BTX (benzene, ethylbenzene, toluene and p-xylene) and meteorological parameters were measured in ambient air of an urban site located in Carmen City, Campeche, Mexico. A total of 412 samples were collected for BTX and...BTX (benzene, ethylbenzene, toluene and p-xylene) and meteorological parameters were measured in ambient air of an urban site located in Carmen City, Campeche, Mexico. A total of 412 samples were collected for BTX and analyzed by Gas Chromatography with Flame Ionization Detection (GC-FID). Meteorological parameters were measured by a portable station. A marked diurnal variation was found for all measured BTX. The highest concentrations occurred during midday (13:00-14:30 h). A clear seasonal pattern was observed too for all compounds registering their highest levels during summer sampling period. Mean concentrations for benzene, ethylbenzene, toluene and p-xylene were: 5.42, 3.97, 11.24 and 8.32 ppbv, respectively. BTX abundance showed the following order: toluene > p-xylene > benzene > ethylbenzene. BTX maximum concentrations were found when winds blowed from E and NE. Important oil industry sources and avenues are located at these directions. These sources could contribute to the levels of BTX in this site.展开更多
Two hundred and seven rain events from April to October 2012 were collected in Carmen Island, Campeche, Mexico, and the concentration of 8 major ions with the pH of the rainwater was analyzed. Chemical composition var...Two hundred and seven rain events from April to October 2012 were collected in Carmen Island, Campeche, Mexico, and the concentration of 8 major ions with the pH of the rainwater was analyzed. Chemical composition variations as a result of seasonal patterns, meteorological conditions, and mixed local and regional sources contribution were assessed. In spite of the fact that nitrate and sulfate levels were higher than background hemispheric values, the average pH values were almost neutral. Carmen Island was under the influence of both, local and long-range transported emissions. Chemical composition showed a dilution effect as a result of the monthly rainfall amount. Ca2+ and Na+ were the most abundant ions, and these ions acted as acid neutralizers and buffered the acidity of the rain, suggesting that marine and crustal aerosols played an important role in the acid-base interactions. Wet deposition fluxes obtained were compared with reference values proposed as critical loads, fluxes obtained in this study did not exceed the critical values reported for sensitive ecosystems in Europe, indicating that this site has yet enough capacity to support acidity, nitrogen and sulfur deposition. However, it is necessary to obtain reference values characteristics for tropical regions.展开更多
Resonant linear and nonlinear properties in terahertz range of 2D materials graphene and silicene placed into a bias magnetic field are investigated theoretically on the base of the quasi-classical kinetic theory. Whe...Resonant linear and nonlinear properties in terahertz range of 2D materials graphene and silicene placed into a bias magnetic field are investigated theoretically on the base of the quasi-classical kinetic theory. When the electromagnetic frequency is close to the cyclotron one, the linear conductivity increases two orders. Under the resonant frequencies nonlinearity becomes essential at low magnitudes of terahertz electric fields. In absence of a bias magnetic field the nonlinear dependences of the surface electric currents on terahertz electric field are practically the same simulated from kinetics and electron hydrodynamics with nonzero “kinetic” electron effective mass. Graphene possesses higher values of nonlinearity of the resonant conductivity, whereas in absence of a bias magnetic field, the electron nonlinearity is higher in silicene.展开更多
Metabolic dysfunction-associated steatotic liver disease(MASLD)is a highly prevalent liver pathology in need of novel pharmacological treatments to complement lifestyle-based interventions.Nuclear receptor agonists ha...Metabolic dysfunction-associated steatotic liver disease(MASLD)is a highly prevalent liver pathology in need of novel pharmacological treatments to complement lifestyle-based interventions.Nuclear receptor agonists have been under scrutiny as potential pharmacological targets and as of today,resmetirom,a thyroid hormone receptor b agonist,is the only approved agent.The dual PPARαandδagonist elafibranor has also undergone extensive clinical testing,which reached the phase III clinical trial but failed to demonstrate a beneficial effect on MASLD.As alcohol-associated liver disease and MASLD can be interconnected,whether elafibranor might be affective against liver disease caused by alcohol consumption is worth investigating.Writing recently in the World Journal of Gastroenterology,Koizumi et al reported using a mouse model of alcoholassociated liver disease and found that hepatic steatosis,liver fibrosis,and hepatocyte apoptosis were alleviated by administration of elafibranor.Although preclinical in nature,these data support the potential beneficial action of elafibranor in alcohol-induced MASLD,warranting the testing of this molecule in patients with steatotic liver disease caused by alcohol consumption.展开更多
Breast cancer is the leading cause of cancer-related mortality in women globally,with its incidence continuing to rise,particularly in low-and middle-income countries,presenting a significant public health challenge w...Breast cancer is the leading cause of cancer-related mortality in women globally,with its incidence continuing to rise,particularly in low-and middle-income countries,presenting a significant public health challenge worldwide[1].According to data from the Institute for Health Metrics and Evaluation(IHME)and the World Health Organization(WHO),the gap in access to healthcare services between high-and low-income countries contributes to delayed detection,increased incidence of advanced-stage disease,and,consequently,higher mortality rates(up to 50%higher compared to high-income countries)[1,2].This translates into inequalities in access to screening and early diagnosis methods,which exacerbate the burden of this disease in low-resource settings where infrastructure,funding,and access to trained professionals are limited[3].展开更多
BACKGROUND Liver disease is a major cause of mortality in Mexico.Liver transplantation(LT)remains severely limited,and there are no reports on equity of access.AIM To analyze geographical disparities in LT access in M...BACKGROUND Liver disease is a major cause of mortality in Mexico.Liver transplantation(LT)remains severely limited,and there are no reports on equity of access.AIM To analyze geographical disparities in LT access in Mexico.METHODS LT waitlist registrations and LT rates in Mexico from 2014 to 2023 were assessed.LT listings per million persons(pmp)were calculated.Observed-to-expected listings were calculated by controlling listings pmp and mortality rate per 10000.LT and waitlist mortality was calculated as 90-day rate,overall rate and rate per 100 person-years.We compared access to waitlist,transplantation and mortality between patients living in Mexican States with higher LT activity and those living in other States.RESULTS There were 2600 new waitlist registrations;1572 registrations(60.4%)living in Mexico City and State,Jalisco and Nuevo Leon.There were 1755 LT;92.5%of them performed in States with higher LT activity,and 1101(62.7%vs 37.3%;P<0.001)done in patients living in those States.Listings pmp in the Mexican States with high LT activity were 3.8,1.5 vs 1.2,0.6(P<0.001);observed-to-expected listings were 1.3,0.4 vs 0.4,0.2(P<0.001);LT pmp were 2.7,0.9 vs 0.7,0.5(P<0.001).After controlling for other variables,patients living in high LT activity States had a HR 1.14(95%CI:1.03-1.26;P=0.009)to be a case of transplantation after listing.CONCLUSION Geographic disparities substantially affect LT access in Mexico.The population living near Transplant Centers has a 3.2-fold higher access to the waiting list and a 3.8-fold higher likelihood of LT.Current referral system,and resource allocation need urgent revision to remove the barriers associated with geographic disparity.展开更多
