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All-dielectric magnetophotonic nanostructures are promising for integrated nanophotonic devices with high resolution and sensitivity, but their design requires computationally demanding electromagnetic simulations evaluated through trial and error. In this paper, we propose a machine-learning approach to accelerate the design of these nanostructures. Using a data set of 12â¯170 samples containing four geometric parameters of the nanostructure and the incidence wavelength, trained neural network and polynomial regression algorithms were capable of predicting the amplitude of the transverse magneto-optical Kerr effect (TMOKE) within a time frame of 10-3 s and mean square error below 4.2%. With this approach, one can readily identify nanostructures suitable for sensing at ultralow analyte concentrations in aqueous solutions. As a proof of principle, we used the machine-learning models to determine the sensitivity (S = |Δθres/Δna|) of a nanophotonic grating, which is competitive with state-of-the-art systems and exhibits a figure of merit of 672 RIU-1. Furthermore, researchers can use the predictions of TMOKE peaks generated by the algorithms to assess the suitability for experimental setups, adding a layer of utility to the machine-learning methodology.
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This study evaluates the performance of large intelligent surface (LIS) technology in the context of a multi-user MIMO mobile communication system (Mu-MIMO) proposed for the sixth generation (6G). LIS employs digitally controlled reflectors to enhance Signal-to-Interference plus Noise Ratio (SINR) and establish line of sight (LoS) connectivity in non-LoS environments, improving transmission security. Analytical expressions are derived to assess LIS performance metrics, including distribution parameters, bit error probability, and secrecy outage probability, considering the presence of eavesdroppers and environmental fading. The study highlights the potential of LIS technology to enhance the confidentiality and reliability of digital communication systems in next-generation networks.
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The authors present a successful case in the conservative treatment of type-III camptodactyly in a patient with Beals-Hecht syndrome. Camptodactyly is a flexion deformity of the proximal interphalangeal (PIP) joint, in the anteroposterior direction, painless and bilateral in 2/3 of the cases. Type-III is the most severe and disabling form, as it usually affects several fingers and is associated with syndromes and other malformations. The case herein reported had the correction achieved with the systematic use of static orthoses started at 7 months of age and completed after 23 and a half months of the intervention.
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Objective To analyze the clinicoepidemiological characteristics of pubalgia in athletes and to define the epidemiological profile of patients complaining of lower abdomen and groin pain at a specialized center. Methodology We conducted a retrospective study based on a case series to evaluate the epidemiological profile of 245 athletes with pubalgia reported in their medical records from October 2015 to February 2018. The selected sample underwent a clinical evaluation, and the results were recorded through the application of a questionnaire. Results The sample consisted of 245 patients aged between 14 and 75 years. Soccer and running were the most prevalent sports. Most subjects (58%) trained or played sports 3 or more days a week. After evaluating specific sports movements, symptoms worsened in 24% of the patients when changing direction; in 23%, when kicking; in 22%, during sprints and speed training; in 17%, during long runs; and in 14%, when jumping. Pain during intercourse was reported by 13% of the patients. For most subjects (80%), the inguinal region, the adductor muscles, and the pubis (midline) were the main pain sites. The tests involving adductor contraction against resistance with an extended knee was positive in 77.6% of the patients, and the one involving simultaneous hip and abdomen flexion against resistance was positive in 76.7% of the sample. Conclusion The present study has demonstrated the predominance of pubalgia in male patients who play soccer and practice running. In most cases (80%), pain occurred in the inguinal region, the adductor muscles, and the pubis. Confirmation of the clinical diagnosis took more than six months for most patients.
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This study addresses the problem of accurately predicting azimuth and elevation angles of signals impinging on an antenna array employing Machine Learning (ML). Using the information obtained at a receiving system when a transmitter's signal hits it, a Decision Tree (DT) model is trained to estimate azimuth and elevation angles simultaneously. Simulation results demonstrate the robustness of the proposed DT-based method, showcasing its ability to predict the Direction of Arrival (DOA) in diverse conditions beyond the ones present in the training dataset, i.e., the results display the model's generalization capability. Additionally, the comparative analysis reveals that DT-based DOA estimation outperforms the state-of-the-art MUltiple SIgnal Classification (MUSIC) algorithm. Our results demonstrate an average reduction of over 90% in the prediction error and 50% in the prediction time achieved by our proposal when compared to the MUSIC algorithm. These results establish DTs as competitive alternatives for DOA estimation in signal reception systems.
