The TNF-related apoptosis inducing ligand (TRAIL)/TRAIL receptor system participates in crucial steps in immune cell activation or differentiation. It is able to inhibit proliferation and activation ...of T cells and to induce apoptosis of neurons and oligodendrocytes, and seems to be implicated in autoimmune diseases. Thus, TRAIL and TRAIL receptor genes are potential candidates for involvement in susceptibility to multiple sclerosis (MS). To test whether single-nucleotide polymorphisms (SNPs) in the human genes encoding TRAIL, TRAILR-1, TRAILR-2, TRAILR-3 and TRAILR-4 are associated with MS susceptibility, we performed a candidate gene case-control study in the Spanish population. 59 SNPs in the TRAIL and TRAIL receptor genes were analysed in 628 MS patients and 660 controls, and validated in an additional cohort of 295 MS patients and 233 controls. Despite none of the SNPs withstood the highly conservative Bonferroni correction, three SNPs showing uncorrected p values<0.05 were successfully replicated: rs4894559 in TRAIL gene, p = 9.8×10(-4), OR = 1.34; rs4872077, in TRAILR-1 gene, p = 0.005, OR = 1.72; and rs1001793 in TRAILR-2 gene, p = 0.012, OR = 0.84. The combination of the alleles G/T/A in these SNPs appears to be associated with a reduced risk of developing MS (p = 2.12×10(-5), OR = 0.59). These results suggest that genes of the TRAIL/TRAIL receptor system exerts a genetic influence on MS.
Background
The optimal management of asymptomatic, petroclival meningiomas remains incompletely defined. The purpose of this study was to evaluate the safety and efficacy of upfront stereotactic ...radiosurgery (SRS) for patients with asymptomatic, petroclival region meningiomas.
Methods
This retrospective, international, multicenter study involved patients treated with SRS for an asymptomatic, petroclival region meningioma. Study endpoints included local tumor control rate, procedural complications, and the emergence of new neurological deficits.
Results
There were 72 patients (22 males, mean age 59.53 years (SD ± 11.9)) with an asymptomatic meningioma located in the petroclival region who were treated with upfront SRS. Mean margin dose and maximum dose were 13.26 (SD ± 2.72) Gy and 26.14 (SD ± 6.75) Gy respectively. Median radiological and clinical follow-up periods post-SRS were 52.5 (IQR 61.75) and 47.5 months (IQR 69.75) respectively. At last follow-up, tumor control was achieved in all patients. SRS-related complications occurred in 6 (8.33%) patients, with 3 of them (4.17%) exhibiting new neurological deficits.
Conclusions
Upfront SRS for asymptomatic, petroclival region meningiomas affords excellent local tumor control and does so with a relatively low risk of SRS-related complications. SRS can be considered at diagnosis of an asymptomatic petroclival region meningioma. If active surveillance is initially chosen, SRS should be recommended when growth is noted during radiological follow-up.
Abstract
INTRODUCTION
To evaluate the outcomes and risks of repeat stereotactic radiosurgery (SRS) for incompletely obliterated cerebral arteriovenous malformations (AVM).
METHODS
Six participating ...centers of the International Gamma Knife Research Foundation (IGKRF) identified 335 patients who had incompletely obliterated AVMs at a median follow-up of 45.6 months after initial SRS (range, 15–283 months). The median AVM target volume at initial SRS was 4.3 cc but was reduced to 1.4cc at the time of the second procedure. The median margin dose at both initial SRS and repeat SRS was 20 Gy. The median follow-up after repeat SRS was 64 months (range, 6–218 months).
RESULTS
>The actuarial rate of total obliteration by angiography or MRI after repeat SRS was 31%, 50%, 61%, and 80% at 3, 4, 5, and 10 years, respectively. Factors associated with a higher rate of AVM obliteration were smaller residual AVM target volume, and >50% of volume reduction after the initial procedure. The cumulative actuarial rates of new AVM hemorrhage after repeat SRS were 1.8%, 4.5%, 6.6%, 8.9% and 14.9% at 1, 2, 3, 5, and 10 years. Factors associated with a higher risk of hemorrhage after repeat SRS were a larger number of a prior hemorrhages, larger AVM target volume, and initial AVM volume reduction <50%. Symptomatic adverse radiation effect (ARE) developed in 29 patients (8.6%) after initial SRS and 27 patients (8.1%) after repeat SRS.
