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1.
Artículo en Inglés | MEDLINE | ID: mdl-38978302

RESUMEN

BACKGROUND: Congenital uterine anomalies include a wide diversity of uterine malformations that can compromise reproductive potential. Uterus transplantation (UTx) proposes an innovative treatment for absolute uterine factor infertility; however, there is a lack of standardized protocols to guide clinical management among this population. OBJECTIVES: To describe recipient and donor characteristics and obstetric outcomes in patients undergoing UTx. SEARCH STRATEGY: We performed a literature search using the PubMed database to retrieve available scientific articles. We analyzed the references of included articles to assess additional articles that could be eligible to be included in the review. Likewise, we identified further studies using other methods, including Google Scholar. SELECTION CRITERIA: Titles and abstracts were screened in duplicate to select original reports with information available for the outcomes of interest. DATA COLLECTION AND ANALYSIS: This review assessed the advantages and disadvantages of the techniques used, patient characteristics, obstetric and non-obstetric complications, functional duration of the organ, and neonatal outcomes. MAIN RESULTS: Among the 36 reports included in this review we found 55 pregnancies and 38 live births following UTx and a higher success rate for in vivo uterine donations. The most common obstetric complications reported included miscarriage, pre-eclampsia, and gestational hypertension. The most common non-obstetric complications reported include episodes of rejection, acute kidney injury, anemia, and cholestasis. Living donors required a comprehensive preoperative workup, decreasing organ rejection, infection, and vascular complications. CONCLUSIONS: More studies are needed to standardize the UTx procedure and improve obstetric, fetal, and neonatal outcomes. Further understanding of which recipient and donor characteristics minimize complications will significantly decrease the risk of adverse outcomes.

2.
Int J Mol Sci ; 25(14)2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-39062815

RESUMEN

Preeclampsia (PE) is a multifactorial pregnancy disorder characterized by hypertension and proteinuria, posing significant risks to both maternal and fetal health. Despite extensive research, its complex pathophysiology remains incompletely understood. This narrative review aims to elucidate the intricate mechanisms contributing to PE, focusing on abnormal placentation, maternal systemic response, oxidative stress, inflammation, and genetic and epigenetic factors. This review synthesizes findings from recent studies, clinical trials, and meta-analyses, highlighting key molecular and cellular pathways involved in PE. The review integrates data on oxidative stress biomarkers, angiogenic factors, immune interactions, and mitochondrial dysfunction. PE is initiated by poor placentation due to inadequate trophoblast invasion and improper spiral artery remodeling, leading to placental hypoxia. This triggers the release of anti-angiogenic factors such as soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng), causing widespread endothelial dysfunction and systemic inflammation. Oxidative stress, mitochondrial abnormalities, and immune dysregulation further exacerbate the condition. Genetic and epigenetic modifications, including polymorphisms in the Fms-like tyrosine kinase 1 (FLT1) gene and altered microRNA (miRNA) expression, play critical roles. Emerging therapeutic strategies targeting oxidative stress, inflammation, angiogenesis, and specific molecular pathways like the heme oxygenase-1/carbon monoxide (HO-1/CO) and cystathionine gamma-lyase/hydrogen sulfide (CSE/H2S) pathways show promise in mitigating preeclampsia's effects. PE is a complex disorder with multifactorial origins involving abnormal placentation, endothelial dysfunction, systemic inflammation, and oxidative stress. Despite advances in understanding its pathophysiology, effective prevention and treatment strategies remain limited. Continued research is essential to develop targeted therapies that can improve outcomes for both mothers and their babies.


Asunto(s)
Estrés Oxidativo , Preeclampsia , Humanos , Preeclampsia/fisiopatología , Preeclampsia/metabolismo , Embarazo , Femenino , Epigénesis Genética , Inflamación/metabolismo , Biomarcadores , Placenta/metabolismo , Placenta/fisiopatología , Receptor 1 de Factores de Crecimiento Endotelial Vascular/metabolismo , Receptor 1 de Factores de Crecimiento Endotelial Vascular/genética
3.
Int J Gynaecol Obstet ; 167(2): 625-630, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38736305

