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1.
R Soc Open Sci ; 11(5): 240061, 2024 May.
Article in English | MEDLINE | ID: mdl-39076817

ABSTRACT

Ancient Chinese is a splendid treasure within Chinese culture. To facilitate its compilation, pre-trained language models for ancient Chinese are developed. After that, researchers are actively exploring the factors contributing to their success. However, previous work did not study how language models organized the elements of ancient Chinese from a holistic perspective. Hence, we adopt complex networks to explore how language models organize the elements in ancient Chinese system. Specifically, we first analyse the characters' and words' co-occurrence networks in ancient Chinese. Then, we study characters' and words' attention networks, generated by attention heads within SikuBERT from two aspects: static and dynamic network analysis. In the static network analysis, we find that (i) most of attention networks exhibit small-world properties and scale-free behaviour, (ii) over 80% of attention networks exhibit high similarity with the corresponding co-occurrence networks, (iii) there exists a noticeable gap between characters' and words' attention networks across layers, while their fluctuations remain relatively consistent, and (iv) the attention networks generated by SikuBERT tend to be sparser compared with those from Chinese BERT. In dynamic network analysis, we find that the sentence segmentation task does not significantly affect network metrics, while the part-of-speech tagging task makes attention networks sparser.

2.
Pest Manag Sci ; 80(6): 2647-2657, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38394076

ABSTRACT

BACKGROUND: The wettability of target crop surfaces affects pesticide wetting and deposition. The structure and properties of the leaf surface of litchi leaves undergo severe changes after infestation by Aceria litchii (Keifer). The objective of this study was to systematically investigate the surface texture and wettability of litchi leaves infested. RESULTS: Firstly, the investigation focused on the surface structure and physicochemical properties of litchi leaves infested with Aceria litchii. Subsequently, different levels of Contact Angle (CA) were measured individually on the infested litchi leaves. Lastly, Surface Free Energy (SFE) and its polar and dispersive components were calculated using the Owens-Wendt-Rabel-Kaelble (OWRK) method. The outcomes revealed distinctive 3D surface structures of the erineum at various stages of mycorrhizal growth. At stage NO. 1, the height of the fungus displayed a peaked appearance, with the skewness value indicating a surface characterized by more crests. In contrast, at stages NO. 2 and NO. 3, the surface appeared relatively flat. Furthermore, post-infestation of litchi leaves, the CA of droplets on the abaxial surface of diseased leaves exhibited an increase, while the SFE value on the abaxial surface of leaves decreased significantly, in contrast to the abaxial surface of healthy leaves. CONCLUSION: The infestation behavior of Aceria litchii changed the surface structure and chemistry of litchi leaves, which directly affected the CA value of foliar liquids and the SFE value of leaves, changing the surface wettability of litchi leaves from hydrophobic to superhydrophobic. This study provides useful information for improving the wetting and deposition behavior of liquid droplets on the surface of infested leaves. © 2024 Society of Chemical Industry.


Subject(s)
Litchi , Plant Leaves , Wettability , Surface Properties , Plant Diseases/parasitology
3.
PeerJ Comput Sci ; 9: e1478, 2023.
Article in English | MEDLINE | ID: mdl-37547407

ABSTRACT

Pre-trained language models such as Bidirectional Encoder Representations from Transformers (BERT) have been applied to a wide range of natural language processing (NLP) tasks and obtained significantly positive results. A growing body of research has investigated the reason why BERT is so efficient and what language knowledge BERT is able to learn. However, most of these works focused almost exclusively on English. Few studies have explored the language information, particularly syntactic information, that BERT has learned in Chinese, which is written as sequences of characters. In this study, we adopted some probing methods for identifying syntactic knowledge stored in the attention heads and hidden states of Chinese BERT. The results suggest that some individual heads and combination of heads do well in encoding corresponding and overall syntactic relations, respectively. The hidden representation of each layer also contained syntactic information to different degrees. We also analyzed the fine-tuned models of Chinese BERT for different tasks, covering all levels. Our results suggest that these fine-turned models reflect changes in conserving language structure. These findings help explain why Chinese BERT can show such large improvements across many language-processing tasks.

