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1.
Mol Biotechnol ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38836983

RESUMO

Cell cycle exit and neuronal differentiation 1 (CEND1), highly expressed in the brain, is a specific transmembrane protein which plays a tumor suppressor role. This study is performed to investigate the role of CEND1 in various cancers through pan-cancer analysis, and further investigate its functions in gliomas by cell experiments. The expression and subcellular localization of CEND1 in different cancer types were analyzed utilizing the data from the GEPIA, UCSC, UALCAN and HPA databases. Relationships of CEND1 expression with prognosis, immunomodulation-related genes, immune checkpoint genes, microsatellite instability (MSI), tumor mutation burden (TMB) and RNA modifications were analyzed based on the TCGA database. The ESTIMATE algorithm was utilized to evaluate tumors' StromalScore, Immune Score, and ESTIMATES Score. The cBioPortal database was employed to analyze the categories and frequencies of CEND1 gene alterations. Biological functions and co-expression patterns of CEND1 in gliomas were explored using the LinkedOmics database, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted. The interactions between CEND1 and drugs were explored employing the Comparative Toxicogenomics Database and molecular docking technology. Cell experiments were conducted to analyze triptonide's effects on glioma cells through CCK-8, flow cytometry and qRT-PCR. CEND1 was lowly expressed in gliomas, and high CEND1 expression was correlated to better overall survival of glioma patients (HR = 0.65, P = 0.02). Deep deletion was the main type of hereditary change of CEND1 mutation. CEND1 expression was markedly associated with immune infiltration, TMB, MSI, and RNA modification in various tumors (r > 0.3, P < 0.05). CEND1 co-expressed genes in gliomas were markedly correlated with immune responses and cell cycle (FDR < 0.05). Triptonide could bind well to CEND1 (-5.0 kcal/mol), and triptonide could facilitate CEND1 expression in glioma cells and cell apoptosis, and block the cell cycle progression (P < 0.05). CEND1 serves as a potential biomarker for pan-cancer. Particularly in gliomas, CEND1 is a key regulator of cell apoptosis and cell cycle, and a potential target for glioma treatment.

2.
Nat Commun ; 15(1): 3409, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649702

RESUMO

Phosphoric acid doped proton exchange membranes often experience performance degradation above 200 °C due to membrane creeping and phosphoric acid evaporation, migration, dehydration, and condensation. To address these issues, here we present gel-state polybenzimidazole membranes with double cross-linked three-dimensional layered structures via a polyphosphoric acid sol-gel process, enabling stable operation above 200 °C. These membranes, featuring proton-conducting cross-linking phosphate bridges and branched polybenzimidazole networks, effectively anchor and retain phosphoric acid molecules, prevent 96% of its dehydration and condensation, improve creep resistance, and maintain excellent proton conductivity stability. The resulting membrane, with superior through-plane proton conductivity of 0.348 S cm-1, delivers outstanding peak power densities ranging from 1.20-1.48 W cm-2 in fuel cells operated at 200-240 °C and a low voltage decay rate of only 0.27 mV h-1 over a 250-hour period at 220 °C, opening up possibilities for their direct integration with methanol steam reforming systems.

3.
J Hazard Mater ; 468: 133727, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38367434

RESUMO

Tight ultra-filtration (TUF) membranes were constructed by in situ growing zinc imidazole frameworks micro-crystalline leaves (ZIF-L) in polyethylene imine (PEI) and polydopamine (PDA) deposit layers on porous polyethylene (PE) substrates. The effects of preparation conditions on the surface physical and chemical structures as well as on the dye/salt separation performance of the formed TUF membranes were systematically investigated. By inserting selective water permeation channels and increasing contacting surface areas, in situ-grown ZIF-L arrays tightly cross-linked in the coating matrix greatly increased water permeation without trading off dye/salt retention selectivity. The morphology of the included ZIF-L particles could be varied by adjusting the ligand/Zn molar ratio (α) in the preparation processes. Optimized PDA-PEI/ZIF-L@PE TUF membranes containing ZIF-L of cross-cross block morphology showed very high pure water permeability of 180 ± 20 L·m-2·h-1·bar-1 (LMHB) and retention selectivity (SCR/Na2SO4 and SMB/Na2SO4) of 267 and 43, respectively, as well as excellent stability and anti-fouling properties.

