Anna was a vivid literature figure in the international literature history. Besides the obvious social factors of Anna 's tragedy, some internal roots of her tragedy shouldn't be neglected, such as her particu...Anna was a vivid literature figure in the international literature history. Besides the obvious social factors of Anna 's tragedy, some internal roots of her tragedy shouldn't be neglected, such as her particular spiritual world, merit and drawback of her character, her love value and conflicts about her thought. Analyzing into internal factors for Anna 's tragedy would offer further appreciation to readers.展开更多
Conventional conductivity methods for measuring the void fraction in gas-liquid multiphase systems are typically affected by accuracy problems due to the presence of fluid flow and salinity.This study presents a novel...Conventional conductivity methods for measuring the void fraction in gas-liquid multiphase systems are typically affected by accuracy problems due to the presence of fluid flow and salinity.This study presents a novel approach for determining the void fraction based on a reciprocating dynamic conductivity probe used to measure the liquid film thickness under forced annular-flow conditions.The measurement system comprises a cyclone,a conductivity probe,a probe reciprocating device,and a data acquisition and processing system.This method ensures that the flow pattern is adjusted to a forced annular flow,thereby minimizing the influence of complex and variable gas-liquid flow patterns on the measurement results;Moreover,it determines the liquid film thickness solely according to circuit connectivity rather than specific conductivity values,thereby mitigating the impact of salinity.The reliability of the measurement system is demonstrated through laboratory experiments.The experimental results indicate that,in a range of gas phase superficial velocities 5–20 m/s and liquid phase superficial velocities 0.079–0.48 m/s,the maximum measurement deviation for the void fraction is 4.23%.展开更多
Many students often raise questions, "Why it is so difficult to improve the listening comprehension?" This cannot be solved easily, because listening is a kind of complex and perceptual knowledge process. Li...Many students often raise questions, "Why it is so difficult to improve the listening comprehension?" This cannot be solved easily, because listening is a kind of complex and perceptual knowledge process. Listening does not only mean the ability to hear, it is also the ability to capture the information that the language carries through hearing organs and the ability of head. As far as I am concerned, such a problem is related to the complexity of various factors: listening itself covers, the language knowledge proficiency listeners possess, and also it is closely connected with the traditional foreign language style.展开更多
Olbers’s paradox, known as the dark night paradox, is an argument in astrophysics that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. Big-Bang theory was used ...Olbers’s paradox, known as the dark night paradox, is an argument in astrophysics that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. Big-Bang theory was used to partially explain this paradox, while introducing new problems. Hereby, we propose a better theory, named Sun Matters Theory, to explain this paradox. Moreover, this unique theory supports and extended the Einstein’s static universe model proposed by Albert Einstein in 1917. Further, we proposed our new universe model, “Sun Model of Universe”. Based on the new model and novel theory, we generated innovative field equation by upgrading Einstein’s Field Equation through adding back the cosmological constant, introducing a new variable and modifying the gravitationally-related concepts. According to the Sun Model of Universe, the dark matter and dark energy comprise the so-called “Sun Matters”. The observed phenomenon like the red shift is explained as due to the interaction of ordinary light with Sun Matters leading to its energy and frequency decrease. In Sun Model, our big universe consists of many universes with ordinary matter at the core mixed and surrounded with the Sun Matters. In those universes, the laws of physics may be completely or partially different from that of our ordinary universe with parallel civilizations. The darkness of night can be easily explained as resulting from the interaction of light with the Sun Matters leading to the sharp decrease in the light intensity. Sun Matters also scatter the light from a star, which makes it shining as observed by Hubble. Further, there is a kind of Sun Matters named “Sun Waters”, surrounding every starts. When lights pass by the sun, the Sun Waters deflect the lights to bend the light path. According to the Sun Model, it is the light bent not the space bent that was proposed in the theory of relativities.展开更多
