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1.
Int J Ophthalmol ; 17(4): 610-615, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38638262

RESUMEN

AIM: To propose an algorithm for automatic detection of diabetic retinopathy (DR) lesions based on ultra-widefield scanning laser ophthalmoscopy (SLO). METHODS: The algorithm utilized the FasterRCNN (Faster Regions with CNN features)+ResNet50 (Residua Network 50)+FPN (Feature Pyramid Networks) method for detecting hemorrhagic spots, cotton wool spots, exudates, and microaneurysms in DR ultra-widefield SLO. Subimage segmentation combined with a deeper residual network FasterRCNN+ResNet50 was employed for feature extraction to enhance intelligent learning rate. Feature fusion was carried out by the feature pyramid network FPN, which significantly improved lesion detection rates in SLO fundus images. RESULTS: By analyzing 1076 ultra-widefield SLO images provided by our hospital, with a resolution of 2600×2048 dpi, the accuracy rates for hemorrhagic spots, cotton wool spots, exudates, and microaneurysms were found to be 87.23%, 83.57%, 86.75%, and 54.94%, respectively. CONCLUSION: The proposed algorithm demonstrates intelligent detection of DR lesions in ultra-widefield SLO, providing significant advantages over traditional fundus color imaging intelligent diagnosis algorithms.

2.
Int J Syst Evol Microbiol ; 63(Pt 1): 224-229, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22389285

RESUMEN

Three filamentous actinomycetes, strains YIM 65594(T), YIM 65638 and YIM 65642, were isolated from the surface-sterilized roots of Artemisia annua L. collected from Yunnan province, south-west China. These strains were found to have morphological and chemotaxonomic characteristics typical of the genus Streptomyces. The organisms formed an extensively branched substrate mycelium, with abundant aerial hyphae that differentiated into spores. The cell wall of the isolates contained ll-diaminopimelic acid and the menaquinones were MK-9(H(8)) and MK-9(H(6)). The major fatty acids were anteiso-C(15 : 0), anteiso-C(17 : 0) and iso-C(16 : 0). Phylogenetic analysis of the 16S rRNA gene sequences of these strains revealed that the strains clustered together and were most closely related to Streptomyces kunmingensis NBRC 14463(T), with 98.5-98.6 % 16S rRNA gene sequence similarity. The results of DNA-DNA hybridization and physiological tests allowed the genotypic and phenotypic differentiation of strains YIM 65594(T), YIM 65638 and YIM 65642 from related species. However, the high level of DNA-DNA relatedness between them showed that these three strains belong to the same species. Strain YIM 65594(T) (= DSM 41984(T) = CCTCC AA 209036(T)) was selected as the type strain to represent this novel species, for which the name Streptomyces endophyticus sp. nov. is proposed.


Asunto(s)
Artemisia annua/microbiología , Filogenia , Raíces de Plantas/microbiología , Streptomyces/clasificación , China , ADN Bacteriano/genética , Ácidos Grasos/análisis , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Streptomyces/genética , Streptomyces/aislamiento & purificación , Vitamina K 2/análogos & derivados , Vitamina K 2/análisis
3.
Int J Syst Evol Microbiol ; 62(Pt 7): 1576-1580, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21873515

RESUMEN

A novel bacterium (strain YIM 65583(T)) belonging to the genus Sphingomonas was isolated from surface-sterilized tissue of Artemisia annua L., which was collected from Yunnan province, south-west China. Its morphology, physiology and biochemical features were consistent with those of members of the genus Sphingomonas. Analysis of the 16S rRNA gene sequence of strain YIM 65583(T) further confirmed that it should be classified as a member of the genus Sphingomonas and was most closely related to Sphingomonas phyllosphaerae FA2(T) (99.7%) and Sphingomonas yunnanensis YIM 003(T) (98.3%). The isolate was Gram-negative and formed yellow-pigmented colonies on ISP 2 medium. It grew optimally at pH 6.0-8.0, at 20-37 °C and in the presence of 0-1% (w/v) NaCl. The major respiratory lipoquinone was ubiquinone-10; C(18:1)ω7c, anteiso-C(16:1), C(14:0)-2OH, C(17:1)ω6c, C(16:0) and C(15:0) were the major fatty acids. Major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and sphingoglycolipid. The G+C content of the genomic DNA was 63.3 mol%. The DNA-DNA relatedness values of the isolate YIM 65583(T) with S. phyllosphaerae FA2(T) and S. yunnanensis YIM 003(T) were 43.1% and 37.9%, respectively. Based on these features, it is concluded that the strain represents a novel species of the genus Sphingomonas, for which the name Sphingomonas endophytica sp. nov. is proposed, with YIM 65583(T) (=CCTCC AA 209035(T)=JCM 17394(T)) as the type strain.


