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1.
ESMO Open ; 9(6): 103594, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38848661

RESUMEN

BACKGROUND: The impact of the most recent advances, including targeted therapies and immune checkpoint inhibitors, on early (3-month) mortality in lung cancer is unknown. The aims of this study were to evaluate the real-world rate of and risk factors for early mortality, as well as trends in early mortality over the last 20 years. MATERIALS AND METHODS: The KBP prospective observational multicenter studies have been conducted every 10 years since 2000. These studies collect data on all newly diagnosed patients with lung cancer (all stages and histologies) over 1 year in non-academic public hospital pulmonology or oncology units in France. In this study, we analyzed data on patient and tumor characteristics from participants in the KBP-2020 cohort and compared the characteristics of patients who died within 3 months of diagnosis with those of all other patients within the cohort. We also carried out a comparative analysis with the KBP-2000 and KBP-2010 cohorts. RESULTS: Overall, 8999 patients from 82 centers were included in the KBP-2020 cohort. Three-month survival data were available for 8827 patients, of whom 1792 (20.3%) had died. Risk factors for early mortality were: male sex, age >70 years, symptomatic disease at diagnosis, ever smoker, weight loss >10 kg, poor Eastern Cooperative Oncology Group performance status (≥1), large-cell carcinoma or not otherwise specified, and stage ≥IIIC disease. The overall 3-month mortality rate was found to have decreased significantly over the last 20 years, from 24.7% in KBP-2000 to 23.4% in KBP-2010 and 20.3% in KBP-2020 (P < 0.0001). CONCLUSION: Early mortality among patients with lung cancer has significantly decreased over the last 20 years which may reflect recent improvements in treatments. However, early mortality remained extremely high in 2020, particularly when viewed in light of improvements in longer-term survival. Delays in lung cancer diagnosis and management could contribute to this finding.


Asunto(s)
Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/mortalidad , Masculino , Femenino , Francia/epidemiología , Anciano , Factores de Riesgo , Persona de Mediana Edad , Estudios Prospectivos , Anciano de 80 o más Años
2.
Med Biol Eng Comput ; 61(1): 45-59, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36323980

RESUMEN

Early detection and diagnosis of brain tumors are essential for early intervention and eventually successful treatment plans leading to either a full recovery or an increase in the patient lifespan. However, diagnosis of brain tumors is not an easy task since it requires highly skilled professionals, making this procedure both costly and time-consuming. The diagnosis process relying on MR images gets even harder in the presence of similar objects in terms of their density, size, and shape. No matter how skilled professionals are, their task is still prone to human error. The main aim of this work is to propose a system that can automatically classify and diagnose glioma brain tumors into one of the four tumor types: (1) necrosis, (2) edema, (3) enhancing, and (4) non-enhancing. In this paper, we propose a combined texture discrete wavelet transform (DWT) and statistical features based on the first- and second-order features for the accurate classification and diagnosis of multiclass glioma tumors. Four well-known classifiers, namely, support vector machines (SVM), random forest (RF), multilayer perceptron (MLP), and naïve Bayes (NB), are used for classification. The BraTS 2018 dataset is used for the experiments, and with the combined DWT and statistical features, the RF classifier achieved the highest average accuracy whether for separated modalities or combined modalities. The highest average accuracy of 89.59% and 90.28% for HGG and LGG, respectively, was reported in this paper. It has also been observed that the proposed method outperforms similar existing methods reported in the extant literature.


Asunto(s)
Neoplasias Encefálicas , Glioma , Humanos , Teorema de Bayes , Neoplasias Encefálicas/diagnóstico por imagen , Glioma/diagnóstico por imagen , Redes Neurales de la Computación , Análisis de Ondículas
3.
J Appl Microbiol ; 132(4): 3155-3167, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32640111

