The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of den...The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of dendritic solidification structures.Combining scanning electron microscopy and energy-dispersive scanning analysis and ANSYS simulation,the high-precision image processing software Mimics Research was utilized to conduct the extraction of dendritic morphologies.Reverse engineering software NX Imageware was employed for the 3D reconstruction of two-dimensional dendritic morphologies,restoring the dendritic characteristics in three-dimensional space.The results demonstrate that in a two-dimensional plane,dendrites connect with each other to form irregularly shaped“ring-like”structures.These dendrites have a thickness greater than 0.1 mm along the Z-axis direction,leading to the envelopment of molten steel by dendrites in a 3D space of at least 0.1 mm.This results in obstructed flow,confirming the“bridging”of dendrites in three-dimensional space,resulting in a tendency for central segregation.Dense and dispersed tiny dendrites,under the influence of heat flow direction,interconnect and continuously grow,gradually forming primary and secondary dendrites in three-dimensional space.After the completion of dendritic solidification and growth,these microdendrites appear dense and dispersed on the two-dimensional plane,providing the nuclei for the formation of new dendrites.When reduction occurs at a solid fraction of 0.46,there is a noticeable decrease in dendritic spacing,resulting in improved central segregation.展开更多
BACKGROUND Congenital cytomegalovirus(CMV)infection represents a significant public health concern as the most prevalent viral infection in newborns,potentially leading to severe neurological and developmental complic...BACKGROUND Congenital cytomegalovirus(CMV)infection represents a significant public health concern as the most prevalent viral infection in newborns,potentially leading to severe neurological and developmental complications.The majority of cases are asymptomatic and remain undetected during pregnancy due to the absence of effective screening methods.CASE SUMMARY A 27-year-old primigravida presented for early pregnancy ultrasound,which revealed an atypical finding:A normal anechoic thalamus appearing hyperechoic on the mid-sagittal view of the fetal head.Subsequent ultrasound examinations during mid and late gestation demonstrated classic intracranial features sug-gestive of congenital CMV infection.Chromosomal karyotyping and microarray analysis of the fetus yielded no significant abnormalities.Following compre-hensive prenatal counseling regarding potential adverse fetal outcomes,the patient elected to continue her pregnancy.She ultimately underwent cesarean delivery at 42 weeks gestation at another facility,resulting in the birth of a female neonate.At five months of age,the infant presented with epilepsy and significant growth and developmental delays.CONCLUSION Congenital CMV infection occurs during the first trimester may manifest as hyperechoic thalamus which can be revealed by ultrasound in the mid-saggital view of the fetal head.Future research should investigate the correlation between echogenic thalamus and developmental outcomes,as well as explore early sc-reening techniques for suspected congenital CMV infection cases.展开更多
Determining the minimal distance between the target state and the convex combination of given states is a fundamental problem in quantum resource theory,offering critical guidance for experimental implementations.In t...Determining the minimal distance between the target state and the convex combination of given states is a fundamental problem in quantum resource theory,offering critical guidance for experimental implementations.In this paper,we embark on an in-depth exploration of the use of a quantum state prepared by the convex combination of given qubit states to optimally approximate the l_(1)-norm of coherence of the target quantum state,striving to make the prepared state and the target state as similar as possible.Here,we present the analytical solution for the optimal distance for any N given quantum states.We find that the optimal approximation problem for any N>4 quantum states can be transformed into an optimal approximation problem for no more than four quantum states,which not only significantly streamlines the problem but also proves advantageous for laboratories in terms of material conservation.Ultimately,a one-to-one comparison between the analytical and numerical solutions verifies the effectiveness of our approach.展开更多
目的比较靶控输注瑞芬太尼和舒芬太尼对老年患者行腹腔镜胃癌根治术麻醉恢复的质量。方法选取2016年9月-2018年12月该院腹腔镜胃癌根治术患者84例,随机分为舒芬太尼组(n=42)和瑞芬太尼组(n=42)。两组患者应用靶控输注舒芬太尼和瑞芬太...目的比较靶控输注瑞芬太尼和舒芬太尼对老年患者行腹腔镜胃癌根治术麻醉恢复的质量。方法选取2016年9月-2018年12月该院腹腔镜胃癌根治术患者84例,随机分为舒芬太尼组(n=42)和瑞芬太尼组(n=42)。两组患者应用靶控输注舒芬太尼和瑞芬太尼为基础的麻醉。记录并比较两组患者唤醒时间、拔管时间、定向力恢复时间、生命体征、应激反应、T细胞亚群分布及不良反应发生率。结果两组患者定向力恢复时间差异无统计学意义(P>0.05)。舒芬太尼组的清醒和拔管时间明显短于瑞芬太尼组,差异均有统计学意义(P<0.05)。舒芬太尼组麻醉结束、麻醉诱导后和麻醉前的心率(HR)、平均动脉压(MAP)和脉搏血氧饱和度(SpO2)比较,差异均无统计学意义(P>0.05),而瑞芬太尼组麻醉结束、麻醉诱导后和麻醉前的HR、MAP和SpO2比较,差异均有统计学意义(P<0.05)。舒芬太尼组在麻醉后、麻醉结束、麻醉结束24 h和麻醉结束72 h 4个时间点,血葡萄糖(GLU)、皮质醇(Cor)、白细胞介素-6(IL-6)和C反应蛋白(CRP)的浓度均明显低于瑞芬太尼组,CD3^+、CD4^+和CD8^+及CD4+/CD8^+明显高于瑞芬太尼组,瑞芬太尼组麻醉不良反应发生率明显高于舒芬太尼组,差异有统计学意义(P<0.05)。结论对于接受腹腔镜胃癌根治术的老年患者,靶控输注舒芬太尼为基础的麻醉具有麻醉过程平稳、应激反应小、抑制细胞免疫轻和不良反应少等优点,值得临床推广。展开更多
