In the media of 0.66,0.96, 2. 16 and 0.54 mol/L ofH2SO4,the heteropoly acids of As,P.Si and Ge are separately reduced to corresponding heteropoly blues by gibberellin, which exhibit maxirnum absorptions at 835, 820, 8...In the media of 0.66,0.96, 2. 16 and 0.54 mol/L ofH2SO4,the heteropoly acids of As,P.Si and Ge are separately reduced to corresponding heteropoly blues by gibberellin, which exhibit maxirnum absorptions at 835, 820, 810 and 805 nm with molar absorptivities of 2.64x104, 2.54x104 3.51x104 and 2.25x104 L.mol-1'cm-1 and linear ranges of 0-30,0-15,0-10 and 0-30 μg/25mL, The method was applied to the determinations of As, P and Si in alloyed steel.展开更多
Kinetics of complexation reaction of Co2+ with 2-benzoylpyridine-4-phenyl-3-thiosemicarbazone(BPPT) was spectrophotometrically examined at 421 nm.The ligand that is developed for a simple kinetic-spectrophotometric de...Kinetics of complexation reaction of Co2+ with 2-benzoylpyridine-4-phenyl-3-thiosemicarbazone(BPPT) was spectrophotometrically examined at 421 nm.The ligand that is developed for a simple kinetic-spectrophotometric determination of Co2+ is based on 1:2 complex formation between Co2+ and BPPT.The complexation reaction was carried out in ethanol-water medium at 25 ℃.Kinetic and activation parameters of the complexation reaction were calculated,and the rate equation and the reaction mechanism were proposed.The calibration graph is linear in the concentration range of 0.10~2.91 mg·L-1 for the tangent method.The species that caused interference were investigated.展开更多
Betulin(BE)can be obtained from many plants,such as those belonging Betulaceae family,and pharmacological investigations showed its notable biological properties and good potential for food and pharmaceutical developm...Betulin(BE)can be obtained from many plants,such as those belonging Betulaceae family,and pharmacological investigations showed its notable biological properties and good potential for food and pharmaceutical development.We investigated the homogeneity,stability,purity,and uncertainty of a newly certified reference material(CRM)of BE.The certified purity value for the CRM of BE was 99.56%with an extended uncertainty of 0.07%(k=2,P=0.95),as determined by differential scanning calorimetry(DSC).In this study,DSC was used for the first time for purity determination of BE.Given its high accuracy,precision,and reproducibility,DSC can be used as an alternative technique for purity determination of CRMs in the pharmaceutical and food industry.展开更多
Background: The etiology of adult obesity is still poorly understood. It has been shown that over-weight children suffer from adverse psychological events, but less is known about the association of adverse psychologi...Background: The etiology of adult obesity is still poorly understood. It has been shown that over-weight children suffer from adverse psychological events, but less is known about the association of adverse psychological factors among normal weight children and adult obesity. Aim: The aim of this study was to examine if the exposure of perception of being bullied during childhood could be associated with development of adult obesity. Methods: Adult, same-sexed twin pairs discordant for BMI were identified from the Danish Twin Registry. The twins underwent an interview and a physical examination. Data were analyzed by means of a growth-curve model and an intra-pair comparison. This design controls for other influences of early lifestyle and socio economic status and is therefore a powerful tool to study independent effects of specific exposures. Results: In total 236 (81.7%) of the twin individuals identified participated in the study. Participants who reported having been bullied in school, had attained a BMI which was on average 1.4 kg/m2 (95% CI = 0.2;2.5, p = 0.02) higher than those not bullied. Two other questions on specific types of bullying resulted in BMI that were 1.1 kg/m2 (CI = 0.1;2.2, p = 0.03) and 1.9 kg/m2 (CI = 0.7;3.1, p = 0.002) larger than subjects who had not been exposed to bullying. There was a direct association between intra pair differences in BMI and exposure to bullying. Conclusion: The results of the study could indicate that being bullied during childhood seems be associated with adult obesity.展开更多
