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OBJECTIVES: Ameloblastoma (AM), a locally aggressive tumor with extensive growth capacity, causes significant damage to the jaw and affects facial appearance. Although the high prevalence of BRAF V600E mutation in AM is known, its specific impacts on patients with AM remain unclear. Thus, the present study investigated the role of BRAF V600E mutation, thereby focusing on its impact on AM invasion and growth. MATERIALS AND METHODS: Immunohistochemical analysis was used to compare BRAF V600E, MMP2, MMP9, and Ki-67 expressions in AM (n = 49), normal oral mucosa (NOM) (n = 10), and odontogenic keratocyst (OKC) (n = 15) tissues. AM was further classified according to the presence or absence of BRAF V600E. The relationship between BRAF V600E and invasion as well as growth was evaluated. In addition, correlation analysis was performed using immunohistochemistry and confirmed via double-labeling immunofluorescence. Finally, comparative analyses using mass spectrometry, immunohistochemistry, and immunofluorescence were performed to explore and identify underlying mechanisms. RESULTS: AM exhibited a higher incidence of BRAF V600E mutation than NOM and OKC. BRAF V600E expression was positively correlated with the invasion-associated proteins MMP2 and MMP9 and the growth-related protein Ki-67. Proteomic data revealed that BRAF V600E primarily activates the MAPK signaling pathway in AM, particularly driving the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). CONCLUSIONS: In summary, the findings suggested that the BRAF V600E mutation enhances the invasion and growth abilities of AM via the MAPK/ERK signaling pathway. Thus, targeting BRAF V600E or the MAPK/ERK pathway may be a potential AM therapy.
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Ameloblastoma , Metaloproteinase 2 da Matriz , Metaloproteinase 9 da Matriz , Mutação , Invasividade Neoplásica , Proteínas Proto-Oncogênicas B-raf , Ameloblastoma/genética , Ameloblastoma/metabolismo , Ameloblastoma/patologia , Humanos , Proteínas Proto-Oncogênicas B-raf/genética , Invasividade Neoplásica/genética , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Feminino , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Masculino , Pessoa de Meia-Idade , Adulto , Neoplasias Maxilomandibulares/genética , Neoplasias Maxilomandibulares/metabolismo , Neoplasias Maxilomandibulares/patologia , Antígeno Ki-67/metabolismo , Cistos Odontogênicos/genética , Cistos Odontogênicos/metabolismo , Cistos Odontogênicos/patologia , Sistema de Sinalização das MAP Quinases/genética , Adulto Jovem , Idoso , Mucosa Bucal/patologia , Mucosa Bucal/metabolismo , AdolescenteRESUMO
Phytochemical investigation on cigar tobacco leaves led to four unknown sesquiterpenoids as well as nine reported ones. Among of them, 3-acetoxy-ß-damascone was first found in tobacco leaves. All the structures were elucidated by intensive spectroscopic analyses and X-ray diffraction. The relationship between the newly isolates and known ones was tried to describe.
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Sesquiterpenos , Produtos do Tabaco , Estrutura Molecular , Difração de Raios X , Sesquiterpenos/químicaRESUMO
Phytochemical studies on cigar tobacco leaves led to the isolation of 18 ionone-type compounds, including previously undescribed cigatobanes E (1) and F (2). Additionally, compounds vomifoliol acetate (3), dehydrovomifoliol (4), 8,9-dihydromegastigmane-4,6-diene-3-one (5), 7α,8α-epoxyblumenol B (6), 3-oxoactinidol (12), and loliolide acetate (15), 4ß-hydroxy-dihydroactinidiolide (17), were found in tobacco leaves for the first time. The structural elucidation of all compounds was accomplished through rigorous spectral analysis.
