Publications by authors named "Juan Alvarado"

Article Synopsis
  • The study aimed to find early indicators of presbycusis (age-related hearing loss) by analyzing auditory brainstem response (ABR) waves in Wistar rats of different ages.
  • Researchers observed that wave II amplitudes decreased significantly in 9-month-old rats, even though hearing thresholds didn't show noticeable decline until 14 months.
  • These results suggest that changes in ABR waves might indicate early signs of hearing loss before any significant changes in hearing ability, which could help in early diagnosis and treatment in humans to improve quality of life for those affected.
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  • Atlantic reef-building corals are declining due to climate change, disease, pollution, and human activities, prompting a reassessment of their extinction risk under the IUCN Red List.
  • The latest evaluation shows an increase in the percentage of species at high extinction risk, with nearly 46% to 54% of shallow water corals now classified as threatened, compared to 15% to 40% in 2008.
  • Although there's been a slight improvement in coral coverage over historical data, projections indicate that severe bleaching events could significantly threaten the future survival of 26 species, which are now labeled as Critically Endangered.
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Thyroid hormone binds to specific nuclear receptors, regulating the expression of target genes, with major effects on cardiac function. Triiodothyronine (T3) increases the expression of key proteins related to calcium homeostasis, such as the sarcoplasmic reticulum calcium ATPase pump, but the detailed mechanism of gene regulation by T3 in cardiac voltage-gated calcium (Cav1.2) channels remains incompletely explored.

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Cisplatin is an election chemotherapeutic agent used for many cancer treatments. Its cytotoxicity against neoplastic cells is mirrored by that taking place in healthy cells and tissues, resulting in serious adverse events. A very frequent one is ototoxicity, causing hearing loss which may permanently affect quality of life after successful oncologic treatments.

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Comprehending the immune defense mechanisms of new aquaculture species, such as the Chilean meagre (), is essential for sustaining large-scale production. Two bioassays were conducted to assess the impact of acute and intermittent hypoxia on the antibacterial activity of juvenile Chilean meagre epidermal mucus against the potential pathogens and . Lysozyme and peroxidase activities were also measured.

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In this work, the vapor-liquid-liquid equilibrium (VLLE) of the water/-pentane, water/-hexane, water/-octane, and water/-decane binary systems is calculated by computer simulation using the NVT-Gibbs ensemble (in the version of three simulation boxes) combined with the configurational bias Monte Carlo method. The combination of both methods, the molecular potential models used, and the simulation details allowed us to calculate the triphasic equilibrium properties of the systems studied: the densities of the three phases in equilibrium, their compositions, and potential energies. In previous works, these simulations were not carried out at a temperature range nor water/-alkanes systems simulated in this work, probably because they are highly nonideal systems; so, to the best of our knowledge, this is the first time that this phenomenon is studied in detail.

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Article Synopsis
  • The study aimed to compare immune cell populations in the blood of infected (n=35) and uninfected (n=27) individuals from rural Bolívar, using specific diagnostic techniques and flow cytometry for analysis.
  • Results showed no significant differences in age or sex between the two groups, with mild infections noted in cases and a slight decrease in neutrophil percentage among infected individuals, though the overall differences in immune cell types were minimal.
  • The study was ethically approved, participants consented, and funding was provided through the Colombian Sistema General de Regalías.
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COVID-19 infection has been a significant contributor to global morbidity and mortality, especially among those patients with chronic diseases. The Centers for Disease Control and Prevention have classified sickle cell disease (SCD) as a condition that increases the risk of severe illness from COVID-19 infection. A retrospective study was conducted using the TRiNetX health research network database to identify SCA patients ( HbSS, Sbeta-thalassemia zero) who had SARS-CoV-2 infection over 2 years; these were compared with similar patients who did not have the infection in terms of demographics, pain control, and laboratory parameters COVID-19 illness impacts [ain crises and ACS, and prior vaccination against influenza and COVID-19 may represent a protective factor for developing pain crises.

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A strong association between the proportion of indigenous South American Mapuche ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest indigenous people in Chile. We set out to assess the confounding-free effect of the individual proportion of Mapuche ancestry on GBC risk and to investigate the mediating effects of gallstone disease and body mass index (BMI) on this association.