Asunto(s)
Artemisia annua/microbiología , Sphingomonas/clasificación , Sphingomonas/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , China , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácidos Grasos/análisis , Concentración de Iones de Hidrógeno , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Fosfolípidos/análisis , Filogenia , Pigmentos Biológicos/metabolismo , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Cloruro de Sodio/metabolismo , Sphingomonas/genética , Sphingomonas/fisiología , Temperatura , Ubiquinona/análisis
4.
Antonie Van Leeuwenhoek ; 101(3): 515-27, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22038129

RESUMEN

Endophytic actinobacteria isolated from Artemisia annua were characterized and evaluated for their bioactivities. A total of 228 isolates representing at least 19 different genera of actinobacteria were obtained and several of them seemed to be novel taxa. An evaluation of antimicrobial activity showed that more isolates possessed activity towards plant pathogens than activity against other pathogenic bacteria or yeasts. High frequencies of PCR amplification were obtained for type I polyketide synthases (PKS-I, 21.1%), type II polyketide synthases (PKS-II, 45.2%) and nonribosomal peptide synthetases (NRPS, 32.5%). The results of herbicidal activity screening indicated that 19 out of 117 samples of fermentation broths completely inhibited the germination of Echinochloa crusgalli. This study indicated that endophytic actinobacteria associated with A. annua are abundant and have potentially beneficial and diverse bioactivities which should be pursued for their biotechnical promise.


Asunto(s)
Actinobacteria/aislamiento & purificación , Artemisia annua/microbiología , Endófitos/aislamiento & purificación , Actinobacteria/química , Actinobacteria/clasificación , Actinobacteria/enzimología , Actinobacteria/genética , Proteínas Bacterianas/aislamiento & purificación , ADN Bacteriano , ADN Ribosómico/genética , Endófitos/química , Endófitos/clasificación , Endófitos/enzimología , Endófitos/genética , Fermentación , Germinación/efectos de los fármacos , Herbicidas/aislamiento & purificación , Herbicidas/farmacología , Datos de Secuencia Molecular , Péptido Sintasas/aislamiento & purificación , Filogenia , Poaceae/efectos de los fármacos , Sintasas Poliquetidas/aislamiento & purificación , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Homología de Secuencia de Ácido Nucleico
5.
IEEE Trans Biomed Circuits Syst ; 16(1): 129-137, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35130169

RESUMEN

Cough detection has aroused great interest because the assessment of cough frequency may improve diagnosis accuracy for dealing with several diseases, such as chronic obstructive pulmonary disease (COPD) and the recent COVID-19 global pandemic crisis. Here, we propose and experimentally demonstrate a wireless smart face mask based on a passive harmonic tag for real-time cough monitoring and alert. Our results show that the cough events can be successfully monitored through non-contact track of the received signal strength indicator (RSSI) at the harmonic frequency. Owing to the frequency orthogonality between the launched and backscattered radio-frequency (RF) signals, the harmonic tag-based smart mask can well suppress the electromagnetic interferences, such as clutters and crosstalks in noisy environments. We envision that this zero-power and lightweight wireless wearable device may be beneficial for cough monitoring and the public health condition in terms of tracking potential contagious person and virus-transmissive events.


