Preliminary chemical characterization of ethanolic extracts from Colombian plants with promising anti - Trypanosoma cruzi activity.

Chagas disease is caused by Trypanosoma cruzi, and it is an important cause of morbidity and mortality in Latin America. There are no vaccines, and the chemotherapy available to treat this infection has serious side effects. In a search for alternative treatments, we determined the in vitro susceptibility of epimastigote and trypomastigote forms of T. cruzi and the cytotoxic effects on peripheral blood mononuclear cells (PBMCs) of ethanolic extracts obtained from six different plant species. The ethanolic extracts of Ageratina vacciniaefolia, Clethra fimbriata and Siparuna sessiliflora showed antiprotozoal activity against epimastigotes and low cytotoxicity in mammalian cells. However, only the ethanolic extract of C. fimbriata showed activity against T. cruzi trypomastigotes, and it had low cytotoxicity in PBMCs. An analysis on the phytochemical composition of C. fimbriata extract showed that its metabolites were primarily represented by two families of compounds: flavonoids and terpenoids. Lastly, we analyzed whether the A. vacciniaefolia, C. fimbriata, or S. sessiliflora ethanolic extracts induced IFN-γ or TNF-α production. Significantly, ethanolic extracts of C. fimbriata induced TNF-α production and S. sessiliflora induced both cytokines. In addition, C. fimbriata and S. sessiliflora induced the simultaneous secretion of IFN-γ and TNF-α in CD8+ T cells. The antiprotozoal and immunomodulatory activity of C. fimbriata may be related to the presence of flavonoid and triterpene compounds in the extract. Thus, these findings suggest that C. fimbriata may represent a valuable source of new bioactive compounds for the therapeutic treatment of Chagas disease that combines trypanocidal activity with the capacity to boost the immune response.

Role of the Interchangeable Cations on the Sorption of Fumaric and Succinic Acids on Montmorillonite and its Relevance in Prebiotic Chemistry.

It has been proposed that clays could have served as key factors in promoting the increase in complexity of organic matter in primitive terrestrial and extraterrestrial environments. The aim of this work is to study the adsorption-desorption of two dicarboxylic acids, fumaric and succinic acids, onto clay minerals (sodium and iron montmorillonite). These two acids may have played a role in prebiotic chemistry, and in extant biochemistry, they constitute an important redox couple (e.g. in Krebs cycle) in extant biochemistry. Smectite clays might have played a key role in the origins of life. The effect of pH on sorption has been tested; the analysis was performed by UV-vis and FTIR-ATR spectroscopy, X-ray diffraction and X-ray fluorescence. The results show that chemisorption is the main responsible of the adsorption processes among the dicarboxylic acids and clays. The role of the ion, present in the clay, is fundamental in the adsorption processes of dicarboxylic acids. These ions (sodium and iron) were selected due to their relevance on the geochemical environments that possibly existed into the primitive Earth. Different mechanisms are proposed to explain the sorption of dicarboxylic acids in the clay. In this work, we propose the formation of complexes among metal cations in the clays and dicarboxylic acids. The organic complexes were probably formed in the prebiotic environments enabling chemical processes, prior to the appearance of life. Thus, the data presented here are relevant to the origin of life studies.

High-order dispersion mapping of an optical fiber.

We report on measurements of high-order dispersion maps of an optical fiber, showing how the ratio between the third and fourth-order dispersion (ß3/ß4) and the zero-dispersion wavelength (λ0) vary along the length of the fiber. Our method is based on Four-Wave Mixing between short pulses derived from an incoherent pump and a weak laser. We find that the variations in the ratio ß3/ß4 are correlated to those in λ0. We present also numerical calculations to illustrate the limits on the spatial resolution of the method. Due to the good accuracy in measuring λ0 and ß3/ß4 (10 -3% and 5% relative error, respectively), and its simplicity, the method can be used to identify fiber segments of good uniformity, suitable to build nonlinear optical devices such as parametric amplifiers and frequency comb generators.

Morphological characterization and first molecular identification of the eleven Eimeria species that infect sheep from Mexico.

