Radiation In Region Research Articles

Viable strategy to minimize trap states of patterned oxide thin films for both exceptional electrical performance and uniformity in sol–gel processed transistors

A sustainable water etchant-based photopatterning method is proposed to achieve simultaneous oxide film patterning and remarkably minimize trap states of dielectric and semiconductor oxide films. By exquisitely controlling each processing parameter, well-defined aluminum oxide (AlOx) dielectric and indium oxide (InOx) semiconductor patterns are formed, despite using acid-free pure water etchant. The water etchant not only dissolves the nonultraviolet-irradiated regions but also promotes an effective hydrolysis reaction of irradiated regions, thereby forming low-defect oxide patterns. As a result, frequency-stable AlOx capacitors with low leakage current and high-performance bias-stable InOx TFTs with low activation energy are fabricated. In particular, photopatterned enhancement-mode InOx TFTs exhibit remarkably improved electrical properties, stability, and uniformity—15-fold higher saturation mobility and remarkably low coefficient of variation of 12.04 cm2 V−1 s−1 and 25.26%, respectively— compared with nonpatterned TFTs. With the proposed method, 3-V operating high-performance InOx/AlOx TFTs are successfully fabricated at a low processing temperature of 250 °C.

Influence of laser-Sn powder coupling on microstructure and mechanical properties of fusion welded AZ31B-alloy to DP590-steel

Microstructure and mechanical properties were studied in fusion welded AZ31B-alloy to DP590-steel at different weld conditions such as with varying laser power, and Sn powder added to lap joint with prefabricated width-settled concave groove. Temperature field and flow field for laser welding including chemical potential of each element are also calculated. The results suggested that Al atom tends to diffuse toward Fe side which contributes to form a FeAl compound reaction layer at interface. Meanwhile, Al accelerates the diffusion of Sn and Fe as a catalyst. The shear force of joint climbs at first, then declines, and the maximum value reaches 1711 N when laser power is 1 kW, which is improved by 38% compared with that of 0.9 kW. The improved joint properties are dominated by metallurgical regulation of Sn power, which benefits from the accelerated flow of molten pool and increased temperature leading to the phase composition transformation from α-Mg + Mg2Sn + FeAl to α-Mg + Mg2Sn + FeSn + Fe3Sn + FeSn2 + FeAl in direct laser irradiation region. However, under the condition of excessive laser power, overreaction occurs at side boundary interface, which leads to the formation of thick IMC and the production of hot crack defect, thus the joint performance decreases.

High-precision four-dimensional hyperspectral imager integrating fluorescence spectral detection and 3D surface shape measurement.

A four-dimensional hyperspectral imager (FDHI) that combines fluorescence spectral detection and 3D surface morphology measurement is proposed. The FDHI consists of a hyperspectral line-scanner, a line structured light stereo vision system, and a line laser. The line laser is used as both the excitation light for the fluorescence and the scanning light line for the 3D profiling. At each scanning step, the system collects both fluorescent and 3D spatial data of the irradiated line region, which are fused to 4D data points based on a line mapping relationship between the datasets, and by scanning across the measurement object, a complete 4D dataset is obtained. The FDHI shows excellent performance with spatial and spectral resolution of 26.0 µm and 3 nm, respectively. The reported FDHI system and its applications provide a solution for 4D detection and analysis of fluorescent objects in meters measurement range, with advantage of high integration as two imaging modules sharing a same laser source.

Laser patterning assisted devitrification and domain engineering of amorphous and nanocrystalline alloys

We have investigated laser-patterning and devitrification as a novel method to realize emergent properties in modified regions at the ribbon surface consisting of periodic localized laser spots thermally treated under rapid heating and cooling conditions. Fe-based amorphous ribbons were annealed for systematically varied laser power. Extremely high heating and cooling rates on the order of 108-1010K/s have been estimated by finite element analysis simulations. Observations suggest surface melting followed by rapid solidification fast enough to quench and form an amorphous structure upon cooling. Diffusion of heat occurs from the laser irradiated surface region so that a finite volume of material surrounding this region rises in temperature above the crystallization temperature relevant for conventional isothermal annealing experiments. The underlying mechanism of laser annealing and consequences of heat transients involved are discussed in terms of impacts upon micro/nanostructure, residual stresses, and magnetic domain structure surrounding the laser irradiated region. The study illustrates the potential to exploit spatially optimized phase transformations in a scalable manufacturing process of amorphous and nanocrystalline alloys to locally access otherwise inaccessible extreme heating and cooling rates.

