Search

OBJECTIVE: To investigate the effects of parecoxib on postoperative cognitive dysfunction, and serum levels of neuron-specific enolase (NSE) and S100β protein (S100β) in elderly patients undergoing surgery. PATIENTS AND METHODS: The retrospective cohort study method was used to collect the clinical data of 94 elderly patients who underwent elective orthopedic and general anesthesia surgery in our hospital from September 2020 to February 2022. 94 patients were divided into the control group (47 cases) and the study group (47 cases), according to different intervention methods. In the study group, 40 mg of parecoxib was injected intravenously into patients 30 min before the induction of anesthesia, and the patients in the control group were given the same dose of normal saline intravenously before the operation. The basic clinical data of the patients were collected. The levels of the indexes before operation and 6 hours after operation were compared between the two groups, including the Montreal Cognitive Scale (MoCA) score, inflammatory factor indicators [tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), interleukin-10 (IL-10), interleukin-1β (IL-1β), monocyte chemokine-1 (MCP-1), and inducible nitric oxide synthase (iNOS)], serum cortisol (CORT), beta-amyloid (β-AP), adiponectin (ADP), NSE, and S100β. RESULTS: No significant differences in the preoperative MoCA score, TNF-α, IL-6, CRP, IL-10, IL-1β, MCP-1, iNOS, CORT, β-AP, ADP, NSE, and S100β levels were observed between the two groups (p>0.05). The postoperative MoCA score in the study group was significantly higher than that in the control group (p<0.05). The postoperative levels of TNF-α, IL-6, CRP and IL-1β in the study group were significantly lower than those in the control group (p<0.05), and the postoperative levels of IL-10, MCP-1 and iNOS in the study group were significantly higher than those in the control group (p<0.05). CONCLUSIONS: Parecoxib can notably inhibit the levels of postoperative inflammatory cytokines, improve neurological dysfunction, and reduce the occurrence of postoperative cognitive dysfunction in patients. The contents of serum NSE and S100β have potential value in the diagnosis of postoperative cognitive dysfunction in elderly patients. [ABSTRACT FROM AUTHOR]

Catalysis by metal cation in olefin polymerization in the gas phase was investigated using ethylene and propylene reactions catalyzed by Ti+. The ion-molecule reactions were observed using the selected ion drift tube with laser vaporization source apparatus. A high dehydrogenation reactivity of bare Ti+ toward ethylene and propylene was observed but it can be affected by the nature of ligands coordinated to Ti+. The mechanisms of the occurence of a Ti+-induced polymerization were analyzed.

Titanium–carbon clusters are investigated by collision induced dissociation (CID) using our newly designed triple quadrupole mass spectrometer coupled with a laser vaporization source. Their fragmentation patterns are determined under various collision conditions. It is observed that the Met–Car Ti8C+12 mainly loses a neutral metal atom in the primary dissociation step and several metal atoms in sequential dissociation processes. The dissociation threshold of the Met–Car Ti8C+12 is estimated to be about 9 eV. In addition, several of the larger TixC+y cluster ions, including those containing nine or ten metal atoms, are found to fragment directly to Ti8C+12 during single step dissociation. Product channels for dissociation of Ti9C+12 establishes the ionization potential for Ti8C12 to be equal to, or less than the IP of the titanium atom. [ABSTRACT FROM AUTHOR]

The chemistry and kinetics of size-selected Co+n cluster-ion (n=2–8) reactions with CO are studied using a selected ion drift tube affixed with a laser vaporization source operated under well-defined thermal conditions. All reactions studied in the present work are found to be association reactions. Their absolute rate constants, which are determined quantitatively, are found to have a strong dependence on cluster size. Similar to the cases of reactions with many other reactants such as H2 and CH4, Co+4 and Co+5 display a higher reactivity toward the CO molecule than do clusters of neighboring size. The multiple-collision conditions employed in the present work have enabled a determination of the maximum coordination number of CO molecules bound onto each Co+n cluster. It is found that the tetramer tends to bond 12 CO molecules, the pentamer 14 CO, hexamer 16 CO, and so on. The results are interpreted in terms of Lauher’s calculation and the polyhedral skeletal electron pair theory. All the measured maximum coordination numbers correlate extremely well with the predictions of these theories, except for the trimer where the measured number is one CO less than the predicted value. The good agreement between experiment and theory enables one to gain some insight into the geometric structure of the clusters. Based on the present findings, the cobalt tetramer cation is interpreted to have a tetrahedral structure, the pentamer a trigonal bipyramid, and the hexamer an octahedral structure. Other cluster structures are also discussed. [ABSTRACT FROM AUTHOR]

During the course of investigating dehydrogenation reactions induced by transition metals, we find that using a carrier gas containing hydrocarbons and ammonia instead of pure helium, in conjunction with a laser vaporization device, enables the facile production of metal–carbon and metal–nitrogen clusters in both the neutral and ionic forms. With only a change in the nature of the carrier gas, a variety of new classes of clusters can be produced. [ABSTRACT FROM AUTHOR]

Continuous wave dual-wavelength lasers at 1342 and 1525 nm are developed by using separate Nd:YVO 4 and YVO 4 crystals to form compactly coupled cavities for fundamental and Raman waves, respectively. The design of the coupled cavity not only reduces the thermal lensing effect in the Nd:YVO 4 crystal, but also improves the stimulated Raman scattering (SRS) efficiency in the undoped YVO 4 crystal. In addition, the Raman crystal is coated to form a highly reflective mirror to minimize cavity losses. By using a plano-concave cavity with a pump power of 40 W, the output powers of the fundamental and Raman waves are 470 mW and 310 mW, respectively. Changed to a concave cavity, the output powers of fundamental and Raman waves are 220 mW and 510 mW, respectively. Basis on the dual-wavelength operation, the maximum output power at 714 nm can reach 2.0 W via the sum frequency generation. A light source at 714 nm can be used for laser spectroscopy of atomic and ionic radium isotopes.

Aim: To investigate the effect of over-expression of Bcl-2 protein on Trail protein-induced apoptosis in human hepatoma cells, and the cytotoxicity of Trail protein on human hepatoma cells in vitro and in vivo., Methods: The Trail gene was cloned and expressed in E coli. The cytotoxicity of the recombinant Trail protein was assayed on human hepatoma cells in vitro and in vivo. The cell viability was assessed by trypan blue exclusion. The stable human hepatoma cells clone in which Bcl-2 protein over-expressed was established by transfecting eukaryotic expression plasmid pcDNA3-Bcl-2 into BEL-7404 human hepatoma cells, and was selected with G418 400 mg/L., Results: The recombinant Trail protein actively killed human hepatoma cells tested in this study such as BEL-7404, BEL-7402, and SMMC-7721. Over-expression of Bcl-2 protein could inhibit apoptosis induced by Trail in BEL-7404 human hepatoma cells in vitro. It was obvious that the purified recombinant Trail protein could inhibit tumor formation of BEL-7404 human hepatoma cells in nude mice., Conclusion: The recombinant Trail protein could kill human hepatoma cells in vitro and in vivo. Over-expression of Bcl-2 protein could inhibit Trail-induced apoptosis in BEL-7404 human hepatoma cells. The results suggested that Trail might be a potential agent for the liver cancer therapy.