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1.
Article in English | MEDLINE | ID: mdl-38700963

ABSTRACT

Intracortical brain computer interfaces (iBCIs) utilizing extracellular recordings mainly employ in vivo signal processing application-specific integrated circuits (ASICs) to detect action potentials (spikes). Conventionally, "brain-switches" based on spiking activity have been employed to realize asynchronous (self-paced) iBCIs, estimating when the user involves in the underlying BCI task. Several studies have demonstrated that local field potentials (LFPs) can effectively replace action potentials, drastically reducing the power consumption and processing requirements of in vivo ASICs. This article presents the first LFP-based brain-switch design and implementation using gated recurrent neural networks (RNNs). Compared to the previously reported brain-switches, our design requires no exhaustive learning phase for the estimation of optimal recording channels or frequency band selection, making it more applicable to practical asynchronous iBCIs. The synthesized ASIC of the designed in vivo LFP-based feature extraction unit, in a standard 180-nm CMOS process, occupies only 0.09 mm2 of silicon area, and the post place-and-route synthesis results indicate that it consumes 91.87 nW of power while operating at 2 kHz. Compared to the previously published ASICs, the proposed LFP-based brain-switch consumes the least power for in vivo digital signal processing and achieves comparable state estimation performance to that of spike-based brain-switches.

2.
Int. j. morphol ; 42(2)abr. 2024.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1558151

ABSTRACT

Las unidades de cuidados intensivos (UCI) y agudos han sido los contenedores del avance de la pandemia por COVID-19. Sin embargo, la estadía prolongada en esta unidad puede repercutir sobre la composición corporal (CC) y la capacidad derealizar ejercicio de los pacientes. El objetivo de esta investigación fue determinar si existe relación entre composición corporal (CC) y la prueba de caminata en 6 minutos (PC6m). Se reclutaron 17 personas (8 mujeres y 9 hombres). Se tomaron las siguientes medidas: PC6m, se consideró su distancia recorrida (DRPC6m) y su velocidad (VelPC6m). Las variables de CC medidas fueron índice de masa corporal (IMC), masa grasa (MG), masa libre de grasa (MLG) y masa magra (MM). La DRPC6m sólo mostró relación significativa con la MM corporal (MMC). Por otra parte, la VelPC6m tuvo una relación significativa con la MMC. Además de esto, la MLG del miembro inferior derecho y la MLG del miembro inferior izquierdo mostraron una relación con la VelPC6m (r=0,422; p=0,041 y r=0,417; p=0,025, respectivamente). También la MM del miembro inferior derecho y la MM del miembro inferior izquierdo se relacionaron significativamente con la VelPC6m (r=0,422; p=0,030 y r=0,420; p=0,042). En conclusión, existe relación entre composición corporal y VelPC6m. Esto permitiría aproximarse de manera rápida al nivel de funcionalidad con la que ingresa un paciente a un programa de rehabilitación.


SUMMARY: The intensive care units (ICU) and acute care units have been the containers for the advance of the COVID-19 pandemic. However, prolonged stay in this unit can impact patients' body composition (WC) and ability to exercise. This research aimed to determine if there is a relationship between body composition (BC) and the 6-minute walk test (6mWT). 17 people were recruited (8 women and 9 men). The following measurements were taken: 6mWT, its distance traveled (6mWTDT) and its speed (6mWTS) were considered. The WC variables measured were body mass index (BMI), fat mass (FM), fat-free mass (FFM), and lean mass (LM). 6mWTDT only showed a significant relationship with body LM (BLM). On the other hand, 6mWTS had a significant relationship with BLM. In addition to this, the FFM of the right lower limb and the FFM of the left lower limb showed a relationship with 6mWTS (r=0.422; p=0.041 and r=0.417; p=0.025, respectively). Also, the LM of the right lower limb and the LM of the left lower limb were significantly related to the 6mWTS (r=0.422; p=0.030 and r=0.420; p=0.042). In conclusion, there is a relationship between body composition and 6mWTS. This would allow us to quickly approach the level of functionality with which a patient enters a rehabilitation program.

