Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
Stem Cell Res Ther ; 14(1): 211, 2023 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-37605271

RESUMO

BACKGROUND: The efficacy of human umbilical cord mesenchymal stem cell (hUC-MSC) transplantation in treating systemic lupus erythematosus (SLE) has been confirmed by small-scale clinical trials. However, these trials focused on severe or refractory SLE, while few studies focused on mild SLE. Therefore, this study focused on the therapeutic effects of hUC-MSC transplantation in early-stage or mild MRL/lpr lupus model mice. METHODS: Commercially available hUC-MSCs were transplanted into 8-week-old MRL/lpr mice by tail vein injection. Flow cytometry was used to analyze B cells and their subsets in the peripheral blood. Further, plasma inflammatory factors, autoantibodies, and plasma biochemical indices were detected using protein chip technology and ELISA kits. In addition, pathological staining and immunofluorescence were performed to detect kidney injury in mice. RESULTS: hUC-MSC transplantation did not affect the mice's body weight, and both middle and high dose hUC-MSC transplantation (MD and HD group) actually reduced spleen weight. hUC-MSC transplantation significantly decreased the proportion of plasmablasts (PB), IgG1- PB, IgG1+ PB, IgG1+ memory B (MB) cells, IgG1+ DN MB, and IgG1+ SP MB cells. The hUC-MSC transplantation had significantly reduced plasma levels of inflammatory factors, such as TNF-α, IFN-γ, IL-6, and IL-13. Pathological staining showed that the infiltration of glomerular inflammatory cells was significantly reduced and that the level of glomerular fibrosis was significantly alleviated in hUC-MSC-transplanted mice. Immunofluorescence assays showed that the deposition of IgG and IgM antibodies in the kidneys of hUC-MSC-transplanted mice was significantly lower than in the control. CONCLUSION: hUC-MSC transplantation could inhibit the proliferation and differentiation of peripheral blood B cells in the early-stage of MRL/lpr mice, thereby alleviating the plasma inflammatory environment in mice, leading to kidney injury remission. The study provides a new and feasible strategy for SLE treatment.


Assuntos
Transplante de Células-Tronco Mesenquimais , Humanos , Animais , Camundongos , Camundongos Endogâmicos MRL lpr , Fatores Imunológicos , Imunoglobulina G , Rim
2.
Foods ; 11(1)2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35010236

RESUMO

Botryococcus braunii, a prestigious energy microalga, has recently received widespread attention because it can secrete large amounts of exopolysaccharides (EPS) with potential applications in food, cosmetics, and nutraceuticals. Unfortunately, the insufficiency of research on the bioactivity and structure-activity relationship of B. braunii EPS has impeded the downstream applications. In the present study, alcohol precipitation, deproteinization, and DEAE-cellulose column chromatography were used to extract and purify B. braunii SCS-1905 EPS. It was found that B. braunii SCS-1905 EPS were high-molecular-weight heteropolysaccharides containing uronic acid (7.43-8.83%), protein (2.30-4.04%), and sulfate groups (1.52-1.95%). Additionally, the EPS primarily comprised galactose (52.34-54.12%), glucose (34.60-35.53%), arabinose (9.41-10.32%), and minor amounts of fucose (1.80-1.99%), with the presence of a pyranose ring linked by a ß-configurational glycosidic bond. Notably, the antioxidant activity of crude exopolysaccharides (CEPS) was stronger, and the half maximal inhibitory concentration (IC50) for ABTS and hydroxyl radicals was significantly lower than that of deproteinized exopolysaccharides (DEPS). Overall, this study indicated a potential application of B. braunii SCS-1905 EPS as a natural antioxidant. In summary, B. braunii EPS could be used as a potential feedstock for the production of antioxidant health foods.

