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1.
Antonie Van Leeuwenhoek ; 117(1): 13, 2024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-38170218

RESUMEN

A Gram-stain-negative, motile (by single polar flagellum) and rod-shaped bacterium, designated W1-6T, was isolated from a sediment of drainage ditch in winery in Guiyang, south-western China. Strain W1-6T showed the highest 16S rRNA gene sequence similarities with the type strain of Acidovorax wautersii (98.1%) and Simplicispira lacusdiani (97.9%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain W1-6T was placed adjacent to the members of the genus Simplicispira and formed a separat subclade. Cells showed oxidase and catalase negative reactions. The only respiratory quinone detected was ubiquinone-8 (Q-8). Summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C16:0 and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c) were predominant cellular fatty acids (> 10%) of strain W1-6T. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and five unidentified phospholipids were found in the polar lipid extraction. The genomic DNA G + C content was 65.6%. Strain W1-6T shared the highest digital DNA-DNA hybridization [dDDH, (27.6%)] and average nucleotide identity [ANI (84.3%)] values with the type strain of S. lacusdiani. The dDDH and ANI values were below the cutoff level (dDDH 70%; ANI 95-96%) for species delineation. The polyphasic characteristics indicated that the strain W1-6T represents a novel species of the genus Simplicispira, for which the name Simplicispira sedimenti sp. nov. is proposed. The type strain is W1-6T (= CGMCC 1.16274T = NBRC 115624T).


Asunto(s)
Ácidos Grasos , Fosfolípidos , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , China , Ubiquinona , ADN , Drenaje , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética
2.
Stroke ; 54(5): 1403-1415, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37094035

RESUMEN

The increasing socio-economic burden of Alzheimer disease (AD) and AD-related dementias has created a pressing need to define targets for therapeutic intervention. Deficits in cerebral blood flow and neurovascular function have emerged as early contributors to disease progression. However, the cause, progression, and consequence of small vessel disease in AD/AD-related dementias remains poorly understood, making therapeutic targets difficult to pinpoint. Animal models that recapitulate features of AD/AD-related dementias may provide mechanistic insight because microvascular pathology can be studied as it develops in vivo. Recent advances in in vivo optical and ultrasound-based imaging of the rodent brain facilitate this goal by providing access to deeper brain structures, including white matter and hippocampus, which are more vulnerable to injury during cerebrovascular disease. Here, we highlight these novel imaging approaches and discuss their potential for improving our understanding of vascular contributions to AD/AD-related dementias.


Asunto(s)
Enfermedad de Alzheimer , Trastornos Cerebrovasculares , Sustancia Blanca , Animales , Sustancia Blanca/patología , Enfermedad de Alzheimer/patología , Encéfalo/patología
3.
Ann Clin Microbiol Antimicrob ; 22(1): 94, 2023 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-37904155

RESUMEN

OBJECTIVES: Antimicrobial susceptibility tests (ASTs) are pivotal tools for detecting and combating infections caused by multidrug-resistant rapidly growing mycobacteria (RGM) but are time-consuming and labor-intensive. DESIGN: We used a Mycobacterium abscessus-based RGM model to develop a rapid (24-h) AST from the beginning of the strain culture, the Clinical Antimicrobials Susceptibility Test Ramanometry for RGM (CAST-R-RGM). The ASTs obtained for 21 clarithromycin (CLA)-treated and 18 linezolid (LZD)-treated RGM isolates. RESULTS: CAST-R-RGM employs D2O-probed Raman microspectroscopy to monitor RGM metabolic activity, while also revealing bacterial antimicrobial drug resistance mechanisms. The results of clarithromycin (CLA)-treated and linezolid (LZD)-treated RGM isolates exhibited 90% and 83% categorical agreement, respectively, with conventional AST results of the same isolates. Furthermore, comparisons of time- and concentration-dependent Raman results between CLA- and LZD-treated RGM strains revealed distinct metabolic profiles after 48-h and 72-h drug treatments, despite similar profiles obtained for both drugs after 24-h treatments. CONCLUSIONS: Ultimately, the rapid, accurate, and low-cost CAST-R-RGM assay offers advantages over conventional culture-based ASTs that warrant its use as a tool for improving patient treatment outcomes and revealing bacterial drug resistance mechanisms.


