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1.
J Am Chem Soc ; 146(17): 11657-11668, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38641862

RESUMO

All protein-directed syntheses of metal nanoclusters (NCs) and nanoparticles (NPs) have attracted considerable attention because protein scaffolds provide a unique metal coordination environment and can adjust the shape and morphology of NCs and NPs. However, the detailed formation mechanisms of NCs or NPs directed by protein templates remain unclear. In this study, by taking advantage of the ferritin nanocage as a biotemplate to monitor the growth of Fe-O NCs as a function of time, we synthesized a series of iron NCs with different sizes and shapes and subsequently solved their corresponding three-dimensional atomic-scale structures by X-ray protein crystallography and cryo-electron microscopy. The time-dependent structure analyses revealed the growth process of these Fe-O NCs with the 4-fold channel of ferritin as nucleation sites. To our knowledge, the newly biosynthesized Fe35O23Glu12 represents the largest Fe-O NCs with a definite atomic structure. This study contributes to our understanding of the formation mechanism of iron NCs and provides an effective method for metal NC synthesis.


Assuntos
Ferritinas , Tamanho da Partícula , Ferritinas/química , Nanopartículas Metálicas/química , Ferro/química , Modelos Moleculares , Cristalografia por Raios X , Compostos Férricos/química
2.
Arch Insect Biochem Physiol ; 115(4): e22114, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38659314

RESUMO

The insect cuticle plays a key role in maintaining the insect's physiological function and behavior. Herein, the yellow-y protein is required to produce black melanin, and is expressed in a pattern that correlates with the distribution of this pigment. However, yellow-y can also have other functions, for instance, in insect behavior, but not much is known. In this study, we have studied the yellow-y gene in one important model and pest species, namely the German cockroach (Blattella germanica), which is to our knowledge the first time reported. In essence, we identified the yellow-y gene (BgY-y) and characterized its function by using RNA interference (RNAi). Silencing of BgY-y gene led to different developmental abnormalities (body weight and wings) in both genders. Specifically, there was an abundant decrease in melanin, turning the body color in pale yellow and the cuticle softer and more transparent. Interestingly, we also observed that the knockdown of BgY-y impaired the male cockroaches to display a weaker response to female-emitted contact sex pheromones, and also that the oviposition ability was weakened in the RNAi females. This study comprehensively analyzed the biological functions of the yellow-y gene in German cockroaches from the perspectives of development, body color, courtship behavior and oviposition, and as a consequence, this may opens new avenues to explore it as a novel pest control gene.


Assuntos
Blattellidae , Proteínas de Insetos , Oviposição , Pigmentação , Interferência de RNA , Animais , Blattellidae/genética , Blattellidae/fisiologia , Feminino , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Masculino , Pigmentação/genética , Corte , Melaninas/metabolismo , Comportamento Sexual Animal
3.
Bull Entomol Res ; 114(2): 271-280, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38623047

RESUMO

Genes involved in melanin production directly impact insect pigmentation and can affect diverse physiology and behaviours. The role these genes have on sex behaviour, however, is unclear. In the present study, the crucial melanin pigment gene black was functionally characterised in an urban pest, the German cockroach, Blattella germanica. RNAi knockdown of B. germanica black (Bgblack) had no effect on survival, but did result in black pigmentation of the thoraxes, abdomens, heads, wings, legs, antennae, and cerci due to cuticular accumulation of melanin. Sex-specific variation in the pigmentation pattern was apparent, with females exhibiting darker coloration on the abdomen and thorax than males. Bgblack knockdown also resulted in wing deformation and negatively impacted the contact sex pheromone-based courtship behaviour of males. This study provides evidence for black function in multiple aspects of B. germanica biology and opens new avenues of exploration for novel pest control strategies.