A spectrophotometric method for the assay of lamivudine in pure form and in dosage form was developed in this study. The method was based on charge-transfer complex formation between the drug, which acted as n-donor w...A spectrophotometric method for the assay of lamivudine in pure form and in dosage form was developed in this study. The method was based on charge-transfer complex formation between the drug, which acted as n-donor while chloranilic acid and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) acted as a p-acceptor in a non-aqueous solvent in each case. Chloranilic acid was found to form a charge-transfer complex in a 1:1 stoichiometry with lamuvudine (lamivudine-chloranilic acid) with a maximium absorption band at 521 nm. Also, DDQ was found to form a charge-transfer complex in a 1:1 stoichiometry with lamivudine (lamivudine-DDQ) with a maximium absorption band at 530 nm. The pH was obeyed at acid range. The complexes obeyed Beer’s law at a concentration range of 0.04 - 0.28 mg/ml. The thermodynamic parameters calculated at different temperatures included the molar absorptivity, association constant, free energy change, enthalpy and entropy. The proposed method has been conveniently applied in the analysis of commercially available lamivudine tablet with good accuracy and precision.展开更多
The electronic and optical properties of TiS2 are studied of density functional theory. A linearized and augmented by using an ab-initio calculation within the frame plane wave basis set with the generalized gradient ...The electronic and optical properties of TiS2 are studied of density functional theory. A linearized and augmented by using an ab-initio calculation within the frame plane wave basis set with the generalized gradient approximation as proposed by Perdew et al. is used for the energy exchange-correlation determination. The results show a metallic character of TiS2, and the plots of total and partial densities of states of TiS2 show the metallic character of the bonds and a strong hybridization between the states d of Ti and p of S below the Fermi energy. The optical properties of the material such as real and imaginary parts of dielectric constant (ε(w) = ε1(w) + iε2(w)), refractive index n(w), optical reflectivity R(w), for E / /x and E / /z are performed for the energy range of 0-.14 eV.展开更多
A new highly sensitive spectrophotometric method has been developed for the determination of micro amounts of bismuth (Ⅲ), based on the formation of Bi (Ⅲ)—meso—tetrakis—(4—N—trimethylammonium phenyl) porphine ...A new highly sensitive spectrophotometric method has been developed for the determination of micro amounts of bismuth (Ⅲ), based on the formation of Bi (Ⅲ)—meso—tetrakis—(4—N—trimethylammonium phenyl) porphine [T (4TMAP) P] complex. In the presence of Cd (Ⅱ), Bi(Ⅲ) reacts almost instantaneously with T (4TMAP)P in a 0. 6 mol/l NaAc—HAC buffer (PH5.8) at room temperature. The composition of the complex is T(4TMAP)P: Bi=1:1. The absorbance complex obeys Beer's law over the Bi(Ⅲ) concentration range 0.1—1.4 μg/ml. The linear relative coefficient γ is 0.9998. The apparent molar absorptivity was 1.75×10~5 1. mol^(-1). cm^(-1) at 463nm. The relative standard deviation of the method is 1.50% for Bi(Ⅲ) 7ug/10ml (10 determinations). The interference of foreign ions has been examined. This simple and rapid method can be applied to the assay of Bi(Ⅲ) in some tablets directly.展开更多
After the recent publication in the Journal of Biophysical Chemistry entitled “Retracted HIV Study Provides New Information about the Status of the in Vitro Inhibition of DNA Replication by Back-bone Methylation”, i...After the recent publication in the Journal of Biophysical Chemistry entitled “Retracted HIV Study Provides New Information about the Status of the in Vitro Inhibition of DNA Replication by Back-bone Methylation”, it is of importance to review the results of Buck’s group on the synthesis and conformation analyses of phosphate-methylated RNAs in order to afford information on the absence of a further investigation with regard to this de facto acceptable approach. In fact these compounds belong to the very first group of RNAs with a modified neutral backbone by phosphatemethylation. In contrast to the corresponding phosphate-methylated DNAs with a frozen B-conformation, the phosphate-methylated RNAs show an A-conformation. The latter is a prerequisite for duplex formation with (complementary) (natural) RNA. A number of experiments support this fundamental statement. After the HIV study was retracted, the overall results concerning the phosphate-methylated RNAs were published without mentioning Buck’s initial proof of concept and his contributions. Generally, the (modified) dimer RNAs and DNAs possess a number of specific biophysical properties. A novel explanation is given for conflicting structural determinations.展开更多
