Short Radiation Research Articles

The radius distribution of M dwarf-hosted planets and its evolution

Abstract M dwarf stars are the most promising hosts for detection and characterization of small and potentially habitable planets, and provide leverage relative to solar-type stars to test models of planet formation and evolution. Using Gaia astrometry, adaptive optics imaging, and calibrated gyrochronologic relations to estimate stellar properties and filter binaries we refined the radii of 117 Kepler Objects of Interest (confirmed or candidate planets) transiting 74 single late K- and early M-type stars, and assigned stellar rotation-based ages to 113 of these. We constructed the radius distribution of 115 small (<4R⊕) planets and assessed its evolution. As for solar-type stars, the inferred distribution contains distinct populations of ‘super-Earths’ (at ∼1.3R⊕) and ‘sub-Neptunes’ (at ∼2.2 R⊕) separated by a gap or ‘valley’ at ≈1.7R⊕that has a period dependence that is significantly weaker (power law index of -0.03$^{+0.01}_{-0.03}$) than for solar-type stars. Sub-Neptunes are largely absent at short periods (<2 days) and high irradiance, a feature analogous to the ‘Neptune desert’ observed around solar-type stars. The relative number of sub-Neptunes to super-Earths declines between the younger and older halves of the sample (median age 3.86 Gyr), although the formal significance is low (p = 0.08) because of the small sample size. The decline in sub-Neptunes appears to be more pronounced on wider orbits and low stellar irradiance. This is not due to detection bias and suggests a role for H2O as steam in inflating the radii of sub-Neptunes and/or regulating the escape of H/He from them.

Botánica aplicada: radiación UV-B para la obtención de brotes de quinua enriquecidos en compuestos fenólicos, con probables usos en protectores solares naturales o como alimentos funcionales

The objective was to evaluate the use of a microgreen system and very short UV-B radiation dose to obtain plant biomass as a source for phenol-enriched extracts with probable cosmetic and/or food uses. Quinoa seedlings, a native species of the Andes, of two different ages were used. The seedlings were irradiated with different doses of UV-B and then evaluated by quantifying indicators of oxidative damage. Also, the contents of phenolic compounds, photosynthetic pigments, antioxidant capacity, and sun protection factor were determined. The results showed that the youngest seedlings responded better to short UVB doses, increasing the content of soluble and insoluble phenols, without showing oxidative damage. These results were correlated with the greater antioxidant power of the extracts and an intermediate sun protection factor. We conclude that this species, grown in a microgreen system, is a promising alternative to obtain phenol-enriched extracts with possible use in formulations of natural sunscreens. In this sense, these results can serve as a starting point for optimization studies through the response surface methodology.

Structure, and the laser cooling scheme for the XF− (X=Li, Na, K, Rb) molecule

For laser-cooling considerations, we have theoretically investigated the electronic structures of the XF− (X=Li, Na, K, Rb) molecule. The potential existence of anions is initially examined through the analysis of their affinity energies and dipole moments of the corresponding neutral molecules. Subsequently, we excluded the effect of spin–orbit coupling on the molecular. Then the calculations reveal that XF− (X=Li, Na, K, Rb) exhibits a highly diagonalized Franck-Condon factor and a short spontaneous radiation lifetime, facilitating the design of laser cooling schemes for each molecular ion. The findings provide an important reference for laser cooling experiments involving alkali metal fluoride anions.

Sensitivity Analysis of C. auris, S. cerevisiae, and C. cladosporioides by Irradiation with Far-UVC, UVC, and UVB.

