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1.
Cell Mol Life Sci ; 81(1): 220, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38763956

RESUMO

Cardiovascular diseases are an array of age-related disorders, and accumulating evidence suggests a link between cardiac resident macrophages (CRMs) and the age-related disorders. However, how does CRMs alter with aging remains elusive. In the present study, aged mice (20 months old) have been employed to check for their cardiac structural and functional alterations, and the changes in the proportion of CRM subsets as well, followed by sorting of CRMs, including C-C Motif Chemokine Receptor 2 (CCR2)+ and CCR2- CRMs, which were subjected to Smart-Seq. Integrated analysis of the Smart-Seq data with three publicly available single-cell RNA-seq datasets revealed that inflammatory genes were drastic upregulated for both CCR2+ and CCR2- CRMs with aging, but genes germane to wound healing were downregulated for CCR2- CRMs, suggesting the differential functions of these two subsets. More importantly, inflammatory genes involved in damage sensing, complement cascades, and phagocytosis were largely upregulated in CCR2- CRMs, implying the imbalance of inflammatory response upon aging. Our work provides a comprehensive framework and transcriptional resource for assessing the impact of aging on CRMs with a potential for further understanding cardiac aging.


Assuntos
Envelhecimento , Perfilação da Expressão Gênica , Macrófagos , Camundongos Endogâmicos C57BL , Receptores CCR2 , Animais , Macrófagos/metabolismo , Envelhecimento/genética , Envelhecimento/metabolismo , Camundongos , Receptores CCR2/metabolismo , Receptores CCR2/genética , Transcriptoma , Miocárdio/metabolismo , Masculino , Análise de Célula Única , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Transdução de Sinais , Fagocitose
2.
Opt Lett ; 49(12): 3472-3475, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38875648

RESUMO

We propose and experimentally demonstrate a dual-wavelength distributed feedback (DFB) laser array utilizing a four-phase-shifted sampled Bragg grating. By using this grating, the coupling coefficient is enhanced by approximately 2.83 times compared to conventional sampled Bragg gratings. The devices exhibit a stable dual-mode lasing achieved by introducing further π-phase shifts at 1/3 and 2/3 positions along the cavity. These devices require only one stage of lithography to define both the ridge waveguide and the gratings, mitigating issues related to misalignment between them. A dual-wavelength laser array has been fabricated with frequency spacings of 320 GHz, 500 GHz, 640 GHz, 800 GHz, and 1 THz. When integrated with semiconductor optical amplifiers, the output power of the device can reach 23.6 mW. Furthermore, the dual-wavelength lasing is maintained across a wide range of injection currents, with a power difference of <3 dB between the two primary modes. A terahertz (THz) signal has been generated through photomixing in a photoconductive antenna, with the measured power reaching 12.8 µW.

3.
J Med Virol ; 95(12): e29293, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38054393

RESUMO

The incidence of human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (OPSCC) is increasing among elderly (≥70 years) patients and the optimal treatment approach is not known. In this study, we aimed to determine disease and toxicity outcomes in an elderly HPV-OPSCC population primarily treated with a chemoradiation (CRT) approach. We identified 70 elderly HPV-OPSCC patients who were treated with either surgery, radiotherapy, or CRT between 2011 and 2021. Time-to-event analysis for overall survival (OS), progression-free survival (PFS), and local control (LC) were conducted using the Kaplan-Meier method. Univariate and multivariable cox regression models were used to estimate the hazard ratio associated with covariates. The median follow-up for our cohort was 43.9 months. Of the 70 elderly patients, 55 (78.6%) receive CRT and 15 (22.4%) received RT alone. Two patients underwent TORS resection. Of the 55 patients treated with CRT, the most common systemic agents were weekly carboplatin/taxol (n = 18), cetuximab (n = 17), and weekly cisplatin (n = 11). The 5-year OS, PFS, and LC were 57%, 52%, and 91%, respectively. On univariate analysis, Eastern Cooperative Oncology Group performance status and Charlson Comorbidity Index (CCI) were significant predictors of OS, while on multivariate analysis only CCI was a significant predictor of OS (p = 0.006). The rate of late peg tube dependency, osteoradionecrosis, and aspiration was 10%, 4%, and 4%, respectively. Definitive local therapy in elderly HPV-OPSCC patients is associated with excellent LC and a low rate of late toxicities. Prospective studies are needed to further stratify subgroups of elderly patients who may benefit from aggressive definitive local therapy.