Asunto(s)
Infecciones por Mycobacterium no Tuberculosas , Mycobacterium abscessus , Mycobacterium , Humanos , Claritromicina/farmacología , Linezolid/farmacología , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Infecciones por Mycobacterium no Tuberculosas/tratamiento farmacológico , Infecciones por Mycobacterium no Tuberculosas/microbiología , Micobacterias no Tuberculosas
4.
Surg Innov ; 30(4): 517-525, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37014171

RESUMEN

INTRODUCTION: Heavy muscle load during operations, caused by static and awkward postures, contributes to the discomfort of surgeons, and imperils surgical quality. We reviewed the supporting devices available to assist surgeons in the operating room and anticipated that physical support devices would help reduce occupational injuries among surgeons and improve surgical performance. METHODS: A systematic literature review was completed. Papers on supporting devices for intraoperative stress reduction were included. Supported body parts and the impact of these devices on the surgeons' performance were extracted from the 21 selected papers. RESULTS: Among the 21 devices introduced, eleven targeted on the upper extremities, 5 targeted on the lower extremities, and 5 were ergonomic chairs. Nine devices were tested in the operating room, 10 in a lab setting with simulated tasks, and 2 were still in development. The data from 7 studies did not show a significant improvement in stress reduction or surgical quality. With 2 devices still in the development phase, the remaining 12 papers showed promising results. DISCUSSION: Although some of the devices were still in testing, most of the research teams believed that physical supporting devices can be useful in reducing muscle load, relieving discomfort, and improving surgical performance intraoperatively.


Asunto(s)
Quirófanos , Cirujanos , Humanos , Ergonomía/métodos , Extremidad Superior , Postura
5.
Molecules ; 28(13)2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37446582

RESUMEN

The use of coal as a precursor for producing hard carbon is favored due to its abundance, low cost, and high carbon yield. To further optimize the sodium storage performance of hard carbon, the introduction of heteroatoms has been shown to be an effective approach. However, the inert structure in coal limits the development of heteroatom-doped coal-based hard carbon. Herein, coal-based P-doped hard carbon was synthesized using Ca3(PO4)2 to achieve homogeneous phosphorus doping and inhibit carbon microcrystal development during high-temperature carbonization. This involved a carbon dissolution reaction where Ca3(PO4)2 reacted with SiO2 and carbon in coal to form phosphorus and CO. The resulting hierarchical porous structure allowed for rapid diffusion of Na+ and resulted in a high reversible capacity of 200 mAh g-1 when used as an anode material for Na+ storage. Compared to unpretreated coal-based hard carbon, the P-doped hard carbon displayed a larger initial coulombic efficiency (64%) and proportion of plateau capacity (47%), whereas the unpretreated carbon only exhibited an initial coulombic efficiency of 43.1% and a proportion of plateau capacity of 29.8%. This work provides a green, scalable approach for effective microcrystalline regulation of hard carbon from low-cost and highly aromatic precursors.


Asunto(s)
Fosfatos , Dióxido de Silicio , Porosidad , Fósforo , Carbono , Carbón Mineral , Iones
6.
Curr Microbiol ; 79(10): 316, 2022 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-36088496

RESUMEN

A Gram-staining negative, aerobic, non-motile and rod-shaped bacterium, designated strain N-S-14T, was isolated from the sediment of a winery in Guiyang, south-western China and subjected to a polyphasic taxonomic characteristics. The cells showed oxidase-negative and catalase-negative reactions. Growth occurred at 5-45 °C (optimum 30 °C), pH 5.0-8.0 (optimum pH 6.0-7.0) and with 0-3% (w/v) NaCl on R2A medium. The major respiratory quinone was ubiquinone-8 (Q-8). The predominant cellular fatty acids (> 10.0%) were identified as iso-C15:0, iso-C17:0 and summed feature 9 (iso-C17:1ω9c or C16:0 10-methyl). The profile of polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, one unidentified aminophospholipid, one unidentified aminolipid and one unidentified lipid. The genomic DNA G + C content was 67.5%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain N-S-14T should be affiliated to the genus Dyella and formed a clade with most closely related Dyella solisilvae DHG54T (98.3%) and Dyella halodurans DHOG02T (97.8%). The digital DNA-DNA hybridization values ranged from 17.7 to 27.1% and the ANI values ranged from 75.2 to 84.0% between strain N-S-14T and other members of the genus Dyella, respectively, and thus the results indicated that strain N-S-14T represented a novel genomic species belonging to the genus Dyella. The polyphasic taxonomic characteristics indicated that the strain N-S-14T represent a novel species of the genus Dyella, for which the name Dyella sedimenti sp. nov. (type strain N-S-14T = CGMCC 1.18717T = KCTC 82384T) is proposed.


