Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 106
Filtrar
1.
ACS Appl Mater Interfaces ; 16(33): 43724-43733, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39121209

RESUMO

AgNW networks show high promise as a conductive material due to excellent flexibility, low resistance, high transparency, and ease of large-scale preparation. However, the application of AgNW networks has been hindered by their inherent characteristics, such as easy oxidation degradation, chemical corrosion, and structural instability at high temperatures. In this study, a dense SiOx protective layer derived from perhydropolysilazane was introduced to fabricate a robust SiOx/AgNW nanocomposite coating through an all-solution process at room temperature. The achieved nanocomposite coating shows outstanding thermal stability up to 450 °C, resistance to ultraviolet radiation, and excellent mechanical performance by maintaining stability after 10,000 cycles of bending at a radius of 2.5 mm, 1000 cycles of peeling, and 1200 cycles of wearing. Meanwhile, the nanocomposite coating demonstrates exceptional chemical tolerance against HCl, Na2S, and organic solvents. A transparent heater based on the nanocomposite coating achieves a remarkable benchmark with a maximum temperature of 400 °C at 20 V. These features highlight the potential of the nanocomposite coating in flexible electronics, optoelectronics, touch screens, and high-performance heaters.

2.
Rep Pract Oncol Radiother ; 29(3): 348-356, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39144264

RESUMO

Background: Definitive concurrent chemoradiotherapy (CRT) is the standard of care in advanced stages of head and neck cancer (HNC). With evident increase in survival rate there is also simultaneous increase in toxicity affecting the quality of life. One of the less researched late toxicity is radiation induced brachial plexopathy (RIBP). In this dosimetric study we intent to contour the brachial plexus (BP) as an organ at risk (OAR) and determine the factors that contribute to dose variations to BP, and clinically evaluate the patients for RIBP during follow-up using a questionnaire. Materials and methods: 30 patients with HNC planned for CRT from September 2020 to June 2022 were accrued. Patients were treated to a dose of 6600 cGy with intensity modulated radiotherapy using the simultaneous integrated boost technique. From the dose-volume histogram (DVH) statistics the BP volume, Dmax and other parameters like V66, V60 were assessed and was correlated with respect to primary tumour and nodal stage. Results: On corelation, more than the T stage, the N stage and the primary location had a significant impact on the Dmax. With a median follow-up of 17.9 months, the incidence of RIBP was 6.67%. The 2-year disease free survival and the 2-year overall survival were 53.7% and 59.4%, respectively. Conclusions: In oropharyngeal/hypopharyngeal primaries and in advanced nodal disease, BP receives higher doses contributing to RIBP. Primary tumor and nodal stage also impacted V60 and V66 of BP. Hence, contouring of BP as an OAR becomes imperative, and respecting the DVH parameters is essential.

3.
Nano Lett ; 24(25): 7688-7697, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38869197

RESUMO

Radiation-tolerance and repairable flexible transistors and integrated circuits (ICs) with low power consumption have become hot topics due to their wide applications in outer space, nuclear power plants, and X-ray imaging. Here, we designed and developed novel flexible semiconducting single-walled carbon nanotube (sc-SWCNT) thin-film transistors (TFTs) and ICs. Sc-SWCNT solid-electrolyte-gate dielectric (SEGD) TFTs showcase symmetric ambipolar characteristics with flat-band voltages (VFB) of ∼0 V, high ION/IOFF ratios (>105), and the recorded irradiation resistance (up to 22 Mrad). Moreover, flexible sc-SWCNT ICs, including CMOS-like inverters and NAND and NOR logic gates, have excellent operating characteristics with low power consumption (≤8.4 pW) and excellent irradiation resistance. Significantly, sc-SWCNT SEGD TFTs and ICs after radiation with a total irradiation dose (TID) ≥ 11 Mrad can be repaired after thermal heating at 100 °C. These outstanding characteristics are attributed to the designed device structures and key core materials including SEGD and sc-SWCNT.