The surface-enhanced Raman scattering(SERS) optical fiber probes were successfully prepared by self-assembling on polyelectrolyte multilayers. Gold nanorods(Au NRs) were used as SERS enhancement material to give excel...The surface-enhanced Raman scattering(SERS) optical fiber probes were successfully prepared by self-assembling on polyelectrolyte multilayers. Gold nanorods(Au NRs) were used as SERS enhancement material to give excellent biological affinity and stability to the SERS optical fiber probes. Au NRs were synthesized by seed growth method. The synergistic effect between AgNO_(3) and surfactant was investigated, and the highest yield was found when AgNO_(3) was 500 uL. Meanwhile, different SERS optical fiber probes were obtained by selecting silane coupling agent, polyelectrolyte multilayer and graphene oxide(GO) to treat quartz fiber. It was found that the SERS optical fiber probes obtained by the self-assembled on polyelectrolyte multilayers method performed better than those by other methods. In addition, Mapping was combined with finite element simulation to analyze the electromagnetic field distribution at the fiber end face.The electromagnetic field distribution of Au NRs was investigated, the difference of electromagnetic field intensity around the Au NRs with different arrangements was compared, the strongest signal was obtained when the Au NRs were head-to-head. Finally, sensitivity of the optimized SERS optical fiber probes could reach 10^(-9)mol/L, with excellent stability and repeatability.展开更多
A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition...A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 nm.Through the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by HPLC.The result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products.展开更多
Cytosolic Ca^(2+)plays a key role in signal transduction in plants.Calcium imaging is the most common approach to studying dynamic changes in the cytoplasmic Ca^(2+)content.Here,we used mature‘Fuji’apples(Malus pumi...Cytosolic Ca^(2+)plays a key role in signal transduction in plants.Calcium imaging is the most common approach to studying dynamic changes in the cytoplasmic Ca^(2+)content.Here,we used mature‘Fuji’apples(Malus pumila Mill.)to obtain viable protoplasts from flesh tissue cells by enzymatic hydrolysis;then,three small-molecule fluorescent probes(fluo-8/AM,fluo-4/AM,and rhod-2/AM)were loaded into the protoplasts.All three Ca^(2+)fluorescent probes successfully entered the cytoplasm but did not enter the vacuole.Both the Ca^(2+)chelator(EGTA)and Ca^(2+)channel blocker(La3+)reduced the fluorescence intensity in the cytoplasm.The calcium ionophore A23187 increased the fluorescence intensity in the cytoplasm at 5μmol/L but decreased it at 50μmol/L.Additionally,A23187 reversed the fluorescence intensity in the cytoplasm,which was decreased by La3+.Ionomycin is also a calcium ionophore that can increase the fluorescence intensity of calcium in the cytoplasm.These results suggest that small-molecule Ca^(2+)fluorescent probes can be used to detect changes in cytosolic calcium levels in the cells of fruit flesh tissue.In addition,the optimum concentration of fluo-8/AM was determined to be 5μmol/L.This was the first time that protoplasts have been isolated from apple flesh tissue cells and small-molecule fluorescent probes have been used to detect calcium in the cytoplasm of flesh tissue cells.This study provides a new method to study calcium signal transduction in fruit flesh tissue.展开更多
Subarachnoid hemorrhage leads to a series of pathological changes,including vascular spasm,cellular apoptosis,blood–brain barrier damage,cerebral edema,and white matter injury.Microglia,which are the key immune cells...Subarachnoid hemorrhage leads to a series of pathological changes,including vascular spasm,cellular apoptosis,blood–brain barrier damage,cerebral edema,and white matter injury.Microglia,which are the key immune cells in the central nervous system,maintain homeostasis in the neural environment,support neurons,mediate apoptosis,participate in immune regulation,and have neuroprotective effects.Increasing evidence has shown that microglia play a pivotal role in the pathogenesis of subarachnoid hemorrhage and affect the process of injury and the prognosis of subarachnoid hemorrhage.Moreover,microglia play certain neuroprotective roles in the recovery phase of subarachnoid hemorrhage.Several approaches aimed at modulating microglia function are believed to attenuate subarachnoid hemorrhage injury.This provides new targets and ideas for the treatment of subarachnoid hemorrhage.However,an in-depth and comprehensive summary of the role of microglia after subarachnoid hemorrhage is still