Asunto(s)
Microbiología del Suelo , Xanthomonadaceae , Técnicas de Tipificación Bacteriana , China , ADN Bacteriano/genética , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
7.
Arch Microbiol ; 203(5): 2343-2350, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33655406

RESUMEN

A Gram-staining negative, facultative anaerobic, motile and short rod-shaped bacterium, designated strain yh7-1T, was isolated from rhizosphere soil of Citrus sinenesis collected from the garden of Citrus sinenesis in Ailao Mountain, south-west China. Cells grew at 15-45 °C, pH 5.0-9.0 and were able to tolerate up to 1% (w/v) NaCl on R2A medium. The respiratory lipoquinone was Q-10 and the major cellular fatty acids contained summed feature 8 (C18:1 ω7c or C18:1 ω6c) and C18:0. Polar lipids in the cellular membrane were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and one unidentified aminophospholipid. The genomic DNA G+C content was 69.9 mol%. On basis of 16S rRNA gene sequence analysis, strain yh7-1T showed the highest similarities with Chthonobacter albigriseus KCTC 42450T (97.6%), Mongoliimonas terrestris KCTC 42635T (97.0%) and lower than 97.0% to other species. Phylogenetic trees based on 16S rRNA gene sequences indicated that strain yh7-1T clustered with C. albigriseus KCTC 42450T. The ANI values ranged between 78.1 and 82.7% for C. albigriseus KCTC 42450T, M. terrestris KCTC 42635T and strain yh7-1T, which were lower than the prokaryotic species delineation threshold of 95.0-96.0%. The digital DNA-DNA hybridization values between C. albigriseus KCTC 42450T, M. terrestris KCTC 42635T and strain yh7-1T indicated that the new isolate represents a novel genomic species. According to the phenotypic and genotypic characteristics, strain yh7-1T should belong to the genus Chthonobacter, for which the name Chthonobacter rhizosphaerae sp. nov. (type strain yh7-1T = CGMCC 1.17236T = CCTCC AB 2019258T = KCTC 82185T) is proposed.


Asunto(s)
Citrus sinensis/microbiología , Methylocystaceae/clasificación , Methylocystaceae/genética , Rizosfera , Técnicas de Tipificación Bacteriana , Composición de Base/genética , ADN Bacteriano/genética , Methylocystaceae/aislamiento & purificación , Fosfolípidos/análisis , Fosfolípidos/química , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Suelo , Microbiología del Suelo
8.
Anal Chem ; 92(12): 8081-8089, 2020 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-32401011

RESUMEN

In Raman-activated cell ejection and sequencing (RACE-Seq), success rate and sequence coverage have generally been low for shotgun sequencing of individual post-RACE cells. Here we quantitatively evaluated the influence of cell lysis condition, nucleic acid amplification condition, and parameters of Raman measurement on RACE-Seq performance. Variations in laser energy input during Raman signal acquisition, but not duration of alkaline lysate lysis, temperature, or measurement under dry or aqueous conditions, are vital to the success of multiple displacement amplification (MDA). In fact, laser irradiation is reversely linked to MDA product quality. However, introduction of oils prior to MDA, by mitigating such negative effects of Raman irradiation, elevates genome coverage of post-RACE Escherichia coli cells from <20% to ∼50%, while greatly improving the success rate of RACE-Seq for soil microbiota. Our findings provide a practical solution for enhancing RACE-Seq performance and pinpoint protection of cells from laser irradiation as a priority in method development.