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Nicotiana , Folhas de Planta , Folhas de Planta/química , Estrutura Molecular , Nicotiana/química , Norisoprenoides/químicaRESUMO
Engineering of genetic networks with artificial signaling pathways (ASPs) can reprogram cellular responses and phenotypes under different circumstances for a variety of diagnostic and therapeutic purposes. However, construction of ASPs between originally independent endogenous genes in mammalian cells is highly challenging. Here we report an amplifiable RNA circuit that can theoretically build regulatory connections between any endogenous genes in mammalian cells. We harness the system of catalytic hairpin assembly with combination of controllable CRISPR-Cas9 function to transduce the signals from distinct messenger RNA expression of trigger genes into manipulation of target genes. Through introduction of these RNA-based genetic circuits, mammalian cells are endowed with autonomous capabilities to sense the changes of RNA expression either induced by ligand stimuli or from various cell types and control the cellular responses and fates via apoptosis-related ASPs. Our design provides a generalized platform for construction of ASPs inside the genetic networks of mammalian cells based on differentiated RNA expression.
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RNA Catalítico , Animais , RNA Catalítico/metabolismo , RNA/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Apoptose , Transdução de Sinais , Redes Reguladoras de Genes , Mamíferos/metabolismoRESUMO
The well-defined 2D or 3D structure of covalent organic frameworks (COFs) makes it have great potential in photoelectric conversion and ions conduction fields. Herein, a new donor-accepter (D-A) COF material, named PyPz-COF, constructed from electron donor 4,4',4â³,4'â³-(pyrene-1,3,6,8-tetrayl)tetraaniline and electron accepter 4,4'-(pyrazine-2,5-diyl)dibenzaldehyde with an ordered and stable π-conjugated structure is reported. Interestingly, the introduction of pyrazine ring endows the PyPz-COF a distinct optical, electrochemical, charge-transfer properties, and also brings plentiful CN groups that enrich the proton by hydrogen bonds to enhance the photocatalysis performance. Thus, PyPz-COF exhibits a significantly improved photocatalytic hydrogen generation performance up to 7542 µmol g-1 h-1 with Pt as cocatalyst, also in clear contrast to that of PyTp-COF without pyrazine introduction (1714 µmol g-1 h-1 ). Moreover, the abundant nitrogen sites of the pyrazine ring and the well-defined 1D nanochannels enable the as-prepared COFs to immobilize H3 PO4 proton carriers in COFs through hydrogen bond confinement. The resulting material has an impressive proton conduction up to 8.10 × 10-2 S cm-1 at 353 K, 98% RH. This work will inspire the design and synthesis of COF-based materials with both efficient photocatalysis and proton conduction performance in the future.
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Chronic HBV infection patients who do not conform to any of the usual immune states are regarded as 'grey zone' patients. We aimed to investigate the proportion of chronic HBV infection patients in the grey zone, and evaluate the clinical characteristics and liver pathological changes in grey zone patients. Clinical data of 1391 treatment-naive chronic HBV infection patients with liver biopsy were collected. Natural history of HBV infection was determined based on European Association for the Study of the Liver (EASL) 2017, American Association for the Study of Liver Diseases (AASLD) 2018 and Chinese 2019 guidelines for the prevention and treatment of chronic HBV infection. Significant liver histological changes and associated risk factors of normal ALT grey zone patients were analysed. According to EASL, AASLD and Chinese criteria, there were 50.0%, 28% and 37.4% chronic HBV infection patients in the grey zone. Among the 353 grey zone patients with normal ALT, 72.4% had significant liver histological changes. ALT (optimal cut-off value 25 IU/L) and HBV DNA (optimal cut-off value 18,000 IU/mL) were independent risk factors of significant liver histological abnormalities. In conclusion, a substantial proportion of grey zone patients with normal ALT have significant liver histological changes that can be predicted by levels of serum ALT and HBV DNA. These results provide guidance of antiviral treatment in grey zone patients.