Asunto(s)
COVID-19 , Dispositivos Electrónicos Vestibles , COVID-19/diagnóstico , Tos/diagnóstico , Humanos , Máscaras , Monitoreo Fisiológico
6.
Int J Syst Evol Microbiol ; 61(Pt 12): 2967-2973, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21278413

RESUMEN

A novel endophytic actinomycete, strain YIM 65646(T), was isolated from the roots of Artemisia annua L. collected from Yunnan Province, south-west China. Growth was observed in the temperature range 10-40 °C (optimum 20-28 °C) and at pH 6.0-9.0 (optimum pH 7.0). The organism formed well-developed, branched substrate mycelia, but aerial mycelium was not produced. Phenotypic characterization and 16S rRNA gene sequence analysis indicated that strain YIM 65646(T) belonged to the family Micromonosporaceae (sharing ≤93.6% sequence similarity with members of this family) and formed a distinct clade in the Micromonosporaceae phylogenetic tree. The strain contained meso-diaminopimelic acid in the cell wall and mannose, ribose, galactose and glucose in whole-cell hydrolysates. The major menaquinones were MK-10(H(4)), MK-10(H(2)), MK-8(H(2)), MK-9(H(2)) and MK-10(H(6)). The major fatty acids were iso-C(15:0), anteiso-C(15:0), anteiso-C(17:0), iso-C(17:0) and iso-C(16:0). The DNA G+C content of strain YIM 65646(T) was 70.0 mol%. On the basis of morphological and chemotaxonomic properties and phylogenetic analysis based on 16S rRNA gene sequence data, it is proposed that this strain should be classified in a novel genus and species, Phytomonospora endophytica gen. nov., sp. nov., in the family Micromonosporaceae. The type strain is YIM 65646(T) (=CCTCC AA 209041(T) =DSM 45386(T)).


Asunto(s)
Artemisia annua/microbiología , Micromonosporaceae/clasificación , Micromonosporaceae/aislamiento & purificación , Raíces de Plantas/microbiología , China , ADN Bacteriano/genética , ADN Ribosómico/genética , Ácidos Grasos/metabolismo , Micromonosporaceae/genética , Micromonosporaceae/metabolismo , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética
7.
Int J Syst Evol Microbiol ; 61(Pt 9): 2141-2145, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20889768

RESUMEN

A novel actinomycete, designated strain YIM 67092(T), was isolated from rhizosphere soil of the perennial vine Tripterygium wilfordii Hook. f. collected from Yunnan province, South-west China. The strain formed well differentiated aerial and substrate mycelia and grew in the presence of up to 7 % (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene showed that strain YIM 67092(T) belonged to the genus Nonomuraea, with highest sequence similarity to Nonomuraea rosea GW 12687(T) (99.0 %). Sequence similarities between strain YIM 67092(T) and other species of the genus Nonomuraea ranged from 97.8 % (Nonomuraea dietziae DSM 44320(T)) to 93.8 % (Nonomuraea kuesteri GW 14-1925(T)). Key morphological, physiological and chemotaxonomic characteristics of strain YIM 67092(T) were congruent with the description of the genus Nonomuraea. The G+C content of the genomic DNA was 69.3 mol%. Based on comparative analysis of physiological, biochemical and chemotaxonomic data, including low DNA-DNA hybridization results, strain YIM 67092(T) represents a novel species of the genus Nonomuraea, for which the name Nonomuraea rhizophila sp. nov. is proposed. The type strain is YIM 67092(T) ( = CCTCC AA 209044(T)  = DSM 45382(T)).


Asunto(s)
Actinomycetales/clasificación , Actinomycetales/aislamiento & purificación , Microbiología del Suelo , Actinomycetales/genética , Actinomycetales/fisiología , Técnicas de Tipificación Bacteriana , Composición de Base , China , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácidos Grasos/análisis , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Filogenia , Quinonas/análisis , ARN Ribosómico 16S/genética , Rizosfera , Análisis de Secuencia de ADN , Cloruro de Sodio/metabolismo , Tripterygium/microbiología
8.
Int J Syst Evol Microbiol ; 61(Pt 9): 2292-2297, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20971834

