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1.
Phys Rev Lett ; 131(5): 051801, 2023 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-37595210

RESUMEN

MINERvA has measured the ν_{µ}-induced coherent π^{+} cross section simultaneously in hydrocarbon (CH), graphite (C), iron (Fe), and lead (Pb) targets using neutrinos from 2 to 20 GeV. The measurements exceed the predictions of the Rein-Sehgal and Berger-Sehgal PCAC based models at multi-GeV ν_{µ} energies and at produced π^{+} energies and angles, E_{π}>1 GeV and θ_{π}<10°. Measurements of the cross-section ratios of Fe and Pb relative to CH reveal the effective A scaling to increase from an approximate A^{1/3} scaling at few GeV to an A^{2/3} scaling for E_{ν}>10 GeV.

2.
Inorg Chem ; 62(10): 4291-4303, 2023 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-36862825

RESUMEN

In this work, we focus on understanding the morphology and photocatalytic properties of CeO2 nanocrystals (NCs) synthesized via a microwave-assisted solvothermal method using acetone and ethanol as solvents. Wulff constructions reveal a complete map of available morphologies and a theoretical-experimental match with octahedral nanoparticles obtained through synthesis using ethanol as solvent. NCs synthesized in acetone show a greater contribution of emission peaks in the blue region (∼450 nm), which may be associated with higher Ce3+ concentration, originating shallow-level defects within the CeO2 lattice while for the samples synthesized in ethanol a strong orange-red emission (∼595 nm) suggests that oxygen vacancies may originate from deep-level defects within the optical bandgap region. The superior photocatalytic response of CeO2 synthesized in acetone compared to that of CeO2 synthesized in ethanol may be associated with an increase in long-/short-range disorder within the CeO2 structure, causing the Egap value to decrease, facilitating light absorption. Furthermore, surface (100) stabilization in samples synthesized in ethanol may be related to low photocatalytic activity. Photocatalytic degradation was facilitated by the generation of ·OH and ·O2- radicals as corroborated by the trapping experiment. The mechanism of enhanced photocatalytic activity has been proposed suggesting that samples synthesized in acetone tend to have lower e'─h· pair recombination, which is reflected in their higher photocatalytic response.

3.
Exp Cell Res ; 363(2): 332-341, 2018 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-29395133

RESUMEN

Growth arrest specific 1 (GAS1) is a signaling mediator for the development of the central nervous system that works as a co-receptor for sonic hedgehog (SHH) to induce the amplification of neural progenitors during the patterning of the mammalian neural tube and establishing granular cells in the cerebellum. Recently, we confirmed that Gas1 is also expressed by neural progenitors of the developing cortex and the dentate gyrus of the hippocampus. The presence of GAS1 in progenitor stages indicates that one of its principal roles is the maintenance of these cells during neurogenic events. However, the signals responsible for the expression of Gas1 in progenitor cells are unknown, an aspect that is relevant to understand its functions during neurogenesis. Here, we focused on elucidating the mechanisms of the transcriptional regulation of Gas1 and using comparative genomics methods found two highly conserved E-boxes in the Gas1 promoter which mediate its up-regulation by NeuroD1. Additionally, we found that GAS1 and NeuroD1 co-localize in the neocortex, the dentate gyrus of the hippocampus and the external granular layer of the cerebellum, suggesting a previously unsuspected regulatory relationship. Our data indicate that Gas1 is a direct target of NeuroD1 during the induction of the neurogenic program.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Proteínas de Ciclo Celular/metabolismo , Regulación de la Expresión Génica/genética , Proteínas Hedgehog/metabolismo , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Proteínas de Ciclo Celular/genética , Proteínas Ligadas a GPI/genética , Hipocampo/metabolismo , Proteínas de la Membrana/metabolismo , Ratones , Tubo Neural/metabolismo , Neurogénesis/fisiología , Transducción de Señal/fisiología , Células Madre/metabolismo
4.
Phys Rev Lett ; 119(1): 011802, 2017 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-28731762

RESUMEN

Neutral-current production of K^{+} by atmospheric neutrinos is a background in searches for the proton decay p→K^{+}ν[over ¯]. Reactions such as νp→νK^{+}Λ are indistinguishable from proton decays when the decay products of the Λ are below detection threshold. Events with K^{+} are identified in MINERvA by reconstructing the timing signature of a K^{+} decay at rest. A sample of 201 neutrino-induced neutral-current K^{+} events is used to measure differential cross sections with respect to the K^{+} kinetic energy, and the non-K^{+} hadronic visible energy. An excess of events at low hadronic visible energy is observed relative to the prediction of the neut event generator. Good agreement is observed with the cross section prediction of the genie generator. A search for photons from π^{0} decay, which would veto a neutral-current K^{+} event in a proton decay search, is performed, and a 2σ deficit of detached photons is observed relative to the genie prediction.