4.
PeerJ Comput Sci ; 8: e899, 2022.
Article in English | MEDLINE | ID: mdl-35494801

ABSTRACT

Pre-trained multilingual models have been extensively used in cross-lingual information processing tasks. Existing work focuses on improving the transferring performance of pre-trained multilingual models but ignores the linguistic properties that models preserve at encoding time-"language identity". We investigated the capability of state-of-the-art pre-trained multilingual models (mBERT, XLM, XLM-R) to preserve language identity through language typology. We explored model differences and variations in terms of languages, typological features, and internal hidden layers. We found the order of ability in preserving language identity of whole model and each of its hidden layers is: mBERT > XLM-R > XLM. Furthermore, all three models capture morphological, lexical, word order and syntactic features well, but perform poorly on nominal and verbal features. Finally, our results show that the ability of XLM-R and XLM remains stable across layers, but the ability of mBERT fluctuates severely. Our findings summarize the ability of each pre-trained multilingual model and its hidden layer to store language identity and typological features. It provides insights for later researchers in processing cross-lingual information.

5.
Eur J Med Chem ; 181: 111541, 2019 Nov 01.
Article in English | MEDLINE | ID: mdl-31382120

ABSTRACT

Based on the significantly synergistic effects of CDK4 and VEGFR2 inhibitors on growth of cancer cells, a series of novel multi-kinase inhibitors targeting CDK4 and VEGFR2 were designed, synthesized and evaluated, among which Roxyl-ZV-5J exhibited potent and balanced activities against both CDK4 and VEGFR2 with half-maximal inhibitory concentration at the nanomolar level. It effectively induced breast and cervical cancer cell cycle arrest and cell apoptosis. Roxyl-ZV-5J also inhibited the proliferation, tube formation and VEGFR2 downstream signaling pathways of HUVECs. Oral administration of Roxyl-ZV-5J led to significant tumor regression and anti-angiogenesis without obvious toxicity in SiHa xenograft mouse model. In addition, this compound showed good pharmacokinetics. This study confirmed a new tool for dual CDK-VEGFR2 pathways inhibition achieved with a single molecule, which provided valuable leads for further structural optimization and anti-angiogenesis and anti-tumor mechanism study.


Subject(s)
Aminopyridines/pharmacology , Antineoplastic Agents/pharmacology , Benzimidazoles/pharmacology , Cyclin-Dependent Kinase 4/antagonists & inhibitors , Neovascularization, Pathologic/drug therapy , Protein Kinase Inhibitors/pharmacology , Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors , Aminopyridines/chemical synthesis , Aminopyridines/chemistry , Anilides/chemical synthesis , Anilides/chemistry , Anilides/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Benzimidazoles/chemical synthesis , Benzimidazoles/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Cyclin-Dependent Kinase 4/metabolism , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Female , Human Umbilical Vein Endothelial Cells/drug effects , Humans , Mice , Mice, Inbred BALB C , Mice, Inbred NOD , Mice, SCID , Molecular Structure , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Neovascularization, Pathologic/metabolism , Neovascularization, Pathologic/pathology , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Pyridines/chemical synthesis , Pyridines/chemistry , Pyridines/pharmacology , Structure-Activity Relationship , Vascular Endothelial Growth Factor Receptor-2/metabolism
6.
Eur J Med Chem ; 181: 111535, 2019 Nov 01.
Article in English | MEDLINE | ID: mdl-31376566

ABSTRACT

A series of novel, highly potent, selective CDK9 inhibitors with cancer stem cells (CSCs) inhibition activity were designed and synthesized for non-small-cell lung cancer (NSCLC) therapy. Structure-activity relationship analysis based on enzymatic and cellular activities led to the discovery of a promising inhibitor 21e. 21e potently inhibited CDK9 with IC50 value of 11 nM and suppressed the stemness properties of NSCLC effectively. It could decrease the stemness phenotypes of NSCLC cells, including tumor sphere formation, side-population and stemness markers abundance. 21e displayed good selectivity over the CDK family kinases and kinase profiling assay against 381 kinases. In addition, 21e inhibited cell proliferation, colony-formation, and cell cycle progression and induced apoptosis in NSCLC. In H1299 xenograft mouse model, a once-daily dose of compound 21e at 20 mg/kg significantly suppressed the tumor growth without obvious toxicity. Studies of mechanisms of action indicated that 21e efficiently inhibited CDK9 signaling pathway and stemness both in vitro and in vivo. Collectively, 21e as a novel CDK9 inhibitor with CSCs inhibition properties could be a promising agent for the treatment of NSCLC.


