The instantaneous total mortality rate(Z) of a fish population is one of the important parameters in fisheries stock assessment. The estimation of Z is crucial to fish population dynamics analysis,abundance and catch ...The instantaneous total mortality rate(Z) of a fish population is one of the important parameters in fisheries stock assessment. The estimation of Z is crucial to fish population dynamics analysis,abundance and catch forecast,and fisheries management. A catch curve-based method for estimating time-based Z and its change trend from catch per unit effort(CPUE) data of multiple cohorts is developed. Unlike the traditional catch-curve method,the method developed here does not need the assumption of constant Z throughout the time,but the Z values in n continuous years are assumed constant,and then the Z values in different n continuous years are estimated using the age-based CPUE data within these years. The results of the simulation analyses show that the trends of the estimated time-based Z are consistent with the trends of the true Z,and the estimated rates of change from this approach are close to the true change rates(the relative differences between the change rates of the estimated Z and the true Z are smaller than 10%). Variations of both Z and recruitment can affect the estimates of Z value and the trend of Z. The most appropriate value of n can be different given the effects of different factors. Therefore,the appropriate value of n for different fisheries should be determined through a simulation analysis as we demonstrated in this study. Further analyses suggested that selectivity and age estimation are also two factors that can affect the estimated Z values if there is error in either of them,but the estimated change rates of Z are still close to the true change rates. We also applied this approach to the Atlantic cod(G adus morhua) fishery of eastern Newfoundland and Labrador from 1983 to 1997,and obtained reasonable estimates of time-based Z.展开更多
This paper reports that high-rate-deposition of microcrystalline silicon solar cells was performed by very-highfrequency plasma-enhanced chemical vapor deposition. These solar cells, whose intrinsic μc-Si：H layers w...This paper reports that high-rate-deposition of microcrystalline silicon solar cells was performed by very-highfrequency plasma-enhanced chemical vapor deposition. These solar cells, whose intrinsic μc-Si：H layers were prepared by using a different total gas flow rate （Ftotal）, behave much differently in performance, although their intrinsic layers have similar crystalline volume fraction, opto-electronic properties and a deposition rate of - 1.0 nm/s. The influence of Ftotal on the micro-structural properties was analyzed by Raman and Fourier transformed infrared measurements. The results showed that the vertical uniformity and the compact degree of μc-Si：H thin films were improved with increasing Ftotal. The variation of the microstructure was regarded as the main reason for the difference of the J V parameters. Combined with optical emission spectroscopy, we found that the gas temperature plays an important role in determining the microstructure of thin films. With Ftotal of 300 sccm, a conversion efficiency of 8.11% has been obtained for the intrinsic layer deposited at 8.5 A/s （1 A=0.1 nm）.展开更多
Total skin electron therapy (TSET) is used for the treatment of Mycosis Fungoides. Several tech-niques have been developed, in order to achieve homogeneous dose distribution over the complete body surface. To implemen...Total skin electron therapy (TSET) is used for the treatment of Mycosis Fungoides. Several tech-niques have been developed, in order to achieve homogeneous dose distribution over the complete body surface. To implement a TSET technique, one has to optimize a variety of parameters. Monte Carlo simulation of TSET can facilitate this optimization. The aim of this study was to commission and optimize a TSET technique using the 4 and 6 MeV electron and the high dose rate facility on the Elekta Precise accelerator. The EGS4nrc/BEAMnrc Monte Carlo code was used. The beam data were calculated and measured at two different scoring planes for a single beam. The Model was validated by comparing the simulation with measurements. Two different vertical angles were used to obtain a uniform dose. The angle was optimized for best dose uniformity. The Rando phantom is placed on a rotating platform and rotates 60 degrees apart to facilitate the six patient position orientations. The doses delivered in a phantom by complete treatment were measured with Kodak EDR2 films and TLDs. The dose distribution varied among various scanning directions by 2 - 3 mm and 3 - 4 mm for 4 and 6 MeV respectively. The composite percentage depth dose of all six dual fields for the 4 and 6 MeV yielded an R80 of ~4 mm and ~6 mm, respectively. Dose uniformity was ±6% for 4 MeV and ±5% for 6 MeV. The bremsstrahlung contamination was 0.9% - 1.3%. Good agreements were found with published literature and inline with international protocols.展开更多
