Over the past century,age-related diseases,such as cancer,type-2 diabetes,obesity,and mental illness,have shown a significant increase,negatively impacting overall quality of life.Studies on aged animal models have un...Over the past century,age-related diseases,such as cancer,type-2 diabetes,obesity,and mental illness,have shown a significant increase,negatively impacting overall quality of life.Studies on aged animal models have unveiled a progressive discoordination at multiple regulatory levels,including transcriptional,translational,and post-translational processes,resulting from cellular stress and circadian derangements.The circadian clock emerges as a key regulator,sustaining physiological homeostasis and promoting healthy aging through timely molecular coordination of pivotal cellular processes,such as stem-cell function,cellular stress responses,and inter-tissue communication,which become disrupted during aging.Given the crucial role of hypothalamic circuits in regulating organismal physiology,metabolic control,sleep homeostasis,and circadian rhythms,and their dependence on these processes,strategies aimed at enhancing hypothalamic and circadian function,including pharmacological and non-pharmacological approaches,offer systemic benefits for healthy aging.Intranasal brain-directed drug administration represents a promising avenue for effectively targeting specific brain regions,like the hypothalamus,while reducing side effects associated with systemic drug delivery,thereby presenting new therapeutic possibilities for diverse age-related conditions.展开更多
This study investigates the influence of electropolymerization conditions on the deposition of polypyrrole(PPy)onto cotton-derived carbon fiber(CF)modified with reduced graphene oxide(rGO)for supercapacitors applicati...This study investigates the influence of electropolymerization conditions on the deposition of polypyrrole(PPy)onto cotton-derived carbon fiber(CF)modified with reduced graphene oxide(rGO)for supercapacitors applications using an experimental/theorical approach.The surface modification of CF by rGO and/or by PPy electrodeposited at 10,25 and 50 mV s^(-1) was thoroughly examined physicochemical and electrochemically.Composite electrodes comprising CF-rGo-PPy,synthesized via electropolymerization at 25 mV s^(-1),demonstrated a remarkable increase in capacitance,showcasing~742 F g^(-1) compared to 153 F g^(-1) for CF.SEM,N_(2)-surface area,XPS,and TD-DFT approach revealed that the higher capacitance observed in CF-rGo-PPy electrodes underscores the influence of morphology and charged nitrogen species on the electrochemical performance of these modified electrodes.Notably,this electrode material achieves a specific capacitance retention of~96%of their initial capacitance after 10000 cycles at 0.5 A g^(-1) measured in a two-electrodes cell configuration.This work also discusses the influence of the scan rate used for pyrrole electropolymerization on the pseudocapacitance contribution of PPy and its possible effect on the porosity of the material.These results highlight the importance of appropriate electropolymerization conditions that allow obtaining the synergistic effect between CF,rGO and PPy.展开更多
Coronavirus disease 2019(COVID-19),caused by the highly pathogenic severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),primarily impacts the respiratory tract and can lead to severe outcomes such as acute resp...Coronavirus disease 2019(COVID-19),caused by the highly pathogenic severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),primarily impacts the respiratory tract and can lead to severe outcomes such as acute respiratory distress syndrome,multiple organ failure,and death.Despite extensive studies on the pathogenicity of SARS-CoV-2,its impact on the hepatobiliary system remains unclear.While liver injury is commonly indicated by reduced albumin and elevated bilirubin and transaminase levels,the exact source of this damage is not fully understood.Proposed mechanisms for injury include direct cytotoxicity,collateral damage from inflammation,drug-induced liver injury,and ischemia/hypoxia.However,evidence often relies on blood tests with liver enzyme abnormalities.In this comprehensive review,we focused solely on the different histopathological manifestations of liver injury in COVID-19 patients,drawing from liver biopsies,complete autopsies,and in vitro liver analyses.We present evidence of the direct impact of SARS-CoV-2 on the liver,substantiated by in vitro observations of viral entry mechanisms and the actual presence of viral particles in liver samples resulting in a variety of cellular changes,including mitochondrial swelling,endoplasmic reticulum dilatation,and hepatocyte apoptosis.Additional ly,we describe the diverse liver pathology observed during COVID-19 infection,encompassing necrosis,steatosis,cholestasis,and lobular inflammation.We also discuss the emergence of long-term complications,notably COVID-19-related secondary sclerosing cholangitis.Recognizing the histopathological liver changes occurring during COVID-19 infection is pivotal for improving patient recovery and guiding decision-making.展开更多
The sandstones of the Late miocene–Pliocene Dibdibba Formation in the Najaf–Karbala Plateau and Basra were examined to determine their source rocks and origin. The rare earth elements(REE) and trace elements(Sc, Co,...The sandstones of the Late miocene–Pliocene Dibdibba Formation in the Najaf–Karbala Plateau and Basra were examined to determine their source rocks and origin. The rare earth elements(REE) and trace elements(Sc, Co, V, and Th) concentrations in these sandstones revealed that they likely derived from a single source. The steep light rare earth elements(LREE) and flat, heavy rare earth element(HREE) patterns, negative Eu anomaly, and high ΣREE contents in sandstones suggest its derivation from a suggests that a passive continental margin environment and originated from felsic source rocks. The average concentration of ΣREE is 93.5 ppm, which is lower than that of the average crustal compositions like Upper Continental Crust and Post Archean Australian Shale. The higher proportion of LREE compared to HREE implies that these sandstones were recycled and derived from a distal source. The Th/Co, Th/Sc, La/Sc, La/Co, Eu/Eu*and(La/Lu)cn elemental ratios indicated that these Late Miocene–Pliocene sandstones were derived from felsic rocks located in the marginal region of the Arabian Shield.展开更多
Hepatocrinology explores the intricate relationship between liver function and the endocrine system.Chronic liver diseases such as liver cirrhosis can cause endocrine disorders due to toxin accumulation and protein sy...Hepatocrinology explores the intricate relationship between liver function and the endocrine system.Chronic liver diseases such as liver cirrhosis can cause endocrine disorders due to toxin accumulation and protein synthesis disruption.Despite its importance,assessing endocrine issues in cirrhotic patients is frequently neglected.This article provides a comprehensive review of the epidemiology,pathophysiology,diagnosis,and treatment of endocrine disturbances in liver cirrhosis.The review was conducted using the PubMed/Medline,EMBASE,and Scielo databases,encompassing 172 articles.Liver cirrhosis is associated with endocrine disturbances,including diabetes,hypoglycemia,sarcopenia,thyroid dysfunction,hypogonadotropic hypogonadism,bone disease,adrenal insufficiency,growth hormone dysfunction,and secondary hyperaldosteronism.The optimal tools for diagnosing diabetes and detecting hypoglycemia are the oral glucose tolerance test and continuous glucose monitoring system,respectively.Sarcopenia can be assessed through imaging and functional tests,while other endocrine disorders are evaluated using hormonal assays and imaging studies.Treatment options include metformin,glucagon-like peptide-1 analogs,sodium-glucose co-transporter-2 inhibitors,and insulin,which are effective and safe for diabetes control.Established standards are followed for managing hypoglycemia,and hormone replacement therapy is often necessary for other endocrine dysfunctions.Liver transplantation can address some of these problems.展开更多
