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Reversible three-electron redox of Cr3+ /Cr6+ in layered cathode materials for rechargeable batteries is very attractive in layered cathode materials, which leads to high capacity and energy density for rechargeable batteries. However, the poor reversibility and Cr-ion migration make it very challenging. In this work, by introducing V ions into tetrahedral sites of layer-structured NaCrO2 , reversible three-electron redox of Cr3+ /Cr6+ is realized successfully in NaCr0.92 V0.05 O2 (NCV05) cathode for potassium-ion batteries with a cut-off voltage of 4.0 V. V ions can weaken the attraction of Cr to electrons, leading to enhanced valence change of Cr ions. On the other hand, V in tetrahedral sites can facilitate the reversible migration of Cr between octahedral and tetrahedral sites via coulombic repulsion to realize the reversible redox between Cr3+ and Cr6+ during charge and discharge processes. In addition, V ions can inhibit the phase transition from O3 phase to O'3 phase during the charge process by adjusting the crystal lattices. As a result, the NaCr0.92 V0.05 O2 cathode exhibits a high reversible capacity of 130 mAh g-1 with promising cycle stability and rate capability. The strategy opens new opportunity for developing high-capacity cathode materials for potassium-ion batteries.
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Ulcerative colitis, an inflammatory bowel disease, manifests with symptoms such as abdominal pain, diarrhea, and mucopurulent feces. The long non-coding RNA (lncRNA) ANRIL exhibits significantly reduced expression in UC, yet its specific mechanism is unknown. This study revealed that ANRIL is involved in the progression of UC by inhibiting IL-6 and TNF-α via miR-191-5P/SATB1 axis. We found that in patients with UC, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were significantly overexpressed in inflamed colon sites, whereas ANRIL was significantly under-expressed and associated with disease severity. The downregulation of ANRIL resulted in the increased expression of IL-6 and TNF-α in LPS-treated FHCs. ANRIL directly targeted miR-191-5p, thereby inhibiting its expression and augmenting SATB1 expression. Moreover, overexpression of miR-191-5p abolished ANRIL-mediated inhibition of IL-6 and TNF-α production. Dual luciferase reporter assays revealed the specific binding of miR-191-5p to ANRIL and SATB1. Furthermore, the downregulation of ANRIL promoted DSS-induced colitis in mice. Together, we provide evidence that ANRIL plays a critical role in regulating IL-6 and TNF-α expression in UC by modulating the miR-191-5p/SATB1 axis. Our study provides novel insights into progression and molecular therapeutic strategies in UC.
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For buried municipal tunnels-such as cable tunnels and utility tunnels with structural defects-due to the sheltering of the internal pipelines, shelves, and other auxiliary facilities, traditional trenchless rehabilitating methods are not applicable since an intact ring is needed for spraying and lining. In these tunnels, only the exposed area at the crown of the ring can be partly rehabilitated. In this paper, three-edge bearing tests (TEBTs) for partially rehabilitated reinforced concrete (RC) pipe sections are carried out to simulate the case of a municipal tunnel and the effects of different repair materials (cement mortar and epoxy resin) and different dimensional parameters of the liner (lining thickness, lining range) on the partial rehabilitation effect of defective RC pipes are studied. The deforming compatibility of the liner-pipe interface is discussed, and the flexural rigidity of the partially rehabilitated section is calculated. The results show that the load-carrying capacities of partial rehabilitated RC pipes are effectively improved.
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The ability to consistently distinguish real protein structures from computationally generated model decoys is not yet a solved problem. One route to distinguish real protein structures from decoys is to delineate the important physical features that specify a real protein. For example, it has long been appreciated that the hydrophobic cores of proteins contribute significantly to their stability. We used two sources to obtain datasets of decoys to compare with real protein structures: submissions to the biennial Critical Assessment of protein Structure Prediction competition, in which researchers attempt to predict the structure of a protein only knowing its amino acid sequence, and also decoys generated by 3DRobot, which have user-specified global root-mean-squared deviations from experimentally determined structures. Our analysis revealed that both sets of decoys possess cores that do not recapitulate the key features that define real protein cores. In particular, the model structures appear more densely packed (because of energetically unfavorable atomic overlaps), contain too few residues in the core, and have improper distributions of hydrophobic residues throughout the structure. Based on these observations, we developed a feed-forward neural network, which incorporates key physical features of protein cores, to predict how well a computational model recapitulates the real protein structure without knowledge of the structure of the target sequence. By identifying the important features of protein structure, our method is able to rank decoy structures with similar accuracy to that obtained by state-of-the-art methods that incorporate many additional features. The small number of physical features makes our model interpretable, emphasizing the importance of protein packing and hydrophobicity in protein structure prediction.