Cooperative communication can enhance the performance of wireless networks via relays, and so how to allocate the relay to obtain the optimal performance of system is a key issue. In this article, we consider a cooper...Cooperative communication can enhance the performance of wireless networks via relays, and so how to allocate the relay to obtain the optimal performance of system is a key issue. In this article, we consider a cooperative system where two users communicate with the destination via relays, and these relays connect with the destination by cable. Through the theoretical derivation and analysis, we obtain the optimal relay allocation strat- egy based on the maximum rate under the condition of relays setting forwarding thresholds. The result shows that the system has the maximum transmission rate when the relays are allocated equivalently between users. Moreover, compared with the single-user system, the results prove that diversity gain has a decisive effect on the performance in low SNR. However, with the SNR increasing, the impact of diversity gain on system rate will be reduced. In high SNR, spatial freedom degree of the channel of multiple users is brought to enhance the performance instead of diversity gain. Numerical results demonstrate the validity of the allocation strategy and conclusion arrived in this study, but we do not find the similar arguments in the literature so far, for comparison with the conclusion of this study.展开更多
This paper introduces the test results of the soil magnetic survey and the integrated gamma-ray TLD and TC methods for sandstone-type uranium exploration and describes the prospecting mechanism. The tests have proved ...This paper introduces the test results of the soil magnetic survey and the integrated gamma-ray TLD and TC methods for sandstone-type uranium exploration and describes the prospecting mechanism. The tests have proved that these approaches have yielded good results on classifying the sedimentary facies, defining the redox transitional zones and reflecting deep mineralization information. They may probably become new methods on searching for sandstone-type uranium deposits.展开更多
Due to diminishing demographic dividend characterized by a falling workingage population and rising dependency ratio, China's long-term potential growth rates will keep declining, likely to be a mere 6.6% during t...Due to diminishing demographic dividend characterized by a falling workingage population and rising dependency ratio, China's long-term potential growth rates will keep declining, likely to be a mere 6.6% during the 13 th Five-Year Plan period(2016-2020). China's economic growth sustainability hinges upon its transition from the previous dependence on demographic dividend to the future reform dividend. In the growth accounting equation, we have simulated various reform initiatives and arrived at the following findings. First, although both the labor participation rate and TFP can increase China's potential growth rate, the former will only achieve a short-term growth effect, which will diminish in the long run. By contrast, the growth effect of TFP demonstrates the tendency of continuous increase. This further indicates that China's economic growth will increasingly rely on TFP improvement instead of traditional factor input. Second, different from the diminishing growth effect of enrolment rate, training may play a pivotal role in human capital development to significantly enhance potential growth rates. Third, if all reform initiatives can achieve their expected effects, integrated reform dividends may reach one or two percentage points of China's potential growth rate.展开更多
Total tanshinones are lipophilic active constituents extracted from Salvia miltiorrhiza Bge.Tanshinone ⅡA and cryptotanshinone are the major components in total tanshinones.However, the bioavailability of both compou...Total tanshinones are lipophilic active constituents extracted from Salvia miltiorrhiza Bge.Tanshinone ⅡA and cryptotanshinone are the major components in total tanshinones.However, the bioavailability of both compounds is low due to poor water solubility. To enhance the solubility and dissolution rate of tanshinone ⅡA, cryptotanshinone and total tanshinones,three common used hydrophilic carriers including PEG 6000, poloxamer 188 and PVP K30 were used to prepare the solid dispersions at different ratios, respectively. The solid dispersions were characterised by scanning electron microscopy(SEM), differential scanning calorimetry(DSC) and Fourier transform infrared spectroscopy(FTIR). The results of powder X-ray diffraction confirmed the microcrystal state of total tanshinones in solid dispersions and no chemical interaction between total tanshinones and carriers was observed in FTIR spectra. The solubility and dissolution rate of tanshinone ⅡA and cryptotanshinone were significantly increased in all solid dispersions. Regarding tanshinone ⅡA, the solubility and dissolution rate of in solid dispersions prepared with poloxamer 188 were significantly higher than that with PEG 6000 and PVP K30. The higher solubility and dissolution rate of cryptotanshinone were obtained in solid dispersion of PVP K30 than that of PEG 6000 solid dispersions but no significant difference from poloxamer 188 solid dispersions. The results indicate that the superior carrier for preparation of tanshinone ⅡA and total tanshinones solid dispersions is poloxamer 188, and that for cryptotanshinone is PVP K30.展开更多
