RESUMO
A universally applicable approach is proposed for the fabrication of fiber-optic polymer sensors. The hollow-core fibers (HCFs) with inner diameters of 30â µm, 50â µm, and 75â µm are spliced coaxially with dual-hole fiber (DHF) or photonic crystal fiber (PCF). Owing to the sized-matched air holes within HCF and DHF/PCF, an interconnected in-fiber microchannel is constructed, which facilitates rapid and complete filling of the HCF's central hole with liquid glue. After the ultraviolet-induced polymerization, a polymer Fabry-Perot interferometer is achieved by cutting the HCF end with a desired cavity length. Besides, the interference visibility is significantly enhanced by adding a refractive-index-modulated polymer cap onto the cutting surface. Experimental results demonstrate the optimized interference spectra and the interconnection of the matched air-hole fibers. The polymer sensor exhibits a signal-to-noise ratio of 56.8â dB for detecting pulsed ultrasonic waves, which is more than twice that of a partially polymer-filled sensor. Due to the hermetically-sealed structure, the sensor probe presents constrained performance with a temperature sensitivity of 230.2 pm/°C and a humidity sensitivity of 93.7 pm/%RH, which can be further improved by releasing the polymer waveguide from fiber cladding. Based on interconnected holey fibers, the proposed approach has a uniform size-controlled polymer waveguide dimension with increased spectrum visibility, rendering it suitable for a diverse range of microstructure-matched optical fibers.
RESUMO
A suspended polymer rod grating is fabricated on a fiber end for highly sensitive ultrasonic detection. Initially, the uniform polymer waveguide is prepared via the interconnection of holey fibers and the photopolymerization of an ultraviolet glue. A femtosecond laser point-by-point technique is then employed to form periodic grating structures inside the customized waveguide. A final uncovered micro-rod is achieved based on different corrosion resistances of the polymer waveguide and the fiber cladding. The polymer rod presents uniform morphology and controllable size with the support of the constructed air-hole microchannel. The self-alignment and the self-adhesion between the polymer waveguide and the fiber core contribute to the stable efficient optical coupling at the fiber-to-polymer joint. When applied to ultrasonic waves, the decreased size and low Young's modulus of the suspended rod provide benefits for the interaction between the polymer grating and the ultrasound strain. This sensor exhibits a noise equivalent pressure of 33 Pa and -10 d B bandwidth of 7.6 MHz. After packing with a waterproof adhesive, the polymer rod shows sufficient robustness for long-term operation. This Letter proposes a new, to the best of our knowledge, strategy for the fabrication of advanced polymer probes in multifunctional sensing.
RESUMO
A micro ultrasonic sensor based on an advanced suspended-core fiber is proposed and employed for in-lab seismic physical modeling. A free suspended core is obtained by acid corrosion and two cascaded uniform fiber Bragg gratings (FBGs) are imprinted in the suspended-core fiber. The sensor response and stability are largely improved due to the using of dual-FBG reflectors instead of weak-reflection fiber mirrors for constructing an in-fiber interferometer. The characteristics of reflection spectra and ultrasonic response of the sensor are analyzed and demonstrated experimentally. Comparative measurements are also carried out to prove the sensor superiority over the conventional weak-reflection one. Moreover, the sensor is used for seismic physical modeling to show its ability of practicable usage. Both the crosswell seismic and surface seismic in seismic exploration are modeled respectively based on reservoir and fault models. Various reservoir velocities are measured and each is consistent with the reported results. The fault features are also well reconstructed in the form of a cross-section model image. The improved sensor approach greatly promotes the application of the suspended-core fiber for weak acoustic detection in seismic physical modeling.
RESUMO
Circular RNAs (circRNAs) are a class of endogenous, covalently closed, single-stranded RNA without 3'-poly(A) and 5'-cap structures. CircRNAs are characterized by universality, diversity, stability and conservation, and have been found to regulate mammalian transcription and be translated into proteins. In this review, we summarized the biogenesis, classification, expression, distribution, biological functions and regulation of circRNAs. In addition, we discussed the association of circRNAs with diseases and the methods for identification and characterization of circRNAs. Finally, we speculated the application prospect and research direction of circRNAs.
