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1.
Small ; 20(38): e2401258, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38794878

RESUMEN

Manganese oxide-based aqueous zinc-ion batteries (ZIBs) are attractive energy storage devices, owing to their good safety, low cost, and ecofriendly features. However, various critical issues, including poor conductivity, sluggish reaction kinetics, and unstable structure still restrict their further development. Oxygen defect engineering is an effective strategy to improve the electrochemical performance of manganese oxides, but challenging in the accurate regulation of oxygen defects. In this work, an effective and controllable defect engineering strategy-controllable electrochemical lithium-ion intercalation - is proposed to tackle this issue. The incorporation of lithium ions and oxygen defects can promote the conductivity, lattice spacing, and structural stability of Mn2O3 (MO), thus improving its capacity (232.7 mAh g-1), rate performance, and long-term cycling stability (99.0% capacity retention after 3000 cycles). Interestingly, the optimal ratio of intercalated lithium-ion varies at different temperature or mass-loading of MO, which provides the possibility to customize diverse ZIBs to meet different application conditions. In addition, the fabricated ZIBs present good flexibility, superior safety, and admirable adaptability under extreme temperatures (-20-100 °C). This work provides an inspiration on the structural customization of metal oxide nanomaterials for diverse ZIBs, and sheds light on the construction of future portable electronics.

2.
Chem Soc Rev ; 52(22): 7687-7706, 2023 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-37877319

RESUMEN

Atomically thin sheets (e.g., graphene and monolayer molybdenum disulfide) are ideal optical and reaction platforms. They provide opportunities for deciphering some important and often elusive photocatalytic phenomena related to electronic band structures and photo-charges. In parallel, in such thin sheets, fine tuning of photocatalytic properties can be achieved. These include atomic-level regulation of electronic band structures and atomic-level steering of charge separation and transfer. Herein, we review the physics and chemistry of electronic band structures and photo-charges, as well as their state-of-the-art characterization techniques, before delving into their atomic-level deciphering and mastery on the platform of atomically thin sheets.

3.
Breast Cancer Res ; 25(1): 77, 2023 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-37381020

RESUMEN

BACKGROUND: The immunohistochemical test (IHC) of HER2 and HR can provide prognostic information and treatment guidance for invasive breast cancer patients. We aimed to develop noninvasive image signatures ISHER2 and ISHR of HER2 and HR, respectively. We independently evaluate their repeatability, reproducibility, and association with pathological complete response (pCR) to neoadjuvant chemotherapy. METHODS: Pre-treatment DWI, IHC receptor status HER2/HR, and pCR to neoadjuvant chemotherapy of 222 patients from the multi-institutional ACRIN 6698 trial were retrospectively collected. They were pre-separated for development, independent validation, and test-retest. 1316 image features were extracted from DWI-derived ADC maps within manual tumor segmentations. ISHER2 and ISHR were developed by RIDGE logistic regression using non-redundant and test-retest reproducible features relevant to IHC receptor status. We evaluated their association with pCR using area under receiver operating curve (AUC) and odds ratio (OR) after binarization. Their reproducibility was further evaluated using the test-retest set with intra-class coefficient of correlation (ICC). RESULTS: A 5-feature ISHER2 targeting HER2 was developed (AUC = 0.70, 95% CI 0.59 to 0.82) and validated (AUC = 0.72, 95% CI 0.58 to 0.86) with high perturbation repeatability (ICC = 0.92) and test-retest reproducibility (ICC = 0.83). ISHR was developed using 5 features with higher association with HR during development (AUC = 0.75, 95% CI 0.66 to 0.84) and validation (AUC = 0.74, 95% CI 0.61 to 0.86) and similar repeatability (ICC = 0.91) and reproducibility (ICC = 0.82). Both image signatures showed significant associations with pCR with AUC of 0.65 (95% CI 0.50 to 0.80) for ISHER2 and 0.64 (95% CI 0.50 to 0.78) for ISHER2 in the validation cohort. Patients with high ISHER2 were more likely to achieve pCR to neoadjuvant chemotherapy with validation OR of 4.73 (95% CI 1.64 to 13.65, P value = 0.006). Low ISHR patients had higher pCR with OR = 0.29 (95% CI 0.10 to 0.81, P value = 0.021). Molecular subtypes derived from the image signatures showed comparable pCR prediction values to IHC-based molecular subtypes (P value > 0.05). CONCLUSION: Robust ADC-based image signatures were developed and validated for noninvasive evaluation of IHC receptors HER2 and HR. We also confirmed their value in predicting treatment response to neoadjuvant chemotherapy. Further evaluations in treatment guidance are warranted to fully validate their potential as IHC surrogates.


