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Phenazine-based supramolecular photosensitizing assemblies:A“smart”selectivity control on catalytic activity of Pd(Ⅱ)nanoparticles
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作者 Aditya Singh Manoj Kumar Vandana Bhalla 《Aggregate》 2023年第1期173-183,共11页
Photosensitizing supramolecular assemblies based on a phenazine derivative(PPA)have been developed,which show a strong affinity toward Pd2+ions to generate supramolecular ensemble PPA@Pd nanoparticles(NPs).The PPA@Pd ... Photosensitizing supramolecular assemblies based on a phenazine derivative(PPA)have been developed,which show a strong affinity toward Pd2+ions to generate supramolecular ensemble PPA@Pd nanoparticles(NPs).The PPA@Pd NPs catalyse the Suzuki cross-coupled reaction under mild conditions(aerial conditions,mixed aqueous media,and visible light radiations).Although PPA@Pd NPs exhibit a strong affinity for arylboronic acid and could catalyse homocoupling of arylboronic acid,the preference of PPA assemblies for aryl halide directed the course of reactions toward the formation of cross-coupled products.The electron-rich PPA assemblies not only facilitate the oxidative addition step through photoinduced electron transfer to Pd^(2+)ions but also bring the reactants closer to the catalytic sites by selective interactions with aryl halides in the presence of arylboronic acid under visible light irradiation.The efficiency of PPA@Pd NPs to catalyse the Suzuki crosscoupled reaction has been demonstrated for the synthesis of unsymmetrically substituted terphenyl derivatives. 展开更多
关键词 ENSEMBLE HOMOCOUPLING PHENAZINE photosensitizing supramolecular assemblies Suzuki cross-coupled
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UiO-66 framework equipped with cadmium-thiocatecholato moieties as photocatalyst bearing stable active sites and intrinsic photosensitizing units for hydrogen evolution reaction 被引量:1
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作者 Gui-Qi Lai Zhixin Jiang +3 位作者 Hao Zhong Lai-Hon Chung Ning Li Jun He 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2023年第6期41-46,共6页
Photocatalytic hydrogen evolution reaction(HER)represents one of the most promising technologies for sus-tainable development.Even though metal-organic framework(MOF),comprising rich topologies and tunable functionali... Photocatalytic hydrogen evolution reaction(HER)represents one of the most promising technologies for sus-tainable development.Even though metal-organic framework(MOF),comprising rich topologies and tunable functionalities,is getting attention as a new generation of photocatalyst,a majority of them only provide unclear active sites along with the use of external noble-metal based photosensitizers and environmentally unfriendly scavengers.Therefore,it is urged to develop MOFs possessing structurally unambiguous active sites along with inherent photosensitizing units and execute photocatalytic HER with greener sacrificial reagents.Herein,we report a UiO-66-type framework,namely UiO-66-dcbdt-Cd(dcbdt^(2-)=1,4-dicarboxylatebenzene-2,3-dithiol),bearing Cd-thiocatecholato moieties as intrinsic photosensitizing units and structurally well-defined active sites for photocatalytic HER in H_(2)O.UiO-66-dcbdt-Cd gave the best HER yield of 5.29 mmol g^(-1)and rate of 1.32 mmol g^(-1)h^(-1),outperforming the negligible HER performance of pristine metal-free UiO-66-dcbdt.This work provides insight to manipulation of thhiocatecholate functionalities inside MOFs to construct inherent photosensitizing units as well as stable structurally unambiguous active sites for sustainable photocatalytic applications. 展开更多
关键词 UiO-66 framework Metal-thiocatecholato Photocatalytic hydrogen evolution Inherent photosensitizer
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Synthesis and Characterization of Novel Schiff Base for Enhanced Dye-Sensitized Solar Cell Photo-Response Mechanism
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作者 Raphael Shadai Oguike Hanatu Akanagn Omolara Oni 《Crystal Structure Theory and Applications》 2024年第2期11-20,共10页
The efficient photo-response mechanism is one of the key factors in the commercialization of dye-sensitized solar cells in a bid to satisfy renewable energy demands. Progress in green technology has put solar energy o... The efficient photo-response mechanism is one of the key factors in the commercialization of dye-sensitized solar cells in a bid to satisfy renewable energy demands. Progress in green technology has put solar energy on the front burner as a provider of clean and affordable energy for a sustainable society. We report the synthesis of a novel Schiff base with optical transparency in the visible and near IR region of the solar spectrum that can find application in the DSSCs photo-response mechanism. The synthesized crystal exhibited features that could handle some of the shortcomings