Assuntos
RNA/genética , Animais , RNA Circular , Pesquisa/tendênciasRESUMO
A high-resolution fiber-optic ultrasonic sensor based on a suspended-core fiber was designed and experimentally demonstrated. The intrinsic Fabry-Perot interferometer consisting of a micro suspended-core from acid corrosion of a grapefruit fiber proved highly sensitive to a wide range of ultrasonic wave (UW) frequencies. A compact interrogation system using spectral sideband filtering was constructed for UW detection. The sensor exhibited significantly improved spatial resolution and detection sensitivity by etching the suspended-core diameter to few microns. Sensor fabrication involves only fiber splicing and corrosion, which provide a self-shielding cladding surrounding and protecting the core from collisions. This sensor is an excellent candidate for high-quality UW detection.
RESUMO
A compact in-line interferometer is proposed and experimentally demonstrated for gas refractive index (GRI) measurement. The sensor comprises a tapered four-core fiber (TFCF) sandwiched between two single-mode fibers (SMFs), forming an in-line SMF-TFCF-SMF structure. The fiber taper acts as a bridge between the external GRI variation and the multimode interference within the TFCF segment. A high sensitivity of 1280.94 dB/refractive index unit is obtained in GRI measurement around 1.0. Temperature change only shifts the interference wavelength, and the cross-sensitivity of temperature can be ignored by intensity demodulation. The proposed gas refractometer, with its improved performance, can be a good candidate for chemical sensing or bio-sensing.
RESUMO
With the oil and gas industry growing rapidly, increasing the yield and profit require advances in technology for cost-effective production in key areas of reservoir exploration and in oil-well production-management. In this paper we review our group's research into fiber Bragg gratings (FBGs) and their applications in the oil industry, especially in the well-logging field. FBG sensors used for seismic exploration in the oil and gas industry need to be capable of measuring multiple physical parameters such as temperature, pressure, and acoustic waves in a hostile environment. This application requires that the FBG sensors display high sensitivity over the broad vibration frequency range of 5 Hz to 2.5 kHz, which contains the important geological information. We report the incorporation of mechanical transducers in the FBG sensors to enable enhance the sensors' amplitude and frequency response. Whenever the FBG sensors are working within a well, they must withstand high temperatures and high pressures, up to 175 °C and 40 Mpa or more. We use femtosecond laser side-illumination to ensure that the FBGs themselves have the high temperature resistance up to 1100 °C. Using FBG sensors combined with suitable metal transducers, we have experimentally realized high- temperature and pressure measurements up to 400 °C and 100 Mpa. We introduce a novel technology of ultrasonic imaging of seismic physical models using FBG sensors, which is superior to conventional seismic exploration methods. Compared with piezoelectric transducers, FBG ultrasonic sensors demonstrate superior sensitivity, more compact structure, improved spatial resolution, high stability and immunity to electromagnetic interference (EMI). In the last section, we present a case study of a well-logging field to demonstrate the utility of FBG sensors in the oil and gas industry.
RESUMO
A fiber-optic Fabry-Perot interferometer (FPI) has been proposed and demonstrated for the ultrasound wave (UW) imaging of seismic-physical models. The sensor probe comprises a single mode fiber (SMF) that is inserted into a ceramic tube terminated by an ultra-thin gold film. The probe performs with an excellent UW sensitivity thanks to the nanolayer gold film, and thus is capable of detecting a weak UW in air medium. Furthermore, the compact sensor is a symmetrical structure so that it presents a good directionality in the UW detection. The spectral band-side filter technique is used for UW interrogation. After scanning the models using the sensing probe in air, the two-dimensional (2D) images of four physical models are reconstructed.
RESUMO
A type of wave-breaking-free mode-locked dual-wavelength square pulse was experimentally observed in a figure-eight erbium-doped fiber laser with ultra-large net-anomalous dispersion. A 2.7 km long single-mode fiber (SMF) was incorporated as a nonlinear optical loop mirror (NOLM) and provided largely nonlinear phase accumulation and anomalous dispersion, which enhanced the four-wave-mixing effect to improve the stability of the dual-wavelength operation. In the NOLM, the long SMF with small birefringence supported the Sagnac interference as a filter to manage the dual-wavelength lasing. The dual-wavelength operation was made switchable by adjusting the intra-cavity polarization loss and phase delay corresponding to two square pulses. When the pump power was increased, the duration of the square pulse increased continuously while the peak pulse power gradually decreased. This square-type pulse can potentially be utilized for signal transmission and sensing.
