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2.
J Environ Manage ; 266: 110572, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32392138

RESUMO

On considering the critical issues in attaining stringent water quality standards and not creating any environmental impacts, we focused for the first time the economically feasible, emerging technology known as Self-assembly flocculating (Saf process). In which, the study investigated the applicability of bioflocculant (a biopolymer-self-assembly in nature) act as a surrogates on relying the removal of broad spectrum of substances under optimized conditions (Dosage: 90 mg/L; pH: 7; CaCl2). On using different techniques, the results have proved in removing the organic matter such as pharmaceuticals (Gentamycin, Cholecalciferol, Fluvoxamine, 3-OH Desogestrel, and Pheniramine), endocrine disturbing compounds [Phthalic acid, Benzene, 1, 2, 4 -Trimethoxy-5-(1-Propenyl)-, Benzene, 1, 2-Dimethoxy-4-(2-Propenyl)-, 1, 2-Benzenedicarboxylic Acid, 3-Cyclohexen-1-ol], fluorescent components (Polysaccharide like material), and others. The toxicological assessment of self-assembly bioflocculant implemented on zebra fish were statistically correlated [r = 0.95, p < 0.01 and 0.05 for P1WW; r = 0.91, p < 0.01 and 0.05 for P2WW] and [r = 0.7 5, p < 0.05 for P1WT; r = 0.095, p < 0.01 and 0.05 for P2WT]. This integrated approach supplemented further information of zeta potential (-16 mV in P1WW and -14.6 mV in P2WW decreased to -1.05 mV and -1.56 mV) with particle size distribution to explain via Saf process. In this research, the new insight has established non-toxic, self-assembly, biodegradable, bioflocculant for effective bioremediation.


Assuntos
Corantes , Águas Residuárias , Animais , Biodegradação Ambiental , Biopolímeros , Floculação
3.
Environ Monit Assess ; 192(6): 377, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424801

RESUMO

Dissolved organic matter (DOM) especially anthropogenic compounds in sewage systems affects their ultimate fate in the environment which is challenging to ascertain the heterogenic nature of the compound and causes co-occurring effects in most aquatic samples. So, our study have focused on current approaches to the chemical and structural characterization of DOM with the detailed classification of individual compounds such as the molecular levels of volatile organic, inorganic materials, drugs and endocrine disrupting compounds. Analytical techniques for example high performance gas chromatography-mass spectrometry (GCMS) with high-resolution liquid chromatography (HR-LCMS), X-ray diffraction (XRD) and three-dimensional fluorescence excitation emission matrix (3D-EEM) has resulted in advancing the parametric studies. In addition, the toxicological assessment of an aquatic organism (zebrafish as a model) has ensued in enlightening the risk of contaminated sources. The result of the research highlighted the efficacy of high-throughput approaches to assess the environmental impact of sewage water.


Assuntos
Monitoramento Ambiental , Esgotos , Poluentes Químicos da Água , Água , Compostos Orgânicos/análise , Esgotos/química , Espectrometria de Fluorescência , Água/química , Poluentes Químicos da Água/análise
4.
J Environ Manage ; 258: 110000, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31929048

RESUMO

Bioflocculant has been recently exploited in various research activities. In this research, we report for the first time that a novel bioflocculant can self-assemble into nanoparticles with an irregular structure in solution. Bioflocculant has been developed from novel consortium encompassing Enterococcus faecalis, Proteus mirabilis, Lysini bacillus sp., inoculated into the modified medium such as hydrolyzed wheat bran and rice bran extract. Characterization of bioflocculant shows that it is made up of mannose, fructose, raffinose, and galactose with a slightly negative charges. They are further characterized by FTIR and XPS. 3D-EEM and MALDITOF-MS are confirmed the proteoglycan nature of the bioflocculant. These bioflocculant not only exhibits greater biosorption of heavy metals by self-flocculating (or) self-aggregating activity, but also possesses mosquitocidal and anti-biofilm activity due to its cell surface modification. Further research have to be carried out regarding the mechanism of self-assembly nature of bioflocculant into nanoparticle in solution which provide a new path for bioremediation and biomedical application.