3.
Front Immunol ; 12: 799788, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34925385

RESUMO

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that was traditionally thought to be closely related to genetic and environmental risk factors. Although treatment options for SLE with hormones, immunosuppressants, and biologic drugs are now available, the rates of clinical response and functional remission of these drugs are still not satisfactory. Currently, emerging evidence suggests that gut microbiota dysbiosis may play crucial roles in the occurrence and development of SLE, and manipulation of targeting the gut microbiota holds great promises for the successful treatment of SLE. The possible mechanisms of gut microbiota dysbiosis in SLE have not yet been well identified to date, although they may include molecular mimicry, impaired intestinal barrier function and leaky gut, bacterial biofilms, intestinal specific pathogen infection, gender bias, intestinal epithelial cells autophagy, and extracellular vesicles and microRNAs. Potential therapies for modulating gut microbiota in SLE include oral antibiotic therapy, fecal microbiota transplantation, glucocorticoid therapy, regulation of intestinal epithelial cells autophagy, extracellular vesicle-derived miRNA therapy, mesenchymal stem cell therapy, and vaccination. This review summarizes novel insights into the mechanisms of microbiota dysbiosis in SLE and promising therapeutic strategies, which may help improve our understanding of the pathogenesis of SLE and provide novel therapies for SLE.


Assuntos
Disbiose/complicações , Disbiose/imunologia , Microbioma Gastrointestinal/imunologia , Lúpus Eritematoso Sistêmico/microbiologia , Animais , Humanos , Lúpus Eritematoso Sistêmico/imunologia
4.
Front Physiol ; 12: 786599, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34950058

RESUMO

Nowadays, with the improvements in living standards and changes in living habits, high-fat diet (HFD) has become much more common in the populations worldwide. Recent studies have shown that HFD could induce lipid accumulation, and structural and functional abnormalities, accompanied by the release of large amounts of pro-inflammatory cytokines, in proximal tubular epithelial cells (PTECs). These findings indicate that, as an emerging risk factor, PTEC injury-induced by HFD may be closely related to inflammation; however, the potential mechanisms underlying this phenomenon is still not well-known, but may involve the several inflammatory pathways, including oxidative stress-related signaling pathways, mitochondrial dysfunction, the myeloid differentiation factor 2/Toll like receptor 4 (MD2/TLR4) signaling pathway, the ERK1/2-kidney injury molecule 1 (KIM-1)-related pathway, and nuclear factor-κB (NF-κB) activation, etc., and the detailed molecular mechanisms underlying these pathways still need further investigated in the future. Based on lipid abnormalities-induced inflammation is closely related to the development and progression of chronic kidney disease (CKD), to summarize the potential mechanisms underlying HFD-induced renal proximal tubular inflammatory injury, may provide novel approaches for CKD treatment.

5.
Front Immunol ; 12: 728190, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34659214

RESUMO

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease. Although previous studies have demonstrated that SLE is related to the imbalance of cells in the immune system, including B cells, T cells, and dendritic cells, etc., the mechanisms underlying SLE pathogenesis remain unclear. Therefore, effective and low side-effect therapies for SLE are lacking. Recently, mesenchymal stem cell (MSC) therapy for autoimmune diseases, particularly SLE, has gained increasing attention. This therapy can improve the signs and symptoms of refractory SLE by promoting the proliferation of Th2 and Treg cells and inhibiting the activity of Th1, Th17, and B cells, etc. However, MSC therapy is also reported ineffective in some patients with SLE, which may be related to MSC- or patient-derived factors. Therefore, the therapeutic effects of MSCs should be further confirmed. This review summarizes the status of MSC therapy in refractory SLE treatment and potential reasons for the ineffectiveness of MSC therapy from three perspectives. We propose various MSC modification methods that may be beneficial in enhancing the immunosuppression of MSCs in SLE. However, their safety and protective effects in patients with SLE still need to be confirmed by further experimental and clinical evidence.


Assuntos
Lúpus Eritematoso Sistêmico/cirurgia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Imunidade Adaptativa , Animais , Microambiente Celular , Humanos , Tolerância Imunológica , Imunidade Inata , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/metabolismo , Transplante de Células-Tronco Mesenquimais/efeitos adversos , Células-Tronco Mesenquimais/imunologia , Células-Tronco Mesenquimais/metabolismo , Fenótipo , Resultado do Tratamento
6.
ACS Omega ; 6(24): 15572-15579, 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34179601

