Don´t give up on mitochondria as a target for the treatment of diabetes and its complications

In this editorial,we discuss an article by Wang et al,focusing on the role of mitochondria in peripheral insulin resistance and insulin secretion.Despite numerous in vitro and pre-clinical studies supporting the involvement of mitochondrial dysfunction and oxidative stress in the pathogenesis of diabetes and its complications,efforts to target mitochondria for glycemic control in diabetes using mitochondria-targeted antioxidants have produced inconsistent results.The intricate functionality of mitochondria is summarized to underscore the challenges it poses as a therapeutic target.While mitochondria-targeted antioxidants have demonstrated improvement in mitochondrial function and oxidative stress in pre-clinical diabetes models,the results regarding glycemic control have been mixed,and no studies have evaluated their hypoglycemic effects in diabetic patients.Nonetheless,pre-clinical trials have shown promising outcomes in ameliorating diabetes-related complications.Here,we review some reasons why mitochondria-targeted antioxidants may not function effectively in the context of mitochondrial dysfunction.We also highlight several alternative approaches under development that may enhance the targeting of mitochondria for diabetes treatment.

Assessing the impact of concurrent high-fructose and highsaturated fat diets on pediatric metabolic syndrome:A review

High-saturated fat(HF)or high-fructose(HFr)consumption in children predispose them to metabolic syndrome(MetS).In rodent models of MetS,diets containing individually HF or HFr lead to a variable degree of MetS.Nevertheless,simultaneous intake of HF plus HFr have synergistic effects,worsening MetS outcomes.In children,the effects of HF or HFr intake usually have been addressed individually.Therefore,we have reviewed the outcomes of HF or HFr diets in children,and we compare them with the effects reported in rodents.In humans,HFr intake causes increased lipogenesis,hypertriglyceridemia,obesity and insulin resistance.On the other hand,HF diets promote low grade-inflammation,obesity,insulin resistance.Despite the deleterious effects of simultaneous HF plus HFr intake on MetS development in rodents,there is little information about the combined effects of HF plus HFr intake in children.The aim of this review is to warn about this issue,as individually addressing the effects produced by HF or HFr may underestimate the severity of the outcomes of Western diet intake in the pediatric population.We consider that this is an alarming issue that needs to be assessed,as the simultaneous intake of HF plus HFr is common on fast food menus.

Multi-temporal NDVI analysis using UAV images of tree crowns in a northern Mexican pine-oak forest

The use of unmanned aerial vehicles(UAV)for forest monitoring has grown significantly in recent years,providing information with high spatial resolution and temporal versatility.UAV with multispectral sensors allow the use of indexes such as the normalized difference vegetation index(NDVI),which determines the vigor,physiological stress and photo synthetic activity of vegetation.This study aimed to analyze the spectral responses and variations of NDVI in tree crowns,as well as their correlation with climatic factors over the course of one year.The study area encompassed a 1.6-ha site in Durango,Mexico,where Pinus cembroides,Pinus engelmannii,and Quercus grisea coexist.Multispectral images were acquired with UAV and information on meteorological variables was obtained from NASA/POWER database.An ANOVA explored possible differences in NDVI among the three species.Pearson correlation was performed to identify the linear relationship between NDVI and meteorological variables.Significant differences in NDVI values were found at the genus level(Pinus and Quercus),possibly related to the physiological features of the species and their phenology.Quercus grisea had the lowest NDVI values throughout the year which may be attributed to its sensitivity to relative humidity and temperatures.Although the use of UAV with a multispectral sensor for NDVI monitoring allowed genera differentiation,in more complex forest analyses hyperspectral and LiDAR sensors should be integrated,as well other vegetation indexes be considered.

Repellent and Insecticidal Activity of Naphthoquinones from the Heartwood of Tectona grandis on Incisitermes marginipennis(Latreille)

