Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral response.Recent studies have shown that brain-derived neurotrophic factor expression in stressed mice ...Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral response.Recent studies have shown that brain-derived neurotrophic factor expression in stressed mice is brain region–specific,particularly involving the corticolimbic system,including the ventral tegmental area,nucleus accumbens,prefrontal cortex,amygdala,and hippocampus.Determining how brain-derived neurotrophic factor participates in stress processing in different brain regions will deepen our understanding of social stress psychopathology.In this review,we discuss the expression and regulation of brain-derived neurotrophic factor in stress-sensitive brain regions closely related to the pathophysiology of depression.We focused on associated molecular pathways and neural circuits,with special attention to the brain-derived neurotrophic factor–tropomyosin receptor kinase B signaling pathway and the ventral tegmental area–nucleus accumbens dopamine circuit.We determined that stress-induced alterations in brain-derived neurotrophic factor levels are likely related to the nature,severity,and duration of stress,especially in the above-mentioned brain regions of the corticolimbic system.Therefore,BDNF might be a biological indicator regulating stress-related processes in various brain regions.展开更多
OBJECTIVES: High-dose statins pretreatment is reasonable before percutaneous coronary intervention (PCI) to reduce the risk of periprocedural myocardial injury。 However, the mechanism underlying this protective effec...OBJECTIVES: High-dose statins pretreatment is reasonable before percutaneous coronary intervention (PCI) to reduce the risk of periprocedural myocardial injury。 However, the mechanism underlying this protective effect has not been elucidated。 The aim of this study is to evaluate the effects of high-dose atorvastatin pretreatment on microvascular function and myocardial injury after elective PCI。 METHODS: Eighty four patients underwent elective PCI were randomly assigned to high-dose atorvastatin (40 mg/d) and low-dose atorvastatin (20 mg/d) treatment for 7 days before PCI。 The index of microcirculatory resistance (IMR) was measured by an intracoronary ressure/temperature sensor-tipped guidewire at maximal hyperemia after PCI。 Fractional flow reserve (FFR) was measured before and after procedure。 Troponin I levels were obtained at baseline and 20-24 h after procedure。 RESULTS: IMR values were significantly lower in high-dose group when compared to low-dose group (16.5 ±6.1 vs。31.2 ±16.0, P <0.001)。 Pre-PCI troponin I levels between the two groups were similar (0.028 ±0.05 vs0.022 ±0.04, P =0.55)。 However, post-PCI troponin I levels in high-dose group were significantly lower than low-dose group (0.11 ±0.02 vs。0.16 ±0.09, P <0.001)。 Multivariate analysis identified maximum inflation pressure >20 atm as an independent predictor of IMR >32 (Odds ratio (OR):3.3,95% confidence intervals (95%CI):1.3-8.5, P =0.02)。 High-dose atorvastatin was the only independent protective factor of IMR >32 (OR:0.29,95%CI:0.11-0.74, P =0.01)。 CONCLUSIONS: The present study confirmed that diminishing microvascular impairment is one of the mechanism underlying protecting effect of high-dose statins pretreatment from myocardial injury during PCI。 These suggest that high-dose statin pretreatment is reasonable in patients undergoing elective PCI。展开更多
After the Tianjin Port 8·12 explosion, an enormous amount of potassium dichromate(K_2Cr_2O_7) and butanone(CH_3COCH_2CH_3) leaked into the coastal soil–groundwater system, which potentially threatened the enviro...After the Tianjin Port 8·12 explosion, an enormous amount of potassium dichromate(K_2Cr_2O_7) and butanone(CH_3COCH_2CH_3) leaked into the coastal soil–groundwater system, which potentially threatened the environment and human health. Determining the transport process of hazards is necessary to establish guidelines for remediating the contaminated area. This work aims to investigate the migration of potassium dichromate and butanone in the coastal soil-groundwater system through a coupling unsaturated–saturated numerical model, incorporating the HYDRUS model into the MODFLOW/MT3D model. In the unsaturated zone, two-dimensional HYDRUS model was applied, and its recharge flux at the bottom boundary was utilized as the input of MODFLOW/MT3D model in the saturated zone. Results showed that Cr_2O_7^(2-) migrated much faster than butanone in the unsaturated zone and reached the water table in about 1 year. In comparison, butanone was unlikely to enter the aquifer even 5 years later with a migration depth of about 2.2 m. Driven by groundwater, the Cr_2O_7^(2-) that entered the aquifer migrated about 161 m toward southeast 5 years later. In the saturated zone, the contamination plume covered mainly the southeast area due to the groundwater flow direction.展开更多