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ABSTRACT Objective: To describe the technique of transurethral harvesting of bladder mucosal graft using the Holmium:YAG (Ho-YAG) laser and describe the preliminary results from 7 cases where this graft was used for urethroplasty. Materials and Methods: We performed a single-stage dorsal onlay urethroplasty using bladder mucosal graft in 7 patients with anterior urethral stricture. Transurethral harvesting was performed with the Ho-YAG laser. We performed a prospective and descriptive analysis with uroflowmetry performed at 30, 90 and 180 days after surgery and applied the PROM translated into Portuguese before and 6 months after urethroplasty. Results: Seven patients were included, 2 (28.5%) with penile urethral stricture, and 5 (71.5%) with bulbar urethral stricture. Mean stricture length was 50mm (range 35-60mm). Stricture etiology was trauma in 3 (42.9%) patients, iatrogenic in 1 (14.3%) patient, and idiopathic in 3 (42.9%) patients. Two patients (28.6%) had previously undergone ventral buccal mucosa urethroplasty. Mean bladder mucosal graft length was 52.86mm (± 13.801), and mean harvest time was 46.43min (± 14.639). Dorsal onlay urethroplasty using bladder mucosa was successfully completed in 5 patients (71.4%). Two patients (28.6%) couldn't have the procedure completed using bladder mucosa, one due to thermal damage of the graft during harvesting, and one due to insufficient graft length. In both cases the procedure was completed using buccal mucosa. Two patients (28.6%) experienced minor hematuria between the twelfth and eighteenth postoperative day, but neither required hospitalization and/or additional procedures. All patients achieved normalization of peak flow, and this was maintained throughout the follow-up period. Mean peak flow was 17.8 ml/s (± 3.271) at 30 days, 20.6 ml/s (± 5.413) at 90 days, and 19.6 ml/s (± 8.019) 180 days. Mean IPSS score decreased from 19.3 to 5.4. Similar improvements were also seen in the ICIQ-MLUTS Score (a mean drop from 3.8 to 2.0) and Peeling's Voiding Picture Score (a mean drop from 4.0 to 2.2). Quality of Life improved post urethroplasty, with increases in EQ-5D (from 0.6371 to 0.7285) and EQ-VAS (from 58.0 to 84.0). Conclusion: Transurethral harvesting of bladder mucosa using the Holmium laser (Ho-YAG) is feasible and reproducible. Our preliminary experience suggests that bladder mucosa grafts achieve comparable results to other grafts when used for dorsal onlay urethroplasty. Further research is needed to confirm these results.
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Abstract Objective To analyze the clinicoepidemiological characteristics of pubalgia in athletes and to define the epidemiological profile of patients complaining of lower abdomen and groin pain at a specialized center. Methodology We conducted a retrospective study based on a case series to evaluate the epidemiological profile of 245 athletes with pubalgia reported in their medical records from October 2015 to February 2018. The selected sample underwent a clinical evaluation, and the results were recorded through the application of a questionnaire. Results The sample consisted of 245 patients aged between 14 and 75 years. Soccer and running were the most prevalent sports. Most subjects (58%) trained or played sports 3 or more days a week. After evaluating specific sports movements, symptoms worsened in 24% of the patients when changing direction; in 23%, when kicking; in 22%, during sprints and speed training; in 17%, during long runs; and in 14%, when jumping. Pain during intercourse was reported by 13% of the patients. For most subjects (80%), the inguinal region, the adductor muscles, and the pubis (midline) were the main pain sites. The tests involving adductor contraction against resistance with an extended knee was positive in 77.6% of the patients, and the one involving simultaneous hip and abdomen flexion against resistance was positive in 76.7% of the sample. Conclusion The present study has demonstrated the predominance of pubalgia in male patients who play soccer and practice running. In most cases (80%), pain occurred in the inguinal region, the adductor muscles, and the pubis. Confirmation of the clinical diagnosis took more than six months for most patients.