Assuntos
Neoplasias de Cabeça e Pescoço , Neoplasias Orofaríngeas , Infecções por Papillomavirus , Humanos , Idoso , Papillomavirus Humano , Infecções por Papillomavirus/complicações , Neoplasias Orofaríngeas/radioterapia , Neoplasias Orofaríngeas/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço , Estudos Retrospectivos
4.
Opt Lett ; 48(19): 5093-5096, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37773393

RESUMO

A dual-wavelength DFB laser array based on four phase-shifted grating and equivalent chirp technology is first proposed, fabricated, and experimentally demonstrated. The dual-wavelength emitting is achieved by symmetrically introducing two π phase shifts into a chirped four phase-shifted sampled grating cavity. Meanwhile, the beating signal of the dual-wavelength output is stabilized by applying an electro-absorption modulator integrated at the rear of the cavity. Under different grating chirp rates, a series of RF signals from 66.8 GHz to 73.6 GHz with a linewidth of less than 210 kHz is obtained.

5.
Int J Gynecol Cancer ; 31(1): 73-77, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33087415

RESUMO

OBJECTIVE: The benefits of adjuvant radiation treatment after hysterectomy have been confirmed in select patients with early-stage endometrial carcinoma. The goal of this study was to evaluate the prognostic impact of the time interval between hysterectomy and starting adjuvant radiation treatment in patients with early-stage endometrial carcinoma. METHODS: Our database was searched for women with early-stage endometrioid endometrial cancer who received adjuvant radiation therapy after hysterectomy. The patients were classified into two groups based on the time interval to adjuvant radiation therapy (≤8 weeks or >8 weeks) after hysterectomy. Recurrence-free survival, disease-specific survival, and overall survival were compared between the two groups. RESULTS: Four hundred and sixty patients were identified. Median follow-up was 70.5 months (range 1-360). One hundred and seventy-six patients (38%) were 2009 International Federation of Gynecology and Obstetrics stage IA, 207 (45%) stage IB, and 77 (17%) stage II. Three hundred and fifty-four women (77%) received adjuvant radiation therapy within 8 weeks after hysterectomy. There was no statistically significant difference between the two groups in baseline demographics, disease and treatment characteristics, except for the modality of adjuvant radiation therapy. Patients who received adjuvant radiation therapy within 8 weeks experienced significantly less disease recurrence (9% vs 18%; p=0.01) and particularly less isolated vaginal recurrence (0% vs 6%, p=0.04). Five-year recurrence-free survival was 89% versus 80% (p=0.04), 5-year disease-specific survival was 93% for both groups, and 5-year overall survival was 86% versus 85% for patients who received adjuvant radiation therapy ≤8 and >8 weeks, respectively (p=0.88). CONCLUSION: Our study suggests that delaying adjuvant radiation therapy beyond 8 weeks after hysterectomy is associated with significantly more cancer recurrences for women with early-stage endometrial carcinoma.


Assuntos
Braquiterapia/métodos , Carcinoma Endometrioide/terapia , Neoplasias do Endométrio/terapia , Histerectomia , Recidiva Local de Neoplasia/etiologia , Radioterapia Adjuvante/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Endometrioide/mortalidade , Carcinoma Endometrioide/patologia , Neoplasias do Endométrio/mortalidade , Neoplasias do Endométrio/patologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estudos Retrospectivos , Medição de Risco , Tempo para o Tratamento
6.
J Appl Clin Med Phys ; 21(11): 195-204, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33073454

