160 research outputs found
Role of partogram in the management of spontaneous labour in primigravida and multigravida
Background: The objective of this study was to analyze the patterns of labour amongst spontaneous parturients using a WHO modified partogram and compare outcomes of labour and their neonatal outcomes amongst the different partogram patternsMethods: This prospective study was carried out in the labour room of the department of obstetrics and gynaecology of Acharya Vinoba Bhave rural hospital, Sawangi Meghe, Wardha, Maharashtra, over a period of two years i.e. from October 2012 to September 2014. Analysis of the progress of labour was done in two hundred and fifty women with the help of modified WHO partogram. The patients were divided into three groups. Group A whose partogram remained to the left of the alert line, group B whose partogram remained between the alert and action line and group C had their partogram crossing the action line. The different types of abnormal labour were studied. The maternal and fetal outcomes were assessed.Results: 67.2% of the women belonged to group A, 22.8% to group B and 10% to group C. Surgical interference and requirement of augmentation increased as the labour curve moved to the right of the alert line. All patients delivered within 12 hours. Timely intervention reduced the incidence of prolonged labour and its sequelae. 82 patients showed abnormal labour patterns. There were no maternal death or neonatal death.Conclusions: The use of modified WHO partogram significantly improves both maternal & neonatal outcome. Routine use of partogram should be implemented in all institutions and all labour rooms in India where delivery care is being given and especially in areas where operative and new-born facilities are lacking to facilitate early referral.
Meso-scale modeling of granular material including grain fracture using grain morphology
This study focuses on a meso-scale approach to numerical simulations of a granular material subjected to quasi-static loadings. The discrete grains used in this approach are comprised of finite elements that capture the microscale stress distribution within individual grains. In addition, the discrete grain topology is formed from the actual grain surface morphology, captured using X-ray tomography, which allows for more accurate characterization of the contact interaction between particles compared with idealized grain packing with simple shapes. The effects of selected finite element formulations and grain discretization approaches are investigated to maximize the ability to capture high-stress concentrations at contact points between grains, where fracture is likely to initiate, yet maintain computational efficiency. Simulations of uniaxial and triaxial compression quasi-static loadings of -Ottawa sand specimens are performed with an FE/FD code, GEODYN-L. The influence of including granular in the numerical simulations is also examined
Morphology, Mechanical Performance and Nanoindentation Behavior of Injection Molded PC/ABS-MWCNT Nanocomposites
"This is the peer reviewed version of the following article: Wegrzyn, M., Sahuquillo, O., Benedito, A., & Gimenez, E. (2015). Morphology, mechanical performance, and nanoindentation behavior of injection molded PC/ABS‐MWCNT nanocomposites. Journal of Applied Polymer Science, 132(22), which has been published in final form at https://doi.org/10.1002/app.42014. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] In this work, nanocomposites of polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) with various loads of multiwall carbon nanotubes (MWCNT) are investigated. Material is previously formed by masterbatch dilution approach and further processed by injection molding at various velocities. Microscopic characterization of nanocomposites morphology reveals stronger