3.
IEEE Trans Biomed Circuits Syst ; 18(3): 691-701, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38285576

ABSTRACT

Conventional in vivo neural signal processing involves extracting spiking activity within the recorded signals from an ensemble of neurons and transmitting only spike counts over an adequate interval. However, for brain-computer interface (BCI) applications utilizing continuous local field potentials (LFPs) for cognitive decoding, the volume of neural data to be transmitted to a computer imposes relatively high data rate requirements. This is particularly true for BCIs employing high-density intracortical recordings with hundreds or thousands of electrodes. This article introduces the first autoencoder-based compression digital circuit for the efficient transmission of LFP neural signals. Various algorithmic and architectural-level optimizations are implemented to significantly reduce the computational complexity and memory requirements of the designed in vivo compression circuit. This circuit employs an autoencoder-based neural network, providing a robust signal reconstruction. The application-specific integrated circuit (ASIC) of the in vivo compression logic occupies the smallest silicon area and consumes the lowest power among the reported state-of-the-art compression ASICs. Additionally, it offers a higher compression rate and a superior signal-to-noise and distortion ratio.


Subject(s)
Algorithms , Brain-Computer Interfaces , Data Compression , Neural Networks, Computer , Signal Processing, Computer-Assisted , Data Compression/methods , Animals , Neurons/physiology , Electroencephalography/methods
4.
Ene ; 18(1): 1-12, 2024. tab
Article in Spanish | IBECS | ID: ibc-232146

ABSTRACT

El nivel bajo de alfabetización en salud constituye un problema de salud pública y se asocia con escaso conocimiento, mayor uso de los servicios públicos y menores conductas de autocuidado. La presente investigación busca determinar la relación entre alfabetización en salud y autocuidado en estudiantes de enfermería. El estudio presentó un diseño descriptivo-correlacional utilizando dos escalas validadas: “Cuestionario H1 Alfabetización en Salud” y “Escala de agencia de autocuidado”. El índice de alfabetización en salud se relaciona de manera positiva y estadísticamente significativa con el puntaje de autovaloración del estado de salud, confirmando así la relación entre ambas variables. (AU)


Low health literacy constitutes a public health problem associated with low knowledge, greater use of public services, and less self-care behaviors. This research examines the link between health literacy and nursing students' self-care. The study presented a descriptive-correlational design using two validated scales: the "H1 Health Literacy Questionnaire" and the "Self-care agency scale." The health literacy index is positively and statistically significantly related to the self-assessment score of the state of health, thus confirming the relationship between both variables. (AU)


Subject(s)
Humans , Male , Female , Young Adult , Adult , Health Literacy , Self Care , Students, Nursing , Chile/epidemiology , Epidemiology, Descriptive , Surveys and Questionnaires
5.
Cells ; 12(24)2023 12 10.
Article in English | MEDLINE | ID: mdl-38132131

ABSTRACT

The antitumor potential of proteins from snake venoms has been studied in recent decades, and evidence has emerged that phospholipases A2 can selectively attack cells of various types of tumors. Previous results have shown that phospholipase A2 "Pllans-II," isolated from Porthidium lansbergii lansbergii snake venom, displayed antitumoral activity on cervical cancer and did not alter the viability of non-tumorigenic cells. However, until now, there was no evidence of its safety at the local and systemic levels, nor had experiments been developed to demonstrate that its production using recombinant technology allows us to obtain a molecule with effects similar to those generated by native phospholipase. Thus, we evaluated the impact caused by Pllans-II on murine biomodels, determining whether it induced local hemorrhage or increased pro-inflammatory and liver damage markers and histological alterations in the liver and kidneys. Additionally, the protein was produced using recombinant technology using a pET28a expression vector and the BL21 (DE3) Escherichia coli strain. Equally, its enzymatic activity and anticancer effect were evaluated on cervical cancer lines such as HeLa and Ca Ski. The results demonstrated that Pllans-II did not generate hemorrhagic activity, nor did it increase the pro-inflammatory cytokines IL-6, IL-1B, or TNF-α at doses of 3.28, 1.64, and 0.82 mg/kg. There was also no evidence of organ damage, and only ALT and AST increased in mild levels at the two highest concentrations. Additionally, the recombinant version of Pllans-II showed conservation in its catalytic activity and the ability to generate death in HeLa and Ca Ski cells (42% and 23%, respectively). These results demonstrate the innocuity of Pllans-II at the lowest dose and constitute an advance in considering a molecule produced using recombinant technology a drug candidate for selective attacks against cervical cancer.


