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1.
Nanoscale Adv ; 5(12): 3279-3286, 2023 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-37325538

RESUMEN

The quantum yield (QY) evaluation of upconverting nanoparticles (UCNPs) is an essential step in the characterisation of such materials. The QY of UCNPs is governed by competing mechanisms of populating and depopulating the electronic energy levels involved in the upconversion (UC), namely linear decay rates and energy transfer rates. As a consequence, at low excitation, the QY excitation power density (ρ) dependence obeys the power law ρn-1, where n represents the number of absorbed photons required for the emission of a single upconverted photon and determines the order of the energy transfer upconversion (ETU) process. At high power densities, the QY transits to a saturation level independent of the ETU process and the number of excitation photons, as a result of an anomalous power density dependence present in UCNPs. Despite the importance of this non-linear process for several applications (e.g., living tissue imaging and super-resolution-microscopy), little has been reported in the literature regarding theoretical studies to describe the UC QY, especially for ETUs with order higher than two. Therefore, this work presents a simple general analytical model, which introduces the concept of the transition power density points and QY saturation to characterise the QY of an arbitrary ETU process. The transition power density points determine where the power density dependence of the QY and the UC luminescence changes. The results provided in this paper from fitting the model to experimental QY data of a Yb-Tm codoped ß-UCNP for 804 nm and 474 nm emissions (ETU2 and ETU3 processes, respectively) exemplify the application of the model. The common transition points found for both processes were compared to each other showing strong agreement with theory, as well as, compared to previous reports when possible.

2.
Acta Neurochir (Wien) ; 164(10): 2719-2730, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35501576

RESUMEN

BACKGROUND: Several prognostic models for outcomes after chronic subdural hematoma (CSDH) treatment have been published in recent years. However, these models are not sufficiently validated for use in daily clinical practice. We aimed to assess the performance of existing prediction models for outcomes in patients diagnosed with CSDH. METHODS: We systematically searched relevant literature databases up to February 2021 to identify prognostic models for outcome prediction in patients diagnosed with CSDH. For the external validation of prognostic models, we used a retrospective database, containing data of 2384 patients from three Dutch regions. Prognostic models were included if they predicted either mortality, hematoma recurrence, functional outcome, or quality of life. Models were excluded when predictors were absent in our database or available for < 150 patients in our database. We assessed calibration, and discrimination (quantified by the concordance index C) of the included prognostic models in our retrospective database. RESULTS: We identified 1680 original publications of which 1656 were excluded based on title or abstract, mostly because they did not concern CSDH or did not define a prognostic model. Out of 18 identified models, three could be externally validated in our retrospective database: a model for 30-day mortality in 1656 patients, a model for 2 months, and another for 3-month hematoma recurrence both in 1733 patients. The models overestimated the proportion of patients with these outcomes by 11% (15% predicted vs. 4% observed), 1% (10% vs. 9%), and 2% (11% vs. 9%), respectively. Their discriminative ability was poor to modest (C of 0.70 [0.63-0.77]; 0.46 [0.35-0.56]; 0.59 [0.51-0.66], respectively). CONCLUSIONS: None of the examined models showed good predictive performance for outcomes after CSDH treatment in our dataset. This study confirms the difficulty in predicting outcomes after CSDH and emphasizes the heterogeneity of CSDH patients. The importance of developing high-quality models by using unified predictors and relevant outcome measures and appropriate modeling strategies is warranted.


Asunto(s)
Hematoma Subdural Crónico , Hematoma Subdural Crónico/diagnóstico , Hematoma Subdural Crónico/cirugía , Humanos , Pronóstico , Calidad de Vida , Recurrencia , Estudios Retrospectivos
3.
Trop Biomed ; 36(1): 257-262, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33597446

RESUMEN

Rickettsioses are a common health problem in many geographical areas, including rural areas in Southeast Asia. Co-infection of rickettsioses and malaria has been reported in Africa, where common reservoir and vectors are available. In this study, blood samples of Malaysian patients microscopically positive (n=148) and negative (n=88) for malaria parasites (Plasmodium knowlesi, Plasmodium malariae, Plasmodium falciparum, and Plasmodium vivax) were screened for the presence of rickettsial DNA, using PCR assays targeting specific genes. A partial fragment of rickettsial ompB gene was successfully amplified and sequenced from a patient microscopically positive for Plasmodium spp. and PCR-positive for P. vivax. BLAST analysis of the ompB sequence demonstrated the highest sequence similarity (99.7% similarity, 408/409nt) with Rickettsia sp. RF2125 (Genbank accession no. JX183538) and 91.4% (374/409 nt) similarity with Rickettsia felis URRWXCal2 (Genbank accession no. CP000053). This study reports rickettsial infection in a malaria patient for the first time in the Southeast Asia region.