Liver transplantation(LT)is the only curative treatment for end-stage liver disease.Although Mexico has made important strides in surgical capacity and institutional development,the country continues to report one of ...Liver transplantation(LT)is the only curative treatment for end-stage liver disease.Although Mexico has made important strides in surgical capacity and institutional development,the country continues to report one of the lowest LT rates in Latin America.Multiple challenges remain,including inequitable access to care,limited organ donation,and structural inefficiencies in allocation systems.To review the current status of LT in Mexico,describe historical trends,highlight significant barriers to progress,and discuss potential opportunities for program expansion.We conducted a narrative review incorporating data from the National Transplant Center(Centro Nacional de Trasplantes in Spanish),relevant peer-reviewed literature,and global benchmarks.The analysis focused on trends in liver transplant volume,donor types,etiology shifts,institutional disparities,and the impact of the coronavirus disease 2019(COVID-19)pandemic.LT activity in Mexico increased from 25 transplants in 1999 to 297 in 2023.However,over 68%of transplants are concentrated in Mexico City,and only eight centers perform more than ten LTs per year.Deceased donors account for most grafts,while living donor transplants remain rare and mostly limited to private institutions.The national waiting list functions primarily as a registry rather than a priority-based allocation system.The COVID-19 pandemic further disrupted transplant programs,particularly in the public sector.Innovative approaches such as donation after circulatory death,hepatitis C virus-positive donor utilization,and advanced perfusion technologies are currently unavailable or underutilized in Mexico.Mexico's LT system faces geographic,regulatory,and resource-related limitations.To improve outcomes and ensure equitable access,strategic reforms focused on donor expansion,centralized allocation,perfusion technologies,and standardization of care are urgently needed.展开更多
Argentina is the country with the highest proportion of arid and semi-arid ecosystems in Latin America.In the rangelands of Southwestern Buenos Aires(Patagones Department),there is a clear advancement of the agricultu...Argentina is the country with the highest proportion of arid and semi-arid ecosystems in Latin America.In the rangelands of Southwestern Buenos Aires(Patagones Department),there is a clear advancement of the agricultural frontier to the detriment of the native forest in this region.Due to rainfall variation and seed acquisition,Thinopyrum ponticum is cultivated as a forage perennial crop in this region.Our objective was to evaluate the performance of T.ponticum as a facilitating crop for the medium-term rehabilitation of natural grasslands in semi-arid areas.The working hypotheses were that:1)native perennial grass cover increases over the years and 2)diversity and specific richness of the vegetation are enhanced by the duration of Tall Wheatgrass implantation.Data were collected from commercial plots where T.ponticum was shown:recent implantation(5–8 years,RI);medium implantation(13–15 years,MI);and old implantation(20–22 years,OI).Thirty-four species were identified and classified into seven functional groups:Annual grasses,annual herbs,perennial herbs,exotic perennial herbs,perennial forage grasses,exotic perennial forage grasses,perennial forage exotic grasses,and nonforage perennial grasses.Thinopyrum ponticum’s total cover was between RI and OI.Total cover,species richness,and Shannon-Weaver diversity index showed no differences among treatments.Perennial forage grasses exhibited higher cover values in sites with greater implantation age and annual grasses showed the opposite response.Our results indicated that T.ponticum does not invade the sampled plots and enhances the colonization of the planted plots by perennial forage native species.However,even though the herbaceous cover had been recovered,the woody layer which could provide environmental services and specific values for conservation was not.展开更多
Non-alcoholic fatty liver disease (NAFLD) includes a spectrum of diseases that have insulin resistance in common and are associated with metabolic conditions such as obesity, type 2 diabetes mellitus, and dyslipidemia...Non-alcoholic fatty liver disease (NAFLD) includes a spectrum of diseases that have insulin resistance in common and are associated with metabolic conditions such as obesity, type 2 diabetes mellitus, and dyslipidemia. NAFLD ranges from simple liver steatosis, which follows a benign course, to nonalcoholic steatohepatitis (NASH), a more severe entity, with necroinflmmation and f ibrosis, which can progress to cryptogenic cirrhosis and end-stage liver disease. Liver biopsy remains the gold standard for evaluating the degree of hepatic necroinflammation and f ibrosis; however, several noninvasive investigations, such as serum biomarkers, have been developed to establish the diagnosis and also to evaluate treatment response. These markers are currently neither available in all centers nor validated in extensive studies. Examples include high-sensitivity C reactive protein and plasma pentraxin 3, which are associated with extensive liver f ibrosis in NASH. Interleukin-6 correlates with inflammation, and cytokeratin-18 represents a marker of hepatocyte apoptosis (prominent in NASH and absent in simple steatosis). Tissue polypep-tide specif ic antigen seems to have a clinical utility in the follow-up of obese patients with NASH.展开更多
BACKGROUND Obesity is a major health problem due to its high prevalence.The relationship between obesity and cardiovascular disease is unclear.Some studies agree that certain conditions associated with obesity,such as...BACKGROUND Obesity is a major health problem due to its high prevalence.The relationship between obesity and cardiovascular disease is unclear.Some studies agree that certain conditions associated with obesity,such as physical inactivity or cardiovascular risk factors,are responsible for cardiovascular risk excess among obese people.Carotid intima-media thickness and carotid plaques(CP)have been associated with cardiovascular adverse events in healthy populations,and recent data suggest a higher prevalence of subclinical carotid atherosclerosis in obese and metabolically unhealthy patients.However,there are no studies correlating subclinical atherosclerosis and adverse events(AE)in obese subjects.AIM To determine the association between carotid disease and AE in obese patients with negative exercise echocardiography(EE).METHODS From January 1,2006 to December 31,2010,2000 consecutive patients with a suspicion of coronary artery disease were submitted for EE and carotid ultrasonography.Exclusion criteria included previous vascular disease,left