Recently, the desiccation effect of the North Atlantic Oscillation(NAO) is found to be positively correlated with violent conflict in pre-industrial Europe, with agricultural shrinkage and its subsequent economic shoc...Recently, the desiccation effect of the North Atlantic Oscillation(NAO) is found to be positively correlated with violent conflict in pre-industrial Europe, with agricultural shrinkage and its subsequent economic shocks to be their causal link. However, it remains unexplored whether the correlation persists if the study period is extended backward in time, a different definition of violent conflict is applied, or the relationship is examined at lower geographic levels. In this study, we based on 835 internal disturbance incidents in Europe during 1049–1800 to conduct long-temporal and multi-scalar examination on the NAO-conflict nexus. ′Time-series′ and ′panel data′ disaggregation approaches, together with Granger Causality, Multiple Regression, and Survival Analyses were applied to verify the nexus quantitatively. Results show that the positive NAO-conflict correlation was significant at the continent and physiographic zone levels. During the positive NAO phases, the annual probability of internal disturbance outbreak increased by 70.0% in the southern Europe and the Mediterranean, a zone most affected by the NAO-induced desiccation effect. Yet, the NAO-conflict correlation was rather inconsistent when it was downscaled to the sub-regional level. Moreover, the NAO-conflict correlation was inflated under the time-series approach, while the panel data approach demonstrated the region-specific nature of the NAO forcing more clearly. The associated implications in examining climate-conflict nexus are discussed. Our findings may be crucial in examining violent conflict in the northwestern Africa, a highly agricultural region affected by the NAO.展开更多
Statistical power, number of replicates and experiment complexity of semi-field and field studies on Apis and non-Apis bee species has become a major issue after publication of the draft European Food Safety Authori...Statistical power, number of replicates and experiment complexity of semi-field and field studies on Apis and non-Apis bee species has become a major issue after publication of the draft European Food Safety Authority (EFSA) Guidance on risk assessment of plant protection products (PPP) on bees (Apis mellifera, Bombus spp. and solitary bees). According to this guidance document, field studies have to be designed to be able to detect significance differences as low as 7% for certain endpoints such as reduction in colony size. This will require an immense number of replicates which is obviously not feasible. In the present study, key endpoints such as mortality, termination rate and number of brood cells in honeybee studies, cocoon production and flight activity in solitary bee studies and number of gynes in bumble bee studies (just to mention some of the endpoints considered) in semi-field studies were analyzed, with Apis mellifera, Bombus terrestris and Osmia bicornis during the past five years (2013-2017). The results indicate huge differences in the percentage minimal detectable differences (%MDDs) (MDD expressed as median of control value of the endpoint in percent) depending on endpoint and species tested. For honeybee semi-field studies, the lowest %MDDs recorded were between 10% and 15% for the endpoints foraging, number of brood cells and colony strength. The highest %MDDs were observed for the endpoint termination rate, with a %MDD of almost 50%. For the endpoints in bumble bee semi-field studies the %MDDs varied between 17% for bumble bee colony weight and 53% for average mortality during the exposure period in the tunnel. The %MDD for the number of gynes (young queens) was slightly below 25%. For the semi-field solitary bee test system, the %MDDs for the measured endpoints seem to be lower than those for the other two species tested. The %MDDs for the endpoints hatching of offspring, nest occupation and number of cocoons were 8%, 13% and 14%, respectively. Most of the %MDDs were between 10% and 30% indicating clearly that the currently performed experimental design for the semi-field pollinator studies allowed to determine relatively small effects on key study endpoints. The analysis indicated that for all the three bee species tested, the semi-field test design detected low %MDDs for most of the endpoints. It was also observed that detectable differences between the control and PPP treatments were much lower in semi-field test designs than in field studies with these bee species. The “perfect sample size” really does not exist but test design and statistical analysis can be adapted to lower the %MDDs. Measured and simulated (according to Student’s t-test-distribution) data and results showed that statistical evaluations parameter selection (e.g., alpha value), data transformation (log10) and the number of replicates had a direct effect on the ability of the test design to detect lower or higher %MDD values. It could show that a change of alpha value from 0.05 to 0.1, increases the ability of the studies to detect lower %MDDs. For most of the measured endpoints, increasing the number of replicates e.g., from four to eight, improved the power of the test design by decreasing the %MDD. The reduction magnitude of the %MDD is dependent on the endpoint and selection of statistical parameters such as the alpha value. Parameters that display effects at a biologically relevant scale will be a better indicator for effects than parameters that are able to detect minor differences that are not biologically relevant.展开更多