To understand the characteristic of circulation flow rate in 250-t RH-TOP vacuum refining process, the 1：4 water model test was established through the bubble behavior and gas holdup in the up-leg to investigate the ...To understand the characteristic of circulation flow rate in 250-t RH-TOP vacuum refining process, the 1：4 water model test was established through the bubble behavior and gas holdup in the up-leg to investigate the effects of different processes and equipment parame- ters on the RH circulation flow rate. With the increases of lifting gas flow rate, liffing bubble travel, and the internal diameter of the up-leg, and the decrease of nozzle diameter, the work done by bubble floatage and the circulation flow rate increase. The expression of circulation flow rate was derived fi＂om the regression analysis of experiment data. Meanwhile, the influences of vacuum chamber pressure and nozzle blockage situation on the circulation flow rate were discussed in detail by the bubble behavior and gas holdup in the up-leg. It is necessary to maintain a certain vacuum chamber liquid level in the molten steel circulation flow. Compared with a nozzle with symmetrical blockage in the up-leg, when a nozzle with non-symmetrical blockage is applied, the lifting gas distribution is non-uniform, causing a great effect on the molten steel circulation flow and making the circulation flow drop largely.展开更多
Heavy oil is characterized by high viscosity.High viscosity makes it challenging to recover and transport.HZSM-5,MoO_(3)/HZSM-5,ZrO_(2)/HZSM-5 and MoO_(3)–ZrO_(2)/HZSM-5 catalysts were developed to promote in situ de...Heavy oil is characterized by high viscosity.High viscosity makes it challenging to recover and transport.HZSM-5,MoO_(3)/HZSM-5,ZrO_(2)/HZSM-5 and MoO_(3)–ZrO_(2)/HZSM-5 catalysts were developed to promote in situ desulfurization and viscosity reduction of heavy oil.The physical and chemical properties of catalysts were characterized by XPS,XRD,TEM,NH3-TPD,etc.The effects of temperature,catalyst type and addition amount on viscosity and composition of heavy oil were evaluated.The results showed that the presence of MoO_(3)–ZrO_(2)/HZSM-5 nanoparticles during aquathermolysis could improve the oil quality by reducing the heavy fractions.It reduced viscosity by 82.56%after the reaction at 280℃ and catalyst addition of 1 wt%.The contents of resins and asphaltic in the oil samples were 5.69%lower than that in the crude oil.Sulfur content decreased from 1.45%to 1.03%.The concentration of H2S produced by the reaction was 2225 ppm.The contents of sulfur-containing functional groups sulfoxide and sulfone sulfur in the oil samples decreased by 19.92%after the catalytic reaction.The content of stable thiophene sulfur increased by 5.71%.This study provided a basis for understanding the mechanism of heavy oil desulfurization and viscosity reduction.展开更多
Hydrodesulfurization(HDS)reaction can significantly reduce the viscosity and sulfur content of heavy oil,while the HDS reaction mechanism of tetrahydrothiophene as the main sulfide in heavy oil is still unclear.The HD...Hydrodesulfurization(HDS)reaction can significantly reduce the viscosity and sulfur content of heavy oil,while the HDS reaction mechanism of tetrahydrothiophene as the main sulfide in heavy oil is still unclear.The HDS experiment of tetrahydrothiophene catalyzed by nickel phosphide(Ni_(2)P)is carried out at 200-300°C.The results indicate that the H_(2)S production under the catalysis of Ni_(2)P increases obviously within 200-250°C.The main gas products of HDS reaction are butane,butene and H_(2)S.Meanwhile,the mechanism of tetrahydrothiophene catalyzed by Ni_(2)P is analyzed based on Density Functional Theory(DFT).It is revealed that the adsorption model is most stable when tetrahydrothiophene is vertically adsorbed on the V-Ni-Hcp1 site of Ni_(2)P(001).The C-S bond is elongated and the C-C bond is shortened after adsorption.Hydrogenation(HYD)is the most possible reaction route of tetrahydrothiophene on Ni_(2)P(001)surface.There are two routes with the lowest activation energy,which are C_(4)H_(8)S→C_(4)H_(8)SH^(*)→C_(4)H_(9)SH^(*)→C_(4)H_(10)+H_(2)S and C_(4)H_(8)S→C_(4)H9S^(*)→C_(4)H_(9)^(*)+SH^(*)→C_(4)H_(10)+H_(2)S.Butane and H_(2)S are produced in the reaction,corresponding to the experimental results.This study provides a basis for understanding of the HDS mechanism of tetrahydrothiophene catalyzed by Ni_(2)P.展开更多
With the swift advancement of renewable energy and escalating demands for energy storage,potassium-ion batteries(PIBs)are increasingly recognized as a potent energy storage techn ology.Various carbon anode materials h...With the swift advancement of renewable energy and escalating demands for energy storage,potassium-ion batteries(PIBs)are increasingly recognized as a potent energy storage techn ology.Various carbon anode materials have been utilized for PIBs anodes owing to their superior K^(+)storage capacity,outstanding cycling performance,elevated capacity,and cost-effectiveness.Therefore,it is imperative to explore and improve carbon anode materials.This review meticulously encapsulates the recent scholarly advancements in carbon anode materials for PIBs.It elucidates the operational mechanisms of carbon anode for PIBs,provides a synopsis of diverse carbon materials,and deliberates on the prevalent challenges,including cycling stability and potassium-ion diffusion rates.Although soft and hard carbon augmented potassiumion capacities,the expansive surface areas coupled with the large ionic radius of K^(+)pose substantial challenges to their structural design and optimization.Consequently,this review outlines strategic approaches to the design of carbon materials for excellent potassium storage performance,including the expansion of interlayer spacing,modification of morphology,heteroatom doping,structural defect regulation,incorporation of porous structures,and development of carbon-carbon composites.Finally,the challenges and prospective solutions of carbon anode materials for PIBs with superior energy density and cycling stability were proposed,providing a reasonable guidance for regulation design of carbon materials.展开更多
