A kind of modified silicone oil( PMS) was synthesized by hydrosilylation with allyl alcohol polyethoxy polypropoxy ether( FB),lauryl methacrylate( LMA) and hydrosilicone oil( PHMS) as starting materials,as well as chloroplatinic acid as catalyst. Optimum reaction conditions were investigated via orthogonal designed experiments as: molar ratio,n( Si- H) ∶ n( C = C) = 1 ∶ 1. 20; dosage of catalyst, 30 μg·g- 1; reaction temperature,90 ℃ for 6 h. Under these conditions,the conversion achieves 93. 45%. The polysiloxane defoamer was prepared by emulsifying of aqueous phase into the oil phase,which was composed of silicone oil paste,blended emulsifying agent and the prepared PMS in a high speed shearing emulsification mixer. The optimized formulation was obtained via application tests as: mass fraction of silicone oil paste,10%; mass fraction of PMS,6%; and mass fraction of blended emulsifying agent( composed of Span 60,Tween 60 and OP- 10 with mass ratio of 3 ∶ 2 ∶ 1),4%. The polysiloxane defoamer product shows good stability and its defoaming property and foam inhibition property is superior to other similar products.
Abstract Background This study aimed to explore the risk factors for early periventricular intraventricular hemorrhage (PIVH) in extremely low birth weight infants (ELBWIs), provide guidance for early intervention, and improve the survival rate and life expectancy of ELBWIs. Methods A retrospective study was conducted on 205 ELBWIs admitted to the Women and Children's Medical Center of Guangzhou Medical University from January 2019 to December 2023. The presence and severity of PIVH were assessed through standard head ultrasound screening (HUS) using the modified Papile classification on days 1–3 and 5–7 postbirth. The infants were categorized into either the PIVH group or the non-PIVH group based on the HUS findings. Univariate analysis and logistic regression were employed to identify the risk factors associated with PIVH. The efficacy of the model was evaluated using a receiver operating characteristic (ROC) curve. Results Among the 205 ELBWIs (97 males and 108 females) included in the study, 82 patients (40.0%) developed PIVH, 26 patients (12.7%) had severe PIVH, and 56 patients (27.3%) had mild PIVH. Of the 82 PIVH cases, 51 occurred within 3 days after birth. The incidence rates of severe PIVH in the 23+ 1-26-, 26+ 1-28-, and 28+ 1-32-week gestational age groups were 40.0% (16/40), 10.7% (10/93), and 1.4% (1/72), respectively (χ2 = 34.392, p = 0.000). Logistic regression analysis revealed that failure to withdraw invasive ventilators within 1 week (OR = 3.668, 95% CI = 1.557–8.641, p = 0.003) and the use of vasoactive drugs within 1 week (OR = 2.193, 95% CI = 1.033–4.658, p = 0.041) were independent risk factors for PIVH (sensitivity = 68.3%).The specificity was 81.3%, and the AUC was 0.792. Conclusion The incidence of PIVH in extremely low birth weight infants is relatively high, particularly within the first three days after birth. The use of vasoactive drugs and delayed removal of invasive ventilators may increase the risk.
