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1.
Int J Biol Macromol ; 240: 124365, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37030460

RESUMO

Wound dressing with an improved structural and functional recapitulation of damaged organs, efficient self-healing and antibacterial properties that can well integrate with tissue are urgently needed in wound management. Supramolecular hydrogels confer control over structural properties in a reversible, dynamic and biomimetic fashion. Herein, a kind of injectable, self-healing and antibacterial supramolecular hydrogel with multi-responses were fabricated by mixing phenylazo-terminated Pluronic F127, quaternized chitosan-graft-cyclodextrin and polydopamine coated tunicate cellulose nanocrystals under physiological conditions. By exploiting the photoisomerization of azobenzene under different wavelengths, a supramolecular hydrogel featuring a changing crosslink density of network was obtained. The corporation of polydopamine coated tunicate cellulose nanocrystals strengthens the hydrogel network with Schiff base bonds and hydrogen bonds, which avoids complete gel-sol transition. The inherent antibacterial property, drug release behavior, self-healing ability, hemostatic performance and biocompatibility were investigated to confirm superiority in wound healing. Moreover, the curcumin loaded hydrogel (Cur-hydrogel) showed multi-responsive release profiles (light, pH, and temperature). A full-thickness skin defect model was built to confirm that Cur-hydrogels significantly accelerated wound healing rate with better granulation tissue thickness and collagen disposition. Overall, the novel photo-responsive hydrogel with coherent antibacterial property has great potential in the healthcare of wound healing.


Assuntos
Quitosana , Nanopartículas , Hidrogéis/farmacologia , Hidrogéis/química , Celulose , Bandagens , Quitosana/química , Antibacterianos/farmacologia , Antibacterianos/química
2.
ACS Appl Mater Interfaces ; 15(13): 17293-17300, 2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-36951487

RESUMO

Building stimulus-responsive units in the hydrogel coatings remains challenging for film sensors consisting of alternated layers of inert substrates and hydrogel coatings. An interesting film sensor with a carboxymethyl starch-based hydrogel coating was developed here. The cross-linking networks of carboxymethyl starch play the roles of structure-constructing units and stimulus-controlling units simultaneously, endowing the coatings with thermal sensing and strain sensing capabilities. The dynamic cross-links formed via the boronic ester bonds are temperature-sensitive, releasing or consuming additional acid ions with temperature alteration, and also as primary networks give the hydrogel strength and stretchability with the assistance of semi-penetrated polyacrylamide chains. Therefore, as-prepared flexible film sensors can be used to detect the periodic changes of human temperature and small-scale motion with multiple working modes, discriminating the physical states related to human health. Moreover, this kind of starch-based coating is degradable in a strongly alkaline solution and the inert substrate layer can protect the skin from erosion caused by direct hydrogel-skin contact, and thereby the film sensor is human- and environmentally friendly. This work also proposes a strategy of building temperature-sensitive units in the film sensor via regulating the chemical networks, instead of tuning physical structures.

3.
Microb Ecol ; 85(1): 76-86, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34997309

RESUMO

Lingyan Temple is an important part of the World Heritage Mixed Property on Mount Taishan, in which numerous cultural heritage monuments, including exquisite painted arhat statues and inscriptions, display the ancient Chinese Buddhist culture. However, these monuments are suffering aesthetic and structural damage due to rich biofilms. In this study, the microbial communities colonized on historical monuments in different microenvironments were characterized through a combination of culture-dependent techniques and high-throughput sequencing. Microbial diversity was significantly different among the historical sites with different microenvironments. For example, Actinobacteria and Ascomycota were the core phyla in the indoor samples, while they were less abundant in the outdoor samples, and phototrophic microorganisms including Cyanobacteria and green algae were only dominant in the samples near springs. The results suggested that environmental factors such as water and airborne microorganisms may be the main causes influencing microbial distribution. Most of the identified dominant species were common on the historical monuments and could contribute to biodeterioration. This analysis of microbiota will provide further information on the biodeterioration processes and preservation strategies of cultural heritage monuments in Lingyan Temple.