RESUMO

About 70% of the remaining oil remains underground after water flooding, and there is a need to better understand the formation and distribution of this remaining macroscopic oil to enhance oil recovery. In this study, three types of visual plate models were devised with different packing sequences: homogeneous (J), high-permeability layer on top (F), and low-permeability layer on top (Z). Based on these models, several visual flooding experiments were conducted to study the water flooding physics and the remaining oil distribution pattern of an offshore thick heavy oil reservoir under the impact of formation heterogeneity, packing sequence, model length, and permeability contrast during water flooding. These displacements were monitored photographically, and the effluent production profiles were recorded. The results showed that layer permeability and gravitational segregation play an important role during the water flooding process in layered porous media. Experimental results based on the model with different lengths show that the breakthrough oil recovery decreases with the increase of well spacing. Finally, a correction was made to the gravity number by introducing a scaling factor that characterized the formation heterogeneity and packing sequence in thick formation, compared to a known gravity number; the modified gravity number showed a better correlation with breakthrough oil recovery of water and polymer flooding. The research results provide effective guidance for the remaining oil distribution and injection and production parameter optimization in actual reservoirs.

7.
ACS Omega ; 6(14): 9362-9367, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33869916

RESUMO

Both polymer injection time and injection rate play an important role in the development of an offshore reservoir with a limited service life of the platform. To quantitatively and qualitatively investigate the influence of the formation packing sequence, injection rate, polymer injection timing, and their interaction on the performance of polymer flooding, a numerical reservoir model is simulated in this study based on the properties of offshore reservoir LD in China. Also, the polymer flooding experimental scheme is designed according to the response surface method and single-factor analysis method. Based on numerical simulation and statistical analysis, a regression model is established to predict the incremental oil recovery factor of polymer flooding. The analysis of variance (ANOVA) shows that the regression model fits well with the experimental data. The three factors' influence capacities on the increased oil recovery factor from large to small are the injection rate, formation rhythm, and injection timing. From the analysis, it is also found that the improved polymer flooding performance can be achieved under an injection rate of 0.07-0.09 PV/a and an injection timing of 30% water cut for positive rhythm formation.

8.
ACS Omega ; 6(3): 2215-2229, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33521461

RESUMO

Adsorption is one of the most important forms of storage of gas in shale reservoirs. Shale gas adsorption in the actual reservoir is not only affected by individual factors such as water content, temperature, and pressure but also by the synergetic effect of these factors. In this study, we conducted laboratory experiments on methane adsorption in dry and wet shale at different pressures and temperatures. The synergetic effect of water content, temperature, and pressure on shale gas adsorption is explored. The results show that increasing temperature weakens the interaction between methane and shale and reduces adsorption capacity due to the exothermic nature of adsorption. Water reduces methane adsorption capacity by occupying adsorption sites and blocking pores in the shale system. Although temperature and water reduce methane adsorption individually, the effect of these two factors weakens each other. Temperature has a more significant effect on methane adsorption in shales with low water content, while water has a more remarkable impact on methane adsorption at a low temperature. Furthermore, the increase in pressure reduces the negative influence of water and temperature on methane adsorption. By quantitatively analyzing the relationship between methane adsorption in dry and wet shales, a predictive adsorption model for wet shale considering the influence of in situ conditions is proposed and validated. Validation shows that the proposed model has high accuracy and broad applicability to shales with different properties.

9.
Front Immunol ; 12: 816956, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35116040

RESUMO

Animal models have played a crucial role in the understanding of the mechanisms and treatments of human diseases; however, owing to the large differences in genetic background and disease-specific characteristics, animal models cannot fully simulate the occurrence and progression of human diseases. Recently, humanized immune system mice, based on immunodeficient mice, have been developed that allow for the partial reconstruction of the human immune system and mimic the human in vivo microenvironment. Systemic lupus erythematosus (SLE) is a complex disease characterized by the loss of tolerance to autoantigens, overproduction of autoantibodies, and inflammation in multiple organ systems. The detailed immunological events that trigger the onset of clinical manifestations in patients with SLE are still not well known. Two methods have been adopted for the development of humanized SLE mice. They include transferring peripheral blood mononuclear cells from patients with SLE to immunodeficient mice or transferring human hematopoietic stem cells to immunodeficient mice followed by intraperitoneal injection with pristane to induce lupus. However, there are still several challenges to be overcome, such as how to improve the efficiency of reconstruction of the human B cell immune response, how to extend the lifespan and improve the survival rate of mice to extend the observation period, and how to improve the development of standardized commercialized models and use them. In summary, there are opportunities and challenges for the development of humanized mouse models of SLE, which will provide novel strategies for understanding the mechanisms and treatments of SLE.