Subject(s)
Crotalid Venoms , Uterine Cervical Neoplasms , Female , Humans , Mice , Animals , Uterine Cervical Neoplasms/drug therapy , Phospholipases A2 , Protein Isoforms , HeLa Cells
6.
Philos Trans R Soc Lond B Biol Sci ; 378(1881): 20220189, 2023 07 17.
Article in English | MEDLINE | ID: mdl-37246381

ABSTRACT

Species diversity underpins all ecosystem services that support life. Despite this recognition and the great advances in detecting biodiversity, exactly how many and which species co-occur and interact, directly or indirectly in any ecosystem is unknown. Biodiversity accounts are incomplete; taxonomically, size, habitat, mobility or rarity biased. In the ocean, the provisioning of fish, invertebrates and algae is a fundamental ecosystem service. This extracted biomass depends on a myriad of microscopic and macroscopic organisms that make up the fabric of nature and which are affected by management actions. Monitoring them all and attributing changes to management policies is daunting. Here we propose that dynamic quantitative models of species interactions can be used to link management policy and compliance with complex ecological networks. This allows managers to qualitatively identify 'interaction-indicator' species, which are highly impacted by management policies through propagation of complex ecological interactions. We ground the approach in intertidal kelp harvesting in Chile and fishers' compliance with policies. Results allow us to identify sets of species that respond to management policy and/or compliance, but which are often not included in standardized monitoring. The proposed approach aids in the design of biodiversity programmes that attempt to connect management with biodiversity change. This article is part of the theme issue 'Detecting and attributing the causes of biodiversity change: needs, gaps and solutions'.


Subject(s)
Biodiversity , Ecosystem , Animals , Invertebrates , Biomass , Fishes
7.
Acta Trop ; 241: 106895, 2023 May.
Article in English | MEDLINE | ID: mdl-36931336

ABSTRACT

Lachesis acrochorda envenomation has a lethality rate of approximately 90%. Despite its high lethality, little is known about its local and systemic effects and its relationship with its protein content. Thus, to increase knowledge of L. acrochorda snake venom from the Southwestern ecoregion of Colombia, we developed a proteomic analysis using a "bottom-up shotgun proteomic profiling" approach. Besides, we evaluated toxinological properties and compared the effects with the Bothrops asper snake venom activities. The RP-HPLC profile showed similarities with the L. acrochorda snake venom from the Northwestern ecoregion of Colombia. However, the results displayed differences in the protein families identified, probably due to the proteomic identification strategy. The in vitro and in vivo tests showed a L. acrochorda snake venom with Phospholipase A2 and metalloproteinase activities related to myotoxic, edematic, and hemorrhagic effects. Nevertheless, the L. acrochorda snake venom displayed a low lethality despite a large amount of inoculated venom. This investigation's results will help us improve the knowledge about the relationship between the clinical manifestations of L. acrochorda envenomation and the venom protein content.