Assuntos
Cianobactérias , Microbiota , Cianobactérias/genética , Biofilmes , China
4.
Int J Biol Macromol ; 225: 1119-1128, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36414077

RESUMO

Building multiple chemical crosslinks is an effective strategy to improve mechanical properties and to diversify final application of polysaccharide nanoparticles reinforced poly(vinyl alcohol) (PVA) physical hydrogels. In this work, PVA/cellulose nanofibers (CNFs) were used as composite substrate to fabricate ionic conductive hydrogels for strain sensor. Three types of characteristic crosslinks, including chemical crosslinking via boronic ester covalent bonds only, and with additional metal coordination bonding, as well as coexistence of physical crosslinks via PVA crystallites and aforementioned two kinds of chemical crosslinks, were constructed. The sample with triple crosslinks has superior mechanical strength and resistance to fatigue, and the polydopamine/Fe3+ ratio act as key to tune final performance because double-network structure prefers to form as Fe3+ is superfluous, while dual-crosslink one forms in the case of insufficient Fe3+. As-optimized ionic conductive hydrogel is suitable as strain sensor for probing human motions. This work provides an interesting insight into the network structure and property regulation for PVA/CNF composite hydrogels with multiple crosslinks.


Assuntos
Nanofibras , Álcool de Polivinil , Humanos , Álcool de Polivinil/química , Celulose/química , Nanofibras/química , Íons , Hidrogéis/química , Condutividade Elétrica
5.
Herit Sci ; 10(1): 105, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35818481

RESUMO

As non-renewable cultural heritage, wall paintings play an important role in society. To reveal the trends in the scientific analysis of mural paintings, 845 relevant research articles published from 2011 to 2021 were collected from the Web of Science database and analyzed. The VOSviewer software was adopted to map the network data of scientific publications, so that relationships among authors, countries, institutions can be displayed, and the co-occurrence of keywords and co-citation can be analyzed. The results revealed close and strong interconnections between the top authors, suggesting a considerable strong research link in this field. The cooperation between research institutions was relatively close. The most productive country of relevant publications was Italy. The leading journals for the scientific analysis of wall paintings were Journal of Raman Spectroscopy and Journal of Cultural Heritage. At present, the hotspots of scientific analysis and research on wall painting are revealing the composition, distribution, origin, and deterioration mechanism of pigments, alongside with evaluating the effects and mechanism of conservation materials and techniques. On the one hand, a possible development direction in this field is introducing more cutting-edge analysis and data processing methods. On the other hand, scientific analysis is increasingly adopted to guide the research and development of mural conservation materials.

6.
Anal Chem ; 93(43): 14440-14447, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34664943

RESUMO

The extraction and identification of silk residues in tombs is of great significance for studying the distribution and spread of early silk. However, the complex organic matter in the tomb hinders the accurate identification of silk. In this study, a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) based on immunomagnetic beads (IMBs) was developed for the rapid enrichment and detection of silk residues. The double-antibody sandwich ELISA method established by pairing the IMBs prepared by the silk fibroin monoclonal antibody SF-3 and the silk fibroin monoclonal-labeled antibody bio-SF-1 had the highest detection sensitivity, with a linear detection range of 10 to 104 ng mL-1 and a detection limit of 5.12 ng mL-1. This method was excellent in the extraction and analysis of silk residues from archaeological imprints and soil samples and successfully identified silk residues in samples at the final stage of silk degradation (physical invisible silk). The proteomics analysis results demonstrated the feasibility and practicability of this method.


Assuntos
Fibroínas , Seda , Anticorpos Monoclonais , Arqueologia , Ensaio de Imunoadsorção Enzimática , Separação Imunomagnética
7.
J Biomater Sci Polym Ed ; 30(15): 1375-1398, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31220422

RESUMO

A thermo- and pH-sensitive hydrogel was prepared by a facile free aqueous radical copolymerization of PEGMA and AAc without any crosslinkers for controlled drug delivery. The successful fabrication of hydrogels was confirmed by Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric analysis (TGA) measurements. The morphological, mechanical and swelling properties of the obtained hydrogels were studied systematically. The results showed that the morphological and mechanical behaviors of the resultant hydrogels were strongly affected by the content of AAc. Moreover, the obtained hydrogels showed an excellent thermo-, pH- and salinity sensitivities. Release profiles of 5-Fu were studied at different pH (gastric pH 1.2 and intestinal pH 7.4) and temperatures (25 °C and 37 °C). The results showed that the release is very low at pH 1.2/37 °C and high at pH 7.4/25 °C. The cytotoxicity of hydrogels to cells was determined by an MTT assay. The result demonstrated that the blank hydrogels had negligible toxicity to cells, whereas the 5-Fu-loaded hydrogels remained high in cytotoxicity for LO2 and HepG-2 cells. Results of the present investigation exemplify the potential of this novel thermo- and pH-sensitive hydrogel for the controlled and targeted delivery of the anti cancer drug 5-Fu.


