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1.
Appl Environ Microbiol ; 88(6): e0208721, 2022 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-35108098

RESUMEN

Hydrophobins are small secreted amphipathic proteins ubiquitous among filamentous fungi. Hydrophobin RolA produced by Aspergillus oryzae attaches to solid surfaces, recruits polyesterase CutL1, and thus promotes hydrolysis of polyesters. Because the N-terminal region of RolA is involved in the interaction with CutL1, the orientation of RolA on the solid surface is important. However, the kinetic properties of RolA adsorption to solid surfaces with various chemical properties remain unclear, and RolA structures assembled after the attachment to surfaces are unknown. Using a quartz crystal microbalance (QCM), we analyzed the kinetic properties of RolA adsorption to the surfaces of QCM electrodes that had been chemically modified to become hydrophobic or charged. We also observed the assembled RolA structures on the surfaces by atomic force microscopy and performed molecular dynamics (MD) simulations of RolA adsorption to self-assembled monolayer (SAM)-modified surfaces. The RolA-surface interaction was considerably affected by the zeta potential of RolA, which was affected by pH. The interactions of RolA with the surface seemed to be involved in the self-assembly of RolA. Three types of self-assembled structures of RolA were observed: spherical, rod-like, and mesh-like. The kinetics of RolA adsorption and the structures formed depended on the amount of RolA adsorbed, chemical properties of the electrode surface, and the pH of the buffer. Adsorption of RolA to solid surfaces seemed to depend mainly on its hydrophobic interaction with the surfaces; this was supported by MD simulations, which suggested that hydrophobic Cys-Cys loops of RolA attached to all SAM-modified surfaces at all pH values. IMPORTANCE The adsorption kinetics of hydrophobins to solid surfaces and self-assembled structures formed by hydrophobin molecules have been studied mostly independently. In this report, we combined the kinetic analysis of hydrophobin RolA adsorption onto solid surfaces and observation of RolA self-assembly on these surfaces. Since RolA, whose isoelectric point is close to pH 4.0, showed higher affinity to the solid surfaces at pH 4.0 than at pH 7.0 or 10.0, the affinity of RolA to these surfaces depends mainly on hydrophobic interactions. Our combined analyses suggest that not only the adsorbed amount of RolA but also the chemical properties of the solid surfaces and the zeta potential of RolA affect the self-assembled RolA structures formed on these surfaces.


Asunto(s)
Aspergillus oryzae , Adsorción , Aspergillus oryzae/metabolismo , Proteínas Fúngicas/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Propiedades de Superficie
2.
Langmuir ; 36(13): 3590-3599, 2020 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-32049537

RESUMEN

The development of a strategy for the assembly of nanoscale building blocks, in particular, anisotropic nanoparticles, into desired structures is important for the construction of functional materials and devices. However, control over the orientation of rod-shaped nanoparticles on a substrate for integration into solid-state devices remains challenging. Here, we report a strategy for the fabrication of finely aligned gold nanorod (GNR) arrays using polymer (DNA) brushes as a nanoscale template. The gold nanorods modified with cationic surface ligands were electrostatically adsorbed onto the DNA brush substrates under various conditions. The orientational behavior of the GNRs was examined by spectral analyses and transmission electron microtomography (TEMT). As a result, we found several important factors, such as moderate interaction between GNRs and polymers and polymer densities on the substrate, related to the vertical alignment of GNRs on the substrates. We also developed a purification method to remove the undesired adsorption of GNRs onto the arrays. Finally, we have succeeded in the fabrication of extensive vertical GNR arrays of high quality via the easy bottom-up process.

3.
Gan To Kagaku Ryoho ; 47(13): 2391-2393, 2020 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-33468971

RESUMEN

We report the case of an elderly male patient with ductal carcinoma in situ(DCIS) of the nipple. A 93-year-old man visited the hospital because of pain and bleeding in and swelling of the right nipple. A benign tumor was suspected, but a definite diagnosis could not be made before surgery based on echo and cytology findings; thus, a malignant tumor could not be ruled out. He underwent partial mastectomy combined with the areola and nipple for diagnosis and treatment. Histologic examination confirmed the diagnosis of DCIS of the nipple. The surgical margin was negative. At 6 months after the surgery, he was doing well with no evidence of disease in the absence of postoperative adjuvant therapy. Thus, clinicians should consider breast carcinoma of the nipple as a differential diagnosis when an elderly man presents with swelling of the nipple.