Assuntos
Bacillus , Metais Pesados , Biodegradação Ambiental , Floculação , Concentração de Íons de Hidrogênio , Consórcios Microbianos
5.
J Photochem Photobiol B ; 190: 8-20, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30453162

RESUMO

Magnesium oxide (MgO) nanostructures were prepared using microwave-assisted (M 1) and hydrothermal (M 2) methods and characterized by XRD, SEM and FT-IR. It exhibits cubic structure with an average crystallite size of 20 nm (M 1) and 14 nm (M 2) and the lattice strain (WH plot) is 0.0017 (M 1), 0.0037 (M 2). It's spherical and rods like structures are confirmed through SEM and TEM. The vibrational stretching mode of MgO is 439 (M 1) and 449 cm-1 (M 2). The optical bandgap is estimated as 5.93 eV (M 1) and 5.85 eV (M 2) through UV-Vis spectra. The fluorescence spectrum shows emission peaks at 414 and 437 (M 1) and 367 and 385 nm (M 2). The photodegradation studies of MgO nanostructures were assessed by monitoring the decolorization of methylene blue and Congo red dyes in aqueous solution under sunlight irradiation. The antibacterial activities of M 1 and M 2 are investigated against the gram-negative (Escherichia coli, Shigella flexneri, Salmonella typhi, Proteus mirabilis, Aeromonas hydrophila and Vibrio cholera) and gram-positive (Bacillus subtilis and Rhodococcus rhodochrous) bacteria. The zone of inhibition of 24 (M 1) and 25 mm (M 2) indicates high antibacterial activity towards the gram negative bacterium A. hydrophila. Confocal laser scanning microscopic (CLSM) analysis was utilized for understanding the variation in antibacterial activity between different orientations of MgO nanostructures. The cytotoxicity assay confirmed that the prepared nanostructures are non - toxic to normal healthy RBC's. In-vitro anticancer efficiency (IC50) of MgO nanostructures against human lung cancer cell line (A549) was investigated.


Assuntos
Antibacterianos/química , Antineoplásicos/química , Óxido de Magnésio/química , Nanopartículas Metálicas/química , Células A549 , Bactérias/efeitos dos fármacos , Catálise , Corantes , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Fotólise , Análise Espectral
6.
Artif Cells Nanomed Biotechnol ; 46(3): 589-598, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28554257

RESUMO

In the present study, a sustainable green chemistry approach was established to fabricate magnetic Fe3O4 nanoparticles (Fe3O4NPs) using the aqueous fruit extract of edible C. guianensis (CGFE). Synthesized NPs were further confirmed with different high-throughput characterization techniques such as UV-visible spectroscopy, FT-IR, XPS, DLS and zeta potential analysis. Additionally, XRD, AFM, HRTEM and SQUID VSM demonstrate the generation of crystalline CGFe3O4NPs with mean diameter of 17 ± 10 nm. Interestingly, CGFe3O4NPs exhibit a stupendous bactericidal action against different human pathogens which depicts its antimicrobial value. A significant dose-dependent cytotoxic effect of CGFe3O4NPs was noticed against treated human hepatocellular carcinoma cells (HepG2).


Assuntos
Antibacterianos , Carcinoma Hepatocelular/tratamento farmacológico , Citotoxinas , Frutas/química , Lecythidaceae/química , Neoplasias Hepáticas/tratamento farmacológico , Nanopartículas de Magnetita , Extratos Vegetais/química , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Citotoxinas/síntese química , Citotoxinas/química , Citotoxinas/farmacologia , Células Hep G2 , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/uso terapêutico
7.
Protein Sci ; 25(11): 2089-2094, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27538185

RESUMO

DNA nanostructures have become an important and powerful tool for studying protein function over the last 5 years. One of the challenges, though, has been the development of universal methods for patterning protein complexes on DNA nanostructures. Herein, we present a new approach for labeling DNA nanostructures by functionalizing them with a GFP nanobody. We demonstrate the ability to precisely control protein attachment via our nanobody linker using two enzymatic model systems, namely adenylyl cyclase activity and myosin motility. Finally, we test the power of this attachment method by patterning unpurified, endogenously expressed Arp2/3 protein complex from cell lysate. By bridging DNA nanostructures with a fluorescent protein ubiquitous throughout cell and developmental biology and protein biochemistry, this approach significantly streamlines the application of DNA nanostructures as a programmable scaffold in biological studies.