4.
Tropical Biomedicine ; : 257-262, 2019.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-751101

RESUMEN

@#Rickettsioses are a common health problem in many geographical areas, including rural areas in Southeast Asia. Co-infection of rickettsioses and malaria has been reported in Africa, where common reservoir and vectors are available. In this study, blood samples of Malaysian patients microscopically positive (n=148) and negative (n=88) for malaria parasites (Plasmodium knowlesi, Plasmodium malariae, Plasmodium falciparum, and Plasmodium vivax) were screened for the presence of rickettsial DNA, using PCR assays targeting specific genes. A partial fragment of rickettsial ompB gene was successfully amplified and sequenced from a patient microscopically positive for Plasmodium spp. and PCR-positive for P. vivax. BLAST analysis of the ompB sequence demonstrated the highest sequence similarity (99.7% similarity, 408/409nt) with Rickettsia sp. RF2125 (Genbank accession no. JX183538) and 91.4% (374/409 nt) similarity with Rickettsia felis URRWXCal2 (Genbank accession no. CP000053). This study reports rickettsial infection in a malaria patient for the first time in the Southeast Asia region.

5.
Tijdschr Psychiatr ; 59(10): 626-631, 2017.
Artículo en Holandés | MEDLINE | ID: mdl-29077138

RESUMEN

BACKGROUND: There is increasing clinical and scientific interest in electroconvulsive therapy (ECT). AIM: To provide an overview of the main research findings of the Flemish-Dutch research consortium ResPECT. METHOD: We report on our review of the relevant literature. RESULTS: Our studies confirm that ECT is one of the most efficient treatments for depression in later life and for depression with psychotic features. Older people with age-related brain pathology can respond well to ECT. It is still preferable to apply a standard pulse-width because this increases the efficacy of the treatment and minimises the cognitive impact. Even vulnerable older people can react favourably to ECT. CONCLUSION: Recent findings of the ResPECT consortium are providing new insights that are applicable in daily clinical practice. Research into mechanisms of action can also increase our understanding of the pathophysiology of severe depression.


Asunto(s)
Trastorno Depresivo Mayor/terapia , Terapia Electroconvulsiva/métodos , Humanos , Resultado del Tratamiento
6.
Trop Biomed ; 34(3): 668-674, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-33592935

RESUMEN

Hemotrophic mycoplasma (hemoplasmas) is a cell wall-less bacterium causing infectious anemia in animals. As data on hemoplasmas infecting cattle in Malaysia is scarce, specific polymerase chain reaction assays were used for detection of hemoplasmas from blood samples of cattle and ticks in this study. Hemoplasma DNA was detected in 69 (69.0%) of 100 cattle blood samples obtained from different breeds. A total of 50.0% of the cattle in this study were infected with only Mycoplasma wenyonii, while 2.0% were infected with only Candidatus Mycoplasma haemobos and 17% were infected with both species. Based on sequence analysis of the partial or nearly full length sequences of hemoplasma 16S rRNA gene, the presence of M. wenyonii and Candidatus M. haemobos was confirmed. Hemoplasmapositive cattle of less than three years appeared to have higher infection rate compared to other age groups. M. wenyonii was identified for the first time in approximately 30% of cattle ticks (Rhipicephalus microplus and Haemaphysalis sp.) in this study. This study presents the first molecular evidence of hemoplasmas in Malaysian cattle and ticks.