4.
Nanotechnology ; 35(43)2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-38815569

RESUMO

This paper proposes a novel circuit-level design in order to enhance the radiation tolerance of an analog switch integrated circuit. After analyzing the mechanisms of single-particle sensitivity in a high-voltage analog switch chip fabricated using a commercial 1µm complementary metal-oxide-semiconductor process, a diode unit was employed to reduce theVGS(voltage between the gate and the base) of the parasitic triode within the metal-oxide-semiconductor field-effect transistor of the switch. This reduction lowered the probability of activating the parasitic triode in response to single-event effect (SEE). Subsequently, single-particle irradiation experiments proceeded with the high-voltage analog switch chip, both with and without the diode unit. In the unreinforced device, the current of the power supply reached 100 mA within 11 s of single-particle irradiation at 75.8 MeV•cm2mg-1. In contrast, in the reinforced device, the current of the power supply remained relatively stable under irradiation at both 37.2 and 75.8 MeV•cm2mg-1. These findings indicate that the reinforced analog switch chip exhibits an SEE tolerance exceeding 75.8 MeV•cm2mg-1, highlighting its potential to enhance the radiation tolerance of analog switches.

5.
Curr Biol ; 34(9): 1819-1830.e6, 2024 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-38614079

RESUMO

Tardigrades can survive remarkable doses of ionizing radiation, up to about 1,000 times the lethal dose for humans. How they do so is incompletely understood. We found that the tardigrade Hypsibius exemplaris suffers DNA damage upon gamma irradiation, but the damage is repaired. We show that this species has a specific and robust response to ionizing radiation: irradiation induces a rapid upregulation of many DNA repair genes. This upregulation is unexpectedly extreme-making some DNA repair transcripts among the most abundant transcripts in the animal. By expressing tardigrade genes in bacteria, we validate that increased expression of some repair genes can suffice to increase radiation tolerance. We show that at least one such gene is important in vivo for tardigrade radiation tolerance. We hypothesize that the tardigrades' ability to sense ionizing radiation and massively upregulate specific DNA repair pathway genes may represent an evolved solution for maintaining DNA integrity.


Assuntos
Reparo do DNA , Raios gama , Radiação Ionizante , Tardígrados , Regulação para Cima , Animais , Reparo do DNA/genética , Tardígrados/genética , Dano ao DNA , Tolerância a Radiação/genética
6.
Cureus ; 16(1): e52283, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38357089

RESUMO

This case report details a rare instance of radiation-induced brachial plexopathy (RIBP) occurring below the typical tolerance dose in a 55-year-old woman following chemoradiotherapy for apical non-small cell lung carcinoma. Despite receiving a radiation dose considered safe (47-48 Gray in 25 fractions), she developed sensory abnormalities and motor weakness in the right upper limb. The diagnostic distinction between RIBP and tumor recurrence was achieved using MRI, which showed characteristic features of radiation-induced damage. The patient's medical history included smoking and rheumatoid arthritis, highlighting the role of patient-specific factors in the development of RIBP. The case underscores the importance of recognizing RIBP as a potential diagnosis in patients with new-onset brachial plexopathy post-radiation therapy, even when radiation exposure is within conventional safety limits. This report contributes to the literature by demonstrating that RIBP can occur at lower-than-expected radiation doses, especially in the presence of contributing factors like neurotoxic chemotherapy and individual patient risks. It emphasizes the need for careful assessment and management in such cases to distinguish between RIBP and cancer recurrence.

7.
Fungal Biol ; 127(12): 1524-1533, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38097326

RESUMO

We investigated conidial mass production of eight isolates of six entomopathogenic fungi (EPF), Aphanocladium album (ARSEF 1329), Beauveria bassiana (ARSEF 252 and 3462), Lecanicillium aphanocladii (ARSEF 6433), Metarhizium anisopliae sensu lato (ARSEF 2341), Metarhizium pingshaense (ARSEF 1545), and Simplicillium lanosoniveum (ARSEF 6430 and 6651) on white or brown rice at four moisture conditions (75-100%). The tolerance of mass-produced conidia of the eight fungal isolates to UV-B radiation and heat (45 °C) were also evaluated. For each moisture content compared, a 20-g sample of rice in a polypropylene bag was inoculated with each fungal isolate in three replicates and incubated at 28 ± 1 °C for 14 days. Conidia were then harvested by washing the substrate, and conidial concentrations determined by haemocytometer counts. Conidial suspensions were inoculated on PDAY with 0.002% benomyl in Petri plates and exposed to 978 mW m-2 of Quaite-weighted UV-B for 2 h. Additionally, conidial suspensions were exposed to 45 °C for 3 h, and aliquots inoculated on PDAY with benomyl. The plates were incubated at 28 ± 1 °C, and germination was assessed at 400 × magnification after 48 h. Conidial production was generally higher on white rice than on brown rice for all fungal species, except for L. aphanocladii ARSEF 6433, regardless of moisture combinations. The 100% moisture condition provided higher conidial production for B. bassiana (ARSEF 252 and ARSEF 3462) and M. anisopliae (ARSEF 2341) isolates, while the addition of 10% peanut oil enhanced conidial yield for S. lanosoniveum isolate ARSEF 6430. B. bassiana ARSEF 3462 on white rice with 100% water yielded the highest conidial production (approximately 1.3 × 1010 conidia g-1 of substrate). Conidia produced on white rice with the different moisture conditions did not differ in tolerance to UV-B radiation or heat. However, high tolerance to UV-B radiation and heat was observed for B. bassiana, M. anisopliae, and A. album isolates. Heat-treated conidia of S. lanosoniveum and L. aphanocladii did not germinate.