Assuntos
Complexo 2-3 de Proteínas Relacionadas à Actina/química , DNA/química , Proteínas de Fluorescência Verde/química , Nanoestruturas/química , Proteínas Recombinantes de Fusão/química , Anticorpos de Domínio Único/química , Animais , Suínos
8.
Nat Nanotechnol ; 10(8): 696-700, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26149240

RESUMO

The sarcomere of muscle is composed of tens of thousands of myosin motors that self-assemble into thick filaments and interact with surrounding actin-based thin filaments in a dense, near-crystalline hexagonal lattice. Together, these actin-myosin interactions enable large-scale movement and force generation, two primary attributes of muscle. Research on isolated fibres has provided considerable insight into the collective properties of muscle, but how actin-myosin interactions are coordinated in an ensemble remains poorly understood. Here, we show that artificial myosin filaments, engineered using a DNA nanotube scaffold, provide precise control over motor number, type and spacing. Using both dimeric myosin V- and myosin VI-labelled nanotubes, we find that neither myosin density nor spacing has a significant effect on the gliding speed of actin filaments. This observation supports a simple model of myosin ensembles as energy reservoirs that buffer individual stochastic events to bring about smooth, continuous motion. Furthermore, gliding speed increases with cross-bridge compliance, but is limited by Brownian effects. As a first step to reconstituting muscle motility, we demonstrate human ß-cardiac myosin-driven gliding of actin filaments on DNA nanotubes.


Assuntos
Modelos Biológicos , Movimento/fisiologia , Miosinas/química , Miosinas/metabolismo , Nanotubos/química , Actinas/química , Actinas/metabolismo , Bioengenharia , DNA/química , DNA/metabolismo , Humanos , Miosinas/ultraestrutura , Nanotecnologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-25546491

RESUMO

CdO-ZnO nanocomposite was prepared by microwave-assisted method and characterized by X-ray crystallography (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR). It exhibits hexagonal cubic structure with an average crystallite size of 27 nm. From the UV-Vis spectra, the bandgap is estimated as 2.92 eV. The fluorescence spectrum shows a near band edge emission at 422 nm. In addition the antibacterial activity of CdO-ZnO nanocomposite was carried out in-vitro against two kinds of bacteria: gram negative bacteria (G -ve) i.e. Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and gram positive bacteria (G +ve): Staphylococcus aureus, Proteus vulgaris and Bacillus spp. This study indicates the zone of inhibition of 40 mm has high antibacterial activity towards the gram positive bacterium S. aureus.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Compostos de Cádmio/síntese química , Micro-Ondas , Nanocompostos/química , Nanotecnologia/métodos , Óxidos/síntese química , Óxido de Zinco/síntese química , Antibacterianos/síntese química , Compostos de Cádmio/farmacologia , Humanos , Luminescência , Testes de Sensibilidade Microbiana , Nanocompostos/ultraestrutura , Óxidos/farmacologia , Espectrometria por Raios X , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Óxido de Zinco/farmacologia
10.
Mol Biotechnol ; 54(3): 795-802, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23224937

RESUMO

A new cry1Ab gene was cloned from the promising local isolate, DOR Bt-1, a Bacillus thuringiensis strain isolated from castor semilooper (Achaea janata L.) cadavers from castor bean (Ricinus communis L.) field. The nucleotide sequence of the cloned cry1Ab gene indicated that the open reading frame consisted of 3,465 bases encoding a protein of 1,155 amino acid residues with an estimated molecular weight of 130 kDa. Homology comparisons revealed that the deduced amino acid sequence of cry1Ab had a variation of seven amino acid residues compared to those of the known Cry1Ab proteins in the NCBI database and this gene has been designated as cry1Ab26 by the B. thuringiensis δ-endotoxin Nomenclature Committee. cry1Ab26 was cloned into pET 29a(+) vector and expressed in E. coli strain BL21 (DE3) under the control of T7 promoter with IPTG induction. ELISA, SDS-PAGE, and Western blot analysis confirmed the expression of 130-kDa protein. Insect bioassays with neonate larvae of Helicoverpa armigera showed that the partially purified Cry1Ab26 caused 97 % mortality within 5 days of feeding.


