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Quality of DOTS Adherence Counselling among Hospitalized Tuberculosis Patients 预览
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作者 Shikongo IN Taati Francis Kalemeera Dan Kibuule 《结核病研究(英文)》 2019年第2期77-94,共18页
Setting: Non-adherence to tuberculosis treatment is a risk factor for multidrug-resistant tuberculosis (MDR-TB). In 2015, 480,000 cases of MDR-TB were notified worldwide, leading to 250,000 deaths. Aim: The quality of... Setting: Non-adherence to tuberculosis treatment is a risk factor for multidrug-resistant tuberculosis (MDR-TB). In 2015, 480,000 cases of MDR-TB were notified worldwide, leading to 250,000 deaths. Aim: The quality of the Directly Observed Treatment (DOT) adherence counselling among patients with drug resistant and sensitive was assessed. Methods: A hospital based crossectional analytical study was conducted at the national TB hospital in Windhoek among patients with MDR-TB and drug susceptible TB (DS-TB). The quality of adherence counselling was assessed against the WHO counselling guidelines using an interviewer-administered questionnaire. Quality was measured by completeness, duration and frequency of the adherence counselling sessions or program as well as patient satisfaction and preferences. Quantitative and qualitative data were by descriptive statistics in SPSS v23 and thematic analysis respectively. Results: Of the 50 patients, 60% were male, 76% were aged Conclusions: The quality of DOT adherence counselling among hospitalized TB patients is sub-optimal. There is need for a standard operating procedure and guidelines for effective adherence counselling among TB patients to optimize treatment outcomes. 展开更多
关键词 QUALITY DOTS ADHERENCE COUNSELLING Namibia
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Advances in green colloidal synthesis of metal selenide and telluride quantum dots
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作者 Dong Yao Yi Liu +1 位作者 Jing Li Hao Zhang 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第2期277-284,共8页
During the past three decades, metal selenide and telluride quantum dots (QDs) have been deemed one of the most vital nanomaterials in virtue of their extensive applications, including lighting, solar harvesting,photo... During the past three decades, metal selenide and telluride quantum dots (QDs) have been deemed one of the most vital nanomaterials in virtue of their extensive applications, including lighting, solar harvesting,photocatalysis, biolabelling, quantum computing and so forth. With the growing demands for the QDrelated products, environmental friendly, energy-efficient and timesaving approaches to synthesize functional metal selenide and telluride QDs are greatly welcome. On the basis of the development in synthesis of chalcogen precursors, this mini review summarizes the recent progress in the green methods for synthesizing metal selenide and telluride QDs. At first, the panorama of basic synthetic methodology of metal chalcogenide QDs is briefly introduced. Then, numerous evolving colloidal synthetic methods are discussed, highlighting the phosphine-free precursors and the aqueous ionic precursors. Finally, this review ends with remaining challenges and future prospects in synthetic schemes. We hope this review will provide some stimulating information to promote further advancement in this area. 展开更多
关键词 Green synthesis METAL selenide/telluride Quantum dots PHOSPHINE-FREE PRECURSOR Aqueous ionic PRECURSOR
Boosting the rate capability of multichannel porous TiCh nanofibers with well-dispersed Cu nanodots and Cu^2+-doping derived oxygen vacancies for sodium-ion batteries
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作者 Ying Wu Zengxi Wei +4 位作者 Rui Xu Yue Gong Lin Gu Jianmin Ma Yan Yu 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第9期2211-2217,共7页