Asunto(s)
Neoplasias de la Mama , Terapia Neoadyuvante , Humanos , Femenino , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Reproducibilidad de los Resultados , Estudios Retrospectivos , Oportunidad Relativa
4.
Brief Bioinform ; 22(5)2021 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-33876189

RESUMEN

Targeting tumor microenvironment (TME), such as immune checkpoint blockade (ICB), has achieved increased overall response rates in many advanced cancers, such as non-small cell lung cancer (NSCLC), however, only in a fraction of patients. To improve the overall and durable response rates, combining other therapeutics, such as natural products, with ICB therapy is under investigation. Unfortunately, due to the lack of systematic methods to characterize the relationship between TME and ICB, development of rational immune-combination therapy is a critical challenge. Here, we proposed a systems pharmacology strategy to identify resistance regulators of PD-1/PD-L1 blockade and develop its combinatorial drug by integrating multidimensional omics and pharmacological methods. First, a high-resolution TME cell atlas was inferred from bulk sequencing data by referring to a high-resolution single-cell data and was used to predict potential resistance regulators of PD-1/PD-L1 blockade through TME stratification analysis. Second, to explore the drug targeting the resistance regulator, we carried out the large-scale target fishing and the network analysis between multi-target drug and the resistance regulator. Finally, we predicted and verified that oxymatrine significantly enhances the infiltration of CD8+ T cells into TME and is a powerful combination agent to enhance the therapeutic effect of anti-PD-L1 in a mouse model of lung adenocarcinoma. Overall, the systems pharmacology strategy offers a paradigm to identify combinatorial drugs for ICB therapy with a systems biology perspective of drug-target-pathway-TME phenotype-ICB combination.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Neoplasias Pulmonares/tratamiento farmacológico , Extractos Vegetales/uso terapéutico , Alcaloides/farmacología , Alcaloides/uso terapéutico , Animales , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Línea Celular Tumoral , Quimioterapia Combinada , Femenino , Redes Reguladoras de Genes/efectos de los fármacos , Redes Reguladoras de Genes/genética , Humanos , Inhibidores de Puntos de Control Inmunológico/farmacología , Estimación de Kaplan-Meier , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Ratones Endogámicos C57BL , Extractos Vegetales/farmacología , Quinolizinas/farmacología , Quinolizinas/uso terapéutico , Sophora/química , Resultado del Tratamiento , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/genética
5.
Methods ; 205: 220-225, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35809769

RESUMEN

U-Net has achieved great success in the task of medical image segmentation. It encodes and extracts information from several convolution blocks, and then decodes the feature maps to get the segmentation results. Our experiments show that in a multi-scale medical segmentation task, excessive downsampling will cause the model to ignore the small segmentation objects and thus fail to complete the segmentation task. In this work, we propose a more complete method Double-branch U-Net (2BUNet) to solve the multi-scale organ segmentation challenge. Our model is divided into four parts: main branch, tributary branch, information exchange module and classification module. The main advantages of the new model consist of: (1) Extracting information to improve model decoding capabilities using the complete encoding structure. (2) The information exchange module is added to the main branch and tributaries to provide regularization for the model, so as to avoid the large gap between the two paths. (3) Main branch structure for extracting major features of large organ. (4) The tributary structure is used to enlarge the image to extract the microscopic characteristics of small organ. (5) A classification assistant module is proposed to increase the class constraint for the output tensor. The comparative experiments show that our method achieves state-of-the-art performances in real scenes.