Assuntos
Acrilatos/química , Portadores de Fármacos/química , Hidrogéis/química , Fenômenos Mecânicos , Polietilenoglicóis/química , Temperatura , Força Compressiva , Portadores de Fármacos/toxicidade , Liberação Controlada de Fármacos , Células Hep G2 , Humanos , Hidrogéis/toxicidade , Concentração de Íons de Hidrogênio , Teste de Materiais
8.
BMC Infect Dis ; 19(1): 108, 2019 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-30717679

RESUMO

BACKGROUND: For definitive diagnosis of cryptococcal meningitis, Cryptococcus neoformans and/or C. gattii must be identified within cerebral spinal fluid from the patients. The traditional methods for detecting Cryptococcus spp. such as India ink staining and culture are not ideal. Although sensitive and specific enough, detection of cryptococcal antigen polysaccharide has a high dose hook effect. Therefore, the aim of this study was to introduce a new rapid and simple detection method of Cryptococcus neoformans and C. gattii in cerebral spinal fluid. METHODS: The lateral flow strips combined with recombinase polymerase amplification (LF-RPA) assay was constructed to detect the specific DNA sequences of C. neoformans and C. gattii. The detection limit was evaluated using serial dilutions of C. neoformans and C. gattii genomic DNA. The specificity was assessed by excessive amount of other pathogens genomic DNA. The optimal detection time and amplification temperature were also analyzed. The diagnostic parameters were first calculated using 114 clinical specimens and then compared with that of other diagnostic method. A brief analysis and comparison of different DNA extraction methods was discussed, too. RESULTS: The LF-RPA assay could detect 0.64 pg of genomic DNA of C. neoformans per reaction within 10 min and was highly specific for Cryptococcus spp.. The system could work well at a wide range of temperature from 25 to 45 °C. The overall sensitivity and specificity were 95.2 and 95.8% respectively. As amplification template for LF-RPA assay, both cell lysates and genomic DNA produce similar experimental results. CONCLUSIONS: The LF-RPA system described here is shown to be a sensitive and specific method for the visible, rapid, and accurate detection of Cryptococcus spp. in cerebral spinal fluid and might be useful for clinical preliminary screening of cryptococcal meningitis.


Assuntos
Criptococose/diagnóstico , Cryptococcus gattii/isolamento & purificação , Cryptococcus neoformans/isolamento & purificação , Meningite Criptocócica/diagnóstico , Reação em Cadeia da Polimerase/métodos , RNA Fúngico/líquido cefalorraquidiano , Antígenos de Fungos/líquido cefalorraquidiano , Antígenos de Fungos/genética , Criptococose/líquido cefalorraquidiano , Cryptococcus gattii/genética , Cryptococcus neoformans/genética , Primers do DNA/genética , Diagnóstico Precoce , Humanos , Limite de Detecção , Meningite Criptocócica/líquido cefalorraquidiano , Técnicas Analíticas Microfluídicas/métodos , RNA Fúngico/análise , Recombinases/genética , Sensibilidade e Especificidade , Temperatura
9.
Nat Prod Res ; 33(4): 612-615, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29149803

RESUMO

The essential oil (EO) from the aerial parts of Leontopodium leontopodioides (Willd.) Beauverd was obtained by hydrodistillation and analysed by GC-FID and GC-MS. Sixty-five compounds were identified which represent 96.2% of the total composition of the EO. The major components of the EO were palmitic acid (11.6%), n-pentadecanal (5.7%), linalool (3.8%), ß-ionone (3.3%), hexahydrofarnesyl acetone (3.2%), bisabolone (3.2%) and ß-caryophyllene (3.2%). The EO exhibited an excellent antibacterial activity against Staphylococcus aureus and Bacillus subtilis according to the MIC values tested by micro-dilution method. It also exhibited a significant cytotoxicity against HepG2 and MCF-7 cell lines with the IC50 values of 67.44 and 70.49 µg/mL according to the MTT assay. However, the antioxidant activity test revealed that the EO exhibited a weak DPPH radical-scavenging activity. In conclusion, the EO of L. leontopodioides could be regarded as a bioactive natural product and deserves further study for its potential therapeutic effects.