RESUMEN

A Gram-positive, aerobic, actinobacterial strain with rod-shaped spores, designated YIM 63158(T), was isolated from the surface-sterilized roots of Artemisia annua L. collected from Yunnan province, south-west China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 63158(T) belonged to the genus Pseudonocardia. The closest neighbours were 'Pseudonocardia sichuanensis' KLBMP 1115 (99.9 % 16S rRNA gene sequence similarity), Pseudonocardia adelaidensis EUM 221(T) (99.1 %) and Pseudonocardia zijingensis DSM 44774(T) (98.8 %); sequence similarities to other members of the genus Pseudonocardia ranged from 98.6 to 94.4 %. The chemotaxonomic characteristics, such as the cell-wall diaminopimelic acid, whole-cell sugars, fatty acid components and major menaquinones, suggested that the isolate belonged to the genus Pseudonocardia. The G+C content of the genomic DNA was 73.3 mol%. On the basis of physiological, biochemical and chemotaxonomic data, including low DNA-DNA relatedness between the isolate and other members of the genus Pseudonocardia, it is proposed that strain YIM 63158(T) represents a novel species in this genus, with the name Pseudonocardia kunmingensis sp. nov. The type strain is YIM 63158(T) ( = DSM 45301(T)  = CCTCC AA 208078(T)). [corrected].


Asunto(s)
Actinomycetales/clasificación , Actinomycetales/aislamiento & purificación , Artemisia annua/microbiología , Raíces de Plantas/microbiología , Actinomycetales/genética , Actinomycetales/fisiología , Aerobiosis , Técnicas de Tipificación Bacteriana , Composición de Base , Carbohidratos/análisis , Pared Celular/química , China , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácido Diaminopimélico/análisis , Ácidos Grasos/análisis , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Filogenia , Quinonas/análisis , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
9.
Int J Syst Evol Microbiol ; 61(Pt 5): 1061-1065, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-20511456

RESUMEN

A novel actinomycete strain, designated YIM 63587(T), was isolated from surface-sterilized roots of Artemisia annua L. collected from Yunnan province, south-west China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 63587(T) was affiliated to the genus Pseudonocardia. 16S rRNA gene sequence similarities between strain YIM 63587(T) and type strains of species of the genus Pseudonocardia were 96.6-93.8 %. The diagnostic cell-wall diamino acid in the peptidoglycan layer of strain YIM 63587(T) was meso-diaminopimelic acid and the whole-cell sugars were arabinose, galactose, mannose and ribose. The predominant menaquinone was MK-8(H(4)) (97.7 %). The phospholipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol mannosides, phosphatidylinositol and an unknown phospholipid. The major cellular fatty acids (>5 %) were iso-C(16 : 0) (44.7 %), iso-C(14 : 0) (10.3 %), iso-C(16 : 1) H (9.8 %) and iso-C(15 : 0) (7.7 %). The G+C content of the genomic DNA was 68.2 mol%. On the basis of phylogenetic, physiological and chemotaxonomic data, strain YIM 63587(T) represents a novel species of the genus Pseudonocardia, for which the name Pseudonocardia artemisiae sp. nov. is proposed. The type strain is YIM 63587(T) ( = DSM 45313(T) = CCTCC AA 208081(T)).


Asunto(s)
Actinomycetales/clasificación , Actinomycetales/aislamiento & purificación , Artemisia annua/microbiología , Actinomycetales/genética , Actinomycetales/metabolismo , ADN Bacteriano/genética , Ácidos Grasos/metabolismo , Datos de Secuencia Molecular , Filogenia , Raíces de Plantas/microbiología , ARN Ribosómico 16S/genética
10.
Int J Syst Evol Microbiol ; 61(Pt 4): 757-761, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20435751

