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1.
Rev Esp Quimioter ; 36 Suppl 1: 59-63, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37997874

RESUMO

New antifungal agents are needed to overcome limitations of available ones such as poor pharmacokinetic traits, toxicity, drug-drug interactions, limited clinical efficacy, and emerging antifungal resistance. New antifungal drugs belong to well-known families (azoles, polyenes, or beta-d-glucan synthase inhibitors) or to drug families showing completely new mechanisms of action. Some drugs have a head start in terms of potential to reach the clinical setting and are here reviewed.


Assuntos
Antifúngicos , Micoses , Humanos , Antifúngicos/uso terapêutico , Antifúngicos/farmacologia , Micoses/tratamento farmacológico , Micoses/microbiologia , Azóis , Farmacorresistência Fúngica , Polienos/farmacologia
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 295: 122571, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-36906933

RESUMO

This paper reports on the luminescence characterization of TLD-100 (LiF: Ti, Mg), TLD-200 (CaF2: Dy), TLD-400 (CaF2: Mn) and GR-200 (LiF: Mg, Cu, P) dosimeters exposed to electro beam, beta and ultraviolet C radiation -UVC-. All of them show high sensitivity to radiation regardless of whether it is ionizing or partially ionizing radiation based on their luminescence properties (cathodoluminescence -CL- or thermoluminescence -TL-). CL emission differs significantly among them in shape and intensity due to their chemical compositions. LiF samples display three maxima at: (i) 300-450 nm linked to intrinsic and structural defects, (ii) a green waveband probably due to F3+ centres or the presence of hydroxyl groups and (iii) the red-infrared emission band associated with F2 centres. However, CL spectra from the CaF2 dosimeters display meaningful differences due to the dopant. TLD-200 is characterized by an emission with four sharp individual peaks in the green-IR spectral region (due to the Dy3+), whilst TLD-400 exhibits a broad maximum peaked at Ì´500 nm (linked to the Mn2+). On the other hand, the variation in the TL glow curves allows to discriminate the TLDs exposed to beta and UVC radiation since they give rise to different chemical-physical processes and that have been studied from the estimation of the kinetic parameters by means of the Computerised Glow Curve Deconvolution (CGCD) method.

6.
Appl Radiat Isot ; 186: 110300, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35635859

RESUMO

Thermoluminescence (TL) emission of tridymite, a quartz-like mineral, could be used for a variety purposes, including basic research, ceramic technology, traditional/medical industry, and dating. The current study focused on the investigation of the thermal effects on both the luminescence emission and structural properties of natural tridymite. Thermally stimulated luminescence of beta and UVC irradiated samples exhibits complex glow curves indicating simultaneous physical-chemistry processes such as phase transitions, dehydration, dehydroxylation or redox reactions involving intrinsic defects (O vacancies giving rise to F+ and F-type centers, Schottky and Frenkel defects), extrinsic defects (dopants) and structural defects (stacking fault defects, linear and planar defects or dislocations). TL glow curves can be analyzed despite the complexity by assuming that photon emission can be fitted to 1st order kinetics. The structural changes observed using thermal X-ray diffraction up to 200 °C indicate that the Miller indices (204) and (321) have only a reversible behavior in the range of 26-29° 2θ. Tests based on the TL also corroborate such reversibility.

