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2.
Nature ; 620(7976): 965-970, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37648757

RESUMO

Subjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Z ratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10-21 s), provide the most stringent tests of modern nuclear-structure theories. Here we report on the first observation of 28O and 27O through their decay into 24O and four and three neutrons, respectively. The 28O nucleus is of particular interest as, with the Z = 8 and N = 20 magic numbers1,2, it is expected in the standard shell-model picture of nuclear structure to be one of a relatively small number of so-called 'doubly magic' nuclei. Both 27O and 28O were found to exist as narrow, low-lying resonances and their decay energies are compared here to the results of sophisticated theoretical modelling, including a large-scale shell-model calculation and a newly developed statistical approach. In both cases, the underlying nuclear interactions were derived from effective field theories of quantum chromodynamics. Finally, it is shown that the cross-section for the production of 28O from a 29F beam is consistent with it not exhibiting a closed N = 20 shell structure.

3.
Hand Surg Rehabil ; 41(5): 638-643, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35850181

RESUMO

Open carpal tunnel release (OCTR) under wide-awake local anesthesia with no tourniquet (WALANT) is a common outpatient procedure in hand surgery worldwide. In our clinic, WALANT has replaced intravenous regional anesthesia with a tourniquet (IVRA, or 'Bier block') as standard practice in OCTR. We therefore wondered what the optimal postoperative setting after OCTR under WALANT is. In this study, we compared patient satisfaction in two postoperative settings: immediate discharge (ID) after the operation, or short postoperative monitoring (PM) period in the outpatient clinic. Our hypothesis was that older patients would prefer a brief postoperative surveillance. We retrospectively analyzed patient satisfaction with the two settings using an adjusted questionnaire based on the standard Swiss grading system. We also assessed postoperative pain, satisfaction with the perioperative preparations and the reasons for unscheduled postoperative consultations, as secondary outcomes. One hundred and nine patients (ID, n = 63; PM, n = 46) were included in this single-center retrospective observational study. Patients were highly satisfied with both postoperative settings (Mean: ID 5.1/6; PM 5.5/6; p = 0.07). Even patients aged ≥80 years reported extremely high satisfaction with both settings (ID 5.6/6; PM 6.0/6; p = 0.08). Fifteen patients (ID, n = 11 [17.5%]; PM, n = 4 [8.7%], p = 0.72) unexpectedly consulted a doctor after surgery. OCTR under WALANT as an outpatient procedure with immediate discharge was associated with high patient satisfaction. However, detailed postoperative monitoring could contribute to the patient's well-being and education on how to cope with the postoperative course, and help with any questions.


Assuntos
Anestesia por Condução , Síndrome do Túnel Carpal , Anestesia por Condução/métodos , Anestesia Local/métodos , Síndrome do Túnel Carpal/cirurgia , Humanos , Estudos Retrospectivos , Torniquetes
4.
Mult Scler Relat Disord ; 57: 103347, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35158456

RESUMO

BACKGROUND: For small molecules such as teriflunomide, used to treat relapsing multiple sclerosis (MS), that are potentially embryotoxic, there is a theoretical risk of transmission of the medication from males on the drug to female sexual partners. However, that risk has been undefined up to now. METHODS: Teriflunomide concentrations were assayed concomitantly in ten sexually active couples, not using barrier methods of contraception, in whom the male partner with MS was on treatment with teriflunomide 14 mg daily for at least two months. These results were compared by male and female age, teriflunomide concentrations and reported average number of incidences of sexual intercourse per month. The threshold level of detection of teriflunomide was 0.020 µg/ml in females. RESULTS: The average age of the cohort was 46.70 for males and 47.10 for females. Four of ten females had detectible teriflunomide concentrations (mean 0.046 µg/ml (range 0.22-0.077, standard deviation 0.025). Male age and both female teriflunomide positive threshold and female teriflunomide concentration were inversely correlated (r = 0.67, R2=0.45, p = 0.034) for the former and (r = 0.62, R2=0.39, p = 0.05, ns) for the latter. No significant correlations were observed for female age, male teriflunomide concentrations, or reported mean monthly episodes of sexual intercourse. CONCLUSION: This limited study suggests that the small risk that low levels of teriflunomide can be transmitted from male to female partners via sexual intercourse is related to male age. This supports the recommendations found in the United States Product Insert (USPI) stating that men taking teriflunomide who do not wish to father a child, and their female partners, should use reliable contraception. Men wishing to father a child should discontinue use of teriflunomide and undergo an accelerated elimination procedure to reduce the plasma concentrations of the medication to less than 0.02 mg/L (0.02 µg/ml1.