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Hepatite B Crônica , Humanos , Hepatite B Crônica/tratamento farmacológico , Vírus da Hepatite B/genética , DNA Viral , Cirrose Hepática , Alanina Transaminase , Antígenos E da Hepatite BRESUMO
Metal-organic frameworks (MOFs), as a porous frame material, exhibit considerable electrical conductivity. In recent decades, research on the proton conductivity of MOFs has made gratifying progress. In this review, the designable guest molecules encapsulated into MOFs are summarized and generalized into four types in terms of promoting proton conductive performance, and then recent progress in the promotion of proton conductivity by MOFs encapsulating guest molecules is discussed. The existing challenges and prospects for the development of this strategy for promoting MOFs' proton conductivity are also listed.
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A metal-organic framework, {Zn3(BTB)2(µ3-OH)[(CH3)2NH2](H2O)}n (1), was synthesized based on H3BTB (1,3,5-tri(4-carboxyphenyl)benzene). An AC impedance test proves that 1 has a relatively high conductivity performance of 1.52 × 10-3 S·cm-1 at 338 K and 98% RH. The proton conductivity of the composite film 1@CS-9 (CS = chitosan) reaches 1.84 × 10-1 S·cm-1 at 328 K and 98% RH. In addition, 1 is discovered to have a good adsorption effect on iodine vapor, and the adsorption capacity reaches 726 mg·g-1. The multifunctionality caused by dimethylamine cations was investigated for the first time, which has implications for multifunctionality generated by host-guest molecules.
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A series of heterometallic tetranuclear clusters, Ln2Ni2(NO3)4L4(µ3-OCH3)2·2(CH3CN) (Ln = Gd(1), Tb(2), Dy(3), Ho(4), Er(5); HL = methyl 3-methoxysalicylate), were synthesized solvothermally. The intramolecular synergistic effect of two metal centers of Ln(III) and Ni(II) and the exposed multimetallic sites serving as Lewis acid activators greatly increase the efficiency of the CO2 conversion, and the yield for cluster 3 can be achieved at 96% at atmospheric pressure and low temperature. In particular, the self-assembly multimetal center with polydentate ligand shows good generality and enhanced recyclability. The design of such 3d-4f heterometallic clusters provides an effective strategy for the conversion of CO2 under greener conditions. Meanwhile, magnetic investigations indicate that cluster 1 is a good candidate for magnetic refrigerant materials with a relatively large magnetocaloric effect (MCE) (-ΔSm = 28.5 J kg-1 K-1 at 3.0 K and 7.0 T), and cluster 3 shows single-molecular magnet behavior under zero dc field. Heterometallic clusters with special magnetic properties and good catalytic behavior for the conversion of CO2 are rare. Thus, they are potential bifunctional materials applied in practice.
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This study analyzed the outcome indicators in randomized controlled trial(RCT) on Chinese medicine as adjuvant therapy for severe pneumonia in the past years, laying a foundation for the design of clinical trials on and construction of core outcome set(COS) for severe pneumonia. To be specific, related RCT was retrieved from CNKI, Wanfang, VIP, SinoMed, PubMed, EMbase, Cochrane Library, Web of Science, Chinese Clinical Trial Registry, and ClinicalTrials.gov(from January 1,2011 to April 9,2022). Then data in the trials were extracted, and the quality of included RCT was assessed according to Cochrane handbook, followed by descriptive analysis of the use of outcome indicators. A total of 11 833 articles were screened out, and finally 34 RCTs were included(2 were protocols). The included trials involved 109 outcome indicators with emergence frequency of 320, which were mainly classified into 9 categories: physicochemical indicators(54, frequency 167), time to achieve the efficacy(15, frequency 38), clinical effective rate(10, frequency 36), quality of life(11, frequency 35), symptoms and signs(7, frequency 18), traditional Chinese medicine(TCM) syndrome(4, frequency 13), safety(3, frequency 8), economic evaluation(1, frequency 1), other indicators(4, frequency 4). The indicators with high frequency followed the order: total effective rate, arterial oxygen partial pressure, C-reactive protein, white blood cell count, arterial blood carbon dioxide partial pressure. A total of 5 articles(14.71%) reported the main outcome indicators and 11 articles(32.35%) adopted the efficacy on TCM syndromes as the outcome indicator. There are many problems in the selection of outcome indicators in RCT on the treatment of severe pneumonia with Chinese medicine, mainly manifested as the disregard of clinical endpoint indicators, the inappropriate selection of surrogate indicators, and the non-standard evaluation criteria for the efficacy on TCM syndrome. It is suggested that the evaluation system for the efficacy of Chinese medicine on severe pneumonia should be established in accordance with the method for international COS to improve the quality of clinical trials.