AIM:To establish a rat ethanol gastritis model,we evaluated the effects of ethanol on gastric mucosa and studied the preventive effects of geranylgeranylacetone on ethanol-induced chronic gastritis.METHODS:One hundred...AIM:To establish a rat ethanol gastritis model,we evaluated the effects of ethanol on gastric mucosa and studied the preventive effects of geranylgeranylacetone on ethanol-induced chronic gastritis.METHODS:One hundred male Sprague-Dawley rats were randomly divided into 4 equal groups:normal control group,undergoing gastric perfusion of normal saline(NS) by gastrogavage;model control group and 2 model therapy groups that underwent gastric perfusion with ethanol(distillate spirits with 56% ethanol content) by gastrogavage for 4 wk.Low or high doses of geranylgeranylacetone were added 1 h before ethanol perfusion in the 2 model therapy groups,while the same amount of NS,instead of geranylgeranylacetone was used in that model control group.The rats were then sacrificed and stomachs were removed.The injury level of the gastric mucosa was observed by light and electron microscopy,and the levels of prostaglandin 2(PGE 2),endothelin-1(ET-1) and nitric oxide(NO) were measured by radioimmunoassay and the Griess method.RESULTS:The gastric mucosal epidermal damage score(EDS;4.5) and ulcer index(UI;12.0) of the model control group were significantly higher than that of the normal control group(0 and 0 respectively,all P = 0.000).The gastric mucosal EDS and UI of the 2 model therapy groups(EDS:2.5 and 2.0;UI:3.5 and 3.0) were significantly lower than that of the model control group(all P < 0.01).There was no statistically significant difference between the low-dose and high-dose model therapy groups.The expression value of plasma ET-1 of the model control group was higher than that of the normal control group(P < 0.01) and the 2 model therapy groups(all P < 0.01).The expression values of gastric mucosal PGE 2 and serum NO of the model control group were lower than those of the normal control group(all P < 0.05) and the 2 model therapy groups(all P < 0.05).The thickness of the gastric mucous layerand the hexosamine content in the model control group were significantly lower than that in the normal control group(all P < 0.01) and the 2 model therapy groups(all P < 0.05).Scanning and transmission electron microscopy observation showed that in the model control group,the epithelial junctions were vague,the intercellular joints disappeared and damage of the intracellular organelles were significantly worse than those in the normal control group.However,in the 2 model therapy groups,damage to the intercellular joints and organelles was ameliorate relative to the model control group.CONCLUSION:Administration of geranylgeranylacetone was correlated with a more favorable pattern of gastric mucosa damage after ethanol perfusion.The mechanism could be related to regulation of ET-1,NO and PGE 2.展开更多
In recent years, the computer drawing technology that deals with three-dimensional (3D) design of footwear has become hot topics. Rhino is a kind of common and practical 3D design software with strong drawing and rend...In recent years, the computer drawing technology that deals with three-dimensional (3D) design of footwear has become hot topics. Rhino is a kind of common and practical 3D design software with strong drawing and rendering graphics function, which is widely used to design industrial products. In this paper, through decomposition and modeling, modeling and drawing methods were analyzed in various parts of footwear by Rhino, as well as the smooth technology and adjustments to its profile curve by an example of lady's high boots. Finally, through a series introductions of rendering effects for footwear in color, light perception, grain characteristic, and 3D graphics, the main technical essential is achieved and difficulties in design of overall footwear styles are solved.展开更多
Autoimmune hepatitis(AIH) has rarely been described as an autoimmune paraneoplastic syndrome of thymoma.This case is the seventh case of AIH revealed by cholestasis few years after the diagnosis of thymoma and the fir...Autoimmune hepatitis(AIH) has rarely been described as an autoimmune paraneoplastic syndrome of thymoma.This case is the seventh case of AIH revealed by cholestasis few years after the diagnosis of thymoma and the first case treated with chemotherapy alone.We report in this paper a new approach to this rare severe condition.A 29 year-old man presented with chest pain and dyspnea with a history of thymoma surgically removed 4 years ago.CT scan showed the recurrence of an anterior mediastinal mass.Biology showed elevated liver enzymes and profound cholestasis.No sign of viral or toxic hepatitis or bile duct abnormalities were observed.Autoimmune antibodies,except for the anti-nuclear antibody,were negative.Liver biopsy showed active chronic AIH.The patient was diagnosed with recurrent thymoma with AIH and underwent 6 cycles of chemotherapy.A complete response on thymoma and cholestasis was obtained after 10 months of follow-up.Steroids and immunosuppressors are the standard treatment for AIH.The effect of chemotherapy as a specific treatment of this paraneoplastic syndrome needs to be considered.展开更多
