Cloning and prokaryotic expression of the globular head domain of hemagglutinin antigen (HA1) of influenza A (H3N2) virus in Escherichia coli and Bacillus subtilis

Background: The influenza virus hemagglutinin is the major surface protein of the influenza A virus which is composed of HA1 and HA2 subunits. HA1 has an important role in binding of virus to cells and designing neutralizing antibodies. Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) both are known as the most useful prokaryotic hosts to express recombinant proteins. The aim of this study was to clone and express recombinant HA1protein in E. coli and B. subtilis bacteria.Materials and Methods: HA1 gene was cloned into pET-28a vector and pHT43 shuttle vector and then, both transformed to E. coli. The recombinant plasmids were extracted and then transformed into the BL21 and WB600 as expressing hosts. After induction with isopropyl-β-d-thiogalactoside (IPTG), expressed recombinant protein was analyzed by SDS-PAGE. Finally, the expressed protein was confirmed by the Western blot.Results: HA1 gene was cloned into pET-28a vector and pHT43 shuttle vector and then, both transformed to E. coli.The recombinant plasmids were extracted and then transformed into the BL21 and WB600 as expressing hosts. After induction with isopropyl-β-d-thiogalactoside (IPTG), expressed recombinant protein was analyzed by SDS-PAGE. Finally, the expressed protein was confirmed by the Western blot.Conclusion: This study demonstrated a strategy for production and purification of recombinant protein in large scale to test as vaccine candidate against influenza and it’s potentially immunogenicity be assessed in animal models

Secular Trend of Birth Height and Weight in a Population of Iranian Neonates during 1991 and 2011

Background: The secular trend in growth is a well-documented and recurrent phenomenon in many developed and developing countries. In this study, we examined the secular trends in birth length and weight among Iranian neonates.Methods: This cross-sectional population-based survey was conducted between 1991 and 2011. Using a two-stage stratified cluster sampling, the birth weights and heights of neonates born in Shahroud, Iran were studied using health records from different households. The mean birth weights and heights for neonates were calculated every year. Secular trends were analyzed using linear regression models and joinpoint regression.Results: A random sample of 11,165 neonates was evaluated, and the mean birth weight of neonates during the investigation period was calculated. The mean birth weight changed from 3232.1±444.1 g in 1991 to 3204.1±436.9 g in 2011, and the mean birth height changed from 49.5±2.2 cm to 49.3±1.9 cm. The mean birth weights and heights between 1991 and 2011 were not significantly different; however, the birth weight increased by 6.75 g annually between 2000 and 2011 (P < 0.021), and the mean birth height increased by 0.03 cm annually between 2003–2011 and 1991–2003 (P = 0.009).Conclusions: The mean birth height and weight of neonates in Shahroud did not change significantly from 1991 to 2011; however, we found a significant improvement after 2000

Secular Trend of Birth Height and Weight in a Population of Iranian Neonates during 1991 and 2011

Background: The secular trend in growth is a well-documented and recurrent phenomenon in many developed and developing countries. In this study, we examined the secular trends in birth length and weight among Iranian neonates.Methods: This cross-sectional population-based survey was conducted between 1991 and 2011. Using a two-stage stratified cluster sampling, the birth weights and heights of neonates born in Shahroud, Iran were studied using health records from different households. The mean birth weights and heights for neonates were calculated every year. Secular trends were analyzed using linear regression models and joinpoint regression.Results: A random sample of 11,165 neonates was evaluated, and the mean birth weight of neonates during the investigation period was calculated. The mean birth weight changed from 3232.1±444.1 g in 1991 to 3204.1±436.9 g in 2011, and the mean birth height changed from 49.5±2.2 cm to 49.3±1.9 cm. The mean birth weights and heights between 1991 and 2011 were not significantly different; however, the birth weight increased by 6.75 g annually between 2000 and 2011 (P < 0.021), and the mean birth height increased by 0.03 cm annually between 2003–2011 and 1991–2003 (P = 0.009).Conclusions: The mean birth height and weight of neonates in Shahroud did not change significantly from 1991 to 2011; however, we found a significant improvement after 2000

Adaptive MAC protocol for wireless sensor networks in periodic data collection applications

In this paper, we propose a new medium access control (MAC) protocol for wireless sensor networks for environmental monitoring applications. The proposed MAC scheme is specifically designed for wireless sensor networks which have periodic traffic with different sampling rates. In our protocol design, only sink can start and maintain synchronization and also determine the time schedule for all other nodes in the network. We discuss the design of TA-PDC-MAC protocol and provide a comparison with the previous PDC-MAC protocol through simulation. Under different traffic generation rate, our protocol outperforms the previous one in terms of energy consumption, packet loss rate and packet delay

Adaptive data collection algorithm for wireless sensor networks

Periodical Data collection from unreachable remote terrain and then transmit information to a base station is one of the targeted application of sensor networks. The energy restriction of battery powered sensor nodes is a big challenge for this network as it is difficult or in some cases not feasible to change the power supply of motes. Therefore, in order to keep the networks operating for long time, efficient utilization of energy is considered with highest priority. In this paper we propose TA-PDC-MAC protocol - a traffic adaptive periodic data collection MAC which is designed in a TDMA fashion. This design is efficient in the ways that it assigns the time slots for nodes’ activity due to their sampling rates in a collision avoidance manner. This ensures minimal consumption of network energy and makes a longer network lifetime, as well as it provides small end-to-end delay and packet loss ratio. Simulation results show that our protocol demonstrates up to 35% better performance than that of most recent protocol that proposed for this kind of application, in respect of energy consumption. Comparative analysis and simulation show that TA-PDC-MAC considerably gives a good compromise between energy efficiency and latency and packet loss rate