The use of TiO2 as an anode in rechargeable sodium-ion batteries(NIBs)is hampered by intrinsic low electronic conductivity of TiO2 and in ferior electrode kinetics.Here,a high-performa nee T1O2 electrode for NIBs is p... The use of TiO2 as an anode in rechargeable sodium-ion batteries(NIBs)is hampered by intrinsic low electronic conductivity of TiO2 and in ferior electrode kinetics.Here,a high-performa nee T1O2 electrode for NIBs is prese nted by desig ning a multicha rinel porous T1O2 nano fibers with well-dispersed Cu nan odots and Cu^2+-doping derived oxyge n vaca ncies(Cu-MPTO).The in-situ grow n well-dispersed copper nano dots of about 3 nm on TiO2 surface could significantly enhance electronic conductivity of the TiO2 fibers.The one-dimensional multichannel porous structure could facilitate the electrolyte to soak in,leadi ng to short tran sport path of Na^+through carb on toward the TiO2 nano particle.The Cu^2+-doping induced oxygen vacancies could decrease the bandgap of T1O2,resulting in easy electron trapping.With this strategy,the Cu-MPTO electrodes render an outstanding rate performance for NIBs(120 mAh·g^-1 at 20 C)and a superior cycling stability for ultralong cycle life(120 mAh·g^-1 at 20 C and 96.5%retention over 2,000 cycles).Density functional theory(DFT)calculations also suggest that Cu^2+doping can enhance the conductivity and electron transfer of T1O2 and lower the sodiation energy barrier.This strategy is confirmed to be a general process and could be extended to improve the performance of other materials with low electronic conductivity applied in energy storage systems. 展开更多
关键词 multicha nnel POROUS T1O2 NANO fibers CU NANO dots Cu^2+dopi ng SODIUM ion batteries density functional theory(DFT)calculati ons
Assembly of carbon nanodots in graphene-based composite for flexible electro-thermal heater with ultrahigh efficiency
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作者 Xin Meng Tianxing Chen +6 位作者 Yao Li Siyuan Liu Hui Pan Yuning Ma Zhixin Chen Yanping Zhang Shenmin Zhu 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第10期2498-2508,共11页
A high-efficiency electro-thermal heater requires simultaneously high electrical and thermal conductivities to generate and dissipate Joule heat efficiently.A low in put voltage is essential to en sure the heaters saf... A high-efficiency electro-thermal heater requires simultaneously high electrical and thermal conductivities to generate and dissipate Joule heat efficiently.A low in put voltage is essential to en sure the heaters safe applications.However,the low voltage gen erally leads to low saturated temperature and heati ng rate and hence a low thermal efficie ncy.How to reduce the in put voltage while maintai ning a high electro-thermal efficiency is still a challenge.Herein,a highly electrical and thermal conductive film was 8nstructed using a graphene-based composite which has an internal three-dimensional(3D)conductive network.In the 3D framework,cellulose nanocrystalline(CNC)phase with chiral liquid crystal manner presents in the form of alig ned helix betwee n the graphe ne oxide(GO)layers.Carbon nano dots(CDs)are assembled泊side the composite as con ductive nano fillers.Subseque nt an neali ng and compressi on results in the formati on of the assembled GO-CNC-CDs film.The carb on ized CNC nano rods(CNR)with the helical alignment act as irrplane and through-pla ne conn ecti ons of n eighbori ng reduced GO(rGO)nano sheets,forming a con ductive network in the composite film.The CDs with ultrafast electr ons tran sfer rates provide additi onal electro ns and phonons tran sport paths for the composite.As a result,the obtai ned graphe ne?based composite film(rGO-CNR-CDs)exhibited a high thermal conductivity of 1,978.6 W m^-1·K^-1 and electrical conductivity of 2,053.4 S·cm^-1,respectively.The composite film showed an outstanding electro-thermal heating efficiency with the saturated temperature of 315℃and maximum heating rate of 44.9℃·s^-1 at a very low in put voltage of 10 V.The freestandi ng graphe ne composite film with the delicate nano structure desig n has a great pote ntial to be integrated into electro-thermal devices. 展开更多
关键词 graphe ne film CARBON nano DOTS self-assembly electro-thermal HEATER three-dime nsional(3D)conductive framework
Direct and single-step sensing of primary ovarian cancers related glycosidases
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作者 Dan Li Ling Liang +3 位作者 Yawei Tang Linna Fu Shehua Xiao Quan Yuan 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第5期1013-1016,共4页