Assuntos
Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Asteraceae/química , Citotoxinas/isolamento & purificação , Óleos Voláteis/química , Monoterpenos Acíclicos , Antibacterianos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Bacillus subtilis/efeitos dos fármacos , Linhagem Celular Tumoral , Citotoxinas/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Testes de Sensibilidade Microbiana , Monoterpenos , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Sesquiterpenos Policíclicos , Sesquiterpenos , Staphylococcus aureus/efeitos dos fármacos
10.
Artigo em Inglês | MEDLINE | ID: mdl-28910712

RESUMO

Cobalt blue is a famous pigment in human history. In the past decade it is widely reported that the cobalt aluminate has been detected in ancient ceramics as blue colorant in glaze, yet the acquired Raman spectra are incredibly different from that of synthesised references, necessitating a reassessment of such contradictory scenario with more accurate analytic strategies. In this study, micro-Raman spectroscopy (MRS) and scanning electron microscopy (SEM) in association with energy dispersive spectrometry (EDS) were performed on under-glaze cobalt pigments from one submerged blue and white porcelain shard dated from Wanli reign (1573-1620CE) of Ming dynasty (1365-1644CE) excavated at Nan'ao I shipwreck off the southern coast of China. The micro-structural inspection reveals that the pigment particles have characteristics of small account, tiny size, heterogeneously distribution, and more importantly, been completely enwrapped by well-developed anorthite crystals in the glaze, indicating that the signals recorded in previous publications are probably not from cobalt pigments themselves but from outside thickset anorthite shell. The further spectromicroscopic analyses confirm this presumption when the accurate spectra of cobalt aluminate pigment and surrounding anorthite were obtained separately with precise optical positioning. Accordingly, we reassess and clarify the previous Raman studies dedicated to cobalt blue pigment in ancient ceramics, e.g. cobalt blue in celadon glaze, and in turn demonstrate the superiority and necessity of coupling spectroscopic analysis with corresponding structure observation, especially in the characterization of pigments from complicated physico-chemical environment like antiquities. Thus, this study promotes a better understanding of Raman spectroscopy study of cobalt blue pigments in art and archaeology field.

11.
Front Microbiol ; 8: 1633, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28890715

RESUMO

The Mausoleum of the Dingtao King (termed 'M2') is a large-scale huangchang ticou tomb that dates to the Western Han Dynasty (206 B.C.-25 A.D.). It is the highest-ranking Han Dynasty tomb discovered to date. However, biodeterioration on the surface of the tomb M2 is causing severe damage to its wooden materials. The aim of the present study was to give insight into the fungal communities colonized the wooden tomb. For this purpose, seven samples were collected from different sections of the tomb M2 which exhibited obvious biodeterioration in the form of white spots. Microbial structures associated with the white spots were observed with scanning electron microscopy. Fungal community structures were assessed for seven samples via a combination of high-throughput sequencing and culture-dependent techniques. Sequencing analyses identified 114 total genera that belonged to five fungal phyla. Hypochnicium was the most abundant genus across all samples and accounted for 98.61-99.45% of the total community composition. Further, Hypochnicium sp. and Mortierella sp. cultures were successfully isolated from the tomb samples, and were distinguished as Hypochnicium sp. WY-DT1 and Mortierella sp. NK-DT1, respectively. Cultivation-dependent experiments indicated that the dominant member, Hypochnicium sp. WY- DT1, could grow at low temperatures and significantly degraded cellulose and lignin. Thus, our results taken together suggest that this fungal strain must be regarded as a serious threat to the preservation of the wooden tomb M2. The results reported here are useful for informing future contamination mitigation efforts for the tomb M2 as well as other similar cultural artifacts.

12.
Mol Cell Probes ; 36: 43-49, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28842221

RESUMO

To definitively diagnose active pulmonary Tuberculosis (TB), Mycobacterium tuberculosis complex (MTBC) bacilli must be identified within clinical specimens from patients. In this study, we introduced a rapid and visual detection method of MTBC using recombinase polymerase amplification (RPA) combined with lateral flow (LF) strips. The LF-RPA assay, read results with naked eyes, could detect as few as 5 genome copies of M. tuberculosis H37Rv (ATCC 27294) per reaction and had no cross-reactions with other control bacteria even using excessive amount of template DNA. The system could work well at a broad range of temperature 25-45 °C and reach detectable level even within 5 min. When testing a total of 137 clinical specimens, the sensitivity and specificity of the LF-RPA assay were 100% (95% CI: 95.94%-100%) and 97.92% (95% CI: 88.93%-99.95%), respectively, compared to culture identification method. Therefore, the LF-RPA system we have demonstrated is a rapid, simple, robust method for MTBC detection which, subject to the availability of a suitable sample extraction method, has the potentiality to diagnose TB at the point-of-care testing.


