14 research outputs found

    Neurological follow-up in a lot of newborns with intrauterine growth restriction

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    Spitalul Clinic de Obstetrică şi Ginecologie „Cuza Vodă”, Iaşi, Divizia de Neonatologie, Departamentul Mama şi Copilul, Universitatea de Medicină şi Farmacie Grigore T.Popa, IaşiIntroducere. Restricţia de creştere intrauterină (IUGR) reprezintă un factor de risc cunoscut pentru morbiditatea perinatală precoce şi tardivă. Scop. Evaluarea patologiei din maternitate şi a riscului de a dezvolta sechele neurologice la un lot de nou-născuţi cu IUGR. Material şi metodă. Studiu prospectiv longitudinal efectuat pe o perioadă de trei ani, asupra unei cohorte de copii IUGR afl aţi în programul de urmărire al nou-născutului cu risc. Parametrii cuantifi caţi: mediul de provenienţă, vârsta de gestaţie (VG), greutatea la naştere (GN), indice ponderal, patologie prezentată în maternitate, rezultatele examenului Amiel-Tison la externarea din maternitate şi riscul fi nal în funcţie de scala BSID II (Bayley Scale of Infant Development). Datele au fost prelucrate SPSS versiunea 20.0. Rezultate. Au întrunit criteriile de includere în studiu 145 nou-născuţi cu VG medie de 35,5 săptămâni (s) cu limite între 28 s şi 42 s, toţi cu GN sub percentila 10. Afecţiuni diagnosticate pe parcursul spitalizării: asfixie perinatală 8,3%, sindrom de detresă respiratorie (SDR) 66,2%, dintre care 17,2% au necesitat ventilaţie mecanică invazivă, apnee 34,5%, hemoragie intraventriculară (IVH) 10,3%, leucomalacie periventriculară (LPV) 2,8%, enterocolită ulcero-necrotică (EUN) 31% (26,7% std I, 73,3% std II), hipoglicemie 27,6%.72,2% dintre nou-născuţii cu hipoglicemie au avut IP < 1,5, (p=0,001), retinopatie de prematuritate (ROP) 4,8%. 11,3% au necesitat peste 60 zile de spitalizare. În lotul studiat nu s-a înregistrat nici un deces pe parcursul spitalizării. La externare, conform evaluării Amiel-Tison, 93% au fost încadraţi în grupul de risc mediu. 49,7% nu au mai venit la control, iar dintre aceştia 60,3% au fost din mediu rural (p=0,037). La finalul evaluărilor, respectiv 2 ani, 69% au fost încadraţi în grupul de risc uşor, 27,6% risc mediu şi 3,4% risc sever. Cel mai ridicat procent (95,9%) au avut la final deficienţe pe sfera motorie, 4,8% pe cea cognitivă şi 4,1% cognitivo-motorie. 10,3% dintre nou-născuţii cu IUGR au fost încadraţi în diferite sindroame genetice asociind risc final sever în procent de 80% (p=0,001). Greutatea sub percentila 10 s-a menţinut la vârsta de un an la 59% dintre copii şi sub 5 la 38% la 2 ani, ambele asociate cu mediul rural de provenienţă (p=0,044) şi cu deficienţe pe sfera motorie (p=0,05). Concluzii. Vârsta de gestaţie mică îşi pune amprenta asupra patologiei şi în cazul nou-născuţilor cu IUGR, respectiv procent mare (66,2%) de copii cu SDR. Subiecţii diagnosticaţi cu IVH, LPV şi ROP au avut VG sub 30 s (p=0,05). EUN a fost diagnosticată la peste 25% (31%) dintre copiii cu IUGR, aspect semnalat şi în literatura de specialitate. Efectuarea evaluărilor regulate asociază risc uşor (69%) indiferent de patologie şi mediul de provenienţă (p=0,894).Greutatea la naştere sub percentila 10, ca factor de risc independent nu afectează gradul de risc neurologic (p=0,001).Introduction. Intrauterine growth restriction (IUGR) is known to be a risk factor for perinatal early and late morbidity. Objective. The aim of this paper was to study the impact of IUGR on clinical evolution and neurological outcome in a lot of selected newborns. Methods. Longitudinal prospective study over a 3 years period of time in a lot of IUGR newborns, included in a follow-up program. We quantify the environment of origin, gestational age (GA), ponderal index, pathology during hospitalization, the result of neurological evaluation according to Amiel-Tison at discharge and at two years of age, according to BSID II (Bayley Scale of Infant Development). The data were analyzed using SPSS Statistics version 20.0. Results. 145 newborns meet the criteria for inclusion in this study, with GA between 28 weeks of gestation (wk)-2,8% and 42 wk-0,7%, all with a birth weight below the 10th percentile for GA. Pathology during hospitalization: respiratory distress syndrome (RDS) -66,2%, 17,2 % among them necessitated invasive ventilation, apnea 34,5%, intraventricular hemorrhage (IVH) 10,3%, periventricular leukomalacia (LPV)- 2,8%, necrotizing enterocolitis (NEC)- 31% (26,7% stage I and 73,3% stage II), hypoglycemia 26,7% (72,2% among them had ponderal index < 1,5- p=0,001), retinopathy of prematurity (ROP)- 4,8%. 11,3 % were admitted over 60 days period of time and no deaths were recorded in the studied lot. At discharge 93% according to Amiel-Tison's evaluation were categorized in the medium-risk group. After discharge, 49,7% didn’t come for evaluation and among them 60,3% were from countryside (p=0,037). At the end of the follow-up program, 2 years of life, 69% were included in the low-risk category, 27,6% medium risk, and 3,4% high risk. Deficiencies in the motor area were recorded in the highest percentage - 95,9%, 4,8% had low scores on the cognitive areas and 4,1% both, cognitive and motor. 10,3% of subjects were diagnosed with genetic syndromes and associated severe risk at final evaluation (p=0,001) Weight under ten percentile were recorded at one year in 59% of patients and under 5 in 38% of patients, both associated with deficiencies in the motor area (p=0,005) and rural provenience (p=0,044). Conclusions. Gestational age remains the main factor that influences pathology also in IUGR newborns - 66.2% presented RDS. We found a correlation between GA under 30 wk and IVH, PVL, and ROP (p=0.005). Similar literature data, NEC were found in more than 25%, respectively in 31% cases. Regular evaluations associate low risk - 69% - no matter of pathology and environment of origin. (p=0.894). Birthweight <10th percentile alone does not appear to be an independent risk factor of neurodevelopmental adverse outcomes