Subject(s)
Antineoplastic Agents/pharmacology , Carcinoma, Non-Small-Cell Lung/drug therapy , Cyclin-Dependent Kinase 9/antagonists & inhibitors , Isothiocyanates/pharmacology , Lung Neoplasms/drug therapy , Protein Kinase Inhibitors/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Apoptosis/drug effects , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Proliferation/drug effects , Cyclin-Dependent Kinase 9/metabolism , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Isothiocyanates/chemical synthesis , Isothiocyanates/chemistry , Lung Neoplasms/metabolism , Molecular Structure , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Structure-Activity Relationship , Sulfoxides , Tumor Cells, Cultured
7.
Cell Death Differ ; 26(10): 1905-1917, 2019 10.
Article in English | MEDLINE | ID: mdl-30644437

ABSTRACT

The expression and activity of CCAAT/enhancer-binding protein α (C/EBPα) are involved in sumoylation modification, which is critical to divert normal cells from differentiation to proliferation. However, the role and underlying mechanism of C/EBPα in cancer is poorly understood. Human MORC2 (microrchidia family CW-type zinc-finger 2), is a member of the MORC proteins family containing a CW-type zinc-finger domain. Here, we found that MORC2 interacted with TE-III domain of C/EBPα, and the overexpression of MORC2 promoted wild-type C/EBPα sumoylation and its subsequent degradation, which didn't significantly observe in mutant C/EBPα-K161R. Furthermore, the overexpression of MORC2 inhibited C/EBPα-mediated C2C12 cell differentiation to maintain cell cycle progression. Moreover, the striking correlation between the decreased C/EBPα expression and the increased MORC2 expression was also observed in the poor differentiation status of gastric cancer tissues. Most notably, the high expression of MORC2 is correlated  with an aggressive phenotype of clinical gastric cancer and shorter overall survival of patients. Taken together, our findings demonstrated that MORC2 expression regulated C/EBPα-mediated the axis of differentiation/proliferation via sumoylation modification, and affected its protein stability, causing cell proliferation and tumorigenesis.


Subject(s)
CCAAT-Enhancer-Binding Protein-alpha/genetics , Sumoylation/genetics , Transcription Factors/genetics , Cell Differentiation , Humans
8.
J Cell Biochem ; 120(5): 8376-8384, 2019 May.
Article in English | MEDLINE | ID: mdl-30485502

ABSTRACT

BACKGROUND: It has been reported that microRNA-145 (miR-145) is downregulated in various cancers, including colorectal cancer (CRC). However, the role of miR-145 in progress of CRC and its mechanism remains unclear. METHODS: The expressions of miR-145 and tumor suppressor candidate 3 (TUSC3) were determined in CRC tissues and cells by real-time quantitative polymerase chain reaction and Western blot analysis. The effects of miR-145 and TUSC3 on cell viability, migration, and invasion of CRC cells were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-trtrazolium bromide assay and trans-well chamber experiment, respectively. The interaction between miR-145 and TUSC3 was explored by bioinformatics analysis, luciferase reporter assay, and Western blot analysis. The abundances of mitogen-activated protein kinase (MAPK) signaling pathway-related proteins were measured by Western blot analysis. RESULTS: miR-145 expression was downregulated in CRC tissues and cell lines, and TUSC3 was upregulated in CRC tissues and correlated inversely with miR-145 abundance. Overexpression of miR-145 and knockdown of TUSC3 suppressed cell viability, migration, and invasion in LS174T and HCT116 cells. Moreover, TUSC3 was indicated as a novel target of miR-145 and its expression was negatively regulated by miR-145. Restoration of TUSC3 can partially reverse the inhibitory effects of miR-145 on phosphorylation of extracellular signal-regulated kinases 1 and 2 in CRC cells. CONCLUSION: miR-145 can inhibit the viability, migration, and invasion through addressing MAPK signaling pathway by targeting TUSC3 in CRC cells, providing a novel biomarker for treatment of CRC.