An analytical model is presented to calculate the disassociation probability and the external quantum efficiency at high field in doped organic electrophosphorescence(EPH) devices. The charge recombination process and...An analytical model is presented to calculate the disassociation probability and the external quantum efficiency at high field in doped organic electrophosphorescence(EPH) devices. The charge recombination process and the triplet(T)-triplet(T) annihilation processes are taken into account in this model. The influences of applied voltage and the thickness of the device on the disassociation probability, and of current density and the thickness of the device on the external quantum efficiency are studied thoroughly by including and ignoring the disassociation of excitons. It is found that the dissociation probability of excitons will come close to 1 at high electric field, and the external EPH quantum efficiency is almost the same at low electric field. There is a large discrepancy of the external EPH quantum efficiency at high electric field for including or ignoring the disassociation of excitons.展开更多
Poly (vinyl butyral) (PVB) hollow fiber membranes were fabricated via thermally induced phase separation (TIPS). The effects of coagulation bath temperature (CBT) on the structure and performance of membranes ...Poly (vinyl butyral) (PVB) hollow fiber membranes were fabricated via thermally induced phase separation (TIPS). The effects of coagulation bath temperature (CBT) on the structure and performance of membranes were investigated in detail. The morphologies of the membranes were studied by scanning electron microscopy (SEM), the performances of water permeability, rejection, breaking strength and elongation were measured, respectively. The results indicate that all the membranes have the asymmetric morphology and the thickness of the skin layer decreases and the pore size of the outer layer increases with the increase of CBT. The permeability of membranes prepared at air gap 1.0 cm and take-up speed 0.253 m/s increases from 1.047×10-7 to 5.909×10-7 m3/(m2·s-kPa) with the CBT increasing from 20 ℃ to 40℃, and sharply increases to 35.226×10 7 m3/(m2.s.kPa)once the CBT arrives at 50 ℃. While the carbonic ink rejections have no significant decrease, totally exceed 98%, but that of acid-maleic acid copolymer greatly decreases with the increase of CBT. Both the breaking strength and elongation decrease with the increase of CBT.展开更多
The energy saving performance of energy efficient windows has strong dependence on window direction. Transmitted insolation level definitely affected the cooling and heating load. Simple simulation on the decrement of...The energy saving performance of energy efficient windows has strong dependence on window direction. Transmitted insolation level definitely affected the cooling and heating load. Simple simulation on the decrement of cooling load and the increment of heating load of a shading window compared with those of a transparent window show the prospect of energy saving effect clearly.From southeastward to southwestward, shading window even enlarges total heating and cooling loads when the thermal transmission is the same. However, if the shading coefficient of window is switched between summer and winter, total cooling and heating load can be reduced. This result clarifies the importance of "smart window".展开更多
Spinel structure Zn2SnO4 was successfully synthesized by microwave-assisted hydrothermal process. The effects of the microwave power on the formation and physical properties of the Zn2SnO4 particles are discussed. The...Spinel structure Zn2SnO4 was successfully synthesized by microwave-assisted hydrothermal process. The effects of the microwave power on the formation and physical properties of the Zn2SnO4 particles are discussed. The products were characterized by X-ray diffraction, atomic force microscopy, infrared spectroscopy, and N2 adsorption. The results indicated that the microwave power had important influence on the formation of the spinel phase. The results also revealed that the physical properties of Zn2SnO4 particles did not change with the increase of the microwave power above 600 W, with 20 min of reaction time. Furthermore, the photocatalytic activity of the Zn2SnO4 particles for the phenol degradation under sunlight was also investigated.展开更多
The response of an optical strain sensor based on the fiber Bragg grating is theoretically analyzed with a different approach of that found usually in the literature. In this model, geometrical changes suffered by the...The response of an optical strain sensor based on the fiber Bragg grating is theoretically analyzed with a different approach of that found usually in the literature. In this model, geometrical changes suffered by the grating itself are taken into account. The results are compared with those from experiments, showing very good agreement.展开更多