Assuntos
Esclerose Múltipla , Crotonatos , Feminino , Humanos , Hidroxibutiratos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/tratamento farmacológico , Nitrilas , Comportamento Sexual , Parceiros Sexuais , Toluidinas , Estados Unidos
5.
Sensors (Basel) ; 21(6)2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33803746

RESUMO

This paper proposes the use of a pseudo-3D ball-lattice artifact to characterize a handheld laser scanner from a metrological standpoint. The artifact allows the computation of local and global errors in measurement by using the reference-frame-independent parameters of size, form, and distance within the measuring volume of the scanner, and in a single point cloud, without the need for registration. A set of tests was performed using the whole measuring volume, and three acquisition parameters, namely the orientation of the sweeps during the scans, the exposure time, and the distance to the scanner were analyzed for their effects on the accuracy of the scan data. A composite error including the errors in measuring size, form, and distance was used as a single figure of merit to characterize the performance of the scanner in relation to the data-acquisition parameters. The orientation of sweeps did not have a considerable effect on the errors. The accuracy of the scan data was strongly affected by exposure time and its interaction with the distance at which the artifact was scanned. The errors followed a quadratic trend with respect to the distance of the artifact to the scanner. The tested scanner performed best at its manufacturer's recommended stand-off distance.

6.
Neoplasma ; 67(4): 939-945, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32567936

RESUMO

Monoclonal gammopathy of undetermined significance (MGUS) is a known precursor of more serious cancers, such as multiple myeloma (MM), Waldenström macroglobulinemia (MW) and other lymphoproliferative disorders. Using 18F-FDG PET/CT, we aimed to evaluate its benefit in early detection of various accompanying disorders and illnesses in MGUS patients. We prospectively analyzed the diagnostic relevance of 18F-FDG PET/CT in 390 newly diagnosed MGUS patients. On 18F-FDG PET/CT scans, the presence of focal or diffuse areas of detectable increased tracer uptake was recorded in 37 (9.5%) MGUS patients. The most frequent pathology was lymphadenopathy (3.8%), followed by thyroid diseases (2.1%), rheumatic diseases (1.8%), and other solid malignancies (1.5%). These results have major implications for confirmed associations of MGUS with numerous malignant and non-malignant disorders. We believe that 18F-FDG PET/CT imaging in newly diagnosed MGUS patients may be useful in early detection of other serious pathologies, not only in predicting progression of MGUS to active MM, and should be strongly recommended if available.


Assuntos
Gamopatia Monoclonal de Significância Indeterminada , Mieloma Múltiplo , Adulto , Fluordesoxiglucose F18 , Humanos , Gamopatia Monoclonal de Significância Indeterminada/diagnóstico por imagem , Mieloma Múltiplo/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons
7.
Plant Biol (Stuttg) ; 22(5): 761-768, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32544284

RESUMO

The partial or complete loss of chlorophylls, or albinism, is a rare phenomenon in plants. In the present study, we provide the first report of the occurrence in albino Delonix regia seedlings and describe the morpho-physiological changes associated with albinism. Wild-type (WT) and albino seedlings were characterized. Leaflets samples were processed following common procedures for analysis with light, scanning and transmission electron microscopy. The chlorophyll a fluorescence parameters and the carbohydrate, lipid and soluble protein content were also determined in leaf and cotyledon samples of both albino and WT seedlings. Albino seedlings showed reduced growth. They also had lower chlorophyll and protein content in foliar tissues than WT seedlings, in addition to lower concentrations of lipids and carbohydrates stored in cotyledons. The chloroplasts of albino seedlings were poorly developed, with an undefined internal membrane system and the presence of plastoglobules. Wild-type seedlings had a uniseriate and hypoestomatic epidermis. The mesophyll was dorsiventral, consisting of a layer of palisade parenchyma and two to four layers of spongy parenchyma. In albino seedlings, the spongy parenchyma was compact, with few intercellular spaces, and the thickness of the mesophyll was larger, resulting in increased thickness of the leaf blade. Albino seedlings had higher stomatal density and number of pavement cells, although the stomata had smaller dimensions. In addition to the partial loss of chlorophylls, albino D. regia showed changes at physiological and structural levels, demonstrating the crucial nature of photosynthetic pigments during the development and differentiation of plant leaf tissues/cells.