Four peptides PSPP1,PSPP2,PSPP3 and PSPP4 were purified from the water-extract of Papaver somniferum pollen.Their sequences,with 21,17,13 and 16 amino acid residues respectively,have been determined by Edman degradati...Four peptides PSPP1,PSPP2,PSPP3 and PSPP4 were purified from the water-extract of Papaver somniferum pollen.Their sequences,with 21,17,13 and 16 amino acid residues respectively,have been determined by Edman degradation-N-terminal dansylation.PSPP2, PSPP3 and PSPP4 were synthesized using solid phase method.The immunopromotive activities of PSPP1,PSPP2,PSPP3,PSPP4 and the initially separated sample PSPP have been also observed by the methods of counting erythrocyte rosette forming cells(ERFC) and T-lymphocyte transformation test in vitro.展开更多
Terbium can form a ternary complex having a ratio of 1:1:1 with acetylacetone and EDTA. By adding cetyl pyridinium chloride into the above system, a marked enhancement of fluorescence intensity is observed and the ter...Terbium can form a ternary complex having a ratio of 1:1:1 with acetylacetone and EDTA. By adding cetyl pyridinium chloride into the above system, a marked enhancement of fluorescence intensity is observed and the ternary complex becomes more stable than before. For analytical application, the derivative spectrofluorimetric method has high sensitivity and the effect of foreign ions is very low. The optimum conditions were obtained. The calibration graph is linear over 5~100μg/mL.展开更多
Dreiser’s Sister Carrie and Lao She’s Camel Xiangzi are two classic novels.Both of them demonstrate the decisive influence of environmental factors on the characters’destiny.This paper tries to explore their tragic...Dreiser’s Sister Carrie and Lao She’s Camel Xiangzi are two classic novels.Both of them demonstrate the decisive influence of environmental factors on the characters’destiny.This paper tries to explore their tragic fates comparatively based on environmental determinism.Actually,the two protagonists of two novels were both dream chasers in social changes at first,and then they transformed into strugglers under the oppression of patriarchy and biological power,and eventually they became victims of the social values under the fateful role of the environment.Obviously,the fights between the two protagonists and the environment have certain enlightening effects on current human life and the process of urbanization.展开更多
Objective: To assess prevalence of cyclical mastalgia and its main determinants in women who attended in health centers of Hamadan City, Iran.Methods: This case–control study was conducted on 400 women(case: cyclical...Objective: To assess prevalence of cyclical mastalgia and its main determinants in women who attended in health centers of Hamadan City, Iran.Methods: This case–control study was conducted on 400 women(case: cyclical mastalgia, n = 240; control: without cyclical mastalgia, n = 160) who attended family planning clinic for routine follow-up in health centers. The cluster sampling was used.Information was collected by interviewing and using a standardized validated questionnaire. Severity of mastalgia was assessed through using visual analog scaling. Data processing and statistical analysis were performed by using SPSS 19.0.Results: The results revealed that majority of women(60.0%) experienced cyclical mastalgia.Out of these, 22.5% and 37.5% were mild and moderate-to-severe mastalgia, respectively. No association was revealed in experience of depression and anxiety in mastalgia group. In a multivariable logistic regression model, the increasing age, age of marriage, history of abortion and history of premenstrual syndrome were main determinants of mastalgia, while use of oral contraceptive and regular exercise was associated with lower incidence of mastalgia.Conclusions: Most of women with breast discomfort suffered cyclical mastalgia which severity can be determined by advanced age, age of marriage, history of abortion and history of premenstrual syndrome, but inversely by oral contraceptive use and exercise activity.展开更多