RESUMEN

OBJECTIVE: To determine the individual learning curves for cordocentesis in a low-cost simulator for maternal-fetal medicine (MFM) fellows. METHODS: This observational, descriptive, educational, and prospective study was performed from July through November 2022. After an introductory course based on a standardized technique for cordocentesis, each second-year MFM fellow who accepted to participate in the study performed this procedure using a low-cost simulation model, and experienced operators supervised the cordocenteses. Learning curves were then created using cumulative sum analysis (CUSUM). RESULTS: Seven second-year MFM fellows with no previous experience in cordocentesis accepted to participate in the study. A total of 2676 procedures were assessed. On average, residents performed 382 ± 70 procedures. The mean number of procedures to achieve proficiency was 369 ± 70, the overall success rate was 84.16%, and the corresponding failure rate was 15.84%. At the end of the study, all fellows were considered competent in cordocentesis. One fellow required 466 attempts to achieve competency, performing a total of 478 procedures, but the resident with the fewest attempts to reach competency required 219 procedures, completing 232 procedures. Some of the most frequent reasons for failed attempts included not reaching the indicated point for vascular access (20.99%) and being unable to retrieve the sample (69.10%). CONCLUSION: CUSUM analysis to assess learning curves, in addition to using low-cost simulation models, helped to appraise individualized learning, allowing an objective demonstration of competency for cordocentesis among MFM fellows.


Asunto(s)
Competencia Clínica , Cordocentesis , Curva de Aprendizaje , Obstetricia , Entrenamiento Simulado , Humanos , Femenino , Estudios Prospectivos , Embarazo , Obstetricia/educación , Entrenamiento Simulado/economía , Entrenamiento Simulado/métodos , Internado y Residencia , Adulto , Becas
4.
Ginecol. obstet. Méx ; Ginecol. obstet. Méx;92(5): 199-214, ene. 2024. tab, graf
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1574921

RESUMEN

Resumen OBJETIVO: Establecer los valores de referencia del índice de pulsatilidad con Doppler pulsado en la valoración materna y fetal de los embarazos en seguimiento entre las 18 y 39 semanas de gestación. MATERIALES Y MÉTODOS: Estudio descriptivo y transversal, efectuado en pacientes con embarazo único, entre las 18 a 40 semanas, que acudieron al Departamento de Medicina Materno Fetal del Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, entre los meses de septiembre de 2017 a mayo de 2018. La evaluación Doppler se practicó con medición del índice de pulsatilidad de las arterias uterinas, umbilical, cerebral media y conducto venoso en cada semana del embarazo. Se crearon tablas de referencia para cada semana de la gestación y se establecieron los percentiles 3, 5, 10, 90 y 95. RESULTADOS: Se registraron 862 pacientes. Los valores del índice de pulsatilidad de la arteria umbilical reportaron 17% en semanas tempranas de la gestación y 21% en edades gestacionales mayores. Los valores de la arteria umbilical fueron 3% menores en edades gestacionales tempranas y 10% menores al término del embarazo; 20% para la arteria umbilical, 15% para el conducto venoso y 10% para la arteria cerebral media. Los valores del índice de pulsatilidad medio de las arterias uterinas fueron mayores un 3% en edades gestacionales tempranas y 28% menores al término del embarazo. CONCLUSIONES: Los hallazgos de este estudio sugieren diferencias significativas con las poblaciones de Europa y Norteamérica; incluso difieren de los valores de referencia utilizados en la actualidad en la población mexicana, lo que supone una subestimación de las condiciones fetales o maternas al hacer las evaluaciones de la unidad fetoplacentaria.


Abstract OBJECTIVE: Establish the reference values for the pulsatility index using pulsed Doppler in the maternal and fetal assessment of pregnancies followed at 18 and 39 weeks of gestation. MATERIALS AND METHODS: Descriptive and cross-sectional study, carried out in patients with a singleton pregnancy, between 18 and 40 weeks, who attended the Department of Maternal Fetal Medicine of the National Institute of Perinatology, from September 2017 to May 2018. The Doppler evaluation was performed, with measurement of the pulsatility index of the uterine, umbilical, middle cerebral arteries, and venous duct in each week of pregnancy. Reference tables were created for each gestational age, establishing percentiles 3, 5, 10, 90 and 95. RESULTS: A total of 862 patients were registered. The umbilical artery pulsatility index values were reported to be 17% at early gestational ages and 21% at older gestational ages; Umbilical artery values were 3% lower at early gestational ages and 10% lower at term of pregnancy; 20% for the umbilical artery, 15% for the ductus venosus and 10% for the middle cerebral artery. The values of the mean pulsatility index of the uterine arteries were 3% higher at early gestational ages and 28% lower at the end of pregnancy. CONCLUSIONS: The findings of this study suggest significant differences with the populations of Europe and North America; They even differ from the reference values currently used in the Mexican population, which represents an underestimation of fetal and/or maternal conditions when carrying out evaluations of the feto-placental unit.