4.
J Hazard Mater ; 452: 131332, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37004442

RESUMO

Development of efficient absorbent materials for detection and treatment of offshore oil spillages remained a challenge. In this work, C-shaped polypropylene oil-absorbent fibers with sub-micron internal pores were prepared by combining spun-bonding technique and thermally induced phase separation (TIPS). The effect of drawing speed on the phase separation and the porous morphology of the shaped fiber non-woven fabric (NWF) was investigated. C-shaped NWF with porous morphology had large water contact angle, higher porosity, larger specific surface area, and increased oil absorption speed and capacity. An online oil spillage detection system was developed using porous C-shaped NWF and an oxygen sensing probe, showing shorter response time and higher signal-to-noise (STN) ratio. The response time for detecting the spillage of soybean oil and diluted crude oil (0.5 mL/0.8 L) in water were only 24 s and 10 s, respectively. The reliable oil detection low detection limit (RLDL) of the oxygen sensing probe was reduced 173 times (from 36.5 g/L to 0.21 g/L) when combined with C-shaped porous fiber NWF.

5.
BMC Nurs ; 22(1): 131, 2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37076918

RESUMO

BACKGROUND: Spiritual needs have been associated with better physical health outcomes and provide a context for patients to gain hope and significance in coping with disease. This study aimed to understand the status of spiritual needs of patients with advanced cancer and conducted a quantitative study on the relationship between patient-reported physical, psychological, and social influencing factors and spiritual needs based on a biopsychosocial-spiritual model. METHODS: In this study, 200 oncology inpatients from Shandong Province were recruited using a convenience sampling method to conduct a cross-sectional survey using general data from December 2020 to June 2022. Correlation analysis was used to analyze the correlation between spiritual needs and cancer-related fatigue, anxiety and depression, the family care index, and social support. Multiple regression analysis was used to analyze the relationship between spiritual needs and the influencing factors. RESULTS: The spiritual needs score of the patients with advanced cancer was high. Multiple regression analysis revealed that cancer-related fatigue, social support, and religious beliefs influenced the spiritual needs of patients with advanced cancer. Compared with married patients, widowed or divorced patients scored 8.531 points higher on spiritual needs. Cancer-related fatigue, social support, religious beliefs, and marital status (divorced or widowed) explained 21.4% of the total variation in the spiritual needs of patients with advanced cancer. CONCLUSION: The spiritual needs of patients with advanced cancer were significantly correlated with cancer-related fatigue, depression, social support, and other factors. Religious beliefs, marital status, cancer-related fatigue, and social support were the main factors influencing the spiritual needs of patients with advanced cancer. This is a quantitative study, and medical staff can provide targeted spiritual care for patients with cancer based on the above influencing factors.

6.
Artigo em Inglês | MEDLINE | ID: mdl-36913424

RESUMO

It is an important initiative to reduce the building energy consumption using energy recovering ventilation (ERV) systems. The application of ERV systems is hindered by the low CO2 barrier performance of commercial total heat exchange membranes (THEMs) that lead to unsatisfactory indoor air refreshing rate, and there is an urgent need for THEMs that have improved CO2 barrier properties and effective energy recovery efficiencies. Here, we report the formation of novel ZIF/PA TFN THEMs based on ZIF-7-X nanoparticles (NPs) with "core-shell" structures and tunable particle sizes, formed from benzimidazole (BIM) ligands and BIM substituted by -NH2, -CH3, -C2H5, and -C3H7 functional groups. The NPs were mixed with pyr omellitic triformyl chloride (TMC) in the organic phase during the interface polymerization process to form ZIF/PA TFN membranes. The total heat exchange performance of ZIF/PA TFN membranes could be effectively modified by the type and quantity of ZIF-7-X NPs added. The CO2 barrier properties and water vapor permeability of ZIF/PA TFN membranes could be improved by the addition of optimal levels of ZIF-7-X NPs, showing low CO2 permeance of 7.76 GPU, high H2O permeance of 663.8 GPU, and excellent enthalpy exchange efficiency of 72.1%. This work provided an effective strategy for tuning not only the nanostructures of ZIF-7 fillers but also the CO2 barrier properties of the formed ZIF/PA TFN membranes.