Wood is a lignocellulosic material that,because of its organic nature,is a source of nutrients for bacteria,fungi,and insects.Incisitermes marginipennis(Latreille)is an interesting dry wood-boring termite.Because it is an extremely destructive pest,difficult to control due to its cryptic lifestyle,and for its role in the biogeochemical cycle of carbon and other elements;it is a fundamental organism.The use of less toxic and eco-friendly substances is important for protecting domestic,cultural,and historical heritage made of wood or lignocellulosic materials.The aim of this study was to evaluate the biological activity of various naphthoquinones extracted from the heartwood of T.grandis on I.marginipennis.First,heartwood flour was used for Soxhlet-type extractions to isolate and characterize the heartwood compounds by thin-layer chromatography.To identify the heartwood compounds,nuclear magnetic resonance and gas chromatography coupled to a mass spectrometer were used.The information obtained was supported using the Interactive Spectroscopy software.The identified heartwood compounds were lapachol,tectoquinone,deoxylapachol,dehydro-α-lapachone,tectol and tecomaquinone-I.Using nymphal termites of I.marginipennis as a biological model,the isolated and identified molecules were under three different tests(repellent,insecticide and protective)and their biological activity was individually evaluated.The results showed that the molecules obtained have a repellent-protective effect against I.marginipennis,although not in all cases,these molecules have high percentages of mortality and decreased the weight loss of the treated material exposed to I.marginipennis.

Assessment of gas tungsten arc welding thermal cycles on Inconel 718 alloy

Heat moving source models along with transient heat analysis by finite element method were used to determine weld thermal cycles and isothermal sections obtained from the application of a gas tungsten arc welding beads on Inconel 718 plates. Analytical (Rosenthal’s thick plate model) and finite element results show an acceptable approximation with the experimental weld thermal cycles. The isothermal sections determined by numerical simulation show a better approximation with the experimental welding profile for double-ellipse model heat distribution than Gauss model. To analyze the microstructural transformation produced by different cooling rates in the fusion and heat affected zones, Vickers microhardness measurements (profile and mapping representation) were conducted. A hardness decrement for the heat affected zone (~200 HV0.2) and fusion zone (~240 HV0.2) in comparison with base material (~350 HV0.2) was observed. This behavior has been attributed to the heterogeneous solubilization process of the γ″ phase (nickel matrix), which, according to the continuous-cooling-transformation curve, produced the Laves phase,δ and MC transition phases, generating a loss in hardness close to the fusion zone.

Design and characterization of Ti6Al4V/20CoCrMo−highly porous Ti6Al4V biomedical bilayer processed by powder metallurgy

The aim of this work was to develop a Ti6Al4V/20CoCrMo−highly porous Ti6Al4V bilayer for biomedical applications.Conventional powder metallurgy technique,with semi-solid state sintering as consolidation step,was employed to fabricate samples with a compact top layer and a porous bottom layer to better mimic natural bone.The densification behavior of the bilayer specimen was studied by dilatometry and the resulting microstructure was observed by scan electron microscopy(SEM)and computed microtomography(CMT),while the mechanical properties and corrosion resistance were evaluated by compression and potentiodynamic tests,respectively.The results indicate that bilayer samples without cracks were obtained at the interface which has no negative impact on the densification.Permeability values of the highly porous layer were in the lower range of those of human bones.The compression behavior is dictated by the highly porous Ti6Al4V layer.Additionally,the corrosion resistance of Ti6Al4V/20CoCrMo is better than that of Ti6Al4V,which improves the performance of the bilayer sample.This work provides an insight into the important aspects of a bilayer fabrication by powder metallurgy and properties of Ti6Al4V/20CoCrMo−highly porous Ti6Al4V structure,which can potentially benefit the production of customized implants with improved wear performance and increased in vivo lifetime.

Effect of electromagnetic interaction on microstructure and corrosion resistance of 7075 aluminium alloy during modified indirect electric arc welding process

The effects of applying an electromagnetic interaction of low intensity (EMILI) on the microstructure and corrosion resistance of 7075-T651 Al alloy plates (13 mm in thickness) during modified indirect electric arc (MIEA) welding were investigated. The welding process was conducted in a single pass with a heat input of ~1.5 kJ/mm. The microstructural observations of the welds were correlated with the effect of EMILI on the local mechanical properties and the corrosion resistance in natural seawater by means of microhardness measurements and electrochemical impedance spectroscopy, respectively. Microstructural characterization of the welds revealed a grain refinement in the weld metal due to the electromagnetic stirring induced by EMILI of 3 mT during welding. In addition, observations in the scanning electron microscope showed that the precipitation of Cu-rich phases and segregation of eutectics were reduced in the heat affected zone (HAZ) also as an effect of EMILI. The high corrosion dissolution of the 7075-T651 welds in natural seawater and the extent of overaging in the HAZ were reduced when welding with EMILI of 3 mT. Thus, EMILI along with the MIEA technique may lead to welded joints with better microstructural characteristics, improved mechanical properties in the HAZ and reduced electrochemical activity.

