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There is variation in care quality and outcomes for children undergoing emergency abdominal surgery, such as appedectomy. Addressing this requires paediatric-specific quality metrics. The aim of this study was to identify perioperative structure and process measures that are associated with improved outcomes for these children.We performed a systematic review searching MEDLINE, Embase, CINAHL, Cochrane Library, and Google Scholar for articles published between January 1, 1980 and September 29, 2020 about the perioperative care of children undergoing emergency abdominal surgery. We also conducted secondary searching of references and citations, and we included international professional publications.We identified and analysed 383 peer-reviewed articles and 18 grey literature publications. High-grade evidence pertaining to the perioperative care of this patient group is limited. Most of the evidence available relates to improving diagnostic accuracy using preoperative blood testing, imaging, and clinical decision tools. Processes associated with clinical outcomes include time lapse between time of presentation or initial assessment and surgery, and the use of particular analgesia and antibiotic protocols. Structural factors identified include hospital and surgeon caseload and the use of perioperative care pathways.This review summarises the structural and process measures associated with outcome in paediatric emergency abdominal surgery. Such measures provide a means of evaluating care and identifying areas of practice that require quality improvement, especially in children with appendicitis.PROSPERO CRD42017055285.

The reinforcement particles present in a metal matrix is a key factor to improve the strength of weld joints. In the present work, in-situ Titanium diboride (TiB2) and ex-situ Boron carbide (B4C) particles were separately reinforced with Al 4043 matrix by ultrasonic cavitation assisted stir casting process. The fabricated composites were cut into composite filler rods to the required size and shape from the reinforced nanocomposites using wire-cut EDM. The TIG welding process was performed on Al 6061 plates using Al 4043 composite filler rod under optimized welding conditions. The tensile strength and microhardness of both type of particle reinforced weldment were compared. Addition of 2 wt% of TiB2 and 2 wt% B4C particles separately produced 59% and 41% higher microhardness compared to base metal weldment respectively. An increase in tensile strength of 201% and 128% respectively was observed when compared to base metal weldment. The High Resolution Transmission Electron Microscopy (HRTEM) and Field Emission Scanning Electron Microscopy (FESEM) were used to characterize the microstructure of B4C and TiB2 reinforced weldments. The re-melting behaviour of TIG welded joints was also investigated for the formulated nanocomposites.

Acral lentiginous melanoma (ALM) is a rare tumor that occurs on non-sun exposed skin areas of the hands and feet. Reports suggest that ALM exhibits poor prognosis, although mechanisms driving this remain poorly understood. Alterations in TERT and the Wnt/β-catenin (Wnt) pathway have been suggested to correlate with prognosis of ALM. Thus, immunohistochemical expression of β-catenin and LEF1 along with TERT amplification by FISH was investigated in 34 primary ALMs, 20 metastatic ALMs, 10 primary non-ALMs, and 15 acral nevi. Foot/toe was the most common primary tumor location (85%) for ALM. TERT amplification was detected in 6 of 28 (21.4%) primary ALM, 2 of 8 (25%) primary non-ALM, and 8 of 18 (44.4%) metastatic ALM, the latter showing significantly higher frequency compared with primary melanomas (P = 0.043). Most metastatic ALMs positive for TERT amplification lacked BRAF V600E (87.5%). Cytoplasmic and nonnuclear expression of β-catenin was variably detected in all cases. Metastatic ALM revealed lower expression of β-catenin compared with primary ALM (P = 0.017). No differences in LEF1 expression were detected among the groups; however, acral nevi showed decreased labeling with dermal descent, in contrast to melanoma. No molecular-genetic alteration correlated with prognosis. TERT amplification by FISH is a frequent finding in primary ALM and appears to increase in metastatic tumors, suggesting a role in tumor progression to metastasis. Although TERT amplification has been reported to be infrequent in primary non-ALM, it showed comparable frequency with ALM in our series. Our immunohistochemical findings are not fully supportive of activation of either canonical or noncanonical Wnt cascades in ALM. TERT amplification by FISH and LEF1 immunohistochemistry may help in the differential diagnosis between primary ALM and acral nevus. TERT amplification appears to be a promising target for therapy in patients with metastatic ALM.

Background : Recent data suggest that beta blockers are associated with increased perioperative risk in hypertensive patients. We investigated whether beta blockers were associated with an increased risk in elderly patients with raised preoperative arterial blood pressure. Methods We conducted a propensity-score-matched cohort study of primary care data from the UK Clinical Practice Research Datalink (2004–13), including 84 633 patients aged 65 yr or over. Conditional logistic regression models, including factors that were significantly associated with the outcome, were constructed for 30-day mortality after elective noncardiac surgery. The effects of beta blockers (primary outcome), renin–angiotensin system (RAS) inhibitors, calcium-channel blockers, thiazides, loop diuretics, and statins were investigated at systolic and diastolic arterial pressure thresholds. Results Beta blockers were associated with increased odds of postoperative 30-day mortality in patients with systolic hypertension (defined as systolic BP >140 mm Hg; adjusted odds ratio [aOR]: 1.92; 95% confidence interval [CI]: 1.05–3.51). After excluding patients for whom prior data suggest benefit from perioperative beta blockade (patients with prior myocardial infarction or heart failure), rather than adjusting for them, the point estimate shifted slightly (aOR: 2.06; 95% CI: 1.09–3.89). Compared with no use, statins (aOR: 0.35; 95% CI: 0.17–0.75) and thiazides (aOR: 0.28; 95% CI: 0.10–0.78) were associated with lower mortality in patients with systolic hypertension. Conclusions These data suggest that the safety of perioperative beta blockers may be influenced by preoperative blood pressure thresholds. A randomised controlled trial of beta-blocker withdrawal, in select populations, is required to identify a causal relationship.