7.
Ther Clin Risk Manag ; 18: 541-550, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35548665

RESUMO

Purpose: To determine which frailty method can better improve the predictive ability of the Surgical Apgar Score combined with American Society of Anesthesiologists physical status classification (SASA). Patients and Methods: A prospective cohort study was conducted. A total of 194 elderly patients undergoing elective abdominal surgery were included. Preoperative frailty using FRAIL questionnaire, frailty index (FI), Clinical Frailty Scale (CFS) and SASA scores was assessed. Primary outcome was in-hospital Clavien-Dindo ≥grade II complications. Multiple logistic regression was used to examine the association between frailty and complications. Receiver operating characteristic curves were used to explore the predictive ability of frailty. Results: According to the FRAIL, FI and CFS criteria, the prevalence of frailty in the study population was 43.8%, 32.5%, and 36.6%, respectively. After adjusting for all covariates, frailty was significantly associated with postoperative complications in hospital by FRAIL [odds ratio: 5.11, 95% CI: 1.41-18.44, P = 0.013], by FI [OR: 4.25, 95% CI: 1.21-14.90, P = 0.024] and by CFS [OR: 5.10, 95% CI: 1.52-17.17, P = 0.008]. The area under the curve (AUC) for SASA was 0.768 (95% CI: 0.702-0.826). Addition of frailty assessment (FRAIL, FI and CFS) increased the AUC to 0.787 (95% CI: 0.722-0.842), 0.798 (95% CI: 0.734-0.852), and 0.815 (95% CI: 0.753-0.867), respectively. Compared to SASA, only addition of CFS had a significant difference (P = 0.0478). Conclusion: Frailty is an effective predictor of postoperative complications in elderly Chinese patients undergoing elective abdominal surgery. Frailty assessment of CFS can better improve the predictive ability of SASA.

8.
ACS Omega ; 7(8): 6674-6681, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35252662

RESUMO

Developing superabsorbents for efficiently separating immiscible oil-water mixtures and oil-water emulsions are highly desirable for addressing oily wastewater pollution problems, but it remains a challenge. Ultralight nanofibrous aerogels (NFAs) with unique wetting properties show great potential in oily wastewater treatment. In this study, a facile and efficient method for producing hierarchical porous structured NFAs with hydrophobicity for high efficiency oil-water separation was developed. The synthesis included three steps: wet electrospinning, freeze drying, and in situ polymerization. The obtained NFA demonstrated outstanding oil absorption capacity toward numerous oils and organic solvents, as well as efficient surfactant-stabilized water-in-oil emulsion separation with high separation flux and excellent separation efficiency. Furthermore, these NFAs displayed excellent corrosion resistance and outstanding recoverability. We assume that the resultant NFAs fabricated by this facile strategy are highly promising as ideal oil absorbents for practical oily wastewater treatment under harsh conditions.

