RESUMO
Treating textile wastewaters were always inhibited by its higher salt concentration and temperature. In this study, a halo-thermophilic bacterial consortium YM was enriched with ability to decolorize acid brilliant scarlet GR (ABS) at 55 °C and 10% salinity. Under optimum conditions of pH (8), temperature (55 °C), and salinity (10%), YM decolorized 97% of ABS under anaerobic conditions. Alteribacillus was identified to be the dominant genus in consortium YM. Consortium YM showed significant decolorization ability under a wide range of salinity (1%-10%), pH (7-9) and temperature (45 °C-60 °C). The degradation pathway of ABS was proposed by the combination of UV-vis spectral analysis, Fourier transform infrared (FTIR), gas chromatography mass spectrometric (GC-MS), and metagenomic analysis. Azoreductase, which was an important enzyme in decolorization process, was identified with great variation in the genome of consortium YM. Meanwhile, the metabolic intermediates after decolorization was identified with low biotoxicity by phytotoxicity tests. This study first identified that Alterbacillus play an important role in azo dye decolorization and degradation process under halo-thermophlic conditions and provided significant knowledge for azo dye decolorization and degradation process.
RESUMO
Graphitic carbon nitride (CN), as a non-metal material, has emerged as a promising photocatalyst to address environmental issues with the favorable band gap and chemical stability. The porous oxygen-doped CN nanosheets (CNO) were synthesized by an ecofriendly and efficient self-assembled approach using a sole urea as the precursor. The CNO photocatalysts were derived from the hydrogen-bonded cyanuric acid-urea supramolecular complex, which were obtained by pretreatment of urea at high temperature and pressure. The homogeneous supramolecular assembly was advantageous to the formation of uniform porous and oxygen-doped CN nanosheets. The formation process of the supramolecular intermediate and the CNO nanosheets were investigated. Moreover, doping amount of O in CNO could be controlled by the time of the high-pressure thermal polymerization of urea. The characterization results shown that the O atoms were successfully doped into the framework of CN by substitution the N atoms to form the C-O structures. The obtained CNO photocatalysts demonstrated the excellent visible-light photocatalytic performances for sulfamerazine (SMR) degradation, which was ascribed to synergistic interaction of porous structure and O doping. The degradation intermediates of SMR were identified and the degradation pathway were also proposed. Furthermore, density functional theory (DFT) calculations proved that O doping changed the electronic structure of CN, resulting in more easier to activate O2. This work provides a novel perceptive for the development of high-performance nonmetal photocatalysts by using the homogeneous supramolecular assembly, which exhibits great potential in the environmental treatment.
Assuntos
Poluentes Ambientais , Oxigênio , Antibacterianos , Catálise , Grafite , Luz , Compostos de Nitrogênio , Oxigênio/química , UreiaRESUMO
The pollutant composition of landfill leachate is complex, and pollutant concentrations change greatly. Moreover, landfill leachates can easily penetrate into the soil and eventually pollute the ground water, which can cause environmental pollution and threaten human health. At present, landfill leachate treatment technology is still not mature. In this paper, the A/O-MBR (Anoxic-Aerobic Membrane Bioreactor) process is proposed to treat landfill leachate. To increase the hydrophilicity of the membranes and reduce the pollution of the membranes, the self-made TiO2 nanoparticles were used to modify the ultrafiltration membranes (PVDF-2). Meanwhile, PVDF-2 composite membranes showed the best separation performance. The optimum operating parameters were determined by changing the concentration of the pollutants in the reactor and selecting the dissolved oxygen, pH, and hydraulic residence time. The results show that the optimum operating conditions of MBR are mixed liquor suspended solids (MLSS) = 3200 mg/L, DO = 1.5-2.5 mg/L in a nitrifying tank, DO = 0-0.5 mg/L in a denitrifying tank, pH = 7-8, and a hydraulic retention time (HRT) = 5 h. To reach the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002), the effluent of the MBR system further enters into the RO system. This work presents an environmentally friendly synthesis of TiO2 nanoparticles and added into PVDF. The addition of self-made TiO2 in PVDF membrane has improved the antifouling performance significantly, which has the potential for the treatment of landfill leachate.