Wear modes in open porosity titanium matrix composites with TiC addition processed by spark plasma sintering

This work focused on the influence of TiC reinforcing particles on the tribological properties of titanium matrix composites(TMCs)with open porosity,processed by spark plasma sintering(SPS).Materials composed of an equimolar mixture of Ti and TiH2 with 0,3,10 and 30 vol.% of TiC were sintered at 850 ℃.Nanoindentation and wear tests were carried out to assess the nanohardness and the wear resistance in a tribometer with a reciprocating sliding ball-on-flat configuration.Results showed a nanohardness increment from 5 to 14 GPa with increasing TiC content.The coefficient of friction(CoF)showed a minimum of 0.2 for 10% TiC grade,which also showed the lowest wear rate.For the low TiC content sample,adhesive wear with severe plastic deformation was identified.Meanwhile,medium content TiC sample showed a mechanical mixed layer(MML),whereas high TiC content composite showed abrasive as the main wear mechanism.In conclusion,the wear mechanisms,CoFs and wear volume changed with TiC content.

Constrained sintering and wear properties of Cu-WC composite coatings

Coatings of metal matrix composites(Cu?WC)were fabricated by solid-state sintering.WC reinforcing particles indifferent quantities from5%up to30%(volume fraction)were mixed with Cu particles.After mixing,the powders were poured ontothe surface of copper substrates.Sintering was carried out at1000°C under a reducing atmosphere in a vertical dilatometer.Sinteringkinetics was affected by both rigid substrates and WC particles which retarded the radial and axial densification of powders.However,the coatings were strongly attached to the substrate,and WC particles were randomly distributed within the matrix.The addition ofthe reinforcing particles enhanced the microhardness and reduced the volume loss in wear tests to1/17compared to the unreinforcedsample.The predominant wear mechanism was identified as abrasion at a load of5N.20%WC(volume fraction)reinforcingparticles led to the maximum values of properties for the composite coating.

Effect of Sn on synthesis of nanocrystalline Ti-based alloy with fcc structure

The effect of the amount of Sn on the formation of fcc phase in Ti-13 Ta-x Sn(x=3,6,9 and 12,at.%)alloys was studied.The alloys were synthesized by mechanical alloying using a planetary mill,jar and balls of stabilized yttrium.Using Rietveld refinement,it was found that the obtained fcc phase has crystallite size smaller than 10 nm and microstrain larger than 10-3.Both conditions are required to form an fcc phase in Ti-based alloys.For all samples,the microstructure of the fcc phase consists of equiaxial crystallites with sizes smaller than 10 nm.The largest presence of fcc phase in the studied Ti alloy was found with 6 at.%Sn,because this alloy exhibits the largest microstrain(1.5×10-2)and crystallite size of 6.5 nm.Experimental data reveal that a solid solution and an amorphous phase were formed during milling.The necessary conditions to promote the formation of solid solution and amorphous phases were determined using thermodynamic calculations.When the amount of Sn increases,the energy required to form an amorphous phase varies from approximately 10 to approximately-5 k J/mol for 3 and 12 at.%Sn,respectively.The thermodynamic calculations are in agreement with XRD patterns analysis and HRTEM results.

Effect of retained austenite and nonmetallic inclusions on the thermal/electrical properties and resistance spot welding nuggets of Si-containing TRIP steels

Five advanced high-strength transformation-induced plasticity(TRIP) steels with different chemical compositions were studied to correlate the retained austenite and nonmetallic inclusion content with their physical properties and the characteristics of the resistance spot welding nuggets. Electrical and thermal properties and equilibrium phases of TRIP steels were predicted using the JMatPro? software. Retained austenite and nonmetallic inclusions were quantified by X-ray diffraction and saturation magnetization techniques. The nonmetallic inclusions were characterized by scanning electron microscopy. The results show that the contents of Si, C, Al, and Mn in TRIP steels increase both the retained austenite and the nonmetallic inclusion contents. We found that nonmetallic inclusions affect the thermal and electrical properties of the TRIP steels and that the differences between these properties tend to result in different cooling rates during the welding process. The results are discussed in terms of the electrical and thermal properties determined from the chemical composition and their impact on the resistance spot welding nuggets.