7.
Appl Radiat Isot ; 185: 110257, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35490590

RESUMO

This study reports cathodoluminescence (CL) and photoluminescence (PL) properties of undoped borate Ca3Y2B4O12 and Ca3Y2B4O12:x Dy3+ (x = 0.5, 1, 2, 3, 5, and 7) synthesized by gel combustion method. Micro-X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), CL and PL under electron beam and 359 nm pulse laser excitation, respectively were used to investigate characterization and luminescence studies of synthesized samples in the visible wavelength. As-prepared samples match the standard Ca3Y2BO4 phase that belongs to the orthorhombic system with space group Pnma (62) based on XRD results. Under electron beam excitation, this borate host shows a broad band emission from about 250 to 450 nm, peaked at 370 nm which is attributed to NBHOC. All as-prepared phosphors exhibited the characteristic PL and CL emissions of Dy3+ ions corresponding to 4F9/2→6HJ transitions when excited with laser at 359 nm. The CL emission spectra of phosphors were identical to those of the PL spectra. Concentration quenching occurred when the doping concentration was 1 mol% in both the CL and PL spectra. The underlying reason for the concentration quenching phenomena observed in the discrete orange-yellow emission peaked at 574 nm of Dy3+ ion-doped Ca3Y2B4O12 phosphor is also discussed. According to these data, we can infer that this new borate can be used as a yellow emitting phosphor in solid-state illumination.

8.
Rev Esp Quimioter ; 35(3): 288-292, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35397483

RESUMO

OBJECTIVE: To assess the impact of COVID-19 at nine nursing homes in Madrid, Spain, during the first wave of COVID-19 infection and lockdown period when preventive measures were taken to avoid transmission among residents. METHODS: Nine hundred forty-two residents and 846 staff members from nine nursing homes participated in the study (April 18 to June 20, 2020). All participants were tested for SARS-CoV-2 in the nasopharynx by PCR and for IgG antibodies detection. Microbiological status at sampling was defined as active infection (positive PCR ± presence of antibodies), past infection (negative PCR + presence of antibodies), or naïve participants (negative PCR + absence of antibodies). RESULTS: Laboratory results helped classify the residents as having active infection (n=224; 23.8%), past infection (n=462; 49.1%), or being naïve (n=256; 27.1%); staff members were actively infected (n=127; 15.1%), had had a past infection (n=290; 34.2%), or were naïve (n=429; 50.7%). Overall, the percentage of participants with COVID-19 was significantly higher in residents than in staff members (72.8% vs 49.2%; P=0.001). The clinical situation of residents vs staff at sampling was as follows: acute manifestations compatible with COVID-19 (7.3% vs 3.9%; P<0.01) and no manifestations of infection (92.7% vs 96.0%; P<0.01). A large proportion of both asymptomatic and symptomatic residents (69.4% vs 86.6%; P=0.015) had positive PCR results (mostly alongside positive IgG determinations). CONCLUSIONS: COVID-19 affects 75% of the residents in nursing homes in Madrid. The high impact in these settings, despite the strict restrictions adopted during the lockdown, demonstrates the ability of SARS-CoV-2 to cause outbreaks.


Assuntos
COVID-19 , COVID-19/epidemiologia , COVID-19/prevenção & controle , Controle de Doenças Transmissíveis , Humanos , Imunoglobulina G , Incidência , Casas de Saúde , SARS-CoV-2 , Espanha/epidemiologia
9.
Rev Esp Quimioter ; 35(4): 307-332, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35277084

RESUMO

Ambient air quality, pollution and its implication on health is a topic of enormous importance that is normally dealt with by major specialists in their particular areas of interest. In general, it is not discussed from multidisciplinary approaches or with a language that can reach everyone. For this reason, the Health Sciences Foundation, from its prevention area, has formulated a series of questions to people with very varied competences in the area of ambient air quality in order to obtain a global panorama of the problem and its elements of measurement and control. The answers have been produced by specialists in each subject and have been subjected to a general discussion that has allowed conclusions to be reached on each point. The subject was divided into three main blocks: external ambient air, internal ambient air, mainly in the workplace, and hospital ambient air and the consequences of its poor control. Along with the definitions of each area and the indicators of good and bad quality, some necessary solutions have been pointed out. We have tried to know the current legislation on this problem and the competences of the different administrations on it. Despite its enormous importance, ambient air quality and health is not usually a topic of frequent presence in the general media and we have asked about the causes of this. Finally, the paper addresses a series of reflections from the perspective of ethics and very particularly in the light of the events that the present pandemic raises. This work aims to provide objective data and opinions that will enable non-specialists in the field to gain a better understanding of this worrying reality.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Poluição do Ar/prevenção & controle , Causalidade , Exposição Ambiental/análise , Humanos , Pandemias
10.
Antimicrob Agents Chemother ; 65(11): e0109321, 2021 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-34370582

