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1.
Microb Pathog ; 192: 106690, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38759935

RESUMEN

The soil comprising organic matter, nutrients, serve as substrate for plant growth and various organisms. In areas where there are large plantations, there is a huge leaf litter fall. The leaf litter upon decomposition releases nutrients and helps in nutrient recycling, for which the soil engineers such as earthworms, ants and termites are important key players. In this context, the present study was conducted to assess the characteristics of the vermicast obtained by vermicomposting neem leaf litter in terms of microbial flora, plant growth promoting properties and antagonistic activities of the vermicast against phytopathogens. Vermicomposting of neem leaf litter was done using two epigeic earthworm species Eisenia fetida and Eudrilus eugeniae. The vermicast exhibited antagonistic potential against plant pathogens. Out of the four vermiwash infusions studied, the 75 % formulation reduced the disease incidence against mealybug by 82 % in the tree Neolamarkia cadamba. The result of the study suggests that vermicast made from neem leaf litter may be a potent combination of a biofertilizer and a pesticide.


Asunto(s)
Azadirachta , Fertilizantes , Oligoquetos , Plaguicidas , Hojas de la Planta , Azadirachta/química , Animales , Oligoquetos/microbiología , Hojas de la Planta/microbiología , Plaguicidas/farmacología , Compostaje , Microbiología del Suelo , Suelo/química , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiología
2.
Soft Matter ; 20(6): 1293-1300, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38240121

RESUMEN

In this investigation, we present empirical observations detailing the manifestation of substantial negative capacitance (NC), reaching up to -1 F, within iodine-doped isomeric polythiophene (IPTh-I2). NC observed in our case is not transient but stable enough to be measured for as long as the optimum concentration of the iodine dopant is available. In contrast, undoped isomeric polythiophene (IPTh) manifests a modest positive capacitance ranging from 30 to 60 µF. The concatenation of IPTh-I2 and IPTh in the series results in an augmentation of the total capacitance of the system (∼170 µF), exemplifying a characteristic feature of NC. Conversely, a bilayer configuration consisting of IPTh:IPTh exhibits a reduction in total capacitance by 38%. A notable amplification in the dielectric constant, escalating from 30 in IPTh to approximately 2000 in IPTh-I2, signifies extensive conformational and structural alterations arising from interactions between the doped polymer chain and various iodide species, attributing to the emergence of NC. Furthermore, we document a single-sided p-n junction diode with a low knee voltage (below 0.5 V) as a model device, illustrating the potential of IPTh as a promising material for the design and development of negative capacitance-based field-effect transistors. This research offers avenues for the scientific community to conceive low knee voltage-operating diodes, transistors, supercapacitors, and various other electronic devices based on all-organic semiconductors.

3.
Soft Matter ; 18(3): 535-544, 2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-34919101

RESUMEN

In this manuscript, we report for the first time a new generation microgel synthesis without using any divinyl functionalized cross-linker. A new generation less crosslinked microgel structure has been achieved by optimizing the amount of N-hydroxy methyl acrylamide (NHMA) and using a fixed amount of styrene (St), acrylic acid (AA) and N-vinyl pyrrolidone (NVP) via a free radical emulsion solution polymerization technique. Poly(NHMA) works as a hydrophilic as well as a crosslinking agent. Furthermore, microgels have been upgraded into a composite by incorporation of Ag nanoparticles for catalytic reduction applications. Microgels and their composites have been characterized by EDAX, FT-IR, particle size analyzer, SEM, TEM, TGA, UV-vis spectroscopy and XRD. Methylene blue (MB) dye and p-nitrophenol (PNP) were chosen as model hazardous pollutants for catalytic reduction applications. Microgels efficiently adsorb both pollutants over the surface and microgel_Ag composites dramatically reduced both pollutants in the non-toxic form at room temperature by using smaller doses of NaBH4.

4.
Soft Matter ; 17(42): 9697-9707, 2021 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-34642719

RESUMEN

Herein we have reported for the first time a one-pot, one step methodology to synthesize isomeric polythiophene (IPTh) possessing 2,2, 2,4 and 5,4 linkages. The method of polymerization of thiophene to IPTh involved reacting thiophene with DDQ in the presence of concentrated H2SO4 at 40 °C and the polymerization is completed in 10 minutes. The synthesized IPTh was characterized by various spectroscopic and microscopic techniques. The formation of polaron and bipolaron in an iodine doped sample (IPTh-I2) has been confirmed by IR, Raman and UV-Vis spectra. The electrical conductivity of the synthesized IPTh and IPTh-I2 have been studied by impedance spectroscopy and found to be ∼10-5 and 10-3 S cm-1 respectively. IPTh exhibits an excellent thermal stability up to 150 °C, and low optical band gap of 3.49 eV suitable for photovoltaic applications. The weight average molecular weight of IPTh has been found to be 18.636 kDa, and it has a better post functionalization capability and hence wider scope than polythiophene (PTh).