Assuntos
Blattellidae , Melaninas , Pigmentação , Animais , Blattellidae/genética , Blattellidae/fisiologia , Masculino , Feminino , Pigmentação/genética , Melaninas/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Comportamento Sexual Animal , Interferência de RNA
4.
J Cell Mol Med ; 28(5): e18042, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37987033

RESUMO

Hepatocellular carcinoma (HCC), the main pathological type of liver cancer, is linked to risk factors such as viral hepatitis, alcohol intake and non-alcoholic fatty liver disease (NAFLD). Recent advances have greatly improved our understanding that NAFLD is playing a major risk factor for HCC. Peroxisome proliferator-activated receptors (PPARs) are a class of transcription factors divided into three subtypes: PPARα (PPARA), PPARδ/ß (PPARD) and PPARγ (PPARG). As important nuclear receptors, PPARs are involved in many physiological processes, and PPARs can improve NAFLD by regulating lipid metabolism, accelerating fatty acid oxidation and inhibiting inflammation. In recent years, some studies have shown that PPARs can participate in the occurrence and development of HCC by regulating metabolic pathways. In addition, PPAR modulators have been reported to inhibit the proliferation and metastasis of HCC cells and can enhance the curative effect of conventional treatments. This article reviews the role of PPARs in the occurrence and development of HCC, as well as its value in the diagnosis, treatment and prognosis of HCC, in order to provide directions for future research.

5.
J Fluoresc ; 2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38157082

RESUMO

In this work, bright yellow fluorescent and multifunctional carbon dots (N-CDs) were prepared by hydrothermal method from O-phenylenediamine and 4-aminobenzoic acid. The fluorescence characterization showed that the N-CDs possessed good optical properties (QY = 32%) and excitation dependent multi-color emission. By exciting with 390 nm, the strong selective interaction of VB12 with N-CDs could result in a sharp decrease in the luminescence of N-CDs at 567 nm. An efficient fluorescence sensor in aqueous solution was constructed which could linearly respond VB12 in wide concentration ranges of 0-90 µM and 140-250 µM. The linear correlation coefficients of N-CDs and VB12 were 0.9950 and 0.9968, respectively, and the detection limit was 0.119 µM. N-CDs were performed for sensitive determination of VB12 in real samples. Moreover, the N-CDs were exploited to image cell. This N-CDs was a sensitive fluorescence probe to monitor VB12 and presented prospective potential in living cells imaging. Schematic diagram of the synthesis process and application research of N-CDs.

6.
Int J Mol Sci ; 24(20)2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37895000

RESUMO

Gastric cancer presents substantial management challenges, and the advent of immunotherapy has ignited renewed hope among patients. Nevertheless, a significant proportion of patients do not respond to immunotherapy, and adverse events associated with immunotherapy also occur on occasion, underscoring the imperative to identify suitable candidates for treatment. Several biomarkers, including programmed death ligand-1 expression, tumor mutation burden, mismatch repair status, Epstein-Barr Virus infection, circulating tumor DNA, and tumor-infiltrating lymphocytes, have demonstrated potential in predicting the effectiveness of immunotherapy in gastric cancer. However, the quest for the optimal predictive biomarker for gastric cancer immunotherapy remains challenging, as each biomarker carries its own limitations. Recently, multi-omics technologies have emerged as promising platforms for discovering novel biomarkers that may help in selecting gastric cancer patients likely to respond to immunotherapy. The identification of reliable predictive biomarkers for immunotherapy in gastric cancer holds the promise of enhancing patient selection and improving treatment outcomes. In this review, we aim to provide an overview of clinically established biomarkers of immunotherapy in gastric cancer. Additionally, we introduce newly reported biomarkers based on multi-omics studies in the context of gastric cancer immunotherapy, thereby contributing to the ongoing efforts to refine patient stratification and treatment strategies.


Assuntos
Infecções por Vírus Epstein-Barr , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/terapia , Neoplasias Gástricas/patologia , Herpesvirus Humano 4/metabolismo , Imunoterapia , Biomarcadores Tumorais , Antígeno B7-H1/metabolismo
7.
Zhongguo Zhong Yao Za Zhi ; 48(22): 6030-6038, 2023 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-38114209