To reveal the formation mechanism and main influencing factors of C-segregation in high carbon steel under different solidification rates(40,80,160,200 and 320μm·s^(-1)),the enrichment characteristics of carbon ...To reveal the formation mechanism and main influencing factors of C-segregation in high carbon steel under different solidification rates(40,80,160,200 and 320μm·s^(-1)),the enrichment characteristics of carbon atoms in the solid-liquid zone of Fe-0.61%C steel were studied using a zone melting liquid metal cooling apparatus and electron probe microanalysis.The relationships among micro-segregation of carbon atoms,solid-liquid interface morphology and solidification rate were fully discussed.The results show that large dendrite spacing and a slow-moving dendritic interface create less resistance and more time for the migration of interdendritic carbon atoms to liquid zone.This results in the continuous enrichment of carbon atoms in liquid zone,further expands the solid-liquid temperature range,prolongs the solidification time of molten steel,and causes the formation of carbon micro-segregation at the solidification end as the solidification rate is 40μm·s^(-1).Conversely,abundant and elongated secondary dendrite arms with small spacing seriously impede the diffusion of interdendritic carbon-rich molten steel to liquid zone.As a result,there is only obvious dendrite segregation,but little difference in the carbon content along the solidification direction as solidification rate exceeds 200μm·s^(-1).展开更多
BACKGROUND Sport help promote healthy physical and mental development of high school students.To date,there have been few studies on the effect of sport on school adaptability,resilience and cell phone addiction tende...BACKGROUND Sport help promote healthy physical and mental development of high school students.To date,there have been few studies on the effect of sport on school adaptability,resilience and cell phone addiction tendency of high school students.AIM To explore the effects of sports on school adaptability,resilience and cell phone addiction of high school students.METHODS A stratified random sampling method was used to select 600 students from two high schools in Lhasa,and Physical Activity Rating Scale,School Adjustment Scale for High School Students,Chinese Adolescents Resilience Scale,and Mobile Phone Addiction Index were used for field questionnaire survey.RESULTS Sport was positively correlated with school adaptability and resilience(P<0.01),school adaptability was positively correlated with resilience(P<0.01)and cell phone addiction was negatively correlated with sports,school adaptability and resilience(P<0.01).The direct effect of sport on cell phone addiction was significant(P<0.001),accounting for 20.51%of the total effect.The mediating effect of school adaptability on sport and cell phone addiction was significant(P<0.001),accounting for 17.38%and 35.36%of the total effect value,respectively.School adjustment and resilience had a significant chain-mediated effect on sport and cell phone addiction(P<0.001),accounting for 26.75%of the total effect.CONCLUSION Sport affected the cell phone addiction tendency of senior high school students through the mediating effect of school adaptability and resilience,and through the chain mediation effect of both.展开更多
Objective:To study the analgesic, anti-inflammatory and antioxidant effects of ultrasound-guided lower extremity nerve block for elderly hip arthroplasty.Methods: A total of 99 elderly patients with femoral neck fract...Objective:To study the analgesic, anti-inflammatory and antioxidant effects of ultrasound-guided lower extremity nerve block for elderly hip arthroplasty.Methods: A total of 99 elderly patients with femoral neck fractures who underwent hip arthroplasty in our hospital between January 2017 and March 2018 were selected, and the anesthetic solutions were reviewed and used to divide the enrolled patients into the control group (n=51) who accepted conventional general anesthesia and the nerve block group (n=48) who accepted ultrasound-guided lower extremity nerve block anesthesia. The differences in the serum levels of pain mediators, inflammatory mediators and oxidative stress indexes were compared between the two groups immediately after surgery (T0), 12 h after surgery (T1) and 24 h after surgery (T2).Results: At T0, serum levels of pain mediators, inflammatory mediators and oxidative stress indexes were not significantly different between the two groups. At T1 and T2, serum pain mediators PGF2a, SP and NPY levels of nerve block group were lower than those of control group;serum inflammatory mediators IL-1β, TNF-α and hs-CRP levels were lower than those of control group;serum oxidative stress indexes T-AOC and SOD levels were higher than those of control group whereas MDA and LHP levels were lower than those of control group.Conclusion:Ultrasound-guided lower limb nerve block for elderly hip arthroplasty has exact analgesic, anti-inflammatory and antioxidant effects.展开更多