Atomic force microscope (AFM), as an important instrument in micro/nano operation, has been widely used to measure sampie's height information. However, the so called compression effect, due to force aroused from t...Atomic force microscope (AFM), as an important instrument in micro/nano operation, has been widely used to measure sampie's height information. However, the so called compression effect, due to force aroused from the contact of AFM tip with a sample surface, would result in imprecision of the surface's height measurement, i.e., the measured height is lower than expected. Up to now, there is not any effective and rapid method to attenuate this kind of measurement error. Thus, in this paper, an algorithm to obtain high accurate height measurement is proposed. Firstly, the concept of force curve is used to analyze the basic principle of the compression effect. Secondly, an automatic compensation method by fusing the height signal and the deflection signal is proposed. The proposed algorithm can also be used to obtain a surface elasticity image. Finally, in order to validate the proposed method, two experiments are conducted with respect to mufti-wall nano-carbon tubes on a silicon substrate and graphemes on a mica substrate.展开更多
The exactly solvable model of quasi-conical quantum dot, having a form of spherical sector, is proposed. Due to the specific symmetry of the problem the separation of variables in spherical coordinates is possible in ...The exactly solvable model of quasi-conical quantum dot, having a form of spherical sector, is proposed. Due to the specific symmetry of the problem the separation of variables in spherical coordinates is possible in the one- electron Sehrodinger equation. Analytical expressions for wave function and energy spectrum are obtained. It is shown that at small values of the stretch angle of spherical sector the problem is reduced to the conical QD problem. The comparison with previously performed works shows good agreement of results. As an application of the obtained results, the quantum transitions in the system are considered.展开更多
The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butt...The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butterfly wings is not only structure-based but also viewing-angle-dependent. Firstly, the discoloration effect of this typical butterfly was confirmed by a series of experiments. Then, the general form, arrangements, and geometrical dimensions of the scales were observed using a stereomicroscope. Scanning electron microscopy was also used to examine the two-dimensional morphologies and structures of a single scale. Afterwards, one model with the optimized three-dimensional profile of the structure was described using Pro-engineer software. The associate model was then analyzed to reconstruct the process between the incident light and the model surface. Finally, the mechanism of the angle-dependent discoloration effect was analyzed by theoretical calculation and optical simulation. Different light propagation paths and the length of the incident light at different angles caused destructive or constructive interference between the light reflected from the different layers. The different spectra of the reflected light make the wings appear with different structural colors, thereby endowing the angle-dependent discoloration effect. The consistency of the calculation and simulation results confirms that these structures possess an excellent angle-dependent discoloration effect. This functional "biomimetic structure" would not only be of great scientific interest but could also have a great impact in a wide range of applications such as reflective displays, credit card security, and military stealth technology.展开更多
OBJECTIVE: To study antimicrobial effect of Sodi- um houttuyfonate (SH) on Staphylococcus epider- midis (SE) and Candida albicans (CA). METHODS: The prepared strain broths (OD600=0.05) containing SE and CA w...OBJECTIVE: To study antimicrobial effect of Sodi- um houttuyfonate (SH) on Staphylococcus epider- midis (SE) and Candida albicans (CA). METHODS: The prepared strain broths (OD600=0.05) containing SE and CA were firstly used to test the minimal inhibitory concentrations (MICs) of SH, azithromycin (AZM) and fluconazole (FLU) by mi- cro-dilution method. Then the biofilms of SE and CA were matured in 96-well plates, and co-cultured with SH, AZM and FLU for 1, 2 and 3 days to assess the antibiofilm efficacies of the agents with differ- ent concentrations by crystal violet staining meth- od. At last, the treated biofilms of SE and CA by 2× MIC agents were observed by scanning electronic microscope. RESULTS: The MlCs of SE and CA were 256 and 1024 μg/mL, respectively. After the 1st, 2nd and3rd day of medications, the suppressions of biofilm were about 60% (P〈0.01), 76% (P=0.000) and 75% (P=0.000) by 2×MIC SH, the suppressions of biofilm were about 90% (P=0.000), 88% (P=0.000) and 90% (P=0.000) by 2×MIC SH, which could be testified by scanning electron microscope results. However, the inhibitions of biofilm attachment had no significant difference for SE by SH and azithromycin and CA by SH and fluconazole. CONCLUSION: SH had widely anti-pathogenic ef- fect on pathogenic biofilm formation of either bac- teria or fungus, had more influence on enclosed cells of SE and CA than the traditional antibiotics, revealing its target might be the extracellular poly- meric substances, and was more active to inhibit the growth of CA than SE.展开更多
