ABSTRACT
ObjectivesBased on the changes of lung lesions in patients with COVID-19 at different stages， a nomogram model describing CT image features was established by radiomics method to explore its efficacy in predicting the progression of the disease. MethodsThis retrospective study enrolled 136 patients with COVID-19 pneumonia who received at least two CTs including three cohorts （training cohort and validation cohort 1 and 2）. Patients in the training cohort were divided into three groups according to time between onset of fever symptoms and the first CT. The clinical manifestations and CT features of each group were analyzed and compared. A nomogram to predict disease progression was constructed according to the CT features of the patients， and its performance was evaluated. ResultsThe training cohort consisted of 41 patients.A nomogram was generated to predict disease progression based on three CT features： irregular strip shadow， air bronchial sign， and the proportion of lesions with irregular shape ≥50%. AUC（95%CI）=0.906（0.817，0.995）.The C index of the training cohort was 0.906， and the C index of the internal verification was 0.892. AUC（95%CI）of the validation cohort 1 （34 cases） =0.889（0.793，0.984）；AUC（95%CI）of the validation cohort 2 （61 cases）=0.876（0.706，1.000）.The calibration curves show that the predicted values of the nomogram are in good agreement with the observed values. ConclusionThe nomogram model based on CT radiomics can predict the outcome of lung lesions in patients with high sensitivity and specificity.According to the changes of CT image characteristics of patients with COVID-19， lung lesions will be improved when the proportion of irregular cable shadow， air bronchogram and irregular lesions is greater than 50%.
ABSTRACT
The biological behavior of carbon dots, especially the mechanism of cellular uptake and intracellular distribution, is the basis of its biomedical applications. In this paper, blue fluorescent carbon quantum dots were synthesized by hydrothermal method with Poria cocos polysaccharide as raw material, and the specific biological behavior of carbon dots entering cells was explored to evaluate its biological activity. It was characterized by transmission electron microscopy, UV-vis absorption spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Two different cell lines, immunocytes-RAW264.7 cells (mouse mononuclear macrophages cells) and cancer cells-4T1 cells (mouse breast cancer cells), were used as the research objects to study the uptake kinetics, uptake pathway, distribution and efflux of polysaccharide carbon dots in cells. The results showed that the carbon dots have a size distribution of 2 to 10 nm, and the average size was 6.85 nm. The carbon dots were mainly composed of C, O and N elements, with abundant surface functional groups such as -OH, C=O, C-N and C=C, and the fluorescence quantum yield was 4.72%. Carbon dots enter cells in a certain concentration and time dependence. Different cell lines have different uptake pathways. RAW264.7 cells enter the cells mainly by macrophage-specific phagocytosis, and a small part of the endocytosis is mediated by caveolin, while 4T1 cells are mainly mediated by grid protein endocytosis and giant cell drinking process. In summary, the synthesized carbon dots have good fluorescence properties, low cytotoxicity and excellent biocompatibility, which can be used for cell imaging applications.
ABSTRACT
In dental esthetic rehabilitation, patients pay great attention to the rehabilitative esthetic effect before teeth preparation, and this is also an important content of doctor-patient communication. Along with the development and combined application of intraoral scan, three-dimensional (3D) face scan, digital design, numerical control machining and 3D printing technology, digital technology is gradually applied to the virtual simulated design before irreversible operation in dental esthetic rehabilitation. Digital technology can be used in dentistry to simulate the esthetic outcome in advance, to assist communication among the dentists, patients and dental technicians, and to realize satisfactory outcome in the final restorations precisely, which, as a result, increases the clinical satisfaction. This review focuses on the application of digital virtual simulated design technology in dental esthetic rehabilitation, analyzes the current research development, deficiency and future prospects, so as to provide guidance for clinical diagnosis and treatment.