Resumo Objetivo Analisar as características clínico-epidemiológicas da pubalgia do atleta, e definir o perfil epidemiológico dos pacientes com queixa de dor na região baixa do abdômen e virilha avaliados em um centro especializado. Metodologia Realizou-se um estudo retrospectivo de uma série de casos, no qual se avaliou o perfil epidemiológico de 245 pacientes esportistas com pubalgia, registrados em prontuário, entre outubro de 2015 e fevereiro de 2018. A amostra selecionada foi submetida a uma avaliação clínica, e os resultados foram documentados a partir da aplicação de um questionário. Resultados A amostra estudada foi de 245 pacientes com idades que variavam entre 14 e 75 anos. O futebol e a corrida foram os esportes mais prevalentes, e 58% treinavam ou praticavam esporte 3 ou mais dias por semana. Após a avaliação dos movimentos esportivos específicos, foi observada piora dos sintomas em 24% com a troca de direção; em 23%, nos chutes; em 22%, nos sprints e treinos de velocidade; em 17%, nas corridas longas; e em 14%, nos saltos. Dor durante o ato sexual foi relatado em 13% dos pacientes. A maior parte dos pacientes (80%) relatou que a região inguinal, os adutores e o púbis (linha média) eram os principais sítios da dor. O teste de contração dos adutores contra resistência com joelho em extensão foi positivo em 77,6% dos pacientes avaliados, e o teste de Flexão simultânea do Quadril + Abdômen contra resistência foi positivo em 76.7% dos pacientes. Conclusão O presente estudo demonstrou o predomínio dessa lesão nos pacientes do sexo masculino praticantes de futebol e de corrida. A dor, na maioria dos casos (80%), estava presente na região inguinal, nos adutores e no púbis. A maioria dos pacientes demorou mais de seis meses para ter o diagnóstico clínico confirmado.
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Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Traumatismos em Atletas/epidemiologia , Esportes , Hérnia InguinalRESUMO
Modern wireless communication systems rely heavily on multiple antennas and their corresponding signal processing to achieve optimal performance. As 5G and 6G networks emerge, beamforming and beam management become increasingly complex due to factors such as user mobility, a higher number of antennas, and the adoption of elevated frequencies. Artificial intelligence, specifically machine learning, offers a valuable solution to mitigate this complexity and minimize the overhead associated with beam management and selection, all while maintaining system performance. Despite growing interest in AI-assisted beamforming, beam management, and selection, a comprehensive collection of datasets and benchmarks remains scarce. Furthermore, identifying the most-suitable algorithm for a given scenario remains an open question. This article aimed to provide an exhaustive survey of the subject, highlighting unresolved issues and potential directions for future developments. The discussion encompasses the architectural and signal processing aspects of contemporary beamforming, beam management, and selection. In addition, the article examines various communication challenges and their respective solutions, considering approaches such as centralized/decentralized, supervised/unsupervised, semi-supervised, active, federated, and reinforcement learning.
