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Background: The Covid-19 epidemic has brought about severe consequences to human lives and societies worldwide. While it is undeniable that vaccines bring great benefits in fighting Covid-19, there are still concerns regarding complications from these urgently circulated vaccines, one of them being blood coagulation. Cauda equina is a rare acute spinal pathology capable of leaving extreme sequelae and even less common when caused by intradural blood-clotting. Case presentation: We would like to introduce a 52-year-old male patient with no medical history. 10 days after receiving his second AstraZeneca dose suddenly experienced paralysis in his left leg, urinary retention, and acute lower back pain. The patient underwent treatment at a local hospital for 07 days and was later transferred to our hospital with no improvements. He received emergency laminectomy of L2, remove intradural blood-clotting, and decompression. Although no pain was retained post-suregery and the patient attended physiotherapy, there was no significant progress in urinary functions as well as his left leg mobility. Discussion and conclusion: Cauda equina due to intradural blood-clotting is rare but, just like other conditions, requires urgent treatment or will otherwise leave severe consequences. Though vaccines’ benefits far outweigh their risks, monitorial and preventive measures should be taken to treat postinoculation blood-clotting.

A major challenge in wireless underground sensor networks is the signal attenuation originated from multi-environment transmission between underground sensor nodes and the above-ground base station. To overcome this issue, an efficient approach is deploying a set of relay nodes aboveground, thereby reducing transmission loss by shortening transmitting distance. However, this introduces several new challenges, including load balancing and transmission loss minimization. This paper tackles the problem of deploying relay nodes to reduce transmission loss under a load balancing constraint by proposing two approximation algorithms. The first algorithm is inspired by Beam Search, combined with a new selection scheme based on Boltzmann distribution. The second algorithm aims to further improve the solutions obtained by the former by reducing the transmission loss. We observe that we can find an optimal assignment between sensor nodes and a set of the chosen relay in polynomial time by reformulating the part of the problem as a bipartite matching problem with minimum cost. Experimental results indicate that the proposed methods perform better than the other existing ones in most of our test instances while reducing the execution time.

Background: Percutaneous vertebroplasty (PV) has become an important minimally invasive surgical technique for vertebral compression fractures. However, indications for PV in these cases due to trauma had many rivals and unclearly. These complications, especially cement leakage still common, has many severe consequent. Object and method research: A 60-years-old man, who underwent vertebroplasty in low medical level. He had complete paralised of two leg, urine retention, and severe low back pain. We examined clinical signs, imaging, find and compared with literatures. Case presentation and discussion: We present a case, 60-years-old man, had labor accident, after that he could returned to state of normality. At the second day, he went to local hospital, had diagnosis: compression fractures of L1-L2. He underwent percutaneous vertebroplasty of L1-2 under local anesthesia. Post-operative, he had complete paralised of two leg, urine retention, and severe low back pain. He had exmined again, MRI and took second surgery to removed part of cement leakage. After the second surgery, radiological showed they had complete removed cement leakage, but the patient’s recovery was uneventful and stable. The patient was hospitalized at our instituation after 03 day with complaints of severe low back pain, urine retention and complete paralised of two leg. Conclusion: This is basic technique, widely and rewarding; also has many severe incident, complications. Consequently, we suggest that this technique have to perform in right indications, in the modern medical centre and fully trained surgeon.

In wireless sensor networks, the majority of data transmitted by sensor nodes is repeated over and over, and performing processes on them in many cases leads to increased power consumption and reduced network lifetime. Data aggregation is one of the techniques in reducing redundancy and improving energy efficiency; it also increases the lifespan of wireless sensor networks. In this paper, we address the issues of constructing the data aggregation tree that minimizes the total energy cost of data transmissions for two types of networks: without relay nodes and using relay nodes. Traditionally, evolutionary algorithms focus on constructing data aggregation trees for either without relay node networks or using relay nodes networks. Therefore, we propose Potential individuals based Multi-factorial Evolutionary Algorithm (P-MFEA) to solve both issues simultaneously. The proposed scheme shows improved performance in terms of energy consumption.

Wireless sensor networks consist of many sensor nodes with limited resources and computing capability. Thus, managing energy consumption to prolong network lifetime is a critical issue. Several approaches have been proposed to extend the network lifetime, one of which involves deploying relay nodes to transfer data from sensors to the base station. However, the limited number of relay nodes is a challenge that often goes overlooked. This paper examines the problem of optimizing the network lifetime and the number of relay nodes in three-dimensional terrains. A novel algorithm called MOEA/D-LS is proposed with the aim of obtaining a better tradeoff between two objectives. The algorithm is a hybridization between multiobjective evolutionary algorithm based on decomposition, and a special local search to optimize the former’s subproblems. Simulation results on 3D datasets show that the proposed algorithm has a significantly better performance compared with existing algorithms on all measured metrics.

Wireless Underground Sensor Networks (WUSNs) have received attention in the past years because of their popularity and cost-effectiveness when they are used in many practical fields such as military applications, environmental applications, and home applications. In WUSNs, sensors are deployed with limited power, once their power is out of, the sensors are ineffectual. The extension of the network’s lifetime is a critical issue in WUSNs, making it a topic of much interest in research. Several approaches have been proposed to keep the sensor nodes active, one of which is deploying relay nodes above ground to transfer data from sensor nodes to the base station. However, this method has faced issues, such as balancing the load of relay nodes and the increased transmission loss between relay nodes and sensor nodes. This paper addresses this concern and proposes two heuristics named Beam Genitor Search and Connection Swap for the relay node placement problem to guarantee load balance among relay nodes and maximize network lifetime. Our experiments show that the proposed methods result in significantly better quality solutions (longer network lifetime) for the problem when compared to the existing methods.

In this paper, the design of a multi-band circularly polarized stacked microstrip antenna for low earth orbit (LEO) satellite communications and precise global positioning system (GPS) is proposed. The microstrip antenna for multi-band frequency is constructed by stacking two different square patches and circular polarization is obtained by different approaches. The top patch has a pair of truncated square corners, and the bottom patch is fed with two pins placed symmetrically on the two main axes. The antenna is designed to operate at L1 (1.575 GHz±12 MHz) and LEO at two frequency ranges uplink (148-150 MHz), downlink (137-139 MHz). All the design details and numerical results will be discussed in this context.