    Exergetic Performance of a PEM Fuel Cell with Laser-Induced Graphene as the Microporous Layer

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    The microporous layer (MPL) constitutes a critical component of the gas diffusion layer within the membrane electrode assembly (MEA) of a proton exchange membrane fuel cell (PEM FC). The MPL plays a fundamental role in various processes during FC operation: control of membrane humidification, heat distribution throughout the MEA, excess water removal from the cathode, and transportation of fuel to the reaction sites. Previously, we investigated the performance of a fuel cell unit employing an MPL based on laser-induced graphene (LIG) produced by the laser pyrolysis of polymeric (polyimide) substrates. The prototype LIG-based unit was tested over the typical range of relative humidity and temperature conditions. The polarization curves observed in that study displayed broad ohmic loss regions and high stability along the concentration loss regions, an interesting electrical behavior that justified developing the present voltage-current density study for the same FC prototype compared to one bearing a commercial pyrolytic carbon black MPL. The same operating conditions as in the first study were applied, in order to properly compare the performance efficiencies between the two systems; these are evaluated by considering the thermodynamic losses influence on the exergy efficiency, to exceed any limitations inherent in the classical energy efficiency analysis

    Hybrid Proton-Exchange Membrane Based on Perfluorosulfonated Polymers and Resorcinol–Formaldehyde Hydrogel