BACKGROUND Despite the increasing number of publications on glioma radiomics,challenges persist in clinical translation.AIM To assess the development and reporting quality of radiomics in brain gliomas since 2019.METH...BACKGROUND Despite the increasing number of publications on glioma radiomics,challenges persist in clinical translation.AIM To assess the development and reporting quality of radiomics in brain gliomas since 2019.METHODS A bibliometric analysis was conducted to reveal trends in brain glioma radiomics research.The Radiomics Quality Score(RQS),a metric for evaluating the quality of radiomics studies,was applied to assess the quality of adult-type diffuse glioma studies published since 2019.The total RQS score and the basic adherence rate for each item were calculated.Subgroup analysis by journal type and research objective was performed,correlating the total RQS score with journal impact factors.RESULTS The radiomics research in glioma was initiated in 2011 and has witnessed a surge since 2019.Among the 260 original studies,the median RQS score was 11,correlating with a basic compliance rate of 46.8%.Subgroup analysis revealed significant differences in domain 1 and its subitems(multiple segmentations)across journal types(P=0.039 and P=0.03,respectively).The Spearman correlation coefficients indicated that the total RQS score had a negative correlation with the Journal Citation Report category(-0.69)and a positive correlation with the five-year impact factors(0.318)of journals.CONCLUSION Glioma radiomics research quality has improved since 2019 but necessitates further advancement with higher publication standards.展开更多
Background:Chronic obstructive pulmonary disease(COPD)and obstructive sleep apnea(OSA)syndrome are highly prevalent respiratory conditions.Their coexistence is referred to as the overlap syndrome.They are both related...Background:Chronic obstructive pulmonary disease(COPD)and obstructive sleep apnea(OSA)syndrome are highly prevalent respiratory conditions.Their coexistence is referred to as the overlap syndrome.They are both related to pulmonary hypertension(PH)development.This study investigated the effects of OSA on PH in patients with COPD and the associated factors.Methods:Consecutive patients with stable COPD were recruited for an observational cross-sectional study from September 2016 to May 2018 at Peking University Third Hospital.In total,106 patients with COPD were enrolled and performed home portable monitoring and echocardiography.OSA was defined by an apnea hypopnea index(AHI)>10 events/h.Based on OSA absence or presence,patients were divided into the COPD with OSA and COPD without OSA groups.Factors affecting pulmonary artery pressure(PAP)and PH were identified using univariate analysis and logistic regression models.Results:In the 106 patients with COPD,the mean age was 69.52 years,91.5%were men,and the mean forced expiratory volume in 1 s(FEV!)percentage of predicted was 56.15%.Fifty-six(52.8%)patients with COPD were diagnosed with OSA,and 24(22.6%)patients with COPD were diagnosed as PH.Compared with COPD without OSA group,the median PAP in COPD with severe OSA group increased by 5 mmHg(36.00[26.00-50.00]mmHg vs.31.00[24.00-34.00]mmHg,P=0.036).COPD with percent of night-time spent with oxygen saturation below 90%(T90)>10%group had higher PAP than COPD with T90<1%group(36.00[29.00-50.00)]mmHg vs.29.00[25.50-34.00]mmHg,F=7.889,P=0.007).Univariate analysis revealed age,FEVi%predicted,T90,and Charlson index had statistically significant effects on PH.Multiple regression analysis showed a significant and independent effect of both FEVj%predicted(odds ratio[OR]=3.46;95%confidence interval[Cl]:1.15-10.46;P=0.028)and AHI(OR=3.20;95%Cl:1.09-19.35;P=0.034)on PH.Conclusions:Patients with COPD with OSA are more susceptible to PH,which is associated with declining lung function and increased severity of OSA.Thus,nocturnal hypoxemia and OSA in elderly patients with COPD should be identified and treated.展开更多
To the Editor： Ossifying fibroma is a benign but rare fibro-osseous tumor in the eraniofacial region. Complete resection is the only way to treat it. Here, we reported one case of maxillary juvenile ossifying fibroma...To the Editor： Ossifying fibroma is a benign but rare fibro-osseous tumor in the eraniofacial region. Complete resection is the only way to treat it. Here, we reported one case of maxillary juvenile ossifying fibroma operated with intranasal endoscopic prelacrimal recess approach in which nasolacrimal duct （NLD） and inferior turbinate （IT） were spared.展开更多
The traditional space-invariant isotropic kernel utilized by a bilateral filter(BF)frequently leads to blurry edges and gradient reversal artifacts due to tlie existence of a large amount of outliers in the local aver...The traditional space-invariant isotropic kernel utilized by a bilateral filter(BF)frequently leads to blurry edges and gradient reversal artifacts due to tlie existence of a large amount of outliers in the local averaging window.However,the efficient and accurate cstiinatioii of space-variant k(4rnels which adapt to image structures,and the fast realization of the corresponding space-variant bilateral filtering are challenging problems.To address these problems,we present a space-variant BF(SVBF).and its linear time and error-bounded acceleration method.First,we accurately estimate spacevariant,anisotropic kernels that vary with image structures in linear time through structure tensor and mininnini spanning tree.Second,we perform SVBF in linear time using two error-bounded approximation methods,namely,low-rank tensor approximation via higher-order singular value decomposition and exponential sum approximation.Tlierefore.the proposed SVBF can efficiently achieve good edge-preserving results.We validate the advantages of the proposed filter in applications including:image denoising,image enhancement,and image focus editing.Experimental results(leinonstrate that our fast and error-bounded SVBF is superior to state-of-the-art methods.展开更多
基金supported by Open Foundation of the State Key Laboratory of Refractories and Metallurgy(No.G201711)the National Natural Science Foundation of China(Nos.52104317 and 51874001).
