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Estimate of Nonuniformity of Dose Distribution in Regime of Total Therapeutic Irradiation with In Vivo Dosimetry Using Semiconductor Detectors
摘要： We have estimated the nonuniformity of the dose distribution along the body of a patient using in vivo dosimetry by semiconductor detectors with total therapeutic irradiation of cancer patients before bone marrow transplantation. The method of in vivo dosimetry was developed and used at the Blokhin Oncology Center since 2007. Based on the results of the investigation of 35 patients, we determined a mean nonuniformity of 10–15% of the dose distribution along the body of the patient, which conforms to international recommendations. We show a linear dependence of the accumulated dose on the mass of the patient.
关键词： total irradiation,in vivo dosimetry,semiconductor detectors,radiation therapy
更新于2025-09-04 15:30:14
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AIP Conference Proceedings [Author(s) 4TH ELECTRONIC AND GREEN MATERIALS INTERNATIONAL CONFERENCE 2018 (EGM 2018) - Bandung, Indonesia (27–28 July 2018)] - Effects of Ag dopant and ultraviolet irradiation on structural properties of zinc oxide nanostructures
摘要： ZnO nanorods are promising UV light driven photocatalyst for the degradation of organic dyes. In this work, the effects of Ag dopant (0.02 to 0.1 mol%) and ultraviolet irradiation (0 to 6 min) on structural, optical and photocatalytic properties of zinc oxide nanorods were investigate. The Ag incorporation ZnO nanoraod have been grown on glass substrate by chemical solution deposition method. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV–vis absorption spectroscopy (UV–vis). The XRD spectra of the Ag incorporation ZnO (Ag-ZnO) films indicate that Ag was incorporated in the wurtzite hexagonal crystal structure of ZnO and the crystallinity were enhanced with increasing of Ag amount as well as ultraviolet irradiation time. SEM micrographs of pure ZnO films revealed the uniform distribution of rod-like nanostructure of size of about 30-40 nm. Increasing Ag amount as well as irradiation time stimulated the optical properties of ZnO nanostructures. The photocatalytic activity of these nanostructures was evaluated by analysing UV irradiation degradation of methyl orange (MO) dye and it was observed that Ag-ZnO show significantly enhanced photocatalytic activity for degradation of MO, as compared to ZnO nanorods.
关键词： structural properties,ZnO nanorods,ultraviolet irradiation,Ag dopant,photocatalytic activity
更新于2025-09-04 15:30:14
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Voltammetric Determination of Bisphenol A Based on Its Anodic Deposition at Chitosan-Graphene Modified Glassy Carbon Electrode under UV Irradiation
摘要： Bisphenol A (BPA) was successfully electrodeposited on glassy carbon electrode modified with the chitosan-graphene (Chit-GR/GCE) by multiple sweep voltammetry under ultraviolet (UV) irradiation. The experimental conditions of the BPA deposits and the probable oxidation mechanism were investigated. Two oxidation peaks (peakⅡ=0.12 V, peakⅢ=0.20 V) appeared in a suitable potential range of 0.0V and 0.2V at the Chit-GR/GC eletrode in the presence of UV light, and it could be seen that the oxidation peak current increased with the increase of UV irradiation time. The emerging peakⅢ was reported firstly in the work, which showed that the Chit-GR modified electrode had catalytic activity on the oxidation of BPA. Based on the oxidation peak (peakⅢ) of BPA oxidative porducts on the Chit-GR/GC electrode under UV irradiation, the electrochemical sensor was fabiracated for determination of BPA. The calibration curve was obtained in the range of 5.0 to 200.0 μM with the limit of detection of 0.34 μM (S/N=3) and the response sensitivity of 0.33 μA μM-1, which was higher than those of the method of determining BPA based on the direct oxidtation of BPA (0.98 μM (S/N=3), 0.12 μA μM-1). It was applied successfully for determination of BPA in lake, soil and plastic bottle samples. The new strategy, based on anodic electrodeposition and photocatalytic oxidation of BPA oxidation porducts, was provided for determination of BPA under UV irradiation. It was green, evironmental and effective.
