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1.
Biomed Res Int ; 2020: 9609731, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33029534

RESUMO

Liver-function decompensation or hepatocellular carcinoma (HCC) gradually appears after chronic hepatitis B progresses to cirrhosis. Effective antiviral treatment can significantly improve the long-term prognosis of decompensated patients, and some patients present recompensation of decompensated hepatitis B cirrhosis. At present, there are limited research data on the recompensation of decompensated hepatitis B cirrhosis. There is still controversy regarding the evaluation time, evaluation indicators, influencing factors, and long-term prognosis of recompensation.

2.
Crit Rev Food Sci Nutr ; : 1-10, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33034197

RESUMO

Citrus (Citrus spp.) species produce a variety of fruits that are popular worldwide. Citrus fruits, however, are susceptible to postharvest decays caused by various pathogenic fungi, including Penicillium digitatum, Penicillium italicum, Geotrichum citri-aurantii, Aspergillus niger, and Aspergillus flavus. Decays resulting from infections by these pathogens cause a significant reduction in citrus quality and marketable yield. Biological control of postharvest decay utilizing antagonistic bacteria and fungi has been explored as a promising alternative to synthetic fungicides. In the present article, the isolation of antagonists utilized to manage postharvest decays in citrus is reviewed, and the mechanism of action including recent molecular and genomic studies is discussed as well. Several recently-postulated mechanisms of action, such as biofilm formation and an oxidative burst of reactive oxygen species have been highlighted. Improvements in biocontrol efficacy of antagonists through the use of a combination of microbial antagonists and additives are also reviewed. Biological control utilizing bacterial and yeast antagonists is a critical component of an integrated management approach for the sustainable development of the citrus industry. Further research will be needed, however, to explore and utilize beneficial microbial consortia and novel approaches like CRISPR/Cas technology for management of postharvest decays.

3.
Acc Chem Res ; 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33034454

RESUMO

ConspectusProduction of hydrogen from nonfossil sources is essential toward the generation of sustainable energy. Hydrogen generation upon hydrolysis of stable hydrogen-rich materials has long been proposed as a possibility of hydrogen disposal on site, because transport of explosive hydrogen gas is dangerous. Hydrolysis of some boron derivatives could rapidly produce large amounts of hydrogen, but this requires the presence of very active catalysts. Indeed, late transition-metal nanocatalysts have recently been developed for the hydrolysis of a few hydrogen-rich precursors.Our research group has focused on the improvement and optimization of highly performing Earth-abundant transition-metal-based nanocatalysts, optimization of remarkable synergies between different metals in nanoalloys, supports including positive synergy with nanoparticles (NPs) for rapid hydrogen generation, comparison between various endo- or exoreceptors working as homogeneous and heterogeneous supports, mechanistic research, and comparison of the nanocatalyzed hydrolysis of several boron hydrides.First, hydrogen production upon hydrolysis of ammonia borane, AB (3 mol H2 per mol AB) was examined with heterogeneous endoreceptors. Thus, a highly performing Ni@ZIF-8 nanocatalyst was found to be superior over other Earth-abundant nanocatalysts and supports. With 85.7 molH2·molcat-1·min-1 at 25 °C, this Ni nanocatalyst surpassed the results of previous Earth-abundant nanocatalysts. The presence of NaOH accelerated the reaction, and a remarkable pH-dependent "on-off" control of the H2 production was established. Bimetallic nanoalloys Ni-Pt@ZIF-8 showed a dramatic volcano effect optimized with a nanoalloy containing 2/3 Ni and 1/3 Pt. The rate reached 600 molH2·molcat-1·min-1 and 2222 molH2·molPt-1·min-1 at 20 °C, which much overtook the performances of both related nanocatalysts Ni@ZIF-8 and Pt@ZIF-8. Next, hydrogen production was also researched via hydrolysis of sodium borohydride (4 mol H2 per mol NaBH4) using nanocatalysts in ZIF-8, and, among Earth-abundant nanocatalysts, Co@ZIF-8 showed the best performance, outperforming previous Co nanocatalysts. For exoreceptors, "click" dendrimers containing triazole ligands on their tripodal tethers were used as supports for homogeneous (semiheterogeneous) catalysis of both AB and NaBH4 hydrolysis. For both reactions, Co was found to be the best Earth-abundant metal, Pt the best noble metal, and Co1Pt1 the best nanoalloy, with synergistic effects. Based on kinetic measurements and kinetic isotope effects for all of these reactions, mechanisms are proposed and the hydrogen produced was further used in tandem reactions. Overall, dramatic triple synergies between these nanocatalyst components have allowed hydrogen release within a few seconds under ambient conditions. These nanocatalyst improvements and mechanistic findings should also inspire further nanocatalyst design in various areas of hydrogen production.