基金Under the auspices of Hui Oi-Chow Trust Fund(No.201302172003,201502172003)Research Grants Council of Government of Hong Kong Special Administrative Region of China(No.HKU758712H,HKU745113H,HKU17610715)
文摘Recently, the desiccation effect of the North Atlantic Oscillation(NAO) is found to be positively correlated with violent conflict in pre-industrial Europe, with agricultural shrinkage and its subsequent economic shocks to be their causal link. However, it remains unexplored whether the correlation persists if the study period is extended backward in time, a different definition of violent conflict is applied, or the relationship is examined at lower geographic levels. In this study, we based on 835 internal disturbance incidents in Europe during 1049–1800 to conduct long-temporal and multi-scalar examination on the NAO-conflict nexus. ′Time-series′ and ′panel data′ disaggregation approaches, together with Granger Causality, Multiple Regression, and Survival Analyses were applied to verify the nexus quantitatively. Results show that the positive NAO-conflict correlation was significant at the continent and physiographic zone levels. During the positive NAO phases, the annual probability of internal disturbance outbreak increased by 70.0% in the southern Europe and the Mediterranean, a zone most affected by the NAO-induced desiccation effect. Yet, the NAO-conflict correlation was rather inconsistent when it was downscaled to the sub-regional level. Moreover, the NAO-conflict correlation was inflated under the time-series approach, while the panel data approach demonstrated the region-specific nature of the NAO forcing more clearly. The associated implications in examining climate-conflict nexus are discussed. Our findings may be crucial in examining violent conflict in the northwestern Africa, a highly agricultural region affected by the NAO.
文摘Statistical power, number of replicates and experiment complexity of semi-field and field studies on Apis and non-Apis bee species has become a major issue after publication of the draft European Food Safety Authority (EFSA) Guidance on risk assessment of plant protection products (PPP) on bees (Apis mellifera, Bombus spp. and solitary bees). According to this guidance document, field studies have to be designed to be able to detect significance differences as low as 7% for certain endpoints such as reduction in colony size. This will require an immense number of replicates which is obviously not feasible. In the present study, key endpoints such as mortality, termination rate and number of brood cells in honeybee studies, cocoon production and flight activity in solitary bee studies and number of gynes in bumble bee studies (just to mention some of the endpoints considered) in semi-field studies were analyzed, with Apis mellifera, Bombus terrestris and Osmia bicornis during the past five years (2013-2017). The results indicate huge differences in the percentage minimal detectable differences (%MDDs) (MDD expressed as median of control value of the endpoint in percent) depending on endpoint and species tested. For honeybee semi-field studies, the lowest %MDDs recorded were between 10% and 15% for the endpoints foraging, number of brood cells and colony strength. The highest %MDDs were observed for the endpoint termination rate, with a %MDD of almost 50%. For the endpoints in bumble bee semi-field studies the %MDDs varied between 17% for bumble bee colony weight and 53% for average mortality during the exposure period in the tunnel. The %MDD for the number of gynes (young queens) was slightly below 25%. For the semi-field solitary bee test system, the %MDDs for the measured endpoints seem to be lower than those for the other two species tested. The %MDDs for the endpoints hatching of offspring, nest occupation and number of cocoons were 8%, 13% and 14%, respectively. Most of the %MDDs were between 10% and 30% indicating clearly that the currently performed experimental design for the semi-field pollinator studies allowed to determine relatively small effects on key study endpoints. The analysis indicated that for all the three bee species tested, the semi-field test design detected low %MDDs for most of the endpoints. It was also observed that detectable differences between the control and PPP treatments were much lower in semi-field test designs than in field studies with these bee species. The “perfect sample size” really does not exist but test design and statistical analysis can be adapted to lower the %MDDs. Measured and simulated (according to Student’s t-test-distribution) data and results showed that statistical evaluations parameter selection (e.g., alpha value), data transformation (log10) and the number of replicates had a direct effect on the ability of the test design to detect lower or higher %MDD values. It could show that a change of alpha value from 0.05 to 0.1, increases the ability of the studies to detect lower %MDDs. For most of the measured endpoints, increasing the number of replicates e.g., from four to eight, improved the power of the test design by decreasing the %MDD. The reduction magnitude of the %MDD is dependent on the endpoint and selection of statistical parameters such as the alpha value. Parameters that display effects at a biologically relevant scale will be a better indicator for effects than parameters that are able to detect minor differences that are not biologically relevant.