关键词： Ultraviolet irradiation,Bisphenol A,Graphene,Anodic deposition
更新于2025-09-04 15:30:14
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Effect of crosslinking stage on photocrosslinking of benzophenone functionalized poly(2-ethyl-2-oxazoline) nanofibers obtained by aqueous electrospinning
摘要： In this study, benzophenone was introduced onto partially hydrolyzed poly(2-ethyl-2-oxazoline) (PEtOx-PEI) to prepare a poly(2-ethyl-2-oxazoline)-benzophenone (PEtOx-BP) copolymer, which was used to produce water stable nanofibers via aqueous electrospinning and photocrosslinking. Three different ultraviolet (UV) irradiation methods, i.e. pre-crosslinking before electrospinning, in-situ crosslinking during electrospinning and post-crosslinking after electrospinning, were used to prepare crosslinked nanofibers. The influence of UV-irradiation at these different stages of the nanofiber production process was investigated in terms of alterations in viscosity, nanofiber morphology and water stability of the fibers. It was shown that pre-crosslinking the polymer solutions had a great influence on the solution viscosity which could both positively or negatively alter the stability of the electrospinning process. Whereas the strategy of crosslinking nanofibers during the production process did not lead to uniform nor water-stable nanofibers, the pre-crosslinking and post-crosslinking strategies greatly increased the water stability of the nanofibers. In both techniques the crosslinking density and therefore water solubility can be easily tuned by manipulating the polymer concentration, UV-irradiation time and membrane thickness. Complete insolubility, i.e. the formation of crosslinked networks, was achieved by the post-crosslinking strategy. This work provides straightforward methods to increase the water stability of the PEtOx nanofibers, which will definitely be of great value to biomedical applications such as drug delivery and tissue engineering.
关键词： nanofibers,benzophenone,crosslinking,UV-irradiation,electrospinning,poly(2-ethyl-2-oxazoline)
更新于2025-09-04 15:30:14
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UV irradiation induces resistance against fruit rot disease and improves the quality of harvested mangosteen
摘要： Fruit rot disease and short shelf life are the limiting factors of mangosteen fruit. This study focused on investigating the effect of ultraviolet (UV) irradiation in controlling fruit rot disease and on quality improvement in harvested mangosteen. Mangosteen fruit artificially inoculated with L. theobromae were treated with UV-B or UV-C irradiation at dosages of 0 (control), 6, 13, 26, and 40 kJ m?2 and stored at 25 °C for 7 d. The results indicate that UV-C treatment exhibited higher fungicidal potential in preventing fruit rot disease than UV-B treatment. UV-C treatment at a dose of 13 kJ m?2 was the most effective in reducing disease incidence and lesion diameter, followed by UV-C at a dose of 26 kJ m?2 and a lower dosage (6 kJ m?2) showed no significant difference from the untreated fruit. Therefore, UV-C irradiation at doses of 13 kJ m?2 was selected to investigate the induction of disease resistance and improvement of mangosteen quality. Naturally infected mangosteen fruit were exposed to UV-C irradiation at a dose of 13 kJ m?2 and untreated fruit served as the control. All fruit samples were kept at 13 °C for 21 d. The results showed that UV-C treatment reduced fruit rot disease and induced the activity of key plant defense-related enzymes, including phenylalanine ammonia lyase (PAL), peroxidase (POD), chitinase and β-1,3-glucanase, besides increasing the content of total phenolics and hydrogen peroxide (H2O2). In addition, the fruit treated with UV-C could delay weight loss, respiration rate, color changes of peel and calyx and maintain total chlorophyll in the calyx of mangosteen. The results suggest that UV-C application is an alternative approach to suppress fruit rot disease and improve the postharvest quality of mangosteen.
关键词： Mangosteen fruit,Fruit rot disease,Defense related enzymes,UV irradiation
更新于2025-09-04 15:30:14
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Manganese phosphinocarbodithioate for RAFT polymerisation with sunlight-induced chain end post-treatment
摘要： A new manganese RAFT agent of the formula Cp(CO)2MnP(Ph)2C(vS)SCH(CH3)Ph was synthesized in a good overall yield by a three-step reaction from cymantrene and diphenylphosphine as the main starting materials. This complex proved to be e?cient for the control of RAFT polymerisation of St, n-BA and DMAAm. The reaction course could be conveniently monitored by 31P NMR spectroscopy. The controlled character of these polymerisations and the integrity of the polymer chain ends were demonstrated by the synthesis of diblock copolymers of St and n-BA. In the case of long polymerisation times (i.e. for PSt), photo-induced polymer chain coupling reactions were detected. Importantly, removal of the Mn-RAFT-ω-chain end by visible light irradiation led to the formation of a monomodal SH-terminated PSt. These phenomena were evidenced by IR spectroscopy, SEC with RI and UV detection modes and by ESI mass spectrometry.
关键词： sunlight-induced chain end post-treatment,visible light irradiation,manganese phosphinocarbodithioate,RAFT polymerisation,diblock copolymers
更新于2025-09-04 15:30:14
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Influence of Light Emitting Diode on Bone Marrow and Healing of Dermatome Wounds
摘要： The irradiation of large surfaces or whole body with light emitting diode LED λ-470 nm and λ-940 nm (LED shower) causes structural changes in bone marrow and stimulates healing of experimental dermatome wounds. The increase of migration of the bone marrow cells in derma and epithelial layers of skin indicates that LED-shower intensifies intercellular interactions and cells migration between tissues.