文摘The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of dendritic solidification structures.Combining scanning electron microscopy and energy-dispersive scanning analysis and ANSYS simulation,the high-precision image processing software Mimics Research was utilized to conduct the extraction of dendritic morphologies.Reverse engineering software NX Imageware was employed for the 3D reconstruction of two-dimensional dendritic morphologies,restoring the dendritic characteristics in three-dimensional space.The results demonstrate that in a two-dimensional plane,dendrites connect with each other to form irregularly shaped“ring-like”structures.These dendrites have a thickness greater than 0.1 mm along the Z-axis direction,leading to the envelopment of molten steel by dendrites in a 3D space of at least 0.1 mm.This results in obstructed flow,confirming the“bridging”of dendrites in three-dimensional space,resulting in a tendency for central segregation.Dense and dispersed tiny dendrites,under the influence of heat flow direction,interconnect and continuously grow,gradually forming primary and secondary dendrites in three-dimensional space.After the completion of dendritic solidification and growth,these microdendrites appear dense and dispersed on the two-dimensional plane,providing the nuclei for the formation of new dendrites.When reduction occurs at a solid fraction of 0.46,there is a noticeable decrease in dendritic spacing,resulting in improved central segregation.
文摘BACKGROUND Congenital cytomegalovirus(CMV)infection represents a significant public health concern as the most prevalent viral infection in newborns,potentially leading to severe neurological and developmental complications.The majority of cases are asymptomatic and remain undetected during pregnancy due to the absence of effective screening methods.CASE SUMMARY A 27-year-old primigravida presented for early pregnancy ultrasound,which revealed an atypical finding:A normal anechoic thalamus appearing hyperechoic on the mid-sagittal view of the fetal head.Subsequent ultrasound examinations during mid and late gestation demonstrated classic intracranial features sug-gestive of congenital CMV infection.Chromosomal karyotyping and microarray analysis of the fetus yielded no significant abnormalities.Following compre-hensive prenatal counseling regarding potential adverse fetal outcomes,the patient elected to continue her pregnancy.She ultimately underwent cesarean delivery at 42 weeks gestation at another facility,resulting in the birth of a female neonate.At five months of age,the infant presented with epilepsy and significant growth and developmental delays.CONCLUSION Congenital CMV infection occurs during the first trimester may manifest as hyperechoic thalamus which can be revealed by ultrasound in the mid-saggital view of the fetal head.Future research should investigate the correlation between echogenic thalamus and developmental outcomes,as well as explore early sc-reening techniques for suspected congenital CMV infection cases.
基金supported by the Fundamental Research Projects of Shanxi Province(Grant No.202203021222225)the National Natural Science Foundation of China(Grant Nos.12175029,12011530014,and 11775040)the Key Research and Development Project of Liaoning Province(Grant No.2020JH2/10500003).
文摘Determining the minimal distance between the target state and the convex combination of given states is a fundamental problem in quantum resource theory,offering critical guidance for experimental implementations.In this paper,we embark on an in-depth exploration of the use of a quantum state prepared by the convex combination of given qubit states to optimally approximate the l_(1)-norm of coherence of the target quantum state,striving to make the prepared state and the target state as similar as possible.Here,we present the analytical solution for the optimal distance for any N given quantum states.We find that the optimal approximation problem for any N>4 quantum states can be transformed into an optimal approximation problem for no more than four quantum states,which not only significantly streamlines the problem but also proves advantageous for laboratories in terms of material conservation.Ultimately,a one-to-one comparison between the analytical and numerical solutions verifies the effectiveness of our approach.