Asunto(s)
Neoplasias de la Mama , Carcinoma Intraductal no Infiltrante , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/cirugía , Carcinoma Intraductal no Infiltrante/diagnóstico por imagen , Carcinoma Intraductal no Infiltrante/cirugía , Humanos , Mastectomía , Mastectomía Segmentaria , Pezones/cirugía
4.
J Infect Chemother ; 25(12): 995-1000, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31239192

RESUMEN

BACKGROUND: Although fluoroquinolones are considered as alternative therapies of pulmonary Mycobacterium avium complex (MAC) disease, the association between fluoroquinolone resistance and MAC genotypes in clinical isolates from individuals not previously treated for MAC infection is not fully clear. METHODS: Totals of 154 M. avium isolates and 35 Mycobacterium intracellulare isolates were obtained from treatment-naïve patients with pulmonary MAC disease at the diagnosis of MAC infection at 8 hospitals in Japan. Their susceptibilities of moxifloxacin were determined by broth microdilution methods. Moxifloxacin-resistant isolates were examined for mutations of gyrA and gyrB. Variable numbers of tandem repeats (VNTR) assay was performed using 15 M. avium VNTR loci and 16 M. intracellulare VNTR loci. RESULTS: Moxifloxacin susceptibility was categorized as resistant and intermediate for 6.5% and 16.9%, respectively, of M. avium isolates and 8.6% and 17.1% of M. intracellulare isolates. Although the isolates of both species had amino acid substitutions of Thr 96 and Thr 522 at the sites corresponding to Ser 95 in the M. tuberculosis GyrA and Gly 520 in the M. tuberculosis GyrB, respectively, these substitutions were observed irrespective of susceptibility and did not confer resistance. The VNTR assays showed revealed three clusters among M. avium isolates and two clusters among M. intracellulare isolates. No significant differences in moxifloxacin resistance were observed among these clusters. CONCLUSIONS: Although resistance or intermediate resistance to moxifloxacin was observed in approximately one-fourth of M. avium and M. intracellulare isolates, this resistance was not associated with mutations in gyrA and gyrB or with VNTR genotypes.


Asunto(s)
Antibacterianos/farmacología , Moxifloxacino/farmacología , Complejo Mycobacterium avium/efectos de los fármacos , Infección por Mycobacterium avium-intracellulare/tratamiento farmacológico , Mycobacterium avium/efectos de los fármacos , Antibacterianos/uso terapéutico , Girasa de ADN/genética , Farmacorresistencia Bacteriana/genética , Genotipo , Humanos , Japón , Pruebas de Sensibilidad Microbiana , Repeticiones de Minisatélite/genética , Moxifloxacino/uso terapéutico , Mutación , Mycobacterium avium/genética , Mycobacterium avium/aislamiento & purificación , Complejo Mycobacterium avium/genética , Complejo Mycobacterium avium/aislamiento & purificación , Infección por Mycobacterium avium-intracellulare/microbiología
5.
Acc Chem Res ; 50(6): 1293-1302, 2017 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-28525260