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Medicamentos de Ervas Chinesas , Pneumonia , Humanos , Medicina Tradicional Chinesa , Medicamentos de Ervas Chinesas/uso terapêutico , Qualidade de Vida , Terapia Combinada , Pneumonia/tratamento farmacológicoRESUMO
A Zr-based metal-organic polyhedron (MOP) was self-assembled in a porous MOF host, DUT-68, successfully to synthesize MOP-1@DUT-68. The MOP guest (MOP-1) has a diameter of about 20â Å, larger than that of the square windows (pore sizes of â¼14â Å) of DUT-68 but smaller than that of the rhombicuboctahedral cage (27.7â Å), which means that the migration and leaching of MOP-1 could be effectively prohibited if MOP-1 is encapsulated in the MOF's cavities. The proton conductivity of MOP-1@DUT-68 is 1.14×10-3 â S cm-1 (at 80 °C under 98 % relative humidity), which is three orders of magnitude higher than that of DUT-68. Compared with MOP-1âDUT-68, which was synthesized by impregnation, MOP-1@DUT-68 is more prone to form faster proton-conduction pathways and thus provides higher proton conductivity.
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A new type of metal-organic framework, [Cd2(pdc)(H2O)(DMA)2]n (pdc = 3,5-pyrazoledicarboxylic acid; DMA = dimethylamine), named Cd-MOF, was synthesized and characterized. There are regular rectangular pore channels containing a large number of dimethylamine cations in the crystal structure. AC impedance test results show the proton conductivity of Cd-MOF reaches 1.15 × 10-3 S cm-1 at 363 K and 98% RH. In order for its application in fuel cells, the Cd-MOF was introduced into a sulfonated polyphenylene oxide matrix to prepare a hybrid membrane, and the proton conductivity of the hybrid membrane has a high value of 2.64 × 10-1 S cm-1 at 343 K and 98% RH, which is higher than those of most MOF polymer hybrid membranes. The proton conductivity of the hybrid membrane of the SPPO polymer still maintains a certain degree of stability in a wide temperature range. To the best of our knowledge, it is the first proton exchange membrane that combines pyrazolecarboxylate cadmium MOFs and an SPPO polymer with high proton conductivity and good stability. This research may help to further develop the application of MOFs in the field of proton exchange membrane fuel cells.
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Ergosterol is an important fungal-specific biomarker, but its use for fungal biomass estimation is still varied. It is important to distinguish between free and esterified ergosterols, which are mainly located on the plasma membrane and the cytosolic lipid particles, respectively. The present study analyzes free and esterified ergosterol contents in: (1) the fifty-nine strains of culturable fungi isolated from mangrove soil, (2) the broken spores of the fungus Ganoderma lucidum stored in capsule for more than 12 years, and (3) the mangrove soil and nearby campus wood soil samples by high performance liquid chromatography (HPLC). The results show that the contents of free and esterified ergosterols varied greatly in fifty-nine strains of fungi after 5 days of growth, indicating the diversity of ergosterol composition in fungi. The average contents of free and total ergosterols from the fifty-nine strains of fungi are 4.4 ± 1.5 mg/g and 6.1 ± 1.9 mg/g dry mycelia, respectively, with an average ergosterol esterification rate of 27.4%. The present study suggests that the fungi might be divided into two classes, one is fungi with high esterification rates (e.g., more than 27%) such as Nectria spp. and Fusarium spp., and the other is fungi with low esterification rates (e.g., less than 27%) such as Penicillium spp. and Trichoderma spp. Moreover, the ergosterol esterification rate in the spores of G. lucidum is 91.4% with a very small amount of free ergosterol (0.015 mg/g), compared with 41.9% with a higher level of free ergosterol (0.499 mg/g) reported in our previous study in 2007, indicating that free ergosterol degrades more rapidly than esterified ergosterol. In addition, the ergosterol esterification rates in mangrove soil and nearby campus wood soil samples range from 0 to 39.0%, compared with 80% in an old soil organic matter reported in a previous study, indicating the potential relationship between aging degree of fungi or soil and esterification rate. The present study proposes that both free and esterified ergosterols should be analyzed for fungal biomass estimation. When the ergosterol esterification rates in soils are higher, free ergosterol might be a better marker for fungal biomass. It is speculated that the ergosterol esterification rate in soils might contain some important information, such as the age of old-growth forests over time scales of centuries to millennia, besides the senescence degree of fungal mycelia in soils. KEY POINTS: ⢠Fungi might be divided into two classes depending on ergosterol esterification rates. ⢠Ergosterol esterification rate of broken spores stored for long time raised evidently. ⢠Both free and esterified ergosterols should be analyzed for fungal biomass estimate. ⢠Free ergosterol is a better marker for fungal biomass with a high esterification rate.
