Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 439
Filter
1.
Article in Chinese | WPRIM | ID: wpr-880394

ABSTRACT

Compared with conventional high energy X-ray radiotherapy, proton/carbon ion has obvious advantages because of its Bragg peak dose distribution. However, proton heavy ion facility has complex structure, high energy and various radiation types due to various nuclear reaction processes, the radiation protection safety brought by the operation of facilities has gradually attracted attention. Taking the proton/carbon ion radiotherapy facility of Shanghai Proton and Heavy Ion Center as an example, the author mainly analyzed the operation principle of proton/carbon ion treatment facility, the basis of radiation protection, analysis of key radiation source points, etc., so as to provide theoretical support and experience for radiation protection.


Subject(s)
China , Heavy Ion Radiotherapy , Heavy Ions , Occupational Exposure/prevention & control , Protons , Radiation Protection , Radiotherapy
2.
Article in English | WPRIM | ID: wpr-741436

ABSTRACT

OBJECTIVE: The purpose of this study was to investigate whether three-dimensional (3D) magnetic resonance imaging could improve diagnostic accuracy for suspected posterior ligamentous complex (PLC) disruption. MATERIALS AND METHODS: We used 20 freshly harvested goat spine samples with 60 segments and intact surrounding soft tissue. The animals were aged 1–1.5 years and consisted of 8 males and 12 females, which were sexually mature but had not reached adult weights. We created a paraspinal contusion model by percutaneously injecting 10 mL saline into each side of the interspinous ligament (ISL). All segments underwent T2-weighted sagittal and coronal short inversion time inversion recovery (STIR) scans as well as coronal and sagittal 3D proton density-weighted spectrally selective inversion recovery (3D-PDW-SPIR) scans acquired at 1.5T. Following scanning, some ISLs were cut and then the segments were re-scanned using the same magnetic resonance (MR) techniques. Two radiologists independently assessed the MR images, and the reliability of ISL tear interpretation was assessed using the kappa coefficient. The chi-square test was used to compare the diagnostic accuracy of images obtained using the different MR techniques. RESULTS: The interobserver reliability for detecting ISL disruption was high for all imaging techniques (0.776–0.949). The sensitivity, specificity, and diagnostic accuracy of the coronal 3D-PDW-SPIR technique for detecting ISL tears were 100, 96.9, and 97.9%, respectively, which were significantly higher than those of the sagittal STIR (p = 0.000), coronal STIR (p = 0.000), and sagittal 3D-PDW-SPIR (p = 0.001) techniques. CONCLUSION: Compared to other MR methods, coronal 3D-PDW-SPIR provides a more accurate diagnosis of ISL disruption. Adding coronal 3D-PDW-SPIR to a routine MR protocol may help to identify PLC disruptions in cases with nearby contusion.


Subject(s)
Adult , Animals , Contusions , Diagnosis , Female , Goats , Humans , Ligaments , Magnetic Resonance Imaging , Male , Models, Animal , Protons , Sensitivity and Specificity , Spine , Tears , Weights and Measures
3.
Article in English | WPRIM | ID: wpr-741415

ABSTRACT

OBJECTIVE: To compare conventional sensitivity encoding (SENSE) to compressed sensing plus SENSE (CS) for high-resolution magnetic resonance imaging (HR-MRI) of intracranial and extracranial arteries. MATERIALS AND METHODS: HR-MRI was performed in 14 healthy volunteers. Three-dimensional T1-weighted imaging (T1WI) and proton density-weighted imaging (PD) were acquired using CS or SENSE under the same total acceleration factors (AF(t))-5.5, 6.8, and 9.7 for T1WI and 3.2, 4.0, and 5.8 for PD-to achieve reduced scanning times in comparison with the original imaging sequence (SENSE T1WI, AF(t) 3.5; SENSE PD, AF(t) 2.0) using the 3-tesla system. Two neuroradiologists measured signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), and used visual scoring systems to assess image quality. Acceptable imaging was defined as a visual score ≥ 2. Repeated measures analysis of variance and Cochran's Q test were performed. RESULTS: CS yielded better image quality and vessel delineation than SENSE in T1WI with AF(t) of 5.5, 6.8, and 9.7, and in PD with AF(t) of 5.8 (p 0.05). SNR and CNR in CS were higher than they were in SENSE, but lower than they were in the original images (p < 0.05). CS yielded higher proportions of acceptable imaging than SENSE (CS T1WI with AF(t) of 6.8 and PD with AF(t) of 5.8; p < 0.0167). CONCLUSION: CS is superior to SENSE, and may be a reliable acceleration method for vessel HR-MRI using AF(t) of 5.5 for T1WI, and 3.2 and 4.0 for PD.