Assuntos
Bacillus thuringiensis/genética , Proteínas de Bactérias/genética , Endotoxinas/genética , Proteínas Hemolisinas/genética , Animais , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/farmacologia , Western Blotting , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Endotoxinas/química , Endotoxinas/metabolismo , Endotoxinas/farmacologia , Ensaio de Imunoadsorção Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Hemolisinas/química , Proteínas Hemolisinas/metabolismo , Proteínas Hemolisinas/farmacologia , Larva/efeitos dos fármacos , Mariposas , Controle Biológico de Vetores , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia
11.
Appl Biochem Biotechnol ; 168(6): 1594-607, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22971833

RESUMO

Microsatellites, also known as simple sequence repeats (SSRs), are the class of repetitive DNA sequences present throughout the genome of many plant and animal species. Recent advances in molecular genetics had been the introduction of microsatellite markers to investigate the genetic structuring of natural plant populations. We have employed an enrichment strategy for microsatellite isolation by using multi-enzymes digestion, microsatellite oligoprobes, and streptavidin magnetic beads in Sesamum (Sesamum indicum L.). More than 200 SSR motifs were detected (SSR motifs ≥2 repeat units or 6 bp); 80 % of the clones contained SSR motifs. When regarding SSRs with four or more repeat units and a minimum length of 10 bp, 132 of them showed repeats. Eighteen SSR markers were initially characterized for optimum annealing temperature using a gradient PCR technique. Among the 18 SSR markers characterized, five were found to be polymorphic and used to analyze 60 Sesamum germplasm accessions. The maximum number of alleles detected was four with a single primer and the least number of two alleles with three primers with an average PIC value of 0.77. SSRs are a valuable tool for estimating genetic diversity and analyzing the evolutionary and historical development of cultivars at the genomic level in sesame breeding programs.


Assuntos
DNA de Plantas/genética , Repetições de Microssatélites , Reação em Cadeia da Polimerase/métodos , Sesamum/genética , Variação Genética , Genoma de Planta , Polimorfismo Genético , Sesamum/classificação
12.
Genomics Proteomics Bioinformatics ; 9(3): 104-12, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21802047

RESUMO

Using 16S rDNA gene sequencing technique, three different species of non-symbiotic bacteria of entomopatho-genic nematodes (EPNs) (Steinernema sp. and Heterorhabditis sp.) were isolated and identified from infected insect cadavers {Galleria mellonella larvae) after 48-hour post infections. Sequence similarity analysis revealed that the strains SRK3, SRK4 and SRK5 belong to Ochrobactrum cytisi, Schineria larvae and Ochrobactrum anthropi, respectively. The isolates O. anthropi and S. larvae were found to be associated with Heterorhabditis indica strains BDU-17 and Yer-136, respectively, whereas O. cytisi was associated with Steinernema siamkayai strain BDU-87. Phenotypically, temporal EPN bacteria were fairly related to symbiotic EPN bacteria (Photorhabdus and Xenorhabdus genera). The strains SRK3 and SRK5 were phylogeographically similar to several non-symbionts and contaminated EPN bacteria isolated in Germany (LMG3311T) and China (X-14), while the strain SRK4 was identical to the isolates of S. larvae (Ll/57, Ll/58, Ll/68 and L2/11) from Wohlfahrtia magnifica in Hungary. The result was further confirmed by RNA secondary structure and minimum energy calculations of aligned sequences. This study suggested that the non-symbionts of these nematodes are phylogeographically diverged in some extent due to phase variation. Therefore, these strains are not host-dependent, but environment-specific isolates.


