To enhance the catalytic activity of copper ferrite(CuFe_(2)O_(4))nanoparticle and promote its application as combustion catalyst,a low-cost silicon dioxide(SiO_(2))carrier was employed to construct a novel CuFe_(2)O_...To enhance the catalytic activity of copper ferrite(CuFe_(2)O_(4))nanoparticle and promote its application as combustion catalyst,a low-cost silicon dioxide(SiO_(2))carrier was employed to construct a novel CuFe_(2)O_(4)/SiO_(2)binary composites via solvothermal method.The phase structure,morphology and catalytic activity of CuFe_(2)O_(4)/SiO_(2)composites were studied firstly,and thermal decomposition,combustion and safety performance of ammonium perchlorate(AP)and 1,3,5-trinitroperhydro-1,3,5-triazine(RDX)with it affecting were then systematically analyzed.The results show that CuFe_(2)O_(4)/SiO_(2)composite can remarkably either advance the decomposition peak temperature of AP and RDX,or reduce the apparent activation energy at their main decomposition zone.Moreover,the flame propagation rate of RDX was promoted by about 2.73 times with SiO_(2)content of 3 wt%,and safety property of energetic component was also improved greatly,in which depressing the electrostatic discharge sensitivity of pure RDX by about 1.89 times.In addition,the effective range of SiO_(2)carrier content in the binary catalyst is found to be 3 to 5 wt%.Therefore,SiO_(2)opens a new insight on the design of combustion catalyst carrier and will promote the application of CuFe_(2)O_(4)catalyst in solid propellant.展开更多
Neuroprotection by ischemic preconditioning has been confirmed by many studies, but the precise mechanism remains unclear. In the present study, we performed cerebral ischemic preconditioning in rats by simulating a t...Neuroprotection by ischemic preconditioning has been confirmed by many studies, but the precise mechanism remains unclear. In the present study, we performed cerebral ischemic preconditioning in rats by simulating a transient ischemic attack twice(each a 20-minute occlusion of the middle cerebral artery) before inducing focal cerebral infarction(2 hour occlusion-reperfusion in the same artery). We also explored the mechanism underlying the neuroprotective effect of ischemic preconditioning. Seven days after occlusion-reperfusion, tetrazolium chloride staining and immunohistochemistry revealed that the infarct volume was significantly smaller in the group that underwent preconditioning than in the model group. Furthermore, vascular endothelial growth factor immunoreactivity was considerably greater in the hippocampal CA3 region of preconditioned rats than model rats. Our results suggest that the protective effects of ischemic preconditioning on focal cerebral infarction are associated with upregulation of vascular endothelial growth factor.展开更多
BACKGROUND Superficial CD34-positive fibroblastoma(SCPFT)is a newly discovered mesenchymal tumor characterized by high polymorphism,low mitotic rate,and diffuse CD34-positive reactions.AIM To further determine the cli...BACKGROUND Superficial CD34-positive fibroblastoma(SCPFT)is a newly discovered mesenchymal tumor characterized by high polymorphism,low mitotic rate,and diffuse CD34-positive reactions.AIM To further determine the clinicopathological features of SCPFT.METHODS We retrospectively analyzed the clinicopathological data,immunohistochemistry results,and differential diagnoses of four patients with SCPFT and performed a literature review.Relevant fusion genes were also detected.RESULTS The tumors were all located in the lower extremities and presented as slowgrowing painless masses located in the dermis and subcutaneous tissue.Microscopically,the tumors were composed of spindle-shaped to epithelioid cells with scattered abnormal and pleomorphic nuclei on a fibrous or fibromyxoid background.Necrosis was not found in the tumor tissues,and mitotic figures were rare.Immunohistochemically,the tumor cells were strongly positive for vimentin and CD34,and CKpan showed focal positivity in two tumors.All four patients were followed(13-57 mo,mean 35 mo),and one patient experienced local recurrence.CONCLUSION SCPFT is a newly discovered borderline mesenchymal tumor that can locally recur or even metastasize.Familiarity with its clinicopathological features will help avoid confusion with skin mesenchymal tumors with similar features.展开更多