Previous investigations have shown that changes in total prostate volume（TPV） are highly variable among aging men,and a considerable proportion of aging men have a stable or decreasing prostate size.Although there i...Previous investigations have shown that changes in total prostate volume（TPV） are highly variable among aging men,and a considerable proportion of aging men have a stable or decreasing prostate size.Although there is an abundance of literature describing prostatic enlargement in association with benign prostatic hyperplasia,less is known about the appropriate age cut-off points for TPV growth rate.In this community-based cohort study,TPV was examined once a year in men who had consecutive health checkup,during a follow-up of 4 years.A total of 5058 men（age 18–92 years old） were included.We applied multiple regression analyses to estimate the correlation between TPV growth rate and age.Overall,3232（63.9%） men had prostate growth,and 1826（36.1%） had a stable or decreased TPV during the study period.The TPV growth rate was correlated negatively with baseline TPV（r= –0.32,P〈0.001）.Among 2620 men with baseline TPV 〈15 cm^3,the TPV growth rate increased with age（β=0.98,95% CI：0.77%–1.18%） only up to 53 years old.Among 2188 men with baseline TPV of 15–33.6 cm3,the TPV growth rate increased with age（β=0.84,95% CI,0.66%–1.01%） only up to 61 years old after adjusting for factors of hypertension,obesity,baseline TPV,diabetes mellitus and dyslipidemia.In this longitudinal study,the TPV growth rate increased negatively with baseline TPV,only extending to a certain age and not beyond.Further research is needed to identify the mechanism underlying such differences in prostate growth.展开更多
This study examines whether a group of captive false killer whales(P seudorca crassidens) showed variations in the vocal rate around feeding times. The high level of motivation to express appetitive behaviors in capti...This study examines whether a group of captive false killer whales(P seudorca crassidens) showed variations in the vocal rate around feeding times. The high level of motivation to express appetitive behaviors in captive animals may lead them to respond with changes of the behavioral activities during the time prior to food deliveries which are referred to as food anticipatory activity. False killer whales at Qingdao Polar Ocean World(Qingdao, China) showed signifi cant variations of the rates of both the total sounds and sound classes(whistles, clicks, and burst pulses) around feedings. Precisely, from the Transition interval that recorded the lowest vocalization rate(3.40 s/m/d), the whales increased their acoustic emissions upon trainers' arrival(13.08 s/m/d). The high rate was maintained or intensifi ed throughout the food delivery(25.12 s/m/d), and then reduced immediately after the animals were fed(9.91 s/m/d). These changes in the false killer whales sound production rates around feeding times supports the hypothesis of the presence of a food anticipatory vocal activity. Although sound rates may not give detailed information regarding referential aspects of the animal communication it might still shed light about the arousal levels of the individuals during different social or environmental conditions. Further experiments should be performed to assess if variations of the time of feeding routines may affect the vocal activity of cetaceans in captivity as well as their welfare.展开更多
Purpose:The aim of this study was to investigate the influence of the cardiorespiratory fitness level on the response to high-intensity interval training(HIIT)with an individually adjusted running speed of the same re...Purpose:The aim of this study was to investigate the influence of the cardiorespiratory fitness level on the response to high-intensity interval training(HIIT)with an individually adjusted running speed of the same relative intensity.The evaluation focused on acute cardiorespiratory response,postexercise cardiac autonomic modulation(heart rate variability(HRV))and biochemical markers of inflammation,oxidative stress,and muscle damage.Methods:Thirty participants were divided into 3 subgroups:well trained,moderately trained,and untrained.All the participants performed30 min HIIT composed of 6×2 min interval exercise with work-to-relief ratio=1 and work intensity 100%of individual velocity at maximal oxygen consumption(VO2max).Acute cardiorespiratory variables,postexercise HRV,lactate,interleukin-6(IL-6),total antioxidant capacity(TAC),creatine kinase,and myoglobin up to 4h after HIIT were