RESUMEN

Self-assembling structures and their dynamical processes in polymeric systems have been investigated using three-dimensional transmission electron microscopy (3D-TEM). Block copolymers (BCPs) self-assemble into nanoscale periodic structures called microphase-separated structures, a deep understanding of which is important for creating nanomaterials with superior physical properties, such as high-performance membranes with well-defined pore size and high-density data storage media. Because microphase-separated structures have become increasingly complicated with advances in precision polymerization, characterizing these complex morphologies is becoming increasingly difficult. Thus, microscopes capable of obtaining 3D images are required. In this article, we demonstrate that 3D-TEM is an essential tool for studying BCP nanostructures, especially those self-assembled during dynamical processes and under confined conditions. The first example is a dynamical process called order-order transitions (OOTs). Upon changing temperature or pressure or applying an external field, such as a shear flow or electric field, BCP nanostructures transform from one type of structure to another. The OOTs are examined by freezing the specimens in the middle of the OOT and then observing the boundary structures between the preexisting and newly formed nanostructures in three-dimensions. In an OOT between the bicontinuous double gyroid and hexagonally packed cylindrical structures, two different types of epitaxial phase transition paths are found. Interestingly, the paths depend on the direction of the OOT. The second example is BCP self-assemblies under confinement that have been examined by 3D-TEM. A variety of intriguing and very complicated 3D morphologies can be formed even from the BCPs that self-assemble into simple nanostructures, such as lamellar and cylindrical structures in the bulk (in free space). Although 3D-TEM is becoming more frequently used for detailed morphological investigations, it is generally used to study static nanostructures. Although OOTs are dynamical processes, the actual experiment is done in the static state, through a detailed morphological study of a snapshot taken during the OOT. Developing time-dependent nanoscale 3D imaging has become a hot topic. Here, the two main problems preventing the development of in situ electron tomography for polymer materials are addressed. First, the staining protocol often used to enhance contrast for electrons is replaced by a new contrast enhancement based on chemical differences between polymers. In this case, no staining is necessary. Second, a new 3D reconstruction algorithm allows us to obtain a high-contrast, quantitative 3D image from fewer projections than is required for the conventional algorithm to achieve similar contrast, reducing the number of projections and thus the electron beam dose. Combining these two new developments is expected to open new doors to 3D in situ real-time structural observation of polymer materials.

6.
Gan To Kagaku Ryoho ; 45(1): 184-186, 2018 Jan.
Artículo en Japonés | MEDLINE | ID: mdl-29362349

RESUMEN

We report the case of a patient with triple negative breast cancer(TNBC)who showed isolated brain metastasis relatively soon after pathological complete response(pCR)to neoadjuvant chemotherapy. A 45-year-old woman with a diagnosis of TNBC(T2N1M0, Stage II B)received neoadjuvant chemotherapy with 5-FU/epirubicin/cyclophosphamide(FEC), followed by docetaxel. After the neoadjuvant chemotherapy, she underwent mastectomy and axillary lymph node dissection. Histological examination of the resected specimens revealed pCR. Brain metastasis, however, developed 7 months after the resection. She underwent total removal of the brain tumor and 50 Gy irradiation to the right frontal lobe. Histological examination confirmed a diagnosis of metastasis from TNBC. She is doing well with no evidence of disease 81 months after resection of the brain metastasis. This case and a review of the literature suggest that the clinician should be aware that brain metastasis from breast cancer may develop even after achieving pCR to neoadjuvant chemotherapy. Surgical resection followed by radiotherapy may provide a survival benefit for selected patients with isolated brain metastasis from breast cancer.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Encefálicas/secundario , Terapia Neoadyuvante , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirugía , Femenino , Humanos , Persona de Mediana Edad , Resultado del Tratamiento , Neoplasias de la Mama Triple Negativas/patología , Neoplasias de la Mama Triple Negativas/cirugía
7.
Gan To Kagaku Ryoho ; 45(13): 2354-2356, 2018 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-30692462

RESUMEN

We report the case ofan elderly patient with squamous cell carcinoma(SCC)ofthe breast, which showed negative conversion after endocrine therapy. An 82-year-old woman with a diagnosis ofER -positive SCC(cT1N0M0, StageⅠ)received primary endocrine therapy with 5 hormonal medicines. Following the endocrine therapy, she underwent mastectomy and axillary node resection. Histological examination confirmed a diagnosis of ER-negative SCC. At 10 months after the operation, she was doing well with no evidence ofdisease without postoperative adjuvant therapy. Thus, clinicians should be aware that the ER status may change after primary endocrine therapy. For elderly patients with breast cancer, it is important to be aware that primary endocrine therapy can become ineffective due to ER-negative conversion and aging due to prolonged treatment.