Assuntos
Beauveria , Metarhizium , Esporos Fúngicos , Temperatura Alta , Benomilo , Controle Biológico de Vetores
8.
Fungal Biol ; 127(12): 1544-1550, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38097328

RESUMO

Metarhizium spp. is used as a biocontrol agent but is limited because of low tolerance to abiotic stress. Metarhizium robertsii is an excellent study model of fungal pathogenesis in insects, and its tolerance to different stress conditions has been extensively investigated. Priming is the time-limited pre-exposure of an organism to specific stress conditions that increases adaptive response to subsequent exposures. Congo red is a water-soluble azo dye extensively used in stress assays in fungi. It induces morphological changes and weakens the cell wall at sublethal concentrations. Therefore, this chemical agent has been proposed as a stressor to induce priming against other stress conditions in entomopathogenic fungi. This study aimed to evaluate the capacity of Congo red to induce priming in M. robertsii. Conidia were grown on potato dextrose agar with or without Congo red.The tolerance of conidia produced from mycelia grown in these three conditions was evaluated against stress conditions, including osmotic, oxidative, heat, and UV-B radiation. Conidia produced on medium supplemented with Congo red were significantly more tolerant to UV-B radiation but not to the other stress conditions assayed. Our results suggest that Congo red confers trans-priming to UV-B radiation but not for heat, oxidative, or osmotic stress.


Assuntos
Metarhizium , Metarhizium/fisiologia , Vermelho Congo , Raios Ultravioleta , Esporos Fúngicos/fisiologia
9.
Pol J Pathol ; 74(2): 122-130, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37728471

RESUMO

CD98 is a marker of cancer stem cells, and it regulates radiosensitivity in head and neck squamous cell carcinoma (HNSCC). The current study aimed to investigate whether CD98 can be used as a prognostic factor and marker of radioresistance. CD98 immunostaining was performed using biopsy specimens collected from patients diagnosed with HNSCC. The average period of postoperative monitoring was 31.6 months. The treatment options were radiation therapy with either cisplatin or cetuximab, and surgery. The participants were divided into groups of low and high fluorescence intensity. CD98 was an independent prognostic factor of radioresistance. In total, 103 patients were treated with chemoradiotherapy or bioradiotherapy. The overall survival rates of patients receiving chemoradiotherapy or bioradiotherapy were 69.2% in the low group and 36.2% in the high group. The progression-free survival rates were 60.0% and 24.6%, respectively. CD98 expression was considered an independent prognostic factor of overall survival and progression-free survival. In total, 99 patients underwent surgical treatment. The surgery group did not differ according to CD98 expression. Via CD98 immunostaining, sensitivity to radiotherapy can be determined in advance. In HNSCC, knowledge about sensitivity to radiotherapy can significantly improve prognosis.


Assuntos
Quimiorradioterapia , Neoplasias de Cabeça e Pescoço , Humanos , Neoplasias de Cabeça e Pescoço/radioterapia , Células-Tronco Neoplásicas , Tolerância a Radiação , Carcinoma de Células Escamosas de Cabeça e Pescoço , Proteína-1 Reguladora de Fusão/metabolismo
10.
J Obstet Gynaecol Res ; 49(8): 2109-2117, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37291943