A large fire of 233 ha in Huascarán National Park in Peru provided an opportunity to compare plant and bird responses in burned and nearby unburned zones of the puna. Heights and live diameters of flagship Puya r...A large fire of 233 ha in Huascarán National Park in Peru provided an opportunity to compare plant and bird responses in burned and nearby unburned zones of the puna. Heights and live diameters of flagship Puya raimondii rosettes(assigned to four broad developmental phases), plant communities(66 species in 24 families and nine growth forms) and bird communities(77 species in six trophic guilds) were monitored after the fire. Although no mortality was observed, Puya raimondii plants were affected by the fire, losing approximately 60% of their photosynthetic area across all developmental phases, but recovered quickly during the first two years after fire. The comparison of Puya rosette recovery after fire was complicated by the changes in live rosette diameter for unburned plants, which showed plasticity of photosynthetic area linked to seasonal and annual fluctuations in precipitation in this relatively dry environment(decreased by 26% for mature adult plants over the study period). Fire caused an immediate change in the density, biomass and composition of vegetation. Although the species present remained similar, their abundances changed significantly immediately after the fire, with notable reductions in dominant tussock grasses. This provided opportunities for other plants, resulting in higher postfire diversity of plant species, genera, families and growth forms. In turn, the changes in vegetation after fire affected the composition of birds according to their trophic guild. Granivores largely disappeared,generalists were mostly unaffected, and other guilds showed a more complex response. As the vegetation recovered, most displaced birds returned within approximately one year.展开更多
Fecal microbiota transplantation(FMT)offers a potential treatment avenue for hepatic encephalopathy(HE)by leveraging beneficial bacterial displacement to restore a balanced gut microbiome.The prevalence of HE varies w...Fecal microbiota transplantation(FMT)offers a potential treatment avenue for hepatic encephalopathy(HE)by leveraging beneficial bacterial displacement to restore a balanced gut microbiome.The prevalence of HE varies with liver disease severity and comorbidities.HE pathogenesis involves ammonia toxicity,gut-brain communication disruption,and inflammation.FMT aims to restore gut microbiota balance,addressing these factors.FMT's efficacy has been explored in various conditions,including HE.Studies suggest that FMT can modulate gut microbiota,reduce ammonia levels,and alleviate inflammation.FMT has shown promise in alcohol-associated,hepatitis B and C-associated,and non-alcoholic fatty liver disease.Benefits include improved liver function,cognitive function,and the slowing of disease progression.However,larger,controlled studies are needed to validate its effectiveness in these contexts.Studies have shown cognitive improvements through FMT,with potential benefits in cirrhotic patients.Notably,trials have demonstrated reduced serious adverse events and cognitive enhancements in FMT arms compared to the standard of care.Although evidence is promising,challenges remain:Limited patient numbers,varied dosages,administration routes,and donor profiles.Further large-scale,controlled trials are essential to establish standardized guidelines and ensure FMT's clinical applications and efficacy.While FMT holds potential for HE management,ongoing research is needed to address these challenges,optimize protocols,and expand its availability as a therapeutic option for diverse hepatic conditions.展开更多
Forest disturbances at gap levels are one of the most important events for the regeneration and establishment of intermediate tree species.Abrupt canopy openings expose plants to high light intensity and high evaporat...Forest disturbances at gap levels are one of the most important events for the regeneration and establishment of intermediate tree species.Abrupt canopy openings expose plants to high light intensity and high evaporative demands that stress shade-acclimated plants.Later,the slow closure of gaps reduces light availability to plants established when the incident irradiation was higher.This work evaluated the morphological and physiological acclimation of Cabralea canjerana(Vell)Mart.regeneration to sudden and to gradual changes in canopy cover.A pot experiment was carried out with plants exposed to a sudden opening.A few days after the light shock,plants rapidly increased photosynthetic rates and decreased leaf water potential.After two months,plants activated physiological responses at leaf and whole plant levels to high light and water stresses,e.g.,increased stoma-tal conductance,stomatal index and reduction of leaf:fine roots ratio and chlorophyll.After seven months,hydraulic conductivity of petioles and the whole leaf increased,and growth was much higher than plants that remained under the canopy.In a field experiment in gaps in the rainforest,plants acclimated to all canopy covers.Seven years after planting,growth was maximum in open environments within the gaps,even if the canopy closed during the first 20 months after planting.In conclusion,if this species is planted to enrich the rainforest,positions within gaps with lower canopy cover should be chosen and gap closure will not affect growth.To manage C.canjerana natural regeneration,the opening of gaps and removal of understory will increase survival and growth without the risk that the stress caused by these sudden openings could lead to the death of seedlings.Com-bining pot and field experiments helps to understand the autecology of trees with particular ecological interest,and to build sound restoration practices.展开更多
We studied the cycles of reproduction and fat bodies of a blue-tailed skink population of an undescribed species of the Plestiodon brevirostris group.Sexual maturity is attained by females and males as they both reach...We studied the cycles of reproduction and fat bodies of a blue-tailed skink population of an undescribed species of the Plestiodon brevirostris group.Sexual maturity is attained by females and males as they both reach about 59 mm of SVL.Vitellogenesis started in June-July,with ovulation occurring during late-October to mid-November,and parturition in mid-spring.Litter size varied from two to six,with a mean of 3.86±0.15 embryos in uterus,and showed a positive correlation with female body mass and SVL.During gestation,a significant increase in the average wet mass of embryos in uterus was evident.In comparison,there were no notable changes in the average dry mass.Juvenile growth data suggest that sexual maturity,both males and females,is reached at 16-17 months of age.Testicles and epididymides exhibited maximal weight during August-September.Testicular regression occurred in September.Mating apparently takes place from mid-summer to early fall.Lipids stored in female fat bodies are used for vitellogenesis and for nutrition during the winter months.In males,the stored lipids appear to be used in reproductive activities during the mating season.展开更多
Rationale:American tegumentary leishmaniasis comprises cutaneous and mucocutaneous manifestations caused by parasitic infections by various Leishmania species.This report details the clinical interventions for a patie...Rationale:American tegumentary leishmaniasis comprises cutaneous and mucocutaneous manifestations caused by parasitic infections by various Leishmania species.This report details the clinical interventions for a patient with American tegumentary leishmaniasis in Mendoza,Argentina,a non-endemic region.Patient concerns:A 43-year-old male was admitted to a tertiary care hospital in Mendoza,Argentina Republic with a history of progressive nasal discharge,septal perforation,facial pain,and pruritus.Despite treatment for presumed nasal myiasis and vasculitis with granulomatosis,symptoms persisted.Diagnosis:American tegumentary leishmaniasis.Interventions:Intravenous liposomal amphotericin B.Outcomes:Follow-up at 30 days showed no recurrence of symptoms with a remarkable clinical improvement of the nasal lesion.Lessons:This case sheds light on the necessity of accurate identification for timely intervention and the need to recognize the diverse manifestations of American tegumentary leishmaniasis to avoid misdiagnosis.展开更多
