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1.
Nanotechnology ; 35(16)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38211321

RESUMO

We investigate the magnetic interlayer coupling and domain structure of ultra-thin ferromagnetic (FM) cobalt (Co) layers embedded between a graphene (G) layer and a platinum (Pt) layer on a silicon carbide (SiC) substrate (G/Co/Pt on SiC). Experimentally, a combination of x-ray photoemission electron microscopy with x-ray magnetic circular dichroism has been carried out at the Co L-edge. Furthermore, structural and chemical properties of the system have been investigated using low energy electron diffraction (LEED) and x-ray photoelectron spectroscopy (XPS).In situLEED patterns revealed the crystalline structure of each layer within the system. Moreover, XPS confirmed the presence of quasi-freestanding graphene, the absence of cobalt silicide, and the appearance of two silicon carbide surface components due to Pt intercalation. Thus, the Pt-layer effectively functions as a diffusion barrier. The magnetic structure of the system was unaffected by the substrate's step structure. Furthermore, numerous vortices and anti-vortices were found in all samples, distributed all over the surfaces, indicating Dzyaloshinskii-Moriya interaction. Only regions with a locally increased Co-layer thickness showed no vortices. Moreover, unlike in similar systems, the magnetization was predominantly in-plane, so no perpendicular magnetic anisotropy was found.

2.
Acta Ortop Mex ; 37(6): 331-337, 2023.
Artigo em Espanhol | MEDLINE | ID: mdl-38467453

RESUMO

INTRODUCTION: chondrosarcoma is the second most common primary malignant tumor, constitutes approximately one quarter of all primary bone sarcomas. Surgical margins in pelvic chondrosarcoma have a direct impact as a prognostic factor, both on overall survival and on recurrence-free survival of this disease. OBJECTIVES: to analyze the impact of surgical margins as a prognostic factor in pelvic chondrosarcoma. MATERIAL AND METHODS: a retrospective database cohort with prospective follow-up of sarcomas in patients diagnosed with primary pelvic chondrosarcoma who underwent surgical treatment. Clinical-demographic variables were obtained, a descriptive analysis of each variable was performed, and these were contrasted with the outcome variables. RESULTS: seventeen patients were included, of which nine were female. The median age was 41 years, ranging from 23 to 65 years. The average tumor size was 20.9 cm (range 5 to 46 cm). The average surgical margin was 5.3 mm, ranging from 1 to 30 mm, with 58% positive margins. The average overall survival was 64 months (range 7 to 108 months). The distribution of pelvic involvement was as follows: zone I in nine patients (52.9%), zone II in two (11.8%), a combination of zones I-III in two (11.8%), I+II in one (5.9%), II+III in one (5.9%), I-III plus sacrum in one (5.9%) and I plus sacrum in one (5.9%). Tumor grades were classified as low in seven patients (41.2%), intermediate in sven (41.2%), high in two (11.8%), and dedifferentiated in one (5.9%). Regarding the type of resection, 12 patients (70.6%) underwent internal hemipelvectomy and five (29.4%) external hemipelvectomy. Recurrence was recorded in five cases (29.4%), metastasis in three (17.6%), and mortality in four (23.5%). CONCLUSIONS: this series represents the largest cohort reported in Latin America of primary pelvic chondrosarcomas. A more favorable prognosis was observed in patients with surgical margins greater than 1 mm. The presence of chondrosarcoma in multiple pelvic zones was associated with a worse oncological prognosis. Additionally, a higher incidence of positive surgical margins and local recurrence rates were identified in pelvic chondrosarcomas compared to those located in the extremities.