ventricular ejection fraction<50%,positive EE,significant valvular heart disease and inferior to submaximal EE.An AE was defined as all-cause mortality,myocardial infarction and cerebrovascular accident.Subclinical atherosclerosis was defined as CP presence according to Manheim and the American Society of Echocardiography Consensus.RESULTS Of the 652 patients who fulfilled the inclusion criteria,226(34.7%)had body mass indexes≥30 kg/m2,and 76 of them(33.6%)had CP.During a mean follow-up time of 8.2(2.1)years,27 AE were found(11.9%).Mean event-free survival at 1,5 and 10 years was 99.1%(0.6),95.1%(1.4)and 86.5%(2.7),respectively.In univariate analysis,CP predicted AE[hazard ratio(HR)2.52,95%confidence interval(CI)1.17-5.46;P=0.019].In multivariable analysis,the presence of CP remained a predictor of AE(HR 2.26,95%CI 1.04-4.95,P=0.041).Other predictors identified were glomerular filtration rate(HR 0.98,95%CI 0.96-0.99;P=0.023),peak metabolic equivalents(HR 0.83,95%CI 0.70–0.99,P=0.034)and moderate mitral regurgitation(HR 5.02,95%CI 1.42–17.75,P=0.012).CONCLUSION Subclinical atherosclerosis defined by CP predicts AE in obese patients with negative EE.These patients could benefit from aggressive prevention measures.展开更多
Granitod batholiths of I-type features （mostly granodiorites and tonalites）, and particularly those forming the large plutonic associations of active continental margins and intracontinental collisional belts, repre...Granitod batholiths of I-type features （mostly granodiorites and tonalites）, and particularly those forming the large plutonic associations of active continental margins and intracontinental collisional belts, represent the most outstanding magmatic episodes occurred in the continental crust. The origin of magmas, however, remains controversial. The application of principles from phase equilibria is crucial to understand the problem of granitoid magma generation. An adequate comparison between rock com- positions and experimental liquids has been addressed by using a projected compositional space in the plane F（Fe ＋ Mg）-Anorthite-Orthoclase. Many calc-alkaline granitoid trends can be considered cotectic liquids. Assimilation of country rocks and other not-cotectic processes are identified in the projected diagram. The identification of cotectic patterns in batholith implies high temperatures of magma segregation and fractionation （or partial melting） from an intermediate （andesitic） source. The com- parison of batholiths with lower crust granulites, in terms of major-element geochemistry, yields that both represent liquids and solid residues respectively from a common andesitic system. This is compatible with magmas being formed by melting, and eventual reaction with the peridotite mantle, of subducted mOlanges that are finally relaminated as magmas to the lower crust. Thus, the off-crust generation of granitoids batholiths constitutes a new paradigm in which important geological implica- tions can be satisfactorily explained. Geochemical features of Cordilleran-type batholiths are totally compatible with this new conception.展开更多
The intake of heavy metals through food consumption is a food safety problem that severely impacts the health of consumers, so information about food intake and heavy metal concentrations in food products is required ...The intake of heavy metals through food consumption is a food safety problem that severely impacts the health of consumers, so information about food intake and heavy metal concentrations in food products is required to estimate the potential risk to the health of the population. The main purpose of this study was to estimate the potential risks to human health from exposure to Cd, Cu, Ni, Pb and Zn through the intake of Malus domestica Golden Delicious consumed in the Mexican southeast, considering the age group and gender. The concentration of each of the metals was quantified by spectrometry of atomic absorption (AAE) and the daily intake of metals (DIM) and health risk indices through the consumption of apple: health risk index (HRI), total health risk index (THRI), target hazard coefficient (THQ) and the probability of carcinogenic risk (CR) were estimated. The concentrations of the metals analyzed in the apple samples showed the following decreasing order: Zn ≥ Ni ≥ Cu ≥ Pb ≥ Cd. The DIM values showed the following decreasing order: child > young adult > adoescent > elders. The health risk assessments (HRI, THRI, THQ and CR) obtained from the samples of Golden Delicious apples are located within the acceptable and/or tolerable limits, however, the increase in the intake of heavy metals through consumption of apples from establishments in the study area or the consumption of various foods contaminated with heavy metals may increase the health risk potential of consumers. For this reason, it is recommended to carry out studies on the concentration of heavy metals in food products, mainly those of greater popular consumption, to guarantee food security of the population.展开更多
Ketone bodies have emerged as central mediators of metabolic health,and multiple beneficial effects of a ketogenic diet,impacting metabolism,neuronal pathologies and,to a certain extent,tumorigenesis,have been reporte...Ketone bodies have emerged as central mediators of metabolic health,and multiple beneficial effects of a ketogenic diet,impacting metabolism,neuronal pathologies and,to a certain extent,tumorigenesis,have been reported both in animal models and clinical research.Ketone bodies,endogenously produced by the liver,act pleiotropically as metabolic intermediates,signaling molecules,and epigenetic modifiers.The endothelium and the vascular system are central regulators of the organism’s metabolic state and become dysfunctional in cardiovascular disease,atherosclerosis,and diabetic micro-and macrovascular complications.As physiological circulating ketone bodies can attain millimolar concentrations,the endothelium is the first-line cell lineage exposed to them.While in diabetic ketoacidosis high ketone body concentrations are detrimental to the vasculature,recent research revealed that ketone bodies in the low millimolar range may exert beneficial effects on endothelial cell(EC)functioning by modulating the EC inflammatory status,senescence,and metabolism.Here,we review the long-held evidence of detrimental cardiovascular effects of ketoacidosis as well as the more recent evidence for a positive impact of ketone bodies—at lower concentrations—on the ECs metabolism and vascular physiology and the subjacent cellular and molecular mechanisms.We also explore arising controversies in the field and discuss the importance of ketone body concentrations in relation to their effects.At low concentration,endogenously produced ketone bodies upon uptake of a ketogenic diet or supplemented ketone bodies(or their precursors)may prove beneficial to ameliorate endothelial function and,consequently,pathologies in which endothelial damage occurs.展开更多