RESUMO
The aim of the study was to verify the effect of bioaugmentation by the bacterial consortium YS with hydroxypropyl-ß-cyclodextrin (HPCD) in a soil slurry. The bacterial consortium YS was enriched from a petroleum-polluted soil using pyrene as sole carbon resource. After 3 weeks, the degradation rate of phenanthrene in CK increased from 22.58% to 55.23 and 78.21% in bioaugmentation (B) and HPCD + bioaugmentation (MB) respectively. The degradation rate of pyrene in CK increased from 17.33% to 51.10% and 60.32% in B and MB respectively in the slurry. The augmented YS persisted in the slurry as monitored by 16S rRNA gene high-throughput sequencing and outcompeted some indigenous bacteria. Enhanced polycyclic aromatic hydrocarbon (PAH) degradation was observed in the addition of HPCD due to the enhanced bioavailability of phenanthrene and pyrene. Additionally, the amount of PAH-degrading bacteria and enzymatic activity in bioaugmentation with HPCD were higher than that in the CK group. The results indicated that bioaugmentation with a bacterial consortium and HPCD is an environmentally friendly method for the bioremediation of PAH-polluted soil.
Assuntos
Fenantrenos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , 2-Hidroxipropil-beta-Ciclodextrina/metabolismo , Bactérias/genética , Bactérias/metabolismo , Biodegradação Ambiental , Reatores Biológicos , Hidrocarbonetos Policíclicos Aromáticos/análise , Pirenos , RNA Ribossômico 16S/genética , Solo , Microbiologia do Solo , Poluentes do Solo/análiseRESUMO
Phosphorus (P) has an important role in eutrophication and it is essential to explore the processes and mechanisms of P mobility in natural waters. In this study, laboratory experiments were conducted to simulate the SW system (sediment and water) and SAW system (sediment, algae, and water) under four hydrodynamic intensity conditions (static control, 50 rpm, 125 rpm, and 200 rpm treatments), to investigate P mobility. Results in SW system showed that sediment was an important source of P for overlying water, and the released total P (TP) increased with stronger hydrodynamic intensity, when P associated with metal pools (redox-sensitive P [BD-P] and meta-oxides bound P [NaOH-P]) were the most unstable and easier to migrate into the overlying water. Stronger hydrodynamic disturbances could enhance the processes including sediment resuspension, dissolution of particles, and release of P, when P mobility had a close relationship with redox conditions near sediment-water interface (SWI). Therefore, the release of TP, BD-P, and NaOH-P from sediment increased and decreased in the control and 50-200 rpm treatments over time. In SAW system, the release of TP significantly increased from sediment comparing to SW system, and the growth of Microcystis aeruginosa could selectively enhance the release of BD-P, NaOH-P, and organic P (OP). Meanwhile, the released P from sediment was quickly accumulated by algal cells. The maximum accumulation ability of P by cells, the highest photosynthetic efficiency, and the best growth of M. aeruginosa were observed in 125 rpm treatment. But with excessively strong hydrodynamic intensity (200 rpm treatment), the accumulation ability of P and alkaline phosphatase activity (APA) of M. aeruginosa was suppressed, which might hinder algal utilization of P and inhibit algal growth. Overall, our findings demonstrated the patterns of P mobility in natural ecosystems and could contribute to the understanding of P cycling.
Assuntos
Cianobactérias , Fósforo , Ecossistema , Sedimentos Geológicos , Hidrodinâmica , Lagos , ÁguaRESUMO
Background: Esophageal squamous carcinoma (ESCC) is a highly lethal malignancy with poor prognosis. The effect of transcriptome characteristics of patient immune microenvironment (TME) on the efficacy of immunosuppressive agents is still poorly understood. Methods: Here we extracted and isolated immune cells from peripheral blood of patients with PD-1 monoclonal antibody sensitivity and resistance, and conducted deep single-cell RNA sequencing to describe the baseline landscape of the composition, lineage, and functional status of infiltrating immune cells in peripheral blood of patients with esophageal cancer. Results: The transcriptome characteristics of immune cells were comprehensively analyzed, and the dynamic changes of cell percentage, heterogeneity of cell subtypes and interactions between cells were explained. Co-expression and pedigree tracking based on T-cell antigen receptors revealed a significant proportion of highly migratory intertissue-effector T cells. GO and KEGG enrichment pathway Analysis of CD8+ effect-T cells ESCC_S group and ESCC_D1,2 group, found that in the up-regulated enrichment pathway, ESCC_S group enriched more PD-L1 and PD-1 checkpoint pathways expressed in tumors (JUN/NFKBIA/FOS/KRAS/IFNG), which also exist in T cell receptor signaling pathways. MT2A, MT1X and MT1E were differentially expressed in ESCC patients with PD-1 monoclonal antibody resistance, which may be related to the resistance of PD-1 mMAB. Conclusions: This study has an in-depth understanding of the influence of peripheral immune cell infiltration on the sensitivity of monoclonal antibody PD-1 in patients with esophageal cancer, which is helpful to promote the immunotherapy of patients with esophageal cancer.
Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Receptor de Morte Celular Programada 1/genética , Carcinoma de Células Escamosas do Esôfago/genética , Células Sanguíneas , Neoplasias Esofágicas/genética , Anticorpos Monoclonais , Microambiente TumoralRESUMO
[This retracts the article DOI: 10.1016/j.omtn.2020.01.024.].
RESUMO
The 3D hollow hierarchical architectures tend to be designed for inhibiting stack of MXene flakes to obtain satisfactory lightweight, high-efficient and broadband absorbers. Herein, the hollow NiCo compound@MXene networks were prepared by etching the ZIF 67 template and subsequently anchoring the Ti3C2Tx nanosheets through electrostatic self-assembly. The electromagnetic parameters and microwave absorption property can be distinctly or slightly regulated by adjusting the filler loading and decoration of Ti3C2Tx nanoflakes. Based on the synergistic effects of multi-components and special well-constructed structure, NiCo layered double hydroxides@Ti3C2Tx (LDHT-9) absorber remarkably achieves unexpected effective absorption bandwidth (EAB) of 6.72 GHz with a thickness of 2.10 mm, covering the entire Ku-band. After calcination, transition metal oxide@Ti3C2Tx (TMOT-21) absorber near the percolation threshold possesses minimum reflection loss (RLmin) value of - 67.22 dB at 1.70 mm within a filler loading of only 5 wt%. This work enlightens a simple strategy for constructing MXene-based composites to achieve high-efficient microwave absorbents with lightweight and tunable EAB.
RESUMO
The aim of this work was to study the bioaugmentation of hydrolysis acidification (HA) by a halophilic bacterial consortium. A bacterial consortium was enriched at 5% salinity, and it decolorized metanil yellow G (MYG) at salinities of 1%-15% and dye concentrations of 100-400 mg/L under static conditions. A HA system was constructed to assess the effectiveness of bioaugmentation by the halophilic bacterial consortium. The HA system showed obviously better performance for decolorization and CODMn removal and presented higher the 5-day biological oxygen demand (BOD5)/CODMn (B/C) ratio after bioaugmentation. MiSeq sequencing results indicated that the bacterial communities remarkably shifted and that the bacterial diversity was increased after bioaugmentation. Marinobacterium invaded the native microbe community and became the dominant bacterial genus in the bioaugmented HA, and it played a key role in azo dye decolorization. Therefore, bioaugmentation with a halophilic bacterial consortium improved the HA system for decolorization of azo compounds.
Assuntos
Corantes , Salinidade , Archaea , Compostos Azo , Biodegradação AmbientalRESUMO
Oxaliplatin (oxa) is widely used in the treatment of colorectal cancer (CRC), but the development of oxaliplatin resistance is a major obstacle to the therapeutic efficacy in patients. MicroRNAs (miRNAs), endogenous noncoding RNAs measuring between 22 and 24 nucleotides, have been shown to be involved in the development of CRC drug resistance. However, the mechanism by which differentially expressed miRNAs induce chemotherapy resistance in CRC has not been fully elucidated to date. Here, we showed the differentially expressed miRNAs in oxaliplatin-sensitive and oxaliplatin-resistant CRC cells through miRNA microarray technology and found that miR-135b-5p was significantly increased in oxaliplatin-resistant cells. And miR-135b-5p was increased in the serum of colorectal cancer patients. More importantly, the miR-135b-5p level in the serum of oxaliplatin-resistant patients was further increased compared to that of oxaliplatin-sensitive patients. Recent studies have shown that protective autophagy is an important mechanism that promotes drug resistance in tumors. The potential role of miR-135b-5p in inducing protective autophagy and promoting oxaliplatin resistance was evaluated in two stable oxaliplatin-resistant CRC cell lines and their parental cells. We further identified MUL1 as a direct downstream target of miR-135b-5p and showed that MUL1 could degrade the key molecule of autophagy, ULK1, through ubiquitination. Mouse xenograft models were adopted to evaluate the correlation between miR-135b-5p and oxaliplatin-induced autophagy in vivo. Furthermore, we also investigated the regulatory factors for the upregulation of miR-135b-5p in CRC cells under oxaliplatin chemotoxicity. These results indicated that miR-135b-5p upregulation in colorectal cancer could induce protective autophagy through the MUL1/ULK1 signaling pathway and promote oxaliplatin resistance. Targeting miR-135b-5p may provide a new treatment strategy for reversing oxaliplatin resistance in CRC.