The World Health Organization has published a list of pathogenic fungi with prior-itizing groups and calls for research and development of antifungal measures, with Candida auris belonging to the group with high priority. The photosensitivity towards short wavelength ultraviolet irradiation (Far-UVC, UVC, and UVB) was investigated and compared to other yeasts (Saccharomyces cerevisiae) and a mold (Cladosporium cladosporioides). The observed 1-log reduction doses were compared to literature values of other representatives of the genus Candida, but also with S. cerevisiae, Aspergillus niger, and A. fumigatus. For the determined 1-log reduction doses, an increase with higher wavelengths was observed. A 1-log reduction dose of 4.3 mJ/cm2 was determined for C. auris when irradiated at 222 nm, a dose of 6.1 mJ/cm2 at 254 nm and a 1-log reduction dose of 51.3 mJ/cm2 was required when irradiated with UVB. It was observed that S. cerevisiae is a possible surrogate for C. auris for irradiation with Far-UVC and UVB due to close 1-log reduction doses. No surrogate suitability was verified for C. cladosporioides in relation to A. niger and A. fumigatus for irradiation with a wavelength of 254 nm and for A. niger at 222 nm.

Model Predictive Temperature Control for Retinal Laser Treatments.

Manual, individual adjustment of the laser power in retinal laser therapies is time-consuming, is inaccurate with respect to uniform effects, and can only prevent over- or undertreatment to a limited extent. Automatic closed-loop temperature control allows for similar temperatures at each irradiated spot despite varying absorption. This is of crucial importance for subdamaging hyperthermal treatments with no visible effects and the safety of photocoagulation with short irradiation times. The aim of this work is to perform extensive experiments on porcine eye explants to demonstrate the benefits of automatic control in retinal laser treatments. To ensure a safe and reliable temperature rise, we utilize a model predictive controller. For model predictive control, the current state and the spot-dependent absorption coefficients are estimated by an extended Kalman filter (EKF). Therein, optoacoustic measurements are used to determine the temperature rise at the irradiated areas in real time. We use fluorescence vitality stains to measure the lesion size and validate the proposed control strategy. By comparing the lesion size with temperature values for cell death, we found that the EKF accurately estimates the peak temperature. Furthermore, the proposed closed-loop control scheme works reliably with regard to similar lesion sizes despite varying absorption with a smaller spread in lesion size compared to open-loop control. Our closed-loop control approach enables a safe subdamaging treatment and lowers the risk for over- and undertreatment for mild coagulations in retinal laser therapies. We demonstrate that modern control strategies have the potential to improve retinal laser treatments for several diseases.

47 A Single Institution Retrospective Study of Pelvic Insufficiency Fractures Following Neoadjuvant Short Course Intensity-Modulated Radiation Therapy for Rectal Cancer

47 A Single Institution Retrospective Study of Pelvic Insufficiency Fractures Following Neoadjuvant Short Course Intensity-Modulated Radiation Therapy for Rectal Cancer

696: Immunoscore-based wait-and-watch after short course radiation and chemotherapy in rectal cancer

696: Immunoscore-based wait-and-watch after short course radiation and chemotherapy in rectal cancer

Comprehensive crosslinking strategy using fluorinated azide to enhance the thermal stability of ceramic-coated separators for Li-ion batteries

Enhancing the thermal and mechanical stabilities of ceramic-coated separators (CCSs) is required for high-safety lithium-ion batteries (LIBs). As both the thickness and areal mass of ceramic coating layers (CCLs) have reduced, various strategies have been developed to overcome the limitations of conventional ceramics and polymeric binders. In this regard, we suggest a comprehensive photocrosslinking approach to form fully crosslinked CCLs using a new fluorinated azide binder that can readily react with aliphatic functional groups in any component of CCSs. When a small amount of azide binder is added to a CCL slurry consisting of Al2O3 particles and a poly(acrylic acid) (PAA) binder, short UV irradiation can lead to inter- and intramolecular crosslinking points within the polyethylene (PE) separator, between the PE separator and the PAA binder, and within the PAA binders in the CCL. Consequently, the thermal stability and the adhesive strength of crosslinked CCS (X-CCS) can be significantly improved compared to the control CCS without azide. Moreover, a LiNi0.6Co0.2Mn0.2O2/graphite cell with X-CCS exhibited a comparable cycle life to that of the PE separator and non-crosslinked CCS. Furthermore, because UV illuminators are easily added to conventional fabrication processes, this strategy is a simple but effective approach for advancing high-safety LIBs.