High sensitive,accurate detection for tumor-associated overexpressed enzyme activity is highly significant for further understanding enzyme function,discovering potential drugs,and early diagnosis and prevention of di... High sensitive,accurate detection for tumor-associated overexpressed enzyme activity is highly significant for further understanding enzyme function,discovering potential drugs,and early diagnosis and prevention of diseases.In this work,we developed a facile,direct and single-step detection platform for primary ovarian cancers related glycosidase activity based on the inner filter effect(IFE)between glycosidase catalytic product and black phosphorus quantum dots(BPQDs).Highly fluorescent BPQDs were successfully synthesized from bulk black phosphorus by a simple liquid exfoliation method.Under the catalysis ofβ-galactosidase,p-nitrophenyl-β-D-galactopyranoside(PNPG)was transformed into pnitrophenol(PNP)andβ-D-galactopyranoside.Meanwhile,the absorption of catalytic product PNP greatly overlapped with the excitation and emission spectra of fluorescent BPQDs,leading to the fluorescence quenching of BPQDs with a high quenching efficiency.The proposed sensing strategy provided a low detection limit of 0.76 U/L,which was 1-2 orders of magnitude lower than most unmodified sensing platforms.D-Galactal was selected as the inhibitor forβ-galactosidase to further assess the feasibility of screening potential inhibitors.The fluorescence recovery of BPQDs suggests that the unmodified sensing platform is feasible to discover potential drugs ofβ-galactosidase.Our work paves a general way in the detection of glycosidase activity with fluorescent BPQDs,which can be promising for glycosidase-related disease diagnosis and pathophysiology elucidation. 展开更多
关键词 Black PHOSPHORUS quantum DOTS Fluorescence SENSING Β-GALACTOSIDASE INNER filter effect
Quantum light source devices of In(Ga)As semiconductor self-assembled quantum dots 预览
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作者 Xiaowu He Yifeng Song +15 位作者 Ying Yu Ben Ma Zesheng Chen Xiangjun Shang Haiqiao Ni Baoquan Sun Xiuming Dou Hao Chen Hongyue Hao Tongtong Qi Shushan Huang Hanqing Liu Xiangbin Su Xinliang Su Yujun Shi Zhichuan Niu 《半导体学报:英文版》 EI CAS CSCD 2019年第7期27-37,共11页
A brief introduction of semiconductor self-assembled quantum dots (QDs) applied in single-photon sources is given. Single QDs in confined quantum optical microcavity systems are reviewed along with their optical prope... A brief introduction of semiconductor self-assembled quantum dots (QDs) applied in single-photon sources is given. Single QDs in confined quantum optical microcavity systems are reviewed along with their optical properties and coupling characteristics. Subsequently, the recent progresses in In(Ga)As QDs systems are summarized including the preparation of quantum light sources, multiple methods for embedding single QDs into different microcavities and the scalability of single-photon emitting wavelength. Particularly, several In(Ga)As QD single-photon devices are surveyed including In(Ga)As QDs coupling with nanowires, InAs QDs coupling with distributed Bragg reflection microcavity and the In(Ga)As QDs coupling with micropillar microcavities. Furthermore, applications in the field of single QDs technology are illustrated, such as the entangled photon emission by spontaneous parametric down conversion, the single-photon quantum storage, the chip preparation of single-photon sources as well as the single-photon resonance-fluorescence measurements. 展开更多
关键词 QUANTUM OPTICS QUANTUM DOTS NANOWIRES light SOURCES
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Ⅲ–Ⅴ compounds as single photon emitters 预览
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作者 Xu Wang Lei Xu +4 位作者 Yun Jiang Zhouyang Yin Christopher C. S. Chan Chaoyong Deng Robert A. Taylor 《半导体学报:英文版》 EI CAS CSCD 2019年第7期63-74,共12页
Single-photon emitters (SPEs) are one of the key components in quantum information applications. The ideal SPEs emit a single photon or a photon-pair on demand, with high purity and distinguishability. SPEs can also b... Single-photon emitters (SPEs) are one of the key components in quantum information applications. The ideal SPEs emit a single photon or a photon-pair on demand, with high purity and distinguishability. SPEs can also be integrated in photonic circuits for scalable quantum communication and quantum computer systems. Quantum dots made from Ⅲ-Ⅴ compounds such as InGaAs or GaN have been found to be particularly attractive SPE sources due to their well studied optical performance and state of the art industrial flexibility in fabrication and integration. Here, we review the optical and optoelectronic properties and growth methods of general SPEs. Subsequently, a brief summary of the latest advantages in Ⅲ-Ⅴ compound SPEs and the research progress achieved in the past few years will be discussed. We finally describe frontier challenges and conclude with the latest SPE fabrication science and technology that can open new possibilities for quantum information applications. 展开更多