Temperature curves reflect geothermal gradients and local temperature anomalies, thus providing a new understanding of the underground reservoir conditions. When encountering caverns or fractures and fissures during d...Temperature curves reflect geothermal gradients and local temperature anomalies, thus providing a new understanding of the underground reservoir conditions. When encountering caverns or fractures and fissures during drilling, lost circulation may occur and result in a change to the original formation temperature field, and in severe cases, even the conventional open hole well logging data cannot be obtained. This paper uses finite element analysis software COMSOL to establish a heat transfer model for the wellbore/reservoir formation system during drilling and shut-in in the presence of lost circulation, and a case study is made in a carbonate reservoir in the Tahe oilfield. On the basis of the above, we analyze the temperature distribution in the leakage zone, and the studies have shown that the leakage and petrophysical properties have an impact on the temperature of the wellbore and formation, hence we can estimate the reservoir permeability using the temperature data. In addition, the determination of the temperature recovery time after some drilling fluids have leaked into the formation will help in recognizing the subsurface temperature field of the carbonate formation correctly, thus enhancing production logging interpretation accuracy and improving the understanding of later measurements.展开更多
Classification of the Asian snake genera Lycodon and Oligodon has proven challenging. We conducted a molecular phylogenetic analysis to estimate the phylogenetic relationships in the genus of Lycodon and clarify the t...Classification of the Asian snake genera Lycodon and Oligodon has proven challenging. We conducted a molecular phylogenetic analysis to estimate the phylogenetic relationships in the genus of Lycodon and clarify the taxonomic status of Oligodon multizonatum using mitochondrial(cyt b, ND4) and nuclear(c-mos) genes. Phylogenetic trees estimated using Maximum Likelihood and Bayesian Inference indicated that O. multizonatum is actually a species of Lycodon. Comparing morphological data from O. multizonatum and its closest relatives also supported this conclusion. Our results imply that a thorough review of the evolutionary relationships in the genus of Lycodon is strong suggested.展开更多
BACKGROUND Peripheral regional block combined with general anesthesia might be a preferable anesthetic regimen for elderly patients undergoing total hip arthroplasty.AIM To investigate whether ultrasound-guided,direct...BACKGROUND Peripheral regional block combined with general anesthesia might be a preferable anesthetic regimen for elderly patients undergoing total hip arthroplasty.AIM To investigate whether ultrasound-guided,direct suprainguinal injection for fascia iliaca block accelerated recovery after general anesthesia and relieved postoperative pain after total hip arthroplasty.METHODS Patients who underwent total hip arthroplasty under general anesthesia in 2015 or 2019 at The Second Affiliated Hospital of Xuzhou Medical University were retrospectively analyzed.The patients were grouped based on whether preoperative suprainguinal fascia iliaca block was performed or not.The time to tracheal extubation and time spent in the post-anesthesia care unit(PACU),intraoperative remifentanil dosage,fentanyl consumption in the PACU,postoperative cumulative fentanyl consumption within 48 h after operation,visual analogue scale at rest and during movement on the first and second days after surgery,and adverse reactions were compared.RESULTS Thirty-one elderly patients who underwent total hip arthroplasty were included in the study(block group,n=16;no-block group,n=15).The visual analog scale scores at rest and during movement on the first and second days were significantly lower in the block group than in the no-block group(all P<0.05).Compared with the no-block group,the intraoperative remifentanil dosage was lower,the time to tracheal extubation and the time spent in the PACU were shorter in the block group(all P<0.01).Fentanyl consumption in the PACU and postoperative cumulative fentanyl consumption in 48 h after operation were lower in the block group(all P<0.01).The incidence of dizziness was higher in the no-block group than in the block group(P=0.037).CONCLUSION Ultrasound-guided,direct suprainguinal injection for fascia iliaca block led to faster recovery after general anesthesia and early postoperative pain relief in elderly patients undergoing total hip arthroplasty.展开更多
基金the National Nature Science Foundation of China(Grant Nos.21673178,22105160)the Natural Science Foundation of Shaanxi Province(Grant No.2023-JC-ZD-07)+1 种基金the Foundation of Key Laboratory of Defense Science and technology(Grant No.6142603032213)the Key Science and Technology Innovation Team of Shaanxi Province(Grant No.2022TD-33).