Inclusion of Immunotherapy in the Management of Primary and Metastatic Malignant Tumours of the Kidney Including Adult Renal Cell Carcinoma: A Review and Update

Inclusion of Immunotherapy in the Management of Primary and Metastatic Malignant Tumours of the Kidney Including Adult Renal Cell Carcinoma: A Review and Update

Radiation electron trajectory modulated DC surface flashover of polyimide in vacuum

Improving surface flashover voltage on vacuum-dielectric interface irradiated by electrons is a long-standing challenge for developing high-voltage and high-power spacecraft technology. The basic issue is understanding the role of radiation electrons in the process of surface flashover. In this paper, a ‘three-segment’ curve concerning the surface flashover properties under electron irradiation is discovered experimentally. As the gap distance of electrodes increase, the surface flashover voltage of polyimide during electron irradiation presents a trend of firstly increasing, then decreasing, and finally stabilizing. According to the simulation of the trajectory distribution for kinetic electrons, this trend is found to correspond with three typical stages respectively. In stage A, the kinetic electrons are completely deflected and the varying electrode parameters mainly affect the electric field distribution. In stage B, the kinetic electrons can irradiate the part of polyimide. The promoting effect of those electrons on flashover process enhance with the enlargement of the irradiated region. In stage C, trajectories are no longer seriously deflected and the role of kinetic electrons do not vary with electrode parameters. Combining with the results above, a model with combined effects of both kinetic and deposited electrons on surface flashover in vacuum is thus proposed, base on which the guidance for the methods of improving surface flashover voltage during electron irradiation is provided.

14 - Harmonisation of radiotherapy practice in lung cancer: East of England Regional Radiotherapy Network Initiative

14 - Harmonisation of radiotherapy practice in lung cancer: East of England Regional Radiotherapy Network Initiative

Characterization of scintillator screens under irradiation of low energy 133Cs ions

An imaging heavy ion beam probe (i-HIBP) diagnostic, for the simultaneous measurement of plasma density, magnetic field and electrostatic potential in the plasma edge, has been installed at ASDEX Upgrade. Unlike standard heavy ion beam probes, in the i-HIBP the probing (heavy) ions are collected by a scintillator detector, creating a light pattern or strike-line, which is then imaged by a camera. Therefore, a good characterization of the scintillator response is needed. Previous works focused on the scintillator behaviour against irradiation with light ions such as hydrogen and alpha particles. In this work we present the characterization of several scintillator screens — TG-Green (SrGa2S4:Eu2 +), YAG-Ce (Y3Al5O12:Ce3 +) and P11 (ZnS:Ag) — against irradiation with 133Cs+ ions, in an energy range between 5 and 70 keV and ion currents between 105 and 107 ions/(s·cm2). Three main properties of the scintillators have been studied: the ionolumenescence efficiency or yield, the linearity and the degradation as a function of the fluence. The highest yield was delivered by the TG-Green scintillator screen with > 8·103 photons/ion at 50 keV. All the samples showed a linear response with increasing incident ion flux. The degradation was quantified in terms of the fluence F1/2, which leads to a reduction of the emissivity by a factor of 2. TG-Green showed the lowest degradation with F1/2= 5.4·1014 ions/cm2. After the irradiation the samples were analyzed by Scanning Electron Microscopy (SEM), Rutherford Backscattering Spectrometry (RBS) and Particle Induced X-ray Emission (PIXE). No trace of Cs was found in the irradiated regions. These results indicate that, among the tested materials, TG-Green is the best candidate for the i-HIBP detector.

Optical Excitation of Converging Surface Acoustic Waves in the Gigahertz Range on Silicon.

