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- 摘要
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过滤筛选
- 2018
- electromagnetic pulse
- cell proliferation
- cell membrane permeability
- cell response to electromagnetic stress
- apoptosis
- cancer therapy
- necrosis
- Intelligent Medical Engineering
- V.N. Karazin Kharkiv National University
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Photocatalytic degradation of pharmaceutical micro-pollutants using ZnO
摘要： This research paper presents the results of an experimental investigation of the degradation of three different contaminants including progesterone (PGS), ibuprofen (IBU), and naproxen (NAP) using ZnO as the photocatalyst and ultraviolet (UV) light as a source for catalysts activation. Two operating parameters, namely, catalyst loading and initial concentration of contaminants, were tested in a batch photocatalytic reactor. To demonstrate the large-scale applications, experiments were also conducted in a submerged membrane photocatalytic reactor. It has proven that ZnO photocatalyst degraded the three contaminants very efficiently under almost all the studied experimental conditions, with efficiency rates of 92.3, 94.5, and 98.7 % for PSG, IBU, and NAP, respectively. The photodegradation kinetics study was performed to calculate the reaction rate constant, which is found to follow pseudo-first order kinetics. The membrane photocatalytic reactor was efficient to remove pollutants and it is observed that the degradation rate increases with increasing the membrane oscillation frequency approaching that of the stirred reactor.
关键词： Photocatalytic degradation,Progesterone,Ibuprofen,Photocatalytic batch reactor,Naproxen,Oscillatory membrane reactor,ZnO
更新于2025-09-23 15:22:29
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Wastewater treatment using a hybrid system combining adsorption, photocatalytic degradation and membrane filtration processes
摘要： In the present study, Chooka’s Wastewater treatment was investigated using di?erent combinations of adsorption, photocatalytic degradation, and membrane ?ltration process. Polymeric membranes were fabricated using wet phase inversion method employing polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP), and dimethylformamide (DMF) as a polymer matrix, hydrophilic additive, and solvent, respectively. Activated carbon and TiO2 nanoparticles were selected as an adsorbent and photocatalyst, respectively. TiO2 nanoparticles were synthesized using the sol-gel method and activated carbon was purchased from Merck Company. Liquid-liquid displacement (LLDP), scanning electron microscope (SEM) and contact angle tests were implemented to characterize the fabricated membranes. FT-IR and XRD analysis were also used for TiO2 nanoparticles characterization. The wastewater of Iran pulp and paper factory (Chooka) was used as the feed in separation processes. In hybrid separation systems, 6 di?erent con?gurations were considered and wastewater compositions were measured to determine the e?ectiveness of the utilized processes before and after treatment. Accordingly, the mean pore size of the fabricated PAN/PVP (16%/3%) membrane obtained from LLDP analysis was 9.72 nm. SEM results also indicated thicker active layer for the PAN/PVP membrane than that of the neat PAN membrane. According to the results of the contact angle tests, with the increasing of PVP content in the polymer matrix, the hydrophilicity of membranes improved. It was also found that membrane ?ltration had the best performance among single stage processes and the best separation performance was achieved when photocatalytic degradation, adsorption, and membrane ?ltration were used in series, respectively.
关键词： Photocatalytic degradation,Membrane ?ltration,Adsorption,Hybrid process,Wastewater treatment
更新于2025-09-23 15:22:29
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Track-etched membrane as fluorescence-based pH biosensor
摘要： Robust and cost-effective stimuli-responsive polymers show prominent advantages to be integrated into detection devices. In addition, modified track-etched membranes with chemical-sensing polymers possess additional robustness features such as including the sensing material into sub-micron pores. In this study, we report the preparation of track-etched PET membranes with fluorescent response in direct relation to changes in the pH of the environment. Immobilised Fluorescein and Green Fluorescent Protein have been used as pH-sensor elements. The former was not sensitive to pH, while the latter had a similar pH sensitivity to that of the free protein. Modifications of track-etched membranes were carried out by grafting polymerisation initiated by the remnant radicals, a straightforward technique for selective modification of the inner wall of pores. The biosensor prepared with the fluorescent protein was able to sense the pH of a buffer solution in the range 4 to 8. Furthermore, this membrane evidenced capacity to sense the pH of the cell growth by in situ fluorescence intensity detection during E.coli cell culture in microwells.