5.
Phys Rev Lett ; 119(8): 082001, 2017 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-28952766

RESUMEN

Charged-current ν_{µ} interactions on carbon, iron, and lead with a final state hadronic system of one or more protons with zero mesons are used to investigate the influence of the nuclear environment on quasielasticlike interactions. The transferred four-momentum squared to the target nucleus, Q^{2}, is reconstructed based on the kinematics of the leading proton, and differential cross sections versus Q^{2} and the cross-section ratios of iron, lead, and carbon to scintillator are measured for the first time in a single experiment. The measurements show a dependence on the atomic number. While the quasielasticlike scattering on carbon is compatible with predictions, the trends exhibited by scattering on iron and lead favor a prediction with intranuclear rescattering of hadrons accounted for by a conventional particle cascade treatment. These measurements help discriminate between different models of both initial state nucleons and final state interactions used in the neutrino oscillation experiments.

6.
Rev Gastroenterol Mex ; 82(3): 210-216, 2017.
Artículo en Inglés, Español | MEDLINE | ID: mdl-28325647

RESUMEN

BACKGROUND: In relation to the number of new cases diagnosed, gastric cancer is the fourth most common cancer worldwide, and the second cause of cancer death. The development of multidetector tomography has improved the preoperative staging of gastric cancer. AIM: To correlate preoperative tomographic studies with the definitive pathologic results according to the TNM staging system. METHODS: A retrospective, cross-sectional study within the time frame of January 2009 to December 2013 was conducted that included the case records of 67 patients. They all had upper endoscopy and preoperative multidetector tomography examinations, underwent surgical resection, and had the corresponding histopathology study. Statistical analysis was carried out with the SPSS version 15.0 software and the sensitivity and specificity calculations were made using the Excel 2011 program for Mac. RESULTS: The majority of the patients included in the case series had clinical stage iii and iv disease. When compared with the histopathologic result, the overall accuracy of multidetector CT was 83% (T0 96%, T1 94%, T2 93%, T3 67%, and T4 67%) for tumor size (T) and was 70% (N0 72%, N1 73%, N2 70%, and N3 66%) for lymph node involvement (N). Overall sensitivity was 48% (T0 100%, T1 0%, T2 33%, T3 44%, and T4 65%) for T and was 41% (N0 58%, N1 56%, N2 15%, and N3 35%) for N. A strong association between the multidetector CT results and the pathology results was demonstrated through the Spearman's correlation, especially in T4 and N3. CONCLUSIONS: Multidetector computed tomography showed greater congruency in detecting stages T4, N0, and N3 in gastric cancer, when compared with the definitive histopathologic results.


Asunto(s)
Adenocarcinoma/diagnóstico por imagen , Adenocarcinoma/patología , Tomografía Computarizada Multidetector , Cuidados Preoperatorios , Neoplasias Gástricas/diagnóstico por imagen , Neoplasias Gástricas/patología , Adenocarcinoma/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Hospitales Militares , Humanos , Masculino , México , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Retrospectivos , Sensibilidad y Especificidad , Neoplasias Gástricas/cirugía
7.
Gac Med Mex ; 153(Supl. 2): S72-S81, 2017.
Artículo en Español | MEDLINE | ID: mdl-29099102

RESUMEN

Objective: To determine the effect of melatonin (MEL) administration on ciclooxigenase 2 (COX-2) activity and serum concentration of nitric oxide metabolites, lipoperoxides and glutathione peroxidase (GPx) activity in patients with Parkinson's disease. Methods: Prospective double-blind randomized clinical pilot trial. 13 patients were included and two groups were formed: MEL at doses of 25 mg orally every 12 hours for 12 months and placebo with corn starch. Patients were assessed using the Unified Parkinson's Disease Scale. A blood sample was taken at baseline and every 3 months until 12 months. Results: COX-2 activity decreased as did nitrates/nitrites (3, 6 and 9 months) and lipoperoxides (9 and 12 months); GPx exhibited no significant differences.


