Pregnancy comes with a combination of physical changes and physiological immunosuppression that increases the susceptibility of women to pathogens and in turn,rises the prevalence of infectious diseases.
The following material is devoted to the generalization of the chaos modeling to random fields in communication channels and its application on the space-time filtering for the incoherent paradigm;that is the purpose ...The following material is devoted to the generalization of the chaos modeling to random fields in communication channels and its application on the space-time filtering for the incoherent paradigm;that is the purpose of this research. The approach, presented hereafter, is based on the “Markovian” trend in modeling of random fields, and it is applied for the first time to the chaos field modeling through the well-known concept of the random “treatment” of deterministic dynamic systems, first presented by A. Kolmogorov, M. Born, etc. The material presents the generalized Stratonovich-Kushner Equations (SKE) for the optimum filtering of chaotic models of random fields and its simplified quasi-optimum solutions. In addition to this, the application of the multi-moment algorithms for quasi-optimum solutions is considered and, it is shown, that for scenarios, when the covariation interval of the input random field is less than the distance between the antenna elements, the gain of the space-time algorithms against their “time” analogies is significant. This is the general result presented in the following.展开更多
The tree shrew(Tupaia belangeri)has long been proposed as a suitable alternative to non-human primates(NHPs)in biomedical and laboratory research due to its close evolutionary relationship with primates.In recent year...The tree shrew(Tupaia belangeri)has long been proposed as a suitable alternative to non-human primates(NHPs)in biomedical and laboratory research due to its close evolutionary relationship with primates.In recent years,significant advances have facilitated tree shrew studies,including the determination of the tree shrew genome,genetic manipulation using spermatogonial stem cells,viral vector-mediated gene delivery,and mapping of the tree shrew brain atlas.However,the limited availability of tree shrews globally remains a substantial challenge in the field.Additionally,determining the key questions best answered using tree shrews constitutes another difficulty.Tree shrew models have historically been used to study hepatitis B virus(HBV)and hepatitis C virus(HCV)infection,myopia,and psychosocial stress-induced depression,with more recent studies focusing on developing animal models for infectious and neurodegenerative diseases.Despite these efforts,the impact of tree shrew models has not yet matched that of rodent or NHP models in biomedical research.This review summarizes the prominent advancements in tree shrew research and reflects on the key biological questions addressed using this model.We emphasize that intensive dedication and robust international collaboration are essential for achieving breakthroughs in tree shrew studies.The use of tree shrews as a unique resource is expected to gain considerable attention with the application of advanced techniques and the development of viable animal models,meeting the increasing demands of life science and biomedical research.展开更多
The Retinoblastoma 1 (RB1) gene, located on chromosome 13q14 and encodes the tumor-suppressor retinoblastoma protein, is the cause of Retinoblastoma. The mutational inactivation of both gene alleles brings on this can...The Retinoblastoma 1 (RB1) gene, located on chromosome 13q14 and encodes the tumor-suppressor retinoblastoma protein, is the cause of Retinoblastoma. The mutational inactivation of both gene alleles brings on this cancer. Retinoblastoma (RB) high-risk histopathological characteristics indicate metastasis or local recurrence with rapid progresses following RB1 inactivation. There is growing interest in regulatory activities unconnected to the coding region of the genome, or exome, in addition to epigenetic control mechanisms. The altered epigenome is significant, though by no means the only, problem in the etiology of Retinoblastoma. After all, cancer development is a multistep process in which numerous dissimilar genetic, epigenetic, and posttranscriptional modifications result in a shared phenotype. This study emphasizes the most recent developments in posttranscriptional change and epigenetics related to retinoblastoma tumor biology. Here, we highlight the novel biomarkers the retinoblastoma tumor has expressed to improve patient survival.展开更多
This material is aimed to attract attention to the “incoherent approach for power NOMA-RIS-MIMO transmission in wireless channels”. Such kind of approach might be successfully applied in future dense networks formed...This material is aimed to attract attention to the “incoherent approach for power NOMA-RIS-MIMO transmission in wireless channels”. Such kind of approach might be successfully applied in future dense networks formed by High-Speed Vehicles (HSV networks, etc.). Those scenarios take place in doubly selective communication channels typical for such kind of radio networks. The proposal for the presented hereafter incoherent view (“paradigm”) is based on several basic principles: 1) Shift from the “coherent “ideology”, i.e. rejection of the application of any type of Channel State Information (CSI, CSIT);2) Application of the so-called “invariant” to the communication channel’s features (distortions) modulation technique together with its incoherent demodulation;3) Orthogonal channel decomposition by means of “universal” eigen basis (in the form of Prolate Spheroidal Wave Functions, PSWF) as “artificial trajectories” of wave propagation;4) Chaotic filtering (chaos parameter settings as UE signatures) together with sequential multiuser parallel detection algorithms for users’ identification (classification). It is shown that the proposed approach might provide an effective use of the radio resource and it is relatively simple for implementation.展开更多
