Objective To investigate an automated pretreatment technology for detecting levels of free silica in workplace dust. Methods An fully automated pretreatment workstation for detecting free silica levels in workplace dust was developed by integrating graphite-controlled digestion temperature, online-controlled dilution of digestion solutions, and filtration endpoint recognition based on monitoring technology, combined with multi-channel synchronous measurements. Results The fully automatic pretreatment workstation was used to digest and filter 14 standard samples of free silica produced by three institutions, and then detected by pyrophosphate method. The result range of high-, medium-, and low-level free silica standard samples detection was 66.5%-84.8%, 40.0%-44.5%, and 2.1%-24.8%, respectively. The mean relative standard deviations were 3.9%, 1.4% and 1.5%. Conclusion The fully automated pretreatment workstation produced results that met relevant requirements. It can effectively replace the manual digestion and filtration steps of the pyrophosphate method to measure free silica levels in workplace dust and enable rapid detection of free silica in dust samples.

Objective:To investigate the relationship between the CT images of a lateral condylar tibial plateau fractures and complete medial collateral ligament (MCL) injury.Methods:Data of 59 patients with lateral condylar fracture of tibial plateau complicated with MCL injury admitted to Tianjin Hospital from January 2020 to November 2021 were collected, including 32 males and 27 females, aged 42.4±12.3 years (range, 19-65 years), there were 26 cases of extension injury and 33 cases of flexion injury. The patients were separated into two groups: those with partial MCL injury and those with total rupture based on preoperative MR examination and intraoperative valgus stress test following fracture fixation. According to the ABC fracture classification of lateral condyle tibial plateau proposed by Sun et al., the fracture locations were determined on CT images, and the lateral plateau collapse depth (LPD) was measured. The relationship between LPD and MCL complete rupture was analyzed by receiver operating characteristic (ROC) curve.Results:Among 59 patients with lateral condylar tibial plateau fracture and MCL injury, 42 had partial injuries and 17 had complete ruptures. According to the ABC fracture classification, there were 26 cases of extension injury (involving area A), 21 cases of AB type, and 5 cases of ABC type; and 33 cases of flexion type injury, 19 cases of B type, 12 cases of BC type, and 2 cases of C type. All the 17 cases of MCL complete fracture occurred in extension injury, including type AB (14 cases) and type ABC (3 cases). The difference between the mean LPDs of the MCL full rupture group and the partial injury group was not statistically significant ( t=0.11, P=0.567), and the mean LPDs of both groups were 11.7±5.3 mm (range, 4.3-28.1 mm) and 11.5±4.8 mm (range, 3.8-23.6 mm), respectively. The area under the curve (AUC) of the ROC curve analysis was 0.504, and there was no statistical correlation between lateral platform collapse depth and MCL injury. Among the 26 patients with extensional injury area, MCL was completely ruptures in 17 cases and partially injury in 9 cases, LPD was 11.7±5.3 mm (range, 4.3-28.1 mm) and 6.6±1.8 mm (range, 3.8-9.4 mm), respectively, and the difference was statistically significant ( t=3.57, P=0.009). The best predictive cut-off value of LPD was 7.25 mm, the sensitivity was 88.2%, the specificity was 77.8%, and the AUC was 0.868. Conclusion:When the lateral condyle fracture of the tibial plateau is located in the extensional injury area (involving the A area in the ABC fracture classification) and the LPD measured on the CT image is greater than 7.25 mm, the complete rupture of the MCL should be considered. Clinical MCL repair is required after the fracture fixation surgery for improved surgical outcomes.

OBJECTIVETo determine the effects and related mechanism of Scutellaria baicalensis stem-leaf total flavonoid (SSTF) on vascular smooth muscle cells (VSMCs) proliferation induced by high triglyceride blood serum (HTG).

METHODVSMCs isolated from rat aorta were cultured in vitro and proliferation was stimulated by HTG, SSTF was added to influence the proliferation of VSMCs. The proliferation and cell cycle of VSMCs were determined by MTT assay and flow cytometry, respectively. CO released into the culture media was quantitated by measuring carbon monoxide hemoglobin (COHb). The protein expressions of HO-1 and extracellular signal-regulated kinase (ERK/p-ERK) were detected by Western blot analysis.

RESULT500 mg x L(-1) SSTF could obviously suppress the cell multiplication by HTG's induction, remarkably increase the production of COHb in VSMCs, obviously suppresse the mitotic cycle progress of VSMCs (P < 0.05, P < 0.01), in the time and dosage dependence. Furthermore, 500 mg x L(-1) SSTF remarkably declined the ERK/p-ERK protein expression (P < 0.01), but did not have the influence on the HO-1 protein's expression.

CONCLUSIONSSTF inhibited the proliferation of VSMCs directly by blocking cell cycle progression, and the ERK signal transduction way possibly participated in the cytoprotection of SSTF.

Animals ; Cell Proliferation ; drug effects ; Cricetinae ; Drugs, Chinese Herbal ; pharmacology ; Flavonoids ; pharmacology ; Gene Expression ; drug effects ; Male ; Mitogen-Activated Protein Kinases ; genetics ; metabolism ; Myocytes, Smooth Muscle ; cytology ; drug effects ; metabolism ; Plant Leaves ; chemistry ; Plant Stems ; chemistry ; Rats ; Rats, Sprague-Dawley ; Scutellaria baicalensis ; chemistry ; Triglycerides ; blood ; pharmacology