Due to a complex geological and biotic history,the Isthmus of Tehuantepec(IT),has been long recognized as a driver for the evolutionary divergence of numerous lowland and highland taxa.Widely distributed in the lowlan...Due to a complex geological and biotic history,the Isthmus of Tehuantepec(IT),has been long recognized as a driver for the evolutionary divergence of numerous lowland and highland taxa.Widely distributed in the lowlands of the American continent,the White-Tipped Dove(Leptotila verreauxi)is a polytypic species with 13 recognized subspecies.Four of these have been recorded in Mexico,and the distribution of three abuts at the IT,suggesting a contact zone.To estimate phylogenetic patterns,divergence times and genetic differentiation,we examined two mt DNA(ND2 and COI)and one n DNA(β-fibint 7)markers.We also used correlative ecological niche models(ENM)to assess whether ecological differences across the IT may have acted as a biogeographical boundary.We estimated paleodistributions during the Middle Holocene,Last Glacial Maximum and Last Interglacial,to evaluate the influence of climate changes on the distribution and demographic changes.Our results showed genetically distinct lineages that diverged approximately 2.5 million years ago.Climatic and ecological factors may have played a dual role in promoting differentiation,but also in the formation of a secondary contact zone in the southern IT.Our ecological niche comparisons indicated that the ecological niche of sympatric lineages at the IT are not identical,suggesting niches divergence;in addition,environmental niche models across the region indicated no abrupt biogeographic barriers,but the presence of regions with low suitability.These results suggest that genetic differentiation originated by a vicariant event probably related to environmental factors,favored the evolution of different ecological niches.Also,the absence of a biogeographic barrier but the presence of less suitable areas in the contact regions,suggest that secondary contact zones may be also maintained by climatic factors for the eastern group,but also by biotic interactions for the western group.展开更多
Identifying factors affecting the survival of individuals is essential for understanding the evolution of life-history traits and population dynamics.Despite numerous studies on this subject in north-temperate environ...Identifying factors affecting the survival of individuals is essential for understanding the evolution of life-history traits and population dynamics.Despite numerous studies on this subject in north-temperate environments,there is a lack of equivalent studies at similar latitudes in the south.Here,we used a 14-year dataset of capture,banding,and resighting to estimate the annual variation in the apparent adult survival probability of a south-temperate population of House Wrens(Troglodytes aedon bonariae).We evaluated temporal variation in sur-vival and the effect of environmental(climatic)and demographic variables(adult abundance,total number of fledglings produced during each breeding season)on survival estimators.We found that the probability of adult survival decreased as the abundance of breeding adults increased.This density-dependent effect could be related to the resident lifestyle of southern House Wrens,which could determine an intense competition for territories and resources that ultimately would affect their survival.展开更多
Anti-ganglioside antibodies are associated with delayed/poor clinical recovery in Guillain-Barrèsyndrome,mostly related to halted axon regeneration.Cross-linking of cell surface gangliosides by anti-ganglioside a...Anti-ganglioside antibodies are associated with delayed/poor clinical recovery in Guillain-Barrèsyndrome,mostly related to halted axon regeneration.Cross-linking of cell surface gangliosides by anti-ganglioside antibodies triggers inhibition of nerve repair in in vitro and in vivo paradigms of axon regeneration.These effects involve the activation of the small GTPase Rho A/ROCK signaling pathways,which negatively modulate growth cone cytoskeleton,similarly to well stablished inhibitors of axon regeneration described so far.The aim of this work was to perform a proof of concept study to demonstrate the effectiveness of Y-27632,a selective pharmacological inhibitor of ROCK,in a mouse model of axon regeneration of peripheral nerves,where the passive immunization with a monoclonal antibody targeting gangliosides GD1a and GT1b was previously reported to exert a potent inhibitory effect on regeneration of both myelinated and unmyelinated fibers.Our results demonstrate a differential sensitivity of myelinated and unmyelinated axons to the pro-regenerative effect of Y-27632.Treatment with a total dosage of 9 mg/kg of Y-27632 resulted in a complete prevention of anti-GD1a/GT1b monoclonal antibody-mediated inhibition of axon regeneration of unmyelinated fibers to skin and the functional recovery of mechanical cutaneous sensitivity.In contrast,the same dose showed toxic effects on the regeneration of myelinated fibers.Interestingly,scale down of the dosage of Y-27632 to 5 mg/kg resulted in a significant although not complete recovery of regenerated myelinated axons exposed to anti-GD1a/GT1b monoclonal antibody in the absence of toxicity in animals exposed to only Y-27632.Overall,these findings confirm the in vivo participation of Rho A/ROCK signaling pathways in the molecular mechanisms associated with the inhibition of axon regeneration induced by anti-GD1a/GT1b monoclonal antibody.Our findings open the possibility of therapeutic pharmacological intervention targeting Rho A/Rock pathway in immune neuropathies associated with the presence of anti-ganglioside antibodies and delayed or incomplete clinical recovery after injury in the peripheral nervous system.展开更多
This study focuses on treating Guadua angustifolia bamboo fibers to enhance their properties for reinforcement applications in composite materials.Chemical(alkali)and physical(dry etching plasma)treatments were used s...This study focuses on treating Guadua angustifolia bamboo fibers to enhance their properties for reinforcement applications in composite materials.Chemical(alkali)and physical(dry etching plasma)treatments were used separately to augment compatibility of Guadua angustifolia fibers with various composite matrices.The influence of these treatments on the fibers’performance,chemical composition,and surface morphology were analyzed.Statistical analysis indicated that alkali treatments reduced the tensile modulus of elasticity and strength of fibers by up to 40%and 20%,respectively,whereas plasma treatments maintain the fibers’mechanical performance.FTIR spectroscopy revealed significant alterations in chemical composition due to alkali treatments,while plasma-treated fibers showed minimal changes.Surface examination through Scanning Electron Microscopy(SEM)revealed post-treatment modifications in both cases;alkali treatments served as a cleanser,eliminating lignin and hemicellulose from the fiber surface,whereas plasma treatments also produce rough surfaces.These results validate the impact of the treatments on the fiber mechanical performance,which opens up possibilities for using Guadua angustifolia fibers as an alternative reinforcement in composite manufacturing.展开更多
Colorectal cancer is one of the predominant tumors in the world,primarily generated by a progression from polyp to cancer which can last several years,giving a great opportunity to the scientific community for its pre...Colorectal cancer is one of the predominant tumors in the world,primarily generated by a progression from polyp to cancer which can last several years,giving a great opportunity to the scientific community for its prevention by screening programs that can be done with invasive and non-invasive tests.In this issue,Lopes et al show us an excellent review of screening,its options,its advantages and disadvantages.展开更多
The studies on hydrothermal alteration-induced eff ects in surface and subsurface rocks provide useful information in the characterization and exploitation of a geothermal reservoir.Generally,these studies are based o...The studies on hydrothermal alteration-induced eff ects in surface and subsurface rocks provide useful information in the characterization and exploitation of a geothermal reservoir.Generally,these studies are based on traditional,and reliable methods like petrography(primary and secondary minerals,and grade of alteration),and geochemistry(mobility of elements,changes in mass and concentration of elements,and fluid inclusions).Recently,apart from these established methods,some methods based on the geochemical(Chemical Index of Alteration,CIA;Weathering Index of Parkar,WIP;Loss on Ignition,LOI;and Sulfur,S)and rock magnetic properties(magnetic susceptibility,χlf;and percentage frequency-dependent susceptibility,χfd%)are also being applied in the identification of whether a rock is an altered or a fresh one.The Acoculco Geothermal Field(AGF),Mexico,is characterized by high temperature and very low permeability,and it is considered a promissory Enhanced Geothermal System.The following changes are observed in the rocks as a result of an increase in hydrothermal alteration:(1)an increase in CIA,LOI,and S values,and a decrease in WIP;(2)an increase in quartz and quartz polymorph minerals(silicification),and clay minerals(argillization);and(3)decrease inχlf values.At AGF,the most altered surface acid rocks are characterized by entirely quartz and its polymorphs,and clay minerals.The present study also indicates the applicability of the binary plots of major elements(felsic vs mafic component)and rock magnetic parameters(χlf vs.χfd%).The rock withχfd%value of 2-10 andχlf value<0.5×10^(-6)m^(3) kg^(-1)indicate the presence of single domain and stable single domain grains,which in turn suggests that it is an altered rock.These methods are simple to apply,rapid,reliable,and have the potential to become eff ective tools for the identifi cation of hydrothermally altered rocks during the initial stage of geothermal exploration.展开更多