RESUMO

This study aimed to explore the correlation between rhizosphere soil microorganisms of wild Arnebia euchroma and the content of medicinal components to provide guidance for the selection of the ecological planting base. The total DNA of rhizosphere soil microorganisms of wild A. euchroma was extracted, and the microbial community structure of rhizosphere soil microorganisms was analyzed by IlluminaMiseq high-throughput sequencing technology. The content of total hydroxynaphthoquinone pigment and ß,ß'-dimethylacrylalkannin in medicinal materials was determined by high-performance liquid chromatography(HPLC). The physicochemical pro-perties of rhizosphere soil of wild A. euchroma in main producing areas were determined, and the correlation of soil microbial abundance with index component content and soil physicochemical properties was analyzed by SPSS software. The results showed that the species composition of rhizosphere fungi and bacteria in A. euchroma from different habitats was similar at the phylum and genus levels, but their relative abundance, richness index(Chao1), and community diversity(Simpson) index were different. Correlation analysis showed that the content of available phosphorus in soil was positively correlated with the content of total hydroxynaphthoquinone pigment and ß,ß'-dimethylacrylalkannin, and the abundance of five fungal genera such as Solicoccozyma and six bacterial genera such as Pseudo-nocardia and Bradyrhizobium was positively correlated with the content of medicinal components in medicinal materials. The abundance of Bradyrhizobium was significantly positively correlated with the content of ß,ß'-dimethylacrylalkanin. The abundance of fungi such as Archaeorhizomyces was significantly positively correlated with the content of available phosphorus in rhizosphere soil, and Bradyrhizobium was significantly negatively correlated with soil pH. Therefore, the abundance of fungi and bacteria in the rhizosphere of A. euchroma has a certain correlation with the medicinal components and the physicochemical properties of the rhizosphere soil, which can provide a scientific basis for the selection of ecological planting bases in the later stage.


Assuntos
Boraginaceae , Rizosfera , Microbiologia do Solo , Bactérias/genética , Fósforo , Solo
8.
Planta Med ; 88(6): 420-428, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34015832

RESUMO

Four undescribed sulfoxide-containing derivatives, sinkiangenoxides A and B, (2Z, 4E)-sinkiangenoxide C, and (2E, 4E)-sinkiangenoxide C (1:  - 4: ), and one known compound, 1-(methylthio)propyl (E)-1-propenyl disulfide (5: ), were isolated from the resin of Ferula sinkiangensis. Their structures were determined based on spectroscopic methods, including IR, UV, HRESIMS, NMR, and CD analysis. Compounds 2:  - 4: showed moderate cytotoxic activities against four human cancer cell lines with IC50 values ranging from 15.0 to 40.3 µM. Sinkiangenoxide B (2: ) was shown to induce apoptosis in HepG2 cells. In addition, compound 5: effectively attenuated lipopolysaccharide-induced nitric oxide release and TNF-α, IL-1ß, IL-6, and IL-10 expression.


Assuntos
Ferula , Linhagem Celular , Ferula/química , Estrutura Molecular , Resinas Vegetais , Sulfóxidos
9.
Bull Environ Contam Toxicol ; 109(1): 30-43, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35678830

RESUMO

Red mud/biochar composite material (RMBC), which was applied as heavy metal passivator in this research, was prepared with red mud (the bauxite residue) and cornstalk under anoxic sintering condition. Based on the batch experiments in Pb contaminated soil, the passivating properties of several materials, including red mud (RM), biochar (BC), RMBC and phosphate-containing RMBC (PRMBC), were investigated in comparison with each other. Some interesting results are as follows: through anoxic thermal activation, a rough and porous structure of RMBC was obtained. Substances such as Fe3O4 and metal-organic complexes generated in RMBC provided effective sites for Pb passivation; and the mechanisms were speculated as the precipitation between Pb2+ and the carbonate (or hydroxide), as well as the complexation reaction between Pb and metal organic complexes through ligand bonding. The pot experiments showed the promotion effects of four passivators on the growth of red onion were in the following order: PRMBC > RMBC > BC > RM. PRMBC stabilized Pb content in soil significantly due to the formation of insoluble substances, with the minimum transfer factor and bioconcentration factor for plant growth. The evidences above implied the composite materials (PRMBC and RMBC) would be potential passivators for heavy metal-contaminated soil.