BACKGROUND Neonatal distal humeral physeal fractures are rare and difficult to diagnose.Thus,missed diagnoses and delayed healing are possible.Few studies have reported surgical treatment,because a callus may develop ...BACKGROUND Neonatal distal humeral physeal fractures are rare and difficult to diagnose.Thus,missed diagnoses and delayed healing are possible.Few studies have reported surgical treatment,because a callus may develop at the fracture site 5 d after the fracture,resulting in difficult reduction,and reduction of the limb may cause further physeal injury.Other surgical challenges include the provision of adequate anesthesia and complexity of the operation.However,without appropriate reduction and fixation,a varus elbow deformity may develop.Manual reduction and percutaneous pin fixation are ideal treatment options.CASE SUMMARY A 4-day-old neonate with left elbow pain accompanied by limited movement for 4 d was admitted,and diagnosed with delayed physeal fracture of the distal humerus based on physical examination,ultrasonography,and magnetic resonance imaging.The patient was treated by manual reduction combined with percutaneous pin fixation under arthrography.Postoperatively,the reduction was successful.The upper limbs could have been lifted and the fingers could have been moved freely on the second day after the operation.CONCLUSION The techniques of manual reduction and percutaneous pin fixation,to treat neonatal distal humeral physeal fractures,are safe and reliable.展开更多
Scattering medium in light path will cause distortion of the light field,resulting in poor signal-to-noise ratio(SNR)of ghost imaging.The disturbance is usually eliminated by the method of pre-compensation.We deduce t...Scattering medium in light path will cause distortion of the light field,resulting in poor signal-to-noise ratio(SNR)of ghost imaging.The disturbance is usually eliminated by the method of pre-compensation.We deduce the intensity fluctuation correlation function of the ghost imaging with the disturbance of the scattering medium,which proves that the ghost image consists of two correlated results:the image of scattering medium and the target object.The effect of the scattering medium can be eliminated by subtracting the correlated result between the light field after the scattering medium and the reference light from ghost image,which verifies the theoretical results.Our research may provide a new idea of ghost imaging in harsh environment.展开更多
To the editor:The impact of the coronavirus disease 2019(COVID-19)pandemic in 2020 on mental health was substantialin Chinai2and various other countries.34 Beyond the direct consequences of COVID-19,the pandemic creat...To the editor:The impact of the coronavirus disease 2019(COVID-19)pandemic in 2020 on mental health was substantialin Chinai2and various other countries.34 Beyond the direct consequences of COVID-19,the pandemic created an environment in which many determinants of mental health were affected.Issues associated with the pandemic,such as loss of livelihood,limited access to medical services,reduced social interactions,and economic downturn,could potentially have adverse effects on the population's mental well-being.5 In November 2021,the World Health Organization(WHO)designated the new variant of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),variant B.1.1.529,as a variant of concern and named it Omicron;its rapid mutation and spread raised a new global health concern.展开更多