RESUMEN

AIMS: To utilize transgenic GMR-Aß42 Drosophila melanogaster as a model to evaluate potential Alzheimer's disease (AD)-reversal effects via the administration of lactic acid bacteria (LAB) strains, and associations of LAB with changes in gut microbiota profiles. METHODS AND RESULTS: Wild-type flies (Oregon-R) were crossed with glass multimer reporter-GAL4 (GMR-GAL4) to produce GMR-OreR (Control), while UAS-Aß42 (#33769) were crossed with GMR-GAL4 to produce transgenic Drosophila line that expressed Aß42 (GMR-Aß42). Feed containing seven different LAB strains (Lactobacillus paracasei 0291, Lactobacillus helveticus 1515, Lactobacillus reuteri 30242, L. reuteri 8513d, Lactobacillus fermentum 8312, Lactobacillus casei Y, Lactobacillus sakei Probio65) were given to GMR-Aß42 respectively, while feed without LAB strains were given to control and transgenic GMR-Aß42.nf Drosophila lines. The morphology of the eyes was viewed with scanning electron microscopy (SEM). The changes in gut microbiota profiles associated with LAB were analysed using 16s high throughput sequencing. Malformation of eye structures in transgenic GMR-Aß42 Drosophila were reversed upon the administration of LAB strains, with more prevalent effects from L. sakei Probio65 and L. paracasei 0291. The GMR-Aß42.nf group showed dominance of Wolbachia in the gut, a genus that was almost absent in the normal control group (P < 0·05). The administration of L. sakei Probio65 and L. paracasei 0291 reduced the abundance of Wolbachia accompanied by increased abundance of Stenotrophomonas and Acetobacter (P < 0·05), resembling the microbial profile of the control group. CONCLUSIONS: Lactobacillus sakei Probio65 and Lactobacillus paracasei 0291 have more prominent effects in reversing malformed eye of transgenic GMR-Aß42 Drosophila, and reducing the abundance of Wolbachia accompanied by an increased abundance of Stenotrophomonas and Acetobacter. SIGNIFICANCE AND IMPACT OF THE STUDY: Potentials of LAB to prevent and/or alleviate the onset and pathogenesis of neurodegenerative diseases such as AD, supporting brain health strategies along the gut-brain axis.


Asunto(s)
Acetobacter , Enfermedad de Alzheimer , Microbioma Gastrointestinal , Lactobacillales , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Animales , Drosophila melanogaster/genética , Drosophila melanogaster/microbiología
4.
Materials (Basel) ; 14(19)2021 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-34640067

RESUMEN

Magnetic nanowires, conceived as individual building blocks for spintronic devices, constitute a well-suited model to design and study magnetization reversal processes, or to tackle fundamental questions, such as the presence of topologically protected magnetization textures under particular conditions. Recently, a skyrmion-tube mediated magnetization reversal process was theoretically reported in diameter modulated cylindrical nanowires. In these nanowires, a vortex nucleates at the end of the segments with larger diameter and propagates, resulting in a first switching of the nanowire core magnetization at small fields. In this work, we show experimental evidence of the so-called Bloch skyrmion-tubes, using advanced Magnetic Force Microscopy modes to image the magnetization reversal process of FeCoCu diameter modulated nanowires. By monitoring the magnetic state of the nanowire during applied field sweeping, a detected drop of magnetic signal at a given critical field unveils the presence of a skyrmion-tube, due to mutually compensating stray field components. That evidences the presence of a skyrmion-tube as an intermediate stage during the magnetization reversal, whose presence is related to the geometrical dimensions of the cylindrical segments.

5.
Sci Rep ; 11(1): 12027, 2021 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-34103560

RESUMEN

We report on the delithiation of LiCoO2 thin films using oxalic acid (C2H2O4) with the goal of understanding the structural degradation of an insertion oxide associated with Li chemical extraction. Using a multi-technique approach that includes synchrotron radiation X-ray diffraction, scanning electron microscopy, micro Raman spectroscopy, photoelectron spectroscopy and conductive atomic force microscopy we reveal the balance between selective Li extraction and structural damage. We identify three different delithiation regimes, related to surface processes, bulk delithiation and damage generation. We find that only a fraction of the grains is affected by the delithiation process, which may create local inhomogeneities. However, the bulk delithiation regime is effective to delithiate the LCO film. All experimental evidence collected indicates that the delithiation process in this regime mimics the behavior of LCO upon electrochemical delithiation. We discard the formation of Co oxalate during the chemical extraction process. In conclusion, the chemical route to Li extraction provides additional opportunities to investigate delithiation while avoiding the complications associated with electrolyte breakdown and simplifying in-situ measurements.