Within livestock production, enteric diseases play an important role, since they cause severe economic losses due to mortality, growth depression, and reduction in the conversion rate. Coccidiosis caused by Eimeria spp. is a parasitic disease of high morbidity that affects various animal species, including sheep. In sheep, eleven species of Eimeria have been identified mainly through microscopical identification of the oocysts; however, this technique has certain limitations that make it difficult to identify the different Eimeria species. The objective of the present study was to morphologically identify the eleven species of Eimeria that infect sheep in the southeastern region of the State of Mexico, as well as obtain the partial sequence of the ITS-1 rRNA region of each species and analyze it phylogenetically. A total of 412 samples were collected from the 13 municipalities that comprise the region I of the State of Mexico, out of which, 40 had approximately 80% of a single Eimeria species. Among these, the eleven Eimeria species reported in sheep were identified. The phylogenetic analysis showed that the species reported in this study are associated with those reported in rabbits, bovines, and birds. It is suggested that the phylogenetic division of sheep in two clades may be associated with the presence or absence of the residual body. It is proposed that the present methodology can be used effectively for diagnosis and to obtain information about the epidemiology of ovine coccidial infection. The results obtained in this study constitute the first report of the ITS-1 region of the eleven Eimeria species that infect sheep worldwide.

Use of sensor-integrated pump therapy to reduce hypoglycaemia in people with Type 1 diabetes: a real-world study in the UK.

AIMS: To assess the efficacy of insulin pumps with automated insulin suspension systems in a real-world setting. METHODS: We analysed anonymized data uploaded to CareLink™ by people (n=920) with Type 1 diabetes using the MiniMed Paradigm Veo system and the MiniMed 640G system (Medtronic International Trading Sàrl, Tolochanez, Switzerland) with SmartGuard technology, with or without automated insulin suspension enabled, between February 2016 and June 2018. Users with ≥15 days of sensor data and ≥70% sensor-wear time were classified as sensor-augmented pump alone, sensor-integrated pump with low glucose suspend enabled or sensor-integrated pump with predictive low glucose management enabled. RESULTS: The median (25th -75th percentile) system use was 161 (58-348) days. The median time spent with sensor glucose values ≤3 mmol/l was 0.8 (0.3-1.7)% in the sensor-augmented pump group, 0.3 (0.1-0.7)% in the sensor-integrated pump with low glucose suspend group, and 0.3 (0.1-0.5)% in the sensor-integrated pump with predictive low glucose management group. In individuals switching from sensor-augmented pump to sensor-integrated pump with low glucose suspend (n=31), there were significant reductions in the monthly rate of hypoglycaemic events <3 mmol/l (rate ratio 0.63, 95% CI 0.45-0.89; P=0.009) and in the percentage of time with glucose values ≤3 mmol/l [sensor-augmented pump: 0.63% (95% CI 0.34-1.29), sensor-integrated pump with low glucose suspend: 0.33% (95% CI 0.16-0.64); P=0.001]. The monthly rate of hypoglycaemic events decreased further in individuals (n=139) switching from sensor-integrated pump with low glucose suspend to sensor-integrated pump with predictive low glucose management [rate ratio 0.82 (95% CI 0.69-0.98); P<0.0274]. Similar results were seen for events <3.9 mmol/l. There was no difference in median time spent in target glucose range. CONCLUSION: Real-world UK data show that increasing automation of insulin suspension reduces hypoglycaemia exposure in people with Type 1 diabetes.

Single nucleotide polymorphisms associated with nonsyndromic cryptorchidism in Mexican patients.

Cryptorchidism is a frequent genitourinary malformation considered as an important risk factor for infertility and testicular malignancy. The aetiology of cryptorchidism is multifactorial in which certain SNPs, capable of inhibiting the development of the gubernaculum, are implicated. We analysed 16 SNPs by allelic discrimination and automated sequencing in 85 patients and 99 healthy people, with the objective to identify the association between these variants and isolated cryptorchidism. In two different patients with unilateral cryptorchidism, we found the variants rs121912556 and p.R105R of INSL3 gene in a heterozygous form associated with cryptorchidism, so we could considered them as risk factors for cryptorchidism. On the other hand, SNPs rs10421916 of INSL3 gene, as well as the variants rs1555633 and rs7325513 in the RXFP2 gene, and rs3779456 variant of the HOXA10 gene were statistically significant, when the patients and controls were compared and could be considered as protective factors since are predominantly present in controls. The genotype-phenotype correlation did not show statistical significance. With these results, we could conclude that these polymorphisms can be considered as important variants in our population and would contribute in the future knowledge of the aetiology and physiopathology of cryptorchidism.

Hadamard circular masks: high focal depth with high throughput.