Real-time microwave transmittance variation of glass fiber composites subjected to laser irradiation

Laser irradiation may have a significant impact on the microwave transmission properties of glass fiber composites. In this study, a two-dimensional microwave transmission transient model of glass fiber composites during the complete laser irradiation process was developed. The numerical results indicate that carbonization during irradiation causes a significant increase in dielectric loss, thus resulting in a decrease in transmittance. After irradiation, the dielectric loss decreased due to the decrease in temperature, which, in turn, led to an increase in transmittance. The increased transmittance after cooling was lower than the original value due to the generation of pyrolytic carbon with a high dielectric loss. The numerical results were verified by conducting an experiment wherein the microwave transmittance of glass fiber composites was measured in real time before, during, and after laser irradiation. In addition, the effects of different laser parameters on the real-time microwave transmittance during laser irradiation were investigated experimentally and numerically. For the same total energy, a laser with a high power density and short irradiation time had a more significant effect on the attenuation of transmittance.

Self-Powered FTO/CdSe/Bi2Se3 Photodetector with Bipolar Photoresponse Characteristics.

Self-powered photodetectors with bipolar photoresponse characteristics are expected to play a critical role in the field of secure optical communication, artificial neuromorphic systems, and intelligent color sensors. In this work, asymmetric heterojunction devices exhibiting wavelength-dependent bipolar photoresponse with a structure of Glass/FTO/CdSe/Bi2Se3/Au were fabricated. Under a short wavelength light irradiation, the top CdSe absorber generates a high carrier concentration; the excited carriers are quickly separated by the built-in electric field induced by the FTO/CdSe diode, resulting in a negative photocurrent. For light with wavelengths beyond the CdSe absorption edge, it is absorbed by the bottom Bi2Se3 absorber, and a positive photocurrent can be observed. Therefore, based on the bandgap difference between the top CdSe absorber and the bottom Bi2Se3 absorber, combined with the photogenerated carriers separated by asymmetric back-to-back diode, a wavelength-dependent bipolar response is realized. In this work, by employing this structure, the responsivities of -33.3 and 0.3 mA/W were achieved under the illumination of 405 and 830 nm, respectively. This work provides important indications in the preparation and performance optimization for wavelength-dependent bipolar photodetectors.

Performance and Selection of Short Life and High Yield Black Rice M3 Gamma Ray Irradiation 200 Gray

Performance and Selection of Short Life and High Yield Black Rice M3 Gamma Ray Irradiation 200 Gray

Ultrafast and Reversible Superwettability Switching of 3D Graphene Foams via Solvent-Exclusive Plasma Treatments.

For highly active electron transfer and ion diffusion, controlling the surface wettability of electrically and thermally conductive 3D graphene foams (3D GFs) is required. Here, we present ultrasimple and rapid superwettability switching of 3D GFs in a reversible and reproducible manner, mediated by solvent-exclusive microwave arcs. As the 3D GFs are prepared with vapors of nonpolar acetone or polar water exclusively, short microwave radiation (≤10 s) leads to plasma hotspot-mediated production of methyl and hydroxyl radicals, respectively. Upon immediate radical chemisorption, the 3D surfaces become either superhydrophobic (water contact angle = ∼170°) or superhydrophilic (∼0°), and interestingly, the wettability transition can be repeated many times due to the facile exchange between previously chemisorbed and newly introduced radicals via the formation of methanol-like intermediates. When 3D GFs of different surficial polarities are incorporated into electric double-layer capacitors with nonpolar ionic liquids or polar aqueous electrolytes, the polarity matching between graphene surfaces and electrolytes results in ≥548.0 times higher capacitance compared to its mismatching at ≥0.5 A g-1, demonstrating the significance of wettability-controlled 3D GFs.