Slime coating of kaolinite on chalcopyrite in saline water flotation

In saline water flotation, the salinity can cause a distinguishable slime coating of clay minerals on chalcopyrite particles through its effect on their electrical double layers in aqueous solutions. In this work, kaolinite was used as a representative clay mineral for studying slime coating during chalcopyrite flotation. The flotation of chalcopyrite in the presence and absence of kaolinite in tap water, seawater, and gypsum-saturated water and the stability of chalcopyrite and kaolinite particles in slurries are presented. Zeta-potential distributions and scanning electron microscopy images were used to characterize and explain the different slime coating degrees and the different flotation performances. Kaolinite particles induced slime coating on chalcopyrite surfaces and reduced chalcopyrite floatability to the greatest extent when the p H value was in the alkaline range. At 0.24 wt% of kaolinite, the chalcopyrite floatability was depressed by more than 10% at alkaline p H levels in tap water. Salinity in seawater and gypsum-saturated water compressed the electrical double layers and resulted in extensive slime coating.

Early performance of two tropical dry forest species after assisted migration to pine-oak forests at different altitudes:strategic response to climate change

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.

Effect of the Melatonin on Morning Blood Pressure Surge and Norepinephrine Endovenous Infusion in Healthy Volunteers

Melatonin, the pineal gland hormone, has been considered as a central hypotension factor. However their roles in the regulation of the human blood pressure and its possible use as antihyper-tensive drug have not been fully determined. The objective of this trial was to determine the effect of melatonin on blood pressure morning increase and a peripheral vasoconstriction challenge in healthy volunteers. Twelve healthy male volunteers were included in a prospective, comparative, randomized, crossover trial in which changes on blood pressure (BP) and heart rate (HR) after the first morning orthostatism and endovenous norepinephrine (NE) infusion were measured one hour after the administration of placebo (PL) or 10 mg of melatonin in double blind conditions. Melatonin blunted the effects of the first orthostatism on BP and HR. Melatonin also reduces the pressor effect of NA. One concludes that melatonin has central and peripheral hypotensive effects that support a potential role of this hormone in cardiovascular therapeutics.

Luminescence Characteristics of LaAlO₃:Eu³⁺Obtained by Modified Pechini’s Method

The aim of the present work was to investigate the luminescent properties of europium-doped lanthanum aluminate (LaAlO3) powder prepared by Modified Pechini (MP) method. Samples were prepared at different Eu3+ concentrations and calcined at 1600°C. Structural and morphology characterizations were obtained by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM). Luminescent properties were analyzed by photoluminescence (PL) and thermoluminescent phenomena. The XRD pattern shows pure lanthanum aluminate oxide LaAlO3 with a rhombohedral structure. Photoluminescence studies of the powders was related to 4f → 4f(5D0 → 7Fi) (i = 1, 2, 3, 4) transitions of Eu3+ ion, the most intense emission of Eu3+ in LaAlO3 was registered for the transition 5D0 → 7F1, for 5% of Eu3+. The recorded TL glow curves of excited samples showed a main TL peak, the main peak appeared its maximum as a function of excitation energy. The investigation demonstrates that polycrystalline LaAlO3:Eu3+ powders calcined at 1600°C have interesting luminescent characteristics.

Antifungal Activity of Crude Extracts of Tectona grandis L.f. against Wood DecayFungi

Wood is mainly made up of cellulose, hemicelluloses, lignin polymers and other organic and inorganic substances, making it susceptible to deteriorate by various biological agents. Tectona grandis L.f. (Teak) is a timberspecies with high resistance to biological deterioration, valued for its durability, beauty, and mechanical resistance.The purpose of this work was to evaluate the antifungal activity of crude extracts from teak on various fungi thatcause wood deterioration. For this, Teak heartwood was obtained, then fragmented and pulverized until obtaininga flour which was used for compounds extraction using the Soxhlet technique coupled to a rotary evaporatorthrough solvents of increasing polarity (hexane, dichloromethane, tetrahydrofuran, and acetone). The extractsobtained were tested against fungal organisms collected in the field, and the LC50 was determined using teak crudeextracts on Artemia salina as a biological model. The results obtained showed that a high flour yield was obtainedwith hexane (0.951 g), followed by tetrahydrofuran (0.446 g), dichloromethane (0.348 g), and acetone (0.152 g). Byusing nine fungal organisms that predominantly correspond to the genus Aspergillus, the extractable compoundswere tested, inhibiting 25% of mycelial growth with tetrahydrofuran (T. versicolor), and 40.9% with dichloromethane(G. trabeum). Likewise, the biological model of A. salina showed an LC50 of 84.9 μg/mL with hexane, 43.3 μg/mLwith dichloromethane, 59.6 μg/mL with tetrahydrofuran, and 54.7 μg/mL with acetone. For this reason, it is concluded that Teak wood contains many extractable compounds in relation to its weight, besides having antimicrobialactivity when extracted through polar compounds such as dichloromethane and tetrahydrofuran.