The optical excitation and propagation of converging surface acoustic waves on silicon with orientations (001) and (111) have been experimentally studied. An axicon-assisted formation of an annular irradiated region on the sample surface served as a source for converging surface waves. Surface wave patterns at different times were recorded using a Sagnac interferometer with spatial resolution. A study of the field distribution at the focus showed that, in spite of elastic anisotropy, which generally leads to aberrations, the acoustic energy can be concentrated into a spot with dimensions close to the diffraction limit. An asymmetric excitation distribution makes it possible to control the structure of the converged wave field at the focus, providing an effective tool for all-optical diagnostics of the local crystal structure as well as electronic properties of quantum objects embedded in the solid-state matrix.

Survival outcome of local vs. radical excision in rectal gastrointestinal stromal tumor: a SEER database analysis

BackgroundThe choice of surgical strategy for patients with rectal gastrointestinal stromal tumor (GIST) remains controversial. This study aims to address whether the surgical procedure [local excision (LE) vs. radical excision (RE)] influences the survival outcomes.MethodsThe information of the patients recruited in this study was obtained from the Surveillance, Epidemiology, and End Results (SEER) database. A survival curve was used to evaluate the differences in cancer-specific survival (CSS).ResultsNo significant difference was detected in the CSS between the LE and RE groups. Also, no significant differences were observed in the CSS between the two groups with respect to different T classification, N classification, tumor differentiation, tumor size, regional LN surgery, age, gender, race, chemotherapy, and radiotherapy. The T classification and age were independent prognostic factors in rectal GIST patients.ConclusionsLE and RE have similar survival time after surgery, and LE could be considered as an effective surgical approach for rectal GIST.

Ion beam-induced bending of TiO2 nanowires with bead-like and prismatic shapes.

Ion beam irradiation is a promising method to manipulate the composition and shape of nanowires. It causes the formation of crystal defects like vacancies and dislocations, and consequently, a volume expansion within the irradiated region, giving rise to the nanowire bending. The bending effect has been extensively discussed within nanowires with different diameters under ion beams with varying energies and ion fluences. However, the behaviors of nanowires with complicated shapes, which may have non-uniform irradiated regions due to the changing angle of incidence and shadowing effect, have remained largely unknown. Herein, the structural changes and bending of TiO2 nanowires with both bead-like and prismatic shapes are investigated under a Ga+ ion beam. The multi-faceted morphology, and consequently, varying angles of incidence, result in inhomogeneous irradiation and volume expansion. As a result, significant bending is only observed in prismatic nanowires. Since irradiation is confined within the half of nanowires facing the ion beam, the bending of nanowires is reversible by changing the direction of the ion beam. In order to provide insights into the tailoring composition and morphology of nanowires, we anticipate that this finding can establish the beam analog at the nanoscale, the bending of which can be tuned by ion irradiation.

Impact of Disease Extent and Distribution on Outcomes in Stage II Follicular Lymphoma Treated with Curative-Intent Radiation Therapy

Impact of Disease Extent and Distribution on Outcomes in Stage II Follicular Lymphoma Treated with Curative-Intent Radiation Therapy

Physical Testing and Surface Morphology Studies of Stainless Steel Irradiated with Xe Ions

6 MeV Xe ions were used to irradiate austenitic stainless steel at room temperature. Three displacement damage levels of 2,7 and 15 dpa were selected. Microstructure and surface morphology were characterized by transmission electron microscopy (TEM), positron annihilation lifetime spectroscopy (PLS) and atomic force microscope (AFM). PLS indicated that vacancy defects were introduced by ions irradiation. Vacancy clusters containing Xe will reduce the positron annihilation lifetime. High density of dislocation loops were observed by TEM. The dislocation loops size and density saturates after 7 dpa and the nature of dislocation loops can be deduced by its distribution. A surface step was detected by AFM measurements between irradiated region (uncovered) and unirradiated region (covered with nickel mesh). This indicate that the irradiation swelling phenomenon occur and swelling is closely related to irradiation damage. According to the step height, the volume swelling is about 1.7% and 4.2% after irradiated to 7 and 15 dpa.

