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Sixty years after melatonin was isolated and with more than 23,000 published studies showing the many functions of this hormone secreted by the pineal gland, guidelines should be discussed and established for its therapeutic use. This is the view expressed by José Cipolla Neto, Full Professor at the University of São Paulo's Biomedical Science Institute (ICB-USP), and Fernanda Gaspar do Amaral, a professor at the Federal University of São Paulo (UNIFESP), both in Brazil, in an article [...]

A simple sheet of graphene has noteworthy properties due to a quantum phenomenon in its electron structure named Dirac cones in honor of British theoretical physicist Paul Dirac (1902-1984), who was awarded the Nobel Prize for Physics in 1933. The system becomes even more interesting if it comprises two superimposed graphene sheets, and one is very slightly turned in its own plane so that the holes in the two carbon lattices no longer completely coincide. For specific angles of twist, the [...]

Brazil's Ministry of Health received reports of 11,524 outbreaks of foodborne diseases between 2000 and 2015, with 219,909 individuals falling sick and 167 dying from the diseases in question. Bacteria caused most outbreaks of such illnesses, including diarrhea and gastroenteritis. The most frequent were Salmonella spp., with 31,700 cases diagnosed in the period (14.4% of the total), Staphylococcus aureus (7.4%), and Escherichia coli (6.1%). According to a survey by the Ministry of Social [...]

The history of the peopling of the Americas has just been interpreted afresh. The largest and most comprehensive study ever conducted on the basis of fossil DNA extracted from ancient human remains found on the continent has confirmed the existence of a single ancestral population for all Amerindian ethnic groups, past and present. Over 17,000 years ago this original contingent crossed the Bering Strait from Siberia to Alaska and began peopling the New World. Fossil DNA shows an affinity [...]

An insect larva found in the caves of Intervales State Park, an Atlantic Rainforest remnant in the municipality of Ribeirão Grande, São Paulo State, Brazil, was initially of no interest to the research group led by biochemist Vadim Viviani, a professor at the Federal University of São Carlos (UFSCar) in Sorocaba. The researchers are investigating bioluminescence, the capacity of living organisms to produce their own light. Nevertheless, the larva of Neoditomyia, a genus of non-luminescent [...]

Throughout the alluvial plains of Amazonia, there are immense forests that are flooded for almost half the year. These Amazonian wetlands encompass a wide array of types of vegetation in or near stream gullies, including blackwater (igapó) and whitewater (várzea) inundation forest, swamp (pântano), white sand savanna (campina), and mangrove (mangue) types. According to a new study, the region's wetlands are inhabited by 3,615 tree species--three times more than previously estimated, making [...]

A lineage of type 1 dengue virus found in Brazil is able to prevail over another even though it multiplies less in vector mosquitoes and infected human cells. This discovery was made under the scope of a Thematic Project supported by the São Paulo Research Foundation - FAPESP involving several Brazilian institutions as well as a university in the United States. According to the study, the lineage activates a weaker immune response in the patient and is less strongly combated. As a result, the [...]

The strategy used by the Oropouche virus to replicate in human cells has been described for the first time by researchers at the University of São Paulo (USP) in Brazil and international collaborators in an article published in the journal PLOS Pathogens. According to the study, shortly after invading the cell, the pathogen "hijacks" an organelle called the Golgi complex, which becomes a veritable virus factory. The virus does this by recruiting host cell protein complexes known as ESCRT [...]

In an article published recently in the journal Nature Communications, researchers affiliated with the University of São Paulo (USP) in Brazil describe the central role played by an enzyme called phosphatidylinositol 3-kinase gamma (PI3K?) in regulating the immune response against Trypanosoma cruzi, the protozoan parasite that causes Chagas disease. "Our results show that the expression of PI3K? increases during infection by T. cruzi in both mice and humans. This appears to be essential to [...]