Umbilical cord blood transplantation: A review of atricles

Interest in umbilical cord blood as an alternative source of hematopietic stem cells is growing rapidly. Umbilical cord blood offers the clinician a source of hematopoietic stem cells that are readily available and rarely contaminated by latent viruses. Moreover, the collection of umbilical cord blood poses no risk to the donor. There is no need for general anesthesia or blood replacement and the procedure causes no discomfort. Current clinical experience suggests that the incidence of GVHD in umbilical cord blood transplantation is low. These results and associated laboratory findings pose intriguing possibilities for the future of umbilical cord blood stem cells in the setting of unrelated donor transplantation. There are other intriguing possibilities for example cord blood may be an optimal source of pluripotential stem cells for use in genetherapy

Microstructure and Mechanical Properties of an AZ91 Magnesium Alloy Processed through Backward Extrusion

A cast AZ91 magnesium alloy was processed via backward extrusion (BE) method at different temperatures of 250, 350 and 450°C. Metallography investigations were conducted at three different regions of BE-processed cup (wall, bottom and flow channel). The main feature observed at the wall of the BE cup was mechanical twins, the frequency of which was decreased by increasing the process temperature. Flow localization in the form of shear banding occurred within the flow channel at all deformation temperatures. The bottom of the BE-processed cup at 250°C exhibited coarse initial grains along with continuous network of eutectic phase at the grain boundaries. However, increasing the process temperature to 350 and 450°C led to the fragmentation of the γ-Mg17Al12 network down to the fine particles, where a considerable grain refinement was also traced particularly at 450°C. Furthermore, shear punch testing method was employed to evaluate the room temperature mechanical properties of the backward extruded specimens. The results show that BE-processed material would benefit from higher strength compared to the as-received material; however, the ductility follows different trends depending on the deformation temperature

Seismic Analysis of Concrete Arch Dam Considering Material Failure Criterion

Since large dams collapse can lead to catastrophic consequences on human's lives and properties, the reliable performance of such structures during a strong earthquake is extremely important. Therefore, applying reliable analysis methods for designing large dams and seismic evaluation of the existing dam is crucial. The present study investigates the behavior of a concrete arch dam during the maximum credible earthquake "MCL" through non-linear time history analysis. A 30-meter height concrete arch dam was simulated in SAP2000-academic version- using 3D solid elements. Rayleigh damping and plasticity-based five-parameter Willam-Warnke model, as a means of failure criterion, were taken into account during non-linear time history analysis. The results indicated that the seismic load combination had a significant impact on final stress distribution in which high tensile cracks penetrated over the upstream heel

Saharan dust episodes and pregnancy

Desert dust is one of the natural contributors to atmospheric particulate matter worldwide. Although particulate pollution has been shown to adversely affect pregnancy, the available evidence on the impact of dust episodes on pregnancy is very scarce. The aim of this study was to evaluate the impact of Saharan dust episodes on pregnancy complications (preeclampsia and bacteriuria) and outcomes (birth weight and gestational age at delivery). This study was based on a cohort of births (N = 3565) that occurred in a major university hospital in Barcelona during 2003–2005. To determine Saharan dust episodes, we developed a two-stage approach based on meteorological evidence of the presence of Saharan dust cloud over the region and unusually high levels of particulate levels on the ground while taking account of traffic sources. The associations between the number of Saharan dust episodes during whole pregnancy as well as each pregnancy trimester and pregnancy complications and outcomes were analysed. There were 152 days (out of 838 days) with Saharan dust cloud over the region from which 45 days were determined as episodic days. We did not observe any statistically significant harmful effect of Saharan dust episodes on our included pregnancy complications and outcomes. However, we observed a small but statistically significant increase in gestational age at delivery in association with the number of episodic days during the third trimester and whole pregnancy (0.8 and 0.5 days respectively). Our findings were not suggestive for any adverse effect of Saharan dust episodes on our included pregnancy complications and outcomes