Asunto(s)
Diagnóstico por Imagen , Procesamiento de Imagen Asistido por Computador , Redes Neurales de la Computación , Diagnóstico por Imagen/métodos , Procesamiento de Imagen Asistido por Computador/métodos
6.
Langenbecks Arch Surg ; 408(1): 262, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37393198

RESUMEN

PURPOSE: The reported threshold of a near-infrared fluorescence detection probe (FDP) for judging parathyroid glands (PGs) is based on the autofluorescence intensity relative to other non-PG tissues, making it unreliable when not enough reference tissues are measured. We aim to convert FDP into a more convenient tool for identifying accidentally resected PGs by quantitative measurements of autofluorescence in resected tissues. METHODS: It was a prospective study approved by the Institutional Review Board. The research was divided into two stages: (1) In order to calibrate the novel FDP system, autofluorescence intensity of different in / ex vivo tissues was measured and the optimal threshold was obtained using receiver operating characteristic (ROC) curve. (2) To further validate the effectiveness of the new system, detection rates of incidental resected PGs by pathology in the control group and by FDP in the experimental group were compared. RESULTS: Autofluorescence of PGs was significantly higher than that of non-PG tissue (43 patients, Mann-Whitney U test, p < 0.0001). An optimal threshold of sensitivity / specificity (78.8% and 85.1%) for discriminating PGs was obtained. The detection rates of experimental group (20 patients) and control group (33 patients) are 5.0% and 6.1% respectively (one-tailed Fisher's exact test, p = 0.6837), indicating the novel FDP system can achieve a similar proportion of PG detection compared with pathological examinations. CONCLUSIONS: The novel FDP system can be used as an easy-to-use adjunct for detecting PG accidentally resected intraoperatively before the tissues are sent for frozen sections during thyroidectomy surgeries. TRIAL REGISTRATION: Registration number: ChiCTR2200057957.


Asunto(s)
Glándulas Paratiroides , Tiroidectomía , Humanos , Glándulas Paratiroides/diagnóstico por imagen , Glándulas Paratiroides/cirugía , Estudios Prospectivos , Curva ROC , Estadísticas no Paramétricas
7.
Int J Mol Sci ; 24(13)2023 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-37445900

RESUMEN

Potato is the world's fourth largest food crop. Due to limited arable land and an ever-increasing demand for food from a growing population, it is critical to increase crop yields on existing acreage. Soil salinization is an increasing problem that dramatically impacts crop yields and restricts the growing area of potato. One possible solution to this problem is the development of salt-tolerant transgenic potato cultivars. In this work, we review the current potato planting distribution and the ways in which it overlaps with salinized land, in addition to covering the development and utilization of potato salt-tolerant cultivars. We also provide an overview of the current progress toward identifying potato salt tolerance genes and how they may be deployed to overcome the current challenges facing potato growers.


Asunto(s)
Solanum tuberosum , Solanum tuberosum/genética , Tolerancia a la Sal/genética , Suelo
8.
Angew Chem Int Ed Engl ; 62(13): e202218016, 2023 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-36593736

RESUMEN

Two-dimensional (2D) transition metal dichalcogenides (TMDs), a rising star in the post-graphene era, are fundamentally and technologically intriguing for photocatalysis. Their extraordinary electronic, optical, and chemical properties endow them as promising materials for effectively harvesting light and catalyzing the redox reaction in photocatalysis. Here, we present a tutorial-style review of the field of 2D TMDs for photocatalysis to educate researchers (especially the new-comers), which begins with a brief introduction of the fundamentals of 2D TMDs and photocatalysis along with the synthesis of this type of material, then look deeply into the merits of 2D TMDs as co-catalysts and active photocatalysts, followed by an overview of the challenges and corresponding strategies of 2D TMDs for photocatalysis, and finally look ahead this topic.

9.
Small ; 18(44): e2203759, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36123132

RESUMEN

Achieving efficient conversion of carbon dioxide (CO2 ) to formic acid (HCOOH) at mild conditions is a promising means to reduce greenhouse gas emission and mitigate the energy crisis. Herein, spin-polarized density functional theory calculations with van der Waals corrections (DFT+D3) are performed to analyze the catalytic activity of seven metals (Ti, Fe, Ni, Cu, Zn, In, and Sn) anchored on a tungsten ditelluride monolayer (M@WTe2 ) and screen favorable CO2 reduction pathways. These results demonstrate that Ni single atoms strongly bind to the WTe2 monolayer and exist in isolated form due to the high diffusion barriers. Also, Ni-anchored WTe2 monolayer (Ni@WTe2 ) possesses a considerably low limiting-potential (-0.11 V vs reversible hydrogen electrode) to convert CO2 to HCOOH due to moderate OCHO adsorption energy and a suppressed competing hydrogen evolution reaction (HER). Therefore, Ni@WTe2 monolayer is a promising electrocatalytic material for the CO2 reduction reaction (CO2 RR). This study sheds light on strategies of designing single metal atom anchored WTe2 catalysts for improved CO2 RR performances.