Subject(s)
Acceleration , Arteries , Healthy Volunteers , Magnetic Resonance Imaging , Methods , Protons , Signal-To-Noise Ratio
4.
Article in English | WPRIM | ID: wpr-740299

ABSTRACT

The persistent antibiotics resistant issue has emerged as an influencing factor to deteriorate community health. So, new antibiotics development is urgent for the treatment of bacterial infections. Alternatively, delafloxacin is an eminent new fluoroquinolone, and chemically distinct from older fluoroquinolones. There is lack of proton substituent that indicates the poor acidic property of the drug. It also has a good intracellular penetration capacity that increases the intensity of the bactericidal property in acidic environment. Delafloxacin is a super active drug against the skin and soft tissue infections (SSTIs) and community-acquired respiratory tract infections. Delafloxacin also exhibits better efficacy against pathogens which are resistant to other fluoroquinolones, such as methicillin-resistant Staphylococcus aureus (MRSA). Delafloxacin received approval from the US Food and Drug Administration (FDA) for the treatment of acute bacterial skin and skin structure infections (ABSSI). Phase III clinical trial among patients with community-acquired pneumonia (CAP) is ongoing to evaluate the effectiveness of delafloxacin. From the aforementioned arguments, delafloxacin will be a prominent candidate for the upcoming antibacterial agent. Similarly, delafloxacin can be a crucial drug to fight against ABSSI.


Subject(s)
Anti-Bacterial Agents , Bacterial Infections , Fluoroquinolones , Humans , Methicillin-Resistant Staphylococcus aureus , Pneumonia , Protons , Respiratory Tract Infections , Skin , Soft Tissue Infections , United States Food and Drug Administration
5.
6.
Article in English | WPRIM | ID: wpr-760178

ABSTRACT

BACKGROUND: An increase in the numbers of patients with gastrointestinal symptoms has recently been observed. PURPOSE: To investigate the effects of proton pump inhibitor (PPI) therapy on intestinal inflammation in children and adolescents as confirmed by clinical manifestations and objectively assessed by fecal calprotectin (FC) level measurement. METHODS: Consecutive children (aged 3–18 years) who presented with gastrointestinal symptoms and were treated with or without PPI for at least 1 month were enrolled. Patients were divided into PPI and non-PPI groups. The PPI group was further subdivided by treatment duration and type of PPI used. Stool samples were collected for FC evaluation at baseline and after treatment and clinical data and FC levels were compared between the groups. RESULTS: Fifty-one patients (15 boys, 36 girls) were enrolled in the study. The PPI group included 37 patients, while the non-PPI group included 14 patients. Clinical symptoms were not significantly different. FC levels and laboratory results, including C-reactive protein levels, white blood cell count, and absolute neutrophil count, were not statistically different before versus after PPI treatment. After treatment, FC levels decreased to 8.1 mg/kg (-575.4 to 340.3 mg/kg) in the PPI group and increased to 5.6 mg/kg (-460.0 to 186.9 mg/kg) in the non-PPI group compared to those before treatment (P=0.841). The number of patients with increased FC levels was not significantly different between the 2 groups (48.6% vs. 64.3%, P=0.363), similar to that observed in patients with an FC level > 50 mg/kg (24.3% and 7.1%, P=0.250). PPI therapy type and duration did not affect the FC levels (P=0.811 and P=0.502, respectively). CONCLUSION: Although we aimed to confirm the evidence of intestinal inflammation due to PPI use in children and adolescents through clinical symptoms and FC measurement, no significant changes were observed.