4.
BMC Med Imaging ; 20(1): 112, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33008318

RESUMO

BACKGROUND: Lung cancer screening revealed that people with small pulmonary nodules are mostly asymptomatic and that some of these people are at risk of developing lung cancer, so we intended to explore the repeatability of small lung nodule measurement in low-dose lung screening. METHODS: We scanned eight ground-glass nodules (GGNs) and solid nodules, with diameters of 3, 5, 8, and 10 mm. They were divided according to the different combination schemes of tube voltage (KV) and tube current (mA) as 70, 80, 100, and 120 KV, and currents of nine tubes were divided as 20, 30, 40, 50, 60, 70, 80, 90, and 100 mAs. RESULTS: Compared with the conventional dose group (120 kVp, 100 mAs), the nodule diameter and solid nodule volume measured by all scanning combinations were more consistent (P > 0.05), the volumes of 10 mm GGNs combinations were consistent (P > 0.05), the volumes of 8 mm GGNs were consistent (P > 0.05), the volumes of 5 mm GGNs combinations were consistent (P > 0.05), and the volumes of 3 mm were consistent (P > 0.05). CONCLUSION: In lung cancer screening, CT parameters should be as follows: tube voltage is more than 80 kVp, and tube current is 80 mAs in order to meet the requirements for the accurate measurement of the diameter and volume of pulmonary nodules.

5.
Front Immunol ; 11: 1717, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33013823

RESUMO

Vascular endothelial injury caused by post-hemorrhagic shock mesenteric lymph (PHSML) return is an important manifestation during refractory hemorrhagic shock. Using human umbilical vein endothelial cells (HUVECs) and transcriptome analysis, this study sought to investigate the molecular mechanism underlying the adverse effect of PHSML on vascular endothelium. Post-hemorrhagic shock mesenteric lymph was collected from male rats after they underwent hemorrhagic shock and following resuscitation, while normal mesenteric lymph (NML) was harvested from sham rats. Human umbilical vein endothelial cells were incubated with the culture medium containing either 10% phosphate buffered saline (Control), NML, or PHSML for 3 h, and then were harvested for RNA sequencing. In comparison with NML treated cells, 37 genes were differentially expressed in PHSML-treated HUVECs, including 32 upregulated genes and five downregulated genes. These differentially expressed genes were mainly enriched in inflammatory pathways, including signaling pathways for activation of the NOD-like receptors, NF-κB, and TNF. Furthermore, we found that C-C motif chemokine ligand 2 (CCL2) was increased significantly after PHSML treatment, and Bindarit, a CCL2 production inhibitor, attenuated the damage of HUVECs induced by PHSML. The results provide molecular evidence on vascular endothelium damage caused by PHSML. C-C motif chemokine ligand 2 might represent a new target for reducing vascular injury after severe hemorrhagic shock.

7.
Artigo em Inglês | MEDLINE | ID: mdl-33052650

RESUMO

Silicon (Si) has been considered as the most potential anode material for next-generation high-energy density lithium-ion batteries (LIBs) because of its extremely high theoretical capacity. However, the performance deterioration caused by volume change and low electrical conductivity of active Si particles greatly limit its commercial use. Here, we designed a nonstoichiometric TiOx-coated Si anode with a litchi-like structure, in which Si-Ti and Si-O dual bonds are expected to form between the Si core and TiOx shell. This unique structure plays a major role in preventing the volume expansion and improving the electrical conductivity of the Si anode. The as-prepared TiOx-coated Si anode could exhibit excellent cycling stability after 1000 cycles at 1000 mA g-1 with a relatively small capacity decay rate of ∼0.04% per cycle, which can be comparable to most of the modified Si anodes in references. This strategy of surface regulating on the Si anode could be extended to other electrodes with large volume expansion during cycling in LIBs for achieving competitive electrochemical properties.