RESUMO

AIM: Uterine cervical cancer (UCC) is the fourth most common cancer in women, responsible for more than 300 000 deaths worldwide. Its early detection, by cervical cytology, and prevention, by vaccinating against human papilloma virus, greatly contribute to reducing cervical cancer mortality in women. However, penetration of the effective prevention of UCC in Japan remains low. Plasma metabolome analysis is widely used for biomarker discovery and the identification of cancer-specific metabolic pathways. Here, we aimed to identify predictive biomarkers for the diagnosis and radiation sensitivity of UCC using wide-targeted plasma metabolomics. METHODS: We analyzed 628 metabolites in plasma samples obtained from 45 patients with UCC using ultra-high-performance liquid chromatography with tandem mass spectrometry. RESULTS: The levels of 47 metabolites were significantly increased and those of 75 metabolites were significantly decreased in patients with UCC relative to healthy controls. Increased levels of arginine and ceramides, and decreased levels of tryptophan, ornithine, glycosylceramides, lysophosphatidylcholine, and phosphatidylcholine were characteristic of patients with UCC. Comparison of metabolite profiles in groups susceptible and non-susceptible to radiation therapy, a treatment for UCC, revealed marked variations in polyunsaturated fatty acid, nucleic acid, and arginine metabolism in the group not susceptible to treatment. CONCLUSIONS: Our findings suggest that the metabolite profile of patients with UCC may be an important indicator for distinguishing these patients from healthy cohorts, and may also be useful for predicting sensitivity to radiotherapy.


Assuntos
Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/diagnóstico , Metabolômica/métodos , Biomarcadores , Metaboloma , Tolerância a Radiação , Arginina/metabolismo
11.
Expert Rev Anticancer Ther ; 23(7): 709-717, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37194207

RESUMO

INTRODUCTION: Brain tumors are the most common solid tumors in children. Neurosurgical excision, radiotherapy, and/or chemotherapy represent the standard of care in most histopathological types of pediatric central nervous system (CNS) tumors. Even though the successful cure rate is reasonable, some patients may develop recurrence locally or within the neuroaxis. AREA COVERED: The management of these recurrences is not easy; however, significant advances in neurosurgery, radiation techniques, radiobiology, and the introduction of newer biological therapies, have improved the results of their salvage treatment. In many cases, salvage re-irradiation is feasible and has achieved encouraging results. The results of re-irradiation depend upon several factors. These factors include tumor type, extent of the second surgery, tumor volume, location of the recurrence, time that elapses between the initial treatment, the combination with other treatment agents, relapse, and the initial response to radiotherapy. EXPERT OPINION: Reviewing the radiobiological basis and clinical outcome of pediatric brain re-irradiation revealed that re-irradiation is safe, feasible, and indicated for recurrent/progressive different tumor types such as; ependymoma, medulloblastoma, diffuse intrinsic pontine glioma (DIPG) and glioblastoma. It is now considered part of the treatment armamentarium for these patients. The challenges and clinical results in treating recurrent pediatric brain tumors were highly documented.


Assuntos
Neoplasias Encefálicas , Neoplasias Cerebelares , Meduloblastoma , Reirradiação , Humanos , Criança , Reirradiação/métodos , Recidiva Local de Neoplasia/patologia , Neoplasias Encefálicas/tratamento farmacológico
12.
Cytoskeleton (Hoboken) ; 80(9-10): 330-355, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37066976

RESUMO

Actin is an abundant and multifaceted protein in eukaryotic cells that has been detected in the cytoplasm as well as in the nucleus. In cooperation with numerous interacting accessory-proteins, monomeric actin (G-actin) polymerizes into microfilaments (F-actin) which constitute ubiquitous subcellular higher order structures. Considering the extensive spatial dimensions and multifunctionality of actin superarrays, the present study analyses the issue if and to what extent environmental stress factors, specifically ionizing radiation (IR) and reactive oxygen species (ROS), affect the cellular actin-entity. In that context, this review particularly surveys IR-response of fungi and plants. It examines in detail which actin-related cellular constituents and molecular pathways are influenced by IR and related ROS. This comprehensive survey concludes that the general integrity of the total cellular actin cytoskeleton is a requirement for IR-tolerance. Actin's functions in genome organization and nuclear events like chromatin remodeling, DNA-repair, and transcription play a key role. Beyond that, it is highly significant that the macromolecular cytoplasmic and cortical actin-frameworks are affected by IR as well. In response to IR, actin-filament bundling proteins (fimbrins) are required to stabilize cables or patches. In addition, the actin-associated factors mediating cellular polarity are essential for IR-survivability. Moreover, it is concluded that a cellular homeostasis system comprising ROS, ROS-scavengers, NADPH-oxidases, and the actin cytoskeleton plays an essential role here. Consequently, besides the actin-fraction which controls crucial genome-integrity, also the portion which facilitates orderly cellular transport and polarized growth has to be maintained in order to survive IR.

