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Hydrogen isotopes, such as protium(H), deuterium(D), and tritium(T), are widely used in medical treatment, nuclear energy, national defense, and other fields. Under the background of the "double carbon" target with carbon peak and carbon neutralization, deuterium-tritium fusion energy is considered to be an important energy strategy in China. However, the relative abundance of deuterium and tritium in nature is extremely low, and it is of great significance to separate hydrogen isotopes economically and effectively. This paper presents the research on water hydrogen isotope separation technology. Firstly, the methods and the principles of hydrogen isotope separation in water are summarized. Then, two perspectives of separation methods were reviewed. From the perspective of engineering application, the electrolysis, distillation and chemical exchange method are focused. From the perspective of laboratory research and development, the membrane separation method and porous material adsorption method are focused. Finally, the separation factors and energy consumption of typical separation technologies are compared. Moreover, to provide a certain reference for the water hydrogen isotope separation technology, several future research directions are prospected.

Abstract The current study aims to contribute to the knowledge the genus Protium occurring in the state of Rio de Janeiro. Collections deposited in national herbaria were examined and field collections were carried out, in addition to research in specialized literature and consultations in online international herbaria. Seven species were cataloged for the state of Rio de Janeiro. Descriptions, illustrations, comments, as well as information on phenology, ecology, conservation, and distribution maps for all species are presented.

The transport of hydrogen isotopes through the elements that make up a fusion reactor, and their corresponding interaction with these materials, have a direct impact on its operation. Consequently, it is essential to master in advance their transport parameters in the different materials proposed to constitute the elements that will compound the fusion reactors, and, consequently, this is one of the main lines of fusion investigation. For reasons of technology, safety and viability, it would be desirable to have the possibility of experimenting only with protium and, from these values, to extrapolate those of deuterium and, above all, tritium. To do so, the classical atomic theory establishes that the ratio of these parameters is inversely proportional to square root of their mass ratio. However, discrepancies have been detected, so its verification has become fundamental. For this reason, this study presents the analysis of a series of tests of permeability carried out at the Fusion Materials Laboratory (UPV/EHU) using protium and deuterium with some samples of SS316 and EUROFER steels, in order to contrast the isotope effect, as well as the variables that could influence its adjustment. The results show that 316 steels present an isotope effect much closer to the theoretical one, while EUROFER steels differ more, increasing their isotopic ratio of permeabilities with temperature. In both cases, the trends are in line with published results.

The EUROFER reduced activation ferritic-martensitic (RAFM) steel is meant to be a firm candidate as structural material to be part of future fusion reactors. The correct definition of the transport parameters of hydrogen isotopes in these materials turns out to be a key issue in this field, as long as it can affect the operation of the reactor itself when quantifying the fuel inventory as well as the radiological safety of the whole facility.Traditionally the diffusion limited regime (DLR) of these kind of RAFM steels has been experimentally tested and values for the permeability and diffusivity have been published, showing some differences depending on the specific composition of the steel, the thermal treatment during the manufacturing processes, etc. However, these RAFM steels will have to operate also under conditions of pressure and temperature that will lead to surface limited regimes (SLR). In this case, there is much less information available and data for the adsorption and recombination constants is not so extensive.This work shows the results for a new set of experimental permeation measurements carried out within the EUROfusion program in order to determine the SLR. The surface rate constants of protium and deuterium were experimentally obtained for Eurofer97-3 at two different facilities (PermRIG at UPV/EHU and Thermoperm at CIEMAT), with consistent results that show a good agreement.

Online monitoring is a key challenge for the continued development of molten salt reactor (MSR) technology. Laser-induced breakdown spectroscopy (LIBS) has previously been demonstrated to be a viable tool for monitoring aerosolized species and noble gases in real time, but the ability to discern varying isotopes in these streams has not yet been investigated for MSR applications. Tritium will form in MSRs from ternary fission and from (n,α)-reactions occurring in lithium-containing salts. This study compares three spectrometers of varying resolutions and types for measuring hydrogen isotope shifts in LIBS spectra of wetted filter paper. For each spectrometer, multivariate models were built (i.e., principal component regression, partial least squares regression, and multivariate curve resolution) to quantify the isotope ratio. The top models were then modified and corrected to apply the models to aerosol samples with varying isotope ratios. This novel calibration strategy offers an 82% reduction in volume of the calibration samples needed and is a more viable pathway for calibrating deployable LIBS systems. Lastly, this calibration model was compared with an all-aerosol trained model for monitoring hydrogen isotopes during a real-time test where the protium/deuterium ratio, along with representative salt species (i.e., lithium, sodium, and potassium) were adjusted dynamically. Results of this test validated the predictive capabilities of the transferred model and highlighted the capabilities of LIBS for real-time monitoring of MSR effluent streams. [ABSTRACT FROM AUTHOR]