The linear dispersion relation of a trapezoidally corrugated slow wave structure (TCSWS) is analyzed and presented. The size parameters of the TCSWS are chosen in such a way that they operate in the x-band frequency...The linear dispersion relation of a trapezoidally corrugated slow wave structure (TCSWS) is analyzed and presented. The size parameters of the TCSWS are chosen in such a way that they operate in the x-band frequency range. The dispersion relation is solved by utilizing the Rayleigh-Fourier method by expressing the radial function in terms of the Fourier series. A highly accurate synthetic technique is also applied to determine the complete dispersion characteristics from experimentally measured resonances (cold test). Periodic structures resonate at specific frequencies when the terminals are shorted numerical calculation, synthetic technique and cold appropriately. The dispersion characteristics obtained from test are compared, and an excellent agreement is achieved.展开更多
With the development of coal mine equipment mechanization, the wide application of </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">...With the development of coal mine equipment mechanization, the wide application of </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">hole instead of roadway</span><span style="font-family:Verdana;">”</span><span style="font-family:Verdana;"> technology greatly reduces the cost of gas control engineering, but puts forward higher requirements for the effect of gas drainage. At present, the drainage effect of coal mine inspection boreholes is mainly evaluated by the drilling field, but the flow rate and gas concentration of each borehole in the drilling field are not the same, which causes the gas drainage effect not to be correctly mastered. In the present study, the pressure relief drilling in the goaf of the working face of a typical multi-coal seam group high gas outburst mining area was taken as the research object. Through the newly developed portable drilling inspection device, the pure amount of drilling drainage was investigated, and the drilling design was dynamically adjusted. The enhancement of the goaf pressure relief gas control effect ensures the gas safety of the mining face. At the same time, this improves the gas extraction rate and reduces the emission of greenhouse gases. If the data from the borehole investigation can be transmitted in real time and analyzed in big data, the optimal extraction negative pressure can be predicted through a regression algorithm. Under the control of the negative pressure of each borehole by the actuator, the extraction system can have the function of intelligent judgment.展开更多
In Britton-Robinson buffer,metronidazole is preconcentreted on HHDE at 0.0 V(Vs.Ag- AgCI),An adsorptive stripping peak is observed at-0.62 V.Tho response is linear from 1x10^(-8)to 1×10^(-6)mol/L with 1.5 min acc...In Britton-Robinson buffer,metronidazole is preconcentreted on HHDE at 0.0 V(Vs.Ag- AgCI),An adsorptive stripping peak is observed at-0.62 V.Tho response is linear from 1x10^(-8)to 1×10^(-6)mol/L with 1.5 min accumulation.The method has been successfully applied to the deternation of metronidazole in human serum and formulations.展开更多
This article argues that the Haitian Vodou spirits(lwas)of fertility and death,Gede,do not promote homosexuality or the fluidity of sexuality in Haitian culture.The latter position is a Western reading of Gede grounde...This article argues that the Haitian Vodou spirits(lwas)of fertility and death,Gede,do not promote homosexuality or the fluidity of sexuality in Haitian culture.The latter position is a Western reading of Gede grounded in postmodern and post-structural identity theorizing.Gede in Haitian ontology and epistemology is lwas of fertility and death not sexual identity confusion or fluidity.展开更多
文摘In the media of 0.66,0.96, 2. 16 and 0.54 mol/L ofH2SO4,the heteropoly acids of As,P.Si and Ge are separately reduced to corresponding heteropoly blues by gibberellin, which exhibit maxirnum absorptions at 835, 820, 810 and 805 nm with molar absorptivities of 2.64x104, 2.54x104 3.51x104 and 2.25x104 L.mol-1'cm-1 and linear ranges of 0-30,0-15,0-10 and 0-30 μg/25mL, The method was applied to the determinations of As, P and Si in alloyed steel.