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OBJECTIVE: To describe the technique of transurethral harvesting of bladder mucosal graft using the Holmium:YAG (Ho-YAG) laser and describe the preliminary results from 7 cases where this graft was used for urethroplasty. MATERIALS AND METHODS: We performed a single-stage dorsal onlay urethroplasty using bladder mucosal graft in 7 patients with anterior urethral stricture. Transurethral harvesting was performed with the Ho-YAG laser. We performed a prospective and descriptive analysis with uroflowmetry performed at 30, 90 and 180 days after surgery and applied the PROM translated into Portuguese before and 6 months after urethroplasty. RESULTS: Seven patients were included, 2 (28.5%) with penile urethral stricture, and 5 (71.5%) with bulbar urethral stricture. Mean stricture length was 50mm (range 35-60mm). Stricture etiology was trauma in 3 (42.9%) patients, iatrogenic in 1 (14.3%) patient, and idiopathic in 3 (42.9%) patients. Two patients (28.6%) had previously undergone ventral buccal mucosa urethroplasty. Mean bladder mucosal graft length was 52.86mm (± 13.801), and mean harvest time was 46.43min (± 14.639). Dorsal onlay urethroplasty using bladder mucosa was successfully completed in 5 patients (71.4%). Two patients (28.6%) couldn't have the procedure completed using bladder mucosa, one due to thermal damage of the graft during harvesting, and one due to insufficient graft length. In both cases the procedure was completed using buccal mucosa. Two patients (28.6%) experienced minor hematuria between the twelfth and eighteenth postoperative day, but neither required hospitalization and/or additional procedures. All patients achieved normalization of peak flow, and this was maintained throughout the follow-up period. Mean peak flow was 17.8 ml/s (± 3.271) at 30 days, 20.6 ml/s (± 5.413) at 90 days, and 19.6 ml/s (± 8.019) 180 days. Mean IPSS score decreased from 19.3 to 5.4. Similar improvements were also seen in the ICIQ-MLUTS Score (a mean drop from 3.8 to 2.0) and Peeling's Voiding Picture Score (a mean drop from 4.0 to 2.2). Quality of Life improved post urethroplasty, with increases in EQ-5D (from 0.6371 to 0.7285) and EQ-VAS (from 58.0 to 84.0). CONCLUSION: Transurethral harvesting of bladder mucosa using the Holmium laser (Ho-YAG) is feasible and reproducible. Our preliminary experience suggests that bladder mucosa grafts achieve comparable results to other grafts when used for dorsal onlay urethroplasty. Further research is needed to confirm these results.
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Lasers de Estado Sólido , Estreitamento Uretral , Humanos , Masculino , Estreitamento Uretral/cirurgia , Estreitamento Uretral/etiologia , Lasers de Estado Sólido/uso terapêutico , Hólmio , Bexiga Urinária , Constrição Patológica/cirurgia , Resultado do Tratamento , Qualidade de Vida , Estudos Prospectivos , Uretra/cirurgia , Mucosa Bucal/transplante , Procedimentos Cirúrgicos Urológicos Masculinos/métodosRESUMO
The demand for wireless connectivity has grown exponentially over the last years. By 2030 there should be around 17 billion of mobile-connected devices, with monthly data traffic in the order of thousands of exabytes. Although the Fifth Generation (5G) communications systems present far more features than Fourth Generation (4G) systems, they will not be able to serve this growing demand and the requirements of innovative use cases. Therefore, Sixth Generation (6G) Networks are expected to support such massive connectivity and guarantee an increase in performance and quality of service for all users. To deal with such requirements, several technical issues need to be addressed, including novel multiple-antenna technologies. Then, this survey gives a concise review of the main emerging Multiple-Input Multiple-Output (MIMO) technologies for 6G Networks such as massive MIMO (mMIMO), extremely large MIMO (XL-MIMO), Intelligent Reflecting Surfaces (IRS), and Cell-Free mMIMO (CF-mMIMO). Moreover, we present a discussion on how some of the expected key performance indicators (KPIs) of some novel 6G Network use cases can be met with the development of each MIMO technology.