Subject(s)
Humans , Computer-Aided Design , Esthetics, Dental , Face , Printing, Three-Dimensional , Tooth PreparationABSTRACT
To study the effect and mechanism of extract of Quzhou Aurantii Fructus(QAF) on liver inflammation in CCl_4-induced liver fibrosis mice. Totally 60 C57 BL/6 male mice were randomly divided into control group(distilled water, oral), model group(distilled water, oral), colchicines group(Col, colchicines 2 mg·kg~(-1)·d~(-1), oral), low-dose QAF group(QAF-L, QAF 100 mg·kg~(-1)·d~(-1), oral) and high-dose QAF group(QAF-H, QAF 300 mg·kg~(-1)·d~(-1), oral) by random number table method. The model group and each administration group were injected with carbon tetrachloride(CCl_4) 1 mL·kg~(-1)(CCl_4-olive oil 1∶4), twice a week, totally 6 weeks. After the last administration, the mice were sacrificed, and serum and liver tissue were collected. Serum ALT and AST levels were measured in each group to observe the liver function of mice. The pathological changes and inflammatory cell infiltration in liver were observed by HE staining and F4/80 immunohistochemical staining. The mRNA expressions of TNF-α, IL-18 and IL-1β were detected by RT-PCR. The protein expressions of IκBα, p-IKKα/β, p-p65, NLRP3, caspase-1 and cleaved caspase-1 were analyzed by Western blot. The results showed that QAF significantly reduced serum ALT and AST levels, and alleviated the degree of liver damage.The results of immunohistochemistry showed that QAF significantly reduced liver inflammatory cell infiltration in liver fibrosis mice. The results of RT-PCR and Western blot showed that QAF significantly inhibited mRNA expressions of TNF-α, IL-18 and IL-1β in liver of fibrosis mice. QAF also suppressed the degradation of IκBα protein and reduced p-IKKα/β, p-p65, NLRP3 and cleaved caspase-1 protein expressions. In conclusion, QAF improves CCl_4-induced liver fibrosis in mice. The mechanism may be related to the inhibition of NF-κB/NLRP3 inflammasome-mediated inflammation signaling pathway.
Subject(s)
Animals , Male , Mice , Inflammasomes/genetics , Inflammation , Liver/pathology , Liver Cirrhosis/genetics , NF-kappa B/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Plant ExtractsABSTRACT
An effective method was developed for determination of pyraclostrobin and BF 500-3 residues in pollen and honey of litchi by QuEChERS coupled with ultra performance liquid chromatography-tandem mass spectrometry. The samples were extracted by acetonitrile and cleaned by primary secondary amine(PSA) and C18. In the positive ion mode and multi reaction monitoring mode,the analytes were quantified by the matrix matching standard solutions, and the pretreatment and mass spectrometry conditions were evaluated. The matrix matched standard solutions of pyraclostrobin and its metabolite BF 500-3 showed good linearities in the concentration range of 1-100 μg/L, with the correlation coefficients (R2) of 0.991-0.999. The average recoveries were 87.0%-97.8% with relative standard deviations of 1.3%-3.7%. The limit of detection (LOD) and the limit of quantification(LOQ) were 0.08-0.20 μg/kg and 0.20-0.50 μg/kg,respectively. The method was easy, quick and highly sensitive, and was suitable for quick determination of pyraclotrobin and its metabolites in pollen and honey of litchi.
ABSTRACT
To study the effects of Nelumbinis Receptaculum (the seedpod of Nelumbo nucifera) extract (NRE) on insulin resistance (IR) in type 2 diabetic rats. The experimental type 2 diabetic rats were established by high-fat diet for 4 weeks and injected with low dose of streptozotocin (STZ, 30 mg/kg). After intervention by ig administration of NRE in low, medium, and high dose groups (100, 300, and 500 mg/kg) for 5 weeks, the effects of NRE on the levels of fasting blood glucose (FBG), fasting insulin (FINS), total cholesterol (TC), triglycerides (TG), high density lipoproteins cholesterol (HDL-C), low density lipoproteins cholesterol (LDL-C), the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hexokinase (HK), the levels of liver glycogen, muscle glycogen, liver malondialdehyde (MDA), reduced glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), plasma leptin, and TNF-α were observed. The insulin sensitivity index (ISI) and IR were calculated accordingly. NRE could decrease the levels of FBG, increase ISI, reduce the levels of IR, plasma leptin, and TNF-α (P < 0.05 or P < 0.01) in type 2 diabetic rats. The dyslipidemia (TC, TG, HDL-C, and LDL-C) and hepatic metabolism (TC, TG, ALT, and AST) could be improved by NRE (P < 0.05 or P < 0.01). NRE could increase the GSH level and antioxidant enzymes activities, and decrease MDA level. In addition, NRE could increase the glycogens content and HK activity. NRE could improve the IR in the experimental type 2 diabetic rats. It might be related to its effects on improving dyslipidemia, hepatic metabolism, and antioxidant capacity of hepatic tissue, as well as reducing leptin and TNF-α levels.