INTRODUCCIÓN: el condrosarcoma (CS), el segundo tumor maligno óseo primario más común, constituye aproximadamente una cuarta parte de todos los sarcomas óseos primarios. Los márgenes quirúrgicos en el condrosarcoma pélvico tienen un impacto directo como factor pronóstico, tanto en la supervivencia global como en la supervivencia libre de recurrencia de esta enfermedad. OBJETIVOS: analizar el impacto de los márgenes quirúrgicos como factor pronóstico en el condrosarcoma de la pelvis. MATERIAL Y MÉTODOS: cohorte de base de datos retrospectiva con seguimiento prospectivo de sarcomas de pacientes con diagnóstico de condrosarcoma primario de la pelvis que fueron sometidos a tratamiento quirúrgico. Se obtuvieron variables clínico-demográficas, se realizó un análisis descriptivo de cada variable y se contrastaron con las variables desenlace. RESULTADOS: se incluyeron 17 pacientes, de los cuales nueve eran mujeres. La mediana de edad fue de 41 años (rango de 23 a 65 años). El tamaño promedio del tumor fue de 20.9 cm (rango de 5 a 46 cm). El margen quirúrgico promedio fue de 5.3 mm, variando entre 1 y 30 mm, con 58% de márgenes positivos. La supervivencia global promedio fue de 64 meses (rango de 7 a 108 meses). La distribución de la afectación pélvica fue: zona I en nueve pacientes (52.9%), zona II en dos (11.8%), combinación de zonas I-III en dos (11.8%), I+II en uno (5.9%), II+III en uno (5.9%), I-III más sacro en uno (5.9%) y I más sacro en uno (5.9%). Los grados tumorales se clasificaron en bajo en siete pacientes (41.2%), intermedio en siete (41.2%), alto en dos (11.8%) y desdiferenciado en uno (5.9%). Respecto al tipo de resección, 12 pacientes (70.6%) se sometieron a hemipelvectomía interna y cinco (29.4%) a hemipelvectomía externa. Se registró recurrencia en cinco casos (29.4%), metástasis en tres (17.6%) y mortalidad en cuatro (23.5%). CONCLUSIONES: esta serie representa la cohorte más extensa reportada en Latinoamérica de condrosarcomas primarios de la pelvis. Se observó un pronóstico más favorable en pacientes con márgenes quirúrgicos superiores a 1 mm. La presencia de condrosarcoma en múltiples zonas pélvicas se asoció con un peor pronóstico oncológico. Además, se identificó una mayor incidencia de márgenes quirúrgicos positivos y tasas de recurrencia local en condrosarcomas de la pelvis en comparación con aquellos ubicados en las extremidades.


Assuntos
Neoplasias Ósseas , Condrossarcoma , Ossos Pélvicos , Sarcoma , Humanos , Feminino , Adulto , Masculino , Margens de Excisão , Prognóstico , Estudos Retrospectivos , Estudos de Coortes , Estudos Prospectivos , Ossos Pélvicos/cirurgia , Ossos Pélvicos/patologia , Neoplasias Ósseas/cirurgia , Neoplasias Ósseas/diagnóstico , Sarcoma/patologia , Sarcoma/cirurgia , Condrossarcoma/cirurgia , Pelve , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia
3.
Lett Appl Microbiol ; 74(4): 543-554, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34951701

RESUMO

The tropical peatlands of southern Brazil are essential for the maintenance of the Atlantic Rain Forest, one of the 25 hotspots of biodiversity in the world. Although diazotrophic micro-organisms are essential for the maintenance of this nitrogen limited ecosystem, so far studies have focused only on micro-organisms involved in the carbon cycle. In this work, peat samples were collected from three tropical peatland regions during dry and rainy seasons and their chemical and microbial characteristics were evaluated. Our results showed that the structure of the diazotrophic communities in the Brazilian tropical peatlands differs in the evaluated seasons. The abundance of the genus Bradyrhizobium showed to be affected by rainfall and peat pH. Despite the shifts of the nitrogen-fixing population in the tropical peatland caused by seasonality it showed to be constantly dominated by α-Proteobacteria followed by Cyanobacteria. In addition, more than 50% of nifH gene sequences have not been classified, indicating the necessity for more studies in tropical peatland, since the reduction of N supply in the peatlands stimulates the recalcitrant organic matter decomposition performed by peatland micro-organisms, influencing the C stock.