GREEN SPACE, HEALTH INEQUALITY, AND PREGNANCY

Green spaces have been suggested to improve physical and mental health and well-being by increasing physical activity, reducing air pollution, noise, and ambient temperature, increasing social contacts and relieving psychophysiological stress. Although these mechanisms also suggest potential beneficial effects of green spaces on pregnancy outcomes, to our knowledge there is no available epidemiological evidence on this impact. We investigated the effects of surrounding greenness and proximity to major green spaces on birth weight and gestational age at delivery and described the effect of socioeconomic position (SEP) on these relationships. This study was based on a cohort of births (N = 8246) that occurred in a major university hospital in Barcelona, Spain, during 2001–2005. We determined surrounding greenness from satellite retrievals as the average of Normalized Difference Vegetation Index (NDVI) in a buffer of 100 m around each maternal place of residence. To address proximity to major green spaces, a binary variable was used to indicate whether maternal residential address is situated within a buffer of 500 m from boundaries of a major green space. For each indicator of green exposure, linear regression models were constructed to estimate change in outcomes adjusted for relevant covariates including individual and area level SEP. None of the indicators of green exposure was associated with birth weight and gestational age. After assessing effect modification based on the level of maternal education, we detected an increase in birth weight (grams) among the lowest education level group (N = 164) who had higher surrounding NDVI (Regression coefficient (95% confidence interval (CI) of 436.3 (43.1, 829.5)) or lived close to a major green space (Regression coefficient (95% CI)) of 189.8 (23.9, 355.7)). Our findings suggest a beneficial effect of exposure to green spaces on birth weight only in the lowest SEP group

Saharan dust episodes and pregnancy

Desert dust is one of the natural contributors to atmospheric particulate matter worldwide. Although particulate pollution has been shown to adversely affect pregnancy, the available evidence on the impact of dust episodes on pregnancy is very scarce. The aim of this study was to evaluate the impact of Saharan dust episodes on pregnancy complications (preeclampsia and bacteriuria) and outcomes (birth weight and gestational age at delivery). This study was based on a cohort of births (N = 3565) that occurred in a major university hospital in Barcelona during 2003-2005. To determine Saharan dust episodes, we developed a two-stage approach based on meteorological evidence of the presence of Saharan dust cloud over the region and unusually high levels of particulate levels on the ground while taking account of traffic sources. The associations between the number of Saharan dust episodes during whole pregnancy as well as each pregnancy trimester and pregnancy complications and outcomes were analysed. There were 152 days (out of 838 days) with Saharan dust cloud over the region from which 45 days were determined as episodic days. We did not observe any statistically significant harmful effect of Saharan dust episodes on our included pregnancy complications and outcomes. However, we observed a small but statistically significant increase in gestational age at delivery in association with the number of episodic days during the third trimester and whole pregnancy (0.8 and 0.5 days respectively). Our findings were not suggestive for any adverse effect of Saharan dust episodes on our included pregnancy complications and outcomes. © The Royal Society of Chemistry 2011.We are grateful to Marta Cirach and Jaume Matamala for providing part of the required maps. Payam Dadvand is funded by a Juan de la Cierva fellowship (JCI-2011-09937) from the Spanish Ministry of Science and Innovation. Aurelio Tobias was funded by Project PI080354 of the Health Research Fund, funded by the Subdirectorate-General for Assessment and Development of Research, Spain.Peer Reviewe

Surrounding greenness and exposure to air pollution during pregnancy: An analysis of personal monitoring data

Background: Green spaces are reported to improve health status, including beneficial effects on pregnancy outcomes. Despite the suggestions of air pollution–related health benefits of green spaces, there is no available evidence on the impact of greenness on personal exposure to air pollution. Objectives: We investigated the association between surrounding greenness and personal exposure to air pollution among pregnant women and to explore the potential mechanisms, if any, behind this association. Methods: In total, 65 rounds of sampling were carried out for 54 pregnant women who resided in Barcelona during 2008–2009. Each round consisted of a 2-day measurement of particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5) and a 1-week measurement of nitric oxides collected simultaneously at both the personal and microenvironmental levels. The study participants were also asked to fill out a time–microenvironment–activity diary during the sampling period. We used satellite retrievals to determine the surrounding greenness as the average of Normalized Difference Vegetation Index (NDVI) in a buffer of 100 m around each maternal residential address. We estimated the impact of surrounding greenness on personal exposure levels, home-outdoor and home-indoor pollutant levels, and maternal time-activity. Results: Higher residential surrounding greenness was associated with lower personal, home-indoor, and home-outdoor PM2.5 levels, and more time spent at home-outdoor. Conclusions: We found lower levels of personal exposure to air pollution among pregnant women residing in greener areas. This finding may be partly explained by lower home-indoor pollutant levels and more time spent in less polluted home-outdoor environment by pregnant women in greener areas