of dye-sensitized solar cells which include wide band solar spectrum absorption and capability for swift charge transfer within the photoelectrodes. The synthesized Schiff base was characterized using x-ray diffractometer, UV/Visible spectrometer, Frontier transmission infrared spectrometer and conductometer. XRD data revealed the grown crystal to have an average crystallite size of 2.08 nm with average microstrain value of about 269.43. The FT-IR recorded transmission wave ѵ (CO) at 1207.7 cm<sup>−1</sup> while dominant wave occurred at ѵ1654.9 and ѵ1592.3 cm<sup>−1</sup> relating to ѵ (CN) stretching and ѵ (NH) bending respectively were observed. The IR spectrum revealed the bonding species and a probable molecular structure of 2,6-bis(benzyloxy)pyridine. The UV/Visible spectra convoluted to maximum peak within the near IR region suggesting that 2,6-bis(benzyloxy)pyridine can absorb both the visible and near IR region while its electrical conductivity was determined to be 4.58 µS/cm. The obtained result of the present study revealed promising characteristics of a photosensitizer that can find application in the photo-response mechanism of DSSCs. 展开更多
关键词 Dye-Sensitized Solar Cell Schiff Base PHOTOSENSITIZER Optical Transparency BENZIL PYRIDINE
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Entropically favoured through space charge transfer‘lighted’photosensitizing assemblies for‘metal free’regulated photooxidation of alcohols and aldehydes
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作者 Gurpreet Kaur Harpreet Kaur +2 位作者 Mandeep Kaur Manoj Kumar Vandana Bhalla 《Aggregate》 2022年第2期143-153,共11页
Strong acceptor-weak acceptor system FN-TPy has been designed and synthesized,which undergoes solvent dependent self-assembly in mixed aqueous media to generate through space intermolecular charge transfer assemblies.... Strong acceptor-weak acceptor system FN-TPy has been designed and synthesized,which undergoes solvent dependent self-assembly in mixed aqueous media to generate through space intermolecular charge transfer assemblies.The as-prepared entropically favoured assemblies of FN-TPy exhibit excellent photostability and photosensitizing properties in the assembled state to activate aerial oxygen for efficient generation of reactive oxygen species through Type-I and Type-II pathways.The FN-TPy exhibits excellent potential for regulated oxidation of alcohols and aldehydes under mild reaction conditions(visible light irradiation,aqueous media,room temperature)using aerial oxygen as the‘oxidant’.The present study demonstrates the potential of FN-TPy assemblies to catalyse controlled oxidation of benzyl alcohol to benzoic acid. 展开更多
关键词 aggregated assemblies molecular oxygen activation OXIDATIONS PHOTOSENSITIZER through space charge transfer
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Fine-mapping and transcriptome analysis of the photosensitive leaf-yellowing gene CaLY1 in pepper(Capsicum annuum L.) 被引量:3
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作者 Sha Yang Zhuqing Zhang +6 位作者 Wenchao Chen Chengliang Liang Xuefeng Li Zhoubin Liu Qingzhi Cui Yanqing Ma Xuexiao Zou 《Horticultural Plant Journal》 SCIE CAS CSCD 2023年第1期122-132,共11页
Leaf color is directly related to altered photosynthesis.Hence,leaf yellowing mutants can be widely used for the researching plant physiology and functional genomes,for cultivating new varieties of popular horticultur... Leaf color is directly related to altered photosynthesis.Hence,leaf yellowing mutants can be widely used for the researching plant physiology and functional genomes,for cultivating new varieties of popular horticultural plants,and for identifying hybrid purity(as markers).Here,we constructed a^(60)Co-γF_(2)population from the leaf-yellowing mutant R24 via radiation mutation with the inbred line WT21 of pepper.Genetic analysis showed that the leaf-yellowing of the mutant was controlled by a single recessive gene.By applying the Bulk Segregation Analysis and Kompetitive Allele Specific PCR markers,the leaf-yellowing gene CaLY1(Capsicum annuum Leaf yellow 1)was mapped on chromosome 9,SNP5791587-SNP6011215,with a size of 214.5 kb.One non-synonymous mutated gene Capana09g000166 was found in the interval.The gene encoded a Psb X,which is the core complex of PSⅡ.Transcriptome analysis further showed that 2301 differentially expressed genes were identified under shading treatment for 24 h in R24.The Gene Ontology enrichment pathways were related to photosynthesis light harvesting,cell wall,activity of quercetin 3-O-glucosyltransferase and flavonoid metabolic process,which likely regulate the response of pepper leaves to different light levels.Functional enrichment analysis indicated that the most abundant pathways were photosynthesis antenna proteins and metabolic. 展开更多
关键词 PEPPER Leaf-color yellow FINE-MAPPING GENE PHOTOSENSITIVE