Assuntos
Floresta Úmida , Microbiologia do Solo , Brasil , Ecossistema , Solo/química
4.
Nat Mater ; 21(2): 188-194, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34857910

RESUMO

The Josephson effect results from the coupling of two superconductors across a spacer such as an insulator, a normal metal or a ferromagnet to yield a phase coherent quantum state. However, in junctions with ferromagnetic spacers, very long-range Josephson effects have remained elusive. Here we demonstrate extremely long-range (micrometric) high-temperature (tens of kelvins) Josephson coupling across the half-metallic manganite La0.7Sr0.3MnO3 combined with the superconducting cuprate YBa2Cu3O7. These planar junctions, in addition to large critical currents, display the hallmarks of Josephson physics, such as critical current oscillations driven by magnetic flux quantization and quantum phase locking effects under microwave excitation (Shapiro steps). The latter display an anomalous doubling of the Josephson frequency predicted by several theories. In addition to its fundamental interest, the marriage between high-temperature, dissipationless quantum coherent transport and full spin polarization brings opportunities for the practical realization of superconducting spintronics, and opens new perspectives for quantum computing.

5.
Lett Appl Microbiol ; 74(4): 604-612, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34967451

RESUMO

The use of Azospirillum brasilense as a crop inoculant has increased in recent years. Thus, the compatibility of the inoculation technology with seed treatments using pesticides needs to be evaluated. In this study, we evaluated the effect of an insecticide and fungicide formulation on A. brasilense strain FP2 population by culturing and culture-independent approaches. In addition, we evaluated the impact of these pesticides on the ability of A. brasilense to promote plant growth by monitoring biometric traits (root and shoot dry mass and length) of wheat grown in Greenhouse conditions. Seed pesticide dressings, mainly fungicide, led to a significant mortality of A. brasilense over time. The ability of A. brasilense to promote wheat growth also decreased due to pesticide treatments combined with sowing delay. Considering that pesticides confer fitness advantages to the wheat in field condition, our results suggest that sowing within the first 4 h after inoculation maintain the beneficial effects of A. brasilense on wheat growth promotion. Furthermore, we conclude that inoculation and treatment of seeds with pesticides may be compatible techniques when carried out immediately before sowing.


Assuntos
Azospirillum brasilense , Fungicidas Industriais , Inseticidas , Fungicidas Industriais/farmacologia , Inseticidas/farmacologia , Raízes de Plantas , Sementes , Triticum
6.
Sci Rep ; 11(1): 20788, 2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34675339

RESUMO

Research on proximity effects in superconductor/ferromagnetic hybrids has most often focused on how superconducting properties are affected-and can be controlled-by the effects of the ferromagnet's exchange or magnetic fringe fields. The opposite, namely the possibility to craft, tailor and stabilize the magnetic texture in a ferromagnet by exploiting superconducting effects, has been more seldom explored. Here we show that the magnetic flux trapped in high-temperature superconducting YBa2Cu3O7-δ microstructures can be used to modify the magnetic reversal of a hard ferromagnet-a cobalt/platinum multilayer with perpendicular magnetic anisotropy-and to imprint unusual magnetic domain distributions in a controlled manner via the magnetic field history. The domain distributions imprinted in the superconducting state remain stable, in absence of an external magnetic field, even after increasing the temperature well above the superconducting critical temperature, at variance to what has been observed for soft ferromagnets with in-plane magnetic anisotropy. This opens the possibility of having non-trivial magnetic configuration textures at room temperature after being tailored below the superconducting transition temperature. The observed effects are well explained by micromagnetic simulations that demonstrate the role played by the magnetic field from the superconductor on the nucleation, propagation, and stabilization of magnetic domains.