Assuntos
Clorofila , Fabaceae , Plântula , Clorofila/genética , Clorofila/metabolismo , Cloroplastos/metabolismo , Fabaceae/anatomia & histologia , Fabaceae/fisiologia , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Plântula/fisiologia
8.
Leukemia ; 34(4): 966-984, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32127639

RESUMO

The therapeutic landscape of chronic myeloid leukemia (CML) has profoundly changed over the past 7 years. Most patients with chronic phase (CP) now have a normal life expectancy. Another goal is achieving a stable deep molecular response (DMR) and discontinuing medication for treatment-free remission (TFR). The European LeukemiaNet convened an expert panel to critically evaluate and update the evidence to achieve these goals since its previous recommendations. First-line treatment is a tyrosine kinase inhibitor (TKI; imatinib brand or generic, dasatinib, nilotinib, and bosutinib are available first-line). Generic imatinib is the cost-effective initial treatment in CP. Various contraindications and side-effects of all TKIs should be considered. Patient risk status at diagnosis should be assessed with the new EUTOS long-term survival (ELTS)-score. Monitoring of response should be done by quantitative polymerase chain reaction whenever possible. A change of treatment is recommended when intolerance cannot be ameliorated or when molecular milestones are not reached. Greater than 10% BCR-ABL1 at 3 months indicates treatment failure when confirmed. Allogeneic transplantation continues to be a therapeutic option particularly for advanced phase CML. TKI treatment should be withheld during pregnancy. Treatment discontinuation may be considered in patients with durable DMR with the goal of achieving TFR.


Assuntos
Antineoplásicos/uso terapêutico , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Mesilato de Imatinib/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Compostos de Anilina/uso terapêutico , Tomada de Decisão Clínica , Conferências de Consenso como Assunto , Dasatinibe/uso terapêutico , Gerenciamento Clínico , Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/metabolismo , Expressão Gênica , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Expectativa de Vida/tendências , Monitorização Fisiológica , Nitrilas/uso terapêutico , Pirimidinas/uso terapêutico , Qualidade de Vida , Quinolinas/uso terapêutico , Análise de Sobrevida
9.
Neoplasma ; 67(3): 650-659, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32064883

RESUMO

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy with aggressive behavior and poor prognosis. We present the first retrospective analysis mapping its incidence and therapeutic outcomes in patients diagnosed and treated from 2000 to 2017 in the Czech Republic. The cohort comprised 14 patients (10 males, 4 females) with a median age at diagnosis of 39 years (range, 5-68 years). Initially, skin involvement was noted in 10 (71%) patients and bone marrow infiltration was present in 9 (64%). The first complete remission was achieved in 6/14 (43%) patients after acute lymphoblastic leukemia/lymphoma induction therapy and in 3/14 (21%) patients after acute myeloid leukemia regimen. Nine patients underwent allogeneic hematopoietic cell transplantation, with two patients achieving the first complete remission only after allogeneic transplantation. Patients undergoing allogeneic hematopoietic cell transplantation had longer overall survival than those treated without transplantation (the median survival over the period 16.4 vs. 8.1 months). Relapse of the disease was a significant predictor of mortality (p=0.05). Over the study period, patients' survival ranged from 3.3 to 44.2 months, with a median overall survival of 13 months. Our results revealed an effectivity of allogeneic hematopoietic cell transplantation on complete remission achievement in refractory/relapsed disease. The study aimed to present the actual data from the Czech Republic and thus contribute to a global understanding of BPDCN.