RESUMO

Susceptibility testing is an important tool in the clinical setting; its utility is based on the availability of categorical endpoints, breakpoints (BPs), or epidemiological cutoff values (ECVs/ECOFFs). CLSI and EUCAST have developed antifungal susceptibility testing, BPs, and ECVs for some fungal species. Although the concentration gradient strip bioMérieux Etest is useful for routine testing in the clinical laboratory, ECVs are not available for all agent/species; the lack of clinical data precludes development of BPs. We reevaluated and consolidated Etest data points from three previous studies and included new data. We defined ECOFFinder Etest ECVs for three sets of species-agent combinations: fluconazole, posaconazole, and voriconazole and 9 Candida spp.; amphotericin B and 3 nonprevalent Candida spp.; and caspofungin and 4 Aspergillus spp. The total of Etest MICs from 23 laboratories (Europe, the Americas, and South Africa) included (antifungal agent dependent): 17,242 Candida albicans, 244 C. dubliniensis, 5,129 C. glabrata species complex (SC), 275 C. guilliermondii (Meyerozyma guilliermondii), 1,133 C. krusei (Pichia kudriavzevii), 933 C. kefyr (Kluyveromyces marxianus), 519 C. lusitaniae (Clavispora lusitaniae), 2,947 C. parapsilosis SC, 2,214 C. tropicalis, 3,212 Aspergillus fumigatus, 232 A. flavus, 181 A. niger, and 267 A. terreus SC isolates. Triazole MICs for 66 confirmed non-wild-type (non-WT) Candida isolates were available (ERG11 point mutations). Distributions fulfilling CLSI ECV criteria were pooled, and ECOFFinder Etest ECVs were established for triazoles (9 Candida spp.), amphotericin B (3 less-prevalent Candida spp.), and caspofungin (4 Aspergillus spp.). Etest fluconazole ECVs could be good detectors of Candida non-WT isolates (59/61 non-WT, 4 of 6 species).


Assuntos
Anfotericina B , Candida , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Aspergillus , Caspofungina , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Fúngica , Kluyveromyces , Testes de Sensibilidade Microbiana , Pichia , Saccharomycetales , Triazóis/farmacologia
11.
Open Forum Infect Dis ; 8(6): ofab250, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34104670

RESUMO

BACKGROUND: There are no clear criteria for antifungal de-escalation after initial empirical treatments. We hypothesized that early de-escalation (ED) (within 5 days) to fluconazole is safe in fluconazole-susceptible candidemia with controlled source of infection. METHODS: This is a multicenter post hoc study that included consecutive patients from 3 prospective candidemia cohorts (2007-2016). The impact of ED and factors associated with mortality were assessed. RESULTS: Of 1023 candidemia episodes, 235 met inclusion criteria. Of these, 54 (23%) were classified as the ED group and 181 (77%) were classified as the non-ED group. ED was more common in catheter-related candidemia (51.9% vs 31.5%; P = .006) and episodes caused by Candida parapsilosis, yet it was less frequent in patients in the intensive care unit (24.1% vs 39.2%; P = .043), infections caused by Nakaseomyces glabrata (0% vs 9.9%; P = .016), and candidemia from an unknown source (24.1% vs 47%; P = .003). In the ED and non-ED groups, 30-day mortality was 11.1% and 29.8% (P = .006), respectively. Chronic obstructive pulmonary disease (odds ratio [OR], 3.97; 95% confidence interval [CI], 1.48-10.61), Pitt score > 2 (OR, 4.39; 95% CI, 1.94-9.20), unknown source of candidemia (OR, 2.59; 95% CI, 1.14-5.86), candidemia caused by Candida albicans (OR, 3.92; 95% CI, 1.48-10.61), and prior surgery (OR, 0.29; 95% CI, 0.08-0.97) were independent predictors of mortality. Similar results were found when a propensity score for receiving ED was incorporated into the model. ED had no significant impact on mortality (OR, 0.50; 95% CI, 0.16-1.53). CONCLUSIONS: Early de-escalation is a safe strategy in patients with candidemia caused by fluconazole-susceptible strains with controlled source of bloodstream infection and hemodynamic stability. These results are important to apply antifungal stewardship strategies.

