Search

Abstract: Representative samples of crude oils from Cusiana, Cupiagua, Apiay, Castilla and Chichimene fields in the Eastern Llanos Basin of Colombia were analyzed to determine its compound-specific stable carbon isotope composition (CSIA) using gas chromatography–isotopic ratio–mass spectrometry (GC–IRMS). GC–IRMS analyses of n-alkanes allowed differentiating between Cretaceous and Cretaceous/Tertiary oil samples. Cretaceous sourced samples have δ 13C-enriched values than Cretaceous/Tertiary sourced samples; the heavier isotope composition of these samples is due to their major terrigenous organic matter input. Their isotope distribution patterns suggest significant algal and/or bacterial contribution (marine origin). The analysis of the n-alkane fractions by GC–IRMS confirms that the organic matter has marine origin in those samples from Cusiana, Cupiagua and Apiay while Castilla and Chichimene have marine origin with terrestrial inputs. The results were confirmed by gas chromatography/FID and gas chromatography/mass spectrometry (GC/MS). Basic geochemical composition show that samples from Cupiagua/Cusiana fields and Apiay/Castilla/Chichimene fields in the Llanos basin, Colombia present different characteristics reflecting a specific for each depositional environment. [Copyright &y& Elsevier]

Presents a study which evaluated the thermal performance of a solar passive cooling system. Experimental platform; Computational model; Results and discussion; Conclusions.

Abstract: While intermittent ureteropelvic junction obstruction is well recognized clinically, intermittent obstruction at the ureterovesical junction has not been previously described. We herein present a case report of intermittent ureterovesical junction obstruction, characterized by intermittent hydroureteronephrosis on ultrasonography and symptoms of flank/abdominal pain, nausea and vomiting. [Copyright &y& Elsevier]

Cerebral palsy (CP) comprises a group of lifelong motor and postural development disorders that can cause static motor encephalopathy. The etiology of CP is attributed to nonprogressive lesions of the central nervous system during fetal or infant brain development. A diagnosis of CP is based on a combination of clinical and neurological signs, typically identified between 12 and 24 months. A medical history, several available standardized tools, including the Neoneuro assessment, and the Hammersmith infant neurological examination (HINE) can be used to predict risk. Magnetic resonance imaging (MRI) can contribute to the diagnosis of CP. The incidence of CP is 2 to 3 per 1000 live births, and in Western industrialized nations, it is 2.0-2.5 per 1000 live births; to our knowledge, no epidemiological studies have reported the incidence of CP in Mexico. To assess the incidence of CP in children aged up to 18 months in northeast Mexico and analyze the risk factors and neuroimaging findings. This was a multicenter, randomized, prospective, cohort, analytical study of newborn children in three community hospitals and an early intervention and CP center in Nuevo Leon, Mexico, from 2017 to 2021. This study included 3861 newborns randomly selected from a population of 75,951 mothers in the immediate puerperium. According to the Neoneuro tool, high-risk children (n = 432) had abnormal neurological results at birth; they were followed and assessed with the Spanish version of the HINE test by a pediatric neurologist and underwent neuroimaging studies. Neonates with normal results were randomly selected to be in the low-risk group (n= 864). These neonates were followed and assessed with the HINE by a neonatologist. The incidence of CP was 4.4 of 1000 up to 18 months old, which was higher than that reported in developed countries. Perinatal risk factors were predominantly recognized in the etiology of CP, such as brain hemorrhage, and prematurity, in addition to congenital anomalies. The most frequent neuroimaging findings were ventricular dilation/cortical atrophy and intraventricular/subependymal hemorrhage and periventricular leukomalacia on MRI. This study is the first on the incidence/prevalence of CP in Mexico, and there are no formal studies in this field in other Latin American countries either. The incidence of CP in northeast Mexico is higher than that reported in developed countries. The follow-up of high-risk young children must be reinforced in the Mexican population, as children with disabilities have high and sequential health-care needs and may usually be lost to follow-up. Neuroimaging of PVL was the more frequent finding by MRI in this population. [ABSTRACT FROM AUTHOR]