monitored.Results:The differences in relatively expressed cardiorespiratory variables(heart rate,VO2)during HIIT were at most moderate,with the most pronounced between-group differences in absolute VO2 values.The disruption of the postexercise HRV was the most pronounced in untrained individuals,and this difference persisted 1 h after HIIT.The highest postexercise IL-6 and TAC concentrations and the lowest changes in creatine kinase and myoglobin were revealed in well-trained individuals.Conclusion:The higher fitness level was associated with the less pronounced postexercise cardiac autonomic changes and their faster restoration,even when there were similar acute cardiorespiratory responses.These findings were simultaneously accompanied by the higher postexercise IL-6 and TAC concentrations and less significant changes in muscle damage biochemical markers in well-trained individuals.展开更多
We consider a replacement policy for a multiple-component cold-standbysystem, and after we analyze this policy, we want to get the mean total cost rate and the preventivepolicy to make it the lowest. In this system, t...We consider a replacement policy for a multiple-component cold-standbysystem, and after we analyze this policy, we want to get the mean total cost rate and the preventivepolicy to make it the lowest. In this system, the failure rate of the component in operation isconstant, and the inspection will control all the processes of the operation. The system isinspected at random points over time to determine whether it is to be replaced. During the process,the replacement decision is based on the number of failed components at the time of inspection.展开更多
Theoretical incompleteness of the existing conservation laws of energy for polar continuum mechanics is further clarified. For completeness, the principles of total work and energy and of total work and energy of incr...Theoretical incompleteness of the existing conservation laws of energy for polar continuum mechanics is further clarified. For completeness, the principles of total work and energy and of total work and energy of incremental rate type are postulated. Via total variations of the former and the latter of them, the principles of virtual displacement and microrotation & stress and couple stress as well as virtual velocity and angular velocity & stress rate and couple stress rate are immediately obtained, respectively. From these principles all balance equations and boundary conditions for micropolar mechanics are naturally and simultaneously deduced. The essential differences between the nontraditional results obtained in this paper and the existing conservation laws of energy are expounded.展开更多
The yearly,quarterly,monthly and daily change tendencies of total solar radiation at Jiamusi station of Sanjiang Plain were analyzed by statistical approach such as linear tendency estimate with its hourly ground mete...The yearly,quarterly,monthly and daily change tendencies of total solar radiation at Jiamusi station of Sanjiang Plain were analyzed by statistical approach such as linear tendency estimate with its hourly ground meteorological observation data during 1986 to 2015.The research results indicated that the yearly tendency rate of total solar radiation was increasing obviously,with the velocity of 114.30 MJ/(m2·10 a),while the yearly total solar radiation was 3 667.28-4 935.88 MJ/m^2,and that of March to September was higher than the average.The summer total solar radiation was the most,followed by spring,and that of all the seasons increased except autumn which decreased.The daily total solar radiation increased rapidly from the last ten days of January and reached the peak at the end of June,while it plummeted from the beginning of September to the middle ten days of November,then tended to be gentle.The amount of 5-year total solar radiation was less after 1980s while it was more before1990s,and the total solar radiation was decreasing from 1996 to 2005 but on the contrary it kept increasing in recent ten years.Over the years the earliest record of solar radiation appeared at 05:00 and the latest at 20:00,and the daily variation of the hourly solar radiation got a normal distribution centered on 12:00 to 13:00.展开更多
On the occasion of the 40th anniversary of reform and opening up, China’s economic growth level has steadily risen and its international status has gradually improved. However, as the global economic downturn, China ...On the occasion of the 40th anniversary of reform and opening up, China’s economic growth level has steadily risen and its international status has gradually improved. However, as the global economic downturn, China is facing tremendous challenges and pressures in the international economic and financial markets. The turbulence of foreign trade and international financial markets has put forward greater requirements for the flexibility of China’s financial strategy. Based on the annual data of China’s total foreign trade, exchange rate, commodity retail price index and the proportion of tertiary industry from 2002 to 2017, this paper constructs a multiple regression model to analyze the main influencing factors of China’s total foreign trade. The empirical results show that there is a positive relationship between the commodities retail price index and the total foreign trade, a negative relationship between the proportion of tertiary industry and the total foreign trade, and a positive relationship between the exchange rate of RMB (taking US dollar as an example) and the total foreign trade. On the basis of empirical analysis, the paper puts forward suggestions on relevant financial policies.展开更多