We present a class of binary masks that encode, in polar coordinates, the values of a Hadamard matrix of order N. For order N ≥ 2, the binary masks increase the Strehl ratio vs. focus error by the factor N, with the highest possible light throughput. Since a Strehl ratio with high tolerance to defocus does not guarantee a modulation transfer function (MTF) with low sensitivity to focus errors, then, we show that for N = 16 the binary mask reduces also the impact of focus error on the MTF. Equivalently, the discrete binary mask has Fisher information with low variations to defocus.

Neonatal respiratory syncytial virus infection has an effect on lung inflammation and the CD4(+) CD25(+) T cell subpopulation during ovalbumin sensitization in adult mice.

In BALB/c adult mice, respiratory syncytial virus (RSV) infection enhances the degree of lung inflammation before and/or after ovalbumin (OVA) respiratory sensitization. However, it is unclear whether RSV infection in newborn mice has an effect on the immune response to OVA respiratory sensitization in adult mice. The aim of this study was to determine if RSV neonatal infection alters T CD4(+) population and lung inflammation during OVA respiratory sensitization in adult mice. BALB/c mice were infected with RSV on the fourth day of life and challenged by OVA 4 weeks later. We found that in adult mice, RSV neonatal infection prior to OVA sensitization reduces the CD4(+) CD25(+) and CD4(+) CD25(+) forkhead protein 3 (FoxP3)(+) cell populations in the lungs and bronchoalveolar lavage. Furthermore, it also attenuates the inflammatory infiltrate and cytokine/chemokine expression levels in the mouse airways. In conclusion, the magnitude of the immune response to a non-viral respiratory perturbation in adult mice is not enhanced by a neonatal RSV infection.

Sustained efficacy of insulin pump therapy compared with multiple daily injections in type 2 diabetes: 12-month data from the OpT2mise randomized trial.

AIMS: To compare insulin pump therapy and multiple daily injections (MDI) in patients with type 2 diabetes receiving basal and prandial insulin analogues. METHODS: After a 2-month dose-optimization period, 331 patients with glycated haemoglobin (HbA1c) levels ≥8.0% and ≤12% were randomized to pump therapy or continued MDI for 6 months [randomization phase (RP)]. The MDI group was subsequently switched to pump therapy during a 6-month continuation phase (CP). The primary endpoint was the between-group difference in change in mean HbA1c from baseline to the end of the RP. RESULTS: The mean HbA1c at baseline was 9% in both groups. At the end of the RP, the reduction in HbA1c was significantly greater with pump therapy than with MDI (-1.1 ± 1.2% vs -0.4 ± 1.1%; p < 0.001). The pump therapy group maintained this improvement to 12 months while the MDI group, which was switched to pump therapy, showed a 0.8% reduction: the final HbA1c level was identical in both arms. In the RP, total daily insulin dose (TDD) was 20.4% lower with pump therapy than with MDI and remained stable in the CP. The MDI-pump group showed a 19% decline in TDD, such that by 12 months TDD was equivalent in both groups. There were no differences in weight gain or ketoacidosis between groups. In the CP, one patient in each group experienced severe hypoglycaemia. CONCLUSIONS: Pump therapy has a sustained durable effect on glycaemic control in uncontrolled type 2 diabetes.

Routine use of continuous glucose monitoring in 10 501 people with diabetes mellitus.

AIMS: To analyse blood glucose control according to continuous glucose monitoring use in data from the CareLink database, and to identify factors associated with continuation of sensor use during sensor-augmented pump therapy. METHODS: The analysis used data from 10 501 people with Type 1 and 2 diabetes mellitus, of whom 7916 (61.7%) had used glucose sensors for ≥ 15 days during any 6-month period over a 2-year observation period. Data were analysed according to the extent of sensor use ( < 25%, 25-49%, 50-74% and ≥ 75% of the time). Time to discontinuation of sensor use was also analysed in new users of glucose sensors. RESULTS: Compared with patients in the lowest sensor usage group and non-users, the highest glucose sensor usage group had significantly (P < 0.0001) lower mean blood glucose and blood glucose sd, were more likely to achieve a mean blood glucose concentration < 8.6 mmol/l, (odds ratio 1.5, 95% CI 1.3-1.7; P < 0.0001), and had 50% fewer hypoglycaemic (blood glucose concentration < 2.8 mmol/l) episodes. Among new users, sensor use during the first month of therapy was an important predictor of subsequent discontinuation. Lack of full reimbursement was also significantly associated with early discontinuation, whereas measures of glycaemic control were predictive of discontinuation during long-term treatment. CONCLUSIONS: The use of continuous glucose monitoring was significantly associated with reductions in hypoglycaemia and improved metabolic control during insulin pump therapy. Sensor use during the first month was strongly associated with long-term adherence; patient education and training may be helpful in achieving this.