BACKGROUND Primary hepatocellular carcinoma(HCC)is a common malignant tumour,and its early symptoms are often not obvious,resulting in many patients experiencing middle-to late-stage disease at the time of diagnosis.T...BACKGROUND Primary hepatocellular carcinoma(HCC)is a common malignant tumour,and its early symptoms are often not obvious,resulting in many patients experiencing middle-to late-stage disease at the time of diagnosis.The optimal time for surgery is often missed for these patients,and those who do undergo surgery have unsatisfactory long-term outcomes and a high recurrence rate within five years.Therefore,postoperative follow-up treatments,such as transhepatic arterial chemoembolization(TACE),have become critical to improving survival and reducing recurrence rates.AIM To validate the prophylactic role of TACE after hepatic resection and to assess its impact on patient prognosis.METHODS This study investigated the efficacy of TACE in patients with intermediate-stage HCC after hepatectomy.When the post-treatment results of the observation group and the control group were compared,it was found that the inclusion of TACE significantly improved the clinical efficacy,reduced the levels of tumour markers and did not aggravate the damage to liver function.Thus,this may be an effective and comprehensive treatment strategy for patients with intermediate-stage HCC that helps to improve their quality of life and survival time.RESULTS When the baseline data were analysed,no statistical differences were found between the two groups in terms of gender,age,hepatitis B virus,cirrhosis,Child-Pugh grading,number of tumours,maximum tumour diameter and degree of tumour differentiation.The assessment of clinical efficacy showed that the post-treatment overall remission rate of the observation group was significantly higher than that of the control group.In terms of changes in tumour markers,the alpha-fetoprotein and carcinoembryonic antigen levels in the patients in the observation group decreased more significantly after treatment compared with those in the control group.When post-treatment changes in liver function indicators were analysed,no statistical differences were found in the total bilirubin,alanine aminotransferase and aspartate aminotransferase levels between the two groups.CONCLUSION In patients with intermediate-stage HCC,post-hepatectomy TACE significantly improved clinical outcomes,reduced tumour-marker levels and may have improved the prognosis by removing residual lesions.Thus,this may be an effective and comprehensive treatment strategy for patients with intermediate-stage HCC.展开更多
<div style="text-align:justify;"> Pomegranate flowers as row materials were used for extraction of polysaccharides by water-extraction and alcohol-precipitation method. After purification, the physical...<div style="text-align:justify;"> Pomegranate flowers as row materials were used for extraction of polysaccharides by water-extraction and alcohol-precipitation method. After purification, the physical and chemical properties, structure, monosaccharide composition and molecular weight were studied. The results showed that the polysaccharides from pomegranate flowers mainly contained two kinds of water soluble acidic polysaccharides, and monosaccharide composition were arabinose and galactose, both contained hydroxyl, carboxyl, amino, hydroxyl radical, sulfate, beta glycosidic bond and alpha glycosidic bond structure. The molecular weight of PP1 and PP2 were 6.16 × 104 (±6.6%) and 9.01 × 104 (±3.2%), respectively. The results of this study laid the foundation for further development and application of polysaccharides from pomegranate flowers. </div>展开更多
This paper is devoted to the study of a (2 + 1)-dimensional extended Potential Boiti-Leon-Manna-Pempinelli equation. Firstly, By means of the standard Weiss Tabor Carnevale approach and Kruskal’s simplification, we p...This paper is devoted to the study of a (2 + 1)-dimensional extended Potential Boiti-Leon-Manna-Pempinelli equation. Firstly, By means of the standard Weiss Tabor Carnevale approach and Kruskal’s simplification, we prove the painlevé non integrability of the equation. Secondly, A new breather solution and lump type solution are obtained based on the parameter limit method and Hirota’s bilinear method. Besides, some interaction behavior between lump type solution and N-soliton solutions (N is any positive integer) are studied. We construct the existence theorem of the interaction solution and give the process of calculation and proof. We also give a concrete example to illustrate the effectiveness of the theorem, and some spatial structure figures are displayed to reflect the evolutionary behavior of the interaction solutions with the change of soliton number N and time t.展开更多