Subject(s)
Proteomics , Viperidae , Animals , Humans , Colombia , Snake Venoms , Hemorrhage
8.
Viruses ; 15(2)2023 01 24.
Article in English | MEDLINE | ID: mdl-36851544

ABSTRACT

Human adenoviruses (HAdV) are one of the most important pathogens detected in acute respiratory diseases in pediatrics and immunocompromised patients. In 1953, Wallace Rowe described it for the first time in oropharyngeal lymphatic tissue. To date, more than 110 types of HAdV have been described, with different cellular tropisms. They can cause respiratory and gastrointestinal symptoms, even urinary tract inflammation, although most infections are asymptomatic. However, there is a population at risk that can develop serious and even lethal conditions. These viruses have a double-stranded DNA genome, 25-48 kbp, 90 nm in diameter, without a mantle, are stable in the environment, and resistant to fat-soluble detergents. Currently the diagnosis is made with lateral flow immunochromatography or molecular biology through a polymerase chain reaction. This review aimed to highlight the HAdV variability and the pandemic potential that a HAdV3 and 7 recombinant could have considering the aggressive outbreaks produced in health facilities. Herein, we described the characteristics of HAdV, from the infection to treatment, vaccine development, and the evaluation of the social determinants of health associated with HAdV, suggesting the necessary measures for future sanitary control to prevent disasters such as the SARS-CoV-2 pandemic, with an emphasis on the use of recombinant AdV vaccines to control other potential pandemics.


Subject(s)
Adenoviruses, Human , COVID-19 , Humans , Child , Adenoviridae , Pandemics/prevention & control , Friends , COVID-19/epidemiology , COVID-19/prevention & control , SARS-CoV-2/genetics , Adenoviruses, Human/genetics
9.
J Neural Eng ; 20(1)2023 01 27.
Article in English | MEDLINE | ID: mdl-36645913

ABSTRACT

Objective.Advances in brain-machine interfaces (BMIs) can potentially improve the quality of life of millions of users with spinal cord injury or other neurological disorders by allowing them to interact with the physical environment at their will.Approach.To reduce the power consumption of the brain-implanted interface, this article presents the first hardware realization of anin vivointention-aware interface via brain-state estimation.Main Results.It is shown that incorporating brain-state estimation reduces thein vivopower consumption and reduces total energy dissipation by over 1.8× compared to those of the current systems, enabling longer better life for implanted circuits. The synthesized application-specific integrated circuit (ASIC) of the designed intention-aware multi-unit spike detection system in a standard 180 nm CMOS process occupies 0.03 mm2of silicon area and consumes 0.63 µW of power per channel, which is the least power consumption among the currentin vivoASIC realizations.Significance.The proposed interface is the first practical approach towards realizing asynchronous BMIs while reducing the power consumption of the BMI interface and enhancing neural decoding performance compared to those of the conventional synchronous BMIs.


Subject(s)
Brain-Computer Interfaces , Quality of Life , Brain , Prostheses and Implants , Computers
10.
Biomed Eng Lett ; 13(1): 73-83, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36711161

ABSTRACT

While brain-implantable neural spike sorting can be realized using efficient algorithms, the presence of noise may make it difficult to maintain high-peformance sorting using conventional techniques. In this article, we explore the use of partially binarized neural networks (PBNNs), to the best of our knowledge for the first time, for sorting of neural spike feature vectors. It is shown that compared to the waveform template-based methods, PBNNs offer robust spike sorting over various datasets and noise levels. The ASIC implementation of the PBNN-based spike sorting system in a standard 180-nm CMOS process is presented. The post place and route simulations results show that the synthesized PBNN consumes only 0.59 µ W of power from a 1.8 V supply while operating at 24 kHz and occupies 0.15 mm 2 of silicon area. It is shown that the designed PBNN-based spike sorting system not only offers comparable accuracy to the state-of-the-art spike sorting systems over various noise levels and datasets, it also occupies a smaller silicon area and consumes less power and energy. This makes PBNNs a viable alternative towards the implementation of brain-implantable spike sorting systems.