Tropical forests are acknowledged to be the largest global source of isoprene (C5H8) and monoterpenes (C10H16) emissions, with current synthesis studies suggesting few tropical species emit isoprenoids (20-38%) and do so with highly variable emission capacities, including within the same genera. This apparent lack of a clear phylogenetic thread has created difficulties both in linking isoprenoid function with evolution and for the development of accurate biosphere-atmosphere models. Here, we present a systematic emission study of "hyperdominant" tree species in the Amazon Basin. Across 162 individuals, distributed among 25 botanical families and 113 species, isoprenoid emissions were widespread among both early and late successional species (isoprene: 61.9% of the species; monoterpenes: 15.0%; both isoprene and monoterpenes: 9.7%). The hyperdominant species (69) across the top five most abundant genera, which make up about 50% of all individuals in the Basin, had a similar abundance of isoprenoid emitters (isoprene: 63.8%; monoterpenes: 17.4%; both 11.6%). Among the abundant genera, only Pouteria had a low frequency of isoprene emitting species (15.8% of 19 species). In contrast, Protium, Licania, Inga, and Eschweilera were rich in isoprene emitting species (83.3% of 12 species, 61.1% of 18 species, 100% of 8 species, and 100% of 12 species, respectively). Light response curves of individuals in each of the five genera showed light-dependent, photosynthesis-linked emission rates of isoprene and monoterpenes. Importantly, in every genus, we observed species with light-dependent isoprene emissions together with monoterpenes including β-ocimene. These observations support the emerging view of the evolution of isoprene synthases from β-ocimene synthases. Our results have important implications for understanding isoprenoid function-evolution relationships and the development of more accurate Earth System Models.

Deuterium, a stable isotope of hydrogen, is a component of water and organic compounds. It is the second most abundant element in the human body after sodium. Although the concentration of deuterium in an organism is much lower than that of protium, a wide variety of morphological, biochemical, and physiological changes are known to occur in deuterium-treated cells, including changes in fundamental processes such as cell division or energy metabolism. The mode and degree of changes in cells and tissues, both with an increase and a decrease in the concentration of deuterium, depends primarily on the time of exposure, as well as on the concentration. The reviewed data show that plant and animal cells are sensitive to deuterium content. Any shifts in the D/H balance outside or inside cells promote immediate responses. The review summarizes reported data on the proliferation and apoptosis of normal and neoplastic cells in different modes of deuteration and deuterium depletion in vivo and in vitro. The authors propose their own concept of the effects of changes in deuterium content in the body on cell proliferation and death. The altered rate of proliferation and apoptosis indicate a pivotal role of the hydrogen isotope content in living organisms and suggest the presence of a D/H sensor, which is yet to be detected. [ABSTRACT FROM AUTHOR]

Online monitoring is a key challenge for the continued development of molten salt reactor (MSR) technology. Laser-induced breakdown spectroscopy (LIBS) has previously been demonstrated to be a viable tool for monitoring aerosolized species and noble gases in real time, but the ability to discern varying isotopes in these streams has not yet been investigated for MSR applications. Tritium will form in MSRs from ternary fission and from (n,α)-reactions occurring in lithium-containing salts. This study compares three spectrometers of varying resolutions and types for measuring hydrogen isotope shifts in LIBS spectra of wetted filter paper. For each spectrometer, multivariate models were built (i.e., principal component regression, partial least squares regression, and multivariate curve resolution) to quantify the isotope ratio. The top models were then modified and corrected to apply the models to aerosol samples with varying isotope ratios. This novel calibration strategy offers an 82% reduction in volume of the calibration samples needed and is a more viable pathway for calibrating deployable LIBS systems. Lastly, this calibration model was compared with an all-aerosol trained model for monitoring hydrogen isotopes during a real-time test where the protium/deuterium ratio, along with representative salt species (i.e., lithium, sodium, and potassium) were adjusted dynamically. Results of this test validated the predictive capabilities of the transferred model and highlighted the capabilities of LIBS for real-time monitoring of MSR effluent streams.