We report the results of carbon stored in soil and aboveground biomass from the most important area of mangroves in Mexico, with dominant vegetation of Red mangrove （Rhizophora mangle L.）, Black mangrove （Avicennia...We report the results of carbon stored in soil and aboveground biomass from the most important area of mangroves in Mexico, with dominant vegetation of Red mangrove （Rhizophora mangle L.）, Black mangrove （Avicennia germinans L.）, white mangrove （Laguncularia racemosa Gaertn.） and button mangrove （Conocarpus erectus L.）. We sampled soils with high fertility during the dry season in 2009 and 2010 at three sites on Atasta Peninsula, Campeche. We used allometric equations to estimate above ground biomass （AGB） of trees. AGB was higher in C. erectus （253.18±32.17 t？ha-1）, lower in A. germinans （161.93±12.63 t？ha-1）, and intermediate in R. mangle （181.70±16.58 t？ha-1） and L. racemosa （206.07±19.12 t？ha-1）. Of the three studied sites, the highest absolute value for AGB was 279.72 t？ha-1 in button mangrove forest at any single site. Carbon stored in soil at the three sites ranged from 36.80±10.27 to 235.77±66.11 t？ha-1. The Tukey test （p 〈0.05） made for AGB was higher for black mangrove showed significant differences in soil carbon content between black mangrove and button mangrove. C. erectus had higher AGB compared with the other species. A. germinans trees had lower AGB because they grew in hypersaline environments, which reduced their development. C. erectus grew on higher ground where soils were richer in nutrients. AGB tended to be low in areas near the sea and increased with distance from the coast. A. germinans usually grew on recently deposited sediments. We assumed that all sites have the same potential to store carbon in soil, and then we found that there were no significant differences in carbon content between the three samples sites： all sites had potential to store carbon for long periods. Carbon storage at the three sampling sites in the state of Campeche, Mexico, was higher than that reported for other locations.展开更多
Obesity and associated metabolic disorders represent a major societal challenge in health and quality of life with large psychological consequences in addition to physical disabilities. They are also one of the leadin...Obesity and associated metabolic disorders represent a major societal challenge in health and quality of life with large psychological consequences in addition to physical disabilities. They are also one of the leading causes of morbidity and mortality. Although, different etiologic factors including excessive food intake and reduced physical activity have been well identified, they cannot explain the kinetics of epidemic evolution of obesity and diabetes with prevalence rates reaching pandemic proportions. Interestingly, convincing data have shown that environmental pollutants, specifically those endowed with endocrine disrupting activities, could contribute to the etiology of these multifactorial metabolic disorders. Within this review, we will recapitulate characteristics of endocrine disruption. We will demonstrate that metabolic disorders could originate from endocrine disruption with a particular focus on convincing data from the literature. Eventually, we will present how handling an original mouse model of chronic exposition to a mixture of pollutants allowed demonstrating that a mixture of pollutants each at doses beyond their active dose could induce substantial deleterious effects on several metabolic end-points. This proof-of-concept study, as well as other studies on mixtures of pollutants, stresses the needs for revisiting the current threshold model used in risk assessment which does not take into account potential effects of mixtures containing pollutants at environmental doses, e.g., the real life exposure. Certainly, more studies are necessary to better determine the nature of the chemicals to which humans are exposed and at which level, and their health impact. As well, research studies on substitute products are essential to identify harmless molecules.展开更多
Assisted migration has been proposed as a strategy for adaptive management of forest species in response to expected effects of climate change,but it is controversial for several reasons.Tropical dry forests are among...Assisted migration has been proposed as a strategy for adaptive management of forest species in response to expected effects of climate change,but it is controversial for several reasons.Tropical dry forests are among the most threatened ecosystems in the world.In Mexico,historically,land-use change and deforestation have been decreasing forest cover,and climate change is shifting the potential distribution of different forest types,exacerbating the risk of local extinctions.Assisted altitudinal migration could be a feasible strategy for reducing local extinctions in response to climate change and lack of landscape connectivity.Our objective was to evaluate survival and growth of Albizia plurijuga and Ceiba aesculifolia,two tropical deciduous forests species in Mexico.We transplanted 4-month-old seedlings to experimental raised beds at three altitudes(2100,2400 and 2700 m a.s.l.),exceeding their upper regional limit of distribution(2000 m a.s.l.).We also tested seed germination at each altitude.We monitored the experiment for 10 months.For both species,as altitude increased and cold weather was more prevalent,plant performance declined.Within species,differences in individual growth were significant among altitudes.Overall survival was 18.5%for A.plurijuga and 24.5%for C.aesculifolia.Both species had higher survival and better growth at lower altitude,and no seedling emergence at any altitude.We conclude that assisted migration can be implemented for each species by an upward attitudinal shift within,and not exceeding,400 m beyond their present upper altitudinal limit of distribution.Our results indicate that for many species that show altitudinal gradients at regional scales,unless current climate conditions change,the potential to establish outside their range is minimal.展开更多
It is known that large amounts of residual lignin are generated in the pulp and paper industry.A new alternative for Kraft lignin valorization,which consists of first a chemical modification using a diisocyanate and t...It is known that large amounts of residual lignin are generated in the pulp and paper industry.A new alternative for Kraft lignin valorization,which consists of first a chemical modification using a diisocyanate and then the efficient dispersion in castor oil to achieve stable gel-like systems,is proposed in this work.Rheological properties and microstructure of these materials were determined by means of small amplitude oscillatory shear tests and viscous flow measurements and atomic force microscopy observations,respectively.Moreover,both standardized penetration tests and tribological assays,usually performed in the lubricant industry,were carried out to evaluate the performance characteristics as lubricating greases.Linear viscoelasticity functions are affected by the lignin/diisocyanate ratio and thickener concentration.The thermorheological response evidenced a softening temperature of around 105°C.The microstructure of these gel-like dispersions is composed of interconnected thin fibers,homogeneously distributed in castor oil.Moreover,the NCO-functionalized lignin gel-like dispersions studied show lower friction coefficients than traditional lubricating greases.展开更多