Subject(s)
Adolescent , C-Reactive Protein , Child , Humans , Inflammation , Leukocyte Count , Leukocyte L1 Antigen Complex , Neutrophils , Proton Pump Inhibitors , Proton Pumps , Protons
7.
Article in Korean | WPRIM | ID: wpr-760106

ABSTRACT

BACKGROUND AND OBJECTIVES: Laryngopharyngeal reflux (LPR) is a prevalent condition with an increasing incidence, and several recent studies have reported the association of LPR with chronic rhinosinusitis (CRS). In this study, we studied the effect of proton-pump inhibitors (PPIs) on symptom improvement for LPR and comorbid CRS. SUBJECTS AND METHOD: Enrolled in the study from January 2017 to December 2017 were 164 patients (54 male, 110 female, mean age 48.8 years) who were diagnosed as LPR by reflux symptom index (RSI) or reflux finding scores (RFS) and comorbid CRS. Sino-Nasal Outcome Test (SNOT)-20 and Lund-Kennedy endoscopic scores were evaluated for CRS severity. The study group was divided into PPI treatment group (Ilaprazole 20 mg, once a day for 8 weeks) and non-treatment group. The RSI, RFS, SNOT-20, and Lund-Kennedy endoscopic scores were repeated at the end of treatment. RESULTS: Ninety-two patients were prescribed PPI and 72 patients were not. Initial RSI, RFS, SNOT-20, and Lund-Kennedy score did not differ between the two groups. RSI and RFS decreased significantly after eight weeks of PPI medication (p=0.002 and p<0.001, respectively). In the non-treatment group, only RFS showed statistically significant decrease. SNOT-20 and Lund-Kennedy endoscopic scores decreased significantly in the treatment group (p=0.005 and p<0.001, respectively) compared to the non-treatment group. CONCLUSION: The results of our study suggest that PPI treatment for 8 weeks was effective in reducing signs and symptoms of both LPR and CRS.


Subject(s)
Female , Humans , Incidence , Laryngopharyngeal Reflux , Male , Methods , Proton Pumps , Protons
8.
Article in English | WPRIM | ID: wpr-759820

ABSTRACT

Anxiety disorders are the most prevalent psychiatric disorders in the general population. The relationship between dyspepsia and particularly gastroesophageal reflux disease (GERD) and psychiatric comorbidity such as anxiety is poorly defined. However, GERD was noted to be strongly associated and often coincident in onset with generalized anxiety disorder in the community. In this paper, we report the case of an adult man who presented with severe weight loss and underlying GERD, and was later found to have an anxiety disorder as the cause of both.


Subject(s)
Adult , Anxiety Disorders , Anxiety , Comorbidity , Dyspepsia , Gastroesophageal Reflux , Humans , Proton Pumps , Protons , Shadowing Technique, Histology , Weight Loss
9.
Article in Korean | WPRIM | ID: wpr-759628

ABSTRACT

OBJECTIVES: The purpose of this study was to investigate the association between fracture risk and proton pump inhibitor (PPI) use to establish evidence for defining high-risk groups of fracture among PPI users. METHODS: A case-control study was performed using the National Health Insurance Sample Cohort Database from January 2002 to December 2013. The cases included all incidences of major fractures identified from January 2011 to December 2013, and up to four controls were matched to each case by age, gender, osteoporosis, and Charlson comorbidity index. Conditional logistic regression was used to calculate the adjusted odds ratio (aOR) and associated 95% confidence interval (CI). RESULTS: Overall, 14,295 cases were identified, and 63,435 controls were matched to the cases. The aOR of fractures related to the use of PPIs was 1.06 (95% CI: 1.01–1.11). There was a statistically significant association between fracture and PPI use within 3 months of the last dose, and a trend of increasing fracture risk with increasing cumulative PPI dose. The risk of fracture was significantly higher in patients who took PPIs for more than 1 year during the 2-year observation period. CONCLUSION: Patients who have been using PPIs for more than 1 year should be warned about the risk of fracture during or at least 3 months after discontinuing the PPI.


Subject(s)
Case-Control Studies , Cohort Studies , Comorbidity , Humans , Incidence , Logistic Models , National Health Programs , Odds Ratio , Osteoporosis , Proton Pumps , Protons
10.
Article in English | WPRIM | ID: wpr-764180

