Two low-temperature geothermal systems located at the Trans-Mexican Volcanic Belt with presence of fluoride and arsenic were studied with the aim to determine hydrogeochemical indicators of the toxic ...elements' presence, and to propose adequate geothermometers. The hydrogeological and geochemical study was carried out in Ixtapan de la Sal and Tonatico (IxS-T) and Santa Cruz de Juventino Rosas (JR), both located at the limits of the Trans-Mexican Volcanic Belt (TMVB). In these regions, low-temperature geothermal activity is present (T=32–47°C), and various fault and fracture systems have been identified. Several faults are active, enabling the upward flow of deep geothermal water. The geothermal waters of IxS-T manifest in the form of springs and have high Na+ and Cl− concentrations, whereas those of JR are captured in wells and mainly present high Na+ and HCO3– concentrations. The hydrochemistry of water samples was analyzed to determine the dominant hydrogeochemical processes in both regions. These data were also useful for understanding the natural origin of the high levels of arsenic and fluoride reported in the water, which are likely due to mineral dissolution processes. The concentrations of these elements surpassed the permissible limits according to Mexican law (Astot=0.025mg/L; F−=1.5mg/L) and represent a toxicity risk for the local populations. The groundwater at JR supplies all needs of the local population, while the water at IxS-T is mainly used for recreational and health spa purposes. Increasing trends of As and F− in the sedimentary aquifer of IxS-T are related with the increase in TDS, Cl−, HCO3– and SiO2, while silicate alteration releasing Na and HCO3– are related with As and F− presence in the volcanic aquifer of JR. Reservoir temperature was adequately estimated with K2/Mg and Na-K-Ca (Mg corrected) geothermometers at IxS-T, and with chalcedony and quartz geothermometers at JR.
•Two low-temperature geothermal systems located at the Trans-Mexican Volcanic Belt shows presence of fluoride and arsenic.•Increasing trends of As and F- in the sedimentary aquifer of IxS-T are related with the increase in TDS, Cl-, HCO3- and SiO2, while silicate alteration releasing Na and HCO3- are related with As and F- presence in the volcanic aquifer of JR.•Reservoir temperature was adequately estimated with K2/Mg and Na-K-Ca (Mg corrected) geothermometers at IxS-T, and with chalcedony and quartz geothermometers at JR.
•Thermal springs from the eastern Trans-Mexican Volcanic Belt were studied•Three water types were identified: Na-Cl, Na-Ca-SO4-HCO3, and Na-HCO3.•High concentrations of B, Li, As, and F− were ...detected.•The presence of geothermal brine and rock-water processes control water chemistry•The geothermometry indicates reservoir temperatures between 90 and 190°C.
This study was aimed at investigating the hydrogeochemical and isotopic characteristics of low-temperature hydrothermal springs in six study sites located in the eastern portion of the Trans-Mexican Volcanic Belt, in order to evaluate the source of the thermal water, rock-water interactions, and reservoir temperature. In addition, based on this, possible similarities and differences among these thermal springs were explored. Samples of thermal waters (12 samples) and non-thermal waters (6 samples) were collected during dry and rainy seasons. Stable isotopes (18O, 2H) as well as major, minor, and trace ions were analyzed for, and saturation indices and reservoir temperatures were estimated. Thermal water temperatures ranged from 33 to 55°C and the pH was slightly acid (and slightly basic in only one case). The electrical conductivity ranged widely, from 0.2 to 27 mS/cm, although most samples had > 8 mS/cm. Using a Piper diagram, three hydrochemical facies were identified: Na-Cl, Na-Ca-SO4-HCO3, and Na-HCO3. The notable minor and trace elements and ions were B, Li, As, and F− . δ18O and δ2H values plot very close to the meteoric water line, although samples from three of the study sites showed a possible isotope exchange between water and minerals at high temperatures. By estimating reservoir temperatures using solute geothermometers and saturation indices, it was possible to determine similarity among the values obtained (90 to 190°C). These data indicate that the hydrochemistry of the thermal waters reflects a water source that is related to geothermal brines in some cases, and with the mixing of a thermal fluid and a recently infiltrated water in other cases, as well as water-rock interactions (mostly with silicates) and carbonate precipitation.