Amid all the Brazilian phytodiversity, in all its shades and shapes, black and white amorphous masses glued to the barks of Burseraceae species stand out as some of the nation's most appreciated plant medicinal resources. Burseraceae resins have been used in all macroregions of Brazil, wherever they occur, for a variety of medicinal purposes. However, despite ongoing interest in them, their cultural and health relevance in the country has been underexamined. This review aimed to illuminate the therapeutic importance and potential of Brazilian Burseraceae by assembling the ethnomedicinal, chemical, and pharmacological data available on its resins used in Brazil. A search for journal articles documenting local ethnomedicinal uses of Burseraceae resins and reporting chemical and pharmacological data associated with their botanical sources was conducted in ScienceDirect, Google Scholar, and PubMed databases. Books and theses were also appraised for such information. At least 21 Burseraceae taxa, belonging to Protium , Trattinnickia , and Commiphora , are recorded as sources of medicinal resins in Brazil. Protium and Trattinickia yield oleoresins typically rich in mono- and triterpenoids, especially the pentacyclic triterpenoids α- and β-amyrin. Although Commiphora oleo-gum-resins are expected to differ significantly from Protium and Trattinickia oleoresins by the presence of gum fractions, they often exhibit distinct terpenoid compositional patterns, characterized by a high proportion of sesquiterpenoids and tetracyclic triterpenoids. Burseraceae resins are more frequently cited in the Brazilian ethnomedicinal literature for relieving headaches and healing wounds. Pharmacological evidence corroborates the potential of Burseraceae resins against these and some other conditions and diseases, however, further studies are needed to confirm their efficacy and safety when used topically and through inhalation—the two primary routes of administration explored for them in Brazil. The present review unearths a consistent, persistent, and cross-cultural pattern of using Burseraceae resins against pain conditions. But to really tap into the Burseraceae's therapeutic potential in Brazil, we first need to address the following gaps: (a) conduct more thorough pharmacological studies, including clinical trials; (b) give more attention to the triterpenoid fraction of Burseraceae oleoresins, not only to essential oils and α- and β-amyrin; and (c) deepen our understanding of the impact of resin aging on chemical composition. [Display omitted] • Burseraceae resins are distinguished components of Brazil's aromatic ethnoflora. • At least 21 taxa are used medicinally in the country. • The resins are principally composed of terpenoids. • Their main medicinal indications are against pains. • Despite the long history of use, the pharmacological data on Neotropical Burseraceae is still preliminary. [ABSTRACT FROM AUTHOR]

In solutions of non-electrolytes, there is a single network of hydrogen bonds, including molecules of dissolved substances, bound water, bulk water, and hydration shells of molecules in solution. Under certain conditions, there should be correlations between the bulk properties of the liquid mixture and the separation factor of the isotopic forms of water between the liquid and vapor phases. The shift of the isotope equilibrium in the liquid–vapor phase system for water during the transition from water to non-electrolyte solutions is associated with a violation of the degree of bonding and structuredness of the water of the mixed solvent. Using urea solutions as an example, it is shown that this effect can be one of the main ones and can determine the increase in the separation factor of the isotopic forms of water upon passing from water to a solution. [ABSTRACT FROM AUTHOR]

The role of stable hydrogen isotopes in the thermoregulation and its regulation is poorly studied. We analyzed fluctuations in body temperature and changes in thermoregulation parameters in mice under conditions of reduced deuterium intake. The study was performed on male C57BL/6 mice that consumed water with a low (10 ppm) and normal (146 ppm) deuterium content. In 7 days, fluctuations of body temperature, locomotor activity, and oxygen uptake were assessed. Deuterium depletion in the body reduced the mean value of minute fluctuations of body temperature and the mean spectral density of minute fluctuations in body temperature in the 2-20-min periods. This attested to a stabilizing effect of deuterium depletion on the rhythms of body temperature fluctuations, without significant shifts in the thermogenesis parameters. Thus, drinking water with reduced deuterium content makes them less sensitive to external influences. [ABSTRACT FROM AUTHOR]