ABSTRACT

PURPOSE: To assess the feasibility of the use of spin-echo echo-planar imaging (SE-EPI) magnetic resonance elastography (MRE) in livers of children and young adults. MATERIALS AND METHODS: Patients (≤ 20 years old) who underwent 3T SE-EPI MRE were included retrospectively. Subjects were divided into three groups according to the purpose of the liver MRI: suspicion of fatty liver or focal fat deposition in the liver (FAT group), liver fibrosis after receiving a Kasai operation from biliary atresia (BA group), and hepatic iron deposition after receiving chemotherapy or transfusions (IRON group). Technical failure of MRE was defined when a stiffness map showed no pixel value with a confidence index higher than 95%, and the patients were divided as success and failure groups accordingly. Clinical findings including age, gender, weight, height, and body mass index and magnetic resonance imaging results including proton density fat fraction (PDFF), T2*, and MRE values were assessed. Factors affecting failure of MRE were evaluated and the image quality in wave propagation image and stiffness map was evaluated using the appropriate scores. RESULTS: Among total 240 patients (median 15 years, 211 patients in the FAT, 21 patients in the BA, and 8 patients in the IRON groups), technical failure was noted in six patients in the IRON group (6/8 patients, 75%), while there were no failures noted in the FAT and BA groups. These six patients had T2* values ranging from 0.9 to 3.8 ms. The image quality scores were not significantly different between the FAT and BA groups (P > 0.999), while the scores were significantly lower in the IRON group (P < 0.001). CONCLUSION: The 3T SE-EPI MRE in children and young adults had a high technical success rate. The technical failure was occurred in children with decreased T2* value (≤ 3.8 ms) from iron deposition.


Subject(s)
Biliary Atresia , Body Mass Index , Child , Drug Therapy , Echo-Planar Imaging , Elasticity Imaging Techniques , Fatty Liver , Humans , Iron , Liver Cirrhosis , Liver , Magnetic Resonance Imaging , Protons , Retrospective Studies , Young Adult
11.
Article in English | WPRIM | ID: wpr-764168

ABSTRACT

Hyperglycemia-induced hemichorea (HGHC) is a rare but characteristic hyperkinetic movement disorder involving limbs on one side of the body. In a 75-year-old woman with a left-sided HGHC, conventional brain MR imaging showed very subtle T1-hyperintensity and unique gadolinium enhancement in the basal ganglia contralateral to movements. Multi-parametric MRI was acquired using pulse sequence with quantification of relaxation times and proton density by multi-echo acquisition. Myelin map was reconstructed based on new tissue classification modeling. In this case report of multi-parametric MRI, quantitative measurement of myelin change related to HGHC in brain structures and its possible explanations are presented. This is the first study to demonstrate myelin loss related to hyperglycemic insult in multi-parametric quantitative MR imaging.


Subject(s)
Aged , Basal Ganglia , Brain , Classification , Extremities , Female , Gadolinium , Humans , Hyperglycemia , Hyperkinesis , Magnetic Resonance Imaging , Movement Disorders , Myelin Sheath , Protons , Relaxation
12.
Article in English | WPRIM | ID: wpr-764167

ABSTRACT

In this study, we report arterial spin labelling perfusion, proton MR spectroscopy and susceptibility-weighted MR findings of acute necrotizing encephalopathy in a child with rotavirus infection.


Subject(s)
Brain Diseases , Child , Humans , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Perfusion , Protons , Rotavirus Infections
13.
Asia Pacific Allergy ; (4): e30-2019.
Article in English | WPRIM | ID: wpr-762879

ABSTRACT

Proton pump inhibitors (PPIs) are widely used for the treatment of gastrointestinal diseases. Incidence of drug hypersensitivity reactions (DHRs) to PPIs has been rising, presumably because of their increased consumption. Most DHR are IgE-mediated, with half of the reactions being anaphylactic. We describe the case of a Caucasian 50-year-old female patient referred to our allergy department after 2 episodes of anaphylaxis. The allergy work-up distinguished PPI as a cause of delayed onset (14 hours) and immediate onset (45 minutes) IgE-mediated DHR.


Subject(s)
Anaphylaxis , Drug Hypersensitivity , Female , Gastrointestinal Diseases , Humans , Hypersensitivity , Incidence , Middle Aged , Proton Pump Inhibitors , Proton Pumps , Protons , Skin Tests
14.
Article in Korean | WPRIM | ID: wpr-766820

ABSTRACT

Angiosarcomas are rare, but aggressive malignancies. Reports of brain metastasis are uncommon. In this report, we describe the clinical features of a 62 year-old man who presented with hemoptysis and right-sided weakness. Chest computed tomography showed multiple ill-defined part solid nodules in both lungs and brain magnetic resonance imaging showed multiple hemorrhagic bran masses. The patient underwent whole body proton emission tomography to identify biopsy site and showed multiple bone lesions. A right acetabulum biopsy in confirmed the diagnosis of angiosarcoma.