7.
J Phys Condens Matter ; 32(46): 465801, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32610298

RESUMO

The dynamics of the magnetic structure in a well ordered ferromagnetic CoPd stripe domain pattern has been investigated upon excitation by femtosecond infrared laser pulses. Time-resolved x-ray magnetic circular dichroism in photoemission electron microscopy (TR-XMCD-PEEM) is used to perform real space magnetic imaging with 100 ps time resolution in order to show local transformations of the domains structures. Using the time resolution of the synchrotron radiation facility of the Helmholtz-Zentrum Berlin, we are able to image the transient magnetic domains in a repetitive pump and probe experiment. In this work, we study the reversible and irreversible transformations of the excited magnetic stripe domains as function of the laser fluence. Our results can be explained by thermal contributions, reducing the XMCD amplitude in each stripe domain below a threshold fluence of 12 mJ cm-2. Above this threshold fluence, irreversible transformations of the magnetic domains are observed. Static XMCD-PEEM images reveal the new partially ordered stripe domain structures characterized by a new local magnetic domain distribution showing an organized pattern at the micrometer scale. This new arrangement is attributed to the recovery of the magnetic anisotropy during heat dissipation under an Oersted field.

8.
J Surg Case Rep ; 2020(6): rjaa146, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32582433

RESUMO

Splenic abscess is a rare disease and a diagnostic challenge for the medical team. Attributable to its high mortality, prompt diagnosis and treatment are essential. A high degree of clinical awareness is required in conjunction with aggressive treatment, as misleading symptoms may delay treatment and worsen the patient's prognosis. The management of splenic abscess is based on medical therapy, antibiotics and splenectomy or percutaneous drainage. We present the case of a 58-year-old patient presented with a splenic abscess after arterial embolization. He underwent surgery and completely recovered.

9.
Soc Neurosci ; 15(4): 398-407, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32107978

RESUMO

Ex-combatants often exhibit atypical Emotional Processing (EP) such as reduced emphatic levels and higher aggressive attitudes. Social Cognitive Training (SCT) addressing socio-emotional components powerfully improve social interaction among Colombian ex-combatants. However, with narrow neural evidence, this study offers a new testimony. A sample of 28 ex-combatants from Colombian illegal armed groups took part in this study, split into 15 for SCT and 13 for the conventional program offered by the Governmental Reintegration Route. All of them were assessed before and after the intervention with a protocol that included an EP task synchronized with electroencephalographic recordings. We drew behavioral scores and brain connectivity (Coherency) metrics from task performance. Behavioral scores yielded no significant effects. Increased post-intervention connectivity in the delta band was observed during negative emotional processing only SCT group. Positive emotions exposed distinctive gamma band connectivity that differentiate groups. These results suggest that SCT can trigger covert neurofunctional reorganization in ex-combatants embarked on the reintegration process even when overt behavioral improvements are not yet apparent. Such covert functional changes may be the neural signature of compensatory mechanisms necessary to reshape behaviors adaptively. This novel framework may inspire cutting-edge translational research at the crossing of neuroscience, sociology, and public policy-making.


Assuntos
Encéfalo/fisiopatologia , Terapia Cognitivo-Comportamental/métodos , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/reabilitação , Veteranos/psicologia , Adulto , Colômbia , Emoções/fisiologia , Feminino , Humanos , Masculino , Transtornos de Estresse Pós-Traumáticos/psicologia
10.
Phys Rev Lett ; 123(17): 177201, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31702247

RESUMO

We probe the current-induced magnetic switching of insulating antiferromagnet-heavy-metal systems, by electrical spin Hall magnetoresistance measurements and direct imaging, identifying a reversal occurring by domain wall (DW) motion. We observe switching of more than one-third of the antiferromagnetic domains by the application of current pulses. Our data reveal two different magnetic switching mechanisms leading together to an efficient switching, namely, the spin-current induced effective magnetic anisotropy variation and the action of the spin torque on the DWs.