目的:应用光学相干断层扫描血管成像技术(OCTA)测量视网膜静脉阻塞(RVO)患者黄斑区血流密度、黄斑中心凹无血管区(FAZ)面积和黄斑中心凹视网膜厚度。方法:选取RVO患者30例30眼,视网膜中央静脉阻塞(CRVO)和视网膜分支静脉阻塞(BRVO)患者...目的:应用光学相干断层扫描血管成像技术(OCTA)测量视网膜静脉阻塞(RVO)患者黄斑区血流密度、黄斑中心凹无血管区(FAZ)面积和黄斑中心凹视网膜厚度。方法:选取RVO患者30例30眼,视网膜中央静脉阻塞(CRVO)和视网膜分支静脉阻塞(BRVO)患者各15例,双眼接受OCTA检查,获取黄斑中心3mm×3mm大小范围的血流密度、FAZ面积、黄斑中心凹视网膜厚度,以及双眼最佳矫正视力(BCVA)。比较患眼与健眼上述指标的变化及其与BCVA的相关性。结果:CRVO患者患眼黄斑区视网膜浅层毛细血管网(SVN)、深层毛细血管网(DVN)总血流密度较健眼降低[SVN:(43.07±4.95)%vs(50.09±2.86)%,DVN:(45.89±4.12)%vs(53.29±2.62)%,均P<0.01],与BCVA呈负相关(r_(s)=-0.6、-0.5,均P<0.05)。BRVO患者患眼SVN、DVN总血流密度较健眼降低[SVN:(45.62±3.04)%vs(52.10±2.98%),DVN:(49.21±3.80)%vs(55.52±3.33%),均P<0.01],与BCVA呈负相关(r_(s)=-0.5、-0.5,均P<0.05)。BRVO患眼病变区域与患眼未病变区域、健眼对应区域比较,SVN、DVN血流密度均下降(均P<0.01);患眼未病变区域DVN血流密度较健眼相应区域下降[(56.86±1.95)%vs(58.15±2.24)%,P=0.02];患眼病变区域DVN血流密度与BCVA呈负相关(r_(s)=-0.6,P=0.01)。CRVO、BRVO患眼SVN的FAZ面积较健眼明显扩大(CRVO:0.515±0.26mm^(2)vs 0.27±0.08mm^(2),P<0.01;BRVO:0.376±0.12mm^(2)vs 0.261±0.07mm^(2),P<0.01),且均与BCVA呈正相关(CRVO:r_(s)=0.6,P=0.01;BRVO:r_(s)=0.5,P=0.01)。CRVO、BRVO患眼黄斑中心凹视网膜厚度均较健眼增加(CRVO:431.2±191.3μm vs 235.5±18.2μm,P<0.01;BRVO:373.2±188.7μm vs 233.8±13.7μm,P=0.01),均与BCVA呈正相关(CRVO:r_(s)=0.9,P=0.01;BRVO:r_(s)=0.6,P=0.01)。结论:OCTA可作为测量RVO患者黄斑区血流密度、FAZ面积及黄斑中心凹视网膜厚度的有效工具。展开更多
近年来,以雾霾为代表的大气污染问题严重影响到经济社会的可持续发展.其中,氮氧化物(NOx)的大量排放是导致雾霾天气的重要原因之一.氨选择性催化还原(NH3-SCR)是目前消除氮氧化物的主流技术,低温NH3-SCR更是广泛应用于钢铁、焦化、水泥...近年来,以雾霾为代表的大气污染问题严重影响到经济社会的可持续发展.其中,氮氧化物(NOx)的大量排放是导致雾霾天气的重要原因之一.氨选择性催化还原(NH3-SCR)是目前消除氮氧化物的主流技术,低温NH3-SCR更是广泛应用于钢铁、焦化、水泥、玻璃、陶瓷和垃圾焚烧等行业的烟气排放治理.传统的V2O5-WO3/Ti O2催化剂活性温度高(300–400 oC)且钒具有生物毒性,因此亟待开发环境友好的低温非钒基脱硝催化剂.最近, Ce Ti Ox基催化剂由于在中高温段(250–400 oC)表现出优异的脱硝性能而得到广泛关注.然而,该催化剂仍面临低温活性差及抗硫性能差的问题,制约了其工业化应用.研究显示,添加过渡金属可提高Ce Ti Ox基催化剂的脱硝活性和抗硫中毒性能,这主要是因为过渡金属的添加可以有效改善催化剂的氧化还原性能和表面酸性.Mo O3作为一种可以提供大量酸性位的氧化物,常被用作助剂改善钒钨钛催化剂的活性.研究显示, Mo O3的引入可以促进催化剂中钒物种的分散度以及提高表面酸性.基于此,我们制备了一系列不同Mo含量的Mo O3/Ce Ti Ox催化剂,以期提高Ce Ti Ox催化剂的低温脱硝性能及抗SO2中毒能力,并着重研究表面Mo的修饰对Ce Ti Ox催化剂物理化学性质的影响.研究发现,表面Mo修饰可以显著提高Ce Ti Ox的低温催化活性,其脱硝效率在150 oC即可达到80%,同时抗SO2中毒能力也得到增强.进一步借助X射线衍射、比表面积测定、氢气程序升温还原、氨气程序升温脱附和X射线光电子能谱等方法对催化剂进行了全面表征分析.结果显示,表面Mo修饰对Ce Ti Ox催化剂物理化学性质的影响与其脱硝性能有着密不可分的关系.首先,钼物种主要是以Mo O3的形式存在于Ce Ti Ox表面,其最佳的负载量为4wt.%.其次,表面Mo的沉积显著提高了催化剂的表面酸量,尤其是Br?nsted酸位的数量,而表面酸位的增加有利于催化剂吸附与活化反应物种NH3;同时,表面Mo修饰还减弱了硝酸盐在催化剂表面的吸附,进一步促使NH3-SCR反应按照Eley-Rideal机理顺利进行.最后,该催化剂在H2O和SO2存在的条件下仍具有最佳的脱硝性能,因而有望用于实际含SO2的低温烟气脱硝.展开更多
A series of ZSM-5 zeolites, with the morphologies of sphere, sphere with cubic particles on the surface, and cubic particles, were synthesized by hydrothermal method using n-butylamine as the template, assisted by the...A series of ZSM-5 zeolites, with the morphologies of sphere, sphere with cubic particles on the surface, and cubic particles, were synthesized by hydrothermal method using n-butylamine as the template, assisted by the addition of NaCl and crystal seed. X-ray diffraction(XRD),scanning electron microscope(SEM), X-ray fluorescence(XRF) and temperature-programmed desorption of ammonia(NH3-TPD) were used to characterize these samples. The samples were tested with toluene methylation reaction. The modified sample composed of spherical particles with 3 μm crystal particles on the surface had a para-xylene selectivity of 95% and maintained 79% of the initial conversion after running the reaction for 50 h. This modified sample showed the best stability among the tested three modified samples.展开更多
Four trawl-resistant bottom mounts, with acoustic Doppler current profilers(ADCPs) embedded, were deployed in the Karimata Strait from November 2008 to June 2015 as part of the South China Sea-Indonesian Seas Transpor...Four trawl-resistant bottom mounts, with acoustic Doppler current profilers(ADCPs) embedded, were deployed in the Karimata Strait from November 2008 to June 2015 as part of the South China Sea-Indonesian Seas Transport/Exchange and Impact on Seasonal Fish Migration(SITE) Program, to estimate the volume and property transport between the South China Sea and Indonesian seas via the strait. The observed current data reveal that the volume transport through the Karimata Strait exhibits significant seasonal variation. The winteraveraged(from December to February) transport is –1.99 Sv(1 Sv=1×10~6 m^3/s), while in the boreal summer(from June to August), the average transport is 0.69 Sv. Moreover, the average transport from January 2009 to December2014 is –0.74 Sv(the positive/negative value indicates northward/southward transport). May and September are the transition period. In May, the currents in the Karimata Strait turn northward, consistent with the local monsoon. In September, the southeasterly trade wind is still present over the strait, driving surface water northward, whereas the bottom flow reverses direction, possibly because of the pressure gradient across the strait from north to south.展开更多
基金supported financially by the National Natural Science Foundation of China,No.82071272(to YZ).