Assuntos
Óptica e Fotônica , Desenho de Equipamento , Tecnologia de Fibra Óptica , Lasers , Lasers de Estado Sólido , Dinâmica não Linear , Refratometria , Processamento de Sinais Assistido por ComputadorRESUMO
Different soliton types are observed in a net-normal group-dispersion fiber laser based on nonlinear polarization rotation for passive mode locking. The proposed laser can deliver a dispersion-managed soliton, typical dissipation solitons, and a quasi-harmonic mode-locked pulse, a soliton bundle, and especially a dark pulse by only appropriately adjusting the linear cavity phase delay bias using one polarization controller at the fixed pump power. These nonlinear waves show different features, including the spectral shapes and time traces. The experimental observations show that the five soliton types could exist in the same laser cavity, which implies that integrable systems, dissipative systems, and dark pulse regimes can transfer and be switched in a passively mode-locked laser. Our studies not only verify the numeral simulation of the different soliton-types formation in a net-normal group-dispersion operation but also provide insight into Ginzburg-Landau equation systems.
Assuntos
Tecnologia de Fibra Óptica/instrumentação , Lasers , Luz , Modelos Teóricos , Refratometria/instrumentação , Espalhamento de Radiação , Simulação por Computador , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de EquipamentoRESUMO
In this paper, the changes in oil body emulsion (OBE) during heptanoic acid demulsification (HD) were investigated from the macro and microscopic points of view. Specifically, the OBE particle size increased from 3.04 to 8.41 µm, while the zeta potential absolute decreased to 2.89 mV. The interfacial tension and apparent viscosity of OBE were reduced significantly. Heptanoic acid could contribute to oil droplets aggregation. The findings indicated that high-molecular proteins, including lipoxygenase (97.58 kDa) and arachin (70.28 kDa), detached from the OBs' interface. HD caused alterations in the secondary structure of protein and the environment around proteins changed. The HD mechanism was speculated that the addition of heptanoic acid resulted in the reduction in pH and changes of environment surrounding OBE, which triggered polymerization and the phase transformation of the oil droplets. Overall, this study is vital for solving the problem of demulsification during aqueous enzymatic extraction (AEE).
RESUMO
The laboratory practice "Primary culture and directional differentiation of rat bone marrow mesenchymal stem cells (BMSCs)" is part of a required course for sophomore medical students at Tongji university, which has been conducted since 2012. Blended learning has been widely applied in medical courses. Based on a student-centered teaching philosophy, we reconstructed a comprehensive stem cell laboratory module with blended learning in 2021, aiming to facilitate students in enhancing their understanding of the multi-lineage differentiation potential of stem cells and improve their experimental skills, self-directed learning ability, and innovative thinking. First, we constructed in-depth online study resources, including videos demonstrating laboratory procedures, a PowerPoint slide deck, and published literature on student self-learning before class. In class, students performed a primary culture of BMSCs, freely chose among adipogenic, osteogenic, or chondrogenic differentiation, and used cytochemical or immunofluorescence staining for identification. After class, the extracurricular part involved performing quantitative polymerase chain reaction to examine the expression of multi-lineage differentiation marker genes, which was designed as an elective. After 2 years of practice, positive feedback was obtained from both students and faculty members who achieved, the learning goal as expected. The reconstructed stem cell laboratory module provides comprehensive practice opportunities for students. Students have a better understanding of BMSC at the molecular, cellular, and functional levels and have improved their experimental skills, which forms a basis for scientific research for medical students. Introducing blended learning into other medical laboratory practices thus seems valuable.
Assuntos
Diferenciação Celular , Células-Tronco Mesenquimais , Estudantes de Medicina , Humanos , Ratos , Animais , Células-Tronco Mesenquimais/citologia , Universidades , Aprendizagem , Laboratórios , Educação de Graduação em Medicina/métodosRESUMO
MicroRNA (miRNAs) are short non-coding RNA molecules that downregulate gene expression at post-transcriptional level. miRNAs are post-transcriptional regulators of gene expression important for neuron development and function. This report demonstrated that a putative and chemically synthesized miRNA rno-mir-541 played an important role in the neuron development. Differentiation of PC12 cells with nerve growth factor (NGF) is associated with neurite outgrowth, a process that involves upregulation of Synapsin I. We predicted, detected and assessed the expression levels of a number of possible miRNAs for synapsin I in rats and our outcomes showed that rno-mir-541 was associated with rat synapsin I expression. miR-541, a brain specific miRNA, plays an important role in repressing neurite extension in cultured PC12 neurons. The neurites of PC12 cells was shortened drasticly as a result of the overexpression of rno-mir-541. In contrast, the neurites of PC12 cell developed well after the knockdown of rno-mir-541 by RNA interference. Our study showed that rno-mir-541 played an important role in neuron-cell proliferation and neurite outgrowth through suppressing the expression of its target gene synapsin I. Furthermore, the introduction of NGF causes downregulation of miR-541, de-repression of its target, Synapsin-I and allows for neuritogenesis. Thus, miR-541 functions in neuronal precursors as an endogenous conditional component between NGF and Synapsin-I.