8.
Sci Total Environ ; : 142639, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33069482

RESUMO

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide. There is no clear evidence of whether COPD patients are more susceptible to respiratory inflammation associated with short-term exposure to air pollutants than those without COPD. OBJECTIVES: This study directly compared air pollutant-associated respiratory inflammation between COPD patients and healthy controls. METHODS: This study is based on the COPDB panel study (COPD in Beijing). Fractional exhaled nitric oxide (FeNO) was repeatedly measured in 53 COPD patients and 82 healthy controls at up to four clinical visits. Concentrations of carbon monoxide (CO), nitrogen monoxide, nitrogen dioxide (NO2), sulfur dioxide (SO2), fine particulate matter (PM2.5), black carbon (BC), ultrafine particles (UFPs), and accumulated-mode particles (Acc) were monitored continuously at a fixed-site monitoring station. Linear mixed-effects models were used to compare the associations between ln-transformed FeNO and average 1-23 h concentrations of air pollutants before the clinical visits. RESULTS: FeNO was positively associated with interquartile range (IQR) increases in average concentrations of CO, NO2, SO2, BC, UFPs, and Acc in all participants, with the strongest associations in different time-windows (range from 6.6% for average 1 h NO2 exposure to 32.1% for average 7 h SO2 exposure). Associations between FeNO and average 13-23 h PM2.5 exposure differed significantly according to COPD status. Increases in FeNO associated with average 1-2 h NO exposure were significant in COPD patients (range 8.9-10.2%), while the associations were nonsignificant in healthy controls. Associations between FeNO and average 1-23 h CO and SO2 exposure tended to be higher in COPD patients than in healthy controls, although the differences were not significant. UFPs-associated respiratory inflammation was robust in both subgroups. CONCLUSIONS: COPD patients are more susceptible to respiratory inflammation following PM2.5, NO, CO, and SO2 exposure than individuals without COPD.

9.
Viruses ; 12(10)2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-33007975

RESUMO

Grapevine leafroll-associated virus 1 (GLRaV-1) is a major pathogen associated with grapevine leafroll disease. However, the molecular mechanisms underlying GLRaV-1 interactions with plant cells are unclear. Using Agrobacterium infiltration-mediated RNA-silencing assays, we demonstrated that GLRaV-1 p24 protein (p24G1) acts as an RNA-silencing suppressor (RSS), inhibiting local and systemic RNA silencing. Electrophoretic mobility shift assays showed that p24G1 binds double-stranded 21-nucleotide small interfering RNA (siRNA), and that siRNA binding is required but not sufficient for its RSS activity. p24G1 localizes in the nucleus and can self-interact through its amino acid 10 to 210 region. Dimerization is needed for p24G1 interaction with importin α1 before moving to the nucleus, but is not required for its siRNA binding and RSS activity. Expression of p24G1 from a binary pGD vector or potato virus X-based vector elicited a strong hypersensitive response in Nicotiana species, indicating that p24G1 may be a factor in pathogenesis. Furthermore, p24G1 function in pathogenesis required its RSS activity, dimerization and nuclear localization. In addition, the region of amino acids 122-139 played a crucial role in the nuclear import, siRNA binding, silencing suppression and pathogenic activity of p24G1. These results contribute to our understanding of the molecular mechanisms underlying GLRaV-1 infection.

10.
PLoS One ; 15(10): e0240232, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33035252

RESUMO

Biases perpetuate when people think that they are innocent whereas others are guilty of biases. We examined whether people would detect biased thinking and behavior in others but not themselves as influenced by preexisting beliefs (myside bias) and social stigmas (social biases). The results of three large studies showed that, across demographic groups, participants attributed more biases to others than to themselves, and that this self-other asymmetry was particularly salient among those who hold strong beliefs about the existence of biases (Study 1 and Study 2). The self-other asymmetry in bias recognition dissipated when participants made simultaneous predictions about others' and their own thoughts and behaviors (Study 3). People thus exhibit bias in bias recognition, and this metacognitive bias may be remedied when it is highlighted to people that we are all susceptible to biasing influences.