7.
Trop Biomed ; 34(3): 675-680, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-33592936

RESUMEN

Coxiella burnetii, the causative agent of Q fever, is an intracellular bacterium of medical and veterinary importance. The reservoirs of C. burnetii are extensive which include mammals and arthropods, particularly ticks. As the organism is difficult to culture, this study was aimed to detect C. burnetii DNA in animal (mainly blood and vaginal samples of cattle, goats and sheep) and tick samples obtained from farm animals, wild rodents and vegetation. Two polymerase chain reaction (PCR) assays targeting IS1111 transposon-like gene (TransPCR) and com1 gene (OMP-PCR) were used for C. burnetii detection. Sequence determination of the amplified fragments and a real-time PCR assay were used to confirm PCR findings. C. burnetii DNA was detected from 9.1% of cattle blood and 4.2% vaginal samples, respectively. A small percentage (5.8%) of ticks (including Amblyomma, Dermacentor, Rhipicephalus and Haemaphysalis spp.) haboring C. burnetii were identified in this study. This study provides molecular evidence on the presence of C. burnetii in cattle and ticks. The possible zoonotic transmission of C. burnetii is yet to be investigated.

8.
Tropical Biomedicine ; : 668-674, 2017.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-631037

RESUMEN

Hemotrophic mycoplasma (hemoplasmas) is a cell wall-less bacterium causing infectious anemia in animals. As data on hemoplasmas infecting cattle in Malaysia is scarce, specific polymerase chain reaction assays were used for detection of hemoplasmas from blood samples of cattle and ticks in this study. Hemoplasma DNA was detected in 69 (69.0%) of 100 cattle blood samples obtained from different breeds. A total of 50.0% of the cattle in this study were infected with only Mycoplasma wenyonii, while 2.0% were infected with only Candidatus Mycoplasma haemobos and 17% were infected with both species. Based on sequence analysis of the partial or nearly full length sequences of hemoplasma 16S rRNA gene, the presence of M. wenyonii and Candidatus M. haemobos was confirmed. Hemoplasmapositive cattle of less than three years appeared to have higher infection rate compared to other age groups. M. wenyonii was identified for the first time in approximately 30% of cattle ticks (Rhipicephalus microplus and Haemaphysalis sp.) in this study. This study presents the first molecular evidence of hemoplasmas in Malaysian cattle and ticks.

9.
Acta Trop ; 155: 25-33, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26658020

RESUMEN

Bartonella elizabethae has been known to cause endocarditis and neuroretinitis in humans. The genomic features and virulence profiles of a B. elizabethae strain (designated as BeUM) isolated from the spleen of a wild rat in Kuala Lumpur, Malaysia are described in this study. The BeUM strain has a genome size of 1,932,479bp and GC content of 38.3%. There is a high degree of conservation between the genomes of strain BeUM with B. elizabethae type strains (ATCC 49927 and F9251) and a rat-borne strain, Re6043vi. Of 2137 gene clusters identified from B. elizabethae strains, 2064 (96.6%) are indicated as the core gene clusters. Comparative genome analysis of B. elizabethae strains reveals virulence genes which are known in other pathogenic Bartonella species, including VirB2-11, vbhB2-B11, VirD4, trw, vapA2-5, hbpA-E, bepA-F, bepH, badA/vomp/brp, ialB, omp43/89 and korA-B. A putative intact prophage has been identified in the strain BeUM, in addition to a 8kb pathogenicity island. The whole genome analysis supports the zoonotic potential of the rodent-borne B. elizabethae, and provides basis for future functional and pathogenicity studies of B. elizabethae.


Asunto(s)
Infecciones por Bartonella/epidemiología , Bartonella/genética , Zoonosis , Animales , Infecciones por Bartonella/microbiología , Reservorios de Enfermedades , Genómica , Humanos , Malasia/epidemiología , Reacción en Cadena de la Polimerasa , Ratas , Zoonosis/epidemiología , Zoonosis/microbiología
13.
Med Vet Entomol ; 28 Suppl 1: 104-8, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25171613

RESUMEN

Rickettsioses are emerging zoonotic diseases reported worldwide. In spite of the serological evidence of spotted fever group rickettsioses in febrile patients in Malaysia, limited studies have been conducted to identify the animal reservoirs and vectors of rickettsioses. This study investigated the presence of rickettsiae in the tissue homogenates of 95 wild rats and 589 animal ectoparasites. Using PCR assays targeting the citrate synthase gene (gltA), rickettsial DNA was detected in the tissue homogenates of 13 (13.7%) wild rats. Sequence analysis of the gltA amplicons showed 98.6-100% similarity with those of Rickettsia honei/R. conorii/R. raoultii (Rickettsiales: Rickettsiaceae). Sequence analysis of outer membrane protein A gene (ompA) identified Rickettsia sp. TCM1 strain from two rats. No rickettsia was detected from Laelaps mites, Rhipicephalus sanguineus and Haemaphysalis bispinosa ticks, and Felicola subrostratus lice in this study. R. felis was identified from 32.2% of 177 Ctenocephalides felis fleas. Sequence analysis of the gltA amplicons revealed two genotypes of R. felis (Rf31 and RF2125) in the fleas. As wild rats and cat fleas play an important role in the enzoonotic maintenance of rickettsiae, control of rodent and flea populations may be able to reduce transmission of rickettsioses in the local setting.