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Passivation engineering via silica‐encapsulated quantum dots for highly sensitive photodetection 被引量:1
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作者 Ji Yun Chun Byung Gi Kim +2 位作者 Jin Young Kim Woongsik Jang Dong Hwan Wang 《Carbon Energy》 SCIE EI CAS CSCD 2023年第9期49-62,共14页
Organometal halide perovskites are promising semiconducting materials for photodetectors because of their favorable optoelectrical properties.Although nanoscale perovskite materials such as quantum dots(QDs)show novel... Organometal halide perovskites are promising semiconducting materials for photodetectors because of their favorable optoelectrical properties.Although nanoscale perovskite materials such as quantum dots(QDs)show novel behavior,they have intrinsic stability issues.In this study,an effectively silane barrier-capped quantum dot(QD@APDEMS)is thinly applied onto a bulk perovskite photosensitive layer for use in photodetectors.QD@APDEMS is synthesized with a silane ligand with hydrophobic CH_(3)-terminal groups,resulting in excellent dispersibility and durability to enable effective coating.The introduction of the QD@APDEMS layer results in the formation of a lowdefect perovskite film with enlarged grains.This is attributed to the grain boundary interconnection effect via interaction between the functional groups of QD@APDEMS and uncoordinated Pb^(2+)in grain boundaries.By passivating the grain boundaries,where various trap sites are distributed,hole chargecarrier injection and shunt leakage can be suppressed.Also,from the energy point of view,the deep highest occupied molecular orbital(HOMO)level of QD@APDEMS can work as a hole charge injection barrier.Improved charge dynamics(generation,transfer,and recombination properties)and reduced trap density of QD@APDEMS are demonstrated.When this perovskite film is used in a photodetector,the device performance(especially the detectivity)stands out among existing perovskites evaluated for energy sensing device applications. 展开更多
关键词 grain boundary passivation perovskite quantum dots PHOTODETECTORS photosensitive layers trap
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Photodynamic therapy with TBZPy regulates the PI3K/AKT and endoplasmic reticulum stress-related PERK/eIF2α pathways in HeLa cells
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作者 YIFAN LI JING ZHANG +6 位作者 YITAO FAN HANDAN XIAO KEXIN KANG YALI ZHOU ZHIWEN ZHANG YUMIN LI MUZHOU TENG 《BIOCELL》 SCIE 2023年第8期1783-1791,共9页
Background:((1-triphenylaminebenzo[c][1,2,5]thiadiazole-4-yl)styryl)-1-methylpyridin methylpyridin-1-ium iodide salt(TBZPy)is a novel photosensitizer that displays excellent photodynamic properties.However,There are f... Background:((1-triphenylaminebenzo[c][1,2,5]thiadiazole-4-yl)styryl)-1-methylpyridin methylpyridin-1-ium iodide salt(TBZPy)is a novel photosensitizer that displays excellent photodynamic properties.However,There are few reports on the mechanism of action of the TBZPy photodynamic.Previous studies revealed that photodynamic therapy(PDT)could induce endoplasmic reticulum stress by acting on the endoplasmic reticulum.Therefore,in this study,we investigated the effects of endoplasmic reticulum stress induced by TBZPy-PDT in treating High-risk human papillomavirus(HR-HPV)infection and their underlying mechanisms.Methods:The human cervical cancer cell line HeLa(containing whole genome of HR-HPV18)was treated with TBZPy-PDT.Cell migration,invasion,and colony-forming ability were evaluated using wound-healing,Transwell invasion,and colonyforming assays,respectively.Through western blot analysis,we determined the level of expression of the PI3K/AKT and PERK/eIF2αpathway proteins and the proteins associated with calcium trafficking and apoptosis.The calcium levels in the cytoplasm were detected via flow cytometry.Results:The result shows that TBZPy-PDT could inhibite the migration,invasion,and colony forming ability of infected HeLa cells by downregulating the PI3K/AKT pathway in vitro.And we found that TBZPy-PDT induced endoplasmic reticulum stress-specific apoptosis via the PERK/eIF2αpathway.Moreover,TBZPy-PDT increased the levels of calcium and calmodulin,while decreasing the levels of endoplasmic reticulum calcium-binding proteins.Conclusions:TBZPy-PDT is effective on treating human papillomavirus-infected cells.Targeting the PI3K/AKT and PERK/eIF2αpathways and the endoplasmic reticulum stress process may help improve the effects of TBZPy-PDT for treating high-risk human papillomavirus infection. 展开更多
关键词 Photodynamic therapy Cervical intraepithelial neoplasia Cervical cancer PHOTOSENSITIZER TBZPy
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3D printing of high-precision and ferromagnetic functional devices
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作者 Zhiyuan Huang Guangbin Shao +3 位作者 Dekai Zhou Xinghong Deng Jing Qiao Longqiu Li 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2023年第3期646-656,共11页