11.
Case Rep Surg ; 2019: 7024172, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30838152

RESUMO

Endometriosis is a common entity among fertile women which unfortunately manifests through variable symptomatology. Intestinal involvement in endometriosis is quite common and can simulate several diseases such as Crohn's disease, appendicitis, tubo-ovarian abscess, or malignant tumors. Intestinal obstruction due to endometriosis is rare, and preoperative diagnosis is difficult because the signs and symptoms are nonspecific and can be easily confused. In the case of patients without a history of endometriosis, diagnosis is further complicated. We present a case of a 41-year-old female patient. She presented to the emergency room with complete bowel obstruction and a mass in the cecum. Surgery was decided, and the patient underwent full recovery. Endometriosis was the final diagnosis for the observed condition.

12.
Phys Rev Lett ; 122(3): 037601, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30735408

RESUMO

The electronic reconstruction occurring at oxide interfaces may be the source of interesting device concepts for future oxide electronics. Among oxide devices, multiferroic tunnel junctions are being actively investigated as they offer the possibility to modulate the junction current by independently controlling the switching of the magnetization of the electrodes and of the ferroelectric polarization of the barrier. In this Letter, we show that the spin reconstruction at the interfaces of a La_{0.7}Sr_{0.3}MnO_{3}/BaTiO_{3}/La_{0.7}Sr_{0.3}MnO_{3} multiferroic tunnel junction is the origin of a spin filtering functionality that can be turned on and off by reversing the ferroelectric polarization. The ferroelectrically controlled interface spin filter enables a giant electrical modulation of the tunneling magnetoresistance between values of 10% and 1000%, which could inspire device concepts in oxides-based low dissipation spintronics.

13.
Cleft Palate Craniofac J ; 55(4): 517-520, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29554446

RESUMO

OBJECTIVES: Among congenital craniofacial anomalies, orofacial clefts (OFCs) are the most common. Global prevalence is 2 in 1000 and in Colombia, 1 in 700. Our goal was to describe cleft palate (CP) prevalence and cleft lip with or without cleft palate (CL±P) from 2001 to 2015 in Bogota and Cali, Colombia. METHOD: Using the ECLAMC case-control design method, information was obtained from the Congenital Anomalies Monitoring and Surveillance Programs in Bogota and Cali. We describe the prevalence of cases classified into the following groups: isolated, polymalformed, and syndromic. The proportion of cases and controls was 1:4. Data were analyzed using frequency distribution and Student t test to compare means and 95% confidence intervals (CIs). RESULTS: We identified 529 OFC cases and 2116 controls from 448,930 births: a rate of 11.8 per 10,000 (CI = 10.80-12.83). From the total cases, 73% were identified with CL/CP compared to 27% with CP. Males had higher CL±P (59%) prevalence, whereas the highest neonatal mortality was observed among polymalformed cases (7%). The most common anomaly identified among our cases was cleft lip without isolated cleft palate (58%). We found that OFCs are linked to birthweight, size, and gestational age and higher parity with statistically significant differences in all variables compared to controls. CONCLUSIONS: OFC is a highly prevalent anomaly in Colombia, with a range of maternal and infant differences across case subgroups. The identification of important OFC subgroups that follow certain patterns of prevalence may prove useful to primary and tertiary care facilities with the goal of reducing further disability.