文摘To enhance the catalytic activity of copper ferrite(CuFe_(2)O_(4))nanoparticle and promote its application as combustion catalyst,a low-cost silicon dioxide(SiO_(2))carrier was employed to construct a novel CuFe_(2)O_(4)/SiO_(2)binary composites via solvothermal method.The phase structure,morphology and catalytic activity of CuFe_(2)O_(4)/SiO_(2)composites were studied firstly,and thermal decomposition,combustion and safety performance of ammonium perchlorate(AP)and 1,3,5-trinitroperhydro-1,3,5-triazine(RDX)with it affecting were then systematically analyzed.The results show that CuFe_(2)O_(4)/SiO_(2)composite can remarkably either advance the decomposition peak temperature of AP and RDX,or reduce the apparent activation energy at their main decomposition zone.Moreover,the flame propagation rate of RDX was promoted by about 2.73 times with SiO_(2)content of 3 wt%,and safety property of energetic component was also improved greatly,in which depressing the electrostatic discharge sensitivity of pure RDX by about 1.89 times.In addition,the effective range of SiO_(2)carrier content in the binary catalyst is found to be 3 to 5 wt%.Therefore,SiO_(2)opens a new insight on the design of combustion catalyst carrier and will promote the application of CuFe_(2)O_(4)catalyst in solid propellant.
文摘Neuroprotection by ischemic preconditioning has been confirmed by many studies, but the precise mechanism remains unclear. In the present study, we performed cerebral ischemic preconditioning in rats by simulating a transient ischemic attack twice(each a 20-minute occlusion of the middle cerebral artery) before inducing focal cerebral infarction(2 hour occlusion-reperfusion in the same artery). We also explored the mechanism underlying the neuroprotective effect of ischemic preconditioning. Seven days after occlusion-reperfusion, tetrazolium chloride staining and immunohistochemistry revealed that the infarct volume was significantly smaller in the group that underwent preconditioning than in the model group. Furthermore, vascular endothelial growth factor immunoreactivity was considerably greater in the hippocampal CA3 region of preconditioned rats than model rats. Our results suggest that the protective effects of ischemic preconditioning on focal cerebral infarction are associated with upregulation of vascular endothelial growth factor.
基金This work was supported by grants from the National Natural Science Foundation of China （No. 30225037, 30400538, 30471991,30570731）；the 973 Program of China （No. 2006CB503909, 2004CB518603）；the ＂111＂ Project, and the Natural Science Foundation of Jiangsu Province （No. BK2004082, BK2006714）.
基金Key Projects of Natural Science Research in Colleges and University of Anhui Province,No.2017A236.
文摘BACKGROUND Superficial CD34-positive fibroblastoma(SCPFT)is a newly discovered mesenchymal tumor characterized by high polymorphism,low mitotic rate,and diffuse CD34-positive reactions.AIM To further determine the clinicopathological features of SCPFT.METHODS We retrospectively analyzed the clinicopathological data,immunohistochemistry results,and differential diagnoses of four patients with SCPFT and performed a literature review.Relevant fusion genes were also detected.RESULTS The tumors were all located in the lower extremities and presented as slowgrowing painless masses located in the dermis and subcutaneous tissue.Microscopically,the tumors were composed of spindle-shaped to epithelioid cells with scattered abnormal and pleomorphic nuclei on a fibrous or fibromyxoid background.Necrosis was not found in the tumor tissues,and mitotic figures were rare.Immunohistochemically,the tumor cells were strongly positive for vimentin and CD34,and CKpan showed focal positivity in two tumors.All four patients were followed(13-57 mo,mean 35 mo),and one patient experienced local recurrence.CONCLUSION SCPFT is a newly discovered borderline mesenchymal tumor that can locally recur or even metastasize.Familiarity with its clinicopathological features will help avoid confusion with skin mesenchymal tumors with similar features.