基金The Project Supported by the Scientific Research Projects (BAP) of Selcuk University, Turkey (EF-2001/064)
文摘Kinetics of complexation reaction of Co2+ with 2-benzoylpyridine-4-phenyl-3-thiosemicarbazone(BPPT) was spectrophotometrically examined at 421 nm.The ligand that is developed for a simple kinetic-spectrophotometric determination of Co2+ is based on 1:2 complex formation between Co2+ and BPPT.The complexation reaction was carried out in ethanol-water medium at 25 ℃.Kinetic and activation parameters of the complexation reaction were calculated,and the rate equation and the reaction mechanism were proposed.The calibration graph is linear in the concentration range of 0.10~2.91 mg·L-1 for the tangent method.The species that caused interference were investigated.
基金supported by National Key R&D Program of China(Grant No.2016YFC1000900)National Science and Technology Major Project of China(Grant Nos.2017ZX09101001003,2018ZX09711001-003-022,2018ZX09711001-010)+1 种基金National Natural Science Foundation of China(NSFC)(Grant No.81703473)CAMS Innovation Fund for Medical Sciences(Grant No.2017-I2M-3-010).
文摘Betulin(BE)can be obtained from many plants,such as those belonging Betulaceae family,and pharmacological investigations showed its notable biological properties and good potential for food and pharmaceutical development.We investigated the homogeneity,stability,purity,and uncertainty of a newly certified reference material(CRM)of BE.The certified purity value for the CRM of BE was 99.56%with an extended uncertainty of 0.07%(k=2,P=0.95),as determined by differential scanning calorimetry(DSC).In this study,DSC was used for the first time for purity determination of BE.Given its high accuracy,precision,and reproducibility,DSC can be used as an alternative technique for purity determination of CRMs in the pharmaceutical and food industry.
文摘Background: The etiology of adult obesity is still poorly understood. It has been shown that over-weight children suffer from adverse psychological events, but less is known about the association of adverse psychological factors among normal weight children and adult obesity. Aim: The aim of this study was to examine if the exposure of perception of being bullied during childhood could be associated with development of adult obesity. Methods: Adult, same-sexed twin pairs discordant for BMI were identified from the Danish Twin Registry. The twins underwent an interview and a physical examination. Data were analyzed by means of a growth-curve model and an intra-pair comparison. This design controls for other influences of early lifestyle and socio economic status and is therefore a powerful tool to study independent effects of specific exposures. Results: In total 236 (81.7%) of the twin individuals identified participated in the study. Participants who reported having been bullied in school, had attained a BMI which was on average 1.4 kg/m2 (95% CI = 0.2;2.5, p = 0.02) higher than those not bullied. Two other questions on specific types of bullying resulted in BMI that were 1.1 kg/m2 (CI = 0.1;2.2, p = 0.03) and 1.9 kg/m2 (CI = 0.7;3.1, p = 0.002) larger than subjects who had not been exposed to bullying. There was a direct association between intra pair differences in BMI and exposure to bullying. Conclusion: The results of the study could indicate that being bullied during childhood seems be associated with adult obesity.
文摘A spectrophotometric method for the assay of lamivudine in pure form and in dosage form was developed in this study. The method was based on charge-transfer complex formation between the drug, which acted as n-donor while chloranilic acid and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) acted as a p-acceptor in a non-aqueous solvent in each case. Chloranilic acid was found to form a charge-transfer complex in a 1:1 stoichiometry with lamuvudine (lamivudine-chloranilic acid) with a maximium absorption band at 521 nm. Also, DDQ was found to form a charge-transfer complex in a 1:1 stoichiometry with lamivudine (lamivudine-DDQ) with a maximium absorption band at 530 nm. The pH was obeyed at acid range. The complexes obeyed Beer’s law at a concentration range of 0.04 - 0.28 mg/ml. The thermodynamic parameters calculated at different temperatures included the molar absorptivity, association constant, free energy change, enthalpy and entropy. The proposed method has been conveniently applied in the analysis of commercially available lamivudine tablet with good accuracy and precision.