Assuntos
Metais Pesados , Poluentes do Solo , Carvão Vegetal/química , Chumbo , Metais Pesados/análise , Solo/química , Poluentes do Solo/análise
10.
Bull Environ Contam Toxicol ; 109(1): 169-179, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35732838

RESUMO

In this study, a new red mud/fly ash composite material (RFCM) for phosphate removal was prepared by granulation and activation methods, using bauxite residue (red mud, RM) as the main raw material, adding with some fly ash and a few adhesives. The effects of different types of RM and adhesives on RFCM for phosphate removal were discussed. It was found that RFCM prepared from sintering red mud and cement waste performed better on phosphate removal than that prepared from Bayer red mud and common industrial adhesives. After calcination activated at appropriate temperature around 800-900℃, the specific surface area of RFCM increased, and new substances with hydroxyl (-OH) appeared on the surface of RFCM, which were the functional groups for phosphate removal. Mechanism of RFCM for phosphate removal was speculated as a combination of physical adsorption, chemical adsorption and chemical precipitation, which mainly depended on ligand exchange and chemical reaction. This research will provide a potential application of bauxite residue in environmental remediation.


Assuntos
Cinza de Carvão , Fosfatos , Adsorção , Óxido de Alumínio , Resíduos Industriais/análise , Fosfatos/química
11.
J Cell Mol Med ; 24(7): 4223-4232, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32105413

RESUMO

Seizure-related 6 homolog (mouse)-like 2 (SEZ6L2) was shown to be involved in transcription of a type 1 transmembrane protein for regulating cell fate. Until now, the expression and function of SEZ6L2 in various cancers, including colorectal cancer (CRC), were unclear. In the present study, we determined the expression of SEZ6L2 in a tissue microarray from patients with CRC and then, analysed the correlation between SEZ6L2 expression and the prognosis of the patients. Furthermore, the potential function of SEZ6L2 in CRC was determined using cell counting kit, colony formation assay and xenograft model in vitro and in vivo. Flow cytometry, Western blotting, immunohistochemical staining and a blocking experiment were employed to investigate the underlying mechanism of SEZ6L2 regulating CRC growth. Our results indicated that SEZ6L2 was significantly up-regulated in tumour tissues of patients with CRC compared with adjacent normal tissues. Up-regulation of SEZ6L2 was correlated with a poor prognosis in patients with CRC. In vitro experiments suggested that the knockdown of SEZ6L2 inhibits CRC cell growth and colony formation, but it has no significant impact on the invasion. The antitumour effects of shSEZ6L2 were also confirmed by a xenograft model. Investigations of the mechanisms indicated that the knockdown of SEZ6L2 impairs the growth of the CRC cells by inducing caspase-dependent apoptosis, which was mediated by mitochondria-related proteins. Furthermore, SEZ6L2 expression was inversely correlated with the expression of cytochrome C in malignant tissues in patients with CRC. Collectively, the present study indicates that SEZ6L2 is a potential prognosis biomarker and therapy target for CRC.


Assuntos
Biomarcadores Tumorais/genética , Proliferação de Células/genética , Neoplasias Colorretais/genética , Proteínas de Membrana/genética , Animais , Apoptose/genética , Caspases/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Neoplasias Colorretais/patologia , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Xenoenxertos , Humanos , Masculino , Camundongos , Mitocôndrias/genética , Mitocôndrias/patologia , Análise Serial de Tecidos
12.
Opt Express ; 27(17): 23751-23762, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31510275

RESUMO

In this paper, the physical layer security (PLS) of fractional orbital angular momentum (OAM) multiplexing under atmospheric turbulence channels is studied. Based on the PLS theory, the secrecy capacities and the probabilities of positive secrecy capacities of fractional OAM (FrOAM) multiplexing systems with different topological charge intervals are analyzed. The influence of the eavesdropping ratio and the power allocation on secrecy capacities are compared. The simulation results show that, under the finite aperture limitation, the FrOAM multiplexing technique provides higher security over the integer OAM multiplexing in terms of the total secrecy capacities under weak and medium turbulence.