6.
J Appl Microbiol ; 130(4): 1307-1322, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32638482

RESUMEN

AIM: The aim of this study was to evaluate the molecular mechanisms of Lactobacillus strains in improving ageing of the musculoskeletal system. METHODS AND RESULTS: The anti-ageing mechanism of three probiotics strains Lactobacillus fermentum DR9, Lactobacillus paracasei OFS 0291 and L. helveticus OFS 1515 were evaluated on gastrocnemius muscle and tibia of d-galactose-induced ageing rats. Upon senescence induction, aged rats demonstrated reduced antioxidative genes CAT and SOD expression in both bone and muscle compared to the young rats (P < 0·05). Strain L. fermentum DR9 demonstrated improved expression of SOD in bone and muscle compared to the aged rats (P < 0·05). In the evaluation of myogenesis-related genes, L. paracasei OFS 0291 and L. fermentum DR9 increased the mRNA expression of IGF-1; L. helveticus OFS 1515 and L. fermentum DR9 reduced the expression of MyoD, in contrast to the aged controls (P < 0·05). Protective effects of L. fermentum DR9 on ageing muscle were believed to be contributed by increased AMPK-α2 expression. Among the osteoclastogenesis genes studied, TNF-α expression was highly elevated in tibia of aged rats, while all three probiotics strains ameliorated the expression. Lactobacillus fermentum DR9 also reduced the expression of IL-6 and TRAP in tibia when compared to the aged rats (P < 0·05). All probiotics treatment resulted in declined proinflammatory cytokines IL-1ß in muscle and bone. CONCLUSIONS: Lactobacillus fermentum DR9 appeared to be the strongest strain in modulation of musculoskeletal health during ageing. SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrated the protective effects of the bacteria on muscle and bone through antioxidative and anti-inflammatory actions. Therefore, L. fermentum DR9 may serve as a promising targeted anti-ageing therapy.


Asunto(s)
Envejecimiento/efectos de los fármacos , Huesos/efectos de los fármacos , Galactosa/efectos adversos , Lacticaseibacillus paracasei/fisiología , Lactobacillus helveticus/fisiología , Limosilactobacillus fermentum/fisiología , Sistema Musculoesquelético/efectos de los fármacos , Probióticos/administración & dosificación , Envejecimiento/genética , Envejecimiento/metabolismo , Animales , Desarrollo Óseo/efectos de los fármacos , Huesos/metabolismo , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Masculino , Desarrollo Musculoesquelético/efectos de los fármacos , Sistema Musculoesquelético/metabolismo , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo
7.
Benef Microbes ; 11(8): 753-766, 2020 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-33245015

RESUMEN

Aging processes affect the brain in many ways, ranging from cellular to functional levels which lead to cognitive decline and increased oxidative stress. The aim of this study was to investigate the potentials of Lactobacillus plantarum DR7 on brain health including cognitive and memory functions during aging and the impacts of high fat diet during a 12-week period. Male Sprague-Dawley rats were separated into six groups: (1) young animals on normal diet (ND, (2) young animals on a high fat diet (HFD), (3) aged animals on ND, (4) aged animals on HFD, (5) aged animals on HFD and L. plantarum DR7 (109 cfu/day) and (6) aged animals receiving HFD and lovastatin. To induce ageing, all rats in group 3 to 6 were injected sub-cutaneously at 600 mg/kg/day of D-galactose daily. The administration of DR7 has reduced anxiety accompanied by enhanced memory during behavioural assessments in aged-HFD rats (P<0.05). Hippocampal concentration of all three pro-inflammatory cytokines were increased during aging but reduced upon administration of both statin and DR7. Expressions of hippocampal neurotransmitters and apoptosis genes showed reduced expressions of indoleamine dioxygenase and P53 accompanied by increased expression of TPH1 in aged- HFD rats administered with DR7, indicating potential effects of DR7 along the pathways of serotonin and oxidative senescence. This study provided an insight into potentials of L. plantarum DR7 as a prospective dietary strategy to improve cognitive functions during aging. This study provided an insight into potentials of L. plantarum DR7 as a prospective dietary strategy to improve cognitive functions during aging.


