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During the continuous casting process, the residual oxygen in the tundish can be significantly reduced by argon blowing from the tundish cover (ABTC). As a result, the effect of protective casting can be obviously improved, which helps to reduce the reoxidation of molten steel in the tundish. In the present work, numerical models for the ABTC of a six-strand continuous casting machine were established and verified by the measured oxygen mass fraction in the tundish during the ABTC. The results indicate that the best conditions for ABTC are to install the argon pipes on either side of the tundish cover holes, seal the baking holes, and keep the stopper rod holes open. The argon flow rate should be ≥120 m3/h during the period of empty tundish and ≥60 m3/h during the period of normal casting. Based on the calculation results, industrial testsof ABTC were carried out. The results indicated that the increased nitrogen content in steel(Δw[N]) decreased by 21.5% from 8.78×10- 6 to 6.89×10-6 , from the end of RH to tundish, and the amount of inclusions except for MnS in bloom (scanned size: 8 mm × 8 mm) decreased by 21.3% from 13.43 to 10.57, and the average size of inclusions decreased by 19.0% from 9.27 μm to 7.51 μm.

Mechanical soft reduction (MSR) is an effective method for elimination of the centerline segregation and porosity of the continuous casting steel slab, and the reduction amount is a key parameter that determines whether the MSR could be applied successfully. In the present work, a 2D heat transfer model was developed for predicting the non-uniform solidification of the wide-thick slab. The measured shell thickness by nail shooting experiment and the measured slab surface temperature by infrared camera were applied to validate the 2D heat transfer model. A new calculation method of theoretical reduction amount that could consider the influence of non-uniform solidification of the wide-thick slab was then derived. Based on the predicted temperature field by the 2D heat transfer model and the newly-proposed calculation method, the required theoretical reduction amount and reduction gradient/rate for the wide-thick slab were calculated and discussed. The difference between the newly-proposed method and the previous method, the influence of the casting speed and slab thickness on the required theoretical reduction amount and reduction gradient/rate were also investigated.

OBJECTIVE: This study aimed to explore the role of NF-κB/P65 signaling pathway in postoperative cognitive dysfunction (POCD) after sevoflurane anesthesia. MATERIALS AND METHODS: A total of 120 male Sprague-Dawley (SD) rats were selected and assigned into five groups (24 rats in each group): the control, sevoflurane, sevoflurane + splenectomy, pyrrolidine dithiocarbamate (PDTC, a specific inhibitor of NF-κB), and sevoflurane + splenectomy + PDTC groups. Electrocardiogram (ECoG) and behavior changes of rats were monitored before and after anesthesia/operation. Ionized calcium-binding adapter molecules 1 (Iba-1) in the hippocampal zones were observed by immunofluorescence staining. Blood-brain barrier (BBB) permeability was determined by immunohistochemistry. The mRNA and protein expressions of NF-κB/P65 signaling pathway-related proteins and inflammatory cytokines were detected by qRT-PCR assay and Western blotting. RESULTS: During the anesthesia/operation, the vital signs of rats were stable, but the ECoG in the sevoflurane and sevoflurane + splenectomy groups mainly presented slow waves. The ECoG arousal response in the sevoflurane + splenectomy + PDTC group was observed. At 24 h after the anesthesia/operation, the expressions of NF-κB and P65 in the hippocampal zone, the expressions of IκBα and inflammatory cytokines (IL-1β, IL-6 and TNF-α), the expression of Iba-1 in rat hippocampal dentate gyrus (DG) zone and CA3 zone, and the permeability of BBB were significantly increased and the behavior of rats changed dramatically (all p < 0.05), while PDTC treatments could eliminate these changes induced by the anesthesia/operation (all p < 0.05). No changes were observed in the expressions of NF-κB, P65, IκBα, Iba-1 and inflammatory cytokines (IL-1β, IL-6 and TNF-α), and the permeability of BBB and the behavior of rats in the sevoflurane and the PDTC groups (all p > 0.05). CONCLUSIONS: These results suggest that the inhibition of NF-κB/P65 signaling pathway may relieve POCD after sevoflurane anesthesia. [ABSTRACT FROM AUTHOR]

