This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in t...This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in the fixed points of the networks, which would be associated with the earthquake preparation. The observation system is characterized by the high accuracy in measurement, long term stability in operation and high level of rejection to the environmental interference. It consists of three main parts, configuration system measurement system, the calibration and inspection system.展开更多
It is a debated topic if there are any observable precursor anomalies prior to the earthquake(EQ hereafter)and if the stronger EQ can be successfully predicted.During last few decades quite a lot of observable electro...It is a debated topic if there are any observable precursor anomalies prior to the earthquake(EQ hereafter)and if the stronger EQ can be successfully predicted.During last few decades quite a lot of observable electromagnetic(EM)precursors were published by using techniques equipped in either satellites or on ground-based stations.But there are only a few cases that the shortterm precursor anomalies of EM field before earthquakes were observed by using alternate EM fields on ground.This paper will present a new EM observation network built in recent years and show a new finding of EM field with the variation of a one-year cycle observed using the network.As an example,the short-term precursor anomalies of apparent resistivity before the Yangbi EQ(Ms 5.1)occurred on March 27,2017 in Yunnan Province will be studied.The observed anomalous phenomena indicate that the anomaly before the EQ can be captured only if reasonable effective methods including sophisticated analytical techniques are used,and it is believed that continuously observed data on the fixed observation network for a long time is an effective means for studying anomalies that appeared before earthquakes.This network can also play an important role in studying the EM environment from space.展开更多
Snow resisting capacity of vegetation is important for secondary distribution of water resources in seasonal snow areas of grassland because it affects the regeneration,growth and nutrient circulation of vegetation in...Snow resisting capacity of vegetation is important for secondary distribution of water resources in seasonal snow areas of grassland because it affects the regeneration,growth and nutrient circulation of vegetation in grassland.This study investigated vegetation characteristics(canopy height,canopy length and crown width)of Caragana microphylla Lam.(shrub)and Achnatherum splendens(Trin.)Nevski.(herb),and snow morphologies(snow depth,snow width and snow braid length)in a typical steppe region of Inner Mongolia,China in 2017.And the influence of vegetation characteristic on snow resisting capacity(the indices of bottom area of snow and snow volume reflect snow resisting capacity)was analyzed.The results showed that snow morphology depends on vegetation characteristics of shrub and herb.The canopy height was found to have the greatest influence on snow depth and the crown width had the greatest influence on snow width.The canopy length was found to have little influence on morphological parameters of snow.When the windward areas of C.microphylla and A.splendens were within the ranges of 0.0-0.5 m2 and 0.0-8.0 m2,respectively,the variation of snow cover was large;however,beyond these areas,the variation of snow cover became gradually stable.The potential area of snow retardation for a single plant was 1.5-2.5 m2 and the amount of snow resistance was 0.15-0.20 m3.The bottom area of snow and snow volume(i.e.,snow resisting capacity)of clumped C.microphylla and A.splendens was found to be 4 and 25 times that of individual plant,respectively.The results could provide a theoretical basis both for the estimation of snow cover and the establishment of a plant-based technical system for the control of windblown snow in the typical steppe region of Inner Mongolia.展开更多
BACKGROUND The incidence of postoperative nausea and vomiting(PONV)in patients undergoing laparoscopic hysterectomy is very high compared with other surgeries,even when many prophylactic measures have been taken.Howev...BACKGROUND The incidence of postoperative nausea and vomiting(PONV)in patients undergoing laparoscopic hysterectomy is very high compared with other surgeries,even when many prophylactic measures have been taken.However,the pathogenesis of PONV is multifactorial.Female sex,a history of motion sickness or PONV,nonsmokers,and perioperative opioid use are the most closely related factors.Among the multiple risk factors,suboptimal gastrointestinal(GI)perfusion may be attributed to some cases of PONV,and increased systemic vascular resistance(SVR)may lead to GI ischemia.The hypothesis of this research was that SVR is related to PONV.AIM To investigate the relationship between SVR and PONV in patients undergoing laparoscopic hysterectomy.METHODS A total of 228 patients who underwent elective laparoscopic hysterectomy were included in this prospective observational study.SVR was monitored using