CONCLUSION
Repeat SRS for incompletely obliterated AVMs increases the eventual obliteration rate but patients remain at risk of hemorrhage until obliteration occurs. The best results for incompletely obliterated AVMs were seen in patients with a smaller residual AVM volume and no prior hemorrhages.
The effect of land use on soil nitrogen (N) and phosphorous (P) stocks and the stoichiometry ratios are not fully understood. We determined the impact of land use on total N and P stocks along with ...some of their fractions and carbon (C), N and P ratios in soils of the Pampas. The effect of human activities on N and P fluxes in agroecosystems was also assessed. We sampled 386 soils under contrasting land uses down to 1 m depth. Well drained uncultivated soils were used as control treatment, paired with forest, cropped and flooded soils. Significant effects of land use on N and P stocks were detected to 1 m depth. Cropping decreased soil total N and P contents, mineralizable N and extractable P by an average of 14, 21 and 63% respectively. Conversely, forest soils had larger total N stocks (17%), mineralization (10%) and extractable P (37%) than uncropped controls. Flooded lands had the lowest fertility. Nitrogen and P pools under cultivation decreased higher as soils had higher initial levels N and P. In some low fertility soils, cropping led to N and P increases. Stoichiometry ratios were minimally impacted by land use. The ratio of the cumulative P surface balance to the N surface balance for the last 140 years was + 0.01 kg P/kg N in uncropped control soils and − 0.08 kg P/kg N in cropped soils. Despite this difference, the soil N/P ratio was unaffected by land use indicating that processes at the profile level regulated it.
Today, embedded systems (ES) tend towards miniaturization and the carrying out of complex tasks in applications such as the Internet of Things, medical systems, telecommunications, among others. ...Currently, ES structures based on artificial intelligence using hardware neural networks (HNNs) are becoming more common. In the design of HNN, the activation function (AF) requires special attention due to its impact on the HNN performance. Therefore, implementing activation functions (AFs) with good performance, low power consumption, and reduced hardware resources is critical for HNNs. In light of this, this paper presents a hardware-based activation function-core (AFC) to implement an HNN. In addition, this work shows a design framework for the AFC that applies a piecewise polynomial approximation (PPA) technique. The designed AFC has a reconfigurable architecture with a wordlength-efficient decoder, i.e., reduced hardware resources are used to satisfy the desired accuracy. Experimental results show a better performance of the proposed AFC in terms of hardware resources and power consumption when it is compared with state of the art implementations. Finally, two case studies were implemented to corroborate the AFC performance in widely used ANN applications.
In a cognitive radio system, the goal is to make better use of the radio electric spectrum, allowing non-licensed users access to those currently unused electromagnetic bands assigned to licensed ...users (LUs). This can be achieved using OFDM, where the non-licensed users must select the temporarily available subcarriers and turn off those subcarriers used by LUs in order to avoid interference. Hence, only a subset of the subcarriers can be used for data or pilot tone transmission. To this end, some pilot allocation algorithms have been proposed for this dynamic scenario, but they are designed in such away that an equispaced pilot placement is respected (as much as possible) while minimizing the mean squared error of the channel estimate. Nevertheless, this equispaced placement can lead to the use of an increased number of pilots in order to achieve a good channel estimation. In this work, a new pilot allocation algorithm based on wavelet transform is presented. The proposed algorithm uses the discrete wavelet transform to analyze the previous channel state information, taking the knowledge of the available subcarriers into account to provide a suboptimal solution for the pilot positions. This solution leads to a non-equispaced pilot placement, which improves the channel estimation and consequently, the system performance. Likewise, the introduced algorithm allows a reduction of the number of necessary pilots, which aids in increasing the data rate. Finally, simulation results corroborate the effectiveness of the algorithm in dynamic channel scenarios.
