC_(50)and LC_(90)values were calculated by probit analysis.Results:In the insect bioassay,the cypermethrin insecticide showed significantly higher LC_(50)values of 14.699 g/L and 15.738 g/L against the Tamil Nadu and Kerala S.litura insect cultures respectively.The body length of 2nd,3rd and 4th instar larvae were significantly higher(P≤0.05)in TTP insect population[(19.2±2.3)mm,(28.05±3.20)mm,(36.1±2.0)mm],when compared with KTK[(18.5±2.7)mm,(23.38±2.00)mm,(31.75±2.70)mm]and control,KBB[(15.65±2.30)mm,(23.65±2.70)mm,(33.2±2.2)mm]populations.The body breadth of 3rd instar larvae was significantly higher(P≤0.05)in TTP insect population(4.9±1.1)mm,when compared with KTK(3.93±0.80)mm and control,KBB(3.65±0.70)mm populations.Conclusions:The present study clearly showed that field collected strains were highly resistant when compared to control.Based on our study,we conclude that reduced use of synthetic pesticides is necessary and IPM is a better way to reduce the development of pesticide resistance among strains of S.litura.

Effect of Thickness of SnO_2:F over Layer on Certain Physical Properties of ZnO:Al Thin Films for Opto-electronic Applications

Bilayered FTO/AZO （fluorine doped tin oxide/aluminium doped zinc oxide） films were fabricated using a simple, cost effective spray pyrolysis technique. X-ray diffraction （XRD） profiles of bilayered films showed that in the case of lower thickness FTO over layers, （002） plane of ZnO phase had the highest intensity, whereas the predominance was changed in favour of （200） plane of SnO2 phase for higher thickness FTO over layer. UV studies showed that bilayered FTO/AZO films exhibited a sharp absorption edge as that of AZO film. The decrease in the photoluminescence （PL） peak at 420 nm with increasing FTO over layer thickness indicated a reduction in the zinc vacancies which caused a reduction in the sheet resistance （Rsh）. Electrical studies revealed that, eventhough the Rsh value （916Ω/□） of bilayered FTO （313 nm）/AZO （314 nm） film was found to be higher than that of FTO single layer film （72Ω/□）, it was much lower than that of AZO single layer film （5661Ω/□））. The atomic force microscopy （AFM） images reflect the characteristic features of both zinc oxide and tin oxide films.

A facile access for the synthesis of some C-2 substituted imidazopyrazines by utilizing the palladium catalyzed Suzuki cross-coupling reaction under microwave irradiation

A rapid, efficient, and facile synthesis of an assortment of C-2 substituted imidazopyrazines has been achieved by utilizing the palladium catalyzed Suzuki cross-coupling of 2-bromo-1H-imidazo[4,5-b]pyrazine with various boronic acids under microwave irradiation. The utilization of（A-^（ta）phos）_2PdCl_2 as a catalyst in combination with Cs F as base and DME-H_2O（4：1） as the solvent system at 100℃ procured the diaryls in acceptable to excellent yields. Prominent features of this developed methodology include short reaction times, fewer side products, and exceptional tolerance to a wide variety of functional groups.

Anti-diabetic effect of methanolic leaf extract of Pongamia pinnata on streptozotocin induced diabetic rats

Objective:To study the anti-diabetic effect of methanolic leaf extract of Pongamia pinnata(P.pinnata)on streptozotocin induced diabetic rats.Methods:Anti-diabetic activity of P.pinnata leaf extract at dosage of 500 mg/kg and 1 g/kg body weight was evaluated.Results:The levels of glucose,triglycerides,total cholesterol and serum glutamic pyruvic transaminase were significantly increased in streptozotocin induced diabetic rats when compared to that of the normal rats.After supplemented with plant extract,significant lower blood glucose level was recorded.Conclusions:The methanolic leaf extract of P.pinnata has been potent anti-diabetic effect in male albino rats.