9.
Theranostics ; 8(18): 4995-5011, 2018.
Article in English | MEDLINE | ID: mdl-30429882

ABSTRACT

Despite initial progress in preclinical models, most known histone deacetylase inhibitors (HDACis) used as a single agent have failed to show clinical benefits in nearly all types of solid tumours. Hence, the efficacy of HDACis in solid tumours remains uncertain. Herein, we developed a hybrid HDAC inhibitor that sensitized solid tumours to HDAC-targeted treatment. Methods: A hybrid molecule, Roxyl-zhc-84 was designed and synthesized with novel architecture. The pharmacokinetics and toxicity of Roxyl-zhc-84 were analysed. The antitumour effects of Roxyl-zhc-84 on solid tumours were investigated by assessing cell growth, apoptosis and cell cycle in vitro and in three in vivo mouse models and compared to those of corresponding control inhibitors alone or in combination. Gene set enrichment analysis was performed, and relevant JAK1-STAT3-BCL2 signalling was identified in vitro and in vivo in mechanistic studies. Results: Roxyl-zhc-84 showed excellent pharmacokinetics and low toxicity. The novel hybrid inhibitor Roxyl-zhc-84 induced cell apoptosis and G1-phase arrest in breast cancer and ovarian cancer cell lines. In three mouse models, oral administration of Roxyl-zhc-84 led to significant tumour regression without obvious toxicity. Moreover, Roxyl-zhc-84 dramatically improved the limited response of traditional HDAC inhibitors in solid tumours via overcoming JAK1-STAT3-BCL2-mediated drug resistance. Roxyl-zhc-84 treatment exhibited vastly superior efficacy than the combination of HDAC and JAK1 inhibitors both in vitro and in vivo. Conclusion: Concurrent inhibition of HDAC and CDK using Roxyl-zhc-84 with additional JAK1 targeting resolved the limited response of traditional HDAC inhibitors in solid tumours via overcoming JAK1-STAT3-BCL2-mediated drug resistance, providing a rational multi-target treatment to sensitize solid tumours to HDACi therapy.


Subject(s)
Antineoplastic Agents/administration & dosage , Breast Neoplasms/drug therapy , Histone Deacetylase Inhibitors/administration & dosage , Ovarian Neoplasms/drug therapy , Signal Transduction/drug effects , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/toxicity , Apoptosis/drug effects , Cell Cycle/drug effects , Cell Proliferation/drug effects , Disease Models, Animal , Female , Gene Expression Profiling , Janus Kinase 1/metabolism , Mice , Models, Theoretical , Proto-Oncogene Proteins c-bcl-2/metabolism , STAT3 Transcription Factor/metabolism , Treatment Outcome
10.
J Enzyme Inhib Med Chem ; 33(1): 1089-1094, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29932010

ABSTRACT

Indoleamine 2,3-dioxygenase 1 (IDO1) activity links to immune escape of cancers. Inhibition of IDO1 provides a new approach for cancer treatment. Most clinical IDO1 drugs show marginal efficacy as single agents. On basis of molecular docking and pharmacophore modelling, a novel inhibitor Roxyl-WL was discovered with a half maximal inhibitory concentration (IC50) value of 1 nM against IDO1 and 10-100-fold increased potent activity compared with IDO1 drugs in clinical trials. Roxyl-WL displayed excellent kinase spectrum selectivity with no activity out of the 337 protein kinases. In vitro, Roxyl-WL effectively augmented the proliferation of T cells and reduced the number of regulatory T cell (Tregs).When administered to melanoma (B16F10) tumor-bearing mice orally, Roxyl-WL significantly suppressed tumor growth and induced immune response.


Subject(s)
Enzyme Inhibitors/pharmacology , Indoleamine-Pyrrole 2,3,-Dioxygenase/antagonists & inhibitors , Melanoma/drug therapy , Animals , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/immunology , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemistry , Female , Indoleamine-Pyrrole 2,3,-Dioxygenase/immunology , Indoleamine-Pyrrole 2,3,-Dioxygenase/metabolism , Melanoma/immunology , Melanoma/metabolism , Mice , Mice, Inbred C57BL , Molecular Docking Simulation , Molecular Structure , Structure-Activity Relationship
11.
J Med Chem ; 61(7): 3166-3192, 2018 04 12.
Article in English | MEDLINE | ID: mdl-29518312

