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1.
Cureus ; 16(1): e52716, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38384604

RESUMO

Malignant peritoneal mesothelioma (MPeM) is a rare cancer of the peritoneum with a poor prognosis and nonspecific clinical course. We discuss a case of MPeM in a 59-year-old male who presented with abdominal pain and distension, without any known previous asbestos exposure. The diagnosis was made after a second biopsy finally confirmed epithelioid MPeM in an advanced stage with pleural effusion. The patient underwent six cycles of chemotherapy with cisplatin and pemetrexed, experienced disease progression, and was then started on pembrolizumab as a second-line treatment. The patient achieved a complete response after two years of treatment with pembrolizumab and has been disease-free for almost four years with an Eastern Cooperative Oncology Group (ECOG) performance status of 0. Despite the lack of evidence to support the treatment with immunotherapy for MPeM, our case report encourages its use, highlighting its ability to enable a complete response with pembrolizumab with an excellent quality of life.

2.
Curr Oncol ; 30(7): 6041-6065, 2023 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-37504311

RESUMO

BACKGROUND: The increased focus on quality indicators (QIs) and the use of clinical registries in real-world cancer studies have increased compliance with therapeutic standards and patient survival. The European Society of Breast Cancer Specialists (EUSOMA) established QIs to assess compliance with current standards in breast cancer care. METHODS: This retrospective study is part of H360 Health Analysis and aims to describe compliance with EUSOMA QIs in breast cancer management in different hospital settings (public vs. private; general hospitals vs. oncology centers). A set of key performance indicators (KPIs) was selected based on EUSOMA and previously identified QIs. Secondary data were retrieved from patients' clinical records. Compliance with target KPIs in different disease stages was compared with minimum and target EUSOMA standards. RESULTS: A total of 259 patient records were assessed. In stages I, II, and III, 18 KPIs met target EUSOMA standards, 5 met minimum standards, and 8 failed to meet minimum standards. Compliance with KPIs varied according to the type of hospital (particularly regarding diagnosis) and disease stage. Although small differences were found in KPI compliance among institutions, several statistical differences were found among treatment KPIs according to disease stage, particularly in stage III. CONCLUSIONS: This study represents the first assessment of the quality of breast cancer care in different hospital settings in Portugal and shows that, although most QIs meet EUSOMA standards, there is room for improvement. Differences have been found across institutions, particularly between oncology centers and general hospitals, in diagnosis and compliance with KPIs among disease stages. Stage III showed the greatest variability in compliance with treatment KPIs, probably related to the lower specificity of the guidelines in this disease stage.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/terapia , Neoplasias da Mama/diagnóstico , Indicadores de Qualidade em Assistência à Saúde , Portugal , Estudos Retrospectivos , Oncologia
3.
Sensors (Basel) ; 21(18)2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34577260

RESUMO

Millimeter-wave and terahertz technologies have been attracting attention from the wireless research community since they can offer large underutilized bandwidths which can enable the support of ultra-high-speed connections in future wireless communication systems. While the high signal attenuation occurring at these frequencies requires the adoption of very large (or the so-called ultra-massive) antenna arrays, in order to accomplish low complexity and low power consumption, hybrid analog/digital designs must be adopted. In this paper we present a hybrid design algorithm suitable for both mmWave and THz multiuser multiple-input multiple-output (MIMO) systems, which comprises separate computation steps for the digital precoder, analog precoder and multiuser interference mitigation. The design can also incorporate different analog architectures such as phase shifters, switches and inverters, antenna selection and so on. Furthermore, it is also applicable for different structures, namely fully-connected structures, arrays of subarrays (AoSA) and dynamic arrays of subarrays (DAoSA), making it suitable for the support of ultra-massive MIMO (UM-MIMO) in severely hardware constrained THz systems. We will show that, by using the proposed approach, it is possible to achieve good trade-offs between spectral efficiency and simplified implementation, even as the number of users and data streams increases.


Assuntos
Algoritmos
4.
BMJ Case Rep ; 14(7)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34326113

RESUMO

A 66-year-old man was referred to the oncological pneumology consultation due to a mass in the right upper lobe observed in a routine X-ray of the chest. The CT scan confirmed a mass in the same location. The biopsy revealed a lung adenocarcinoma. It was decided to start chemotherapy adapted to kidney function. In April 2020, the patient contracted SARS-CoV-2 infection and developed bilateral pneumonia with partial respiratory failure. He was transferred to the intensive care unit, where he had a positive evolution. In the next 5 months, there was a clinical improvement; however, the CT scan of the chest showed disease progression. After a new multidisciplinary approach, it was decided to start a second line with atezolizumab. After four cycles of atezolizumab, there was a clear clinical improvement, and a reduction by more than 50% in the tumour size, without significant adverse effects.