Summary Background Increasing Helicobacter pylori resistance has led to decreases in treatment effectiveness. Aim To test the effectiveness of susceptibility‐guided therapy vs a locally highly effective empiric modified bismuth quadruple therapy for first‐line H pylori treatment in a region with high antimicrobial resistance . Methods We compared 14‐day susceptibility‐guided with empiric therapy using a multicentre superiority‐design trial, which randomised H pylori infected subjects 3:1 to (a) susceptibility‐guided therapies contained esomeprazole 20 mg and amoxicillin 1 g b.d. plus clarithromycin 500 mg, metronidazole 400 mg b.d., or levofloxacin 500 mg daily for susceptible infections or bismuth 220 mg b.d. and metronidazole 400 mg q.d.s. for triple‐resistant infections; (b) Empiric therapy contained esomeprazole 20 mg, bismuth 220 mg b.d., amoxicillin 1 g and metronidazole 400 mg t.d.s. Primary outcome was H pylori eradication. Results Between February 2017 and March 2018, 491 subjects were screened and 382 were randomised. Both the susceptibility‐guided and the empiric regimens were highly successful with per‐protocol eradication rates of 97.7% (250/256) vs 97.6% (81/83, P = 1.00) and intent‐to‐treat eradication rates of 91.6% (262/286) vs 85.4% (82/96, P = 0.12). Overall, susceptibility‐guided therapy was not superior to empiric therapy with 0.1% per‐protocol (95% CI −3.1% to 3.2%) and 6.2% intent‐to‐treat (−0.3% to 12.7%) eradication difference. Both approaches had high adherence and low adverse event rates. Conclusions Both susceptibility‐guided and empiric therapies provided excellent eradication rates. Clinically, the choice would hinge on availability of susceptibility testing and/or a locally highly effective empiric therapy.
Supramolecular chemistry addresses intermolecular forces and consequently promises great flexibility and precision. Biological systems are often the inspirations for supramolecular research. The G-quadruplex (G4) belongs to one of the most important secondary structures in nucleic acids. Until recently, the supramolecular manipulation of the G4 has not been reported. The present study is the first to disclose a supramolecular switch for the reversible control of human telomere G4s. Moreover, this supramolecular switch has been successfully used to manipulate an enzymatic reaction. Using various methods, we show that cucurbit[7]uril preferably locks and encapsulates the positively charged piperidines of Razo through supramolecular interactions. They can switch the conformations of the DNA inhibitor between a flexible state and the rigid G4 and are therefore responsible for the reversible control of the thrombin activity. Thus, our findings open a promising route and exhibit potential applications in future studies of chemical biology.
This experiment was conducted to evaluate the effects of different levels of tannic acid (TA) on growth performance, diarrhea rate, nutrient digestibility and intestinal health in weaned piglets. A total of 180 weaned piglets (Duroc × Landrace × Yorkshire, 24 d of age, initial average BW = 7.77 ± 0.17 kg) were allotted to 5 groups (6 pigs/pen and 6 replicates/group) in a randomized complete block design according to their gender and body weight. Piglets were fed a basal diet, or the basal diet supplemented with 0.05%, 0.1%, 0.2% or 0.4% TA for 28 d. The supplementary levels of TA in the diets were obtained by adding tannalbin containing 51% TA and 40.17% protein. The results showed that, compared with the CON group, dietary TA did not affect ADFI, ADG or F:G, and linearly reduced (P < 0.01) the diarrhea rate and diarrhea index of piglets. There were no significant effects on apparent total tract digestibility (ATTD) in the 0.05%, 0.1% and 0.2% TA groups, while negative effects (P < 0.05) on apparent digestibility of crude protein and gross energy were observed in the 0.4% TA group. In addition, the nutrient digestibility of dry matter, crude protein and gross energy linearly decreased (P < 0.01) with the increase of TA dosage. Supplementation of TA increased (P < 0.05) the villus height of the duodenum and jejunum, as well as increased (P < 0.05) catalase (CAT) activity in serum. Dietary TA improved (P < 0.05) the Bacillus counts in cecal digesta. Further, TA significantly improved (P < 0.05) Bacillus counts and reduced (P < 0.05) the Escherichia coli counts in colonic digesta. The concentration of acetic acid, propionic acid, butyric acid and isovaleric acid in cecal digesta were significantly increased (P < 0.05). The mRNA expression level of zonula occludens-1 (ZO-1), zonula occludens-2 (ZO-2), and claudin-2 (CLDN-2) in the jejunum were greater (P < 0.05) in TA supplemented groups. The study showed that, compared to the control, TA prevented post-weaning diarrhea and improved intestinal health of weaned piglets, and the appropriate level of TA supplementation would be from 0.1% to 0.2%.
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