Assuntos
Fenda Labial/epidemiologia , Fissura Palatina/epidemiologia , Estudos de Casos e Controles , Colômbia/epidemiologia , Feminino , Humanos , Recém-Nascido , Masculino , Prevalência , Estudos Retrospectivos
14.
Nanoscale ; 10(16): 7407-7419, 2018 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-29557439

RESUMO

Magnetospirillum gryphiswaldense is a microorganism with the ability to biomineralize magnetite nanoparticles, called magnetosomes, and arrange them into a chain that behaves like a magnetic compass. Rather than straight lines, magnetosome chains are slightly bent, as evidenced by electron cryotomography. Our experimental and theoretical results suggest that due to the competition between the magnetocrystalline and shape anisotropies, the effective magnetic moment of individual magnetosomes is tilted out of the [111] crystallographic easy axis of magnetite. This tilt does not affect the direction of the chain net magnetic moment, which remains along the [111] axis, but explains the arrangement of magnetosomes in helical-like shaped chains. Indeed, we demonstrate that the chain shape can be reproduced by considering an interplay between the magnetic dipolar interactions between magnetosomes, ruled by the orientation of the magnetosome magnetic moment, and a lipid/protein-based mechanism, modeled as an elastic recovery force exerted on the magnetosomes.

15.
Rev. med. vet. zoot ; 64(2): 70-76, mayo-ago. 2017. ilus
Artigo em Espanhol | LILACS | ID: biblio-902174

RESUMO

Los desórdenes del desarrollo sexual se pueden presentar en diferentes animales domésticos, aunque no son muy comunes. Se clasifican en tres grupos de anormalidades: del desarrollo cromosómico, del desarrollo gonadal y del sexo fenotípico, y presentan diferentes subcategorías. El objetivo de este trabajo fue describir las características fenotípicas, cromosómicas y anatómicas de los órganos reproductores de un paciente canino, aparentemente hembra, de 3 años de edad, con desorden del desarrollo sexual, que presentaba una protuberancia a nivel vaginal con sangrado y presencia de pus; en la anamnesis reportan comportamiento de macho. Se realizó un examen general por sistemas, ecografía abdominal ventral, radiografía latero-lateral, cuadro hemático y cariotipo con bandas R-replicativas. Tras la evaluación se encontró un clítoris agrandado (pseudopene) con orificio uretral que mostró resistencia a la colocación de una sonda. La radiografía mostró una estructura similar al hueso del pene y la ecografía reveló una estructura compatible con el cuello del útero en una hembra y una estructura lateral parecida al tejido gonadal. El cariotipo fue típico de un macho, compatible con un macho seudohermafrodita, lo cual permite clasificar al individuo como XY, con un desorden del desarrollo sexual fenotípico (78, XY) según la nueva clasificación. Con las herramientas diagnósticas disponibles en Colombia es posible realizar un diagnóstico diferencial adecuado. Sin embargo, falta disponibilidad de pruebas diagnósticas específicas como FISH y mediciones serológicas.


The disorders of sex development can occur in different domestic animals, but they are not very common. They are classified as sex chromosomic disorders, gonadal sex development disorders and phenotypic sex disorders and have different subcategories. The aim of this study was to describe the phenotypic, chromosomal and anatomical traits of the reproductive organs of a canine patient 3-year-old, apparently female with disorder of sexual development, which presented a protuberance into the vagina with bleeding and pus, which anamnesis male behavior report. A general examination was performed by systems, ventral abdominal ultrasound, latero-lateral radiography, blood count and karyotype whit R-replicative bands. After the evaluation found an enlarged clitoris (pseudopene) with urethral opening that showed resistance to placing a catheter. Radiography showed a structure similar to penis bone and the ultrasonography a structure consistent with the cervix in a female and a structure similar to gonadal tissue in the side. The karyotype was typical of a male, compatible with a male pseudo-hermaphrodite, which classifies the individual as XY with a phenotypic disorder of sex development (78, XY) according to the new classification. With the diagnostic tools found in Colombia is possible to make an appropriate differential diagnosis. But nevertheless, lack of availability of specific diagnostic tests such as FISH and serological measurements.