关键词 single PHOTON EMITTERS solid-states QUANTUM DOTS 2D materials
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Electrically driven uniaxial stress device for tuning in situ semiconductor quantum dot symmetry and exciton emission in cryostat 预览
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作者 Hao Chen Xiuming Dou +1 位作者 Kun Ding Baoquan Sun 《半导体学报:英文版》 EI CAS CSCD 2019年第7期75-79,共5页
Uniaxial stress is a powerful tool for tuning exciton emitting wavelength, polarization, fine-structure splitting (FSS), and the symmetry of quantum dots (QDs). Here, we present a technique for applying uniaxial stres... Uniaxial stress is a powerful tool for tuning exciton emitting wavelength, polarization, fine-structure splitting (FSS), and the symmetry of quantum dots (QDs). Here, we present a technique for applying uniaxial stress, which enables us in situ to tune exciton optical properties at low temperature down to 15 K with high tuning precision. The design and operation of the device are described in detail. This technique provides a simple and convenient approach to tune QD structural symmetry, exciton energy and biexciton binding energy. It can be utilized for generating entangled and indistinguishable photons. Moreover, this device can be employed for tuning optical properties of thin film materials at low temperature. 展开更多
关键词 UNIAXIAL stress electrically DRIVEN DEVICE low temperature quantum DOTS thin film materials
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Highly luminescence manganese doped carbon dots
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作者 Shuangjiao Sun Qingwen Guan +3 位作者 Yao Liu Bin Wei Yuanyuan Yang Zhiqiang Yu 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第5期1051-1054,共4页
Heteroatom doped carbon dots(CDs)with distinct merits are of great attractions in various fields such as solar cells,catalysis,trace element detection and photothermal therapy.In this work,we successfully synthesized ... Heteroatom doped carbon dots(CDs)with distinct merits are of great attractions in various fields such as solar cells,catalysis,trace element detection and photothermal therapy.In this work,we successfully synthesized blue-fluorescence and photostability manganese-doped carbon dots(Mn-CDs)with a quantum yield up to 7.5%,which was prepared by a facile one-step hydrothermal method with sodium citrate and manganese chloride.The Mn-CDs is the high mono-dispersity,uniform spherical nanoparticles.The Mn element plays a critical role in achieving a high quantum yield in synthesis of carbon dots,which was confirmed by the structure analysis using XPS and FTIR.Spectroscopic investigations proved that the decent PLQY and luminescence properties of Mn-CDs are due to the heteroatom doped,oxidized carbon-based surface passivation.In addition,the Mn-CDs are demonstrated as promising fluorescent sensors for iron ions with a linear range of 0–500 μmol/L and a detection limit of2.1 nmol/L(turn-off),indicating their great potential as a fluorescent probe for chemical sensing. 展开更多
关键词 Manganese-doped carbon DOTS MANGANESE FLUORESCENT SENSORS Quantum yield
Quantum dots enhanced Cerenkov luminescence imaging 预览
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作者 Chang-Ran Geng Yao Ai +4 位作者 Xiao-Bin Tang Di-Yun Shu Chun-Hui Gong Ming-Hua Du Fa-Quan Ji 《核技术:英文版》 SCIE CAS CSCD 2019年第5期9-13,共5页
Cerenkov luminescence imaging (CLI) has been widely investigated for biological imaging. However, the luminescence generated from Cerenkov effect is relatively weak and has poor penetration ability in biological tissu... Cerenkov luminescence imaging (CLI) has been widely investigated for biological imaging. However, the luminescence generated from Cerenkov effect is relatively weak and has poor penetration ability in biological tissues. These limitations consequently hindered the clinical translation of CLI. In this study, we proposed an in vitro experimental study for the demonstration of quantum dots (QDs) configurations affected by the improvement of the signal intensity of CLI. Results revealed that the optimal concentrations were 0.1 mg/mL and 0.25 mg/mL for the studied CdSe/ZnS QDs with fluorescence emission peaks of 580 nm and 660 nm, respectively. The detected optical signal intensity with long-wavelength emission QDs were stronger than those with short-wavelength emission QDs. This study illustrates an experiment to study the effects of concentrations and fluorescence emission peaks of QDs on an enhanced optical signal for the external detection of CLI. 展开更多