13.
BMC Psychiatry ; 19(1): 403, 2019 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-31842818

RESUMO

BACKGROUND: Accumulating evidence suggests that serum vascular endothelial growth factor (VEGF) in many neurobiological processes potentially contributes to the pathophysiology of psychiatric disorders, particularly cognitive decline. The purpose of this study was to explore the differences in neurocognition, social cognition and VEGF among remitted first-episode schizophrenic patients, non-remitters and normal control subjects. Moreover, we investigated the association between serum VEGF levels and cognitive functions. METHOD: 65 remission (RS) and 45 nonremission patients (NRS) after first-episode schizophrenia, as well as 58 healthy controls (HC) were enrolled in this study. Social cognition was assessed using the Chinese Facial Emotion Test (CFET); neurocognition was measured with a test battery consisting of Hopkins Verbal Learning Test-Revised, Verbal Fluency Test, Trail Making Tests, Digit Span Tests (DST) and Stroop Tests. Blood samples were collected for VEGF measurements. Data was analyzed with SPSS 22.0 (Chicago, IL, USA). RESULTS: On nearly all neurocognitive tests (except for DST), RS performed significantly worse than HC but better than NRS (P < 0.05). NRS, but not RS, exhibited markedly poorer social cognition than HC (except for Happiness and Surprise subscales of the CFET) (P < 0.05). VEGF levels showed a gradient change among three groups (HC > RS > NRS). CONCLUSION: Compared to HC, RS demonstrated poorer neurocognitive but intact social cognition functioning. These results indicate that VEGF levels decreased gradually with the severity of cognitive impairment in schizophrenia. VEGF may be involved in the pathological mechanism of cognitive performance in RS.


Assuntos
Cognição/fisiologia , Esquizofrenia/sangue , Psicologia do Esquizofrênico , Comportamento Social , Percepção Social , Fator A de Crescimento do Endotélio Vascular/sangue , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Adulto Jovem
14.
Gastric Cancer ; 19(1): 245-54, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25609451

RESUMO

BACKGROUND: To evaluate the safety and efficacy of a concurrent three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) plus oxaliplatin, 5-fluorouracil and leucovorin (FOLFOX) regimen in completely resected gastric cancer patients with D2 lymph node dissection. MATERIALS AND METHODS: Patients with stage IB-IIIC gastric cancer (per the AJCC, 7th edition) who had undergone R0 and D2 gastrectomy were recruited. Two cycles of FOLFOX with concurrent 3D-CRT or IMRT (50.4 Gy/28f) were administered. One and an additional five cycles of FOLFOX were delivered before and after concurrent chemoradiotherapy, respectively. Primary endpoints were relapse-free survival (RFS) and overall survival (OS), with adverse events as secondary endpoints. RESULTS: From 2008 to 2011, 110 patients were evaluable. The 1-, 2- and 3-year RFS and OS were 86.2, 72.2, 67.8 and 94.7, 87.2, 77.6%, respectively. On multivariate analysis, stage (≤ IIIA vs. >IIIA) was a statistically significant factor affecting both RFS and OS. Additionally, the T-category (≤ T4a vs. = T4b) was a statistically significant factor affecting only the RFS. The most commonly observed grade 3 or 4 adverse events were nausea and vomiting, decreased appetite, leukopenia/neutropenia and fatigue, each of which occurred in 14.5, 11.8, 9.1 and 6.4% patients, respectively. CONCLUSIONS: Adjuvant 3D-CRT/IMRT to a dose of 50.4 Gy/28f with concurrent FOLFOX is safe and effective in patients following radical gastrectomy with D2 lymph node dissection.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Radioterapia Conformacional/métodos , Neoplasias Gástricas/terapia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Quimiorradioterapia/métodos , Quimiorradioterapia Adjuvante/métodos , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/uso terapêutico , Gastrectomia/métodos , Humanos , Leucovorina/administração & dosagem , Leucovorina/uso terapêutico , Excisão de Linfonodo , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/uso terapêutico , Oxaliplatina , Radioterapia de Intensidade Modulada , Neoplasias Gástricas/patologia , Taxa de Sobrevida , Resultado do Tratamento , Adulto Jovem
15.
BMC Cancer ; 15: 257, 2015 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-25879580