13.
Head Neck ; 45(5): 1130-1140, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36856128

RESUMO

BACKGROUND: In intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC), priority is often given minimize dose to the critical organs at risk (OARs) to avoid potential morbid sequelae. However, in T4 NPC, dosimetric inadequacy enforced by dose constraints on OARs may significantly impact tumor control. METHODS: This was a single-institute cohort that patients diagnosed between July 2005 and December 2010 with T4 NPC treated with IMRT. All patients were re-classification according to the 7th-AJCC stage. RESULTS: Overall, the average doses such as Dmax , D1% , D2% and D1cc for various Central nervous system (CNS) OARs including brainstem, optic nerve, chiasm, temporal lobes and spinal cord were found to exceed published guidelines as RTOG0225. However, no clinical toxicities were seen during the follow-up period except for 13% patients with temporal lobe necrosis. CONCLUSION: Our retrospective review showed that its feasible to maximize gross tumor volume dose coverage while exceeding most CNS OAR constraint standards, with ideal local control and no obvious increase of craniocerebral toxicity.


Assuntos
Neoplasias Nasofaríngeas , Radioterapia de Intensidade Modulada , Humanos , Carcinoma Nasofaríngeo/patologia , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/patologia , Neoplasias Nasofaríngeas/radioterapia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada/efeitos adversos , Carga Tumoral
14.
Technol Cancer Res Treat ; 22: 15330338231165125, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36960537

RESUMO

BACKGROUND: To assess the radiosensitivity of liver tumors harboring different genetic mutations, mouse liver tumors were generated in vivo through the hydrodynamic injection of clustered regularly interspaced short palindromic repeat/caspase 9 (CRISPR/Cas9) constructs encoding single-guide RNAs (sgRNAs) targeting Tp53, Pten, Nf1, Nf2, Tsc2, Cdkn2a, or Rb1. METHODS: The plasmid vectors were delivered to the liver of adult C57BL/6 mice via hydrodynamic tail vein injection. The vectors were injected into 10 mice in each group. Organoids were generated from mouse liver tumors. The radiation response of the organoids was assessed using an ATP cell viability assay. RESULTS: The mean survival period of mice injected with vectors targeting Nf2 (4.8 months) was lower than that of other mice. Hematoxylin and eosin staining, immunohistochemical (IHC) staining, and target sequencing analyses revealed that mouse liver tumors harbored the expected mutations. Tumor organoids were established from mouse liver tumors. Histological evaluation revealed marked morphological similarities between the mouse liver tumors and the generated tumor organoids. Moreover, IHC staining indicated that the parental tumor protein expression pattern was maintained in the organoids. The results of the ATP cell viability assay revealed that the tumor organoids with mutated Nf2 were more resistant to high-dose radiation than those with other gene mutations. CONCLUSIONS: This study developed a radiation response assessment system for mouse tumors with mutant target genes using CRISPR/Cas9 and organoids. The Tp53 and Pten double mutation in combination with the Nf2 mutation increased the radiation resistance of tumors. The system used in this study can aid in elucidating the mechanism underlying differential intrinsic radiation sensitivity of individual tumors.


Assuntos
Sistemas CRISPR-Cas , Neoplasias Hepáticas , Camundongos , Animais , Sistemas CRISPR-Cas/genética , Camundongos Endogâmicos C57BL , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/metabolismo , Mutação , Organoides/metabolismo , Organoides/patologia , Trifosfato de Adenosina
15.
Head Neck ; 45(5): 1088-1096, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36840723

RESUMO

BACKGROUND: To determine if the extent of high-dose gross tumor volume (GTV) to clinical target volume (CTV) expansion is associated with local control in patients with p16-positive oropharynx cancer (p16+ OPC) treated with definitive intensity modulated proton therapy (IMPT). METHODS: We performed a retrospective analysis of patients with p16+ OPC treated with IMPT at a single institution between 2016 and 2021. Patients with a pre-treatment PET-CT and restaging PET-CT within 4 months following completion of IMPT were analyzed. RESULTS: Sixty patients were included for analysis with a median follow-up of 17 months. The median GTV to CTV expansion was 5 mm (IQR: 2 mm). Thirty-three percent of patients (20 of 60) did not have a GTV to CTV expansion. There was one local failure within the expansion group (3%). CONCLUSION: Excellent local control was achieved using IMPT for p16+ OPC independent of GTV expansion. IMPT with minimal target expansions represent a potential harm-minimization technique for p16-positive oropharynx cancer.


