RESUMEN
In this study, an in vitro method was used to simulate lung fluids [Artificial lysosomal fluid (ALF) and Gamble's solution (GS)] to assess how the bioaccessibility of rare earth elements (REEs) in airborne particulate matter (PM) affects human health. Airborne PM samples (PM10 and PM2.5) were collected in Daqing in Northeast China. The bioaccessible proportions determined for REEs in PM10 and PM2.5 had high variability, which can be attributable to the heterogenic feature of airborne PM and its components, as well as sampling time. Overall, the bioaccessiblity of the REEs in the airborne PM samples was time-dependent. The bioaccessiblity of the REEs varied in PM with different sizes, and it was an order of magnitude higher in ALF than in GS. During both heavy and light pollution, the bioaccessiblity of the REEs in PM2.5 was higher than in PM10 after 24 h of ALF extraction, whereas bioaccessiblity of the REEs in GS followed the opposite trend. The REEs associated with airborne PM had much greater bioaccessiblity as the exposure time increased. The results of this study emphasize the necessity of conducting bioaccessibility experiments with field samples for the proper evaluation of human health risks.
Asunto(s)
Contaminantes Atmosféricos , Metales de Tierras Raras , Contaminantes Atmosféricos/análisis , China , Ciudades , Monitoreo del Ambiente , Contaminación Ambiental , Humanos , Material Particulado/análisisRESUMEN
<p><b>OBJECTIVE</b>To investigate the correlation between arterial partial pressure of CO2 (PaCO2) and end expiratory tidal partial pressure of CO2 (Pet-CO2) in morbidly obese patients during anesthesia for laparoscopic gastric bypass surgery.</p><p><b>METHODS</b>Forty morbidly obese patients with a body mass index (BMI) between 35 and 50 kg/m(2) underwent laparoscopic gastric bypass surgery under general anesthesia. PaCO2 and Pet-CO2 were measured after intubation and before induction of pneumoperitoneum (T0), at 30 min (T1), 60 min (T2), and 120 min (T3) during pneumoperitoneum, and at 30 min (T4) and 60 min (T5) after deflation.</p><p><b>RESULTS</b>At each time point of measurement, Pet-CO2 was lower than PaCO2 in all the patients. PaCO2 and Pet-CO2 were positively correlated before, during, and after pneumoperitoneum (P<0.05). At a moderate pressure of CO2 pneumoperitoneum (16 mmHg), the level of correlation between PaCO2 and Pet-CO2 at T1, T2, and T3 differed from that before and after post-pneumoperitoneum.</p><p><b>CONCLUSIONS</b>PaCO2 and Pet-CO2 are closely correlated during a moderate CO2 pneumoperitoneum in morbidly obese patients undergoing laparoscopic gastric bypass surgery.</p>
Asunto(s)
Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Anestesia , Presión Arterial , Análisis de los Gases de la Sangre , Dióxido de Carbono , Sangre , Derivación Gástrica , Laparoscopía , Obesidad Mórbida , Sangre , Cirugía General , Neumoperitoneo ArtificialRESUMEN
<p><b>OBJECTIVE</b>To study the effects of dopamine and phenylephrine for treatment of hypotension during cesarean section under combined spinal epidural anesthesia (CSEA) on the stereology of the placenta.</p><p><b>METHODS</b>Forty puerperants undergoing cesarean section under CSEA were randomly divided into dopamine group and phenylephrine group. Ropivacaine (16 mg) was administered immediately after spinal anethesia. Blood pressure was maintained near the baseline by adjusting the drug infusion rate. Fetal blood gas, Apgar score, and placental villus microvascular stereological changes were observed during the operation.</p><p><b>RESULTS</b>The microvascular density was significantly lower in dopamine group than in phenylephrine group (P<0.05). Phenylephrine group showed significantly lower umbilical artery blood pH than dopamine group (P<0.05). The Apgar score and blood pressure were comparable between the two groups (P>0.05). Compared to the baseline, both of the two groups showed significantly lowered heart rate during the operation (P<0.01).</p><p><b>CONCLUSION</b>Dopamine is associated with the risk of fetal acidosis. Phenylephrine is helpful for preventing hypotension by increasing placental blood flow and improving oxygen supply to ensure maternal and fetal safety during cesarean section.</p>