Asunto(s)
Envejecimiento/fisiología , Apoptosis/fisiología , Disfunción Cognitiva/prevención & control , Lactobacillus plantarum/metabolismo , Probióticos/farmacología , Serotonina/metabolismo , Animales , Ansiedad/tratamiento farmacológico , Cognición/fisiología , Disfunción Cognitiva/fisiopatología , Citocinas/análisis , Dieta Alta en Grasa/efectos adversos , Hipocampo/metabolismo , Masculino , Memoria/efectos de los fármacos , Enfermedades Neurodegenerativas/prevención & control , Estrés Oxidativo , Ratas , Ratas Sprague-Dawley
8.
Philos Trans A Math Phys Eng Sci ; 378(2169): 20190188, 2020 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-32114911

RESUMEN

Optical wireless communication (OWC) is a promising technology that can provide high data rates while supporting multiple users. The optical wireless (OW) physical layer has been researched extensively, however, less work was devoted to multiple access and how the OW front end is connected to the network. In this paper, an OWC system which employs a wavelength division multiple access (WDMA) scheme is studied, for the purpose of supporting multiple users. In addition, a cloud/fog architecture is proposed for the first time for OWC to provide processing capabilities. The cloud/fog-integrated architecture uses visible indoor light to create high data rate connections with potential mobile nodes. These OW nodes are further clustered and used as fog mini servers to provide processing services through the OW channel for other users. Additional fog-processing units are located in the room, the building, the campus and at the metro level. Further processing capabilities are provided by remote cloud sites. Two mixed-integer linear programming (MILP) models were proposed to numerically study networking and processing in OW systems. The first MILP model was developed and used to optimize resource allocation in the indoor OWC systems, in particular, the allocation of access points (APs) and wavelengths to users, while the second MILP model was developed to optimize the placement of processing tasks in the different fog and cloud nodes available. The optimization of tasks placement in the cloud/fog-integrated architecture was analysed using the MILP models. Multiple scenarios were considered where the mobile node locations were varied in the room and the amount of processing and data rate requested by each OW node was varied. The results help to identify the optimum colour and AP to use for communication for a given mobile node location and OWC system configuration, the optimum location to place processing and the impact of the network architecture. This article is part of the theme issue 'Optical wireless communication'.

9.
Benef Microbes ; 11(1): 79-89, 2020 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-32066253

RESUMEN

Alzheimer's disease (AD) is a progressive disease and one of the most common forms of neurodegenerative disorders. Emerging evidence is supporting the use of various strategies that modulate gut microbiota to exert neurological and psychological changes. This includes the utilisation of probiotics as a natural and dietary intervention for brain health. Here, we showed the potential AD-reversal effects of Lactobacillus probiotics through feeding to our Drosophila melanogaster AD model. The administration of Lactobacillus strains was able to rescue the rough eye phenotype (REP) seen in AD-induced Drosophila, with a more prominent effect observed upon the administration of Lactobacillus plantarum DR7 (DR7). Furthermore, we analysed the gut microbiota of the AD-induced Drosophila and found elevated levels of Wolbachia. The administration of DR7 restored the gut microbiota diversity of AD-induced Drosophila with a significant reduction in Wolbachia's relative abundance, accompanied by an increase of Stenotrophomonas and Acetobacter. Through functional predictive analyses, Wolbachia was predicted to be positively correlated with neurodegenerative disorders, such as Parkinson's, Huntington's and Alzheimer's diseases, while Stenotrophomonas was negatively correlated with these neurodegenerative disorders. Altogether, our data exhibited DR7's ability to ameliorate the AD effects in our AD-induced Drosophila. Thus, we propose that Wolbachia be used as a potential biomarker for AD.


Asunto(s)
Enfermedad de Alzheimer , Microbioma Gastrointestinal/efectos de los fármacos , Lactobacillus plantarum , Enfermedades Neurodegenerativas/microbiología , Probióticos/administración & dosificación , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/microbiología , Animales , Biomarcadores , Modelos Animales de Enfermedad , Drosophila melanogaster , Enfermedades Neurodegenerativas/tratamiento farmacológico , Probióticos/farmacología , Wolbachia/efectos de los fármacos
10.
Benef Microbes ; 10(4): 355-373, 2019 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-30882244