Assuntos
Neoplasias Orofaríngeas , Terapia com Prótons , Radioterapia de Intensidade Modulada , Humanos , Terapia com Prótons/métodos , Estudos Retrospectivos , Carga Tumoral , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Dosagem Radioterapêutica , Neoplasias Orofaríngeas/etiologia , Radioterapia de Intensidade Modulada/métodos , Planejamento da Radioterapia Assistida por Computador
16.
Lung Cancer ; 176: 56-74, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36621035

RESUMO

Huge technological and biomedical advances have improved the survival and quality of life of lung cancer patients treated with radiotherapy. However, during treatment planning, a probability that the patient will experience adverse effects is assumed. Radiotoxicity is a complex entity that is largely dose-dependent but also has important intrinsic factors. One of the most studied is the genetic variants that may be associated with susceptibility to the development of adverse effects of radiotherapy. This review aims to present the current status of radiogenomics in lung cancer, integrating results obtained in association studies of SNPs (single nucleotide polymorphisms) related to radiotherapy toxicities. We conclude that despite numerous publications in this field, methodologies and endpoints vary greatly, making comparisons between studies difficult. Analyzing SNPs from the candidate gene approach, together with the study in cohorts limited by the sample size, has complicated the possibility of having validated results. All this delays the incorporation of genetic biomarkers in predictive models for clinical application. Thus, from all analysed SNPs, only 12 have great potential as esophagitis genetic risk factors and deserve further exploration. This review highlights the efforts that have been made to date in the radiogenomic study of radiotoxicity in lung cancer.


Assuntos
Neoplasias Pulmonares , Lesões por Radiação , Radioterapia (Especialidade) , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/radioterapia , Polimorfismo de Nucleotídeo Único , Qualidade de Vida , Genômica por Radiação , Lesões por Radiação/genética , Tolerância a Radiação/genética
17.
Small ; 19(1): e2204537, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36366937

RESUMO

Carbon nanotube (CNT) field-effect transistors (FETs) have been considered ideal building blocks for radiation-hard integrated circuits (ICs), the demand for which is exponentially growing, especially in outer space exploration and the nuclear industry. Many studies on the radiation tolerance of CNT-based electronics have focused on the total ionizing dose (TID) effect, while few works have considered the single event effects (SEEs) and displacement damage (DD) effect, which are more difficult to measure but may be more important in practical applications. Measurements of the SEEs and DD effect of CNT FETs and ICs are first executed and then presented a comprehensive radiation effect analysis of CNT electronics. The CNT ICs without special irradiation reinforcement technology exhibit a comprehensive radiation tolerance, including a 1 × 104 MeVcm2 mg-1 level of the laser-equivalent threshold linear energy transfer (LET) for SEEs, 2.8 × 1013 MeV g-1 for DD and 2 Mrad (Si) for TID, which are at least four times higher than those in conventional radiation-hardened ICs. The ultrahigh intrinsic comprehensive radiation tolerance will promote the applications of CNT ICs in high-energy solar and cosmic radiation environments.


Assuntos
Nanotubos de Carbono , Transistores Eletrônicos , Tolerância a Radiação
18.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-993224