RESUMO

PURPOSE: Rising evidence suggests that cardiac substructures are highly radiosensitive. However, they are not routinely considered in treatment planning as they are not readily visualized on treatment planning CTs (TPCTs). This work integrated the soft tissue contrast provided by low-field MRIs acquired on an MR-linac via image registration to further enable cardiac substructure sparing on TPCTs. METHODS: Sixteen upper thoracic patients treated at various breathing states (7 end-exhalation, 7 end-inhalation, 2 free-breathing) on a 0.35T MR-linac were retrospectively evaluated. A hybrid MR/CT atlas and a deep learning three-dimensional (3D) U-Net propagated 13 substructures to TPCTs. Radiation oncologists revised contours using registered MRIs. Clinical treatment plans were re-optimized and evaluated for beam arrangement modifications to reduce substructure doses. Dosimetric assessment included mean and maximum (0.03cc) dose, left ventricular volume receiving 5Gy (LV-V5), and other clinical endpoints. As metrics of plan complexity, total MU and treatment time were evaluated between approaches. RESULTS: Cardiac sparing plans reduced the mean heart dose (mean reduction 0.7 ± 0.6, range 0.1 to 2.5 Gy). Re-optimized plans reduced left anterior descending artery (LADA) mean and LADA0.03cc (0.0-63.9% and 0.0 to 17.3 Gy, respectively). LV0.03cc was reduced by >1.5 Gy for 10 patients while 6 cases had large reductions (>7%) in LV-V5. Left atrial mean dose was equivalent/reduced in all sparing plans (mean reduction 0.9 ± 1.2 Gy). The left main coronary artery was better spared in all cases for mean dose and D0.03cc . One patient exhibited >10 Gy reduction in D0.03cc to four substructures. There was no statistical difference in treatment time and MU, or clinical endpoints to the planning target volume, lung, esophagus, or spinal cord after re-optimization. Four patients benefited from new beam arrangements, leading to further dose reductions. CONCLUSIONS: By introducing 0.35T MRIs acquired on an MR-linac to verify cardiac substructure segmentations for CT-based treatment planning, an opportunity was presented for more effective sparing with limited increase in plan complexity. Validation in a larger cohort with appropriate margins offers potential to reduce radiation-related cardiotoxicities.


Assuntos
Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada , Coração/diagnóstico por imagem , Humanos , Órgãos em Risco , Dosagem Radioterapêutica , Estudos Retrospectivos
7.
Cancer Invest ; 36(7): 389-394, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30188744

RESUMO

PURPOSE: Outcomes after adjuvant radiotherapy for cutaneous melanoma with perineural invasion (PNI). METHODS: Seven patients (5 cutaneous, 2 recurrent nerve lesions) received radiotherapy. RESULTS: At a median 4.5 years: Two patients did not recur; no local failures occurred. Three patients who omitted nodal irradiation developed regional failures (2 out-of-field, 1 in-field). Three patients developed distant metastases. Four died with disease (median, 3.6 years); 1 died from intercurrent disease (13.0 years). Two are alive without disease (6.8 and 11.6 years). No patient experienced grade ≥3 toxicity. CONCLUSIONS: Postoperative radiotherapy can reduce local recurrences; primary radiotherapy for unresectable disease is recommended.


Assuntos
Melanoma/tratamento farmacológico , Nervos Periféricos/efeitos da radiação , Neoplasias Cutâneas/radioterapia , Universidades , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Intervalo Livre de Doença , Feminino , Florida , Humanos , Masculino , Melanoma/mortalidade , Melanoma/secundário , Pessoa de Meia-Idade , Invasividade Neoplásica , Recidiva Local de Neoplasia , Nervos Periféricos/patologia , Radioterapia Adjuvante , Estudos Retrospectivos , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/patologia , Fatores de Tempo , Resultado do Tratamento
8.
Cancer Invest ; 36(5): 289-295, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30040495

RESUMO

We conducted a retrospective study of stereotactic ablative radiotherapy (SABR) for 94 patients with non-small-cell lung cancer at our institution. The patients were treated with either 50 Gy in five treatments or 48 Gy in four treatments, corresponding to biologically effective doses (BED) of 100 Gy or 105.6 Gy, respectively. The results demonstrate that, with relatively low BEDs, we can achieve excellent local control with minimal toxicity.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/cirurgia , Fracionamento da Dose de Radiação , Neoplasias Pulmonares/cirurgia , Recidiva Local de Neoplasia/prevenção & controle , Pneumonite por Radiação/prevenção & controle , Radiocirurgia/métodos , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Planejamento da Radioterapia Assistida por Computador , Estudos Retrospectivos , Taxa de Sobrevida
9.
Nanoscale Adv ; 6(12): 3211-3219, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38868815