The development of projection-based stereolithography additive manufacturing techniques and magnetic photosensitive resins has provided a powerful approach to fabricate miniaturized magnetic functional devices with co... The development of projection-based stereolithography additive manufacturing techniques and magnetic photosensitive resins has provided a powerful approach to fabricate miniaturized magnetic functional devices with complex three-dimensional spatial structures.However,the present magnetic photosensitive resins face great challenges in the trade-off between high ferromagnetism and excellent printing quality.To address these challenges,we develop a novel NdFeB-Fe_(3)O_(4) magnetic photosensitive resin comprising 20 wt.%solid loading of magnetic particles,which can be used to fabricate high-precision and ferromagnetic functional devices via micro-continuous liquid interface production process.This resin combining ferromagnetic NdFeB microparticles and strongly absorbing Fe_(3)O_(4) nanoparticles is able to provide ferromagnetic capabilities and excellent printing quality simultaneously compared to both existing soft and hard magnetic photosensitive resins.The established penetration depth model reveals the effect of particle size,solid loading,and absorbance on the curing characteristics of magnetic photosensitive resin.A high-precision forming and ferromagnetic capability of the NdFeB-Fe_(3)O_(4) magnetic photosensitive resin are comprehensively demonstrated.It is found that the photosensitive resin(NdFeB:Fe_(3)O_(4)=1:1)can print samples with sub-40μm fine features,reduced by 87%compared to existing hard magnetic photosensitive resin,and exhibits significantly enhanced coercivity and remanence in comparison with existing soft magnetic photosensitive resins,showing by an increase of 24 times and 6 times,respectively.The reported NdFeB-Fe_(3)O_(4) magnetic photosensitive resin is anticipated to provide a new functional material for the design and manufacture of next-generation micro-robotics,electromagnetic sensor,and magneto-thermal devices. 展开更多
关键词 magnetic device magnetic photosensitive resins 3D printing NDFEB Fe_(3)O_(4)
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Advances in photodynamic therapy for port-wine stain and our experience
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作者 Lixin Zhang Hanru Ying +1 位作者 Gang Ma Xiaoxi Lin 《Chinese Journal of Plastic and Reconstructive Surgery》 2023年第2期96-99,共4页
Port-wine stain(PWS)is a congenital capillary malformation that occurs in 0.3%–0.5%of newborns.The pulsed dye laser is the current gold standard treatment for PWS;however,its efficacy is poor.Photosensitizer photodyn... Port-wine stain(PWS)is a congenital capillary malformation that occurs in 0.3%–0.5%of newborns.The pulsed dye laser is the current gold standard treatment for PWS;however,its efficacy is poor.Photosensitizer photodynamic therapy(PDT)is considered a promising treatment for PWS.Here we provide a comprehensive overview of PDT. 展开更多
关键词 Port-wine stain Photodynamic therapy PHOTOSENSITIZER
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Imaging assessment of photosensitizer emission induced by radionuclide-derived Cherenkov radiation using charge-coupled device optical imaging and long-pass filters
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作者 Winn Aung Atsushi B Tsuji +3 位作者 Kazuaki Rikiyama Fumihiko Nishikido Satoshi Obara Tatsuya Higashi 《World Journal of Radiology》 2023年第11期315-323,共9页
BACKGROUND Radionuclides produce Cherenkov radiation(CR),which can potentially activate photosensitizers(PSs)in phototherapy.Several groups have studied Cherenkov energy transfer to PSs using optical imaging;however,c... BACKGROUND Radionuclides produce Cherenkov radiation(CR),which can potentially activate photosensitizers(PSs)in phototherapy.Several groups have studied Cherenkov energy transfer to PSs using optical imaging;however,cost-effectively identifying whether PSs are excited by radionuclide-derived CR and detecting fluorescence emission from excited PSs remain a challenge.Many laboratories face the need for expensive dedicated equipment.AIM To cost-effectively confirm whether PSs are excited by radionuclide-derived CR and distinguish fluorescence emission from excited PSs.METHODS The absorbance and fluorescence spectra of PSs were measured using a microplate reader and fluorescence spectrometer to examine the photo-physical properties of PSs.To mitigate the need for expensive dedicated equipment and achieve the aim of the study,we developed a method that utilizes a chargecoupled device optical imaging system and appropriate long-pass filters of different wavelengths(manual sequential application of long-pass filters of 515,580,645,700,750,and 800 nm).Tetrakis(4-carboxyphenyl)porphyrin(TCPP)was utilized as a model PS.Different doses of copper-64(^(64)CuCl_(2))(4,2,and 