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Algoritmos , Biologia Computacional , Dobramento de Proteína , Proteínas/química , Conformação ProteicaRESUMO
There have been several studies suggesting that protein structures solved by NMR spectroscopy and X-ray crystallography show significant differences. To understand the origin of these differences, we assembled a database of high-quality protein structures solved by both methods. We also find significant differences between NMR and crystal structures-in the root-mean-square deviations of the C α atomic positions, identities of core amino acids, backbone, and side-chain dihedral angles, and packing fraction of core residues. In contrast to prior studies, we identify the physical basis for these differences by modeling protein cores as jammed packings of amino acid-shaped particles. We find that we can tune the jammed packing fraction by varying the degree of thermalization used to generate the packings. For an athermal protocol, we find that the average jammed packing fraction is identical to that observed in the cores of protein structures solved by X-ray crystallography. In contrast, highly thermalized packing-generation protocols yield jammed packing fractions that are even higher than those observed in NMR structures. These results indicate that thermalized systems can pack more densely than athermal systems, which suggests a physical basis for the structural differences between protein structures solved by NMR and X-ray crystallography.
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Aminoácidos/química , Cristalografia por Raios X/métodos , Ressonância Magnética Nuclear Biomolecular/métodos , Proteínas/química , Sequência de Aminoácidos , Cristalização , Conjuntos de Dados como Assunto , Conformação Proteica , Proteínas/ultraestrutura , SoluçõesRESUMO
Dense packing of hydrophobic residues in the cores of globular proteins determines their stability. Recently, we have shown that protein cores possess packing fraction Ï≈0.56, which is the same as dense, random packing of amino-acid-shaped particles. In this article, we compare the structural properties of protein cores and jammed packings of amino-acid-shaped particles in much greater depth by measuring their local and connected void regions. We find that the distributions of surface Voronoi cell volumes and local porosities obey similar statistics in both systems. We also measure the probability that accessible, connected void regions percolate as a function of the size of a spherical probe particle and show that both systems possess the same critical probe size. We measure the critical exponent τ that characterizes the size distribution of connected void clusters at the onset of percolation. We find that the cluster size statistics are similar for void percolation in packings of amino-acid-shaped particles and randomly placed spheres, but different from that for void percolation in jammed sphere packings. We propose that the connected void regions are a defining structural feature of proteins and can be used to differentiate experimentally observed proteins from decoy structures that are generated using computational protein design software. This work emphasizes that jammed packings of amino-acid-shaped particles can serve as structural and mechanical analogs of protein cores, and could therefore be useful in modeling the response of protein cores to cavity-expanding and -reducing mutations.
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Modelos Moleculares , Proteínas/química , Conformação ProteicaRESUMO
BACKGROUND AND AIM: Budesonide is a second-generation steroid with prominent topical effects and minimal systemic activity for patients with ulcerative colitis (UC). We perform a systematic review and meta-analysis of randomized placebo-controlled trials to assess the efficacy and safety of budesonide foam in mild-to-moderate distal UC. METHODS: Comprehensive searches were performed to identify all eligible studies. Outcome measures were clinical remission, endoscopic improvement, elimination of rectal bleeding, and adverse events. The risk ratio (RR) with 95% confidence interval (CI) was estimated for each outcome. All statistical analyses were performed in STATA 12.0. RESULTS: Three randomized placebo-controlled trials recruiting 711 patients with mild-to-moderate distal UC were included in this study. No significant bias and heterogeneity was identified. Pooled analyses showed that budesonide foam was significantly superior to placebo for induction of clinical remission (RR = 1.83, 95%CI: 1.41, 2.37; P < 0.001) and endoscopic improvement (RR = 1.44, 95%CI: 1.23, 1.68; P < 0.001), and eliminating rectal bleeding at week 2 (RR = 2.00, 95%CI: 1.50, 2.66; P < 0.001), week 4 (RR = 1.73, 95%CI: 1.42, 2.12; P < 0.001), and week 6 (RR = 1.76, 95%CI: 1.45, 2.14; P < 0.001). No statistically significant difference was observed in the incidence of treatment-related adverse events and therapeutic discontinuation because of adverse events between budesonide foam and placebo. CONCLUSIONS: Budesonide foam is well tolerated and superior to placebo in inducing clinical remission and endoscopic improvement, and eliminating rectal bleeding for mild-to-moderate distal UC.
