Effect of dexmedetomidine on intestinal barrier function in mice with traumatic brain injury and the role of Nrf2/HO-1 signaling pathway / 中华麻醉学杂志

Objective:To evaluate the effect of dexmedetomidine on intestinal barrier function in mice with traumatic brain injury (TBI) and the role of nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway.Methods:Thirty ICR male wild-type (WT) and 30 Nrf2 knockout (Nrf2-KO) mice, aged 6-8 weeks, weighing 20-25 g, were divided into 3 groups ( n=10 each) using a random number table method: control group (group C), TBI group (group T) and TBI+ dexmedetomidine group (group T+ D). A 100 g of stainless steel impactor was used to produce a free fall acceleration strike on the head from 12 cm height in anesthetized animals.Dexmedetomidine 30 μg/kg was intraperitoneally injected at 30 min before TBI in group T+ D, while the equal volume of normal saline was given instead in C and TBI groups.The mouse bladder was emptied at 18 h after TBI, the test solution 200 μl containing 13.3 mg lactulose and 10.1 mg mannitol was given via a gastric tube.Urine was collected at 24 h after TBI, and the ratio of lactulose to mannitol was measured to estimate the intestinal barrier permeability.Blood samples were collected from heart to measure the concentration of lipopolysaccharide in plasma.Then the mice were sacrificed, and the tissues of ileum were collected to detect the contents of tumor necrosis factor-alpha(TNF-α), interleukin-1beta(IL-1β), IL-6 and 8-iso-prostaglandin F 2α (8-iso-PGF 2α) (by enzyme-linked immunosorbent assay), contents of superoxide dismutase (SOD) and catalase (CAT) (by hydroxylamine method and ammonium molybdate colorimetric method, respectively), content of malondialdehvde (MDA) (by thibabituric acid method), and expression of Nrf2 and HO-1 (by Western blot). Results:For WT mice Compared with group C, the intestinal barrier permeability, concentration of LPS in plasma, and contents of TNF-α, IL-1β, IL-6, MDA and 8-iso-PGF 2α were significantly increased, the activities of intestinal CAT and SOD were decreased, and the expression of Nrf2 and HO-1 was up-regulated in T and T+ D groups ( P<0.05). Compared with group T, the intestinal barrier permeability, concentration of LPS in plasma, and contents of TNF-α, IL-1β, IL-6, MDA and 8-iso-PGF 2α were significantly decreased, the activities of intestinal CAT and SOD were increased, and the expression of Nrf2 and HO-1 was up-regulated in group T+ D ( P<0.05). For Nrf2-KO mice Compared with group C, the intestinal barrier permeability, concentration of LPS in plasma, and contents of TNF-α, IL-1β, IL-6, MDA and 8-iso-PGF 2α were significantly increased, and no significant change was found in the activities of intestinal CAT and SOD in T and T+ D groups( P>0.05). There was no significant difference in the expression of HO-1 among the three groups ( P>0.05). Conclusion:Dexmedetomidine can improve the intestinal barrier dysfunction in mice with TBI, and the mechanism is related to activating Nrf2/HO-1 signaling pathway.

Disparity of minnesota multiphasic personality inventory between positions and its relationship with job burnout in a general hospital / 中华劳动卫生职业病杂志

Objective@#To explore the difference of personality characteristics of physicians, nurses, medical skills and administrative personnel in a general hospital and its influence on job burnout.@*Methods@#Employee entered the hospital before 2018 were enrolled in the current study and the position was classified as physicians, nurses, medical technician and administrative staff. Minnesota Multiphasic Personality Inventory (MMPI) was completed by the employee at the time of entering the hospital. Status of job burnout was assessed in 2018 using the Maslach Burnout Inventory-General Survey (MBI-GS) .@*Results@#Physicians have a higher rate of paranoia than others (P<0.05) , and administrative staff and medical technician have a slightly higher score than the other two categories of people (P<0.05) , and administrators lie at a higher rate than others (P<0.05) . Further analysis found that personality traits did not have a significant association with job burnout at the time of entry.@*Conclusion@#The administrative and medical staff is slightly more irritable, the administrative staff lying slightly higher score, the staff after the entry of job burnout is not affected by the personality characteristics of the onboarding.

Synthesis, tribological and hydrolysis stability study of novel benzotriazole borate derivative.

Benzotriazole and borate derivatives have long been used as multifunctional additives to lubricants. A novel, environmentally friendly additive borate ester (NHB), which contains boron, ethanolamine, and benzotriazole groups in one molecule, was synthesized by a multi-step reaction, and its tribological properties in rapeseed oil (RSO) were investigated by a four-ball tribometer. The hydrolysis stability of the additive was investigated by half-time and open observation methods, and the mechanism of hydrolysis stability was discussed through Gaussian calculation. The novel compound NHB showed excellent performance under extreme pressure, against wearing, and in reducing friction, and its hydrolysis time is more than 1,220 times, which is better than that of triethyl borate. The mass ratio of NHB is bigger than that of the mixed liquid of triethyl borate and ethanolamine. The lone electron of amino N atoms forms a coordination effect with the B atom to compensate for the shortage of electrons in the B atom and to improve the hydrolysis stability of NHB. The surface morphology and the traces of different elements in the tribofilms formed with 1.0 wt.% NHB in were detected with scanning electron microscopy(SEM), energy dispersive X-ray spectroscopy (EDX)and X-ray photoelectron spectroscopy(XPS). The results shown that the additive caused a tribochemical reaction with the steel ball surface during the lubricating process. A mixed boundary lubrication film that contains organic nitrogen and inorganic salts, such as BN, B2O3, FeOx, Fe-O-B, and FeB, was also formed, and the formation of the lubricating film improved the tribological properties of the base oil.

Tribological and antioxidation synergistic effect study of sulfonate-modified nano calcium carbonate.

A middle base number sulphonate-modified nano calcium carbonate (SMC) with an average size of 35 nm was synthesized, and its tribological and antioxidation synergistic behaviors with ashless antioxidant N-phenyl-α-naphthylamine (T531) in hydrogenated oil (5Cst) were evaluated. The results demonstrate that adding this synthesized additive even at a low amount (<2.0 wt.%) can evidently improve its load-carrying capacity by 1.5 times and enhance its antiwear performance; in addition, the friction-reducing effect of additive in the high load was better than that in low load. The SMC have a good synergistic antioxidation effect with T531, which verifies the nano calcium carbonate compound was a kind of multifunctional and high-performance additive. The chemical composition of the rubbing surface which formed on the boundary film was analyzed by using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results indicating that the excellent antiwear and load-carrying performance could be attributed to the forming of boundary lubrication film which composed of calcium carbonate, oxides, ferrites, sulphide and FeSO4, and so on. Its ability to increase oxidation free energy of base oil is the main reason for increasing its antioxidant collaboration property with ashless antioxidant T531.

Study of the volatilization inhibitor for formalin / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To find an inhibitor to reduce the volatilization of formalin.</p><p><b>METHOD</b>The saturated solution of sodium hydrosulphite (SHS) was sprayed on the surface of the anatomy specimens, then the concentration of formaldehyde in the air was tested.</p><p><b>RESULTS</b>The concentration of formaldehyde in the air of SHS sprayed group [(3.10 +/- 1.22) mg/m3] was significantly lower than that of the control group [(8.36 +/- 4.11) mg/m3, P < 0.01].</p><p><b>CONCLUSION</b>SHS may be a volatilization inhibitor for formalin, which could reduce the concentration of formaldehyde in the air.</p>