Assuntos
COVID-19 , Neoplasias Pulmonares , Idoso , Humanos , Pulmão , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/tratamento farmacológico , Masculino , SARS-CoV-2 , Tomografia Computadorizada por Raios X
6.
Sensors (Basel) ; 20(3)2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32050676

RESUMO

In the last years, the evolution of digital communications has been harnessed by medical applications. In that context, wireless communications are preferable over wired communications, as they facilitate the work of health technicians by reducing cabling on the stretchers. However, the use of wireless communications is challenging, especially when high data rates and low latencies are required. In those scenarios, multiple-input multiple-output (MIMO) techniques might have an important role, thanks to the high capacity gains that they can exhibit, which ideally increase with the MIMO size. In this work, we study the propagation scenario of a typical medical laboratory through ray-tracing techniques. By taking into account the derived channel model, we study the potential of MIMO techniques in an IEEE 802.11ax environment. Through a set of performance results regarding the system capacity, we show that the MIMO gains might not be as high as supposed in the medical laboratory, being far from the ideal scenario. Therefore, the large data rates required by the modern medical imaging applications might only be achieved with a combination of MIMO systems and large bandwidths.


Assuntos
Algoritmos , Tecnologia sem Fio , Diagnóstico por Imagem
7.
Sensors (Basel) ; 20(2)2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31968706

RESUMO

Most of the previous work on hybrid transmit and receive beamforming focused on narrowband channels. Because the millimeter wave channels are expected to be wideband, it is crucial to propose efficient solutions for frequency-selective channels. In this regard, this paper proposes an iterative analog-digital multi-user equalizer scheme for the uplink of wideband millimeter-wave massive multiple-input-multiple-output (MIMO) systems. By iterative equalizer we mean that both analog and digital parts are updated using as input the estimates obtained at the previous iteration. The proposed iterative analog-digital multi-user equalizer is designed by minimizing the sum of the mean square error of the data estimates over the subcarriers. We assume that the analog part is fixed for all subcarriers while the digital part is computed on a per subcarrier basis. Due to the complexity of the resulting optimization problem, a sequential approach is proposed to compute the analog phase shifters values for each radio frequency (RF) chain. We also derive an accurate, semi-analytical approach for obtaining the bit error rate (BER) of the proposed hybrid system. The proposed solution is compared with other hybrid equalizer schemes, recently designed for wideband millimeter-wave (mmWave) massive MIMO systems. The simulation results show that the performance of the developed analog-digital multi-user equalizer is close to full-digital counterpart and outperforms the previous hybrid approach.

8.
Sensors (Basel) ; 19(21)2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31683931

RESUMO

Multi-Input, Multi-Output (MIMO) techniques are seeing widespread usage in wireless communication systems due to their large capacity gains. On the other hand, security is a concern of any wireless system, which can make schemes that implement physical layer security key in assuring secure communications. In this paper, we study the physical layer security issues of MIMO with Singular Value Decomposition (SVD) schemes, employed along with Single-Carrier with Frequency-Domain Equalization (SC-FDE) techniques. More concretely. the security potential against an unintended eavesdropper is analysed, and it is shown that the higher the distance between the eavesdropper and the transmitter or receiver, the higher the secrecy rate. In addition, in a scenario where there is Line of Sight (LOS) between all users, it is shown that the secrecy rate can be even higher than in the previous scenario. Therefore, MIMO-SVD schemes combined with SC-FDE can be an efficient option for highly secure MIMO communications.