Our effort is to analyze the effect of the rampant over the economies of 10 affected nations by studying their stock market values during the COVID-19 episode. We have endowed the nations with their respective stock markets stated in brackets - Brazil(Ibovespa), Canada (S&P/TSX Composite), France (AEX), Germany (DAX 30), India (NIFTY 50), Italy (FTSE MIB), Russia (IMOEX), Spain (IBEX 35), U.K. (FTSE 100), U.S.A. (DOW JONES INDUSTRIAL AVERAGE). We have gathered the indices of stock per country from 2 March to 23rd June, collected from official website of respective stocks. In order to collect data, we had to inculcate the fundamental lessons of Statistics. R-software aided us to plot the curves of stock values providing an ease to master our project. We also formulated a Python 3.7 language program code to solidify analysis on various aspects of economy of the countries and comparison between these aspects.

Latent fingerprints (LFPs) are the major physical evidences for the identification of individuals during crime spot investigation. Till date, numerous methods were followed to visualize LFPs. However, simple, accurate, and cost-effective method has wide scope in advanced forensic field. In our work, Ca2SiO4:Dy3+ nanopowders (NPs) were fabricated via solution combustion route. The optimized sample was employed for the visualization of overlapped LFPs by the cost effective powder dusting method. The obtained results reveals the complete three levels of ridge characteristics with high sensitivity, reproducibility, selectivity, and reliability on various complex surfaces. The photoluminescence (PL) spectra consist of intense peaks at ∼ 480 and 574 nm owing to 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 4f transitions of Dy3+ ions, respectively. The photometric properties confirm that the samples exhibit intense white emission with high color purity. Therefore, the prepared NPs could be a definitive choice as an advanced luminescent NPs for forensic, solid state lighting and portable FED devices.

Additive manufacturing (AM) is gaining attention as an alternative to traditional manufacturing processes. Of the available AM methods, material extrusion (ME) AM is predominant. High-quality ME AM demands accurate synchronization between positioning (motion) control and extrusion control, as poor synchronization leads to printing defects like over- and under-extrusion. Typically, extrusion control in ME AM is achieved via feedforward (FF) control techniques due to difficulties in sensing extrusion rate in real-time for feedback control. However, existing FF extrusion control techniques rely on simple linear models to control the highly nonlinear extrusion process, leading to quality issues like over- and under-extrusion. This paper presents two FF control strategies for mitigating over- and under-extrusion defects in ME AM. The first strategy uses a standard linear model of extrusion system but applies it to FF motion control rather than FF extrusion control. This has the net effect of synchronizing motion and extrusion control while avoiding some nonlinearities associated with the extrusion process. In the second approach, an empirical nonlinear model of the extrusion process is developed and adopted for the design of a nonlinear FF extrusion controller. Both approaches were validated experimentally on a fused filament fabrication (FFF) 3D printer, and respectively demonstrated up to 40.45% and 35.98% improvement in deposition accuracy (i.e., reduced over- and under-extrusion) compared to a standard FF extrusion control approach typically used in the literature. In addition, the proposed nonlinear FF controller was shown to be more versatile and lead to faster ME AM compared to the proposed linear FF motion control approach. A practical application of the proposed techniques for improving the quality of a variable-width pattern printed using a new concept of continuously varied extrusion was demonstrated.

Machine tool feed drives are often subject to variable-frequency disturbance (cutting) forces due to varying spindle speeds or cutting tools. A proxy-based control allocation method has been proposed for energy optimal control of over-actuated systems (i.e., systems with more actuators than the number of outputs to be controlled). It has been applied to an over-actuated hybrid feed drive, consisting of a linear motor drive coupled to a screw drive, and its effectiveness has been demonstrated under fixed-frequency disturbance forces. This paper discusses the fundamental limit of the fixed-frequency approach and extends the proxy-based control allocation method to account for variable-frequency disturbance forces via a linear parameter-varying formulation. The controller gains are optimized using linear matrix inequality and scheduled as a function of disturbance frequency. Significant improvements in energy efficiency are demonstrated in simulations and experiments using the proposed gain-scheduling approach compared to the existing fixed-frequency approach.