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Ergosterol/química , Fungos/metabolismo , Microbiologia do Solo , Esporos Fúngicos/metabolismo , Biomassa , Cromatografia Líquida de Alta Pressão , Esterificação , Fungos/classificação , Fungos/isolamento & purificação , Micélio/metabolismo , Reishi/isolamento & purificação , Reishi/metabolismo , Áreas AlagadasRESUMO
We aimed to compare the diagnostic efficiency of proGRP and NSE on SCLC and to investigate whether the change of proGRP level would predict therapeutic response. Patients who were firstly diagnosed pathologically in Nanjing Chest Hospital and measured proGRP level consecutively were enrolled in the study. ProGRP level was detected using Elecsys ProGRP Assay. Totally 75 SCLC, 234 NSCLC and 264 benign lung diseases (BLD) were enrolled. Both proGRP and NSE levels in SCLC were significantly higher than those in NSCLC and BLD, and proGRP in extensive stage SCLC was higher than which in limited stage (P ≤ .001). The diagnostic efficiency of proGRP on SCLC was higher than that of NSE, but when the two biomarkers were bind together, the diagnostic efficiency was the best. When SCLC was differentiated from NSCLC and BLD, the cut-off values were 114.35 pg/mL and 162.55 pg/mL respectively. For treatment responsive patients, proGRP level decreased markedly after the first cycle of therapy and kept a continued momentum of decline during treatment. But for unresponsive patients, no obvious decline was observed. ProGRP had higher diagnostic efficiency on SCLC when compared to NSE, and it could better predict therapeutic response of pulmonary target lesions on chemotherapy.
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Biomarcadores Tumorais/sangue , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Neoplasias Pulmonares/diagnóstico , Neoplasias/diagnóstico , Fragmentos de Peptídeos/sangue , Fosfopiruvato Hidratase/sangue , Carcinoma de Pequenas Células do Pulmão/diagnóstico , Adulto , Idoso , Antineoplásicos/uso terapêutico , Área Sob a Curva , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , China , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/patologia , Fragmentos de Peptídeos/genética , Fosfopiruvato Hidratase/genética , Proteínas Recombinantes/sangue , Proteínas Recombinantes/genética , Estudos Retrospectivos , Sensibilidade e Especificidade , Carcinoma de Pequenas Células do Pulmão/sangue , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/patologiaRESUMO
BACKGROUND/AIMS: Non-small cell lung cancer (NSCLC) is one of the deadliest cancers worldwide. Dopamine receptor D2 (DRD2) has multiple roles in clinical progression of NSCLC and functional maintenance of cancer cells. However, little is known about the molecular mechanism. Here, we clarified whether DRD2 inhibits lung cancer progression and identified the underlying downstream signaling. METHODS: DRD2 mRNA and protein levels were detected in clinical specimens by qRT-PCR and immunohistochemistry, respectively. MTT and colony formation assays were applied to analyze cell proliferation. The underlying molecular mechanism was identified by dual luciferase, western blot, qRT-PCR, cAMP detection, immunoprecipitation, and chromatin immunoprecipitation assays. A murine NSCLC model was used to clarify the role of DRD2 in tumor cell proliferation. RESULTS: We found that DRD2 ablated tumor cell growth. DRD2 expression in NSCLC tissues was lower than in adjacent normal lung tissues. Moreover, DRD2 mRNA and protein levels in NSCLC were negatively correlated with the tumor size, TNM status, and patient overall survival. In vitro experiments showed that disruption of DRD2 promoted the proliferation of NSCLC cell lines A549 and SK-MES-1 by inhibiting the NF-κB signaling pathway. Furthermore, DRD2 overexpression not only blocked lipopolysaccharide-induced A549 and SK-MES-1 cell proliferation and growth, but also inhibited the tumorigenesis in murine xenograft models. CONCLUSION: These results indicate that DRD2 may be a potential therapeutic target for lung cancer patients with high DRD2 expression by ablating the NF-κB signaling pathway.
