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1.
BMC Genomics ; 25(1): 354, 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38594645

ABSTRACT

The homeodomain-leucine zipper (HD-Zip) gene family plays a pivotal role in plant development and stress responses. Nevertheless, a comprehensive characterization of the HD-Zip gene family in kiwifruit has been lacking. In this study, we have systematically identified 70 HD-Zip genes in the Actinidia chinensis (Ac) genome and 55 in the Actinidia eriantha (Ae) genome. These genes have been categorized into four subfamilies (HD-Zip I, II, III, and IV) through rigorous phylogenetic analysis. Analysis of synteny patterns and selection pressures has provided insights into how whole-genome duplication (WGD) or segmental may have contributed to the divergence in gene numbers between these two kiwifruit species, with duplicated gene pairs undergoing purifying selection. Furthermore, our study has unveiled tissue-specific expression patterns among kiwifruit HD-Zip genes, with some genes identified as key regulators of kiwifruit responses to bacterial canker disease and postharvest processes. These findings not only offer valuable insights into the evolutionary and functional characteristics of kiwifruit HD-Zips but also shed light on their potential roles in plant growth and development.


Subject(s)
Actinidia , Homeodomain Proteins , Homeodomain Proteins/genetics , Genome, Plant , Phylogeny , Actinidia/genetics , Leucine Zippers/genetics , Gene Expression Regulation, Plant , Plant Proteins/genetics , Gene Expression Profiling
2.
Plant Commun ; 5(6): 100856, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38431772

ABSTRACT

Actinidia arguta, the most widely distributed Actinidia species and the second cultivated species in the genus, can be distinguished from the currently cultivated Actinidia chinensis on the basis of its small and smooth fruit, rapid softening, and excellent cold tolerance. Adaptive evolution of tetraploid Actinidia species and the genetic basis of their important agronomic traits are still unclear. Here, we generated a chromosome-scale genome assembly of an autotetraploid male A. arguta accession. The genome assembly was 2.77 Gb in length with a contig N50 of 9.97 Mb and was anchored onto 116 pseudo-chromosomes. Resequencing and clustering of 101 geographically representative accessions showed that they could be divided into two geographic groups, Southern and Northern, which first diverged 12.9 million years ago. A. arguta underwent two prominent expansions and one demographic bottleneck from the mid-Pleistocene climate transition to the late Pleistocene. Population genomics studies using paleoclimate data enabled us to discern the evolution of the species' adaptation to different historical environments. Three genes (AaCEL1, AaPME1, and AaDOF1) related to flesh softening were identified by multi-omics analysis, and their ability to accelerate flesh softening was verified through transient expression assays. A set of genes that characteristically regulate sexual dimorphism located on the sex chromosome (Chr3) or autosomal chromosomes showed biased expression during stamen or carpel development. This chromosome-level assembly of the autotetraploid A. arguta genome and the genes related to important agronomic traits will facilitate future functional genomics research and improvement of A. arguta.


Subject(s)
Actinidia , Genome, Plant , Tetraploidy , Actinidia/genetics , Evolution, Molecular , Adaptation, Physiological/genetics , Biological Evolution
3.
Chem Commun (Camb) ; 60(3): 332-335, 2024 Jan 02.
Article in English | MEDLINE | ID: mdl-38073511

ABSTRACT

We propose a noncovalent backbone planarization strategy to fabricate a gas/phototheranostic nanocomposite (B-E-NO NPs) in the near-infrared-II (NIR-II, 1000-1700 nm) window by incorporating noncovalent conformational locks. B-E-NO NPs display a giant NIR-II extinction coefficient, realizing multimodal imaging-guided high-efficiency NIR-II photothermal therapy (η = 45.4%) and thermal-initiated nitric oxide combination therapy.