RESUMEN

Probiotics have been reported to exert beneficial effects along the gut-brain axis. This randomised, double-blind and placebo-controlled human study aimed to evaluate such properties of Lactobacillus plantarum DR7 and its accompanying mechanisms in stressed adults. One hundred and eleven (n=111; DR7 n=56, placebo n=55) stressed adults were recruited based on moderate stress levels using the PSS-10 questionnaire. The consumption of DR7 (1×109 cfu/day) for 12 weeks reduced symptoms of stress (P=0.024), anxiety (P=0.001), and total psychological scores (P=0.022) as early as 8 weeks among stressed adults compared to the placebo group as assessed by the DASS-42 questionnaire. Plasma cortisol level was reduced among DR7 subjects as compared to the placebo, accompanied by reduced plasma pro-inflammatory cytokines, such as interferon-γ and transforming growth factor-α and increased plasma anti-inflammatory cytokines, such as interleukin 10 (P<0.05). DR7 better improved cognitive and memory functions in normal adults (>30 years old), such as basic attention, emotional cognition, and associate learning (P<0.05), as compared to the placebo and young adults (<30 years old). The administration of DR7 enhanced the serotonin pathway, as observed by lowered expressions of plasma dopamine ß-hydroxylase (DBH), tyrosine hydroxylase (TH), indoleamine 2,3-dioxygenase and tryptophan 2,3-dioxygenase accompanied by increased expressions of tryptophan hydroxylase-2 and 5-hydroxytryptamine receptor-6, while stabilising the dopamine pathway as observed via stabilised expressions of TH and DBH over 12 weeks as compared to the placebo (P<0.05). Our results indicated that DR7 fulfil the requirement of a probiotic strain as per recommendation of FAO/WHO and could be applicable as a natural strategy to improve psychological functions, cognitive health and memory in stressed adults.


Asunto(s)
Ansiedad/prevención & control , Lactobacillus plantarum/fisiología , Probióticos/administración & dosificación , Estrés Psicológico/terapia , Adulto , Ansiedad/microbiología , Ansiedad/psicología , Cognición/fisiología , Citocinas/sangre , Método Doble Ciego , Humanos , Hidrocortisona/sangre , Memoria/fisiología , Persona de Mediana Edad , Neurotransmisores/sangre , Serotonina/sangre , Estrés Psicológico/microbiología , Estrés Psicológico/psicología , Resultado del Tratamiento , Adulto Joven
11.
Benef Microbes ; 10(8): 883-892, 2019 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-31965837

RESUMEN

This study aimed to evaluate the anti-ageing effects of different strains of lactobacilli putative probiotics on an ageing rat model as induced by D-galactose and a high fat diet. Male Sprague-Dawley rats were fed with high fat diet (54% kcal fat) and injected with D-galactose daily for 12 weeks to induce ageing. The effects of putative probiotic strains on age-related impairment such as telomere length, plasma lipid peroxidation, hepatic 5'adenosine monophosphate-activated protein kinase (AMPK) expression, as well as endurance performance were evaluated. Administration of statin, Lactobacillus plantarum DR7 (LP-DR7), Lactobacillus fermentum DR9 (LF-DR9), and Lactobacillus reuteri 8513d (LR-8513d) significantly reduced the shortening of telomere and increased the expression of AMPK subunit-α1 (P<0.05). Plasma lipid peroxidation was lower (P<0.05) in groups administered with statin and LF-DR9 as compared to the control. AMPK subunit-α2 was elevated in rats administered with LP-DR7 as compared to the control (P<0.05). Using an in vivo ageing rat model, the current study has illustrated the potentials of lactobacilli putative probiotics in alleviation of age-related impairment in a strain-dependent manner.


Asunto(s)
Proteínas Quinasas Activadas por AMP/genética , Envejecimiento Prematuro/metabolismo , Lactobacillus/fisiología , Probióticos/farmacología , Acortamiento del Telómero/efectos de los fármacos , Envejecimiento Prematuro/inducido químicamente , Envejecimiento Prematuro/patología , Animales , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Galactosa/administración & dosificación , Galactosa/efectos adversos , Expresión Génica/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Masculino , Resistencia Física/efectos de los fármacos , Probióticos/administración & dosificación , Ratas , Ratas Sprague-Dawley
12.
Curr Med Imaging Rev ; 15(4): 386-394, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31989908