文摘Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral response.Recent studies have shown that brain-derived neurotrophic factor expression in stressed mice is brain region–specific,particularly involving the corticolimbic system,including the ventral tegmental area,nucleus accumbens,prefrontal cortex,amygdala,and hippocampus.Determining how brain-derived neurotrophic factor participates in stress processing in different brain regions will deepen our understanding of social stress psychopathology.In this review,we discuss the expression and regulation of brain-derived neurotrophic factor in stress-sensitive brain regions closely related to the pathophysiology of depression.We focused on associated molecular pathways and neural circuits,with special attention to the brain-derived neurotrophic factor–tropomyosin receptor kinase B signaling pathway and the ventral tegmental area–nucleus accumbens dopamine circuit.We determined that stress-induced alterations in brain-derived neurotrophic factor levels are likely related to the nature,severity,and duration of stress,especially in the above-mentioned brain regions of the corticolimbic system.Therefore,BDNF might be a biological indicator regulating stress-related processes in various brain regions.
文摘OBJECTIVES: High-dose statins pretreatment is reasonable before percutaneous coronary intervention (PCI) to reduce the risk of periprocedural myocardial injury。 However, the mechanism underlying this protective effect has not been elucidated。 The aim of this study is to evaluate the effects of high-dose atorvastatin pretreatment on microvascular function and myocardial injury after elective PCI。 METHODS: Eighty four patients underwent elective PCI were randomly assigned to high-dose atorvastatin (40 mg/d) and low-dose atorvastatin (20 mg/d) treatment for 7 days before PCI。 The index of microcirculatory resistance (IMR) was measured by an intracoronary ressure/temperature sensor-tipped guidewire at maximal hyperemia after PCI。 Fractional flow reserve (FFR) was measured before and after procedure。 Troponin I levels were obtained at baseline and 20-24 h after procedure。 RESULTS: IMR values were significantly lower in high-dose group when compared to low-dose group (16.5 ±6.1 vs。31.2 ±16.0, P <0.001)。 Pre-PCI troponin I levels between the two groups were similar (0.028 ±0.05 vs0.022 ±0.04, P =0.55)。 However, post-PCI troponin I levels in high-dose group were significantly lower than low-dose group (0.11 ±0.02 vs。0.16 ±0.09, P <0.001)。 Multivariate analysis identified maximum inflation pressure >20 atm as an independent predictor of IMR >32 (Odds ratio (OR):3.3,95% confidence intervals (95%CI):1.3-8.5, P =0.02)。 High-dose atorvastatin was the only independent protective factor of IMR >32 (OR:0.29,95%CI:0.11-0.74, P =0.01)。 CONCLUSIONS: The present study confirmed that diminishing microvascular impairment is one of the mechanism underlying protecting effect of high-dose statins pretreatment from myocardial injury during PCI。 These suggest that high-dose statin pretreatment is reasonable in patients undergoing elective PCI。
基金supported by the National Natural Science Foundation of China(No.21656001)
文摘After the Tianjin Port 8·12 explosion, an enormous amount of potassium dichromate(K_2Cr_2O_7) and butanone(CH_3COCH_2CH_3) leaked into the coastal soil–groundwater system, which potentially threatened the environment and human health. Determining the transport process of hazards is necessary to establish guidelines for remediating the contaminated area. This work aims to investigate the migration of potassium dichromate and butanone in the coastal soil-groundwater system through a coupling unsaturated–saturated numerical model, incorporating the HYDRUS model into the MODFLOW/MT3D model. In the unsaturated zone, two-dimensional HYDRUS model was applied, and its recharge flux at the bottom boundary was utilized as the input of MODFLOW/MT3D model in the saturated zone. Results showed that Cr_2O_7^(2-) migrated much faster than butanone in the unsaturated zone and reached the water table in about 1 year. In comparison, butanone was unlikely to enter the aquifer even 5 years later with a migration depth of about 2.2 m. Driven by groundwater, the Cr_2O_7^(2-) that entered the aquifer migrated about 161 m toward southeast 5 years later. In the saturated zone, the contamination plume covered mainly the southeast area due to the groundwater flow direction.