RESUMEN

A Gram-stain-positive, aerobic, non-motile actinomycete strain, designated YIM 65601(T), was studied by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain YIM 65601(T) should be assigned to the genus Nonomuraea, with highest 16S rRNA gene sequence similarities to Nonomuraea candida HMC10(T) (98.8 %), N. salmonea DSM 43678(T) (98.7 %), N. turkmeniaca DSM 43926(T) (98.5 %), N. roseola DSM 43767(T) (98.4 %), N. dietziae IFO 14309(T) (98.2 %) and N. kuesteri GW 14-1925(T) (98.1 %). 16S rRNA gene sequence similarities to strains of other Nonomuraea species were below 98.0 %. Morphological and chemotaxonomic properties of the isolate were consistent with those of members of the genus Nonomuraea. The results of DNA-DNA hybridization and physiological and biochemical tests and fatty acid profiles allowed genotypic and phenotypic differentiation of strain YIM 65601(T) from closely related species. Thus, YIM 65601(T) represents a novel species of the genus Nonomuraea, for which the name Nonomuraea endophytica sp. nov. is proposed, with YIM 65601(T) ( = CCTCC AA 209037(T)  = DSM 45385(T)) as the type strain.


Asunto(s)
Actinomycetales/clasificación , Actinomycetales/aislamiento & purificación , Artemisia annua/microbiología , Actinomycetales/genética , Actinomycetales/fisiología , Aerobiosis , Técnicas de Tipificación Bacteriana , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácidos Grasos/análisis , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
11.
Opt Express ; 18(1): 378-85, 2010 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-20173857

RESUMEN

In this paper, we presented fabrication of nickel based metal mold with 45 degrees tilted surfaces on both ends of the channel waveguide through electroplating process. To obtain a precise 45 degrees tilted angle, a 50microm thick SU-8 layer was UV exposed under de-ionized water, with repeatable error control of 0.5 degrees . The polymeric waveguide array with 45 degrees micro-mirrors, which is formed by a UV imprinting method with the fabricated metallic mold, shows total insertion losses around 4dB, propagation loss around 0.18dB/cm and 75% coupling efficiency.


Asunto(s)
Compuestos Epoxi/química , Lentes , Níquel/química , Dispositivos Ópticos , Polímeros/química , Refractometría/instrumentación , Transductores , Diseño Asistido por Computadora , Diseño de Equipo , Análisis de Falla de Equipo , Miniaturización , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Propiedades de Superficie
12.
Antonie Van Leeuwenhoek ; 98(1): 77-83, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20354787

RESUMEN

During the course of our research on new actinobacterial sources, a novel actinomycete strain YIM 67013(T) was isolated from rhizosphere soil of Tripterygium wilfordii Hook. f. collected from Yunnan province, south-west China. The strain formed well-differentiated aerial and substrate mycelia, grew in the presence of up to 15% NaCl (optimum, 0-3% NaCl). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 67013(T) belongs to the genus Pseudonocardia, with highest similarity to Pseudonocardia thermophila DSM 43832(T) (97.6%). Sequence similarities between strain YIM 67013(T) and the other Pseudonocardia species ranged from 96.6 to 93.2%. Key morphological and physiological characteristics as well as chemotaxonomic features of strain YIM 67013(T) were congruent with the description of the genus Pseudonocardia. The G+C content of the genomic DNA was 69.7 mol%. Based on comparative analysis of physiological, biochemical and chemotaxonomic data, including low DNA-DNA hybridization results, it is proposed that strain YIM 67013(T) represents a novel species of the genus Pseudonocardia, named Pseudonocardia rhizophila sp. nov. The type strain is YIM 67013(T) (= CCTCC AA 209043(T) = DSM 45381(T)).


Asunto(s)
Actinomycetales/clasificación , Actinomycetales/aislamiento & purificación , Raíces de Plantas/microbiología , Microbiología del Suelo , Actinomycetales/genética , Actinomycetales/fisiología , Técnicas de Tipificación Bacteriana , Composición de Base , China , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácidos Grasos/análisis , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
13.
J Photochem Photobiol B ; 182: 27-34, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29601971