RESUMO

BACKGROUND: To assess the safety and efficacy of simultaneous integrated boost (SIB) or late course accelerated boost (LCAB) with external beam radiotherapy (EBRT) to the vaginal cuff for high risk cervical cancer patients after radical hysterectomy. METHODS: Between October 2009 and January 2012, patients with high risk cervical cancer who had undergone radical surgery followed by EBRT to the vaginal cuff were enrolled. Patients were treated with either intensity modulated radiotherapy (IMRT)/volumetric modulated arc therapy (VMAT) with SIB (arm A) or IMRT/VMAT to the pelvis followed by LCAB (arm B) to vaginal cuff. In arm A, the pelvic and boost doses were 50.4 Gy and 60.2 Gy in 28 fractions, respectively. In arm B, pelvic irradiation to 50 Gy in 25 fractions followed by a boost of 9 Gy in 3 fractions were delivered. Chemotherapy was given concurrently. RESULTS: Overall, 80 patients were analyzed in this study (42 in arm A, 38 in arm B). In arm A and B, median follow-up was 37 and 32 months, respectively. The 3-year disease-free survival and overall survival in arms A vs B were 88.7% vs. 93.4% (p = 0.89), and 91.8% vs.100% (p = 0.21), respectively. The 3-year local-regional control and distant failure were 97.6% vs. 100% (p = 0.34), and 4.8% vs. 5.3% (p = 0.92), respectively. Grade 3-4 acute leukopenia and dermatitis were seen in 11 (26.2%) and 8 (19.0%) patients in Arm A, vs. 7 (17.8%) and 6 (15.8%) patients in Arm B, respectively (p > 0.05). Only Grade 1-2 chronic gastrointestinal (GI) and genitourinary (GU) toxicities were observed. CONCLUSIONS: Our results indicate that both SIB and LCAB to vaginal cuff for high risk cervical cancer patients after radical hysterectomy are associated with excellent survival, local control and low toxicity.


Assuntos
Terapia com Prótons/efeitos adversos , Radioterapia de Intensidade Modulada/efeitos adversos , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/radioterapia , Adulto , Idoso , Quimiorradioterapia Adjuvante/efeitos adversos , Intervalo Livre de Doença , Fracionamento da Dose de Radiação , Feminino , Seguimentos , Humanos , Histerectomia Vaginal , Pessoa de Meia-Idade , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/cirurgia
16.
Inorg Chem ; 54(15): 7415-23, 2015 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-26196681

RESUMO

Four Preyssler P5W30 based inorganic-organic hybrids, formulated as {[Cu12(pbtz)2(Hpbtz)2(OH)4(H2O)16][Na(H2O)P5W30O110]}·16H2O (1; H2pbtz = 5'-(pyridin-2-yl)-1H,2'H-3,3'-bi(1,2,4-triazole)), {[Cu10(ttbz)2(Httbz)4(OH)6(H2O)8][K(H2O)H2P5W30O110]}·30H2O (2; Httbz = 1-(tetrazo-5-yl)-4-(triazo-1-yl)benzene), {[Ni6(bpz)6(H2O)16][Na(H2O)H2P5W30O110]}·36H2O (3; bpz = 3,3',5,5'-tetramethyl-4,4-bipyrazole), {[Co4(bpz)6(H2O)9][K(H2O)H6P5W30O110]}·46H2O (4), have been isolated and structurally identified via microanalysis, thermogravimetry (TG), infrared (IR) spectroscopy, and X-ray single-crystal diffraction. Compound 1 exhibits a 3D binodal (3,6)-connected ant framework composed of dodeca-supported P5W30 polyoxometalate (POM) clusters and discrete [Cu6(pbtz)(Hpbtz)(OH)2(H2O)8] subunits. Compound 2 is a pillared-layer 3D network constructed from [Cu5(ttbz)(Httbz)2(OH)3(H2O)4] sheets pillared by individual P5W30 clusters. Compound 3 contains octa-supporting P5W30 POM clusters and novel [Ni6(bpz)6] crown-like metallamacrocycles, which construct a (4,4)-connected pts network. Compound 4 displays a complicated 3D (5,5)-connected {4(5)·6(4)·8}{4(5)·6(5)} network built by pentasupporting P5W30 POM clusters and discrete [Co4(bpz)6(H2O)9] subunits. In 1-4, the unified features are the Preyssler-type [P5W30O110] POM as the fundamental building block, which supports the transition-metal compounds with different modes to give the resultant diverse networks. The magnetism studies indicated antiferromagnetically coupled systems for the hexa- and pentanuclear Cu(II) units in 1 and 2, respectively. The electrochemical properties demonstrate that all compounds have electrocatalytic abilities toward the reduction of hydrogen peroxide. Furthermore, the catalytic activities of 1 in the cyanosilylation of aldehydes reaction have been investigated.