Abstract Plant defense chemistry is often hypothesized to drive ecological and evolutionary success in diverse tropical forests, yet detailed characterizations of plant secondary metabolites in tropical plants are logistically challenging. Here, we explore a new integrative approach that combines visible‐to‐shortwave infrared (VSWIR) spectral reflectance data with detailed plant metabolomics data from 19 Protium (Burseraceae) tree species. Building on the discovery that different Protium species have unique chemistries yet share many secondary metabolites, we devised a method to test for associations between metabolites and VSWIR spectral data. Given species‐level variation in metabolite abundance, we correlated the concentration of particular chemicals with the reflectance of the spectral bands in a wavelength band per secondary metabolite matrix. We included 45 metabolites that were shared by at least 5 Protium species and correlated their per‐species foliar abundances against each one of 210 wavelength bands of field‐measured VSWIR spectra. Finally, we tested whether classes of similar metabolites showed similar relationships with spectral patterns. We found that many secondary metabolites yielded strong correlations with VSWIR spectra of Protium. Furthermore, important Protium metabolite classes such as procyanidins (condensed tannins) and phytosterols were grouped together in a hierarchical clustering analysis (Ward’s algorithm), confirming similarity in their associations with plant spectral patterns. We also found a significant correlation in the phenolics content between juvenile and canopy trees of the same species, suggesting that species‐level variation in defense chemistry is consistent across life stages and geographic distribution. We conclude that the integration of spectral and metabolic approaches could represent a powerful and economical method to characterize important aspects of tropical plant defense chemistry.

The efficiency of mass transfer in the separation of hydrogen isotopes by water distillation in the presence of urea as a separating agent has been estimated. Experiments have been performed for vapor–liquid and vapor–aqueous salt solution systems under conditions with independent flows. Two regimes of mass transfer have been considered: the first one when the operating concentration of deuterium in the liquid phase is lower than that in equilibrium with the vapor (xD< ) and the second one when it is higher than that in equilibrium with the vapor (xD> ). A substantial difference in the number of theoretical separation stages for these regimes has been found. At xD> , in the presence of urea as a separating agent, the number of theoretical separation stages is three times lower than that for the vapor–water system. Thus, in the distillation of the hydrogen isotopes of water, urea hinders the transport of deuterium from the liquid phase to the vapor phase, forming nonvolatile complexes with water molecules that contain deuterium. [ABSTRACT FROM AUTHOR]

Plant defense chemistry is often hypothesized to drive ecological and evolutionary success in diverse tropical forests, yet detailed characterizations of plant secondary metabolites in tropical plants are logistically challenging. Here, we explore a new integrative approach that combines visible‐to‐shortwave infrared (VSWIR) spectral reflectance data with detailed plant metabolomics data from 19 Protium (Burseraceae) tree species. Building on the discovery that different Protium species have unique chemistries yet share many secondary metabolites, we devised a method to test for associations between metabolites and VSWIR spectral data. Given species‐level variation in metabolite abundance, we correlated the concentration of particular chemicals with the reflectance of the spectral bands in a wavelength band per secondary metabolite matrix. We included 45 metabolites that were shared by at least 5 Protium species and correlated their per‐species foliar abundances against each one of 210 wavelength bands of field‐measured VSWIR spectra. Finally, we tested whether classes of similar metabolites showed similar relationships with spectral patterns. We found that many secondary metabolites yielded strong correlations with VSWIR spectra of Protium. Furthermore, important Protium metabolite classes such as procyanidins (condensed tannins) and phytosterols were grouped together in a hierarchical clustering analysis (Ward's algorithm), confirming similarity in their associations with plant spectral patterns. We also found a significant correlation in the phenolics content between juvenile and canopy trees of the same species, suggesting that species‐level variation in defense chemistry is consistent across life stages and geographic distribution. We conclude that the integration of spectral and metabolic approaches could represent a powerful and economical method to characterize important aspects of tropical plant defense chemistry. [ABSTRACT FROM AUTHOR]