Assuntos
Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Kit de Reagentes para Diagnóstico , Recombinases/metabolismo , Humanos , Limite de Detecção , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Temperatura , Fatores de Tempo
13.
Water Sci Technol ; 75(5-6): 1051-1058, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28272034

RESUMO

Hydrazinolyzed cellulose-graft-polymethyl acrylate (Cell-g-PMA-HZ), an efficient adsorbent for removal of Cd(II) and Pb(II) from aqueous solution, has been prepared by ceric salt-initiated graft polymerization of methyl acrylate from microcrystalline cellulose surface and subsequent hydrazinolysis. The influences of initial pH, contact time, and temperature on adsorption capacity of Cell-g-PMA-HZ as well as adsorption equilibrium, kinetic and thermodynamic properties were examined in detail. As for Cd(II) adsorption, kinetic adsorption can be explained by pseudo-second-order, while adsorption isotherm fits well with Langmuir isotherm model, from which maximum equilibrium adsorption capacity can be derived as 235.85 mg g-1 at 28 °C. Further thermodynamic investigation indicated that adsorption of Cd(II) by adsorbent Cell-g-PMA-HZ is endothermic and spontaneous under studied conditions. On the other hand, isotherm of Pb(II) adsorption fits well with Freundlich isotherm model and is more likely to be a physical-adsorption-dominated process. Consecutive adsorption-desorption experiments showed that Cell-g-PMA-HZ is reusable with satisfactory adsorption capacity.


Assuntos
Resinas Acrílicas/química , Cádmio/isolamento & purificação , Celulose/análogos & derivados , Celulose/química , Hidrazinas/química , Chumbo/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Concentração de Íons de Hidrogênio , Íons/química , Cinética , Temperatura , Fatores de Tempo
14.
Biomed Rep ; 4(6): 737-740, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27284415

RESUMO

The present cross-sectional study consisted of 18,265 Chinese patients not previously diagnosed with diabetes mellitus, and who underwent physical examination at the Third People's Hospital of Shenzhen between June 2014 and May 2015 (mean patient age, 51.312±15.252 years). The study was composed of 11,770 males and 6,495 females. The aim was to investigate the association between glycated hemoglobin A1c (HbA1c) levels, gender and age. HbA1c values were measured using a Bio-Rad VARIANT™ II HbA1c Reorder Pack. All data was collected for analysis of the HbA1c levels in different gender and age groups, in order to investigate the association between HbA1c levels and age. Analysis of the 18,265 total cases and 16,734 cases with HbA1c levels <6.5%, demonstrated a positive correlation between levels of HbA1c and patient age. Linear regression for patient age and HbA1c levels demonstrated that HbA1c (%) = 0.020 × age (years) + 4.523 (r=0.369, P<0.0001) and HbA1c (%) = 0.014 × age (years) + 4.659 (r=0.485, P<0.0001), respectively. HbA1c levels of the male group were significantly higher than those of the female group (P<0.0001). Furthermore, in different gender groups, HbA1c levels gradually rose with increasing age. Therefore, HbA1c levels are associated with age and gender in Chinese populations, and this should be considered when selecting HbA1c as a criterion for future diabetes screening.

15.
Bing Du Xue Bao ; 30(4): 346-52, 2014 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-25272585

RESUMO

Bel1, a transactivator of prototype foamy virus (PFV), plays pivotal roles in the replication of PFV. Previous studies have shown that Bel1 bears a nuclear localization signal (NLS), but its amino acid sequence remains unclear and the corresponding importins have not been identified. In this report, we inserted various fragments of Bel1 into an EGFP-GST fusion protein and investigated their subcellular localization by fluorescence microscopy. We found that the 215PRQKRPR221 fragment could direct nuclear localization, which accords with the consensus sequence K(K/R)X(K/R) of monopartite NLS. Point mutation experiments revealed that K218, R219, and R221 are essential for the nuclear localization of Bel1. The results of the GST-pulldown showed that the Bel1 fragment with residues 215-223, which bears the NLS, interacts with KPNA1, KPNA6, and KPNA7. This result suggests that KPNA1, KPNA6, and KPNA7 maybe involved in Bel1 nuclear translocation.