9.
J Hazard Mater ; 421: 126788, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34364204

RESUMO

Development of efficient absorbent materials for oil spillage clean-up and environmental pollution remediation is highly desired but remains a challenge. In this work, superhydrophobic/superoleophilic polysulfone based ZIF-7 composite (SPZ) foams were fabricated via chemical modification of polysulfone and integrating with hydrophobic coin-shaped ZIF-7 particles. The synergistic approaches provided the SPZ foams with high porosity, low density and superhydrophobic/superoleophilic features (θwater=162.3°, θoil=0°) and outstanding self-cleaning property. The as-prepared SPZ foams exhibited highly selective absorption capacity (up to 3800 wt%) for various kinds of oils and organic solvents. Furthermore, the SPZ foams still maintained 95.2% of its pristine absorption capacity and the θwater remained at 143.6° after ten absorption/distillation cycles. The SPZ foam showed outstanding separation ability towards different types of emulsions with separation efficiency all above 97%. The high oil/water separation efficiency and robust reusability made the SPZ foams promising absorbent in dealing with practical oil spills.


Assuntos
Poluição por Petróleo , Água , Interações Hidrofóbicas e Hidrofílicas , Óleos , Polímeros , Sulfonas
10.
Biomed Res Int ; 2021: 4604258, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34660789

RESUMO

Diabetes mellitus- (DM-) associated hyperglycemia promotes apoptosis of disc nucleus pulposus (NP) cells, which is a contributor to intervertebral disc degeneration (IDD). Melatonin is able to protect against cell apoptosis. However, its effects on apoptosis of NP cell in a high-glucose culture remain unclear. The purpose of the present study was to investigate the effects and molecular mechanism of melatonin on NP cell apoptosis in a high-glucose culture. NP cells were cultured in the baseline medium supplemented with a high-glucose concentration (0.2 M) for 3 days. The control cells were only cultured in the baseline medium. Additionally, the pharmaceutical inhibitor LY294002 was added along with the culture medium to investigate the possible role of the PI3K/Akt pathway. Apoptosis, autophagy, and activity of the PI3K/Akt pathway of NP cells among these groups were evaluated. Compared with the control NP cells, high glucose significantly increased cell apoptosis ratio and caspase-3/caspase-9 activity and decreased mRNA expression of Bcl-2, whereas it increased mRNA or protein expression of Bax, caspase-3, cleaved caspase-3, cleaved PARP, and autophagy-related molecules (Atg3, Atg5, Beclin-1, and LC3-II) and decreased protein expression of p-Akt compared with the control cells. Additionally, melatonin partly inhibited the effects of high glucose on those parameters of cell apoptosis, autophagy, and activation of PI3K/Akt. In conclusion, melatonin attenuates apoptosis of NP cells through inhibiting the excessive autophagy via the PI3K/Akt pathway in a high-glucose culture. This study provides new theoretical basis of the protective effects of melatonin against disc degeneration in a DM patient.


Assuntos
Apoptose , Autofagia , Glucose/toxicidade , Melatonina/farmacologia , Núcleo Pulposo/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Animais , Células Cultivadas , Depressores do Sistema Nervoso Central/farmacologia , Núcleo Pulposo/metabolismo , Núcleo Pulposo/patologia , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Transdução de Sinais , Edulcorantes/toxicidade
11.
RSC Adv ; 11(35): 21279-21290, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35478813

RESUMO

In this study, an efficient on-site marine oil spillage monitoring probe was developed by fixing oxygen consumption sensors into hydrophobic/oleophilic oil-absorbing porous materials. The impact of thickness and characters of the porous materials, the types of spilled oil, and the presence of salts and vibration in water on the parameters of the obtained signals was investigated. The probe could be used to detect the various representative types of spilled oils including lubricating oil, corn oil, soybean oil, n-hexane, petroleum ether and toluene, even in simulated sea water vibrating at different levels, having over 33 times reduced reliable low detection limit (RLDL) in detecting soybean oil in water (from 36.5 g L-1 to 1.1 g L-1). The response time and signal-to-noise ratios (SNRs) of the probe varied greatly with the dynamic absorbing speed and oxygen barrier property of the spilled oils in the porous material, respectively. The probe showing the highest SNR of 190 dB for a 50 g L-1 on-site soybean oil spillage and the fastest response time of 9 s for a 50 g L-1 on-site toluene spillage in water may potentially be used as a key component in near-shore marine oil spillage monitoring systems to provide early-stage pollution warning.