Most described Mesozoic ants belong to stem groups that existed only during the Cretaceous period.Previously,the earliest known crown ants were dated to the Turonian(Late Cretaceous,ca.94-90 million years ago(Ma))depo...Most described Mesozoic ants belong to stem groups that existed only during the Cretaceous period.Previously,the earliest known crown ants were dated to the Turonian(Late Cretaceous,ca.94-90 million years ago(Ma))deposits found in the USA,Kazakhstan,and Botswana.However,the recent discovery of an alate male ant in Kachin amber from the earliest Cenomanian(ca.99 Ma),representing a new genus and species,Antiquiformica alata,revises the narrative on ant diversification.Antiquiformica can be distinctly differentiated from all known male stem ants by its geniculate antennae with elongated scape,extending far beyond the occipital margin of the head and half the length of the funiculus,as well as its partly reduced forewing venation.Furthermore,the combination of a one-segmented waist with a well-developed node,elongated scape extending beyond the occipital margin,and reduced forewing venation,particularly the completely reduced m-cu and rs-m crossveins and absence of rm and mcu closed cells,firmly places the fossil within the extant subfamily Formicinae.Fourier transform infrared spectroscopy(FTIR)confirmed that the amber containing Antiquiformica alata originated from the Kachin mines in Myanmar.This discovery significantly revises our understanding of the early evolution of Formicinae.The presence of Antiquiformica in Cenomanian amber indicates that the subfamily Formicinae emerged at least by the start of the Late Cretaceous,with crown ants likely originating earlier during the earliest Cretaceous or possibly the Late Jurassic,although paleontological evidence is lacking to support the latter hypothesis.展开更多
Semiarid Patagonia represents 25%of the rangeland area in Argentina,and sheep overgrazing has degraded about a third of it in the past.In this century,depleted domestic stocks have mostly stabilized,but Guanaco popula...Semiarid Patagonia represents 25%of the rangeland area in Argentina,and sheep overgrazing has degraded about a third of it in the past.In this century,depleted domestic stocks have mostly stabilized,but Guanaco populations have grown.These native camelids share habitat and diets with sheep,but their effect on vegetation is poorly understood and has long been debated.We set up an exclusion experiment in Monte León and Cañadón Vaca,a semiarid shrubland grassland in southern Patagonia,currently grazed only by guanacos.Vegetation baselines were studied in 2016 in twelve plots,and half of them were protected from guanaco grazing.Thirty-six plots were cleared to study revegetation.Vegetation was reassessed in 2021,and changes were evaluated using a paired t-test.Within protected plots,vegetation cover increased,bare soil diminished,and vegetated patches grew in size,but the density of the patch-interpatch arrangement did not change.Biodiversity,measured by richness and the Shan-non-Wiener(SW)index,grew significantly.Nutrient recycling increased,as did the Stability and Infiltration Land Function indexes,although these last differences were not significant.Vegetation cover under guanaco grazing also increased,mainly due to the growth of dwarf shrubs,a typical tendency in sheep grazing-induced transitions in the region.Vegetated patches under grazing fragmented,resulting in smaller patches and denser patch struc-tures,while diversity and land function indexes remained unchanged.Young plants established in cleared plots without guanacos showed higher cover density and individual size.These effects are similar to those observed in numerous experimental sheep exclosures.Guanaco grazing may thus prevent restoration and contribute to the generalized land degradation processes that overgrazing has been causing in Patagonia for over a century.展开更多
Non-traditional lignocellulosic materials are a significant resource for producing high-value products,including nanocellulose.This work studied the nanocellulose obtention from chemical pulps of the two fast-growing ...Non-traditional lignocellulosic materials are a significant resource for producing high-value products,including nanocellulose.This work studied the nanocellulose obtention from chemical pulps of the two fast-growing bamboo species,Guadua trinii,and Guadua angustifolia.Chemical pulps were produced by soda-anthraquinone(S)pulping from both autohydrolysis-pretreated(H)and unpretreated bamboo chips.Autohydrolysis-pretreated(SHP)and unpretreated soda-anthraquinone(AQ)(SP)pulps were characterized by yield,Kappa number,alpha,beta,and gamma cellulose,degree of polymerization,water retention value,and crystallinity.The nanocellulose was produced by a sequential chemical oxidation treatment(2,2,6,6-tetramethylpiperidine-1-oxyl,TEMPO reagent)and mechanical nanofibrillation.Nanocellulose was characterized by carboxylic group content and viscosity.The results revealed that autohydrolysis pretreatment resulted in a higher hemicelluloses extraction in G.angustifolia.In contrast,the pulping yield of unpretreated samples was higher for G.trinii,and the soda-AQ pulps from this species exhibited better delignification than the autohydrolysis-pretreated pulps.The crystallinity index values of the obtained pulps were high(>80%),and the alpha-cellulose contents were similar.The viscosities of the aqueous nanocellulose suspensions were higher for the nanocellulose solutions obtained from the unpretreated soda-AQ pulps.Besides,nanocellulose from G.trinii unpretreated soda-AQ pulps had a higher rate of carboxylic groups.The results of this work are significant in assessing the potential of both bamboo species as a source of high-value products within the biorefinery framework because the viscosities of the aqueous nanocellulose suspensions depend on the size and shape of nanofibrils.It has significant importance for industrial unit operations and potential applications.展开更多
Parkinsonism by unilateral,intranigralβ-sitosterolβ-D-glucoside administration in rats is distinguished in that theα-synuclein insult begins unilaterally but spreads bilaterally and increases in severity over time,...Parkinsonism by unilateral,intranigralβ-sitosterolβ-D-glucoside administration in rats is distinguished in that theα-synuclein insult begins unilaterally but spreads bilaterally and increases in severity over time,thus replicating several clinical features of Parkinson’s disease,a typicalα-synucleinopathy.As Nurr1 repressesα-synuclein,we evaluated whether unilateral transfected of rNurr1-V5 transgene via neurotensin-polyplex to the substantia nigra on day 30 after unilateralβ-sitosterolβ-D-glucoside lesion could affect bilateral neuropathology and sensorimotor deficits on day 30 post-transfection.This study found that rNurr1-V5 expression but not that of the green fluorescent protein(the negative control)reducedβ-sitosterolβ-D-glucoside-induced neuropathology.Accordingly,a bilateral increase in tyrosine hydroxylase-positive cells and arborization occurred in the substantia nigra and increased tyrosine hydroxylase-positive ramifications in the striatum.In addition,tyrosine hydroxylase-positive cells displayed less senescence markerβ-galactosidase and more neuron-cytoskeleton markerβIII-tubulin and brain-derived neurotrophic factor.A significant decrease in activated microglia(positive to ionized calcium-binding adaptor molecule 1)and neurotoxic astrocytes(positive to glial fibrillary acidic protein and complement component 3)and increased neurotrophic astrocytes(positive to glial fibrillary acidic protein and S100 calcium-binding protein A10)also occurred in the substantia nigra.These effects followed the bilateral reduction inα-synuclein aggregates in the nigrostriatal system,improving sensorimotor behavior.Our results show that unilateral rNurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neurodegeneration(senescence and loss of neuron-cytoskeleton and tyrosine hydroxylase-positive cells),neuroinflammation(activated microglia,neurotoxic astrocytes),α-synuclein aggregation,and sensorimotor deficits.Increased neurotrophic astrocytes and brain-derived neurotrophic factor can mediate the rNurr1-V5 effect,supporting its potential clinical use in the treatment of Parkinson’s disease.展开更多
基金supported by National Council of Science and Technology(CONACYT)(grants FC 2016/2672 and FOSISS 272757),INMEGEN(09/2017/I)the Ministry of Education,Science,Technology and Innovation of Mexico City(SECTEI)(grant 228/2021).