11.
Artigo em Inglês | MEDLINE | ID: mdl-33029764

RESUMO

Hospital-acquired pneumonia (HAP) is a significant nosocomial infection; data on the distribution and antimicrobial resistance profiles of HAP in China are limited. We included 2827 adult patients with HAP from the Chinese Antimicrobial Resistance Surveillance of Nosocomial Infections network admitted in 15 Chinese teaching hospitals between 2007 and 2016. Clinical data and antimicrobial susceptibility of isolated pathogens were obtained from the medical records and central laboratory, respectively. Multivariable logistic regression was performed to determine the risk factors for mortality and multidrug resistance (MDR). A total of 386 (13.7%) patients died in the hospital, while 1181 (41.8%) developed ventilator-associated pneumonia (VAP). Active immunosuppressant therapy (OR 1.915 (95% CI 1.475-2.487)), solid tumor (OR 1.860 (95% CI 1.410-2.452)), coma (OR 1.783 (95% CI 1.364-2.333)), clinical pulmonary infection score ≥7 (OR 1.743 (95% CI 1.373-2.212)), intensive care unit stay (OR 1.652 (95% CI 1.292-2.111)), age ≥65 years (OR 1.621 (95% CI 1.282-2.049)), and tracheal cannula insertion (OR 1.613 (95% CI 1.169-2.224)) were independent risk factors for in-hospital mortality. Liver cirrhosis (OR 3.120 (95% CI 1.436-6.780)) and six other variables were independent predictors of MDR. Acinetobacter baumannii (25.6%), Pseudomonas aeruginosa (20.1%), Klebsiella pneumoniae (15.4%), and Staphylococcus aureus (12.6%) were the most common pathogens (MDR prevalence 64.9%). Isolates from VAP patients showed more A. baumannii and less K. pneumoniae and E. coli strains (p < 0.001, respectively) than those from patients without VAP. The proportion of methicillin-resistant S. aureus strains decreased; that of carbapenem-resistant A. baumannii and Enterobacterales strains increased. There had been changes in the antibiotic resistance profiles of HAP pathogens in China. Risk factors for mortality and MDR are important for the selection of antimicrobials for HAP in China.

12.
J Vis Exp ; (163)2020 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-33044460

RESUMO

Dynamic fMRI responses vary largely according to the physiological conditions of animals either under anesthesia or in awake states. We developed a real-time fMRI platform to guide experimenters to monitor fMRI responses instantaneously during acquisition, which can be used to modify the physiology of animals to achieve desired hemodynamic responses in animal brains. The real-time fMRI set-up is based on a 14.1T preclinical MRI system, enabling the real-time mapping of dynamic fMRI responses in the primary forepaw somatosensory cortex (FP-S1) of anesthetized rats. Instead of a retrospective analysis to investigate confounding sources leading to the variability of fMRI signals, the real-time fMRI platform provides a more effective scheme to identify dynamic fMRI responses using customized macro-functions and a common neuroimage analysis software in the MRI system. Also, it provides immediate troubleshooting feasibility and a real-time biofeedback stimulation paradigm for brain functional studies in animals.

13.
Biotechnol Lett ; 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33048255

RESUMO

OBJECTIVE: To construct convenient CRISPR/Cas9-mediated genome editing systems in industrial enzyme-producing fungi Penicillium oxalicum and Trichoderma reesei. RESULTS: Employing the 5S rRNA promoter from Aspergillus niger for guide RNA expression, the ß-glucosidase gene bgl2 in P. oxalicum was deleted using a donor DNA carrying 40-bp homology arms or a donor containing no selectable marker gene. Using a markerless donor DNA as editing template, precise replacement of a small region was achieved in the creA gene. In T. reesei, the A. niger 5S rRNA promoter was less efficient than that in P. oxalicum when used for gene editing. Using a native 5S rRNA promoter, stop codons were introduced into the lae1 coding region using a markerless donor DNA with an editing efficiency of 36.67%. CONCLUSIONS: Efficient genome editing systems were developed in filamentous fungi P. oxalicum and T. reesei by using heterologous or native 5S rRNA promoters for guide RNA expression.