Assuntos
Oxaliplatina , Animais , Autofagia , Resistencia a Medicamentos Antineoplásicos , Camundongos , Transdução de SinaisRESUMO
In this manuscript, we constructed a Ni/MWCNTs absorber and properly adjusted the permittivity resulted from absorber content in the PVDF to optimize impedance matching properties. Both ε' and εⳠincrease obviously with the increasing content of Ni/MWCNTs in PVDF, demonstrating that dielectric properties are dependent on the conductivity. Moderate dielectric properties and excellent impedance matching can be obtained for the filler content of 20 wt% Ni/MWCNTs. Reasonable impedance matching allows electromagnetic waves to propagate into the materials and finally realize energy dissipation through dielectric loss and interfacial polarization. As expected, the minimum reflection loss (RL) of -46.85 dB at 6.56 GHz with a low filler loading (20 wt%) and wide effective bandwidth (RL<-10 dB) of 14.0 GHz in the thickness range of 1.5-5.0 mm was obtained for the commercial Ni/MWCNTs composites, which is promising for mass production in industrial applications. Our findings offer an effective and industrialized way to design high-performance material to facilitate the research in microwave absorption.
RESUMO
Phosphorus (P) plays a critical role in eutrophication and algal growth; therefore, improving our understanding of the impact of P is essential to control harmful algal blooms. In this study, Microcystis aeruginosa was treated with 5-h ambient irradiation in the medium with different dissolved inorganic P (DIP) concentrations, DIP-free, moderate-DIP, and high-DIP, to explore its growth and other physiological responses. Compared to photosynthetically active radiation (PAR), UV-A (320-400â¯nm) and UV-B (280-320â¯nm) radiation had inhibitive effects on the photosynthesis and growth of M. aeruginosa, while high P availability could alleviate or eliminate the negative effects of UV radiation. The photosynthetic parameters had a minimum reduction and quickly recovered after re-inoculation under high-DIP conditions. Confirmed by SEM, photosynthetic pigments, the generation of reactive oxygen species (ROS), superoxide dismutase (SOD) activity and other methods, ambient UV radiation exerted oxidative stresses rather than direct lethal effects on M. aeruginosa. Photosynthetic parameters indicated that algal UV-adaptation processes could include decreasing photo-induced damages and increasing self-repair efficiency. The P acquired by M. aeruginosa cells can have two function, which included alleviating UV-induced negative effects and sustaining algal growth. Consequently, UV-adaptation processes of M. aeruginosa resulted in an elevated demand for DIP, which resulted to increased P uptake rates and cellular P quota under moderate and high-DIP conditions. Therefore, the production of carotenoid and phycocyanin, and SOD activity increased under UV stress, leading to a better adaptation capability of M. aeruginosa and decreased negative effects of UV radiation on its growth. Overall, our findings demonstrated the significant interactive effects of P enrichment and irradiation on typical cyanobacteria, and the strong adaptation capability of M. aeruginosa in the eutrophic UV-radiated waters.