文摘Over the past century,age-related diseases,such as cancer,type-2 diabetes,obesity,and mental illness,have shown a significant increase,negatively impacting overall quality of life.Studies on aged animal models have unveiled a progressive discoordination at multiple regulatory levels,including transcriptional,translational,and post-translational processes,resulting from cellular stress and circadian derangements.The circadian clock emerges as a key regulator,sustaining physiological homeostasis and promoting healthy aging through timely molecular coordination of pivotal cellular processes,such as stem-cell function,cellular stress responses,and inter-tissue communication,which become disrupted during aging.Given the crucial role of hypothalamic circuits in regulating organismal physiology,metabolic control,sleep homeostasis,and circadian rhythms,and their dependence on these processes,strategies aimed at enhancing hypothalamic and circadian function,including pharmacological and non-pharmacological approaches,offer systemic benefits for healthy aging.Intranasal brain-directed drug administration represents a promising avenue for effectively targeting specific brain regions,like the hypothalamus,while reducing side effects associated with systemic drug delivery,thereby presenting new therapeutic possibilities for diverse age-related conditions.
基金CONCYTEC and PROCIENCIA agencies from Peru in the framework of the call for Basic Research Projects2019-01[contract number401-2019-FONDECYT].
文摘This study investigates the influence of electropolymerization conditions on the deposition of polypyrrole(PPy)onto cotton-derived carbon fiber(CF)modified with reduced graphene oxide(rGO)for supercapacitors applications using an experimental/theorical approach.The surface modification of CF by rGO and/or by PPy electrodeposited at 10,25 and 50 mV s^(-1) was thoroughly examined physicochemical and electrochemically.Composite electrodes comprising CF-rGo-PPy,synthesized via electropolymerization at 25 mV s^(-1),demonstrated a remarkable increase in capacitance,showcasing~742 F g^(-1) compared to 153 F g^(-1) for CF.SEM,N_(2)-surface area,XPS,and TD-DFT approach revealed that the higher capacitance observed in CF-rGo-PPy electrodes underscores the influence of morphology and charged nitrogen species on the electrochemical performance of these modified electrodes.Notably,this electrode material achieves a specific capacitance retention of~96%of their initial capacitance after 10000 cycles at 0.5 A g^(-1) measured in a two-electrodes cell configuration.This work also discusses the influence of the scan rate used for pyrrole electropolymerization on the pseudocapacitance contribution of PPy and its possible effect on the porosity of the material.These results highlight the importance of appropriate electropolymerization conditions that allow obtaining the synergistic effect between CF,rGO and PPy.
文摘Coronavirus disease 2019(COVID-19),caused by the highly pathogenic severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),primarily impacts the respiratory tract and can lead to severe outcomes such as acute respiratory distress syndrome,multiple organ failure,and death.Despite extensive studies on the pathogenicity of SARS-CoV-2,its impact on the hepatobiliary system remains unclear.While liver injury is commonly indicated by reduced albumin and elevated bilirubin and transaminase levels,the exact source of this damage is not fully understood.Proposed mechanisms for injury include direct cytotoxicity,collateral damage from inflammation,drug-induced liver injury,and ischemia/hypoxia.However,evidence often relies on blood tests with liver enzyme abnormalities.In this comprehensive review,we focused solely on the different histopathological manifestations of liver injury in COVID-19 patients,drawing from liver biopsies,complete autopsies,and in vitro liver analyses.We present evidence of the direct impact of SARS-CoV-2 on the liver,substantiated by in vitro observations of viral entry mechanisms and the actual presence of viral particles in liver samples resulting in a variety of cellular changes,including mitochondrial swelling,endoplasmic reticulum dilatation,and hepatocyte apoptosis.Additional ly,we describe the diverse liver pathology observed during COVID-19 infection,encompassing necrosis,steatosis,cholestasis,and lobular inflammation.We also discuss the emergence of long-term complications,notably COVID-19-related secondary sclerosing cholangitis.Recognizing the histopathological liver changes occurring during COVID-19 infection is pivotal for improving patient recovery and guiding decision-making.
文摘The sandstones of the Late miocene–Pliocene Dibdibba Formation in the Najaf–Karbala Plateau and Basra were examined to determine their source rocks and origin. The rare earth elements(REE) and trace elements(Sc, Co, V, and Th) concentrations in these sandstones revealed that they likely derived from a single source. The steep light rare earth elements(LREE) and flat, heavy rare earth element(HREE) patterns, negative Eu anomaly, and high ΣREE contents in sandstones suggest its derivation from a suggests that a passive continental margin environment and originated from felsic source rocks. The average concentration of ΣREE is 93.5 ppm, which is lower than that of the average crustal compositions like Upper Continental Crust and Post Archean Australian Shale. The higher proportion of LREE compared to HREE implies that these sandstones were recycled and derived from a distal source. The Th/Co, Th/Sc, La/Sc, La/Co, Eu/Eu*and(La/Lu)cn elemental ratios indicated that these Late Miocene–Pliocene sandstones were derived from felsic rocks located in the marginal region of the Arabian Shield.
文摘Hepatocrinology explores the intricate relationship between liver function and the endocrine system.Chronic liver diseases such as liver cirrhosis can cause endocrine disorders due to toxin accumulation and protein synthesis disruption.Despite its importance,assessing endocrine issues in cirrhotic patients is frequently neglected.This article provides a comprehensive review of the epidemiology,pathophysiology,diagnosis,and treatment of endocrine disturbances in liver cirrhosis.The review was conducted using the PubMed/Medline,EMBASE,and Scielo databases,encompassing 172 articles.Liver cirrhosis is associated with endocrine disturbances,including diabetes,hypoglycemia,sarcopenia,thyroid dysfunction,hypogonadotropic hypogonadism,bone disease,adrenal insufficiency,growth hormone dysfunction,and secondary hyperaldosteronism.The optimal tools for diagnosing diabetes and detecting hypoglycemia are the oral glucose tolerance test and continuous glucose monitoring system,respectively.Sarcopenia can be assessed through imaging and functional tests,while other endocrine disorders are evaluated using hormonal assays and imaging studies.Treatment options include metformin,glucagon-like peptide-1 analogs,sodium-glucose co-transporter-2 inhibitors,and insulin,which are effective and safe for diabetes control.Established standards are followed for managing hypoglycemia,and hormone replacement therapy is often necessary for other endocrine dysfunctions.Liver transplantation can address some of these problems.