关键词 CERENKOV LUMINESCENCE IMAGING Quantum DOTS Optical signal WAVELENGTH shift
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Cytotoxicity and autophagy induction by graphene quantum dots with different functional groups
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作者 Yichun Xie Bin Wan +3 位作者 Yu Yang Xuejing Cui Yan Xin Liang-Hong Guo 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第3期198-209,共12页
Graphene quantum dots(GQDs) possess great potential in various applications due to their superior physicochemical properties and wide array of available surface modifications.However, the toxicity of GQDs has not been... Graphene quantum dots(GQDs) possess great potential in various applications due to their superior physicochemical properties and wide array of available surface modifications.However, the toxicity of GQDs has not been systematically assessed, thus hindered their further development;especially, the risk of surface modifications of GQDs is largely unknown. In this study, we employed a lung carcinoma A549 cells as the model to investigate the cytotoxicity and autophagy induction of three types GQDs, including cGQDs(COOH-GQDs), hGQDs(OH-GQDs), and aGQDs(NH2-GQDs). The results showed hGQDs was the most toxic, as significant cell death was induced at the concentration of 100 μg/mL,determining by WST-1 assay as well as Annexin-V-FITC/PI apoptosis analysis, whereas cGQDs and aGQDs were non-cytotoxic within the measured concentration. Autophagy detection was performed by TEM examination, LC3 fluorescence tracking, and Westernblot. Both aGQDs and hGQDs induced cellular autophagy to various degrees except for cGQDs. Further analysis on autophagy pathways indicated all GQDs significantly activated p-p38 MAPK;p-ERK1/2 was inhibited by aGQDs and hGQDs but activated by c GQDs. p-JNK was inhibited by aGQDs and c GQDs, while activated by hGQDs. Simultaneously, Akt was activated by hGQDs but inhibited by aGQDs. Inhibition of autophagy by 3-MA significantly increased the cytotoxicity of GQDs, suggesting that autophagy played a protective role against the toxicity of GQDs. In conclusion, c GQDs showed excellent biocompatibility and may be considered for biological applications. Autophagy induction may be included in the health risk assessment of GQDs as it reflects the stress status which may eventually lead to diseases. 展开更多
关键词 GRAPHENE quantum DOTS CYTOTOXICITY AUTOPHAGY Surface functional group
Preparation of Different Lights Irradiated ZnSe/GSH QDs and Their Interaction with BSA
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作者 丁玲 HE Huan +4 位作者 李世迁 ZHOU Jin HUANG Kuntao CHENG Zhengzai GAUTHIER Mario 《武汉理工大学学报:材料科学英文版》 SCIE EI CAS 2019年第4期858-865,共8页
Using L-glutathione(GSH) as a capping agent,Zn Se/GSH quantum dots(QDs) were prepared under microwave irradiation and irradiated under dark, ultraviolet light and incandescent light, respectively. The properties and i... Using L-glutathione(GSH) as a capping agent,Zn Se/GSH quantum dots(QDs) were prepared under microwave irradiation and irradiated under dark, ultraviolet light and incandescent light, respectively. The properties and interaction of different lights irradiated ZnSe/GSH QDs and bovine serum albumin(BSA) were studied systematically. The fluorescence(FL) spectra results reveal that the quenching mechanism are all the static quenching in nature. The quenching constant(Ksv) and binding constant(K) value of different irradiated Zn Se/GSH QDs and BSA all increased with the change of light types from dark to incandescent light and UV light. The number of binding site(n) is close to 1 at different temperatures. The lighting types influence the enthalpy and entropy changes. The Fourier transform infrared(FTIR) spectra indicate that the light induced GSH ligand will facilitate photocatalytic oxidation on the surface of ZnSe/GSH QDs. The circular dichroism(CD)results show that the α-helicity content of BSA decreases from 60.34%, 59.31%, to 58.79% under UV lighting,incandescent lighting and dark conditions. The interaction results of different lights illuminated ZnSe/GSH QDs with BSA by CD spectra method matches well with that by FL and FTIR spectra. That is, the interaction of ZnSe/GSH QDs and BSA from strong to weak is UV light, incandescent light and dark in sequence. 展开更多
关键词 lights IRRADIATED ZnSe/GSH quantum dots PREPARATION bovine serum albumin INTERACTION thermodynamics
Molecular beam epitaxial growth of high quality InAs/GaAs quantum dots for 1.3-μm quantum dot lasers