RESUMEN

BACKGROUND: In the presence of Cloud Environment and the migration of Electronic Health Systems and records to the Cloud, patient privacy has become an emergent problem for healthcare institutions. Government bylaws, electronic health documentation, and innovative internet health services generate numerous security issues for healthcare conformity and information security groups. To deal with these issues, healthcare institutes must protect essential IT infrastructure from unauthorized use by insiders and hackers. The Cloud Computing archetype allows for EHealth methods that improve the features and functionality of systems on the cloud. On the other hand, sending patients' medical information and records to the Cloud entails a number of risks in the protection and privacy of the health records during the communication process. AIM: In this paper, a solution is proposed for the security of Electronic Health Records (EHRs) in cloud environment during the process of sending the data to the cloud. In addition, the proposed method uses biometric images that allow for unified patient identification across cloud-based EHRs and across medical institutions. METHOD: To protect the privacy of patients' information and streamline the migration process, a watermarking-based method is proposed for health care providers to ensure that patients' data are only accessible to authorized personnel. Patients' information, such as name, id, symptoms, diseases, and previous history, is secured in biometric images of patients as an encrypted watermark. RESULTS: Quality and impeccability analysis and robustness were performed to test the proposed method. The PSNR values show that the proposed method produced excellent results. CONCLUSION: The robustness and impressibility of the proposed method were tested by subjecting the watermarked images to different simulated attacks. The watermarks were largely impermeable to varied and repeated attacks.


Asunto(s)
Seguridad Computacional , Registros Electrónicos de Salud , Gestión de la Información , Privacidad , Biometría , Humanos
13.
J Phys Condens Matter ; 30(26): 264003, 2018 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-29762135

RESUMEN

The surface morphology of molybdenum silicide (Mo x Si1-x ) films has been studied after low-energy Ar+ ion beam sputtering (IBS) to explore eventual pattern formation on compound targets and, simultaneously, gather information about the mechanisms behind silicide-assisted nanopatterning of silicon surfaces by IBS. For this purpose, Mo x Si1-x films with compositions below, equal and above the MoSi2 stoichiometry (x = 0.33) have been produced by magnetron sputtering, as assessed by Rutherford backscattering spectrometry (RBS). The surface morphology of silicon and silicide films before and after IBS has been imaged by atomic force microscopy (AFM), comprising conditions where typical nanodot or ripple patterns emerge on the former. In the case of irradiated Mo x Si1-x surfaces, AFM shows a marked surface smoothing at normal incidence with and without additional Mo incorporation (the former results in nanodot patterns on Si). The morphological analysis also provides no evidence of ion-induced phase separation in irradiated Mo x Si1-x . Contrary to silicon, Mo x Si1-x surfaces also do not display ripple formation for (impurity free) oblique irradiations, except at grazing incidence conditions where parallel ripples emerge in a more evident fashion than in the Si counterpart. By means of RBS, irradiated Mo x Si1-x films with 1 keV Ar+ at normal incidence have also been used to measure experimentally the (absolute) sputtering yield and rate of Si and Mo x Si1-x materials. The analysis reveals that, under the present working conditions, the erosion rate of silicides is larger than for silicon, supporting simulations from the TRIDYN code. This finding questions the shielding effect from silicide regions as roughening mechanism in metal-assisted nanopatterning of silicon. On the contrary, the results highlight the relevance of in situ silicide formation. Ripple formation on Mo x Si1-x under grazing incidence is also attributed to the dominance of sputtering effects under this geometry. In conclusion, our work provides some insights into the complex morphological evolution of compound surfaces and solid experimental evidences regarding the mechanisms behind silicide-assisted nanopatterning.

14.
Lasers Med Sci ; 32(9): 2089-2095, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28967036

RESUMEN

The study of the effects of low-level laser (LLL) radiation on blood is important for elucidating the mechanisms behind the interaction of LLL radiation and biologic tissues. Different therapy methods that involve blood irradiation have been developed and used for clinical purposes with beneficial effects. The aim of this study was to compare the effects of different irradiation protocols using a diode-pumped solid-state LLL (λ = 405 nm) on samples of human blood by measuring the erythrocyte sedimentation rate (ESR). Human blood samples were obtained through venipuncture into tubes containing EDTA as an anticoagulant. Every sample was divided into two equal aliquots to be used as an irradiated sample and a non-irradiated control sample. The irradiated aliquot was subjected to a laser beam with a wavelength of 405 nm and an energy density of 72 J/cm2. The radiation source had a fixed irradiance of 30 mW/cm2. The ESR change was observed for three different experimental protocols: irradiated whole blood, irradiated red blood cells (RBCs) samples re-suspended in non-irradiated blood plasma, and non-irradiated RBCs re-suspended in irradiated blood plasma. The ESR values were measured after laser irradiation and compared with the non-irradiated control samples. Irradiated blood plasma in which non-radiated RBCs were re-suspended was found to result in the largest ESR decrease for healthy human RBCs, 51%, when compared with RBCs re-suspended in non-irradiated blood plasma. The decrease in ESR induced by LLL irradiation of the plasma alone was likely related to changes in the plasma composition and an increase in the erythrocyte zeta potential upon re-suspension of the RBCs in the irradiated blood plasma.