Assuntos
Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , República Tcheca , Células Dendríticas/patologia , Feminino , Neoplasias Hematológicas/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Indução de Remissão , Estudos Retrospectivos , Adulto Jovem
12.
Sci Robot ; 4(29)2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-31414071

RESUMO

While all minimally invasive procedures involve navigating from a small incision in the skin to the site of the intervention, it has not been previously demonstrated how this can be done autonomously. To show that autonomous navigation is possible, we investigated it in the hardest place to do it - inside the beating heart. We created a robotic catheter that can navigate through the blood-filled heart using wall-following algorithms inspired by positively thigmotactic animals. The catheter employs haptic vision, a hybrid sense using imaging for both touch-based surface identification and force sensing, to accomplish wall following inside the blood-filled heart. Through in vivo animal experiments, we demonstrate that the performance of an autonomously-controlled robotic catheter rivals that of an experienced clinician. Autonomous navigation is a fundamental capability on which more sophisticated levels of autonomy can be built, e.g., to perform a procedure. Similar to the role of automation in fighter aircraft, such capabilities can free the clinician to focus on the most critical aspects of the procedure while providing precise and repeatable tool motions independent of operator experience and fatigue.

13.
Arq. bras. med. vet. zootec. (Online) ; 71(2): 594-602, mar.-abr. 2019. tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-1011288

RESUMO

O objetivo deste trabalho foi avaliar a concentração sérica de cálcio, cloretos, ferro, fósforo e magnésio, as características morfométricas ósseas e a deposição de cálcio e fósforo nas tíbias de frangos de corte recebendo dieta com zero, 0,25 ou 0,50% de bentonita. Um ensaio foi conduzido com 288 frangos de corte de 14 a 21 dias de idade, submetidos a três dietas experimentais: sem inclusão (0,0); com inclusão de 0,25 e com inclusão de 0,50% do adsorvente bentonita. Não foram observadas diferenças (P>0,05) no desempenho das aves, nos níveis séricos de cálcio, cloretos, ferro e magnésio, no entanto os níveis de fósforo foram reduzidos (P<0,05) nas aves que ingeriram dieta com 0,50% de bentonita. Em relação às tíbias, observou-se redução (P<0,05) na matéria mineral (g e %) e no teor de cálcio com a inclusão de 0,50% de bentonita. Houve redução (P<0,05) nos níveis de fósforo das tíbias com a inclusão de 0,25 e 0,50% de bentonita. Conclui-se que a inclusão de até 0,50% do adsorvente de micotoxinas bentonita na dieta de frangos de corte não altera o desempenho zootécnico das aves. A inclusão de 0,25% de bentonita, na dieta de frangos de corte, não altera a concentração dos minerais séricos e a deposição de minerais nas tíbias, entretanto a inclusão de 0,5% reduz os níveis séricos de fósforo, o teor de matéria mineral e a concentração de cálcio e fósforo ósseos, sem afetar as características morfométricas ósseas.(AU)


The aim of this study was to evaluate performance, serum concentration of calcium, chloride, iron, magnesium, phosphorus, and bone characteristics, ash, calcium, and phosphorus in tibias of broilers receiving diet with zero, 0.25 or 0.50% of bentonite. No differences were found on performance of poultry, on serum mineral calcium, chloride, iron, magnesium, however phosphorus levels of broilers fed on diets containing 0.5% bentonite was reduced. With respect to tibia, reduction was observed on mineral matter (g and %) and calcium levels with inclusion of 0.50% bentonite, and reduction on phosphorus levels with inclusion of 0.25 or 0.50% of bentonite on diet. We conclude that the inclusion of up to 0.50% of mycotoxin adsorbent bentonite in diet of broiler does not change broiler performance. The inclusion of 0.25% of bentonite in diet of broiler does not change serum mineral concentration and mineral deposition; however, the inclusion of 0.5% decrease serum levels of phosphorus, the content of bone mineral matter, with not effects on bone morphometric characteristics.(AU)