RESUMO

Quinclorac is an important precursor for pharmaceutical, agricultural, and synthetic chemistry. The state-of-the-art synthesis of quinclorac via condensation, chlorination and oxidative hydrolysis often uses homogeneous catalysts and strong acid oxidant agents to promote the catalytic oxidation, which requires huge manpower input for the late-stage purification process and is usually environmentally unfriendly. In this work, we successfully fabricated a stable cobalt phthalocyanine (CoPc) Co-based composite (CoPc/Ti3C2) by anchoring CoPc on the surface of Ti3C2 nanosheets for the selective oxidation of 3,7-dichloro-8-dichloro methyl quinoline (3,7-D-8-DMQ) into quinclorac. More impressively, CoPc/Ti3C2-4.5%-Mn-Br exhibits a high selectivity of 91.8% for the catalytic oxidation of 3,7-D-8-DMQ to quinclorac in acetic acid, with a quinclorac yield of 87.5%, which is approximately 2.46 times higher than that of pristine CoPc-Mn-Br. The obtained heterogeneous catalytic system shows good reusability. Detailed mechanistic investigations reveal that the system works through the free radical mechanism via the formation of Co2+/Co3+ redox cycles. This work provides a new understanding for the stabilization of reaction intermediates and facilitates the design of catalysts for selective catalytic oxidation.

10.
Artigo em Inglês | MEDLINE | ID: mdl-38797498

RESUMO

INTRODUCTION: Cardiac substructure dose metrics are more strongly linked to late cardiac morbidities than whole-heart metrics. MR-guided radiation therapy (MRgRT) enables substructure visualization during daily localization, allowing potential for enhanced cardiac sparing. We extend a publicly available state-of-the-art deep learning (DL) framework, nnU-Net, to incorporate self-distillation (nnU-Net.wSD) for substructure segmentation for MRgRT. METHODS: Eighteen (Institute A) patients who underwent thoracic or abdominal radiation therapy on a 0.35 T MR-guided linac were retrospectively evaluated. On each image, one of two radiation oncologists delineated reference contours of 12 cardiac substructures (chambers, great vessels, and coronary arteries) used to train (n=10), validate (n=3), and test (n=5) nnU-Net.wSD leveraging a teacher-student network and comparing to standard 3D U-Net. The impact of using simulation data or including 3-4 daily images for augmentation during training was evaluated for nnU-Net.wSD. Geometric metrics (Dice similarity coefficient (DSC), mean distance to agreement (MDA), and 95% Hausdorff distance (HD95)), visual inspection, and clinical dose volume histograms (DVHs) were evaluated. To determine generalizability, Institute A's model was tested on an unlabeled dataset from Institute B (n=22) and evaluated via consensus scoring and volume comparisons. RESULTS: nnU-Net.wSD yielded a DSC (reported mean ± standard deviation) of 0.65±0.25 across the 12 substructures (Chambers: 0.85±0.05, Great Vessels: 0.67±0.19, and Coronary Arteries 0.33±0.16, mean MDA <3 mm, and mean HD95 <9 mm) while outperforming the 3D U-Net (0.583±0.28, p<0.01). Leveraging fractionated data for augmentation improved over a single MR-SIM timepoint (0.579±0.29, p<0.01). Predicted contours yielded DVHs that closely matched the clinical treatment plans where mean and D0.03cc doses deviated by 0.32±0.5 Gy and 1.42±2.6 Gy respectively. No statistically significant differences between Institute A and B volumes (p>0.05) for 11 of 12 substructures with larger volumes requiring minor changes and coronary arteries exhibiting more variability. CONCLUSIONS: This work is a critical step to rapid and reliable cardiac substructure segmentation to improve cardiac sparing in low-field MRgRT.