10.
Small ; 17(50): e2103052, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34719844

RESUMEN

Manganese dioxide (MnO2 ), with naturally abundant crystal phases, is one of the most active candidates for toluene degradation. However, it remains ambiguous and controversial of the phase-activity relationship and the origin of the catalytic activity of these multiphase MnO2 . In this study, six types of MnO2 with crystal phases corresponding to α-, ß-, γ-, ε-, λ-, and δ-MnO2 are prepared, and their catalytic activity toward ozone-assisted catalytic oxidation of toluene at room temperature are studied, which follow the order of δ-MnO2  > α-MnO2  > ε-MnO2  > γ-MnO2  > λ-MnO2  > ß-MnO2 . Further investigation of the specific oxygen species with the toluene oxidation activity indicates that high catalytic activity of MnO2 is originated from the rich oxygen vacancy and the strong mobility of oxygen species. This work illustrates the important role of crystal phase in determining the oxygen vacancies' density and the mobility of oxygen species, thus influencing the catalytic activity of MnO2 catalysts, which sheds light on strategies of rational design and synthesis of multiphase MnO2 catalysts for volatile organic pollutants' (VOCs) degradation.


Asunto(s)
Nanoestructuras , Ozono , Catálisis , Compuestos de Manganeso , Óxidos , Tolueno
11.
Cancer Cell Int ; 21(1): 529, 2021 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-34641869

RESUMEN

BACKGROUND: Targeting tumor microenvironment (TME) may provide therapeutic activity and selectivity in treating cancers. Therefore, an improved understanding of the mechanism by which drug targeting TME would enable more informed and effective treatment measures. Glycyrrhiza uralensis Fisch (GUF, licorice), a widely used herb medicine, has shown promising immunomodulatory activity and anti-tumor activity. However, the molecular mechanism of this biological activity has not been fully elaborated. METHODS: Here, potential active compounds and specific targets of licorice that trigger the antitumor immunity were predicted with a systems pharmacology strategy. Flow cytometry technique was used to detect cell cycle profile and CD8+ T cell infiltration of licorice treatment. And anti-tumor activity of licorice was evaluated in the C57BL/6 mice. RESULTS: We reported the G0/G1 growth phase cycle arrest of tumor cells induced by licorice is related to the down-regulation of CDK4-Cyclin D1 complex, which subsequently led to an increased protein abundance of PD-L1. Further, in vivo studies demonstrated that mitigating the outgrowth of NSCLC tumor induced by licorice was reliant on increased antigen presentation and improved CD8+ T cell infiltration. CONCLUSIONS: Briefly, our findings improved the understanding of the anti-tumor effects of licorice with the systems pharmacology strategy, thereby promoting the development of natural products in prevention or treatment of cancers.

12.
Zhonghua Nan Ke Xue ; 27(7): 626-629, 2021 Jul.
Artículo en Zh | MEDLINE | ID: mdl-34914230

RESUMEN

OBJECTIVE: To investigate the efficiency and complications of modified urethral reconstruction with lingual mucosa in the treatment of complicated anterior urethral stricture (CAUS). OBJECTIVE: To investigate the sexual experience and feelings of male patients with bladder cancer after transurethral resection of bladder tumor (TURBT), and provide some evidence for doctors and nurses in giving advice about the sexual problems of the patients. METHODS: This study included 32 male patients with bladder cancer after treated by TURBT from March 2020 to March 2021. The patients were aged 33-63 (51.91 ± 6.75) years, with a disease course of 13-38 (20.56 ± 7.49) month, and the interviews lasting 31-63 (39.06 ± 8.04) minutes. Among them, 10 (31.25%) lived in the rural area, 22 (68.75%) lived in the urban area, 12 (37.5%) had college education or above, 7 (21.88%) had senior high school education, 10 (31.25%) had junior high school education, and 3 (9.37%) had primary school education. Using the semi-structured method, we conducted interviews with the patients about their sexual experience and needs for sexual function rehabilitation and subjected the results of interviews to Colaizzi analysis. RESULTS: The interviews with the patients covered five topics, which showed intentional refraining from sexual life in 6 (18.75%) of the cases, worrying about hurting the partner by sexual contact in 8 (25%), neglecting sexual troubles in 8 (25%), negative emotions in 5 (15.63%), and expecting medical support in 17 (53.13%). CONCLUSIONS: Male patients with bladder cancer have poor sexual experience after TURBT. Doctors and nurses should inform the patients of potential sexual troubles during the treatment and follow-up, and provide relevant active intervention.