RESUMEN

The aim of this work was to prepare, characterize and evaluate the potential of novel ZnO/stellerite composite photocatalysts against Staphylococcus aureus (S. aureus). SEM/EDS studies employed to study the surface morphological properties revealed stellerite as the catalysts carrier played a role of dispersant for ZnO nanoparticles. The XRD patterns of the ZnO/stellerite indicated hexagonal crystal structure with 20-30 nm size. It was found that the crystallite size of ZnO/stellerite was much smaller as compared to pure ZnO and increased with increasing ZnO loading amount. The results of optical properties of ZnO/stellerite showed smaller band gap in contrast to pure ZnO, investigated by UV-vis absorption. Due to the optimum ZnO loading, the as-prepared ZnO-20 composite had the highest BET surface area and the pore volume. Using the TG-DSC measurement, the high thermal stability of the product was studied for different temperature values. Antibacterial activity of ZnO/stellerite affected by the ZnO loading, concentration of samples and light conditions (under dark and UV irradiation conditions) was examined by disinfection of S. aureus. The as-prepared ZnO-20 composite with 100 mg/L was found to exhibit excellent inactivation efficiencies (87.65% in the dark and 97.67% under UV illumination) towards S. aureus. Compared with pure ZnO, the obtained composite photocatalysts showed significantly better antibacterial performance by studying the disinfection kinetics of S. aureus. Thus, the present study reveals that the novel ZnO/stellerite shows great potential for its use in the targeted disinfection applications.


Asunto(s)
Desinfectantes/química , Desinfectantes/farmacología , Luz , Nanocompuestos/química , Staphylococcus aureus/efectos de los fármacos , Antibacterianos/química , Antibacterianos/farmacología , Cristalización , Estabilidad de Medicamentos , Cinética , Microscopía Electrónica de Rastreo , Modelos Moleculares , Tamaño de la Partícula , Temperatura , Difracción de Rayos X , Óxido de Zinc/química , Óxido de Zinc/farmacología
14.
Sci Rep ; 6: 18795, 2016 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-26732251

RESUMEN

Autonomous liquid-volume monitoring is crucial in ubiquitous healthcare. However, conventional approach is based on either human visual observation or expensive detectors, which are costly for future pervasive monitoring. Here we introduce a novel approach based on passive harmonic transponder antenna sensor and frequency hopping spread spectrum (FHSS) pattern analysis, to provide a very low cost wireless µL-resolution liquid-volume monitoring without battery or digital circuits. In our conceptual demonstration, the harmonic transponder comprises of a passive nonlinear frequency multiplier connected to a metamaterial-inspired 3-D antenna designed to be highly sensitive to the liquid-volume within a confined region. The transponder first receives some FHSS signal from an interrogator, then converts such signal to its harmonic band and re-radiates through the antenna sensor. The harmonic signal is picked up by a sniffer receiver and decoded through pattern analysis of the high dimensional FHSS signal strength data. A robust, zero power, absolute accuracy wireless liquid-volume monitoring is realized in the presence of strong direct coupling, background scatters, distance variance as well as near-field human-body interference. The concepts of passive harmonic transponder sensor, metamaterial-inspired antenna sensor, and FHSS pattern analysis based sensor decoding may help establishing cost-effective, energy-efficient and intelligent wireless pervasive healthcare monitoring platforms.


Asunto(s)
Modelos Teóricos , Tecnología de Sensores Remotos , Tecnología Inalámbrica , Algoritmos , Humanos , Reproducibilidad de los Resultados
15.
Microsyst Nanoeng ; 2: 16018, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-31057821

RESUMEN

Modern internet of things (IoTs) and ubiquitous sensor networks could potentially take advantage of chemically sensitive nanomaterials and nanostructures. However, their heterogeneous integration with other electronic modules on a networked sensor node, such as silicon-based modulators and memories, is inherently challenging because of compatibility and integration issues. Here we report a novel paradigm for sensing modulators: a graphene field-effect transistor device that directly modulates a radio frequency (RF) electrical carrier signal when exposed to chemical agents, with a memory effect in its electrochemical history. We demonstrated the concept and implementation of this graphene-based sensing modulator through a frequency-modulation (FM) experiment conducted in a modulation cycle consisting of alternating phases of air exposure and ethanol or water treatment. In addition, we observed an analog memory effect in terms of the charge neutrality point of the graphene, V cnp, which strongly influences the FM results, and developed a calibration method using electrochemical gate-voltage pulse sequences. This graphene-based multifunctional device shows great potential for use in a simple, low-cost, and ultracompact nanomaterial-based nodal architecture to enable continuous, real-time event-based monitoring in pervasive healthcare IoTs, ubiquitous security systems, and other chemical/molecular/gas monitoring applications.