文摘BACKGROUND Neonatal distal humeral physeal fractures are rare and difficult to diagnose.Thus,missed diagnoses and delayed healing are possible.Few studies have reported surgical treatment,because a callus may develop at the fracture site 5 d after the fracture,resulting in difficult reduction,and reduction of the limb may cause further physeal injury.Other surgical challenges include the provision of adequate anesthesia and complexity of the operation.However,without appropriate reduction and fixation,a varus elbow deformity may develop.Manual reduction and percutaneous pin fixation are ideal treatment options.CASE SUMMARY A 4-day-old neonate with left elbow pain accompanied by limited movement for 4 d was admitted,and diagnosed with delayed physeal fracture of the distal humerus based on physical examination,ultrasonography,and magnetic resonance imaging.The patient was treated by manual reduction combined with percutaneous pin fixation under arthrography.Postoperatively,the reduction was successful.The upper limbs could have been lifted and the fingers could have been moved freely on the second day after the operation.CONCLUSION The techniques of manual reduction and percutaneous pin fixation,to treat neonatal distal humeral physeal fractures,are safe and reliable.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61871431,61971184,and 62001162)。
文摘Scattering medium in light path will cause distortion of the light field,resulting in poor signal-to-noise ratio(SNR)of ghost imaging.The disturbance is usually eliminated by the method of pre-compensation.We deduce the intensity fluctuation correlation function of the ghost imaging with the disturbance of the scattering medium,which proves that the ghost image consists of two correlated results:the image of scattering medium and the target object.The effect of the scattering medium can be eliminated by subtracting the correlated result between the light field after the scattering medium and the reference light from ghost image,which verifies the theoretical results.Our research may provide a new idea of ghost imaging in harsh environment.
基金supported by the National Key Research and Development Programme of China(2020YFC2006000).
文摘To the editor:The impact of the coronavirus disease 2019(COVID-19)pandemic in 2020 on mental health was substantialin Chinai2and various other countries.34 Beyond the direct consequences of COVID-19,the pandemic created an environment in which many determinants of mental health were affected.Issues associated with the pandemic,such as loss of livelihood,limited access to medical services,reduced social interactions,and economic downturn,could potentially have adverse effects on the population's mental well-being.5 In November 2021,the World Health Organization(WHO)designated the new variant of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),variant B.1.1.529,as a variant of concern and named it Omicron;its rapid mutation and spread raised a new global health concern.
文摘BACKGROUND Primary hepatocellular carcinoma(HCC)is a common malignant tumour,and its early symptoms are often not obvious,resulting in many patients experiencing middle-to late-stage disease at the time of diagnosis.The optimal time for surgery is often missed for these patients,and those who do undergo surgery have unsatisfactory long-term outcomes and a high recurrence rate within five years.Therefore,postoperative follow-up treatments,such as transhepatic arterial chemoembolization(TACE),have become critical to improving survival and reducing recurrence rates.AIM To validate the prophylactic role of TACE after hepatic resection and to assess its impact on patient prognosis.METHODS This study investigated the efficacy of TACE in patients with intermediate-stage HCC after hepatectomy.When the post-treatment results of the observation group and the control group were compared,it was found that the inclusion of TACE significantly improved the clinical efficacy,reduced the levels of tumour markers and did not aggravate the damage to liver function.Thus,this may be an effective and comprehensive treatment strategy for patients with intermediate-stage HCC that helps to improve their quality of life and survival time.RESULTS When the baseline data were analysed,no statistical differences were found between the two groups in terms of gender,age,hepatitis B virus,cirrhosis,Child-Pugh grading,number of tumours,maximum tumour diameter and degree of tumour differentiation.The assessment of clinical efficacy showed that the post-treatment overall remission rate of the observation group was significantly higher than that of the control group.In terms of changes in tumour markers,the alpha-fetoprotein and carcinoembryonic antigen levels in the patients in the observation group decreased more significantly after treatment compared with those in the control group.When post-treatment changes in liver function indicators were analysed,no statistical differences were found in the total bilirubin,alanine aminotransferase and aspartate aminotransferase levels between the two groups.CONCLUSION In patients with intermediate-stage HCC,post-hepatectomy TACE significantly improved clinical outcomes,reduced tumour-marker levels and may have improved the prognosis by removing residual lesions.Thus,this may be an effective and comprehensive treatment strategy for patients with intermediate-stage HCC.