lacking.This review describes the activation of microglia after subarachnoid hemorrhage and their roles in the pathological processes of vasospasm,neuroinflammation,neuronal apoptosis,blood–brain barrier disruption,cerebral edema,and cerebral white matter lesions.It also discusses the neuroprotective roles of microglia during recovery from subarachnoid hemorrhage and therapeutic advances aimed at modulating microglial function after subarachnoid hemorrhage.Currently,microglia in subarachnoid hemorrhage are targeted with TLR inhibitors,nuclear factor-κB and STAT3 pathway inhibitors,glycine/tyrosine kinases,NLRP3 signaling pathway inhibitors,Gasdermin D inhibitors,vincristine receptorαreceptor agonists,ferroptosis inhibitors,genetic modification techniques,stem cell therapies,and traditional Chinese medicine.However,most of these are still being evaluated at the laboratory stage.More clinical studies and data on subarachnoid hemorrhage are required to improve the treatment of subarachnoid hemorrhage.展开更多
Curcumin and its derivatives have good electrical and optical properties due to the highly symmetric structure of delocalized π electrons. Apart from that, curcumin and its derivatives can interact with numerous mole...Curcumin and its derivatives have good electrical and optical properties due to the highly symmetric structure of delocalized π electrons. Apart from that, curcumin and its derivatives can interact with numerous molecular targets, thereby exerting less side effects on human body. The fluorescence emission wavelength and fluorescence intensity of curcumin can be enhanced by modifying its π-conjugated system and β-diketone structure. Some curcumin-based fluorescent probes have been utilized to detect soluble/insoluble amyloid-β protein, intracranial reactive oxygen species, cysteine, cancer cells, etc. Based on the binding characteristics of curcumin-based fluorescent probes with various target molecules, the factors affecting the fluorescence intensity and emission wavelength of the probes are analyzed, in order to obtain a curcumin probe with higher sensitivity and selectivity. Such an approach will be greatly applicable to in vivo fluorescence imaging.展开更多
By simple arguments, it is shown how alkaline types of atoms can be seen in dense molecular clouds depending on the average temperature of such regions of the Universe. This paper predicts infrared lines of such atoms...By simple arguments, it is shown how alkaline types of atoms can be seen in dense molecular clouds depending on the average temperature of such regions of the Universe. This paper predicts infrared lines of such atoms that could be seen in molecular clouds. The theory is developed in the first part and the predicted experimental results will follow. It results that the alkaline atoms modelized using the short-range polarization potential are found in quantum states <em>n</em><sub>*</sub> > 2.展开更多
Soft condensed-state physics is a disciplinary frontier of 20th-century physics. An interdiscipline in nature, it involves biology, chemistry and even pure mathematics. Taking the liquid crystal (LC) biomembrane as an...Soft condensed-state physics is a disciplinary frontier of 20th-century physics. An interdiscipline in nature, it involves biology, chemistry and even pure mathematics. Taking the liquid crystal (LC) biomembrane as an example, this article expounds the current development trend of this new and promising branch of contemporary physics.展开更多
At the present time, mass me- dia and new media play an important part in establish- ing and constructing a civil society. This paper will focus on educa- tional roles of the media and will probe the major experiences...At the present time, mass me- dia and new media play an important part in establish- ing and constructing a civil society. This paper will focus on educa- tional roles of the media and will probe the major experiences and challenges related to constructing news events with human rights as the framework.展开更多
[Objective] This paper aimed to improve the detection rate of probe EUB338 for eubacteria.[Methods] Sixteen strains were used as materials for the experiment and analyzed through fluorescence in situ hybridization.[Re...[Objective] This paper aimed to improve the detection rate of probe EUB338 for eubacteria.[Methods] Sixteen strains were used as materials for the experiment and analyzed through fluorescence in situ hybridization.[Result] The average detection rate of probe EUB338 was 63.9%,which can be increased to 71.3% through modified FISH.[Conclusion] This research was able to provide scientific basis for the detection of eubacteria in soil from the perspective of molecular biology.展开更多