基金supported by the Universidad Nacional Mayor de San Marcos: Resolución Rectoral (RR) N° 00883-R-06, project code 061001191RR N° 00914-R-07, project code 071001281and RR N°03556-R-19, project code D19120061。
文摘A large fire of 233 ha in Huascarán National Park in Peru provided an opportunity to compare plant and bird responses in burned and nearby unburned zones of the puna. Heights and live diameters of flagship Puya raimondii rosettes(assigned to four broad developmental phases), plant communities(66 species in 24 families and nine growth forms) and bird communities(77 species in six trophic guilds) were monitored after the fire. Although no mortality was observed, Puya raimondii plants were affected by the fire, losing approximately 60% of their photosynthetic area across all developmental phases, but recovered quickly during the first two years after fire. The comparison of Puya rosette recovery after fire was complicated by the changes in live rosette diameter for unburned plants, which showed plasticity of photosynthetic area linked to seasonal and annual fluctuations in precipitation in this relatively dry environment(decreased by 26% for mature adult plants over the study period). Fire caused an immediate change in the density, biomass and composition of vegetation. Although the species present remained similar, their abundances changed significantly immediately after the fire, with notable reductions in dominant tussock grasses. This provided opportunities for other plants, resulting in higher postfire diversity of plant species, genera, families and growth forms. In turn, the changes in vegetation after fire affected the composition of birds according to their trophic guild. Granivores largely disappeared,generalists were mostly unaffected, and other guilds showed a more complex response. As the vegetation recovered, most displaced birds returned within approximately one year.
文摘Fecal microbiota transplantation(FMT)offers a potential treatment avenue for hepatic encephalopathy(HE)by leveraging beneficial bacterial displacement to restore a balanced gut microbiome.The prevalence of HE varies with liver disease severity and comorbidities.HE pathogenesis involves ammonia toxicity,gut-brain communication disruption,and inflammation.FMT aims to restore gut microbiota balance,addressing these factors.FMT's efficacy has been explored in various conditions,including HE.Studies suggest that FMT can modulate gut microbiota,reduce ammonia levels,and alleviate inflammation.FMT has shown promise in alcohol-associated,hepatitis B and C-associated,and non-alcoholic fatty liver disease.Benefits include improved liver function,cognitive function,and the slowing of disease progression.However,larger,controlled studies are needed to validate its effectiveness in these contexts.Studies have shown cognitive improvements through FMT,with potential benefits in cirrhotic patients.Notably,trials have demonstrated reduced serious adverse events and cognitive enhancements in FMT arms compared to the standard of care.Although evidence is promising,challenges remain:Limited patient numbers,varied dosages,administration routes,and donor profiles.Further large-scale,controlled trials are essential to establish standardized guidelines and ensure FMT's clinical applications and efficacy.While FMT holds potential for HE management,ongoing research is needed to address these challenges,optimize protocols,and expand its availability as a therapeutic option for diverse hepatic conditions.
基金supported by UCAR,Ministerio de Agricultura,Ganadería y Pesca de la Nación,Argentina(PIA 12010 and 14,031)ANPCyT-MINCyT,Argentina(PUE INFIVE:10520180101142CO).
文摘Forest disturbances at gap levels are one of the most important events for the regeneration and establishment of intermediate tree species.Abrupt canopy openings expose plants to high light intensity and high evaporative demands that stress shade-acclimated plants.Later,the slow closure of gaps reduces light availability to plants established when the incident irradiation was higher.This work evaluated the morphological and physiological acclimation of Cabralea canjerana(Vell)Mart.regeneration to sudden and to gradual changes in canopy cover.A pot experiment was carried out with plants exposed to a sudden opening.A few days after the light shock,plants rapidly increased photosynthetic rates and decreased leaf water potential.After two months,plants activated physiological responses at leaf and whole plant levels to high light and water stresses,e.g.,increased stoma-tal conductance,stomatal index and reduction of leaf:fine roots ratio and chlorophyll.After seven months,hydraulic conductivity of petioles and the whole leaf increased,and growth was much higher than plants that remained under the canopy.In a field experiment in gaps in the rainforest,plants acclimated to all canopy covers.Seven years after planting,growth was maximum in open environments within the gaps,even if the canopy closed during the first 20 months after planting.In conclusion,if this species is planted to enrich the rainforest,positions within gaps with lower canopy cover should be chosen and gap closure will not affect growth.To manage C.canjerana natural regeneration,the opening of gaps and removal of understory will increase survival and growth without the risk that the stress caused by these sudden openings could lead to the death of seedlings.Com-bining pot and field experiments helps to understand the autecology of trees with particular ecological interest,and to build sound restoration practices.
基金funded by the Biology Major of the Facultad de Estudios Superiores Zaragoza,Universidad Nacional Autónoma de México(UNAM)Scientific collecting permit issued by Semarnat(SGPA/DGVS 12013/12)。
文摘We studied the cycles of reproduction and fat bodies of a blue-tailed skink population of an undescribed species of the Plestiodon brevirostris group.Sexual maturity is attained by females and males as they both reach about 59 mm of SVL.Vitellogenesis started in June-July,with ovulation occurring during late-October to mid-November,and parturition in mid-spring.Litter size varied from two to six,with a mean of 3.86±0.15 embryos in uterus,and showed a positive correlation with female body mass and SVL.During gestation,a significant increase in the average wet mass of embryos in uterus was evident.In comparison,there were no notable changes in the average dry mass.Juvenile growth data suggest that sexual maturity,both males and females,is reached at 16-17 months of age.Testicles and epididymides exhibited maximal weight during August-September.Testicular regression occurred in September.Mating apparently takes place from mid-summer to early fall.Lipids stored in female fat bodies are used for vitellogenesis and for nutrition during the winter months.In males,the stored lipids appear to be used in reproductive activities during the mating season.
基金supported by the Consejo Nacional de Investigaciones Cientıfícas y Técnicas(CONICET)(PIP 2021-2023/11220200102779CO).
文摘Rationale:American tegumentary leishmaniasis comprises cutaneous and mucocutaneous manifestations caused by parasitic infections by various Leishmania species.This report details the clinical interventions for a patient with American tegumentary leishmaniasis in Mendoza,Argentina,a non-endemic region.Patient concerns:A 43-year-old male was admitted to a tertiary care hospital in Mendoza,Argentina Republic with a history of progressive nasal discharge,septal perforation,facial pain,and pruritus.Despite treatment for presumed nasal myiasis and vasculitis with granulomatosis,symptoms persisted.Diagnosis:American tegumentary leishmaniasis.Interventions:Intravenous liposomal amphotericin B.Outcomes:Follow-up at 30 days showed no recurrence of symptoms with a remarkable clinical improvement of the nasal lesion.Lessons:This case sheds light on the necessity of accurate identification for timely intervention and the need to recognize the diverse manifestations of American tegumentary leishmaniasis to avoid misdiagnosis.