4.
Light Sci Appl ; 12(1): 30, 2023 Jan 31.
Article in English | MEDLINE | ID: mdl-36720850

ABSTRACT

Doping and blending strategies are crucial means to precisely control the excited states and energy level in conjugated molecular systems. However, effective models and platforms are rarely proposed to systematically explore the effects of the formation of trapped doped centers on heterogeneous structures, energy level and ultrafast photophysical process. Herein, for deeply understanding the impact of molecular doping in film energy levels and photoexcitation dynamics, we set a supramolecular N-B coordination composed by the conjugated molecules of pyridine functionalized diarylfluorene (host material), named as ODPF-Phpy and ODPF-(Phpy)2, and the molecule of tris(perfluorophenyl)borane (BCF) (guest material). The generation of the molecular-level coordination bond increased the binding energy of N atoms and tuned the band-gap, leading to a new fluorescent emission center with longer excitation wavelength and emission wavelength. The intermolecular Förster resonance energy transfer (FRET) in blending films make it present inconsistent fluorescent behaviors compared to that in solution. The charge transfer (CT) state of N-B coordinated compounds and the changed dielectric constant of blending films resulted in a large PL spectra red-shift with the increased dopant ratio, causing a wide-tunable fluorescent color. The excited state behaviors of two compounds in blending system was further investigated by the transient absorption (TA) spectroscopy. Finally, we found supramolecular coordination blending can effectively improve the films' photoluminescence quantum yield (PLQY) and conductivity. We believe this exploration in the internal coordination mechanisms would deepen the insights about doped semiconductors and is helpful in developing novel high-efficient fluorescent systems.

5.
J Neuroinflammation ; 19(1): 207, 2022 Aug 18.
Article in English | MEDLINE | ID: mdl-35982473

ABSTRACT

BACKGROUND: Intracerebral hemorrhage (ICH) is associated with high morbidity and mortality rates. However, extant investigations have mainly focused on gray matter injury within the primary injury site after ICH rather than on white matter (WM) injury in the brain and spinal cord. This focus partly accounts for the diminished therapeutic discovery. Recent evidence suggests that chondroitin sulphate proteoglycans (CSPG), which can bind to the neural transmembrane protein tyrosine phosphatase-sigma (PTPσ), may facilitate axonal regrowth and remyelination by ameliorating neuroinflammation. METHODS: A clinically relevant ICH model was established using adult C57BL/6 mice. The mice were then treated systemically with intracellular sigma peptide (ISP), which specifically targets PTPσ. Sensorimotor function was assessed by various behavioral tests and electrophysiological assessment. Western blot was used to verify the expression levels of Iba-1 and different inflammatory cytokines. The morphology of white matter tracts of brain and spinal cord was evaluated by immunofluorescence staining and transmission electron microscopy (TEM). Adeno-associated virus (AAV) 2/9 injection was used to assess the ipsilateral axonal compensation after injury. Parallel in vitro studies on the effects of CSPG interference on oligodendrocyte-DRG neuron co-culture explored the molecular mechanism through which ISP treatment promoted myelination capability. RESULTS: ISP, by targeting PTPσ, improved WM integrity and sensorimotor recovery via immunomodulation. In addition, ISP administration significantly decreased WM injury in the peri-hematomal region as well as cervical spinal cord, enhanced axonal myelination and facilitated neurological restoration, including electrophysiologically assessed sensorimotor functions. Parallel in vitro studies showed that inhibition of PTPσ by ISP fosters myelination by modulating the Erk/CREB signaling pathway. CONCLUSIONS: Our findings revealed for the first time that manipulation of PTPσ signaling by ISP can promote prolonged neurological recovery by restoration of the integrity of neural circuits in the CNS through modulation of Erk/CREB signaling pathway.


Subject(s)
Hemorrhagic Stroke , White Matter , Animals , Cerebral Hemorrhage/drug therapy , Chondroitin Sulfate Proteoglycans/metabolism , Mice , Mice, Inbred C57BL , Peptides/pharmacology , Phosphoric Monoester Hydrolases/metabolism , Proteoglycans/metabolism , Receptor-Like Protein Tyrosine Phosphatases, Class 2/metabolism , White Matter/metabolism
6.
Data Brief ; 43: 108440, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35864872

ABSTRACT

This dataset includes many indexes of global cities. The variables of congestion level, skyscraper index, whether a city was bombed in WWII (World War II), and global cities' population are key variables. (1) The congestion level data were collected from TOMTOM company. The congestion level data include five indexes which are "Congestion level", "Morning peak Congestion level", "Evening peak Congestion level", "Highways Congestion level", "Non-highways Congestion level" in 2004, but only include two indexes in 2020 which are "Time lost per year" and "Congestion level". (2) The data of skyscraper index calculated using the data of building height from the Council on Tall Buildings and Urban Habitat, from which we can obtain accurate data on the number of buildings taller than 150 m. With these data, we constructed an index of skyscrapers taller than 150 m in a city. A building receives a score of 1.5 if it is taller than 150 m and shorter than 200 m, 2.0 if it is between 200 m and 300 m, and so on. Then, we summed the scores for skyscrapers in the city as the "skyscraper index" of the city. (3) The data of whether a city was bombed in WWII is dummy variable, if the urban area of a city was bombed in WWII, it is 1, and 0 otherwise. The authors consulted various historical files and determined the value. (4) The data of global cities' population, as well as the area and density of the city, are on the city-level, and were collected from the website of the cities or countries' statistics department. These indicators are good measures of the level of congestion, urban spatial structure, IV(instrumental variable) for urban spatial structure, and urban population in global cities, and can be reused in other analysis.