1 mCi)were used as CR-producing radionuclides.Imaging and data acquisition were performed 0.5 h after sample preparation.Differential image analysis was conducted by using ImageJ software(National Institutes of Health)to visually evaluate TCPP fluorescence.RESULTS The maximum absorbance of TCPP was at 390-430 nm,and the emission peak was at 670 nm.The CR and CRinduced TCPP emissions were observed using the optical imaging system and the high-transmittance long-pass filters described above.The emission spectra of TCPP with a peak in the 645-700 nm window were obtained by calculation and subtraction based on the serial signal intensity(total flux)difference between^(64)CuCl_(2)+TCPP and^(64)CuCl_(2).Moreover,the differential fluorescence images of TCPP were obtained by subtracting the^(64)CuCl_(2)image from the^(64)CuCl_(2)+TCPP image.The experimental results considering different^(64)CuCl_(2)doses showed a dosedependent trend.These results demonstrate that a bioluminescence imaging device coupled with different longpass filters and subtraction image processing can confirm the emission spectra and differential fluorescence images of CR-induced TCPP.CONCLUSION This simple method identifies the PS fluorescence emission generated by radionuclide-derived CR and can contribute to accelerating the development of Cherenkov energy transfer imaging and the discovery of new PSs. 展开更多
关键词 Tetrakis(4-carboxyphenyl)porphyrin Photosensitizer emission RADIONUCLIDE Cherenkov radiation Optical imaging Long-pass filters
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Design of Intelligent Agricultural Greenhouse Environment Monitoring System
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作者 CHEN Ruizhou KONG Ming +1 位作者 JI Pengcheng LIU Hengxing 《Instrumentation》 2023年第2期40-48,共9页
Aiming at the problem of greenhouse environmental information collection in agricultural production,this paper designs a greenhouse monitoring system based on STM32 microcontroller.The system uses STM32F103 series MCU... Aiming at the problem of greenhouse environmental information collection in agricultural production,this paper designs a greenhouse monitoring system based on STM32 microcontroller.The system uses STM32F103 series MCU as the main control unit,which is used to receive the detection results of the sensor.The host computer software displays and processes the monitoring data.The temperature and humidity sensors monitor air temperature and humidity.The capacitive soil moisture detection sensor monitors soil moisture.The carbon dioxide sensor monitors the concentration of carbon dioxide.The photosensitive sensor monitors light intensity.This design has low hardware cost and high data acquisition accuracy,which can be applied to the actual greenhouse agricultural production and has wide practicability. 展开更多
关键词 STM32F103 Microcontroller Temperature and Humidity Sensor Photosensitive Sensor PC Software
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Strategies for engineering metal-organic frameworks as efficient photocatalysts 被引量:12
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作者 沈丽娟 梁若雯 吴棱 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第12期2071-2088,共18页
Environmental pollution and energy deficiency represent major problems for the sustainability of the modern world. Photocatalysis has recently emerged as an effective and environmentally friendly technique to address ... Environmental pollution and energy deficiency represent major problems for the sustainability of the modern world. Photocatalysis has recently emerged as an effective and environmentally friendly technique to address some of these sustainability issues,although the key to the success of this approach is dependent on the photocatalysts themselves. Based on their attractive physic chemical properties,including their ultrahigh surface areas,homogeneous active sites and tunable functionality,metal-organic frameworks(MOFs) have become interesting platforms for the development of solar energy conversion devices. Furthermore,MOFs have recently been used in a wide variety of applications,including heterogeneous photocatalysis for pollutant degradation,organic transformations,hydrogen production and CO2 reduction. In this review,we have highlighted recent progress towards the application of MOFs in all of these areas. We have collected numerous reported examples of the use of MOFs in these areas,as well as providing some analysis of the key factors influencing the efficiency of these systems. Moreover,we have provided a detailed discussion of new strategies that have been developed for enhancing the photocatalytic activity of MOFs. Finally,we have provided an outlook for this area in terms of the future challenges and potential prospects for MOFs in photocatalysis. 展开更多
关键词 Metal-organic frameworks PHOTOCATALYSIS LIGAND FUNCTIONALIZATION PHOTOSENSITIZATION CO-CATALYST Composite