Effect of Epimedium Flavone Total(EFT) on the immunofunction of mice which was burdened with Ehrlich Ascites Cancer (EAC) was studied. The results showed that EFT could increase phagocytosis activity of macrophagocyte...Effect of Epimedium Flavone Total(EFT) on the immunofunction of mice which was burdened with Ehrlich Ascites Cancer (EAC) was studied. The results showed that EFT could increase phagocytosis activity of macrophagocyte (P<0 05), promote lymphocyte transformation rate (P<0 01), increased the sero antibody level meanly (P<0 05), low dosage group could increased Plaque Forming Cell (PFC) signficantly (P<0 05), raise the ratio of spleen to body (P<0 05) of EAC bearing mice. EFT may be enhance burdened mice's immunofunction. Low dosage can improve sero antibody level. Effect on regulating cellular immunofunction are related to dosage. EFT may be inhibit the growth of EAC cells to some degree.展开更多
基金Supported by the USDA Cooperative State Research,Education and Extension Service,Hatch Project(No.0210510)the National Natural Science Foundations of China(Nos.31270527,40801225)+1 种基金the Natural Science Foundation of Zhejiang Province(No.LY13D010005)the Young Academic Leaders Climbing Program of Zhejiang Province(No.pd2013222)
文摘The instantaneous total mortality rate(Z) of a fish population is one of the important parameters in fisheries stock assessment. The estimation of Z is crucial to fish population dynamics analysis,abundance and catch forecast,and fisheries management. A catch curve-based method for estimating time-based Z and its change trend from catch per unit effort(CPUE) data of multiple cohorts is developed. Unlike the traditional catch-curve method,the method developed here does not need the assumption of constant Z throughout the time,but the Z values in n continuous years are assumed constant,and then the Z values in different n continuous years are estimated using the age-based CPUE data within these years. The results of the simulation analyses show that the trends of the estimated time-based Z are consistent with the trends of the true Z,and the estimated rates of change from this approach are close to the true change rates(the relative differences between the change rates of the estimated Z and the true Z are smaller than 10%). Variations of both Z and recruitment can affect the estimates of Z value and the trend of Z. The most appropriate value of n can be different given the effects of different factors. Therefore,the appropriate value of n for different fisheries should be determined through a simulation analysis as we demonstrated in this study. Further analyses suggested that selectivity and age estimation are also two factors that can affect the estimated Z values if there is error in either of them,but the estimated change rates of Z are still close to the true change rates. We also applied this approach to the Atlantic cod(G adus morhua) fishery of eastern Newfoundland and Labrador from 1983 to 1997,and obtained reasonable estimates of time-based Z.
基金supported by the National Basic Research Program of China (Grant Nos 2006CB202602 and 2006CB202603)the Tianjin Assistant Foundation for the National Basic Research Program of China (Grant No 07QTPTJC29500)the Natural Science Foundation of Tianjin (Grant No 07JCYBJC04000)
文摘This paper reports that high-rate-deposition of microcrystalline silicon solar cells was performed by very-highfrequency plasma-enhanced chemical vapor deposition. These solar cells, whose intrinsic μc-Si：H layers were prepared by using a different total gas flow rate （Ftotal）, behave much differently in performance, although their intrinsic layers have similar crystalline volume fraction, opto-electronic properties and a deposition rate of - 1.0 nm/s. The influence of Ftotal on the micro-structural properties was analyzed by Raman and Fourier transformed infrared measurements. The results showed that the vertical uniformity and the compact degree of μc-Si：H thin films were improved with increasing Ftotal. The variation of the microstructure was regarded as the main reason for the difference of the J V parameters. Combined with optical emission spectroscopy, we found that the gas temperature plays an important role in determining the microstructure of thin films. With Ftotal of 300 sccm, a conversion efficiency of 8.11% has been obtained for the intrinsic layer deposited at 8.5 A/s （1 A=0.1 nm）.