The chemistry of rainwater has been subject to numerous investigations during the last two decades due to the increase of environmental problems caused by the acid deposition. The present study focuses on one aspect o...The chemistry of rainwater has been subject to numerous investigations during the last two decades due to the increase of environmental problems caused by the acid deposition. The present study focuses on one aspect of air pollution, the chemical composition of wet deposition of an industrial zone. The sampling period was from March to December 2009. The station was located on the roof of the Chemistry School at the University of Nuevo León, an area in the north of Monterrey where the majority of pollution is generated. Twenty-five wet precipitation samples were collected with an automatic sampler and analyzed for pH, ions (, , Cl<sup>-</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, Na<sup>+</sup>, K<sup>+</sup>) and conductivity. The results show that the average pH is higher than 5.6;the characteristics of the rainwater studied are of alkaline nature due to the values of pH found;there is an evident anthropogenic source contributing to the alkaline of rain water. In order to find possible association between ions and consequently the possible sources of pollutants correlation study was applied using the program SPSS v.12. Good correlations were found between ions and along with Ca<sup>2+</sup> and Mg<sup>2+</sup>. The local extraction industry and surrounding aerosols might be causing of alkaline rain which may be due to the neutralization effect of particulate matter. This study represents a continuation of the studies of rainwater chemistry in the Northeast of Mexico.展开更多
The neuroanatomy of the mid-sized theropod Sinosaurus triassicus from the Lower Jurassic Lufeng Formation, Lufeng Basin in Yunnan Province, China was studied using X-ray computed tomography. The braincase is character...The neuroanatomy of the mid-sized theropod Sinosaurus triassicus from the Lower Jurassic Lufeng Formation, Lufeng Basin in Yunnan Province, China was studied using X-ray computed tomography. The braincase is characterized by a large supraoccipital knob that is capped by a posterior projection of the parietal and two external foramina for the caudal middle cerebral vein, which is completely enclosed by the supraoccipital. The basicranium has well defined, short basipterygoid processes that project ventral to the basal tubera. The basisphenoid is expanded, projects posteroventrally, and is pierced by four pneumatic recesses. The endocranial morphology resembles that observed in other basal theropods—in particular some allosauroids—and has a strongly marked pontine flexure and a large dorsal expansion. The inner ear morphology is also similar to that observed in other basal theropods, with slender semicircular canals. The anterior semicircular canal is 20% larger than the posterior semicircular canal, and the angle formed between them is less than 90° when seen in dorsal view.展开更多
文摘BTX (benzene, ethylbenzene, toluene and p-xylene) and meteorological parameters were measured in ambient air of an urban site located in Carmen City, Campeche, Mexico. A total of 412 samples were collected for BTX and analyzed by Gas Chromatography with Flame Ionization Detection (GC-FID). Meteorological parameters were measured by a portable station. A marked diurnal variation was found for all measured BTX. The highest concentrations occurred during midday (13:00-14:30 h). A clear seasonal pattern was observed too for all compounds registering their highest levels during summer sampling period. Mean concentrations for benzene, ethylbenzene, toluene and p-xylene were: 5.42, 3.97, 11.24 and 8.32 ppbv, respectively. BTX abundance showed the following order: toluene > p-xylene > benzene > ethylbenzene. BTX maximum concentrations were found when winds blowed from E and NE. Important oil industry sources and avenues are located at these directions. These sources could contribute to the levels of BTX in this site.
文摘Two hundred and seven rain events from April to October 2012 were collected in Carmen Island, Campeche, Mexico, and the concentration of 8 major ions with the pH of the rainwater was analyzed. Chemical composition variations as a result of seasonal patterns, meteorological conditions, and mixed local and regional sources contribution were assessed. In spite of the fact that nitrate and sulfate levels were higher than background hemispheric values, the average pH values were almost neutral. Carmen Island was under the influence of both, local and long-range transported emissions. Chemical composition showed a dilution effect as a result of the monthly rainfall amount. Ca2+ and Na+ were the most abundant ions, and these ions acted as acid neutralizers and buffered the acidity of the rain, suggesting that marine and crustal aerosols played an important role in the acid-base interactions. Wet deposition fluxes obtained were compared with reference values proposed as critical loads, fluxes obtained in this study did not exceed the critical values reported for sensitive ecosystems in Europe, indicating that this site has yet enough capacity to support acidity, nitrogen and sulfur deposition. However, it is necessary to obtain reference values characteristics for tropical regions.
文摘Resonant linear and nonlinear properties in terahertz range of 2D materials graphene and silicene placed into a bias magnetic field are investigated theoretically on the base of the quasi-classical kinetic theory. When the electromagnetic frequency is close to the cyclotron one, the linear conductivity increases two orders. Under the resonant frequencies nonlinearity becomes essential at low magnitudes of terahertz electric fields. In absence of a bias magnetic field the nonlinear dependences of the surface electric currents on terahertz electric field are practically the same simulated from kinetics and electron hydrodynamics with nonzero “kinetic” electron effective mass. Graphene possesses higher values of nonlinearity of the resonant conductivity, whereas in absence of a bias magnetic field, the electron nonlinearity is higher in silicene.
文摘Metabolic dysfunction-associated steatotic liver disease(MASLD)is a highly prevalent liver pathology in need of novel pharmacological treatments to complement lifestyle-based interventions.Nuclear receptor agonists have been under scrutiny as potential pharmacological targets and as of today,resmetirom,a thyroid hormone receptor b agonist,is the only approved agent.The dual PPARαandδagonist elafibranor has also undergone extensive clinical testing,which reached the phase III clinical trial but failed to demonstrate a beneficial effect on MASLD.As alcohol-associated liver disease and MASLD can be interconnected,whether elafibranor might be affective against liver disease caused by alcohol consumption is worth investigating.Writing recently in the World Journal of Gastroenterology,Koizumi et al reported using a mouse model of alcoholassociated liver disease and found that hepatic steatosis,liver fibrosis,and hepatocyte apoptosis were alleviated by administration of elafibranor.Although preclinical in nature,these data support the potential beneficial action of elafibranor in alcohol-induced MASLD,warranting the testing of this molecule in patients with steatotic liver disease caused by alcohol consumption.
文摘Breast cancer is the leading cause of cancer-related mortality in women globally,with its incidence continuing to rise,particularly in low-and middle-income countries,presenting a significant public health challenge worldwide[1].According to data from the Institute for Health Metrics and Evaluation(IHME)and the World Health Organization(WHO),the gap in access to healthcare services between high-and low-income countries contributes to delayed detection,increased incidence of advanced-stage disease,and,consequently,higher mortality rates(up to 50%higher compared to high-income countries)[1,2].This translates into inequalities in access to screening and early diagnosis methods,which exacerbate the burden of this disease in low-resource settings where infrastructure,funding,and access to trained professionals are limited[3].