6.
J Matern Fetal Neonatal Med ; 36(2): 2262077, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38015495

RESUMEN

OBJECTIVE: To assess the predictive value of abdominal circumference growth velocity (ACGV) between the second and third trimesters to predict adverse perinatal outcomes in a cohort of small-for-gestational-age fetuses without evidence of placental insufficiency (i.e. fetal growth restriction). MATERIAL AND METHODS: This is a single-center retrospective cohort study of all singleton pregnancies with small-for-gestational-age fetuses diagnosed and delivered at a quaternary institution. Crude and adjusted odds ratios (ORs) and corresponding confidence intervals (CIs) were calculated via logistic regression models to assess the potential association between abnormal ACGV (i.e. ≤10th centile) and adverse perinatal outcomes defined as a composite outcome (i.e. umbilical artery pH <7.1, 5-min Apgar score <7, admission to the neonatal intensive care unit, hypoglycemia, intrapartum fetal distress requiring expedited delivery, and perinatal death). Furthermore, the area under the receiver-operating characteristic curve (AUC) of three logistic regression models based on estimated fetal weight and ACGV for predicting the composite outcome is also reported. RESULTS: A total of 154 pregnancies were included for analysis. The median birthweight for the cohort was 2,437 g (interquartile range [IQR] 2280, 2635). Overall, the primary composite outcome was relatively common (29.2%). In addition, there was a significant association between abnormal ACGV and adverse perinatal outcomes (OR 3.37, 95% CI 1.60, 7.13; adjusted OR 4.30, 95% CI 1.77, 10.49). Likewise, the AUC for the ACGV was marginally higher (0.64) than the estimated fetal weight (0.54) and ACGV + estimated fetal weight (0.54). Still, no significant difference was detected between the curves (p = 0.297). CONCLUSIONS: Our results suggest that an ACGV below the 10th centile is a risk factor for adverse perinatal outcomes among small-for-gestational-age fetuses.


Asunto(s)
Retardo del Crecimiento Fetal , Peso Fetal , Embarazo , Recién Nacido , Humanos , Femenino , Estudios Retrospectivos , Placenta , Feto
7.
J Matern Fetal Neonatal Med ; 36(2): 2286433, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38010351

RESUMEN

Objective: To compare neonatal outcomes in pregnancies with fetal growth restriction (FGR) by intended delivery mode.Methods: This is a retrospective cohort study of singleton pregnancies with FGR that were delivered ≥34.0 weeks gestation. Neonatal outcomes were compared according to the intended delivery mode, which the attending obstetrician determined. Of note, none of the subjects had a contraindication to labor. Crude and adjusted odds ratios (ORs) and corresponding confidence intervals (CIs) were calculated via logistic regression models to assess the potential association between intended delivery mode and neonatal morbidity defined as a composite outcome (i.e. umbilical artery pH ≤7.1, 5-min Apgar score ≤7, admission to the neonatal intensive care unit, hypoglycemia, intrapartum fetal distress requiring expedited delivery, and perinatal death). A sensitivity analysis excluded intrapartum fetal distress requiring emergency cesarean delivery from the composite outcome since only patients with spontaneous labor or labor induction could meet this criterion. Potential confounders in the adjusted effects models included maternal age, body mass index, hypertensive disorders, diabetes, FGR type (i.e. early or late), and oligohydramnios.Results: Seventy-two (34%) patients had an elective cesarean delivery, 73 (34%) had spontaneous labor and were expected to deliver vaginally, and 67 (32%) underwent labor induction. The composite outcome was observed in 65.3%, 89%, and 88.1% of the groups mentioned above, respectively (p < 0.001). Among patients with spontaneous labor and those scheduled for labor induction, 63% and 47.8% required an emergency cesarean delivery for intrapartum fetal distress. Compared to elective cesarean delivery, spontaneous labor (OR 4.32 [95% CI 1.79, 10.42], p = 0.001; aOR 4.85 [95% CI 1.85, 12.66], p = 0.001), and labor induction (OR 3.92 [95% CI 1.62, 9.49] p = 0.002; aOR 5.29 [95% CI 2.01, 13.87], p = 0.001) had higher odds of adverse neonatal outcomes.Conclusion: In this cohort of FGR, delivering at ≥34 weeks of gestation, pregnancies with spontaneous labor, and those that underwent labor induction had higher odds of neonatal morbidity than elective cesarean delivery.


