RESUMEN
While many freshwater invaders originate from saline habitats, the physiological mechanisms involved are poorly understood. We investigated the evolution of ion transporter Na+/K+-ATPase (NKA) protein expression between ancestral saline and freshwater invading populations of the copepod Eurytemora carolleae (Atlantic clade of the E. affinis complex). We compared in situ NKA expression between populations under common-garden conditions at three salinities in the maxillary glands. We found the evolution of reduced NKA expression in the freshwater population under freshwater conditions and reduced plasticity (canalization) across salinities, relative to the saline population. Our results support the hypothesis that maxillary glands are involved in ion reabsorption from excretory fluids at low-salinity conditions in the saline population. However, mechanisms of freshwater adaptation, such as increased ion uptake from the environment, might reduce the need for ion reabsorption in the freshwater population. These patterns of ion transporter expression contribute insights into the evolution of ionic regulation during habitat change.
RESUMEN
Nanobiotechnology is one of the leading research areas in biomedical science, developing rapidly worldwide. Among various types of nanoparticles, carbon nanomaterials (CNMs) have attracted a great deal of attention from the scientific community, especially with respect to their prospective application in the field of disease diagnosis and therapy. The unique features of these nanomaterials, including favorable size, high surface area, and electrical, structural, optical, and chemical properties, have provided an excellent opportunity for their utilization in theranostic systems. Carbon nanotubes, carbon quantum dots, graphene, and fullerene are the most employed CNMs in biomedical fields. They have been considered safe and efficient for non-invasive diagnostic techniques such as fluorescence imaging, magnetic resonance imaging, and biosensors. Various functionalized CNMs exhibit a great capacity to improve cell targeting of anti-cancer drugs. Due to their thermal properties, they have been extensively used in cancer photothermal and photodynamic therapy assisted by laser irradiation and CNMs. CNMs also can cross the blood-brain barrier and have the potential to treat various brain disorders, for instance, neurodegenerative diseases, by removing amyloid fibrils. This review has summarized and emphasized on biomedical application of CNMs and their recent advances in diagnosis and therapy.
RESUMEN
Although scientists know that overheating kills many organisms, they do not agree on the mechanism. According to one theory, referred to as oxygen- and capacity-limitation of thermal tolerance, overheating occurs when a warming organism's demand for oxygen exceeds its supply, reducing the organism's supply of ATP. This model predicts that an organism's heat tolerance should decrease under hypoxia, yet most terrestrial organisms tolerate the same amount of warming across a wide range of oxygen concentrations. This point is especially true for adult insects, who deliver oxygen through highly efficient respiratory systems. However, oxygen limitation at high temperatures may be more common during immature life stages, which have less developed respiratory systems. To test this hypothesis, we measured the effects of heat and hypoxia on the survival of South American locusts (Schistocerca cancellata) throughout development and during specific instars. We demonstrate that the heat tolerance of locusts depends on oxygen supply during the first instar but not during later instars. This finding provides further support for the idea that oxygen limitation of thermal tolerance depends on respiratory performance, especially during immature life stages.