11.
Cancers (Basel) ; 16(5)2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38473406

RESUMO

OBJECTIVES: Patients with recurrent and metastatic head and neck cancer (HNC) have limited treatment options. 'QuadShot' (QS), a hypofractionated palliative radiotherapy regimen, can provide symptomatic relief and local control and may potentiate the effects of immune checkpoint inhibitors (ICIs). We compared outcomes of QS ± concurrent ICIs in the palliative treatment of HNC. MATERIALS AND METHODS: We identified patients who received ≥three cycles of QS from 2017 to 2022 and excluded patients without post-treatment clinical evaluation or imaging. Outcomes for patients who received QS alone were compared to those treated with ICI concurrent with QS, defined as receipt of ICI within 4 weeks of QS. RESULTS: Seventy patients were included, of whom 57% received concurrent ICI. Median age was 65.5 years (interquartile range [IQR]: 57.9-77.8), and 50% patients had received prior radiation to a median dose of 66 Gy (IQR: 60-70). Median follow-up was 8.8 months. Local control was significantly higher with concurrent ICIs (12-month: 85% vs. 63%, p = 0.038). Distant control (12-month: 56% vs. 63%, p = 0.629) and median overall survival (9.0 vs. 10.0 months, p = 0.850) were similar between the two groups. On multivariable analysis, concurrent ICI was a significant predictor of local control (HR for local failure: 0.238; 95% CI: 0.073-0.778; p = 0.018). Overall, 23% patients experienced grade 3 toxicities, which was similar between the two groups. CONCLUSIONS: The combination of QS with concurrent ICIs was well tolerated and significantly improved local control compared to QS alone. The median OS of 9.4 months compares favorably to historical controls for patients with HNC treated with QS. This approach represents a promising treatment option for patients with HNC unsuited for curative-intent treatment and warrants prospective evaluation.

12.
Cancers (Basel) ; 16(6)2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38539538

RESUMO

BACKGROUND: Salivary duct carcinomas (SDC) are a rare and aggressive subtype of salivary gland neoplasm. They can present with distinct immunoprofiles, such as androgen receptor (AR) and HER-2/Neu-positivity. To date, no consensus exists on how to best manage this entity. METHODS: All patients diagnosed with nonmetastatic AR+ SDC of the parotid from 2013 to 2019 treated with curative intent were included. Immunologic tumor profiling was conducted using 24 distinct markers. Kaplan-Meier analyses were used to estimate locoregional recurrence (LRR), distant control, and overall survival (OS). RESULTS: Fifteen patients were included. Nine (60%) patients presented with T4 disease and eight (53%) had positive ipsilateral cervical lymphadenopathy. Ten (67%) patients underwent trimodality therapy, including surgery followed by adjuvant radiation and concurrent systemic therapy. The median follow-up was 5.5 years (interquartile range, 4.8-6.1). The estimated 5-year rates of LRR, distant progression, and OS were 6%, 13%, and 87%, respectively. CONCLUSION: Despite only including AR+ SDC of the parotid, immunoprofiles, such as expression of HER-2, were highly variable, highlighting the potential to tailor systemic regimens based on individual histologic profiles in the future. Studies with larger patient numbers using tumor-specific molecular profiling and tumor heterogeneity analyses are justified to better understand the biology of these tumors. Molecularly informed treatment approaches, including the potential use of AR- and HER-2/Neu-directed therapies upfront in the definitive setting, may hold future promise to further improve outcomes for these patients.

13.
Am J Clin Oncol ; 46(3): 114-120, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36625449

RESUMO

OBJECTIVE: To report the impact of race on clinical outcomes in patients with stage IIIC endometrial carcinoma. MATERIALS AND METHODS: A retrospective multi-institutional study included 90 black and 568 non-black patients with stage IIIC endometrial carcinoma who received adjuvant chemotherapy and radiation treatments. Overall survival (OS) and recurrence-free survival (RFS) were calculated by the Kaplan-Meier method. Propensity score matching (PSM) was conducted. Statistical analyses were conducted using SPSS version 27. RESULTS: The Median follow-up was 45.3 months. black patients were significantly older, had more nonendometrioid histology, grade 3 tumors, and were more likely to have >1 positive paraaortic lymph nodes compared with non-black patients (all P <0.0001). The 5-year estimated OS and RFS rates were 45% and 47% compared with 77% and 68% for black patients versus non-black patients, respectively ( P <0.001). After PSM, the 2 groups were well-balanced for all prognostic covariates. The estimated hazard ratios of black versus non-black patients were 1.613 ( P value=0.045) for OS and 1.487 ( P value=0.116) for RFS. After PSM, black patients were more likely to receive the "Sandwich" approach and concurrent chemoradiotherapy compared with non-black ( P =0.013) patients. CONCLUSIONS: Black patients have higher rates of nonendometrioid histology, grade 3 tumors, and number of involved paraaortic lymph nodes, worse OS, and RFS, and were more likely to receive the "Sandwich" approach compared with non-black patients. After PSM, black patients had worse OS with a nonsignificant trend in RFS. Access to care, equitable inclusion on randomized trials, and identification of genomic differences are warranted to help mitigate disparities.