11.
Rev. colomb. reumatol ; 29(4)oct.-dic. 2022.
Article in English | LILACS | ID: biblio-1536212

ABSTRACT

BehÒ«et's disease is a low prevalence disorder that is difficult to diagnose. Its forms of presentation are often confused with infectious processes that involve multiple treatments and prolonged hospital stays. This article presents the case of a 30-year-old man who consulted with non-specific symptoms that represented a diagnostic challenge for the medical team.


La enfermedad de BehÒ«et es una patología de baja prevalencia y difícil diagnóstico; sus formas clínicas de presentación suelen confundirse con procesos infecciosos que implican múltiples tratamientos y estancias hospitalarias prolongadas. Este artículo presenta el caso de un hombre de 30 arios quien consulta de manera repetitiva con síntomas inespecíficos, lo que representa un reto diagnóstico para el equipo médico.


Subject(s)
Humans , Male , Adult , Autoimmune Diseases , Stomatognathic Diseases , Behcet Syndrome , Mouth Diseases
12.
J Neural Eng ; 19(4)2022 07 22.
Article in English | MEDLINE | ID: mdl-35820400

ABSTRACT

Objective.The ability to reliably detect neural spikes from a relatively large population of neurons contaminated with noise is imperative for reliable decoding of recorded neural information.Approach.This article first analyzes the accuracy and feasibility of various potential spike detection techniques forin vivorealizations. Then an accurate and computationally-efficient spike detection module that can autonomously adapt to variations in recording channels' statistics is presented.Main results.The accuracy of the chosen candidate spike detection technique is evaluated using both synthetic and real neural recordings. The designed detector also offers the highest decoding performance over two animal behavioral datasets among alternative detection methods.Significance.The implementation results of the designed 128-channel spike detection module in a standard 180 nm CMOS process is among the most area and power-efficient spike detection ASICs and operates within the tissue-safe constraints for brain implants, while offering adaptive noise estimation.


Subject(s)
Algorithms , Signal Processing, Computer-Assisted , Action Potentials , Animals , Neurons/physiology , Signal-To-Noise Ratio
13.
Biomed Eng Lett ; 12(2): 185-195, 2022 May.
Article in English | MEDLINE | ID: mdl-35529345

ABSTRACT

Conventional spike sorting and motor intention decoding algorithms are mostly implemented on an external computing device, such as a personal computer. The innovation of high-resolution and high-density electrodes to record the brain's activity at the single neuron level may eliminate the need for spike sorting altogether while potentially enabling in vivo neural decoding. This article explores the feasibility and efficient realization of in vivo decoding, with and without spike sorting. The efficiency of neural network-based models for reliable motor decoding is presented and the performance of candidate neural decoding schemes on sorted single-unit activity and unsorted multi-unit activity are evaluated. A programmable processor with a custom instruction set architecture, for the first time to the best of our knowledge, is designed and implemented for executing neural network operations in a standard 180-nm CMOS process. The processor's layout is estimated to occupy 49 mm 2 of silicon area and to dissipate 12 mW of power from a 1.8 V supply, which is within the tissue-safe operation of the brain.

14.
Life (Basel) ; 12(4)2022 Apr 05.
Article in English | MEDLINE | ID: mdl-35455024

ABSTRACT

In December 2019, a case of atypical pneumonia was reported in Wuhan, China. It was named COVID-19 and caused by SARS-CoV-2. In a few months, scientific groups around the world developed vaccines to reduce the disease's severity. The objective was to evaluate the humoral and cellular immune response post immunization with three different vaccination schedules administered in Chile until January 2022. Sixty volunteers were recruited with a three-dose schedule, who had no history of infection nor close contact with a positive patient. IgG against the spike antigenic domain was detected, and the neutralization capacity against two groups of variants, Original/Alpha and Beta/Gamma, was also measured. Finally, the cellular response with interferon release was measured through IGRA. Results showed that there were significant differences in the neutralizing antibodies for the original and alpha variant when comparing three Comirnaty doses with Coronavac and Vaxzevria. A high number of reactive subjects against the different SARS-CoV-2 variants, alpha, gamma, and delta, were observed, with no significant differences between any of the three schemes, confirming the existence of a cellular immune response against SARS-CoV-2. In conclusion, the three vaccine schemes generated a cellular immune response in these volunteers.