Assuntos
Mariposas/microbiologia , Filogenia , Rabditídios/microbiologia , Animais , Larva/microbiologia , Larva/parasitologia , Dados de Sequência Molecular , Mariposas/crescimento & desenvolvimento , Mariposas/parasitologia , Ochrobactrum/isolamento & purificação , Ochrobactrum anthropi/isolamento & purificação , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Simbiose , Xanthomonadaceae/isolamento & purificação
13.
Theor Appl Genet ; 120(7): 1415-41, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20098978

RESUMO

This study presents the development and mapping of simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers in chickpea. The mapping population is based on an inter-specific cross between domesticated and non-domesticated genotypes of chickpea (Cicer arietinum ICC 4958 x C. reticulatum PI 489777). This same population has been the focus of previous studies, permitting integration of new and legacy genetic markers into a single genetic map. We report a set of 311 novel SSR markers (designated ICCM-ICRISAT chickpea microsatellite), obtained from an SSR-enriched genomic library of ICC 4958. Screening of these SSR markers on a diverse panel of 48 chickpea accessions provided 147 polymorphic markers with 2-21 alleles and polymorphic information content value 0.04-0.92. Fifty-two of these markers were polymorphic between parental genotypes of the inter-specific population. We also analyzed 233 previously published (H-series) SSR markers that provided another set of 52 polymorphic markers. An additional 71 gene-based SNP markers were developed from transcript sequences that are highly conserved between chickpea and its near relative Medicago truncatula. By using these three approaches, 175 new marker loci along with 407 previously reported marker loci were integrated to yield an improved genetic map of chickpea. The integrated map contains 521 loci organized into eight linkage groups that span 2,602 cM, with an average inter-marker distance of 4.99 cM. Gene-based markers provide anchor points for comparing the genomes of Medicago and chickpea, and reveal extended synteny between these two species. The combined set of genetic markers and their integration into an improved genetic map should facilitate chickpea genetics and breeding, as well as translational studies between chickpea and Medicago.


Assuntos
Mapeamento Cromossômico , Cicer/genética , Genes de Plantas/genética , Loci Gênicos/genética , Medicago truncatula/genética , Repetições Minissatélites/genética , Polimorfismo de Nucleotídeo Único/genética , Sequência de Bases , Etiquetas de Sequências Expressas , Biblioteca Gênica , Ligação Genética , Marcadores Genéticos , Genótipo , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Filogenia , Homologia de Sequência do Ácido Nucleico
14.
Biophys J ; 97(11): 2993-9, 2009 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-19948129

RESUMO

A relatively unknown protein structure motif forms stable isolated single alpha-helices, termed ER/K alpha-helices, in a wide variety of proteins and has been shown to be essential for the function of some molecular motors. The flexibility of the ER/K alpha-helix determines whether it behaves as a force transducer, rigid spacer, or flexible linker in proteins. In this study, we quantify this flexibility in terms of persistence length, namely the length scale over which it is rigid. We use single-molecule optical trapping and small-angle x-ray scattering, combined with Monte Carlo simulations to demonstrate that the Kelch ER/K alpha-helix behaves as a wormlike chain with a persistence length of approximately 15 nm or approximately 28 turns of alpha-helix. The ER/K alpha-helix length in proteins varies from 3 to 60 nm, with a median length of approximately 5 nm. Knowledge of its persistence length enables us to define its function as a rigid spacer in a translation initiation factor, as a force transducer in the mechanoenzyme myosin VI, and as a flexible spacer in the Kelch-motif-containing protein.


Assuntos
Proteínas/química , Motivos de Aminoácidos , Animais , Escherichia coli/genética , Humanos , Modelos Moleculares , Método de Monte Carlo , Pinças Ópticas , Engenharia de Proteínas , Estrutura Secundária de Proteína , Proteínas/genética , Proteínas/metabolismo , Espalhamento a Baixo Ângulo , Suínos , Temperatura , Difração de Raios X
15.
Bioprocess Biosyst Eng ; 31(5): 483-92, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18175153

RESUMO

An endosymbiotic Pseudomonas sp. (MSI057), which could produce high yields of lipase, was isolated from marine sponge Dendrilla nigra, collected from the peninsular coast of India. Maximum production of enzyme was obtained in minimal medium supplemented with 1% tributyrin. Catabolite repression was observed when the medium was supplemented with readily available carbon sources. The optimum temperature and pH for the enzyme production was 30 degrees C and 9.0, respectively. The enzyme exhibited maximum activity in pH range of 8-9 with an optimum pH 9.0. The activity of purified enzyme was optimum at 37 degrees C and showed 80% activity at 20 degrees C and the enzyme activity decreased dramatically above 50 degrees C. Based on the present findings, the enzyme was characterized as psychrophilic alkaline lipase, which can be developed for industrial applications.