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Budesonida/administração & dosagem , Colite Ulcerativa/tratamento farmacológico , Adulto , Formas de Dosagem , Método Duplo-Cego , Composição de Medicamentos , Feminino , Humanos , Masculino , Estudos Multicêntricos como Assunto , Efeito Placebo , Ensaios Clínicos Controlados Aleatórios como Assunto , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
Aquaporin 9 (AQP9) is the main aquaglyceroporin in the liver. Few studies have been performed regarding the role of AQP9 in liver cancer. Here we report AQP9 expression and function in liver cancer. We found that AQP9 mRNA and protein levels were reduced in human hepatocellular cancer compared to the para-tumor normal liver tissues. Human hepatoma cell line SMMC7721 expressed low basal levels of AQP9. When AQP9 was overexpressed in SMMC7721 cell line, cell proliferation was inhibited due to cell cycle arrest at G1 phase and increased apoptosis. At the molecular level, AQP9 overexpression decreased the protein levels of phosphatidylinositol-3-kinase (PI3K), leading to reduced phosphorylation of Akt. Subsequently, the protein levels of forkhead box protein O1 (FOXO1) were increased, resulting in down-regulation of proliferating cell nuclear antigen (PCNA) expression and up-regulation of caspase-3 expression. AQP9 overexpression inhibited growth of subcutaneously xenografted liver tumors in nude mice. These findings suggest that AQP9 expression is down-regulated in liver cancer compared to the normal liver tissue and restoration of AQP9 expression can inhibit development of liver cancer.
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Aquaporinas/genética , Carcinoma Hepatocelular/genética , Proteína Forkhead Box O1/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , Adulto , Animais , Aquaporinas/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Feminino , Proteína Forkhead Box O1/metabolismo , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transplante Heterólogo , Regulação para CimaRESUMO
BACKGROUND AND AIM: The efficacy and safety of transarterial chemoembolization (TACE) plus sorafenib for patients with hepatocellular carcinoma (HCC) have been explored by many studies, but the results were controversial. Therefore, we performed this meta-analysis of high-quality randomized controlled trials to evaluate the efficacy and safety of TACE plus sorafenib versus TACE monotherapy in the early or intermediate stage HCC. METHODS: Multi-databases were systematically searched to identify all eligible literatures. The hazard ratio (HR) or risk ratio (RR) with 95% confidence intervals (95%CIs) for time to progression (TTP), overall survival (OS), objective response rate (ORR), disease control rate (DCR) and the incidence of treatment-related adverse events (AEs) were pooled using a fixed or random effect model in STATA 12.0. RESULTS: Four randomized controlled trials, including a total of 887 patients with early or intermediate stage HCC, were included in this meta-analysis. The pooled results showed that TACE plus sorafenib significantly improved TTP (HR=0.77, 95% CI: 0.64-0.92; P=0.005). Nevertheless, the OS (HR=0.97, 95% CI: 0.72-1.29; P=0.828), ORR (RR=1.20, 95% CI: 0.88-1.64; P=0.257) and DCR (RR=1.04, 95% CI: 0.90-1.02; P=0.568) were not improved. The incidence of treatment-related AEs was higher in the TACE plus sorafenib. CONCLUSIONS: Evidences from the meta-analysis of high-quality randomized controlled trials indicate that TACE plus sorafenib can significantly improve TTP but not OS, ORR and DCR in early or intermediate stage HCC. In addition, the combination therapy increases the adverse events which usually disturb the treatment progress and should be increased attention.