14.
BMC Plant Biol ; 20(1): 451, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004006

RESUMO

BACKGROUND: The HD-Zip transcription factors are unique to plants and play an essential role in plant growth, development and stress responses. The HD-Zip transcription factor family consists of a highly conserved homeodomain (HD) and a leucine zipper domain (LZ) domain. Although the HD-Zip gene family has been extensively studied in many plant species, a systematic study of the Eucalyptus HD-Zip family has not been reported until today. Here, we systematically identified 40 HD-Zip genes in Eucalyptus (Eucalyptus grandis). Besides, we comprehensively analyzed the HD-Zips of Eucalyptus by studying the homology, conserved protein regions, gene structure, 3D structure of the protein, location of the genes on the chromosomes and the expression level of the genes in different tissues. RESULTS: The HD-Zip family in Eucalyptus has four subfamilies, which is consistent with other plants such as Arabidopsis and rice. Moreover, genes that are in the same group tend to have similar exon-intron structures, motifs, and protein structures. Under salt stress and temperature stress, the Eucalyptus HD-Zip transcription factors show a differential expression pattern. CONCLUSIONS: Our findings reveal the response of HD-Zip transcription factors under salt and temperature stresses, laying a foundation for future analysis of Eucalyptus HD-Zip transcription factors.

15.
Ecotoxicol Environ Saf ; 207: 111379, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33017691

RESUMO

The use of irrigation water containing arsenic (As) had led to large areas of As-contaminated farmland, and as a result, plants and food have become severely poisoned. Humic acid (HA) can be complexed with metals, which in turn affects the metals' behavior. Herein, we explored the accumulation of arsenate in lettuce treated with different concentrations of arsenate and studied the effects of HA on the accumulation and toxicity of arsenate. The addition of HA did not cause significant changes in the arsenate content in lettuce but had a significant effect on the activity of antioxidant enzymes, which improved the antioxidant capability of the lettuce plants. Furthermore, HA promoted the accumulation of nutrients, such as magnesium (Mg), calcium (Ca), molybdenum (Mo) and manganese (Mn), in the leaves. Arsenate disrupted metabolic pathways, such as amino acid metabolism, carbohydrate metabolism, and aminoacyl-tRNA biosynthesis. The addition of HA increased the contents of amino acids and sugars, thereby improving lettuce growth. The present study explored the effects of HA on As accumulation and related physiological changes (antioxidant enzyme activities, absorption of nutrients and metabolic mechanisms) and provided insights into the regulation of As contamination by HA, which is relatively inexpensive.

16.
Chemosphere ; 264(Pt 1): 128417, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-33007565

RESUMO

As contamination of rice plants has aroused worldwide concern because of the threats posed to human health through its accumulation in the food chain. However, no data are currently available on the effect of Se nanoparticles (SeNPs) on the fate of As in higher plants, and previously reported relationships between As and Se are inconsistent. Therefore, in this study, the possible mediating roles of SeNPs or selenite on the uptake, translocation, subcellular distribution, and transformation of arsenite and arsenate in rice seedlings (Oryza sativa L.) were investigated through hydroponic experiments. The results showed that, when supplied as arsenite and arsenate, selenite significantly increased root As uptake by 71.7% and 45.9% but decreased shoot As content by 48.9% and 52.4%, respectively. In comparison, the reducing effect of SeNPs on shoot As content (37.1%) was only significant in arsenite-treated rice plants. Furthermore, selenite significantly reduced and increased the As content of different shoot and root subcellular fractions, respectively; and SeNPs also led to a dramatic decrease in the As content of the different shoot subcellular fractions of arsenite-treated rice plants. Moreover, As(III) and As(V) content was reduced in rice shoots while enhanced in rice roots by selenite. Generally, neither As(III) nor As(V) content in rice tissues was dramatically changed by SeNPs. Our results indicate that both SeNPs and selenite are effective in mitigating As toxicity in rice plants, although selenite showed a stronger inhibiting effect on As translocation.