Assuntos
Neoplasias do Endométrio , Feminino , Humanos , Quimioterapia Adjuvante , Neoplasias do Endométrio/patologia , Linfonodos/patologia , Estadiamento de Neoplasias , Estudos Retrospectivos
14.
Int J Med Inform ; 165: 104828, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35780651

RESUMO

BACKGROUND: Machine learning (ML), a type of artificial intelligence (AI) technology that uses a data-driven approach for pattern recognition, has been shown to be beneficial for many tasks across healthcare. To characterize the commercial availability of AI/ML applications in the clinic, we performed a detailed analysis of AI/ML-enabled medical devices approved/cleared by the US Food and Drug Administration (FDA) by June 2021. METHODS/MATERIALS: The publicly available approval letters by the FDA on 343 AI/ML-enabled medical devices compiled by the agency were reviewed. The characteristics of the devices and the patterns of their intended use were analyzed, and basic descriptive statistical analysis was performed on the aggregated data. RESULTS: Most devices were reviewed by radiology (70.3%) and cardiovascular (12.0%) medical specialty panels. The growth of these devices sharply rose since the mid-2010s. Most (95.0%) devices were cleared under the 510(k) premarket notification pathway, and 69.4% were software as a medical device (SaMD). Of the 241 radiology-related devices, the most common applications were for diagnostic assistance (48.5%) and image reconstruction (14.1%). Of the 117 radiology-related devices for diagnostic assistance, 20.5% were developed for breast lesion assessment and 14.5% for cardiac function assessment on echocardiogram. Of the 41 cardiology-related devices, the most common applications were electrocardiography-based arrhythmia detection (46.3%) and hemodynamics & vital signs monitoring (26.8%). CONCLUSION: In this study, we characterized the patterns and trends of AI/ML-enabled medical devices approved or cleared by the FDA. To our knowledge, this is the most up-to-date and comprehensive analysis of the landscape as of 2021.


Assuntos
Cardiologia , Aprovação de Equipamentos , Inteligência Artificial , Humanos , Aprendizado de Máquina , Estados Unidos , United States Food and Drug Administration
15.
Phys Med Biol ; 67(22)2022 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-36270582

RESUMO

Reinforcement learning takes sequential decision-making approaches by learning the policy through trial and error based on interaction with the environment. Combining deep learning and reinforcement learning can empower the agent to learn the interactions and the distribution of rewards from state-action pairs to achieve effective and efficient solutions in more complex and dynamic environments. Deep reinforcement learning (DRL) has demonstrated astonishing performance in surpassing the human-level performance in the game domain and many other simulated environments. This paper introduces the basics of reinforcement learning and reviews various categories of DRL algorithms and DRL models developed for medical image analysis and radiation treatment planning optimization. We will also discuss the current challenges of DRL and approaches proposed to make DRL more generalizable and robust in a real-world environment. DRL algorithms, by fostering the designs of the reward function, agents interactions and environment models, can resolve the challenges from scarce and heterogeneous annotated medical image data, which has been a major obstacle to implementing deep learning models in the clinic. DRL is an active research area with enormous potential to improve deep learning applications in medical imaging and radiation therapy planning.