Asunto(s)
Antioxidantes/farmacología , Ciclooxigenasa 2/metabolismo , Glutatión Peroxidasa/sangre , Peróxidos Lipídicos/sangre , Melatonina/farmacología , Óxido Nítrico/metabolismo , Enfermedad de Parkinson/metabolismo , Antioxidantes/administración & dosificación , Método Doble Ciego , Humanos , Melatonina/administración & dosificación , Estrés Oxidativo , Proyectos Piloto , Estudios Prospectivos
8.
Rev Gastroenterol Mex ; 80(3): 198-204, 2015.
Artículo en Inglés, Español | MEDLINE | ID: mdl-26249139

RESUMEN

BACKGROUND: Invasive management of pancreatic pseudocysts (PP) is currently indicated in those patients with symptoms or complications. Treatment options are classified as surgical (open and laparoscopic) and non-surgical (endoscopic and radiologic). AIM: To describe the morbidity, mortality, and efficacy in terms of technical and clinical success of the laparoscopic surgical approach in the treatment of patients with PP in the last 3 years at our hospital center. METHODS: We included patients with PP treated with laparoscopic surgery within the time frame of January 2012 and December 2014. The morbidity and mortality associated with the procedure were determined, together with the postoperative results in terms of effectiveness and recurrence. RESULTS: A total of 38 patients were diagnosed with PP within the last 3 years, but only 20 of them had invasive treatment. Laparoscopic surgery was performed on 17 of those patients (mean pseudocyst diameter of 15.3, primary drainage success rate of 94.1%, complication rate of 5.9%, and a 40-month follow-up). CONCLUSIONS: The results obtained with the laparoscopic technique used at our hospital center showed that this approach is feasible, efficacious, and safe. Thus, performed by skilled surgeons, it should be considered a treatment option for patients with PP.


Asunto(s)
Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Laparoscopía/métodos , Seudoquiste Pancreático/cirugía , Adolescente , Adulto , Anciano , Estudios Transversales , Femenino , Hospitales Generales , Humanos , Masculino , México/epidemiología , Persona de Mediana Edad , Seudoquiste Pancreático/epidemiología , Seudoquiste Pancreático/mortalidad , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
9.
Biol Sport ; 32(2): 123-8, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26060335

RESUMEN

The purpose of this study was to compare the acute effects of general, specific and combined warm-up (WU) on explosive performance. Healthy male (n = 10) subjects participated in six WU protocols in a crossover randomized study design. Protocols were: passive rest (PR; 15 min of passive rest), running (Run; 5 min of running at 70% of maximum heart rate), stretching (STR; 5 min of static stretching exercise), jumping [Jump; 5 min of jumping exercises - 3x8 countermovement jumps (CMJ) and 3x8 drop jumps from 60 cm (DJ60)], and combined (COM; protocols Run+STR+Jump combined). Immediately before and after each WU, subjects were assessed for explosive concentric-only (i.e. squat jump - SJ), slow stretch-shortening cycle (i.e. CMJ), fast stretch-shortening cycle (i.e. DJ60) and contact time (CT) muscle performance. PR significantly reduced SJ performance (p =0.007). Run increased SJ (p =0.0001) and CMJ (p =0.002). STR increased CMJ (p =0.048). Specific WU (i.e. Jump) increased SJ (p =0.001), CMJ (p =0.028) and DJ60 (p =0.006) performance. COM increased CMJ performance (p =0.006). Jump was superior in SJ performance vs. PR (p =0.001). Jump reduced (p =0.03) CT in DJ60. In conclusion, general, specific and combined WU increase slow stretch-shortening cycle (SSC) muscle performance, but only specific WU increases fast SSC muscle performance. Therefore, to increase fast SSC performance, specific fast SSC muscle actions must be included during the WU.

10.
Waste Manag ; 181: 176-187, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38614039

RESUMEN

This study presented the influence of two types of clay: kaolin (Kao) and red clay (RC) on the chemical and physical properties of ceramic specimens when galvanic sludge (GS) is incorporated to encapsulate heavy metals. Samples were obtained of GS from the industrial district of Manaus - Amazonas State, Brazil, and kaolin (Kao), and red clay (RC) from the Central Amazon. A fourth sample was prepared by mixing GS, Kao, and RC in the ratio 1:1:8 (GS + Kao + RC). This mixture was ground, and ceramic specimens were prepared, and heat treated at 950 °C and 1200 °C for three hours for phase detection, compressive strength, leaching of Fe, Ni and Cr metals and life cycle assessment. Galvanic sludge, Kao, and RC were also, and heat treated to at 950 °C and 1200 °C for three hours, obtaining GS950, GS1200, Kao950, Kao1200, RC950, and RC1200. The samples were submitted to XRF, XRD, Rietveld refinement, Mössbauer spectroscopy, TG/DTG/DSC, and SEM. The results show that the formation of nickel oxide and a spinel solid solution of the type Fe3+{Fe1-y3+,Fe1-x2+,Nix2+,Cry3+}O4 (in which [] = tetrahedral site, {} octahedral site) occurs in GS1200, which is caused by sulfate decomposition to SO2. At 1200 °C, heavy metals are encapsulated, forming other phases such as nickel silicate and hematite. Life cycle assessment was used to verify the sustainability and value of GS in clay for making bricks, and it indicated that the production of ceramics is feasible, reduces the use of clays, and is sustainable.


Asunto(s)
Cerámica , Arcilla , Caolín , Metales Pesados , Aguas del Alcantarillado , Caolín/química , Arcilla/química , Metales Pesados/química , Metales Pesados/análisis , Cerámica/química , Aguas del Alcantarillado/química , Brasil
11.
Reproduction ; 146(3): R91-9, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23740082

RESUMEN

Cellular prion protein (PrP(C)) has been well described as an essential partner of prion diseases due to the existence of a pathological conformation (PrP(Sc)). Recently, it has also been demonstrated that PrP(C) is an important element of the pluripotency and self-renewal matrix, with an increasing amount of evidence pointing in this direction. Here, we review the data that demonstrate its role in the transcriptional regulation of pluripotency, in the differentiation of stem cells into different lineages (e.g. muscle and neurons), in embryonic development, and its involvement in reproductive cells. Also highlighted are recent results from our laboratory that describe an important regulation by PrP(C) of the major pluripotency gene Nanog. Together, these data support the appearance of new strategies to control stemness, which could represent an important advance in the field of regenerative medicine.


Asunto(s)
Desarrollo Embrionario , Células Madre Embrionarias/fisiología , Regeneración , Animales , Diferenciación Celular , Proliferación Celular , Células Germinativas/metabolismo , Humanos , Masculino , Maduración del Esperma
12.
Reproduction ; 146(5): 481-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23988666

RESUMEN

The role of the epididymis as a quality control organ in preventing infertile gametes entering the ejaculate has been extensively explored, and it has been suggested that a specific region of mammalian epididymis is able to phagocytose abnormal germ cells. This study examines whether the epithelium of certain zones of the mouse epididymis can act as a selection barrier by removing immature germ cells from the lumen by phagocytosis. To detect the presence of immature germ cells in the epididymis, we generated transgenic mice expressing enhanced green fluorescent protein under the deleted in azoospermia-like (mDazl) promoter to easily identify immature germ cells under fluorescence microscopy. Using this technique, we observed that during the first stage of spermatogenesis in prepuberal mice, a wave of immature germ cells is released into the epididymis and that the immature epididymis is not able to react to this abnormal situation. By contrast, when immature germ cells were artificially released into the epididymis in adult mice, a phagocytic response was observed. Phagosomes appeared inside principal cells of the epididymal epithelium and were observed to contain immature germ cells at different degradation stages in different zones of the epididymis, following the main wave of immature germ cells. In this paper, we describe how the epididymal epithelium controls sperm quality by clearing immature germ cells in response to their artificially induced massive shedding into the epididymal lumen. Our observations indicate that this phenomenon is not restricted to a given epididymis region and that phagocytic capacity is gradually acquired during epididymal development.


Asunto(s)
Células Madre Embrionarias/citología , Epidídimo/citología , Fagocitosis , Fagosomas/metabolismo , Maduración del Esperma , Espermátides/citología , Animales , Biomarcadores/metabolismo , Línea Celular Transformada , Colchicina/farmacología , Células Madre Embrionarias/efectos de los fármacos , Células Madre Embrionarias/metabolismo , Células Madre Embrionarias/ultraestructura , Epidídimo/efectos de los fármacos , Epidídimo/crecimiento & desarrollo , Epidídimo/metabolismo , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Masculino , Ratones , Ratones Transgénicos , Microscopía Fluorescente , Fagocitosis/efectos de los fármacos , Fagosomas/efectos de los fármacos , Fagosomas/ultraestructura , Regiones Promotoras Genéticas/efectos de los fármacos , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Proteínas Recombinantes/metabolismo , Análisis de Semen , Maduración del Esperma/efectos de los fármacos , Espermátides/efectos de los fármacos , Espermátides/metabolismo , Espermátides/ultraestructura , Moduladores de Tubulina/farmacología
13.
Nat Genet ; 28(3): 232-40, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11431693

RESUMEN

In mice and humans, the locus encoding the gene for small nuclear ribonucleoprotein N (SNRPN/Snrpn), as well as other loci in the region are subject to genomic imprinting. The SNRPN promoter is embedded in a maternally methylated CpG island, is expressed only from the paternal chromosome and lies within an imprinting center that is required for switching to and/or maintenance of the paternal epigenotype. We show here that a 0.9-kb deletion of exon 1 of mouse Snrpn did not disrupt imprinting or elicit any obvious phenotype, although it did allow the detection of previously unknown upstream exons. In contrast, a larger, overlapping 4.8-kb deletion caused a partial or mosaic imprinting defect and perinatal lethality when paternally inherited.


Asunto(s)
Síndrome de Angelman/genética , Autoantígenos/genética , Impresión Genómica , Síndrome de Prader-Willi/genética , Regiones Promotoras Genéticas , Ribonucleoproteínas Nucleares Pequeñas/genética , Animales , Secuencia de Bases , Quimera , Islas de CpG , Modelos Animales de Enfermedad , Exones , Femenino , Genotipo , Masculino , Ratones , Ratones Mutantes , Datos de Secuencia Molecular , Linaje , Fenotipo , Proteínas Nucleares snRNP
14.
Rev Gastroenterol Mex ; 78(1): 12-20, 2013.
Artículo en Español | MEDLINE | ID: mdl-23374541

RESUMEN

BACKGROUND: Helicobacter pylori (Hp) is recognized as a type 1 carcinogen for gastric cancer associated with pre-neoplastic lesions (atrophy and intestinal metaplasia [IM]). Its relation with p53, which intervenes in the cell cycle, has had contradictory results. AIMS: To analyze p53 expression in gastric mucosa and its relation with Hp infection. METHODS: A 3-month prospective, observational, cross-sectional study was conducted. Patients that had no evidence of acute or clinically significant gastric pathology had biopsies taken according to the Sydney system at the Hospital Juárez de México and the histopathologic studies were done at the Hospital Español de México. RESULTS: Hp prevalence was 32.7% in 104 patients. There were no cases of atrophy or dysplasia. A total of 91% of the infected patients were positive for p53. Of the non-infected patients, 14% were positive for p53 and 60% of them had IM. Of the IM patients, 75% presented with positive p53. Of the patients without IM, 31 presented with positive p53, and Hp was positive in 85% of them. There was association between Hp and p53 and between p53 and IM (P<.0001 and P<.0006, respectively). CONCLUSIONS: Significant association was shown between Hp and p53 expression, even in patients with pre-neoplastic lesions that no longer presented with Hp. Given that the identification of pre-neoplastic lesions is important for the prevention of cancer, immunohistochemistry could benefit routine biopsy carried out during endoscopy for the detection of Hp, by identifying patients with expression of the important oncogene regulator, p53.


Asunto(s)
Mucosa Gástrica/metabolismo , Expresión Génica/fisiología , Genes p53/fisiología , Infecciones por Helicobacter/metabolismo , Helicobacter pylori , Proteína p53 Supresora de Tumor/biosíntesis , Adulto , Biopsia , Estudios Transversales , Femenino , Mucosa Gástrica/patología , Expresión Génica/genética , Genes p53/genética , Infecciones por Helicobacter/genética , Infecciones por Helicobacter/microbiología , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Estudios Prospectivos
15.
Heliyon ; 9(11): e22219, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38045214

RESUMEN

Accidents at work are a problem in today's economic structures, but if they result in the loss of human lives, the economic and social cost is even higher. The development of prevention policies, both at governmental and sectoral level, has led to a progressive reduction of occupational accidents, but number of fatal accidents remain high. The aim of this study is to explore the evolution of fatal accidents at work in Spain for the period 2009-2021, analyse the relationship between the main variables, and propose a predictive model of fatal occupational accidents in Spain. Data for this study are collected from occupational accident reports via the Delt@ (Electronic declaration of injured workers) IT system. The study variables were classified into five groups: temporal, personal, business, circumstances, and consequences. Fatal accidents at work are more common in males and in older workers, especially in workers between 40 and 59 years old. Companies with less than five workers have the highest percentage of fatal accidents, and the transport subsector and that the worker is carrying out his/her usual work have a strong correlation in the fatal accidents. Results can help to the agents involved in the health and safety management to develop preventive measures, and action plans.

16.
Braz J Biol ; 83: e275698, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37937631

RESUMEN

The pandemic and the geopolitical conflict between Russia and Ukraine are events that have caused economic instability in Peru. Reason that was investigated on the analysis of the biological and chemical characteristics of cabbage fed with compost based on sugarcane residues. The objective was to analyze the physical, chemical and biological characteristics of cabbage from the adequate dose of compost based on sugarcane residues and distance between plants. It is based on the methodology applied with an experimental approach, for which the Completely Random Block Design with a 4x 2 factorial arrangement was used, which consisted of 3 blocks and 8 treatments that were the combination: F1 with 0, F2 with 8, T3 with 10 and F4 with 12 t/ha and spacing (D1) with 0.30 m between plants and 0.60 m between rows and (D2) with 0.35 m between plants and 0.60 m between rows. The physical characteristics of cabbage were evaluated and processed by analysis of variance, nutrient concentrations in leaves and stomatal density were analyzed. The results determined that T7 stood out in plant height with 41.88 cm, yield with 26.76 tn/ha and T6 in root length with 20.22 cm. In chemical analysis of leaves T1 stood out in nitrogen, phosphorus, potassium and T4 in calcium, magnesium and sulfur. In T7 stomata density with 977 stomata/mm2. It concludes that at an adequate dose and greater distance that T7 stands out in the concentration of nutrients that are within normal values and high density of stomata; Therefore, these characteristics influenced the optimal biochemical reactions, which obtained good development and yield that differed at 51.39% and 32.17% with respect to the controls T1 and T5.


Asunto(s)
Brassica , Compostaje , Saccharum , Brassica/química , Federación de Rusia
17.
Reprod Fertil Dev ; 25(1): 38-47, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23244827

RESUMEN

Preimplantation developmental plasticity has evolved in order to offer the best chances of survival under changing environments. Conversely, environmental conditions experienced in early life can dramatically influence neonatal and adult biology, which may result in detrimental long-term effects. Several studies have shown that small size at birth, which is associated with a greater risk of metabolic syndrome, is largely determined before the formation of the blastocysts because 70%-80% of variation in bodyweight at birth has neither a genetic nor environmental component. In addition, it has been reported that adult bodyweight is programmed by energy-dependent process during the pronuclear stage in the mouse. Although the early embryo has a high developmental plasticity and adapts and survives to adverse environmental conditions, this adaptation may have adverse consequences and there is strong evidence that in vitro culture can be a risk factor for abnormal fetal outcomes in animals systems, with growing data suggesting that a similar link may be apparent for humans. In this context, male and female preimplantation embryos display sex-specific transcriptional and epigenetic regulation, which, in the case of bovine blastocysts, expands to one-third of the transcripts detected through microarray analysis. This sex-specific bias may convert the otherwise buffered stochastic variability in developmental networks in a sex-determined response to the environmental hazard. It has been widely reported that environment can affect preimplantation development in a sex-specific manner, resulting in either a short-term sex ratio adjustment or in long-term sex-specific effects on adult health. The present article reviews current knowledge about the natural phenotypic variation caused by epigenetic mechanisms and the mechanisms modulating sex-specific changes in phenotype during early embryo development resulting in sex ratio adjustments or detrimental sex-specific consequences for adult health. Understanding the natural embryo sexual dimorphism for programming trajectories will help understand the early mechanisms of response to environmental insults.


Asunto(s)
Desarrollo Embrionario , Epigénesis Genética , Crecimiento , Animales , Peso al Nacer , Exposición a Riesgos Ambientales/efectos adversos , Femenino , Desarrollo Fetal , Retardo del Crecimiento Fetal/etiología , Retardo del Crecimiento Fetal/patología , Humanos , Masculino , Caracteres Sexuales , Aumento de Peso
18.
Rev Gastroenterol Mex ; 77(3): 148-52, 2012.
Artículo en Español | MEDLINE | ID: mdl-22951042

RESUMEN

Pancreatic pseudocysts are defined as homogeneous pancreatic or peripancreatic collections that are not associated with necrotic tissue and are surrounded by granulated or fibrous tissue with no epithelium. Management has been classified as surgical (conventional and laparoscopic) and nonsurgical (endoscopic and radiologic). The aim of this report is to describe our initial experience in the management of a pancreatic pseudocyst by means of laparoscopic posterior cyst-gastrostomy anastomosis, performed at the Pancreas Clinic of the Hospital General "Dr. Manuel Gea González" in Mexico City. New techniques and instrumentation have contributed to the relatively recent development of laparoscopic pancreatic surgery. Our technique has practical advantages that have been confirmed by other authors, such as simple hemostasis, a wide viewing angle enabling adequate necrosectomy, anastomosis that does not require the use of staples, and the possibility of resolving other associated intra-abdominal pathologies, as in this case.


Asunto(s)
Drenaje/métodos , Laparoscopía/métodos , Seudoquiste Pancreático/cirugía , Adulto , Endoscopía Gastrointestinal , Humanos , Masculino , Páncreas/patología , Páncreas/cirugía , Tomografía Computarizada por Rayos X
19.
Int J Biol Macromol ; 222(Pt B): 1688-1699, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36179871

RESUMEN

Corn starch dispersions (CSD) were hydrolyzed with citric acid and compared with CSD co-treated with citric acid combined with ultrasonication for 1 to 18 days, which are designated as single modification (CSD-SM) and dual modification (CSD-DM), respectively. The logistic functions monitor the dynamics of the hydrolysis advance (%) of the CSD-SM and CSD-DM as a function of time, where the zones most vulnerable to the single-treatment and/or co-treatment of the corn starch granules (CSG) are the amorphous or disordered regions. The characterization results of CSD-DM suggest that the structural changes caused by dual modification affected the morphology, sequence, and microstructure of the CSG. The heterogeneous changes caused by the dual modification changed the configuration of the CSG, generating a kind of destemming of the amorphous lamellae (depolymerization), an increase in the percentage of relative crystallinity of the CSD-DM and an active rearrangement of the intralamellar chains that promoted the relative amount of double helix for 18 days of double modification. The synergistic effect of the dual modification for CSD by the sequential combination of a chemical treatment followed by a physical one improved the hydrolyzed advance by 12 %, the relative crystallinity by 10 %, and the promotion of double helices by 25 % during 18 days of co-treatment.


Asunto(s)
Almidón , Zea mays , Almidón/química , Hidrólisis , Zea mays/química , Ácido Cítrico/química , Cinética
20.
Rev Gastroenterol Mex (Engl Ed) ; 87(1): 13-19, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35090672

RESUMEN

INTRODUCTION AND AIMS: Endoscopic submucosal dissection (ESD) is a well-established treatment for superficial gastrointestinal tumors and enables en bloc resection. Adequate tissue tension is important for safe and effective dissection. Simplified magnetic anchor-guided ESD (MAG-ESD) with a neodymium magnet has potential benefits, compared with other current traction methods. We evaluated the feasibility of simplified MAG-ESD in an ex vivo porcine model. MATERIALS AND METHODS: An experimental study was conducted, utilizing the standard ESD technique. An external magnet and an internal magnet, both neodymium magnets, were used for the magnetic anchoring. The internal magnet was attached to an arm of a hemoclip with a 2-0 silk suture. After the incision, the clip with the internal magnet was placed at the edge of the lesion. The external magnet was maneuvered around the surface to apply adequate tension. RESULTS: A total of 15 en bloc ESDs (5 with no magnetic anchoring and 10 with magnetic anchoring) were carried out. Traction and dissection were feasible in all cases and the procedures were completed in fewer than 90min. Lesion size ranged from 15 to 50mm (mean 30mm). Two cases in the group with magnetic anchoring presented with punctate perforation (13.3%). CONCLUSIONS: Our study demonstrated the feasibility of simplified MAG-ESD and en bloc resection in an ex vivo porcine model.


Asunto(s)
Resección Endoscópica de la Mucosa , Animales , Disección , Humanos , Fenómenos Magnéticos , Imanes , Neodimio , Porcinos
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