Assuntos
Diferenciação Celular , MicroRNAs/metabolismo , Neuritos/fisiologia , Sinapsinas/metabolismo , Animais , Proliferação de Células , Regulação para Baixo , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Fator de Crescimento Neural/farmacologia , Neuritos/efeitos dos fármacos , Células PC12 , Interferência de RNA , Ratos , Transfecção , Regulação para CimaRESUMO
OBJECTIVE: To investigate the expression variation of RAR-ß2, RASSF1A, and CDKN2A gene in the process of nickel-induced carcinogenesis. METHODS: Nickel subsulfide (Ni(3)S(2)) at dose of 10 mg was given to Wistar rats by intramuscular injection. The mRNA expression of the three genes in induced tumors and their lung metastasis were examined by Real-time PCR. The methylation status of the 5' region of these genes were detected by Quantitative Real-time methylation specific PCR. RESULTS: The mRNA expressions of the three genes both in muscle and lung tumor were decreased distinctly in comparison with normal tissue. But hypermethylation was found only in muscle tumor. CONCLUSION: These findings suggest that loss of function or decrease of RAR-ß2, RASSF1A, and CDKN2A, as well as the hypermethylation of 5' region of these genes, are related with nickel exposure.
Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Neoplasias Pulmonares/metabolismo , Níquel/toxicidade , Receptores do Ácido Retinoico/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Carcinógenos/toxicidade , Ilhas de CpG , Inibidor p16 de Quinase Dependente de Ciclina/genética , Metilação de DNA , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Pulmonares/induzido quimicamente , Masculino , Neoplasias Musculares/induzido quimicamente , Neoplasias Musculares/metabolismo , Ratos , Ratos Wistar , Receptores do Ácido Retinoico/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
Seizure-related gene 6 (sez-6) was originally identified in a study of pentylenetetrazole-treated cortical neurons. Further studies on the structure and expression pattern suggested that Sez-6 may play an important role in neuronal development and function. In the present study, PC12 cells were used as a model to investigate the role of Sez-6 in neurite outgrowth. After a period of NGF treatment, the expression of Sez-6 in PC12 cells was increased. When Sez-6 expression was suppressed by the addition of an effective short hairpin RNA (shRNA) plasmid, the neurite outgrowth was significantly inhibited. In addition, we detected the expression level of protein kinase Cgamma (PKCgamma), and found that the PKCgamma protein level was reduced in the differentiated PC12 cells but increased in PC12 cells lacking Sez-6. Taken together, our results indicate that Sez-6 acts on the neurite outgrowth of PC12 cells likely through the PKCgamma signaling pathways.
Assuntos
Proteínas do Tecido Nervoso/fisiologia , Neuritos , Proteína Quinase C/metabolismo , Transdução de Sinais , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Primers do DNA , Imuno-Histoquímica , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/química , Células PC12 , Ratos , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Parkinson's disease (PD) is an age-related and second most common neurodegenerative disorder. In recent years, increasing evidence revealed that peripheral immune cells might be able to infiltrate into brain tissues, which could arouse neuroinflammation and aggravate neurodegeneration. This study aimed to illuminate the landscape of peripheral immune cells and signature genes associated with immune infiltration in PD. Several transcriptomic datasets of substantia nigra (SN) from the Gene Expression Omnibus (GEO) database were separately collected as training cohort, testing cohort, and external validation cohort. The immunoscore of each sample calculated by single-sample gene set enrichment analysis was used to reflect the peripheral immune cell infiltration and to identify the differential immune cell types between PD and healthy participants. According to receiver operating characteristic (ROC) curve analysis, the immunoscore achieved an overall accuracy of the area under the curve (AUC) = 0.883 in the testing cohort, respectively. The immunoscore displayed good performance in the external validation cohort with an AUC of 0.745. The correlation analysis and logistic regression analysis were used to analyze the correlation between immune cells and PD, and mast cell was identified most associated with the occurrence of PD. Additionally, increased mast cells were also observed in our in vivo PD model. Weighted gene co-expression network analysis (WGCNA) was used to selected module genes related to a mast cell. The least absolute shrinkage and selection operator (LASSO) analysis and random-forest analysis were used to analyze module genes, and two hub genes RBM3 and AGTR1 were identified as associated with mast cells in the training cohort. The expression levels of RBM3 and AGTR1 in these cohorts and PD models revealed that these hub genes were significantly downregulated in PD. Moreover, the expression trend of the aforementioned two genes differed in mast cells and dopaminergic (DA) neurons. In conclusion, this study not only exhibited a landscape of immune infiltrating patterns in PD but also identified mast cells and two hub genes associated with the occurrence of PD, which provided potential therapeutic targets for PD patients (PDs).