Asunto(s)
Procedimientos de Cirugía Plástica , Neoplasias de la Vejiga Urinaria , Cistectomía , Progresión de la Enfermedad , Humanos , Masculino , Investigación Cualitativa , Neoplasias de la Vejiga Urinaria/cirugía
13.
J Environ Sci (China) ; 93: 164-169, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32446452

RESUMEN

There are good prospects for phosphorus recovery from excess sludge by vivianite crystallization while a large number of extracellular polymeric substances in sludge will have impact on vivianite precipitation. In this study, as a representative of extracellular polymeric substance, the effect of sodium alginate (SA) on phosphorus recovery by vivianite precipitation under different initial SA concentrations (0-800 mg/L), pH values (6.5-9.0) and Fe/P molar ratios (1:1-2.4:1) was investigated using synthetic wastewater. The results showed that SA in low concentrations (≤400 mg/L) had little inhibitory effect on the phosphorus recovery rate. However, when the concentration of SA was larger than 400 mg/L, the phosphorus recovery rate decreased significantly with increasing SA concentrations. The inhibition rate of 800 mg/L SA was about 3 times as large as that of 400 mg/L SA. It was worth noting that the inhibitory effect of SA on vivianite precipitation decreased with increasing initial pH and Fe/P molar ratios. Additionally, SA has no obvious influence on the composition of products, but the morphology of harvested crystals was transformed from branches to plates or rods in uneven sizes.


Asunto(s)
Fósforo , Eliminación de Residuos Líquidos , Alginatos , Precipitación Química , Matriz Extracelular de Sustancias Poliméricas , Compuestos Ferrosos , Fosfatos , Aguas del Alcantarillado
14.
J Appl Clin Med Phys ; 20(11): 104-110, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31580532

RESUMEN

The incidence of brain metastases is increasing and various treatment modalities exist for brain metastases. The aim of this study was to investigate the dosimetric quality and delivery efficiency of robotic radiosurgery (CyberKnife) for multiple brain metastases compared with C-arm linear accelerator (linac) based plans. C-arm linac based plans included intensity-modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT) and non-coplanar VMAT with 1, 3 and 5 non-coplanar arcs, respectively (NC1, NC3 and NC5). For 20 patients, six plans with a prescription dose of 30 Gy in three fractions were generated. The gradient index (GI), conformity index (CI), maximum dose (Dmax ) of organs at risk (OARs), normal brain tissue volume (V3 Gy -V24 Gy ), monitor units (MUs) and beam on time (BT) were evaluated. The GI of CyberKnife plans (3.60 ± 0.70) was lower than IMRT (6.21 ± 2.26, P < 0.05), VMAT (6.04 ± 1.93, P < 0.05), NC1 (5.16 ± 1.71, P < 0.05), NC3 (5.02 ± 1.59, P < 0.05) and NC5 (5.03 ± 1.72, P < 0.05). The CI of the VMAT plans (both coplanar and non-coplanar) was larger than IMRT and CK plans. The Dmax for most OARs of the CyberKnife plan was lower than the C-arm linac based plans, although some differences were not statistically significant. The normal brain tissue volume of CyberKnife plan was lower than the C-arm linac based plans, and the normal brain tissue volume of non-coplanar VMAT plans was lower than IMRT and VMAT plans at high-moderate dose level. However, the MUs and BT of CyberKnife plans was more than C-arm linac based plans. CyberKnife plan was better than C-arm linac based plans in protecting normal brain tissue and OARs for patients with multiple brain metastases. C-arm linac based plan with non-coplanar arc provided better protection of normal brain tissue than coplanar plan. However, the BT of CyberKnife plan was longer than C-arm linac based plans.