7.
Article in English | MEDLINE | ID: mdl-35584065

ABSTRACT

Electroencephalography (EEG) is widely used for mental stress classification, but effective feature extraction and transfer across subjects remain challenging due to its variability. In this paper, a novel deep neural network combining convolutional neural network (CNN) and adversarial theory, named symmetric deep convolutional adversarial network (SDCAN), is proposed for stress classification based on EEG. The adversarial inference is introduced to automatically capture invariant and discriminative features from raw EEG, which aims to improve the classification accuracy and generalization ability across subjects. Experiments were conducted with 22 human subjects, where each participant's stress was induced by the Trier Social Stress Test paradigm while EEG was collected. Stress states were then calibrated into four or five stages according to the changing trend of salivary cortisol concentration. The results show that the proposed network achieves improved accuracies of 87.62% and 81.45% on the classification of four and five stages, respectively, compared to conventional CNN methods. Euclidean space data alignment approach (EA) was applied and the improved generalization ability of EA-SDCAN across subjects was also validated via the leave-one-subject-out-cross-validation, with the accuracies of four and five stages being 60.52% and 48.17%, respectively. These findings indicate that the proposed SDCAN network is more feasible and effective for classifying the stages of mental stress based on EEG compared with other conventional methods.


Subject(s)
Electroencephalography , Neural Networks, Computer , Attention , Electroencephalography/methods , Humans
8.
Biomaterials ; 280: 121319, 2022 01.
Article in English | MEDLINE | ID: mdl-34923313

ABSTRACT

Designing conjugated polymers (CPs) with both efficient second near-infrared wavelength (NIR-II) fluorescence and NIR-II photothermal therapy performance remains a huge challenge, as the introduction of excessively strong electron donor and acceptor units significantly increase non-radiative decay. Herein, we describe an "electron acceptor density adjustment" strategy to address this problem, since a lower electron acceptor density in the conjugated polymer backbone can enhance the radiative rate constant and improve NIR-II fluorescence brightness. We used quaterthiophene (4T) with four repeated thiophene chain units and bithiophene (2 TC) modified with long alkyl side chains to reduce the electron acceptor density in the conjugated polymer backbone. The resultant 1064 nm absorption polymer, TTQ-2TC-4T displayed approximately 7.30-folds enhancement in NIR-II emission intensity compared to that of undoped TTQ-1T at the same mass concentration in toluene solution. Furthermore nanoparticles (TTQ-MnCO NPs) based on TTQ-2TC-4T and CO donors (Mn2(CO)10) were developed to realize NIR-II FI-guided 1064 nm laser-triggered NIR-II PTT/Gas synergistic therapy. The TTQ-MnCO NPs nanoparticles exhibited high photothermal conversion efficiency (η) of 44.43% at 1064 nm and high specific NIR-II fluorescence imaging of the cerebral vasculature of live mice. The in vivo results demonstrate that TTQ-MnCO NPs nanoparticles have excellent PTT/Gas synergistic therapeutic effects in MCF-7 tumor-bearing mice under 1064 nm laser irradiation. This study provides a new approach for optimizing both NIR-II fluorescence and NIR-II photothermal performance of NIR-II absorption conjugated polymers.


Subject(s)
Nanoparticles , Polymers , Animals , Cell Line, Tumor , Electrons , Mice , Nanoparticles/chemistry , Optical Imaging , Phototherapy , Photothermal Therapy , Polymers/chemistry
9.
J Colloid Interface Sci ; 587: 581-589, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33234311

ABSTRACT

The design of electrocatalysts with lower overpotential is of great significance for water splitting. Herein, cobalt hydroxide carbonate (CCH) has been used as a model to demonstrate the boost of its oxygen evolution reaction (OER) activity by atomic doping of W6+ (W-CCH). The 5 at % W doping reduced the OER overpotential of CCH by 95.3 mV at 15 mA cm-2, and increased the current density by 2.8 times at 1.65 V. 5%W-PCCH || 5%W-CCH-based electrolyzer only required a potential of 1.65 V to afford 10 mA cm-2 for full water splitting. The W6+ in CCH are active sites for O2- adsorption and induced an incesaed electron density near the Fermi level, which facilitates the charge transfer during electrocatalysis. The W6+ doping has been validated as an efficient booster for transition-metal carbonate hydroxides-based electrocatalysts, which has half or more than half-filled d-bands.