The objective of this work was to evaluate the effect of Beauveria bassiana(Bb 1205)on controlling Fusarium oxysporum f.sp.lycopersici(Fol 17108)in tomato plants in greenhouse conditions.Inoculation of Bb 1205 was the...The objective of this work was to evaluate the effect of Beauveria bassiana(Bb 1205)on controlling Fusarium oxysporum f.sp.lycopersici(Fol 17108)in tomato plants in greenhouse conditions.Inoculation of Bb 1205 was the most promising among the agronomic variables and expression of the activity of the enzymesβ-1,3-glucanases and chitinases.Inoculation of Bb 1205 occurred at a concentration of 1×108 conidia·mL−1,which was administered onto the leaves,directly into the soil and via injection.Infection with Fol 17108 occurred with 1×106 spores·mL−1,which were added directly to the soil.Spectrophotometry was used for measuring agronomic parameters,namely activity of chitinases andβ-1,3-glucanases in foliage and roots.When Bb 1205 was added to the soil,the chlorophyll index and aerial part length showed significant differences.In addition,it was determined that root length,fresh weight of foliage,flower,and fruit count increased 82 days after inoculation(dai).Chitinase activity induced by Bb 1205 in leaves and roots of tomato plants infected with Fol 17108 was observed when injected into the stem at 32 dai(41.8 and 11.6-fold,respectively).Inoculation on the foliage showed a 10-fold increase ofβ-1,3-glucanases in the roots after 82 dpi.As for leaves,a 3.8-fold increase was found when the stem was inoculated.In the different in vivo applications,Bb 1205 activated its defenses by expressing the chitinase enzymes andβ-1,3-glucanase,thus reducing the damage caused by Fol 17108,demonstrating increase plant growth thereafter.展开更多
Aluminum alloy samples, 6061-T6 and 2219-T42, were exposed to Caribbean seawater for 90 d. The fluctuations of open circuit potential, considered as electrochemical noise (EN), were used to characterize and compare in...Aluminum alloy samples, 6061-T6 and 2219-T42, were exposed to Caribbean seawater for 90 d. The fluctuations of open circuit potential, considered as electrochemical noise (EN), were used to characterize and compare initial pitting events, which appeared on their surfaces. EN analysis was carried out using the power spectral density (PSD) vs frequency. The decrease of the β exponent in PSD graphs indicated a release of spontaneous energy with the progress of pit formation in seawater. The fluctuations were associated with the breakdown and formation of new corrosion layers. The values of β exponent in PSD graphs suggest that corrosion process of AA2219-T42 alloy occurs as a persistent non-stationary process, the dynamics of which is controlled by fractional Brownian motion (fBm), while on AA6061-T6 alloy the corrosion process was dominated by stationary and weakly persistent features, with the contribution of fractional Gaussian noise (fGn). After the exposure in seawater, SEM-EDX analysis revealed insoluble intermetallic particles on the alloys, rich in Cu or Fe and irregularly distributed. The preferential dissolution of Mg and Al occurs from the S-phase (Al2CuMg) of AA2219-T42 alloy.展开更多
AIM:To compare the effect of phacoemulsification on intraocular pressure(IOP)in patients with primary open angle glaucoma(POAG)and pseudoexfoliation glaucoma(PXG).METHODS:A retrospective comparative case serie...AIM:To compare the effect of phacoemulsification on intraocular pressure(IOP)in patients with primary open angle glaucoma(POAG)and pseudoexfoliation glaucoma(PXG).METHODS:A retrospective comparative case series conducted at the Glaucoma Department at the Association to Prevent Blindness in Mexico.The study enrolled consecutive patients having phacoemulsification with intraocular lens(IOL)implantation and a diagnosis of POAG or PXG.Data about IOP values and number of glaucoma medications used was collected at baseline,1,3,6 and12mo postoperatively.RESULTS:The study enrolled 88 patients(88 eyes).After phacoemulsification,there was a statistically significant reduction in IOP values and glaucoma medications use compared to baseline in both POAG and PXG patients(P〈0.001).In the POAG group,a 20%decrease in IOP values was evidenced,and a 56.5%reduction in the number of medications used at the one-year follow-up.The PXG group showed a 20.39%,and a 34.46%decrease in IOP and number of medications used,respectively.A significant difference in the meanΔIOP(postoperative changes in IOP)was evidenced between groups(P=0.005).The reduction of the postsurgical IOP mean values in both groups,the POAG group showed a greater reduction in IOP values compared to the PXG group.CONCLUSION:In both types of glaucoma,phacoemulsification cataract surgery can result in a significant IOP reduction(20%)over a 12mo follow-up period.The number of medications used is also significantly reduced up to 12mo after surgery,especially in the PXG group.展开更多
