RESUMO
The optical vortex (OV) carries unique orbital angular momentum (OAM) and experiences a Doppler frequency shift when backscattered from a spinning object. This rotational Doppler effect (RDE) has provided a solution for the non-contact detection of rotating motion. The reported RDE researches mainly use a single OV that generates frequency shifts proportional to its topological charge and has low robustness to light incidence. Here, we show the distinctive RDE of superimposed optical vortex array (SOVA). We analyze the holistic OAM of SOVA which is represented in terms of a superposition of azimuthal harmonics and displays a unique modal gathering effect. In the experiment of RDE, the frequency shift signals of SOVA show a precise mapping to the OAM modes and the modal gathering effect contributes to enhance the amplitude of signals, which has the potential to enhance robustness against non-coaxial incidence. This finding provides a new aspect of RDE and a pioneered example for introducing various SOVAs into rotation detection.
RESUMO
Vortex beams (VBs) with orbital angular momentum have shown great potential in the detection of transverse rotational motion of spatial targets which is undetectable in the classical radar scheme. However, most of the reported rotational Doppler measurements based on VBs can only be realized under ideal experimental conditions. The long-range detection is still a challenge. The detection distance based on rotational Doppler effect (RDE) is mainly limited by the scattered signal's signal-to-noise ratio (SNR). In this work, we investigated the influence of multi-ring vortex beams (MVBs) on the rotational Doppler frequency spectrum of scattered light from an object based on RDE and proposed a method of SNR enhancement of RDE signal. Firstly, different types of MVBs composed of a set of single-ring VBs with the same topological charge and different radii are designed, including multi-ring Laguerre Gaussian beam (MLGB), multi-ring perfect vortex beams (MPVB), and high-order Laguerre Gaussian beam (HLGB). Then, the influence of the number of rings and radial radius interval on the intensity profiles of MVBs and rotational Doppler frequency spectra under aligned and misaligned conditions is studied in detail. And the reasons why different types of MVBs lead to different SNR enhancement effectiveness with the increase of rings are also analyzed theoretically. Finally, proof-of-concept experiments were conducted to verify the effectiveness of the SNR enhancement method for RDE signals. The results showed that the amplitudes of the Doppler spectra generated by the MLGB and MPVB are improved substantially with the increase of rings, but the enhancement effect caused by the former is superior to the latter. The gain of HLGB on the RDE signal is the lowest. This study provides a useful reference for the optimization of rotational Doppler detection systems and may be of great application value in telemetry, long-range communication and optical imaging.
RESUMO
The rotational Doppler effect of the vortex beam is a recently emerged promising application of the optical vortex with orbital angular momentum. In this paper, we combine the method of the micro-Doppler effect of the traditional radar and the rotational Doppler effect of the vortex beam and propose an approach of rotational micro-Doppler effect, realizing the simultaneous measurement of spin and precession. We firstly analyze the rotational micro-Doppler characteristic introduced by precession under the illuminating of vortex beam and calculate the rotational micro-Doppler parameters related to the spin and precession. Then we conduct an experiment of using the vortex beam to detect a spinning object with precession and the rotational micro-Doppler frequency is successfully observed. By extracting the rotational micro-Doppler parameters, the simultaneous and independent measurement of spin and precession is realized. Both the theoretical analysis and experimental results indicate that the rotational micro-Doppler effect is an effective extension of the rotational Doppler effect and is also a feasible application of the vortex beam detection.
RESUMO
Satellite pose estimation plays a crucial role within the aerospace field, impacting satellite positioning, navigation, control, orbit design, on-orbit maintenance (OOM), and collision avoidance. However, the accuracy of vision-based pose estimation is severely constrained by the complex spatial environment, including variable solar illumination and the diffuse reflection of the Earth's background. To overcome these problems, we introduce a novel satellite pose estimation network, FilterformerPose, which uses a convolutional neural network (CNN) backbone for feature learning and extracts feature maps at various CNN layers. Subsequently, these maps are fed into distinct translation and orientation regression networks, effectively decoupling object translation and orientation information. Within the pose regression network, we have devised a filter-based transformer encoder model, named filterformer, and constructed a hypernetwork-like design based on the filter self-attention mechanism to effectively remove noise and generate adaptive weight information. The related experiments were conducted using the Unreal Rendered Spacecraft On-Orbit (URSO) dataset, yielding superior results compared to alternative methods. We also achieved better results in the camera pose localization task, indicating that FilterformerPose can be adapted to other computer vision downstream tasks.