Assuntos
Núcleo Celular/virologia , Sinais de Localização Nuclear/genética , Infecções por Retroviridae/metabolismo , Proteínas dos Retroviridae/metabolismo , Spumavirus/genética , Transativadores/metabolismo , alfa Carioferinas/metabolismo , Linhagem Celular , Núcleo Celular/genética , Núcleo Celular/metabolismo , Humanos , Sinais de Localização Nuclear/metabolismo , Ligação Proteica , Transporte Proteico , Infecções por Retroviridae/genética , Infecções por Retroviridae/virologia , Proteínas dos Retroviridae/química , Proteínas dos Retroviridae/genética , Spumavirus/química , Spumavirus/fisiologia , Transativadores/química , Transativadores/genética , alfa Carioferinas/genética
16.
Virology ; 449: 215-23, 2014 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-24418555

RESUMO

Prototype foamy virus encodes a transactivator called Bel1 that enhances viral gene transcription and is essential for PFV replication. Nuclear localization of Bel1 has been reported to rely on two proximal basic motifs R(199)H(200) and R(221)R(222)R(223) that likely function together as a bipartite nuclear localization signal. In this study, we report that mutating R(221)R(222)R(223), but not R(199)H(200), relocates Bel1 from the nucleus to the cytoplasm, suggesting an essential role for R(221)R(222)R(223) in the nuclear localization of Bel1. Although not affecting the nuclear localization of Bel1, mutating R(199)H(200) disables Bel1 from transactivating PFV promoters. Results of EMSA reveal that the R(199)H(200) residues are vital for the binding of Bel1 to viral promoter DNA. Moreover, mutating R(199)H(200) in Bel1 impairs PFV replication to a much greater extent than mutating R(221)R(222)R(223). Collectively, our findings suggest that R(199)H(200) directly participate in Bel1 binding to viral promoter DNA and are indispensible for Bel1 transactivation activity.


Assuntos
Núcleo Celular/virologia , Regulação Viral da Expressão Gênica , Regiões Promotoras Genéticas , Infecções por Retroviridae/virologia , Proteínas dos Retroviridae/química , Proteínas dos Retroviridae/metabolismo , Spumavirus/metabolismo , Sequências Repetidas Terminais , Transativadores/química , Transativadores/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Humanos , Dados de Sequência Molecular , Ligação Proteica , Transporte Proteico , Proteínas dos Retroviridae/genética , Spumavirus/química , Spumavirus/genética , Transativadores/genética , Ativação Transcricional
17.
PLoS One ; 7(12): e50932, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23226549

RESUMO

BACKGROUND: Interferon-induced 35-kDa protein (IFP35) plays important roles in antiviral defense and the progression of some skin cancer diseases. It can be induced by interferon-γ (IFN-γ) in multiple human cells. However, the mechanisms by which IFN-γ contributes to IFP35 induction remain to be elucidated. METHODS/PRINCIPAL FINDINGS: We identified the transcription start sites of IFP35 by 5' rapid amplification of cDNA ends (RACE) and cloned the promoter of IFP35. Sequence analysis and luciferase assays revealed two GC boxes and an IFN-stimulated response element (ISRE) in the 5' upstream region of the transcription start sites, which were important for the basal transcription of IFP35 gene. Furthermore, we found that interferon regulatory factor 1 (IRF-1) and IRF-2 could bind to IFP35 promoter and upregulate endogenous IFP35 protein level. Depletion of endogenous IRF-1 by interfering RNA reduced the constitutive and IFN-γ-dependent expression of IFP35, whereas depletion of IRF-2 had little effect on IFN-γ-inducible IFP35 expression. Moreover, IRF-1 was recruited to the ISRE site in IFP35 promoter in IFN-γ treated HeLa cells, as demonstrated by electrophoretic mobility shift and chromatin immunoprecipitation assays. CONCLUSIONS/SIGNIFICANCE: These findings provide the first evidence that IRF-1 and IRF-2 are involved in constitutive IFP35 expression in HeLa cells, while IRF-1 also activates IFP35 expression in an IFN-γ-inducible manner. Our data therefore identified a new IRF-1 and IRF-2 target gene, which may expand our current understanding of the versatile functions of IRF-1 and IRF-2.