Assuntos
Modelos Animais de Doenças , Lúpus Eritematoso Sistêmico/etiologia , Lúpus Eritematoso Sistêmico/metabolismo , Camundongos Transgênicos , Animais , Autoanticorpos/imunologia , Autoantígenos/imunologia , Doenças Autoimunes , Autoimunidade , Biomarcadores , Gerenciamento Clínico , Suscetibilidade a Doenças/imunologia , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/terapia , Camundongos
10.
Front Immunol ; 12: 792884, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35003113

RESUMO

Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are two common multisystem autoimmune diseases that share, among others, many clinical manifestations and serological features. The role of long non-coding RNAs (lncRNAs) has been of particular interest in the pathogenesis of autoimmune diseases. Here, we aimed to summarize the roles of lncRNAs as emerging novel biomarkers and therapeutic targets in SLE and RA. We conducted a narrative review summarizing original articles on lncRNAs associated with SLE and RA, published until November 1, 2021. Based on the studies on lncRNA expression profiles in samples (including PBMCs, serum, and exosomes), it was noted that most of the current research is focused on investigating the regulatory mechanisms of these lncRNAs in SLE and/or RA. Several lncRNAs have been hypothesized to play key roles in these diseases. In SLE, lncRNAs such as GAS5, NEAT1, TUG1, linc0949, and linc0597 are dysregulated and may serve as emerging novel biomarkers and therapeutic targets. In RA, many validated lncRNAs, such as HOTAIR, GAS5, and HIX003209, have been identified as promising novel biomarkers for both diagnosis and treatment. The shared lncRNAs, for example, GAS5, may participate in SLE pathogenesis through the mitogen-activated protein kinase pathway and trigger the AMP-activated protein kinase pathway in RA. Here, we summarize the data on key lncRNAs that may drive the pathogenesis of SLE and RA and could potentially serve as emerging novel biomarkers and therapeutic targets in the coming future.


Assuntos
Artrite Reumatoide/genética , Lúpus Eritematoso Sistêmico/genética , RNA Longo não Codificante/genética , Animais , Biomarcadores , Humanos , Terapia de Alvo Molecular , Transdução de Sinais , Transcriptoma
11.
Front Genet ; 12: 784135, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35140738

RESUMO

SLC22A18 (solute carrier family 22 member 18) is an imprinted gene, but its role in growth and development is not clear. In the present study, we recorded the clinical information of six male patients of six unrelated families. Real-time quantitative PCR, Sanger sequencing, and DNA methylation sequencing were performed in these patients. The results suggested that the patients with the clinical characteristics of allergic allergy, short stature, and fatty liver had a lower expression of SLC22A18. One novel variant (chr11: 2899732 delA) with clinical significance was found in the core promoter region of the patients. Overall, this study found a syndrome associated with SLC22A18.

12.
ACS Omega ; 5(48): 31069-31075, 2020 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-33324815

RESUMO

To solve the problem of poor adaptability of the single slug polymer injection mode which lead to profile inversion, non-effective circulation of polymer solution in the high permeability zone during the development of conventional heavy oil, new technology of alternative injection, and three-stage slug injection for further improving polymer flooding performance were developed. Parallel sandpack flooding experiment was conducted to study the oil displacement efficiency of different injection modes, and reasonable injection mode and optimal slug combination of polymer flooding are selected. The results show that under the same polymer dosage, the high and low mass concentration polymer slug alternative injection is better than the three-stage slug and single slug polymer flooding, and with the increase of the alternating rounds, the polymer flooding performance increased first and then decreased. Compared with the single slug injection, the alternative injection increased the recovery factor by 4%. When the three-stage slug is injected, the concentration of the front and post slug has a significant effect on the oil displacement process. The optimal oil displacement formulations are as follows: main slug 5000 mg/L × 0.125 PV, secondary slug 3000 mg/L × 0.208 PV, alternating two rounds.