Physical dormancy occurs in all three subfamilies of Fabaceae, namely Mimosoideae, Papilionoideae and Caesalpinioideae, making it one of the largest plant families in terms of number of species with physical dormancy. However, little is known about the water gap structure and germination ecology of species in Caesalpinioideae. Freshly collected seeds of Delonix regia (Caesalpinioideae) did not imbibe water, thus they had physical dormancy. Both dry heat and wet heat were effective in breaking dormancy, however, longer duration was required at 80 °C and shorter duration at 90 °C. Seeds buried in the field for 2 years germinated to 21% and 42% after the first and second summer, respectively, compared with 3% germination in seeds at the time of maturity. Seeds incubated at 15/60 °C in the laboratory (mimicking summer conditions) for 3 months supported this conclusion, as dormancy was relieved in 18% and 24% of seeds stored dry and watered intermediately, respectively. All the dormancy breaking treatments resulted in lifting of palisade layers in the lens region to form a circular lid-like opening, i.e. water gap (Type II simple). Blocking experiments confirmed that water entered only through the lens and no secondary water entry point was observed. No apparent changes in morphology/anatomy of the hilum region were noted in dormant and non-dormant (water permeable) seeds. These results suggest that summer temperatures could open the lens in a proportion of seeds every year and that germination occurs during the subsequent wet season in the tropics. [ABSTRACT FROM AUTHOR]

In this paper, the forced vibration of a flexible beam undergoing both global motion and elastic deformation is investigated. The deformation field of the beam is described by its exact linear vibration modes. The coupled nonlinear equation which takes into account the stiffening effect is derived by applying the Lagrange equation for the moving beam. Based on the Newmark direct integration method and the Newton–Raphson iteration method, the computational procedures of the numerical method for solving the nonlinear equation are given. The simulation result of the rotating blade is compared with the others to demonstrate the efficiency of the present method. [ABSTRACT FROM AUTHOR]

Objective: To explore the consistency of peripheral whole blood and venous serum procalcitonin (PCT) levels, and the value of peripheral whole blood PCT in evaluating pediatric bacterial infection. Methods: This multicenter cross-sectional parallel control study was conducted in 11 children's hospital. All the 1 898 patients older than 28 days admitted to these hospitals from March 2018 to February 2019 had their peripheral whole blood and venous serum PCT detected simultaneously with unified equipment, reagent and method. According to the venous serum PCT level, the patients were stratified to subgroups. Analysis of variance and chi-square test were used to compare the demographic characteristics among groups. And the correlation between the peripheral blood and venous serum PCT level was investigated by quantitative Pearson correlation analysis.The PCT resultes were also converted into ranked data to further test the consistency between the two sampling methods by Spearman's rank correlation test. Furthermore, the ranked data were converted into binary data to evaluate the consistency and investigate the best cut-off of peripheral blood PCT level in predicting bacterial infection. Results: A total of 1 898 valid samples were included (1 098 males, 800 females),age 27.4(12.2,56.7) months. There was a good correlation between PCT values of peripheral whole blood and venous serum ( r= 0.97 , P< 0.01). The linear regression equation was PCT venous serum =0.135+0.929×PCT peripheral whole blood . However, when stratified to 5 levels, PCT results showed diverse and unsatisfied consistency between the two sampling methods ( r= 0.51-0.92, all P< 0.01). But after PCT was converted to ordinal categorical variables, the stratified analysis showed that the coincidence rate of the measured values by the two sampling methods in each boundary area was 84.9%-97.1%. The dichotomous variables also showed a good consistency (coincidence rate 96.8%-99.3%, Youden index 0.82-0.89). According to the severity of disease, the serum PCT value was classified into 4 intervals（<0.5、0.5-<2.0、2.0-<10.0、≥10.0 μg/L）, and the peripheral blood PCT value also showed a good predictive value (AUC value was 0.991 2-0.997 9). The optimal cut points of peripheral whole blood PCT value 0.5、1.0、2.0、10.0 μg/L corresponding to venous serum PCT values were 0.395, 0.595, 1.175 and 3.545 μg/L, respectively. Conclusions: There is a good correlation between peripheral whole blood PCT value and the venous serum PCT value, which means that the peripheral whole blood PCT could facilitate the identification of infection and clinical severity. Besides, the sampling of peripheral whole blood is simple and easy to repeat.