关键词： Bone marrow,Dermatome wounds,Light emitting diode irradiation,Morphology
更新于2025-09-04 15:30:14
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Optoelectronic and photocatalytic properties of zinc sulfide nanowires synthesized by vapor-liquid-solid process
摘要： Zinc sul?de (ZnS) is a wide band-gap semiconductor with excellent optoelectronic properties suitable for photo-sensing devices and photocatalysts. Herein, the ZnS nanowires (ZnS NWs) have been successfully synthesized using thermal evaporation based on vapor-liquid-solid (VLS) method. From the examinations of photosensing device under ultraviolet B (UVB) irradiation, the photocurrent gain (Pg), responsivity (Rλ), response time and recovery time are 0.572, 2.761 mW/cm2, 3.2 s and 3.6 s, respectively. As to photocatalytic activity for methylene blue (MB), the apparent rate coe?cient (K) of ZnS NWs is 9.78 × 10?3 (min?1). Although ZnS NWs-based photodetector cannot be workable under ultraviolet A (UVA) irradiation, with referring to recent medical literatures, UVB radiation is the major environmental risk factor for developing human skin cancer, the most common cancer worldwide. Thus, the most important contribution in this work is that the ZnS NWs-based UVB radiation-oriented photodetector has been successfully demonstrated via a simple process.
关键词： Photodetector,Zinc sul?de nanowires (ZnS NWs),Photocurrent gain (Pg),Optoelectronic,Vapor-liquid-solid (VLS),Apparent rate coe?cient (K),Responsivity (Rλ),Ultraviolet B (UVB) irradiation
更新于2025-09-04 15:30:14
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Controlling ZnSe/GaAs interface properties: The role of elemental exposure and photon irradiation during growth initiation
摘要： Incorporating dissimilar semiconductors into a single platform can offer additional degrees of freedom for optoelectronic device design. However, bonding of elements with mixed valence at heterovalent interfaces often leads to defect formation and poor material quality. Using ZnSe/GaAs as a model system, we investigate the use of above-bandgap photon irradiation in combination with elemental surface treatments as a route to modify the interface properties. We find that this approach produces large changes in the behavior of the interfaces. Specifically, treating the GaAs surface with light and a short exposure to Se flux results in strong excitonic emission from both layers and an abrupt interface between them. We propose that these improvements arise from controlled desorption of As atoms from the GaAs surface and the subsequent Se enrichment of the interface. These results suggest that illumination with above-bandgap photons and proper choice of elemental exposure prior to heterovalent epitaxial layer growth may aid the synthesis of heterovalent semiconductor heterostructures.
关键词： interface properties,photon irradiation,heterovalent interfaces,elemental exposure,ZnSe/GaAs
更新于2025-09-04 15:30:14
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Preparation of reduced Graphene Oxide (rGO) assisted by microwave irradiation and hydrothermal for reduction methods
摘要： Graphite is a natural carbon source that can be used for graphene synthesis because of its abundant availability and relatively low cost. In this research, Graphene Oxide (GO) and reduced Graphene Oxide (rGO) have been prepared through modified Hummers method that uses microwave irradiation and hydrothermal process as reduction methods. This research can be divided into two main steps, i.e. preparation of GO and preparation of rGO. The preparation of GO was done using modified Hummers method that refers to graphite powder oxidation for five days. Then, preparation of rGO was done using two methods, i.e. microwave irradiation for 8 minutes at 1,000 watts and hydrothermal process for 10 hours at 200°C. The characterization of the samples was observed by Fourier-Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Ultraviolet-Visible Spectroscopy (UV-Vis). XRD pattern of GO sample shows a peak at 2θ = 10.63°, rGO sample from hydrothermal process at 2θ = 25.94°, and rGO sample from microwave irradiation method at 2θ = 25.94° with low intensity and at 2θ = 10.63° that indicates the presence of GO. IR spectroscopy data shows an absorption peak of aromatic C=C at 1,573 cm-1 that indicates rGO formation. SEM images of GO illustrates a structure of stacked flakes. While the morphology of rGO has a structure of stacked flakes that is more transparent than GO. According to UV-Vis spectroscopy, GO and rGO of samples show absorption peak at λmax = 225 nm and λmax = 274 nm, respectively, which indicates π→π* transition of aromatic C=C bond. Based on the results of this study, the preparation of rGO using modified Hummers that combined with hydrothermal reduction method is more effective than microwave irradiation reduction method.
关键词： Graphene Oxide,hydrothermal process,Hummers method,reduced Graphene Oxide,microwave irradiation
更新于2025-09-04 15:30:14