Microstructure characterization of reactor pressure vessel steel A508-3 irradiated by heavy ion

As one of the key structures used in nuclear power plants, the study of irradiation effects of pressure vessel steel (RPV) is of great scientific value to nuclear safety. The RPV steel was irradiated by Fe ions up to three different irradiation damage levels (0.08 dpa, 0.15 dpa, and 0.6 dpa). The transmission electron microscope was utilized to measure the irradiated microstructure and it was found that after the irradiation of 0.08 dpa, the density and size of dislocation loops in Fe ions irradiated samples was small and the dislocation loops were distributed near the surface. When irradiation dose was up to 0.15 dpa, many black dots were distributed in the whole irradiation region and some large size dislocation loops appeared. In the case of 0.6 dpa, a large number of dislocation loops were produced and the distribution of dislocation loops extended to the whole irradiation region owing to the production and growth of defects such as vacancies and black dots.

ATR-FTIR spectroscopy probing of structural alterations in the cellular membrane of abscopal liver cells.

In this study, we utilize ATR-FTIR spectroscopy to investigate the structural damages in the cell membrane lipids and proteins as a result of the oxidative stress in abscopal liver tissue of rats either whole-body, cranially or lower limb irradiated as compared with sham-irradiated group. We also question whether the original irradiation region would influence the induction of the abscopal effect. The data present compelling evidence that an abscopal effect was induced in the liver tissue following both cranial and lower limb irradiations, marked by damage in the membrane-associated lipids and proteins. Lipid damage manifestation is evident by; 1) decrease in the lipid/protein ratio. 2) Degradation of lipid as marked by the decrease in the area ratio CH 2 asymmetric/CH 3 asymmetric stretching bands. 3) Increase in the carbonyl content evident by the increase in the band area ratio of carbonyl ester/lipid. 4) Increase in the degree of methylation as indicated by the increase in the band area ratio of CH3/lipid. 5) Disorder in the phospholipid acyl chains marked by the shift in the CH2 asymmetric stretching and olefinic HCCH absorption bands. Protein damage was indicated by 1) Shifts in the position of amide I and amide II bands. 2) Decrease in the area ratio amide I/amide II. 3) Broadening in amide II band. Our data strongly suggest similar induction of the abscopal effect as a result of either cranial or lower limb irradiation, which means that the original irradiation region did not influence the induced abscopal effect in the examined system.

Research on the mechanism of DD6 single crystal superalloy wear resistance improvement by femtosecond laser modification

The wear resistance of turbine blades tenon is critical to its fretting fatigue life. A method to improve the wear resistance of DD6 single crystal superalloy (DSCS) by femtosecond laser modification (FLM) is proposed. In this paper, the FLM was performed on the surface of DSCS under atmospheric condition without protective layer and confinement layer. The wear behavior after FLM at various laser energies (10, 100, and 240 μJ) was investigated. Results indicate that the wear resistance increases by about 25 % to 58 % after FLM, attributable to surface hardening layer and generation of wear debris layer by removal of asperity during the sliding wear. The formation of asperity and hardening layer is the combined effects of strong laser shock wave and slight ablation in the irradiated region. Finally, the femtosecond laser-affected region can be divided into oxide zone, severe deformed zone, and moderate deformed zone near the surface. Femtosecond laser provides a new possibility and method for wear resistance and friction reduction.

Contemporary Outcomes After Multimodality Therapy in Patients With Breast Cancer Presenting With Ipsilateral Supraclavicular Node Involvement

