Standard Deviation
Mostrando 1-12 de 1651 artigos, teses e dissertações.
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1. Carbon Dots from Pilosocereus gounellei for Fluorimetric Determination of Tannin in Tea Using a Flow-Batch System
In this study, xiquexique (Pilosocereus gounellei) native endemic cactus from the Brazilian semiarid was used for the first time as a natural carbon source (“green precursor”) for the synthesis of highly fluorescent carbon dots (CDs). These CDs were successfully used to develop a fast, low-cost, eco-friendly fluorescence method for the determination of t
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Autonomic heart rate modulation in patients with coronavirus disease 2019 in mechanical ventilation
SUMMARY BACKGROUND: Patients with coronavirus disease 2019 on automatic mechanical ventilation have greater heart rate modulation with greater parasympathetic modulation. OBJECTIVE: To analyze the autonomic modulation of heart rate in critically ill patients with coronavirus disease 2019 on invasive mechanical ventilation. METHODS: A cross-section study w
Revista da Associação Médica Brasileira. Publicado em: 2023
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3. Comparison of the autonomic nervous system dysfunction between different chronic spine disorders: neck pain versus low back pain
SUMMARY OBJECTIVE: This study aims to compare heart rate variability (HRV) between patients with chronic neck pain and patients with chronic low back pain and to correlate the chronic pain variables with heart rate variability indices. METHODS: This is a cross-sectional study. We divided the sample into two groups: neck pain (n=30) and low back pain (n=30)
Revista da Associação Médica Brasileira. Publicado em: 2022
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4. MGF Methods for Fixed and Gain Saturated Optically Preamplified FSO Links Impaired by Misalignments and Atmospheric Turbulence
Abstract The Gaussian approximation is commonly used to evaluate the performance of free space optical communication systems. However, other performance evaluation methods such as the saddle point approximation, Chernoff bound and the modified Chernoff bound have also been used. This paper investigates the performance of fixed and gain saturated optically pr
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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5. Acceptance of Low-Sodium Hospital Diet by Cardiac Patients: A Randomized Controlled Crossover Trial
Abstract Background Cardiovascular diseases are the major cause of hospitalization. Dietary salt restriction is indicated as part of clinical treatment, however, it is not always well accepted by the patients, resulting in low food intake and malnutrition. Objective To compare acceptance of a low-sodium diet cooked with salt with a standard low-sodium di
International Journal of Cardiovascular Sciences. Publicado em: 2022
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6. Thermal Infrared Enthalpimetry Method for the Determination of Hypochlorite in Bleaching Solutions
Thermal infrared enthalpimetry (TIE) was used for hypochlorite determination in commercial hypochlorite-based bleaching solutions. Experimental parameters were evaluated for the reaction with a hydrogen peroxide solution. The most relevant conditions were 5% H2O2 (m/m) solution, stirring speed of 250 rpm, dispensing rate of 0.57 mL s-1, and 10 s after reacti
Journal of the Brazilian Chemical Society. Publicado em: 2022
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7. Selective Neck Dissection for Node-Positive Oral Cavity Squamous Cell Carcinoma: A Retrospective Cohort Study
Abstract Introduction Selective neck dissection inclinically node-negative neckisconsidered the standard of care for oral squamous cell carcinomas (SCCs). Controversy still prevailsinnode-positive disease regarding the extent of neck dissection. In our part of the world, comprehensive neck dissection is mostly considered to be the minimal optimal treatment
International Archives of Otorhinolaryngology. Publicado em: 2022
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8. Screening for Celiac Disease in Patients with Irritable Bowel Syndrome Fulfilling Rome III Criteria
Abstract Background Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder. Celiac disease (CD), a treatable autoimmune enteropathy, with varied presentations, may simulate clinically symptoms of IBS. The aim of the present study is to screen for CD in patients with IBS diagnosed based on the Rome III criteria. Patients and Method
Journal of Coloproctology (Rio de Janeiro). Publicado em: 2022
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9. Development of a Disposable Pipette Extraction Method Using Coffee Silverskin as an Adsorbent for Chromium Determination in Wastewater Samples by Solid Phase Extraction
A procedure using disposable pipette tips adapted for solid-phase extraction, known as DPX SPE, was used as an alternative way for the chromium determination in wastewater samples. DPX-SPE consists of a device which allows a dynamic contact between the sample and the solid-phase. A residue obtained from the processing of coffee beans, denominate coffee silve
Journal of the Brazilian Chemical Society. Publicado em: 2022
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10. DEVELOPMENT AND OPTIMIZATION OF A SPECTROPHOTOMETRIC METHOD WITH CLOUD POINT EXTRACTION FOR DETERMINATION OF GADOLINIUM
This work describes a simple, sensible, and low-cost analytical method, based on cloud-point extraction (CPE) of the surfactant (1,1,3,3-Tetramethylbutyl)phenyl-polyethylene glycol (Triton X-114), for the efficient extraction and sensible determination of gadolinium after its complexation with 1-(2-pyridylazo)-2-naphthol (PAN) and subsequent determination by
Química Nova. Publicado em: 2022
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11. ASSESSMENT OF α-AMYLASE INHIBITION ACTIVITY BY AN OPTIMIZED AND VALIDATED IN VITRO MICROSCALE METHOD
Metabolic disorders, including hyperglycemia, characterize type-2 diabetes. One of the treatment methods used for postprandial hyperglycemia includes using potential therapeutic agents to inhibit α-amylase activity. This study utilized fractional design and the simplex method to optimize in vitro microscale assay inhibition conditions using Miller’s react
Química Nova. Publicado em: 2022
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12. Simultaneous GC-NCI-MS Determination of Persistent Organic Pollutants and Current-Use Pesticides in Breast Milk Samples
To preserve human health, persistent organic pollutants (POPs) and current-use pesticides (CUPs) should be monitored in fatty tissues, including breast milk. Therefore, this study aimed to optimize sample preparation conditions using a 32 factorial design for the determination of POPs and CUPs by gas chromatography coupled to mass spectrometry with negative
Journal of the Brazilian Chemical Society. Publicado em: 2022