Subject(s)
Acetabulum , Biopsy , Brain , Diagnosis , Hemangiosarcoma , Hemoptysis , Humans , Lung , Magnetic Resonance Imaging , Neoplasm Metastasis , Protons , Thorax
15.
Article in English | WPRIM | ID: wpr-766331

ABSTRACT

OBJECTIVES: This study sought to investigate the association between the systemic intake of proton pump inhibitors (PPI) and the early failure of dental implants. MATERIALS AND METHODS: A retrospective cohort study involving 1,918 dental implants in 592 patients (69 implants in 24 PPI users and 1,849 implants in 568 nonusers, respectively) was conducted. The effect of PPI intake on the osseointegration of dental implants was evaluated using patient- and implant-level models. RESULTS: Among 24 PPI users, two patients experienced implant failure, one of whom had three and the other of whom had one failed implant, respectively. Thus, the rate of failure for this population was 8.3%. Separately, 11 nonusers each experienced one implant failure, and the failure rate for these patients was 1.9%. Fisher's exact test revealed statistically significant differences between PPI users and nonusers at the implant level (P=0.002) but failed to show any significance at the patient level (P=0.094). The odds of implant failure were 4.60 times greater among PPI users versus nonusers. Dental implants that were placed in patients using PPIs were found to be 4.30 times more likely to fail prior to loading. CONCLUSION: The findings of this study suggest that PPI intake may be associated with an increased risk of early dental implant failure.


Subject(s)
Cohort Studies , Dental Implantation , Dental Implants , Humans , Morinda , Osseointegration , Proton Pump Inhibitors , Proton Pumps , Protons , Rehabilitation , Retrospective Studies , Risk Factors
16.
Article in English | WPRIM | ID: wpr-761798

ABSTRACT

Sperm function and male fertility are closely related to pH dependent K⁺ current (KSper) in human sperm, which is most likely composed of Slo3 and its auxiliary subunit leucine-rich repeat-containing protein 52 (LRRC52). Onion peel extract (OPE) and its major active ingredient quercetin are widely used as fertility enhancers; however, the effect of OPE and quercetin on Slo3 has not been elucidated. The purpose of this study is to investigate the effect of quercetin on human Slo3 channels. Human Slo3 and LRRC52 were co-transfected into HEK293 cells and pharmacological properties were studied with the whole cell patch clamp technique. We successfully expressed and measured pH sensitive and calcium insensitive Slo3 currents in HEK293 cells. We found that OPE and its key ingredient quercetin inhibit Slo3 currents. Inhibition by quercetin is dose dependent and this degree of inhibition decreases with elevating internal alkalization and internal free calcium concentrations. Functional moieties in the quercetin polyphenolic ring govern the degree of inhibition of Slo3 by quercetin, and the composition of such functional moieties are sensitive to the pH of the medium. These results suggest that quercetin inhibits Slo3 in a pH and calcium dependent manner. Therefore, we surmise that quercetin induced depolarization in spermatozoa may enhance the voltage gated proton channel (Hv1), and activate non-selective cation channels of sperm (CatSper) dependent calcium influx to trigger sperm capacitation and acrosome reaction.


Subject(s)
Acrosome Reaction , Calcium , Fertility , HEK293 Cells , Humans , Hydrogen-Ion Concentration , Male , Onions , Phosphatidylinositols , Protons , Quercetin , Sperm Capacitation , Spermatozoa
18.
Article in English | WPRIM | ID: wpr-760892

ABSTRACT

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children. The global prevalence of pediatric NAFLD from general populations is 7.6%. In obese children, the prevalence is higher in Asia. NAFLD has a strong heritable component based on ethnic difference in the prevalence and clustering within families. Genetic polymorphisms of patatin-like phospholipase domain–containing protein 3 (PNPLA3), transmembrane 6 superfamily member 2, and glucokinase regulatory protein (GCKR) are associated with the risk of NAFLD in children. Variants of PNPLA3 and GCKR are more common in Asians. Alterations of the gut microbiome might contribute to the pathogenesis of NAFLD. High fructose intake increases the risk of NAFLD. Liver fibrosis is a poor prognostic factor for disease progression to cirrhosis. Magnetic resonance spectroscopy and magnetic resonance proton density fat fraction are more accurate for steatosis quantification than ultrasound. Noninvasive imaging methods to assess liver fibrosis, such as transient elastography, shear-wave elastography, and magnetic resonance elastography are useful in predicting advanced fibrosis, but they need further validation. Longitudinal follow-up studies into adulthood are needed to better understand the natural history of pediatric NAFLD.