Key factors for establishing and sustaining a successful palliative radiation oncology program: a survey of the Society for Palliative Radiation Oncology.

Dedicated palliative radiation oncology programs (PROPs) within radiation oncology (RO) practices have been shown to improve quality and decrease costs of radiation therapy (RT) in advanced cancer patients. Despite this, relatively few PROPs currently exist, highlighting an unmet need to understand characteristics of the few existing PROPs and the potential barriers and facilitators that exist in starting and maintaining a successful PROP. We sought to assess the attributes of existing PROPs, the facilitators and barriers to establishing these programs, and the resources needed to create and maintain a successful program. A 15-item online survey was sent to 157 members of the Society of Palliative Radiation Oncology (SPRO) in July 2019. Of the 157 members, 48 (31%) responded. Most practiced in an academic center (71% at main center and 15% at satellite) and 75% were from a larger group practice (≥6 physicians). Most (89%) believed the development and growth of a dedicated PROPs was either important (50%) or most important (39%) to the field of RO. Only 36% of respondents had a PROP, 38% wanted to establish one, and 13% were currently developing one. Of those with PROPs (N=16), 75% perceived an increase in the number of referrals for palliative RT since starting the program. A majority had an ability to refer to an outside palliative care specialist (64%), an outpatient RO service (53%), and specialized clinical processes for managing palliative radiotherapy patients (53%), with 41% having an inpatient RO consult service. Resources considered most essential were access to specialist-level palliative care, advanced practice provider support, a radiation oncologist with an interest in palliative care, having an outpatient palliative RO clinic, an emphasis on administering short radiation courses, and opportunities for educational development. Of those with a PROP or those who have tried to start one, the greatest perceived barriers to initiating a PROP were committed resources (83%), blocked out clinical time (61%), challenges coordinating management of patients (61%), and support from leaders/colleagues (61%). Perceived barriers to sustaining a PROP were similar. For those without a PROP, the perceived most important resources for starting one included access to palliative care specialist by referral (83%), published guidelines with best practices (80%), educational materials for referring physicians and patients (80%), educational sessions for clinical staff (83%), and standardized clinical pathways (80%). PROPs are not widespread, exist mainly within academic centers, are outpatient, have access to palliative care specialists by referral, and have specialized clinical processes for palliative radiation patients. Lack of committed resources was the single most important perceived barrier for initiating or maintaining a PROP. Best practice guidelines, educational resources, access to palliative care specialists and standardized pathways are most important for those who wish to develop a PROP. These insights can inform discussions and help align resources to develop, grow, and maintain a successful PROP.

Short course irradiation in rectal cancer: Dosimetry study comparing 3D conformal radiotherapy versus intensity-modulated radiotherapy versus volumetric modulated arc therapy

The standard radiotherapy planning technique for locally advanced rectal cancer (LARC) was 3D Conformal Radiotherapy (3DCRT). Modern radiation delivery techniques, including Intensity-Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) techniques, have been developed in recent years in terms of dose delivery to the target while minimizing the dose to the organ at risk (OAR). The objective of this study was to identify the most suitable treatment plan technique from the available options of 3DCRT, IMRT and VMAT for LARC using short course radiotherapy (SCRT). Therefore, twenty-five adult patients with LARC in the last five-year period (2017–2021) were involved in this study. For each patient, three radiotherapy treatment plans were generated for dosimetric comparison of short course irradiation (25 Gy/5 fractions, which is the new standard of care) using Varian Eclipse software to generate 3DCRT in comparison with IMRT and VMAT plans. The conformity index (CI), the homogeneity index (HI), and the organs at risk (OAR), including bladder, small bowel, and femoral heads, were compared between the three plans. The results revealed that VMAT and IMRT plans had a higher level of conformity for the planning target volume (PTV) with 0.996 and 0.994, respectively, compared to the 3DCRT planning of 0.947 (both p < 0.005). The PTV dose distribution was less homogeneous with 3DCRT than with VMAT or IMRT plans. VMAT offered superior homogeneity to IMRT and 3DCRT plans with 1.055, 1.066, and 1.089, respectively (p < 0.005). The findings showed that VMAT is superior to IMRT and 3DCRT in almost all parameters, including dose distribution conformity and homogeneity of the target volume, as well as providing better OAR sparing in LARC patients.