Antifeedant Activity of Caesalpinia coriaria Essential Oil Against Incisitermes marginipennis (Latreille)

This study scrutinized the possibility of finding toxicant or deterrent plant metabolites against the dry wood termite Incisitermes marginipennis(Latreille).Plant deterrent agents act as repellents or antifeedants to prevent wood decay and increase its useful life.The potential of the tree Caesalpinia coriaria(Fabaceae)as a biological source of molecules with deterrent effects against the dry wood termite was assessed by a phytochemical fractionation guided by repellence and antifeedant activities.The gas chromatography-mass spectrometry analysis of the leaf essential oil showed geraniol to be one of the major components and its repellent and antifeedant effects were determined.Geraniol had only an antifeedant effect without affecting the body weight or survival of the dry wood termite.Unlike the leaf essential oil,geraniol did not exhibit a repellency effect.An in-silico approach of the activity of acetylcholinesterase in interaction with geraniol resulted in an affinity energy of−7.5 Kcal/mol.Geraniol interacted with the amino acid tyrosine 324 located in the enzyme’s active site while citronellol(negative control)interacted with tryptophan 83 located adjacent to the active site.These deterring terpenes have not been implemented for the preservation and restoration of wood products exposed to the attack of the dry wood termite.However,they are an important natural control alternative.

Analysis of Growth and Productivity of Green Chickpea Using Nitrogen and Phosphorus Fertilization

Chickpea contains high levels of protein,vitamins and minerals.Acceptable chickpea yield is the result of meeting nitrogen and phosphorus requirements.The effect of appropriately meeting such requirements reflects on growth and can easily be evaluated using growth analysis.This research determined:(a)The effect of nitrogen and phosphorus fertilization on phenology,net assimilation rate,number of green leaves,leaf area,leaf area index and leaf area duration;(b)Green chickpea yield and number of pods due to fertilization;and(c)The combination of nitrogen and phosphorus fertilization that yields the most net revenue.Nitrogen and phosphorus fertilization was evaluated;each at the doses of 0,75 and 150 kg ha–1(N0,N75,N150;P0,P75 and P150,respectively).The combination of the levels of both nutrients generated nine combinations of treatments which were distributed in the field in a randomized complete block design in an arrangement of divided plots with four repetitions.Timing of phenological phases were similar among treatments.Nitrogen and phosphorus fertilization increased number of leaves,leaf area index,and leaf area duration that translated into increased green chickpea yield(GCY).Combinations N150-P75 and N150-P150 produced the highest GCY.The highest net revenue and revenue per peso invested was obtained with N150-P75.

Diversity of Saxicolous Lichens along an Aridity Gradient in Central México

Lichens are symbiotic organisms that comprise a fungus and a photosynthetic partner wich are recognized as a good indicator of climate change.However,our understanding of how aridity affects the diversity of saxicolous lichens in drylands is still limited.To evaluate the relationship between saxicolous lichen diversity and aridity in a central México dryland,a geographical transect was established of 100 km to build an aridity gradient in the semiarid zone of the State of Querétaro,Mexico,comprising ten sampling sites with a 10 km separation.Species richness,abundance and diversity of soil lichen species were recorded using two sampling methods:the quadrat-intercept and the line-intercept method,to compare their performance in assessing soil lichen diversity in drylands.The number of species and Shannon diversity of saxicolous lichens were higher at intermediate values of the aridity index(AI=0.10-0.34).Quadrat intercept and point intercept methods gave quite similar results,which means that the selected method does not influence the results in a significant way.This study confirms the role of saxicolous lichens as climate change indicators and reveals the importance of the sampling method selection in the evaluation of different parameters of soil lichen diversity in drylands.

Sintering kinetics of Ni_2FeSb powder alloys produced by mechanical milling

A ternary Ni2FeSb shape memory alloy was fabricated by powder metallurgy route. Sintering kinetics was estimated from dilatometry tests; whereas the microstructure and morphology of the powder and consolidated bulk samples were evaluated by XRD and SEM, respectively. Microhardness tests were performed on the surface of sintered samples. The results indicated that milling time has an effect on the shape and particle size as well as the homogeneity of the crystalline structures of the powders. Samples with longer milling time presented higher relative densities, better distribution of the elements on the alloy as well as the L21 and martensite phases, which will give the shape memory effect. The estimated activation energy values ranged from 109 to 282 kJ/mol at temperatures between 750 and 1273 K, indicating that sintering is controlled mainly by volume diffusion. Microhardness was improved by increasing the milling time and the heating rate.