Intracerebroventricular administration (ICV) of streptozotocin (STZ) in rats has been associated to desensitization of the insulin receptor (IR) and biochemical changes similar to those occurring in Alzheimer’s disea...Intracerebroventricular administration (ICV) of streptozotocin (STZ) in rats has been associated to desensitization of the insulin receptor (IR) and biochemical changes similar to those occurring in Alzheimer’s disease (AD) or older brains, so it has been proposed as a suitable model for studying some of the pathological features of AD sporadic type (SAD). In this study, we investigated the role of glycogen synthase kinase 3β (GSK3β) and protein phosphatase 2A (PP2A) in the regulation of the phosphorylation of tau (p-tau). Results showed that ICV-STZ treated rats had deficits in short- (1.5-h) and long-term (24- and 48-h) memory after one month of ICV-STZ treatment and six months relative to control rats. The memory deficit was associated to increasing [F(3, 12) = 31.48, p β (p-GSK3β) and PP2A in hippocampus and PFC, indicating that GSK3β and PP2A contributed to regulation of p-tau. These data supporting the model with ICV-STZ in rat are adequate to study the progressive memory impairment associated to hyperphosphorylation of tau and the cascade of insulin receptor signaling;confirm that phosphatidyl-inositol-3 kinase-protein kinase B (PI3K-PKB/Akt-GSK3β) and PP2A are involved in the modulation of proteins responsible for the regulation of neurodegeneration in AD.展开更多
Due to the environmental policies and economic reasons,the water used in some flotation operations of complex sulfide ores is recirculated,causing the ion concentration of some species to increase over time,affecting ...Due to the environmental policies and economic reasons,the water used in some flotation operations of complex sulfide ores is recirculated,causing the ion concentration of some species to increase over time,affecting the flotation of the minerals of interest.In this work,an experimental and thermodynamic analysis of the synthetic solutions was presented with a high content of calcium and sulfate ions.The study focused on evaluating the use of two aluminum compounds for the precipitation of Ca^(2+)and SO_(4)^(2−)in the form of ettringite.The amorphous aluminum hydroxide was found to be more efficient than the crystalline one,giving rise to 83%calcium and 91%sulfate removal.The XRD analysis of the solids showed the main reaction product of ettringite,accompanied by small amounts of calcite,due to the absorption of atmospheric carbon dioxide.The final solution after the chemical treatment showed residual calcium and sulfate concentrations below 200 mg/L.Finally,the kinetics of calcium removal appeared to correspond to a second order reaction with respect to calcium concentration,with an apparent activation energy of 53.48 kJ/mol,which may suggest that the ettringite precipitation process is governed by the chemical reaction.展开更多
We studied the influence of antimony on the modification rate of the silicon eutectic with sodium and/or strontium for castiig of A1-Si alloys, and introduced controlled Ca and Sb to the system and studied the resulti...We studied the influence of antimony on the modification rate of the silicon eutectic with sodium and/or strontium for castiig of A1-Si alloys, and introduced controlled Ca and Sb to the system and studied the resulting compounds, which were determined to be CazSb and A1Sb. Scanning electron microscopy together with the complementary technique of electron backscatter diffraction (EBSD) were used to characterize the materials. The experimental results provided the basis for us to establish that antimony removal from AI occurs mainly through the reaction (Sb)A1 + 2Ca = Ca^Sb + A1.展开更多
This paper presents two contributions to the stability analysis of periodic systems modeled by a Hill equation: The first is a new method for the computation of the Arnold Tongues associated to a given Hill equation w...This paper presents two contributions to the stability analysis of periodic systems modeled by a Hill equation: The first is a new method for the computation of the Arnold Tongues associated to a given Hill equation which is based on the discretization of the latter. Using the proposed method, a vibrational stabilization is performed by a change in the periodic function which guarantees stability, given that the original equation has unbounded solutions. The results are illustrated by some examples.展开更多
Nucleation of Fe-rich intermetallic phases on α-Al2O3 oxide films was analyzed in five experimental Al-Fe-Mn-Si alloys. In an attempt to verify the role of α-Al2O3 films in nucleating Fe-rich intermetallics, experim...Nucleation of Fe-rich intermetallic phases on α-Al2O3 oxide films was analyzed in five experimental Al-Fe-Mn-Si alloys. In an attempt to verify the role of α-Al2O3 films in nucleating Fe-rich intermetallics, experiments have been conducted under conditions where formed in situ oxide films were present. Some Fe-rich intermetallics are observed to be related with the oxide films in the microstructure, the present results are in accordance with some research that suggest that the Fe-rich intermetallic phases nucleate upon the oxide films. The intermetallic phases and α-Al2O3 films were unambiguously identified with the help of complementary techniques such as thermal analysis, SEM/EDS and X-ray diffraction.展开更多