Asunto(s)
Neoplasias de la Mama , Carcinoma de Células Escamosas , Anciano de 80 o más Años , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/cirugía , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/cirugía , Terapia Combinada , Femenino , Humanos , Escisión del Ganglio Linfático , Mastectomía , Receptores de Estrógenos/análisis
8.
Soft Matter ; 13(32): 5428-5436, 2017 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-28702567

RESUMEN

Block copolymer micelles have been extensively discussed for many decades because of their applications, such as lithography and drug delivery. However, controlling the morphologies of nanostructure assembly using block copolymer micelles as building elements remains a great challenge. In this work, we developed a novel route to induce micelle assembly in confined geometries. Polystyrene-block-polydimethylsiloxane (PS-b-PDMS) micelle solutions were used to prepare micelle nanostructures, and the critical parameters affecting the morphologies were determined. Micelle nanorods, micelle nanospheres, and multi-component nanopeapods were prepared by wetting anodic aluminum oxide (AAO) templates with micelle solutions. Rayleigh-instability-driven transformation was discovered to play an important role in controlling the morphologies of the micelle nanostructures. This study not only proposes a versatile approach to preparing block copolymer micelle nanostructures, but it also provides deeper insight into the controlling factors of block copolymer micelle morphologies in cylindrical confinement.

9.
Pediatr Int ; 59(8): 869-877, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28453894

RESUMEN

BACKGROUND: There have been few reports on the efficacy and safety of oral propranolol at 3 mg/kg/day for infantile hemangioma (IH) in Japanese patients. METHODS: A multicenter, open-label phase III study was conducted to evaluate the efficacy and safety of oral propranolol solution in Japanese infants aged 35-150 days with proliferating IH. Thirty-two patients were enrolled in the study, received propranolol solution for 24 weeks at 3 mg/kg/day, and completed the study. RESULTS: The success rate (complete or nearly complete resolution) at week 24 (primary endpoint) was 78% (95%CI: 60-91%). The improvement rate since the previous visit was 100% (32/32) after week 5. Overall, the IH surface area, maximum diameter, and color intensity all decreased over time. Consistency in assessment between the centralized and the investigator on-site assessments was observed in 26 patients. Of the 32 patients, 11 needed further treatment other than the study drug. The incidence of adverse events (AE) and drug-related AE was 97% and 31%, respectively. AE that occurred in ≥two patients were either typical of propranolol use (such as blood pressure decrease) or common events in infants. AE that resulted in dose reduction were observed in two patients, but no serious AE or AE that led to study drug discontinuation were observed. CONCLUSION: Oral propranolol solution at 3 mg/kg/day is effective and safe in Japanese IH patients.


Asunto(s)
Antagonistas Adrenérgicos beta/uso terapéutico , Hemangioma Capilar/tratamiento farmacológico , Propranolol/uso terapéutico , Administración Oral , Esquema de Medicación , Femenino , Estudios de Seguimiento , Humanos , Lactante , Japón , Masculino , Resultado del Tratamiento
10.
J Am Chem Soc ; 138(10): 3274-7, 2016 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-26924649

RESUMEN

We demonstrate that binary mixtures of small and large gold nanoparticles (GNPs) (5/15, 5/30, 10/30, and 15/30 nm in diameter) in the presence of a glucose-terminated fluorinated oligo(ethylene glycol) ligand can spontaneously form size-segregated assemblies. The outermost layer of the assembly is composed of a single layer of small-sized GNPs, while the larger-sized GNPs are located in the interior, forming what is referred to as a yolk/shell assembly. Time course study reveals that small and large GNPs aggregate together, and these kinetically trapped aggregations were transformed into a size-segregated structure by repeating fusions. A yolk/shell structure was directly visualized in solution by X-ray laser diffraction imaging, indicating that the structure was truly formed in solution, but not through a drying process.

11.
Soft Matter ; 12(27): 5905-14, 2016 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-27337660

RESUMEN

We numerically study a set of coupled Cahn-Hilliard equations as a means to find morphologies of diblock copolymers in three-dimensional spherical confinement. This approach allows us to find a variety of energy minimizers including rings, tennis balls, Janus balls and multipods among several others. Phase diagrams of confined morphologies are presented. We modify the size of the interface between microphases to control the number of holes in multipod morphologies. Comparison to experimental observation by transmission electron microtomography of multipods in polystyrene-polyisoprene diblock copolymers is also presented.