a noninvasive hemodynamic monitoring system.Four indices of SVR,the baseline,mean,area under the curve(AUC),and weighted AUC,were used for analysis.The incidence and severity of nausea and vomiting were evaluated while patients were awake and throughout the intervals from 0 to 2 h,2 to 6 h,and 6 to 24 h starting upon arrival at the post-anesthesia care unit.The associations between various SVR indices and PONV were investigated by logistic regression.P<0.05 was considered statistically significant.RESULTS The incidence of PONV in the study was 56.14%(128/228),and PONV tended to appear within 6 h after surgery.Five variables were significant in univariate analyses,however,only SVR mean[odds ratio(OR)=1.015,95%CI:1.005-1.109,P=0.047]and duration of surgery(OR=1.316,95%CI:1.003-2.030,P=0.012)were associated with PONV after logistic regression analysis.Furthermore,patients with high SVR mean were more likely to suffer from PONV after laparoscopic hysterectomy.On average,patients who developed PONV needed more time to tolerate diet and demonstrated poorer sleep quality on the first night after surgery.CONCLUSION In this study,PONV was a common complication after laparoscopic hysterectomy.SVR was associated with PONV,and high SVR mean was associated with a significantly increased risk of PONV.展开更多
Several related substances were detected at trace level in (2R)-2,3-dihydro-2-methyl-6-nitro-2-[[4-[4-[4-(trifluoromethoxy)phenoxy]-1-piperidinyl] phenoxy] methyl]imidazo[2, 1-b]oxazole drug substance by a newly devel...Several related substances were detected at trace level in (2R)-2,3-dihydro-2-methyl-6-nitro-2-[[4-[4-[4-(trifluoromethoxy)phenoxy]-1-piperidinyl] phenoxy] methyl]imidazo[2, 1-b]oxazole drug substance by a newly developed high-performance liquid chromatography method. All related substances were characterized rapidly but some impurities were found to be intermediates. Proposed structures were further confirmed by characterization using NMR, FT-IR, and HRMS techniques. Based on the spectroscopic data;unknown related sub-stances were characterized as 1-(Methylsulfonyl)-4-[4-(trifluoromethoxy) phenoxy]piperidine;4-{4-[4-(Tri-fluoromethoxy)-phenoxy]piperidin-1-yl}phenol and 4-{4-[4-(trifluoromethoxy)phenoxy]piperidin-1-yl}phenyl methane sulfonate;4-Bromophenyl methane sulfonate, Ethyl 3,6-dihydro-1(2H)-pyridine carboxylate, (2S)-3-(4-Bromophenoxy)-2-hydroxy-2-methylpropyl methane sulfonate, (2S)-3-(4-Bromophenoxy)-2-methylpropane-1,2-diyldimethane-sulfonate, (2S)-2-Methyl-3-(4-{4-[4-(trifluoromethoxy) phenoxy]-piperidin-1-yl} phenoxy)-propane-1,2-diyldimethane sulfonate, (S)-3-(4-Bromophenoxy)-2-methyl-propane-1,2-diol and corresponding Enantiomer, (2R)-2-[(4-Bromo-phenoxy)methyl]-2-methyloxirane and (2R)-2-[(4-bromophenoxy)methyl]-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b][1,3]oxazole. A possible mechanism for the formation of these related substances is also proposed.展开更多
文摘This paper deals with the design and development of the observational system of geo-electrical resistivity on the basis of the demands for exploring the temporal variations of electrical properties of Earth media in the fixed points of the networks, which would be associated with the earthquake preparation. The observation system is characterized by the high accuracy in measurement, long term stability in operation and high level of rejection to the environmental interference. It consists of three main parts, configuration system measurement system, the calibration and inspection system.
基金National Development and Reform Committee of China(No.15212Z0000001)National Science Foundation of China(No.41374077)。
文摘It is a debated topic if there are any observable precursor anomalies prior to the earthquake(EQ hereafter)and if the stronger EQ can be successfully predicted.During last few decades quite a lot of observable electromagnetic(EM)precursors were published by using techniques equipped in either satellites or on ground-based stations.But there are only a few cases that the shortterm precursor anomalies of EM field before earthquakes were observed by using alternate EM fields on ground.This paper will present a new EM observation network built in recent years and show a new finding of EM field with the variation of a one-year cycle observed using the network.As an example,the short-term precursor anomalies of apparent resistivity before the Yangbi EQ(Ms 5.1)occurred on March 27,2017 in Yunnan Province will be studied.The observed anomalous phenomena indicate that the anomaly before the EQ can be captured only if reasonable effective methods including sophisticated analytical techniques are used,and it is believed that continuously observed data on the fixed observation network for a long time is an effective means for studying anomalies that appeared before earthquakes.This network can also play an important role in studying the EM environment from space.
基金This work was supported by the National Natural Science Foundation of China(41361012)the Postgraduate Research and Innovation Funding Project of Inner Mongolia Autonomous Region(B2018111951).
