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1.
Adv Synth Catal ; 363(17): 4177-4181, 2021 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-34690626

RESUMEN

Several manganese-PNP pincer catalysts for the formal hydroamination of allylic alcohols are presented. The resulting γ-amino alcohols are selectively obtained in high yields applying Mn-1 in a tandem process under mild conditions.

2.
Angew Chem Int Ed Engl ; 60(2): 550-565, 2021 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-32668079

RESUMEN

Hydrosilylation reactions, which allow the addition of Si-H to C=C/C≡C bonds, are typically catalyzed by homogeneous noble metal catalysts (Pt, Rh, Ir, and Ru). Although excellent activity and selectivity can be obtained, the price, purification, and metal residues of these precious catalysts are problems in the silicone industry. Thus, a strong interest in more sustainable catalysts and for more economic processes exists. In this respect, recently disclosed hydrosilylations using catalysts based on earth-abundant transition metals, for example, Fe, Co, Ni, and Mn, and heterogeneous catalysts (supported nanoparticles and single-atom sites) are noteworthy. This minireview describes the recent advances in this field.

3.
PLoS One ; 15(9): e0237627, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32877420

RESUMEN

The ongoing COVID-19 epidemics poses a particular challenge to low and middle income countries, making some of them consider the strategy of "vertical confinement". In this strategy, contact is reduced only to specific groups (e.g. age groups) that are at increased risk of severe disease following SARS-CoV-2 infection. We aim to assess the feasibility of this scenario as an exit strategy for the current lockdown in terms of its ability to keep the number of cases under the health care system capacity. We developed a modified SEIR model, including confinement, asymptomatic transmission, quarantine and hospitalization. The population is subdivided into 9 age groups, resulting in a system of 72 coupled nonlinear differential equations. The rate of transmission is dynamic and derived from the observed delayed fatality rate; the parameters of the epidemics are derived with a Markov chain Monte Carlo algorithm. We used Brazil as an example of middle income country, but the results are easily generalizable to other countries considering a similar strategy. We find that starting from 60% horizontal confinement, an exit strategy on May 1st of confinement of individuals older than 60 years old and full release of the younger population results in 400 000 hospitalizations, 50 000 ICU cases, and 120 000 deaths in the 50-60 years old age group alone. Sensitivity analysis shows the 95% confidence interval brackets a order of magnitude in cases or three weeks in time. The health care system avoids collapse if the 50-60 years old are also confined, but our model assumes an idealized lockdown where the confined are perfectly insulated from contamination, so our numbers are a conservative lower bound. Our results discourage confinement by age as an exit strategy.


Asunto(s)
Infecciones por Coronavirus/patología , Modelos Teóricos , Neumonía Viral/patología , Factores de Edad , Betacoronavirus/aislamiento & purificación , Brasil/epidemiología , COVID-19 , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/transmisión , Infecciones por Coronavirus/virología , Humanos , Cadenas de Markov , Método de Montecarlo , Pandemias , Neumonía Viral/epidemiología , Neumonía Viral/transmisión , Neumonía Viral/virología , Cuarentena , SARS-CoV-2
4.
Int J Biol Macromol ; 155: 142-152, 2020 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-32224174

RESUMEN

Chitosan film, Spirulina sp. film and its blend were developed as biosorbents to remove Cr6+ and Pb2+ ions from aqueous solutions. The kinetic study and the pH effect on biosorption efficiency were evaluated to comprehend the interactions between the ions and biosorbents. The characterization analyses pointed out that occurred interaction between both biomaterials, which resulted in structural alterations through the blend. The Spirulina sp. film exhibited the highest biosorption capacities for Cr6+ (43.2 mg g-1) and Pb2+ (35.6 mg g-1) ions, however, its physical integrity was not kept in acid medium. The blend film showed results slightly lower (35.8 mg g-1 for Cr6+ and 31.6 mg g-1 for Pb2+), but its physical integrity remained intact in all assays. Chitosan film presented the lower biosorption capacities (15.4 mg g-1 for Cr6+ and 20.9 mg g-1 for Pb2+). Elovich and pseudo-second order models were the most suitable to express the kinetic behaviors for Cr6+ and Pb2+, respectively. Therefore, chitosan/Spirulina sp. blend could be a green alternative for Cr6+ and Pb2+ removal, because this biosorbent showed high biosorption capacity obtained from Spirulina sp. and great physical integrity obtained of chitosan.