Screening of Lactobacillus strains for their ability to produce conjugated linoleic acid in milk and to adhere to the intestinal tract.

Conjugated linoleic acid (CLA) has been shown to provide beneficial effects on health; however, the amount consumed in food is far from that required for the desired effects. Thus, increasing the CLA content in dairy foods through milk fermentation with specific lactic acid bacteria (LAB) offers an interesting alternative. Moreover, some LAB may be able to adhere to the intestinal mucosa and produce CLA through endogenous synthesis. Therefore, the objective of this study was to screen LAB isolates for their ability to produce CLA in skim milk and in simulated gastrointestinal conditions. Additionally, the ability of selected CLA-producing LAB to adhere to the intestinal mucosa in a murine model was assessed. Results showed that of 13 strains of Lactobacillus tested, only 4 were able to produce CLA in skim milk supplemented with linoleic acid (13.44 ± 0.78 to 50.9 ± 0.26 µg/mL). Furthermore, these 4 Lactobacillus strains were able to survive and produce CLA in simulated gastrointestinal conditions and to adhere to the intestinal mucosa of Wistar rats after 7 d of oral inoculation with fluorescently labeled bacteria. Accordingly, these 4 Lactobacillus strains may be used to manufacture fermented dairy foods to increase CLA content, and consumption of these fermented milks may result in CLA produced endogenously by these LAB.

Vitamin E protection of obesity-enhanced vascular calcification in uremic rats.

This study aimed to determine the extent of extraskeletal calcification in uremic Zucker rats, by comparing obese and lean phenotypes, and to evaluate the influence of vitamin E (VitE) on the development of calcifications in both uremic rats and human vascular smooth muscle cells (HVSMCs) cultured in vitro. Zucker rats of lean and obese phenotypes with normal renal function [control (C); C-lean and C-obese groups] and with uremia [5/6 nephrectomy (Nx); Nx-lean and Nx-obese groups] and uremic rats treated with VitE (Nx-lean + VitE and Nx-obese + VitE groups) were studied. Uremic groups were subjected to Nx, fed a 0.9% phosphorus diet, and treated with calcitriol (80 ng/kg ip). The aortic calcium concentration was significantly higher (P < 0.05) in Nx-obese rats (10.0 ± 2.1 mg/g tissue) than in Nx-lean rats (3.6 ± 1.3 mg/g tissue). A decrease in plasma glutathione peroxidase activity was observed in Nx-obese rats compared with Nx-lean rats (217.2 ± 18.2 vs. 382.3 ± 15.5 nmol·min(-1)·ml(-1), P < 0.05). Treatment with VitE restored glutathione peroxidase activity and reduced the aortic calcium concentration to 4.6 ± 1.3 mg/g tissue. The differences in mineral deposition between Nx-lean, Nx-obese, Nx-lean + VitE, and Nx-obese + VitE rats were also evidenced in other soft tissues. In HVSMCs incubated with high phosphate, VitE also prevented oxidative stress and reduced calcium content, bone alkaline phosphatase, and gene expression of core-binding factor-α1. In conclusion, uremic obese rats develop more severe calcifications than uremic lean rats and VitE reduces oxidative stress and vascular calcifications in both rats and cultures of HVSMCs.

Infertility in rats subjected to genitofemoral nerve section is not associated with testicular damage.

This work was aimed at assessing the relationship between testicular ascent and infertility induced by genitofemoral nerve (GFN) section in rats. Eighteen male rats were assigned to three experimental groups as follows: (i) Group SGFN was subjected to surgical section of genitofemoral nerve; (ii) Group Sham; (iii) Control group. The GFN was cut at puberty (28D), and the contralateral testis removed at 90D, with fertility tests at 120D. At 150D, maturity index, epithelial area and histopathological index of seminiferous tubules of all rats were determined and statistically compared between superior and inferior testicle poles, and between groups. There were no differences in testicular parameters, sperm morphology or sperm concentrations (P > 0.05). Section of NGF interfered with fertility (58.3 ± 15.4 in SGFN versus 83.3 ± 10.5 in Sham) and litter size (6.2 ± 1.1 in SGFN versus 10.7 ± 1.4 in Sham). Cremaster of SGFN group showed early neuropathy. The GFN section induced partial testicular ascent and diminished fertility without damage on testicular morphology or spermatic parameters, because, cremaster could affect the contractibility and ejaculation mechanisms in which it participates. The study of the damage on cremaster induced by an injury on GFN could have an overview of the mechanisms inherent in the testicular ascent induced by this iatrogenic alteration and their potential risks on fertility.