文摘Temperature curves reflect geothermal gradients and local temperature anomalies, thus providing a new understanding of the underground reservoir conditions. When encountering caverns or fractures and fissures during drilling, lost circulation may occur and result in a change to the original formation temperature field, and in severe cases, even the conventional open hole well logging data cannot be obtained. This paper uses finite element analysis software COMSOL to establish a heat transfer model for the wellbore/reservoir formation system during drilling and shut-in in the presence of lost circulation, and a case study is made in a carbonate reservoir in the Tahe oilfield. On the basis of the above, we analyze the temperature distribution in the leakage zone, and the studies have shown that the leakage and petrophysical properties have an impact on the temperature of the wellbore and formation, hence we can estimate the reservoir permeability using the temperature data. In addition, the determination of the temperature recovery time after some drilling fluids have leaked into the formation will help in recognizing the subsurface temperature field of the carbonate formation correctly, thus enhancing production logging interpretation accuracy and improving the understanding of later measurements.
基金supported by the National Natural Science Foundation of China (NSFC 31071913)
文摘Classification of the Asian snake genera Lycodon and Oligodon has proven challenging. We conducted a molecular phylogenetic analysis to estimate the phylogenetic relationships in the genus of Lycodon and clarify the taxonomic status of Oligodon multizonatum using mitochondrial(cyt b, ND4) and nuclear(c-mos) genes. Phylogenetic trees estimated using Maximum Likelihood and Bayesian Inference indicated that O. multizonatum is actually a species of Lycodon. Comparing morphological data from O. multizonatum and its closest relatives also supported this conclusion. Our results imply that a thorough review of the evolutionary relationships in the genus of Lycodon is strong suggested.
文摘BACKGROUND Peripheral regional block combined with general anesthesia might be a preferable anesthetic regimen for elderly patients undergoing total hip arthroplasty.AIM To investigate whether ultrasound-guided,direct suprainguinal injection for fascia iliaca block accelerated recovery after general anesthesia and relieved postoperative pain after total hip arthroplasty.METHODS Patients who underwent total hip arthroplasty under general anesthesia in 2015 or 2019 at The Second Affiliated Hospital of Xuzhou Medical University were retrospectively analyzed.The patients were grouped based on whether preoperative suprainguinal fascia iliaca block was performed or not.The time to tracheal extubation and time spent in the post-anesthesia care unit(PACU),intraoperative remifentanil dosage,fentanyl consumption in the PACU,postoperative cumulative fentanyl consumption within 48 h after operation,visual analogue scale at rest and during movement on the first and second days after surgery,and adverse reactions were compared.RESULTS Thirty-one elderly patients who underwent total hip arthroplasty were included in the study(block group,n=16;no-block group,n=15).The visual analog scale scores at rest and during movement on the first and second days were significantly lower in the block group than in the no-block group(all P<0.05).Compared with the no-block group,the intraoperative remifentanil dosage was lower,the time to tracheal extubation and the time spent in the PACU were shorter in the block group(all P<0.01).Fentanyl consumption in the PACU and postoperative cumulative fentanyl consumption in 48 h after operation were lower in the block group(all P<0.01).The incidence of dizziness was higher in the no-block group than in the block group(P=0.037).CONCLUSION Ultrasound-guided,direct suprainguinal injection for fascia iliaca block led to faster recovery after general anesthesia and early postoperative pain relief in elderly patients undergoing total hip arthroplasty.