文摘BACKGROUND Liver disease is a major cause of mortality in Mexico.Liver transplantation(LT)remains severely limited,and there are no reports on equity of access.AIM To analyze geographical disparities in LT access in Mexico.METHODS LT waitlist registrations and LT rates in Mexico from 2014 to 2023 were assessed.LT listings per million persons(pmp)were calculated.Observed-to-expected listings were calculated by controlling listings pmp and mortality rate per 10000.LT and waitlist mortality was calculated as 90-day rate,overall rate and rate per 100 person-years.We compared access to waitlist,transplantation and mortality between patients living in Mexican States with higher LT activity and those living in other States.RESULTS There were 2600 new waitlist registrations;1572 registrations(60.4%)living in Mexico City and State,Jalisco and Nuevo Leon.There were 1755 LT;92.5%of them performed in States with higher LT activity,and 1101(62.7%vs 37.3%;P<0.001)done in patients living in those States.Listings pmp in the Mexican States with high LT activity were 3.8,1.5 vs 1.2,0.6(P<0.001);observed-to-expected listings were 1.3,0.4 vs 0.4,0.2(P<0.001);LT pmp were 2.7,0.9 vs 0.7,0.5(P<0.001).After controlling for other variables,patients living in high LT activity States had a HR 1.14(95%CI:1.03-1.26;P=0.009)to be a case of transplantation after listing.CONCLUSION Geographic disparities substantially affect LT access in Mexico.The population living near Transplant Centers has a 3.2-fold higher access to the waiting list and a 3.8-fold higher likelihood of LT.Current referral system,and resource allocation need urgent revision to remove the barriers associated with geographic disparity.
文摘Liver transplantation(LT)is the only curative treatment for end-stage liver disease.Although Mexico has made important strides in surgical capacity and institutional development,the country continues to report one of the lowest LT rates in Latin America.Multiple challenges remain,including inequitable access to care,limited organ donation,and structural inefficiencies in allocation systems.To review the current status of LT in Mexico,describe historical trends,highlight significant barriers to progress,and discuss potential opportunities for program expansion.We conducted a narrative review incorporating data from the National Transplant Center(Centro Nacional de Trasplantes in Spanish),relevant peer-reviewed literature,and global benchmarks.The analysis focused on trends in liver transplant volume,donor types,etiology shifts,institutional disparities,and the impact of the coronavirus disease 2019(COVID-19)pandemic.LT activity in Mexico increased from 25 transplants in 1999 to 297 in 2023.However,over 68%of transplants are concentrated in Mexico City,and only eight centers perform more than ten LTs per year.Deceased donors account for most grafts,while living donor transplants remain rare and mostly limited to private institutions.The national waiting list functions primarily as a registry rather than a priority-based allocation system.The COVID-19 pandemic further disrupted transplant programs,particularly in the public sector.Innovative approaches such as donation after circulatory death,hepatitis C virus-positive donor utilization,and advanced perfusion technologies are currently unavailable or underutilized in Mexico.Mexico's LT system faces geographic,regulatory,and resource-related limitations.To improve outcomes and ensure equitable access,strategic reforms focused on donor expansion,centralized allocation,perfusion technologies,and standardization of care are urgently needed.
基金supported by the National University of Río Negro(PI UNRN 40-C-873 GP,DAS and PI UNRN 40-C-1088 JMZ,GP,DAS).
文摘Argentina is the country with the highest proportion of arid and semi-arid ecosystems in Latin America.In the rangelands of Southwestern Buenos Aires(Patagones Department),there is a clear advancement of the agricultural frontier to the detriment of the native forest in this region.Due to rainfall variation and seed acquisition,Thinopyrum ponticum is cultivated as a forage perennial crop in this region.Our objective was to evaluate the performance of T.ponticum as a facilitating crop for the medium-term rehabilitation of natural grasslands in semi-arid areas.The working hypotheses were that:1)native perennial grass cover increases over the years and 2)diversity and specific richness of the vegetation are enhanced by the duration of Tall Wheatgrass implantation.Data were collected from commercial plots where T.ponticum was shown:recent implantation(5–8 years,RI);medium implantation(13–15 years,MI);and old implantation(20–22 years,OI).Thirty-four species were identified and classified into seven functional groups:Annual grasses,annual herbs,perennial herbs,exotic perennial herbs,perennial forage grasses,exotic perennial forage grasses,perennial forage exotic grasses,and nonforage perennial grasses.Thinopyrum ponticum’s total cover was between RI and OI.Total cover,species richness,and Shannon-Weaver diversity index showed no differences among treatments.Perennial forage grasses exhibited higher cover values in sites with greater implantation age and annual grasses showed the opposite response.Our results indicated that T.ponticum does not invade the sampled plots and enhances the colonization of the planted plots by perennial forage native species.However,even though the herbaceous cover had been recovered,the woody layer which could provide environmental services and specific values for conservation was not.
文摘Non-alcoholic fatty liver disease (NAFLD) includes a spectrum of diseases that have insulin resistance in common and are associated with metabolic conditions such as obesity, type 2 diabetes mellitus, and dyslipidemia. NAFLD ranges from simple liver steatosis, which follows a benign course, to nonalcoholic steatohepatitis (NASH), a more severe entity, with necroinflmmation and f ibrosis, which can progress to cryptogenic cirrhosis and end-stage liver disease. Liver biopsy remains the gold standard for evaluating the degree of hepatic necroinflammation and f ibrosis; however, several noninvasive investigations, such as serum biomarkers, have been developed to establish the diagnosis and also to evaluate treatment response. These markers are currently neither available in all centers nor validated in extensive studies. Examples include high-sensitivity C reactive protein and plasma pentraxin 3, which are associated with extensive liver f ibrosis in NASH. Interleukin-6 correlates with inflammation, and cytokeratin-18 represents a marker of hepatocyte apoptosis (prominent in NASH and absent in simple steatosis). Tissue polypep-tide specif ic antigen seems to have a clinical utility in the follow-up of obese patients with NASH.
文摘BACKGROUND Obesity is a major health problem due to its high prevalence.The relationship between obesity and cardiovascular disease is unclear.Some studies agree that certain conditions associated with obesity,such as physical inactivity or cardiovascular risk factors,are responsible for cardiovascular risk excess among obese people.Carotid intima-media thickness and carotid plaques(CP)have been associated with cardiovascular adverse events in healthy populations,and recent data suggest a higher prevalence of subclinical carotid atherosclerosis in obese and metabolically unhealthy patients.However,there are no studies correlating subclinical atherosclerosis and adverse events(AE)in obese subjects.AIM To determine the association between carotid disease and AE in obese patients with negative exercise echocardiography(EE).METHODS From January 1,2006 to December 31,2010,2000 consecutive patients with a suspicion of coronary artery disease were submitted for EE and carotid ultrasonography.Exclusion criteria included previous vascular disease,left ventricular ejection fraction<50%,positive EE,significant valvular heart disease and inferior to submaximal EE.An AE was defined as all-cause mortality,myocardial infarction and cerebrovascular accident.Subclinical atherosclerosis was defined as CP presence according to Manheim and the American Society of Echocardiography Consensus.RESULTS Of the 652 patients who fulfilled the inclusion criteria,226(34.7%)had body mass indexes≥30 kg/m2,and 76 of them(33.6%)had CP.During a mean follow-up time of 8.2(2.1)years,27 AE were found(11.9%).Mean event-free survival at 1,5 and 10 years was 99.1%(0.6),95.1%(1.4)and 86.5%(2.7),respectively.In univariate analysis,CP predicted AE[hazard ratio(HR)2.52,95%confidence interval(CI)1.17-5.46;P=0.019].In multivariable analysis,the presence of CP remained a predictor of AE(HR 2.26,95%CI 1.04-4.95,P=0.041).Other predictors identified were glomerular filtration rate(HR 0.98,95%CI 0.96-0.99;P=0.023),peak metabolic equivalents(HR 0.83,95%CI 0.70–0.99,P=0.034)and moderate mitral regurgitation(HR 5.02,95%CI 1.42–17.75,P=0.012).CONCLUSION Subclinical atherosclerosis defined by CP predicts AE in obese patients with negative EE.These patients could benefit from aggressive prevention measures.