Asunto(s)
Materiales Biocompatibles/química , Cadmio/química , Quitosano/química , Plomo/química , Spirulina/química , Adsorción , Cinética , Agua/química , Contaminantes Químicos del Agua/química
5.
World Neurosurg ; 137: e517-e525, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32081819

RESUMEN

BACKGROUND: In the presence of a skull deformity after large decompressive craniectomy (DC), neurologic deterioration manifesting as epileptic syndrome (ES) may occur independently of the primary disease or spontaneous improvement may be unduly impaired, and these unfavorable outcomes have sometimes been reversed by cranioplasty. The objective of this study was to analyze the influence of cranioplasty on the presence of ES in patients who underwent DC. METHODS: A prospective study was performed from October 2016 to October 2017 involving patients who underwent DC and subsequent cranioplasty. Electroencephalographic (EEG) status before and after cranioplasty was analyzed in the presence of seizures and was compared with results after DC. RESULTS: The sample included 52 patients. Male sex (78.8%) and traumatic brain injury (82.7%) were common indications for DC. ES after DC was verified in 26.9% of patients, and 50% of patients presented with abnormal EEG status. ES after cranioplasty was noted in 21.2% and 36.3% of patients followed by abnormal EEG status. All patients with precranioplasty epileptogenic paroxysms showed better EEG tracings after the procedure. CONCLUSIONS: In routine clinical practice, altered amplitudes were observed in the region of bone defects. Although cranioplasty reduced pathologic EEG status (epileptogenic paroxysms), it was not able to produce new EEG tracings that could predict changes in seizure discharge or reduce ES.


Asunto(s)
Craniectomía Descompresiva/efectos adversos , Síndromes Epilépticos/cirugía , Complicaciones Posoperatorias/cirugía , Convulsiones/cirugía , Cráneo/cirugía , Adulto , Lesiones Traumáticas del Encéfalo/cirugía , Electroencefalografía , Síndromes Epilépticos/etiología , Síndromes Epilépticos/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Defectos del Tubo Neural , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/fisiopatología , Estudios Prospectivos , Procedimientos Quirúrgicos Reconstructivos , Convulsiones/etiología , Convulsiones/fisiopatología , Resultado del Tratamiento , Adulto Joven
6.
Surg Neurol Int ; 10: 177, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31583174

RESUMEN

Background: Brain aneurysms are mostly discovered during the investigation of subarachnoid hemorrhage (SAH). Some patients present neurological signs that may suggest the aneurysm's topography, and the oculomotor nerve palsy (ONP) of the same side of the aneurysm is the most common sign. Only one case report of contralateral palsy was previously described in the medical literature. Case Description: Authors describe a patient who presented a classic manifestation of SAH associated with complete ONP, whose vascular investigation demonstrated a brain aneurysm located in the contralateral intracranial carotid. The patient was surgically treated with great neurologic outcome, and late angiography did not evidence other vascular abnormalities. Conclusion: The ipsilateral ONP is a common sign found in posterior communicating artery aneurysms; however, such aneurysm can have different presentations due to the elevation of intracranial pressure, and, in rarer cases, the ONP cannot be operated as a localizing sign.

7.
World Neurosurg ; 110: e479-e483, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29146435

RESUMEN

OBJECTIVE: This retrospective study reports the epidemiology, clinical aspects, and management of spinal trauma in children and adolescents. METHODS: Multicenter study of 215 cases of spinal trauma in individuals <18 years of age. All patients were submitted to preoperative and postoperative radiologic and clinical evaluation. The fractures were classified according to the AOSpine fracture classification. Neurological evaluation was performed using the Frankel scale at admission to hospital and at the last follow-up. RESULTS: Mean age was 14.7 (± 2.5) years and most of the patients were male (72.6%). Falls were responsible for 52.6% of the spinal trauma. Compression fracture was the most common type of fracture, observed in 48.4% of the cases. Most spinal fractures were located at the thoracic level (58.7%). Associated injuries were observed in 37.2% of the cases. The complication rates were 15.8%. Normal neurological examination was observed in 160 cases (74.4%) at the final follow-up. Neurological impairment was mostly observed due to shallow water diving, dislocation fractures types, and fractures located between the lower cervical spine and the thoracic spine. Surgical treatment was performed in 73.8% of the cases. Better neurological outcome was observed in fractures due to falls, fractures located in the upper cervical (C1-C2) and lower lumbar spine injuries (L3-L5). CONCLUSIONS: Surgical treatment is often necessary in children and adolescents after spinal trauma. Higher incidence of spinal cord injury was observed after shallow water diving, fractures located in the lower cervical spine and thoracic spine, and type B and C fractures.