Asunto(s)
ADN Bacteriano/genética , Escherichia coli K12/genética , Análisis de Secuencia de ADN , Escherichia coli K12/citología , Técnicas de Amplificación de Ácido Nucleico , Espectrometría Raman
9.
J Sep Sci ; 43(8): 1423-1430, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32003152

RESUMEN

An online high-pH reversed-phase liquid chromatography× low-pH reversed-phase liquid chromatography tandem electrospray ionization mass spectrometry combined with pulse elution gradient in the first dimension was constructed to separate and identify alkaloids from Macleaya cordata (willd.) R. Br. The modulation was performed by using a dual second dimensional columns interface combined with a make-up dilution pump, which is responsible for dilution and neutralization of the first dimensional effluent, and the dual second dimensional columns integrated the trapping and the separation function to reduce the second dimension system dead volume. Taking advantage of the dissociable characteristics of alkaloids, mobile phases with different pH values were applied in the first dimension (pH 9.0) and the second dimension (pH 2.6) to improve the orthogonality of two-dimension separation. Besides, the pulse elution gradient in first dimension and second dimensional gradient were carefully optimized and much better separation was achieved compared to the separation with the traditional two-dimensional liquid chromatography approach. Finally, mass measurement was performed for alkaloids in M. cordata (willd.) R. Br. by coupling proposed two-dimensional liquid chromatography system with triple quadrupole mass spectrometry, and 39 alkaloids were successfully identified by comparing the obtained result with the former reported results.


Asunto(s)
Alcaloides/análisis , Papaveraceae/química , Cromatografía Liquida , Cromatografía de Fase Inversa , Concentración de Iones de Hidrógeno , Espectrometría de Masa por Ionización de Electrospray
10.
Am J Physiol Heart Circ Physiol ; 317(2): H255-H263, 2019 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-31125259

RESUMEN

Capillary derecruitment distal to a coronary stenosis is implicated as the mechanism of reversible perfusion defect and potential myocardial ischemia during coronary hyperemia; however, the underlying mechanisms are not defined. We tested whether pericyte constriction underlies capillary derecruitment during hyperemia under conditions of stenosis. In vivo two-photon microscopy (2PM) and optical microangiography (OMAG) were used to measure hyperemia-induced changes in capillary diameter and perfusion in wild-type and pericyte-depleted mice with femoral artery stenosis. OMAG demonstrated that hyperemic challenge under stenosis produced capillary derecruitment associated with decreased RBC flux. 2PM demonstrated that hyperemia under control conditions induces 26 ± 5% of capillaries to dilate and 19 ± 3% to constrict. After stenosis, the proportion of capillaries dilating to hyperemia decreased to 14 ± 4% (P = 0.05), whereas proportion of constricting capillaries increased to 32 ± 4% (P = 0.05). Hyperemia-induced changes in capillary diameter occurred preferentially in capillary segments invested with pericytes. In a transgenic mouse model featuring partial pericyte depletion, only 14 ± 3% of capillaries constricted to hyperemic challenge after stenosis, a significant reduction from 33 ± 4% in wild-type littermate controls (P = 0.04). These results provide for the first time direct visualization of hyperemia-induced capillary derecruitment distal to arterial stenosis and demonstrate that pericyte constriction underlies this phenomenon in vivo. These results could have important therapeutic implications in the treatment of exercise-induced ischemia. NEW & NOTEWORTHY In the setting of coronary arterial stenosis, hyperemia produces a reversible perfusion defect resulting from capillary derecruitment that is believed to underlie cardiac ischemia under hyperemic conditions. We use optical microangiography and in vivo two-photon microscopy to visualize capillary derecruitment distal to a femoral arterial stenosis with cellular resolution. We demonstrate that capillary constriction in response to hyperemia in the setting of stenosis is dependent on pericytes, contractile mural cells investing the microcirculation.