Asunto(s)
Eritrocitos/efectos de la radiación , Láseres de Estado Sólido , Adulto , Sedimentación Sanguínea/efectos de la radiación , Forma de la Célula/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Recuento de Eritrocitos , Volumen de Eritrocitos/efectos de la radiación , Hematócrito , Humanos , Plasma/efectos de la radiación
15.
Sci Rep ; 7(1): 11576, 2017 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-28912534

RESUMEN

Cylindrical nanowires synthesized by controlled electrodeposition constitute excellent strategic candidates to engineer magnetic domain configurations. In this work, multisegmented CoNi/Ni nanowires are synthesized for tailoring a periodic magnetic structure determined by the balance between magnetocrystalline and magnetostatic energies. High-resolution Transmission Electron Microscopy confirms the segmented growth and the sharp transition between layers. Although both CoNi and Ni segments have similar fcc cubic crystal symmetry, their magnetic configuration is quite different as experimentally revealed by Magnetic Force Microscopy (MFM) imaging. While the Ni segments are single domain with axial magnetization direction, the CoNi segments present two main configurations: a single vortex state or a complex multivortex magnetic configuration, which is further interpreted with the help of micromagnetic simulations. This original outcome is ascribed to the tight competition between anisotropies. The almost monocrystalline fcc structure of the CoNi segments, as revealed by the electron diffraction patterns, which is atypical for its composition, contributes to balance the magnetocrystalline and shape anisotropies. The results of MFM measurements performed under in-plane magnetic field demonstrate that it is possible to switch from the multivortex configuration to a single vortex configuration with low magnetic fields.

16.
Nanoscale ; 9(31): 11269-11278, 2017 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-28758656

RESUMEN

We present a detailed study of the magnetic behavior of Permalloy (Ni80Fe20 alloy) circular nanodots with small radii (30 nm and 70 nm) and different thicknesses (30 nm or 50 nm). Despite the small size of the dots, the measured hysteresis loops manifestly display the features of classical vortex behavior with zero remanence and lobes at high magnetic fields. This is remarkable because the size of the magnetic vortex core is comparable to the dot diameter, as revealed by magnetic force microscopy and micromagnetic simulations. The dot ground states are close to the border of the vortex stability and, depending on the dot size, the magnetization distribution combines attributes of the typical vortex, single domain states or even presents features resembling magnetic skyrmions. An analytical model of the dot magnetization reversal, accounting for the large vortex core size, is developed to explain the observed behavior, providing a rather good agreement with the experimental results. The study extends the understanding of magnetic nanodots beyond the classical vortex concept (where the vortex core spins have a negligible influence on the magnetic behavior) and can therefore be useful for improving emerging spintronic applications, such as spin-torque nano-oscillators. It also delimits the feasibility of producing a well-defined vortex configuration in sub-100 nm dots, enabling the intracellular magneto-mechanical actuation for biomedical applications.

17.
J Nutr Health Aging ; 21(4): 473-479, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28346575

RESUMEN

OBJECTIVE: To explore the perceptions of healthcare professionals' (HCPs) in a South East Asian nation towards percutaneous endoscopic gastrostomy (PEG) feeding. DESIGN: Semi-structured, qualitative interviews. SETTINGS: A teaching hospital in Kuala Lumpur, Malaysia. PARTICIPANTS: A total of 17 healthcare professionals aged 23-43 years, 82% women. RESULTS: Thematic analysis revealed five themes that represent HCPs' perceptions in relation to the usage of PEG feeding: 1) knowledge of HCPs, 2) communication, 3) understanding among patients, and 4) financial and affordability. CONCLUSION: The rationale for reluctance towards PEG feeding observed in this regions was explained by lack of education, knowledge, communication, team work, and financial support. Future studies should assess the effects of educational programmes among HCPs and changes in policies to promote affordability on the utilization of PEG feeding in this region.