Asunto(s)
Fracturas de la Columna Vertebral/epidemiología , Fracturas de la Columna Vertebral/terapia , Adolescente , Niño , Manejo de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Examen Neurológico , Estudios Retrospectivos , Traumatismos de la Médula Espinal/diagnóstico por imagen , Traumatismos de la Médula Espinal/epidemiología , Traumatismos de la Médula Espinal/etiología , Traumatismos de la Médula Espinal/terapia , Fracturas de la Columna Vertebral/diagnóstico por imagen , Fracturas de la Columna Vertebral/etiología
8.
World Neurosurg ; 111: e1-e6, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29175570

RESUMEN

BACKGROUND: Spinal metastatic disease compromises the quality of life and prognosis of the patients. Prognosis is an important factor for the decision-making process and needs to be precise in order to adjust the intensity of therapy. The Tokuhashi score is a universal instrument to determine the prognosis. The objective was to analyze the effectiveness of the Tokuhashi score in determining the prognosis of the patients with spine metastasis by comparing the expected survival time from the Tokuhashi score with the survival time observed among surgical patients. METHODS: This retrospective study was performed from October 2008 to October 2015. The inclusion criteria were symptomatic patients with spinal metastasis who underwent spinal cord decompression and had a minimum of 1-year follow-up. The exclusion criteria were patients without histologic confirmation and were lost to follow-up. The Tokuhashi score was applied, and once the expected survival was defined, it was compared with the survival time observed in the follow-up. RESULTS: The sample studied was 117 patients. The commonly female (58%) and breast spinal metastasis was often observed (25.6%). The patients were followed for a minimum period of 12 months. The actual survival was beyond that estimated by the Tokuhashi score (P < 0.05). CONCLUSION: The Tokuhashi score was not reliable to predict the prognosis. Patients with lower scores that surgical treatment was not recommended by the Tokuhashi score had better quality of life and longer survival after surgery. Tokuhashi score is not a precise tool to establish the best therapy and survival in patients with spinal metastasis.


Asunto(s)
Neoplasias de la Columna Vertebral/diagnóstico , Neoplasias de la Columna Vertebral/secundario , Anciano , Descompresión Quirúrgica , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Calidad de Vida , Reproducibilidad de los Resultados , Estudios Retrospectivos , Neoplasias de la Columna Vertebral/cirugía , Columna Vertebral/cirugía , Análisis de Supervivencia
9.
PLoS One ; 10(8): e0135006, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26247784

RESUMEN

Employing reference genes to normalize the data generated with quantitative PCR (qPCR) can increase the accuracy and reliability of this method. Previous results have shown that no single housekeeping gene can be universally applied to all experiments. Thus, the identification of a suitable reference gene represents a critical step of any qPCR analysis. Setaria viridis has recently been proposed as a model system for the study of Panicoid grasses, a crop family of major agronomic importance. Therefore, this paper aims to identify suitable S. viridis reference genes that can enhance the analysis of gene expression in this novel model plant. The first aim of this study was the identification of a suitable RNA extraction method that could retrieve a high quality and yield of RNA. After this, two distinct algorithms were used to assess the gene expression of fifteen different candidate genes in eighteen different samples, which were divided into two major datasets, the developmental and the leaf gradient. The best-ranked pair of reference genes from the developmental dataset included genes that encoded a phosphoglucomutase and a folylpolyglutamate synthase; genes that encoded a cullin and the same phosphoglucomutase as above were the most stable genes in the leaf gradient dataset. Additionally, the expression pattern of two target genes, a SvAP3/PI MADS-box transcription factor and the carbon-fixation enzyme PEPC, were assessed to illustrate the reliability of the chosen reference genes. This study has shown that novel reference genes may perform better than traditional housekeeping genes, a phenomenon which has been previously reported. These results illustrate the importance of carefully validating reference gene candidates for each experimental set before employing them as universal standards. Additionally, the robustness of the expression of the target genes may increase the utility of S. viridis as a model for Panicoid grasses.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Genes Esenciales , Genes de Plantas , Hojas de la Planta/genética , Proteínas de Plantas/genética , Setaria (Planta)/genética , Algoritmos , Perfilación de la Expresión Génica , Proteínas de Dominio MADS/genética , Anotación de Secuencia Molecular , Péptido Sintasas/genética , Fosfoglucomutasa/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/normas , Estándares de Referencia , Reproducibilidad de los Resultados
10.
Int J Psychol ; 49(4): 233-9, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24812019