12.
Soft Matter ; 12(40): 8448, 2016 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-27714344

RESUMEN

Correction for 'Frustrated phases under three-dimensional confinement simulated by a set of coupled Cahn-Hilliard equations' by Edgar Avalos et al., Soft Matter, 2016, 12, 5905-5914.

13.
Jpn J Antibiot ; 69(2): 101-10, 2016 Apr.
Artículo en Japonés | MEDLINE | ID: mdl-27544978

RESUMEN

A study was conducted of the 1,225 Pseudomonas aeruginosa strains that were isolated at 20 medical institutions in the Kinki district between 2011 and 2013 to determine their antimicrobial susceptibility and to characterize the strains of multidrug-resistant Pseudomonas aeruginosa (MDRP) and the metallo-ß-lactamase (MBL) -producing strains. The MIC50/MIC90 values (µg/mL) of the various antimicrobial agents were as follows: imipenem, 2/>8; meropenem, 1/>8; doripenem, 0.5/8; biapenem, 1/>8; tazobactam/piperacillin, 8/>64; piperacillin, 8/>64; sulbactam/cefoperazone, 8/64; cefepime, 4/16; cefozopran, 2/>16; aztreonam, 8/>16; amikacin, 4/16; levofloxacin, 1/>4; and ciprofloxacin, 0.25/>2. From the viewpoint of the annual changes in the susceptibility rates (according to the CLSI guidelines [M100-S22]), the susceptibility to tazobactam/piperacillin, piperacillin, cefepime, cefozopran and aztreonam decreased in 2013. On the other hand, two antimicrobial agents showed high susceptibility rates each year; amikacin (94.0-95.6%) showed the highest rate, followed by doripenem (80.3-82.6%). With the exception of amikacin, there were substantial inter-institutional differences in antimicrobial susceptibility. In comparison to the previous CLSI guidelines (M100-S21), the new CLSI guidelines (M100-S22) on the use of carbapenems and penicillins show that the MIC80 has been affected. The MDRP detection rates in 2011, 2012 and 2013 were 1.8% (8 strains), 1.8% (8 strains), and 2.8% (10 strains), respectively. The MBL detection rates were as follows: bla(VIM-2), 0.2% (1 strain) in 2011; bla(IMP-1), 0.9% (4 strains) in 2012, and 1.7% (6 strains, including bla(IMP-1) [3 strains], bla(IMP-2) [2 strains] and bla(VIM-2) [1 strain]) in 2013.


Asunto(s)
Antibacterianos/farmacología , Pseudomonas aeruginosa/aislamiento & purificación , Farmacorresistencia Bacteriana Múltiple , Humanos , Japón , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa/efectos de los fármacos
14.
Kekkaku ; 91(11-12): 717-725, 2016 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-30648375

RESUMEN

[Objective] The infectious disease control law has been amended in May 2015, and the category definition of Mycobacterium tuberculosis as infectious pathogen has been changed, following the definition of extensively drug-resistant M.tuberculosis (XDR-TB) by World Health Organization. To assess the diagnostic capacity of XDR-TB, we conducted an external quality assessment (EQA) for the anti-tuberculosis drug susceptibility testing (DST). [Method] A total of 10 M.tuberculosis strains with known drug susceptibility were sent to each participating laboratory. The drugs assessed were isoniazid (INH), rifampicin (RFP), streptomycin (SM), ethambutol (EB), levofloxacin (LVFX), and kanamycin (KM). DST was performed using each routine method(s), and the results were compared with the judicial diagnoses. The sensitivity, specificity, overall agreement (effi- ciency) and kappa coefficient were calculated for each drug tested. In addition, the diagnostic accuracy of multidrug-resis- tant M. tuberculosis (MDR-TB) and XDR-TB was assessed. [Results] A total of 88 institutes including 67 hospitals, 16 commercial laboratories, and 5 public health laboratories par- ticipated in the EQA. With 2 laboratories submitting 2 sets of results, a total of 90 independent data sets were analyzed. As for INH, RFP and LVFX, the efficiency was over 95%, but we found two strains each for SM, EB and KM with the efficiency less than 95%. Especially, strain 1 and strain 2 showed efficiency of 72.2% and 71.1% to SM, respectively. This error was mainly found in a certain test kit. If we consider the passing score as showing ≥95 % sensitivity and specificity both to INH and RFP, the diagnostic accuracy of MDR-TB was 92.2% (83/90) in this study. With the same criteria to INH, RFP, LVFX and KM, that of XDR-TB was 79.7% (63/79). [Discussion] The diagnostic capacity of XDR-TB was not sufficient in the current study. Good case management and pathogen control requires higher accuracy. The government may need to conduct a constant EQA and relevant remedial actions.