RESUMO
OBJECTIVE: To identify the active material of anti-hepatic fibrosis from Amydae Carapax. METHODS: Membrane separation technology was adopted to screen active fraction in Amydae Carapax, and the active components were isolated from the active fraction using gel chromatography and high performance liquid chromatography. The purified active components in Amydae Carapax were further analyzed using 4700 series time-of-flight mass spectrometer. RESULTS: Proteins and peptides of Amydae Carapax with molecular weight less than 6000 were proved to have biological activity. 8 components (Bj1-Bj8) were isolated from the active fraction. Bj4, Bj6 and Bj7 were screened as active components. Bj7 was further purified, resulting in 7 components (Bj701-Bj707). Bj704 and Bj707 showed significant biological activity. Mass spectrometry showed three molecular ion peaks with highest abundance, i.e. m/e 526, 542 and 572, i.e. m/e 526, 542 and 572, in Bj707 -A The amino acid sequences of above three peptide compounds were NDDY (Asn-Asp-Asp-Tyr), NPNPT (Asn-Pro-Asn-Pro-Thr), and HGRFG (His-Gly-Arg-Phe-Gly), respectively. And M572 was the most abandunt components. CONCLUSION: Three active peptide compounds of anti-hepatic fibrosis of Amydae Carapax were identified.
Assuntos
Cirrose Hepática , Medicina Tradicional Chinesa , Extratos de Tecidos/isolamento & purificação , Extratos de Tecidos/farmacologia , Animais , Linhagem Celular , HumanosRESUMO
BACKGROUND: Human naïve pluripotency state cells can be derived from direct isolation of inner cell mass or primed-to-naïve resetting of human embryonic stem cells (hESCs) through different combinations of transcription factors, small molecular inhibitors, and growth factors. Long noncoding RNAs (lncRNAs) have been identified to be crucial in diverse biological processes, including pluripotency regulatory circuit of mouse pluripotent stem cells (PSCs), but few are involved in human PSCs' regulation of pluripotency and naïve pluripotency derivation. This study initially planned to discover more lncRNAs possibly playing significant roles in the regulation of human PSCs' pluripotency, but accidently identified a lncRNA whose knockdown in human PSCs induced naïve-like pluripotency conversion. METHODS: Candidate lncRNAs tightly correlated with human pluripotency were screened from 55 RNA-seq data containing human ESC, human induced pluripotent stem cell (iPSC), and somatic tissue samples. Then loss-of-function experiments in human PSCs were performed to investigate the function of these candidate lncRNAs. The naïve-like pluripotency conversion caused by CCDC144NL-AS1 knockdown (KD) was characterized by quantitative real-time PCR, immunofluorescence staining, western blotting, differentiation of hESCs in vitro and in vivo, RNA-seq, and chromatin immunoprecipitation. Finally, the signaling pathways in CCDC144NL-AS1-KD human PSCs were examined through western blotting and analysis of RNA-seq data. RESULTS: The results indicated that knockdown of CCDC144NL-AS1 induces naïve-like state conversion of human PSCs in the absence of additional transcription factors or small molecular inhibitors. CCDC144NL-AS1-KD human PSCs reveal naïve-like pluripotency features, such as elevated expression of naïve pluripotency-associated genes, increased developmental capacity, analogous transcriptional profiles to human naïve PSCs, and global reduction of repressive chromatin modification marks. Furthermore, CCDC144NL-AS1-KD human PSCs display inhibition of MAPK (ERK), accumulation of active ß-catenin, and upregulation of some LIF/STAT3 target genes, and all of these are concordant with previously reported traits of human naïve PSCs. CONCLUSIONS: Our study unveils an unexpected role of a lncRNA, CCDC144NL-AS1, in the naïve-like state conversion of human PSCs, providing a new perspective to further understand the regulation process of human early pluripotency states conversion. It is suggested that CCDC144NL-AS1 can be potentially valuable for future research on deriving higher quality naïve state human PSCs and promoting their therapeutic applications.