Asunto(s)
Capilares/fisiopatología , Arteria Femoral/fisiopatología , Músculo Grácil/irrigación sanguínea , Hiperemia/fisiopatología , Pericitos/patología , Enfermedad Arterial Periférica/fisiopatología , Vasoconstricción , Angiografía , Animales , Constricción Patológica , Modelos Animales de Enfermedad , Femenino , Arteria Femoral/cirugía , Hiperemia/metabolismo , Hiperemia/patología , Ligadura , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Masculino , Ratones , Ratones Transgénicos , Microscopía de Fluorescencia por Excitación Multifotónica , Mutación , Pericitos/metabolismo , Enfermedad Arterial Periférica/metabolismo , Enfermedad Arterial Periférica/patología , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/genética , Flujo Sanguíneo Regional , Vasodilatación
11.
Biochem Biophys Res Commun ; 518(3): 492-499, 2019 10 20.
Artículo en Inglés | MEDLINE | ID: mdl-31443963

RESUMEN

Dysregulated microRNAs (miRNAs) play crucial roles in the occurrence and development of multiple tumours, but their roles in the progression of nasal squamous cell carcinoma (NSCC) remain unknown. The aim of our study was to investigate the potential function and molecular mechanism of miR-143-3p in NSCC. Expression of miRNA and mRNA was detected by quantitative real-time reverse transcription-PCR (qRT-PCR). Forced overexpression of miR-143-3p was established by transfecting mimics into NSCC cell line. Then, we investigated the role of miR-143-3p in human NSCC cell proliferation, apoptosis, cycle and migration by using MTT, flow cytometry and transwell assays. Bioinformatics analysis, qRT-PCR, Western blot and luciferase reporter analysis were performed to validate the relationship between miR-143-3p and its potential targets. We found that miR-143-3p was substantially downregulated in human NSCC tissues and cell line. Forced upregulation of miR-143-3p significantly attenuated cell proliferation and migration. Furthermore, this change could induce apoptosis and G1-phase arrest of NSCC cells. Mechanistically, miR-143-3p directly targeted and significantly suppressed Bcl-2 and IGF1R expression. In summary, miR-143-3p regulation of the proliferation, apoptosis, cell cycle and migration of NSCC probably partly depends on inhibition of Bcl-2 and IGF1R, indicating that miR-143-3p may be a novel molecular therapeutic target for NSCC.


Asunto(s)
Carcinoma de Células Escamosas/genética , MicroARNs/genética , Neoplasias Nasales/genética , Proteínas Proto-Oncogénicas c-bcl-2/genética , Receptor IGF Tipo 1/genética , Carcinoma de Células Escamosas/patología , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Progresión de la Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Nasales/patología
12.
Opt Express ; 27(5): 7036-7046, 2019 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-30876276

RESUMEN

A novel approach to realizing an optoelectronic oscillator (OEO) based on an integrated multi-section (IMS) distributed feedback (DFB) laser is proposed and experimentally demonstrated. Our scheme adopts the method of direct modulation and a built-in microwave photonic filter (MPF), making the structure simpler and more flexible than an external modulator and electrical bandpass filter (EBPF). The IMS-DFB laser, which can overcome the drawbacks of using discrete lasers, is the key device in the scheme. Further, the two DFB sections, which are fabricated by Reconstruction Equivalent Chirp (REC) technique, are injected mutually. The SSB phase noise of the generated signal at the frequency of 20.3 GHz is -115.3 dBc/Hz@10kHz and -92.9 dBc/Hz@1kHz. The sidemode suppression ratio (SMSR) is 60.94 dB, which is a 40 dB improvement over a single loop. Furthermore, we demonstrate that the phase noise improves about 8 dB at the frequency offset of 1 kHz, when employing 13 km and 5.4 km fibers as the dual loop. The simple and compact structure, which consists of an IMS-DFB laser with high wavelength controlling accuracy and low process requirement, is a promising development for OEO integration.