基金Financial support for this research comes from Grants P09-RNM-05378 and CGL2010-22022-C02-01
文摘Granitod batholiths of I-type features （mostly granodiorites and tonalites）, and particularly those forming the large plutonic associations of active continental margins and intracontinental collisional belts, represent the most outstanding magmatic episodes occurred in the continental crust. The origin of magmas, however, remains controversial. The application of principles from phase equilibria is crucial to understand the problem of granitoid magma generation. An adequate comparison between rock com- positions and experimental liquids has been addressed by using a projected compositional space in the plane F（Fe ＋ Mg）-Anorthite-Orthoclase. Many calc-alkaline granitoid trends can be considered cotectic liquids. Assimilation of country rocks and other not-cotectic processes are identified in the projected diagram. The identification of cotectic patterns in batholith implies high temperatures of magma segregation and fractionation （or partial melting） from an intermediate （andesitic） source. The com- parison of batholiths with lower crust granulites, in terms of major-element geochemistry, yields that both represent liquids and solid residues respectively from a common andesitic system. This is compatible with magmas being formed by melting, and eventual reaction with the peridotite mantle, of subducted mOlanges that are finally relaminated as magmas to the lower crust. Thus, the off-crust generation of granitoids batholiths constitutes a new paradigm in which important geological implica- tions can be satisfactorily explained. Geochemical features of Cordilleran-type batholiths are totally compatible with this new conception.
文摘The intake of heavy metals through food consumption is a food safety problem that severely impacts the health of consumers, so information about food intake and heavy metal concentrations in food products is required to estimate the potential risk to the health of the population. The main purpose of this study was to estimate the potential risks to human health from exposure to Cd, Cu, Ni, Pb and Zn through the intake of Malus domestica Golden Delicious consumed in the Mexican southeast, considering the age group and gender. The concentration of each of the metals was quantified by spectrometry of atomic absorption (AAE) and the daily intake of metals (DIM) and health risk indices through the consumption of apple: health risk index (HRI), total health risk index (THRI), target hazard coefficient (THQ) and the probability of carcinogenic risk (CR) were estimated. The concentrations of the metals analyzed in the apple samples showed the following decreasing order: Zn ≥ Ni ≥ Cu ≥ Pb ≥ Cd. The DIM values showed the following decreasing order: child > young adult > adoescent > elders. The health risk assessments (HRI, THRI, THQ and CR) obtained from the samples of Golden Delicious apples are located within the acceptable and/or tolerable limits, however, the increase in the intake of heavy metals through consumption of apples from establishments in the study area or the consumption of various foods contaminated with heavy metals may increase the health risk potential of consumers. For this reason, it is recommended to carry out studies on the concentration of heavy metals in food products, mainly those of greater popular consumption, to guarantee food security of the population.
基金Supported by Polish National Science Centre,Project Grant NCN Harmonia,No.2019/30/M/NZ3/00682NAWA/Campusfrance Polonium,No.PPN/X/RJ/1876/2019.
文摘Ketone bodies have emerged as central mediators of metabolic health,and multiple beneficial effects of a ketogenic diet,impacting metabolism,neuronal pathologies and,to a certain extent,tumorigenesis,have been reported both in animal models and clinical research.Ketone bodies,endogenously produced by the liver,act pleiotropically as metabolic intermediates,signaling molecules,and epigenetic modifiers.The endothelium and the vascular system are central regulators of the organism’s metabolic state and become dysfunctional in cardiovascular disease,atherosclerosis,and diabetic micro-and macrovascular complications.As physiological circulating ketone bodies can attain millimolar concentrations,the endothelium is the first-line cell lineage exposed to them.While in diabetic ketoacidosis high ketone body concentrations are detrimental to the vasculature,recent research revealed that ketone bodies in the low millimolar range may exert beneficial effects on endothelial cell(EC)functioning by modulating the EC inflammatory status,senescence,and metabolism.Here,we review the long-held evidence of detrimental cardiovascular effects of ketoacidosis as well as the more recent evidence for a positive impact of ketone bodies—at lower concentrations—on the ECs metabolism and vascular physiology and the subjacent cellular and molecular mechanisms.We also explore arising controversies in the field and discuss the importance of ketone body concentrations in relation to their effects.At low concentration,endogenously produced ketone bodies upon uptake of a ketogenic diet or supplemented ketone bodies(or their precursors)may prove beneficial to ameliorate endothelial function and,consequently,pathologies in which endothelial damage occurs.
文摘We report the results of carbon stored in soil and aboveground biomass from the most important area of mangroves in Mexico, with dominant vegetation of Red mangrove （Rhizophora mangle L.）, Black mangrove （Avicennia germinans L.）, white mangrove （Laguncularia racemosa Gaertn.） and button mangrove （Conocarpus erectus L.）. We sampled soils with high fertility during the dry season in 2009 and 2010 at three sites on Atasta Peninsula, Campeche. We used allometric equations to estimate above ground biomass （AGB） of trees. AGB was higher in C. erectus （253.18±32.17 t？ha-1）, lower in A. germinans （161.93±12.63 t？ha-1）, and intermediate in R. mangle （181.70±16.58 t？ha-1） and L. racemosa （206.07±19.12 t？ha-1）. Of the three studied sites, the highest absolute value for AGB was 279.72 t？ha-1 in button mangrove forest at any single site. Carbon stored in soil at the three sites ranged from 36.80±10.27 to 235.77±66.11 t？ha-1. The Tukey test （p 〈0.05） made for AGB was higher for black mangrove showed significant differences in soil carbon content between black mangrove and button mangrove. C. erectus had higher AGB compared with the other species. A. germinans trees had lower AGB because they grew in hypersaline environments, which reduced their development. C. erectus grew on higher ground where soils were richer in nutrients. AGB tended to be low in areas near the sea and increased with distance from the coast. A. germinans usually grew on recently deposited sediments. We assumed that all sites have the same potential to store carbon in soil, and then we found that there were no significant differences in carbon content between the three samples sites： all sites had potential to store carbon for long periods. Carbon storage at the three sampling sites in the state of Campeche, Mexico, was higher than that reported for other locations.