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To evaluate the hydrogeochemical processes related to the presence, mobility, and transport of uranium and thorium in the southeastern Sierra de Guanajuato of the Bajio Guanajuatense, Mexico, the ...concentration of these elements in volcanic rocks and in groundwater were determined. Acidic volcanic rocks contained uranium concentrations of 1.04–6.88 ppm and thorium concentrations of 3.13–15.58 ppm. A basalt rock sample contained 2.58 and 4.07 ppm of uranium and thorium, respectively, and an andesite rock sample contained 4.07 and 8.7 ppm of uranium and thorium, respectively. Scanning electron microscopy with energy-dispersive X-ray spectroscopy showed that U and Th are disseminated throughout the matrix of felsic rocks; in addition, phosphate minerals (probably monazite) containing both elements are present. The concentration of uranium in water samples ranged from 2.23 to 10.3 ppb and of thorium ranged from 0.33 to 0.39 ppb. Geochemical modeling indicated that uranium was mobilized through the transport of the uranyl ions (UO
2
2+
) and their complexes, especially carbonates, although other elements such as Fe, Mg, HCO
3
, and Ca could also be involved in the mobility and transportation of uranium. The obtained results suggest that the mobilization of thorium is very low, almost negligible in some cases, so this element did not present a quantifiable hydrogeochemical pattern. In spite of the low concentrations of U and Th, the existence of high radon concentrations in several samples indicates that additional radioactive species could be naturally present in the hydrogeological environment.
The intensive use of the Aquifer of the Metropolitan Zone of Mexico City (AMZMC) has increased the concentrations of some trace elements due to natural or anthropogenic sources, as the release of ...elements from the heterogeneous mixture of the volcanic rocks and/or alluvial clay deposits, which play a very important hydrogeological role in the behavior of the aquifer. This study characterizes, examines, and compares the concentrations of Ba, B, Sr, and Rb in some wells of the AMZMC. Characterization of major elements and Ba, B, Sr concentration and their behavior in the aquifer, and some ionic ratios have been used to identify the dominant hydrogeochemical processes and the different sources of Rb, Ba, B, Sr in the water, in which mineral alteration, ion exchange, redox reactions are the dominant processes, and may intensify as the salinity, temperature and ionic strength in the medium increases. This information may be indirectly relevant as a contribution to the development of appropriate water management strategies in Mexico City. In addition to providing new data on the distribution and behavior of Rb, Ba, B, Sr in groundwater of the Mexico City Aquifer, which is used for drinking water supply.
•The aquifer located in a fractured volcanic environment has natural Ba, B, Sr and Rb high contents.•Ba, B, Sr and Rb mobilization is consequence to hydrogeochemical reactions such as ion exchange, silicate weathering, carbonate dissolution and redox reactions that take place at depth.•The cationic exchange affects Ca and Sr concentrations, when increase the salinity and ionic strength by an increase in Cl-.•The behavior of Ba, Sr, B, Rb and K can decrease and increase due to redox conditions and pH in the aquifer.
A hydrogeochemical and isotopic study was conducted in the western portion of the Celaya Valley Aquifer, Mexico, to assess the role of dissolved carbon dioxide in groundwater contamination. The ...partial pressure of carbon dioxide value is used to evaluate a complex hydrogeochemical environment, and the carbon dioxide behavior is used to identify the natural and anthropogenic processes related to pollution sources in a thermal aquifer located in the western portion of the Celaya Valley Aquifer. Results indicate that during groundwater migration from the recharge zone to the center of the basin, a hydrogeochemical evolution from calcium bicarbonated and calcium–bicarbonate–chloride type to sodium–bicarbonate type occurs. During this process, deep fluids that migrate through the fault system interact with the aquifer; these fluids contain carbon dioxide released from the metamorphism of the carbonated basement, although another source is not discarded as the dissolved inorganic carbon typical of meteoric groundwater produced from atmospheric carbon dioxide. The hydrogeochemical and isotopic evidences of delta carbon thirteen, delta oxygen eighteen and delta deuterium indicate that the dissolved content of carbon dioxide in the aquifer is involved in the silicate weathering process that plays a major role during water type evolution. In some cases, during weathering, potentially toxic elements are released in amounts that represent an environmental risk, among which arsenic and fluoride stand out, mainly in depth wells. Additionally, other isotopic and hydrogeochemical evidence indicates a biological source of carbon dioxide in the shallow aquifer, primarily due to the agricultural activity carried out in the entire study area.
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Diabetic neuropathy (DN) encompasses a group of clinical or subclinical manifestations involving a dysfunction in the peripheral nervous system. The cause of the dysfunction is the development of ...microvascular complications related to diabetes, a disease that affects about 381 million people worldwide. Approximately 50% of patients currently diagnosed with diabetes are expected to manifest DN in the next 10 years. The diagnosis can be made clinically by establishing a good patient history and delving into the symptoms to rule out other etiologies. Treatment of DN focuses on glycemic control and the use of medications to reduce pain, including NSAIDs, antidepressants and antiepileptic drugs. The pathogenesis is of multifactorial origin, associated with various metabolic, vascular, inflammatory and neurodegenerative disorders. The three fundamental cellular alterations participating in the development of DN are chronic inflammation, endothelial dysfunction and oxidative stress. Since the combination of all three is capable of giving rise to nerve ischemia and direct axonal injury, these factors play a key role in the development of polyneuropathy. However, neuronal and microvascular changes do not occur in the same way in all patients with DN, some of whom have no detectable blood abnormalities.