12.
Appl Radiat Isot ; 166: 109434, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32979757

RESUMO

La2MoO6 orange-red phosphors with high efficiency incorporated with Eu, Dy and Sm have been synthesized through a gel combustion method. The influences of rare earth doping in synthesized samples were analysed by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and cathodoluminescence. Rare earth doped La2MoO6 samples show strong emission bands in the range of 400-750 nm and optimal doping concentration for all samples was 2 mol%. La2MoO6 host doped Eu ion showed intense and predominant emission peaks in 450-750 nm range. The electrical multipolar interaction contributed to the non-radiative energy transfer between Eu3+ ions in La2MoO6 host matrix. Sm doped La2MoO6 host exhibited orange-red CL emission peaks at 564, 608, 652 and 708 nm La2MoO6:Dy3+ phosphor displayed emissions at 484, 574 and 670 nm, respectively. The observed intense and sharp emission peaks indicate that La2MoO6 is promising host for lanthanides doped phosphor materials in the applications of optoelectronic.

13.
Clin Microbiol Infect ; 26(11): 1464-1472, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32562861

RESUMO

BACKGROUND: EUCAST has revised the definition of the susceptibility category I from 'Intermediate' to 'Susceptible, Increased exposure'. This implies that I can be used where the drug concentration at the site of infection is high, either because of dose escalation or through other means to ensure efficacy. Consequently, I is no longer used as a buffer zone to prevent technical factors from causing misclassifications and discrepancies in interpretations. Instead, an Area of Technical Uncertainty (ATU) has been introduced for MICs that cannot be categorized without additional information as a warning to the laboratory that decision on how to act has to be made. To implement these changes, the EUCAST-AFST (Subcommittee on Antifungal Susceptibility Testing) reviewed all, and revised some, clinical antifungal breakpoints. OBJECTIVES: The aim was to present an overview of the current antifungal breakpoints and supporting evidence behind the changes. SOURCES: This document is based on the ten recently updated EUCAST rationale documents, clinical breakpoint and breakpoint ECOFF documents. CONTENT: The following breakpoints (in mg/L) have been revised or established for Candida species: micafungin against C. albicans (ATU = 0.03); amphotericin B (S ≤/> R = 1/1), fluconazole (S ≤/> R = 2/4), itraconazole (S ≤/> R = 0.06/0.06), posaconazole (S ≤/> R = 0.06/0.06) and voriconazole (S ≤/> R = 0.06/0.25) against C. dubliniensis; fluconazole against C. glabrata (S ≤/> R = 0.001/16); and anidulafungin (S ≤/> R = 4/4) and micafungin (S ≤/> R = 2/2) against C. parapsilosis. For Aspergillus, new or revised breakpoints include itraconazole (ATU = 2) and isavuconazole against A. flavus (S ≤/> R = 1/2, ATU = 2); amphotericin B (S ≤/> R = 1/1), isavuconazole (S ≤ /> R = 1/2, ATU = 2), itraconazole (S ≤/> R = 1/1, ATU = 2), posaconazole (ATU = 0.25) and voriconazole (S ≤/> R = 1/1, ATU = 2) against A. fumigatus; itraconazole (S ≤/> R = 1/1, ATU = 2) and voriconazole (S ≤/> R = 1/1, ATU = 2) against A. nidulans; amphotericin B against A. niger (S ≤/> R = 1/1); and itraconazole (S ≤/> R = 1/1, ATU = 2) and posaconazole (ATU = 0.25) against A. terreus. IMPLICATIONS: EUCAST-AFST has released ten new documents summarizing existing and new breakpoints and MIC ranges for control strains. A failure to adopt the breakpoint changes may lead to misclassifications and suboptimal or inappropriate therapy of patients with fungal infections.


Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Candida/efeitos dos fármacos , Anfotericina B/farmacologia , Fluconazol/farmacologia , Itraconazol/farmacologia , Testes de Sensibilidade Microbiana , Guias de Prática Clínica como Assunto , Triazóis/farmacologia , Voriconazol/farmacologia
15.
Med Mycol ; 57(1): 63-70, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29444330

RESUMO

In this study we evaluated the capacity of MALDI-TOF MS (Bruker Daltonics, Bremen, Germany) to identify clinical mould isolates. We focused on two aspects of MALDI-TOF MS identification: the sample processing and the database. Direct smearing of the sample was compared with a simplified processing consisting of mechanical lysis of the moulds followed by a protein extraction step. Both methods were applied to all isolates and the Filamentous Fungi Library 1.0 (Bruker Daltonics) was used for their identification. This approach allowed the correct species-level identification of 25/34 Fusarium spp. and 10/10 Mucor circinelloides isolates using the simplified sample processing. In addition, 7/34 Fusarium spp. and 1/21 Pseudallescheria/Scedosporium spp. isolates were correctly identified at the genus level. The remaining isolates-60-could not be identified using the commercial database, mainly because of the low number of references for some species and the absence of others. Thus, an in-house library was built with 63 local isolates previously characterized using DNA sequence analysis. Its implementation allowed the accurate identification at the species level of 94 isolates (91.3%) and the remaining nine isolates (8.7%) were correctly identified at the genus level. No misidentifications at genus level were detected. In conclusion, with improvements of both the sample preparation and the feeding of the database, MALDI-TOF MS is a reliable, ready to use method to identify moulds of clinical origin in an accurate, rapid, and cost-effective manner.


Assuntos
Bases de Dados Factuais , Fungos/classificação , Técnicas de Tipagem Micológica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Análise por Conglomerados , Bases de Dados Factuais/normas , Proteínas Fúngicas/análise , Fungos/química , Fungos/isolamento & purificação , Humanos , Micoses/microbiologia , Análise de Sequência de DNA , Manejo de Espécimes , Fatores de Tempo
16.
Artigo em Inglês | MEDLINE | ID: mdl-30323038

RESUMO

Although the Sensititre Yeast-One (SYO) and Etest methods are widely utilized, interpretive criteria are not available for triazole susceptibility testing of Candida or Aspergillus species. We collected fluconazole, itraconazole, posaconazole, and voriconazole SYO and Etest MICs from 39 laboratories representing all continents for (method/agent-dependent) 11,171 Candida albicans, 215 C. dubliniensis, 4,418 C. glabrata species complex, 157 C.guilliermondii (Meyerozyma guilliermondii), 676 C. krusei (Pichia kudriavzevii), 298 C.lusitaniae (Clavispora lusitaniae), 911 C.parapsilosissensu stricto, 3,691 C.parapsilosis species complex, 36 C.metapsilosis, 110 C.orthopsilosis, 1,854 C.tropicalis, 244 Saccharomyces cerevisiae, 1,409 Aspergillus fumigatus, 389 A.flavus, 130 A.nidulans, 233 A.niger, and 302 A.terreus complex isolates. SYO/Etest MICs for 282 confirmed non-wild-type (non-WT) isolates were included: ERG11 (C. albicans), ERG11 and MRR1 (C. parapsilosis), cyp51A (A. fumigatus), and CDR2 and CDR1 overexpression (C. albicans and C. glabrata, respectively). Interlaboratory modal agreement was superior by SYO for yeast species and by the Etest for Aspergillus spp. Distributions fulfilling CLSI criteria for epidemiological cutoff value (ECV) definition were pooled, and we proposed SYO ECVs for S. cerevisiae and 9 yeast and 3 Aspergillus species and Etest ECVs for 5 yeast and 4 Aspergillus species. The posaconazole SYO ECV of 0.06 µg/ml for C. albicans and the Etest itraconazole ECV of 2 µg/ml for A. fumigatus were the best predictors of non-WT isolates. These findings support the need for method-dependent ECVs, as, overall, the SYO appears to perform better for susceptibility testing of yeast species and the Etest appears to perform better for susceptibility testing of Aspergillus spp. Further evaluations should be conducted with more Candida mutants.


Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Candida/efeitos dos fármacos , Triazóis/farmacologia , Aspergilose/tratamento farmacológico , Aspergilose/epidemiologia , Aspergilose/microbiologia , Aspergillus/classificação , Aspergillus/isolamento & purificação , Candida/classificação , Candida/isolamento & purificação , Candidíase/tratamento farmacológico , Candidíase/epidemiologia , Candidíase/microbiologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Fúngica , Fluconazol/farmacologia , Humanos , Hospedeiro Imunocomprometido , Itraconazol/farmacologia , Voriconazol/farmacologia
17.
Clin Microbiol Infect ; 25(6): 681-687, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30268672

RESUMO

BACKGROUND: The emergence of azole-resistant Aspergillus fumigatus isolates is a matter of significant concern in Europe, with countries reporting resistance rates (which can be as high as 30%) in hospitalized patients. Consequently, the treatment guidelines in The Netherlands, the country with the highest documented prevalence of azole-resistant A. fumigatus, has just been revised to now recommend initial therapy with combination therapy until the susceptibility pattern is known. Therefore, susceptibility testing of clinically relevant isolates has been strongly recommended in the ESCMID-EFISG aspergillosis guidelines. Furthermore, mixed azole-susceptible and azole-resistant (isogenic as well as non-isogenic) infections have been reported to occur, which implies that colonies of clinical cultures may harbour various phenotypes of azole susceptibility. OBJECTIVES: The EUCAST-AFST (European Committee on Antimicrobial Susceptibility Testing Subcommittee on Antifungal Susceptibility Testing) has released a new screening method document (E.Def 10.1) for the detection of azole-resistant A. fumigatus isolates and updated the QC tables for antifungal susceptibility testing with associated QC endpoints. This review described in detail how to perform the screening test. SOURCES: This "How to document" is based on the EUCAST azole agar screening method document E.Def 10.1 and the QC tables for antifungal susceptibility testing document, v 2.0 (available at http://www.eucast.org/ast_of_fungi/qcafsttables/) CONTENTS: The method is based on the inoculation of azole-containing and azole-free agars and visual determination of fungal growth after one and two days of incubation. It can easily be implemented in routine laboratories of clinical microbiology and has been validated for simultaneous testing of up to five A. fumigatus colonies using itraconazole and voriconazole (mandatory), and posaconazole (optional). IMPLICATIONS: This easy-to-use screening procedure for the detection of azole resistance in clinical A. fumigatus isolates will allow rapid testing in the daily routine of the microbiology laboratory and thus facilitate earlier appropriate therapy.


Assuntos
Antifúngicos/farmacologia , Aspergillus fumigatus/efeitos dos fármacos , Azóis/farmacologia , Farmacorresistência Fúngica , Testes de Sensibilidade Microbiana/métodos , Ágar , Aspergilose/microbiologia , Meios de Cultura , Humanos , Programas de Rastreamento/métodos , Países Baixos , Guias de Prática Clínica como Assunto
18.
Appl Radiat Isot ; 141: 101-106, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30196246

RESUMO

This work reports on the cathodoluminescence (CL) and thermoluminescence (TL) properties of gem-quality diaspore samples from Milas/Mugla (Turkey) after 100 h of ultraviolet-C (UVC) exposure. The UVC exposure induces significant changes in the intensity of the CL emission in the range of 400-800 nm that would be mainly associated with photo-oxidation processes of the impurities (Cr3+, Ti3+, Fe2+) that substitute for Al3+ in the diaspore (α-AlOOH) lattice. The UVC effect on the 400 nm-TL behavior of beta irradiated samples in the range of 0.1-8 Gy modifies the TL glow curves probably due to both photo-transfer process where electrons release from deeper to shallower traps and redox reactions involving, also, breakages-linkages of chemical bonds. Meanwhile, the 'as received' samples consist of three maxima centered at about 120, 180, and 234 °C, the 100 h UVC-irradiated samples display three maxima at 122, 220 and 270 °C. The physical trapping parameters (intensity and peak position, trap depth and pre-exponential factor) for each TL curve were estimated by using a computerized glow curve analysis program.