Objective: To investigate the effect of sleep fragmentation on perioperative neurocognitive disorders (PND) and central neuroinflammation by simulating sleep patterns of postoperative patients with sleep fragmentation in aged mice. Methods: Thirty-two elderly ICR mice were randomly divided into four groups ( n= 8): normal group (C), surgery group (S), fragmented sleep group (F), and surgery+fragmented sleep group (D). Fragmented sleep was conducted after internal fixation of tibia fractures, cognitive function was evaluated by novel object recognition (NOR) and fear conditioning (FC) test, and changes in expression of inflammatory cytokines in hippocampus were detected by ELISA. Results: NOR test: the recognition index (RI) of mice in group C, group S, group F and group D was 0.69±0.07, 0.48±0.07, 0.54±0.10 and 0.50±0.12, respectively. The RI of mice in group S, group F and group D was significantly lower than that in group C ( t= 4.885, 3.521 and 4.433, all P< 0.01). There was no significant difference in RI between group S and group D ( t= 0.967 1, P> 0.05). Contextual FC test: the freezing time of mice in group C, group S, group F and group D was(21.34±6.48), (13.83±4.26), (11.50±6.25) and (6.17±4.77) s, respectively. The freezing time of mice in group S, group F and group D was significantly lower than that in group C ( t= 2.722, 3.566, 5.496, P< 0.05 or P< 0.01). The freezing time of mice in group D was significantly lower than that in group S ( t= 2.774, P< 0.05). Cue FC test: the freezing time of mice in group C, group S, group F and group D was (74.36±17.09), (43.91±9.71), (46.34±13.43) and (24.90±14.21) s, respectively. The freezing time of mice in group S, group F and group D was significantly lower than that in group C ( t= 4.393, 4.043 and 7.136, all P< 0.01). The freezing time of mice in group D was significantly lower than that in group S ( t= 2.743, P< 0.05). The levels of TNF-α, IL-6 and IL-1β in hippocampus of mice in group S, F and D were significantly higher than those in group C, while the levels of TNF-α and IL-6 in hippocampus of mice in group D were significantly higher than those in group S, with statistically significant differences ( P< 0.05 or P< 0.01). Conclusion: Postoperative fragmented sleep aggravates postoperative cognitive impairment and increases the hippocampal neuroinflammation in aged mice.

Objective: To explore the effects of remifentanil gradual withdrawal on remifentanil induced postoperative hyperalgesia. Methods: Ninety patients from January to June 2018 undergoing elective laparoscopic hysterectomy under general anaesthesia at Ningbo NO.2 hospital, ASA Ⅰ or Ⅱ grade, aged 20-60, were enrolled in this study and randomly assigned to 3 groups ( n= 30): Group L (low dose remifentanil), Group H (high dose remifentanil) and Group G (high dose remifentanil with gradual withdrawal). Mechanical pain thresholds (MPT), visual analogue scale (VAS) and additional analgesics were recorded at 6 and 24 hours after the operation. Results: There was no significant difference among the VAS and additional analgesics in three groups at 6 and 24 hours after operation ( P> 0.05). There was no significant difference among the MPT in three groups before operation ( P> 0.05). The MPT of group L, group H and group G were (49.8±12.2), (35.5±13.0) and (48.6±11.4) g at 6 hours after surgery, and (51.4±14.3), (36.9±11.1) and (48.8±11.5) g at 24 hours after surgery, respectively, with statistically significant differences ( F= 12.6, 11.668, both P< 0.01). The MPT of group H at 6 h and 24 h after surgery was lower than that of group L (all P< 0.01), while the MPT of group G at 6 h and 24 h after surgery was significantly higher than that of group H (all P< 0.01). No correlation was observed between MPT and VAS scores or additional analgesics at 6 and 24 hours postoperatively ( P> 0.05). Conclusion: Remifentanil gradual withdrawal significantly alleviated intraoperative administration of remifentanil induced postoperative hyperalgesia in laparoscopic hysterectomy patients.

Background: Selenium is a crucial mineral with antioxidant and immune functions, and selenium deficiency may increase the risk of coronary heart disease (CHD). However, the effect of selenium supplementation on CHD is still controversial according to numerous randomized controlled trials (RCTs). The aim of our meta-analysis study was to investigate the impact of selenium on CHD., Methods: PUBMED, EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials databases were systematically searched to identify RCTs evaluating the effect of selenium supplementation on CHD mortality, blood lipid profile (high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total cholesterol), serum C-reactive protein (CRP), and the level of glutathione peroxidase (GSH-PX) from inception until September 20, 2016. Odds ratio of CHD mortality and the associated 95% confidence intervals (CIs) were calculated using the fixed effect model. Weighted mean difference or standardized mean difference (SMD) and 95% confidence intervals (CIs) were calculated to determine the lipid profile, serum CRP, and GSH-PX using fixed effect or random effect models depending on the observed heterogeneity., Results: A total of 16 eligible RCTs with 43998 participants were included. Significant effects were observed for serum CRP (SMD=-0.48; 95% CI, -0.96 to 0; p=0.049) and GSH-PX (SMD=0.5; 95% CI, 0.36-0.64; p<0.001) after selenium supplementation. However, selenium supplementation was not statistically associated with CHD mortality and an aberrant lipid profile., Conclusion: Selenium supplementation decreased serum CRP and increased the GSH-PX level, suggesting a positive effect on reducing oxidative stress and inflammation in CHD. However, selenium supplementation is not sufficient to reduce mortality and to improve the lipid status., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