文摘<div style="text-align:justify;"> Pomegranate flowers as row materials were used for extraction of polysaccharides by water-extraction and alcohol-precipitation method. After purification, the physical and chemical properties, structure, monosaccharide composition and molecular weight were studied. The results showed that the polysaccharides from pomegranate flowers mainly contained two kinds of water soluble acidic polysaccharides, and monosaccharide composition were arabinose and galactose, both contained hydroxyl, carboxyl, amino, hydroxyl radical, sulfate, beta glycosidic bond and alpha glycosidic bond structure. The molecular weight of PP1 and PP2 were 6.16 × 104 (±6.6%) and 9.01 × 104 (±3.2%), respectively. The results of this study laid the foundation for further development and application of polysaccharides from pomegranate flowers. </div>
文摘This paper is devoted to the study of a (2 + 1)-dimensional extended Potential Boiti-Leon-Manna-Pempinelli equation. Firstly, By means of the standard Weiss Tabor Carnevale approach and Kruskal’s simplification, we prove the painlevé non integrability of the equation. Secondly, A new breather solution and lump type solution are obtained based on the parameter limit method and Hirota’s bilinear method. Besides, some interaction behavior between lump type solution and N-soliton solutions (N is any positive integer) are studied. We construct the existence theorem of the interaction solution and give the process of calculation and proof. We also give a concrete example to illustrate the effectiveness of the theorem, and some spatial structure figures are displayed to reflect the evolutionary behavior of the interaction solutions with the change of soliton number N and time t.
文摘目的:应用光学相干断层扫描血管成像技术(OCTA)测量视网膜静脉阻塞(RVO)患者黄斑区血流密度、黄斑中心凹无血管区(FAZ)面积和黄斑中心凹视网膜厚度。方法:选取RVO患者30例30眼,视网膜中央静脉阻塞(CRVO)和视网膜分支静脉阻塞(BRVO)患者各15例,双眼接受OCTA检查,获取黄斑中心3mm×3mm大小范围的血流密度、FAZ面积、黄斑中心凹视网膜厚度,以及双眼最佳矫正视力(BCVA)。比较患眼与健眼上述指标的变化及其与BCVA的相关性。结果:CRVO患者患眼黄斑区视网膜浅层毛细血管网(SVN)、深层毛细血管网(DVN)总血流密度较健眼降低[SVN:(43.07±4.95)%vs(50.09±2.86)%,DVN:(45.89±4.12)%vs(53.29±2.62)%,均P<0.01],与BCVA呈负相关(r_(s)=-0.6、-0.5,均P<0.05)。BRVO患者患眼SVN、DVN总血流密度较健眼降低[SVN:(45.62±3.04)%vs(52.10±2.98%),DVN:(49.21±3.80)%vs(55.52±3.33%),均P<0.01],与BCVA呈负相关(r_(s)=-0.5、-0.5,均P<0.05)。BRVO患眼病变区域与患眼未病变区域、健眼对应区域比较,SVN、DVN血流密度均下降(均P<0.01);患眼未病变区域DVN血流密度较健眼相应区域下降[(56.86±1.95)%vs(58.15±2.24)%,P=0.02];患眼病变区域DVN血流密度与BCVA呈负相关(r_(s)=-0.6,P=0.01)。CRVO、BRVO患眼SVN的FAZ面积较健眼明显扩大(CRVO:0.515±0.26mm^(2)vs 0.27±0.08mm^(2),P<0.01;BRVO:0.376±0.12mm^(2)vs 0.261±0.07mm^(2),P<0.01),且均与BCVA呈正相关(CRVO:r_(s)=0.6,P=0.01;BRVO:r_(s)=0.5,P=0.01)。CRVO、BRVO患眼黄斑中心凹视网膜厚度均较健眼增加(CRVO:431.2±191.3μm vs 235.5±18.2μm,P<0.01;BRVO:373.2±188.7μm vs 233.8±13.7μm,P=0.01),均与BCVA呈正相关(CRVO:r_(s)=0.9,P=0.01;BRVO:r_(s)=0.6,P=0.01)。结论:OCTA可作为测量RVO患者黄斑区血流密度、FAZ面积及黄斑中心凹视网膜厚度的有效工具。
基金supported by the National Natural Science Foundation of China(21773106,21707066,21677069,and 21806077)the China Postdoctoral Science Foundation(2018M642206)~~
