Increasing Radiation Dose Research Articles

Biphasic dose-response and effects of near-infrared photobiomodulation on erythrocytes susceptibility to oxidative stress in vitro

The effect of simultaneous application of tert-butyl hydroperoxide (tBHP) and polychromatic near-infrared (NIR) radiation on bovine blood was examined to determine whether NIR light decreases the susceptibility of red blood cells (RBCs) to oxidative stress. The study assessed various exposure methods, wavelength ranges, and optical filtering types. Continuous NIR exposure revealed a biphasic response in cell-free hemoglobin changes, with antioxidative effects observed at low fluences and detrimental effects at higher fluences. Optimal exposure duration was identified between 60 s and 15 min. Protective effects were also tested across wavelengths in the range of 750–1100 nm, with all of them reducing hemolysis, notably at 750 nm, 875 nm, and 900 nm. Comparing broadband NIR and far-red light (750 nm) showed no significant difference in hemolysis reduction. Pulse-dosed NIR irradiation allowed safe increases in radiation dose, effectively limiting hemolysis at higher doses where continuous exposure was harmful. These findings highlight NIR photobiomodulation's potential in protecting RBCs from oxidative stress and will be helpful in the effective design of novel medical therapeutic devices.

Study on irradiation effect and damage mechanism in cascode GaN HEMT irradiated by 10 MeV electron

This study investigated the irradiation effect of cascode-structure GaN HEMT (High Electron Mobility Transistor) devices, employing high-energy electrons with an energy of 10 MeV and irradiation doses ranging from 5 to 80 Mrad(Si). The variation of electrical properties of the device under annealing condition was analyzed. Geant4 and TCAD simulations were used to analyze the irradiation effect and damage mechanisms. The results show that the threshold voltage has obvious negative drift and the drain current increases after irradiation. The threshold voltage deviation amplitude of the device increases with the increase of irradiation dose, and the maximum deviation is 1.41V. Annealing at high temperatures (80 °C, 120 °C and 145 °C) partially restores the electrical properties, with a 0.49 V restoration in threshold voltage at 145 °C. Geant4 simulations reveal that enhanced Si MOSFET is more susceptible to total dose effects. TCAD simulations of enhanced Si MOSFET devices demonstrate an increase in electric field intensity, trapped electron concentration, and hole concentration in Si and SiO2 layers with the increase of irradiation dose. These findings can provide support for the space application and irradiation hardening of cascode GaN HEMT devices.

High versus standard radiation dose of definitive chemoradiotherapy combined with immunotherapy for inoperable esophageal squamous cell carcinoma: A multicenter propensity score matching analysis.

e16118 Background: There is no consensus of the radiation dose for esophageal squamous cell carcinoma (ESCC) in the setting of definitive chemoradiotherapy (dCRT) combined with immunotherapy. This study aimed to compare the efficacy and safety of high-dose (HD) versus standard-dose radiotherapy (SD) for locally inoperable ESCC. Methods: Patients with locally advanced unresectable ESCC or advanced ESCC with supraclavicular lymph node metastases only who received high-dose (≥ 60Gy) or standard-dose (50-50.4Gy) radiation in dCRT combined with anti-PD-1 antibody as the first-line treatment from four academic cancer centers were enrolled. Propensity score matching (PSM) was conducted to minimize the potential confounding effects. Results: Between March 2019 and July 2022, 328 patients were enrolled from four cancer centers in China, with 163 patients in the HD and 165 patients in the SD groups, respectively. The median follow-up time in the HD and SD groups were 28.9 and 25.9 months, respectively. There was no significant difference in overall survival (OS) (median OS: not reached in both, P = 0.080), progression-free survival (PFS) (median PFS: not reached vs. 30.3 months, P = 0.073), locoregional progression-free survival (LRPFS) and distant metastasis survival (DM) between the HD and SD groups. After 1:2 PSM, 156 patients in the HD and 78 patients in the SD groups were selected for further analyses. The results remained consistent and showed that the HD group had no significant benefits in OS (hazard ratio [HR] = 0.87, 95% confidence interval [CI] = 0.50-1.51, P = 0.624), PFS (HR = 0.79, 95%CI = 0.51-1.23, P = 0.300), LRPFS (HR = 0.75, 95%CI = 0.47-1.19, P = 0.228) and DM (HR = 1.05, 95%CI = 0.64-1.73, P = 0.849), compared with the SD group. In terms of failure patterns, the incidences of locoregional failure only (13.5% vs. 16.7%, P = 0.512), distant failure only (10.9% vs. 9.0%, P = 0.648) and synchronous locoregional and distant failure (2.6% vs. 6.4%, P = 0.164) were similar between two groups. No significant difference was found in the incidences of hematological toxicities, esophagitis, pneumonia (12.2% vs. 10.3%, P = 0.664) and fistula (7.1% vs 9.0%, P = 0.603) between the HD and SD groups. Conclusions: Compared with a radiation dose of 50-50.4Gy, the increase in radiation dose (≥60Gy) did not result in survival benefits for inoperable ESCC patients receiving dCRT combined with immunotherapy. Furthermore, similar failure patterns and toxicities were observed between the two treatment groups.