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INTRODUCTION: In Brazil, scorpion stings are recorded in high numbers with an increasing epidemiological situation in most municipalities. In the present study, data between 1998 and 2018 in Americana, São Paulo, were analyzed. METHODS: In total, 4122 records on scorpion stings were georeferenced using a Garmin eTREX 30X global positioning system device, with WGS84 datum projection and Universal Transverse Mercator zone 23S. Multiple Poisson regression was used to explore the relationship between the incidence rates of stings and urban planning areas (UPAs). Eight quantitative variables were used to establish the environmental and anthropic characterization of UPAs associated or not associated with scorpionism. A spatial analysis was performed for geoprocessing maps of Americana using spatial statistics tools (optimized hotspot analysis and kernel density function) from cartographic clusters in the ArcMap software, version 10.5. RESULTS: The optimized hotspot analysis tool identified spatial clusters with high values of the incidence of scorpion stings in the surroundings of all UPAs in the municipality. The estimation of the kernel function of event intensity showed a wide distribution of stings across the area of the entire municipal territory, with UPA-02 and UPA-06 exhibiting the highest occurrence of scorpion stings. Six significant hotspots were established as highest-event-density areas (with occurrences of 160-270) and were contiguous to 4 environmental protection areas, located in more peripheral regions, and to 2 municipal cemeteries, which were located in urban central areas. CONCLUSIONS: This analysis showed that the risk of scorpion stings in different Americana's UPAs has increased occurrence and incidence intensity.
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Picadas de Escorpião , Venenos de Escorpião , Animais , Humanos , Picadas de Escorpião/etiologia , Picadas de Escorpião/complicações , Brasil/epidemiologia , Análise Espacial , Escorpiões , AcidentesRESUMO
To assist sixth-generation wireless systems in the management of a wide variety of services, ranging from mission-critical services to safety-critical tasks, key physical layer technologies such as reconfigurable intelligent surfaces (RISs) are proposed. Even though RISs are already used in various scenarios to enable the implementation of smart radio environments, they still face challenges with regard to real-time operation. Specifically, high dimensional fully passive RISs typically need costly system overhead for channel estimation. This paper, however, investigates a semi-passive RIS that requires a very low number of active elements, wherein only two pilots are required per channel coherence time. While in its infant stage, the application of deep learning (DL) tools shows promise in enabling feasible solutions. We propose two low-training overhead and energy-efficient adversarial bandit-based schemes with outstanding performance gains when compared to DL-based reflection beamforming reference methods. The resulting deep learning models are discussed using state-of-the-art model quality prediction trends.
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Object detection is a common application within the computer vision area. Its tasks include the classic challenges of object localization and classification. As a consequence, object detection is a challenging task. Furthermore, this technique is crucial for maritime applications since situational awareness can bring various benefits to surveillance systems. The literature presents various models to improve automatic target recognition and tracking capabilities that can be applied to and leverage maritime surveillance systems. Therefore, this paper reviews the available models focused on localization, classification, and detection. Moreover, it analyzes several works that apply the discussed models to the maritime surveillance scenario. Finally, it highlights the main opportunities and challenges, encouraging new research in this area.
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Fenômenos Biológicos , Navios , Redes Neurais de ComputaçãoRESUMO
Magnetoplasmonic permittivity-near-zero (ε-near-zero) nanostructures hold promise for novel highly integrated (bio)sensing devices. These platforms merge the high-resolution sensing from the magnetoplasmonic approach with the ε-near-zero-based light-to-plasmon coupling (instead of conventional gratings or bulky prism couplers), providing a way for sensing devices with higher miniaturization levels. However, the applications are mostly hindered by tedious and time-consuming numerical analyses, due to the lack of an analytical relation for the phase-matching condition. There is, therefore, a need to develop mechanisms that enable the exploitation of magnetoplasmonic ε-near-zero nanostructures' capabilities. In this work, we developed a genetic algorithm (GA) for the rapid design (in a few minutes) of magnetoplasmonic nanostructures with optimized TMOKE (transverse magneto-optical Kerr effect) signals and magnetoplasmonic sensing. Importantly, to illustrate the power and simplicity of our approach, we designed a magnetoplasmonic ε-near-zero sensing platform with a sensitivity higher than 56∘/RIU and a figure of merit in the order of 102. These last results, higher than any previous magnetoplasmonic ε-near-zero sensing approach, were obtained by the GA intelligent program in times ranging from 2 to 5 min (using a simple inexpensive dual-core CPU computer).