Asunto(s)
Neoplasias Encefálicas/cirugía , Aceleradores de Partículas/instrumentación , Garantía de la Calidad de Atención de Salud/normas , Radiocirugia/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Procedimientos Quirúrgicos Robotizados/métodos , Neoplasias Encefálicas/secundario , Humanos , Órganos en Riesgo/efectos de la radiación , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada/métodos , Estudios Retrospectivos
15.
J Appl Clin Med Phys ; 19(3): 142-148, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29603564

RESUMEN

Monte Carlo (MC) simulation, as the most accurate dose calculation algorithm, is available in the MultiPlan treatment planning system for Cyberknife. The main purpose of this work was to perform experiments to thoroughly investigate the accuracy of the MC dose calculation algorithm. Besides the basic MC beam commissioning, two test scenarios were designed. First, single beam tests were performed with a solid water phantom to verify the MC source model in simple geometry. Then, a lung treatment plan on a CIRS thorax phantom was created to mimic the clinical patient treatment. The plan was optimized and calculated using ray tracing (RT) algorithm and then recalculated using MC algorithm. Measurements were performed in both a homogeneous phantom and a heterogeneous phantom (CIRS). Ion-chamber and radiochromic film were used to obtain absolute point dose and dose distributions. Ion-chamber results showed that the differences between measured and MC calculated dose were within 3% for all tests. On the film measurements, MC calculation results showed good agreements with the measured dose for all single beam tests. As for the lung case, the gamma passing rate between measured and MC calculated dose was 98.31% and 97.28% for homogeneous and heterogeneous situation, respectively, using 3%/2 mm criteria. However, RT algorithm failed with the passing rate of 79.25% (3%/2 mm) for heterogeneous situation. These results demonstrated that MC dose calculation algorithm in the Multiplan system is accurate enough for patient dose calculation. It is strongly recommended to use MC algorithm in heterogeneous media.


Asunto(s)
Algoritmos , Método de Montecarlo , Fantasmas de Imagen , Radiocirugia/métodos , Planificación de la Radioterapia Asistida por Computador/normas , Neoplasias Torácicas/cirugía , Humanos , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos
16.
J Appl Clin Med Phys ; 18(6): 49-57, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28905514

RESUMEN

PURPOSE: To investigate the dosimetric characteristics of the new GMS BT-125-1 125 I radioactive seed, including dose rate constant, radial dose functions, and anisotropy functions. METHODS: Dosimetric parameters of GMS BT-125-1 125 I seed including dose rate constant, radial dose functions, and anisotropy functions were calculated using the Monte Carlo code of MCNP5, and measured with thermoluminescent dosimeters (TLDs). The results were compared with those of PharmaSeed BT-125-1, PharmaSeed BT-125-2 125 I, and model 6711 125 I seeds. RESULTS: The dose rate constant of GMS BT-125-1 125 I seed was 0.959 cGy·h-1·U-1, with the difference of 0.94%, 0.83%, and 0.73% compared with the PharmaSeed BT-125-1 125 I seed, PharmaSeed BT-125-2 125 I seed, and Model 6711 125 I seed, respectively. For radial dose function, the differences between the Monte Carlo and the experimental g(r) results were mostly within 10%. Monte Carlo results of g(r) for GMS BT-125-1 125 I seed were found in agreement (within 3.3%) with corresponding results for the PharmaSeed BT-125-2 125 I seed. The largest differences were 8.1% and 6.2% compared with PharmaSeed BT-125-1 125 I seed and model 6711 125 I seed, respectively. For anisotropy function, the difference between GMS BT-125-1 125 I seed and PharmaSeed BT-125-2 125 I seed was typically <10%. CONCLUSIONS: The measured dose rate constant, radial dose functions, and two-dimensional anisotropy functions for the GMS BT-125-1 125 I seed showed good agreement with the Monte Carlo results. The dose rate constant of the GMS BT-125-1 125 I seed is similar to that of the PharmaSeed BT-125-1 125 I seed, the PharmaSeed BT-125-2 125 I seed, and the model 6711 125 I seed. For radial dose functions and two-dimensional anisotropy functions, the GMS BT-125-1 125 I seed is similar to the PharmaSeed BT-125-2 125 I seed but different from the PharmaSeed BT-125-1 125 I seed and the model 6711 125 I seed.