13.
Microvasc Res ; 121: 37-45, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30267716

RESUMEN

We report the development of a 1300 nm swept-source optical coherence tomography (SS-OCT) system specifically designed to perform OCT imaging and optical microangiography (OMAG) in rat eyes in vivo and its use in evaluating the effects of intraocular pressure (IOP) elevation on ocular circulation. The swept laser is operated in single longitude mode with a 90 nm bandwidth centered at 1300 nm and 200 kHz A-line rate, providing remarkable sensitivity fall-off performance along the imaging depth, a larger field of view of 2.5 × 2.5 mm2 (approximately 35°), and more time-efficient imaging acquisition. The advantage of the SS-OCT/OMAG is highlighted by an increased imaging depth of the entire posterior thickness of optic nerve head (ONH) and its surrounding vascular anatomy, to include, for the first time in vivo, the vasculature at the scleral opening, allowing visualization of the circle of Zinn-Haller and posterior ciliary arteries (PCAs). Furthermore, the capillary-level resolution angiograms achieved at the retinal and choroidal layers over a larger field of view enable a significantly improved quantification of the response of vascular area density (VAD) to elevated IOP. The results indicate that reduction in perfusion of the choroid in response to elevated IOP is delayed compared to that seen in the retina; while choroidal VAD doesn't reach 50% of baseline until ~70 mmHg, the same effect is seen for the retinal VAD at ~60 mmHg. The superior image quality offered by SS-OCT may allow more comprehensive investigation of IOP-related ocular perfusion changes and their pathological roles in glaucomatous optic nerve damage.


Asunto(s)
Coroides/irrigación sanguínea , Técnicas de Diagnóstico Oftalmológico/instrumentación , Presión Intraocular , Microcirculación , Hipertensión Ocular/diagnóstico por imagen , Imagen de Perfusión/instrumentación , Vasos Retinianos/diagnóstico por imagen , Tomografía de Coherencia Óptica/instrumentación , Animales , Velocidad del Flujo Sanguíneo , Modelos Animales de Enfermedad , Diseño de Equipo , Hipertensión Ocular/fisiopatología , Valor Predictivo de las Pruebas , Ratas Endogámicas BN , Flujo Sanguíneo Regional , Vasos Retinianos/fisiopatología , Factores de Tiempo
14.
Opt Lett ; 44(20): 5037-5040, 2019 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-31613257

RESUMEN

We report the use of an electrically tunable lens (ETL) in a 1.3 µm spectral-domain optical coherence tomography (SD-OCT) system to overcome the depth of focus (DOF) limitation in conventional OCT systems for OCT angiography (OCTA) in a mouse cerebral cortex. The ETL provides fast and dynamic control of the axial focus of the probe beam along the entire range of the mouse cortex, upon which we performed cerebral blood flow imaging of all cortical layers by stitching the OCTA images automatically captured at six focal depths. Capillary vasculature and axial blood flow velocity were revealed in distinctive cortical layers and, for the first time, to the best of our knowledge, in white matter. The results have shown the system capability to conveniently investigate the hemodynamics in deep cortical layers in the mouse brain. More importantly, the compact integration of an ETL will benefit the future design of handheld or intra-cavity OCT probes for a wide range of applications in research and clinical fields.


Asunto(s)
Corteza Cerebral/irrigación sanguínea , Corteza Cerebral/diagnóstico por imagen , Circulación Cerebrovascular , Electricidad , Tomografía de Coherencia Óptica/instrumentación , Animales , Lentes , Ratones
15.
Int J Syst Evol Microbiol ; 69(7): 2082-2088, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31099732

RESUMEN

A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium, designated strain X7XT, was isolated from a rhizosphere soil sample of Nicotiana tabacum L. collected from a tobacco factory located in Kunming, south-western China. The cells showed oxidase-positive and catalase-positive reactions. Growth occurred at 20-40 °C and pH 6.0-8.0, with optimal growth at 30 °C and pH 7.0. The predominant respiratory quinone was MK-7. The major fatty acids were identified as iso-C15 : 0, iso-C17 : 0 3OH and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c). The cellular polar lipids contained phosphatidylethanolamine, an unidentified aminophospholipid, two unidentified glycolipids, four unidentified aminolipids and four unidentified lipids. The genomic DNA G+C content was 49.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain X7XT should be affiliated to the genus Flavisolibacter. Results from further analysis showed that strain X7XT had highest 16S rRNA gene sequence similarity to Flavisolibacter metallilatus TX0661T (96.4 %) and 'Flavisolibacter swuensis' SR2-4-2T (96.4 %), followed by other species of the genus Flavisolibacter. The polyphasic taxonomic characteristics indicated that strain X7XT represents a novel species of the genus Flavisolibacter, for which the name Flavisolibacternicotianae sp. nov. (type strain X7XT=KCTC 62326T=CGMCC 16451T) is proposed.