基金the financial support for this study by PAPIIT-UNAM grant(IN222817)to LAS-Gthe Fran?ois Vuilleumier Fund for Neotropical Bird Research from the Neotropical Ornithological Society(NOS)awarded to OJE-C。
文摘Due to a complex geological and biotic history,the Isthmus of Tehuantepec(IT),has been long recognized as a driver for the evolutionary divergence of numerous lowland and highland taxa.Widely distributed in the lowlands of the American continent,the White-Tipped Dove(Leptotila verreauxi)is a polytypic species with 13 recognized subspecies.Four of these have been recorded in Mexico,and the distribution of three abuts at the IT,suggesting a contact zone.To estimate phylogenetic patterns,divergence times and genetic differentiation,we examined two mt DNA(ND2 and COI)and one n DNA(β-fibint 7)markers.We also used correlative ecological niche models(ENM)to assess whether ecological differences across the IT may have acted as a biogeographical boundary.We estimated paleodistributions during the Middle Holocene,Last Glacial Maximum and Last Interglacial,to evaluate the influence of climate changes on the distribution and demographic changes.Our results showed genetically distinct lineages that diverged approximately 2.5 million years ago.Climatic and ecological factors may have played a dual role in promoting differentiation,but also in the formation of a secondary contact zone in the southern IT.Our ecological niche comparisons indicated that the ecological niche of sympatric lineages at the IT are not identical,suggesting niches divergence;in addition,environmental niche models across the region indicated no abrupt biogeographic barriers,but the presence of regions with low suitability.These results suggest that genetic differentiation originated by a vicariant event probably related to environmental factors,favored the evolution of different ecological niches.Also,the absence of a biogeographic barrier but the presence of less suitable areas in the contact regions,suggest that secondary contact zones may be also maintained by climatic factors for the eastern group,but also by biotic interactions for the western group.
基金supported by the University of Buenos Aires(UBACyT,20020090200117)CONICET(PIP112-200901-00011)grants to GJF.
文摘Identifying factors affecting the survival of individuals is essential for understanding the evolution of life-history traits and population dynamics.Despite numerous studies on this subject in north-temperate environments,there is a lack of equivalent studies at similar latitudes in the south.Here,we used a 14-year dataset of capture,banding,and resighting to estimate the annual variation in the apparent adult survival probability of a south-temperate population of House Wrens(Troglodytes aedon bonariae).We evaluated temporal variation in sur-vival and the effect of environmental(climatic)and demographic variables(adult abundance,total number of fledglings produced during each breeding season)on survival estimators.We found that the probability of adult survival decreased as the abundance of breeding adults increased.This density-dependent effect could be related to the resident lifestyle of southern House Wrens,which could determine an intense competition for territories and resources that ultimately would affect their survival.
基金supported by Fondo para la Investigación Cientifica y Tecnológica(FONCy T),Argentina,grant#PICT 2015-2473(to PHHL)supported by grants from National Institute of Health/National Institute of Neurological Disorders and Stroke(NIH/NINDS,USA)(NS121621)+2 种基金Department of Defense,USA(Do D-CL1)(PR200530)partially financed with a fellowship for Research in Medicine from Fundación Florencio Fiorinisupported with a PhD fellowship from CONICET。
文摘Anti-ganglioside antibodies are associated with delayed/poor clinical recovery in Guillain-Barrèsyndrome,mostly related to halted axon regeneration.Cross-linking of cell surface gangliosides by anti-ganglioside antibodies triggers inhibition of nerve repair in in vitro and in vivo paradigms of axon regeneration.These effects involve the activation of the small GTPase Rho A/ROCK signaling pathways,which negatively modulate growth cone cytoskeleton,similarly to well stablished inhibitors of axon regeneration described so far.The aim of this work was to perform a proof of concept study to demonstrate the effectiveness of Y-27632,a selective pharmacological inhibitor of ROCK,in a mouse model of axon regeneration of peripheral nerves,where the passive immunization with a monoclonal antibody targeting gangliosides GD1a and GT1b was previously reported to exert a potent inhibitory effect on regeneration of both myelinated and unmyelinated fibers.Our results demonstrate a differential sensitivity of myelinated and unmyelinated axons to the pro-regenerative effect of Y-27632.Treatment with a total dosage of 9 mg/kg of Y-27632 resulted in a complete prevention of anti-GD1a/GT1b monoclonal antibody-mediated inhibition of axon regeneration of unmyelinated fibers to skin and the functional recovery of mechanical cutaneous sensitivity.In contrast,the same dose showed toxic effects on the regeneration of myelinated fibers.Interestingly,scale down of the dosage of Y-27632 to 5 mg/kg resulted in a significant although not complete recovery of regenerated myelinated axons exposed to anti-GD1a/GT1b monoclonal antibody in the absence of toxicity in animals exposed to only Y-27632.Overall,these findings confirm the in vivo participation of Rho A/ROCK signaling pathways in the molecular mechanisms associated with the inhibition of axon regeneration induced by anti-GD1a/GT1b monoclonal antibody.Our findings open the possibility of therapeutic pharmacological intervention targeting Rho A/Rock pathway in immune neuropathies associated with the presence of anti-ganglioside antibodies and delayed or incomplete clinical recovery after injury in the peripheral nervous system.
文摘This study focuses on treating Guadua angustifolia bamboo fibers to enhance their properties for reinforcement applications in composite materials.Chemical(alkali)and physical(dry etching plasma)treatments were used separately to augment compatibility of Guadua angustifolia fibers with various composite matrices.The influence of these treatments on the fibers’performance,chemical composition,and surface morphology were analyzed.Statistical analysis indicated that alkali treatments reduced the tensile modulus of elasticity and strength of fibers by up to 40%and 20%,respectively,whereas plasma treatments maintain the fibers’mechanical performance.FTIR spectroscopy revealed significant alterations in chemical composition due to alkali treatments,while plasma-treated fibers showed minimal changes.Surface examination through Scanning Electron Microscopy(SEM)revealed post-treatment modifications in both cases;alkali treatments served as a cleanser,eliminating lignin and hemicellulose from the fiber surface,whereas plasma treatments also produce rough surfaces.These results validate the impact of the treatments on the fiber mechanical performance,which opens up possibilities for using Guadua angustifolia fibers as an alternative reinforcement in composite manufacturing.
文摘Colorectal cancer is one of the predominant tumors in the world,primarily generated by a progression from polyp to cancer which can last several years,giving a great opportunity to the scientific community for its prevention by screening programs that can be done with invasive and non-invasive tests.In this issue,Lopes et al show us an excellent review of screening,its options,its advantages and disadvantages.
基金Rock magnetic instruments used in this work are procured with the funding from CEMIE Geo project 207032(Fondo de Sustentabilidad Energética de CONACy T-SENER,Government of Mexico)。
文摘The studies on hydrothermal alteration-induced eff ects in surface and subsurface rocks provide useful information in the characterization and exploitation of a geothermal reservoir.Generally,these studies are based on traditional,and reliable methods like petrography(primary and secondary minerals,and grade of alteration),and geochemistry(mobility of elements,changes in mass and concentration of elements,and fluid inclusions).Recently,apart from these established methods,some methods based on the geochemical(Chemical Index of Alteration,CIA;Weathering Index of Parkar,WIP;Loss on Ignition,LOI;and Sulfur,S)and rock magnetic properties(magnetic susceptibility,χlf;and percentage frequency-dependent susceptibility,χfd%)are also being applied in the identification of whether a rock is an altered or a fresh one.The Acoculco Geothermal Field(AGF),Mexico,is characterized by high temperature and very low permeability,and it is considered a promissory Enhanced Geothermal System.The following changes are observed in the rocks as a result of an increase in hydrothermal alteration:(1)an increase in CIA,LOI,and S values,and a decrease in WIP;(2)an increase in quartz and quartz polymorph minerals(silicification),and clay minerals(argillization);and(3)decrease inχlf values.At AGF,the most altered surface acid rocks are characterized by entirely quartz and its polymorphs,and clay minerals.The present study also indicates the applicability of the binary plots of major elements(felsic vs mafic component)and rock magnetic parameters(χlf vs.χfd%).The rock withχfd%value of 2-10 andχlf value<0.5×10^(-6)m^(3) kg^(-1)indicate the presence of single domain and stable single domain grains,which in turn suggests that it is an altered rock.These methods are simple to apply,rapid,reliable,and have the potential to become eff ective tools for the identifi cation of hydrothermally altered rocks during the initial stage of geothermal exploration.