文摘目的比较靶控输注瑞芬太尼和舒芬太尼对老年患者行腹腔镜胃癌根治术麻醉恢复的质量。方法选取2016年9月-2018年12月该院腹腔镜胃癌根治术患者84例,随机分为舒芬太尼组(n=42)和瑞芬太尼组(n=42)。两组患者应用靶控输注舒芬太尼和瑞芬太尼为基础的麻醉。记录并比较两组患者唤醒时间、拔管时间、定向力恢复时间、生命体征、应激反应、T细胞亚群分布及不良反应发生率。结果两组患者定向力恢复时间差异无统计学意义(P>0.05)。舒芬太尼组的清醒和拔管时间明显短于瑞芬太尼组,差异均有统计学意义(P<0.05)。舒芬太尼组麻醉结束、麻醉诱导后和麻醉前的心率(HR)、平均动脉压(MAP)和脉搏血氧饱和度(SpO2)比较,差异均无统计学意义(P>0.05),而瑞芬太尼组麻醉结束、麻醉诱导后和麻醉前的HR、MAP和SpO2比较,差异均有统计学意义(P<0.05)。舒芬太尼组在麻醉后、麻醉结束、麻醉结束24 h和麻醉结束72 h 4个时间点,血葡萄糖(GLU)、皮质醇(Cor)、白细胞介素-6(IL-6)和C反应蛋白(CRP)的浓度均明显低于瑞芬太尼组,CD3^+、CD4^+和CD8^+及CD4+/CD8^+明显高于瑞芬太尼组,瑞芬太尼组麻醉不良反应发生率明显高于舒芬太尼组,差异有统计学意义(P<0.05)。结论对于接受腹腔镜胃癌根治术的老年患者,靶控输注舒芬太尼为基础的麻醉具有麻醉过程平稳、应激反应小、抑制细胞免疫轻和不良反应少等优点,值得临床推广。
文摘To understand the characteristic of circulation flow rate in 250-t RH-TOP vacuum refining process, the 1：4 water model test was established through the bubble behavior and gas holdup in the up-leg to investigate the effects of different processes and equipment parame- ters on the RH circulation flow rate. With the increases of lifting gas flow rate, liffing bubble travel, and the internal diameter of the up-leg, and the decrease of nozzle diameter, the work done by bubble floatage and the circulation flow rate increase. The expression of circulation flow rate was derived fi＂om the regression analysis of experiment data. Meanwhile, the influences of vacuum chamber pressure and nozzle blockage situation on the circulation flow rate were discussed in detail by the bubble behavior and gas holdup in the up-leg. It is necessary to maintain a certain vacuum chamber liquid level in the molten steel circulation flow. Compared with a nozzle with symmetrical blockage in the up-leg, when a nozzle with non-symmetrical blockage is applied, the lifting gas distribution is non-uniform, causing a great effect on the molten steel circulation flow and making the circulation flow drop largely.
基金support provided by the National Science and Technology Major Project of the Ministry of Science and Technology of China(2016ZX05012-002-005)Shandong Provincial Natural Science Foundation(Grant no.:ZR2021QE051)+1 种基金National Natural Science Foundation of China(Grant no.:52206291)the Fundamental Research Funds for the Central Universities(Grant no.:22CX06030A).
文摘Heavy oil is characterized by high viscosity.High viscosity makes it challenging to recover and transport.HZSM-5,MoO_(3)/HZSM-5,ZrO_(2)/HZSM-5 and MoO_(3)–ZrO_(2)/HZSM-5 catalysts were developed to promote in situ desulfurization and viscosity reduction of heavy oil.The physical and chemical properties of catalysts were characterized by XPS,XRD,TEM,NH3-TPD,etc.The effects of temperature,catalyst type and addition amount on viscosity and composition of heavy oil were evaluated.The results showed that the presence of MoO_(3)–ZrO_(2)/HZSM-5 nanoparticles during aquathermolysis could improve the oil quality by reducing the heavy fractions.It reduced viscosity by 82.56%after the reaction at 280℃ and catalyst addition of 1 wt%.The contents of resins and asphaltic in the oil samples were 5.69%lower than that in the crude oil.Sulfur content decreased from 1.45%to 1.03%.The concentration of H2S produced by the reaction was 2225 ppm.The contents of sulfur-containing functional groups sulfoxide and sulfone sulfur in the oil samples decreased by 19.92%after the catalytic reaction.The content of stable thiophene sulfur increased by 5.71%.This study provided a basis for understanding the mechanism of heavy oil desulfurization and viscosity reduction.
基金the financial support provided by the National Science and Technology Major Project of the Ministry of Science and Technology of China(2016ZX05012002-005)National Natural Science Foundation of China(No.51874333)Natural Science Foundation of Shandong Province,China(No.ZR2017MEE030)
文摘Hydrodesulfurization(HDS)reaction can significantly reduce the viscosity and sulfur content of heavy oil,while the HDS reaction mechanism of tetrahydrothiophene as the main sulfide in heavy oil is still unclear.The HDS experiment of tetrahydrothiophene catalyzed by nickel phosphide(Ni_(2)P)is carried out at 200-300°C.The results indicate that the H_(2)S production under the catalysis of Ni_(2)P increases obviously within 200-250°C.The main gas products of HDS reaction are butane,butene and H_(2)S.Meanwhile,the mechanism of tetrahydrothiophene catalyzed by Ni_(2)P is analyzed based on Density Functional Theory(DFT).It is revealed that the adsorption model is most stable when tetrahydrothiophene is vertically adsorbed on the V-Ni-Hcp1 site of Ni_(2)P(001).The C-S bond is elongated and the C-C bond is shortened after adsorption.Hydrogenation(HYD)is the most possible reaction route of tetrahydrothiophene on Ni_(2)P(001)surface.There are two routes with the lowest activation energy,which are C_(4)H_(8)S→C_(4)H_(8)SH^(*)→C_(4)H_(9)SH^(*)→C_(4)H_(10)+H_(2)S and C_(4)H_(8)S→C_(4)H9S^(*)→C_(4)H_(9)^(*)+SH^(*)→C_(4)H_(10)+H_(2)S.Butane and H_(2)S are produced in the reaction,corresponding to the experimental results.This study provides a basis for understanding of the HDS mechanism of tetrahydrothiophene catalyzed by Ni_(2)P.