文摘AIM:To establish a rat ethanol gastritis model,we evaluated the effects of ethanol on gastric mucosa and studied the preventive effects of geranylgeranylacetone on ethanol-induced chronic gastritis.METHODS:One hundred male Sprague-Dawley rats were randomly divided into 4 equal groups:normal control group,undergoing gastric perfusion of normal saline(NS) by gastrogavage;model control group and 2 model therapy groups that underwent gastric perfusion with ethanol(distillate spirits with 56% ethanol content) by gastrogavage for 4 wk.Low or high doses of geranylgeranylacetone were added 1 h before ethanol perfusion in the 2 model therapy groups,while the same amount of NS,instead of geranylgeranylacetone was used in that model control group.The rats were then sacrificed and stomachs were removed.The injury level of the gastric mucosa was observed by light and electron microscopy,and the levels of prostaglandin 2(PGE 2),endothelin-1(ET-1) and nitric oxide(NO) were measured by radioimmunoassay and the Griess method.RESULTS:The gastric mucosal epidermal damage score(EDS;4.5) and ulcer index(UI;12.0) of the model control group were significantly higher than that of the normal control group(0 and 0 respectively,all P = 0.000).The gastric mucosal EDS and UI of the 2 model therapy groups(EDS:2.5 and 2.0;UI:3.5 and 3.0) were significantly lower than that of the model control group(all P < 0.01).There was no statistically significant difference between the low-dose and high-dose model therapy groups.The expression value of plasma ET-1 of the model control group was higher than that of the normal control group(P < 0.01) and the 2 model therapy groups(all P < 0.01).The expression values of gastric mucosal PGE 2 and serum NO of the model control group were lower than those of the normal control group(all P < 0.05) and the 2 model therapy groups(all P < 0.05).The thickness of the gastric mucous layerand the hexosamine content in the model control group were significantly lower than that in the normal control group(all P < 0.01) and the 2 model therapy groups(all P < 0.05).Scanning and transmission electron microscopy observation showed that in the model control group,the epithelial junctions were vague,the intercellular joints disappeared and damage of the intracellular organelles were significantly worse than those in the normal control group.However,in the 2 model therapy groups,damage to the intercellular joints and organelles was ameliorate relative to the model control group.CONCLUSION:Administration of geranylgeranylacetone was correlated with a more favorable pattern of gastric mucosa damage after ethanol perfusion.The mechanism could be related to regulation of ET-1,NO and PGE 2.
文摘In recent years, the computer drawing technology that deals with three-dimensional (3D) design of footwear has become hot topics. Rhino is a kind of common and practical 3D design software with strong drawing and rendering graphics function, which is widely used to design industrial products. In this paper, through decomposition and modeling, modeling and drawing methods were analyzed in various parts of footwear by Rhino, as well as the smooth technology and adjustments to its profile curve by an example of lady's high boots. Finally, through a series introductions of rendering effects for footwear in color, light perception, grain characteristic, and 3D graphics, the main technical essential is achieved and difficulties in design of overall footwear styles are solved.