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Background The association between the administration of sodium–glucose cotransporter 2 inhibitors (SGLT2is) during acute kidney injury (AKI) and the incidence of major adverse kidney events (MAKEs) ...is not known. Methods This retrospective cohort study included patients with AKI and compared the outcomes for those who were treated with SGLT2is during hospitalization and those without SGLT2i treatment. The associations of SGLT2i use with MAKEs at 10 and 30–90 days, each individual MAKE component, and the pre-specified patient subgroups were analyzed. Results From 2021 to 2023, 374 patients were included in the study—316 without SGLT2i use and 58 with SGLT2i use. Patients who were treated with SGLT2is were older; had a greater prevalence of diabetes, hypertension, chronic heart failure, and chronic kidney disease; required hemodialysis less often; and presented stage 3 AKI less frequently than those who were not treated with SGLT2is. Logistic regression analysis with nearest-neighbor matching revealed that SGLT2i use was not associated with the risk of MAKE10 (OR 1.08 0.45–2.56) or with MAKE30–90 (OR 0.76 0.42–1.36). For death, the stepwise approach demonstrated that SGLT2i use was associated with a reduced risk (OR 0.08; 0.01–0.64), and no effect was found for kidney replacement therapy (KRT). The subgroups of patients who experienced a reduction in the risk of MAKEs in patients with AKI treated with SGLT2is were those older than 61 years, those with an eGFR >81, and those without a history of hypertension or DM ( p ≤ 0.05 for all). Conclusion The use of SGLT2is during AKI had no effect on short- or medium-term MAKEs, but some subgroups of patients may have experienced benefits from SGLT2i treatment.
Abstract Under the recently adopted Kunming‐Montreal Global Biodiversity Framework, 196 Parties committed to reporting the status of genetic diversity for all species. To facilitate reporting, three ...genetic diversity indicators were developed, two of which focus on processes contributing to genetic diversity conservation: maintaining genetically distinct populations and ensuring populations are large enough to maintain genetic diversity. The major advantage of these indicators is that they can be estimated with or without DNA‐based data. However, demonstrating their feasibility requires addressing the methodological challenges of using data gathered from diverse sources, across diverse taxonomic groups, and for countries of varying socio‐economic status and biodiversity levels. Here, we assess the genetic indicators for 919 taxa, representing 5271 populations across nine countries, including megadiverse countries and developing economies. Eighty‐three percent of the taxa assessed had data available to calculate at least one indicator. Our results show that although the majority of species maintain most populations, 58% of species have populations too small to maintain genetic diversity. Moreover, genetic indicator values suggest that IUCN Red List status and other initiatives fail to assess genetic status, highlighting the critical importance of genetic indicators.
Mexico's 2009 "narcomenudeo reform" decriminalized small amounts of drugs, shifting some drug law enforcement to the states and mandating drug treatment diversion instead of incarceration. Data from ...Tijuana suggested limited implementation of this harm reduction-oriented policy. We studied whether a police education program (PEP) improved officers' drug and syringe policy knowledge, and aimed to identify participant characteristics associated with improvement of drug policy knowledge.
Pre- and post-training surveys were self-administered by municipal police officers to measure legal knowledge. Training impact was assessed through matched paired nominal data using McNemar's tests. Multivariable logistic regression was used to identify predictors of improved legal knowledge, as measured by officers' ability to identify conceptual legal provisions related to syringe possession and thresholds of drugs covered under the reform.
Of 1750 respondents comparing pre- versus post training, officers reported significant improvement (p < 0.001) in their technical understanding of syringe possession (56 to 91%) and drug amounts decriminalized, including marijuana (9 to 52%), heroin (8 to 71%), and methamphetamine (7 to 70%). The training was associated with even greater success in improving conceptual legal knowledge for syringe possession (67 to 96%) (p < 0.001), marijuana (16 to 91%), heroin (11 to 91%), and methamphetamine (11 to 89%). In multivariable modeling, those with at least a high school education were more likely to exhibit improvement of conceptual legal knowledge of syringe possession (adjusted odds ratio aOR 2.6, 95% CI 1.4-3.2) and decriminalization for heroin (aOR 2.7, 95% CI 1.3-4.3), methamphetamine (aOR 2.2, 95% CI 1.4-3.2), and marijuana (aOR 2.5, 95% CI 1.6-4).
Drug policy reform is often necessary, but not sufficient to achieve public health goals because of gaps in translating formal laws to policing practice. To close such gaps, PEP initiatives bundling occupational safety information with relevant legal content demonstrate clear promise. Our findings underscore additional efforts needed to raise technical knowledge of the law among personnel tasked with its enforcement. Police professionalization, including minimum educational standards, appear critical for aligning policing with harm reduction goals.
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