RESUMEN

The abundance of scholarship on test development and use generally is higher in English-speaking than in Iberian Latin American countries. The purpose of this article is to help overcome this imbalance by describing and identifying similarities and differences in test development and use in two Iberian (Portugal and Spain) and three of the largest Latin American (Argentina, Brazil, and Venezuela) countries. The stages of test development in each country, roles of professional associations, presence of standards for test use, professionals' educational training, commonly used tests, together with prominent challenges to continued progress are discussed. Test development and use in these five countries are transitioning from a dependence on the use of translated tests to greater reliance on adapted and finally nationally constructed tests. Continued growth requires adherence to international standards guiding test development and use. Stronger alliance among professional associations in the Iberian Latin American countries could serve as a catalyst to promote test development in these regions.


Asunto(s)
Pruebas Psicológicas/normas , Psicología Aplicada/normas , Traducciones , Argentina , Brasil , Humanos , Portugal , Psicología Aplicada/tendencias , Estándares de Referencia , Estados Unidos , Venezuela
11.
Parasitol Res ; 113(4): 1313-7, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24481905

RESUMEN

Neurocysticercosis (NCC) is the most common helminthic infection and neglected disease of the central nervous system. It is the leading cause of acquired epilepsy and seizures worldwide. Therefore, to study this important neglected disease, it is important to use experimental models. There is no report in the literature on how the parasite's metabolism reacts to antihelminthic treatment when it is still within the central nervous system of the host. Therefore, the aim of this study was to investigate the energetic metabolism of cysticerci experimentally inoculated in the encephala of BALB/c mice after treatment with low dosages (not sufficient to kill the parasite) of albendazole (ABDZ) and praziquantel (PZQ). BALB/c mice were intracranially inoculated with Taenia crassiceps cysticerci and, after 30 days, received treatment with low dosages of ABDZ and PZQ. After 24 h of treatment, the mice were euthanized, and the cysticerci were removed and analyzed through high-performance liquid chromatography (HPLC) to quantify the organic acids related to the energetic metabolism of the parasite. The partial reverse of the TCA cycle was enhanced by the ABDZ and PZQ treatments both with the higher dosage, as the organic acids of this pathway were significantly increased when compared to the control group and to the other dosages. In conclusion, it was possible to detect the increase of this pathway in the parasites that were exposed to low dosages of ABDZ and PZQ, as it is a mechanism that would amplify the energy production in a hostile environment.


Asunto(s)
Antihelmínticos/uso terapéutico , Ciclo del Ácido Cítrico , Neurocisticercosis/tratamiento farmacológico , Taenia/metabolismo , Albendazol/uso terapéutico , Animales , Encéfalo/parasitología , Cromatografía Líquida de Alta Presión , Ratones , Ratones Endogámicos BALB C , Neurocisticercosis/parasitología , Praziquantel/uso terapéutico , Taenia/efectos de los fármacos
12.
Dental Press J Orthod ; 18(1): 86-93, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23876955