文摘Autoimmune hepatitis(AIH) has rarely been described as an autoimmune paraneoplastic syndrome of thymoma.This case is the seventh case of AIH revealed by cholestasis few years after the diagnosis of thymoma and the first case treated with chemotherapy alone.We report in this paper a new approach to this rare severe condition.A 29 year-old man presented with chest pain and dyspnea with a history of thymoma surgically removed 4 years ago.CT scan showed the recurrence of an anterior mediastinal mass.Biology showed elevated liver enzymes and profound cholestasis.No sign of viral or toxic hepatitis or bile duct abnormalities were observed.Autoimmune antibodies,except for the anti-nuclear antibody,were negative.Liver biopsy showed active chronic AIH.The patient was diagnosed with recurrent thymoma with AIH and underwent 6 cycles of chemotherapy.A complete response on thymoma and cholestasis was obtained after 10 months of follow-up.Steroids and immunosuppressors are the standard treatment for AIH.The effect of chemotherapy as a specific treatment of this paraneoplastic syndrome needs to be considered.
基金Excellent Youth Foundation of Hunan Province(03JJY1008) Science Foundation for Post-doctorate of China(2004035083) National Science Foundation of Hunan Province(06JJ20034)
文摘An analytical model is presented to calculate the disassociation probability and the external quantum efficiency at high field in doped organic electrophosphorescence(EPH) devices. The charge recombination process and the triplet(T)-triplet(T) annihilation processes are taken into account in this model. The influences of applied voltage and the thickness of the device on the disassociation probability, and of current density and the thickness of the device on the external quantum efficiency are studied thoroughly by including and ignoring the disassociation of excitons. It is found that the dissociation probability of excitons will come close to 1 at high electric field, and the external EPH quantum efficiency is almost the same at low electric field. There is a large discrepancy of the external EPH quantum efficiency at high electric field for including or ignoring the disassociation of excitons.
基金Project(21176264)supported by the National Natural Science Foundation of ChinaProject(11JJ2010)supported by the Hunan Provincial Natural Science Foundation of China
文摘Poly (vinyl butyral) (PVB) hollow fiber membranes were fabricated via thermally induced phase separation (TIPS). The effects of coagulation bath temperature (CBT) on the structure and performance of membranes were investigated in detail. The morphologies of the membranes were studied by scanning electron microscopy (SEM), the performances of water permeability, rejection, breaking strength and elongation were measured, respectively. The results indicate that all the membranes have the asymmetric morphology and the thickness of the skin layer decreases and the pore size of the outer layer increases with the increase of CBT. The permeability of membranes prepared at air gap 1.0 cm and take-up speed 0.253 m/s increases from 1.047×10-7 to 5.909×10-7 m3/(m2·s-kPa) with the CBT increasing from 20 ℃ to 40℃, and sharply increases to 35.226×10 7 m3/(m2.s.kPa)once the CBT arrives at 50 ℃. While the carbonic ink rejections have no significant decrease, totally exceed 98%, but that of acid-maleic acid copolymer greatly decreases with the increase of CBT. Both the breaking strength and elongation decrease with the increase of CBT.
文摘The energy saving performance of energy efficient windows has strong dependence on window direction. Transmitted insolation level definitely affected the cooling and heating load. Simple simulation on the decrement of cooling load and the increment of heating load of a shading window compared with those of a transparent window show the prospect of energy saving effect clearly.From southeastward to southwestward, shading window even enlarges total heating and cooling loads when the thermal transmission is the same. However, if the shading coefficient of window is switched between summer and winter, total cooling and heating load can be reduced. This result clarifies the importance of "smart window".
文摘Spinel structure Zn2SnO4 was successfully synthesized by microwave-assisted hydrothermal process. The effects of the microwave power on the formation and physical properties of the Zn2SnO4 particles are discussed. The products were characterized by X-ray diffraction, atomic force microscopy, infrared spectroscopy, and N2 adsorption. The results indicated that the microwave power had important influence on the formation of the spinel phase. The results also revealed that the physical properties of Zn2SnO4 particles did not change with the increase of the microwave power above 600 W, with 20 min of reaction time. Furthermore, the photocatalytic activity of the Zn2SnO4 particles for the phenol degradation under sunlight was also investigated.
文摘The response of an optical strain sensor based on the fiber Bragg grating is theoretically analyzed with a different approach of that found usually in the literature. In this model, geometrical changes suffered by the grating itself are taken into account. The results are compared with those from experiments, showing very good agreement.