15.
Int J Mol Sci ; 24(1)2022 Dec 29.
Article in English | MEDLINE | ID: mdl-36613986

ABSTRACT

ATP binding cassette (ABC) transporters are the primary means by which bacteria acquire trace elements from the environment. They rely on solute binding proteins (SBPs) to bind the relevant substrate and deliver it to the integral membrane permease for ATP-powered import into the cytoplasm. SBPs of cluster A-I are known to facilitate the transport of essential metals zinc, manganese, and iron, and many have been characterized to date. A group of ABC transporter operons dubbed zinc-regulated genes (zrg) have recently been shown to transport zinc with putative SBPs (zrgA) bearing no homology to the classical cluster A-I family, and a recent crystal structure of a representative protein from Pseudomonas aeruginosa shows no structural similarity to classical SBPs. Thus, the ZrgA proteins appear to represent a newly discovered family of zinc SBPs widespread among Gram-negative bacteria, including human pathogens. Here, we have determined the crystal structure of ZrgA from Vibrio cholerae and characterized its zinc binding in vitro and function in vivo. We also assessed the role of a histidine-rich sequence that appears to be a hallmark of ZrgA proteins that is particularly long in V. cholerae ZrgA. The results show that the zrgA gene is critical to the function of the operon, consistent with a function as an SBP in this system. Further, the His-rich region is not essential to the function of ZrgA, but it does provide additional zinc binding sites in vitro. The structure and zinc binding data for ZrgA reveal interesting differences between it and its homologue from P. aeruginosa, illustrating diversity within this little-studied protein family.


Subject(s)
Bacterial Proteins , Zinc , Humans , Bacterial Proteins/metabolism , Zinc/metabolism , ATP-Binding Cassette Transporters/metabolism , Binding Sites , Adenosine Triphosphate/metabolism , Protein Binding
16.
Rev. colomb. anestesiol ; 49(4): e302, Oct.-Dec. 2021. tab
Article in English | LILACS, COLNAL | ID: biblio-1341241

ABSTRACT

Abstract Fibromyalgia is a chronic disease of unclear etiology, involving a neural oversensitization and impaired pain modulation, in addition to a clinical deficiency of the endocannabinoid system. Fibromyalgia is associated with a number of somatic and psychological disorders and hence multiple pharmacological approaches have been used, including opioids, antidepressants, antiepileptics, and more recently medical cannabis. This narrative review comprises a review of the current literature on the efficacy of cannabinoids in fibromyalgia. The studies describe a possible influence of cannabis on pain control in patients with fibromyalgia, with positive effects on quality of life and sleep. The use of cannabis seems to be beneficial in patients with fibromyalgia; however, more robust studies are still needed to establish is actual efficacy in pain management, quality of life and improvement of associated symptoms.


Resumen La fibromialgia es una enfermedad crónica, cuya etiología no es clara, en la que se involucra una sobresensibilización neural y disminución de la modulación del dolor, así como una deficiencia clínica del sistema endocannabinoide. Está asociada a una variedad de trastornos somáticos y psicológicos, por lo cual se han utilizado múltiples abordajes farmacológicos, entre ellos opioides, antidepresivos, antiepilépticos y, recientemente, cannabis medicinal. En esta revisión narrativa se hace una reseña de la literatura actual relacionada con la eficacia de los cannabinoides en la fibromialgia. Los estudios describen una posible influencia del cannabis sobre el control del dolor en pacientes con fibromialgia, con efectos positivos sobre la calidad de vida y el sueño. El uso del cannabis parece tener beneficios en los pacientes con fibromialgia; sin embargo, aún se requieren estudios más robustos para establecer su verdadera eficacia en el manejo del dolor, calidad de vida y mejoría de los síntomas asociados.