Modulation of Ionizing Radiation-Induced Apoptosis by Taurine in Human Peripheral Blood Lymphocytes: Flow Cytometry-based Quantification.

Radiotherapy, a highly effective method of radiation-based treating cancers, can reduce the size of tumors and affect healthy tissues. Radiation-induced lymphopenia as a side effect of radiation therapy can reduce the effectiveness of the treatment. This study aimed to examine how taurine can protect peripheral blood lymphocytes from radiation-based apoptosis. In this experimental study, the effects of the taurine on lymphocytes were studied, and blood samples were divided into three groups: a negative control group that was not treated, a positive control group that was treated with cysteine (100 μg/ml), and a group that was treated with taurine (100 µg. mL-1) in three different doses (4, 8 & 12 Gy) before irradiation. The percentage of apoptotic and necrotic lymphocytes was measured using flow cytometry 48 and 72 hours after the irradiation, respectively. According to the groups treated with taurine, the number of lymphocytes undergoing apoptosis was lower and higher compared to the negative and positive control groups, respectively. The decrease in this value was more pronounced 48 hours after radiation compared to 72 hours. Furthermore, there was a slight increase in the number of apoptotic lymphocytes with increasing radiation dose. Taurine effectively protects human peripheral blood lymphocytes from radiation-based apoptosis.

Significantly enhanced photo response of hydrazine hydrate reduced graphene oxide films modified with swift heavy ion irradiation of silver (Ag8+) ions

In this paper, a multistep reduction process of graphene oxide (GO) is discussed. It is basically a two-step reduction process. In the first step, the GO sample is reduced by hydrazine hydrate. In the second step, it is further reduced by a swift heavy ion irradiation beam of silver (Ag8+) ions of 100 MeV energies. Ion beam irradiation causes defects in the hydrazine hydrate reduced graphene oxide (rGO) samples. FTIR study confirms the removal of oxygen containing functional groups. The pore volume and pore density of the samples seem to increase with increase in the ion irradiation doses. It is also seen that the electrical conductivity and specific surface area increases with dose of ion irradiation. The prepared samples were tested for photo response measurement and among all the sample, R5 had the highest photo response of 6.25 % at 30 mW/cm2. The photodetection response seems to increase with increase in intensity of light.

The effect of methyl yellow concentrations on the optical properties of polyvinyl chloride-methyl yellow film as a radiation dosimeter

A dosimetry system's ability to monitor absorbed doses is crucial for the quality assurance and control of products that have been exposed to radiation. Here, we propose a polyvinyl chloride (PVC)-methyl yellow (MY) film as a potential dosimeter for irradiation facilities. The PVC-MY film was prepared with a simple solvent-casting method at different MY concentrations from 0.3 to 1.2 mM. To evaluate the dosimeter's performance, the film was exposed to gamma-irradiation with irradiation doses of 0–25 kGy. The optical characteristics of the films examined using a UV–Vis spectrophotometer showed that the color of the films changed from yellow to red with increasing irradiation doses, and the color change sensitivity of the films increased with increasing MY concentrations. The absorption spectra of the irradiated PVC-MY films showed three maximum absorption peaks at 417, 522, and 547 nm. As irradiation doses increased, the film absorption at 417 nm decreased, while the film absorption at 522 and 547 nm increased. The film's stability studies suggest storage of the irradiated film in a cold-dark conditions is recommended to prevent damage and maintain response stability. The findings in this study emphasize the potential of the PVC-MY film as a dosimeter for irradiation facilities.