基金supported by the CAS FEA International Partnership Program for Creative Research Teams
文摘Atomic force microscope (AFM), as an important instrument in micro/nano operation, has been widely used to measure sampie's height information. However, the so called compression effect, due to force aroused from the contact of AFM tip with a sample surface, would result in imprecision of the surface's height measurement, i.e., the measured height is lower than expected. Up to now, there is not any effective and rapid method to attenuate this kind of measurement error. Thus, in this paper, an algorithm to obtain high accurate height measurement is proposed. Firstly, the concept of force curve is used to analyze the basic principle of the compression effect. Secondly, an automatic compensation method by fusing the height signal and the deflection signal is proposed. The proposed algorithm can also be used to obtain a surface elasticity image. Finally, in order to validate the proposed method, two experiments are conducted with respect to mufti-wall nano-carbon tubes on a silicon substrate and graphemes on a mica substrate.
文摘The exactly solvable model of quasi-conical quantum dot, having a form of spherical sector, is proposed. Due to the specific symmetry of the problem the separation of variables in spherical coordinates is possible in the one- electron Sehrodinger equation. Analytical expressions for wave function and energy spectrum are obtained. It is shown that at small values of the stretch angle of spherical sector the problem is reduced to the conical QD problem. The comparison with previously performed works shows good agreement of results. As an application of the obtained results, the quantum transitions in the system are considered.
基金supported by the National Natural Science Foundation of China(Grant Nos.51325501,51505183&51290292)China Postdoctoral Science Foundation Funded Project(Project No.2015 M571360)
文摘The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butterfly wings is not only structure-based but also viewing-angle-dependent. Firstly, the discoloration effect of this typical butterfly was confirmed by a series of experiments. Then, the general form, arrangements, and geometrical dimensions of the scales were observed using a stereomicroscope. Scanning electron microscopy was also used to examine the two-dimensional morphologies and structures of a single scale. Afterwards, one model with the optimized three-dimensional profile of the structure was described using Pro-engineer software. The associate model was then analyzed to reconstruct the process between the incident light and the model surface. Finally, the mechanism of the angle-dependent discoloration effect was analyzed by theoretical calculation and optical simulation. Different light propagation paths and the length of the incident light at different angles caused destructive or constructive interference between the light reflected from the different layers. The different spectra of the reflected light make the wings appear with different structural colors, thereby endowing the angle-dependent discoloration effect. The consistency of the calculation and simulation results confirms that these structures possess an excellent angle-dependent discoloration effect. This functional "biomimetic structure" would not only be of great scientific interest but could also have a great impact in a wide range of applications such as reflective displays, credit card security, and military stealth technology.
基金Supported by the National Natural Science Foundation of China(No.81173629)
文摘OBJECTIVE: To study antimicrobial effect of Sodi- um houttuyfonate (SH) on Staphylococcus epider- midis (SE) and Candida albicans (CA). METHODS: The prepared strain broths (OD600=0.05) containing SE and CA were firstly used to test the minimal inhibitory concentrations (MICs) of SH, azithromycin (AZM) and fluconazole (FLU) by mi- cro-dilution method. Then the biofilms of SE and CA were matured in 96-well plates, and co-cultured with SH, AZM and FLU for 1, 2 and 3 days to assess the antibiofilm efficacies of the agents with differ- ent concentrations by crystal violet staining meth- od. At last, the treated biofilms of SE and CA by 2× MIC agents were observed by scanning electronic microscope. RESULTS: The MlCs of SE and CA were 256 and 1024 μg/mL, respectively. After the 1st, 2nd and3rd day of medications, the suppressions of biofilm were about 60% (P〈0.01), 76% (P=0.000) and 75% (P=0.000) by 2×MIC SH, the suppressions of biofilm were about 90% (P=0.000), 88% (P=0.000) and 90% (P=0.000) by 2×MIC SH, which could be testified by scanning electron microscope results. However, the inhibitions of biofilm attachment had no significant difference for SE by SH and azithromycin and CA by SH and fluconazole. CONCLUSION: SH had widely anti-pathogenic ef- fect on pathogenic biofilm formation of either bac- teria or fungus, had more influence on enclosed cells of SE and CA than the traditional antibiotics, revealing its target might be the extracellular poly- meric substances, and was more active to inhibit the growth of CA than SE.