Asunto(s)
Actitud del Personal de Salud , Nutrición Enteral/métodos , Gastrostomía/métodos , Conocimientos, Actitudes y Práctica en Salud , Personal de Salud/psicología , Adulto , Anciano , Trastornos de Deglución/patología , Femenino , Hospitales de Enseñanza , Humanos , Malasia , Masculino , Persona de Mediana Edad , Percepción , Encuestas y Cuestionarios , Adulto Joven
18.
Lasers Med Sci ; 32(2): 405-411, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28044209

RESUMEN

Low-level laser irradiation (LLLI) has various effects on cultured human lymphocytes in vitro, but little is known about such effects in whole blood. This study investigated whether LLLI affected lymphocyte count in human whole blood in vitro. A total number of 130 blood samples were collected from apparently healthy adult patients through venipuncture into tubes containing EDTA. Each sample was divided into two equal aliquots to be used as a non-irradiated control sample and an irradiated sample. The irradiated aliquot was subjected to laser wavelengths of 405, 589, and 780 nm with different fluences of 36, 54, 72, and 90 J/cm2, at a fixed irradiance of 30 mW/cm2. A paired student t test was used to compare between non-irradiated and irradiated samples. The lymphocyte counts were measured using a computerized hematology analyzer and showed a significant (P < 0.02) maximum increase (1.6%) at a fluence of 72 J/cm2 when compared with non-irradiated samples. This increase in lymphocyte count upon irradiation was confirmed by flow cytometry. At a wavelength of 589 nm and fluence of 72 J/cm2, irradiation of whole blood samples showed a significant increase in CD45 lymphocytes and natural killer (NK) (CD16, CD56) cells, but no significant changes in CD3 T lymphocytes, T-suppressor (CD3, CD8) cells, T-helper (CD3, CD4) cells, and CD19 B lymphocytes when compared with their non-irradiated counterparts. Our results clearly demonstrate that NK cell count is altered by irradiation, which ultimately affects the whole lymphocyte count significantly.


Asunto(s)
Terapia por Luz de Baja Intensidad , Linfocitos/efectos de la radiación , Adulto , Relación Dosis-Respuesta en la Radiación , Femenino , Humanos , Recuento de Linfocitos , Subgrupos Linfocitarios/efectos de la radiación , Masculino
19.
J Med Syst ; 41(2): 35, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28063016

RESUMEN

The goal of this paper is to implement the secretion mechanism of the Thyroid Hormone (TH) based on bio-mathematical differential eqs. (DE) on an FPGA chip. Hardware Descriptive Language (HDL) is used to develop a behavioral model of the mechanism derived from the DE. The Thyroid Hormone secretion mechanism is simulated with the interaction of the related stimulating and inhibiting hormones. Synthesis of the simulation is done with the aid of CAD tools and downloaded on a Field Programmable Gate Arrays (FPGAs) Chip. The chip output shows identical behavior to that of the designed algorithm through simulation. It is concluded that the chip mimics the Thyroid Hormone secretion mechanism. The chip, operating in real-time, is computer-independent stand-alone system.


Asunto(s)
Simulación por Computador , Modelos Biológicos , Hormonas Tiroideas/metabolismo , Algoritmos , Humanos , Tiroxina/metabolismo , Triyodotironina/metabolismo , Interfaz Usuario-Computador
20.
Addict Behav ; 66: 41-47, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27871044

RESUMEN

Waterpipe tobacco usage is spreading rapidly worldwide, with reports of more youth being waterpipe users compared to adults. In many areas of the world, waterpipe usage surpasses cigarette smoking. Waterpipes and cigarettes are both mechanisms for inhalation of tobacco smoke and therefore have serious health consequences. However, because of the many differences between the two products, prevention and control strategies that have proven effective for cigarettes may not transfer readily to waterpipe. This report highlights the differences between waterpipes and cigarettes in toxicant exposure and physiologic effects, patterns of use, social norms, the extent of evidence, and the policy environment. There is little evidence to date around effective interventions for waterpipe prevention and control. The current state of evidence for intervention to curb or control waterpipe is at ground zero and critically needs attention from both scientists and policy makers. National and global efforts aimed at cigarette prevention have succeeded, particularly in developed countries. We suggest the time has come to harness what we know works for cigarette prevention and control and adapt it to tackle the growing epidemic of waterpipe tobacco use.


Asunto(s)
Prevención del Hábito de Fumar/métodos , Fumar en Pipa de Agua , Edad de Inicio , Actitud Frente a la Salud , Diseño de Equipo , Educación en Salud , Política de Salud , Humanos , Percepción , Normas Sociales , Contaminación por Humo de Tabaco/análisis
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