The hardware of the matrix inversion architecture using QR decomposition with Givens Rotations (GR) and a back substitution (BS) block is required for many signal processing algorithms. However, the ...hardware of the GR algorithm requires the implementation of complex operations, such as the reciprocal square root (RSR), which is typically implemented using LookUp Table (LUT) and COordinate Rotation DIgital Computer (CORDICs), among others, conveying to either high-area consumption or low throughput. This paper introduces an Field-Programmable Gate Array (FPGA)-based full matrix inversion architecture using hybrid piecewise polynomial approximation systolic cells. In the design, a hybrid segmentation technique was incorporated for the implementation of piecewise polynomial systolic cells. This hybrid approach is composed by an external and internal segmentation, where the first is nonuniform and the second is uniform, fitting the curve shape of the complex functions achieving a better signal-quantization-to noise-ratio; furthermore, it improves the time performance and area resources. Experimental results reveal a well-balanced improvement in the design achieving high throughput and, hence, less resource utilization in comparison to state-of-the-art FPGA-based architectures. In our study, the proposed design achieves 7.51 Mega-Matrices per second for performing 4 × 4 matrix operations with a latency of 12 clock cycles; meanwhile, the hardware design requires only 1474 slice registers, 1458 LUTs in an FPGA Virtex-5 XC5VLX220T, and 1474 slice registers and 1378 LUTs when a FPGA Virtex-6 XC6VLX240T is used.
RESUMEN En 1986 se enunció el concepto de prevención cuaternaria. Su propuesta se realizó en 1995 y su aceptación fue en 1999. En el 2003 se incluyó en el Diccionario de medicina general y de familia ...de la Organización Mundial de Médicos de Familia. Los descriptores de ciencias de la salud lo registraron en el 2015. Sin embargo, a pesar del reconocimiento del concepto por organizaciones internacionales, en Cuba no ha sido muy difundido y se ha publicado muy poco en revistas nacionales sobre el tema. El presente trabajo tiene el objetivo de describir los referentes teóricos relacionados con la prevención cuaternaria, a partir de la revisión bibliográfica en bases de datos referenciales a textos completos, índices y publicaciones periódicas académicas. P4 debe ser una actividad básica en medicina y en salud pública, que contribuye a la seguridad del paciente e intenta minimizar riesgos y evitar o limitar los daños innecesarios de la actividad sanitaria. Es un nuevo nombre para una vieja actividad médica.
The prognostic role of cerebrospinal fluid biomarkers in patients with incidental radiological findings of white matter abnormalities or radiologically isolated syndromes (RIS) has yet to be defined. ...Matute-Blanch et al. report that RIS patients with oligoclonal bands and high neurofilament light chain levels have increased risk of clinical conversion.
Abstract
The prognostic role of cerebrospinal fluid molecular biomarkers determined in early pathogenic stages of multiple sclerosis has yet to be defined. In the present study, we aimed to investigate the prognostic value of chitinase 3 like 1 (CHI3L1), neurofilament light chain, and oligoclonal bands for conversion to clinically isolated syndrome and to multiple sclerosis in 75 patients with radiologically isolated syndrome. Cerebrospinal fluid levels of CHI3L1 and neurofilament light chain were measured by enzyme-linked immunosorbent assay. Uni- and multivariable Cox regression models including as covariates age at diagnosis of radiologically isolated syndrome, number of brain lesions, sex and treatment were used to investigate associations between cerebrospinal fluid CHI3L1 and neurofilament light chain levels and time to conversion to clinically isolated syndrome and multiple sclerosis. Neurofilament light chain levels and oligoclonal bands were independent risk factors for the development of clinically isolated syndrome (hazard ratio = 1.02, P = 0.019, and hazard ratio = 14.7, P = 0.012, respectively) and multiple sclerosis (hazard ratio = 1.03, P = 0.003, and hazard ratio = 8.9, P = 0.046, respectively). The best cut-off to classify cerebrospinal fluid neurofilament light chain levels into high and low was 619 ng/l, and high neurofilament light chain levels were associated with a trend to shorter time to clinically isolated syndrome (P = 0.079) and significant shorter time to multiple sclerosis (P = 0.017). Similarly, patients with radiologically isolated syndrome presenting positive oligoclonal bands converted faster to clinically isolated syndrome and multiple sclerosis (P = 0.005 and P = 0.008, respectively). The effects of high neurofilament light chain levels shortening time to clinically isolated syndrome and multiple sclerosis were more pronounced in radiologically isolated syndrome patients with ≥37 years compared to younger patients. Cerebrospinal fluid CHI3L1 levels did not influence conversion to clinically isolated syndrome and multiple sclerosis in radiologically isolated syndrome patients. Overall, these findings suggest that cerebrospinal neurofilament light chain levels and oligoclonal bands are independent predictors of clinical conversion in patients with radiologically isolated syndrome. The association with a faster development of multiple sclerosis reinforces the importance of cerebrospinal fluid analysis in patients with radiologically isolated syndrome.
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