Subject(s)
Humans , Female , Adult , Middle Aged , Cannabis , Fibromyalgia/therapy , Medical Marijuana , Dronabinol , Cannabinoids , Review Literature as Topic , Fibromyalgia
17.
Rev Chilena Infectol ; 38(2): 144-151, 2021 04.
Article in Spanish | MEDLINE | ID: mdl-34184703

ABSTRACT

BACKGROUND: The SARS-CoV-2 outbreak originated in the Hubei province in China spread rapidly throughout the world during the first months of 2020. On March 3, the first case was reported in Chile; at 17 days the first case of COVID-19 healthcare worker (HCW) was notified in our institution. AIM: To describe the demographic characteristics and the incidence of SARS-CoV-2 infection in the HCW of a university hospital in Chile. MATERIAL AND METHOD: Retrospective study of SARS-CoV-2 infection on HCW in a university hospital between March 1 and May 31, 2020. RESULTS: There were 273 positive cases. In the period under study, we had an incidence of 5.8%. When we separated the cases into clinical and non-clinical personnel, it was observed that their incidences were practically identical (5.8 vs. 5.7% p = 0.9430). 88% of the officials were oligosymptomatic or asymptomatic at the beginning of the clinical presentation and only 12% had a fever before the medical consultation. CONCLUSION: The incidence reported in the study was around 5 times that reported in Wuhan. If we apply the current definition of cases, we would lose 4 out of 5 cases. 88% of HPW did not present criteria to be considered suspicious, so it would be advisable in HCW to eliminate fever as a criterion to improve the research and trace their contacts on time.


Subject(s)
COVID-19 , SARS-CoV-2 , Chile/epidemiology , Health Personnel , Hospitals, University , Humans , Retrospective Studies
18.
Rev. chil. infectol ; 38(2): 144-151, abr. 2021. ilus, tab
Article in Spanish | LILACS | ID: biblio-1388224

ABSTRACT

INTRODUCCIÓN: El brote de SARS-CoV-2 originado en la provincia de Hubei en la República Popular China, se fue extendiendo aceleradamente en el mundo durante los primeros meses del año 2020. El 3 de marzo se notificó el primer caso en Chile; a los 17 días se notificó el primer caso de un Personal de Salud (PS) COVID-19 en nuestra institución. OBJETIVO: Describir las características demográficas y la incidencia de infección por SARS-CoV-2 en el PS de un hospital universitario de alta complejidad. MATERIAL Y MÉTODO: Estudio retrospectivo de los casos de infección por SARS-CoV-2 del PS entre el 1 de marzo y 31 de mayo de 2020. RESULTADOS: Hubo 273 casos positivos, con una incidencia de 5,8% en el período en estudio. Al dividir los casos en personal clínico y no clínico se observó que sus incidencias fueron prácticamente idénticas (5,8 vs 5,7% p = 0,9430). El 88% de los funcionarios fue oligo-sintomático o asintomático al inicio del cuadro clínico y sólo 12% tuvo fiebre antes de la consulta médica. CONCLUSIÓN: La incidencia reportada en el estudio fue alrededor de cinco veces la reportada en Wuhan. Al aplicar la definición de casos vigente, se perderían cuatro de cada cinco casos. Destaca que 88% del PS no presentaba criterios para ser considerado sospechoso, por lo que sería recomendable en el PS eliminar la fiebre como criterio para mejorar la pesquisa y trazar sus contactos de forma oportuna.