Assuntos
Redes Neurais de Computação , Reforço Psicológico , Humanos , Algoritmos , Radiografia , Imagem de Difusão por Ressonância Magnética
16.
J Hazard Mater ; 431: 128549, 2022 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-35220118

RESUMO

Biochar was used as a heterogeneous activator for peroxymonosulfate (PMS), and the activation performance strongly depended on the structure, functional groups, and modification of the biochar. In this study, a new type of modified biochar was synthesized by utilizing the Mn(II) adsorption capacity of bacteria. After one-step pyrolysis of Mn(II)-adsorbed bacterial cells at 800 °C, a Mn-incorporated bacterial-derived biochar (Mn-BBC) was successfully produced. It exhibited structural heterogeneity, with MnO located at the surface of the BBC matrix, as shown on the result of SEM and XRD. Compared to BBC, Mn-BBC showed a 10-fold increase (0.0727 min-1 versus 0.0069 min-1) of pollutant removal rate. In addition, it also showed anti-interference capacity against common water matrix (except 10 mM CO32-) and great stability/reusability. Chemical quenching, electron spin resonance, and pyrophosphate trapping indicated an indirect but important role of the superoxide, formed during the self-decomposition of PMS. The MnO on Mn-BBC can be oxidized by superoxide to produce surface Mn(III), which then binds to PMS and forms a surface complex. This complex promotes electron transfer from the pollutant to the Mn-BBC, facilitating the oxidation of the contaminants. Overall, this study confirmed the PMS activation capacity and mechanism of Mn-BBC, which expands the application of BBC-based materials derived from metal-adsorbed microbes.


Assuntos
Poluentes Ambientais , Superóxidos , Bactérias , Carvão Vegetal , Peróxidos
17.
J Hazard Mater ; 427: 127938, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-34863569

RESUMO

Heterogeneous sulfate radical-based advanced oxidation processes (SR-AOPs) have been widely reported over the last decade as a promising technology for pollutant removal from wastewater. In this study, a novel peroxymonosulfate (PMS) activator was obtained by visible-light-driven Mn(II) oxidation in the presence of nitrate. The photochemically synthesized manganese oxides (PC-MnOx) were polymorphic amorphous nanoparticles and nanorods, with an average oxidation state of approximately 3.0. It possesses effective PMS activation capacity and can remove 20 mg L-1 acid organic II (AO7) within 30 min. The AO7 removal performance of PC-MnOx was slightly decreased in natural waterbodies and in the presence of CO32-, while it showed an anti-interference capacity for Cl-, NO3- and humic acid. Chemical quenching, reactive oxygen species (ROS) trapping, X-ray photoelectric spectroscopy (XPS), in-situ Raman spectroscopy, and electrochemical experiments supported a nonradical mechanism, i.e., electron transfer from AO7 to the metastable PC-MnOx-PMS complex, which was responsible for AO7 oxidation. The PC-MnOx-PMS system also showed substrate preferences based on their redox potentials. Moreover, PC-MnOx could activate periodate (PI) but not peroxydisulfate (PDS) or H2O2. Overall, this study provides a new catalyst for PMS activation through a mild and green synthesis approach.

18.
J Hazard Mater ; 424(Pt C): 127692, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-34800842

RESUMO

Periodate (PI)-based advanced oxidation processes are a newly discovered approach for effective pollutant elimination. In this study, we demonstrated that biochar obtained from pyrolysis of anaerobic sewage sludge without any pretreatment can be used for PI activation. The biochar obtained at 800 °C (SBC-800) exhibited the best PI activation capacity using acid organic II (AO7) as substrate. The PI activation was strongly dependent on pH and exhibited the highest AO7 removal rate at pH 3.0. Meanwhile, the anti-interference capacity with common wastewater components and reusability of the SBC-800/PI system were confirmed. Combined with the results of chemical quenching, reactive oxygen species (ROS) trapping, X-ray photoelectric spectroscopy (XPS), electrochemical and density function theory (DFT)-based calculations, singlet oxygen production and electron transfer mediated by the SBC-800-PI complex were the dominant AO7 oxidation mechanisms. This study provides easily prepared catalysts for PI activation and paves the way for solid waste recycling and reuse.