基金supported by the National Natural Science Foundation of China(32270467,32020103006)National Research Foundation of Ukraine(2020/02/0369 to A.G.R.)CONCYTEC through the PROCIENCIA“Interinstitutional Alliances for Doctorate Programs”(PE501084299-2023-PROCIENCIA-BM to M.S.E.)。
文摘Most described Mesozoic ants belong to stem groups that existed only during the Cretaceous period.Previously,the earliest known crown ants were dated to the Turonian(Late Cretaceous,ca.94-90 million years ago(Ma))deposits found in the USA,Kazakhstan,and Botswana.However,the recent discovery of an alate male ant in Kachin amber from the earliest Cenomanian(ca.99 Ma),representing a new genus and species,Antiquiformica alata,revises the narrative on ant diversification.Antiquiformica can be distinctly differentiated from all known male stem ants by its geniculate antennae with elongated scape,extending far beyond the occipital margin of the head and half the length of the funiculus,as well as its partly reduced forewing venation.Furthermore,the combination of a one-segmented waist with a well-developed node,elongated scape extending beyond the occipital margin,and reduced forewing venation,particularly the completely reduced m-cu and rs-m crossveins and absence of rm and mcu closed cells,firmly places the fossil within the extant subfamily Formicinae.Fourier transform infrared spectroscopy(FTIR)confirmed that the amber containing Antiquiformica alata originated from the Kachin mines in Myanmar.This discovery significantly revises our understanding of the early evolution of Formicinae.The presence of Antiquiformica in Cenomanian amber indicates that the subfamily Formicinae emerged at least by the start of the Late Cretaceous,with crown ants likely originating earlier during the earliest Cretaceous or possibly the Late Jurassic,although paleontological evidence is lacking to support the latter hypothesis.
基金Resources for this study were obtained from INTA Projects.
文摘Semiarid Patagonia represents 25%of the rangeland area in Argentina,and sheep overgrazing has degraded about a third of it in the past.In this century,depleted domestic stocks have mostly stabilized,but Guanaco populations have grown.These native camelids share habitat and diets with sheep,but their effect on vegetation is poorly understood and has long been debated.We set up an exclusion experiment in Monte León and Cañadón Vaca,a semiarid shrubland grassland in southern Patagonia,currently grazed only by guanacos.Vegetation baselines were studied in 2016 in twelve plots,and half of them were protected from guanaco grazing.Thirty-six plots were cleared to study revegetation.Vegetation was reassessed in 2021,and changes were evaluated using a paired t-test.Within protected plots,vegetation cover increased,bare soil diminished,and vegetated patches grew in size,but the density of the patch-interpatch arrangement did not change.Biodiversity,measured by richness and the Shan-non-Wiener(SW)index,grew significantly.Nutrient recycling increased,as did the Stability and Infiltration Land Function indexes,although these last differences were not significant.Vegetation cover under guanaco grazing also increased,mainly due to the growth of dwarf shrubs,a typical tendency in sheep grazing-induced transitions in the region.Vegetated patches under grazing fragmented,resulting in smaller patches and denser patch struc-tures,while diversity and land function indexes remained unchanged.Young plants established in cleared plots without guanacos showed higher cover density and individual size.These effects are similar to those observed in numerous experimental sheep exclosures.Guanaco grazing may thus prevent restoration and contribute to the generalized land degradation processes that overgrazing has been causing in Patagonia for over a century.
文摘Non-traditional lignocellulosic materials are a significant resource for producing high-value products,including nanocellulose.This work studied the nanocellulose obtention from chemical pulps of the two fast-growing bamboo species,Guadua trinii,and Guadua angustifolia.Chemical pulps were produced by soda-anthraquinone(S)pulping from both autohydrolysis-pretreated(H)and unpretreated bamboo chips.Autohydrolysis-pretreated(SHP)and unpretreated soda-anthraquinone(AQ)(SP)pulps were characterized by yield,Kappa number,alpha,beta,and gamma cellulose,degree of polymerization,water retention value,and crystallinity.The nanocellulose was produced by a sequential chemical oxidation treatment(2,2,6,6-tetramethylpiperidine-1-oxyl,TEMPO reagent)and mechanical nanofibrillation.Nanocellulose was characterized by carboxylic group content and viscosity.The results revealed that autohydrolysis pretreatment resulted in a higher hemicelluloses extraction in G.angustifolia.In contrast,the pulping yield of unpretreated samples was higher for G.trinii,and the soda-AQ pulps from this species exhibited better delignification than the autohydrolysis-pretreated pulps.The crystallinity index values of the obtained pulps were high(>80%),and the alpha-cellulose contents were similar.The viscosities of the aqueous nanocellulose suspensions were higher for the nanocellulose solutions obtained from the unpretreated soda-AQ pulps.Besides,nanocellulose from G.trinii unpretreated soda-AQ pulps had a higher rate of carboxylic groups.The results of this work are significant in assessing the potential of both bamboo species as a source of high-value products within the biorefinery framework because the viscosities of the aqueous nanocellulose suspensions depend on the size and shape of nanofibrils.It has significant importance for industrial unit operations and potential applications.
文摘Parkinsonism by unilateral,intranigralβ-sitosterolβ-D-glucoside administration in rats is distinguished in that theα-synuclein insult begins unilaterally but spreads bilaterally and increases in severity over time,thus replicating several clinical features of Parkinson’s disease,a typicalα-synucleinopathy.As Nurr1 repressesα-synuclein,we evaluated whether unilateral transfected of rNurr1-V5 transgene via neurotensin-polyplex to the substantia nigra on day 30 after unilateralβ-sitosterolβ-D-glucoside lesion could affect bilateral neuropathology and sensorimotor deficits on day 30 post-transfection.This study found that rNurr1-V5 expression but not that of the green fluorescent protein(the negative control)reducedβ-sitosterolβ-D-glucoside-induced neuropathology.Accordingly,a bilateral increase in tyrosine hydroxylase-positive cells and arborization occurred in the substantia nigra and increased tyrosine hydroxylase-positive ramifications in the striatum.In addition,tyrosine hydroxylase-positive cells displayed less senescence markerβ-galactosidase and more neuron-cytoskeleton markerβIII-tubulin and brain-derived neurotrophic factor.A significant decrease in activated microglia(positive to ionized calcium-binding adaptor molecule 1)and neurotoxic astrocytes(positive to glial fibrillary acidic protein and complement component 3)and increased neurotrophic astrocytes(positive to glial fibrillary acidic protein and S100 calcium-binding protein A10)also occurred in the substantia nigra.These effects followed the bilateral reduction inα-synuclein aggregates in the nigrostriatal system,improving sensorimotor behavior.Our results show that unilateral rNurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neurodegeneration(senescence and loss of neuron-cytoskeleton and tyrosine hydroxylase-positive cells),neuroinflammation(activated microglia,neurotoxic astrocytes),α-synuclein aggregation,and sensorimotor deficits.Increased neurotrophic astrocytes and brain-derived neurotrophic factor can mediate the rNurr1-V5 effect,supporting its potential clinical use in the treatment of Parkinson’s disease.