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作者 郝慧明 苏向斌 +2 位作者 张静 倪海桥 牛智川 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第7期495-498,共4页
Systematic investigation of InAs quantum dot(QD) growth using molecular beam epitaxy has been carried out, focusing mainly on the InAs growth rate and its effects on the quality of the InAs/GaAs quantum dots.By optimi... Systematic investigation of InAs quantum dot(QD) growth using molecular beam epitaxy has been carried out, focusing mainly on the InAs growth rate and its effects on the quality of the InAs/GaAs quantum dots.By optimizing the growth rate, high quality InAs/GaAs quantum dots have been achieved.The areal quantum dot density is 5.9× 1010 cm-2, almost double the conventional density(3.0 × 1010 cm-2).Meanwhile, the linewidth is reduced to 29 meV at room temperature without changing the areal dot density.These improved QDs are of great significance for fabricating high performance quantum dot lasers on various substrates. 展开更多
关键词 QUANTUM DOTS growth rate DOT density LINEWIDTH
Modulation of magnetic and electrical properties of bilayer graphene quantum dots using rotational stacking faults
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作者 杨宏平 原文娟 +1 位作者 罗俊 朱静 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第7期504-510,共7页
Bilayer graphene quantum dots with rotational stacking faults(RSFs) having different rotational angles were studied.Using the first-principles calculation, we determined that these stacking faults could quantitatively... Bilayer graphene quantum dots with rotational stacking faults(RSFs) having different rotational angles were studied.Using the first-principles calculation, we determined that these stacking faults could quantitatively modulate the magnetism and the distribution of spin and energy levels in the electronic structures of the dots.In addition, by examining the spatial distribution of unpaired spins and Bader charge analysis, we found that the main source of magnetic moment originated from the edge atoms of the quantum dots.Our research results can potentially provide a new path for producing all-carbon nanodevices with different electrical and magnetic properties. 展开更多
关键词 BILAYER graphene quantum DOTS ROTATIONAL STACKING FAULTS FIRST-PRINCIPLES calculation
In Situ Synthesis of Fluorescent Mesoporous Silica–Carbon Dot Nanohybrids Featuring Folate Receptor-Overexpressing Cancer Cell Targeting and Drug Delivery 预览
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作者 Shuai Zhao Shan Sun +6 位作者 Kai Jiang Yuhui Wang Yu Liu Song Wu Zhongjun Li Qinghai Shu Hengwei Lin 《纳微快报:英文版》 CAS CSCD 2019年第2期193-205,共13页
Multifunctional nanocarrier-based theranostics is supposed to overcome some key problems in cancer treatment.In this work,a novel method for the preparation of a fluorescent mesoporous silica–carbon dot nanohybrid wa... Multifunctional nanocarrier-based theranostics is supposed to overcome some key problems in cancer treatment.In this work,a novel method for the preparation of a fluorescent mesoporous silica–carbon dot nanohybrid was developed.Carbon dots(CDs),from folic acid as the raw material,were prepared in situ and anchored on the surface of amino-modified mesoporous silica nanoparticles(MSNs–NH2) via a microwave-assisted solvothermal reaction.The as-prepared nanohybrid(designated MSNs–CDs) not only exhibited strong and stable yellow emission but also preserved the unique features of MSNs(e.g.,mesoporous structure,large specific surface area,and good biocompatibility),demonstrating a potential capability for fluorescence imagingguided drug delivery.More interestingly,the MSNs–CDs nanohybrid was able to selectively target folate receptor-overexpressing cancer cells(e.g.,HeLa),indicating that folic acid still retained its function even after undergoing the solvothermal reaction.Benefited by these excellent properties,the fluorescent MSNs–CDs nanohybrid can be employed as a fluorescence-guided nanocarrier for the targeted deliveryof anticancer drugs(e.g.,doxorubicin),thereby enhancing chemotherapeutic efficacy and reducing side effects.Our studies may provide a facile strategy for the fabrication of multifunctional MSN-based theranostic platforms,which is beneficial in the diagnosis and therapy of cancers in future. 展开更多
关键词 MESOPOROUS silica nanoparticles CARBON DOTS Fluorescence imaging Targeted drug delivery Chemotherapy
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Core(Au)-shell(Ag)structure nitrogen dots for the recognition of nitroaniline isomers by surface-enhanced Raman scattering