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Metabolic Changes in Rats with Photochemically Induced Cerebral Infarction and the Effects of Batroxobin:A Study by Magnetic Resonance Imaging,~1H-and ^(31)p-Magnetic Resonance Spectroscopy 被引量:6
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作者 管兴志 吴卫平 +6 位作者 匡培根 匡培梓 高杨 管林初 李丽云 毛希安 刘买利 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2001年第1期59-67,共9页
Metabolic changes in rats with photochemically induced cerebral infarction and the effects of batroxobin were investigated 1, 3, 5 and 7 days after infarction by means of magnetic resonance imaging (MRI), 1H- and 31P-... Metabolic changes in rats with photochemically induced cerebral infarction and the effects of batroxobin were investigated 1, 3, 5 and 7 days after infarction by means of magnetic resonance imaging (MRI), 1H- and 31P-magnetic resonance spectroscopy (MRS). A region of T2 hyperintensity was observed in left temporal neocortex in infarction group and batroxobin group 1, 3, 5 and 7 days after infarction. The volume of the region gradually decreased from 1 day to 7 days after infarction. The ratio of NAA/Cho + Cr in the region of T2 hyperintensity in the infarction group was significantly lower than that in the corresponding region in the sham-operated group 3, 5 and 7 days after infarction respectively (P 展开更多
关键词 Animals Aspartic Acid BATROXOBIN Cerebral Infarction Magnetic Resonance Imaging Male PHOTOCHEMISTRY photosensitizing Agents Random Allocation RATS Rats Sprague-Dawley Rose Bengal
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High-Integrated-Photosensitivity Negative-Electron-Affinity GaAs Photocathodes with Multilayer Be-Doping Structures
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作者 王晓峰 曾一平 +4 位作者 王保强 朱占平 杜晓晴 李敏 常本康 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第9期1692-1698,共7页
The effect of changing Be doping concentration in GaAs layer on the integrated photosensitivity for nega- tive-electron-affinity GaAs photocathodes is investigated. Two GaAs samples with the monolayer structure and th... The effect of changing Be doping concentration in GaAs layer on the integrated photosensitivity for nega- tive-electron-affinity GaAs photocathodes is investigated. Two GaAs samples with the monolayer structure and the muhilayer structure are grown by molecular beam epitaxy. The former has a constant Be concentration of 1 × 10^19 cm^-3, while the latter includes four layers with Be doping concentrations of 1 × 10^19, 7 × 10^18, 4 × 10^18, and 1 × 10^18 cm^-3 from the bottom to the surface. Negative-electron-affinity GaAs photocathodes are fabricated by exciting the sample surfaces with alternating input of Cs and O in the high vacuum system. The spectral response results measured by the on-line spectral response measurement system show that the integrated photosensitivity of the photocathode with the muhilayer structure enhanced by at least 50% as compared to that of the monolayer structure. This attributes to the improvement in the crystal quality and the increase in the surface escape probability. Different stress situations are observed on GaAs samples with monolayer structure and muhilayer structure, respectively. 展开更多
关键词 integrated photosensitivity muhilayer structure NEA photocathode diffusion length surface escape probability
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Photoactivated Activities on Spodoptera litura Cell, Singlet Oxygen and Photostability of Photosensitizers
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作者 王平 孟志远 +1 位作者 陈思 陈小军 《Agricultural Science & Technology》 CAS 2014年第5期769-773,816,共6页
[Objective ]The aim of this study was to improve the photostability of pho-tosensitizers. [Method] 2,5-Diphenylthiophene and 2,5-dithienylethynylthiophene were synthesized by replacing thiophene rings of α-terthienyl... [Objective ]The aim of this study was to improve the photostability of pho-tosensitizers. [Method] 2,5-Diphenylthiophene and 2,5-dithienylethynylthiophene were synthesized by replacing thiophene rings of α-terthienyl (α-T) with benzene rings. Photoactivated activities on Spodoptera litura (SL) cells, singlet oxygen with UV and photostability of photosensitizers were investigated. [Result] The cytotoxicity of pho-tosensitizer 2,5-diphenylthiophene on SL cells was 0.22 and 0.16 μg/ml after treat-ment for 24 and 48 h, respectively, while that of 2,5-dithienylethynylthiophene on SL cells was 0.06 and 0.04 μg/ml. Singlet oxygen of 2,5-diphenylthiophene and 2,5-dithienylethynylthiophene was 1.047 5, 1.529 4 μg/mmol under UV, respectively. Degradation dynamic equations of 2,5-diphenylthiophene and 2,5-dithienylethynylthio-phene in methanol were Ct= 5.227 1e-0.006 1t, Ct= 5.084 2e-0.097 3t and half life was 111.79, 7.12 h. [Conclusion] Photosensitizer 2,5-diphenylthiophene has high singlet oxygen production ability, and high photoactivated cytotoxicity on SL cells under UV. Moreover, 2,5-diphenylthiophene has overcome the deficiency of photoactivated in-secticides, which is not applied directly in field because it degrades quickly in the environment. 展开更多
