[Safety and efficacy of different doses of tranexamic acid in posterior cervical laminectomy with lateral mass screw fixation and bone graft fusion].

Objective: To investigate the safety and efficacy of different doses of tranexamic acid (TXA) in posterior cervical laminectomy with lateral mass screw fixation and bone graft fusion by a prospective clinical study. Methods: The middle-aged and elderly patients with cervical spondylotic myelopathy, who were admitted between January 2020 and January 2022 and scheduled to undergo posterior cervical laminectomy with lateral mass screw fixation and bone graft fusion, were studied as the research subjects. Among them, 165 patients met the selection criteria and were included in the study. The patients were allocated into 3 groups ( n=55) by random double-blind lottery. Groups A and B were given intravenous infusion of TXA at 30 minutes before operation according to the standards of 15 and 30 mg/kg, respectively; and group C was given normal saline in the same way. There was no significant difference in gender, age, body mass index, and preoperative D-dimer, hemoglobin (Hb), and hematocrit (HCT) between groups ( P>0.05). The intraoperative bleeding, intraoperative blood transfusion, postoperative drainage volume, drainage days, and postoperative hospital stay were recorded. The Hb, HCT, and D-dimer were compared before operation and at 3 days after operation. Venous ultrasonography of the lower extremities was taken after operation to assess thrombosis; and the postoperative hematoma and epilepsy were also observed. Results: All operations were successfully completed, and the incisions healed by first intention. The differences in intraoperative bleeding volume, postoperative drainage volume, drainage days, and postoperative hospital stay between groups were significant ( P<0.05). The above indexes were significantly less in group B than in groups A and C. During operation, 14 patients in group A and 23 patients in group C were transfused, and no patient in group B had blood transfusions. Compared with groups A and C, the blood transfusion volume in group B significantly decreased ( P<0.05), and the difference between groups A and C was not significant ( P>0.05). There was no significant difference in the differences of D-dimer, Hb, and HCT before and after operation between groups ( P>0.05). At 5 days after operation, the venous ultrasonography of the lower extremities showed that the 2 cases of intermuscular venous thrombosis occurred in groups A, B, and C, respectively. No hematoma or epilepsy occurred after operation. Conclusion: The application of 15 and 30 mg/kg TXA in posterior cervical laminectomy with lateral mass screw fixation and bone graft fusion can reduce intraoperative bleeding and postoperative drainage volume, postoperative drainage days, and postoperative hospital stay. And application of 30 mg/kg TXA can reduce intraoperative blood transfusion, without increasing the risk of lower extremity venous thrombosis, hematoma, and epilepsy.

Microstructure and Thermal Deformation Behavior of Hot-Pressing Sintered Zr-6Al-0.1B Alloy.

Zr-6Al-0.1B alloy rich in Zr3Al phase is prepared by hot-pressing sintering. The thermal deformation behavior of sintered Zr-6Al-0.1B is analyzed by isothermal compression tests at deformation temperatures of 950, 1050, and 1150 °C with strain rates of 0.01, 0.1, and 1 s-1. The results indicate that at the early stage of thermal deformation, the stress increases rapidly with the increase of strain and then reaches the peak value. Subsequently, the stress decreases with the increase of strain under the softening effect. On the whole, the true stress-strain curve shifts to the high stress area with the increase of strain rate or the decrease of deformation temperature, so the sintered Zr-6Al-0.1B alloy belongs to the temperature and strain rate sensitive material. For the microstructure evolution of sintered Zr-6Al-0.1B during the isothermal compression, the high strain rate can improve the grain refinement. However, because sintered Zr-6Al-0.1B is a low plastic material, too high strain rate will exceed the deformation capacity of the material, resulting in an increase in defects. The increase of deformation temperature also contributes to grain refinement, but when the temperature is too high, due to the decomposition of Zr3Al phase, the deformation coordination of the material decreases, leading to the increase of the probability of the occurrence of defects. This study verified the feasibility of hot-pressing sintering to prepare Zr-6Al-0.1B alloy rich in Zr3Al phase and laid the foundation of "hot-pressing sintering + canning hot-extrusion" process of Zr-6Al-0.1B alloy components.

Phytase-Producing Rahnella aquatilis JZ-GX1 Promotes Seed Germination and Growth in Corn (Zea mays L.).

Phytase plays an important role in crop seed germination and plant growth. In order to fully understand the plant growth-promoting mechanism by Rahnella aquatilis JZ-GX1, the effect of this strain on germination of maize seeds was determined in vitro, and the colonization of maize root by R. aquatilis JZ-GX1 was observed by scanning electron microscope. Different inoculum concentrations and Phytate-related soil properties were applied to investigate the effect of R. aquatilis JZ-GX1 on the growth of maize seedlings. The results showed that R. aquatilis JZ-GX1 could effectively secrete indole acetic acid and had significantly promoted seed germination and root length of maize. A large number of R. aquatilis JZ-GX1 cells colonized on the root surface, root hair and the root interior of maize. When the inoculation concentration was 107 cfu/mL and the insoluble organophosphorus compound phytate existed in the soil, the net photosynthetic rate, chlorophyll content, phytase activity secreted by roots, total phosphorus concentration and biomass accumulation of maize seedlings were the highest. In contrast, no significant effect of inoculation was found when the total P content was low or when inorganic P was sufficient in the soil. R. aquatilis JZ-GX1 promotes the growth of maize directly by secreting IAA and indirectly by secreting phytase. This work provides beneficial information for the development and application of R. aquatilis JZ-GX1 as a microbial fertilizer in the future.

Excellent low-temperature NH3-SCR NO removal performance and enhanced H2O resistance by Ce addition over the Cu0.02Fe0.2CeyTi1-yOx (y = 0.1, 0.2, 0.3) catalysts.