MgB[formula omitted] Josephson Junctions fabricated by Focused Helium Ion Beam with different irradiation doses on SiC and MgO substrates

Recently, high quality MgB2 single junctions and junction arrays fabricated by Focused Helium Ion Beam irradiation (He-FIB) have been reported. However, the effects of irradiation doses and substrates on junction properties have not been analysed systematically. In this work, 30 nm MgB2 thin films were deposited on SiC (0001) and MgO (111) substrates using Hybrid Physical–Chemical Vapour Deposition (HPCVD) technique and then etched into 2–4 μm wide microbridges. 2000–6000 ions/nm doses of He-FIB were irradiated across these microbridges, creating narrow junction barriers. R–T curves exhibit a clear foot-like structure that enlarges as irradiation dose increases. Temperature dependence of junction properties (critical current Ic, junction normal state resistance Rn, characteristic voltage Vc) shows that all junctions in our experiment exhibit superconductor–normal–superconductor (SNS) like behaviour and higher irradiation doses create thicker junction barriers. Furthermore, we analyse junction properties dependence on irradiation doses which yields an exponential change law. Finally, Fraunhofer diffraction-like patterns and Shapiro steps of junctions are also measured. Our results show MgB2 Josephson Junctions with adjustable properties can be fabricated by He-FIB on SiC and MgO substrates, which provides a solid foundation for future application devices research.

Exploring the Impact of Irradiation on Glioblastoma Blood-Brain-Barrier Permeability: Insights from Dynamic-Contrast-Enhanced-MRI and Histological Analysis.

(1) Background: Glioblastoma (GB) presents a formidable challenge in neuro-oncology due to its aggressive nature, limited treatment options, and poor prognosis. The blood-brain barrier (BBB) complicates treatment by hindering drug delivery to the tumor site, particularly to the infiltrative cells in the margin of the tumor, which are mainly responsible for tumor recurrence. Innovative strategies are therefore needed to enhance drug delivery in the margins of the tumor. This study explores whether irradiation can enhance BBB permeability by assessing hemodynamic changes and the distribution of contrast agents in the core and the margins of GB tumors. (2) Methods: Mice grafted with U-87MG cells were exposed to increasing irradiation doses. The distribution of contrast agents and hemodynamic parameters was evaluated using both non-invasive magnetic resonance imaging (MRI) techniques with gadolinium-DOTA as a contrast agent and invasive histological analysis with Evans blue, a fluorescent vascular leakage marker. Diffusion-MRI was also used to assess cytotoxic effects. (3) Results: The histological study revealed a complex dose-dependent effect of irradiation on BBB integrity, with increased vascular leakage at 5 Gy but reduced leakage at higher doses (10 and 15 Gy). However, there was no significant increase in the diffusion of Gd-DOTA outside the tumor area by MRI. (4) Conclusions: The increase in BBB permeability could be an interesting approach to enhance drug delivery in glioblastoma margins for low irradiation doses. In this model, DCE-MRI analysis was of limited value in assessing the BBB opening in glioblastoma after irradiation.

Anomalous exchange bias behavior of NiFe/NiO bilayers induced by high-energy Xe+ ion irradiation

The alteration of the microstructure and magnetic performance of an exchange bias system, induced by ion irradiation, adversely affects the practical application of spintronic/storage devices in extreme environments. Here, we report systematically the correlation between static and dynamic magnetism and microstructure changes in NiFe/NiO exchange-biased bilayers after high-energy Xe+ ion irradiation. The effect of cascade collision induced by irradiation on exchange bias is studied through Monte Carlo simulations. It is distinguished from the traditional modification caused by keV-level ion irradiation. At low doses, the transition from amorphous to recrystallization occurs in the NiFe layer and the anomalous exchange bias behavior is induced. A step-like structure appears in the magnetic hysteresis loop and the step gradually shifts downward as the dose increases. At high doses, the exchange bias effect is suppressed due to the disordered antiferromagnetic moment caused by heat accumulation during cascade collision, which significantly decreases the thermal stability of the sample by 5–6 times. In addition, the non-monotonic evolution of high-frequency magnetic properties is observed with increasing irradiation doses. This work provides important foundational data for designing future spintronic/memory devices to enhance radiation tolerance and stability.