关键词 PHOTOSENSITIZER Singlet oxygen Photoactivated activity Spodoptera lituracell
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Separation and identification of the major components of Photocarcinorin and their tumor-photobiological activities
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作者 陈文晖 段祥生 许德余 《Journal of Medical Colleges of PLA(China)》 CAS 1991年第4期309-318,共10页
It has been shown by the results-of HPLC analysis in combination with spectrographicdeterminations that PsD-007 is composed of 7 different porphyrins,In order of the proportion inPsD-007,they are:3 (or 8)-(l-methox... It has been shown by the results-of HPLC analysis in combination with spectrographicdeterminations that PsD-007 is composed of 7 different porphyrins,In order of the proportion inPsD-007,they are:3 (or 8)-(l-methoxyethyl)-8 (or 3)-(l-hydroxyethyl)-deuteroporphyrin Ⅸ(MHD);3,8-di-(l-methoxyethyl)-deuteroporphyrin Ⅸ(DMD);3(or 8)-(l-methoxyethyl)-8 (or3)-vinyl-deuteroporphyrin Ⅸ(MVD);3(or 8)-(l-hydroxyethyl)-8(or 3)-vinyl-deuteroporphyrin Ⅸ(HVD);hernatoporphyrin Ⅸ (Hp);protoporphyrin Ⅸ (Pp) and 3(or 8)-(O-aceylethyl)-8(or 3)-(l-hydroxyethyl)-deuteroporphrin Ⅸ (AHD),which presented only in crude PsD-007 and hasbeen transformed into MHD and Hp,respectively during the separation and preparing the clinicalpreparation of PsD-007.Structures of these porphyrins were further eonfirmed by the corre-sponding anthentic samples obtained by synthetic method.It was found on the basis of the experi-mental data of photosensitizing ability in cell-free systems and photoinactivation of human cancercells in vitro as well as efficacy of photodynamic therapy for sarcoma.S<sub>180</sub> in mice of the ma-jor components MILD,DMD and MVD composed of which more over 85% of the totalamount of PsD-007,that they all exhibited comparatively high photosensitizing ability andphotodynamic effects on cancer cells and tram-planted animal tumor. 展开更多
关键词 PHOTOCARCINORIN NEOPLASMS photodynamic therapy photolocalization photochemodiagnosis and PHOTOCHEMOTHERAPY photosensitizing ability PHOTOINACTIVATION photobiological activity SEPARATION and identificatio
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Rare earth ion modified TiO_2 sols for photocatalysis application under visible light excitation 被引量:39
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作者 XIEYibing YUANChunwei 《Rare Metals》 SCIE EI CAS CSCD 2004年第1期20-26,共7页
TiO_2 sols modified by rare earth (RE) ions (Ce^(4+), Eu^(3+), or Nd^(3+))were prepared by coprecipitation-peptization method. The photocatalysis activity was studied byinvestigating the photodegradation effects of ac... TiO_2 sols modified by rare earth (RE) ions (Ce^(4+), Eu^(3+), or Nd^(3+))were prepared by coprecipitation-peptization method. The photocatalysis activity was studied byinvestigating the photodegradation effects of active brilliant red dye X-3B. It is found that TiO_2sols modified by Ce^(4+), Eu^(3+), or Nd^(3+) have the anatase crystalline structure, which areprepared at 70℃. All RE^(n+)-TiO_2 sol samples have uniform nanoparticles with similar morphology,which are homogenously distributed in aqueous colloidal systems. The particle sizes are 10, 8, and12 nm for Nd^(3+)-TiO_2, Eu^(3+)-TiO_2, and Ce^(4+)-TiO_2, respectively. The character of ultrafineand positive charge sol particles contributes to the good adsorption of X-3B dye molecule on thesurface of titania (about 30% X-3B adsorption amount). Experimental results exhibit thatRE^(n+)-TiO_2 sol photocatalysts have the capability to photodegrade X-3B under visible lightirradiation. Nd^(3+)-TiO_2 and Eu^(3+)-TiO_2 show higher photocatalytic activity than Ce^(4+)-TiO_2,which is due to the difference of standard redox potential of RE^(n+)/RE^((n-1)+). RE^(n+)-TiO_2sols demonstrate more excellent interfacial adsorption and photodegradation effects to X-3B thanP_(25) TiO_2 crystallites. Moreover, the degradation mechanism of X-3B is proposed as dyephotosensitization and electron scavenging by rare earth ions. 展开更多
关键词 PHOTOCATALYSIS TiO_2 rare earth ion PHOTOSENSITIZATION
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Photodynamic therapy guidelines for the management of oral leucoplakia 被引量:19
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作者 Qianming Chen Hongxia Dan +5 位作者 Fan Tang Jiongke Wang Xiaoying Li Junxin Cheng Hang Zhao Xin Zeng 《International Journal of Oral Science》 SCIE CAS CSCD 2019年第2期103-107,共5页