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Nanoestruturas , Algoritmos , Nanoestruturas/químicaRESUMO
Strawberries are sensitive fruits that are afflicted by various pests and diseases. Therefore, there is an intense use of agrochemicals and pesticides during production. Due to their sensitivity, temperatures or humidity at extreme levels can cause various damages to the plantation and to the quality of the fruit. To mitigate the problem, this study developed an edge technology capable of handling the collection, analysis, prediction, and detection of heterogeneous data in strawberry farming. The proposed IoT platform integrates various monitoring services into one common platform for digital farming. The system connects and manages Internet of Things (IoT) devices to analyze environmental and crop information. In addition, a computer vision model using Yolo v5 architecture searches for seven of the most common strawberry diseases in real time. This model supports efficient disease detection with 92% accuracy. Moreover, the system supports LoRa communication for transmitting data between the nodes at long distances. In addition, the IoT platform integrates machine learning capabilities for capturing outliers in collected data, ensuring reliable information for the user. All these technologies are unified to mitigate the disease problem and the environmental damage on the plantation. The proposed system is verified through implementation and tested on a strawberry farm, where the capabilities were analyzed and assessed.
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Fragaria , Internet das Coisas , Agricultura , Fazendas , UmidadeRESUMO
Preterm birth (PTB) and postpartum depression (PPD) are important public health issues, and although literature mainly supports the association between them, some reviews have highlighted methodological limitations in the studies in this field, restricting the interpretation of such finding. This study aimed at assessing the association between PTB and PPD, by comparing groups of preterm and full-term mothers in two Brazilian cities with contrasting sociodemographic indicators. This prospective convenience cohort study assessed 1421 women during pregnancy, at childbirth, and in the postpartum period. The Edinburgh Postnatal Depression Scale (EPDS) was administrated to assess PPD within 6 months after delivery and women were considered probably depressed if scores were EDPS ≥ 12. PTB was defined as the delivery before 37 completed weeks of pregnancy. A multivariate Poisson regression was used to estimate relative risk for PPD in mothers of preterm infants, and the final analysis models were adjusted for psychosocial variables, selected according to the directed acyclic graph (DAG) approach. Frequencies of PPD were not significantly different in mothers of preterm and full-term infants, in neither city. In the final adjusted model, PTB was not associated with PPD. The association between PTB and PPD was not confirmed in two large samples from two Brazilian cities with contrasting socioeconomic profile. However, maternal health during pregnancy plays an important role in predicting PPD. Prenatal care should promote maternal mental health as an effort towards decreasing unfavored outcomes for mothers, infants, and families.
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Depressão Pós-Parto , Nascimento Prematuro , Brasil/epidemiologia , Estudos de Coortes , Depressão Pós-Parto/diagnóstico , Depressão Pós-Parto/epidemiologia , Depressão Pós-Parto/psicologia , Feminino , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Gravidez , Nascimento Prematuro/epidemiologia , Estudos ProspectivosRESUMO
ABSTRACT Introduction: Tissue transfer has been used in urethral reconstruction for decades, and several grafts have been described (1, 2). The ideal graft would have optimal tissue characteristics and lead to minimal morbidity at the donor site. Urethroplasty using bladder mucosa was first described by Memmelaar in 1947 (3). The main limitation in using bladder mucosal grafts has been the invasiveness of open harvesting (4). We describe an endoscopic technique using Holmium: YAG laser to harvest bladder mucosal graft for substitution urethroplasty. Methodology: A 33-year-old male with no history of urethral instrumentation, trauma, or infection presented with obstructive lower urinary tract symptoms. On retrograde urethrogram a 6cm bulbar urethral stricture was identified. Several options were discussed, and the patient opted for a one-sided onlay dorsal urethroplasty (5) using a bladder mucosal graft. Equipment used to harvest the graft included an 18.5Fr continuous flow laser endoscope with a Kuntz working element (RZ) and a 60W Holmium Laser (Quanta) with 550μm laser fiber. The procedure was started by making a perineal incision, urethral mobilization and incision of the stricture segment. The laser endoscope was then introduced via the perineum. Settings of 0.5J, 30 Hz, and long pulse were used and a 7 x 2.5cm graft was harvested from the posterior bladder wall. Hemostasis of the harvest site was performed. The bladder mucosal graft was thinned in similar fashion to a buccal mucosal graft and sutured as per previously described techniques. Conclusion: Endoscopic Holmium Laser harvesting of bladder mucosal graft is feasible and may allow this graft to become an alternative to buccal mucosa. Further studies are required to define its role in urethral reconstruction.