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Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica , Neoplasias Hepáticas/terapia , Niacinamida/análogos & derivados , Compostos de Fenilureia/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Carcinoma Hepatocelular/mortalidade , Progressão da Doença , Humanos , Neoplasias Hepáticas/mortalidade , Niacinamida/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , SorafenibeRESUMO
Aquaporin 9 (AQP9) is the main aquaglyceroporin in the liver. Few studies have been performed regarding the role of AQP9 in hepatocellular carcinoma (HCC). Here, we report the expression and function of AQP9 in HCC tissues and cell lines. We found that AQP9 mRNA and protein levels were down-regulated in HCC tissues and human hepatoma cell lines compared to the para-cancer normal liver tissues and normal hepatocyte line, respectively. In a human HCC SMMC-7721 cell line, over-expression of AQP9 suppressed cell invasion in vitro and xenograft tumor growth in vivo. AQP9 over-expression increased the expression of E-cadherin and decreased the expression of N-cadherin in SMMC-7721 cells and xenografted tumors, which was correlated with decreased levels of phosphoinositide 3-kinase (PI3K) and p-Akt. Conversely, using siRNA to knock down AQP9 over-expression could reverse the phenotype caused by AQP9 over-expression. Our findings suggest that AQP9 is down-regulated in hepatocellular carcinoma and its over-expression suppresses hepatoma cell invasion through inhibiting epithelial-to-mesenchymal transition.
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Aquaporinas/metabolismo , Carcinoma Hepatocelular/metabolismo , Movimento Celular , Transição Epitelial-Mesenquimal , Neoplasias Hepáticas/metabolismo , Neoplasias Pulmonares/metabolismo , Adulto , Animais , Aquaporinas/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/secundário , Feminino , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/prevenção & controle , Neoplasias Pulmonares/secundário , Masculino , Camundongos Nus , Pessoa de Meia-Idade , Invasividade Neoplásica , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , Transdução de Sinais , Fatores de Tempo , Transfecção , Carga TumoralRESUMO
Although a flow cytometer, being one of the most popular research and clinical tools for biomedicine, can analyze cells based on the cell size, internal structures such as granularity, and molecular markers, it provides little information about the physical properties of cells such as cell stiffness and physical interactions between the cell membrane and fluid. In this paper, we propose a computational cell analysis technique using cells' different equilibrium positions in a laminar flow. This method utilizes a spatial coding technique to acquire the spatial position of the cell in a microfluidic channel and then uses mathematical algorithms to calculate the ratio of cell mixtures. Most uniquely, the invented computational cell analysis technique can unequivocally detect the subpopulation of each cell type without labeling even when the cell type shows a substantial overlap in the distribution plot with other cell types, a scenario limiting the use of conventional flow cytometers and machine learning techniques. To prove this concept, we have applied the computation method to distinguish live and fixed cancer cells without labeling, count neutrophils from human blood, and distinguish drug treated cells from untreated cells. Our work paves the way for using computation algorithms and fluidic dynamic properties for cell classification, a label-free method that can potentially classify over 200 types of human cells. Being a highly cost-effective cell analysis method complementary to flow cytometers, our method can offer orthogonal tests in companion with flow cytometers to provide crucial information for biomedical samples.