The aim of this study was to evaluate the effect of copper and iron on acidogenic biomass immobilized on clinoptilolite in an anaerobic packed bed reactor. Copper and iron were fed to the reactor at concentrations of ...The aim of this study was to evaluate the effect of copper and iron on acidogenic biomass immobilized on clinoptilolite in an anaerobic packed bed reactor. Copper and iron were fed to the reactor at concentrations of 100 and 300 mg·L-1, respectively. Both metal ions had insignificant inhibitory effect over the metabolism of the biomass, specifically, on substrate consumption and production of volatile fatty acids (VFAs). The microstructural characterization of the biofilm by Scanning Electron Microscopy showed no effect on the morphology of the microorganisms after the metals treatment. Copper and iron removal was also measured in the reactor, achieving a breakthrough time of 3 days, during which removal efficiencies were higher than 90%. It was also observed that the biomass had a greater affinity for copper. The results indicate that acidogenic biomass can be used effectively as a sorbent agent. The pollution of river-streams with heavy metals—mainly copper and iron—was one of the most compelling motivations for conducting this investigation. The San Pedro River Basin, a trans-boundary river that originates near the mining town of Cananea, Sonora, México, and flows to Arizona, USA, exemplifies this environmental issue.展开更多
Heatmap cluster figures are often used to represent data sets in the?omic sciences. The default option of the frequently used R heatmap function is to cluster data according to Euclidean distance, which groups data ma...Heatmap cluster figures are often used to represent data sets in the?omic sciences. The default option of the frequently used R heatmap function is to cluster data according to Euclidean distance, which groups data mainly to their numerical value and not to its relative behaviour. The disadvantage of using the default clustering?dendrograms of R is demonstrated. Instead, a script is provided that uses correlation as distance function, which better reveals biologically meaningful information. This optimized script was used to detect heterotic groups in Vitamaize hybrids (purple maize with high nutraceutical value). A field trial with different genetic combinations was performed through an agricultural phenomics approach (holistic evaluation of the phenotype). The grain yield data and other phenotypic variables were represented through heatmap figures. In the data set of Mexican tropical maize germplasm, at least three heterotic groups were detected, in contrast to only two heterotic groups reported earlier in temperate yellow maize from USA and Europe. This optimized script for heatmap correlation bicluster can also be used to better represent metabolomic fingerprints and transcriptomic data sets.展开更多
In the “Laguna” region of Coahuila state, Mexico like other places in the world, the groundwater needs to be treated to meet the quality required for human consumption. The study had probed that a Mexican fly ash ca...In the “Laguna” region of Coahuila state, Mexico like other places in the world, the groundwater needs to be treated to meet the quality required for human consumption. The study had probed that a Mexican fly ash can be used as a raw material to obtain effective low cost adsorbents for drinking water treatment, as well evaluated the effects of pH, ion coexistence, dose, arsenic (As) concentration and temperature on the As(V) uptake by using P and W modified zeolites (PMOD and WMOD) obtained from a Mexican fly ash. The As(V) adsorption capacity of the WMOD zeolite was not affected by pH and As(V) concentrations in aqueous solution was achieved 0.01 mg/L in the studied pH range;however, the As(V) removal by using PMOD zeolite decreased at high pH values. Carbonate concentration had a negative effect on the As(V) uptake of both zeolites but this effect was higher for the PMOD zeolite. The maximum adsorption capacities (Qmax) were 76.11 and 44.44 mg of As(V)/g of zeolite for the WMOD and the PMOD zeolites, respectively. The adsorption process was endothermic, spontaneous and occurred by chemical exchange. The experimental data were best interpreted by a pseudo-second order kinetic model. The WMOD zeolite showed a higher adsorption capacity and rate than the PMOD even at the highest evaluated As(V) concentration. The adsorption capacity of the regenerated WMOD zeolite was similar to the original zeolite. Because of the high As(V) adsorption capacity, chemical stability and regenerability, the WMOD zeolite is potentially useful as low-cost adsorbent for As(V) removal from aqueous effluents.展开更多
The knowledge generated from the identification of plant promoters has been very important for plant biotechnology development. The use of promoters in transgenic plants allows a reasonable level of regulating protein...The knowledge generated from the identification of plant promoters has been very important for plant biotechnology development. The use of promoters in transgenic plants allows a reasonable level of regulating protein expression. With the application of reporter genes, such as <i>gus</i>A (<i>uid</i>A,) the production of a colored protein, <i>β</i>-glucuronidase, can be detected and measured both qualitatively and quantitatively, and the activity of the promoter can be assessed. In this work we use a promoter of an abundant banana fruit protein gene <i>Musa acuminata</i> Acidic Chitinase class III a monocot species, to drive expression of <i>gus</i>A in a dicot species, like tomato. We evaluated the monocot promoter capabilities by localizing and quantifying <i>β</i>-glucuronidase (GUS) expression through fluorometric assays during tomato fruit ripening. Our results suggest that this promoter could be used for specifically strong fruit protein expression in dicot plants.展开更多