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作者 Jiani Yang Ling Xia +3 位作者 Zhenhua Lin Zhijiao Tang Gongke Li Yuling Hu 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第3期638-642,共5页
In this work, we report a facile synthesis method for NDs-Au@AgNPs surface-enhanced Raman scattering(SERS) substrate using Au seeds prepared by nitrogen-rich quantum dots(NDs). As a new member of quantum-dots family, ... In this work, we report a facile synthesis method for NDs-Au@AgNPs surface-enhanced Raman scattering(SERS) substrate using Au seeds prepared by nitrogen-rich quantum dots(NDs). As a new member of quantum-dots family, NDs are rich in nitrogen and oxygen-containing functional groups and therefore can be used as an efficient reducing and stabilizing agent for the synthesis of AuNPs. The NDs-Au@AgNPs with core-shell structures was synthesized by seed-mediated growth method in presence of NDs-AuNPs seeds and exhibited high SERS activity with a high SERS enhancement factor of 10~7. The NDs-Au@AgNPs SERS substrate was effectively used for the recognition and detection of isomers of meta, ortho and para nitroanilines, while commercial SERS substrate cannot. In addition, the possible adsorption behavior was further studied, which is of great significance for the related work about differentiation of isomers and the mechanism of SERS enhancement. 展开更多
关键词 Nitrogen-rich quantum DOTS NDs-Au@AgNPs NITROANILINE ISOMERS Surface-enhanced Raman SCATTERING Adsorption behavior
TiO2 sensitized by red-,green-,blue-emissive carbon dots for enhanced H2 production
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作者 Dong-Xue Yang Dan Qu +5 位作者 Xiang Miao Wen-Shuai Jiang Li An Yuan-Jing Wen Dan-Dan Wu Zai-Cheng Sun 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第5期404-412,共9页
Carbon dots(Cdots)with a broad light absorption range could be a potential stable sensitizer for TiO2,which is an excellent ultraviolet(UV)response photocatalyst.Herein,we systematically investigated the different col... Carbon dots(Cdots)with a broad light absorption range could be a potential stable sensitizer for TiO2,which is an excellent ultraviolet(UV)response photocatalyst.Herein,we systematically investigated the different color emissive Cdots-sensitized TiO2 for H2 production.Firstly,all kinds of Cdots enhanced the photocatalytic properties of TiO2.All the Cdots-sensitized TiO2 exhibits visible light H2 production due to their absorption in the visible light region.The photocurrent and H2 production amount display strong dependence on the light absorption range of Cdots.The blue-emissive Cdots endow the weak H2 production rate due to its weak absorption in the visible light.The enhanced photocatalytic activities are mainly contributed to the strong light absorbance and high-efficient charge separation.The light absorption of green-and red-emissive Cdots is another main factor for the high catalytic activities besides charge separation. 展开更多
关键词 TIO2 Carbon DOTS VISIBLE light absorption SENSITIZER H2 PRODUCTION
CdS magic-size clusters exhibiting one sharp ultraviolet absorption singlet peaking at 361 nm
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作者 Junbin Tang Juan Hui +6 位作者 Meng Zhang Hongsong Fan Nelson Rowell Wen Huang Yingnan Jiang Xiaoqin Chen Kui Yu 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第6期1437-1444,共8页
We report,for the first time,the synthesis of CdS magic-size clusters (MSCs) which exhibit a single sharp absorption peaking at ~ 361 nm,along with sharp band edge photoemission at ~ 377 nm and broad trap emission pea... We report,for the first time,the synthesis of CdS magic-size clusters (MSCs) which exhibit a single sharp absorption peaking at ~ 361 nm,along with sharp band edge photoemission at ~ 377 nm and broad trap emission peaking at ~ 490 nm.These MSCs are produced in a singleensemble form without the contamination of conventional quantum dots (QDs) and/or other-bandgap clusters.They are denoted as MSC-361.We present the details of several controlled syntheses done in oleylamine (OLA),using C,d(NO3)2 or C,d(OAc)2 as a C,d source and thioacetamide (TAA) or elementary sulfur (S) as a S source.A high synthetic reproducibility of the reaction of Cd(NO3)2 and TAA to single-ensemble MSC-361 is achieved,the product of which is not contaminated by other bandgap clusters and/or QDs.In some cases,the reaction product exhibits an additional absorption peak at ~ 322 nm.We demonstrate that the two peaks,at 361 and 322 nm,do not evolve synchronously.Therefore,the 322 nm peak is not a higher order electronic transition of MSC-361,but due to the presence of another ensemble,namely MSC-322.The present study suggests that there is an outstanding need for the development of a physical model to narrow the knowledge gap regarding the electronic structure in these colloidal semiconductor CdS MSCs. 展开更多
