137 research outputs found
Pre-anaesthetic assessment of intracranial pressure using optic nerve sheath diameter in patients scheduled for elective tumour craniotomy
Background: The objective of study was to determine the pre-anaesthetic status of intracranial pressure (ICP), using ultrasonographic measurement of optic nerve sheath diameter (ONSD) inpatient scheduled for elective tumour craniotomy. The secondary objective was to compare the diagnostic accuracy of ONSD guided rise in ICP with clinical and radiographic parameters. This is prospective observational study, conducted at single neurosurgical theatre of The Aga Khan University over a period of one year.Methods: After getting ethical approval and informed consent patient fulfilling inclusion criteria and planned for elective tumour craniotomy were enrolled in study. The clinical and radiographic signs predicting the status of ICP were recorded. The ultrasonographic measurement of ONSD was done using liner array probe. Value more than 5 mm was considered as abnormal.Results: Total 26 cases were enrolled. Seventy percent patients showed rise in ICP based on clinical parameters, while 65% diagnosed to have raised ICP on the basis of radiographic findings. The ultrasonographic measurement of ONSD predicted this rise in 61% of cases. The diagnostic accuracy of ONSD in detecting raised ICP in comparison to clinical and radiographic evidence was 87.5% respectively.Conclusions: The ultrasonographic-guided ONSD was used successfully for predicting the status of ICP in pre-induction phase of anaesthesia. It also showed good correlation in diagnosing rise in ICP as compared to clinical and radiographic parameters, which indicates that test can be used reliably in preoperative period for patients planned for tumour craniotomy
Dissimilarity Gaussian Mixture Models for Efficient Offline Handwritten Text-Independent Identification using SIFT and RootSIFT Descriptors
Handwriting biometrics is the science of identifying the behavioural aspect of an individual’s writing style and exploiting it to develop automated writer identification and verification systems. This paper presents an efficient handwriting identification system which combines Scale Invariant Feature Transform (SIFT) and RootSIFT descriptors in a set of Gaussian mixture models (GMM). In particular, a new concept of similarity and dissimilarity Gaussian mixture models (SGMM and DGMM) is introduced. While a SGMM is constructed for every writer to describe the intra-class similarity that is exhibited between the handwritten texts of the same writer, a DGMM represents the contrast or dissimilarity that exists between the writer’s style on one hand and other different handwriting styles on the other hand. Furthermore, because the handwritten text is described by a number of key point descriptors where each descriptor generates a SGMM/DGMM score, a new weighted histogram method is proposed to derive the intermediate prediction score for each writer’s GMM. The idea of weighted histogram exploits the fact that handwritings from the same writer should exhibit more similar textual patterns than dissimilar ones, hence, by penalizing the bad scores with a cost function, the identification rate can be significantly enhanced. Our proposed system has been extensively assessed using six different public datasets (including three English, two Arabic and one hybrid language) and the results have shown the superiority of the proposed system over state-of-the-art techniques
Effect of Individualized vs Standard Blood Pressure Management Strategies on Postoperative Organ Dysfunction Among High-Risk Patients Undergoing Major Surgery
Objective: To determine the effect of individualized blood pressure management targeted upon the physiology of individual patient could help in decreasing the risk postoperative organ dysfunction. Methodology It was a randomized trial carried out in department of general medicine from March 2016 to March 2017. An approval from Ethics committee was taken. An informed consent in the form of a written document was taken from every patient. Data was analyzed by using SPSS version 24. Student t-test and χ2 test that was unadjusted was performed for the analysis of primary outcome. P value ≤ 0.05 was considered as significant. Results: in the Individualized group, Primary composite outcome was noted as (36.7%) n=55. Acute kidney injury according to RIFLE criteria; Risk, injury and failure was observed as (17.3%) n=26, (9.3%) n=14 and (6%) n=9 respectively. Use of renal replacement therapy was noted as (8%) n=12. Acute heart failure occurred in (6%) n=9. respectively. For Standard treatment group, Primary composite outcome was noted as (48.7%) n=73. Use of renal replacement therapy was noted as (6.7%) n=10. Acute heart failure occurred in (1.3%) n=2. Need for noninvasive or invasive ventilation and sepsis was noted as (30.7%) n=46 and (18%) n=27 respectively. Conclusion: High Postoperative risk patients having major abdominal surgery, the mode of management directed towards the individual blood pressure as compared to standard mode of management proves to be fruitful in decreasing the risk for postoperative organ dysfunction. Keywords: Blood Pressure, Organ Dysfunction, Postoperative complications, Sepsis