文摘近年来,以雾霾为代表的大气污染问题严重影响到经济社会的可持续发展.其中,氮氧化物(NOx)的大量排放是导致雾霾天气的重要原因之一.氨选择性催化还原(NH3-SCR)是目前消除氮氧化物的主流技术,低温NH3-SCR更是广泛应用于钢铁、焦化、水泥、玻璃、陶瓷和垃圾焚烧等行业的烟气排放治理.传统的V2O5-WO3/Ti O2催化剂活性温度高(300–400 oC)且钒具有生物毒性,因此亟待开发环境友好的低温非钒基脱硝催化剂.最近, Ce Ti Ox基催化剂由于在中高温段(250–400 oC)表现出优异的脱硝性能而得到广泛关注.然而,该催化剂仍面临低温活性差及抗硫性能差的问题,制约了其工业化应用.研究显示,添加过渡金属可提高Ce Ti Ox基催化剂的脱硝活性和抗硫中毒性能,这主要是因为过渡金属的添加可以有效改善催化剂的氧化还原性能和表面酸性.Mo O3作为一种可以提供大量酸性位的氧化物,常被用作助剂改善钒钨钛催化剂的活性.研究显示, Mo O3的引入可以促进催化剂中钒物种的分散度以及提高表面酸性.基于此,我们制备了一系列不同Mo含量的Mo O3/Ce Ti Ox催化剂,以期提高Ce Ti Ox催化剂的低温脱硝性能及抗SO2中毒能力,并着重研究表面Mo的修饰对Ce Ti Ox催化剂物理化学性质的影响.研究发现,表面Mo修饰可以显著提高Ce Ti Ox的低温催化活性,其脱硝效率在150 oC即可达到80%,同时抗SO2中毒能力也得到增强.进一步借助X射线衍射、比表面积测定、氢气程序升温还原、氨气程序升温脱附和X射线光电子能谱等方法对催化剂进行了全面表征分析.结果显示,表面Mo修饰对Ce Ti Ox催化剂物理化学性质的影响与其脱硝性能有着密不可分的关系.首先,钼物种主要是以Mo O3的形式存在于Ce Ti Ox表面,其最佳的负载量为4wt.%.其次,表面Mo的沉积显著提高了催化剂的表面酸量,尤其是Br?nsted酸位的数量,而表面酸位的增加有利于催化剂吸附与活化反应物种NH3;同时,表面Mo修饰还减弱了硝酸盐在催化剂表面的吸附,进一步促使NH3-SCR反应按照Eley-Rideal机理顺利进行.最后,该催化剂在H2O和SO2存在的条件下仍具有最佳的脱硝性能,因而有望用于实际含SO2的低温烟气脱硝.
文摘A series of ZSM-5 zeolites, with the morphologies of sphere, sphere with cubic particles on the surface, and cubic particles, were synthesized by hydrothermal method using n-butylamine as the template, assisted by the addition of NaCl and crystal seed. X-ray diffraction(XRD),scanning electron microscope(SEM), X-ray fluorescence(XRF) and temperature-programmed desorption of ammonia(NH3-TPD) were used to characterize these samples. The samples were tested with toluene methylation reaction. The modified sample composed of spherical particles with 3 μm crystal particles on the surface had a para-xylene selectivity of 95% and maintained 79% of the initial conversion after running the reaction for 50 h. This modified sample showed the best stability among the tested three modified samples.
基金The National Key Research and Development Program of China under contract No.2016YFC1402604the Scientific and Technological Innovation Project financially supported by Qingdao National Laboratory for Marine Science and Technology under contract No.2015ASKJ01+4 种基金the SOA Program on Global Change and Air-Sea Interactions under contract Nos GASI-IPOVAI-03,GASI-IPOVAI-02 and GASI-IPOVAI-01-02the National Natural Science Foundation of China under contract Nos 40476025,41876027and 41506036the China-Indonesia Maritime Cooperation Fund under contract No.U1406405the National Science Foundation of the United States under contract No.OCE-07-25935the Office of Naval Research of United States under contract No.N00014-08-01-0618
文摘Four trawl-resistant bottom mounts, with acoustic Doppler current profilers(ADCPs) embedded, were deployed in the Karimata Strait from November 2008 to June 2015 as part of the South China Sea-Indonesian Seas Transport/Exchange and Impact on Seasonal Fish Migration(SITE) Program, to estimate the volume and property transport between the South China Sea and Indonesian seas via the strait. The observed current data reveal that the volume transport through the Karimata Strait exhibits significant seasonal variation. The winteraveraged(from December to February) transport is –1.99 Sv(1 Sv=1×10~6 m^3/s), while in the boreal summer(from June to August), the average transport is 0.69 Sv. Moreover, the average transport from January 2009 to December2014 is –0.74 Sv(the positive/negative value indicates northward/southward transport). May and September are the transition period. In May, the currents in the Karimata Strait turn northward, consistent with the local monsoon. In September, the southeasterly trade wind is still present over the strait, driving surface water northward, whereas the bottom flow reverses direction, possibly because of the pressure gradient across the strait from north to south.
