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In this paper, we present a solution to the SLAM problem that enables a mobile robot to create visual maps of a given environment. A visual map is formed by a set of significant points that are detected in a three-dimensional space. Those points are extracted from images taken from the environment. In this work, the significant points extracted are used as landmarks in the environment that can be detected from a set of poses in the environment, thus allowing the localization of the robot. We suppose that the robot is equipped with a stereo vision system that enables it to obtain relative measurements to the landmarks while it navigates along the environment. In the work presented here, the map is formed by a set of landmarks, each one described by a three-dimensional position in space referred to a global reference system. In addition, each landmark is associated with a visual descriptor that partially differentiates it from others. The solution presented here is based on a Rao-Blackwellised particle filter and allows to simultaneously estimate the path followed by the robot and the most probable map of the environment. The algorithm is validated with results in simulation, supposing that the vehicle possesses a noisy odometry and is able to obtain measurements to the landmarks in the environment, also corrupted with Gaussian noise. The main contribution of the paper is the assessment in the parameters of the filter. We propose the most adequate configuration of the filter that enables to solve the SLAM problem. For this purpose we used typical odometry a stereo vision noise models, commonly found in mobile robot applications. [ABSTRACT FROM PUBLISHER]

Background: Head and Neck Squamous Cell Carcinomas (HNSCCs) are heterogeneous malignancies that comprise 90% of the head and neck cancers. HNSCCs originate from the mucosal lining epithelium of the upper aerodigestive tract. Cancer stem cells (CSCs) that generate HNSCCs with the CD44, CD133, and ALDH phenotype and are resistant to radiotherapy and chemotherapy. In the current, the quantitative alteration in CD44 and CD133 expression pre- and post-tumor resection and radiotherapy was evaluated in HNSCC patients. Moreover, the alterations in the expression of Bax, Bak, Bcl-2, ALDH, and PTEN genes were measured. Materials and Methods: Flow cytometry was performed to evaluate the alterations in CD44 and CD133 surface markers pre- and posttumor resection and radiotherapy. Quantitative real-time RT-PCR (qRT-PCR) was conducted to investigate the mRNA expression levels of Bax, Bak, Bcl-2, ALDH, and PTEN. Results: The results indicated that the cancer stem cell CD44 surface marker significantly decreased after tumor resection and radiotherapy in HNSCC cases, while the decrease was insignificant for CD133 marker expression. mRNA expression level of Bcl-2 and ALDH was increased, but Bax and Bak gene expressions were reduced significantly Conclusion: The results also indicated that the expression of CD44 significantly decreased after tumor resection and radiotherapy. The upregulation of mRNA level of Bcl-2 and ALDH, and the downregulation of Bax and Bak gene expression were noted in these cases when compared to the healthy control group., Competing Interests: Authors declare that they do not have any conflict of interest., (Copyright © 2024 Tehran University of Medical Sciences.)

Head and neck cancers are highly prevalent worldwide. Most of these lesions are diagnosed in the advanced stages of the disease. Thus, they do not often have a good long-term prognosis. Like other cancer types, head and neck cancers are managed by surgery, radiotherapy, and chemotherapy. Despite significant advances in the treatment of oral squamous cell carcinoma (OSCC), physicians encounter several challenges in the course of treatment. Various mechanisms mediate the clinical responses of a certain cancer to medications. Thus, efficient treatment planning requires adequate knowledge about the genes involved in drug resistance and the evaluation of the frequency percentage of resistance. Several studies have evaluated the causes and frequency percentages of 5-fluorouracil (5-FU) and cisplatin resistance. In this systematic review, all the relevant articles published until November 30, 2019, were retrieved from the Scopus, Embase, Medline, ISI, Web of Science, and Cochrane databases using certain MeSH and EMTTree keywords. A total of 2164 articles were retrieved of which, 18 were included in the review since they had reported the frequency percentages of drug resistance. Of all, 10 articles had evaluated cisplatin (1317 samples). A meta-analysis of the results revealed a frequency of 33% for cisplatin resistance. Eight studies had evaluated 5-FU (476 samples). A meta-analysis of the results revealed a frequency of 40.2 % for 5-FU resistance. Overcoming cisplatin resistance or 5-FU resistance can significantly enhance recovery in advanced HNSCC. Attempts should be made to eliminate the cause and use multi-drug regimens to increase the success rate of treatment., (© 2021 The Author(s).)

A study was carried out about the general features of myocutaneous flap taken from the pectoralis major muscle. This flap is employed in the reconstructive step after ablative surgery for carcinomata of the oropharynx, tongue, floor of the mouth, hypopharynx and other growths of the neck with skin involvement. The AA. review their 31 cases results, both cosmetic and functionally, and consider that the end-condition is favorable and hopeful in the whole.