17.
Sensors (Basel) ; 15(1): 1964-97, 2015 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-25602270

RESUMO

Interference alignment (IA) has been put forward as a promising technique which can mitigate interference and effectively increase the throughput of wireless sensor networks (WSNs). However, the number of users is strictly restricted by the IA feasibility condition, and the interference leakage will become so strong that the quality of service will degrade significantly when there are more users than that IA can support. In this paper, a novel joint spatial-code clustered (JSCC)-IA scheme is proposed to solve this problem. In the proposed scheme, the users are clustered into several groups so that feasible IA can be achieved within each group. In addition, each group is assigned a pseudo noise (PN) code in order to suppress the inter-group interference via the code dimension. The analytical bit error rate (BER) expressions of the proposed JSCC-IA scheme are formulated for the systems with identical and different propagation delays, respectively. To further improve the performance of the JSCC-IA scheme in asymmetric networks, a random grouping selection (RGS) algorithm is developed to search for better grouping combinations. Numerical results demonstrate that the proposed JSCC-IA scheme is capable of accommodating many more users to communicate simultaneously in the same frequency band with better performance.


Assuntos
Redes de Comunicação de Computadores , Tecnologia sem Fio , Algoritmos , Análise por Conglomerados , Análise Numérica Assistida por Computador
18.
Biochem Cell Biol ; 92(1): 23-32, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24471915

RESUMO

The eukaryotic acid ribosomal P0, P1, and P2 proteins share a conserved flexible C-terminal tail that is rich in acidic residues, which are involved in the interaction with elongation factor 2 during protein synthesis. Our previous work suggested that the acidic ribosomal P proteins from Euplotes octocarinatus have a special C-terminal domain. To further understand this characteristic feature, both P2 and elongation factor 2 from E. octocarinatus were overexpressed, for the first time, in Escherichia coli in this study. GST pull-down assay indicated that P2 protein from E. octocarinatus (EoP2) interacted specifically with the N-terminal domain of elongation factor 2 from E. octocarinatus (EoEF-2) in vitro. The interacting part of EoP2 is in the C-terminal domains, consistent with the observation in other organisms. Phosphorylation of the recombinant EoP2 was performed in vitro using multiple methods such as (31)P-NMR spectroscopy, native PAGE, and Phos-tag(TM) SDS-PAGE. Results showed that ribosomal protein EoP2 was phosphorylated by casein kinase II at serine 21 located at the N terminus. This phosphorylation site identified in EoP2 is quite different from that of P2 from other organisms, in which the phosphorylation site is located in the conserved C-terminal region.


Assuntos
Euplotes/metabolismo , Fosfoproteínas/química , Proteínas de Protozoários/química , Proteínas Ribossômicas/química , Sequência de Bases , Caseína Quinase II/química , Dados de Sequência Molecular , Fator 2 de Elongação de Peptídeos/química , Fosforilação , Estrutura Terciária de Proteína , Serina/química
19.
Inorg Chem ; 53(20): 11046-50, 2014 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-25272140

RESUMO

Two extended Preyssler P5W30 polyoxometalate-based inorganic-organic hybrid materials exhibiting anion-induced supramolecular isomerism were reported. Because of the cis-trans isomerism in the octahedral CoN2O4 coordination geometry, the Preyssler P5W30 polyoxometalates are extended by double O-Co-O bridges in 1α and a single O-Co-O bridge in 1ß to form the isomeric 2D 4-connected 4(4)-sql and 3D 8-connected bcu networks, respectively. Both compounds show electrocatalytic abilities on the reduction of H2O2.

20.
ScientificWorldJournal ; 2014: 481312, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24782661

RESUMO

A fast and robust ellipse-detection method based on sorted merging is proposed in this paper. This method first represents the edge bitmap approximately with a set of line segments and then gradually merges the line segments into elliptical arcs and ellipses. To achieve high accuracy, a sorted merging strategy is proposed: the merging degrees of line segments/elliptical arcs are estimated, and line segments/elliptical arcs are merged in descending order of the merging degrees, which significantly improves the merging accuracy. During the merging process, multiple properties of ellipses are utilized to filter line segment/elliptical arc pairs, making the method very efficient. In addition, an ellipse-fitting method is proposed that restricts the maximum ratio of the semimajor axis and the semiminor axis, further improving the merging accuracy. Experimental results indicate that the proposed method is robust to outliers, noise, and partial occlusion and is fast enough for real-time applications.


Assuntos
Modelos Teóricos , Algoritmos
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