13.
Front Immunol ; 11: 1047, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32625200

RESUMO

Pathogenic autoantibodies can cause inflammation and tissue injury in systemic lupus erythematosus (SLE). Although IgG4 is considered non-inflammatory owing to the unique structure of its hinge region, the role of IgG4 autoantibodies in SLE remains largely unknown. The titers of serum anti-nuclear-IgG antibodies (ANA-IgG) and anti-nuclear-IgG4 antibodies (ANA-IgG4) in newly diagnosed SLE patients were detected. The effects of IgG4 purified from SLE patients (SLE IgG4) and healthy controls on complement consumption and inflammatory cytokine production were evaluated in vitro. The therapeutic effects of mouse IgG1 (functionally resembles human IgG4) purified from lupus-prone MRL-lpr/lpr mice (lupus IgG1) and control mice on disease progression were examined in MRL-lpr/lpr mice. The results showed that SLE patients with equal titers of total serum ANA-IgG (1:3,200) were divided into group I with lower ANA-IgG4 titers (≤ 1:10) and group II with higher ANA-IgG4 titers (≥ 1:100), and disease activity, inflammatory cytokine production, complement consumption, and renal-function parameters in group I SLE patients were more severe than those in group II. Further, compared with control IgG4, SLE IgG4 inhibited complement consumption by autoantibody-autoantigen immune complexes, and also inhibited inflammatory cytokines production by SLE PBMCs in vitro. Moreover, compared with control IgG1, lupus IgG1 exhibited a therapeutic effect on lupus by attenuating disease progression in MRL-lpr/lpr mice. These findings, for the first time, suggest that IgG4 autoantibodies can attenuate SLE progression by suppressing complement consumption and inflammatory cytokine production. Hence, this study may provide novel therapeutic strategies against SLE and other autoimmune diseases.


Assuntos
Autoanticorpos/imunologia , Proteínas do Sistema Complemento/metabolismo , Citocinas/biossíntese , Imunoglobulina G/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/terapia , Adolescente , Adulto , Animais , Complexo Antígeno-Anticorpo/metabolismo , Autoanticorpos/administração & dosagem , Autoanticorpos/sangue , Estudos de Casos e Controles , Criança , Modelos Animais de Doenças , Progressão da Doença , Feminino , Humanos , Imunoglobulina G/administração & dosagem , Imunoglobulina G/sangue , Técnicas In Vitro , Mediadores da Inflamação/metabolismo , Leucócitos Mononucleares/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos MRL lpr , Modelos Imunológicos , Pesquisa Translacional Biomédica , Adulto Jovem
14.
Photosynth Res ; 138(1): 73-102, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30039359

RESUMO

In this study, we presented cellular morphological changes, time-resolved biochemical composition, photosynthetic performance and proteomic profiling to capture the photosynthetic physiological response of Scenedesmus acuminatus under low nitrogen (3.6 mM NaNO3, N-) and high nitrogen supplies (18.0 mM NaNO3, N+). S. acuminatus cells showed extensive lipid accumulation (53.7% of dry weight) and were enriched in long-chain fatty acids (C16 & C18) under low nitrogen supply. The activity of PSII and photosynthetic rate decreases, whereas non-photochemical quenching and dark respiration rates were increased in the N- group. In addition, the results indicated a redistribution of light excitation energy between PSII and PSI in S. acuminatus exists before lipid accumulation. The iTRAQ results showed that, under high nitrogen supply, protein abundance of the chlorophyll biosynthesis, the Calvin cycle and ribosomal proteins decreased in S. acuminatus. In contrast, proteins associated with the photosynthetic machinery, except for F-type ATPase, were increased in the N+ group (N+, 3 vs. 9 days and 3 days, N+ vs. N-). Under low nitrogen supply, proteins involved in central carbon metabolism, fatty acid synthesis and branched-chain amino acid metabolism were increased, whereas the abundance of proteins of the photosynthetic machinery had decreased, with exception of PSI (N-, 3 vs. 9 days and 9 days, N+ vs. N-). Collectively, the current study has provided a basis for the metabolic engineering of S. acuminatus for biofuel production.