Asunto(s)
Proteínas de la Membrana Bacteriana Externa/genética , Citrato (si)-Sintasa/genética , Ctenocephalides/microbiología , Ratas , Infecciones por Rickettsia/veterinaria , Rickettsia/genética , Enfermedades de los Roedores/epidemiología , Animales , Femenino , Malasia , Masculino , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa/veterinaria , Rickettsia/clasificación , Rickettsia/aislamiento & purificación , Infecciones por Rickettsia/epidemiología , Infecciones por Rickettsia/microbiología , Enfermedades de los Roedores/microbiología , Análisis de Secuencia de ADN/veterinaria
14.
Trop Biomed ; 31(4): 769-76, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25776603

RESUMEN

This study was conducted to determine the occurrence of Anaplasma spp. in the blood samples of cattle, goats, deer and ticks in a Malaysian farm. Using polymerase chain reaction (PCR) and sequencing approach, Anaplasma spp. was detected from 81(84.4%) of 96 cattle blood samples. All blood samples from 23 goats and 22 deer tested were negative. Based on the analysis of the Anaplasma partial 16S ribosomal RNA gene, four sequence types (genotypes 1 to 4) were identified in this study. Genotypes 1-3 showed high sequence similarity to those of Anaplasma platys/ Anaplasma phagocytophilum, whilst genotype 4 was identical to those of Anaplasma marginale/ Anaplasma centrale/ Anaplasma ovis. Anaplasma DNA was detected from six (5.5%) of 109 ticks which were identified as Rhipicephalus (formely known as Boophilus) microplus ticks collected from the cattle. This study reported for the first time the detection of four Anaplasma sequence types circulating in the cattle population in a farm in Malaysia. The detection of Anaplasma DNA in R. microplus ticks in this study provides evidence that the ticks are one of the potential vectors for transmission of anaplasmosis in the cattle.


Asunto(s)
Anaplasma/clasificación , Anaplasma/aislamiento & purificación , Anaplasmosis/epidemiología , Enfermedades de los Bovinos/microbiología , Ciervos/microbiología , Enfermedades de las Cabras/microbiología , Garrapatas/microbiología , Anaplasma/genética , Anaplasmosis/microbiología , Animales , Secuencia de Bases , Sangre/microbiología , Bovinos , Enfermedades de los Bovinos/epidemiología , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Genotipo , Enfermedades de las Cabras/epidemiología , Cabras , Malasia/epidemiología , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
15.
Tropical Biomedicine ; : 769-776, 2014.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-630434

RESUMEN

This study was conducted to determine the occurrence of Anaplasma spp. in the blood samples of cattle, goats, deer and ticks in a Malaysian farm. Using polymerase chain reaction (PCR) and sequencing approach, Anaplasma spp. was detected from 81(84.4%) of 96 cattle blood samples. All blood samples from 23 goats and 22 deer tested were negative. Based on the analysis of the Anaplasma partial 16S ribosomal RNA gene, four sequence types (genotypes 1 to 4) were identified in this study. Genotypes 1-3 showed high sequence similarity to those of Anaplasma platys/ Anaplasma phagocytophilum, whilst genotype 4 was identical to those of Anaplasma marginale/ Anaplasma centrale/ Anaplasma ovis. Anaplasma DNA was detected from six (5.5%) of 109 ticks which were identified as Rhipicephalus (formely known as Boophilus) microplus ticks collected from the cattle. This study reported for the first time the detection of four Anaplasma sequence types circulating in the cattle population in a farm in Malaysia. The detection of Anaplasma DNA in R. microplus ticks in this study provides evidence that the ticks are one of the potential vectors for transmission of anaplasmosis in the cattle.