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Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Receptores de Dopamina D2/metabolismo , Animais , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Receptores de Dopamina D2/química , Receptores de Dopamina D2/genética , Transdução de Sinais , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The p53 signaling network is indispensible in cellular stress responses and tumor suppression. Negative regulations of p53 by mouse double minute 2 (MDM2) and its homolog MDM4 are an integrated component of the network and have been implicated in regulating the stress responses and the maintenance of normal development and homeostasis of multiple somatic cell lineages. However, the regulatory role of MDM2 on p53 and stress responses in female germ cells remains undetermined. Here, we used the Cre-loxP system to delete Mdm2 in oocytes at different stages of folliculogenesis in mice. Mdm2 deletion resulted in a clear p53 nuclear accumulation in the oocytes and impeded fertilities with early follicular loss in mice, resembling human premature ovarian failure phenotypes. These phenotypes were fully rescued by concurrent deletion of p53 in mice. In addition, Nutlin-3, a small molecule compound that inhibited the binding of MDM2 to p53, also promoted p53-dependent oocyte death. Although cancer therapeutic agents 5-fluorouracil and doxorubicin could not induce a robust p53 activation in the wild-type oocytes, they induced p53 nuclear accumulation in the Mdm2 and Mdm4 double heterozygous oocytes. These results demonstrated a critical prosurvival role for MDM2 in the oocytes. Moreover, they suggested a more tightened and rigorous regulatory mode for the MDM2/MDM4-p53 network in female germ cells under stress situations.
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Oócitos/metabolismo , Oogênese/fisiologia , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Western Blotting , Feminino , Imunofluorescência , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oócitos/crescimento & desenvolvimentoRESUMO
Recently, considerable attention has been paid to European eggs that were found to contain the poisonous insecticide fipronil. Excessive consumption of fipronil can harm the human body, in particular, the liver, thyroid, nervous system and kidneys. As a consequence, there is an urgent need to develop a method to detect fipronil. In this work, a lanthanide coordination polymer [Eu(SIP)(H2O)4]n (1) (NaH2SIP = 5-sulfoisophthalic acid monosodium salt) was synthesized and characterized by single-crystal X-ray crystallography, elemental analysis, infrared spectrum and powder X-ray diffractions. The X-ray studies show that 1 is a two-dimensional layered structure, which is constructed of fused {[Eu(H2O)4]3(SIP)3} pseudo-hexagonal grids. The luminescence properties of 1 exhibit effective recognition for fipronil in methanol solution. Furthermore, a wide linear range (10-6-10-4 M), a low detection limit of 0.8 µM, high selectivity and excellent recyclability, reveal that 1 can potentially act as a luminescence-based sensor for quantitative and highly sensitive detection of fipronil. To the best of our knowledge, it is the first time that a metal-organic coordination polymer, as a fluorescent-based probe, has been used for the detection of fipronil. Moreover, fluorescent-based test papers of 1 have also been prepared, which can be regarded as a simple and practical method for detecting fipronil.