The immense plant diversity that is characteristic of tropical rain forests often makes it difficult for ecological and conservation studies to identify individual plant species and measure biodiversity. DNA barcoding is a species identification technique that utilizes standard, short dnA sequences to distinguish between species when traditional taxonomic identification is not practical. Accurate identification of animals with DNA barcoding has been well established, but a universally accepted DNA barcode for plants still does not exist. The use of nuclear DNA markers and plastid DNA markers from the chloroplast are the two contending approaches to DNA barcoding. This study compares the utility of the nuclear DNA marker ItS and the plastid DNA marker rbcL as DNA barcodes among 35 Burseraceae tree species from the Peruvian Amazon. I found that the proposed DNA barcode rbcL greatly underperformed the nuclear marker ItS as a DNA barcode. While both markers exhibited greater than 90% amplification success ItS demonstrated a mean pairwise percentage sequence divergence of 5.4% while rbcL demonstrated 0.83%. Additionally, at 1% sequence divergence resolution ItS discriminated between 99% of species-pairs while rbcL only discriminated between 26%. The results of my study suggest that ItS should not be completely discounted from the plant DNA barcode debate and rbcL be reevaluated as a proposed universal barcode.

Protium subserratum (Burseraceae) is a neotropical tree species that is comprised of several habitat-specific ecotypes having distinct defense chemical profiles. A previously unknown triterpene, 25,30-dicarboxy-26,27,28,29-tetraacetoxy-10,11,14,15-tetrahydrosqualene, was isolated from P. subserratum young leaf tissue of one ecotype growing in Peru. The structure of 1 was determined by spectroscopic study, including 1 and 2D nuclear magnetic resonance experiments.

Abstract Crude non-volatile oleoresin from Burseraceae species (breu), a non-timber forest product of the Amazon, still lacks methods for its quality control even though its pharmacological activities have been associated to the major triterpenes α-amyrin (αAA), β-amyrin, α-amyrenone, β-amyrenone and lupeol (LU). Its chemical characterization has usually been determined by gas chromatography (GC) using columns with phases of low polarity, which are ineffective in the separation of αAA and LU. The present study aimed to develop a GC method to characterize and quantify triterpenes in commercial breu with good selectivity and resolution. Columns with phases of different polarity (DB-35, DB-1701, DB-17HT and DB-Innowax) were tested, and DB-17HT separated αAA and LU without signal suppression or high retention of other constituents. This column allowed the quantification of breu triterpenes using flame ionization detection and cholesterol as a reference standard. Good similarity between the calibration curves of cholesterol and αAA was verified. Internal and external standardizations led to different (p < 0.05) quantifications, but the latter showed less deviation (RSD ≤ 3%). This work provides a reproducible GC method for the quality control of commercial breu, clearly evidencing the presence of lupeol and allowing the accurate quantification of major triterpenes.

The oleoresin produced by species of genus Protium sp. is rich in alpha and beta-amyrins, two triterpenes with many pharmacogical activities. Considering the need to make the improved obtainment of these products feasible, this study sought to optimize techniques for the extraction and isolation of amyrins from resin. Two methods of extraction (maceration and sonication) with different solvents were compared to direct isolation from crude resin. The isolation of triterpenes was performed by chromatographic columns and the yields of extracts and fractions were analyzed by analysis of variance. The best extraction solvent for amyrins was hexane for both maceration and sonication methods (38.16±2.06% and 37.67±8.21%, respectively). There was no statistical difference between these methods and the direct method (32.05±2.40%). Additionally, the direct method is cheaper and more environmentally friendly. Thus, this study showed that it is possible to obtain a large quantity of amyrins by means of cheap, fast and ecological methods. [ABSTRACT FROM AUTHOR]

Abstract—It is established that a medium with a reduced content of deuterium has no effect on the secondary structure of horseradish peroxidase and bovine serum albumin and caused no conformational changes in the structures of these proteins. The placement of these proteins in a buffer solution prepared based on deuterium-depleted water led to a decrease in the intensity of intrinsic tryptophan fluorescence, while the circular dichroism spectra remained virtually unchanged. A decrease in the content of deuterium in the reaction medium led to a decrease in the activity of the peroxidase oxidation reaction of o-dianisidine and luminal with hydrogen peroxide. [ABSTRACT FROM AUTHOR]