The aim of this study was to determinate the gene expression levels of angiotensinogen, angiotensin converting enzyme, renin, (pro)renin receptor, and the final rennin-angiotensin system (RAS) products Angiotensin (An...The aim of this study was to determinate the gene expression levels of angiotensinogen, angiotensin converting enzyme, renin, (pro)renin receptor, and the final rennin-angiotensin system (RAS) products Angiotensin (Ang) II and Ang 1-7 inthe remnant kidney of 5/6 nephrectomized rats and its response to RAS pharmacological blockade. Male Wistar rats were divided into five groups: sham operated (SO), 5/6 nephrectomized (NFX), NFX + captopril (50 mg/ kg/day), NFX + losartan (10 mg/kg/day), and NFX + aliskiren (10 mg/kg/day). Animals were followed up for 60 days and protein urine excretion was measured. Systolic blood pressure, renal tissue RAS mRNA expression levels, plasma Ang II, and plasma Ang 1-7 were evaluated at day 60 after nephrectomy. Blood pressure and urine protein were increased after 5/6 nephrectomy. Ang II levels were increased 9.4 fold, whereas Ang 1-7 decreased 72.9% in NFX animals compared with SO rats. 5/6 nephrectomy increased renal angiotensinogen and (pro)renin receptor mRNA expression but down-regulated renin mRNA expression. RAS blockade restored the systolic blood pressure to normal values and slowed down urinary protein excretion, and also prevented changes in Ang II and Ang 1-7. RAS blockade reduced (pro)renin receptor, ACE, and AGT mRNA expression in the remnant kidney. However, renin mRNA expression increased compared with NFX rats. In conclusion these results suggest that inhibition of Ang II synthesis by RAS blockade is associated with renal regulation of RAS mRNA expression and this may be through a mechanism related with the Ang II/Ang 1-7 balance.展开更多
基金supported by Dirección General del Personal Académico(DGAPA)PAPIIT IN207123,UNAM(to AZ)。
文摘Pregnancy comes with a combination of physical changes and physiological immunosuppression that increases the susceptibility of women to pathogens and in turn,rises the prevalence of infectious diseases.
文摘The following material is devoted to the generalization of the chaos modeling to random fields in communication channels and its application on the space-time filtering for the incoherent paradigm;that is the purpose of this research. The approach, presented hereafter, is based on the “Markovian” trend in modeling of random fields, and it is applied for the first time to the chaos field modeling through the well-known concept of the random “treatment” of deterministic dynamic systems, first presented by A. Kolmogorov, M. Born, etc. The material presents the generalized Stratonovich-Kushner Equations (SKE) for the optimum filtering of chaotic models of random fields and its simplified quasi-optimum solutions. In addition to this, the application of the multi-moment algorithms for quasi-optimum solutions is considered and, it is shown, that for scenarios, when the covariation interval of the input random field is less than the distance between the antenna elements, the gain of the space-time algorithms against their “time” analogies is significant. This is the general result presented in the following.
基金supported by the STI2030-Major Projects(2021ZD0200900 to Y.G.Y.)"Light of West China" Program of the Chinese Academy of Sciences(xbzg-zdsys-202302 to Y.G.Y.)
文摘The tree shrew(Tupaia belangeri)has long been proposed as a suitable alternative to non-human primates(NHPs)in biomedical and laboratory research due to its close evolutionary relationship with primates.In recent years,significant advances have facilitated tree shrew studies,including the determination of the tree shrew genome,genetic manipulation using spermatogonial stem cells,viral vector-mediated gene delivery,and mapping of the tree shrew brain atlas.However,the limited availability of tree shrews globally remains a substantial challenge in the field.Additionally,determining the key questions best answered using tree shrews constitutes another difficulty.Tree shrew models have historically been used to study hepatitis B virus(HBV)and hepatitis C virus(HCV)infection,myopia,and psychosocial stress-induced depression,with more recent studies focusing on developing animal models for infectious and neurodegenerative diseases.Despite these efforts,the impact of tree shrew models has not yet matched that of rodent or NHP models in biomedical research.This review summarizes the prominent advancements in tree shrew research and reflects on the key biological questions addressed using this model.We emphasize that intensive dedication and robust international collaboration are essential for achieving breakthroughs in tree shrew studies.The use of tree shrews as a unique resource is expected to gain considerable attention with the application of advanced techniques and the development of viable animal models,meeting the increasing demands of life science and biomedical research.
文摘The Retinoblastoma 1 (RB1) gene, located on chromosome 13q14 and encodes the tumor-suppressor retinoblastoma protein, is the cause of Retinoblastoma. The mutational inactivation of both gene alleles brings on this cancer. Retinoblastoma (RB) high-risk histopathological characteristics indicate metastasis or local recurrence with rapid progresses following RB1 inactivation. There is growing interest in regulatory activities unconnected to the coding region of the genome, or exome, in addition to epigenetic control mechanisms. The altered epigenome is significant, though by no means the only, problem in the etiology of Retinoblastoma. After all, cancer development is a multistep process in which numerous dissimilar genetic, epigenetic, and posttranscriptional modifications result in a shared phenotype. This study emphasizes the most recent developments in posttranscriptional change and epigenetics related to retinoblastoma tumor biology. Here, we highlight the novel biomarkers the retinoblastoma tumor has expressed to improve patient survival.