Asunto(s)
Simulación por Computador , Radioisótopos de Yodo/uso terapéutico , Método de Montecarlo , Fantasmas de Imagen , Planificación de la Radioterapia Asistida por Computador/métodos , Anisotropía , Humanos , Radiometría/métodos , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada/métodos , Dosimetría Termoluminiscente
17.
Beijing Da Xue Xue Bao Yi Xue Ban ; 47(6): 952-6, 2015 Dec 18.
Artículo en Zh | MEDLINE | ID: mdl-26679656

RESUMEN

OBJECTIVE: To evaluate the six-degree setup errors of tumors of cervical vertebra, thoracic vertebra and lumbar vertebra by image guided radiotherapy. METHODS: From May 2013 to June 2014, 30 patients with spinal malignant tumors(10 patients of cervical vertebra, thoracic vertebra and lumbar vertebra respectively) were treated with Elekata Synergy accelerator (Elekta company,Sweden). Six-degree set up errors were corrected using HexaPODTMevoRT bed under image of on board cone beam computed tomography (CBCT) guided. All the patients received kilovoltage CBCT before receiving radiotherapy and after correction. The acquired images were co-registered with planning CT with bone window. The data of 838 CT images were analyzed and the errors of translational directions X(lateral), Y(lngitudinal),Z(vertical)and rotational directions RX(pitch), RY(roll), RZ(yaw) were recorded. The data were compared by t-test using SPSS 13.0. RESULTS: The absolute translational setup errors in X, Y and Z axes of cervical vertebra before correction were (1.71 ± 0.10) mm, (1.81 ± 0.11) mm and (1.94 ± 0.09) mm respectively: (3.17 ± 0.19) mm, (4.26 ± 0.28) mm and (2.18 ± 0.12) mm for thoracic vertebra, and (2.69 ± 0.24) mm, (3.33 ± 0.26) mm and (2.86 ± 0.21) mm for lumbar vertebra. The residual setup errors in X, Y and Z axes of cervical vertebra were (0.5 ± 2.4) mm,(0.01 ± 2.4) mm and (2.4 ± 1.4) mm, respectively after correction;(1.17 ± 0.11) mm,(0.26 ± 0.30) mm and (0.08 ± 0.12) mm for thoracic vertebra and (1.09 ± 0.24) mm,(2.03 ± 1.26) mm and (0.06 ± 0.51) mm for lumbar vertebra. The t-test of paired data of set up errors before and after CBCT showed significant difference in three translational directions of cervical vertebra and thoracic vertebra, only Z(t=-3.518,P<0.001) for lumbar vertebra. The absolute rotational setup errors in RX,RY and RZ axes of cervical vertebra before correction were 0.67° ± 0.04°,1.06° ± 0.06° and 0.78° ± 0.05° respectively. 0.62° ± 0.05°, 0.75° ± 0.06°, and 0.84° ± 0.06° for thoracic vertebra, 0.59° ± 0.06°, 0.80° ± 0.07°, and 0.73° ± 0.06° for lumbar vertebra. The rotational directions RX, RY and RZ axes of cervical vertebra were 0.27° ± 0.14°, 1.20° ± 0.04° and 0.28° ± 0.05° respectively; 0.02° ± 0.20°, 0.05°±0.26° and 0.64° ± 0.16° for thoracic vertebra and 0.09° ± 0.26°, 0.50°±0.05°,and 0.03°±0.16° for lumbar vertebra. The t-test of paired data of set up errors before and after CBCT showed significant difference in three rotational directions of cervical vertebra and lumbar vertebra, only RY(t=7.106, P<0.001)for thoracic vertebra. All the patients acquired pain relief and there was no radiation-induced toxicity detected clinically during a median follow-up of 6 months. CONCLUSION: Six-degree set up errors of spine tumors were corrected effectively with HexaPODTMevoRT bed under CBCT image guided and its feasibility in day-to-day clinical practice has been demonstrated.