Assuntos
Aclimatação , Microcystis/fisiologia , Fósforo/metabolismo , Raios Ultravioleta , Carotenoides , Cianobactérias , Proliferação Nociva de Algas , Microcystis/crescimento & desenvolvimento , Estresse Oxidativo , Fotossíntese/efeitos dos fármacos , Ficocianina , Espécies Reativas de OxigênioRESUMO
Bi2Fe4O9(BFO) nanocubes were prepared in proportion using a simple and easy hydrothermal method, and were then assembled on reduced graphene oxide (rGO) multilayered sheets. The excellent microwave absorption properties of Bi2Fe4O9/rGO nanohybrids were achieved by properly adjusting the impedance matching and getting a high attenuation capability contributed from different ratios of the BFO and rGO. A minimum reflection loss value of -61.5 dB at 12.8 GHz was obtained with a Bi2Fe4O9/rGO ratio of 2:1, and the broadest bandwidth below -10 dB was up to 5.0 GHz (from 10.8 to 15.8 GHz) with a thickness of 2.4 mm. Additionally, the elementary mechanism of wave absorption performance is also investigated.
RESUMO
Exosomes, membranous nanovesicles, naturally carry proteins, mRNAs, and microRNAs (miRNAs) and play important roles in tumor pathogenesis. Here we showed that gastric cancer (GC) cell-derived exosomes can function as vehicles to deliver miR-155 to promote angiogenesis in GC. In this study, we first detected that the expression of miR-155 and c-MYB was negatively correlated in GC and that c-MYB was a direct target of miR-155. We next characterized the promotional effect of exosome-delivered miR-155 on angiogenesis and tumor growth in GC. We found that miR-155 could inhibit c-MYB but increase vascular endothelial growth factor (VEGF) expression and promote growth, metastasis, and tube formation of vascular cells, causing the occurrence and development of tumors. We also used a tumor implantation mouse model to show that exosomes containing miR-155 significantly augment the growth rate of the vasculature and tumors in vivo. Our results illustrate the potential mechanism between miR-155 and angiogenesis in GC. These findings contribute to our understanding of the function of miR-155 and exosomes for GC therapy.
RESUMO
Electromagnetic absorption materials have gained increasing attention. In this study, we report NiO decorated biomass porous carbon derived from pine nut shells as a promising microwave absorbing material by a facile strategy. The NiO/biomass porous carbon (BPC) is thermally converted from Ni(OH)2/BPC with BPC as the base for precipitation. All products were characterized by XRD, Raman, and SEM techniques, which reveals that the NiO nanoflakes were uniformly self-assembled on the surface of the activated carbon. Compared with counterparts of pure Ni(OH)2 and Ni(OH)2/BPC, a large reflection loss peak of -33.8 dB at 16.4 GHz is achieved for the NiO/BPC composites, and the absorption bandwidth less than -10 dB can reach up to about 6.7 GHz (from 11.3 to 18.0 GHz) with a thickness of 8 mm. The enhanced microwave absorption properties originate from the electric/dielectric polarization and the unique NiO decorated BPC structures. The expanded interfaces, such as NiO-NiO, Ni-BPC and NiO-paraffin interfaces in the complicated porous composites, could boost the interfacial polarization as well as related relaxation which results in enhanced dielectric loss and electromagnetic absorbing properties. In addition, NiO/BPC nanocomposites exhibit comparatively better matching of permittivity and permeability. It is expected that our present investigation could provide a new possibility for biomass based fabrication of potential microwave absorbing materials.
RESUMO
TiO2/g-C3N4/PVDF composite membranes were prepared by a phase inversion method. A comparison of the performance and morphology was carried out among pure PVDF, g-C3N4/PVDF, TiO2/PVDF and TiO2/g-C3N4/PVDF composite membranes. The results of permeability and instrumental analysis indicated that TiO2 and g-C3N4 organic-inorganic composites obviously changed the performance and structure of the PVDF membranes. The porosity and water content of 0.75TiO2/0.25g-C3N4/PVDF composite membranes were 97.3 and 188.3 L/(m²·h), respectively. The porosity and water content of the 0.75TiO2/0.25g-C3N4 membranes were increased by 20.8% and 27.4%, respectively, compared with that of pure PVDF membranes. This suggested that the combination of organic-inorganic composite with PVDF could remarkably improve UTS, membrane porosity and water content.