PurposePatients with breast cancer and ipsilateral supraclavicular (SCV) node involvement at the time of diagnosis (TNM cN3c) have historically had poor outcomes. Radiation therapy (RT) has an important role because SCV nodes are not routinely surgically dissected. However, optimal locoregional management, contemporary outcomes, and prognostic factors are not well defined. Methods and MaterialsWe reviewed the data of patients with cN3c breast cancer treated at our institution between 2014 and 2019 with curative intent, including neoadjuvant chemotherapy, surgery, and adjuvant RT. All patients received comprehensive regional RT, including to the SCV nodes. Institutional guidelines recommend a 10-Gy or 16-Gy boost to resolved and unresolved N3 nodes, respectively. Overall survival (OS), recurrence-free survival (RFS), locoregional recurrence-free survival (LRRFS), and supraclavicular recurrence-free survival (SCRFS) were analyzed. ResultsData from 173 consecutive patients were analyzed with a median follow-up time of 2.8 years. The median age was 54 years, 76 patients (44%) were estrogen receptor positive/human epidermal growth factor receptor 2 negative, 100 patients (58%) had T3/4 disease, and 10 patients (6%) underwent a neck dissection. In addition, 156 patients (90%) received a cumulative SCV dose of ≥60 Gy. The 5-year OS, SCRFS, LRRFS, and RFS rates were 73%, 95%, 86%, and 50%, respectively. The 5-year OS rate for a cumulative SCV dose of ≥60 Gy versus <60 Gy was 75% versus 39% (P = .04). In the multivariable analysis, a cumulative SCV dose of ≥60 Gy, extranodal extension, receptor status, and Eastern Cooperative Oncology Group performance status were associated with OS. The 5-year SCRFS rates with and without neck dissection were 100% versus 95% (P = .57). Among patients with a postchemotherapy SCV node size of ≥1 cm without neck dissection, the 5-year SCRFS rate was 83%. ConclusionsIn one of the largest series of patients with cN3c breast cancer, multimodality therapy using adjuvant RT with a SCV boost resulted in a 5-year LRRFS rate of 86%. There is a limited role for neck dissection as the 5-year SCRFS rate was 95% overall and 83% for residual SCV disease ≥1 cm after chemotherapy with RT alone. A cumulative SCV dose of ≥60 Gy was associated with improved OS, but not SCRFS, LRRFS, or RFS. A SCV boost should be considered in these patients as treatment was well-tolerated. Despite advances in systemic therapy, nearly half of patients developed distant metastases, highlighting the need for close observation after treatment.

HF-free and fast fabrication of long, rectangular microchannels in fused silica: Novel femtosecond laser irradiation geometry

We report the fabrication of truly rectangular buried microchannels of record lengths in fused silica, using a novel femtosecond laser irradiation geometry, at 1030 nm, followed by chemical etching in hot KOH alone. As the result of a judicious choice of the laser parameters and writing geometry, an effective chemical etching rate of 500 μm per hour in the laser irradiated region is achieved, competing with the traditional and hazardous HF based etching, and faster than all earlier reports with KOH. This has resulted in the longest reported (6 mm) rectangular, microchannels, in a record etching time of 6 h. Linear and Cross microchannels have been fabricated with mean surface roughness less than 200 nm of the sidewalls. These results have been validated using an optical microscope, SEM and AFM imaging. The use of fused silica, the much eased safety concerns with KOH, the simplicity of our method, together with the enhanced ability to image from the top surface of smooth, rectangular, buried micro-channels, will motivate microfluidics for Optofluidic lab-on-chip applications, especially for biomedical diagnostics.

The 3-Year Outcome of 3D High-Dose-Rate Brachytherapy in Combination With Regional Metastatic Lymph Nodes Intensity-Modulated Radiotherapy in Peripheral Locally Advanced Non-Small Cell Lung Cancer: A Phase I/II Clinical Trial

To determine the safety, late toxicities and locoregional control of three-dimensional(3D) high-dose-rate (HDR) brachytherapy in combination with regional metastatic lymph nodes intensity-modulated radiotherapy (IMRT) in patients with peripheral locally advanced non-small cell lung cancer (LA-NSCLC).Eligible patients with LA-NSCLC were recruited to this prospective, phase I/II clinical study. The primary lung tumors were treated with the CT-guided interstitial HDR brachytherapy, DT:30Gy/F. The IMRT was applied to the regional positive lymph nodes, DT: 60-70Gy/30-33F/ 6-7W. The concurrent chemotherapy regimens include used Etoposide and cisplatin, the sequential chemotherapy consisted of paclitaxel/pemetrexed + cisplatin/carboplatin. The safety analysis included operational complications and toxicity related to radiotherapy and chemotherapy. Clinical evaluation includes short-term efficacy, survival, and quality of life scores.A total of 83 patients were enrolled in this study. There were 56 males and 27 females, with a median age of 65 years (45-80 years). The median follow-up time was 55 months (32-114 months) up to November 2020. The operational complications included mild pneumothorax (16.8%) and minor hemorrhage around the needle (19.3%). The major toxicity was myelosuppression and gastrointestinal reaction during the concurrent chemoradiotherapy and sequential chemotherapy. The clinical symptoms alleviated after symptomatic supportive treatment. The radiotherapy was completed successfully without grade 4 or more serious acute toxicity. Grade 1 late radiation pneumonitis was found by in 5 patients (6.1%), and only showed imaging changes after radiotherapy. There were 61 patients achieved complete remission, 20 patients achieved partial remission, and 2 patients were in stable disease in the primary tumor, the total response rate was 97.6%. There were 55 patients achieved complete remission, 22 patients achieved partial remission, 5 patients were in stable disease and 1 patient with progressive disease in the positive lymph nodes, the total response rate was 92.8%. The 1-,2-,3-year overall survival rates were 90.6%, 70.6% and 62.4%. The 1-,2-,3-year local control rates were 90.0%,81.0% and 54.5%. The 1-,2-,3-year disease-free survival rates were 68.3%,42.2% and 23.9%. The 1-,2-,3-year metastasis-free survival rates were 73.3%, 50.9% and 39.5%. The patient who treated with 3D interstitial high dose rate brachytherapy has a higher life quality score than the baseline level.3D interstitial high dose rate brachytherapy combined with regional positive lymph node intensity-modulated radiotherapy is safe and feasible for the locally advanced peripheral non-small cell lung cancer, with low adverse reactions, increased the survival, and improved the life quality. But it still needs a phase III randomized controlled trial to investigate its clinical utility and promotion, compared to IMRT.