Enhancing starch functionality through synergistic modification via sequential treatments with cold plasma and electron beam irradiation

The impact of dual sequential modifications using radio-frequency (RF) plasma and electron beam irradiation (EBI) on starch properties was investigated and compared with single treatments within an irradiation dose range of 5–20 kGy. Regardless of sequence, dual treatments synergistically affected starch properties, increasing acidity, solubility, and paste clarity, while decreasing rheological features with increasing irradiation dose. The molecular weight distribution was also synergistically influenced. Amylopectin distribution broadened particularly below 10 kGy. Amylose narrowed its distribution across all irradiation doses. This was due to dominating EBI-induced degradation and molecular rearrangements from RF plasma. With the highest average radiation-chemical yield (G) and degradation rate constant (k) of (2.12 ± 0.14) × 10−6 mol·J−1 and (3.43 ± 0.23) × 10−4 kGy−1, respectively, upon RF plasma pre-treatment, amylose underwent random chain scission. In comparison to single treatments, dual modification caused minor alterations in spectral characteristics and crystal short-range order structure, along with increased granule aggregation and surface irregularities. The synergistic effect was dose-dependent, significant up to 10 kGy, irrespective of treatment sequence. The highest synergistic ratio was observed when RF plasma preceded irradiation, demonstrating the superior efficiency of plasma pre-treatment in combination with EBI. This synergy has the potential to lower costs and extend starch's technological uses by enhancing radiation sensitivity and reducing the irradiation dose.

Sustainable and fast synthesis of zinc-phthalocyanine for gamma radiation dosimeter application

In the present research, the two different systems of dye based on zinc phthalocyanine were prepared by microwave-induced synthesis and conventional methods. They were evaluated as new effective chemical-based dosimeters for gamma irradiation. The sensitivity of the prepared dosimeters was examined by studying the comparative results between them through the changes in structural and optical properties upon exposure to different gamma irradiation doses. The color bleaching of the solutions was followed spectrophotometrically. Gradual changes from blue to light yellow color of zinc phthalocyanine solution, with the increase of the gamma radiation dose, were observed due to the decomposition of the dyes based on the zinc phthalocyanine. The synthesized zinc phthalocyanine chemical-based dosimeters for measurement of gamma irradiation up to 25kGy showed excellent stability after irradiation in terms of morphology and structure, which makes them a suitable novel material as composite-based dosimeters of gamma irradiation.

Role of defects in tailoring the structural, electrical and optical properties of Schottky diodes based on GaAsBi alloy through gamma radiation

This work provides an extensive study of the influence of γ-rays on structural, electrical, and optical characteristics of GaAsBi Schottky diodes fabricated through Molecular Beam Epitaxy (MBE) on GaAs substrates. An important finding is the direct correlation observed between the radiation dose and the consequent increase in the turn-on voltage of the devices. X-ray diffraction (XRD) showed that only phases related to the GaAs and GaAs1-xBix layers were observed. Raman spectroscopy proved to be a powerful tool to elucidate the effects of ionizing radiation on GaAsBi samples. From the results of electrical measurements, such as current density-voltage, the characteristic parameters of the devices improved as a function of the radiation dose. Conversely, the Capacitance-Voltage (C–V) characteristics indicated a rise in the concentration of free carriers in all irradiated samples, suggesting an enhancement in the performance of the diodes. Assessment through Deep Level Transient Spectroscopy (DLTS) further revealed a reduction in the number of electrically active traps following irradiation. Consequently, the findings presented here highlight the potential improvements in diode performance resulting from sample irradiation. Upon subjecting the samples to irradiation doses of 50 kGys and 100 kGys, we identified the presence of three and two electron traps, respectively. This differs from the unirradiated diodes, which displayed four electron traps. Interestingly, the photoluminescence intensity of the main peak exhibited an increment with increasing irradiation dose. This observation implies an enhancement in the optical characteristic, as well as annihilation/contribution of Bi-related traps. These findings corroborate the electrical results obtained in our study. Finally, the Raman results showed that the decrease in the lifetime of the photoexcited carriers leads to a higher recombination rate which in turn leads to a higher photoluminescence (PL) intensity after radiation.

Complex dislocation loop networks as natural extensions of the sink efficiency of saturated grain boundaries in irradiated metals.