RESUMO
AIMS AND OBJECTIVES: To describe the experiences of radiation-induced xerostomia in patients with head and neck cancer. BACKGROUND: Xerostomia is the most commonly occurring complication during and following radiotherapy. It can persist for several months or years and can have a significant impact on patients' quality of life. DESIGN: This was a qualitative descriptive study. METHODS: Semi-structured interviews were conducted with a sample of 20 participants. Inductive content analysis was used to analyse the qualitative data. RESULTS: Analysis of the manifest content identified five categories: communication problems, physical problems, psychosocial problems, treatment problems and relief strategies. The latent content was formulated into a theme: due to lack of information from professionals, the patients had to find their own solutions for their problems. CONCLUSIONS: Xerostomia is not only a biophysical symptom but also has a profound effect on the emotional, intellectual and sociocultural dimensions of life. The majority of patients continued to suffer from xerostomia and its associated symptoms after radiotherapy, in part, because of a lack of professional support, including the inability of nurses to provide oral health care. RELEVANCE TO CLINICAL PRACTICE: Nurses need to be knowledgeable about the effects of radiotherapy on oral mucosa and about appropriate interventions. The healthcare system requires a symptom management platform for radiation-induced complications, to help patients, their families and healthcare professionals obtain information about self-care, treatments and relief strategies.
Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Enfermagem Oncológica/métodos , Lesões por Radiação/etiologia , Lesões por Radiação/enfermagem , Radioterapia/efeitos adversos , Xerostomia/etiologia , Xerostomia/enfermagem , Adulto , Idoso , Idoso de 80 Anos ou mais , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Qualidade de VidaRESUMO
Rad51c is critical for homologous recombination repair and genomic stability and may play roles in tumorigenesis and cancer therapy. We investigated the expression level and clinical significance of Rad51c in non-small cell lung cancer (NSCLC) and determined the effect of Rad51c on NSCLC cell chemosensitivity and radiosensitivity. Rad51c expression was detected using immunohistochemistry and was higher in NSCLC patient samples than in adjacent normal tissues. Kaplan-Meier analysis revealed that high Rad51c expression was an independent predictor of short overall survival (OS) and disease-free survival (DFS) in NSCLC patients receiving chemotherapy and/or radiotherapy. Furthermore, Rad51c knockdown increased the killing effect of ionizing radiation (IR) and enhanced cisplatin-induced apoptotic cells in NSCLC cells by disrupting the repair of cisplatin- and IR-induced DNA damage. In addition, ectopic expression of Rad51c dramatically enhanced NSCLC cell resistance to cisplatin and radiotherapy. These findings suggest that increased expression of Rad51c may confer resistance to chemotherapy and/or radiotherapy of NSCLC, and also be an independent prognostic factor for patient outcome. Therefore, targeting Rad51c may represent an improved therapeutic strategy for NSCLC patients with locally advanced disease.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Quimiorradioterapia , Cisplatino/farmacologia , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares/patologia , Tolerância a Radiação , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Adenocarcinoma/terapia , Antineoplásicos/farmacologia , Apoptose , Western Blotting , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/terapia , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Estudos de Casos e Controles , Proliferação de Células , Feminino , Citometria de Fluxo , Imunofluorescência , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Taxa de Sobrevida , Células Tumorais CultivadasRESUMO
PURPOSE: Myelosuppression induced by concurrent chemotherapy and radiotherapy can be a significant problem in patients with non-small cell lung cancer (NSCLC), but its risk factors remain largely unknown. The objective of this study was to retrospectively evaluate clinical data obtained before chemoradiotherapy (CRT) to identify the risk factors for myelosuppression in patients with advanced NSCLC. METHODS: Between January 2007 and January 2012, 141 patients with advanced NSCLC were treated with curative intent according to the CRT protocol (50-70 Gy at 2 Gy/day with paclitaxel 135-175 mg/m(2) and carboplatin 100 mg/m(2) on days 1, 22, and 43). The endpoint of this survey was the occurrence of grade 3 or higher myelosuppression (neutropenia, leukopenia, thrombocytopenia, or anemia). Risk factors significantly related to myelosuppression were extracted using logistic regression analysis. RESULTS: Grade 3 or higher neutropenia, leukopenia, thrombocytopenia, or anemia occurred in 19.9, 16.3, 14.9, and 0% of the patients, respectively. According to the multivariate analysis, the risk factors included age, albumin, and body surface area (BSA) for neutropenia; performance status and bone metastases for leukopenia; and age, gender, and serum creatinine concentration for thrombocytopenia (p < 0.05). CONCLUSIONS: It was found that age, BSA, creatinine level, and female gender were the most important factors for CRT-induced myelosuppression in advanced NSCLC. By identifying these risk factors, medical staff can improve application of appropriate medical care to reduce the myelosuppression in advanced NSCLC patients treated by CRT.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/terapia , Quimiorradioterapia/efeitos adversos , Doenças Hematológicas/etiologia , Neoplasias Pulmonares/terapia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Superfície Corporal , Carboplatina/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/patologia , Quimiorradioterapia/métodos , Creatinina/metabolismo , Feminino , Doenças Hematológicas/epidemiologia , Humanos , Modelos Logísticos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Paclitaxel/administração & dosagem , Estudos Retrospectivos , Fatores de Risco , Fatores SexuaisRESUMO