Assuntos
Reatores Biológicos/microbiologia , Técnicas de Cultura de Células/métodos , Lipase/química , Lipase/metabolismo , Poríferos/microbiologia , Pseudomonas/classificação , Pseudomonas/fisiologia , Álcalis/química , Álcalis/isolamento & purificação , Álcalis/metabolismo , Animais , Interações Hidrofóbicas e Hidrofílicas , Lipase/isolamento & purificação , Oceanos e Mares , Especificidade da Espécie
16.
Opt Express ; 14(4): 1451-7, 2006 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-19503469

RESUMO

We demonstrated that a power limiting mechanism could potentially be used for self-adaptive, all-optical Fourier image processing. Reverse saturable absorbers like porphyrins are chosen due to their fluence dependent power limiting property, which triggers at relatively low intensities. At low input intensities, below the power-limiting threshold, the 4-f configuration will image the object onto the CCD camera without any spatial frequency filtering. As the input intensity is increased above the threshold level, dc and low spatial frequencies are blocked resulting in edge-enhanced images containing high spatial frequencies. The incident intensity sets the higher limit on the band of frequencies blocked. In addition, the use of the same experimental setup for both power limiting experiments and optical image processing demonstrates that in the case of any bright image bearing laser beam, the sensitive detectors are protected, by blocking the intense low spatial frequencies.

17.
J Biomech Eng ; 127(6): 1030-4, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16438245

RESUMO

This paper introduces passive wireless telemetry based operation for high frequency acoustic sensors. The focus is on the development, fabrication, and evaluation of wireless, battery-less SAW-IDT MEMS microphones for biomedical applications. Due to the absence of batteries, the developed sensors are small and as a result of the batch manufacturing strategy are inexpensive which enables their utilization as disposable sensors. A pulse modulated surface acoustic wave interdigital transducer (SAW-IDT) based sensing strategy has been formulated. The sensing strategy relies on detecting the ac component of the acoustic pressure signal only and does not require calibration. The proposed sensing strategy has been successfully implemented on an in-house fabricated SAW-IDT sensor and a variable capacitor which mimics the impedance change of a capacitive microphone. Wireless telemetry distances of up to 5 centimeters have been achieved. A silicon MEMS microphone which will be used with the SAW-IDT device is being microfabricated and tested. The complete passive wireless sensor package will include the MEMS microphone wire-bonded on the SAW substrate and interrogated through an on-board antenna. This work on acoustic sensors breaks new ground by introducing high frequency (i.e., audio frequencies) sensor measurement utilizing SAW-IDT sensors. The developed sensors can be used for wireless monitoring of body sounds in a number of different applications, including monitoring breathing sounds in apnea patients, monitoring chest sounds after cardiac surgery, and for feedback sensing in compression (HFCC) vests used for respiratory ventilation. Another promising application is monitoring chest sounds in neonatal care units where the miniature sensors will minimize discomfort for the newborns.


Assuntos
Acústica/instrumentação , Engenharia Biomédica/instrumentação , Diagnóstico por Computador/instrumentação , Monitorização Ambulatorial/instrumentação , Espectrografia do Som/instrumentação , Telemetria/instrumentação , Transdutores , Engenharia Biomédica/métodos , Diagnóstico por Computador/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Miniaturização , Monitorização Ambulatorial/métodos , Espectrografia do Som/métodos , Telemetria/métodos
18.
Biochem Genet ; 41(11-12): 361-74, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14994825

RESUMO

Downy mildew, caused by Sclerospora graminicola, is an economically important disease of pearl millet in the semiarid regions of Asia and Africa. Amplified restriction fragment length polymorphism (AFLP) was used to detect the extent of genomic variation among 19 fungal isolates from different cultivars of pearl millet grown in various regions of India. Fourteen AFLP primer combinations produced 184 polymorphic bands. An unweighted pair-group method of averages cluster analysis represented by dendrogram and principal coordinate analysis separated the mildew collections into four distinct groups. Isolates having characteristic opposite mating abilities, geographic relatedness, virulence, common host cultivars, and changes through asexual generations reflected heterogeneity of the pathogen. The use of AFLP to detect genetic variation is particularly important in selecting mildew isolates to screen breeding material for identification of resistant millet and monitoring changes in S. graminicola in relation to changes in host for effective disease management.