The development of radiation-tolerant structural materials is an essential element for the success of advanced nuclear energy concepts. A proven strategy to increase radiation resistance is to create microstructures with a high density of internal defect sinks, such as grain boundaries (GBs). However, as GBs absorb defects, they undergo internal transformations that limit their ability to capture defects indefinitely. Here, we show that, as the sink efficiency of GBs becomes exhausted with increasing irradiation dose, networks of irradiation loops form in the vicinity of saturated or near-saturated GB, maintaining and even increasing their capacity to continue absorbing defects. The formation of these networks fundamentally changes the driving force for defect absorption at GB, from "chemical" to "elastic." Using thermally-activated dislocation dynamics simulations, we show that these networks are consistent with experimental measurements of defect densities near GB. Our results point to these networks as a natural continuation of the GB once they exhaust their internal defect absorption capacity.

Ar-ion- and electron-irradiated ZrC layers in ZrC-SiC-coated surrogate TRISO fuel particles

Surrogate tristructural isotropic (TRISO) particles, including ZrC and SiC layers, were manufactured through fluidized-bed chemical vapor deposition and irradiated. ZrC layers exhibited C/Zr atomic ratio of 0.95 without distinct crevices at interfaces in microscopy, but underwent significant microstructural changes post-irradiation. Defects included black dots and Frank loops, with increasing irradiation doses augmenting their area fractions. Frank loop density reduced at 9.4dpa due to the formation of fewer, fully circular loops. The ZrC hardness and modulus rose by 25% and 26% following Ar-ion irradiation at 9.4dpa, linked to the formed defects and implanted Ar ions. Electron irradiation expanded the defect-prone zone up to 100nm from the ZrC grain boundary and led to ZrO2 formation. ZrC grains recrystallized post electron irradiation at 700 °C, causing initial grain decomposition, amorphization, and nanocrystal formation. These nanocrystals, formed at 3.3dpa, closely aligned with ZrC diffraction patterns with no preferred orientations.

Effects of EB irradiation on the properties of xanthan in solid state for utilization as adjuvant to improve foliar applications

AbstractIn this study, xanthan was irradiated by electron beam accelerator (EB) in solid state and the viscosity and molecular weight of the irradiated xanthan were investigated to provide a better understanding on the EB radiation effect on molecular properties of xanthan. Both viscosity and molecular weight of xanthan were greatly decreased by EB at 25 kGy then slowly decreased with further increase of irradiation dose to 200 kGy. Contact angles and adhesion degrees of the irradiated xanthan solutions were rather smaller than those of commercial xanthan. These results suggested that the xanthan was EB irradiated at 100 kGy can be utilized as a good adjuvant to improve spraying application of foliar fertilizer for promoting the growth and yield of water spinach.

Chemical Hydrolysis-Gamma Irradiation Processes for Cellulose Nanofibers Isolation from Rice Straw

Utilization of agriculture biomass waste into high value product is still potential to develop. In this study, cellulose nanofibers (CNF) as valuable materials were isolated from rice straw. Sodium hydroxide pulping and hydrogen peroxide bleaching were conducted as cellulose pretreatment. The CNF was prepared using 1 M hydrochloric acid hydrolysis followed gamma irradiation with various radiation doses, i.e. 40, 60, 80, 100 and 120 kGy. Compositions of α–cellulose and water retention of each stage processes increased inversely with hemicellulose, lignin and degrees of polymerization which had been strengthened by Fourier transform infrared spectroscopy (FTIR) spectra. X-ray Diffraction (XRD) analysis revealed that crystallinity index was more intense than rice straw, i.e. 80.85 %. Particle Size Analyzer (PSA) studies described the isolation process of CNF succeed with the smallest size 77.8 nm. The CNF functional groups of hydrophilic both hydroxyl and carboxylate slightly diminished with increasing of radiation doses followed water retention reducing, however the crystallinity had not changed significantly. Increasing radiation doses also could improve the thermal stability with the highest Tg 153.1 0C therefore the obtained CNF could be used as suitable nanocomposite.

Optimizing CT Abdomen-Pelvis Scan Radiation Dose: Examining the Role of Body Metrics (Waist Circumference, Hip Circumference, Abdominal Fat, and Body Mass Index) in Dose Efficiency.