ABSTRACT

A series of novel, highly potent, selective inhibitors targeting both CDK4/9 and HDAC1 have been designed and synthesized. N1-(4-((7-Cyclopentyl-6-(dimethylcarbamoyl)-7 H-pyrrolo[2,3- d] pyrimidin-2-yl)amino)phenyl)- N8-hydroxyoctanediamide (6e) was discovered. The lead compound 6e with excellent CDK4/9 and HDAC1 inhibitory activity of IC50 = 8.8, 12, and 2.2 nM, respectively, can effectively induce apoptosis of cancer cell lines. The kinase profiling of compound 6e showed excellent selectivity and specificity. Compound 6e induces G2/M arrest in high concentration and G0/G1 arrest in low concentration to prevent the proliferation and differentiation of cancer cells. Mice bared-breast cancer treated with 6e showed significant antitumor efficacy. The insight into mechanisms of 6e indicated that it could induce cancer cell death via cell apoptosis based on CDK4/9 and HDAC1 repression and phosphorylation of p53. Our data demonstrated the novel compound 6e could be a promising drug candidate for cancer therapy.


Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , Cyclin-Dependent Kinase 4/antagonists & inhibitors , Cyclin-Dependent Kinase 9/antagonists & inhibitors , Histone Deacetylase 1/antagonists & inhibitors , Histone Deacetylase Inhibitors/chemical synthesis , Histone Deacetylase Inhibitors/pharmacology , Animals , Antineoplastic Agents/pharmacokinetics , Apoptosis/drug effects , Cell Cycle Checkpoints/drug effects , Cell Differentiation/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Female , Histone Deacetylase Inhibitors/pharmacokinetics , Humans , Male , Mice , Mice, Inbred BALB C , Models, Molecular , Phosphorylation/drug effects , Structure-Activity Relationship , Substrate Specificity , Tumor Suppressor Protein p53/metabolism
12.
J Med Chem ; 61(3): 881-904, 2018 02 08.
Article in English | MEDLINE | ID: mdl-29308895

ABSTRACT

On the basis of novel pyrazino[2,3-c]quinolin-2(1H)-one scaffold, we designed and identified a highly selective, potent and oral mTOR inhibitor, 9m. Compound 9m showed low nanomolar activity against mTOR (IC50 = 7 nM) and greater selectivity over the related PIKK family kinases, which demonstrated only modest activity against 3 out of the 409 protein kinases. In vitro assays, compound 9m exhibited high potency against human breast and cervical cancer cells and induced tumor cell cycle arrest and autophagy. 9m inhibited cellular phosphorylation of mTORC1 (pS6 and p4E-BP1) and mTORC2 (pAKT (S473)) substrates. In T-47D xenograft mouse model, oral administration of compound 9m led to significant tumor regression without obvious toxicity. In addition, this compound showed good pharmacokinetics. Collectively, due to its high potency and selectivity, compound 9m could be used as a mTOR drug candidate.


Subject(s)
Antineoplastic Agents/administration & dosage , Antineoplastic Agents/pharmacology , Autophagy/drug effects , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/pharmacology , TOR Serine-Threonine Kinases/antagonists & inhibitors , Administration, Oral , Cell Line, Tumor , Humans , Models, Molecular , Phosphorylation/drug effects , Protein Domains , TOR Serine-Threonine Kinases/chemistry
13.
J Tradit Chin Med ; 36(6): 784-8, 2016 12.
Article in English | MEDLINE | ID: mdl-29949712

ABSTRACT

OBJECTIVE: To investigate the effect and underlying mechanisms of combined medicated thread moxibustion therapy plus needle picking therapy of Zhuang nationality medicine on antioxidant levels in a rat model of sciatica. METHODS: One hundred Wistar rats, of specific pathogen free level, were randomly divided into five groups: normal control group, model group, medicated thread moxibustion group, needle picking group, and combination group. Each group contained 20 rats. In the model, medicated thread moxibustion, needle picking, and combination groups, sciatica models were established through chronic constriction injury of the sciatic nerve. After the model was established, the rats in the medicated thread moxibustion, needle picking, and combination groups were given the corresponding therapies for 21 days. The control and model groups received no treatment. Reactive oxygen species, superoxide dismutase, malondialdehyde, and total antioxidant capacity changes were determined. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit NADPH oxidases 4 (NOX4) mRNA expression and the morphology of cells were observed to detect apoptosis of gamma- aminobutyric acid ergic (GABAergic) neurons. RESULTS: Compared with control group, reactive oxygen species and malondialdehyde levels rose significantly in the model group (P < 0.01), while superoxide dismutase and total antioxidant capacity levels were lowered (P < 0.05). Compared with the model group, reactive oxygen species and malondialdehyde decreased in the needle picking group (P < 0.05), while superoxide dismutase levels were increased (P < 0.05); reactive oxygen species and malondialdehyde significantly decreased in the combination group (P < 0.01). In addition, the model group had higher NOX4 mRNA expression than that of the control group (P < 0.05), and the combination group had lower expression levels than that of the model group (P < 0.05). Apoptosis of GABAergic neurons was observed in the model group, and was attenuated after combined therapy. CONCLUSION: The medicated thread moxibustion therapy plus needle picking therapy of Zhuang nationality medicine can prevent oxidative damage in the rat model of sciatica via down-regulating NOX4 expression, improving antioxidant capacity, and inhibiting the oxidative damage pathway of GABAergic neurons.


Subject(s)
Acupuncture Therapy , Moxibustion , Sciatica/therapy , Acupuncture Points , Animals , Antioxidants/metabolism , Combined Modality Therapy , Disease Models, Animal , Female , Humans , Male , Malondialdehyde/metabolism , NADPH Oxidase 4/genetics , NADPH Oxidase 4/metabolism , Oxidative Stress , Rats , Rats, Wistar , Sciatica/genetics , Sciatica/metabolism , Superoxide Dismutase/genetics , Superoxide Dismutase/metabolism
14.
Dalton Trans ; 44(35): 15523-30, 2015 Sep 21.
Article in English | MEDLINE | ID: mdl-26238501

ABSTRACT

Three meso-2'-linked porphyrin-BODIPY hybrids which contain one, two, and four BODIPY units (, , and ), respectively, were synthesized. Their photophysical properties were investigated by UV-vis and fluorescence spectroscopy, cyclic voltammetry, and femtosecond transient absorption spectroscopy, as well as by theoretical calculations. The electronic properties of the constituent chromophores were found to be largely retained in these hybrids. Meanwhile, efficient and rapid energy transfers from (1)* to were evaluated to be 1.2 × 10(11), 1.5 × 10(11), and 1.1 × 10(11) s(-1), respectively.

15.
Opt Express ; 23(10): 12935-41, 2015 May 18.
Article in English | MEDLINE | ID: mdl-26074546

ABSTRACT

We propose and demonstrate a novel method to improve the long-term stability of the wideband tunable optoelectronic oscillator (OEO) where a dynamic compensation scheme is achieved to offset the parameter variation of the fiber. In our method, a 900 MHz calibration signal transmits in the fiber link of the OEO's feedback loop for establishing a servo system which can extract the time delay of the feedback loop. The time delay varies with the external environment because refractive index and length of the fiber fluctuate with ambient temperature variations. Taking the extracted information as the reference, the wavelength of the tunable laser used in the OEO can be controlled precisely and continually to offset the random delay fluctuation in the fiber. Consequently, the long-term stability of the microwave signal generated by the OEO can be optimized. The experiment results show that Allan deviation achieved in 1000-s averaging time is improved more than two orders of magnitude when the tunable OEO worked at 2.4 GHz.

16.
Opt Express ; 23(8): 9772-6, 2015 Apr 20.
Article in English | MEDLINE | ID: mdl-25969016

ABSTRACT

A polarization multiplexing technique based on phase-shift-induced polarization modulation-to-intensity modulation (PloM-to-IM) convertor and a Mach-Zehnder modulator (MZM) is proposed to generate multi-band signals. Successful transmission of the traditional radio frequency, microwave (MW) and millimeter wave (MMW) signals is simultaneously achieved. Meanwhile, the intensity-constant optical carrier (OC) is reused for upstream 25-km transmission.

17.
ACS Appl Mater Interfaces ; 7(17): 9015-22, 2015 May 06.
Article in English | MEDLINE | ID: mdl-25874363

ABSTRACT

A novel class of metal-free organic dyes based on benzo[a]carbazole have been designed, synthesized, and used in dye-sensitized solar cells for the first time. These types of dyes consisted of a cyanoacrylic acid moiety as the electron acceptor/anchoring group and different electron-rich spacers such as thiophene (JY21), furan (JY22), and oligothiophene (JY23) as the π-linkers. The photophysical, electrochemical, and photovoltaic properties, as well as theoretical calculations of these dyes were investigated. The photovoltaic performances of these dyes were found to be highly relevant to the π-conjugated linkers. In particular, dye JY23 exhibited a broad IPCE response with a photocurrent signal up to about 740 nm covering the most region of the UV-visible light. A DSSC based on JY23 showed the best photovoltaic performance with a Jsc of 14.8 mA cm(-2), a Voc of 744 mV, and a FF of 0.68, achieving a power conversion efficiency of 7.54% under standard AM 1.5 G irradiation.