BACKGROUND: The SARS-CoV-2 outbreak originated in the Hubei province in China spread rapidly throughout the world during the first months of 2020. On March 3, the first case was reported in Chile; at 17 days the first case of COVID-19 healthcare worker (HCW) was notified in our institution. AIM: To describe the demographic characteristics and the incidence of SARS-CoV-2 infection in the HCW of a university hospital in Chile. MATERIAL AND METHOD: Retrospective study of SARS-CoV-2 infection on HCW in a university hospital between March 1 and May 31, 2020. RESULTS: There were 273 positive cases. In the period under study, we had an incidence of 5.8%. When we separated the cases into clinical and non-clinical personnel, it was observed that their incidences were practically identical (5.8 vs. 5.7% p = 0.9430). 88% of the officials were oligosymptomatic or asymptomatic at the beginning of the clinical presentation and only 12% had a fever before the medical consultation. CONCLUSION: The incidence reported in the study was around 5 times that reported in Wuhan. If we apply the current definition of cases, we would lose 4 out of 5 cases. 88% of HPW did not present criteria to be considered suspicious, so it would be advisable in HCW to eliminate fever as a criterion to improve the research and trace their contacts on time.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Health Personnel , COVID-19/epidemiology , Chile/epidemiology , Incidence , Retrospective Studies , SARS-CoV-2 , Hospitals, University
19.
Article in English | MEDLINE | ID: mdl-33296305

ABSTRACT

This article presents the design and efficient hardware implementation of binarized neural networks (BNNs) for brain-implantable neural spike sorting. In contrast to the conventional artificial neural networks (ANNs), in which the weights and activation functions of neurons are represented using real values, the BNNs utilize binarized weights and activation functions to dramatically reduce the memory requirement and computational complexity of the ANNs. The designed BNN is trained using several realistic neural datasets to verify its accuracy for neural spike sorting. The application-specific integrated circuit (ASIC) implementation of the designed BNN in a standard 0.18- [Formula: see text] CMOS process occupies 0.33 mm 2 of silicon area. Power consumption estimation of the ASIC layout shows that the BNN dissipates [Formula: see text] of power from a 1.8 V supply while operating at 24 kHz. The designed BNN-based spike sorting system is also implemented on a field-programmable gate array and is shown to reduce the required on-chip memory by 89% compared to those of the alternative state-of-the-art spike sorting systems. To the best of our knowledge, this is the first work employing BNNs for real-time in vivo neural spike sorting.


Subject(s)
Algorithms , Signal Processing, Computer-Assisted , Action Potentials , Humans , Neural Networks, Computer , Neurons
20.
Int J Mol Sci ; 21(23)2020 Nov 30.
Article in English | MEDLINE | ID: mdl-33265916

ABSTRACT

Bacterial ATP binding cassette (ABC) transporters mediate the influx of numerous substrates. The cluster A-I ABC transporters are responsible for the specific uptake of the essential metals zinc, manganese or iron, making them necessary for survival in metal-limited environments, which for pathogens include the animal host. In Paracoccus denitrificans, there are two zinc ABC transporter systems: ZnuABC and AztABCD with apparently redundant functions under zinc-limited conditions. The unusual presence of two zinc ABC transporter systems in the same organism allowed for the investigation of specificity in the interaction between the solute binding protein (SBP) and its cognate permease. We also assessed the role of flexible loop features in the SBP in permease binding and zinc transport. The results indicate that the SBP-permease interaction is highly specific and does not require the flexible loop features of the SBP. We also present an expanded table of the properties of characterized cluster A-I SBPs and a multiple sequence alignment highlighting the conserved features. Through this analysis, an apparently new family of binding proteins associated with ABC transporters was identified. The presence of homologues in several human pathogens raises the possibility of using it as a target for the development of new antimicrobial therapies.


Subject(s)
ATP-Binding Cassette Transporters/metabolism , Bacterial Proteins/metabolism , Paracoccus denitrificans/metabolism , Zinc/metabolism , ATP-Binding Cassette Transporters/chemistry , Bacterial Proteins/chemistry , Biological Transport , Protein Binding , Protein Structure, Secondary
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