基金INSERM to Inserm U1060“Région Rh?ne-Alpes”,No.ARC 2013-ARC1 SANTE-13-018955-01(to Labaronne E)
文摘Obesity and associated metabolic disorders represent a major societal challenge in health and quality of life with large psychological consequences in addition to physical disabilities. They are also one of the leading causes of morbidity and mortality. Although, different etiologic factors including excessive food intake and reduced physical activity have been well identified, they cannot explain the kinetics of epidemic evolution of obesity and diabetes with prevalence rates reaching pandemic proportions. Interestingly, convincing data have shown that environmental pollutants, specifically those endowed with endocrine disrupting activities, could contribute to the etiology of these multifactorial metabolic disorders. Within this review, we will recapitulate characteristics of endocrine disruption. We will demonstrate that metabolic disorders could originate from endocrine disruption with a particular focus on convincing data from the literature. Eventually, we will present how handling an original mouse model of chronic exposition to a mixture of pollutants allowed demonstrating that a mixture of pollutants each at doses beyond their active dose could induce substantial deleterious effects on several metabolic end-points. This proof-of-concept study, as well as other studies on mixtures of pollutants, stresses the needs for revisiting the current threshold model used in risk assessment which does not take into account potential effects of mixtures containing pollutants at environmental doses, e.g., the real life exposure. Certainly, more studies are necessary to better determine the nature of the chemicals to which humans are exposed and at which level, and their health impact. As well, research studies on substitute products are essential to identify harmless molecules.
基金This research was supported by Comunidad de Nuevo San Juan Parangaricutiro in Michoacan state.
文摘Assisted migration has been proposed as a strategy for adaptive management of forest species in response to expected effects of climate change,but it is controversial for several reasons.Tropical dry forests are among the most threatened ecosystems in the world.In Mexico,historically,land-use change and deforestation have been decreasing forest cover,and climate change is shifting the potential distribution of different forest types,exacerbating the risk of local extinctions.Assisted altitudinal migration could be a feasible strategy for reducing local extinctions in response to climate change and lack of landscape connectivity.Our objective was to evaluate survival and growth of Albizia plurijuga and Ceiba aesculifolia,two tropical deciduous forests species in Mexico.We transplanted 4-month-old seedlings to experimental raised beds at three altitudes(2100,2400 and 2700 m a.s.l.),exceeding their upper regional limit of distribution(2000 m a.s.l.).We also tested seed germination at each altitude.We monitored the experiment for 10 months.For both species,as altitude increased and cold weather was more prevalent,plant performance declined.Within species,differences in individual growth were significant among altitudes.Overall survival was 18.5%for A.plurijuga and 24.5%for C.aesculifolia.Both species had higher survival and better growth at lower altitude,and no seedling emergence at any altitude.We conclude that assisted migration can be implemented for each species by an upward attitudinal shift within,and not exceeding,400 m beyond their present upper altitudinal limit of distribution.Our results indicate that for many species that show altitudinal gradients at regional scales,unless current climate conditions change,the potential to establish outside their range is minimal.
文摘It is known that large amounts of residual lignin are generated in the pulp and paper industry.A new alternative for Kraft lignin valorization,which consists of first a chemical modification using a diisocyanate and then the efficient dispersion in castor oil to achieve stable gel-like systems,is proposed in this work.Rheological properties and microstructure of these materials were determined by means of small amplitude oscillatory shear tests and viscous flow measurements and atomic force microscopy observations,respectively.Moreover,both standardized penetration tests and tribological assays,usually performed in the lubricant industry,were carried out to evaluate the performance characteristics as lubricating greases.Linear viscoelasticity functions are affected by the lignin/diisocyanate ratio and thickener concentration.The thermorheological response evidenced a softening temperature of around 105°C.The microstructure of these gel-like dispersions is composed of interconnected thin fibers,homogeneously distributed in castor oil.Moreover,the NCO-functionalized lignin gel-like dispersions studied show lower friction coefficients than traditional lubricating greases.
文摘The chemistry of rainwater has been subject to numerous investigations during the last two decades due to the increase of environmental problems caused by the acid deposition. The present study focuses on one aspect of air pollution, the chemical composition of wet deposition of an industrial zone. The sampling period was from March to December 2009. The station was located on the roof of the Chemistry School at the University of Nuevo León, an area in the north of Monterrey where the majority of pollution is generated. Twenty-five wet precipitation samples were collected with an automatic sampler and analyzed for pH, ions (, , Cl<sup>-</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, Na<sup>+</sup>, K<sup>+</sup>) and conductivity. The results show that the average pH is higher than 5.6;the characteristics of the rainwater studied are of alkaline nature due to the values of pH found;there is an evident anthropogenic source contributing to the alkaline of rain water. In order to find possible association between ions and consequently the possible sources of pollutants correlation study was applied using the program SPSS v.12. Good correlations were found between ions and along with Ca<sup>2+</sup> and Mg<sup>2+</sup>. The local extraction industry and surrounding aerosols might be causing of alkaline rain which may be due to the neutralization effect of particulate matter. This study represents a continuation of the studies of rainwater chemistry in the Northeast of Mexico.
文摘The neuroanatomy of the mid-sized theropod Sinosaurus triassicus from the Lower Jurassic Lufeng Formation, Lufeng Basin in Yunnan Province, China was studied using X-ray computed tomography. The braincase is characterized by a large supraoccipital knob that is capped by a posterior projection of the parietal and two external foramina for the caudal middle cerebral vein, which is completely enclosed by the supraoccipital. The basicranium has well defined, short basipterygoid processes that project ventral to the basal tubera. The basisphenoid is expanded, projects posteroventrally, and is pierced by four pneumatic recesses. The endocranial morphology resembles that observed in other basal theropods—in particular some allosauroids—and has a strongly marked pontine flexure and a large dorsal expansion. The inner ear morphology is also similar to that observed in other basal theropods, with slender semicircular canals. The anterior semicircular canal is 20% larger than the posterior semicircular canal, and the angle formed between them is less than 90° when seen in dorsal view.