9.
Ecancermedicalscience ; 13: 937, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31552110

RESUMO

BACKGROUND: Depression is one of the major psychiatric morbidities in cancer patients. The purpose of our study was to evaluate the impact of depressive symptoms in the quality of life (QoL) of patients with breast cancer undergoing chemotherapy and monoclonal antibodies treatments. METHODS: Observational, cross-sectional study conducted between April and November 2016. To evaluate the QoL, the EORTC QLQ-C30 and QLQ-BR23 questionnaire were used. The patients were screened for depressive symptoms using the Hospital Anxiety and Depression Scale (HADS-D) and those with a positive HADS-D positive questionnaire were referenced to the Psychiatry and Mental Health Department for further assessment and follow-up. RESULTS: We included 45 female patients. Sixteen (35.6%) patients had a positive HADS-D questionnaire and depressive symptoms confirmed by a psychiatric physician. Of those patients, 7 (15.6%) had a major depressive episode confirmed by psychiatric interview. There was a significant association of depressive symptoms with the future perspectives scale (p = 0.022), breast symptoms scale (p = 0.011) and arm symptom scale (p = 0.005). Significant differences were found in the fatigue (p = 0.024), pain (p = 0.037) and dyspnea (p = 0.009) subscales being worse in patients with depressive symptoms. The association between having depressive symptoms or not was shown to be significant or marginally significant for the variables stage of the tumour (p = 0.057), presence of distant metastasis (p = 0.072) and previous diagnosis of depression (p = 0.011). The patients treated with regimens containing monoclonal antibodies presented better outcomes in various subscales of the EORTC QLQ-C30 and QLQ-B23 questionnaires than those patients treated with chemotherapy regimens without monoclonal antibodies. CONCLUSIONS: Despite the small sample of our study, this study provided evidence that depressive symptoms in patients with breast cancer undergoing chemotherapy and monoclonal antibodies treatments detrimentally reduced various aspects of QoL.

10.
Sensors (Basel) ; 19(5)2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30866552

RESUMO

In this paper, we present a few novel simultaneous wireless information and power transfer (SWIPT) schemes that can be effectively used in various 5G wireless network implementations. First, we study the possibility of integrating distributed energy beamforming with the data rate fairness beamforming in a cooperative communication system with multiple cooperative relays and multiple destination users communicating simultaneously. We show that the system exploits significant performance gain using such a joint energy and data rate fairness beamforming scheme. Further, we propose an enhanced version of the SWIPT scheme, the energy-efficient modulation-based non-orthogonal multiple access (M-NOMA) SWIPT scheme, and observe its system efficiency in terms of more harvested energy. Finally, we consider an energy-harvesting SWIPT scheme where the channel response is estimated using the energy-harvesting signal as pilots superimposed on the information signal. For such a scheme, we compute the optimum transmit power ratio between the pilot and information signals under varying SNR conditions and improve the accuracy of the decoding process at the reception.

11.
Sensors (Basel) ; 19(1)2019 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-30621229

RESUMO

Massive multiple input multiple output (MIMO) technology is one of the promising technologies for fifth generation (5G) cellular communications. In this technology, each cell has a base station (BS) with a large number of antennas, allowing the simultaneous use of the same resources (e.g., frequency and/or time slots) by multiple users of a cell. Therefore, massive MIMO systems can bring very high spectral and power efficiencies. However, this technology faces some important issues that need to be addressed. One of these issues is the performance degradation due to hardware impairments, since low-cost RF chains need to be employed. Another issue is the channel estimation and channel aging effects, especially in fast mobility environments. In this paper we will perform a comprehensive study on these two issues considering two of the most promising candidate waveforms for massive MIMO systems: Orthogonal frequency division multiplexing (OFDM) and single-carrier frequency domain processing (SC-FDP). The studies and the results show that hardware impairments and inaccurate channel knowledge can degrade the performance of massive MIMO systems extensively. However, using suitable low complex estimation and compensation techniques and also selecting a suitable waveform can reduce these effects.

12.
Sensors (Basel) ; 18(4)2018 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-29671832

RESUMO

This work revises existing solutions for a problem of target localization in wireless sensor networks (WSNs), utilizing integrated measurements, namely received signal strength (RSS) and angle of arrival (AoA). The problem of RSS/AoA-based target localization became very popular in the research community recently, owing to its great applicability potential and relatively low implementation cost. Therefore, here, a comprehensive study of the state-of-the-art (SoA) solutions and their detailed analysis is presented. The beginning of this work starts by considering the SoA approaches based on convex relaxation techniques (more computationally complex in general), and it goes through other (less computationally complex) approaches, as well, such as the ones based on the generalized trust region sub-problems framework and linear least squares. Furthermore, a detailed analysis of the computational complexity of each solution is reviewed. Furthermore, an extensive set of simulation results is presented. Finally, the main conclusions are summarized, and a set of future aspects and trends that might be interesting for future research in this area is identified.