Synthesis, photo- and thermo-luminescent properties of Mg2P2O7:Tm3+ phosphors.

In this work, both undoped and Thulium (Tm3+) doped (0.3-10 mol%) magnesium pyrophosphate (Mg2P2O7) powders were synthesized by the solvent evaporation method to study their photo-and thermoluminescent properties. Two crystalline phases were observed in the powders by X-Ray diffraction (XRD), the main phase being Mg2P2O7 and the second one thulium phosphate (TmPO4). The superficial morphology was analyzed by scanning electron microscopy (SEM), which revealed that the powders are agglomerates with an undefined form and grains with non-uniform size distribution. The photoluminescence (PL) emission spectra of Tm3+ doped powders show the 1D2 → 3F4 transition, associated with Tm3+ ions, at 452 and 458 nm. The thermoluminescence (TL) properties were analyzed in the undoped and Tm3+ doped powders exposed to 90Sr beta source. The TL glow curve of Tm3+ doped powders exhibits three maxima at about ⁓64-66 °C, ⁓198-202 °C, and ⁓301 °C. The TL dose-response is sub-linear from 0.11 to 0.54 Gy, linear between 0.79 and 24.95 Gy, and supra-linear from 34.99 to 599.95 Gy. Acceptable repeatability with a coefficient of variation of ∼1% was obtained after ten cycles of irradiation and readout. At 63 d of storage, the powders show fading of 30%, and at 1.6 years (585 d), the integrated TL intensity decays by 47%. The kinetic parameters of activation energy and frequency factor were evaluated using the Initial Rise, Booth, Bohun, and Porfianovitch (BBP) and Hoogenstraaten methods and Glow Curve Deconvolution with a general order kinetic model.

Translation, validation, and cultural adaptation of the HSS-ES scale (Hospital for Special Surgery's [HSS] Shoulder Surgery Expectations Survey). / Traducción, adaptación cultural y validación del cuestionario HSS-ES (Hospital for Special Surgery [HSS] Shoulder Surgery Expectations Survey).

INTRODUCTION: The questionnaire Hospital for Special Surgery Shoulder Surgery Expectations Survey (HSS-ES) is a tool used to assess the preoperative expectations of patients with shoulder pathologies. The purpose of this study is to translate, culturally adapt, and validate the Spanish version of the HSS-ES questionnaire to assess preoperative expectations in Spanish-speaking patients. METHODOLOGY: Questionnaire validation study, using a structured method where a survey-type tool was processed, evaluated and validated. The study involved 70 patients from the shoulder surgery outpatient clinic of a tertiary care hospital, with shoulder pathologies requiring surgery. RESULTS: The version of the questionnaire translated into Spanish presented a very good internal consistency with a Cronbach's Alpha of 0.94 and a very good reproducibility with an Intraclass Correlation Coefficient (ICC) of 0.99. CONCLUSION: The HSS-ES questionnaire presents an adequate intragroup validation and a strong intergroup correlation according to the internal consistency analysis of the questionnaire and the ICC. Therefore, it is considered an adequate questionnaire to use in the Spanish-speaking population.

[Translated article] Translation, validation, and cultural adaptation of the HSS-ES scale (Hospital for Special Surgery's [HSS] Shoulder Surgery Expectations Survey).

INTRODUCTION: The questionnaire Hospital for Special Surgery Shoulder Surgery Expectations Survey (HSS-ES) is a tool used to assess the preoperative expectations of patients with shoulder pathologies. The purpose of this study is to translate, culturally adapt, and validate the Spanish version of the HSS-ES questionnaire to assess preoperative expectations in Spanish-speaking patients. METHODOLOGY: Questionnaire validation study, using a structured method where a survey-type tool was processed, evaluated and validated. The study involved 70 patients from the shoulder surgery outpatient clinic of a tertiary care hospital, with shoulder pathologies requiring surgery. RESULTS: The version of the questionnaire translated into Spanish presented a very good internal consistency with a Cronbach's Alpha of 0.94 and a very good reproducibility with an Intraclass Correlation Coefficient (ICC) of 0.99. CONCLUSION: The HSS-ES questionnaire presents an adequate intragroup validation and a strong intergroup correlation according to the internal consistency analysis of the questionnaire and the ICC. Therefore, it is considered an adequate questionnaire to use in the Spanish-speaking population.