16.
Nat Nanotechnol ; 10(1): 84-90, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25437745

RESUMEN

The rapidly increasing global demand for energy combined with the environmental impact of fossil fuels has spurred the search for alternative sources of clean energy. One promising approach is to convert solar energy into hydrogen fuel using photoelectrochemical cells. However, the semiconducting photoelectrodes used in these cells typically have low efficiencies and/or stabilities. Here we show that a silicon-based photocathode with a capping epitaxial oxide layer can provide efficient and stable hydrogen production from water. In particular, a thin epitaxial layer of strontium titanate (SrTiO3) was grown directly on Si(001) by molecular beam epitaxy. Photogenerated electrons can be transported easily through this layer because of the conduction-band alignment and lattice match between single-crystalline SrTiO3 and silicon. The approach was used to create a metal-insulator-semiconductor photocathode that, under a broad-spectrum illumination at 100 mW cm(-2), exhibits a maximum photocurrent density of 35 mA cm(-2) and an open circuit potential of 450 mV; there was no observable decrease in performance after 35 hours of operation in 0.5 M H2SO4. The performance of the photocathode was also found to be highly dependent on the size and spacing of the structured metal catalyst. Therefore, mesh-like Ti/Pt nanostructured catalysts were created using a nanosphere lithography lift-off process and an applied-bias photon-to-current efficiency of 4.9% was achieved.

17.
IEEE J Transl Eng Health Med ; 2: 1700108, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-27170865

RESUMEN

Miniaturized helix antennas are integrated with drug reservoirs to function as RFID wireless tag sensors for real-time drug dosage monitoring. The general design procedure of this type of biomedical antenna sensors is proposed based on electromagnetic theory and finite element simulation. A cost effective fabrication process is utilized to encapsulate the antenna sensor within a biocompatible package layer using PDMS material, and at the same time form a drug storage or drug delivery unit inside the sensor. The in vitro experiment on two prototypes of antenna sensor-drug reservoir assembly have shown the ability to monitor the drug dosage by tracking antenna resonant frequency shift from 2.4-2.5-GHz ISM band with realized sensitivity of 1.27 [Formula: see text] for transdermal drug delivery monitoring and 2.76-[Formula: see text] sensitivity for implanted drug delivery monitoring.

18.
Philos Trans A Math Phys Eng Sci ; 370(1967): 2433-47, 2012 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-22509065

RESUMEN

Breast cancer accounted for 15 per cent of total cancer deaths in female patients in 2010. Although significant progress has been made in treating early-stage breast cancer patients, there is still no effective therapy targeting late-stage metastatic breast cancers except for the conventional chemotherapy interventions. Until effective therapy for later-stage cancers emerges, the identification of biomarkers for the early detection of tumour metastasis continues to hold the key to successful management of breast cancer therapy. Our study concentrated on the low molecular weight (LMW) region of the serum protein and the information it contains for identifying biomarkers that could reflect the ongoing physiological state of all tissues. Owing to technical difficulties in harvesting LMW species, studying these proteins/peptides has been challenging until now. In our study, we have recently developed nanoporous chip-based technologies to separate small proteins/peptides from the large proteins in serum. We used nanoporous silica chips, with a highly periodic nanostructure and uniform pore size distribution, to isolate LMW proteins and peptides from the serum of nude mice with MDA-MB-231 human breast cancer lung metastasis. By matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and biostatistical analysis, we were able to identify protein signatures unique to different stages of cancer development. The approach and results reported in this study possess a significant potential for the discovery of proteomic biomarkers that may significantly enhance personalized medicine targeted at metastatic breast cancer.