Quantifying Risk of Ipsilateral Arm Lymphedema Causing Functional Impairment in Breast Cancer Patients: Results From a Prospective, Multi-Centre International Study of Treatment Toxicity

Breast cancer related lymphedema (BCRL) of the ipsilateral arm remains a highly morbid long-term side effect of breast cancer treatment, one which can lead to functional impairment. We sought to independently examine clinical and treatment related risk factors for the development of lymphedema-associated functional impairment.The REQUITE Consortium is a multi-center cohort study of patients with breast cancer treated at 26 hospitals in 8 countries from 2014-2017 who were prospectively evaluated for treatment toxicity. All patients received lumpectomy and adjuvant radiotherapy (RT) with or without chemotherapy at the discretion of their treating physician, and were enrolled prior to beginning RT. Arm circumference measurements and patient reported outcome (PRO) toxicity assessments were obtained before RT and annually after RT for a minimum of two years. Lymphedema-associated functional impairment was determined by PRO lymphedema that constrains activity and self-care. Grade 2+ BCRL was defined as ≥10% discrepancy in ipsilateral arm circumference compared to the contralateral arm. Cumulative incidence curves were stratified by the extent of axillary surgery and RT. Multivariable Cox models adjusted for axillary surgery, radiation, body mass index, and chemotherapy.The cohort included 1921 patients followed for a median of 27 months: 1345 received sentinel node biopsy (SLNBx) alone, 90 received SLNBx and regional lymph node RT (RLNR), 136 received axillary node dissection (ALND) alone, 200 received ALND+RLNR, and 150 received no axillary treatment. Invasive breast cancer was present in 1678 (87%) patients, while 591 (30.7%) received chemotherapy. Among the whole cohort, four times as many patients reported functional impairment than Grade 2+ BCRL (4.6% vs 1.1%). On multivariable analysis, taxane-based chemotherapy resulted in a significantly higher risk of functional impairment (hazard ratio [HR] 1.90, P = 0.01), as did ALND (HR 11.92, P = 0.02) and higher BMI (HR 1.06, P < 0.001). Although RLNR and SLNBx did not confer significantly higher risk on multivariable analysis when evaluated individually, the SLNBx+RLNR treatment group demonstrated a trend towards significantly higher risk of functional impairment compared to no axillary treatment (HR 8.21, P = 0.05). The risk of functional impairment was highest in those receiving ALND+RLNR (HR 15.52, P = 0.008) and ALND alone (HR 14.58, P = 0.01), with a 3-year cumulative incidence rate of 21% in both groups.Patients treated with taxane-based chemotherapy and those receiving more extensive axillary surgery are at significantly higher risk of developing ipsilateral arm lymphedema causing functional impairment. Additional variation in this toxicity may be due to genetic predisposition, which is under investigation in REQUITE. Lymphedema-associated functional impairment occurred substantially more often than Grade 2+ BCRL, highlighting the importance of capturing PROs.