The blast loading on aboveground structures

Call number: LD2668 .R4 1963 L19

Arthroscopic Simulation: The Future of Surgical Training: A Systematic Review.

BACKGROUND: Arthroscopic simulation has rapidly evolved recently with the introduction of higher-fidelity simulation models, such as virtual reality simulators, which provide trainees an environment to practice skills without causing undue harm to patients. Simulation training also offers a uniform approach to learn surgical skills with immediate feedback. The aim of this article is to review the recent research investigating the use of arthroscopy simulators in training and the teaching of surgical skills. METHODS: A systematic review of the Embase, MEDLINE, and Cochrane Library databases for English-language articles published before December 2019 was conducted. The search terms included arthroscopy or arthroscopic in combination with simulation or simulator. RESULTS: We identified a total of 44 relevant studies involving benchtop or virtually simulated ankle, knee, shoulder, and hip arthroscopy environments. The majority of these studies demonstrated construct and transfer validity; considerably fewer studies demonstrated content and face validity. CONCLUSIONS: Our review indicates that there is a considerable evidence base regarding the use of arthroscopy simulators for training purposes. Further work should focus on the development of a more uniform simulator training course that can be compared with current intraoperative training in large-scale trials with long-term follow-up at tertiary centers

Rapid Determination of Manganese by Differential Pulse and Alternating Current (1st harmonic) Polarography

85-8

Design and performance comparison of different adaptive control schemes for pitch angle control in a twin – rotor – MIMO – system

The Twin Rotor MIMO System is a higher order non-linear plant and is inherently unstable due to cross coupling between tail and main rotor. In this paper only the control of main rotor is considered which is non-linear and stable by using adaptive schemes. The control problem is to achieve perfect tracking for input reference signals while maintaining robustness and stability. Four adaptive schemes were implemented, two using Model Reference Adaptive Control under which MIT rule and Modified MIT rule are used. The other two using Adaptive Interaction, namely, Adaptive PID and Approximate Adaptive PID. It is observed that adaptive schemes fulfill all the three system performance requirements at the same time. Modified MIT rule was found to give superior performance in comparison to other controllers. Also Approximate Adaptive PID was able to stabilize the main rotor and cancel the effect of cross coupling between tail rotor and main rotor when operating simultaneously without the need for designing decouplers for the system. Thus the main rotor can be made independent from the state of the tail rotor by using Approximate Adaptive PID

3D Engineered Peripheral Nerve: Towards A New Era of Patient-Specific Nerve Repair Solutions

Reconstruction of peripheral nerve injuries (PNIs) with substance loss remains challenging because of limited treatment solutions and unsatisfactory patient outcomes. Currently, nerve autografting is the first-line management choice for bridging critical-sized nerve defects. The procedure, however, is often complicated by donor site morbidity and paucity of nerve tissue, raising a quest for better alternatives. The application of other treatment surrogates, such as nerve guides remains questionable, and inefficient in irreducible nerve gaps. More importantly, these strategies lack customization for personalized patient therapy, which is a significant drawback of these nerve repair options. This negatively impacts the fascicle-to-fascicle regeneration process, critical to restoring the physiological axonal pathway of the disrupted nerve. Recently, the use of additive manufacturing (AM) technologies has offered major advancements to the bioengineering solutions for PNI therapy. These techniques aim to reinstate the native nerve fascicle pathway using biomimetic approaches, thereby augmenting end-organ innervation. AM-based approaches, such as 3D bioprinting, are capable of biofabricating 3D engineered nerve graft scaffolds in a patient-specific manner with high precision. Moreover, realistic in vitro models of peripheral nerve tissues that represent the physiologically and functionally relevant environment of human organs could also be developed. However, the technology is still nascent and faces major translational hurdles. In this review, we spotlighted the clinical burden of PNIs and most up-to-date treatment to address nerve gaps. Next, a summarized illustration of the nerve ultrastructure that guides research solutions is discussed. This is followed by a contrast of the existing bioengineering strategies used to repair peripheral nerve discontinuities. In addition, we elaborated on the most recent advances in 3D printing (3DP) and biofabrication applications in peripheral nerve modeling and engineering. Finally, the major challenges that limit the evolution of the field along with their possible solutions are also critically analyzed