Objective: To explore the effects of lappaconitine on intraoperative administration of remifentanil induced postoperative hyperalgesia in general anaesthesia patients. Methods: One hundred and twenty patients from March to October 2016 undergoing elective thyroid operation under general anaesthesia at Ningbo NO.2 hospital, American Society of Anesthesiologists(ASA) Ⅰ or Ⅱ grade, aged 20-60, were enrolled in this study and randomly assigned to 3 groups ( n =40). Remifentanil was intraoperatively infused at 0.1 μg·kg(-1)·min(-1) (Group S) or 0.3 μg·kg(-1)·min(-1) (Groups L and G), and patients in group G received lappaconitine 8 mg 30 minutes before the ending of surgery. Mechanical pain thresholds, visual analogue scale (VAS) and additional analgesics were recorded at 2, 6 and 24 hours after the operation. Results: There was no significant difference among the VAS and additional analgesics in three groups at 2, 6 and 24 h after operation (all P >0.05). There was no significant difference among the mechanical pain thresholds in three groups before and 2 h after operation (all P >0.05). The mechanical pain thresholds of group S, L and G was (45.7±15.6), (35.8±15.0), (47.6±16.4)g at 6 h and (50.7±17.0), (33.7±14.0), (49.7±13.9 )g at 24 h after operation. There was significant difference among the mechanical pain thresholds in group S, L and G at 6 h and 24 h after operation ( F =6.586, 16.089, all P <0.01). Compared to group S, the mechanical pain thresholds significantly decreased in group L at 6 h and 24 h after operation ( q =2.837, 5.045, all P <0.01). While there was a significantly increase in pain thresholds at 6 h and 24 h postoperatively in group G, as compared with the group L ( q =3.384, 4.770, all P <0.01). Conclusion: Lappaconitine significantly alleviated intraoperative administration of remifentanil induced postoperative hyperalgesia in general anaesthesia patients.

Endogenous retinoic acid may play a role in inducing smooth muscle differentiation in the fetal ductus arteriosus. Maternal administration of retinoic acid may accelerate the process. This study was designed to investigate the effect of vitamin A on developmental changes in the contractile system of the ductus. Vitamin A was injected into pregnant rats and the ductus was isolated from the fetus at 19, 20, or 21 d of gestation. The fetus at 19 d of gestation served as a model of the preterm fetus. The force of contraction and [Ca]i were measured. Membrane depolarization caused by high KCl induced ductal contraction in all age groups studied. In the 19-d fetus, O2 did not cause significant contraction or changes in [Ca]i in the control group, but it did induce a significant contraction and increases in [Ca]i in the vitamin A-treated group. In the 20- and 21-d fetuses, 5% O2-induced contraction in the vitamin A-treated group was significantly greater than in the control group. In the 19-d fetus, noradrenaline-induced contraction and increases in [Ca]i, indicators of the size of the intracellular Ca pool, were observed and they were similar in the control group and in the vitamin A-treated group. These data suggest that 1) in the preterm fetus, the contractile system, including membrane depolarization, [Ca]i increase, and its activation of contractile proteins, is already functioning, but the O2-sensing mechanism is underdeveloped, 2) vitamin A accelerates the development of the O2-sensing mechanism of the ductus arteriosus.

Thirty patients with advanced colorectal cancer were treated preoperatively by combined regional radiofrequency hyperthermia and 5-FU. After the treatment, the gross tumor regressive rate was 76.7%, and the tumor integral resection rate of colorectal cancer was 92.3%. Nine patients with advanced colorectal cancer, considered unoperable and treated with thermochemotherapy, underwent a successful en bloc resection of their tumors. Marked destruction of cancer cells was observed after thermochemotherapy. Moderate-severe damage of cancer cells was observed in 76.9% of patients in the thermochemotherapy group, 33.3% in the chemotherapy group, and 42.3% in the operation group (P less than 0.005). The results indicate that the treatment is more effective in the treatment of colorectal cancer than 5-FU chemotherapy alone.