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181.
T J F Branco L F Vieira Ferreira A M Botelho do Rego A S Oliveira J P Da Silva 《Photochemical & photobiological sciences》2006,5(11):1068-1077
Diffuse reflectance and luminescence techniques were used to study the photophysics and photochemistry of pyrene within p-tert-butylcalix[n]arenes with n = 4, 6, and 8, and to study their ability to form inclusion complexes in heterogeneous media. Evidences for inclusion complex formation were found for the three hosts under study. Ground state diffuse reflectance results have shown the formation of ground state dimers of pyrene inside the cavity of calix[6]arene and calix[8]arene, with this feature much more evident for calix[6]arene. For calix[4]arene, only a monomer fits inside the cavity and the presence of pyrene microcrystals outside the cavity was detected. A luminescence lifetime distribution analysis was performed, revealing the presence of prompt emissions from the pyrene microcrystals outside the cavity in the case of calix[4]arene and from the constrained dimers inside the cavities of calix[6]arene and calix[8]arene. Transient absorption results have shown the presence of pyrene radical cation and also of trapped electrons for the three hosts under study. The formation of the phenoxyl radical of the calixarene following the laser pulsed excitation of pyrene at 355 nm is increased for calix[6]arene and calix[8]arene. This feature is particularly relevant for calix[6]arene, suggesting a very favourable situation for the hydrogen atom abstraction to occur. The analysis of the degradation products revealed the presence of hydroxypyrene as a major photodegradation product for the three hosts. Dihydro-hydroxypyrene was also formed in the case of calix[6]arene and calix[8]arene. The formation of the calixarene's phenoxyl radical and subsequent hydrogen abstraction is consistent with the formation of dihydro-dihydroxypyrene. 相似文献
182.
Recent collections of isopods in Alboran Island and Algeria included several specimens of the species Stenosoma stephensenisp. n. This is the fourteenth species described in the genus Stenosoma Leach, 1814. Examination of two specimens collected during the Danish oceanographic cruises of the Thor (1908-10) close to the Galite Islands, and identified as Stenosoma acuminatum Leach, 1814, revealed that both belong to Stenosoma stephensenisp. n. In light of these findings, the Mediterranean records of Stenosoma acuminatum are revised, and it is proposed that Stenosoma acuminatum is a strictly Atlantic species. An updated diagnosis for the genus Stenosoma is given, together with a key for the identification of its species. The nomenclatural status of the name Synisoma Collinge, 1917 is addressed, and although it is in prevailing usage, it is shown that Stenosoma Leach, 1814 is the valid name of the genus. 相似文献
183.
As the prevalence of cancer and transmittable disease persists, the development of new and more advanced therapies remains a priority in medical research. An emerging platform for the treatment of these illnesses is the use of materials formed via peptide assembly where the bulk material itself acts as the therapeutic. Higher ordered peptide structures with defined chemistry are capable of cellular targeting, recognition, and internalization. Recent design efforts are being made to exploit the nanoscale definition of the materials formed by assembling peptides to target cancer and microbial cells and to function as vaccines. This review focuses on assembled peptide materials that actively participate in the biological processes important to cancer and transmittable diseases to exert an anticipated functional outcome. 相似文献
184.
Characterization of modular bacteriophage endolysins from Myoviridae phages OBP, 201φ2-1 and PVP-SE1
Peptidoglycan lytic enzymes (endolysins) induce bacterial host cell lysis in the late phase of the lytic bacteriophage replication cycle. Endolysins OBPgp279 (from Pseudomonas fluorescens phage OBP), PVP-SE1gp146 (Salmonella enterica serovar Enteritidis phage PVP-SE1) and 201φ2-1gp229 (Pseudomonas chlororaphis phage 201φ2-1) all possess a modular structure with an N-terminal cell wall binding domain and a C-terminal catalytic domain, a unique property for endolysins with a Gram-negative background. All three modular endolysins showed strong muralytic activity on the peptidoglycan of a broad range of Gram-negative bacteria, partly due to the presence of the cell wall binding domain. In the case of PVP-SE1gp146, this domain shows a binding affinity for Salmonella peptidoglycan that falls within the range of typical cell adhesion molecules (K(aff) = 1.26 × 10(6) M(-1)). Remarkably, PVP-SE1gp146 turns out to be thermoresistant up to temperatures of 90 °C, making it a potential candidate as antibacterial component in hurdle technology for food preservation. OBPgp279, on the other hand, is suggested to intrinsically destabilize the outer membrane of Pseudomonas species, thereby gaining access to their peptidoglycan and exerts an antibacterial activity of 1 logarithmic unit reduction. Addition of 0.5 mM EDTA significantly increases the antibacterial activity of the three modular endolysins up to 2-3 logarithmic units reduction. This research work offers perspectives towards elucidation of the structural differences explaining the unique biochemical and antibacterial properties of OBPgp279, PVP-SE1gp146 and 201φ2-1gp229. Furthermore, these endolysins extensively enlarge the pool of potential antibacterial compounds used against multi-drug resistant Gram-negative bacterial infections. 相似文献