关键词： Track-etched PET membrane,Nanopore functionalisation,GFP immobilisation,Glycidyl methacrylate
更新于2025-09-23 15:22:29
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Self-Floating Carbonized Tissue Membrane Derived from Commercial Facial Tissue for Highly Efficient Solar Steam Generation
摘要： Solar steam generation holds a great promise for practically utilizing solar energy in sea water desalination and sewage purification on a large scale. It has been proven that local heating of the superficial water can maximize the energy efficiency for steam generation. So the photothermal materials are required to float on water while working. However, the fabrication of a photothermal material with self-floating ability, low cost and easy-preparation for solar steam generation is highly challenged. Herein, self-floating carbonized tissue membrane for high efficiency solar steam generation is prepared via the carbonization of the commercial facial tissue. The low-cost and scalable carbonized tissue membrane can float on water without any assistance, and can effectively generate water steam at the rate of 4.45 kg m-2 h-1 with photothermal conversion efficiency of as high as 95 % under 3-sun illumination. The self-floating ability, high solar steam generation performance and low cost make the carbonized tissue membrane to be potential alternative for practical application in the future.
关键词： Self-floating,Membrane,One-step synthesis,Carbon material,Solar steam generation
更新于2025-09-23 15:22:29
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Osmolarity and spectrophotometric property of brilliant blue green define the degree of toxicity on retinal pigment epithelial cells exposed to surgical endoilluminator
摘要： Objective: To evaluate the effect of varying concentrations of brilliant blue green (BBG) and their different biochemical characteristics on retinal pigment epithelial (RPE) cells under xenon light source illumination at varying distances to identify safe parameters for intraoperative use. Methods: Human retinal RPE cells (ARPE-19) were exposed to two concentrations (0.25 and 0.50 mg/mL) of BBG and illuminated with a xenon surgical illuminator at varying distances (10 and 25 mm), intensity levels, and time intervals (1, 5, and 15 minutes). Additionally, the effect of osmolarity was examined by diluting BBG in different concentrations of glucose. Cytotoxicity of BBG and osmolarity effects on cell viability were evaluated using a WST-1 assay. Light absorption and emission characteristic of BBG in different solvents were measured using a plate reader at different wavelengths. Lastly, the activity of caspase-3 was also studied. Results: Cell viability of ARPE-19 cells was 77.4%±12.7%, 78.7%±17.0%, and 65.0%±19.7% at 1, 5, and 15 minutes to exposure of high illumination xenon light at 10 mm (P<0.05) compared to controls. At both distances of illumination (10 and 25 mm), similar cell viabilities were seen between 1 and 5 minutes of exposure. However, there was a decline in viability when the illumination was carried out to 15 minutes in all groups (P<0.05). There was no significant reduction in cell viability in presence or absence of xenon light in different osmolar solutions concentrations of glucose (P>0.05). Maximal light absorption of BBG was noted between 540 and 680 nm. Activated caspase-3 level was not significant in both the concentrations of BBG (P>0.05). Conclusion: Our findings suggest that BBG at 0.25 mg/mL during vitreoretinal surgery is safe and not toxic to RPE cells up to 5 minutes under focal high illumination (10 mm) and up to 15 minutes under medium diffuse illumination (25 mm). BBG was safe to be mixed with isotonic glucose solution at the concentration range of 2.5%–10%, regardless of the illumination status.