Objectives: To investigate the short-term efficacy and radiotoxicity 3.543of chronoradiotherapy in patients with cervical cancer. We also examined the overall symptom score and quality of life (QOL) of patients who underwent morning radiotherapy and evening radiotherapy. Methods: We conducted a multicenter randomized controlled trial to compare the effects of morning radiotherapy (9:00-11:00 AM) with evening radiotherapy (7:00-9:00 PM) in cervical cancer patients receiving radiotherapy. From November 2021 to June 2022, 114 cervical cancer patients admitted to eight cancer center hospitals in Tianjin, Chongqing, Hubei, Shanxi, Shandong, Shaanxi, Hebei, and Cangzhou were randomly divided into the morning radiotherapy group (MG; N = 61) and the evening radiotherapy group (EG; N = 53). The short-term efficacy of radiotherapy on cervical cancer patients at different time points and the occurrence of radiotoxicity were explored after patients had undergone radiotherapy. Results: The total effective response (partial remission [PR] + complete remission [CR]) rate was similar across the two groups (93.5% vs. 96.3%, p > 0.05). However, the incidence of bone marrow suppression and intestinal reaction in the two groups were significantly different (p < 0.05). The patients in the MG had significantly higher Anderson symptom scores than patients in the EG (21.64 ± 7.916 vs. 18.53 ± 4.098, p < 0.05). In terms of physical activity, functional status, and overall QOL, the MG had significantly lower scores than the EG (p < 0.05). No other measures showed a significant difference between the groups. Conclusion: The radiotherapy effect of the MG was consistent with that of the EG. The incidence of radiation enteritis and radiation diarrhea in the MG was significantly higher than that in the EG; however, bone marrow suppression and blood toxicity in the EG were more serious than in the MG. Because of the small sample size of the study, we only examined the short-term efficacy of radiotherapy. Therefore, further clinical trials are needed to verify the efficacy and side effects of chronoradiotherapy. Clinical Trial Registration: http://www.chictr.org.cn/searchproj.aspx, Registration Number: ChiCTR2100047140.
RESUMO
The magnetically suspended control and sense gyroscope (MSCSG) integrates spacecraft attitude measurement and control function; this paper proposes a double spherical rotor (DSR) for MSCSG. The DSR realizes the five degrees of freedom (DOFs) full active control and full channel magnetic path decoupling by the following design: the spherical axial/radial reluctance magnetic bearings are adopted to control the 3DOFs translation of rotor in the range of double spherical envelope, Lorentz force magnetic bearing (LFMB) is used to precisely drive the 2DOFs universal deflection of rotor. The optimization model is established based on the structural mechanical analysis, taking the deviation between rotor centroid and shape center as the optimization objective, choosing the first order resonance frequency, maximum equivalent stress, rigid body displacement, polar moment of inertia and inertia ratio as constraints. Then the DSR is optimized and simulated by the finite element, the MSCSG principle prototype based on DSR is successfully developed, the online dynamic balance experiment and modal test of the DSR are conducted, where the vibration amount of the DSR decreases from 20 µm before the experiment to 0.14 µm after the experiment, which decreases by 99.3%, the first test modal is 2881 Hz which is 5% different from the finite element simulation value of 3034 Hz. The results show that the DSR has the good mechanical properties and magnetic circuit decoupling characteristics.
RESUMO
PURPOSE: The prevalence of weight loss in esophageal carcinoma patients is high and associated with impairment of physical function, increased psychological distress and low quality of life. It is not known which factors may contribute to weight loss in patients with esophageal carcinoma during radiotherapy in China. The objective of this study was to identify the associated demographic and clinical factors influencing weight loss. METHODS: We evaluated 159 esophageal carcinoma patients between August 2010 and August 2013 in a cross- sectional, descriptive study. Patient characteristics, tumor and treatment details, psychological status, adverse effects, and dietary intake were evaluated at baseline and during radiotherapy. A multivariate logistic regression analyss was performed to identify the potential factors leading to weight loss. RESULTS: 64 (40.3%) patients had weight loss ≥ 5% during radiotherapy. According to logistic regression analysis, depression, esophagitis, and loss of appetite were adverse factors linked to weight loss. Dietary counseling, early stage disease and total energy intake ≥ 1,441.3 (kcal/d) were protective factors. CONCLUSIONS: It was found that dietary counseling, TNM stage, total energy intake, depression, esophagitis, and loss of appetite were the most important factors for weight loss. The results underline the importance of maintaining energy intake and providing dietary advice in EC patients during RT. At the same time, by identifying associated factors, medical staff can provide appropriate medical care to reduce weight loss. Further studies should determine the effect of these factors on weight loss and propose a predictive model.