17.
Bioorg Med Chem ; 28(23): 115778, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-33007609

RESUMO

A series of new Fangchinoline derivatives with the carbamate moiety (compounds 1a-1l, 2a-2l) were synthesized by utilizing phenolic hydroxyl to react with isocyanate. The potential fungicidal activity of all the target compounds has been screened against six species of plant pathogen fungi, including Pp. adianticola (Phomopsis adianticola), A. adianticola (Altermaria adianticola), C. fructicola (Colletotrichum fructicola), P. theae (Pestalotiopsis theae), P. adianticola (Phoma adianticola), and G. zeae (Gibberella zeae). Almost all the derivatives showed better fungicidal activity than Fangchinoline. Compounds 1f, 1g, 1h, and 1k exhibited obviously better activity against G. zeae, and Pp. adianticola than Azoxystrobin. Especially compounds 1k displayed high fungicidal activity against G. zeae, Pp. adianticola, and P. theae.

18.
Environ Pollut ; 268(Pt B): 115734, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-33017745

RESUMO

Sediment serves as a sink for metals, thus it is critical to assess its contamination and associated risk. A typical riparian wetland close to a Zn-smelting operation in karst areas in southwest China was investigated. Sediment and reed plant (Phragmites australis) samples from wet and dry seasons were analyzed for total As, Cu, and Zn concentrations. Metal pollution in the sediment was assessed based on geoaccumulation index (Igeo). Further, metals in the sediment were fractionated into exchangeable, water and acid-soluble, reducible, oxidizable, and residual fractions based on the BCR sequential extraction. The results showed that the As, Cu, and Zn concentrations in the sediment were significantly higher than the background values (740-4081, 96-228, and 869-3331 vs. 10, 22, and 70 mg kg-1). With the Igeo being 10-17, the data indicate that the sediment was highly-polluted. While total As, Cu and Zn in the sediment increased from dry to wet season, their available concentrations decreased except Cu. With 62-94% of As, Cu, and Zn being in the residual fraction, metal availability in the sediment was low based on fractionation data. The data are consistent with low metal uptake by reed as their concentration ratios in plant roots to the sediment were 0.01-0.32. The results suggest that the riparian sediment was highly-polluted with As, Cu and Zn, but showing low metal availability and limited plant uptake.

19.
Spectrochim Acta A Mol Biomol Spectrosc ; 246: 118986, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-33032116

RESUMO

We propose a new wavelength selection algorithm based on combined moving window (CMW) and variable dimension particle swarm optimization (VDPSO) algorithm. CMW retains the advantages of the moving window algorithm, and different windows can overlap each other to realize automatic optimization of spectral interval width and number. VDPSO algorithms improve the PSO algorithm. They can search the data space in different dimensions, and reduce the risk of limited local extrema and over fitting. Four different high-performance variable selection algorithms-BOSS, VCPA, iVISSA and IRF-are compared in three NIR data sets (corn, beer and fuel). The results show that VDPSO-CMW has better performance. The Matlab codes for implementing PSO-CWM and VDPSO-CMW are freely available on the website: https://www.mathworks.com/matlabcentral/fileexchange/75828-a-variable-selection-method.

20.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 45(9): 1104-1108, 2020.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-33051425

RESUMO

OBJECTIVES: To study the effect of rotation errors on the γ pass rate of volume-modulated arc therapy (VMAT) plan in rectal cancer based on the ArcCheck phantom. METHODS: CT data from 20 rectal cancer patients underwent VMRT were selected randomly for this study. Targeting areas were selected, and clinical radiotherapy and validation plans were formulated. ArcCheck model was selected to validate the radiotherapy plans. The effect of the rotation errors on the dosimetric verification for VMAT in rectal cancer was simulated and analyzed with ArcCheck model software. RESULTS: When there was no rotation errors, the γ pass rate of VMRT plans was more than 95%. When the absolute rotation angle was less than or equal to 1°, the γ pass rate of VMAT plans was more than 90%, meeting the clinical requirements. When the absolute rotation angle was greater than 1°, the γ pass rate was less than 90%, which did not meet clinical requirements. CONCLUSIONS: The rotation errors affect the γ pass rate of VMAT plans. The larger the rotation angle, the lower the γ pass rate. It meets clinical requirements when the rotation error is less than or equal to 1°.


Assuntos
Radioterapia de Intensidade Modulada , Neoplasias Retais , Humanos , Radiometria , Planejamento da Radioterapia Assistida por Computador , Neoplasias Retais/radioterapia , Rotação
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