Assuntos
RNA Longo não Codificante/metabolismo , Linhagem Celular , Análise por Conglomerados , Regulação para Baixo , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células-Tronco Embrionárias Humanas/citologia , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Cariótipo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Interferência de RNA , RNA Longo não Codificante/antagonistas & inibidores , RNA Longo não Codificante/genética , RNA Interferente Pequeno/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , TranscriptomaRESUMO
Perfluoroisobutylene (PFIB) is produced as a main by-product in large quantities by the fluoropolymer industry. As a highly toxic compound, even the case of brief inhalation of PFIB can result in acute lung injury (ALI), pulmonary edema and even death. To test for any preventive or therapeutic effects of pyrrolidine dithiocarbamate (PDTC), a NF-kappaB activation inhibitor, against PFIB inhalation-induced ALI, mice were exposed in a flow-past exposure system to PFIB and the prophylactic and therapeutic effects of PDTC were studied. The inhibitory effects of PDTC on ALI, the activation of NF-kappaB, as well as the expression of cytokines (IL-1beta and IL-8) after PFIB exposure were evaluated. The results demonstrated that pretreatment with PDTC (120 mg/kg, 30 min before PFIB exposure) could significantly lower the lung coefficient (wet lung-to-body weight ratio, dry lung-to-body weight ratio, water content in the lung, and lung wet-to-dry weight ratio) and protein content in bronchoalveolar lavage fluid (BALF), but no effects of PDTC were found when PDTC was treated after PFIB inhalation, suggesting a preventative effect rather than a therapeutic effect of PDTC. Furthermore, the above preventative effects of PDTC (when given at 30 min before PFIB exposure) on PFIB-induced lung injury were achieved in a dose-dependent manner. In support of these preventive effects of PDTC, our toxicological studies demonstrated that PFIB-inhalation induced a quick activation of NF-kappaB (0.5 h post PFIB exposure) and expression of IL-1beta and IL-8 (0.5 h and 1 h post PFIB exposure, respectively). Pretreatment with PDTC (120 mg/kg, 30 min before PFIB exposure) resulted in a significant inhibitive effect on the activation of NF-kappaB (0.5 h post PFIB exposure) and expression of IL-1beta and IL-8 (1 h post PFIB exposure). The mortality, the extent of lung injury of the mice indexed by lung coefficients, the content of total protein and albumin in BALF, as well as the lung histopathologic changes, were dramatically alleviated in PFIB exposure after pretreatment with PDTC, clearly suggesting that PDTC has a prophylactic role against PFIB inhalation-induced ALI, and that NF-kappaB activation might play a central role in initiating an acute inflammatory response and in causing injury to the lungs after PFIB inhalation.
Assuntos
Antioxidantes/farmacologia , Fluorocarbonos/toxicidade , Pneumopatias/induzido quimicamente , Pneumopatias/prevenção & controle , Pirrolidinas/farmacologia , Tiocarbamatos/farmacologia , Administração por Inalação , Análise de Variância , Animais , Líquido da Lavagem Broncoalveolar/química , Fluorocarbonos/administração & dosagem , Masculino , CamundongosRESUMO
Optical manipulation using optical micro- and nano-fibers has shown potential for controlling bacterial activities such as E. coli trapping, propelling, and binding. Most of these manipulations have been performed using the propagation of the fundamental mode through the fiber. However, along the maximum mode-intensity axis, the higher-order modes have longer evanescent field extensions and larger field amplitudes at the fiber waist than the fundamental mode, opening up new possibilities for manipulating E. coli bacteria. In this work, a compact seven-core fiber (SCF)-based micro-fiber/optical tweezers was demonstrated for trapping, propelling, and rotating E. coli bacteria using the excitation of higher-order modes. The diameter of the SCF taper was 4 µm at the taper waist, which was much larger than that of previous nano-fiber tweezers. The laser wavelength was tunable from 1500 nm to 1600 nm, simultaneously causing photophoretic force, gradient force, and scattering force. This work provides a new opportunity for better understanding optical manipulation using higher-order modes at the single-cell level.