文摘This material is aimed to attract attention to the “incoherent approach for power NOMA-RIS-MIMO transmission in wireless channels”. Such kind of approach might be successfully applied in future dense networks formed by High-Speed Vehicles (HSV networks, etc.). Those scenarios take place in doubly selective communication channels typical for such kind of radio networks. The proposal for the presented hereafter incoherent view (“paradigm”) is based on several basic principles: 1) Shift from the “coherent “ideology”, i.e. rejection of the application of any type of Channel State Information (CSI, CSIT);2) Application of the so-called “invariant” to the communication channel’s features (distortions) modulation technique together with its incoherent demodulation;3) Orthogonal channel decomposition by means of “universal” eigen basis (in the form of Prolate Spheroidal Wave Functions, PSWF) as “artificial trajectories” of wave propagation;4) Chaotic filtering (chaos parameter settings as UE signatures) together with sequential multiuser parallel detection algorithms for users’ identification (classification). It is shown that the proposed approach might provide an effective use of the radio resource and it is relatively simple for implementation.
基金funded by the Tecnológico Nacional de México(TECNM):Project No.6602.18-P.
文摘The objective of this work was to evaluate the effect of Beauveria bassiana(Bb 1205)on controlling Fusarium oxysporum f.sp.lycopersici(Fol 17108)in tomato plants in greenhouse conditions.Inoculation of Bb 1205 was the most promising among the agronomic variables and expression of the activity of the enzymesβ-1,3-glucanases and chitinases.Inoculation of Bb 1205 occurred at a concentration of 1×108 conidia·mL−1,which was administered onto the leaves,directly into the soil and via injection.Infection with Fol 17108 occurred with 1×106 spores·mL−1,which were added directly to the soil.Spectrophotometry was used for measuring agronomic parameters,namely activity of chitinases andβ-1,3-glucanases in foliage and roots.When Bb 1205 was added to the soil,the chlorophyll index and aerial part length showed significant differences.In addition,it was determined that root length,fresh weight of foliage,flower,and fruit count increased 82 days after inoculation(dai).Chitinase activity induced by Bb 1205 in leaves and roots of tomato plants infected with Fol 17108 was observed when injected into the stem at 32 dai(41.8 and 11.6-fold,respectively).Inoculation on the foliage showed a 10-fold increase ofβ-1,3-glucanases in the roots after 82 dpi.As for leaves,a 3.8-fold increase was found when the stem was inoculated.In the different in vivo applications,Bb 1205 activated its defenses by expressing the chitinase enzymes andβ-1,3-glucanase,thus reducing the damage caused by Fol 17108,demonstrating increase plant growth thereafter.
基金the partial financial support of this study from CONACYT (Grant 179110)
文摘Aluminum alloy samples, 6061-T6 and 2219-T42, were exposed to Caribbean seawater for 90 d. The fluctuations of open circuit potential, considered as electrochemical noise (EN), were used to characterize and compare initial pitting events, which appeared on their surfaces. EN analysis was carried out using the power spectral density (PSD) vs frequency. The decrease of the β exponent in PSD graphs indicated a release of spontaneous energy with the progress of pit formation in seawater. The fluctuations were associated with the breakdown and formation of new corrosion layers. The values of β exponent in PSD graphs suggest that corrosion process of AA2219-T42 alloy occurs as a persistent non-stationary process, the dynamics of which is controlled by fractional Brownian motion (fBm), while on AA6061-T6 alloy the corrosion process was dominated by stationary and weakly persistent features, with the contribution of fractional Gaussian noise (fGn). After the exposure in seawater, SEM-EDX analysis revealed insoluble intermetallic particles on the alloys, rich in Cu or Fe and irregularly distributed. The preferential dissolution of Mg and Al occurs from the S-phase (Al2CuMg) of AA2219-T42 alloy.
文摘AIM:To compare the effect of phacoemulsification on intraocular pressure(IOP)in patients with primary open angle glaucoma(POAG)and pseudoexfoliation glaucoma(PXG).METHODS:A retrospective comparative case series conducted at the Glaucoma Department at the Association to Prevent Blindness in Mexico.The study enrolled consecutive patients having phacoemulsification with intraocular lens(IOL)implantation and a diagnosis of POAG or PXG.Data about IOP values and number of glaucoma medications used was collected at baseline,1,3,6 and12mo postoperatively.RESULTS:The study enrolled 88 patients(88 eyes).After phacoemulsification,there was a statistically significant reduction in IOP values and glaucoma medications use compared to baseline in both POAG and PXG patients(P〈0.001).In the POAG group,a 20%decrease in IOP values was evidenced,and a 56.5%reduction in the number of medications used at the one-year follow-up.The PXG group showed a 20.39%,and a 34.46%decrease in IOP and number of medications used,respectively.A significant difference in the meanΔIOP(postoperative changes in IOP)was evidenced between groups(P=0.005).The reduction of the postsurgical IOP mean values in both groups,the POAG group showed a greater reduction in IOP values compared to the PXG group.CONCLUSION:In both types of glaucoma,phacoemulsification cataract surgery can result in a significant IOP reduction(20%)over a 12mo follow-up period.The number of medications used is also significantly reduced up to 12mo after surgery,especially in the PXG group.