13.
Sensors (Basel) ; 17(11)2017 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-29160797

RESUMO

This work addresses the problem of tracking a signal-emitting mobile target in wireless sensor networks (WSNs) with navigated mobile sensors. The sensors are properly equipped to acquire received signal strength (RSS) and angle of arrival (AoA) measurements from the received signal, while the target transmit power is assumed not known. We start by showing how to linearize the highly non-linear measurement model. Then, by employing a Bayesian approach, we combine the linearized observation model with prior knowledge extracted from the state transition model. Based on the maximum a posteriori (MAP) principle and the Kalman filtering (KF) framework, we propose new MAP and KF algorithms, respectively. We also propose a simple and efficient mobile sensor navigation procedure, which allows us to further enhance the estimation accuracy of our algorithms with a reduced number of sensors. Model flaws, which result in imperfect knowledge about the path loss exponent (PLE) and the true mobile sensors' locations, are taken into consideration. We have carried out an extensive simulation study, and our results confirm the superiority of the proposed algorithms, as well as the effectiveness of the proposed navigation routine.

14.
BMJ Case Rep ; 20172017 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-28219911

RESUMO

A woman aged 35 years was diagnosed with triple-negative breast cancer in October 2012. During the investigation, it was discovered that she was pregnant, the patient decided to have an abortion. She was submitted to a radical modified mastectomy and adjuvant chemotherapy followed by adjuvant breast radiotherapy of the left breast. 2 months after the adjuvant treatment, she began to have headaches and dizziness. The cranial MRI (head MRI) showed brain metastasis. She was then treated with whole brain radiotherapy, stereotactic radiosurgery and concomitant temozolomide which resulted in complete response. 1.5 year later, she was able to get pregnant and gave birth to a baby without complications. The previous imaging reassessment performed in September 2016 shows no evidence of recurrent breast cancer.


Assuntos
Neoplasias Encefálicas/secundário , Carcinoma Ductal de Mama/secundário , Complicações Neoplásicas na Gravidez/patologia , Neoplasias de Mama Triplo Negativas/patologia , Aborto Induzido , Adulto , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/terapia , Carcinoma Ductal de Mama/terapia , Feminino , Necrose da Cabeça do Fêmur/cirurgia , Humanos , Metástase Linfática , Imageamento por Ressonância Magnética , Gravidez , Complicações Neoplásicas na Gravidez/terapia , Neoplasias de Mama Triplo Negativas/terapia
15.
Sensors (Basel) ; 14(10): 18410-32, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25275350

RESUMO

In this paper, we propose a new approach based on convex optimization to address the received signal strength (RSS)-based cooperative localization problem in wireless sensor networks (WSNs). By using iterative procedures and measurements between two adjacent nodes in the network exclusively, each target node determines its own position locally. The localization problem is formulated using the maximum likelihood (ML) criterion, since ML-based solutions have the property of being asymptotically efficient. To overcome the non-convexity of the ML optimization problem, we employ the appropriate convex relaxation technique leading to second-order cone programming (SOCP). Additionally, a simple heuristic approach for improving the convergence of the proposed scheme for the case when the transmit power is known is introduced. Furthermore, we provide details about the computational complexity and energy consumption of the considered approaches. Our simulation results show that the proposed approach outperforms the existing ones in terms of the estimation accuracy for more than 1:5 m. Moreover, the new approach requires a lower number of iterations to converge, and consequently, it is likely to preserve energy in all presented scenarios, in comparison to the state-of-the-art approaches.

16.
ScientificWorldJournal ; 2014: 619454, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24678274

RESUMO

Interference alignment (IA) is a promising technique that allows high-capacity gains in interference channels, but which requires the knowledge of the channel state information (CSI) for all the system links. We design low-complexity and low-bit rate feedback strategies where a quantized version of some CSI parameters is fed back from the user terminal (UT) to the base station (BS), which shares it with the other BSs through a limited-capacity backhaul network. This information is then used by BSs to perform the overall IA design. With the proposed strategies, we only need to send part of the CSI information, and this can even be sent only once for a set of data blocks transmitted over time-varying channels. These strategies are applied to iterative MMSE-based IA techniques for the downlink of broadband wireless OFDM systems with limited feedback. A new robust iterative IA technique, where channel quantization errors are taken into account in IA design, is also proposed and evaluated. With our proposed strategies, we need a small number of quantization bits to transmit and share the CSI, when comparing with the techniques used in previous works, while allowing performance close to the one obtained with perfect channel knowledge.


Assuntos
Modelos Teóricos , Telecomunicações , Tecnologia sem Fio , Algoritmos
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