Assuntos
Fator Regulador 1 de Interferon/metabolismo , Interferon gama/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Regulação para Cima/genética , Sequência de Bases , Sítios de Ligação/genética , Sequência Consenso/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Fatores Reguladores de Interferon/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Elementos de Resposta/genética , Fator de Transcrição STAT1/metabolismo , Transcrição Gênica/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
18.
Acc Chem Res ; 43(6): 936-44, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20455571

RESUMO

Replacing or repairing masonry mortar is usually necessary in the restoration of historical constructions, but the selection of a proper mortar is often problematic. An inappropriate choice can lead to failure of the restoration work, and perhaps even further damage. Thus, a thorough understanding of the original mortar technology and the fabrication of appropriate replacement materials are important research goals. Many kinds of materials have been used over the years in masonry mortars, and the technology has gradually evolved from the single-component mortar of ancient times to hybrid versions containing several ingredients. Beginning in 2450 BCE, lime was used as masonry mortar in Europe. In the Roman era, ground volcanic ash, brick powder, and ceramic chip were added to lime mortar, greatly improving performance. Because of its superior properties, the use of this hydraulic (that is, capable of setting underwater) mortar spread, and it was adopted throughout Europe and western Asia. Perhaps because of the absence of natural materials such as volcanic ash, hydraulic mortar technology was not developed in ancient China. However, a special inorganic-organic composite building material, sticky rice-lime mortar, was developed. This technology was extensively used in important buildings, such as tombs, in urban constructions, and even in water conservancy facilities. It may be the first widespread inorganic-organic composite mortar technology in China, or even in the world. In this Account, we discuss the origins, analysis, performance, and utility in historic preservation of sticky rice-lime mortar. Mortar samples from ancient constructions were analyzed by both chemical methods (including the iodine starch test and the acid attack experiment) and instrumental methods (including thermogravimetric differential scanning calorimetry, X-ray diffraction, Fourier transform infrared, and scanning electron microscopy). These analytical results show that the ancient masonry mortar is a special organic-inorganic composite material. The inorganic component is calcium carbonate, and the organic component is amylopectin, which is presumably derived from the sticky rice soup added to the mortar. A systematic study of sticky rice-lime mortar technology was conducted to help determine the proper courses of action in restoring ancient buildings. Lime mortars with varying sticky rice content were prepared and tested. The physical properties, mechanical strength, and compatibility of lime mortar were found to be significantly improved by the introduction of sticky rice, suggesting that sticky rice-lime mortar is a suitable material for repairing mortar in ancient masonry. Moreover, the amylopectin in the lime mortar was found to act as an inhibitor; the growth of the calcium carbonate crystals is controlled by its presence, and a compact structure results, which may explain the enhanced performance of this organic-inorganic composite compared to single-component lime mortar.

19.
Lin Chuang Er Bi Yan Hou Ke Za Zhi ; 16(2): 51-3, 2002 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-15510625

RESUMO

OBJECTIVE: To investigate the classification criterion and the treatment of lamina papyracea blow-out fracture. METHOD: A clinic analysis was made on 108 case with lamina papyracea blow-out fracture. According to the classification, different treatments were taken differently. RESULT: The classification of 108 cases were reported as follows: 71 cases were classified as level 1, 33 cases as level 2, 4 cases as level 3. There was no special treat-ment for 43 cases (level 1) who had no diplopia. 28 cases (level 1) who had symptom of diplopia were treated conservatively. Its cure rate was 92. 9% (26/28). Other 34 cases were operated. Among them, 33 cases were classified as at least level 2, 1 case who had no satisfactory curative effect with conservative therapy was classified as level 1. The cure rate was 88. 2% (30/34). The other 4 cases classified as level 2 or 3 who didn't accept operation were treated conservatively, the cure rate was 25% (1/4). CONCLUSION: The classification of lamina papyracea blowout fracture facilitates the judgement of patient's condition and the selection of treatment. The transnasal endoscopic operation on serious lamina papyracea blow-out fracture cases produces a good curative effect.


Assuntos
Seio Etmoidal/lesões , Fraturas Orbitárias/classificação , Adolescente , Adulto , Idoso , Criança , Endoscopia , Seio Etmoidal/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas Orbitárias/cirurgia , Fraturas Orbitárias/terapia
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