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Humanos , Masculino , Adulto , Estreitamento Uretral/cirurgia , Lasers de Estado Sólido/uso terapêutico , Uretra/cirurgia , Bexiga Urinária/cirurgia , Mucosa Bucal/transplanteRESUMO
INTRODUCTION: Tissue transfer has been used in urethral reconstruction for decades, and several grafts have been described (1, 2). The ideal graft would have optimal tissue characteristics and lead to minimal morbidity at the donor site. Urethroplasty using bladder mucosa was first described by Memmelaar in 1947 (3). The main limitation in using bladder mucosal grafts has been the invasiveness of open harvesting (4). We describe an endoscopic technique using Holmium:YAG laser to harvest bladder mucosal graft for substitution urethroplasty. METHODOLOGY: A 33-year-old male with no history of urethral instrumentation, trauma, or infection presented with obstructive lower urinary tract symptoms. On retrograde urethrogram a 6cm bulbar urethral stricture was identified. Several options were discussed, and the patient opted for a one-sided onlay dorsal urethroplasty (5) using a bladder mucosal graft. Equipment used to harvest the graft included an 18.5Fr continuous flow laser endoscope with a Kuntz working element (RZ) and a 60W Holmium Laser (Quanta) with 550µm laser fiber. The procedure was started by making a perineal incision, urethral mobilization and incision of the stricture segment. The laser endoscope was then introduced via the perineum. Settings of 0.5J, 30 Hz, and long pulse were used and a 7 x 2.5cm graft was harvested from the posterior bladder wall. Hemostasis of the harvest site was performed. The bladder mucosal graft was thinned in similar fashion to a buccal mucosal graft and sutured as per previously described techniques. CONCLUSION: Endoscopic Holmium Laser harvesting of bladder mucosal graft is feasible and may allow this graft to become an alternative to buccal mucosa. Further studies are required to define its role in urethral reconstruction.
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Lasers de Estado Sólido , Estreitamento Uretral , Adulto , Humanos , Lasers de Estado Sólido/uso terapêutico , Masculino , Mucosa Bucal/transplante , Uretra/cirurgia , Estreitamento Uretral/cirurgia , Bexiga Urinária/cirurgiaRESUMO
Large intelligent surfaces (LIS) are a new trend to achieve higher spectral efficiency and signal-to-noise ratio in mobile communications. For this reason, this paper proposes metrics to analyze the performance of systems with multiple antennas aided by LIS and derive the spectral efficiency, secrecy outage probability, and bit error probability in an environment with Nakagami-m distributed fading. In addition to an eavesdropper, there is a single-antenna user, an array of antennas at the transmitter side and the possibility of a direct link between transmitter and receiver. This study assumes that the LIS performs non-ideal phase cancellation leading to a residual phase error that follows a Von Mises distribution, and shows that the resulting channel can be accurately approximated by a Gamma distributed SNR whose parameters are analytically derived. From these formulas, it is possible to evaluate the effect of the strength of the line-of-sight link by varying the Nakagami parameter, m.
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This work considers a base station equipped with an M-antenna uniform linear array and L users under line-of-sight conditions. As a result, one can derive an exact series expansion necessary to calculate the mean sum-rate channel capacity. This scenario leads to a mathematical problem where the joint probability density function (JPDF) of the eigenvalues of a Vandermonde matrix WWH are necessary, where W is the channel matrix. However, differently from the channel Rayleigh distributed, this joint PDF is not known in the literature. To circumvent this problem, we employ Taylor's series expansion and present a result where the moments of mn are computed. To calculate this quantity, we resort to the integer partition theory and present an exact expression for mn. Furthermore, we also find an upper bound for the mean sum-rate capacity through Jensen's inequality. All the results were validated by Monte Carlo numerical simulation.