关键词： human retinal RPE cells,vitrectomy,internal limiting membrane peel,brilliant blue green dye,endoilluminator
更新于2025-09-23 15:22:29
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Eficacia de la imagen precoz con 68Ga-PSMA-I&T para la discriminación de lesiones en los pacientes con cáncer de próstata
摘要： Objective: 68Ga-PSMA-uptake shows accumulation in the malignant lesions of prostate cancer patients as early as 5 min p.i. Studies indicate the value of adding an early image of the pelvis to the imaging protocol of 68Ga-PSMA-11 PET/CT scan showed contradictory results. In this study we planned to assess the significance of an additional early imaging in 68Ga-PSMA-I&T PET/CT imaging in prostate cancer patients. Materials and methods: A total of 35 prostate cancer patients referred to 68Ga-PSMA-I&T PET/CT imaging for restaging of the disease due to suspicion of relapse after definitive therapy were enrolled. First an early static pelvic image was obtained at a maximum of 300 s following injection of the radiotracer. Sixty minutes postinjection a whole-body PET/CT scan was conducted with an emission time of 3 min per bed position. The lesions which were categorized as local recurrence, bone lesion and lymph node metastasis in the early images, were compared with the late images in terms of number of lesions detected and SUVmax values. Results: 68Ga-PSMA-I&T PET/CT was positive in 23 of 35 patients (65.7%). A pathological uptake was observed in the prostatic bed site, in the pelvic lymph nodes, and in the bones in 17 patients (48.5%), 12 patients (34.2%), and 13 patients (37.1%), respectively. In one patient, focal pathological increased uptake in the prostatic bed with a SUVmax value of 5.8 was detected but this lesion disappeared in the late images. The average SUVmax values of the lesions in the prostatic bed were 13.7 ± 12.1 versus 26.3 ± 23.8 in the 5 min and 60 min studies respectively (p < 0.001). In one patient, the pathological uptake in the lymph node in the early study cleared in the late study, whereas in another accumulation of activity was detected in a pelvic lymph node in the late study, while there was no lymph node detected in the early study. The average SUVmax values of the lymph nodes were 12.1 ± 8.8 versus 26.3 ± 22.6 in the 5 min and 60 min studies respectively (p < 0.001). The average SUVmax values of the bone lesions were 11.4 ± 6.9 versus 15 ± 10.7 in the 5 min and 60 min studies respectively. Conclusion: Our study is the first in the literature to evaluate the impact of adding an early static pelvic image to the 68Ga-PSMA-I&T scan, in the detection rate of the lesions. Although there was no marked discordance between the 2 sets of images, the addition of an early image to the imaging protocol of 68Ga-PSMA-I&T scan would increase the efficacy of detection of malignant lesions in the pelvis, which might show rapid clearance and has the risk of being masked by the urinary system activity.
关键词： Prostate-specific membrane antigen,68Ga-PSMA-I&T,PET/CT,Lymph node metastases,Prostate cancer
更新于2025-09-23 15:22:29
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Photooxidation of unilamellar vesicles by a lipophilic pterin: Deciphering biomembrane photodamage
摘要： Pterins are natural products that can photosensitize the oxidation of DNA, proteins and phospholipids. Recently, a new series of decyl-chain (i.e., lipophilic) pterins were synthesized and their photophysical properties investigated. These decyl-pterins led to efficient intercalation in large unilamellar vesicles and produce, under UVA irradiation, singlet molecular oxygen, a highly oxidative species that react with polyunsaturated fatty acids (PUFAs) to form hydroperoxides. Here, we demonstrate that the association of 4-(decyloxy)pteridin-2-amine (O-decyl-Ptr) to lipid membranes is key to its ability to trigger phospholipid oxidation in unilamellar vesicles of phosphatidylcholine rich in PUFAs used as model biomembranes. Our results show that O-decyl-Ptr is at least one order of magnitude more efficient photosensitizer of lipids than pterin (Ptr), the unsubstituted derivative of the pterin family, which is more hydrophilic and freely passes across lipid membranes. Lipid peroxidation photosensitized by O-decyl-Ptr was detected by the formation of conjugated dienes and oxidized lipids, such as hydroxy and hydroperoxides derivatives. These primary products undergo a rapid conversion into short-chain secondary products by cleavage of the fatty acid chains some of which are due to subsequent photosensitized reactions. As a consequence, a fast increase in membrane permeability is observed. Therefore, lipid oxidation induced by O-decyl-Ptr could promote cell photodamage due to the biomembrane integrity loss which, in turn, may trigger cell death.