文摘The electronic and optical properties of TiS2 are studied of density functional theory. A linearized and augmented by using an ab-initio calculation within the frame plane wave basis set with the generalized gradient approximation as proposed by Perdew et al. is used for the energy exchange-correlation determination. The results show a metallic character of TiS2, and the plots of total and partial densities of states of TiS2 show the metallic character of the bonds and a strong hybridization between the states d of Ti and p of S below the Fermi energy. The optical properties of the material such as real and imaginary parts of dielectric constant (ε(w) = ε1(w) + iε2(w)), refractive index n(w), optical reflectivity R(w), for E / /x and E / /z are performed for the energy range of 0-.14 eV.
文摘A new highly sensitive spectrophotometric method has been developed for the determination of micro amounts of bismuth (Ⅲ), based on the formation of Bi (Ⅲ)—meso—tetrakis—(4—N—trimethylammonium phenyl) porphine [T (4TMAP) P] complex. In the presence of Cd (Ⅱ), Bi(Ⅲ) reacts almost instantaneously with T (4TMAP)P in a 0. 6 mol/l NaAc—HAC buffer (PH5.8) at room temperature. The composition of the complex is T(4TMAP)P: Bi=1:1. The absorbance complex obeys Beer's law over the Bi(Ⅲ) concentration range 0.1—1.4 μg/ml. The linear relative coefficient γ is 0.9998. The apparent molar absorptivity was 1.75×10~5 1. mol^(-1). cm^(-1) at 463nm. The relative standard deviation of the method is 1.50% for Bi(Ⅲ) 7ug/10ml (10 determinations). The interference of foreign ions has been examined. This simple and rapid method can be applied to the assay of Bi(Ⅲ) in some tablets directly.
文摘After the recent publication in the Journal of Biophysical Chemistry entitled “Retracted HIV Study Provides New Information about the Status of the in Vitro Inhibition of DNA Replication by Back-bone Methylation”, it is of importance to review the results of Buck’s group on the synthesis and conformation analyses of phosphate-methylated RNAs in order to afford information on the absence of a further investigation with regard to this de facto acceptable approach. In fact these compounds belong to the very first group of RNAs with a modified neutral backbone by phosphatemethylation. In contrast to the corresponding phosphate-methylated DNAs with a frozen B-conformation, the phosphate-methylated RNAs show an A-conformation. The latter is a prerequisite for duplex formation with (complementary) (natural) RNA. A number of experiments support this fundamental statement. After the HIV study was retracted, the overall results concerning the phosphate-methylated RNAs were published without mentioning Buck’s initial proof of concept and his contributions. Generally, the (modified) dimer RNAs and DNAs possess a number of specific biophysical properties. A novel explanation is given for conflicting structural determinations.
文摘Four peptides PSPP1,PSPP2,PSPP3 and PSPP4 were purified from the water-extract of Papaver somniferum pollen.Their sequences,with 21,17,13 and 16 amino acid residues respectively,have been determined by Edman degradation-N-terminal dansylation.PSPP2, PSPP3 and PSPP4 were synthesized using solid phase method.The immunopromotive activities of PSPP1,PSPP2,PSPP3,PSPP4 and the initially separated sample PSPP have been also observed by the methods of counting erythrocyte rosette forming cells(ERFC) and T-lymphocyte transformation test in vitro.
基金Project supported by the National Natural Science Foundation of China
文摘Terbium can form a ternary complex having a ratio of 1:1:1 with acetylacetone and EDTA. By adding cetyl pyridinium chloride into the above system, a marked enhancement of fluorescence intensity is observed and the ternary complex becomes more stable than before. For analytical application, the derivative spectrofluorimetric method has high sensitivity and the effect of foreign ions is very low. The optimum conditions were obtained. The calibration graph is linear over 5~100μg/mL.
基金This work is the one of the results of“Study on ethical Ethics of Mantel’s Fiction”(Project Number:2021GH016)supported by key humanities and social science research project among universities in Zhejiang Province.
文摘Dreiser’s Sister Carrie and Lao She’s Camel Xiangzi are two classic novels.Both of them demonstrate the decisive influence of environmental factors on the characters’destiny.This paper tries to explore their tragic fates comparatively based on environmental determinism.Actually,the two protagonists of two novels were both dream chasers in social changes at first,and then they transformed into strugglers under the oppression of patriarchy and biological power,and eventually they became victims of the social values under the fateful role of the environment.Obviously,the fights between the two protagonists and the environment have certain enlightening effects on current human life and the process of urbanization.