文摘Snow resisting capacity of vegetation is important for secondary distribution of water resources in seasonal snow areas of grassland because it affects the regeneration,growth and nutrient circulation of vegetation in grassland.This study investigated vegetation characteristics(canopy height,canopy length and crown width)of Caragana microphylla Lam.(shrub)and Achnatherum splendens(Trin.)Nevski.(herb),and snow morphologies(snow depth,snow width and snow braid length)in a typical steppe region of Inner Mongolia,China in 2017.And the influence of vegetation characteristic on snow resisting capacity(the indices of bottom area of snow and snow volume reflect snow resisting capacity)was analyzed.The results showed that snow morphology depends on vegetation characteristics of shrub and herb.The canopy height was found to have the greatest influence on snow depth and the crown width had the greatest influence on snow width.The canopy length was found to have little influence on morphological parameters of snow.When the windward areas of C.microphylla and A.splendens were within the ranges of 0.0-0.5 m2 and 0.0-8.0 m2,respectively,the variation of snow cover was large;however,beyond these areas,the variation of snow cover became gradually stable.The potential area of snow retardation for a single plant was 1.5-2.5 m2 and the amount of snow resistance was 0.15-0.20 m3.The bottom area of snow and snow volume(i.e.,snow resisting capacity)of clumped C.microphylla and A.splendens was found to be 4 and 25 times that of individual plant,respectively.The results could provide a theoretical basis both for the estimation of snow cover and the establishment of a plant-based technical system for the control of windblown snow in the typical steppe region of Inner Mongolia.
文摘BACKGROUND The incidence of postoperative nausea and vomiting(PONV)in patients undergoing laparoscopic hysterectomy is very high compared with other surgeries,even when many prophylactic measures have been taken.However,the pathogenesis of PONV is multifactorial.Female sex,a history of motion sickness or PONV,nonsmokers,and perioperative opioid use are the most closely related factors.Among the multiple risk factors,suboptimal gastrointestinal(GI)perfusion may be attributed to some cases of PONV,and increased systemic vascular resistance(SVR)may lead to GI ischemia.The hypothesis of this research was that SVR is related to PONV.AIM To investigate the relationship between SVR and PONV in patients undergoing laparoscopic hysterectomy.METHODS A total of 228 patients who underwent elective laparoscopic hysterectomy were included in this prospective observational study.SVR was monitored using a noninvasive hemodynamic monitoring system.Four indices of SVR,the baseline,mean,area under the curve(AUC),and weighted AUC,were used for analysis.The incidence and severity of nausea and vomiting were evaluated while patients were awake and throughout the intervals from 0 to 2 h,2 to 6 h,and 6 to 24 h starting upon arrival at the post-anesthesia care unit.The associations between various SVR indices and PONV were investigated by logistic regression.P<0.05 was considered statistically significant.RESULTS The incidence of PONV in the study was 56.14%(128/228),and PONV tended to appear within 6 h after surgery.Five variables were significant in univariate analyses,however,only SVR mean[odds ratio(OR)=1.015,95%CI:1.005-1.109,P=0.047]and duration of surgery(OR=1.316,95%CI:1.003-2.030,P=0.012)were associated with PONV after logistic regression analysis.Furthermore,patients with high SVR mean were more likely to suffer from PONV after laparoscopic hysterectomy.On average,patients who developed PONV needed more time to tolerate diet and demonstrated poorer sleep quality on the first night after surgery.CONCLUSION In this study,PONV was a common complication after laparoscopic hysterectomy.SVR was associated with PONV,and high SVR mean was associated with a significantly increased risk of PONV.
文摘Several related substances were detected at trace level in (2R)-2,3-dihydro-2-methyl-6-nitro-2-[[4-[4-[4-(trifluoromethoxy)phenoxy]-1-piperidinyl] phenoxy] methyl]imidazo[2, 1-b]oxazole drug substance by a newly developed high-performance liquid chromatography method. All related substances were characterized rapidly but some impurities were found to be intermediates. Proposed structures were further confirmed by characterization using NMR, FT-IR, and HRMS techniques. Based on the spectroscopic data;unknown related sub-stances were characterized as 1-(Methylsulfonyl)-4-[4-(trifluoromethoxy) phenoxy]piperidine;4-{4-[4-(Tri-fluoromethoxy)-phenoxy]piperidin-1-yl}phenol and 4-{4-[4-(trifluoromethoxy)phenoxy]piperidin-1-yl}phenyl methane sulfonate;4-Bromophenyl methane sulfonate, Ethyl 3,6-dihydro-1(2H)-pyridine carboxylate, (2S)-3-(4-Bromophenoxy)-2-hydroxy-2-methylpropyl methane sulfonate, (2S)-3-(4-Bromophenoxy)-2-methylpropane-1,2-diyldimethane-sulfonate, (2S)-2-Methyl-3-(4-{4-[4-(trifluoromethoxy) phenoxy]-piperidin-1-yl} phenoxy)-propane-1,2-diyldimethane sulfonate, (S)-3-(4-Bromophenoxy)-2-methyl-propane-1,2-diol and corresponding Enantiomer, (2R)-2-[(4-Bromo-phenoxy)methyl]-2-methyloxirane and (2R)-2-[(4-bromophenoxy)methyl]-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b][1,3]oxazole. A possible mechanism for the formation of these related substances is also proposed.