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    Organic resorcinol–formaldehyde (RF) hydrogels were introduced into a hybrid cation-exchange membrane in order to enhance its following properties: water uptake, thermal stability, and ionic conductivity. This study was aimed to investigate the modifications induced by the RF organic clusters that form a uniform distributed network within the perflourosulfonated acid (PFSA) matrix. RF concentration was controlled by resorcinol and formaldehyde impregnation time using water or ethanol solvents. The specific morphological and structural properties were characterized by atomic force microscopy, UV–Vis, and Fourier transform infrared spectroscopy. Thermo-gravimetric analysis was employed to study the thermal stability and degradation processes of the composite membranes. Proton conductivity, as a function of relative humidity (RH) at 80 °C, was measured using in-plane four-point characterization technique. Compared to the pristine membrane, the PFSA–RF hybrid membranes showed improved thermal stability at up to 46 °C and higher ionic conductivity for low RF content, especially at low relative humidity, when using ethanol-based solvents. Single fuel cell testing on RF-based membrane–electrode assembly revealed impeccable fuel crossover and power performance at 80 °C and 40% relative humidity, delivering a 76% increase in power density compared to a reference assembled with a pristine membrane and the same catalyst loadings

    Bucureºti) ♦ 60♦ Nr

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    Experiments regarding the electro deposition and the characterization of polyaniline (PANI) films o

    Carbon-Nanowall Microporous Layers for Proton Exchange Membrane Fuel Cell

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    The cathode microporous layer (MPL), as one of the key components of the proton exchange membrane fuel cell (PEM-FC), requires specialized carbon materials to ensure the two-phase flow and interfacial effects. In this respect, we designed a novel MPL based on highly hydrophobic carbon nanowalls (CNW). Employing plasma-assisted chemical vapor deposition techniques directly on carbon paper, we produced high-quality microporous layers at a competitive yield-to-cost ratio with distinctive MPL properties: high porosity, good stability, considerable durability, high hydrophobicity, and substantial conductivity. The specific morphological and structural properties were determined by scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. Thermo-gravimetric analysis was employed to study the nanostructures&rsquo; thermal stability and contact angle measurements were performed on the CNW substrate to study the hydrophobic character. Platinum ink, serving as a fuel cell catalyst, was sprayed directly onto the MPLs and incorporated in the FC assembly by hot-pressing against a polymeric membrane to form the membrane-electrode assembly and gas diffusion layers. Single-fuel-cell testing, at moderate temperature and humidity, revealed improved power performance comparable to industrial quality membrane assemblies (500 mW cm&minus;2 mg&minus;1 of cathodic Pt load at 80 &deg;C and 80% RH), with elevated working potential (0.99 V) and impeccable fuel crossover for a low-cost system

    Optical manipulation of complex molecular systems by high density green photons: experimental and theoretical evidence

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    The recent revolution in modern optical techniques revealed that light interaction with matter generates a force, known as optical force, which produces material properties known in physics as optical matter. The basic technique of the domain uses forces exerted by a strongly focused beam of light to trap small objects and subsequently to manipulate their local structures. The purpose of this paper is to develop an alternative approach, using irradiations with high-density-green-photons, which induce electric dipoles by polarization effects. The materials used for the experiments were long carbon chains which represent the framework of biological macromolecules. The physical techniques used to reveal the locally induced molecular arrangements were: dynamic viscosity, zeta potential, chemiluminescence, liquid chromatography; mass spectrometry, and Raman and infrared spectroscopy. The principal result of our experiments was the detection of different molecular arrangements within the mixture of alkane chains, generated by our optical manipulations. This induced “optical matter” displayed two material properties: antioxidant effects and large molecular aggregation effects. In order to bring the experimental results in relation with theory, we developed a physical model and the interacting force between polarizable bodies was computed. By numerical calculations stable structures for N = 6 and N = 8 particles were obtained

    Functionalized Carbon Nanotubes for Chemical Sensing: Electrochemical Detection of Hydrogen Isotopes

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    In this study, we propose a palladium-functionalized CNT composite working as a sensitive material to evaluate the deuterium concentration in aqueous samples. The sensitive material was prepared by the deposition of Pd nanoparticles onto MWCNT–OH by the micellization process. A modified electrode was prepared by drop casting 60 μL of Pd-decorated MWCNT suspension on a clean glassy carbon electrode surface. The sensing behavior was investigated in a series of deuterium-enriched solutions ranging from 25 to 10,000 ppm. We performed cyclic voltammetry and impedance spectroscopy studies on the samples. The process is quasi-reversible with the reduction curve more pronounced than the oxidation curve, which indicates a low tendency to desorption for the hydrogen atoms
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