Subject(s)
Asia , Asian Continental Ancestry Group , Child , Diagnosis , Disease Progression , Elasticity Imaging Techniques , Epidemiology , Fibrosis , Follow-Up Studies , Fructose , Gastrointestinal Microbiome , Genetics , Glucokinase , Humans , Liver Cirrhosis , Liver Diseases , Magnetic Resonance Spectroscopy , Microbiota , Natural History , Non-alcoholic Fatty Liver Disease , Phospholipases , Polymorphism, Genetic , Prevalence , Protons , Ultrasonography
19.
Article in English | WPRIM | ID: wpr-760891

ABSTRACT

PURPOSE: On the basis of evidence, we aimed to reevaluate the necessity of the empirical proton pump inhibitor (PPI) trial for children with suspected gastroesophageal reflux disease (GERD). METHODS: We analyzed the frequency of GERD in 85 school-age children with gastroesophageal reflux (GER) symptoms, who received 24-hour esophageal pH monitoring and/or upper endoscopy. According to the reflux index (RI), the children were classified into normal (RI <5%), intermediate (5%≤ RI <10%), or abnormal (RI ≥10%) groups. RESULTS: Fifty six were female and 29 were male. Their mean age was 12.6±0.5 (±standard deviation) years (range: 6.8–18.6). The RI analysis showed that the normal group included 76 patients (89.4%), the intermediate group included 6 patients (7.1%), and the abnormal group included 3 patients (3.5%). The DeMeester score was 5.93±4.65, 14.68±7.86 and 40.37±12.96 for the normal, intermediate and abnormal group, respectively (p=0.001). The longest reflux time was 5.56±6.00 minutes, 9.53±7.84 minutes, and 19.46±8.35 minutes in the normal, intermediate, and abnormal group, respectively (p=0.031). Endoscopic findings showed reflux esophagitis in 7 patients. On the basis of the Los Angeles Classification of Esophagitis, 5 of these patients were included in group A, 1 patient, in group B and 1 patient, in group C. CONCLUSION: The incidence of GERD was very low in school-age children with GER symptoms. Therefore, injudicious diagnostic PPI trials would be postponed until the actual prevalence of GERD is verified in future prospective studies.


Subject(s)
Child , Classification , Endoscopy , Esophageal pH Monitoring , Esophagitis , Esophagitis, Peptic , Female , Gastroesophageal Reflux , Humans , Incidence , Male , Prevalence , Prospective Studies , Proton Pump Inhibitors , Proton Pumps , Protons
20.
Article in Chinese | WPRIM | ID: wpr-774161

ABSTRACT

The deoxyribonucleic acid (DNA) molecule damage simulations with an atom level geometric model use the traversal algorithm that has the disadvantages of quite time-consuming, slow convergence and high-performance computer requirement. Therefore, this work presents a density-based spatial clustering of applications with noise (DBSCAN) clustering algorithm based on the spatial distributions of energy depositions and hydroxyl radicals (·OH). The algorithm with probability and statistics can quickly get the DNA strand break yields and help to study the variation pattern of the clustered DNA damage. Firstly, we simulated the transportation of protons and secondary particles through the nucleus, as well as the ionization and excitation of water molecules by using Geant4-DNA that is the Monte Carlo simulation toolkit for radiobiology, and got the distributions of energy depositions and hydroxyl radicals. Then we used the damage probability functions to get the spatial distribution dataset of DNA damage points in a simplified geometric model. The DBSCAN clustering algorithm based on damage points density was used to determine the single-strand break (SSB) yield and double-strand break (DSB) yield. Finally, we analyzed the DNA strand break yield variation trend with particle linear energy transfer (LET) and summarized the variation pattern of damage clusters. The simulation results show that the new algorithm has a faster simulation speed than the traversal algorithm and a good precision result. The simulation results have consistency when compared to other experiments and simulations. This work achieves more precise information on clustered DNA damage induced by proton radiation at the molecular level with high speed, so that it provides an essential and powerful research method for the study of radiation biological damage mechanism.


Subject(s)
Algorithms , Computer Simulation , DNA , Radiation Effects , DNA Damage , Linear Energy Transfer , Monte Carlo Method , Protons
SELECTION OF CITATIONS
SEARCH DETAIL