Asunto(s)
Retardo del Crecimiento Fetal , Trabajo de Parto , Embarazo , Recién Nacido , Femenino , Humanos , Retardo del Crecimiento Fetal/epidemiología , Retardo del Crecimiento Fetal/etiología , Estudios Retrospectivos , Sufrimiento Fetal/epidemiología , Sufrimiento Fetal/etiología , Cesárea/efectos adversos , Trabajo de Parto Inducido/efectos adversos , Edad Gestacional
9.
Materials (Basel) ; 16(10)2023 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-37241440

RESUMEN

The leaching of minerals is one of the main unit operations in the metal dissolution process, and in turn it is a process that generates fewer environmental liabilities compared to pyrometallurgical processes. As an alternative to conventional leaching methods, the use of microorganisms in mineral treatment processes has become widespread in recent decades, due to advantages such as the non-production of emissions or pollution, energy savings, low process costs, products compatible with the environment, and increases in the benefit of low-grade mining deposits. The purpose of this work is to introduce the theoretical foundations associated with modeling the process of bioleaching, mainly the modeling of mineral recovery rates. The different models are collected from models based on conventional leaching dynamics modeling, based on the shrinking core model, where the oxidation process is controlled by diffusion, chemically, or by film diffusion until bioleaching models based on statistical analysis are presented, such as the surface response methodology or the application of machine learning algorithms. Although bioleaching modeling (independent of modeling techniques) of industrial (or large-scale mined) minerals is a fairly developed area, bioleaching modeling applied to rare earth elements is a field with great growth potential in the coming years, as in general bioleaching has the potential to be a more sustainable and environmentally friendly mining method than traditional mining methods.

10.
Front Med (Lausanne) ; 10: 1050923, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36760397

RESUMEN

Objective: To identify and quantify the effects of maternal characteristics and medical history on the distribution of Placental Growth Factor (PlGF), mean arterial pressure (MAP), and Uterine Artery Mean Pulsatility Index (UtA-PI); and to standardize the expected values for these biomarkers in the first trimester to create unique multiples of the median (MoMs) for Latin-American population. Methods: This is a prospective cohort built exclusively for research purposes of consecutive pregnant women attending their first-trimester screening ultrasound at a primary care center for the general population in Mexico City between April 2019 and October 2021. We excluded fetuses with chromosomal abnormalities, major fetal malformations, and women delivering in another care center. Linear regression was used on log-transformed biomarkers to assess the influence of maternal characteristics on non-preeclamptic women to create MoM. Results: Of a total of 2,820 pregnant women included in the final analysis, 118 (4.18%) developed PE, of which 22 (0.78%) delivered before 34 weeks of gestation, 74 (2.62%) before 37 weeks, and 44 (1.56%) from 37 weeks gestation. Characteristics that significantly influenced PLGF were fetal crown rump length (CRL), maternal age, nulliparity, body mass index (BMI), chronic hypertension, Lupus, spontaneous pregnancy, polycystic ovary syndrome (PCOS), hypothyroidism, preeclampsia (PE) in a previous pregnancy, and mother with PE. MAP had significant influence from CRL, maternal age, PE in a previous pregnancy, induction of ovulation, a mother with PE, chronic hypertension, BMI, and hypothyroidism. UtA-PI was influenced by CRL, maternal age, a mother with PE, chronic hypertension, and gestational diabetes mellitus (GDM) in a previous pregnancy. Conclusion: Population-specific multiples of the median (MoMs) for PlGF, MAP, and UtA-PI in the first trimester adequately discriminate among women developing preeclampsia later in pregnancy.