Trade-off between energy consumption and target delay for wireless sensor network

Wireless sensor networks (WSN) consists of unattended sensors with limited storage, energy (battery power) and computational and communication capabilities. Since battery power is the most crucial resource for sensor nodes and delay time is a critical metric for certain WSN applications, data diffusion between source sensors and sink should be done in an energy efficient and timely manner. We characterize the trade off between the energy consumption and source to sink delay in order to extend the operation of individual sensors and hence increase the lifetime of the WSN. To achieve this goal, the transmission range of sensors is first decomposes into certain ranges based on a minimal distance between consecutive forwarding sensors and then classifies these ranges due to Degree of Interest. It is also shown that the use of sensor nodes which lie on or closely to the shortest path between the source and the sink helps minimize these two metrics

Energy efficiency in MAC 802.15.4 for wireless sensor networks

Recent technological advances in sensors, low power integrated circuits, and wireless communications have enabled the design of low-cost, lightweight, and intelligent physiological sensor nodes. The IEEE 802.15.4 is a new wireless personal area network designed for wireless monitoring and control applications. The fast progress of research on energy efficiency in wireless sensor networks, and the need to compare with the solutions adopted in the standards motivates the need for this work. In the analysis presented, the star network configuration of 802.15.4 standard at 868 MHz is considered for a Zigbee network. In this paper, we analyze the active duration of the superframe and entered the sleep mode status inside this period. It happens when sensors do not have any data to send. The nonpersistent CSMA uses the adaptive backoff exponent. This method helps the network to be reliable under traffic changes due to save the energy consumption. The introduction of sleep state has shown incredible reduction of the power consumption in all network load changes

Autophagy induction regulates influenza virus replication in a time-dependent manner

Autophagy plays a key role in host defence responses against microbial infections by promoting degradation of pathogens and participating in acquired immunity. The interaction between autophagy and viruses is complex, and this pathway is hijacked by several viruses. Influenza virus (IV) interferes with autophagy through its replication and increases the accumulation of autophagosomes by blocking lysosome fusion. Thus, autophagy could be an effective area for antiviral research.Methodology. In this study, we evaluated the effect of autophagy on IV replication. Two cell lines were transfected with Beclin-1 expression plasmid before (prophylactic approach) and after (therapeutic approach) IV inoculation.Results/Key findings. Beclin-1 overexpression in the cells infected by virus induced autophagy to 26 %. The log10haemagglutinin titre and TCID50 (tissue culture infective dose giving 50 % infection) of replicating virus were measured at 24 and 48 h post-infection. In the prophylactic approach, the virus titre was enhanced significantly at 24 h post-infection (P≤0.01), but it was not significantly different from the control at 48 h post-infection. In contrast, the therapeutic approach of autophagy induction inhibited the virus replication at 24 and 48 h post-infection. Additionally, we showed that inhibition of autophagy using 3-methyladenine reduced viral replication. Conclusion. This study revealed that the virus (H1N1) titre was controlled in a time-dependent manner following autophagy induction in host cells. Manipulation of autophagy during the IV life cycle can be targeted both for antiviral aims and for increasing viral yield for virus production

Evidence Supporting Diagnostic Value of Liver Imaging Reporting and Data System for CT- and MR Imaging-based Diagnosis of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

Background: Based on the Liver Imaging Data and Reporting System (LI-RADS) guidelines, Hepatocellular Carcinoma (HCC) can be diagnosed using imaging criteria in patients at risk of HCC.Objective: This study aimed to assess the diagnostic value of LI-RADS in high-risk patients with HCC.Material and Methods: This systematic review is conducted on international databases, including Google Scholar, Web of Science, PubMed, Embase, PROQUEST, and Cochrane Library, with appropriate keywords. Using the binomial distribution formula, the variance of each study was calculated, and all the data were analyzed using STATA version 16. The pooled sensitivity and specificity were determined using a random-effects meta-analysis approach. Also, we used the chi-squared test and I2 index to calculate heterogeneity among studies, and Funnel plots and Egger tests were used for evaluating publication bias.Results: The pooled sensitivity was estimated at 0.80 (95% CI: 0.76-0.84). According to different types of Liver Imaging Reporting and Data Systems (LI-RADS), the highest pooled sensitivity was in version 2018 (0.83 (95% CI: 0.79-0.87) (I2: 80.6%, P of chi 2 test for heterogeneity: <0.001 and T2: 0.001). The pooled specificity was estimated as 0.89 (95% CI: 0.87-0.92). According to different types of LI-RADS, the highest pooled specificity was in version 2014 (93.0 (95% CI: 89.0-96.0) (I2: 81.7%, P of chi 2 test for heterogeneity: <0.001 and T2: 0.001).  Conclusion: LI-RADS can assist radiologists in achieving the required sensitivity and specificity in high-risk patients suspected to have HCC. Therefore, this strategy can serve as an appropriate tool for identifying HCC