关键词： alkyl-pterins,membrane permeability,lipid peroxidation,photosensitization
更新于2025-09-23 15:21:21
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Increasing Membrane Permeability by Increasing the Polymer Crystallinity: The Unique Case of Polythiophenes
摘要： It is generally accepted in membrane technology that crystalline zones in polymeric membranes do not contribute to transport of liquids or gases. In the current study, poly(3-alkylthiophene)s (P3ATs), i.e., homopolymers and random copolymers, were synthesized to study the influence of the supramolecular organization on membrane gas separations. The monomers were polymerized via KCTCP, and GPC analysis shows that the polymers have a narrow dispersity. DSC analysis of the polymers reveals that the homopolymers, in contrast to the copolymers, crystallized, confirming their higher degree of supramolecular organization. This was supported by UV?vis absorption spectra of the polymer films, where a red-shift and a characteristic shoulder absorption peak around 600 nm were observed for the homopolymers, while absent for the copolymers. More surprisingly, the homopolymers were found to be 2 orders of magnitude more permeable to CO2 than the copolymers and also more selective.
关键词： selectivity,gas separations,permeability,membrane technology,supramolecular organization,poly(3-alkylthiophene)s,crystallinity
更新于2025-09-23 15:21:21
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Silicon Nitride MOMS Oscillator for Room Temperature Quantum Optomechanics
摘要： Optomechanical SiN nano-oscillators in high-finesse Fabry–Perot cavities can be used to investigate the interaction between mechanical and optical degree of freedom for ultra-sensitive metrology and fundamental quantum mechanical studies. In this paper, we present a nano-oscillator made of a high-stress round-shaped SiN membrane with an integrated on-chip 3-D acoustic shield properly designed to reduce mechanical losses. This oscillator works in the range of 200 kHz to 5 MHz and features a mechanical quality factor of Q ≈ 107 and a Q-frequency product in excess of 6.2 × 1012 Hz at room temperature, fulfilling the minimum requirement for quantum ground-state cooling of the oscillator in an optomechanical cavity. The device is obtained by MEMS deep reactive-ion etching (DRIE) bulk micromachining with a two-side silicon processing on a silicon-on-insulator wafer. The microfabrication process is quite flexible such that additional layers could be deposited over the SiN membrane before the DRIE steps, if required for a sensing application. Therefore, such oscillator is a promising candidate for quantum sensing applications in the context of the emerging field of quantum technologies.
关键词： reactive ion etching,MOMS oscillator,quantum optomechanics,SiN thin membrane
更新于2025-09-23 15:21:21
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Atomic Force Microscopy in Molecular and Cell Biology || Assessment of Pathological or Drug-Dependent Changes in Cell Membrane Morphology and Cell Biomechanical Properties by Atomic Force Microscopy
摘要： Identification of the nanoscale changes that take place in cell membrane (CM) morphology or cell biomechanical properties (CBPs) in disease states or in response to drug treatment enable for a better understanding of the effects of the drugs on disease pathogenesis and recovery. CM proteins and CBPs have a crucial role in the regulation of many physiological and pathological processes. Direct assessment of the CM and CBPs is therefore useful not only for a better appreciation of cell structure but also for a better understanding of cell pathophysiology. Atomic force microscopy (AFM) is a technique that can be employed to assess CM structure and CBPs at the nanometer scale. In the first part of this chapter, we describe the principles of AFM and appraise its value in the assessment of CM morphology and CBPs. In the second part, we review examples of disease- or drug- dependent changes in CM morphology and CBPs that have been elucidated using AFM.
关键词： Nanoscale,Atomic force microscopy,Cell membrane
更新于2025-09-23 15:21:21