5.
Lett Appl Microbiol ; 73(4): 506-514, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34089202

RESUMEN

Cervicitis is predominantly caused by Neisseria gonorrhoeae and Chlamydia trachomatis, which accounts for almost half of all the cases of cervicitis. The role of newer organisms like Mycoplasma genitalium and Ureaplasma sp. and association of bacterial load with cervicitis are also not well established. So the study aimed to determine the relative frequency of these organisms and their load in association with cervicitis cases from north India. A case-control study involving 300 women was conducted using quantitative real-time PCR from endocervical swabs for identification of organisms and quantification of bacterial load. Among 150 cervicitis cases, C. trachomatis, N. gonorrhoeae, M. genitalium and Ureaplasma parvum were detected in 5 (3·3%), 10 (6·6%), 37(24·6%) and 47 (31·3%) respectively. Old age (<0·001, chi-squared test) and irregular menstrual cycles (<0·001, chi-squared test) were significantly associated with cervicitis. M genitalium was the only organism to be associated significantly with cervicitis with regard to age (<0·031) and symptoms like discharge (P < 0·033, chi-squared test) and dysuria (P < 0·044, chi-squared test) in multivariate analysis. Our finding suggests that the bacterial load of these organisms is not significantly associated with cervicitis. However, we found significant association of M. genitalium infection with clinical characteristics of cervicitis cases.


Asunto(s)
Infecciones por Mycoplasma , Mycoplasma genitalium , Cervicitis Uterina , Estudios de Casos y Controles , Chlamydia trachomatis/genética , Femenino , Humanos , Infecciones por Mycoplasma/epidemiología , Mycoplasma genitalium/genética , Neisseria gonorrhoeae , Ureaplasma , Ureaplasma urealyticum , Cervicitis Uterina/epidemiología
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 232: 118153, 2020 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-32086042

RESUMEN

A twisted intramolecular charge transfer (TICT) based probe, dicyanovinyl-9-phenylanthracene (DPA) has been designed and synthesized for the detection of hydrazine (N2H4) with good limit of detection (LOD, 7.85 nM (0.25 ppb)). Upon interaction with hydrazine the terminal electron withdrawing dicyanovinyl function is changed to electron donating amino/hydrazone function. Consequently, the significant change in the photophysical property of the probe is attributed to a change in orientation of charge propagation. The probe with hydrazine shows ratiometric fluorescence "turn-on" response as well as naked-eye sensitive color change in the medium. The surface morphology studies (SEM and TEM) suggested about amorphousness and crystalline nature of the probe DPA and derivative DPA-HDz, respectively. The conducting behavior of the probe decreases upon interaction with hydrazine because of decrease in amorphousness of the matrix and increase in relatively more rigid crystalline structure. Additionally, the probe been utilized to detect hydrazine vapor in solution and on test paper strip with good naked-eye sensitive responses.

7.
Front Pharmacol ; 11: 584770, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33192524

RESUMEN

Alzheimer's disease (AD) is characterized by memory dysfunction, Aß plaques together with phosphorylated tau-associated neurofibrillary tangles. Unfortunately, the present existing drugs for AD only offer mild symptomatic cure and have more side effects. As such, developments of effective, nontoxic drugs are immediately required for AD therapy. Present study demonstrates a novel role of Chinese medicine prescription Yuan-Hu Zhi Tong (YZT) in treating AD, and it has substantiated the in vivo effectiveness of YZT in two different transgenic mice models of AD, namely P301S tau and 3XTg-AD mice. Oral treatment of YZT significantly ameliorates motor dysfunction as well as promotes the clearance of aggregated tau in P301S tau mice. YZT improves the cognitive function and reduces the insoluble tau aggregates in 3XTg-AD mice model. Furthermore, YZT decreases the insoluble AT8 positive neuron load in both P301S tau and 3XTg-AD mice. Using microarray and the "Connectivity Map" analysis, we determined the YZT-induced changes in expression of signaling molecules and revealed the potential mechanism of action of YZT. YZT might regulate ubiquitin proteasomal system for the degradation of tau aggregates. The research results show that YZT is a potential drug candidate for the therapy of tau pathogenesis and memory decline in AD.

