The whole world is going through an unprecedented period during the pandemic of COVID-19. This pandemic has affected all aspects of daily life with far-reaching implications, especially in most aspects of healthcare. Practice of surgery across the globe is in a standstill as of now. When we restart surgical practices across world, we have to bring new protocols and practices in place to combat the transmission. This article discusses the major changes in surgical practice, which need to be brought in. This article is based on scientific information about transmission of virus and experiences of some of the authors from China, a country which successfully dealt with and contained the virus outbreak. © Association of Surgeons of India 2020.Sequential pattern mining (SPM) has been applied in many fields. However, traditional SPM neglects the pattern repetition in sequence. To solve this problem, gap constraint SPM was proposed and can avoid finding too many useless patterns. Nonoverlapping SPM, as a branch of gap constraint SPM, means that any two occurrences cannot use the same sequence letter in the same position as the occurrences. Nonoverlapping SPM can make a balance between efficiency and completeness. The frequent patterns discovered by existing methods normally contain redundant patterns. To reduce redundant patterns and improve the mining performance, this paper adopts the closed pattern mining strategy and proposes a complete algorithm, named Nettree for Nonoverlapping Closed Sequential Pattern (NetNCSP) based on the Nettree structure. NetNCSP is equipped with two key steps, support calculation and closeness determination. A backtracking strategy is employed to calculate the nonoverlapping support of a pattern on the corresponding Nettree, which reduces the time complexity. This paper also proposes three kinds of pruning strategies, inheriting, predicting, and determining.  https://www.selleckchem.com/products/epoxomicin-bu-4061t.html  These pruning strategies are able to find the redundant patterns effectively since the strategies can predict the frequency and closeness of the patterns before the generation of the candidate patterns. Experimental results show that NetNCSP is not only more efficient but can also discover more closed patterns with good compressibility. Furtherly, in biological experiments NetNCSP mines the closed patterns in SARS-CoV-2 and SARS viruses. The results show that the two viruses are of similar pattern composition with different combinations. © 2020 Elsevier B.V. All rights reserved.As is well known, multimedia has been widely used in VoIP and mobile communications. Research on how to establish covert communication channel over the above popular public applications has been flourishing in recent years. This paper tries to present a novel and effective method to construct a covert channel over common compressed speech stream by embedding sense information into it. In our method, after analysing the characteristic features of the excitation pulse positions of the ITU-T G.723.1 and G.729A speech codec, we design a novel and effective covert communication channel by finely modulating the codes of excitation pulse positions of the above two codecs in line with the secret information to be hidden. To improve the embedding capacity of the proposed method, we also use all the odd/even characteristics of pulse code positions to conduct information hiding. To test and verify the proposed approach, experiments are conducted on several different scenarios. Experimental results show that our methods and algorithms perform a higher degree of secrecy and sound information embedding efficacy compared with exiting similar methods. © Springer-Verlag London Ltd., part of Springer Nature 2020.The approach of this timely review considers the current literature that is focused on the interface nanostructure/cell-wall microorganism to understand the annihilation mechanism. Morphological studies use optical and electronic microscopes to determine the physical damage on the cell-wall and the possible cell lysis that confirms the viability and microorganism death. The key parameters of the tailoring the surface of the photoactive nanostructures such as the metal functionalization with bacteriostatic properties, hydrophilicity, textural porosity, morphology and the formation of heterojunction systems, can achieve the effective eradication of the microorganisms under natural conditions, ranging from practical to applications in environment, agriculture, and so on. However, to our knowledge, a comprehensive review of the microorganism/nanomaterial interface approach has rarely been conducted. The final remarks point the ideal photocatalytic way for the effective prevention/eradication of microorganisms, considering the resistance that the microorganism could develop without the appropriate regulatory aspects for human and ecosystem safety. © 2020 Elsevier B.V. All rights reserved.This research develops the notion of operational resilience and investigates its relationship with operational efficiency under differing conditions of operational disruption. Operational resilience is conceptualized as a multi-dimensional construct, consisting of two theoretically distinct components (i.e., disruption absorption and recoverability), which are argued to have unique effects on operational efficiency under varying operational disruption conditions. The study's hypotheses are empirically tested on primary data from a sample of 259 firms in a sub-Saharan African economy. Using structural equation modeling as an analytical tool, the study finds that both disruption absorption and recoverability have positive effects on operational efficiency. Additionally, the study finds that while the effect of disruption absorption on operational efficiency is stronger under conditions of high operational disruption, the effect of recoverability on operational efficiency is stronger under conditions of low operational disruption. A major implication of these findings is that the nature of operational resilience and the disruption circumstances under which it is deployed shape its efficiency value, thus advancing knowledge on the nuances associated with how and when operational resilience influences operational efficiency. © 2020 Published by Elsevier B.V.