Assuntos
Metabolismo dos Lipídeos , Nitrogênio/metabolismo , Scenedesmus/fisiologia , Aminoácidos/metabolismo , Ácidos Graxos/análise , Microalgas/fisiologia , Fotossíntese/fisiologia , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Pigmentos Biológicos/metabolismo , Proteínas de Plantas/metabolismo , Proteômica , Scenedesmus/química , Scenedesmus/ultraestrutura
15.
Langmuir ; 32(45): 11736-11744, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27754675

RESUMO

A large amount of residual oil, which exists as isolated oil slugs, remains trapped in reservoirs after water flooding. Numerous numerical studies are performed to investigate the fundamental flow mechanism of oil slugs to improve flooding efficiency. Dynamic contact angle models are usually introduced to simulate an accurate contact angle and meniscus displacement of oil slugs under a high capillary number. Nevertheless, in the oil slug flow simulation process, it is unnecessary to introduce the dynamic contact angle model because of a negligible change in the meniscus displacement after using the dynamic contact angle model when the capillary number is small. Therefore, a critical capillary number should be introduced to judge whether the dynamic contact model should be incorporated into simulations. In this study, a direct numerical simulation method is employed to simulate the oil slug flow in a capillary tube at the pore scale. The position of the interface between water and the oil slug is determined using the phase-field method. The capacity and accuracy of the model are validated using a classical benchmark: a dynamic capillary filling process. Then, different dynamic contact angle models and the factors that affect the dynamic contact angle are analyzed. The meniscus displacements of oil slugs with a dynamic contact angle and a static contact angle (SCA) are obtained during simulations, and the relative error between them is calculated automatically. The relative error limit has been defined to be 5%, beyond which the dynamic contact angle model needs to be incorporated into the simulation to approach the realistic displacement. Thus, the desired critical capillary number can be determined. A three-dimensional universal chart of critical capillary number, which functions as static contact angle and viscosity ratio, is given to provide a guideline for oil slug simulation. Also, a fitting formula is presented for ease of use.

16.
Sci Rep ; 6: 32393, 2016 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-27587293

RESUMO

To investigate the gas flow characteristics in tight porous media, a microscale lattice Boltzmann (LB) model with the regularization procedure is firstly adopted to simulate gas flow in three-dimensional (3D) digital rocks. A shale digital rock and a sandstone digital rock are reconstructed to study the effects of pressure, temperature and pore size on microscale gas flow. The simulation results show that because of the microscale effect in tight porous media, the apparent permeability is always higher than the intrinsic permeability, and with the decrease of pressure or pore size, or with the increase of temperature, the difference between apparent permeability and intrinsic permeability increases. In addition, the Knudsen numbers under different conditions are calculated and the results show that gas flow characteristics in the digital rocks under different Knudsen numbers are quite different. With the increase of Knudsen number, gas flow in the digital rocks becomes more uniform and the effect of heterogeneity of the porous media on gas flow decreases. Finally, two commonly used apparent permeability calculation models are evaluated by the simulation results and the Klinkenberg model shows better accuracy. In addition, a better proportionality factor in Klinkenberg model is proposed according to the simulation results.

17.
AMB Express ; 6(1): 32, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27112931

RESUMO

Her2, which is frequently overexpressed in breast cancer, is one of the most studied tumor-associated antigens for cancer therapy. Anti-HER2 monoclonal antibody, trastuzumab, has achieved significant clinical benefits in metastatic breast cancer. In this study, we describe a novel bispecific antibody Her2-S-Fab targeting Her2 by linking a single domain anti-CD16 VHH to the trastuzumab Fab. The Her2-S-Fab antibody can be efficiently expressed and purified from Escherichia coli, and drive potent cancer cell killing in HER2-overexpressing cancer cells. In xenograft model, the Her2-S-Fab suppresses tumor growth in the presence of human immune cells. Our results suggest that the bispecific Her2-S-Fab may provide a valid alternative to Her2 positive cancer therapy.