基金financially supported by the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2022QNRC001)Beijing Nova Program(No.Z211100002121082)+1 种基金Beijing Natural Science Foundation(No.2232081)Anhui Province universities excellent scientific research and innovation team(No.2022AH010024)。
文摘With the swift advancement of renewable energy and escalating demands for energy storage,potassium-ion batteries(PIBs)are increasingly recognized as a potent energy storage techn ology.Various carbon anode materials have been utilized for PIBs anodes owing to their superior K^(+)storage capacity,outstanding cycling performance,elevated capacity,and cost-effectiveness.Therefore,it is imperative to explore and improve carbon anode materials.This review meticulously encapsulates the recent scholarly advancements in carbon anode materials for PIBs.It elucidates the operational mechanisms of carbon anode for PIBs,provides a synopsis of diverse carbon materials,and deliberates on the prevalent challenges,including cycling stability and potassium-ion diffusion rates.Although soft and hard carbon augmented potassiumion capacities,the expansive surface areas coupled with the large ionic radius of K^(+)pose substantial challenges to their structural design and optimization.Consequently,this review outlines strategic approaches to the design of carbon materials for excellent potassium storage performance,including the expansion of interlayer spacing,modification of morphology,heteroatom doping,structural defect regulation,incorporation of porous structures,and development of carbon-carbon composites.Finally,the challenges and prospective solutions of carbon anode materials for PIBs with superior energy density and cycling stability were proposed,providing a reasonable guidance for regulation design of carbon materials.
基金support from the State Key Laboratory of Refractories and Metallurgy(Wuhan University of Science and Technology)(Grant No.G201902)the National Natural Science Foundation of China(Grant Nos.51874001,U1760108)。
文摘To reveal the formation mechanism and main influencing factors of C-segregation in high carbon steel under different solidification rates(40,80,160,200 and 320μm·s^(-1)),the enrichment characteristics of carbon atoms in the solid-liquid zone of Fe-0.61%C steel were studied using a zone melting liquid metal cooling apparatus and electron probe microanalysis.The relationships among micro-segregation of carbon atoms,solid-liquid interface morphology and solidification rate were fully discussed.The results show that large dendrite spacing and a slow-moving dendritic interface create less resistance and more time for the migration of interdendritic carbon atoms to liquid zone.This results in the continuous enrichment of carbon atoms in liquid zone,further expands the solid-liquid temperature range,prolongs the solidification time of molten steel,and causes the formation of carbon micro-segregation at the solidification end as the solidification rate is 40μm·s^(-1).Conversely,abundant and elongated secondary dendrite arms with small spacing seriously impede the diffusion of interdendritic carbon-rich molten steel to liquid zone.As a result,there is only obvious dendrite segregation,but little difference in the carbon content along the solidification direction as solidification rate exceeds 200μm·s^(-1).
基金Supported by the General Project for Humanities and Social Sciences Research,Ministry of Education of China,No.19XZJC890001。
文摘BACKGROUND Sport help promote healthy physical and mental development of high school students.To date,there have been few studies on the effect of sport on school adaptability,resilience and cell phone addiction tendency of high school students.AIM To explore the effects of sports on school adaptability,resilience and cell phone addiction of high school students.METHODS A stratified random sampling method was used to select 600 students from two high schools in Lhasa,and Physical Activity Rating Scale,School Adjustment Scale for High School Students,Chinese Adolescents Resilience Scale,and Mobile Phone Addiction Index were used for field questionnaire survey.RESULTS Sport was positively correlated with school adaptability and resilience(P<0.01),school adaptability was positively correlated with resilience(P<0.01)and cell phone addiction was negatively correlated with sports,school adaptability and resilience(P<0.01).The direct effect of sport on cell phone addiction was significant(P<0.001),accounting for 20.51%of the total effect.The mediating effect of school adaptability on sport and cell phone addiction was significant(P<0.001),accounting for 17.38%and 35.36%of the total effect value,respectively.School adjustment and resilience had a significant chain-mediated effect on sport and cell phone addiction(P<0.001),accounting for 26.75%of the total effect.CONCLUSION Sport affected the cell phone addiction tendency of senior high school students through the mediating effect of school adaptability and resilience,and through the chain mediation effect of both.
文摘Objective:To study the analgesic, anti-inflammatory and antioxidant effects of ultrasound-guided lower extremity nerve block for elderly hip arthroplasty.Methods: A total of 99 elderly patients with femoral neck fractures who underwent hip arthroplasty in our hospital between January 2017 and March 2018 were selected, and the anesthetic solutions were reviewed and used to divide the enrolled patients into the control group (n=51) who accepted conventional general anesthesia and the nerve block group (n=48) who accepted ultrasound-guided lower extremity nerve block anesthesia. The differences in the serum levels of pain mediators, inflammatory mediators and oxidative stress indexes were compared between the two groups immediately after surgery (T0), 12 h after surgery (T1) and 24 h after surgery (T2).Results: At T0, serum levels of pain mediators, inflammatory mediators and oxidative stress indexes were not significantly different between the two groups. At T1 and T2, serum pain mediators PGF2a, SP and NPY levels of nerve block group were lower than those of control group;serum inflammatory mediators IL-1β, TNF-α and hs-CRP levels were lower than those of control group;serum oxidative stress indexes T-AOC and SOD levels were higher than those of control group whereas MDA and LHP levels were lower than those of control group.Conclusion:Ultrasound-guided lower limb nerve block for elderly hip arthroplasty has exact analgesic, anti-inflammatory and antioxidant effects.
基金Supported by Sichuan Science and Technology Program,No.2023YFQ0002Deyang Science and Technology Program,No.2023SZZ093.
