Objective To investigate the effects of oral care using hydrogen peroxide and sodium bicarbonate to prevent neonatal ventilator associated pneumonia(VAP). Methods Totally 209 neonates were recruited and divided into the experimental group with 104 cases and the control group with 105 cases by using random number table method. Based on conventional mechanical ventilation nursing,the experimental group received oral care using 1.5%hydrogen peroxide combined with 2.5% sodium bicarbonate,Q8H,while the control group received oral care using only 2.5% sodium bicarbonate,Q8H. Positive results of bacteria detection in tracheal sputum culture,the incidence rate of VAP,mechanical ventilation time,hospitalization time and hospitalization costs were compared between two groups. Results After 48 hours of mechanical ventilation,the difference in positive results of bacteria detection in tracheal sputum culture between two groups was statistically significant(P<0.05). The difference of incidence rate of VAP between two groups showed no statistical significance(P>0.05) when the duration of the mechanical ventilation was 48 hours. While after 48 hours of the mechanical ventilation,the difference of the incidence rate of VAP between two groups was statistically significant(P<0.05). The differences in mechanical ventilation time and hospitalization time between two groups were statistically significant(P<0.05). The hospitalization costs of the experimental group was higher than that of the control group,while the difference showed no statistical significance(P>0.05). Conclusion The combined usage of hydrogen peroxide and sodium bicarbonate for oral care can effectively eliminate neonatal oral bacteria colonization and prevent neonatal VAP,so as to reduce the time of mechanical ventilation and hospitaliza-tion, and decrease hospitalization costs.

ABSTRACT OBJECTIVE：To establish a method for content determination of paclitaxel in malignant ascites of tumor patients. METHODS：LC-MS/MS method was adopted. Using vindoline as internal standard，the content of paclitaxel in ascites of tumor patients was determined. The separation was performed on Zorbax SB-C18 column with mobile phase consisted of aqueous solution （containing 0.1％ formic acid and 10 mmol/L ammonium acetate）-acetonitrile（40 ∶ 60，V/V）at the flow rate of 0.25 mL/min. the column temperature was 30 ℃，and sample size was 5 μL. The ion source was electrospray ion source，and the detection mode was multiple ion monitoring positive ion mode. MS parameters were set as following as dry gas temperature 350 ℃，dry gas flow rate 10 L/min，capillary voltage 4 000 V. Quantitative determination was operated in the multiple reaction monitoring（MRM）mode， with the ion transitions m/z 876.5→308.0 for paclitaxel and m/z 457.3→188.1 for the internal standard. The fragment voltage/ collision energy for paclitaxel and the internal standard were 250 V/30 eV，and 150 V/20 eV，respectively. RESULTS：The linear range of paclitaxel were 25-2 500 ng/mL（r2＝0.996 5，n＝7）. The lowest limit of quantitation was 25 ng/mL. RSDs of inter-day and intra-day precision tests were 0.61％ -3.62％（n＝5，3）. Accuracies were 95.34％ -98.76％（n＝5，3）. RSDs of extraction recovery were 3.19％-3.72％（n＝3）. CV of matrix effect were 1.52％-2.93％（n＝3）. RE of stability tests were lower than 3％（n＝ 3）. CONCLUSIONS：The method is simple，accurate and suitable for the content determination of paclitaxel in malignant ascites of tumor patients.

Background Osteoclast stimulatory transmembrane protein (OC-STAMP) is involved in silicosis fibrosis induced by silicon oxide (SiO₂) exposure. Its role in silicosis fibrosis by inducing ferroptosis of alveolar type II epithelial cells and its related mechanism remain unclear. Objective To explore the effect and possible mechanism of OC-STAMP on ferroptosis of alveolar type II epithelial cells and silicosis fibrosis in rats under SiO₂ exposure. Methods Twenty male Wistar rats of SPF grade were randomly divided into two groups: control (Sham) group and SiO₂ group, 15 rats in each group. Rats in the SiO₂ group were given 1 mL of 50 mg·L⁻¹ SiO₂ suspension at one time through the non-exposed intratracheal instillation method to establish an animal model of silicosis, and rats in the Sham group were give 1 mL of 0.9% sodium chloride solution in the same way. Rats were sacrificed after 8 weeks. Samples of lung tissue were fixed in glutaraldehyde or paraformaldehyde for observing ultrastructure of mitochondria by transmission electron microscopy; HE, Masson, VG, and Prussian blue were used to observe changes in lung tissue structure and iron deposition. The expression level of OC-STAMP and the degree of lung fibrosis were evaluated by immunohistochemistry and immunofluorescence. The expression level of OC-STAMP in rat lung tissue was detected and the transfection effect of OC-STAMP was verified by real-time fluorescence quantitative polymerase chain reaction (RT-PCR). Overexpression (OCS group) and inhibition expression (SI-OC group) models were constructed by OC-STAMP plasmid and OC-STAMP small interfering RNA (siRNA) transfection to cultured MLE-12 cells, respectively. The relative expression levels of glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11), and other proteins in lung tissue and MLE-12 were detected by Western blotting. Results The results of HE, Masson, and VG staining showed that the silicosis modeling was successful after 8 weeks of SiO₂ exposure. The immunofluorescence results showed that OC-STAMP and ATP binding cassette subfamily A member 3 (ABCA3) co-localized in alveolar type II epithelium. The immunohistochemical results showed that the levels of OC-STAMP and collagen I in the SiO₂ group were significantly higher than those in the Sham group (P<0.01). The RT-PCR results showed that the OC-STAMP mRNA in the lung tissue of the SiO₂ group was significantly higher than that of the Sham group (P<0.01). The Prussian blue staining in the lung tissue of the SiO₂ group showed positive brownish-yellow particles. Compared with the Sham group which showed normal mitochondrial structure, the mitochondrial structure was generally swollen and the mitochondrial cristae dissolved and disappeared in the SiO₂ group by transmission electron microscope observation. The Western blotting results showed that the expression levels of SLC7A11 and GPX4 both decreased in the lung tissue of the SiO₂ group (P<0.05, P<0.01), and the expression level of Vimentin increased (P<0.01). In the transfected MLE-12 cells, compared with the Sham group, the expression levels of SLC7A11 and GPX4 in the OCS group were significantly reduced (P<0.05, P<0.01). Conclusion OC-STAMP may affect the expression of proteins related to ferroptosis, and promote lung fibrosis induced by SiO₂ exposure.