文摘Intracerebroventricular administration (ICV) of streptozotocin (STZ) in rats has been associated to desensitization of the insulin receptor (IR) and biochemical changes similar to those occurring in Alzheimer’s disease (AD) or older brains, so it has been proposed as a suitable model for studying some of the pathological features of AD sporadic type (SAD). In this study, we investigated the role of glycogen synthase kinase 3β (GSK3β) and protein phosphatase 2A (PP2A) in the regulation of the phosphorylation of tau (p-tau). Results showed that ICV-STZ treated rats had deficits in short- (1.5-h) and long-term (24- and 48-h) memory after one month of ICV-STZ treatment and six months relative to control rats. The memory deficit was associated to increasing [F(3, 12) = 31.48, p β (p-GSK3β) and PP2A in hippocampus and PFC, indicating that GSK3β and PP2A contributed to regulation of p-tau. These data supporting the model with ICV-STZ in rat are adequate to study the progressive memory impairment associated to hyperphosphorylation of tau and the cascade of insulin receptor signaling;confirm that phosphatidyl-inositol-3 kinase-protein kinase B (PI3K-PKB/Akt-GSK3β) and PP2A are involved in the modulation of proteins responsible for the regulation of neurodegeneration in AD.
文摘Due to the environmental policies and economic reasons,the water used in some flotation operations of complex sulfide ores is recirculated,causing the ion concentration of some species to increase over time,affecting the flotation of the minerals of interest.In this work,an experimental and thermodynamic analysis of the synthetic solutions was presented with a high content of calcium and sulfate ions.The study focused on evaluating the use of two aluminum compounds for the precipitation of Ca^(2+)and SO_(4)^(2−)in the form of ettringite.The amorphous aluminum hydroxide was found to be more efficient than the crystalline one,giving rise to 83%calcium and 91%sulfate removal.The XRD analysis of the solids showed the main reaction product of ettringite,accompanied by small amounts of calcite,due to the absorption of atmospheric carbon dioxide.The final solution after the chemical treatment showed residual calcium and sulfate concentrations below 200 mg/L.Finally,the kinetics of calcium removal appeared to correspond to a second order reaction with respect to calcium concentration,with an apparent activation energy of 53.48 kJ/mol,which may suggest that the ettringite precipitation process is governed by the chemical reaction.
文摘We studied the influence of antimony on the modification rate of the silicon eutectic with sodium and/or strontium for castiig of A1-Si alloys, and introduced controlled Ca and Sb to the system and studied the resulting compounds, which were determined to be CazSb and A1Sb. Scanning electron microscopy together with the complementary technique of electron backscatter diffraction (EBSD) were used to characterize the materials. The experimental results provided the basis for us to establish that antimony removal from AI occurs mainly through the reaction (Sb)A1 + 2Ca = Ca^Sb + A1.
文摘This paper presents two contributions to the stability analysis of periodic systems modeled by a Hill equation: The first is a new method for the computation of the Arnold Tongues associated to a given Hill equation which is based on the discretization of the latter. Using the proposed method, a vibrational stabilization is performed by a change in the periodic function which guarantees stability, given that the original equation has unbounded solutions. The results are illustrated by some examples.
基金the National Council for Science and Technology of Mexico(Conacyt)for the financial support provided to carry out this work(Project No.149030).
文摘Nucleation of Fe-rich intermetallic phases on α-Al2O3 oxide films was analyzed in five experimental Al-Fe-Mn-Si alloys. In an attempt to verify the role of α-Al2O3 films in nucleating Fe-rich intermetallics, experiments have been conducted under conditions where formed in situ oxide films were present. Some Fe-rich intermetallics are observed to be related with the oxide films in the microstructure, the present results are in accordance with some research that suggest that the Fe-rich intermetallic phases nucleate upon the oxide films. The intermetallic phases and α-Al2O3 films were unambiguously identified with the help of complementary techniques such as thermal analysis, SEM/EDS and X-ray diffraction.
文摘The aim of this study was to evaluate the effect of copper and iron on acidogenic biomass immobilized on clinoptilolite in an anaerobic packed bed reactor. Copper and iron were fed to the reactor at concentrations of 100 and 300 mg·L-1, respectively. Both metal ions had insignificant inhibitory effect over the metabolism of the biomass, specifically, on substrate consumption and production of volatile fatty acids (VFAs). The microstructural characterization of the biofilm by Scanning Electron Microscopy showed no effect on the morphology of the microorganisms after the metals treatment. Copper and iron removal was also measured in the reactor, achieving a breakthrough time of 3 days, during which removal efficiencies were higher than 90%. It was also observed that the biomass had a greater affinity for copper. The results indicate that acidogenic biomass can be used effectively as a sorbent agent. The pollution of river-streams with heavy metals—mainly copper and iron—was one of the most compelling motivations for conducting this investigation. The San Pedro River Basin, a trans-boundary river that originates near the mining town of Cananea, Sonora, México, and flows to Arizona, USA, exemplifies this environmental issue.