11.
Ginecol. obstet. Méx ; Ginecol. obstet. Méx;91(2): 140-146, ene. 2023. graf
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1448325

RESUMEN

Resumen ANTECEDENTES: La exposición prenatal al misoprostol puede asociarse con un espectro de defectos congénitos que varían desde anomalías del sistema nervioso central, secuencia de Moebius, defectos en la pared abdominal, defectos transversales en las extremidades hasta alteraciones fetales. Esos defectos se observan más comúnmente con esquemas de solo misoprostol para inducción del aborto. Por esos antecedentes es importante que la historia clínica de toda paciente obstétrica sea exhaustiva para permitir identificar el antecedente de la exposición prenatal luego de un aborto fallido. CASO CLINICO: Paciente de 21 años, con 32 semanas de embarazo, con diagnóstico de feto con ventriculomegalia. En la evaluación ecográfica destacó la ventriculomegalia triventricular severa, simétrica y la angulación de ambas extremidades inferiores en varo. La resonancia magnética reportó: ventriculomegalia no comunicante severa, bilateral, simétrica, por probable estenosis del acueducto de Silvio. Cariotipo 46,XY y perfil TORCH negativo. El embarazo finalizó mediante cesárea, por indicación fetal a las 35 semanas. La evaluación al nacimiento reportó: parálisis facial bilateral, macrocefalia y pie equino varo bilateral. Al volver a interrogar a la paciente refirió haber sido tratada con misoprostol en el primer trimestre del embarazo, con fines abortivos. Al descartar las alteraciones cromosómicas e infecciosas se estableció el diagnóstico de secuencia Moebius. CONCLUSIONES: La exposición prenatal al misoprostol está relacionada con la aparición de defectos vasculares en algunos fetos expuestos. Aún no se ha determinado el espectro preciso ni la estimación potencial de teratogenicidad. La historia clínica es el pilar para la asociación en estos casos.


Abstract BACKGROUND: Prenatal misoprostol exposure can be associated with a spectrum of birth defects, ranging from central nervous system abnormalities, Moebius sequence, abdominal wall defects, as well as transverse limb defects, fetal abnormalities are more commonly seen with the use of the misoprostol-only regimen for induction of abortion, such that a thorough medical history is essential to detect a history of prenatal exposure after a failed abortion. CLINICAL CASE: A 21-year-old patient, with a 32-week pregnancy, who attended the institute with a diagnosis of a fetus with ventriculomegaly, the ultrasound evaluation highlighted severe symmetric triventricular ventriculomegaly and angulation of both lower extremities in varus, magnetic resonance imaging reported severe non-communicating ventriculomegaly Symmetric bilateral, due to probable stenosis of the aqueduct of Silvio, the karyotype reported 46, XY, as well as a negative TORCH profile, however, a cesarean section was performed for fetal indication at 35 weeks, the evaluation at birth showed bilateral facial paralysis, macrocephaly and foot Bilateral equinus varus, upon re-examination the patient referred the use of misoprostol in the first trimester of pregnancy for abortive purposes, so as there were no chromosomal or infectious alterations, a Moebius sequence was suggested. CONCLUSIONS : Prenatal exposure to misoprostol is related to the appearance of vascular disruption defects in some exposed fetuses, the precise spectrum and potential estimation of teratogenicity have not yet been determined, the clinical history is the mainstay for the association in these cases.

14.
Front Pediatr ; 10: 883185, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35844759

RESUMEN

Passive transplacental immunity is crucial for neonatal protection from infections. Data on the correlation between neonatal immunity to SARS-CoV-2 and protection from adverse outcomes is scarce. This work aimed to describe neonatal seropositivity in the context of maternal SARS-CoV-2 infection, seropositivity, and neonatal outcomes. This retrospective nested case-control study enrolled high-risk pregnant women with a SARS-CoV-2 RT-PCR positive test who gave birth at the Instituto Nacional de Perinatología in Mexico City and their term neonates. Anti-SARS-CoV-2 IgG antibodies in maternal and cord blood samples were detected using a chemiluminescent assay. In total, 63 mother-neonate dyads (mean gestational age 38.4 weeks) were included. Transplacental transfer of SARS-CoV-2 IgG occurred in 76% of neonates from seropositive mothers. A positive association between maternal IgG levels and Cycle threshold (Ct) values of RT-qPCR test for SARS-CoV-2 with neonatal IgG levels was observed. Regarding neonatal outcomes, most seropositive neonates did not require any mechanical ventilation, and none developed any respiratory morbidity (either in the COVID-19 positive or negative groups) compared to 7 seronegative neonates. Furthermore, the odds of neonatal respiratory morbidity exhibited a tendency to decrease when neonatal IgG levels increase. These results add further evidence suggesting passive IgG transfer importance.