16.
Ultramicroscopy ; 183: 104-108, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28396080

RESUMO

The antiferromagnetic to ferromagnetic phase transition in FeRh can be induced globally by either heating the material above its phase transition temperature or applying a combination of external stimuli (such as mechanical strain, electric/magnetic fields) on the material preheated close to its transition temperature. On the other hand, to locally induce this phase transition is more desirable for applications and requires a confined source of energy such as a focused laser beam. Here we combine laser excitation with X-ray magnetic imaging to determine the effect of laser heating on the local and transient magnetization of FeRh using time-resolved photoelectron emission microscopy. Excitation by an ultrashort laser pulse generates a local ferromagnetic state within 0.6ns which recovers its initial antiferromagnetic state after a further 2ns. The form of the domains during the growth and diminution of ferromagnetic ordering suggests an intrinsic speed limit for magnetic and structural changes.

17.
Int J Tuberc Lung Dis ; 21(4): 446-451, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28284261

RESUMO

SETTING: Mozambique, one of the world's high tuberculosis (TB) burden countries, has conducted only one national-level drug resistance survey, in 2007-2008. OBJECTIVE: To determine the drug resistance patterns of laboratory-confirmed TB cases. DESIGN: This was a population-level survey conducted over a 1-year period in the district of Manhiça. All laboratory-confirmed cases were evaluated for first-line anti-tuberculosis drug susceptibility testing using liquid culture. RESULTS: Resistance to at least one first-line drug was observed in 44 of 276 isolates (15.9%). Prevalence of drug resistance to each of the five anti-tuberculosis drugs tested was 4.0% for streptomycin, 10.1% for isoniazid (INH), 6.2% for rifampicin, 3.6% for ethambutol and 1.1% for pyrazinamide. The overall prevalence of multidrug-resistant TB (MDR-TB) was 5.1%: 3.8% (95%CI 2.0-7.0) in new and 13.2% (95%CI 5.8-27.3) in retreatment cases. Respectively 4.6% and 2.6% of new and retreatment cases were INH-monoresistant. Previous history of anti-tuberculosis treatment was associated with having MDR-TB (OR 4.3, 95%CI 1.3-14.1). CONCLUSION: The prevalence of drug resistance in the district of Manhiça is slightly higher than, but still compatible with, previous national estimates. INH monoresistance was high, posing the risk of hidden monotherapy in the continuation phase.


Assuntos
Antituberculosos/farmacologia , Isoniazida/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Adulto , Farmacorresistência Bacteriana , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Moçambique/epidemiologia , Mycobacterium tuberculosis/isolamento & purificação , Prevalência , Estudos Prospectivos , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia
18.
Curr Opin Insect Sci ; 15: 131-8, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27436743

RESUMO

Transgenic crops producing Bacillus thuringiensis- (Bt) insecticidal proteins (Bt crops) have provided useful pest management tools to growers for the past 20 years. Planting Bt crops has reduced the use of synthetic insecticides on cotton, maize and soybean fields in 11 countries throughout Latin America. One of the threats that could jeopardize the sustainability of Bt crops is the development of resistance by targeted pests. Governments of many countries require vigilance in measuring changes in Bt-susceptibility in order to proactively implement corrective measures before Bt-resistance is widespread, thus prolonging the usefulness of Bt crops. A pragmatic approach to obtain information on the effectiveness of Bt-crops is directly asking growers, crop consultants and academics about Bt-resistance problems in agricultural fields, first-hand information that not necessarily relies on susceptibility screens performed in laboratories. This type of information is presented in this report. Problematic pests of cotton and soybeans in five Latin American countries currently are effectively controlled by Bt crops. Growers that plant conventional (non-Bt) cotton or soybeans have to spray synthetic insecticides against multiple pests that otherwise are controlled by these Bt crops. A similar situation has been observed in six Latin American countries where Bt maize is planted. No synthetic insecticide applications are used to control corn pests because they are controlled by Bt maize, with the exception of Spodoptera frugiperda. While this insect in some countries is still effectively controlled by Bt maize, in others resistance has evolved and necessitates supplemental insecticide applications and/or the use of Bt maize cultivars that express multiple Bt proteins. Partial control of S. frugiperda in certain countries is due to its natural tolerance to the Bt bacterium. Of the 31 pests targeted and controlled by Bt crops in Latin America, only S. frugiperda has shown tolerance to certain Bt proteins in growers' fields, the most reliable indication of the status of Bt-susceptibility in most of the American continent.