16.
J Neurol Neurosurg Psychiatry ; 80(6): 686-8, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19448096

RESUMEN

Generally, activation of the frontal eye field during seizures can cause versive (forced) gaze deviation, while non-versive head deviation is hypothesised to result from ictal neglect after inactivation of the ipsilateral temporo-parietal area. Almost all non-versive head deviations occurring during temporal lobe seizures are directed to the side of seizure onset, so in derogatory cases it is worth while explaining the paradoxical event. We present a patient with a paradoxical direction of gaze deviation during temporal lobe seizures with an unexpected explanation. Electrocortical stimulation of the temporo-parieto-occipital junction elicited an irrepressible urge to look towards an illusory shadow person besides the patient. Paradoxical non-versive gaze deviations in temporal lobe seizures may be due to illusory experiences masked by postictal amnesia.


Asunto(s)
Dominancia Cerebral/fisiología , Epilepsia del Lóbulo Temporal/fisiopatología , Movimientos Oculares/fisiología , Ilusiones Ópticas/fisiología , Orientación/fisiología , Adulto , Mapeo Encefálico , Estimulación Eléctrica , Electrodos Implantados , Electroencefalografía , Epilepsia del Lóbulo Temporal/cirugía , Femenino , Fijación Ocular/fisiología , Lóbulo Frontal/fisiopatología , Alucinaciones/fisiopatología , Humanos , Monitoreo Ambulatorio , Lóbulo Occipital/fisiopatología , Lóbulo Parietal/fisiopatología , Procesamiento de Señales Asistido por Computador , Lóbulo Temporal/fisiopatología
18.
Tijdschr Psychiatr ; 50(2): 99-104, 2008.
Artículo en Holandés | MEDLINE | ID: mdl-18264900

RESUMEN

BACKGROUND: Psychotropic medication is sometimes tapered prior to electroconvulsive therapy (ECT) because of concern about interactions. METHOD: The published literature is reviewed to find grounds for these concerns. RESULTS: ECT can be combined safely with most psychotropics. Combination treatment with lithium can cause complications, but termination of lithium is not always necessary. Combination treatment with venlafaxin in doses higher than 300 mg daily can cause serious complications. CONCLUSION: The recommendation in the Dutch guidelines not to combine ECT with psychotropics because of possible interactions needs to be reconsidered. A specific recommendation is needed for each psychotropic medication.


Asunto(s)
Terapia Combinada , Terapia Electroconvulsiva/métodos , Trastornos Psicóticos/terapia , Psicotrópicos/uso terapéutico , Ciclohexanoles/efectos adversos , Ciclohexanoles/uso terapéutico , Interacciones Farmacológicas , Terapia Electroconvulsiva/efectos adversos , Humanos , Compuestos de Litio/efectos adversos , Compuestos de Litio/uso terapéutico , Guías de Práctica Clínica como Asunto , Psicotrópicos/efectos adversos , Seguridad , Resultado del Tratamiento , Clorhidrato de Venlafaxina
19.
Neuropsychologia ; 46(4): 1170-8, 2008 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-18076955

RESUMEN

UNLABELLED: Functional imaging studies have demonstrated involvement of the anterior temporal cortex in sentence comprehension. It is unclear, however, whether the anterior temporal cortex is essential for this function. We studied two aspects of sentence comprehension, namely syntactic and prosodic comprehension in temporal lobe epilepsy patients who were candidates for resection of the anterior temporal lobe. METHODS: Temporal lobe epilepsy patients (n=32) with normal (left) language dominance were tested on syntactic and prosodic comprehension before and after removal of the anterior temporal cortex. The prosodic comprehension test was also compared with performance of healthy control subjects (n=47) before surgery. RESULTS: Overall, temporal lobe epilepsy patients did not differ from healthy controls in syntactic and prosodic comprehension before surgery. They did perform less well on an affective prosody task. Post-operative testing revealed that syntactic and prosodic comprehension did not change after removal of the anterior temporal cortex. DISCUSSION: The unchanged performance on syntactic and prosodic comprehension after removal of the anterior temporal cortex suggests that this area is not indispensable for sentence comprehension functions in temporal epilepsy patients. Potential implications for the postulated role of the anterior temporal lobe in the healthy brain are discussed.


Asunto(s)
Comprensión/fisiología , Epilepsia del Lóbulo Temporal/fisiopatología , Epilepsia del Lóbulo Temporal/cirugía , Lóbulo Temporal/fisiopatología , Adolescente , Adulto , Análisis de Varianza , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Psicolingüística , Lóbulo Temporal/cirugía
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