18.
Zhen Ci Yan Jiu ; 40(1): 20-4, 2015 Feb.
Article in Chinese | MEDLINE | ID: mdl-25845215

ABSTRACT

OBJECTIVE: To observe the effect of Zhuang-medical thread moxibustion combined with needle-pricking on vascular oxidative stress injury in oxidative stress injury rats. METHODS: Eighty Wistar rats were randomly allocated to normal control, sham operation (sham), model, and combined treatment groups (n=20 in each group). The oxidative stress injury model was established by ligation of the left sciatic nerve to induce chronic constriction injury (CCI) pain stress stimulation. Zhuang-medical thread moxibustion was applied to bilateral "Zusanli" (ST 36), once a day for 3 weeks. Needle-pricking was applied to left "Yanglingquan" (GB 34) and left "Huantiao" (GB 30), once a day for 3 weeks except Sundays. Plasma 6-keto-PGF 1α, thromboxane B 2 (TXB 2), NO and ET contents were assayed by radioimmunoassay. COX-2 immunoactivity of the femoral artery was determined by immunohistochemistry, and pathological changes of the femoral artery were detected by H. E. staining. RESULTS: Compared with the control group, the levels of plasma 6-keto-PGF 1α and NO in the model group were significantly reduced (P<0.05), while those of plasma TXB 2 and ET and COX-2 expression in the femoral artery were obviously increased in the model group (P<0.01). After moxibustion plus needle-pricking treatment, CCI-induced decrease of plasma 6-keto-PGF 1α and NO contents, and increase of plasma TXB 2 and ET and COX-2 expression levels were obviously reversed (P<0.05, P<0.01). The tubal wall of the femoral artery in rats of the model group got thicker, while that of the combined treatment group was relatively thinner, suggesting an inhibition of vascular intimal hyperplasia after the treatment. CONCLUSION: Zhuang-medical thread moxibustion combined with needle-pricking of ST 36, GB 34 and GB 30 can reduce the expression of femoral artery COX-2 and regulate the balance of both plasma PGI 2/TXA 2 and plasma NO/ET in CCI-induced oxidative stress rats, which may contribute to its effect in suppressing oxidative stress-induced vascular intimal hyperplasia.


Subject(s)
Acupuncture Therapy , Blood Vessels/injuries , Moxibustion , Oxidative Stress , Vascular Diseases/therapy , Acupuncture Points , Animals , Blood Vessels/enzymology , Blood Vessels/metabolism , Combined Modality Therapy , Cyclooxygenase 2/metabolism , Female , Humans , Male , Rats , Rats, Wistar , Thromboxane B2/blood , Vascular Diseases/enzymology , Vascular Diseases/metabolism
19.
Chem Commun (Camb) ; 51(18): 3782-5, 2015 Mar 04.
Article in English | MEDLINE | ID: mdl-25647634

ABSTRACT

A novel double D-π-A branched dye () was synthesized and applied as a sensitizer for DSSCs. exhibited broader and stronger light absorption capability than the single D-π-A dye (). In the meantime, the orthogonal conformation of was found to be favorable for impeding intermolecular aggregation. Consequently, a power conversion efficiency of 5.33% was achieved under AM 1.5G conditions.

20.
Org Biomol Chem ; 13(9): 2566-9, 2015 Mar 07.
Article in English | MEDLINE | ID: mdl-25614288

ABSTRACT

An efficient and general Fe(OTf)3-mediated oxidative coupling method was developed for the synthesis of doubly or triply linked porphyrin dimers. Besides the central metal and peripheral substituent, regioselectivity of the oxidative coupling was found to be closely relevant to the onset oxidation potential of the porphyrin substrate, and the reactant with higher E(onset(ox)) tends to generate meso-ß doubly fused porphyrin dimer.

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