12.
ANZ J Surg ; 91(3): 335-340, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33021042

RESUMO

BACKGROUND: To compare the predictive power of three different evaluation methods of frailty for 90-day outcomes of elderly patients undergoing elective abdominal surgery. METHODS: A prospective cohort study was conducted with 194 patients and a postoperative follow-up period of 90 days. Preoperative frailty was evaluated using the five-item FRAIL questionnaire, 54-item frailty index (FI), and nine-item Clinical Frailty Scale (CFS). Receiver operating curves were used to compare the predictive ability for 90-day mortality and long-term hospitalization (LTH), and logistic regression was used to calculate odds ratios and 95% confidence intervals. RESULTS: The incidence rates of frailty assessed using FRAIL, FI, and CFS criteria were 43.8%, 32.5% and 36.6%, respectively. The 90-day mortality and LTH of frail patients were significantly higher than those of non-frail patients regardless of which criteria were used. The CFS and FI predicted 90-day mortality better than FRAIL (CFS versus FRAIL: P = 0.005; FI versus FRAIL: P = 0.041), and the CFS predicted LTH better than FRAIL (P = 0.032). CONCLUSIONS: Patients diagnosed with frailty had significantly higher 90-day mortality and LTH regardless of which criteria were used. The CFS and FI were better predictors of 90-day mortality, and the CFS was a better predictor of LTH.


Assuntos
Fragilidade , Idoso , Idoso Fragilizado , Fragilidade/diagnóstico , Fragilidade/epidemiologia , Avaliação Geriátrica , Humanos , Tempo de Internação , Estudos Prospectivos
13.
Nanotechnology ; 31(42): 425710, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32610299

RESUMO

A facile approach is established to prepare zwitterionic nanocapsules (ZN C s) with controlled diameters and core/shell structures based on an inverse reversible addition-fragmentation transfer (RAFT) miniemulsion interfacial polymerization method. The diameters and core volume fractions of ZNCs can be tuned finely from 61 to 220 nm and from 0.22 to 0.61, respectively. Furthermore, the thermal-responsive property of the prepared zwitterionic nanocapsules was systematically studied relating to core/shell ratios and cross-linking degrees. These ZNCs could be particularly useful in constructing polymeric materials with well-defined nanoporous structures for nano-void membranes, drug delivery devices and catalytic carriers.

14.
Nano Lett ; 19(5): 2953-2959, 2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-30969778

RESUMO

In order to lower the capital and operational cost of desalination and wastewater treatment processes, nanofiltration (NF) membranes need to have a high water permeation and ionic rejection, while also maintaining a stable performance through antifouling resistance. Recently, Turing-type reaction conditions [ Science 2018, 360, 518-521] and sacrificed metal organic frame (MOF) nanoparticles [ Nat. Commun. 2018, 9, 2004] have been reported to introduce nanovoids into thin-film composite (TFC) polyamide (PA) NF membranes for an improved performance. Herein, we report a one-step fabrication of thin-film nanocomposite membranes (TFNM) with controllable nanovoids in the polyamide layer by introducing hollow zwitterionic nanocapsules (HZNCs) during interfacial polymerization. It was found that embedding HZNCs increases the membrane internal free volume, external surface area, and hydrophilicity, thus enhancing the water permeation and antifouling resistance without trading off the rejection of multivalent ions. For example, water permeation of the NF membranes embedded with about 19.0 wt % of HZNCs (73 L m-2 h-1) increased by 70% relative to the value of the control TFC NF membrane without HZNCs (43 L m-2 h-1). This increase comes while also maintaining 95% rejection of Na2SO4. Further, we also determined the effect of the mass loading of HZNCs on the top surface of the TFC NF membranes on the membrane performance. This work provided a direct and simple route to fabricate advanced desalination membranes with a superior separation performance.

