[Comparative study on fracture toughness of digital light processing three-dimensional printing zirconia and milled zirconia]

Objective: To investigate the influence of digital light processing (DLP) and computer numerical controlmilling (CNC) on the mechanical behavior of zirconia. Methods: Prepared DLP samples (experimental group, n=52) and CNC samples (control group, n=52) with 12 samples in each group were randomly selected using random number table to measure density, grain size and crystal phase composition. According to the different methods fracture toughness test, the samples were divided into indentation method group (IM) and single-edge-V-notch-beam group (SEVNB), with 30 DLP and 30 CNC samples in IM group, 10 DLP and 10 CNC samples in SEVNB group. The IM group was tested under three different loads (49.03 N, 98.07 N, 196.10 N), there were 10 samples for each load and each sample was tested at 15 points, and the load with the ratio of crack length to indentation diagonal length greater than 2.5 was selected as the indentation load to calculate its IM fracture toughness. At the same time, the SEVNB group was tested with four point bending test to record the maximum load at the time of fracture and calculate the SEVNB fracture toughness. Finally, the indentation and fracture surface were observed using optical microscope and scanning electron microscope, and the results of DLP group and CNC group were further compared to explore the difference in fracture mechanism. Results: The microstructure of DLP and CNC zirconia was basically the same, the density of DLP group was (6.020±0.021) g/cm³, the grain size was (0.603±0.033) μm; the density of CNC group was (6.038±0.012) g/cm³, the grain size was (0.591±0.033) μm. Both groups were composed of tetragonal zirconia. The load of 196.10 N was chosen as the indentation load for two groups to calculate the IM fracture toughness. In terms of fracture toughness, there was no significant difference between the two groups (P>0.05). Scanning electron microscope images of fracture surface showed the intergranular fracture was the leading fracture mode of two groups. The IM and SEVNB fracture toughness of DLP zirconia were (6.111±0.179) MPa·m^1/2 and (7.221±0.809) MPa·m^1/2, respectively. The IM and SEVNB fracture toughness of CNC zirconia were (6.126±0.383) MPa·m^1/2 and (7.408±0.533) MPa·m^1/2, respectively. Conclusions: The microstructure of DLP and CNC zirconia is almost the same, and there is little difference in the fracture toughness of zirconia between two processing technologies.

[Analysis of the clinicopathologic features as well as diagnosis and treatment of 59 patients with Castleman disease]

Objective: To investigate the clinicopathologic features, treatment, and prognosis in patients with Castleman disease (CD) . Methods: We retrospectively analyzed the clinicopathologic data of 59 patients for whom a diagnosis of Castleman disease was confirmed using pathological examination from October 2011 to October 2019 at the Henan Cancer Hospital. The patients were divided into the following two groups as per the following clinical classifications: unicentric CD (UCD, n=47) and multicentric CD (MCD, n=12) . Data on clinical manifestations, laboratory findings, treatment, and prognosis were analyzed. Results: There was no significant difference in the median age and the ratio of male to female between the UCD and MCD. UCD was characterized by asymptomatic enlargement of the single lymph node. The main pathological type was hyaline vascular histopathology (83.0%) . Of these, 44 patients chose surgical resection, and their prognosis was good. Treatment. MCD was characterized by multiple enlarged superficial and/or deep lymph nodes with B symptoms, weakness, and hepatosplenomegaly. Anemia, hypoproteinemia, and globulin level were increased on laboratory examinations. Plasmacyte histopathology was the main pathological type and was present in about 50.0% of the subjects. Only chemotherapy was performed for these MCD patients, followed by chemotherapy or chemotherapy followed by radiotherapy, and the efficient was 58.3% (7/12) . Conclusions: UCD, characterized by asymptomatic enlargement of the single lymph node, shows good postoperative prognosis. MCD has relatively complex clinical manifestations and poor prognosis, and optimal treatment is yet to be established.

The water extract of Veratrilla baillonii could attenuate the subacute toxicity induced by Aconitum brachypodum

BACKGROUND

Aconitum brachypodum Diels (Family Ranunculaceae) is a Chinese ethnodrug and is well known for both its therapeutic application and high toxicity. However, no detoxication strategy is available for the complete elimination of the toxicity of Aconitum plants. Veratrilla baillonii Franch is believed to possess antitoxic effects on the toxicity induced by Aconitum plants and has been clinically used for hundreds of time by Naxi and Lisu nationalities in Yunnan Province of China. To further address the mechanism of the detoxication of Veratrilla baillonii, the effect of water decoction of Veratrilla baillonii (WVBF) on subacute toxicology of SD rats induced by Aconitum brachypodum (CFA), a genus Aconitum, was determined and studied in the present work.

METHODS

The clinical behavior and number of survivors for different dosage of WVBF (25, 50, 100mg/kg) on CFA (4mg/kg) induced rats were observed until day 28. Histological changes and haematological parameters were evaluated. Moreover, Na⁺-K⁺-ATPase pathway in heart as well as key enzymes in liver were determined to further discuss the mechanism.

RESULTS

The results showed that the exposure of CFA led to some subacute toxicity to rats, especially male ones, accompanied with abnormality of serum biochemical index in rats' serum. The toxicological target organs of CFA may be the heart, liver, kidney and brain. It is demonstrated that WVBF could attenuate the toxicity induced by Aconitum brachypodum via promoting the metabolic enzymes CYP3A1 and CYP3A2 in liver, downregulating the expression of Sodium/Calcium exchanger 1 (NCX1) and SCN5A sodium channal mRNA, and inducing Na⁺/K⁺-ATPase activity in heart. This study provides insights into detoxifying measures of Aconitum plants.

CONCLUSIONS

Aconitum brachypodum may lead to subacute toxicity of rats after long term of administration, and the toxicity could be attenuated by Veratrilla baillonii via promoting the metabolic enzymes in liver, downregulating the expression of NCX1 and SCN5A mRNA, and inducing Na⁺/K⁺-ATPase activity in heart.

Gentiopicroside and sweroside from Veratrilla baillonii Franch. induce phosphorylation of Akt and suppress Pck1 expression in hepatoma cells

The use of phytochemicals and herbal medicines has accompanied human history. Advances in modern biomedical sciences have allowed us to investigate the functional mechanisms of herbal medicines and phytochemicals. Veratrilla baillonii Franch. has long been used as a medicinal herb in southwestern China. Here, we analyzed the effects of an ethanol extract from V. baillonii (VBFE) on the expression levels of the cytosolic form of the phosphoenolpyruvate carboxykinase gene (Pck1) mRNA and components of the insulin signalling cascade in HL1C hepatoma cells. Compared with the insulin control, VBFE treatment inhibited the expression of Pck1 mRNA in a dose-dependent manner. This was associated with the phosphorylation of Akt and Erk1/2 in a time-dependent manner. Further analysis of the purified components of VBFE indicated that gentiopicroside and sweroside from VBFE, alone and in combination, suppressed Pck1 expression and induced Akt and Erk1/2 phosphorylation. In conclusion, gentiopicroside and sweroside suppress Pck1 expression and induce phosphorylation of components in the insulin signalling cascade. This is the first study to demonstrate that gentiopicroside and sweroside show insulin-mimicking effects on the regulation of Pck1 expression. Further studies are warranted to explore the potential of gentiopicroside and sweroside in the control of blood glucose in animals.