Asunto(s)
Bacteroidetes/clasificación , Nicotiana/microbiología , Filogenia , Rizosfera , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Bacteroidetes/aislamiento & purificación , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/química , Glucolípidos/química , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
16.
Appl Microbiol Biotechnol ; 103(12): 4859-4868, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31025075

RESUMEN

Actin-regulating kinase (Ark) plays an important role in controlling endocytosis, which has been shown to be involved in the development and virulence of several fungal pathogens. However, it remains unclear whether Ark1 is required for the development and pathogenicity of an entomopathogenic fungus. Here, MrArk1 (MAA_03415), a homologue of yeast Ark1, was characterized in the insect pathogenic fungus, Metarhizium robertsii. Disruption of MrArk1 led to defects in endocytosis and a marked reduction (58%) in conidiation capacity. The reduced conidiation level was accompanied by repression of several key conidiation-related genes, including brlA, abaA, and wetA. Additionally, the deletion mutant showed a significant decrease in its tolerance to heat shock, but not to UV-B irradiation. Bioassays demonstrated attenuated virulence for the deletion mutant against Galleria mellonella via normal cuticle infection, accompanied by suppressed appressorium formation and reduced transcript levels of several genes involved in cuticle penetration. Taken together, our results indicate that MrArk1 is involved in the heat tolerance, sporulation, and virulence of M. robertsii, and thus is an important factor for sustaining the fungal potential against insect pests.


Asunto(s)
Endocitosis/genética , Metarhizium/genética , Metarhizium/patogenicidad , Proteínas Serina-Treonina Quinasas/genética , Animales , Bioensayo , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Genes Fúngicos , Cinesinas/genética , Cinesinas/metabolismo , Lepidópteros/microbiología , Metarhizium/crecimiento & desarrollo , Mutación , Proteínas Serina-Treonina Quinasas/metabolismo , Esporas Fúngicas/genética , Esporas Fúngicas/crecimiento & desarrollo , Virulencia
17.
Opt Express ; 26(8): 9676-9685, 2018 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-29715916

RESUMEN

Photonic generation of linearly chirped microwave waveforms (LCMWs) using a monolithic integrated three-section laser is experimentally demonstrated in this work. All three sections of the laser cavity, including the front DFB section, phase section and rear DFB section, have the same active layer, which can avoid the butt-joint re-growth process. The gratings in both DFB sections are fabricated by the Reconstruction Equivalent Chirp technique, which can significantly decrease the difficulties in realizing precise grating structure. By adjusting the integrated three-section semiconductor laser to work in the period-one (P1) state and applying a sweeping signal to the front DFB section, the beating signal, i.e., an LCMW with a large time bandwidth product (TBWP), can be generated. In the current proof-of-concept experiment, an LCMW with a large TBWP up to 5.159 × 105 is generated, of which the bandwidth and the duration time are 6.7 GHz and 77 us respectively. The compressed pulse width is 150 ps. In addition, by adjusting the bias currents of the rear DFB section and front DFB section as well as the amplitude of the sweeping signals, LCMWs with tunable center frequency and tunable bandwidth can be achieved.

18.
Int J Syst Evol Microbiol ; 68(8): 2574-2579, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29944093

RESUMEN

A Gram-staining-negative, aerobic, motile and rod-shaped bacterium, designated strain X1-8T, was isolated from rhizosphere soil of Nicotiana tabacum L. collected from the tobacco produce base located in Kunming, south-west PR China. Cells showed oxidase-negative and catalase-positive reactions and were motile by means of peritrichous flagella. Growth occurred at 25-40 °C and pH 6.0-8.0 with optimal growth at 30-35 °C, pH 7.0. The major respiratory lipoquinone was Q-10. C16 : 0 and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) were identified as major cellular fatty acids. The profile of polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, sphingoglycolipid, phosphatidylcholine and one unidentified glycolipid. The major polyamine was sym-homospermidine. The genomic DNA G+C content was 66.5 mol%. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that X1-8T should be affiliated to the genus Sphingomonasand formed a clade with most closely related species Sphingomonas changbaiensisNBRC 104936T. The results of 16S rRNA gene sequences similarity analysis indicated that X1-8T had the highest similarity with S. changbaiensisNBRC 104936T (98.4 %) and lower than 96.0 % with other species of the genus Sphingomonas. DNA-DNA hybridization data indicated that X1-8T represented a novel genomic species of the genus Sphingomonas. The characteristics determined in the polyphasic taxonomic study indicated that X1-8T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas tabacisoli sp. nov. (type strain X1-8T=KCTC 62032T=CGMCC 1.16275T) is proposed.


