Background: Advanced maternal age, over 35 years, is a well-known risk factor for poor pregnancy outcomes. It is commonly associated with various pregnancy complications, such as spontaneous miscarriage, preeclampsia/...Background: Advanced maternal age, over 35 years, is a well-known risk factor for poor pregnancy outcomes. It is commonly associated with various pregnancy complications, such as spontaneous miscarriage, preeclampsia/ toxemia, gestational diabetes mellitus, preterm labor, stillbirth, chromosomal abnormalities, and cesarean delivery. Objectives: This study assessed obstetric and neonatal complications associated with advanced maternal age. Methods: We reviewed the medical records of 199 pregnant women over 35 years old at King Abdulaziz University Hospital in Jeddah, Saudi Arabia, from January to June 2022. We gathered data on age, nationality, number of antenatal visits, results of ultrasound scans for dating and viability, nuchal translucency and anatomy surveys, medications and multivitamins taken during pregnancy, smoking status, pregnancy, and fetal complications, and mode of delivery. Results: The prevalence of obstetric complications was 71.4% (preeclampsia/toxemia, 4.5%;antepartum hemorrhage, 4%;postpartum hemorrhage, 1%;and gestational diabetes, 23.1%). The most frequent complication was preterm labor between 34 and 36 weeks (48%), and only 12.6% of all deliveries were associated with fetal and neonatal complications such as congenital anomalies and neonatal jaundice. The prevalence of anemia during pregnancy was 10.1%, 21.1%, and 28.6% in the first, second, and third trimesters, respectively, and pregnancies complicated with antepartum or postpartum hemorrhage were associated with higher rates of anemia in the second trimester. A significant relationship was found between mean maternal age (38.84 ± 2.75 years) and the development of maternal complications (p < 0.05). Newborns with neonatal complications were much more likely to be born to mothers with a history of antepartum hemorrhage and anemia in the second trimester. Conclusion: Our findings confirm that pregnancy at an advanced maternal age is associated with increased overall maternal complications. The most frequent complication was preterm labor (48%). Other complications, such as preeclampsia/toxemia, antepartum hemorrhage, postpartum hemorrhage, gestational diabetes, and anemia, were less frequent in the sample we reviewed.展开更多
It is difficult to solve complete coverage path planning directly in the obstructed area. Therefore, in this paper, we propose a method of complete coverage path planning with improved area division. Firstly, the bous...It is difficult to solve complete coverage path planning directly in the obstructed area. Therefore, in this paper, we propose a method of complete coverage path planning with improved area division. Firstly, the boustrophedon cell decomposition method is used to partition the map into sub-regions. The complete coverage paths within each sub-region are obtained by the Boustrophedon back-and-forth motions, and the order of traversal of the sub-regions is then described as a generalised traveling salesman problem with pickup and delivery based on the relative positions of the vertices of each sub-region. An adaptive large neighbourhood algorithm is proposed to quickly obtain solution results in traversal order. The effectiveness of the improved algorithm on traversal cost reduction is verified in this paper through multiple sets of experiments. .展开更多
This research aimed at optimizing the reaction conditions for the catalytic hydrothermal liquefaction (HTL) of water hyacinth using iron oxide/nickel oxide nanocomposite as catalysts. The iron oxide/nickel oxide nanoc...This research aimed at optimizing the reaction conditions for the catalytic hydrothermal liquefaction (HTL) of water hyacinth using iron oxide/nickel oxide nanocomposite as catalysts. The iron oxide/nickel oxide nanocomposite was synthesized by the co-precipitation method and used in the hydrothermal liquefaction of water hyacinth. The composition and structural morphology of the synthesized catalysts were determined using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic absorption spectroscopy (AAS). The particle size distribution of the catalyst nanoparticles was determined by the Image J software. Three reaction parameters were optimized using the response surface methodology (RSM). These were: temperature, residence time, and catalyst dosage. A maximum bio-oil yield of 59.4 wt% was obtained using iron oxide/nickel oxide nanocomposite compared to 50.7 wt% obtained in absence of the catalyst. The maximum bio-oil yield was obtained at a temperature of 320°C, 1.5 g of catalyst dosage, and 60 min of residence time. The composition of bio-oil was analyzed using gas chromatography-mass spectroscopy (GC-MS) and elemental analysis. The GC-MS results showed an increase of hydrocarbons from 58.3% for uncatalyzed hydrothermal liquefaction to 88.66% using iron oxide/nickel oxide nanocomposite. Elemental analysis results revealed an increase in the hydrogen and carbon content and a reduction in the Nitrogen, Oxygen, and Sulphur content of the bio-oil during catalytic HTL compared to HTL in absence of catalyst nanoparticles. The high heating value increased from 33.5 MJ/Kg for uncatalyzed hydrothermal liquefaction to 38.6 MJ/Kg during the catalytic HTL. The catalyst nanoparticles were recovered from the solid residue by sonication and magnetic separation and recycled. The recycled catalyst nanoparticles were still efficient as hydrothermal liquefaction (HTL) catalysts and were recycled four times. The application of iron oxide/ nickel oxide nanocomposites in the HTL of water hyacinth increases the yield of bio-oil and improves its quality by reducing hetero atoms thus increasing its energy performance as fuel. Iron oxide/nickel oxide nanocomposites used in this study are widely available and can be easily recovered magnetically and recycled. This will potentially lead to an economical, environmentally friendly, and sustainable way of converting biomass into biofuel.展开更多