Plant-Based Phytochemicals for Synthesis of Z-Scheme In2O3/CdS Heterostructures: DFT Analysis and Photocatalytic CO2 Reduction to HCOOH and CO.

Photocatalytic CO2 reduction shows potential for mitigating industrial emissions. Z-scheme In2O3/CdS(bio) heterostructures (25 nm, 217.0 m2 g-1 surface area) with a more negative conduction band synthesized using phytochemicals present in Aegle marmelos with short microwave irradiation inhibit CdS(bio) photocorrosion forming SO42-. In2O3/CdS(bio) increased the photocurrent density (0.82 μA cm-2) and CO2 adsorption (0.431 mmol g-1) significantly compared to CdS(bio) and In2O3(bio) NPs. Heterostructures increased decay time and reduced PL intensity by 46.28 and 61.80% over those of CdS(bio) and In2O3(bio) NPs. Density functional theory (DFT)-optimized geometry, band structure analysis, and density of states (DOS) studies indicate that the DOS of CdS is modified with In2O3 incorporation, enhancing charge separation. Optimal 0.4In2O3/CdS(bio) heterostructures exhibit remarkable CO2 conversion to HCOOH/CO production of 514.4/162 μmol g-1 h-1 (AQY 4.44/2.45%), surpassing CdS(bio) and In2O3(bio) by 9 and 6.5 times, and retain their morphological and structural stability. This study provides valuable insight for developing bio-based CdS heterostructures for photocatalytic CO2 reduction.

Phenomenological toy model for flash effect in proton therapy

We present a simple model based on general assumptions for the FLASH effect in radiotherapy, leading to a rate equation with only three free parameters. The model can predict the biological effect ratio between healthy and tumoral tissue for arbitrary input treatments, given as a dose rate versus time function. We analyze the behavior of the model and its sensitivity to its free parameters, and decide on suitable parameter values in accordance with available experimental data from the literature. Then we apply our model to study different sets of treatments, modeled as square pulse periodic functions with different pulse peak dose rate, pulse width and repetition period, in order to illustrate how it may be used to guide future experiment design. The model predicts that, for a given average dose rate above the FLASH threshold, a more prominent FLASH effect would be observed for continuous beams than for ultra-pulsated beams with an infinitely short irradiation time. This finding needs to be validated with suitable experiments.

Short course versus long course neoadjuvant radiation for patients with locally advanced rectal cancer (LARC): National Cancer Database (NCDB) analysis of the years 2004-2020.

Short course versus long course neoadjuvant radiation for patients with locally advanced rectal cancer (LARC): National Cancer Database (NCDB) analysis of the years 2004-2020.

Disease response of neoadjuvant chemoradiation guiding local excision approach in localized rectal cancer: A systematic review and meta-analysis of prospective data.