Objective: This study investigates the correlation between patient body metrics and radiation dose in abdominopelvic CT scans, aiming to identify significant predictors of radiation exposure. Methods: Employing a cross-sectional analysis of patient data, including BMI, abdominal fat, waist, abdomen, and hip circumference, we analyzed their relationship with the following dose metrics: the CTDIvol, DLP, and SSDE. Results: Results from the analysis of various body measurements revealed that BMI, abdominal fat, and waist circumference are strongly correlated with increased radiation doses. Notably, the SSDE, as a more patient-centric dose metric, showed significant positive correlations, especially with waist circumference, suggesting its potential as a key predictor for optimizing radiation doses. Conclusions: The findings suggest that incorporating patient-specific body metrics into CT dosimetry could enhance personalized care and radiation safety. Conclusively, this study highlights the necessity for tailored imaging protocols based on individual body metrics to optimize radiation exposure, encouraging further research into predictive models and the integration of these metrics into clinical practice for improved patient management.

60Co γ‐radiation at low‐dose level alters volatile compounds of blueberry during storage

Summary60Co γ‐radiation was applied to blueberry fruits in an effort to investigate a safe, eco‐friendly and effective blueberry preservation technique. However, the preservation effects were variable depending on tissue tolerance to irradiation doses. Moreover, irradiation may cause off‐odour. In this study, we examined the effects of three low doses of 60Co γ‐radiation on the physical and flavour attributes of blueberry. The results showed that 60Co γ‐radiation did not significantly improve fruit quality but extend the shelf life up to 15 days at 25 °C and 30 days at 4 °C. Compared with the control group, the preservation effect of 0.5–1.0 kGy irradiation treatment on blueberry fruit was not obvious before 15 days but maintained 65% of fruit firmness and reduced the loss of nutrients afterwards at 4 °C. At 25 °C, irradiation treatment caused up to a 150% increase in polyphenol oxidase activity, which was relevant to colour changes in late storage. Headspace Gas Chromatography Ion Mobility Spectrometry (HS‐GC‐IMS) was applied, and 33 volatile organic compounds (VOCs) in blueberry treated with different radiation doses were identified, including 11 esters, 8 aldehydes, 7 alcohols, 6 ketones and other substances, which increased with increasing radiation dose. Radiation reduced the green taste of blueberry and promoted their ripening. Radiation above the level of 1.02 kGy led to the flavour deterioration of blueberry such as ethyl trans‐2‐butenoate. The side effects of radiation on the aroma of blueberry could be offset by low‐temperature storage. Blueberry stored at 4 °C contained more aldehydes with a heavier fresh/green aroma. Six aromas were proposed to be characteristic odour markers of radiated blueberry.

Effect of electron beam irradiation pretreatment and different fatty acid types on the formation, structural characteristics and functional properties of starch-lipid complexes

The effects of different electron beam irradiation doses (2, 4, 8 KGy) and various types of fatty acids (lauric acid, stearic acid, and oleic acid) on the formation, structure, physicochemical properties, and digestibility of starch-lipid complex were investigated. The complexing index of the complexes was higher than 85 %, indicating that the three fatty acids could easily form complexes with starch. With the increase of electron beam irradiation dose, the complexing index increased first and then decreased. The highest complexing index was lauric acid (97.12 %), stearic acid (96.80 %), and oleic acid (97.51 %) at 2 KGy radiation dose, respectively. Moreover, the microstructure, crystal structure, thermal stability, rheological properties, and starch solubility were analyzed. In vitro digestibility tests showed that adding fatty acids could reduce the content of hydrolyzed starch, among which the resistant starch content of the starch-oleic acid complex was the highest (54.26 %). The lower dose of electron beam irradiation could decrease the digestibility of starch and increase the content of resistant starch.

Microstructural evolution of ion-irradiated commercially pure titanium

Radiation-induced dislocation loop evolution in ion-irradiated commercially pure (CP) Ti was investigated through both ex situ 4 MeV Ar beams and by in situ TEM irradiation with 1 MeV Kr ion beams at different temperatures. The dominant mechanism for dislocation loop growth was loop coalescence. Both <a>- and c-component loops exhibited an increase in size and density with increased irradiation dose and temperature. C-component loops were observed only after reaching a threshold incubation dose (TID). In CP Ti, these loops initiated at lower doses compared to previous observations in Zr, and the TID decreased with increasing temperature.