15.
Materials (Basel) ; 15(3)2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-35161082

RESUMEN

Current challenges in froth flotation are the presence of complex gangues and the use of low-quality waters, such as seawater. In this scenario, the recovery of molybdenum minerals is difficult, mainly due to the hydrophobic faces' physicochemical changes. In the present study, the natural floatability of pure molybdenite was analyzed by using microflotation assays, and hydrophobicity was measured by performing contact-angle measurements. The impact of two clays, kaolin (non-swelling) and Na-montmorillonite (swelling), was studied. The behavior in freshwater and seawater at pH 8 was compared, considering the current condition of the Cu/Mo mining industries, which use seawater in their operations. The presence of clays lowered the natural floatability of molybdenite precisely because they adhere to the surface and reduce its contact angle. However, the intensity with which they cause this phenomenon depends on the type of water and clay. Kaolin strongly adheres to the valuable mineral in both freshwater and seawater. For its part, Na-montmorillonite does it with greater intensity in a saline medium, but in freshwater, a high concentration of phyllosilicate is required to reduce the hydrophobicity of molybdenite. The clays' adherence was validated by scanning electron microscopy (SEM) analysis.

16.
Materials (Basel) ; 15(3)2022 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-35161099

RESUMEN

Complex gangues and low-quality waters are a concern for the mining industries, particularly in water shortage areas, where the closure of hydric circuits and reduction in water use are essential to maintain the economic and environmental sustainability of mineral processing. This study analyzes the phenomena involved in the water recovery stage, such as sedimentation of clay-based tailings flocculated with anionic polyelectrolyte in industrial water and seawater. Flocculation-sedimentation batch tests were performed to ascertain the aggregate size distribution, the hindered settling rate, and the structure of flocs expressed through their fractal dimension and density. The aggregates' properties were characterized by the Focused Beam Reflectance Measurement (FBRM) and Particle Vision Microscope (PVM) techniques. The impact of the type of water depends on the type of clay that constitutes the suspension. For quartz/kaolin, the highest performance was obtained in industrial water, with bigger aggregates and faster settling rates. However, the tailings composed of quartz/Na-montmorillonite reversed this trend. The type of water impacted the efficiency of primary-particle aggregation. The trials in industrial water generated a portion of non-flocculated particles, which was observed through a bimodal distribution in the unweighted chord-length distribution. This behavior was not observed in seawater, where a perceptible fraction of non-flocculated particles was not found. The additional cationic bonds that offer seawater favor finer primary-particle agglomeration for all tailings types.

17.
Polymers (Basel) ; 14(2)2022 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-35054745

RESUMEN

In areas where access to water for mineral processing is limited, the direct use of seawater in processing has been considered as an alternative to the expense of its desalination. However, efficient flotation of copper sulfides from non-valuable phases is best achieved at a pH > 10.5, and raising the pH of seawater leads to magnesium precipitates that adversely affect subsequent tailings dewatering. Seawater pre-treatment with lime can precipitate the majority of magnesium present, with these solids then being removed by filtration. To understand how such treatment may aid tailings dewatering, treated seawater (TSw) was mixed with raw seawater (Rsw) at different ratios, analyzing the impact on the flocculated settling rate, aggregate size as measured by focused beam reflectance measurement (FBRM), and vane yield stress for two synthetic clay-based tailings. A higher proportion of Tsw (10 mg/L Mg2+) led to larger aggregates and higher settling rates at a fixed dosage, with FBRM suggesting that higher calcium concentrations in Tsw may also favor fines coagulation. The yield stress of concentrated suspensions formed after flocculation decreased with higher proportions of Tsw, a consequence of lower flocculant demand and the reduced presence of precipitates; while the latter is a minor phase by mass, their high impact on rheology reflects a small particle size. Reducing magnesium concentrations in seawater in advance of use in processing offers advantages in the water return from thickening and subsequent underflow transport. However, this may not require complete removal, with blending Tsw and Rsw an option to obtain acceptable industrial performance.