19.
Clin Microbiol Infect ; 24(12): 1343.e1-1343.e4, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30025834

RESUMO

OBJECTIVES: Isavuconazole is a triazole previously shown to have potent in vitro activity against Aspergillus spp., Mucorales and Candida spp. Unlike other azoles, it is unclear whether isavuconazole induces a trailing effect. We studied isavuconazole MICs for a large collection of Candida isolates from blood samples and determined the extent of the trailing effect when using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) E.Def 7.3.1 method. METHODS: A total of 762 molecularly identified Candida isolates from blood samples of 743 patients admitted to hospital (January 2007 to September 2017) were evaluated and further tested for in vitro susceptibility to isavuconazole following the EUCAST E.Def 7.3.1 test method. RESULTS: C. albicans showed the highest susceptibility, followed by C. parapsilosis and C. tropicalis (geometric mean MIC 0.0029 vs. 0.0049/0.0052, respectively; p <0.001). In contrast, C. glabrata and C. krusei had significantly higher MIC values (geometric mean MIC 0.171 vs. 0.117, respectively). Isavuconazole MIC distributions were not truncated at the lowest concentration tested except for C. albicans. Overall, the mean percentage of trailing was 13.6%, but differences among species were observed: C. glabrata, C. albicans and C. tropicalis exhibited higher trailing compared to C. parapsilosis and non-Candida yeasts (p <0.001). The percentage of non-wild-type C. albicans (considering the heavy trailer isolates as wild type), C. parapsilosis and C. glabrata isolates were 1.1% (4/357), 1.5% (3/201) and 1.1% (1/86), respectively. CONCLUSIONS: Isavuconazole showed high in vitro activity against Candida spp., particularly against C. albicans. A trailing effect is commonly observed with isavuconazole, particularly with C. glabrata.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candidemia/microbiologia , Nitrilas/efeitos adversos , Nitrilas/farmacologia , Piridinas/efeitos adversos , Piridinas/farmacologia , Triazóis/efeitos adversos , Triazóis/farmacologia , Candida/genética , Candida albicans/efeitos dos fármacos , Candida glabrata/efeitos dos fármacos , Farmacorresistência Fúngica , Humanos , Testes de Sensibilidade Microbiana
20.
Appl Radiat Isot ; 139: 34-39, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29702363

RESUMO

Undoped and Pr, Sm and Tb activated BaAl2O4 phosphors have been synthesized by solid state reaction method and combustion method. The structure and morphological observation of the phosphor samples were monitored by X-ray powder diffraction (XRD) and environmental scanning electron microscope (ESEM) coupled to an energy dispersive X-ray spectrometer (EDS). The all diffraction peaks are well assigned to standard data card (PDF♯17-306). Emission properties of the samples were explored using light emission induced by an electron beam (i.e cathodoluminescence, CL) at room temperature (RT). Undoped BaAl2O4 sample exhibits a broad defect emission from 300 to 500 nm from the aluminate defect centres. CL spectra recorded at room temperature display that the as-prepared BaAl2O4:Ln (Ln=Pr, Sm and Tb) phosphors exhibit different luminescence colors coming from different rare earth activator ions. The transition 4G5/2 → 6H7/2 located at 606 and 610 nm for Sm3+ can occur as hypersensitive transition having the selection rule ΔJ = ±â€¯1. For the Tb3+ doped samples, they exhibit D45 green line emissions. The proposed luminescent mechanisms of all doped rare earth ions are also discussed.

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