With recent developments in photosensitizers and light delivery systems,topical 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) has become the fourth alternative therapeutic approach in the management of... With recent developments in photosensitizers and light delivery systems,topical 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) has become the fourth alternative therapeutic approach in the management of oral leucoplakia (OLK) due to its minimally invasive nature,efficacy,and low risk of systemic side effects and disfigurement.This report presents step-by-step guidelines for applying topical ALA-PDT in the management of OLK based on both the clinical experience of the authors and a systematic review of the current literature.Studies using protocols with standardized parameters and randomized clinical trials at multiple centres with adequate sample sizes and both interim and long-term follow-ups are needed before universally applicable guidelines can be produced in this field. 展开更多
关键词 MANAGEMENT ORAL leucoplakia PHOTOSENSITIZERS ALA-PDT
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Visible Light Induced Photocatalysis of Cerium Ion Modified Titania Sol and Nanocrystallites 被引量:5
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作者 Yibing XIE and Chunwei YUANKey Laboratory of Molecular & Biomolecular Electronics, Southeast University, Ministry of Education, Nanjing 210096, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第1期14-18,共5页
The cerium ion(Ce4+) doped titania sol and nanocrystallites were prepared by chemical coprecipitation-peptization and hydrothermal synthesis methods, respectively. The X-ray diffraction pattern shows that Ce4+-TiO2 xe... The cerium ion(Ce4+) doped titania sol and nanocrystallites were prepared by chemical coprecipitation-peptization and hydrothermal synthesis methods, respectively. The X-ray diffraction pattern shows that Ce4+-TiO2 xerogel powder has semicrystalline structure and thermal sintering sample has crystalline structure. Ce4+-TiO2 nanocrystallites are composed of the major anatase phase titania (88.82 wt pct) and a small amount of crystalline cerium titanate. AFM micrograph shows that primary particle size of well-dispersed ultrafine sol particles is below 15 nm in diameter. The particle sizes are 30 nm for xerogel sample and 70 nm for nanocrystallites sample, which is different from the estimated values (2.41 nm and 4.53 nm) by XRD Scherrer's formula. The difference is mainly due to aggregation of nanocrystallites. The experimental results exhibit that photocatalysts of Ce4+-TiO2 sol and nanocrystallites have the ability to photodegrade reactive brilliant red dye (X-3B ) under visible light irradiation with the ion-TiO2/VIS/dye system. Moreover, Ce4+ doped titania sol has shown higher efficiency than the nanocrystallites sample in respect of potocatalytic activity. Meanwhile, dye photodegradation mechanisms are proposed to different photocatalytic reaction systems, which are dye photosensitization, ion-dye photosensitization and interband photocatalysis & dye photosensitization with respect to TiO2 nanocrystallites, Ce4+-TiO2 sol and Ce4+-TiO2 nanocrystallites system. 展开更多
关键词 Photocatalytic activity SOL NANOCRYSTALLITES PHOTOSENSITIZATION Reaction mechanism
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Photosensitizer Nanoparticles Boost Photodynamic Therapy for Pancreatic Cancer Treatment 被引量:5
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作者 Huanyu Yang Renfa Liu +2 位作者 Yunxue Xu Linxue Qian Zhifei Dai 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第2期246-261,共16页
Patients with pancreatic cancer(PCa)have a poor prognosis apart from the few suitable for surgery.Photodynamic therapy(PDT)is a minimally invasive treatment modality whose efficacy and safety in treating unresectable ... Patients with pancreatic cancer(PCa)have a poor prognosis apart from the few suitable for surgery.Photodynamic therapy(PDT)is a minimally invasive treatment modality whose efficacy and safety in treating unresectable localized PCa have been corroborated in clinic.Yet,it suffers from certain limitations during clinical exploitation,including insufficient photosensitizers(PSs)delivery,tumor-oxygenation dependency,and treatment escape of aggressive tumors.To overcome these obstacles,an increasing number of researchers are currently on a quest to develop photosensitizer nanoparticles(NPs)by the use of a variety of nanocarrier systems to improve cellular uptake and biodistribution of photosensitizers.Encapsulation of PSs with NPs endows them significantly higher accumulation within PCa tumors due to the increased solubility and stability in blood circulation.A number of approaches have been explored to produce NPs co-delivering multi-agents affording PDT-based synergistic therapies for improved response rates and durability of response after treatment.This review provides an overview of available data regarding the design,methodology,and oncological outcome of the innovative NPs-based PDT of PCa. 展开更多
关键词 Photodynamic therapy PHOTOSENSITIZER NANOPARTICLE Pancreatic cancer Combined therapy
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