Asunto(s)
Neoplasias de la Mama/patología , Nanopartículas , Dióxido de Silicio , Animales , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Progresión de la Enfermedad , Femenino , Humanos , Neoplasias Pulmonares/secundario , Ratones , Ratones Desnudos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
19.
PLoS One ; 7(12): e51410, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23251523

RESUMEN

Endophytic actinobacteria colonize internal tissues of their host plants and are considered as a rich and reliable source of diverse species and functional microorganisms. In this study, endophytic actinobacterial strain YIM 63111 was isolated from surface-sterilized tissue of the medicinal plant Artemisia annua. We identified strain YIM 63111 as a member of the genus Pseudonocardia. A. annua seedlings grown under both sterile and greenhouse conditions were inoculated with strain YIM 63111. The growth of A. annua seedlings was strongly reduced when YIM 63111 was inoculated at higher concentrations under sterile conditions. However, no growth inhibition was observed when A. annua was grown under greenhouse conditions. Using an enhanced green fluorescent protein (EGFP) expressing YIM 63111 strain, we also observed the endophytic colonization of A. annua seedling using confocal laser-scanning microscopy. The transcription levels of the key genes involved in artemisinin biosynthesis were investigated using real time RT-PCR, revealing that cytochrome P450 monooxygenase (CYP71AV1) and cytochrome P450 oxidoreductase (CPR) expression were up-regulated in A. annua upon inoculation with strain YIM 63111 under certain conditions. The up-regulation of these genes was associated with the increased accumulation of artemisinin. These results suggest that endophytic actinobacteria effectively stimulate certain plant defense responses. Our data also demonstrate the use of Pseudonocardia sp. strain YIM 63111 as a promising means to enhance artemisinin production in plants.


Asunto(s)
Actinomycetales/fisiología , Artemisia annua/metabolismo , Artemisia annua/microbiología , Artemisininas/metabolismo , Endófitos/fisiología , Actinomycetales/citología , Artemisia annua/genética , Artemisia annua/crecimiento & desarrollo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Recuento de Colonia Microbiana , Endófitos/citología , Regulación de la Expresión Génica de las Plantas , Genes Bacterianos/genética , Proteínas Fluorescentes Verdes/metabolismo , Microscopía Confocal , Datos de Secuencia Molecular , Raíces de Plantas/microbiología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Esterilización
20.
Int J Syst Evol Microbiol ; 60(Pt 1): 27-32, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19648351

RESUMEN

The taxonomic position of an actinomycete strain YIM 63135(T), which was isolated from the surface-sterilized tissue of Artemisia annua L. collected from Yunnan province, south-west China, was determined by using a polyphasic approach. Morphological and chemical characteristics of the novel strain were consistent with those of the genus Streptomyces. It developed a pinkish aerial mycelium and pinkish-brown substrate mycelium on oatmeal agar. The cell wall of the strain contained ll-diaminopimelic acid. The menaquinones comprised MK-9(H(6)) (62.8 %), MK-9(H(8)) (31.4 %) and MK-9(H(4)) (5.9 %). The phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, an unknown glucosamine-containing phospholipid (GluNu), phosphatidylinositol mannosides and four unknown ninhydrin-negative phospholipids. The major fatty acids were iso-C(16 : 0) (30.0 %), anteiso-C(17 : 0) (27.3 %) and anteiso-C(15 : 0) (17.0 %). The DNA G+C content of strain YIM 63135(T) was 72.6 mol%. Phylogenetic analysis of 16S rRNA gene sequences revealed that strain YIM 63135(T) is a member of the genus Streptomyces and exhibited 99.9 % gene sequence similarity to Streptomyces armeniacus NBRC 12555(T), while low sequence similarity values (<97.0 %) distinguished strain YIM 63135(T) from all other Streptomyces species. DNA-DNA hybridization studies suggested that strain YIM 63135(T) represents a different genomic species. On the basis of phenotypic and phylogenetic characteristics, strain YIM 63135(T) was considered to represent a novel species of the genus Streptomyces, for which the name Streptomyces artemisiae sp. nov. is proposed, with YIM 63135(T) (=CCTCC AA 208059(T) =DSM 41953(T)) as the type strain.


Asunto(s)
Artemisia annua/microbiología , Streptomyces/clasificación , Streptomyces/aislamiento & purificación , Composición de Base , ADN Bacteriano/genética , ADN Ribosómico/genética , Ácidos Grasos/metabolismo , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética , Streptomyces/genética , Streptomyces/metabolismo
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