10.
Polymers (Basel) ; 12(10)2020 Oct 13.
Article in English | MEDLINE | ID: mdl-33066184

ABSTRACT

The industrial advancement of high-performance technologies directly depends on the thermo-mechanical properties of materials. Here we give an account of a facile approach for the bulk production of a polyethylene terephthalate (PET)/polypropylene (PP)-based nanocomposite blend with Inorganic Fullerene Tungsten Sulfide (IF-WS2) nanofiller using a single extruder. Nanofiller IF-WS2 was produced by the rotary chemical vapor deposition (RCVD) method. Subsequently, IF-WS2 nanoparticles were dispersed in PET and PP in different loadings to access impact and their dispersion behavior in polymer matrices. As-prepared blend nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic differential scanning (DSC), dynamic mechanical analysis (DMA), and X-ray diffraction (XRD). In this work, the tensile strength of the PP/PET matrix with 1% IF-WS2 increased by 31.8%, and the thermal stability of the sample PP/PET matrix with 2% increased by 18 °C. There was an extraordinary decrease in weight loss at elevated temperature for the nanocomposites in TGA analysis, which confirms the role of IF-WS2 on thermal stability versus plain nanocomposites. In addition, this method can also be used for the large-scale production of such materials used in high-temperature environments.

11.
Front Hum Neurosci ; 14: 215, 2020.
Article in English | MEDLINE | ID: mdl-32760257

ABSTRACT

Many studies have revealed the structural or functional brain changes induced by occupational factors. However, it remains largely unknown how occupation-related connectivity shapes the brain. In this paper, we denote occupational neuroplasticity as the neuroplasticity that takes place to satisfy the occupational requirements by extensively professional training and to accommodate the long-term, professional work of daily life, and a critical review of occupational neuroplasticity related to the changes in brain structure and functional networks has been primarily presented. Furthermore, meta-analysis revealed a neurophysiological mechanism of occupational neuroplasticity caused by professional experience. This meta-analysis of functional neuroimaging studies showed that experts displayed stronger activation in the left precentral gyrus [Brodmann area (BA)6], left middle frontal gyrus (BA6), and right inferior frontal gyrus (BA9) than novices, while meta-analysis of structural studies suggested that experts had a greater gray matter volume in the bilateral superior temporal gyrus (BA22) and right putamen than novices. Together, these findings not only expand the current understanding of the common neurophysiological basis of occupational neuroplasticity across different occupations and highlight some possible targets for neural modulation of occupational neuroplasticity but also provide a new perspective for occupational science research.

12.
Front Psychol ; 11: 613659, 2020.
Article in English | MEDLINE | ID: mdl-33762985

ABSTRACT

Previous studies have noted that personality traits are important predictors of well-being, but how big five personality influences social well-being is still unknown. This study aims to examine the link between big five personality and five dimensions of social well-being in the Chinese cultural context and whether social support can play the mediating effect in the process. This study included 1,658 participants from different communities in China, and regression analyses were conducted. Results revealed that five personality traits were significantly related to overall social well-being; extraversion was significantly related to social integration; agreeableness was positively related to all five dimensions of social well-being; conscientiousness was positively related to social actualization, social coherence, and social contribution; neuroticism was negatively related to social integration, social acceptance, social actualization, and social coherence; openness was positively related to social integration, social acceptance, social coherence, and social contribution. Social support plays mediating roles in the relationships between extraversion/agreeableness/conscientiousness/neuroticism/openness and social well-being, respectively.

13.
Plant Pathol J ; 35(4): 372-380, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31481860

ABSTRACT

Pseudomonas syringae pv. actinidiae (Psa) is by far the most important pathogen of kiwifruit. Sustainable expansion of the kiwifruit industry requires the use of Psa-tolerant or resistant genotypes for the breeding of tolerant cultivars. However, the resistance of most existing kiwifruit cultivars and wild genotypes is poorly understood, and suitable evaluation methods of Psa resistance in Actinidia have not been established. A unique in vitro method to evaluate Psa resistance has been developed with 18 selected Actinidia genotypes. The assay involved debarking and measuring the lesions of cane pieces inoculated with the bacterium in combination with the observation of symptoms such as callus formation, sprouting of buds, and the extent to which Psa invaded xylem. Relative Psa resistance or tolerance was divided into four categories. The division results were consistent with field observations. This is the first report of an in vitro assay capable of large-scale screening of Psa-resistance in Actinidia germplasm with high accuracy and reproducibility. The assay would considerably facilitate the breeding of Psa-resistant cultivars and provide a valuable reference and inspiration for the resistance evaluation of other plants to different pathogens.

14.
Chem Commun (Camb) ; 55(64): 9487-9490, 2019 Aug 07.
Article in English | MEDLINE | ID: mdl-31328194

ABSTRACT

We designed 1300 nm absorption semiconducting polymer nanoparticles (SPNs3) based on a two-acceptor semiconducting polymer to realize in vivo NIR-II photothermal therapy (PTT) treatment guided by commercial small-animal NIR-II photoacoustic imaging (PAI) systems.


Subject(s)
Nanoparticles/chemistry , Photoacoustic Techniques/methods , Polymers/chemistry , Spectroscopy, Near-Infrared/methods , Animals , Cell Line, Tumor , Mice
15.
ACS Appl Mater Interfaces ; 11(18): 16311-16319, 2019 May 08.
Article in English | MEDLINE | ID: mdl-30993963

ABSTRACT

Low-band gap conjugated polymers with donor-acceptor (D-A) structures have emerged as  second near-infrared (NIR-II) fluorescence probes for biological imaging. However, how to control the intramolecular charge transfer (ICT) to maintain the low band gap and improve the NIR-II fluorescence intensity is an urgent issue. Here, the quinoid polymers have been developed to effectively regulate the ICT for brighter NIR-II fluorescence signals. Thiophene repeat chain units of different lengths (T, 2T, and 3T) were utilized to link with electron-withdrawing ester-substituted thieno[3,4- b]thiophene (TT) to alter the density of the electron-withdrawing side groups for controlling the ICT. By increasing the thiophene chain length from TT-T to TT-3T, the density of the electron-withdrawing groups decreased and the ICT was weakened. In the case of NIR absorption and NIR-II emission, weakened ICT leads to brighter NIR-II fluorescence. After the preparation of the water-soluble quinoid polymer probes (CPs), TT-3T CPs with weak ICT exhibited the brightest NIR-II fluorescent signals among the three quinoid polymer probes. Several NIR-II biomedical imaging applications, including in vivo cell tracking, blood vascular system images, and lymphatic drainage mapping, show that the TT-3T CP-based nanoprobe had excellent characteristics of long-term stability and high NIR-II spatial resolutions in vivo.


Subject(s)
Cell Tracking/methods , Fluorescent Dyes/chemistry , Nanoparticles/chemistry , Polymers/chemistry , Electrons , Fluorescent Dyes/therapeutic use , Humans , Molecular Structure , Polymers/therapeutic use , Spectrometry, Fluorescence , Spectroscopy, Near-Infrared , Thiophenes/chemistry
16.
Adv Sci (Weinh) ; 6(1): 1801455, 2019 Jan 09.
Article in English | MEDLINE | ID: mdl-30643727

ABSTRACT

Electrically pumped organic lasing requires the integration of electrodes contact into the laser cavity in an organic light-emitting diode (OLED) or organic field effect transistor configuration to enable charge injection. Efficient and balanced carrier injection requires in turn alignment of the energy levels of the organic active layers with the Fermi levels of the cathode and anode. This can be achieved through chemical substitution with specific aromatic functional groups, although paying the price for a substantial (and often detrimental) change in the emission and light amplifying properties of the organic gain medium. Here, using host-guest energy transfer mixtures with hosts bearing a systematic and gradual shift in molecular orbitals is proposed, which reduces the amplified spontaneous emission (ASE) threshold of the organic gain medium significantly while leaving the peak emission unaffected. By virtue of the low guest doping required for complete host-to-guest energy transfer, the injection levels in the blends are attributed to the host whereas the gain properties solely depend on the guest. It is demonstrated that the ASE peak and thresholds of blends with different hosts do not differ while the current efficiency of OLEDs devices is deeply influenced by molecular orbital tuning of the hosts.