Assuntos
Insetos/fisiologia , Controle Biológico de Vetores/estatística & dados numéricos , Animais , Bacillus thuringiensis/química , Resistência a Inseticidas/genética , América Latina , Plantas Geneticamente Modificadas
19.
Indian J Dermatol Venereol Leprol ; 82(6): 673-676, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27212282

RESUMO

BACKGROUND: Progressive macular hypomelanosis is an acquired disorder characterized by hypopigmented macules mostly on the trunk and upper extremities. Although many treatment modalities have been proposed for this condition with variable success rates, there are few reports comparing their efficacy and relapse rates. AIM: To compare the efficacy and relapse rates of different treatment modalities for progressive macular hypomelanosis. METHODS: Case records of patients diagnosed with progressive macular hypomelanosis and treated in National Skin Centre for a six year period between 2008 and 2014 were reviewed. Patient demographics, distribution of hypopigmented macules, treatment efficacy and relapse rates were noted. RESULTS: A total of 108 patients were seen for progressive macular hypomelanosis over the study period; of these, 40 opted for no treatment but were followed up. Thirty-six were treated with topical antimicrobials and 32 with phototherapy. Of those untreated, 23% recovered spontaneously while 38% in the antimicrobial group and 90% in the phototherapy had remission of their hypopigmentation. After 2 years of follow-up, relapse occurred only in the phototherapy group. LIMITATIONS: The main limitation is the retrospective design whereby diagnosis is dependent on the attending dermatologist. CONCLUSIONS: Narrow-band ultraviolet B therapy appears to be the most effective treatment for progressive macular hypomelanosis but also has the highest potential for relapse. Response rates for antimicrobial therapy are lower and slower, but patients who responded did not relapse. A combination of topical/systemic antimicrobials with narrow-band ultraviolet B therapy might be the best option to hasten recovery and minimize relapse.


Assuntos
Anti-Infecciosos/administração & dosagem , Progressão da Doença , Hipopigmentação/diagnóstico , Hipopigmentação/terapia , Macula Lutea/patologia , Fototerapia/tendências , Administração Tópica , Adolescente , Adulto , Feminino , Seguimentos , Humanos , Macula Lutea/efeitos dos fármacos , Masculino , Recidiva , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
20.
Nat Phys ; 12(5): 484-492, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27158255

RESUMO

At interfaces between conventional materials, band bending and alignment are classically controlled by differences in electrochemical potential. Applying this concept to oxides in which interfaces can be polar and cations may adopt a mixed valence has led to the discovery of novel two-dimensional states between simple band insulators such as LaAlO3 and SrTiO3. However, many oxides have a more complex electronic structure, with charge, orbital and/or spin orders arising from strong Coulomb interactions between transition metal and oxygen ions. Such electronic correlations offer a rich playground to engineer functional interfaces but their compatibility with the classical band alignment picture remains an open question. Here we show that beyond differences in electron affinities and polar effects, a key parameter determining charge transfer at correlated oxide interfaces is the energy required to alter the covalence of the metal-oxygen bond. Using the perovskite nickelate (RNiO3) family as a template, we probe charge reconstruction at interfaces with gadolinium titanate GdTiO3. X-ray absorption spectroscopy shows that the charge transfer is thwarted by hybridization effects tuned by the rare-earth (R) size. Charge transfer results in an induced ferromagnetic-like state in the nickelate, exemplifying the potential of correlated interfaces to design novel phases. Further, our work clarifies strategies to engineer two-dimensional systems through the control of both doping and covalence.

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