关键词 COLLOIDAL semiconductor CDS magic-size CLUSTERS (MSCs) MSC-361 quantum dots (QDs) electronic structures
In situ TEM observation of neck formation during oriented attachment of PbSe nanocrystals
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作者 Yu Wang Xinxing Peng +6 位作者 Alex Abelson Bing-Kai Zhang Caroline Qian Peter Ercius Lin-Wang Wang Matt Law Haimei Zheng 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第10期2549-2553,共5页
Oriented attachment of nanocrystals is an important route to constructing epitaxially-connected nanocrystal superlattices for various applications.During oriented attach me nt of semic on ductor nano crystals,neck can... Oriented attachment of nanocrystals is an important route to constructing epitaxially-connected nanocrystal superlattices for various applications.During oriented attach me nt of semic on ductor nano crystals,neck can be formed betwee n nan ocrystals and it strongly influe nces the properties of the resulting superlattice.However,the neck formation mechanism is poorly understood.Here,we use in situ liquid cell transmission electro n microscopy(TEM)to directly observe the initiatio n and growth of homoepitaxial n ecks betwee n PbSe nano crystals with atomic details.We find that neck initiatio n occurs slowly(~10 s)whe n two nano crystals approach to each other within an edge-to-edge dista nee of 0.6 nm.During neck initiation,Pb and Se atoms defuse from other facets into the gap,forming"dynamic reversible"filaments.Once the filament(n eck)width is larger than a critical size of 0.9 nm,it gradually(15 s)widens into a 3-nm-wide n eck.The atomic structure of the neck is further obtained using ex situ aberration-corrected seanning TEM imaging.Neck initiation and growth mechanisms are elucidated with density functional theory calculati ons.Our direct unveiling of the atomic pathways of neck formatio n duri ng oriented attach me nt shed light into the fabrication of nanocrystal superlattices with improved structural order and electronic properties. 展开更多
关键词 PBSE NANOCRYSTALS quantum DOTS SUPERLATTICES NECKING oriented attachment liquid cell transmission electron microscopy(TEM)
pH and H2O2 dual-responsive carbon dots for biocatalytic transformation monitoring
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作者 Wenxin Lv Xin Wang +2 位作者 Jiahui Wu Haiyin Li Feng Li 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第9期1635-1638,共4页
Development of sensitive biosensors for biocatalytic transformations monitoring is in high demand but remains a great challenge. It is ascribed to the current strategies that focused on the single metabolite detection... Development of sensitive biosensors for biocatalytic transformations monitoring is in high demand but remains a great challenge. It is ascribed to the current strategies that focused on the single metabolite detection, which may bring about the relatively low sensitivity and false diagnosis result. Herein, we report the design and fabrication of novel carbon dots(CDs) with strong orange light emission, pH and H2O2 dual-responsive characteristics. The fluorescence quenching of CDs by H+and H2O2 enables the highly sensitive detection of H+/H2O2-generating biocatalytic transformations. This is exemplified by the glucose oxidase-mediated catalytic oxidation reaction on glucose, in which H+and H2O2 would be formed. As compared to the case in which glucose is present, significant fluorescence reduction is detected, and the fluorescence intensity is negatively proportional to glucose concentration. Thus, highly sensitive detection of glucose was readily achieved with a detection limit down to 10.18 nmol/L. The prepared CDs not only realize the highly sensitive detection of glucose, but also allows the probing other substances by changing the enzymes, thus providing a versatile platform, and demonstrating good potential to be used for biocatalytic transformations effective monitoring. 展开更多
关键词 Carbon DOTS Dual-responsive PH H2O2 GLUCOSE Biocatalytic TRANSFORMATIONS
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