15.
Membranes (Basel) ; 9(1)2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30650661

RESUMO

A ternary nanocomposite consisting of N-doped graphene (NGR)/TiO2/activated carbon (NGRT@AC) was prepared, and the components' synergetic effect on dye degradation was investigated after deposition on the surface of a polysulfone membrane (PSF). As far as we know, this ternary composite catalyst has never previously been used to degrade dyes nor been used as a functional layer for separation membranes. The surface morphology and structure of the as-prepared membranes were analyzed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The NGRT@AC-modified PSF membrane (NGRT@AC-PSF) presents excellent photodegradation efficiency to methyl orange (MO) under both UV (95.2%) and sunlight (78.1%) irradiation, much higher than those values of PSF, TiO2- modified PSF (TiO2-PSF), and N-doped graphene/TiO2 (NGRT)-modified PSF membranes (NGRT-PSF) under the same conditions. The high flux recovery ratio (95.5%) demonstrates that the NGRT@AC-PSF membrane shows improved antifouling performance. The photocatalytic results prove that surface deposition method (95.2%) was better than the blending method (31.1%) for forming high-performance membranes. Therefore, the NGRT@AC-PSF membrane has the potential for broad applications in dye degradation to treat waste water from textile industries.

16.
Mater Sci Eng C Mater Biol Appl ; 74: 159-166, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28254281

RESUMO

Poly(vinyl pyrrolidone) (PVP) and its copolymers have been widely employed for the modification of hemodiafiltration membranes due to their excellent hydrophilicity, antifouling and hemocompatibility. However, challenges still remain to simplify the modification procedure and to improve the utilization efficiency. In this paper, antifouling and hemocompatibility polysulfone (PSf) hemodiafiltration membranes were fabricated via in situ cross-linked polymerization of vinyl pyrrolidone (VP) and vinyltriethoxysilane (VTEOS) in PSf solutions and non-solvent induced phase separation (NIPS) technique. The prepared membranes were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), which suggested that VP and VTEOS have been cross-linked copolymerized in PSf membranes. The modified PSf membranes with high polymer content showed improved hydrophilicity, ultrafiltration and protein antifouling ability. In addition, the modified PSf membranes showed lower protein adsorption, inhibited platelet adhesion and deformation, prolonged the activated partial thromboplastin time (APTT), prothrombin time (PT), and decreased the content of fibrinogen (FIB) transferring to fibrin, indicating enhanced hemocompatibility. In a word, the present work provides a simple and effective one-step modification method to construct PSf membranes with improved hydrophilicity, antifouling and hemocompatibility.


Assuntos
Materiais Biocompatíveis/química , Membranas Artificiais , Polímeros/química , Cloreto de Polivinila/química , Sulfonas/química , Adsorção , Materiais Biocompatíveis/farmacologia , Incrustação Biológica/prevenção & controle , Plaquetas/citologia , Adesão Celular/efeitos dos fármacos , Hemodiafiltração , Humanos , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Varredura , Tempo de Tromboplastina Parcial , Espectroscopia Fotoeletrônica , Polimerização , Porosidade , Proteínas/química , Proteínas/metabolismo , Tempo de Protrombina , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Sci Rep ; 6: 24096, 2016 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-27297030

RESUMO

Sub-gap density of states (DOS) is a key parameter to impact the electrical characteristics of semiconductor materials-based transistors in integrated circuits. Previously, spectroscopy methodologies for DOS extractions include the static methods, temperature dependent spectroscopy and photonic spectroscopy. However, they might involve lots of assumptions, calculations, temperature or optical impacts into the intrinsic distribution of DOS along the bandgap of the materials. A direct and simpler method is developed to extract the DOS distribution from amorphous oxide-based thin-film transistors (TFTs) based on Dual gate pulse spectroscopy (GPS), introducing less extrinsic factors such as temperature and laborious numerical mathematical analysis than conventional methods. From this direct measurement, the sub-gap DOS distribution shows a peak value on the band-gap edge and in the order of 10(17)-10(21)/(cm(3)·eV), which is consistent with the previous results. The results could be described with the model involving both Gaussian and exponential components. This tool is useful as a diagnostics for the electrical properties of oxide materials and this study will benefit their modeling and improvement of the electrical properties and thus broaden their applications.