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In this research, 97 pieces of rock in Xingcheng, Liaoning Province, China were collected to measure the spectral reflectance in 350~2 500 nm, chemical content, and complex dielectric constant of some samples. The absorption depths were calculated by using continuum- removal method. With correlation analysis method, two kinds of correlation curves were obtained based on the theory of spectral characteristics of chemical contents and the principle of dielectric constant. One described the relationship between chemical content and spectral absorption depth, and the other one represented the correlation of complex dielectric constant and reflectance. By summarizing curves morphological characteristics, several conclusions were drawn as follows: (1)There was a strong correlation between the chemical content (SiO2, Al2O3, CaO, K2O, MgO, burnt-loss) and spectral absorption depth in 1 900~2 500 nm, furthermore, at around 1 900, 2 200, 2 300 nm and other identifying characteristic bands, local extreme maximum / minimum values appeared. At Fe3+ characteristic band (400~550 nm), correlation coefficient reached -0.406 between Fe2O3 content and absorption in igneous rock samples collection. Exploring the relationship between rock spectral absorption features and its chemical contents had a positive effect on metallogenic prediction and lithology identification with remote sensing image. (2) Reflectance and complex dielectric constant were negatively correlated totally, compared with the imaginary part; the real part had a better relation reached -0.753 at around 1 900 nm. Curves showed that there were great correlations around 1 900 and 2 200 nm, so, our study adopted different models to simulate response relationships. Dielectric constant of media is one of the basic physical properties, and now most analyses of existing research between electromagnetic characteristics and dielectric constant are studied in microwave band, however, our research is conducted in visible and near infrared range. The conclusions will be useful for further exploration on dielectric characteristics and spectral features of rocks.
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The mineral composition of rock is one of the main factors affecting the spectral reflectance characteristics, and it's an important reason for generating various rock characteristic spectra. This study choose the rock samples provided by Jet Propulsion Laboratory (JPL) (including all kinds of mineral percentage of rocks, and spectral reflectances range from 0.35 to 2.50 µm wavelength measured by ASD spectrometer), and the various types of mineral spectral reflectances contained within the rocks are the essential data. Using the spectral linear mixture model of rocks and their minerals, firstly, a simulation study on the mixture of rock and mineral composition is achieved, the experimental results indicate that rock spectral curves using the model which based on the theory of the linear mixture are able to simulate better and preserve the absorption characteristics of various mineral components well. Then, 8 samples which contain biotite mineral are picked from the rock spectra of igneous, biotite contents and the absorption depth characteristics of spectral reflection at 2.332 µm, furthermore, a variety of linear and nonlinear normal statistical models are used to fit the relationship between the depth of absorption spectra and the content of the mineral composition of biotite, finally, a new simulation model is build up with the Growth and the Exponential curve model, and a statistical response relationship between the spectral absorption depth and the rock mineral contents is simulated by using the new model, the fitting results show that the correlation coefficient reaches 0.9984 and the standard deviation is 0.572, although the standard deviation using Growth and Exponential model is less than the two model combined with the new model fitting the standard deviation, the correlation coefficient of the new model had significantly increased, which suggesting that the, new model fitting effect is closer to the measured values of samples, it proves that the simulation results of new model is closer to the measured value.
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It chooses 15 kinds of rock from the three major rock categories as the rock samples (the number of rock samples is 208) and obtains the density, susceptibility and reflection spectrum at the wave band of 350~2500 nm. It calculates the correlative coefficients with the aim of studying the characteristic relationship between the property (including the density and the susceptibility) of the rock and the reflectivity. It concludes the wave band of the reflection spectrum which owes the prospect to discuss the density and susceptibility of the rock qualitatively or quantitatively, meanwhile, it sums up the characteristic of the curves of the correlative coefficients. In this paper, the discussion and analysis based on the results show that the study on the character relationship between the property of rock (density and susceptibility) and the reflection spectrum is meaningful and workable.