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Citometria de Fluxo , Técnicas Analíticas Microfluídicas , Algoritmos , Linhagem Celular Tumoral , Tamanho Celular , Humanos , Neutropenia/diagnóstico , Neutrófilos/citologiaRESUMO
Aquaglyceroporins (AQPs) are a subset of the aquaporin family, and are permeable to water and glycerol. The aim of the present study was to determine the expression and clinical significance of three AQPs, AQP3, 7 and 9 in hepatocellular carcinoma (HCC). Fresh HCC and adjacent nontumorous liver tissues were collected from 68 patients diagnosed with HCC. The expression levels of AQP3, 7 and 9 were detected by reverse transcriptionquantitative polymerase chain reaction, western blotting and immunohistochemical analysis. The association between the expression of AQPs and clinicopathological parameters of HCC were investigated. Compared with nontumorous liver tissue, HCC tissues exhibited a significant (P<0.05) increase in the expression of AQP3 and a concomitant reduction in the expression levels of AQP7 and AQP9, at both the mRNA and protein levels. Immunohistochemistry revealed that AQP9 was dominantly localized on the plasma membrane of hepatocytes, while AQP3 and AQP7 exhibited a predominantly cytoplasmic and nuclear distribution. High expression of AQP3 was significantly (P<0.05) associated with low expression levels of AQP7 and AQP9. High expression of AQP3 was correlated with tumor grade (P=0.017), tumor stage (P=0.010) and lymphatic metastasis (P=0.031). Low expression of AQP7 was correlated with tumor grade (P=0.043). AQP3 was upregulated, and AQP7 and AQP9 were downregulated in HCC. A high expression of AQP3 and low expression of AQP7 was significantly associated with the aggressive features of HCC.
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Aquagliceroporinas/biossíntese , Carcinoma Hepatocelular/metabolismo , Membrana Celular/metabolismo , Regulação Neoplásica da Expressão Gênica , Hepatócitos/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas de Neoplasias/biossíntese , Carcinoma Hepatocelular/patologia , Membrana Celular/patologia , Feminino , Hepatócitos/patologia , Humanos , Neoplasias Hepáticas/patologia , MasculinoRESUMO
Aquaporin (AQP) 9 transports glycerol and water, and belongs to the aquaglyceroporin subfamily. Insulin acts as a negative regulator of AQP9, and FOXO1 has the ability to mediate the regulatory effects of insulin on target gene expression. The aim of the present study was to determine whether insulininduced repression of AQP9 involved an epigenetic mechanism. HepG2 human hepatocyte cells were treated with 500 µM insulin for different durations. AQP9 mRNA expression levels were determined by quantitative polymerase chain reaction (qPCR), and histone H3 acetylation, phosphorylation and methylation at the insulin responsive element (IRE) of the AQP9 promoter was assessed using chromatin immunoprecipitation coupled with qPCR. The effects of lentiviral FOXO1 overexpression on AQP9 expression levels and H3 modifications at the AQP9 promoter were also determined. The insulin treatment resulted in a significant and timedependent reduction in AQP9 mRNA expression levels in HepG2 cells, as compared with untreated cells (P<0.05). In the insulintreated cells, the levels of H3 acetylation and phosphorylation were significantly reduced (P<0.05), but the level of H3 methylation was increased. Enforced expression of FOXO1 increased AQP9 mRNA and protein expression levels in HepG2 cells. Furthermore, FOXO1 overexpression promoted H3 acetylation and phosphorylation, and reduced H3 methylation at the IRE locus of the AQP9 promoter. These data provide, to the best of our knowledge, the first evidence that insulininduced transcriptional suppression of AQP9 expression in hepatocytes involves FOXO1mediated H3 modifications at the IRE locus in the promoter.
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Aquaporinas/genética , Epigênese Genética , Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Hepatócitos/metabolismo , Insulina/farmacologia , Aquaporinas/metabolismo , Linhagem Celular , Proteína Forkhead Box O1 , Expressão Gênica , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Histonas/metabolismo , Humanos , Regiões Promotoras Genéticas , Processamento Pós-Transcricional do RNA/efeitos dos fármacos , Elementos de RespostaRESUMO
Sensitivity, dynamic range and detection efficiency are among the key figures of merit for 1550 nm wavelength detectors that find applications in communications, sensing, and imaging. Some fundamental material and device limits have added tremendous difficulties for a single device to achieve high sensitivity and dynamic range without significant trade-offs. We present a concept that can potentially overcome this performance bottleneck. Preliminary results have shown a sensitivity of 10 photons (six photons from the quantum limit) and a large dynamic range (in the sense that output increases monotonically with input). The concept opens up a new avenue for detecting single photons in non-Geiger-mode with near 100% detection efficiency.