Assuntos
Impressões Digitais de DNA/métodos , Oomicetos/genética , Pennisetum/microbiologia , Polimorfismo de Fragmento de Restrição , Índia , Oomicetos/isolamento & purificação , Doenças das Plantas/microbiologia , Polimorfismo Genético
19.
Mycopathologia ; 155(3): 171-8, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12617504

RESUMO

Genetic variability among 43 isolates of Fusarium oxysporum f.sp. ciceri, the chickpea wilt pathogen, collected from nine states of India including the four well-characterized races of the pathogen were assessed using the molecular markers, RAPDs and AFLP. Principal coordinate analysis of the similarity index data generated from the molecular marker studies mostly gave three different clusters: Of these two clusters represented race-1 and race-2, and the third cluster consisted of race-3 and race-4 pathogen isolates. In RAPDs a fourth cluster was seen which did not go with any of the four races of the pathogen. The molecular markers established the distinctness of race-1 and race-2 pathogen isolates and the close similarity of pathogen isolates of race-3 with that of race-4. AFLP was found to be more informative as it differentiated more number of the pathogen isolates with the known races with minimum of outliers. The high levels of DNA polymorphism observed with the molecular markers suggest the rapid evolution of new recombinants of the pathogen in the chickpea growing fields.


Assuntos
Cicer/microbiologia , Fusarium/genética , Variação Genética , Biomarcadores , DNA Fúngico/análise , Fusarium/isolamento & purificação , Polimorfismo de Fragmento de Restrição
20.
J Neurosci ; 21(8): 2861-77, 2001 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11306638

RESUMO

The inferior colliculus (IC) processes auditory information ascending from the brainstem. The response of the IC to this information and its ability to transform it is partly determined by the types of ionic currents that generate the intrinsic discharge patterns of IC neurons and their susceptibility to changes in the external environment. We have used whole-cell patch-clamp techniques on IC neurons in rat brain slices to characterize the potassium currents present and to correlate them with the firing patterns observed. Neurons in the IC can be classified into six physiologically distinct cell types. Each of these cell types has a firing pattern that is generated by a unique potassium current and set of cellular parameters. Sustained-regular cells show mainly delayed rectifier K(+) channels. Onset cells have a unique high-threshold tetraethylammonium-sensitive K(+) current. Pause-build cells have an A-current. Rebound-regular cells have calcium-dependent rebound depolarizations. Rebound-adapting cells have both an apamin-sensitive calcium-dependent K(+) current and a calcium-dependent rebound depolarization. Transient-rebound cells have a charybdotoxin-sensitive calcium-dependent K(+) current and a calcium-dependent rebound. Our data suggest that there would be similarities as well as differences among IC neurons in their responses to excitatory or inhibitory inputs. Furthermore, some cells are likely to show little or no plasticity and behave as simple relays of temporal and intensity information, whereas others are likely to transform their inputs.


Assuntos
Colículos Inferiores/citologia , Colículos Inferiores/metabolismo , Neurônios/metabolismo , Canais de Potássio/metabolismo , 4-Aminopiridina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/fisiologia , Animais , Apamina/farmacologia , Cálcio/metabolismo , Cálcio/farmacologia , Charibdotoxina/farmacologia , Estimulação Elétrica , Técnicas In Vitro , Colículos Inferiores/efeitos dos fármacos , Neurônios/classificação , Neurônios/citologia , Neurônios/efeitos dos fármacos , Técnicas de Patch-Clamp , Potássio/metabolismo , Bloqueadores dos Canais de Potássio , Ratos , Ratos Long-Evans , Tetraetilamônio/farmacologia , Tetrodotoxina/farmacologia
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