Asunto(s)
Planificación de la Radioterapia Asistida por Computador , Radioterapia Guiada por Imagen , Neoplasias de la Columna Vertebral/radioterapia , Vértebras Cervicales/patología , Tomografía Computarizada de Haz Cónico , Humanos , Vértebras Lumbares/patología , Traumatismos por Radiación , Vértebras Torácicas/patología
18.
ACS Nano ; 18(20): 12598-12609, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38723158

RESUMEN

This review presents an overview of the application of electrochemical liquid-phase transmission electron microscopy (ELP-TEM) in visualizing rechargeable battery reactions. The technique provides atomic-scale spatial resolution and real-time temporal resolution, enabling direct observation and analysis of battery materials and processes under realistic working conditions. The review highlights key findings and insights obtained by ELP-TEM on the electrochemical reaction mechanisms and discusses the current limitations and future prospects of ELP-TEM, including improvements in spatial and temporal resolution and the expansion of the scope of materials and systems that can be studied. Furthermore, the review underscores the critical role of ELP-TEM in understanding and optimizing the design and fabrication of high-performance, long-lasting rechargeable batteries.

19.
Front Oncol ; 14: 1433225, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39351348

RESUMEN

Purpose: The 3D U-Net deep neural network structure is widely employed for dose prediction in radiotherapy. However, the attention to the network depth and its impact on the accuracy and robustness of dose prediction remains inadequate. Methods: 92 cervical cancer patients who underwent Volumetric Modulated Arc Therapy (VMAT) are geometrically augmented to investigate the effects of network depth on dose prediction by training and testing three different 3D U-Net structures with depths of 3, 4, and 5. Results: For planning target volume (PTV), the differences between predicted and true values of D98, D99, and Homogeneity were statistically 1.00 ± 0.23, 0.32 ± 0.72, and -0.02 ± 0.02 for the model with a depth of 5, respectively. Compared to the other two models, these parameters were also better. For most of the organs at risk, the mean and maximum differences between the predicted values and the true values for the model with a depth of 5 were better than for the other two models. Conclusions: The results reveal that the network model with a depth of 5 exhibits superior performance, albeit at the expense of the longest training time and maximum computational memory in the three models. A small server with two NVIDIA GeForce RTX 3090 GPUs with 24 G of memory was employed for this training. For the 3D U-Net model with a depth of more than 5 cannot be supported due to insufficient training memory, the 3D U-Net neural network with a depth of 5 is the commonly used and optimal choice for small servers.

20.
Phys Med ; 125: 104498, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39163802

RESUMEN

PURPOSE: The formulation and optimization of radiation therapy plans are complex and time-consuming processes that heavily rely on the expertise of medical physicists. Consequently, there is an urgent need for automated optimization methods. Recent advancements in reinforcement learning, particularly deep reinforcement learning (DRL), show great promise for automating radiotherapy planning. This review summarizes the current state of DRL applications in this field, evaluates their effectiveness, and identifies challenges and future directions. METHODS: A systematic search was conducted in Google Scholar, PubMed, IEEE Xplore, and Scopus using keywords such as "deep reinforcement learning", "radiation therapy", and "treatment planning". The extracted data were synthesized for an overview and critical analysis. RESULTS: The application of deep reinforcement learning in radiation therapy plan optimization can generally be divided into three categories: optimizing treatment planning parameters, directly optimizing machine parameters, and adaptive radiotherapy. From the perspective of disease sites, DRL has been applied to cervical cancer, prostate cancer, vestibular schwannoma, and lung cancer. Regarding types of radiation therapy, it has been used in HDRBT, IMRT, SBRT, VMAT, GK, and Cyberknife. CONCLUSIONS: Deep reinforcement learning technology has played a significant role in advancing the automated optimization of radiation therapy plans. However, there is still a considerable gap before it can be widely applied in clinical settings due to three main reasons: inefficiency, limited methods for quality assessment, and poor interpretability. To address these challenges, significant research opportunities exist in the future, such as constructing evaluators, parallelized training, and exploring continuous action spaces.


Asunto(s)
Aprendizaje Profundo , Planificación de la Radioterapia Asistida por Computador , Planificación de la Radioterapia Asistida por Computador/métodos , Humanos
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