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Objective： A method for simple and rapid determination of potassium content in cigarette paper will be built for workshops of cigarette factory. Methods: An ion-selective electrode method was used by comparing with the pretreatment methods for cigarette paper samples and potential response behaviors of potassium ion-selective electrodes in different buffer solutions. Results: The potassium ion selective electrode possessed excellent response performance for K+ in lithium acetate buffer solution （0.1 mol/L, pH 7.0） with a linear response range of 1.0×10-5 ~1.0×10-2 mol/L, a slope of 55.79 mV/dec （25 ℃）, and a lower limit of detection of 2.14×10-6 mol/L. The average relative standard deviations of the K+ selective electrode on cigarette paper samples were 0.55% for intra-day test and 2.8% for inter-day test, both less than 5%. The test results of the electrode method were in well agreement with that of ion chromatography, with an average relative deviation of 4.1% （n=10） and recoveries between 95.0% and 101.9%. It was demonstrated effectively through a consecutive test over one week. Conclusion: Among the pretreatment methods for cigarette paper samples, the ultrasonic extraction of potassium ions with 1% diluted acetic acid for 30 min has been found to be fast, simple and environmentally friendly. The ion-selective electrode method is accurate and reliable, which is suitable for the rapid detection of potassium in cigarette paper.

Background: The aim of this study was to review current delivery room (DR) resuscitation intensity in Chinese tertiary neonatal intensive care units and to investigate the association between DR resuscitation intensity and short-term outcomes in preterm infants born at 24+0–31+6 weeks' gestation age (GA). Methods: This was a retrospective cross-sectional study. The source population was infants born at 24+0–31+6 weeks' GA who were enrolled in the Chinese Neonatal Network 2019 cohort. Eligible infants were categorized into five groups: (1) regular care; (2) oxygen supplementation and/or continuous positive airway pressure (O2/CPAP); (3) mask ventilation; (4) endotracheal intubation; and (5) cardiopulmonary resuscitation (CPR). The association between DR resuscitation and short-term outcomes was evaluated by inverse propensity score-weighted logistic regression. Results: Of 7939 infants included in this cohort, 2419 (30.5%) received regular care, 1994 (25.1%) received O2/CPAP, 1436 (18.1%) received mask ventilation, 1769 (22.3%) received endotracheal intubation, and 321 (4.0%) received CPR in the DR. Advanced maternal age and maternal hypertension correlated with a higher need for resuscitation, and antenatal steroid use tended to be associated with a lower need for resuscitation (P < 0.001). Severe brain impairment increased significantly with increasing amounts of resuscitation in DR after adjusting for perinatal factors. Resuscitation strategies vary widely between centers, with over 50% of preterm infants in eight centers requiring higher intensity resuscitation. Conclusions: Increased intensity of DR interventions was associated with increased mortality and morbidities in very preterm infants in China. There is wide variation in resuscitative approaches across delivery centers, and ongoing quality improvement to standardize resuscitation practices is needed. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of using Bifidobacterium bifidum TMC3115 in early life on intestinal microbiota and immune functions and the long-term impact on inflammatory bowel disease., Methods: Fourteen pregnant BALB/c mice were purchased and 84 newborn BALB/c mice were subsequently obtained. Then, the newborn mice were randomly assigned to a normal saline (NS) group and a TMC3115 group, given via oral gavage normal saline and TMC3115, respectively, at a daily volume of 0.2 mL for each mouse. About 42 mice were assigned to each group. The gavage was stopped after 3 weeks. At this point, half of the mice in each group were sacrificed, and then the remaining mice in each group were randomly divided into NS-water group, NS-DSS group, TMC3115-water group, and TMC3115-DSS group, with about 10 mice in each group. The mice were given regular feed until the end of week 6 when they were given 3% dextran sulphate sodium (DSS) ad libitum for 4 days to establish the enteritis model, while the non-modeling groups were given pure water ad libitum . The experiment ended after 6 weeks and 4 days. The weekly body mass changes of the mice were documented. The intestinal tissue at the end of the experiment and the fecal samples, spleen and serum of the mice at 3 weeks and at the end of the experiment were collected to determine the pathology scores of colonic inflammation, the composition of fecal gut microbiota, spleen organ index and the mass concentration of serum cytokines., Results: 1) At the end of the experiment, the inflammatory pathology score was significantly lower in the TMC3115-DSS group compared with that of the Saline-DSS group ( P <0.05), with less disruption of colonic crypt structures and other structures, less inflammatory infiltration, and more intact epithelial structures. 2) At 3 weeks, in comparison with those of the NS group, the relative abundance of Bifidobacterium was significantly higher in the feces of the TMC3115 ( P <0.05), the relative abundance of both Enterococcus and Staphylococcus was lower ( P <0.05), the splenic organ index was significantly higher ( P <0.05), and interleukin (IL)-10 was significantly decreased ( P <0.05), while there was no significant change in IL-6 or TNF-α ( P >0.05). At the end of the experiment, in comparison with those of the NS-DSS group that undergone DSS induction, the TMC3115-DSS group had reduced relative abundance of Staphylococcus , Staphylococcus tumefaciens and Escherichia / Shigella in the feces ( P <0.05), while the splenic organ index was significantly higher ( P <0.05), and there were no significant changes in IL-6 or TNF-α ( P >0.05)., Conclusion: The use of TMC3115 in early life promotes the construction of gut microbiota in neonatal mice, thereby producing a long-term effect that alleviates colitis in mice, but the mechanisms involved are still not fully understood., (Copyright© by Editorial Board of Journal of Sichuan University (Medical Sciences).)