Assuntos
Carvão Vegetal , Esgotos , Anaerobiose , Ácido Periódico
19.
Artigo em Inglês | MEDLINE | ID: mdl-35682093

RESUMO

Chloramine and chloroform are widespread in tap water due to water disinfection processes. This study was designed to explore the associations between trimester-specific exposure to chloramine and chloroform in tap water and adverse outcomes. This retrospective cohort study included 109,182 mother-infant singleton pairs in Shanghai. A logistic regression model was used to evaluate the associations of chloramine and chloroform concentrations averaged over the whole pregnancy and in each trimester with adverse outcomes, including gestational diabetes mellitus (GDM), gestational hypertensive disorders (GHD), low birthweight (LBW), small for gestational age (SGA), preterm birth (PTB) and prelabor rupture of membranes (PROM). The use of tap water with elevated chloramine levels in the first trimester was associated with GDM (OR = 1.06, 95% CI: 1.03, 1.09), while that in the second trimester was related to GHD (OR = 1.13, 95% CI: 1.09, 1.17). Chloroform levels in the third trimester were associated with LBW (OR = 1.13, 95% CI: 1.09, 1.16), PTB (OR = 1.05, 95% CI: 1.01, 1.08) and PROM (OR = 1.01, 95% CI: 1.00, 1.01). However, tap water chloroform exposure in the second trimester was negatively associated with LBW (OR = 0.95, 95% CI: 0.93, 0.98) and PTB (OR = 0.97, 95% CI: 0.94, 0.99). In conclusion, there are probably no casual associations between current tap water chloroform and chloramine levels and perinatal outcomes. However, more research focusing on the effect of chloramine and chloroform on perinatal outcomes are still warranted.


Assuntos
Diabetes Gestacional , Hipertensão Induzida pela Gravidez , Nascimento Prematuro , China/epidemiologia , Cloraminas , Clorofórmio , Feminino , Humanos , Recém-Nascido , Gravidez , Resultado da Gravidez/epidemiologia , Estudos Retrospectivos , Água
20.
Biomed Phys Eng Express ; 8(4)2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34781281

RESUMO

Purpose.To utilize radiomic features extracted from CT images to characterize Human Papilloma Virus (HPV) for patients with oropharyngeal cancer squamous cell carcinoma (OPSCC).Methods.One hundred twenty-eight OPSCC patients with known HPV-status (60-HPV + and 68-HPV-, confirmed by immunohistochemistry-P16-protein testing) were retrospectively studied. Radiomic features (11 feature-categories) were extracted in 3D from contrast-enhanced (CE)-CT images of gross-tumor-volumes using 'in-house' software ('ROdiomiX') developed and validated following the image-biomarker-standardization-initiative (IBSI) guidelines. Six clinical factors were investigated: Age-at-Diagnosis, Gender, Total-Charlson, Alcohol-Use, Smoking-History, and T-Stage. A Least-Absolute-Shrinkage-and-Selection-Operation (Lasso) technique combined with a Generalized-Linear-Model (Lasso-GLM) were applied to perform regularization in the radiomic and clinical feature spaces to identify the ranking of optimal feature subsets with most representative information for prediction of HPV. Lasso-GLM models/classifiers based on clinical factors only, radiomics only, and combined clinical and radiomics (ensemble/integrated) were constructed using random-permutation-sampling. Tests of significance (One-way ANOVA), average Area-Under-Receiver-Operating-Characteristic (AUC), and Positive and Negative Predictive values (PPV and NPV) were computed to estimate the generalization-error and prediction performance of the classifiers.Results.Five clinical factors, including T-stage, smoking status, and age, and 14 radiomic features, including tumor morphology, and intensity contrast were found to be statistically significant discriminators between HPV positive and negative cohorts. Performances for prediction of HPV for the 3 classifiers were: Radiomics-Lasso-GLM: AUC/PPV/NPV = 0.789/0.755/0.805; Clinical-Lasso-GLM: 0.676/0.747/0.672, and Integrated/Ensemble-Lasso-GLM: 0.895/0.874/0.844. Results imply that the radiomics-based classifier enabled better characterization and performance prediction of HPV relative to clinical factors, and that the combination of both radiomics and clinical factors yields even higher accuracy characterization and predictive performance.Conclusion.Albeit subject to confirmation in a larger cohort, this pilot study presents encouraging results in support of the role of radiomic features towards characterization of HPV in patients with OPSCC.


Assuntos
Alphapapillomavirus , Neoplasias de Cabeça e Pescoço , Infecções por Papillomavirus , Adolescente , Humanos , Papillomaviridae , Infecções por Papillomavirus/diagnóstico por imagem , Projetos Piloto , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico por imagem
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