Delayed spinal cord infarction following anterior cervical surgical decompression
Anterior cervical discectomy and fusion (ACDF) for cord compression is a safe and effective procedure with good outcomes. However, worsening of myelopathy is the most feared adverse event of the surgery. We report the case of a 36-year-old male patient who presented with an acute non-traumatic C5-6 cervical disc herniation causing incomplete quadriparesis. He underwent an uncomplicated ACDF at C5-6, and after an initial period of improvement, he developed a delayed onset of an anterior cord syndrome on day 3, without any discerning cause. We have reviewed similar cases reported in the literature and believe that our patient\u27s postsurgical course is consistent with a delayed ischaemic/reperfusion injury to the cord following surgical decompression and restoration of blood flow through the anterior spinal artery and we make suggestions for management of such clinical events
Effect of alloying elements on the compressive mechanical properties of biomedical titanium alloys: A systematic review
Due to problems such as the stress-shielding effect, strength-ductility trade-off dilemma, and use of rare-earth, expensive elements with high melting points in Ti alloys, the need for the design of new Ti alloys for biomedical applications has emerged. This article reports the effect of various alloying elements on the compressive mechanical performance of Ti alloys for biomedical applications for the first time as a systematic review following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines on this subject. The search strategy in this systematic review used Scopus, Web of Science, and PubMed databases and searched the articles using (Beta-type OR β) AND Titanium AND (Mechanical property OR Microstructure) AND Alloying element keywords. Original articles from 2016 to 2022 published in English have been selected for this study as per the inclusion criteria. The results have shown that Nb can be used as the primary alloying element with Ti as it is a strong β-stabilizer element which also reduces the elastic modulus of Ti alloys. The β-eutectic elements (Fe, Cr, and Mn) have also emerged as cost-effective alloying elements that could improve the mechanical performance of Ti alloys. Ti-Nb-Zr-Ta alloyed with Si has shown potential to withstand the strength-ductility trade-off dilemma. The combination of a Ti-Nb binary alloy has emerged as an attractive material for designing low elastic modulus Ti alloys. The mechanical performance of the Ti-Nb alloy can be further improved using the β-eutectic (Fe, Cr, and Mn) and neutral (Zr, Sn) elements to be alloyed with a Ti-Nb binary alloy. The strength-ductility trade-off issue can be overcome using Si as an alloying element in Ti-Nb-Zr-Ta alloys
Robust off-line text independent writer identification using bagged discrete cosine transform features
Efficient writer identification systems identify the authorship of an unknown sample of text with high confidence. This has made automatic writer identification a very important topic of research for forensic document analysis. In this paper, we propose a robust system for offline text independent writer identification using bagged discrete cosine transform (BDCT) descriptors. Universal codebooks are first used to generate multiple predictor models. A final decision is then obtained by using the majority voting rule from these predictor models. The BDCT approach allows for DCT features to be effectively exploited for robust hand writer identification. The proposed system has first been assessed on the original version of hand written documents of various datasets and results have shown comparable performance with state-of-the-art systems. Next, blurry and noisy documents of two different datasets have been considered through intensive experiments where the system has been shown to perform significantly better than its competitors. To the best of our knowledge this is the first work that addresses the robustness aspect in automatic hand writer identification. This is particularly suitable in digital forensics as the documents acquired by the analyst may not be in ideal conditions