19.
Water Sci Technol ; 73(9): 2159-67, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27148717

RESUMO

Dual layer polyvinylidene fluoride (PVDF), antibacterial, hollow fiber, ultra-filtration composite membranes with antibacterial particles (silver (Ag) nano-particles loaded zeolite (Z-Ag)) in the outer layer were prepared with high water flux and desired pore sizes. The amounts of Ag(+) released from the composite membranes, freshly made and stored in water and salt solution, were measured. The result indicated that dual layer PVDF antibacterial hollow fiber containing Z-Ag (M-1-Ag) still possessed the ability of continuous release of Ag(+) even after exposure to water with high ionic content, showing a longer term resistance to bacterial adhesion and antibacterial activity than membrane doped with Z-Ag(+) (M-1). Results from an anti-adhesion and bacteria killing test with Escherichia coli supported that the antibacterial efficiency of dual hollow fiber PVDF membranes with Z-Ag was much higher than those with Z-Ag(+) after long time storage in water or exposure to phosphate buffered saline (PBS) solution. This novel hollow fiber membrane may find applications in constructing sea water pretreatment devices with long term antifouling capability for the desalination processes.


Assuntos
Membranas Artificiais , Nanopartículas Metálicas/química , Polivinil , Prata/química , Zeolitas , Antibacterianos/química , Antibacterianos/farmacologia , Escherichia coli , Cloreto de Sódio/química , Ultrafiltração/instrumentação , Ultrafiltração/métodos , Água/química , Purificação da Água/métodos
20.
ACS Appl Mater Interfaces ; 7(32): 17748-55, 2015 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-26222398

RESUMO

Poly(lactic acid) (PLA) hemodialysis membranes with enhanced antifouling capability and hemocompatibility were developed using poly(lactic acid)-block-poly(2-hydroxyethyl methacrylate) (PLA-PHEMA) copolymers as the blending additive. PLA-PHEMA block copolymers were synthesized via reversible addition-fragmentation (RAFT) polymerization from aminolyzed PLA. Gel permeation chromatography (GPC) and (1)H-nuclear magnetic resonance ((1)H NMR) were applied to characterize the synthesized products. By blending PLA with the amphiphilic block copolymer, PLA/PLA-PHEMA membranes were prepared by nonsolvent induced phase separation (NIPS) method. Their chemistry and structure were characterized with X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and atomic force microscopy (AFM). The results revealed that PLA/PLA-PHEMA membranes with high PLA-PHEMA contents exhibited enhanced hydrophilicity, water permeability, antifouling and hemocompatibility. Especially, when the PLA-PHEMA concentration was 15 wt %, the water flux of the modified membrane was about 236 L m(-2) h(-1). Its urea and creatinine clearance was more than 0.70 mL/min, lysozyme clearance was about 0.50 mL/min, BSA clearance was as less as 0.31 mL/min. All the results suggest that PLA-PHEMA copolymers had served as effective agents for optimizing the property of PLA-based membrane for hemodialysis applications.


Assuntos
Ácido Láctico/química , Membranas Artificiais , Poliésteres/química , Polímeros/química , Ácidos Polimetacrílicos/química , Diálise Renal , Adsorção , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Incrustação Biológica , Plaquetas/química , Plaquetas/citologia , Plaquetas/metabolismo , Bovinos , Adesão Celular/efeitos dos fármacos , Cromatografia em Gel , Humanos , Interações Hidrofóbicas e Hidrofílicas , Espectroscopia de Ressonância Magnética , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Poliésteres/síntese química , Poliésteres/farmacologia , Ácidos Polimetacrílicos/síntese química , Ácidos Polimetacrílicos/farmacologia , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo
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