Objective: To investigate the possible mechanisms of miR-21-mediated regulation of proliferation and activation of hepatic oval cells., Methods: The 2-acetamidofluorene/partial hepatectomy (2-AAF/PH) method was applied to generate hepatic oval cell activation model in male Sprague-Dawley rats; after the 7 days of 2-AAF/PH or PH alone (control), the rats were sacrificed at 0 h, 6 h, 12 h, 24 h, 72 h and 168 h. Expression of miR-21 was detected by real-time PCR and differences between groups were evaluated using the two-sample t-test. Differential transcription of miR-21 target genes was assessed bioinformatically, and with western blotting to detect changes in protein expression of the target gene., Results: The rat hepatic oval cell activation model was successfully established.The 2-AAF/PH rats showed miR-21 expression beginning to increase at 12 h, peaking at 24 h, and decreasing thereafter until an increase at 168 h.For the control group, the miR-21 expression began to increase at 6 h, until 24 h when expression began steadily declining to reach the original level.Compared to the control group, the experimental group showed expression of miR-21 that was significantly less at 6 h (P=0.039, t =3.029) and significantly more at 24 h and 168 h (P=0.026, t =-3.433 and P=0.007, t =-5.105). Among the predicted target genes of miR-21 were WW domain containing E3 ubiquitin protein ligase 1 (WWD), Smad family member 7 (Smad7), and polybromo-1 (Pbrm1).Smad7 protein expression began to decrease at 6 h in the control group, until reaching its minimum at 24 h when it increased; in the experimental group, SMAD7 expression increased at 6 h, then began to decrease with the minimum detected at 168 hour.In the control group, the Smad7 mRNA expression decreased slightly at 6 h, then began to increase, reaching its peak at 24 h when the expression fell to the original level. In the experimental group, the Smad7 mRNA expression began to increase at 6 h and reached its peak at 24 h when it decreased; the expression was little more than its original level at 168 h.Smad7 protein expression was negatively correlated with miR-21, and Smad7 mRNA expression was positively correlated with miR-21 but negatively correlated with Smad7 protein expression., Conclusion: miR-21 may play a vital role in the activation and proliferation of hepatic oval cells.As a target gene of miR-21, Smad7 might be involved in the process.

To establish a fluorescent quantitative PCR method (FQ-PCR) with TaqMan probe for simultaneous detection of polyomavirus (BKV) and cytomegalovirus (CMV) and to evaluate its clinical application in the renal transplantation recipients. The conservative sequences of BKV and CMV were targeted and amplified by nested PCR technique. The PCR products were cloned into the plasmids pcDNA3. 1(+). The recombinant plasmid containing target sequences of BKV and CMV were constructed as external standards. The TaqMan-based assay was optimized. For evaluating the assay, the sensitivity was determinated by diluted standard (5 X 103-10icopies/mL), and the specificity was verified by negative control and positive control, and the precision was assessed by intra-assay coefficient of variation (ICV) through detecting standard repeatedly (20 times). A total of 480 blood samples of renal transplantation recipients were used to detect BKV and CMV DNA simultaneously with FQ-PCR, and the concentrations of FK506 were measured by ELISA. The association of DNA copy and concentrations of FK506 was analyzed. The cloned target BKV and CMV DNA was confirmed by sequencing and analysis. The sensitivity of the FQ-PCR assay reached 5 X 103 copies/ml in detecting BKV or CMV DNA. Control DNA verified the assay specifically detecting target DNA. The precision of the assay to quantif target DNA copies was acceptable (Intra-assay CV was 3.44% for BKV and 2.23% for CMV; Inter-assay CV was 4. 98% for BKV and 3.76% for CMV;). Of 480 samples, 130 samples (27. 08%) were CMV DNA positive, significantly higher than the BKV DNA positive (13.33%, 64/480, P<0.05). The positive BKV or CMV DNA was found to be associated with high concentrations of FK506 (P<0. 05). In conclusion, the developed real-time PCR assay for detecting both CMV and BKV DNA simultaneously was s high sensitive, precise and time-effectiveand could be applied in the monitoring of the CMV and BKV infection in the renal transplantation recipients.