The Photoconductance Decay (PCD) method in a standard version allows determination of the bulk properties of semiconductors but is not suitable for evaluation of the surface and near-surface region of the wafer during processing. This experiment is concerned with PCD measurements devised specifically for the purpose of electrical probing using temporary contacts of the near-surface (ns-PCD) region of semiconductor substrates, including thin films. The method is tested through the measurements of the single-crystal, indirect bandgap elemental semiconductor wafers (Si and Ge), as well as selected direct bandgap compound semiconductor wafers (GaAs and InP). In the former case, surface properties of the material tested are altered in a controlled fashion and the PCD response to the surface alteration, in terms of the minority carrier lifetime, is measured. In the case of all substrates studied, a direct correlation between carrier lifetime measured using PCD and the condition of the wafer surface was observed. Furthermore, the ns-PCD method was proven very effective in measuring minority carrier lifetime at the semiconductor-dielectric interface without having to form MOS test structures. The results obtained suggest that the modified PCD method employing temporary contacts to the measured surface can be used to monitor the condition of semiconductor surfaces during device processing.

Knowledge of residence time distribution (RTD), mean residence time (MRT) and degree of axial mixing of solid phase is required for efficient operation of coal gasification process. Radiotracer technique was used to measure the RTD of coal particles in a pilot-scale fluidized bed gasifier (FBG). Two different radiotracers i.e. lanthanum-140 and gold-198 labeled coal particles (100 gm) were independently used as radiotracers. The radiotracer was instantaneously injected into the coal feed line and monitored at the ash extraction line at the bottom and gas outlet at the top of the gasifier using collimated scintillation detectors. The measured RTD data were treated and MRTs of coal/ash particles were determined. The treated data were simulated using tanks-in-series model. The simulation of RTD data indicated good degree of mixing with small fraction of the feed material bypassing/short-circuiting from the bottom of the gasifier. The results of the investigation were found useful for optimizing the design and operation of the FBG, and scale-up of the gasification process.

This paper describes novel pseudo-online built-in self-test based techniques for detecting and locating multiple faults in lookup tables (LUTs), interconnects and dedicated clock lines of field programmable gate arrays (FPGAs). The techniques use the partial reconfiguration capabilities of modern FPGAs. The methods proposed in this paper find extensive applications in safety critical systems like space probes, which comprises of several subcircuits mapped onto the FPGA and employs online checkers to report misbehaviour of any of these subcircuits. When an online checker reports misbehaviour of one such subcircuit, the methods proposed in this paper attempt to detect and locate the faults, if any, within the faulty subcircuit without shutting down the other subcircuits. The methods presented in the paper preserve the routing structure of the configured application in-place. Experimentally, it is shown that the proposed methods provide good fault-coverage in identifying faults in LUTs, interconnects and dedicated clock lines. ? 2004 Elsevier B.V. All rights reserved.

In recent years some of the models for Economic Lot Scheduling Problem (ELSP) have been extended to incorporate Just-in-Time (JIT) concepts, by allowing setup costs, setup times and capacity, to be decision variables. All these models result in some forms of cyclic schedules. Hall (1988) proposes “cyclic scheduling for improvement” as a central theme under Just-in-Time and recommends a continual “cycle time analysis for improvement”. This paper presents expanded economic lot scheduling models based on Common Cycle Policy under the framework of “cycle time analysis for improvement”, and proposes a step-by-step procedure for such an analysis, using the various models. The procedure is illustrated with a numerical example.

Numerical control (NC) systems are widely used in industry today, especially in the metal working industry. In developing countries, many industries are introducing NC machines and the economics of the change assume great significance. In some cases, even conventional machines (automatic mass production or transfer line machines) are good enough. Hence the decision of machining a component through an NC machine is in the hands of management. This warrants a direct and simple approach to decision making for selecting the more economical of the two machining methods. This paper attempts to arrive at a yardstick, termed the complexity index , used for deciding whether the component should be routed through the conventional machine or the NC machine. A rigorous and quantitative approach of discriminant analysis is adopted for various manufacturing components to obtain the discriminant function. The complexity index for a manufacturing component is taken to be its discriminant score which is used for assigning the components either to the conventional or to the NC machines. Statistical tests of significance of such a classification procedure are performed. An acceptance level for each group (conventional and NC groups) is calculated (based on the mean score of each group) to determine the minimum complexity index for arriving at the decision rule. In this paper, the approach is presented with the aid of a case study.

We discuss the use of a pair of oxen to generate electricity for rural households.

A group of 306 spare parts items in a transport organisation are classified into nine subgroups, based on multiple criteria. Each subgroup is assigned a specified service level under constraints. The inventory system total variable cost is evaluated and plotted against weighted service level for different valid combinations of service levels, chosen from accountably infinite possible combinations by an extreme value methodology suggested in this paper. The results indicate the existence of a number of local minima and a global minimum for the total variable cost curve. Also, the total variable cost is seen to be bounded in a region yielding a minimum cost curve. The identification of this global minimum cost curve is a pointer to effective minimum cost inventory management of groups of spare parts.