文摘Total skin electron therapy (TSET) is used for the treatment of Mycosis Fungoides. Several tech-niques have been developed, in order to achieve homogeneous dose distribution over the complete body surface. To implement a TSET technique, one has to optimize a variety of parameters. Monte Carlo simulation of TSET can facilitate this optimization. The aim of this study was to commission and optimize a TSET technique using the 4 and 6 MeV electron and the high dose rate facility on the Elekta Precise accelerator. The EGS4nrc/BEAMnrc Monte Carlo code was used. The beam data were calculated and measured at two different scoring planes for a single beam. The Model was validated by comparing the simulation with measurements. Two different vertical angles were used to obtain a uniform dose. The angle was optimized for best dose uniformity. The Rando phantom is placed on a rotating platform and rotates 60 degrees apart to facilitate the six patient position orientations. The doses delivered in a phantom by complete treatment were measured with Kodak EDR2 films and TLDs. The dose distribution varied among various scanning directions by 2 - 3 mm and 3 - 4 mm for 4 and 6 MeV respectively. The composite percentage depth dose of all six dual fields for the 4 and 6 MeV yielded an R80 of ~4 mm and ~6 mm, respectively. Dose uniformity was ±6% for 4 MeV and ±5% for 6 MeV. The bremsstrahlung contamination was 0.9% - 1.3%. Good agreements were found with published literature and inline with international protocols.
基金supported by the National Natural Science Foundation of China under Grant numbers 61032002,61101090, and 60902026the Chinese Important National Science & Technology Specific Projects under Grant number 2011ZX03001-007-01
文摘Cooperative communication can enhance the performance of wireless networks via relays, and so how to allocate the relay to obtain the optimal performance of system is a key issue. In this article, we consider a cooperative system where two users communicate with the destination via relays, and these relays connect with the destination by cable. Through the theoretical derivation and analysis, we obtain the optimal relay allocation strat- egy based on the maximum rate under the condition of relays setting forwarding thresholds. The result shows that the system has the maximum transmission rate when the relays are allocated equivalently between users. Moreover, compared with the single-user system, the results prove that diversity gain has a decisive effect on the performance in low SNR. However, with the SNR increasing, the impact of diversity gain on system rate will be reduced. In high SNR, spatial freedom degree of the channel of multiple users is brought to enhance the performance instead of diversity gain. Numerical results demonstrate the validity of the allocation strategy and conclusion arrived in this study, but we do not find the similar arguments in the literature so far, for comparison with the conclusion of this study.
文摘This paper introduces the test results of the soil magnetic survey and the integrated gamma-ray TLD and TC methods for sandstone-type uranium exploration and describes the prospecting mechanism. The tests have proved that these approaches have yielded good results on classifying the sedimentary facies, defining the redox transitional zones and reflecting deep mineralization information. They may probably become new methods on searching for sandstone-type uranium deposits.
基金the National Social Sciences Foundation Program "A Study on the Effects of Changing Demographic Structure on China's Economic Deceleration and Countermeasures"
文摘Due to diminishing demographic dividend characterized by a falling workingage population and rising dependency ratio, China's long-term potential growth rates will keep declining, likely to be a mere 6.6% during the 13 th Five-Year Plan period(2016-2020). China's economic growth sustainability hinges upon its transition from the previous dependence on demographic dividend to the future reform dividend. In the growth accounting equation, we have simulated various reform initiatives and arrived at the following findings. First, although both the labor participation rate and TFP can increase China's potential growth rate, the former will only achieve a short-term growth effect, which will diminish in the long run. By contrast, the growth effect of TFP demonstrates the tendency of continuous increase. This further indicates that China's economic growth will increasingly rely on TFP improvement instead of traditional factor input. Second, different from the diminishing growth effect of enrolment rate, training may play a pivotal role in human capital development to significantly enhance potential growth rates. Third, if all reform initiatives can achieve their expected effects, integrated reform dividends may reach one or two percentage points of China's potential growth rate.
文摘Total tanshinones are lipophilic active constituents extracted from Salvia miltiorrhiza Bge.Tanshinone ⅡA and cryptotanshinone are the major components in total tanshinones.However, the bioavailability of both compounds is low due to poor water solubility. To enhance the solubility and dissolution rate of tanshinone ⅡA, cryptotanshinone and total tanshinones,three common used hydrophilic carriers including PEG 6000, poloxamer 188 and PVP K30 were used to prepare the solid dispersions at different ratios, respectively. The solid dispersions were characterised by scanning electron microscopy(SEM), differential scanning calorimetry(DSC) and Fourier transform infrared spectroscopy(FTIR). The results of powder X-ray diffraction confirmed the microcrystal state of total tanshinones in solid dispersions and no chemical interaction between total tanshinones and carriers was observed in FTIR spectra. The solubility and dissolution rate of tanshinone ⅡA and cryptotanshinone were significantly increased in all solid dispersions. Regarding tanshinone ⅡA, the solubility and dissolution rate of in solid dispersions prepared with poloxamer 188 were significantly higher than that with PEG 6000 and PVP K30. The higher solubility and dissolution rate of cryptotanshinone were obtained in solid dispersion of PVP K30 than that of PEG 6000 solid dispersions but no significant difference from poloxamer 188 solid dispersions. The results indicate that the superior carrier for preparation of tanshinone ⅡA and total tanshinones solid dispersions is poloxamer 188, and that for cryptotanshinone is PVP K30.
