Gestational age impacts birth to placental weight ratio and umbilical cord oxygen values with implications for the fetal oxygen margin of safety

Background: We determined the impact of gestational age (GA) from near term to term to post-term on birth/placental weight ratio and cord oxygen values with implications for placental transport efficiency for oxygen, fetal O2 consumption relative to delivery or fractional O2 extraction, and oxygen margin of safety. Materials and methods: A hospital database was used to obtain birth/placental weight ratios, cord PO2 and other information on patients delivering between Jan 1, 1990 and Jun 15, 2011 with GA \u3e 34 completed weeks (N=69,852). Oxygen saturation was calculated from the cord PO2 and pH data, while fractional O2 extraction was calculated from the oxygen saturation data. The effect of GA grouping on birth/placental weight ratio, cord PO2, O2 saturation, and fractional O2 extraction values, was examined in all patients adjusting for pregnancy and labor/delivery covariates, and in a subset of low-risk patients. Results: Birth/placental weight ratio and umbilical venous O2 values increased with advancing GA, supporting the conjecture of increasing placental transport efficiency for oxygen. However, umbilical arterial O2 values decreased while fractional O2 extraction increased with successive GA groupings, indicating that fetal O2 consumption must be increasing relative to delivery. Conclusions: Fetal O2 consumption can be seen as ever ‘outgrowing’ O2 delivery over the last weeks of pregnancy and leading to a continued lowering in systemic oxygen levels. While this lowering in oxygen may trigger feedback mechanisms with survival benefit, the ‘oxygen margin of safety’ will also be lowered increasing perinatal morbidity and mortality which appear to be hypoxia related

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Soft robotic jamming gripper design II

The increasing population density has been taking its toll on the agricultural sector as farms are under pressure to increase production to meet the growing demand while also facing labour shortages as people are less willing to dedicate their livelihoods to farmwork. To overcome these challenges, the agricultural sector has turned to technological innovations to optimise the harvesting process of fruits and vegetables, and effectively expediting a labour-intensive and time-consuming process. The development of the soft jamming gripper is an additional enhancement to the robotic arm, and it is specifically designed to optimise the fruit harvesting process by minimising fruit damage. The objective of this project was to develop an improved jamming gripper by modifying the jamming membrane material and replacing the soft silicone skin with fabric. The performance of the jamming gripper was compared to that of a conventional gripper without a jamming membrane. The new jamming membrane material, consisting of 50% rice and four-layered cloth with a vacuum bag, was tested for its characteristics through three-point bending, feasibility, and strength tests.Bachelor of Engineering (Mechanical Engineering

Peripartum hyperhemolysis prophylaxis and management in sickle cell disease: A case report and narrative review.

BACKGROUND: Sickle cell disease (SCD) is associated with hematologic complications including delayed hemolytic transfusion reactions (DHTRs) and pregnancy-related morbidity and mortality. Hyperhemolysis syndrome (HS) is the most severe form of DHTR in patients with SCD, in which both transfused and native red blood cells are destroyed. Further transfusions are avoided after a history of HS. Immunosuppressive agents can be used as prophylaxis against life-threatening hemolysis when transfusion is necessary. There is a paucity of evidence for the use of HS prophylaxis before transfusions, the continuation of hydroxyurea (HU) in lieu of chronic transfusion, and the use of erythropoiesis-stimulating agents (ESA) in pregnant SCD patients. CASE REPORT: We present a case of a pregnant patient with SCD and a previous history of HS. HS prophylaxis was given before transfusion with corticosteroids, intravenous immunoglobulin, and rituximab. In addition, HU was continued during pregnancy to control SCD, along with the use of concomitant ESA to maintain adequate hemoglobin levels and avoid transfusion. We describe a multidisciplinary approach to pregnancy and delivery management including tailored anesthetic and obstetric planning. CONCLUSION: This is the first published case of HS prophylaxis in a pregnant SCD patient, with good maternal and fetal outcomes after transfusion. HU and ESAs were able to control SCD and mitigate anemia in lieu of prophylactic transfusions during pregnancy. Further prospective studies are necessary to elucidate the ideal management of pregnant SCD patients with a history of HS or other contraindications to chronic transfusion

The impact of maternal diabetes on birth to placental weight ratio and umbilical cord oxygen values with implications for fetal-placental development

Introduction We determined the impact of gestational diabetes (GDM) and pre-existing diabetes (DM) on birth/placental weight and cord oxygen values with implications for placental efficiency and fetal-placental growth and development. Methods A hospital database was used to obtain birth/placental weight, cord PO2 and other information on patients delivering between Jan 1, 1990 and Jun 15, 2011 with GA \u3e34 weeks (N = 69,854). Oxygen saturation was calculated from the cord PO2 and pH data, while fetal O2 extraction was calculated from the oxygen saturation data. The effect of diabetic status on birth/placental weight and cord oxygen values was examined adjusting for covariates. Results Birth/placental weights were stepwise decreased in GDM and DM compared to non-diabetics with placentas disproportionally larger indicating decreasing placental efficiency. Umbilical vein oxygen was marginally increased in GDM but decreased in DM attributed to the previously reported hyper-vascularization in diabetic placentas with absorbing surface area of capillaries initially increased, but then constrained by increasing distance from maternal blood within the intervillous space. Umbilical artery oxygen was unchanged in GDM and DM, with fetal O2 extraction decreased in DM indicating that fetal O2 delivery must be increased relative to O2 consumption and likely due to increased umbilical blood flow. Discussion Increased villous density/hyper-vascularization in GDM and DM with placentas disproportionately larger and umbilical blood flow increased, are postulated to normalize umbilical artery oxygen despite increased birth weights and growth-related O2 consumption. These findings have implications for mechanisms signaling fetal-placental growth and development in diabetic pregnancies and differ from that reported with maternal obesity

Dynamics of RASSF1A/MOAP-1 Association with Death Receptors▿ †

RASSF1A is a tumor suppressor protein involved in death receptor-dependent apoptosis utilizing the Bax-interacting protein MOAP-1 (previously referred to as MAP-1). However, the dynamics of death receptor recruitment of RASSF1A and MOAP-1 are still not understood. We have now detailed recruitment to death receptors (tumor necrosis factor receptor 1 [TNF-R1] and TRAIL-R1/DR4) and identified domains of RASSF1A and MOAP-1 that are required for death receptor interaction. Upon TNF-α stimulation, the C-terminal region of MOAP-1 associated with the death domain of TNF-R1; subsequently, RASSF1A was recruited to MOAP-1/TNF-R1 complexes. Prior to recruitment to TNF-R1/MOAP-1 complexes, RASSF1A homodimerization was lost. RASSF1A associated with the TNF-R1/MOAP-1 or TRAIL-R1/MOAP-1 complex via its N-terminal cysteine-rich (C1) domain containing a potential zinc finger binding motif. Importantly, TNF-R1 association domains on both MOAP-1 and RASSF1A were essential for death receptor-dependent apoptosis. The association of RASSF1A and MOAP-1 with death receptors involves an ordered recruitment to receptor complexes to promote cell death and inhibit tumor formation

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical science. © The Author(s) 2019. Published by Oxford University Press