Asunto(s)
Antituberculosos , Tuberculosis Extensivamente Resistente a Drogas , Antituberculosos/uso terapéutico , Tuberculosis Extensivamente Resistente a Drogas/diagnóstico , Humanos , Pruebas de Sensibilidad Microbiana , Mycobacterium tuberculosis/efectos de los fármacos
15.
Biochem Biophys Res Commun ; 464(1): 94-9, 2015 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-26119690

RESUMEN

Intravenous immunoglobulin (IVIG) is periodically administered to immunocompromised patients together with antimicrobial agents. The evidence that supports the effectiveness of IVIG is mostly based on data from randomized clinical trials; the underlying mechanisms are poorly understood. A recent study revealed that killing of multidrug-resistant bacteria and drug-sensitive strains by neutrophils isolated from healthy donors is enhanced by an IVIG preparation. However, the effectiveness of IVIG in immunocompromised patients remains unclear. The present study found that IVIG increased both killing activity and O2(-) release by neutrophils isolated from six patients receiving immune-suppressive drugs after hematopoietic stem cell transplantation (HSCT); these neutrophils killed both multidrug-resistant extended-spectrum ß-lactamase-producing Escherichia coli (E. coli) and multidrug-resistant Pseudomonas aeruginosa (P. aeruginosa). Moreover, IVIG increased the autophagy of the neutrophils, which is known to play an important role in innate immunity. These results suggest that IVIG promotes both the killing activity and autophagy of neutrophils isolated from immunocompromised patients against multidrug-resistant bacteria.


Asunto(s)
Neoplasias Hematológicas/inmunología , Huésped Inmunocomprometido , Inmunoglobulinas Intravenosas/administración & dosificación , Inmunosupresores/uso terapéutico , Neutrófilos/inmunología , Superóxidos/agonistas , Adulto , Antibacterianos/farmacología , Autofagia/efectos de los fármacos , Autofagia/inmunología , Técnicas de Cocultivo , Farmacorresistencia Bacteriana Múltiple , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Escherichia coli/inmunología , Femenino , Neoplasias Hematológicas/patología , Neoplasias Hematológicas/terapia , Trasplante de Células Madre Hematopoyéticas , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Neutrófilos/citología , Neutrófilos/efectos de los fármacos , Cultivo Primario de Células , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/crecimiento & desarrollo , Pseudomonas aeruginosa/inmunología , Superóxidos/metabolismo , beta-Lactamasas/biosíntesis
16.
Soft Matter ; 10(17): 2919-31, 2014 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-24695767

RESUMEN

This paper reviews recent progress concerning polymeric self-assemblies in confined spaces, including phase-separated structures of polymer blends and block copolymers. Although a wide variety of polymer self-assemblies have been studied in terms of conventional parameters, such as blend ratio, interaction of constituent polymers, block ratio, and molecular weight, a series of unique structures appear when the systems are self-assembled under confined conditions. Due to the limited space for phase separation, the polymers in the confinement are frustrated, and the resulting morphologies are distinctly different from those formed in free space. We give an overview of experimental and theoretical studies of the frustrated morphologies. We begin by defining confinement with respect to dimensionality and surface properties, and then introduce methods for producing various shapes and sizes of three-dimensional confinement. Finally, we present morphological and application-oriented studies and discuss the prospects for this research area.