In the present work, a serial of Cu0.02Fe0.2CeyTi1-yOx catalysts are prepared by sol-gel method and applied for NH3-SCR of NO, meanwhile Cu0.02Fe0.2Ce0.2Ti0.8Ox shows good low-temperature NH3-SCR performance with/without water and an outstanding water resistance. The bulk structure, redox ability, surface acidity and surface species of Cu0.02Fe0.2CeyTi1-yOx are measured and discussed by series of characterization in details to illuminate the reasons for the good low-temperature activity and water resistance. The Ce modification can tune the surface acidic distribution, improve the surface oxygen content and surface oxidation reduction cycle (Ce4+ + Fe2+ ↔ Ce3+ + Fe3+), which contribute the good activity. In addition, the effect of water on NH3-SCR performance over Cu0.02Fe0.2TiOx and Cu0.02Fe0·2Ce0·2Ti0.8Ox are investigated emphatically by in situ DRIFTS.

Expression Level of MiRNA-126 in Serum Exosomes of Allergic Asthma Patients and Lung Tissues of Asthmatic Mice.

BACKGROUND: To investigate MiRNA-126 amounts in serum exosomes from allergic asthma patients as well as lung tissues of asthmatic mice, evaluating the expression of its target gene DNMT1 in mouse specimens. METHODS: MiRNA-126 amounts in serum exosomes from asthmatic patients were detected by real-time PCR. The mouse model of allergic asthma was established by OVA-sensitization, and allergic symptoms were recorded; serum IL-4 and sIgE level evaluation (ELISA), broncho alveolar lavage fluid (BALF) cell count and H&E staining were performed to assess airway inflammation. MiRNA-126 and DNMT1 levels in the lung of asthmatic and control mice were detected by real-time PCR; DNMT1 protein levels were detected by immunoblot. RESULTS: MiRNA-126 amounts in peripheral blood exosomes from patients with allergic asthma were significantly higher than that of healthy volunteers (P<0.05). The frequencies of scratching of both sides of the nose and sneezing were elevated within 10 min of excitation in asthmatic rats compared with controls. Meanwhile, OVA-sIgE and IL-4 levels were significantly higher in asthmatic animals than controls (P<0.05). In the asthma group, narrowed bronchial lumen and thickened wall were observed, and bronchial and peripheral vessels showed overt inflammatory cell infiltration. Eosinophil, neutrophil and mast cell amounts in the BALF of asthmatic mice were significantly higher than control values. Furthermore, lung miRNA-126 expression in asthmatic mice was significantly higher than that of controls. Finally, DNMT1 mRNA and protein levels were significantly lower in asthmatic animals compared with controls (P < 0.01). CONCLUSION: MiRNA-126 is highly expressed in serum exosomes from allergic asthma patients and lung tissues of asthmatic mice, suggesting that it may be involved in the pathogenesis of bronchial asthma.

Hot Deformation Behavior of Q345 Steel and Its Application in Rapid Shear Connection.

The high-temperature deformation behavior of Q345 steel is detected by a Gleeble-3800 thermal simulator. The Arrhenius constitutive equation for high-temperature flow stress and the dynamic recrystallization model are constructed. With the secondary development technology, customized modifications are made on existing Deform-3D software. The constructed constitutive model and dynamic recrystallization model are embedded into Deform-3D to realize the secondary development of Deform-3D. The grain size and volume percentage distribution of dynamic recrystallization are obtained by simulating the shear connection process at high temperature and high speed. The results show that the constitutive equation and the dynamic recrystallization model constructed in this paper can be used to predict the evolution of the microstructure. The difference between the prediction results and the experimental data is about 3%. The accuracy of Arrhenius constitutive equation, dynamic recrystallization model and the feasibility of software secondary development are verified.

[The anatomy study of the frontal beak approach of Draf II b frontal sinusotomy].

OBJECTIVE: To investigate the possibility and anatomy landmark of the frontal beak approach of endoscopic frontal sinusotomy to the frontal sinus lesions. METHOD: (1)Twenty cases of frozen cadaveric head underwent spiral computed tomography scans. Then data were transferred into the Mimics image workstation to reorganize CT images in the coronal, sagittal, and axial planes. The anatomic parameters related to surgical approach points were measured, such as the distance between vertical plate of the middle turbinate and lamina papyracea and the thickness of the frontal beak. (2) 3D visual model of the frontal cell and the drainage way of the frontal sinus was produced with the application of Sinuses Trachea I software. (3)The endoscopic frontal sinus surgery were performed on 20 cases of subjects (objects)to find out the anatomy landmarks of the frontal beak approach, measure the parameters such as the distance between middle turbinate and lamina papyracea, and evaluate the potential surgical complications during operation. RESULT: (1)The frontal beak is a white bony arcs located at the attachment point of middle turbinate front inserted to the skull base. Its position was relatively constant, before frontal sinus above. (2)The distance between the middle turbinate vertical plate and lamina papyracea was (7. 61 ± 1. 34) mm. The thickness of the frontal beak in surgical approach was (3. 27 ± 0. 91) mm. (3) 3D visual structure of the frontal sinus and its ventilation pathway: the shape of unilateral frontal sinus looked like the cone, which was transited by the drainage pathway of the frontal sinus. The front part of the frontal sinus ostium is surrounded by the frontal beak. The upper part the frontal beak connected to the floor of the frontal sinus. (4) Frontal beak can be used as an landmark of frontal beak approach in the endoscopic frontal sinus surgery. But the lateral view of frontal sinus still was limited in the operation. CONCLUSION: The endoscopic frontal sinus surgery with the approach of the frontal beak is easy to operate and learn. In this area between the double "L", the operation is safe.