Assuntos
Animais , Masculino , Bentonita/administração & dosagem , Bentonita/uso terapêutico , Desenvolvimento Ósseo , Antitoxinas/administração & dosagem , Galinhas/crescimento & desenvolvimento , Dieta/veterinária , Aditivos Alimentares/uso terapêutico , Ração Animal , Minerais/análise , Minerais/sangue , Galinhas/microbiologia
14.
Sci Rep ; 9(1): 3274, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30824737

RESUMO

Lanthanum tungstate (LWO) and LWO with 20 at.% and 35 at.% molybdenum substituting tungsten were prepared by the Pechini method. Phase purity and successful Mo substitution inside these dense LWO membrane materials were confirmed by conventional and high resolution transmission electron microscopy techniques. The split of La2/W2 site by around 0.3 Å was proven. Extra reflections show up in the diffraction patterns from Mo-substituted LWO, and together with simulations, these reflections were recognized as forbidden reflections in a non-substituted LWO system, while the extinction rules are broken by Mo substitution due to the different scattering factors of W and Mo. Energy-dispersive X-ray chemical mapping allowed direct visualization of individual atomic columns, and revealed that all Mo is located at the W1 sites in the Mo-substituted LWO. Moreover, the diffuse scattering in diffraction patterns provides direct evidence of short range clustering of oxygen vacancies and could be further related to the oxygen conduction of the LWO membranes.

15.
Schmerz ; 33(1): 49-56, 2019 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-29294211

RESUMO

BACKGROUND: Up to now, the investigation of joint pain in adolescents, especially in adolescent elite athletes, has been neglected. This is critical because the musculoskeletal system is still in growth and consecutive trauma and irreversible damage can result. OBJECTIVES: To shed light into the research area of joint pain in elite adolescent athletes, we studied the willingness to compete while having joint pain as part as the phenomenon of "playing hurt". Our aim was to describe which athletes are more willing to compete in spite of joint pain and which individual and sport-specific characteristics are associated with it. MATERIALS AND METHODS: We used data of the nationwide GOAL study which included 1138 adolescent athletes from 51 Olympic sports (56.1% male, 14-18 years of age). RESULTS: Altogether, 43.8% of the German elite adolescent athletes were willing to participate in competition in spite of joint pain. The willingness was higher among female athletes, athletes with a higher number of competitions, athletes living in a boarding school, and athletes in weight-dependent sports. CONCLUSIONS: The fact that more than four out of ten adolescent elite athletes are willing to compete despite joint pain is alarming because joint pain can have severe long-term health consequences. It is important that trainers, managers and physicians offer assistance in the treatment of joint pain and support them as much as possible in therapy and pain management. The overarching aim should be to prevent irreversible damage as well as a premature end of the sports career.


Assuntos
Atletas , Esportes , Adolescente , Artralgia , Traumatismos em Atletas , Feminino , Humanos , Masculino
16.
Leukemia ; 33(4): 969-980, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30315239

RESUMO

We report follow-up results from the randomized, placebo-controlled, phase 3 HELIOS trial of ibrutinib+bendamustine and rituximab (BR) for previously treated chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) without deletion 17p. Overall, 578 patients were randomized 1:1 to either ibrutinib (420 mg daily) or placebo, in combination with 6 cycles of BR, followed by ibrutinib or placebo alone. Median follow-up was 34.8 months (range: 0.1-45.8). Investigator-assessed median progression-free survival (PFS) was not reached for ibrutinib+BR, versus 14.3 months for placebo+BR (hazard ratio [HR] [95% CI], 0.206 [0.159-0.265]; P < 0.0001); 36-month PFS rates were 68.0% versus 13.9%, respectively. The results are consistent with the primary analysis findings (HR = 0.203, as assessed by independent review committee, with 17-month median follow-up). Median overall survival was not reached in either arm; HR (95% CI) for ibrutinib+BR versus placebo: 0.652 (0.454-0.935; P = 0.019). Minimal residual disease (MRD)-negative response rates were 26.3% for ibrutinib+BR and 6.2% for placebo+BR (P < 0.0001). Incidence of treatment-emergent adverse events (including grades 3-4) were generally consistent with the initial HELIOS report. These long-term data support improved survival outcomes and deepening responses with ibrutinib+BR compared with BR in relapsed CLL/SLL.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Adenina/análogos & derivados , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cloridrato de Bendamustina/administração & dosagem , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Pessoa de Meia-Idade , Piperidinas , Prognóstico , Pirazóis/administração & dosagem , Pirimidinas/administração & dosagem , Rituximab/administração & dosagem , Taxa de Sobrevida , Adulto Jovem
18.
Ultramicroscopy ; 193: 151-158, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30075368