基金Supported by Research Deputy of Hamadan University of Medical Sciences,Hamadan,Iran(Grant No.16.35.1.1642)
文摘Objective: To assess prevalence of cyclical mastalgia and its main determinants in women who attended in health centers of Hamadan City, Iran.Methods: This case–control study was conducted on 400 women(case: cyclical mastalgia, n = 240; control: without cyclical mastalgia, n = 160) who attended family planning clinic for routine follow-up in health centers. The cluster sampling was used.Information was collected by interviewing and using a standardized validated questionnaire. Severity of mastalgia was assessed through using visual analog scaling. Data processing and statistical analysis were performed by using SPSS 19.0.Results: The results revealed that majority of women(60.0%) experienced cyclical mastalgia.Out of these, 22.5% and 37.5% were mild and moderate-to-severe mastalgia, respectively. No association was revealed in experience of depression and anxiety in mastalgia group. In a multivariable logistic regression model, the increasing age, age of marriage, history of abortion and history of premenstrual syndrome were main determinants of mastalgia, while use of oral contraceptive and regular exercise was associated with lower incidence of mastalgia.Conclusions: Most of women with breast discomfort suffered cyclical mastalgia which severity can be determined by advanced age, age of marriage, history of abortion and history of premenstrual syndrome, but inversely by oral contraceptive use and exercise activity.
文摘The linear dispersion relation of a trapezoidally corrugated slow wave structure (TCSWS) is analyzed and presented. The size parameters of the TCSWS are chosen in such a way that they operate in the x-band frequency range. The dispersion relation is solved by utilizing the Rayleigh-Fourier method by expressing the radial function in terms of the Fourier series. A highly accurate synthetic technique is also applied to determine the complete dispersion characteristics from experimentally measured resonances (cold test). Periodic structures resonate at specific frequencies when the terminals are shorted numerical calculation, synthetic technique and cold appropriately. The dispersion characteristics obtained from test are compared, and an excellent agreement is achieved.
文摘With the development of coal mine equipment mechanization, the wide application of </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">hole instead of roadway</span><span style="font-family:Verdana;">”</span><span style="font-family:Verdana;"> technology greatly reduces the cost of gas control engineering, but puts forward higher requirements for the effect of gas drainage. At present, the drainage effect of coal mine inspection boreholes is mainly evaluated by the drilling field, but the flow rate and gas concentration of each borehole in the drilling field are not the same, which causes the gas drainage effect not to be correctly mastered. In the present study, the pressure relief drilling in the goaf of the working face of a typical multi-coal seam group high gas outburst mining area was taken as the research object. Through the newly developed portable drilling inspection device, the pure amount of drilling drainage was investigated, and the drilling design was dynamically adjusted. The enhancement of the goaf pressure relief gas control effect ensures the gas safety of the mining face. At the same time, this improves the gas extraction rate and reduces the emission of greenhouse gases. If the data from the borehole investigation can be transmitted in real time and analyzed in big data, the optimal extraction negative pressure can be predicted through a regression algorithm. Under the control of the negative pressure of each borehole by the actuator, the extraction system can have the function of intelligent judgment.
文摘In Britton-Robinson buffer,metronidazole is preconcentreted on HHDE at 0.0 V(Vs.Ag- AgCI),An adsorptive stripping peak is observed at-0.62 V.Tho response is linear from 1x10^(-8)to 1×10^(-6)mol/L with 1.5 min accumulation.The method has been successfully applied to the deternation of metronidazole in human serum and formulations.
文摘This article argues that the Haitian Vodou spirits(lwas)of fertility and death,Gede,do not promote homosexuality or the fluidity of sexuality in Haitian culture.The latter position is a Western reading of Gede grounded in postmodern and post-structural identity theorizing.Gede in Haitian ontology and epistemology is lwas of fertility and death not sexual identity confusion or fluidity.