The effect of deuterium-depleted water on oxidative processes in the rat brain under physiological or hypoxic conditions was studied. The results obtained by a tissue culture method that characterize the functional parameters of neurons under stress are also presented. Results on free radical processes in the rat brain tissues demonstrated that consumption of deuterium-depleted water over 2 weeks has a stress effect. The long-term consumption of deuterium-depleted water caused activation of non-specific protective systems. The effect of a saline solution prepared with deuterium-depleted water on a cerebellar tissue culture was also studied. When incubation occurred in a saline solution based on deuterium-depleted water, glucose deprivation and temperature stress (39°C) were found to result in increased cell death in the neuronal culture. The neuron death rates under physiological conditions were similar in the case of both 150 and 50 ppm deuterium. At the same time, the mitochondrial membrane potential of cerebellar neurons decreased in the deuterium-depleted medium. Thus, incubation of cerebellar neurons in the deuterium-depleted saline solution had no cytoprotective effect. [ABSTRACT FROM AUTHOR]

We studied functional changes in rat pituitary—thyroid axis after a short-term shift in deuterium body content. Male Wistar rats consumed deuterium-enriched (500,000 ppm) or deuterium-depleted water (10 ppm) for 24 h. Rats of both experimental groups demonstrated elevated concentration of bound with transport proteins thyroxine and reduced level of thyroid-stimulating hormone in serum. No changes in the rate of thyroxine conversion to triiodothyronine were found. Thus, both the increase and reduction of deuterium body content produced similar changes in the function of the pituitary—thyroid axis with primary affection of the thyroid gland, indicative of its higher sensitivity to shift in deuterium levels. [ABSTRACT FROM AUTHOR]

The Burseraceae are known to comprise one of the most important tree families in Amazonia, but examination of Burseraceae diversity indicates that this importance is achieved differently in different parts of the Amazon, generally showing greater relative density compared to relative diversity in the east and greater relative diversity compared to relative density in the west, but both high relative density and diversity in central Amazonia. The patterns of relative density may be explained by current climates and by soils, but those of diversity are more likely a function of historical events. Revision of the Burseraceae for two projects near Manaus, Brazil revealed four new taxa. Protium hebetatum is widespread in western Amazonia, but it is one of the most common trees in central and west-central Amazonia; it resembles P. grandifolium. Protium tonyanum is a distinctive new species in poorly resolved sect. Sarcoprotium. Protium paniculatum var. modestum is known thus far only from the vicinity of Manaus plus several localities in the state of Amazonas, Venezuela; a key to the varieties is provided. Dacryodes hopkinsii is one of a group of four species in that genus from Amazonia and the Venezuelan Guayana with relatively large and fleshy flowers that are functionally bisexual. The discovery of these new taxa underscores the biological importance of Manaus and vicinity as a center of diversity for many taxa and exemplifies the synergy between well-designed floristic projects and systematics. [ABSTRACT FROM AUTHOR]

Protium cornutum is described and illustrated. This species exemplifies the enormous number of unnamed species languishing in herbaria, as well as the shallowness of our sampling of tropical floras. [ABSTRACT FROM AUTHOR]

Experimental data on single and double shock compression of initially liquid and gaseous (compressed by initial pressure) hydrogen isotopes (protium and deuterium) at pressures of ≈10-180 GPa and temperatures of ≈3000-20 000 K are considered. The mean values of the measured variables (pressure, density, internal energy, and temperature) show that hydrogen at a pressure of ≈41 GPa in the temperature interval of ≈3500-5700 K and at a pressure of ≈74 GPa in the temperature interval of ≈5000-7500 K is characterized by a negative value of the Grüneisen coefficient. Such an anomaly may play a key role in some processes, including those proceeding in the Jupiter gas envelope, which mainly consists of protium (≈90%) and helium (≈10%). In the range of pressures (depths) of its manifestation, convection in the protium envelope is forbidden with an increase in temperature in the envelope with increasing pressure. Possibly, a comparatively low fraction of helium does not suppress the anomaly, and it serves as a barrier for large-scale convection in the Jupiter envelope. Additional refining experiments are required to confirm this anomaly. [ABSTRACT FROM AUTHOR]