RESUMO
BACKGROUND: Detection of clustered microcalcification (MC) from mammograms plays essential roles in computer-aided diagnosis for early stage breast cancer. OBJECTIVE: To tackle problems associated with the diversity of data structures of MC lesions and the variability of normal breast tissues, multi-pattern sample space learning is required. METHODS: In this paper, a novel grouped fuzzy Support Vector Machine (SVM) algorithm with sample space partition based on Expectation-Maximization (EM) (called G-FSVM) is proposed for clustered MC detection. The diversified pattern of training data is partitioned into several groups based on EM algorithm. Then a series of fuzzy SVM are integrated for classification with each group of samples from the MC lesions and normal breast tissues. RESULTS: From DDSM database, a total of 1,064 suspicious regions are selected from 239 mammography, and the measurement of Accuracy, True Positive Rate (TPR), False Positive Rate (FPR) and EVL = TPR* 1-FPR are 0.82, 0.78, 0.14 and 0.72, respectively. CONCLUSION: The proposed method incorporates the merits of fuzzy SVM and multi-pattern sample space learning, decomposing the MC detection problem into serial simple two-class classification. Experimental results from synthetic data and DDSM database demonstrate that our integrated classification framework reduces the false positive rate significantly while maintaining the true positive rate.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Mamografia/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Máquina de Vetores de Suporte , Algoritmos , Mama/diagnóstico por imagem , Mama/patologia , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Calcinose/diagnóstico , Calcinose/patologia , Feminino , Lógica Fuzzy , Humanos , Modelos EstatísticosRESUMO
Carbon spheres (CS)@MnO2 core-shell nanocomposites, with MnO2 nanoflakes uniformly coating at the surface of CS cores, were successfully synthesized by a facile water-bathing method. MnO2 amounts is estimated to be 24.7 wt% in CS@MnO2 nanocomposites. A high dielectric loss value and an electromagnetic shielding effectiveness of 16â23 dB were observed for the CS@MnO2 in the frequency range of 8â18 GHz, which is mainly attributed to the enhanced absorption loss. The incorporation of the CS with MnO2 improves the electrical conductivity. Meanwhile, the electromagnetic impendence matching has been significantly ameliorated. Moreover, the increasing interfaces between the CS and MnO2 facilitate the microwave attenuation as well. Thus, the electromagnetic shielding performances were greatly enhanced. Our findings provide an effective methodology for the synthesis of the CS@MnO2 core-shell nanocomposite for potential electromagnetic applications.
RESUMO
Gene expression profiles have great potential for accurate tumor diagnosis. It is expected to enable us to diagnose tumors precisely and systematically, and also bring the researchers of machine learning two challenges, the curse of dimensionality and the small sample size problems. We propose a manifold learning based dimensional reduction algorithm named orthogonal local discriminant embedding (O-LDE) and apply it to tumor classification. Comparing with the classical local discriminant embedding (LDE), O-LDE aims to obtain an orthogonal linear projection matrix by solving an optimization problem. After being projected into a low-dimensional subspace by O-LDE, the data points of the same class maintain their intrinsic neighbor relations, whereas the neighboring points of the different classes are far from each other. Experimental results on a public tumor dataset validate the effectiveness and feasibility of the proposed algorithm.
Assuntos
Análise Discriminante , Leucemia/diagnóstico , Neoplasias/diagnóstico , Neoplasias/genética , Algoritmos , Inteligência Artificial , Simulação por Computador , Bases de Dados Factuais , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Leucemia/classificação , Modelos Teóricos , Neoplasias/classificaçãoRESUMO
The preparation of nanoscale oxide/polyvinylidene fluoride (PVDF) composite hollow fiber membrane by phase transition process was introduced. The effects of nanoscale titania and alumina particles on structure and property of composite hollow fiber membrane were investigated. The separation property, microstructure and crystalline phase of composite membranes were characterized by bovine serum albumin (BSA) rejection experiment, scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR), respectively. The results show that the properties of composite membrane are improved greatly compared to the pure PVDF membranes. The BSA rejection ratios of pure PVDF, Al2O3/PVDF and TiO2/PVDF membranes were 3.27%, 67.20% and 86.67%, respectively. The pure water fluxes of Al2O3/PVDF and TiO2/PVDF membranes were 2.3 and 2.6 times higher than that of pure PVDF membranes. Moreover, the pore size and its distribution of composite membrane characterized by nitrogen isothermal absorption measurement are smaller and narrower than pure PVDF membranes.