RESUMO

A large-chamber scanning electron microscope (LC-SEM) provides an ideal platform for the installation of large-scale in situ experiments. Our LC-SEM has internal chamber dimensions of 1,2 × 1,3 × 1,4 m3 (W × H × D) (Fig.1) and makes it possible to incorporate novel in situ experimental devices, which are reported on here. The present manuscript describes in detail the development of in situ test equipment for the study of a broad range of processes in production engineering. Direct observation of the materials modification mechanisms provides fundamental insight into the underlying process characteristics. An in situ turning device was developed, tested and used to observe the chip formation on the microstructure scale of a 43CrMo4-sample. Laser beam micro welding was integrated into the LC-SEM to achieve in situ analysis of the welding process on stainless steel 1.4310. A heating module was employed for in situ wetting experiments to observe the formation and solidification of the melt of a tin-copper brazing filler on an aluminium cast alloy.

19.
Epidemiol Infect ; 146(12): 1550-1555, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29914582

RESUMO

Escherichia coli O157:H7 is the largest cause of hemolytic uremic syndrome (HUS). Previous studies proposed that HUS risk varies across the E. coli O157:H7 phylogenetic tree (hypervirulent clade 8), but the role of age in the association is unknown. We determined phylogenetic lineage of E. coli O157:H7 isolates from 1160 culture-confirmed E. coli O157:H7 cases reported in Washington State, 2004-2015. Using generalised estimating equations, we tested the association between phylogenetic lineage and HUS. Age was evaluated as an effect modifier. Among 1082 E. coli O157:H7 cases with both phylogenetic lineage and HUS status (HUS n = 76), stratified analysis suggested effect modification by age. Lineages IIa and IIb, relative to Ib, did not appear associated with HUS in children 0-9-years-old. For cases 10-59-years-old, lineages IIa and IIb appeared to confer increased risk of HUS, relative to lineage Ib. The association reversed in ⩾60-year-olds. Results were similar for clade 8. Phylogenetic lineage appears to be associated with HUS risk only among those ⩾10-years-old. Among children <10, the age group most frequently affected, lineage does not explain progression to HUS. However, lineage frequency varied across age groups, suggesting differences in exposure and/or early disease manifestation.


Assuntos
Infecções por Escherichia coli/microbiologia , Escherichia coli O157/isolamento & purificação , Síndrome Hemolítico-Urêmica/microbiologia , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Infecções por Escherichia coli/epidemiologia , Feminino , Síndrome Hemolítico-Urêmica/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Filogenia , Estudos Retrospectivos , Washington/epidemiologia
20.
Sci Rep ; 8(1): 3774, 2018 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-29491379

RESUMO

Perovskites such as SrTiO3, BaTiO3, and CaTiO3 have become key materials for future energy-efficient memristive data storage and logic applications due to their ability to switch their resistance reversibly upon application of an external voltage. This resistance switching effect is based on the evolution of nanoscale conducting filaments with different stoichiometry and structure than the original oxide. In order to design and optimize memristive devices, a fundamental understanding of the interaction between electrochemical stress, stoichiometry changes and phase transformations is needed. Here, we follow the approach of investigating these effects in a macroscopic model system. We show that by applying a DC voltage under reducing conditions on a perovskite slab it is possible to induce stoichiometry polarization allowing for a controlled decomposition related to incongruent sublimation of the alkaline earth metal starting in the surface region. This way, self-formed mesoporous layers can be generated which are fully depleted by Sr (or Ba, Ca) but consist of titanium oxides including TiO and Ti3O with tens of micrometre thickness. This illustrates that phase transformations can be induced easily by electrochemical driving forces.

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