文摘Heatmap cluster figures are often used to represent data sets in the?omic sciences. The default option of the frequently used R heatmap function is to cluster data according to Euclidean distance, which groups data mainly to their numerical value and not to its relative behaviour. The disadvantage of using the default clustering?dendrograms of R is demonstrated. Instead, a script is provided that uses correlation as distance function, which better reveals biologically meaningful information. This optimized script was used to detect heterotic groups in Vitamaize hybrids (purple maize with high nutraceutical value). A field trial with different genetic combinations was performed through an agricultural phenomics approach (holistic evaluation of the phenotype). The grain yield data and other phenotypic variables were represented through heatmap figures. In the data set of Mexican tropical maize germplasm, at least three heterotic groups were detected, in contrast to only two heterotic groups reported earlier in temperate yellow maize from USA and Europe. This optimized script for heatmap correlation bicluster can also be used to better represent metabolomic fingerprints and transcriptomic data sets.
文摘In the “Laguna” region of Coahuila state, Mexico like other places in the world, the groundwater needs to be treated to meet the quality required for human consumption. The study had probed that a Mexican fly ash can be used as a raw material to obtain effective low cost adsorbents for drinking water treatment, as well evaluated the effects of pH, ion coexistence, dose, arsenic (As) concentration and temperature on the As(V) uptake by using P and W modified zeolites (PMOD and WMOD) obtained from a Mexican fly ash. The As(V) adsorption capacity of the WMOD zeolite was not affected by pH and As(V) concentrations in aqueous solution was achieved 0.01 mg/L in the studied pH range;however, the As(V) removal by using PMOD zeolite decreased at high pH values. Carbonate concentration had a negative effect on the As(V) uptake of both zeolites but this effect was higher for the PMOD zeolite. The maximum adsorption capacities (Qmax) were 76.11 and 44.44 mg of As(V)/g of zeolite for the WMOD and the PMOD zeolites, respectively. The adsorption process was endothermic, spontaneous and occurred by chemical exchange. The experimental data were best interpreted by a pseudo-second order kinetic model. The WMOD zeolite showed a higher adsorption capacity and rate than the PMOD even at the highest evaluated As(V) concentration. The adsorption capacity of the regenerated WMOD zeolite was similar to the original zeolite. Because of the high As(V) adsorption capacity, chemical stability and regenerability, the WMOD zeolite is potentially useful as low-cost adsorbent for As(V) removal from aqueous effluents.
文摘The knowledge generated from the identification of plant promoters has been very important for plant biotechnology development. The use of promoters in transgenic plants allows a reasonable level of regulating protein expression. With the application of reporter genes, such as <i>gus</i>A (<i>uid</i>A,) the production of a colored protein, <i>β</i>-glucuronidase, can be detected and measured both qualitatively and quantitatively, and the activity of the promoter can be assessed. In this work we use a promoter of an abundant banana fruit protein gene <i>Musa acuminata</i> Acidic Chitinase class III a monocot species, to drive expression of <i>gus</i>A in a dicot species, like tomato. We evaluated the monocot promoter capabilities by localizing and quantifying <i>β</i>-glucuronidase (GUS) expression through fluorometric assays during tomato fruit ripening. Our results suggest that this promoter could be used for specifically strong fruit protein expression in dicot plants.
文摘The aim of this study was to determinate the gene expression levels of angiotensinogen, angiotensin converting enzyme, renin, (pro)renin receptor, and the final rennin-angiotensin system (RAS) products Angiotensin (Ang) II and Ang 1-7 inthe remnant kidney of 5/6 nephrectomized rats and its response to RAS pharmacological blockade. Male Wistar rats were divided into five groups: sham operated (SO), 5/6 nephrectomized (NFX), NFX + captopril (50 mg/ kg/day), NFX + losartan (10 mg/kg/day), and NFX + aliskiren (10 mg/kg/day). Animals were followed up for 60 days and protein urine excretion was measured. Systolic blood pressure, renal tissue RAS mRNA expression levels, plasma Ang II, and plasma Ang 1-7 were evaluated at day 60 after nephrectomy. Blood pressure and urine protein were increased after 5/6 nephrectomy. Ang II levels were increased 9.4 fold, whereas Ang 1-7 decreased 72.9% in NFX animals compared with SO rats. 5/6 nephrectomy increased renal angiotensinogen and (pro)renin receptor mRNA expression but down-regulated renin mRNA expression. RAS blockade restored the systolic blood pressure to normal values and slowed down urinary protein excretion, and also prevented changes in Ang II and Ang 1-7. RAS blockade reduced (pro)renin receptor, ACE, and AGT mRNA expression in the remnant kidney. However, renin mRNA expression increased compared with NFX rats. In conclusion these results suggest that inhibition of Ang II synthesis by RAS blockade is associated with renal regulation of RAS mRNA expression and this may be through a mechanism related with the Ang II/Ang 1-7 balance.