• The study of the interaction of hydrogen isotopes with the materials that will make up the fusion reactors is a critical factor. • It is important to be able to relate the parameters of protium, deuterium and tritium. • Classical theory indicates that they are related according to the root of the inverse ratio of their masses. • Some authors confirm this relationship and some authors differ from it, so it is relevant to compile all related studies. • The isotope effect seems to be related to the microstructure of the metals. The characterization of hydrogen transport parameters is essential for a good prediction of its behavior and a correct design of the elements that will make up nuclear fusion reactors. It is therefore essential to determine the isotopic ratio of the transport parameters between protium (H), deuterium (D) and tritium (T), both for economic and safety reasons. Classical theory predicts that the ratio of their diffusivities and permeabilities should be proportional to the inverse square root of their atomic mass, while solubility values would be independent of their masses, but there are discrepancies in the literature. Despite this, it has not yet been possible to obtain either a correct value for the ratio or any uniform conclusion on the matter. This article presents a review of the works published in the field of the isotope effect of hydrogen permeability and diffusivity to date, focusing on protium and deuterium isotopes, which are the isotopes that have been most extensively analyzed experimentally. The conclusion is clear: the theoretical value cannot be stated to be correct and the results are very varied, although they seem to be related to the microstructure of the material tested. In addition, some factors that could have an influence on it have been analyzed, which would be interesting to take into account for future studies. [ABSTRACT FROM AUTHOR]

Protium decorum is described and illustrated. The distribution of this new taxon exemplifies a rather common pattern around the southern periphery of the Amazon. [ABSTRACT FROM AUTHOR]

Catalytic activity of 4–40 nm gold nanoparticles supported on γ-Al 2 O 3 in the reaction of ortho – para conversion of protium has been studied. The results of test indicate that nanoparticles exhibit a high catalytic activity and the rate of reaction, virtually does not depend on the particle size. [ABSTRACT FROM AUTHOR]

When the long term tritium storage is intended, metal hydride materials, particularly the titanium (Ti) beds, seems to be the recommended option, due to its compliance with the criteria of selection (e.g. material cost, stability, storage capacity, loading and unloading conditions, or radioactivity). However few experimental and numerical analyses have been published so far to better support the understanding of the recovery capabilities for different forms of titanium beds. In this work, an investigation on the recovery of different hydrogen isotopes from two types of titanium (Ti) beds, namely Ti powder and Ti sponge, has been performed. Hydrogen isotope release was experimentally verified up to a temperature of 600 °C for both Ti powder and Ti sponge beds. The desorption percentages were determined to be from 24.98 to 20.54 in the case of D 2 on Ti sponge, and from 34.36 to 29.77 in the case of H 2 on Ti sponge. The paper describes in detail the experimental set up, the measurements and the drawn conclusions. [ABSTRACT FROM AUTHOR]

α-Amyrenone and β-amyrenone are triterpenoid isomers that occur naturally in very low concentrations in several oleoresins from Brazilian Amazon species of Protium (Burseraceae). This mixture can also be synthesized by oxidation of α,β-amyrins, obtained as major compounds from the same oleoresins. Using a very simple, high yield procedure, and using a readily commercially available mixture of α,β-amyrins as substrate, the binary compound α,β-amyrenone was synthesized and submitted to physico-chemical characterization using different techniques such as high-performance liquid chromatography, nuclear magnetic resonance (1H and 13C), mass spectrometry, scanning electron microscopy, differential scanning calorimetry, thermogravimetry and derivative thermogravimetry, and Fourier transform infrared spectroscopy (FTIR). Biological effects were also evaluated by studying the inhibition of enzymes involved in the carbohydrate and lipid absorption process, such as α-amylase, α-glucosidase, lipase, and their inhibitory concentration values of 50% of activity (IC50) were also determined. α,β-Amyrenone significantly inhibited α-glucosidase (96.5% ± 0.52%) at a concentration of 1.6 g/mL. α,β-Amyrenone, at a concentration of 100 µg/mL, showed an inhibition rate on lipase with an IC50 value of 82.99% ± 1.51%. The substances have thus shown in vitro inhibitory effects on the enzymes lipase, α-glucosidase, and α-amylase. These findings demonstrate the potential of α,β-amyrenone for the development of drugs in the treatment of chronic metabolic diseases. [ABSTRACT FROM AUTHOR]