Asunto(s)
Polímeros/química , Modelos Moleculares , Propiedades de Superficie
17.
J Infect Chemother ; 20(1): 48-51, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24462425

RESUMEN

With the increase in extended spectrum ß-lactamase (ESBL)-producing bacteria in the community, cases are often seen in which treatment of infectious diseases with oral antimicrobial agents is difficult. Therefore, we measured the antimicrobial activities of 14 currently available oral antimicrobial agents against ESBL-producing Escherichia coli and Klebsiella pneumoniae. Based on the standard of the Clinical and Laboratory Standards Institute (CLSI), E. coli showed high susceptibility rates of 99.4% to faropenem (FRPM). In terms of fluoroquinolones, the susceptibility rate of E. coli to levofloxacin (LVFX) was low at 32.2%, whereas it showed a good susceptibility rate of 93.1% to sitafloxacin (STFX). With respect to other antimicrobial agents, susceptibility rates to fosfomycin (FOM) and colistin (CL) were more than 90% each, whereas rates of the two antimicrobial agents expected as therapeutic agents, minocycline (MINO) and sulfamethoxazole-trimethoprim (ST), were low at 62.4% and 44.3%, respectively. Based on the CLSI standard, K. pneumoniae showed high susceptibility rates to ceftibuten (CETB) (91.89%), LVFX (86.49%), and STFX (94.6%), indicating that K. pneumoniae showed higher rates than those of E. coli, particularly to fluoroquinolones. Comparison of susceptibility rates according to E. coli genotype showed that many antimicrobial agents existed to which the CTX-M-9 group showed high susceptibility rates. However, there were many agents to which the CTX-M-1 group showed low susceptibility rates, particularly to CETB (51.1%) and LVFX (17.0%). Although there was no significant difference by genotype between FRPM, STFX, and FOM, a significant difference was observed between LVFX, MINO, and ST. Antibiotic-resistant bacteria with highly pathogenic strains have spread in the community, appropriate use of oral antimicrobial agents is required.


Asunto(s)
Antibacterianos/farmacología , Escherichia coli/efectos de los fármacos , Klebsiella pneumoniae/efectos de los fármacos , beta-Lactamasas/metabolismo , Escherichia coli/metabolismo , Klebsiella pneumoniae/metabolismo , Pruebas de Sensibilidad Microbiana/métodos
18.
Langmuir ; 29(48): 14971-5, 2013 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-24256149

RESUMEN

We have demonstrated the fabrication of fluorine-free liquid marbles from halloysite nanotube. Halloysite is a naturally occurring inorganic nanotube that has a high aspect ratio, and the surface was modified with octadecyltrimethoxysilane. The surface-modified halloysite formed pincushion agglomerates on the surface of the liquid droplets, which create superhydrophobic surface similar to that of the plant gall surface prepared by aphids. As a result, the liquid marbles showed high mechanical strength upon impact without the use of low surface energy fluoroalkyl or fluorine-modified materials. Our results suggest a new strategy for designing novel materials for liquid marbles inspired by nature.


Asunto(s)
Nanotubos de Carbono/química , Tamaño de la Partícula , Porosidad , Propiedades de Superficie
20.
Acta Crystallogr C ; 69(Pt 12): 1494-7, 2013 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-24311498

RESUMEN

The title salts calcium (glycinato-κ(2)N,O)oxidobis(peroxido-κ(2)O,O')vanadate(V) tetrahydrate, Ca[VO(O2)2(NH2CH2COO)]·4H2O, and strontium (glycinato-κ(2)N,O)oxidobis(peroxido-κ(2)O,O')vanadate(V) tetrahydrate, Sr[VO(O2)2(NH2CH2COO)]·4H2O, crystallized at pH ca 7.4 with similar lattice parameters. The glycinate anion acts as a bidentate N,O-chelating ligand, and the V atom has a pentagonal bipyramidal geometry, with two η(2)-peroxo groups and the glycinate N atom in the equatorial plane, and one terminal oxo and a glycinate O atom at the axial positions. The H atoms of three of the four water molecules in the strontium salt exhibited disorder over three positions for each molecule.


Asunto(s)
Calcio/química , Complejos de Coordinación/química , Sales (Química)/química , Estroncio/química , Cristalografía por Rayos X , Enlace de Hidrógeno , Concentración de Iones de Hidrógeno , Estructura Molecular
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