RESUMEN

OBJECTIVE: To evaluate the in vitro ionic degradation and slot base corrosion of metallic brackets subjected to brushing with dentifrices, through analysis of chemical composition by Energy Dispersive Spectroscopy (EDS) and qualitative analysis by Scanning Electron Microscopy (SEM). METHODS: Thirty eight brackets were selected and randomly divided into four experimental groups (n = 7). Two groups (n = 5) worked as positive and negative controls. Simulated orthodontic braces were assembled using 0.019 x 0.025-in stainless steel wires and elastomeric rings. The groups were divided according to surface treatment: G1 (Máxima Proteção Anticáries®); G2 (Total 12®); G3 (Sensitive®); G4 (Branqueador®); Positive control (artificial saliva) and Negative control (no treatment). Twenty eight brushing cycles were performed and evaluations were made before (T0) and after (T1) experiment. RESULTS: The Wilcoxon test showed no difference in ionic concentrations of titanium (Ti), chromium (Cr), iron (Fe) and nickel (Ni) between groups. G2 presented significant reduction (p < 0.05) in the concentration of aluminium ion (Al). Groups G3 and G4 presented significant increase (p < 0.05) in the concentration of aluminium ion. The SEM analysis showed increased characteristics indicative of corrosion on groups G2, G3 and G4. CONCLUSION: The EDS analysis revealed that control groups and G1 did not suffer alterations on the chemical composition. G2 presented degradation in the amount of Al ion. G3 and G4 suffered increase in the concentration of Al. The immersion in artificial saliva and the dentifrice Máxima Proteção Anticáries® did not alter the surface polishing. The dentifrices Total 12®, Sensitive® and Branqueador® altered the surface polishing.


Asunto(s)
Corrosión , Dentífricos/química , Metales/química , Soportes Ortodóncicos , Estrés Mecánico , Iones/química , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Saliva Artificial , Espectrometría por Rayos X , Propiedades de Superficie
13.
J Bras Nefrol ; 33(2): 160-5, 2011.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-21789428

RESUMEN

INTRODUCTION: Nephrolithiasis is com>mon and has a high rate of recurrence. OBJECTIVES: To assess the prevalence of the main metabolic and anatomical changes and the chemical analysis of stone found in patients with nephrolithiasis in the West region of Paraná. METHODS: Retrospective study with 681 adult patients with nephrolithiasis. The laboratory investigation included at least two samples of 24-hour urine test with doses of calcium, uric acid, citrate, oxalate, sodium and creatinine; qualitative cystinuria, urinary pH following 12-hour fast and water restriction, urine culture and chemical analysis, when the stones were available. Renal imaging techniques included at least renal ultrasound and excretory urogram. RESULTS: The metabolic changes most frequently found were: hypercalciuria (51.8%), hyperuricosuria (27.6%), and hypocitraturia (23.5%). Chemical analysis of stones showed calcium oxa late in 85.7% of the cases. The most frequently anatomical changes were renal cyst, duplicated ureter, and ureteropelvic junction obstruction. CONCLUSIONS: This paper served as a base for knowing the characteristics of patients with nephrolithiasis in the West area of Paraná.


Asunto(s)
Nefrolitiasis/diagnóstico , Adulto , Brasil , Femenino , Humanos , Masculino , Estudios Retrospectivos
14.
Behav Brain Res ; 170(2): 175-81, 2006 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-16569447

RESUMEN

Electrical stimulation of the dorsal periaqueductal grey matter (DPAG) and deep layers of the superior colliculus (DLSC) of the rat elicits anxiety-like reactions such as freezing and flight. The temporal course of the effects of the aversive electrical stimulation of the DPAG (5, 15 and 30 min afterward) and DLSC (5, 10 and 15 min afterward) on the defensive response of rats exposed to elevated T-maze were determined. The elevated T-maze generates two defensive behaviors, inhibitory avoidance and one-way escape, which have been related, respectively, to generalized anxiety and panic disorders. Prior electrical stimulation of the DPAG (15 min) and DLSC (5 min) enhanced inhibitory avoidance when compared to no-operated and sham animals, although not affecting escape. Therefore, stimulation of the DPAG and DLSC causes a heightened responsivity to anxiogenic stimulus, but not to panicogenic stimulus, inherent to elevated T-maze. These findings support the participation of the DPAG and DLSC in the elaboration of adaptive responses to stressful situations. Besides, the data supports the view that prior electrical stimulation of DPAG and DLSC is selective in sensitizing rats to anxiety-like behaviors, but not to panic-like behaviors in the elevated T-maze test.


Asunto(s)
Ansiedad/etiología , Estimulación Eléctrica , Aprendizaje por Laberinto/efectos de la radiación , Sustancia Gris Periacueductal/efectos de la radiación , Colículos Superiores/efectos de la radiación , Animales , Ansiedad/fisiopatología , Reacción de Prevención/efectos de la radiación , Conducta Animal/efectos de la radiación , Reacción de Fuga/efectos de la radiación , Inhibición Psicológica , Masculino , Ratas , Ratas Wistar , Tiempo de Reacción/efectos de la radiación , Factores de Tiempo
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