18.
Wei Sheng Wu Xue Bao ; 56(7): 1168-77, 2016 Jul 04.
Artigo em Chinês | MEDLINE | ID: mdl-29733178

RESUMO

Objective: In order to improve biofuel production by Desmodesmus insignis, we studied the effect of different nitrogen sources and concentrations on the growth, total lipids, carbohydrate and starch accumulation of Desmodesmus insignis. Methods: D. insignis was cultivated in basic general-11 medium containing 5 different initial nitrogen concentrations (3, 6, 9, 12 and 18 mmol/L) supplied in the form of sodium nitrate, ammonium bicarbonate and urea. Biomass was determined by dry weight, total lipids by gravimeter, and carbohydrates and starch by phenolsulfuric acid method. Results: NaNO3, NH4HCO3 and CO(NH2)2 were all suitable for the growth of D. Insignis. When 3 mmol/L NaNO3 was used, the peak lipid content reached to 32.61% (d.w). The maximum content and productivity of carbohydrate and starch were 56.54% (d·w), 55.33% (d·w) and 0.24 g/(L·d), 0.23 g/(L·d) respectively, when 18 mmol/L NH4HCO3 was used. Urea could also obtain relative high content of biomass, total lipids, carbohydrates and starch. Conclusion: Integrating these results with production costs, we could suggest ammonium bicarbonate and urea as nitrogen source at the concentration of 18 mmol/L.


Assuntos
Clorófitas/metabolismo , Lipídeos/biossíntese , Microalgas/metabolismo , Nitrogênio/metabolismo , Amido/biossíntese , Bicarbonatos/metabolismo , Biocombustíveis/análise , Biomassa , Clorófitas/crescimento & desenvolvimento , Microalgas/crescimento & desenvolvimento , Nitratos/metabolismo
19.
Bioresour Technol ; 197: 495-501, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26369279

RESUMO

Flocculation of microalgae with chitosan, polyacrylamide, Al2(SO4)3, NaOH and HNO3 was evaluated. Their flocculation efficiencies and optimal dosages were discussed. The effects of the flocculants on cells viability were also investigated and the cells were found to be intact during the flocculation process. Moreover, the effects of flocculants on the extractions were evaluated. Lipid content after flocculants treatments showed no significant differences. Carbohydrate content was lower but protein content was higher after NaOH treatment than those after other treatments. Furthermore, the five flocculated media maintained approximate growth yields to that of the fresh medium in microalgal cultivation, indicating the five flocculated media could be recycled, thereby reducing the cost of biodiesel production from microalgae. Finally, economic comparison of the flocculants was made and the cost of using HNO3, including flocculating cells and recycling medium, was found to be the lowest.


Assuntos
Biotecnologia/métodos , Floculação , Microalgas/fisiologia , Resinas Acrílicas/química , Resinas Acrílicas/economia , Resinas Acrílicas/farmacologia , Biocombustíveis , Biotecnologia/economia , Quitosana/química , Quitosana/economia , Quitosana/farmacologia , Custos e Análise de Custo , Meios de Cultura , Metabolismo dos Lipídeos/efeitos dos fármacos , Microalgas/química , Microalgas/efeitos dos fármacos , Ácido Nítrico/química , Ácido Nítrico/economia , Ácido Nítrico/farmacologia , Proteínas de Plantas/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Reciclagem , Scenedesmus/efeitos dos fármacos , Scenedesmus/fisiologia , Hidróxido de Sódio/química , Hidróxido de Sódio/economia , Hidróxido de Sódio/farmacologia
20.
Angew Chem Int Ed Engl ; 54(8): 2351-5, 2015 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-25582712

RESUMO

In sharp contrast to the prevailing view that a stationary charge outside a nanochannel impedes water permeation across the nanochannel, molecular dynamics simulations show that a vibrational charge outside the nanochannel can promote water flux. In the vibrational charge system, a decrease in the distance between the charge and the nanochannel leads to an increase in the water net flux, which is contrary to that of the fixed-charge system. The increase in net water flux is the result of the vibrational charge-induced disruption of hydrogen bonds when the net water flux is strongly affected by the vibrational frequency of the charge. In particular, the net flux is reaches a maximum when the vibrational frequency matches the inherent frequency of hydrogen bond inside the nanochannel. This electromanipulating transport phenomenon provides an important new mechanism of water transport confined in nanochannels.


Assuntos
Nanoestruturas/química , Água/química , Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Nanotubos de Carbono/química , Movimentos da Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...