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OBJECTIVE: To study the effect of oleic acid (OA) on expression of aquaglyceroporin genes, AQP3 and AQP9, in hepatocyte steatosis and to investigate the underlying molecular mechanisms using an in vitro system. METHODS: HepG2 cells were treated with OA at different concentration to establish in vitro models of nonalcoholic hepatocyte steatosis. The corresponding extents of hepatic steatosis modeling were assessed by oil red O staining and optical density (OD) measurements of the intracellular fat content. The model lines were then treated with inhibitors of the PI3K/Akt and p38 MAPK signaling pathway factors and effects on AQP3/9 expression was measured by real time RT-PCR and western blotting. RESULTS: The fat concentration, indicative of hepatic steatosis, increased in conjunction with increased concentrations of OA (0 less than 250 less than 500 mumol/L). OA exposure also down-regulated AQP3 mRNA and up-regulated AQP9 mRNA levels in a concentration-dependent manner. The most robust changes in expression occurred in response to the 500 mumol/L concentration of OA for both AQP3 (0.47+/-0.18; t = 4.5450, P less than 0.05) and AQP9 (1.57+/-0.21; t = 3.0306, P less than 0.05). Treatment with OA + PI3K pathway inhibitor (LY294004) significantly decreased AQP9 mRNA expression (4.55+/-0.62) as compared to the control group (1.00+/-0.10; t = 9.7909, P less than 0.01), that 500 mumol/L OA group (2.43+/-0.53; t = 4.5018, P less than 0.05), and the LY294002 group (1.90+/-0.16; t = 7.1683, P less than 0.01). Treatment with p38 MAPK pathway inhibitor (SB230580) significantly increased the OA-suppressed level of AQP3 mRNA to the level detected in the control group (1.27+/-0.11; t = 5.7455, P less than 0.01) and decreased the OA-stimulated AQP9 mRNA (0.38+/-0.09; t = 6.5727, P less than 0.01). No significant changes in mRNA expression of AQP3/9 were observed with inhibition of the ERK1/2 and JNK signal transduction pathways. The OA-induced changes in protein expression levels of AQR3 and AQP9 followed a similar trend of the genes. Finally, OA suppressed the level of phosphorylated Akt (from 0.21+/-0.02 to 0.13+/-0.03; t = 3.8431, P less than 0.05) but elevated the level of phosphorylated p38 (from 0.58+/-0.06 to 1.02+/-0.10; t = 12.5289, P less than 0.01). Again, OA treatment produced no significant affect on ERK1/2 and JNK phosphorylation. CONCLUSION: OA down-regulates AQP3 expression by stimulating the p38 MAPK signaling pathway, and up-regulates the AQP9 by blocking the PI3K/Akt pathway and activating the p38 MAPK signaling pathway.
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Aquaporina 3/metabolismo , Aquaporinas/metabolismo , Ácido Oleico/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Regulação da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
A unique optofluidic lab-on-a-chip device that can measure optically encoded forward scattering signals has been demonstrated. From the design of the spatial pattern, the position and velocity of each cell in the flow can be detected and then a spatial cell distribution over the cross section of the channel can be generated. According to the forward scattering intensity and position information of cells, a data-mining method, support vector machines (SVMs), is applied for cell classification. With the help of SVMs, the multi-dimensional analysis can be performed to significantly increase all figures of merit for cell classification.
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We have demonstrated a microfluidic device that can not only achieve three-dimensional flow focusing but also confine particles to the center stream along the channel. The device has a sample channel of smaller height and two sheath flow channels of greater height, merged into the downstream main channel where 3D focusing effects occur. We have demonstrated that both beads and cells in our device display significantly lower CVs in velocity and position distributions as well as reduced probability of coincidental events than they do in conventional 2D-confined microfluidic channels. The improved particle confinement in the microfluidic channel is highly desirable for microfluidic flow cytometers and in fluorescence-activated cell sorting (FACS). We have also reported a novel method to measure the velocity of each individual particle in the microfluidic channel. The method is compatible with the flow cytometer setup and requires no sophisticated visualization equipment. The principles and methods of device design and characterization can be applicable to many types of microfluidic systems.