文摘Background: Advanced maternal age, over 35 years, is a well-known risk factor for poor pregnancy outcomes. It is commonly associated with various pregnancy complications, such as spontaneous miscarriage, preeclampsia/ toxemia, gestational diabetes mellitus, preterm labor, stillbirth, chromosomal abnormalities, and cesarean delivery. Objectives: This study assessed obstetric and neonatal complications associated with advanced maternal age. Methods: We reviewed the medical records of 199 pregnant women over 35 years old at King Abdulaziz University Hospital in Jeddah, Saudi Arabia, from January to June 2022. We gathered data on age, nationality, number of antenatal visits, results of ultrasound scans for dating and viability, nuchal translucency and anatomy surveys, medications and multivitamins taken during pregnancy, smoking status, pregnancy, and fetal complications, and mode of delivery. Results: The prevalence of obstetric complications was 71.4% (preeclampsia/toxemia, 4.5%;antepartum hemorrhage, 4%;postpartum hemorrhage, 1%;and gestational diabetes, 23.1%). The most frequent complication was preterm labor between 34 and 36 weeks (48%), and only 12.6% of all deliveries were associated with fetal and neonatal complications such as congenital anomalies and neonatal jaundice. The prevalence of anemia during pregnancy was 10.1%, 21.1%, and 28.6% in the first, second, and third trimesters, respectively, and pregnancies complicated with antepartum or postpartum hemorrhage were associated with higher rates of anemia in the second trimester. A significant relationship was found between mean maternal age (38.84 ± 2.75 years) and the development of maternal complications (p < 0.05). Newborns with neonatal complications were much more likely to be born to mothers with a history of antepartum hemorrhage and anemia in the second trimester. Conclusion: Our findings confirm that pregnancy at an advanced maternal age is associated with increased overall maternal complications. The most frequent complication was preterm labor (48%). Other complications, such as preeclampsia/toxemia, antepartum hemorrhage, postpartum hemorrhage, gestational diabetes, and anemia, were less frequent in the sample we reviewed.
文摘It is difficult to solve complete coverage path planning directly in the obstructed area. Therefore, in this paper, we propose a method of complete coverage path planning with improved area division. Firstly, the boustrophedon cell decomposition method is used to partition the map into sub-regions. The complete coverage paths within each sub-region are obtained by the Boustrophedon back-and-forth motions, and the order of traversal of the sub-regions is then described as a generalised traveling salesman problem with pickup and delivery based on the relative positions of the vertices of each sub-region. An adaptive large neighbourhood algorithm is proposed to quickly obtain solution results in traversal order. The effectiveness of the improved algorithm on traversal cost reduction is verified in this paper through multiple sets of experiments. .
文摘This research aimed at optimizing the reaction conditions for the catalytic hydrothermal liquefaction (HTL) of water hyacinth using iron oxide/nickel oxide nanocomposite as catalysts. The iron oxide/nickel oxide nanocomposite was synthesized by the co-precipitation method and used in the hydrothermal liquefaction of water hyacinth. The composition and structural morphology of the synthesized catalysts were determined using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic absorption spectroscopy (AAS). The particle size distribution of the catalyst nanoparticles was determined by the Image J software. Three reaction parameters were optimized using the response surface methodology (RSM). These were: temperature, residence time, and catalyst dosage. A maximum bio-oil yield of 59.4 wt% was obtained using iron oxide/nickel oxide nanocomposite compared to 50.7 wt% obtained in absence of the catalyst. The maximum bio-oil yield was obtained at a temperature of 320°C, 1.5 g of catalyst dosage, and 60 min of residence time. The composition of bio-oil was analyzed using gas chromatography-mass spectroscopy (GC-MS) and elemental analysis. The GC-MS results showed an increase of hydrocarbons from 58.3% for uncatalyzed hydrothermal liquefaction to 88.66% using iron oxide/nickel oxide nanocomposite. Elemental analysis results revealed an increase in the hydrogen and carbon content and a reduction in the Nitrogen, Oxygen, and Sulphur content of the bio-oil during catalytic HTL compared to HTL in absence of catalyst nanoparticles. The high heating value increased from 33.5 MJ/Kg for uncatalyzed hydrothermal liquefaction to 38.6 MJ/Kg during the catalytic HTL. The catalyst nanoparticles were recovered from the solid residue by sonication and magnetic separation and recycled. The recycled catalyst nanoparticles were still efficient as hydrothermal liquefaction (HTL) catalysts and were recycled four times. The application of iron oxide/ nickel oxide nanocomposites in the HTL of water hyacinth increases the yield of bio-oil and improves its quality by reducing hetero atoms thus increasing its energy performance as fuel. Iron oxide/nickel oxide nanocomposites used in this study are widely available and can be easily recovered magnetically and recycled. This will potentially lead to an economical, environmentally friendly, and sustainable way of converting biomass into biofuel.