RESUMO

Objective:To investigate the effect of ubiquitin binding enzyme 2T (UBE2T) on the radiosensitivity of lung adenocarcinoma and unravel its possible mechanism.Methods:A total of 45 patients pathologically diagnosed with different stages of lung adenocarcinoma and treated with radiotherapy in the Second Affiliated Hospital of Zunyi Medical University from March, 2019 to December, 2021 were enrolled, and the efficacy was evaluated according to response evaluation criteria in solid tumors (RECIST1.1). All patients were divided into radiosensitive group ( n=25) and radioresistant group ( n=20). Radiosensitive group was complete remission (CR)+partial remission (PR), and radioresistant group was stable disease (SD) + progression disease (PD). Immunohistochemistry (IHC) was used to calculate the score based on the staining intensity and the number of positive cells. Chi-square test was combined to analyze the correlation between the expression level of UBE2T in paraffin specimens of lung adenocarcinoma patients and the radiosensitivity of patients. Lentivirus UBE2T-interfered (UBE2Tsh) A549 and UBE2T-overexpressed SPC-A-1 lung adenocarcinoma cells and their respective controls were constructed for irradiation and colony formation assay. The survivor fraction curve was fitted by single-hit multi-target model. The DNA double-strand break (DSB) marker γH2AX foci were detected by immunofluorescence (IF). The expression levels of UBE2T, γH 2AX and Rad51 proteins were detected by Western blot. Cell cycle and apoptosis rate of A549 were determined by flow cytometry. Binary variables were statistically analyzed by Fisher's exact probability method and measurement data were assessed by t-test. Results:High-expression level of UBE2T was correlated with the radiosensitivity of lung adenocarcinoma patients ( P<0.05). UBE2Tsh improved the radiosensitivity of A549 lung adenocarcinoma cells, and the sensitizing enhancement ratio (SER) was 1.795. UBE2T overexpression decreased the radiosensitivity of SPC-A-1 lung adenocarcinoma cells with an SER of 0.293. γH2AX foci number per cell were significantly increased in UBE2Tsh A549 cells after irradiation ( P<0.01) . Compared with the control group, the expression level of γH2AX protein was up-regulated ( P<0.01)and that of Rad51 protein was down-regulated in UBE2Tsh A549 cells after radiation ( P<0.001). Compared with the control group, the expression level of γH2AX protein was down-regulated ( P<0.05) and that of Rad51 protein was up-regulated in UBE2T overexpressed SPC-A-1 cells ( P<0.001). The proportion of UBE2Tsh A549 cells in G 2 phase was decreased ( P<0.01) and cell apoptosis was increased ( P<0.001). Conclusions:UBE2T might promote the radioresistance of lung adenocarcinoma cells by enhancing DNA DSB repair induced by radiotherapy, inducing cell cycle G 2 phase arrest, and reducing cell apoptosis.

19.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-993257

RESUMO

Ferroptosis is a new form of regulated cell death discovered in recent years, which is iron-dependent cell death characterized by peroxidation of polyunsaturated fatty acid phospholipids. Recent studies have shown that radiotherapy can induce ferroptosis in cancer cells via ionizing radiation. Targeting ferroptosis plays a synergistic role in tumor suppression with radiation, which not only further deepens the connotation of radiobiology, but also provides a new perspective for tumor radiosensitization. This review systematically summarizes the occurrence and defense of ferroptosis, focusing on the key role of ferroptosis in the radiobiological effects of tumor cells and the potential application of ferroptosis in radiosensitization.

20.
Hepat Oncol ; 9(3): HEP44, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36176484

RESUMO

Materials & methods: High dose rate interstitial brachytherapy (HDR-IBT) treatment plan for 15 metastatic liver lesions in a patient with pancreatic cancer was retrieved and analyzed for liver dose parameters and diaphragm dose. Serial 18F-FDG PET-CT scans were reviewed for disease response assessment and left liver lobe volume. Serial laboratory records were analyzed for liver parameters. Results: Left liver lobe volume increased from 241 cm3 pre-HDR-IBT to estimated 600 cm3 after seven sessions of HDR-IBT. Metabolic complete response (CR) and subsequently pathological CR was confirmed in the right hepatotectomy specimen for all the 15 PET-CT avid lesions treated with HDR-IBT. Maximum diaphragm dose in a single fraction was 82 Gy. The liver parameters were stable and patient did not develop radiation induced liver disease. Discussion: This is the largest reported series of HDR-IBT to liver lesions in a single patient. This first ever reported combined treatment of immunotherapy (IT) and HDR-IBT had likely rendered this patient disease free both at local the liver and systemically. Metabolic CR by PET-CT can be seen as early as 46 days after HDR-IBT. Diaphragm can tolerate very high doses of radiation and repeated treatment. Conclusion: In this patient HDR-IBT for multiple liver lesions with IT is well tolerated. PET-CT can be used for response assessment of HDR-IBT liver. Synergistic effect of IT with HDR-IBT and it's role as bridging for liver resection has clinical potential and should be further studied in prospective trials.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA