Objective:To explore the implementation of gastrointestinal endoscopy technology and endoscopic narrow-band imaging(NBI)in the early screening of gastric cancer and to observe and study their application effects.Metho...Objective:To explore the implementation of gastrointestinal endoscopy technology and endoscopic narrow-band imaging(NBI)in the early screening of gastric cancer and to observe and study their application effects.Methods:During the period from March 2023 to August 2023,312 patients who received gastroscopy in the Kunming Guandu District People’s Hospital were selected,and they underwent both conventional gastroscopy and endoscopic NBI,with clinicopathological tissue biopsy serving as the gold standard.The application value for early screening of gastric cancer was observed and analyzed.Results:The scoring data showed that the clarity of gastric mucosal glandular tube structure,microvascular structure clarity,and lesion contour scoring data of conventional gastroscopy were lower than those of the NBI technology(P<0.05).The screening rate of pathological biopsy in 312 patients was 18.59%(58 cases).Conventional gastroscopy showed a screening rate of 11.53%(36 cases),while NBI technology examined a screening rate of 17.63%(55 cases),and the two-by-two comparison of the screening rate data of the three groups was not statistically significant(P>0.05).The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of conventional gastroscopy appeared to be lower than those of NBI technology(P<0.05).Conclusion:In the early screening of gastric cancer,endoscopic NBI technology can be applied to patients.Compared with conventional gastroscopy,it provides a clearer visualization of the structure of the gastric mucosal glandular structure and microvascular structure,with a certain screening rate.Additionally,its sensitivity,specificity,accuracy,positive predictive value,and negative predictive value are higher,demonstrating outstanding effectiveness.展开更多
[Objectives]To explore the anti-tumor activity of the extracts of petroleum ether,ethyl acetate,n-butanol and aqueous solution from Mahoniae caulis.[Methods]The extracts were extracted with petroleum ether,ethyl aceta...[Objectives]To explore the anti-tumor activity of the extracts of petroleum ether,ethyl acetate,n-butanol and aqueous solution from Mahoniae caulis.[Methods]The extracts were extracted with petroleum ether,ethyl acetate,n-butanol and aqueous solution respectively,and then concentrated.The inhibitory effects of these extracts on the growth of three tumor cell lines in vitro were detected by CCK-8 method,and the IC 50 value was calculated.[Results]The four extracts inhibited the growth of the three tumor cell lines in vitro,among which the n-butanol extract had the best anti-tumor activity.The IC 50 values of the n-butanol extract on human gastric cancer(SGC-7901),human breast cancer(MCF-7)and human liver cancer(BEL-7404)cell lines were 0.23,0.25 and 0.58 mg/mL,respectively.[Conclusions]The ethanol extract of Mahoniae caulis under petroleum ether,ethyl acetate,n-butanol and aqueous solution had certain anti-tumor effect,and n-butanol extract had the best anti-tumor activity.展开更多
This study compared HPV testing and liquid-based cytology (LCT) as performance indicators for cervical cancer screening in a hospital-based study. A total of 61,193 outpatients were screened initially by LCT. Sample...This study compared HPV testing and liquid-based cytology (LCT) as performance indicators for cervical cancer screening in a hospital-based study. A total of 61,193 outpatients were screened initially by LCT. Samples with screening results showing atypical squamous cells of undetermined significance (ASC-US) or worse were referred for colposcopy, and some samples were tested for high-risk HPV types with the Hybrid Capture II system (HC II). Data on LCT (n=61,193) and HC II (n=1056) results were analysed. Overall test positivity for LCT was 2.53% using an ASC-US threshold, 3.11% using a low-grade squamous intraepithelial lesion (LSIL) threshold, and 0.67% using a high-grade squamous intraepithelial lesion (HSIL) threshold. A total of 1839 women (84% of the 3893 patients with abnormal cytology) underwent colposcopy-directed biopsy. HPV was positive in 80.3% of women with cervical intraepithelial neoplasia 1 (CIN1), 88.3% of those with CIN2, 79.2% of women with CIN3 and 50% (2 of 4) of women with invasive cancer. There was a significant increase in the detection of CIN2 or worse with adjunct HPV testing of women with ASC-US and LSIL However, there were detection of CIN2+ cases no differences in the with adjunct HPV testing of women with HSlI.. The results indicate that HPV testing for HSlL triage should not be recommended in cervical cancer screening.展开更多
Objective:To develop a rapid,cost effective RT-PCR method for the mass scale diagnosis of such diseases at the vireraia stage to find out the actual disease burden in that area.Methods:For this purpose,cases with the ...Objective:To develop a rapid,cost effective RT-PCR method for the mass scale diagnosis of such diseases at the vireraia stage to find out the actual disease burden in that area.Methods:For this purpose,cases with the history of only short febrile illness were considered.Thus 157 samples with the history of dengue/chikungunya like illness and only 58 samples with a history of acute encephalitis syndrome(AES)were selected.Results:Out of 157 samples,42 and 74 were detected as dengue and chikungunya,respectively and out of 58 AES cases only 23 could be detected as Japanese encephalitis by this RT-PCR method.Conclusions:This cost effective RT-PCR method can detect the total positive cases that remain undetected by EL1SA method.Moreover,this method is capable to detect the viral RNA from patients'sera even after the appearance of IgM antibody at one fifth costs as compared with the other commercially available kits.展开更多
The screening effect of the random-phase-approximation on the states of shallow donor impurities in free strained wurtzite GaN/AlxGa1-xN heterojunctions under hydrostatic pressure and an external electric field is inv...The screening effect of the random-phase-approximation on the states of shallow donor impurities in free strained wurtzite GaN/AlxGa1-xN heterojunctions under hydrostatic pressure and an external electric field is investigated by using a variational method and a simplified coherent potential approximation. The variations of Stark energy shift with electric field, impurity position, A1 component and areal electron density are discussed. Our results show that the screening dramatically reduces both the blue and red shifts as well as the binding energies of impurity states. For a given impurity position, the change in binding energy is more sensitive to the increase in hydrostatic pressure in the presence of the screening effect than that in the absence of the screening effect. The weakening of the blue and red shifts, induced by the screening effect, strengthens gradually with the increase of electric field. Furthermore, the screening effect weakens the mixture crystal effect, thereby influencing the Stark effect. The screening effect strengthens the influence of energy band bending on binding energy due to the areal electron density.展开更多
The redox cycle of iron and manganese is a major geochemical process at the boundary layers of lake sediments. Lake Aha, which lies in the suburbs of Guiyang City,Guizhou Province, China, is a medium-sized artificial ...The redox cycle of iron and manganese is a major geochemical process at the boundary layers of lake sediments. Lake Aha, which lies in the suburbs of Guiyang City,Guizhou Province, China, is a medium-sized artificial reservoir with seasonally anoxic hypolimnion. Long-term sedimentary accumulation of iron and manganese resulted in their enrichment in the upper sediments. In the anoxic season, Fe2+ and Mn2+, formed by biological oxidation, would diffuse up to overlying waters from sedlments. However, the concentration of Fe2+ increased later and decreased earlier than that of Mn2+. Generally, sulfate reduction occurred at 6 cm below the sediment-water interface. Whereas, in the anoxic season, the reduction reached upper sediments, inhibiting the release of Fe2+. The Fe concentration of anoxic water is quickly decreased from high to low as a result of reduction Of the sulphur system.展开更多
When seismic waves propagate through the geological formation,there is a significant loss of energy and a decrease in imaging resolution,because of the viscoacoustic properties of subsurface medium.This profoundly imp...When seismic waves propagate through the geological formation,there is a significant loss of energy and a decrease in imaging resolution,because of the viscoacoustic properties of subsurface medium.This profoundly impacts seismic wavefield propagation,imaging and interpretation.To accurately image the true structure of subsurface medium,the consensus among geophysicists is to no longer treat subsurface medium as ideal homogeneous medium,but rather to incorporate the viscoacoustic properties of subsurface medium.Based on the generalized screen propagator using conventional acoustic wave equation(acoustic GSP),our developed method introduces viscoacoustic compensation strategy,and derives a one-way wave generalized screen propagator based on time-fractional viscoacoustic wave equation(viscoacoustic GSP).In numerical experiments,we conducted tests on two-dimensional multi-layer model and the Marmousi model.When comparing with the acoustic GSP using the acoustic data,we found that the imaging results of the viscoacoustic GSP using the viscoacoustic data showed a significant attenuation compensation effect,and achieved imaging results for both algorithms were essentially consistent.However,the imaging results of acoustic GSP using viscoacoustic data showed significant attenuation effects,especially for deep subsurface imaging.This indicates that we have proposed an effective method to compensate the attenuated seismic wavefield.Our application on a set of real seismic data demonstrated that the imaging performance of our proposed method in local areas surpassed that of the conventional acoustic GSP.This suggests that our proposed method holds practical value and can more accurately image real subsurface structures while enhancing imaging resolution compared with the conventional acoustic GSP.Finally,with respect to computational efficiency,we gathered statistics on running time to compare our proposed method with conventional Q-RTM,and it is evident that our method exhibits higher computational efficiency.In summary,our proposed viscoacoustic GSP method takes into account the true properties of the medium,still achieves migration results comparable to conventional acoustic GSP.展开更多
Two similar words, effectiveness and efficacy, have comparable insight and nearly describe analogous mea-ning for a screening test, yet clear understanding and perception of their diverse meanings will help clarify th...Two similar words, effectiveness and efficacy, have comparable insight and nearly describe analogous mea-ning for a screening test, yet clear understanding and perception of their diverse meanings will help clarify the basis of the differing conclusions about whether screening tests for different cancers reduce morbidity and mortality. Screening test may not be effective even when it sounds to be efficacious, on the other hand it should be efficacious when the test is effective.展开更多
This paper presents the fully differential cross sections (FDCS) for 102eV electron impact single ionization of helium for both the coplanar and perpendicular plane asymmetric geometries within the framework of dyna...This paper presents the fully differential cross sections (FDCS) for 102eV electron impact single ionization of helium for both the coplanar and perpendicular plane asymmetric geometries within the framework of dynamically screened three-Coulomb-wave theory. Comparisons are made with the experimental data and those of the three-Coulomb wave function model and second-order distorted-wave Born method. The angular distribution and relative heights of the present FDCS is found to be in very good agreement with the experimental data in the perpendicular plane geometry. It is shown that dynamical screening effects are significant in this geometry. Three-body coupling is expected to be weak in the coplanar geometry, although the precise absolute value of the cross section is still sensitive to the interaction details.展开更多
[Objectives]This study was conducted to investigate the antitussive and anti-inflammatory effects of Miao medicine Aspidistra caespitosa C.Pei.[Methods]A mouse cough model was made by the SO 2 cough induction method,a...[Objectives]This study was conducted to investigate the antitussive and anti-inflammatory effects of Miao medicine Aspidistra caespitosa C.Pei.[Methods]A mouse cough model was made by the SO 2 cough induction method,and the antitussive effects of different extraction fractions of A.caespitosa were observed.The inflammation models of acute inflammatory ear swelling in mice caused by xylene,granuloma in mice caused by cotton balls,and footpad swelling in mice caused by carrageenan were made,and the different extraction fractions were used to observe the effects of different extraction fractions on mouse ear swelling,granuloma and footpad swelling.And the levels of interleukin 6(IL-6)and tumor necrosis factor(TNF-a)in the serum of different groups of mice were detected to screen out the extraction fractions of A.caespitosa with good antitussive and anti-inflammatory activity.[Results]Antitussive experiments on mice showed that the water layer extraction fraction,ethyl acetate extraction fraction and petroleum ether extraction fraction of Miao medicine A.caespitosa could prolong the incubation period of cough in mice and reduce the number of coughs within 2 min to varying degrees,and its different extraction fractions all had different inhibitory effects on mouse ear swelling,granuloma and footpad swelling.Compared with the blank control group,the different extraction fractions could reduce IL-6,TNF-a and other indicators to different degrees.[Conclusions]Ethyl acetate extraction fraction of A.caespitosa has good antitussive and anti-inflammatory effects.展开更多
Higher order rnultipole potentials and electrostatic screening effects are introduced to incorporate the dan gling bonds on the surface of a metallic nanopaticle and to modify the coulornb like potential energy terms,...Higher order rnultipole potentials and electrostatic screening effects are introduced to incorporate the dan gling bonds on the surface of a metallic nanopaticle and to modify the coulornb like potential energy terms, respectively. The total interaction energy function for any rnetallic nanoparticle is represented in terms of two- and three-body potentials. The two-body part is described by dipole-dipole interaction potential, and in the three-body part, triple-dipole (DDD) and dipole-dipole-quadrupole (DDQ) terrns are included. The size-dependent cohesive energy and bulk modulus are observed to decrease with decreasing sizes, a result which is in good agreement with the experimental values of Mo and W nanoparticles.展开更多
Plasma-screening effects on positronium (Ps) formation for positron-hydrogen collisions in a Debye plasma environ- ment is further investigated using the screening approximation model with the inclusion of the modif...Plasma-screening effects on positronium (Ps) formation for positron-hydrogen collisions in a Debye plasma environ- ment is further investigated using the screening approximation model with the inclusion of the modified structure of Ps. More accurate Ps formation cross sections (n = 1,2) are obtained for various Debye lengths from the Ps formation thresh- olds to 50 eV. The influence of considering modified bound-state wave functions and eigenenergies for the Ps is found to result in the reduction of the Ps formation cross sections at low energies, whereas it cannot counteract the enhancement of the Ps formation by the Debye screening.展开更多
In a biased dissipative photovoltaic-photorefractive system, this paper investigates the temperature effect on the evolution and the self-deflection of the dissipative holographic screening-photovoltaic (DHSP) solit...In a biased dissipative photovoltaic-photorefractive system, this paper investigates the temperature effect on the evolution and the self-deflection of the dissipative holographic screening-photovoltaic (DHSP) solitons. The results reveal that, the evolution and the self-deflection of the bright and dark DHSP solitons are influenced by the system temperature. At a given temperature, for a stable DHSP soliton originally formed in the dissipative system, it attempts to evolve into another DHSP soliton when the temperature change is appropriately small, whereas it will become unstable or break down if the temperature departure is large enough. Moreover, the self-deflection degree of the solitary beam centre increases as temperature rises in some range, while it is decided by the system parameters and is slight under small-signal condition. The system temperature can be adjusted to change the formation and the self-deflection of the solitary beam in order to gain certain optical ends. In a word, the system temperature plays a role for the DHSP solitons in the dissipative system.展开更多
AIM: To discuss the efficacy of endoscopic mass screening for gastric cancer.METHODS: The data used in this study were the results of mass screening programs for gastric cancer in Niigata City from 2002 to 2004. The...AIM: To discuss the efficacy of endoscopic mass screening for gastric cancer.METHODS: The data used in this study were the results of mass screening programs for gastric cancer in Niigata City from 2002 to 2004. The number of participants was 35089 in 2002, 34557 in 2003 and 36600 in 2004. The finding ratio referred to the final diagnosis of gastric cancer after a double check of endoscopic files and histological findings. The costs of identifying one case of gastric cancer were calculated based on the total expense for each screening program and additional close examinations. RESULTS: From the analysis of individual screening program with endoscopy, individual screening program with X-ray (ISX) and mass screening program with photofluorography (MSP) in reference to the finding ratio of gastric cancer, endoscopic examination was the best for detecting early gastric cancer, the finding ratio was 0.87% in 2004, approximately 2.7 and 4.6 times higher than those of the ISX and MSP groups. In addition, this novel method was the cheapest means regarding the cost of identifying one case of gastric cancer, which was estimated to be 1608000 Japanese yen in 2004. CONCLUSION: Endoscopic mass screening is a promising method and can be effectively applied if a sufficient number of skilled endoscopists become available to staff the system and if city offices support it.展开更多
An array of rigid piles used as a screening barrier for plane shear (S) waves is investigated in a homogeneous unbounded space. The dynamic poroelastic theory of Biot is employed, under the assumption of an incompress...An array of rigid piles used as a screening barrier for plane shear (S) waves is investigated in a homogeneous unbounded space. The dynamic poroelastic theory of Biot is employed, under the assumption of an incompressible solid grain. Using Fourier-Bessel series, the problem of multiple scattering is solved by imposing continuity conditions and equilibrium conditions at the soil-pile interfaces with the translational addition theorem. A parametric analysis is conducted to investigate the influence of the permeability of poroelastic soil, separation between piles, number of piles and frequency of incident waves on screening effectiveness of the barrier, and the results are compared with those in an elastic soil medium. Computed results show that the intrinsic permeability of the soil medium displays an apparent effect on the screening of plane S waves.展开更多
Newborn hearing screening is an effective strategy for early identification of hearing loss in the newborn which result in early intervention and best outcome.However implementing universal screening strategy is a cha...Newborn hearing screening is an effective strategy for early identification of hearing loss in the newborn which result in early intervention and best outcome.However implementing universal screening strategy is a challenge in many resource constrained settings.There are various limitations towards successful implementation of hearing screening program in the developing countries.The cost effectiveness of the screening program also needs to be considered in a resource constrained settings.We attempt to provide a viewpoint that can be potentially helpful for the successful implementation of hearing screening in a resource constrained settings of the developing countries.展开更多
Electromagnetic screening is studied from the perspective of fluid mechanics by generalizing the Drude theory, which unifies three known results: Thomas–Fermi screening of the longitudinal field in both metals and s...Electromagnetic screening is studied from the perspective of fluid mechanics by generalizing the Drude theory, which unifies three known results: Thomas–Fermi screening of the longitudinal field in both metals and superconductors, the skin effect of the transverse field in metals, and the Meissner effect in superconductors. In the special case of superfluid electrons, we slightly generalize the London equations to incorporate the longitudinal electric fields. Moreover, regarding the experiments, our study points out that the dynamical measurement may overestimate the superfluid density.展开更多
[ Objective] The paper was to select the suitable herbicides for summer sowing breomcom millet and reduce labor costs. [ Method ] More than 20 kinds of herbicides commonly used in fields had been preliminarily screene...[ Objective] The paper was to select the suitable herbicides for summer sowing breomcom millet and reduce labor costs. [ Method ] More than 20 kinds of herbicides commonly used in fields had been preliminarily screened, and six kinds of herbicides were selected for further field herbicidal effect experiment. [ Re- suit] The herbicidal effects of 2,4-D butylate, MCPA-Na, tribenuren, 2,4-D isooctyl ester and monosulfuren plus prepasine against Pharbitis nil ( lAan. ) Choisy, Amaranth mangostanus L. and Portulaca oleracea L. were greater than 70%, and the weed control effect on fresh weight by leaf and stem spray of tribenu- ran and MCPA-Na were greater than 96% after herbicide application for 20 d. [ Concluslon] The study provides the guidance for production of breomcom millet.展开更多
Nonlinear screening of a test charge in plasma by electrons trapped or untrapped is studied. The obtained results are in rigorous estimations mathematically in comparison with the corresponding Debye screening forms.M...Nonlinear screening of a test charge in plasma by electrons trapped or untrapped is studied. The obtained results are in rigorous estimations mathematically in comparison with the corresponding Debye screening forms.Meanwhile their validity is physically discussed and some confusions in literature are clarified.展开更多
文摘Objective:To explore the implementation of gastrointestinal endoscopy technology and endoscopic narrow-band imaging(NBI)in the early screening of gastric cancer and to observe and study their application effects.Methods:During the period from March 2023 to August 2023,312 patients who received gastroscopy in the Kunming Guandu District People’s Hospital were selected,and they underwent both conventional gastroscopy and endoscopic NBI,with clinicopathological tissue biopsy serving as the gold standard.The application value for early screening of gastric cancer was observed and analyzed.Results:The scoring data showed that the clarity of gastric mucosal glandular tube structure,microvascular structure clarity,and lesion contour scoring data of conventional gastroscopy were lower than those of the NBI technology(P<0.05).The screening rate of pathological biopsy in 312 patients was 18.59%(58 cases).Conventional gastroscopy showed a screening rate of 11.53%(36 cases),while NBI technology examined a screening rate of 17.63%(55 cases),and the two-by-two comparison of the screening rate data of the three groups was not statistically significant(P>0.05).The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of conventional gastroscopy appeared to be lower than those of NBI technology(P<0.05).Conclusion:In the early screening of gastric cancer,endoscopic NBI technology can be applied to patients.Compared with conventional gastroscopy,it provides a clearer visualization of the structure of the gastric mucosal glandular structure and microvascular structure,with a certain screening rate.Additionally,its sensitivity,specificity,accuracy,positive predictive value,and negative predictive value are higher,demonstrating outstanding effectiveness.
基金Supported by Guangxi Key Research and Development Plan Project(Gui Ke AB18221095)2023 Innovation Project of Youjiang Medical University for Nationalities Graduate Education(YXCXJH2023009)Scientific Research Project of High-level Talents of Youjiang Medical University for Nationalities(01002018079).
文摘[Objectives]To explore the anti-tumor activity of the extracts of petroleum ether,ethyl acetate,n-butanol and aqueous solution from Mahoniae caulis.[Methods]The extracts were extracted with petroleum ether,ethyl acetate,n-butanol and aqueous solution respectively,and then concentrated.The inhibitory effects of these extracts on the growth of three tumor cell lines in vitro were detected by CCK-8 method,and the IC 50 value was calculated.[Results]The four extracts inhibited the growth of the three tumor cell lines in vitro,among which the n-butanol extract had the best anti-tumor activity.The IC 50 values of the n-butanol extract on human gastric cancer(SGC-7901),human breast cancer(MCF-7)and human liver cancer(BEL-7404)cell lines were 0.23,0.25 and 0.58 mg/mL,respectively.[Conclusions]The ethanol extract of Mahoniae caulis under petroleum ether,ethyl acetate,n-butanol and aqueous solution had certain anti-tumor effect,and n-butanol extract had the best anti-tumor activity.
基金funded by Beijing Municipal Science & Technology Commission(No.Y0905001000091)
文摘This study compared HPV testing and liquid-based cytology (LCT) as performance indicators for cervical cancer screening in a hospital-based study. A total of 61,193 outpatients were screened initially by LCT. Samples with screening results showing atypical squamous cells of undetermined significance (ASC-US) or worse were referred for colposcopy, and some samples were tested for high-risk HPV types with the Hybrid Capture II system (HC II). Data on LCT (n=61,193) and HC II (n=1056) results were analysed. Overall test positivity for LCT was 2.53% using an ASC-US threshold, 3.11% using a low-grade squamous intraepithelial lesion (LSIL) threshold, and 0.67% using a high-grade squamous intraepithelial lesion (HSIL) threshold. A total of 1839 women (84% of the 3893 patients with abnormal cytology) underwent colposcopy-directed biopsy. HPV was positive in 80.3% of women with cervical intraepithelial neoplasia 1 (CIN1), 88.3% of those with CIN2, 79.2% of women with CIN3 and 50% (2 of 4) of women with invasive cancer. There was a significant increase in the detection of CIN2 or worse with adjunct HPV testing of women with ASC-US and LSIL However, there were detection of CIN2+ cases no differences in the with adjunct HPV testing of women with HSlI.. The results indicate that HPV testing for HSlL triage should not be recommended in cervical cancer screening.
基金supported by the Department of Science and Technology,Goverment of West Bengal.India[grant No.705(Sanc.)ST/P/S&T/9G-27/2007]
文摘Objective:To develop a rapid,cost effective RT-PCR method for the mass scale diagnosis of such diseases at the vireraia stage to find out the actual disease burden in that area.Methods:For this purpose,cases with the history of only short febrile illness were considered.Thus 157 samples with the history of dengue/chikungunya like illness and only 58 samples with a history of acute encephalitis syndrome(AES)were selected.Results:Out of 157 samples,42 and 74 were detected as dengue and chikungunya,respectively and out of 58 AES cases only 23 could be detected as Japanese encephalitis by this RT-PCR method.Conclusions:This cost effective RT-PCR method can detect the total positive cases that remain undetected by EL1SA method.Moreover,this method is capable to detect the viral RNA from patients'sera even after the appearance of IgM antibody at one fifth costs as compared with the other commercially available kits.
基金Project supported by the National Natural Science Foundation of China (Grant No 60566002)the Specialized Research Fundfor the Doctoral Program of Higher Education of China (Grant No 20070126001)
文摘The screening effect of the random-phase-approximation on the states of shallow donor impurities in free strained wurtzite GaN/AlxGa1-xN heterojunctions under hydrostatic pressure and an external electric field is investigated by using a variational method and a simplified coherent potential approximation. The variations of Stark energy shift with electric field, impurity position, A1 component and areal electron density are discussed. Our results show that the screening dramatically reduces both the blue and red shifts as well as the binding energies of impurity states. For a given impurity position, the change in binding energy is more sensitive to the increase in hydrostatic pressure in the presence of the screening effect than that in the absence of the screening effect. The weakening of the blue and red shifts, induced by the screening effect, strengthens gradually with the increase of electric field. Furthermore, the screening effect weakens the mixture crystal effect, thereby influencing the Stark effect. The screening effect strengthens the influence of energy band bending on binding energy due to the areal electron density.
文摘The redox cycle of iron and manganese is a major geochemical process at the boundary layers of lake sediments. Lake Aha, which lies in the suburbs of Guiyang City,Guizhou Province, China, is a medium-sized artificial reservoir with seasonally anoxic hypolimnion. Long-term sedimentary accumulation of iron and manganese resulted in their enrichment in the upper sediments. In the anoxic season, Fe2+ and Mn2+, formed by biological oxidation, would diffuse up to overlying waters from sedlments. However, the concentration of Fe2+ increased later and decreased earlier than that of Mn2+. Generally, sulfate reduction occurred at 6 cm below the sediment-water interface. Whereas, in the anoxic season, the reduction reached upper sediments, inhibiting the release of Fe2+. The Fe concentration of anoxic water is quickly decreased from high to low as a result of reduction Of the sulphur system.
基金financially supported by the National Natural Science Foundation of China (grant Nos.42004103,42374149)Sichuan Science and Technology Program (grant No.2023NSFSC0257)CNPC Innovation Found (2022DQ02-0306)。
文摘When seismic waves propagate through the geological formation,there is a significant loss of energy and a decrease in imaging resolution,because of the viscoacoustic properties of subsurface medium.This profoundly impacts seismic wavefield propagation,imaging and interpretation.To accurately image the true structure of subsurface medium,the consensus among geophysicists is to no longer treat subsurface medium as ideal homogeneous medium,but rather to incorporate the viscoacoustic properties of subsurface medium.Based on the generalized screen propagator using conventional acoustic wave equation(acoustic GSP),our developed method introduces viscoacoustic compensation strategy,and derives a one-way wave generalized screen propagator based on time-fractional viscoacoustic wave equation(viscoacoustic GSP).In numerical experiments,we conducted tests on two-dimensional multi-layer model and the Marmousi model.When comparing with the acoustic GSP using the acoustic data,we found that the imaging results of the viscoacoustic GSP using the viscoacoustic data showed a significant attenuation compensation effect,and achieved imaging results for both algorithms were essentially consistent.However,the imaging results of acoustic GSP using viscoacoustic data showed significant attenuation effects,especially for deep subsurface imaging.This indicates that we have proposed an effective method to compensate the attenuated seismic wavefield.Our application on a set of real seismic data demonstrated that the imaging performance of our proposed method in local areas surpassed that of the conventional acoustic GSP.This suggests that our proposed method holds practical value and can more accurately image real subsurface structures while enhancing imaging resolution compared with the conventional acoustic GSP.Finally,with respect to computational efficiency,we gathered statistics on running time to compare our proposed method with conventional Q-RTM,and it is evident that our method exhibits higher computational efficiency.In summary,our proposed viscoacoustic GSP method takes into account the true properties of the medium,still achieves migration results comparable to conventional acoustic GSP.
文摘Two similar words, effectiveness and efficacy, have comparable insight and nearly describe analogous mea-ning for a screening test, yet clear understanding and perception of their diverse meanings will help clarify the basis of the differing conclusions about whether screening tests for different cancers reduce morbidity and mortality. Screening test may not be effective even when it sounds to be efficacious, on the other hand it should be efficacious when the test is effective.
基金Project supported by the Natural Science Foundation of Shanxi Province,China (Grant No 20051008)the Science Foundation for Returnee of Shanxi Province of China (Grant No 02-16)
文摘This paper presents the fully differential cross sections (FDCS) for 102eV electron impact single ionization of helium for both the coplanar and perpendicular plane asymmetric geometries within the framework of dynamically screened three-Coulomb-wave theory. Comparisons are made with the experimental data and those of the three-Coulomb wave function model and second-order distorted-wave Born method. The angular distribution and relative heights of the present FDCS is found to be in very good agreement with the experimental data in the perpendicular plane geometry. It is shown that dynamical screening effects are significant in this geometry. Three-body coupling is expected to be weak in the coplanar geometry, although the precise absolute value of the cross section is still sensitive to the interaction details.
基金Scientific and Technological Research Project of Traditional Chinese Medicine and Ethnic Medicine of Guizhou Administration of Traditional Chinese Medicine(QZYY2017-116)Scientific Research Project of Guizhou University of Traditional Chinese Medicine(GZYKYN[2017]28).
文摘[Objectives]This study was conducted to investigate the antitussive and anti-inflammatory effects of Miao medicine Aspidistra caespitosa C.Pei.[Methods]A mouse cough model was made by the SO 2 cough induction method,and the antitussive effects of different extraction fractions of A.caespitosa were observed.The inflammation models of acute inflammatory ear swelling in mice caused by xylene,granuloma in mice caused by cotton balls,and footpad swelling in mice caused by carrageenan were made,and the different extraction fractions were used to observe the effects of different extraction fractions on mouse ear swelling,granuloma and footpad swelling.And the levels of interleukin 6(IL-6)and tumor necrosis factor(TNF-a)in the serum of different groups of mice were detected to screen out the extraction fractions of A.caespitosa with good antitussive and anti-inflammatory activity.[Results]Antitussive experiments on mice showed that the water layer extraction fraction,ethyl acetate extraction fraction and petroleum ether extraction fraction of Miao medicine A.caespitosa could prolong the incubation period of cough in mice and reduce the number of coughs within 2 min to varying degrees,and its different extraction fractions all had different inhibitory effects on mouse ear swelling,granuloma and footpad swelling.Compared with the blank control group,the different extraction fractions could reduce IL-6,TNF-a and other indicators to different degrees.[Conclusions]Ethyl acetate extraction fraction of A.caespitosa has good antitussive and anti-inflammatory effects.
基金Supported by King Saud University,College of Science-Research Center,Project Number PHYS/2009/19
文摘Higher order rnultipole potentials and electrostatic screening effects are introduced to incorporate the dan gling bonds on the surface of a metallic nanopaticle and to modify the coulornb like potential energy terms, respectively. The total interaction energy function for any rnetallic nanoparticle is represented in terms of two- and three-body potentials. The two-body part is described by dipole-dipole interaction potential, and in the three-body part, triple-dipole (DDD) and dipole-dipole-quadrupole (DDQ) terrns are included. The size-dependent cohesive energy and bulk modulus are observed to decrease with decreasing sizes, a result which is in good agreement with the experimental values of Mo and W nanoparticles.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11404223,11447158,and 11604223)the Doctoral Program Foundation of Shenyang Aerospace University,China(Grant No.13YB26)
文摘Plasma-screening effects on positronium (Ps) formation for positron-hydrogen collisions in a Debye plasma environ- ment is further investigated using the screening approximation model with the inclusion of the modified structure of Ps. More accurate Ps formation cross sections (n = 1,2) are obtained for various Debye lengths from the Ps formation thresh- olds to 50 eV. The influence of considering modified bound-state wave functions and eigenenergies for the Ps is found to result in the reduction of the Ps formation cross sections at low energies, whereas it cannot counteract the enhancement of the Ps formation by the Debye screening.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10574051 and 10174025)
文摘In a biased dissipative photovoltaic-photorefractive system, this paper investigates the temperature effect on the evolution and the self-deflection of the dissipative holographic screening-photovoltaic (DHSP) solitons. The results reveal that, the evolution and the self-deflection of the bright and dark DHSP solitons are influenced by the system temperature. At a given temperature, for a stable DHSP soliton originally formed in the dissipative system, it attempts to evolve into another DHSP soliton when the temperature change is appropriately small, whereas it will become unstable or break down if the temperature departure is large enough. Moreover, the self-deflection degree of the solitary beam centre increases as temperature rises in some range, while it is decided by the system parameters and is slight under small-signal condition. The system temperature can be adjusted to change the formation and the self-deflection of the solitary beam in order to gain certain optical ends. In a word, the system temperature plays a role for the DHSP solitons in the dissipative system.
文摘AIM: To discuss the efficacy of endoscopic mass screening for gastric cancer.METHODS: The data used in this study were the results of mass screening programs for gastric cancer in Niigata City from 2002 to 2004. The number of participants was 35089 in 2002, 34557 in 2003 and 36600 in 2004. The finding ratio referred to the final diagnosis of gastric cancer after a double check of endoscopic files and histological findings. The costs of identifying one case of gastric cancer were calculated based on the total expense for each screening program and additional close examinations. RESULTS: From the analysis of individual screening program with endoscopy, individual screening program with X-ray (ISX) and mass screening program with photofluorography (MSP) in reference to the finding ratio of gastric cancer, endoscopic examination was the best for detecting early gastric cancer, the finding ratio was 0.87% in 2004, approximately 2.7 and 4.6 times higher than those of the ISX and MSP groups. In addition, this novel method was the cheapest means regarding the cost of identifying one case of gastric cancer, which was estimated to be 1608000 Japanese yen in 2004. CONCLUSION: Endoscopic mass screening is a promising method and can be effectively applied if a sufficient number of skilled endoscopists become available to staff the system and if city offices support it.
基金Project (No. 50778136) supported by the National Natural Science Foundation of China
文摘An array of rigid piles used as a screening barrier for plane shear (S) waves is investigated in a homogeneous unbounded space. The dynamic poroelastic theory of Biot is employed, under the assumption of an incompressible solid grain. Using Fourier-Bessel series, the problem of multiple scattering is solved by imposing continuity conditions and equilibrium conditions at the soil-pile interfaces with the translational addition theorem. A parametric analysis is conducted to investigate the influence of the permeability of poroelastic soil, separation between piles, number of piles and frequency of incident waves on screening effectiveness of the barrier, and the results are compared with those in an elastic soil medium. Computed results show that the intrinsic permeability of the soil medium displays an apparent effect on the screening of plane S waves.
文摘Newborn hearing screening is an effective strategy for early identification of hearing loss in the newborn which result in early intervention and best outcome.However implementing universal screening strategy is a challenge in many resource constrained settings.There are various limitations towards successful implementation of hearing screening program in the developing countries.The cost effectiveness of the screening program also needs to be considered in a resource constrained settings.We attempt to provide a viewpoint that can be potentially helpful for the successful implementation of hearing screening in a resource constrained settings of the developing countries.
基金Project supported by the National Natural Science Foundation of China(Grant No.11504164)
文摘Electromagnetic screening is studied from the perspective of fluid mechanics by generalizing the Drude theory, which unifies three known results: Thomas–Fermi screening of the longitudinal field in both metals and superconductors, the skin effect of the transverse field in metals, and the Meissner effect in superconductors. In the special case of superfluid electrons, we slightly generalize the London equations to incorporate the longitudinal electric fields. Moreover, regarding the experiments, our study points out that the dynamical measurement may overestimate the superfluid density.
基金Supported by Screening and Processing of Functional Health Millet Varieties Suitable for Diabetes and Obesity(12230301D)
文摘[ Objective] The paper was to select the suitable herbicides for summer sowing breomcom millet and reduce labor costs. [ Method ] More than 20 kinds of herbicides commonly used in fields had been preliminarily screened, and six kinds of herbicides were selected for further field herbicidal effect experiment. [ Re- suit] The herbicidal effects of 2,4-D butylate, MCPA-Na, tribenuren, 2,4-D isooctyl ester and monosulfuren plus prepasine against Pharbitis nil ( lAan. ) Choisy, Amaranth mangostanus L. and Portulaca oleracea L. were greater than 70%, and the weed control effect on fresh weight by leaf and stem spray of tribenu- ran and MCPA-Na were greater than 96% after herbicide application for 20 d. [ Concluslon] The study provides the guidance for production of breomcom millet.
文摘Nonlinear screening of a test charge in plasma by electrons trapped or untrapped is studied. The obtained results are in rigorous estimations mathematically in comparison with the corresponding Debye screening forms.Meanwhile their validity is physically discussed and some confusions in literature are clarified.