dependence of MWCNT dispersion on processing parameters at higher nanofiller load. Dispersion of carbon nanotubes at various distances from the injection gate is studied by Raman spectroscopy showing lower deviation at elevated injection velocity. Nanoindentation results that are in agreement with uniaxial tensile testing show a slight decrease of nanocomposites¿ mechanical performance at 3.0 wt % MWCNT in samples injected at reduced velocity. This is explained by the increase of agglomeration behavior at these conditions.This work is funded by the European Community's Seventh Framework Program (FP7-PEOPLE-ITN-2008) within the CONTACT project Marie Curie Fellowship under grant number 238363.Wegrzyn, M.; Sahuquillo, O.; Benedito, A.; Giménez Torres, E. (2015). Morphology, Mechanical Performance and Nanoindentation Behavior of Injection Molded PC/ABS-MWCNT Nanocomposites. Journal of Applied Polymer Science. 132(22):1-8. https://doi.org/10.1002/app.42014S1813222Alig, I., Lellinger, D., Engel, M., Skipa, T., & Pötschke, P. (2008). Destruction and formation of a conductive carbon nanotube network in polymer melts: In-line experiments. Polymer, 49(7), 1902-1909. doi:10.1016/j.polymer.2008.01.073Sathyanarayana, S., Wegrzyn, M., Olowojoba, G., Benedito, A., Gimenez, E., Huebner, C., & Henning, F. (2013). Multiwalled carbon nanotubes incorporated into a miscible blend of poly(phenylenether)/polystyrene – Processing and characterization. Express Polymer Letters, 7(7), 621-635. doi:10.3144/expresspolymlett.2013.59Xiong, Z.-Y., Wang, L., Sun, Y., Guo, Z.-X., & Yu, J. (2013). Migration of MWCNTs during melt preparation of ABS/PC/MWCNT conductive composites via PC/MWCNT masterbatch approach. Polymer, 54(1), 447-455. doi:10.1016/j.polymer.2012.11.044Sun, Y., Guo, Z.-X., & Yu, J. (2010). Effect of ABS Rubber Content on the Localization of MWCNTs in PC/ABS Blends and Electrical Resistivity of the Composites. Macromolecular Materials and Engineering, 295(3), 263-268. doi:10.1002/mame.200900242Göldel, A., Kasaliwal, G. R., Pötschke, P., & Heinrich, G. (2012). The kinetics of CNT transfer between immiscible blend phases during melt mixing. Polymer, 53(2), 411-421. doi:10.1016/j.polymer.2011.11.039Tiusanen, J., Vlasveld, D., & Vuorinen, J. (2012). Review on the effects of injection moulding parameters on the electrical resistivity of carbon nanotube filled polymer parts. Composites Science and Technology, 72(14), 1741-1752. doi:10.1016/j.compscitech.2012.07.009Ma, P.-C., Siddiqui, N. A., Marom, G., & Kim, J.-K. (2010). Dispersion and functionalization of carbon nanotubes for polymer-based nanocomposites: A review. 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Load-settlement modeling of axially loaded steel driven piles using CPT-based recurrent neural networks
The design of pile foundations requires good estimation of the pile load-carrying capacity and settlement. Design for bearing capacity and design for settlement have been traditionally carried out separately. However, soil resistance and settlement are influenced by each other and design of pile foundations should thus consider the bearing capacity and settlement inseparably. This requires the full load-settlement response of piles to be well predicted. However, it is well known that the actual load-settlement response of pile foundations can only be obtained by load tests carried out in-situ, which are expensive and time-consuming. In this technical note, the recurrent neural networks (RNNs) were used to develop a prediction model that can resemble the load-settlement response of steel driven piles subjected to axial loading. The developed RNN model was calibrated and validated using several in-situ full-scale pile load tests, as well as cone penetration test (CPT) data. The results indicate that the developed RNN model has the ability to reliably predict the load-settlement response of axially loaded steel driven piles and can thus be used by geotechnical engineers for routine design practice
Torsion of a rectangular bar Complex phase distribution in 304L steel revealed by neutron tomography
Metastable austenitic stainless steel 304L samples with a rectangular cross section were plastically deformed in torsion during which they experienced multiaxial stresses that led to a complex martensitic phase distribution owing to the transformation induced plasticity effect. A three dimensional characterization of the phase distributions in these cm sized samples was carried out by wavelength selective neutron tomography. It was found that quantitatively correct results are obtained as long as the samples do not exhibit any considerable preferential grain orientation. Optical microscopy, electron backscatter diffraction, and finite element modeling were used to verify and explain the results obtained by neutron tomography. Altogether, neutron tomography was shown to extend the range of microstructure characterization methods towards the meso and macroscal
Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery
Peer reviewe
The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study
AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease
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