文摘BACKGROUND Despite the increasing number of publications on glioma radiomics,challenges persist in clinical translation.AIM To assess the development and reporting quality of radiomics in brain gliomas since 2019.METHODS A bibliometric analysis was conducted to reveal trends in brain glioma radiomics research.The Radiomics Quality Score(RQS),a metric for evaluating the quality of radiomics studies,was applied to assess the quality of adult-type diffuse glioma studies published since 2019.The total RQS score and the basic adherence rate for each item were calculated.Subgroup analysis by journal type and research objective was performed,correlating the total RQS score with journal impact factors.RESULTS The radiomics research in glioma was initiated in 2011 and has witnessed a surge since 2019.Among the 260 original studies,the median RQS score was 11,correlating with a basic compliance rate of 46.8%.Subgroup analysis revealed significant differences in domain 1 and its subitems(multiple segmentations)across journal types(P=0.039 and P=0.03,respectively).The Spearman correlation coefficients indicated that the total RQS score had a negative correlation with the Journal Citation Report category(-0.69)and a positive correlation with the five-year impact factors(0.318)of journals.CONCLUSION Glioma radiomics research quality has improved since 2019 but necessitates further advancement with higher publication standards.
基金supported by the grants from the Chronic Non-Communicable Diseases Prevention and Control Research of National Key Research and Development Program of China(No.2016YFC1304301)Precision Medical Project of National Key Research and Development Program(No.2016YFC0903601 and 2016YFC0901102)the Beijing New-star Plan of Science and Technology program(No.Z171100001117124).
文摘Background:Chronic obstructive pulmonary disease(COPD)and obstructive sleep apnea(OSA)syndrome are highly prevalent respiratory conditions.Their coexistence is referred to as the overlap syndrome.They are both related to pulmonary hypertension(PH)development.This study investigated the effects of OSA on PH in patients with COPD and the associated factors.Methods:Consecutive patients with stable COPD were recruited for an observational cross-sectional study from September 2016 to May 2018 at Peking University Third Hospital.In total,106 patients with COPD were enrolled and performed home portable monitoring and echocardiography.OSA was defined by an apnea hypopnea index(AHI)>10 events/h.Based on OSA absence or presence,patients were divided into the COPD with OSA and COPD without OSA groups.Factors affecting pulmonary artery pressure(PAP)and PH were identified using univariate analysis and logistic regression models.Results:In the 106 patients with COPD,the mean age was 69.52 years,91.5%were men,and the mean forced expiratory volume in 1 s(FEV!)percentage of predicted was 56.15%.Fifty-six(52.8%)patients with COPD were diagnosed with OSA,and 24(22.6%)patients with COPD were diagnosed as PH.Compared with COPD without OSA group,the median PAP in COPD with severe OSA group increased by 5 mmHg(36.00[26.00-50.00]mmHg vs.31.00[24.00-34.00]mmHg,P=0.036).COPD with percent of night-time spent with oxygen saturation below 90%(T90)>10%group had higher PAP than COPD with T90<1%group(36.00[29.00-50.00)]mmHg vs.29.00[25.50-34.00]mmHg,F=7.889,P=0.007).Univariate analysis revealed age,FEVi%predicted,T90,and Charlson index had statistically significant effects on PH.Multiple regression analysis showed a significant and independent effect of both FEVj%predicted(odds ratio[OR]=3.46;95%confidence interval[Cl]:1.15-10.46;P=0.028)and AHI(OR=3.20;95%Cl:1.09-19.35;P=0.034)on PH.Conclusions:Patients with COPD with OSA are more susceptible to PH,which is associated with declining lung function and increased severity of OSA.Thus,nocturnal hypoxemia and OSA in elderly patients with COPD should be identified and treated.
文摘To the Editor： Ossifying fibroma is a benign but rare fibro-osseous tumor in the eraniofacial region. Complete resection is the only way to treat it. Here, we reported one case of maxillary juvenile ossifying fibroma operated with intranasal endoscopic prelacrimal recess approach in which nasolacrimal duct （NLD） and inferior turbinate （IT） were spared.
基金the National Natural Science Foundation of China under Grant Nos.61620106003.61701235,61772523,61471338 and 61571046the Beijing Natural Science Foundation of China under Grant,No.LI82059+1 种基金the Fundamental Research Funds for the Central Universities of China under Grant No.30917011323the Open Projects Program of National Laboratory of Pattern Recognition of China under Grant No.201900020.
文摘The traditional space-invariant isotropic kernel utilized by a bilateral filter(BF)frequently leads to blurry edges and gradient reversal artifacts due to tlie existence of a large amount of outliers in the local averaging window.However,the efficient and accurate cstiinatioii of space-variant k(4rnels which adapt to image structures,and the fast realization of the corresponding space-variant bilateral filtering are challenging problems.To address these problems,we present a space-variant BF(SVBF).and its linear time and error-bounded acceleration method.First,we accurately estimate spacevariant,anisotropic kernels that vary with image structures in linear time through structure tensor and mininnini spanning tree.Second,we perform SVBF in linear time using two error-bounded approximation methods,namely,low-rank tensor approximation via higher-order singular value decomposition and exponential sum approximation.Tlierefore.the proposed SVBF can efficiently achieve good edge-preserving results.We validate the advantages of the proposed filter in applications including:image denoising,image enhancement,and image focus editing.Experimental results(leinonstrate that our fast and error-bounded SVBF is superior to state-of-the-art methods.