基金supported by National Natural Science Foundation of China(No.81370468)
文摘Previous investigations have shown that changes in total prostate volume（TPV） are highly variable among aging men,and a considerable proportion of aging men have a stable or decreasing prostate size.Although there is an abundance of literature describing prostatic enlargement in association with benign prostatic hyperplasia,less is known about the appropriate age cut-off points for TPV growth rate.In this community-based cohort study,TPV was examined once a year in men who had consecutive health checkup,during a follow-up of 4 years.A total of 5058 men（age 18–92 years old） were included.We applied multiple regression analyses to estimate the correlation between TPV growth rate and age.Overall,3232（63.9%） men had prostate growth,and 1826（36.1%） had a stable or decreased TPV during the study period.The TPV growth rate was correlated negatively with baseline TPV（r= –0.32,P〈0.001）.Among 2620 men with baseline TPV 〈15 cm^3,the TPV growth rate increased with age（β=0.98,95% CI：0.77%–1.18%） only up to 53 years old.Among 2188 men with baseline TPV of 15–33.6 cm3,the TPV growth rate increased with age（β=0.84,95% CI,0.66%–1.01%） only up to 61 years old after adjusting for factors of hypertension,obesity,baseline TPV,diabetes mellitus and dyslipidemia.In this longitudinal study,the TPV growth rate increased negatively with baseline TPV,only extending to a certain age and not beyond.Further research is needed to identify the mechanism underlying such differences in prostate growth.
基金Supported by grants from the Institute of Hydrobiology,Chinese Academy of Sciences
文摘This study examines whether a group of captive false killer whales(P seudorca crassidens) showed variations in the vocal rate around feeding times. The high level of motivation to express appetitive behaviors in captive animals may lead them to respond with changes of the behavioral activities during the time prior to food deliveries which are referred to as food anticipatory activity. False killer whales at Qingdao Polar Ocean World(Qingdao, China) showed signifi cant variations of the rates of both the total sounds and sound classes(whistles, clicks, and burst pulses) around feedings. Precisely, from the Transition interval that recorded the lowest vocalization rate(3.40 s/m/d), the whales increased their acoustic emissions upon trainers' arrival(13.08 s/m/d). The high rate was maintained or intensifi ed throughout the food delivery(25.12 s/m/d), and then reduced immediately after the animals were fed(9.91 s/m/d). These changes in the false killer whales sound production rates around feeding times supports the hypothesis of the presence of a food anticipatory vocal activity. Although sound rates may not give detailed information regarding referential aspects of the animal communication it might still shed light about the arousal levels of the individuals during different social or environmental conditions. Further experiments should be performed to assess if variations of the time of feeding routines may affect the vocal activity of cetaceans in captivity as well as their welfare.
基金supported by Ostrava University under Grant SGS06/PdF2014
文摘Purpose:The aim of this study was to investigate the influence of the cardiorespiratory fitness level on the response to high-intensity interval training(HIIT)with an individually adjusted running speed of the same relative intensity.The evaluation focused on acute cardiorespiratory response,postexercise cardiac autonomic modulation(heart rate variability(HRV))and biochemical markers of inflammation,oxidative stress,and muscle damage.Methods:Thirty participants were divided into 3 subgroups:well trained,moderately trained,and untrained.All the participants performed30 min HIIT composed of 6×2 min interval exercise with work-to-relief ratio=1 and work intensity 100%of individual velocity at maximal oxygen consumption(VO2max).Acute cardiorespiratory variables,postexercise HRV,lactate,interleukin-6(IL-6),total antioxidant capacity(TAC),creatine kinase,and myoglobin up to 4h after HIIT were monitored.Results:The differences in relatively expressed cardiorespiratory variables(heart rate,VO2)during HIIT were at most moderate,with the most pronounced between-group differences in absolute VO2 values.The disruption of the postexercise HRV was the most pronounced in untrained individuals,and this difference persisted 1 h after HIIT.The highest postexercise IL-6 and TAC concentrations and the lowest changes in creatine kinase and myoglobin were revealed in well-trained individuals.Conclusion:The higher fitness level was associated with the less pronounced postexercise cardiac autonomic changes and their faster restoration,even when there were similar acute cardiorespiratory responses.These findings were simultaneously accompanied by the higher postexercise IL-6 and TAC concentrations and less significant changes in muscle damage biochemical markers in well-trained individuals.