[Translated article] Relationship between low lying peroneus brevis muscle belly and peroneal tendons dislocation.

INTRODUCTION: Peroneal tendon pathologies are an important cause of pain in the lateral aspect of the ankle. It has been proposed in the literature that low lying peroneus brevis muscle belly occupies more space in the retromalleolar groove and could cause laxity of the superior retinaculum which would promote tendon dislocation, tenosynovitis or ruptures. The objective of the study is to characterise the population with low lying peroneus brevis muscle belly and determine the association between the low lying peroneus brevis muscle belly found on magnetic resonance imaging and clinical peroneal tendon dislocation. METHODS: A case-control study was developed with a sample of 103 patients. The cases were patients with low lying peroneus brevis muscle belly and peroneal dislocation and the controls were patients with normal implantation of the peroneus brevis muscle and peroneal tendon dislocation. RESULTS: The prevalence of clinical peroneal dislocation in patients with low implantation of the peroneal brevis muscle belly was 7.64%, and the prevalence of clinical peroneal dislocation in patients with normal implantation of the peroneus brevis muscle belly was 8.88%. The OR was 0.85 (CI 0.09-7.44, p=0.88). DISCUSSION: Our findings indicate that there is no statistically significant relationship between low lying peroneus brevis muscle belly and clinical dislocation of the peroneal tendons.

Relationship between low lying peroneus brevis muscle belly and peroneal tendons dislocation. / Relación entre implantación baja del vientre muscular del peroneo corto y luxación de los tendones peroneos.

INTRODUCTION: Peroneal tendon pathologies are an important cause of pain in the lateral aspect of the ankle. It has been proposed in the literature that low lying peroneus brevis muscle belly occupies more space in the retromalleolar groove and could cause laxity of the superior retinaculum which would promote tendon dislocation, tenosynovitis or ruptures. The objective of the study is to characterize the population with low lying peroneus brevis muscle belly and determine the association between the low lying peroneus brevis muscle belly found on magnetic resonance imaging and clinical peroneal tendon dislocation. METHODS: A case-control study was developed with a sample of 103 patients. The cases were patients with low lying peroneus brevis muscle belly and peroneal dislocation and the controls were patients with normal implantation of the peroneus brevis muscle and peroneal tendon dislocation. RESULTS: The prevalence of clinical peroneal dislocation in patients with low implantation of the peroneal brevis muscle belly was 7.64%, and the prevalence of clinical peroneal dislocation in patients with normal implantation of the peroneus brevis muscle belly was 8.88%. The OR was 0.85 (CI 0.09-7.44, P=0.88). DISCUSSION: Our findings indicate that there is no statistically significant relationship between low lying peroneus brevis muscle belly and clinical dislocation of the peroneal tendons.

Thermoluminescence properties and identification of irradiated cocoa beans during long-term storage.

This work reports on the thermoluminescence (TL) properties and detection of contaminating minerals isolated from Mexican cocoa beans irradiated with gamma radiation and stored for 4 years. Contaminating minerals isolated from cocoa beans consisting of quartz, diopside, plagioclase, albite, and iron oxide with irregular and rectangular grains and average length of 135 µm. Cocoa beans are detected as irradiated even after 4 years of storage using the shape and maximum temperature of the TL glow curve of contaminating minerals. The TL properties of dose-response, and fading of minerals were also analysed. The TL dose-response is linear from 5 to 100 Gy, supra-linear between 250 and 1000 Gy, and sub-linear above 1500 Gy. Based on the TL1/TL2 ratio the minerals are identified as irradiated from 250 Gy to 4500 Gy in the dose-response test and after different storage times in the darkness at room temperature. A continuum trap distribution can be associated with the TL glow curve of minerals using the Tm-Tstop method. First order kinetic peaks were used in the Glow Curve Deconvolution of natural and irradiated (1 and 10 kGy) TL curves.

Gamma irradiation of adenine and guanine adsorbed into hectorite and attapulgite.

This study focuses on the radiolysis (up to 36 kGy) of guanine and adenine (nitrogenous bases) adsorbed in hectorite and attapulgite to highlight the potential role of clays as protective agents against ionizing radiation in prebiotic processes. In this framework, the study investigated the nitrogenous bases' behavior in two types of systems: a) aqueous suspension of adenine-clay systems and b) guanine-clay systems in the solid state. This research utilized spectroscopic and chromatographic techniques for its analytical purposes. Regardless of the reaction medium conditions, the results reveal that nitrogenous bases are stable under ionizing irradiation when adsorbed on both clays.