e15639 Background: Total Mesorectal Excision (with or without chemoradiation) has been the established standard of care for the treatment of localized rectal cancer. Neoadjuvant Chemoradiation (nCRT) followed by Local Excision (LE) has been proven as a safe alternative approach for selected patients. This study aims to review the current evidence of this strategy, guided by the disease response from the nCRT. Methods: database research was performed through PubMed, Embase, and Cochrane Central for prospective studies evaluating the use of nCRT followed by LE in localized rectal cancer patients. Our primary outcomes were Local Recurrence Rates (LRR) correlated to patients’ pathological response status. We pooled the proportions of binary outcomes and their 95% confidence intervals. I² analysis was used to assess heterogeneity. We performed statistical analyses using R software version 4.3.1 with a random-effects model. Our analysis was prospectively registered with the number CRD42024499095 (PROSPERO). Results: A pool of 760 citations was initially screened, and 5 prospective trials assessing nCRT following LE in at least one of the arms were selected with a pooled analysis of 438 patients (including CRT-LE single arm, or randomization with CRT followed by total mesorectal excision and short course radiation alone). Neoadjuvant treatment was performed with a radiation dose ranging between 45 - 54Gy and concomitant fluoropyrimidine (5-fluorouracil or Capecitabine) isolated or in combination with Oxaliplatin. The extracted data was subgrouped into favorable responders (FR) (complete or near-complete pathological response) or unfavorable responders (UR). Looking specifically at the nCRT+LE arm, 284 patients were identified, from which 168 were classified as FR (59.1%). The pooled LRR was 0.02 (95% CI 0.00-0.06; I² = 27%) for this group. A total of 116 patients were classified as UR, with a polled LRR of 0.09 (95% CI 0.05-0.16; I² = 0%). Conclusions: Our analysis demonstrate that nCRT + LE is a safe strategy, with data from 5 prospective trials demonstrating very low local recurrence rate, especially in the group of patients who achieved a good response to the neoadjuvant approach. Treatment intensification protocols aiming to achieve a higher response rate can potentially reduce the local recurrence in those patients.

Effects of neutron sources and moderator materials on therapeutic dose delivery to deep-seated lesions in proton accelerator-based boron neutron capture therapy

This study aimed to identify the optimal conditions for delivering sufficient doses to deep-seated lesions within short irradiation times for two boron carriers of different T/N ratios. The therapeutic depth and irradiation time of a neutron beam for beam shaping assemblies (BSAs) with a Li or Be target and a MgF2 or CaF2 moderator were examined with the fast-neutron dose per epithermal neutron (FNR) as a parameter. When T/N = 3.61, the therapeutic depth was almost saturated at an FNR of about 10 × 10−13 Gy cm2; when the FNR value was about 10 × 10−13 Gy cm2, the therapeutic depth of the neutron beam for the BSA with a Be target and a MgF2 moderator was almost identical to that for the neutron beam for the BSA with a Be target and a CaF2 moderator, and slightly greater than those for the neutron beams for the BSAs with a Li target and a MgF2 or CaF2 moderator; moreover, the irradiation time of the neutron beam for the BSA with a Be target and a MgF2 moderator was shorter than that for the neutron beam for the BSA with a Be target and a CaF2 moderator. When T/N = 100, the therapeutic depths of the neutron beams for the BSAs varied greatly depending on the FNR, and were greater than the corresponding values for T/N = 3.61. We therefore concluded that the BSA with a Be target and a MgF2 moderator that produced a neutron beam with an FNR of about 10 × 10−13 Gy cm2 is optimal for delivering sufficient doses to deep-seated lesions in short irradiation times when T/N = 3.61, and stricter control over FNR is required when T/N = 100.

Chemical characterization of cement samples by radio-analytical methods namely external (in air) PIGE, INAA and ED-XRF for assessing their quality and method validation of radioanalytical techniques

This paper demonstrates novel application of neutron and proton based nuclear analytical techniques for the rapid evaluation of cement quality in terms of compressive strength using Ca to Si ratios. Preliminary phase characterization was performed using X-ray diffraction patterns. External PIGE method was optimized and applied for direct analysis of “as received” samples in thin mylar foils with reduced turn-around time of analysis. Moreover, Pneumatic Carrier Facility at Dhruva reactor of BARC was utilized for NAA for rapid and short irradiation of samples followed by analysis. Quality control of both NAA and PIGE methods were done using several geological Certified / Standard Reference Materials (CRMs and SRMs). EDXRF was employed as alternative analytical technique for comparative evaluation. Statistical evaluation was performed in terms of t-test and F-tests to understand the reliability of measurement and acceptable variance of the results. Eight cementitious samples were analyzed and their compressive strengths were evaluated using NAA and PIGE.