文摘We consider a replacement policy for a multiple-component cold-standbysystem, and after we analyze this policy, we want to get the mean total cost rate and the preventivepolicy to make it the lowest. In this system, the failure rate of the component in operation isconstant, and the inspection will control all the processes of the operation. The system isinspected at random points over time to determine whether it is to be replaced. During the process,the replacement decision is based on the number of failed components at the time of inspection.
文摘Theoretical incompleteness of the existing conservation laws of energy for polar continuum mechanics is further clarified. For completeness, the principles of total work and energy and of total work and energy of incremental rate type are postulated. Via total variations of the former and the latter of them, the principles of virtual displacement and microrotation & stress and couple stress as well as virtual velocity and angular velocity & stress rate and couple stress rate are immediately obtained, respectively. From these principles all balance equations and boundary conditions for micropolar mechanics are naturally and simultaneously deduced. The essential differences between the nontraditional results obtained in this paper and the existing conservation laws of energy are expounded.
文摘The yearly,quarterly,monthly and daily change tendencies of total solar radiation at Jiamusi station of Sanjiang Plain were analyzed by statistical approach such as linear tendency estimate with its hourly ground meteorological observation data during 1986 to 2015.The research results indicated that the yearly tendency rate of total solar radiation was increasing obviously,with the velocity of 114.30 MJ/(m2·10 a),while the yearly total solar radiation was 3 667.28-4 935.88 MJ/m^2,and that of March to September was higher than the average.The summer total solar radiation was the most,followed by spring,and that of all the seasons increased except autumn which decreased.The daily total solar radiation increased rapidly from the last ten days of January and reached the peak at the end of June,while it plummeted from the beginning of September to the middle ten days of November,then tended to be gentle.The amount of 5-year total solar radiation was less after 1980s while it was more before1990s,and the total solar radiation was decreasing from 1996 to 2005 but on the contrary it kept increasing in recent ten years.Over the years the earliest record of solar radiation appeared at 05:00 and the latest at 20:00,and the daily variation of the hourly solar radiation got a normal distribution centered on 12:00 to 13:00.
文摘On the occasion of the 40th anniversary of reform and opening up, China’s economic growth level has steadily risen and its international status has gradually improved. However, as the global economic downturn, China is facing tremendous challenges and pressures in the international economic and financial markets. The turbulence of foreign trade and international financial markets has put forward greater requirements for the flexibility of China’s financial strategy. Based on the annual data of China’s total foreign trade, exchange rate, commodity retail price index and the proportion of tertiary industry from 2002 to 2017, this paper constructs a multiple regression model to analyze the main influencing factors of China’s total foreign trade. The empirical results show that there is a positive relationship between the commodities retail price index and the total foreign trade, a negative relationship between the proportion of tertiary industry and the total foreign trade, and a positive relationship between the exchange rate of RMB (taking US dollar as an example) and the total foreign trade. On the basis of empirical analysis, the paper puts forward suggestions on relevant financial policies.
文摘Effect of Epimedium Flavone Total(EFT) on the immunofunction of mice which was burdened with Ehrlich Ascites Cancer (EAC) was studied. The results showed that EFT could increase phagocytosis activity of macrophagocyte (P<0 05), promote lymphocyte transformation rate (P<0 01), increased the sero antibody level meanly (P<0 05), low dosage group could increased Plaque Forming Cell (PFC) signficantly (P<0 05), raise the ratio of spleen to body (P<0 05) of EAC bearing mice. EFT may be enhance burdened mice's immunofunction. Low dosage can improve sero antibody level. Effect on regulating cellular immunofunction are related to dosage. EFT may be inhibit the growth of EAC cells to some degree.