Factors associated with gestational diabetes among women registered at secondary hospitals in Karachi, Pakistan

Introduction: Few things are proven, there are modifiable and non-modifiable factors that could impact on the health of pregnant women who have Gestational Diabetes Millitus (GDM). However, case control studies are lacking that explore the modifiable factors and identify which modifiable factors are associated with GDM.Purpose: The aim of this study was to identify the modifiable associated risk factors of GDM among women at 32 to 40 weeks of gestation.Methodology: A case-control study design was conducted at secondary hospitals for women and children in Karachi, Pakistan. The data were collected from 100 cases and same number of controls, through a structured questionnaire. The data was analyzed by means of descriptive and inferential statistics, using Stata(TM) Version 12.0.Results: The majority of the study participants had a past history of GDM and had a Body Mass Index (BMI) greater than 25kg/m2. Most of the participants were graduates or post-graduates. The results of the study identified that the modifiable factors which were significantly associated with GDM included household physical activities, transportation related physical activities, recreational activities (i.e., walking, number of stairs climbed daily), use of fruits and eggs, and night time sleep duration. Only 12% of the participants reported that they spent greater than or equal to six hours in recreational physical activities. About one-third (35%) of the participants reported sleeping more than six hours a night.Conclusion: The present study identified the association of some modifiable factors with GDM. There is a dire need to develop preventive strategies that can promote a healthy lifestyle among pregnant women. Attention should be given to increasing physical activity, promoting a healthy diet, and having proper sleep. In light of the current study findings, a study with a large sample size, including multi-center settings, is needed

Correlation between maternal serum biochemical markers with karyotyping for prenatal screening of foetal chromosomal abnormalities

Background: Prenatal screening for chromosomal abnormalities can be done by biochemical screening tests like dual marker test (DMT), triple marker test (TMT) and quadruple marker test (QMT). It is important to identify ideal screening test among them which best correlates with result of karyotyping which is confirmatory test of foetal chromosomal abnormalities. This helps to decrease need for invasive prenatal tests for foetal karyotyping. This study aims to evaluate sensitivity, specificity, diagnostic accuracy and correlation of DMT, TMT, and QMT with results of karyotyping.Methods: Retrospective observational study was conducted in tertiary care maternity hospital over one year- 1st January 2015 to 31st December 2015. Women with singleton pregnancy undergoing DMT, TMT or QMT were included.Results: Of the 529 women screened by biochemical marker tests, 462 (87.33%) were screen negative and 67 (12.66%) women were screen positive. In 56 women, it was false positive (83.58%) and in 11 women true positive (16.41%). In 461 women the test results were true negative (99.78%), but in one case, result was false negative (0.21%).  3/11 (27.27%)women with foetal chromosomal abnormalities were primigravidae. 4/11 (36.36%)women were below 35 years. DMT and QMT had higher sensitivity (both 100%) and specificity (90.00% and 93.18% respectively) than TMT (sensitivity 80% and specificity 82.61%). Positive likelihood ratio (LR+) was 1.00 in DMT. Diagnostic odds ratio was highest with DMT (DOR=115.11) and best correlated with karyotyping results (coefficient of correlation 0.4).Conclusions: Universal screening of antenatal women, irrespective of their age and parity is suggested. DMT has highest diagnostic value and best correlation with the results of karyotyping. Hence the dual marker test can be considered to be better test for screening for aneuploidy

Morbidity and mortality meetings; a new digital portal to enhance learning and objectivity

Morbidity and mortality meetings have long been part of surgical education and practice. They have undergone several modifications over time to include improvement in patient safety and outcomes as an essential utility of conducting morbidity and mortality meetings. Time and again, it has been proposed in literature that standardisation of case discussion results in the efficiency of these meetings. Learning opportunities can be compiled for system improvement. The current review article was planned to present a newly implemented digital morbidity and mortality portal at the Aga Khan University Hospital (AKUH), Karachi, aiming at homogenising the discussion and to add objectivity to the outcome. It is believed that this uniform system across all surgical specialties may play a significant role in enhancing surgical trainees\u27 learning experience