Asunto(s)
Nicotiana/microbiología , Filogenia , Rizosfera , Microbiología del Suelo , Sphingomonas/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/química , Glucolípidos/química , Hibridación de Ácido Nucleico , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Espermidina/análogos & derivados , Espermidina/química , Sphingomonas/genética , Sphingomonas/aislamiento & purificación , Ubiquinona/química
19.
Appl Opt ; 57(13): 3539-3545, 2018 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-29726528

RESUMEN

Laser-induced breakdown spectroscopy (LIBS) is a new technique for seashell elemental analysis, and now that application is in rapid development. In this work, LIBS was applied for scallop shell [Chlamys (Azumapecten) farreri] analysis using the element ratio Sr/Ca, and the analytical result was compared under objective lens (OL) focusing and single lens (SL) focusing, respectively. It is interesting to find that, under the two focusing arrangements, the ratio (Sr/Ca) variation on the shell cross section performed completely differently, while in technical aspects, the two focusing arrangements presented almost the same characteristics in a standard sample. Also, the seashell annual growth could be well indicated by high values of Sr/Ca intensity ratio when using OL, but under SL focusing no pattern was found. The difference of shell sampling amount and size might be the reason for inconsistent analysis performance under the two focusing arrangements. The scanning electron microscopy (SEM)-energy dispersive spectrometer (EDS) scanning results of the shell proved that LIBS analysis under OL focusing was closer to the actual Sr/Ca distribution than that under SL focusing. The obtained results might be useful for the methodology of LIBS in seashell applications.


Asunto(s)
Exoesqueleto/química , Calcio/análisis , Láseres de Estado Sólido , Pectinidae , Análisis Espectral/métodos , Estroncio/análisis , Animales
20.
Lasers Surg Med ; 50(3): 183-193, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29356051

RESUMEN

BACKGROUND: In clinical dermatology, the identification of subsurface vascular and structural features known to be associated with numerous cutaneous pathologies remains challenging without the use of invasive diagnostic tools. OBJECTIVE: To present an advanced optical coherence tomography angiography (OCTA) method to directly visualize capillary-level vascular and structural features within skin in vivo. METHODS: An advanced OCTA system with a 1310 nm wavelength was used to image the microvascular and structural features of various skin conditions. Subjects were enrolled and OCTA imaging was performed with a field of view of approximately 10 × 10 mm. Skin blood flow was identified using an optical microangiography (OMAG) algorithm. Depth-resolved microvascular networks and structural features were derived from segmented volume scans, representing tissue slabs of 0-132, 132-330, and 330-924 µm, measured from the surface of the skin. RESULTS: Subjects with both healthy and pathological conditions, such as benign skin lesions, psoriasis, chronic graft-versus-host-disease (cGvHD), and scleroderma, were OCTA scanned. Our OCTA results detailed variations in vascularization and local anatomical characteristics, for example, depth-dependent vascular, and structural alterations in psoriatic skin, alongside their resolve over time; vascular density changes and distribution irregularities, together with corresponding structural depositions in the skin of cGvHD patients; and vascular abnormalities in the nail folds of a patient with scleroderma. CONCLUSION: OCTA can image capillary blood flow and structural features within skin in vivo, which has the potential to provide new insights into the pathophysiology, as well as dynamic changes of skin diseases, valuable for diagnoses, and non-invasive monitoring of disease progression and treatment. Lasers Surg. Med. 50:183-193, 2018. © 2018 Wiley Periodicals, Inc.


Asunto(s)
Angiografía , Enfermedades de la Piel/diagnóstico por imagen , Tomografía de Coherencia Óptica , Humanos , Microvasos/diagnóstico por imagen
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