18.
Lima; Organismo Andino de Salud Convenio Hipólito Unanue; 102; 25 ene, 2022. 3 p.
No convencional en Español | LILACS, LIVECS | ID: biblio-1381225

RESUMEN

Webinar N° 102 del ORAS-CONHU, realizado el 25 de enero de 2022, se realizó un webinar sobre el impacto de la Telesalud en las atenciones de salud en el contexto de la pandemia por COVID-19 en Bolivia, Colombia y Perú. Como reto en nuestra región se resalta: Expandir los avances de la telesalud al campo de la Salud Digital, que permita materializar los ocho principios rectores de la transformación digital del sector de la salud. Conferencistas del webinar: Ernesto Lima, Responsable del Programa de Telesalud, Ministerio de Salud y Deportes de Bolivia, Sandra Gallegos, equipo de la Dirección de Prestación de Servicios y Atención Primaria Ministerio de Salud y Protección Social de Colombia; Bernardette Cotrina, Directora General de Telesalud, Referencia y Urgencias, Ministerio de Salud de Perú.


Asunto(s)
Telemedicina , COVID-19 , Perú , Venezuela , Bolivia , Chile , Colombia , Infecciones por Coronavirus , Ecuador
19.
J Matern Fetal Neonatal Med ; 35(25): 5927-5931, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33771080

RESUMEN

BACKGROUND: COVID-19 symptoms vary widely among pregnant women. We aimed to assess the most frequent symptoms amongst pregnant women with SARS-CoV-2 infection in a tertiary hospital in Mexico City. METHODS: A cross-sectional study of pregnant women attending the National Institute of Perinatology in Mexico City was performed. All women who attended the hospital, despite their symptoms, were tested for SARS-CoV-2. A multivariate-age-adjusted logistic regression was used to assess the association between the main outcome and each characteristic of the clinical history. RESULTS: A total of 1880 women were included in the data analysis. Among all women, 30.74% (n = 578) had a positive PCR for SARS-CoV-2 from which 2.7 (n = 50) were symptomatic. Symptoms associated with a positive PCR result were headache (p=.01), dyspnea (p=.043), and myalgia (p=.043). CONCLUSIONS: At universal screening for SARS-CoV-2, one-third of the population had a positive result, while those symptoms associated with a positive PCR were headache, dyspnea, and myalgia.


Asunto(s)
COVID-19 , Complicaciones Infecciosas del Embarazo , Femenino , Embarazo , Humanos , COVID-19/epidemiología , SARS-CoV-2 , Mujeres Embarazadas , Estudios Transversales , Mialgia , México/epidemiología , Complicaciones Infecciosas del Embarazo/diagnóstico , Complicaciones Infecciosas del Embarazo/epidemiología , Factores de Riesgo , Disnea , Cefalea
20.
Viruses ; 13(9)2021 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-34578466

RESUMEN

(1) This study aimed to evaluate characteristics, perinatal outcomes, and placental pathology of pregnant women with or without SARS-CoV-2 infection in the context of maternal PCR cycle threshold (CT) values. (2) This was a retrospective case-control study in a third-level health center in Mexico City with universal screening by RT-qPCR. The association of COVID-19 manifestations, preeclampsia, and preterm birth with maternal variables and CT values were assessed by logistic regression models and decision trees. (3) Accordingly, 828 and 298 women had a negative and positive test, respectively. Of those positive, only 2.6% of them presented mild to moderate symptoms. Clinical characteristics between both groups of women were similar. No associations between CT values were found for maternal features, such as pre-gestational BMI, age, and symptomatology. A significantly higher percentage of placental fibrinoid was seen with women with low CTs (<25; p < 0.01). Regarding perinatal outcomes, preeclampsia was found to be significantly associated with symptomatology but not with risk factors or CT values (p < 0.01, aOR = 14.72). Moreover, 88.9% of women diagnosed with COVID-19 at <35 gestational weeks and symptomatic developed preeclampsia. (4) The data support strong guidance for pregnancies with SARS-CoV-2 infection, in particular preeclampsia and placental pathology, which need further investigation.


Asunto(s)
COVID-19/epidemiología , COVID-19/virología , Complicaciones Infecciosas del Embarazo/epidemiología , Complicaciones Infecciosas del Embarazo/virología , SARS-CoV-2/fisiología , Adulto , Biopsia , COVID-19/diagnóstico , Femenino , Humanos , Inmunohistoquímica , Transmisión Vertical de Enfermedad Infecciosa , Placenta/patología , Placenta/virología , Reacción en Cadena de la Polimerasa , Embarazo , Complicaciones Infecciosas del Embarazo/diagnóstico , Resultado del Embarazo , Estudios Retrospectivos , Adulto Joven
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