Unemployment: A Missing Link
Developing countries like Pakistan face a host of economic problems in the form of stagnant exports, low economic growth, inadequate private investment, and inefficient utilization of foreign direct investment. Given these problems, we have examined macroeconomic factors impact on unemployment in Pakistan from 1967 to 2018. We also tested the proposed hypotheses through “VAR, fully modified least squares, and Granger causality tests.†Our results suggest that exports did not stimulate jobs in Pakistan. Perhaps, Pakistan needs to diversify its exports by focusing on non-conventional value-added goods. The results also indicate that although FDI and government expenditures have created jobs, they are below expectations. Although we found that private investment has helped job creation, the effect is small compared to other developing countries. Furthermore, we find that macroeconomic factors have had little impact on unemployment in the long run
Mycovirus Hunting Revealed the Presence of Diverse Viruses in a Single Isolate of the Phytopathogenic Fungus Diplodia seriata From Pakistan
Diplodia seriata in the family Botryosphaeriaceae is a cosmopolitan phytopathogenic fungus and is responsible for causing cankers, fruit rot and leaf spots on economically important plants. In this study, we characterized the virome of a single Pakistani strain (L3) of D. seriata. Several viral-like contig sequences were obtained via a previously conducted next-generation sequencing analysis. Multiple infection of the L3 strain by eight RNA mycoviruses was confirmed through RT-PCR using total RNA samples extracted from this strain; the entire genomes were determined via Sanger sequencing of RT-PCR and RACE clones. A BLAST search and phylogenetic analyses indicated that these eight mycoviruses belong to seven different viral families. Four identified mycoviruses belong to double-stranded RNA viral families, including Polymycoviridae, Chrysoviridae, Totiviridae and Partitiviridae, and the remaining four identified mycoviruses belong to single-stranded RNA viral families, i.e., Botourmiaviridae, and two previously proposed families "Ambiguiviridae" and "Splipalmiviridae". Of the eight, five mycoviruses appear to represent new virus species. A morphological comparison of L3 and partially cured strain L3ht1 suggested that one or more of the three viruses belonging to Polymycoviridae, "Splipalmiviridae" and "Ambiguiviridae" are involved in the irregular colony phenotype of L3. To our knowledge, this is the first report of diverse virome characterization from D. seriata
Axial Load-carrying Capacity of Steel Tubed Concrete Short Columns Confined with Advanced FRP Composites
Fiber Reinforced Polymers (FRPs) have wide applications in the field of concrete construction due to their superior performance over conventional materials. This research focuses on the structural behavior of steel tube FRP jacket–confined concrete (STFC) columns under axial concentric loading and proposes a new empirical equation for predicting the axial load-carrying capacity of STFC columns having thickness of FRP-fabric ranging from 0.09 mm to 5.9 mm. A large database of 700 FRP-confined concrete specimens is developed with the detailed information of critical parameters, i.e. elastic modulus of FRPs (Ef), compressive strength of unconfined concrete (fc’o), diameter of specimen (D), height of specimen (H), total thickness of FRPs (N.tf), and the ultimate strength of confined concrete (fc’c). After the preliminary evaluation of constructed database, a new empirical model is proposed for the prediction of axial compressive strength of FRP-confined specimens using general regression analysis by minimizing the error functions such as root mean squared error (RMSE) and coefficient of determination (R2). The proposed FRP-confinement strength model presented higher accuracy as compared with previously proposed models. Finally, an equation is proposed for the predictions of axial load carrying capacity of STFC columns. For the validation of proposed equation, an extensive parametric study is performed using the proposed nonlinear finite element model (FEM). The FEM is calibrated using the load-deflection results of STFC columns from literature. A close agreement was observed between the predictions of proposed finite element model and proposed capacity equation
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