8.
J Hosp Infect ; 100(4): e253-e256, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29605188

RESUMEN

Bevacizumab, a recombinant humanized monoclonal antibody to inhibit tumour angiogenesis, is available for off-label use for treating choroidal neovascularization. Outbreaks have been reported after use of this drug, either because of contamination during manufacturing or the practice of multiple doses being administered from a single vial to different patients. In our institute we investigated one endophthalmitis outbreak following intravitreal injection of bevacizumab, rapidly identified the Stenotrophomonas maltophilia as the causative agent, and established the contaminated bevacizumab vial as the source using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF-MS) typing. The study emphasizes the need for early diagnosis of the source and pathogen for appropriate control measures.


Asunto(s)
Brotes de Enfermedades , Contaminación de Medicamentos , Endoftalmitis/epidemiología , Infecciones por Bacterias Gramnegativas/epidemiología , Inyecciones Intravítreas/efectos adversos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Stenotrophomonas maltophilia/aislamiento & purificación , Técnicas Bacteriológicas/métodos , Bevacizumab/administración & dosificación , Estudios de Cohortes , Endoftalmitis/microbiología , Infecciones por Bacterias Gramnegativas/microbiología , Humanos , Factores Inmunológicos/metabolismo , Stenotrophomonas maltophilia/química
9.
Int J Biol Macromol ; 104(Pt A): 1204-1211, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28668614

RESUMEN

The present article reports the application of ß-cyclodextrin grafted polyacrylamides synthesized through solution and microwave assisted polymerization techniques as flocculants and then the employment of partially hydrolyzed products of best grade of each technique in-vitro drug release study of diclofenac sodium. Five different grades of ß-cyclodextrin grafted polyacrylamides by each of solution and microwave assisted polymerization techniques have been synthesized, by varying the monomer concentration. The synthesized polymers have been well characterized and their flocculation performances have been evaluated in kaolin suspension through settling and jar test methods Then the best performing grades of both the techniques have been partially hydrolyzed to prepare three different grades each technique by varying the concentration aqueous NaOH solution. Flocculation efficiencies of these polymers have been investigated in kaolin suspension. Thus best grades of partially hydrolyzed grafted polymers of each technique have been chosen for further study of drug delivery. In-vitro drug release study has been done using diclofenac sodium loaded microbeads prepared by ionic gelation method with two partially hydrolyzed grafted polymers (one from each technique) in phosphate buffer solution (PBS) at 37±0.5 ○C and pH 7.4. The drug load and release have been analyzed by UV-vis spectroscopy.


Asunto(s)
Resinas Acrílicas/química , Resinas Acrílicas/síntesis química , Portadores de Fármacos/química , Liberación de Fármacos , Microondas , Purificación del Agua/métodos , beta-Ciclodextrinas/química , Técnicas de Química Sintética , Diclofenaco/química , Floculación , Hidrólisis , Polimerizacion , Soluciones , Aguas Residuales/química
10.
Carbohydr Polym ; 127: 275-81, 2015 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-25965484

RESUMEN

The synthesis of novel cationic flocculants based on amylopectin (AP), acrylamide (AM) and (3-acrylamidopropyl) trimethylammonium chloride (ATMAC) were done by free radical polymerization using ammonium persulphate (APS) as an initiator. Three different grades of novel cationic flocculants (AP-g-C 1 to AP-g-C 3) were synthesized by varying the proportion of acrylamide and (3-acrylamidopropyl) trimethylammonium chloride monomers. Through the hydrolysis of these flocculants, in presence of NaOH, three different grades of amphoteric polymers (AP-AT-C 1 to AP-AT-C 3) were synthesized. The synthesized polymers were characterized by various methods, namely, infrared spectroscopy, NMR spectroscopy, thermal analysis, viscosity measurement, scanning electron microscopy and X-ray diffractometry. The flocculation performance of AP-g-C and AP-AT-C were studied in kaolin suspension using jar test and settling test methods at neutral pH. Dye (Methylene blue) removal tests were performed using polymer beads and analysed by UV-vis spectroscopy.