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Carla GS Saad Ana CM Ribeiro Julio CB Moraes Liliam Takayama Celio R Goncalves Marcelo B Rodrigues Ricardo M de Oliveira Clovis A Silva Eloisa Bonfa Rosa MR Pereira 《Arthritis research & therapy》2012,14(5):R216
Introduction
Sclerostin levels have been reported to be low in ankylosing spondylitis (AS), but there is no data regarding the possible role of this Wnt inhibitor during anti-tumor necrosis factor (TNF) therapy. The present study longitudinally evaluated sclerostin levels, inflammatory markers and bone mineral density (BMD) in AS patients under anti-TNF therapy.Methods
Thirty active AS patients were assessed at baseline, 6 and 12 months after anti-TNF therapy regarding clinical parameters, inflammatory markers, BMD and baseline radiographic damage (mSASSS). Thirty age- and sex-matched healthy individuals comprised the control group. Patients'' sclerostin levels, sclerostin binding low-density lipoprotein receptor-related protein 6 (LRP6) and BMD were evaluated at the same time points and compared to controls.Results
At baseline, AS patients had lower sclerostin levels (60.5 ± 32.7 vs. 96.7 ± 52.9 pmol/L, P = 0.002) and comparable sclerostin binding to LRP6 (P = 0.387) than controls. Improvement of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), Ankylosing Spondylitis quality of life (ASQoL) was observed at baseline vs. 6 vs. 12 months (P < 0.01). Concomitantly, a gradual increase in spine BMD (P < 0.001) and a positive correlation between baseline mSASSS and spine BMD was found (r = 0.468, P < 0.01). Inflammatory parameters reduction was observed comparing baseline vs. 6 vs. 12 months (P <0.01). Sclerostin levels progressively increased [baseline (60.5 ± 32.7) vs. 6 months (67.1 ± 31.9) vs. 12 months (72.7 ± 32.3) pmol/L, P <0.001]. At 12 months, the sclerostin levels remained significantly lower in patients compared to controls (72.7 ± 32.3 vs. 96.70 ± 52.85 pmol/L, P = 0.038). Moreover, sclerostin serum levels at 12 months were lower in the 10 patients with high C reactive protein (CRP) (≥ 5 mg/l) compared to the other 20 patients with normal CRP (P = 0.004). Of note, these 10 patients with persistent inflammation also had lower sclerostin serum levels at baseline compared to the other patients (P = 0.023). Univariate logistic regression analysis demonstrated that AS patients with lower sclerostin serum levels had an increased risk to have high CRP at 12 months (odds ratio = 7.43, 95% CI 1.23 to 45.01, P = 0.020) than those with higher sclerostin values.Conclusions
Persistent low sclerostin levels may underlie continuous inflammation in AS patients under anti-TNF therapy. 相似文献188.
Viviane Castelo Branco Reis André Moraes Nicola Osmar de Souza Oliveira Neto Vinícius Daniel Ferreira Batista Lidia Maria Pepe de Moraes Fernando Araripe Gon?alves Torres 《Journal of industrial microbiology & biotechnology》2012,39(11):1673-1683
Used for millennia to produce beverages and food, Saccharomyces cerevisiae also became a workhorse in the production of biofuels, most notably bioethanol. Yeast strains have acquired distinct characteristics that are the result of evolutionary adaptation to the stresses of industrial ethanol production. JP1 is a dominant industrial S. cerevisiae strain isolated from a sugarcane mill and is becoming increasingly popular for bioethanol production in Brazil. In this work, we carried out the genetic characterization of this strain and developed a set of tools to permit its genetic manipulation. Using flow cytometry, mating type, and sporulation analysis, we verified that JP1 is diploid and homothallic. Vectors with dominant selective markers for G418, hygromycin B, zeocin, and ρ-fluoro-dl-phenylalanine were used to successfully transform JP1 cells. Also, an auxotrophic ura3 mutant strain of JP1 was created by gene disruption using integration cassettes with dominant markers flanked by loxP sites. Marker excision was accomplished by the Cre/loxP system. The resulting auxotrophic strain was successfully transformed with an episomal vector that allowed green fluorescent protein expression. 相似文献
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Catarina Addobbati Jordão Cavalcanti Jaqueline de Azevêdo Silva Will de Barros Pita Tiago Degani Veit Odirlei Andre Monticielo Ricardo Machado Xavier João Carlos Tavares Brenol Cleiton Viegas Brenol Thiago Sotero Fragoso Alexandre Domingues Barbosa Ângela Luiza Branco Pinto Duarte Renê Donizeti Ribeiro Oliveira Paulo Louzada-Júnior Eduardo Antônio Donadi Sergio Crovella José Artur Bogo Chies Paula Sandrin-Garcia 《Molecular biology reports》2016,43(1):41-51