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Since 2006, Chile has been implementing a gallbladder cancer (GBC) prevention program based on prophylactic cholecystectomy for gallstone patients aged 35 to 49 years. The effectiveness of this prevention program has not yet been comprehensively evaluated. We conducted a retrospective study of 473 Chilean GBC patients and 2137 population-based controls to develop and internally validate three GBC risk prediction models.

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Commercially available oxygen scavengers used to prevent lipid autoxidation, microbial growth and enzymatic browning in food products present several issues, which include the usage of metals and their moisture dependence to work properly. We present the synthesis and characterization of a moisture-independent oil-based oxygen scavenging system comprised of linseed oil and silica nanoparticles. The system was synthesized via sol-gel chemistry and was characterized using morphological analysis (SEM, AFM, TEM, and N adsorption/desorption), oil-loading analysis (TGA), and surface analysis (ζ-potential and ATR-FTIR).

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Kanamycin and cisplatin are ototoxic drugs. The mechanisms are incompletely known. With subcutaneous kanamycin (400 mg/kg, 15 days), auditory threshold shifts were detected at days 12-13 at 16 and 32 kHz, extending to 8 and 4 kHz at days 14-15.

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On 11 March 2020, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) was declared as a pandemic by the World Health Organization (WHO). As the COVID-19 pandemic has ravaged worldwide, children have not been unaffected. Information gleaned from adult experience with the disease has aided in disease detection and treatment strategies in children.

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Scientific diasporas are organized groups of professionals who work together to contribute to their country of origin. Since the start of the COVID-19 pandemic in 2020, scientific diasporas around the world have focused their efforts to support the public health response in their countries of origin. As the first cases of COVID-19 were reported in Guatemala in March of 2020, a team of four Guatemalan nationals, residing abroad and in-country, started collaborating to tackle COVID-19 misinformation and issues with healthcare services navigation.

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Coral reefs in Culebra Bay (North Pacific of Costa Rica) are threatened by multiple anthropogenic disturbances including global warming, overfishing, eutrophication, and invasive species outbreaks. It is possible to assist their recovery by implementing ecological restoration techniques. This study used artificial hexagonal steel structures, called "spiders" to compare growth of spp.

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We have previously reported that young adult rats exposed to daily, short-duration noise for extended time periods, develop accelerated presbycusis starting at 6 months of age. Auditory aging is associated with progressive hearing loss, cell deterioration, dysregulation of the antioxidant defense system, and chronic inflammation, among others. To further characterize cellular and molecular mechanisms at the crossroads between noise and age-related hearing loss (ARHL), 3-month-old rats were exposed to a noise-accelerated presbycusis (NAP) protocol and tested at 6 and 16 months of age, using auditory brainstem responses, Real-Time Reverse Transcription-Quantitative PCR (RT-qPCR) and immunocytochemistry.

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Long noncoding RNAs (lncRNAs) play key roles in cell processes and are good candidates for cancer risk prediction. Few studies have investigated the association between individual genotypes and lncRNA expression. Here we integrate three separate datasets with information on lncRNA expression only, both lncRNA expression and genotype, and genotype information only to identify circulating lncRNAs associated with the risk of gallbladder cancer () using robust linear and logistic regression techniques.

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As it is well known, a worldwide improvement in life expectancy has taken place. This has brought an increase in chronic pathologies associated with aging. Cardiovascular, musculoskeletal, psychiatric, and neurodegenerative conditions are common in elderly subjects.

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Objective: Ultrasound is considered a real-time imaging method in neuro-oncology because of its highly rapid image acquisition time. However, to our knowledge, there are no studies that analyze the additional surgical time that it requires.

Methods: A prospective study of 100 patients who underwent intra-axial brain tumor resection with navigated intraoperative ultrasound.

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Noise induces oxidative stress in the cochlea followed by sensory cell death and hearing loss. The proof of principle that injections of antioxidant vitamins and Mg prevent noise-induced hearing loss (NIHL) has been established. However, effectiveness of oral administration remains controversial and otoprotection mechanisms are unclear.

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We live in a world continuously immersed in noise, an environmental, recreational, and occupational factor present in almost every daily human activity. Exposure to high-level noise could affect the auditory function of individuals at any age, resulting in a condition called noise-induced hearing loss (NIHL). Given that by 2018, more than 400 million people worldwide were suffering from disabling hearing loss and that about one-third involved noise over-exposure, which represents more than 100 million people, this hearing impairment represents a serious health problem.

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