Asunto(s)
Acrilamida/química , Amilopectina/química , Polimerizacion , Compuestos de Amonio Cuaternario/química , Sulfato de Amonio/química , Amilopectina/análogos & derivados , Cationes/química , Floculación , Hidrólisis , Hidróxido de Sodio/química
11.
Artículo en Inglés | MEDLINE | ID: mdl-25845576

RESUMEN

The electrocardiogram (ECG) is one of the most significant outputs of a computational model of cardiac electrophysiology because it relates the numerical results to clinical data and is a universal tool for diagnosing heart diseases. One key features of the ECG is the T-wave, which is caused by longitudinal and transmural heterogeneity of the action potential duration (APD). Thus, in order to model a correct wave of repolarization, different cell properties resulting in different APDs must be assigned across the ventricular wall and longitudinally from apex to base. To achieve this requirement, a regional parametrization of the heart is necessary. We propose a robust approach to obtain the transmural and longitudinal segmentation in a general heart geometry without relying on ad hoc procedures. Our approach is based on auxiliary harmonic lifting analyses, already used in the literature to generate myocardial fiber orientations. Specifically, the solution of a sequence of Laplace boundary value problems allows parametrically controlled segmentation of both heart ventricles. The flexibility and simplicity of the proposed method is demonstrated through several representative examples, varying the locations and extents of the epicardial, midwall, and endocardial layers. Effects of the control parameters on the T-wave morphology are illustrated via computed ECGs.


Asunto(s)
Modelos Cardiovasculares , Función Ventricular/fisiología , Potenciales de Acción , Electrocardiografía , Corazón/anatomía & histología , Corazón/fisiología , Humanos
12.
Carbohydr Polym ; 110: 388-95, 2014 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-24906771

RESUMEN

Graft copolymers based on dextran (Dx) and 2-acrylamido-2-methyl-1-propane sulphonic acid (AMPS) were synthesized by free radical initiated solution polymerization technique using ceric ammonium nitrate as initiator. These graft copolymers were used to prepare Cu(II) and Ni(II) chelates by reactions with Cu(II) and Ni(II) metal ions respectively. Graft copolymer and metal chelates were characterized by elemental analysis, intrinsic viscosity, FT-IR, scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA) and powder X-ray diffraction (XRD). Elemental analysis, intrinsic viscosity and FT-IR studies revealed the incorporation of metal ions to form metal chelates. SEM studies showed the change in morphology due to metal incorporation. From AFM studies it was observed that there was increase in Root mean square (RMS) roughness values in case of metal complexes. Metal chelates were observed to be thermally more stable than graft copolymer from TGA. UV-vis spectroscopy study revealed increase in absorbance values and cyclic voltammetric (CV) studies showed more than tenfold increase in redox current due to formation of Cu(II) and Ni(II) metal chelates. The binding constants of each complex determined by using UV-visible spectroscopy revealed that Cu(II) has more binding ability than Ni(II).


Asunto(s)
Acrilamidas/química , Quelantes/química , Cobre/química , Dextranos/química , Níquel/química , Ácidos Sulfónicos/química , Acrilamidas/síntesis química , Quelantes/síntesis química , Dextranos/síntesis química , Técnicas Electroquímicas , Metilación , Espectroscopía Infrarroja por Transformada de Fourier , Ácidos Sulfónicos/síntesis química , Viscosidad , Difracción de Rayos X
13.
Carbohydr Polym ; 95(1): 295-8, 2013 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-23618272

RESUMEN

Triprop-2-ynyl benzene-1,3,5-tricarboxylate (A) is synthesized by the reaction of 1,3,5-benzenetricarbonyl trichloride with propargyl alcohol and (A) is clicked with mono-6-deoxy-6-azido-ß-cyclodextrin (N3-ß-CD) in the presence of copper(I) bromide catalyst. N3-ß-CD has been prepared from ß-cyclodextrin (ß-CD) on treatment with toluenesulfonyl chloride (TsCl) and then with sodium azide (NaN3) in two consecutive steps. Further trimer of ß-CD is characterized by (1)H NMR and FTIR studies. Solubility of ß-cyclodextrin (ß-CD) in water can be increased by increasing the number of alcoholic OH functionalities and hydrophobic cavities in a molecule by the trimerization of ß-CD.


Asunto(s)
Ácidos Tricarboxílicos/química , beta-Ciclodextrinas/química , Química Clic , Espectroscopía de Resonancia Magnética , Espectroscopía Infrarroja por Transformada de Fourier
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