17.
Chem Asian J ; 13(24): 3920-3927, 2018 Dec 18.
Article in English | MEDLINE | ID: mdl-30338647

ABSTRACT

There have been many reports on the application of pyrene derivatives as organic semiconductors, but 1,8-subsituted pyrene semiconductors are less well-developed. Two p-type 1,8-substituted pyrene derivatives were synthesized that were composed of a pyrene core, thiophene or bithiophene arms, and end-capped octyl chains. These structures were not completely symmetrical and the dihedral angles between the pyrene core and the adjacent thiophene units had a difference of approximately two degrees. The field-effect performance of these materials was tested on a variety of dielectric surfaces. The performance of both materials with a spin-coated polystyrene layer on SiO2 (PS-treated SiO2 ) was better than that with an octadecyltrichlorosilane self-assembled monolayer on SiO2 (OTS-treated SiO2 ), which was mainly attributed to the presence of large grains on the low-leakage and high-capacitance PS films. The thiophene-contained compound presented a hole mobility of up to 0.18 cm2 V-1 s-1 on PS-treated SiO2 , which was 45 times that of the bithiophene-contained compound, owing to less steric hindrance, high crystallinity, and large grain size.

18.
Angew Chem Int Ed Engl ; 57(28): 8425-8431, 2018 07 09.
Article in English | MEDLINE | ID: mdl-29766632

ABSTRACT

Smart materials with ultralong phosphorescence are rarely investigated and reported. Herein we report on a series of molecules with unique dynamic ultralong organic phosphorescence (UOP) features, enabled by manipulating intermolecular interactions through UV light irradiation. Our experimental data reveal that prolonged irradiation of single-component organic phosphors of PCzT, BCzT, and FCzT under ambient conditions can activate UOP with emission lifetimes spanning from 1.8 to 1330 ms. These phosphors can also be deactivated back to their original states with short-lived phosphorescence by UV irradiation for 3 h at room temperature or through thermal treatment. Additionally, the dynamic UOP was applied successfully for a visual anti-counterfeiting application. These findings may provide unique insight into dynamic molecular motion for optical processing and expand the scope of smart-response materials for broader applications.

19.
Nanoscale ; 10(14): 6294-6299, 2018 Apr 05.
Article in English | MEDLINE | ID: mdl-29577131

ABSTRACT

Atomically thin transition metal dichalcogenides (TMDCs) with exceptional electrical and optical properties have drawn tremendous attention for use in novel optoelectronic applications as photodetectors, transistors, light emitters, etc. However, electron bound trions formed through the combination of neutral excitons and electrons significantly decrease the photoluminescence (PL) efficiency of TMDCs. In this study, we report a simple yet efficient chemical doping strategy to modulate the optical properties of monolayer tungsten disulfide (WS2). As a demonstrative example, a chemically doped monolayer of WS2 exhibits remarkable PL enhancement of about one order of magnitude higher than that of pristine WS2. This outstanding PL enhancement is attributed to the fact that excess electrons, which promote the formation of electron-bound trions, are reduced in number through charge transfer from WS2 to the chemical dopant. Furthermore, an improved degree of circular polarization from ∼9.0% to ∼41.5% was also observed in the chemically doped WS2 monolayer. This work describes a feasible strategy to manipulate the optical properties of TMDCs via exciton modulation, making TMDCs promising candidates for versatile semiconductor-based photonic devices.

20.
J Mater Chem B ; 6(18): 2778-2784, 2018 May 14.
Article in English | MEDLINE | ID: mdl-32254230

ABSTRACT

The development of smart photosensitizers with tumor microenvironment-activable fluorescence turn-on and singlet oxygen generation plays an important role in tumor bioimaging and photodynamic therapy. Herein, a pH-activable heavy-atom-free photosensitizer (C60-RB) has been successfully synthesized through introducing a fullerene unit onto rhodamine B hydrazide. Under acidic conditions, C60-RB, having a spirolactam structure, can be activated to its ring-opened structure C60-RB-H and thus, visible-light absorbance enhancement, fluorescence turn-on and triplet excited state generation can be accomplished. In the presence of hydrion, the fullerene unit in C60-RB C60-RB-H acting as an intramolecular spin converter can cause good intersystem crossing, and the energy gap between S1 and T1 (ΔEST) is lowered to 0.017 eV. Through encapsulation with amphiphilic DSPE-mPEG2000, water-soluble nanoparticles (NPs) of C60-RB are obtained. In vitro experiments indicate that C60-RB NPs are capable of universal cellular uptake and lysosomal activation (pH 4.5-5.0), and they also exhibit excellent photodynamic therapeutic effect. The fluorescence turn-on and efficient singlet oxygen generation enabled by pH-activated C60-RB NPs testify their great potential applications for cancer diagnosis and treatment.

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