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Citometria de Fluxo/instrumentação , Microfluídica , Microfluídica/instrumentação , Microfluídica/métodosRESUMO
The aim of this study is to investigate the efficacy and safety of extracorporeal high-intensity focused ultrasound (HIFU) in treatment of hypersplenism. Fifteen adult dogs, weighing 13-18 kg were divided into three groups: sham group, SVL group undergoing splenic vein ligation (SVL) after laparotomy, and SVL + HIFU group receiving SVL followed by extracorporeal HIFU. Pathologic and hematologic analyses were performed. We also reviewed the clinical data of 19 patients with secondary hypersplenism caused by liver cirrhosis or hepatocellular carcinoma who underwent extracorporeal HIFU. Extracorporeal HIFU significantly diminished the volume of the spleen of animals, coupled with occurrence of coagulation necrosis and fibrosis in the target area. Both platelet and red blood cell counts were significantly restored by HIFU intervention. Similarly, HIFU treatment improved the hematologic parameters in patients with hypersplenism, and no major complications were encountered. Extracorporeal HIFU intervention is effective and safe in managing secondary hypersplenism.
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Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Hiperesplenismo/etiologia , Hiperesplenismo/terapia , Cirrose Hepática/complicações , Cirrose Hepática/terapia , Adulto , Idoso , Animais , Cães , Feminino , Humanos , Hiperesplenismo/diagnóstico por imagem , Cirrose Hepática/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , UltrassonografiaRESUMO
We demonstrated a unique optofluidic lab-on-a-chip device that can measure optically encoded forward scattering signals. From the design of the spatial pattern, we can measure the position and velocity of each cell in the flow and generate a 2-D cell distribution plot over the cross section of the channel. Moreover, we have demonstrated that the cell distribution is highly sensitive to its size and stiffness. The latter is an important biomarker for cell classification and our method offers a simple and unequivocal method to classify cells by their size and stiffness. We have proved the concept using live and fixed HeLa cells. Due to the stiffness and size difference of neutrophils compared to other types of white blood cells, we have demonstrated detection of neutrophils from other blood cells. Finally, we have performed the test using 5 µL of human blood. In a greatly simplified blood preparation process, skipping the usual steps of anticoagulation, centrifuge, antibody labelling or staining, filtering, etc., we have demonstrated that our device and detection principle can count neutrophils in whole human blood. Our system is compact, inexpensive and simple to fabricate and operate, having a commodity laser diode and a Si PIN photoreceiver as the main pieces of hardware. Although the results are still preliminary, the studies indicate that this optofluidic device holds promise to be a point-of-care and home care device to measure neutrophil concentration, which is the key indicator of the immune functions for cancer patients undergoing chemotherapy.
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Técnicas Analíticas Microfluídicas/instrumentação , Neutrófilos/citologia , Óptica e Fotônica/instrumentação , Células Sanguíneas/citologia , Tamanho Celular , Células HeLa , Humanos , Dispositivos Lab-On-A-Chip , Lasers , Técnicas Analíticas Microfluídicas/métodos , Silício/químicaRESUMO
A microfluidic lab-on-a-chip Coulter counter was demonstrated to count micro particles and leukocytes from whole blood. Instead of electroplated or deposited metal electrodes, off-the-shelf gold pins were used as electrodes to simplify fabrication process, reduce cost, enhance device durability, and above all, achieve superior uniformity in E-field distribution for improved signal quality. A custom-designed, low-cost demodulation circuit was developed to detect the AC impedance signals of the particles and cells passing the detection area defined by the microfluidic channels. A mixture of polystyrene beads with three different sizes was used to characterize the device. The results showed high throughput at 2000 particles/s and clear separation among different sizes of beads with coefficients of variation (CV) of 13.53%, 10.35% and 5.67% for 7.66 µm, 10.5 µm and 14.7 µmbeads, respectively. To demonstrate the potential for a point-of-care or self-administered device for cancer patients going through chemotherapy, we have used the lab-on-a-chip device to count leukocytes from whole blood, generating encouraging preliminary results comparable to the results from a commercial flow cytometer.