AIM:To review applications of confocal laser endomicroscopy(CLE) in pancreatobiliary lesions and studies that assessed training and interpretation of images. METHODS: A computerized literature search was performed usi...AIM:To review applications of confocal laser endomicroscopy(CLE) in pancreatobiliary lesions and studies that assessed training and interpretation of images. METHODS: A computerized literature search was performed using OVID MEDLINE, EMBASE, Cochrane library, and the ISI Web of Knowledge from 1980 to October 2014. We also searched abstracts from major meetings that included the Digestive Disease Week, Canadian Digestive Disease Week and the United European Gastroenterology Week using a combination of controlled vocabulary and text words related to p CLE, confocal, endomicroscopy, probe-based confocal laser endomicroscopy, and bile duct to identify reports of trials. In addition, recursive searches and crossreferencing was performed, and manual searches of articles identified after the initial search was also completed. We included fully published articles and those in abstract form. Given the relatively recent introduction of CLE we included randomized trials and cohort studies.R E S U LT S : In the evaluation of indeterminate pancreatobiliary strictures CLE with ERCP compared to ERCP alone can increase the detection of cancerous strictures with a sensitivity of(98% vs 45%) andhas a negative predictive value(97% vs 69%), but decreased the specificity(67% vs 100%) and the positive predictive value(71% vs 100%) when compared to index pathology. Modifications in the classification systems in indeterminate biliary strictures have increased the specificity of p CLE from 67% to 73%. In pancreatic cystic lesions there is a need to develop similar systems to interpret and characterize lesions based on CLE images obtained. The presence of superficial vascular network predicts serous cystadenomas accurately. Also training in acquiring and interpretation of images is feasible in those without any prior knowledge in CLE in a relatively simple manner and computer-aided diagnosis software is a promising innovation. CONCLUSION: The role of p CLE in the evaluation of pancreatobiliary disorders might be better suited for those with an intermediate and low probability.展开更多
To extract gold from a low-grade(13.43 g/t) and high-sulfur(39.94wt% sulfide sulfur) Carlin-type gold concentrate from the Nibao deposit, Guizhou, a bio-pretreatment followed by carbon-in-pulp(CIP) cyanide leaching pr...To extract gold from a low-grade(13.43 g/t) and high-sulfur(39.94wt% sulfide sulfur) Carlin-type gold concentrate from the Nibao deposit, Guizhou, a bio-pretreatment followed by carbon-in-pulp(CIP) cyanide leaching process was used. Various methods were used to detect the low-grade gold in the concentrate; however, only time-of-flight secondary-ion mass spectrometry(TOF-SIMS) was successful. With bio-pretreatment, the gold recovery rate increased by approximately 70.16% compared with that obtained by direct cyanide leaching of the concentrate. Various attempts were made to increase the final gold recovery rate. However, approximately 20wt% of the gold was non-extractable. To determine the nature of this non-extractable gold, mineralogy liberation analysis(MLA), formation of secondary product during the bio-pretreatment, and the preg-robbing capacity of the carbonaceous matter in the ore were investigated. The results indicated that at least four factors affected the gold recovery rate: gold occurrence, tight junctions of gold-bearing pyrite with gangue minerals, jarosite coating of the ore, and the carbonaceous matter content.展开更多
Water temperature,turbidity,chlorophyll-a and suspended sediment concentration (SSC) were investigated at 61 stations of eight sections in the southern Huanghai Sea (HS) and the East China Sea (ECS) during the s...Water temperature,turbidity,chlorophyll-a and suspended sediment concentration (SSC) were investigated at 61 stations of eight sections in the southern Huanghai Sea (HS) and the East China Sea (ECS) during the summer (28 June to 15 July) of 2006.The horizontal distribution of suspended parti culate matter (SPM) displayed a high concentration inshore and a low value offshore.The maximum value can reach 10.4 mg/dm 3,which can be found at the Changjiang River mouth.For the same site,the SSC was generally higher at the bottom than on the surface.In the vertical direction,distribution characteristics of turbidity can be divided into two types:in the southern HS high values at the bottom while low values on the surface,and in the ECS high values inshore with low values offshore.The thermocline in the HS and the Taiwan Warm Current in the ECS could be important factors preventing the SPM from diffusing upward and seaward.Even the typhoon Ewiniar was not able to work on the major sediment transport under the thermocline during the observation.展开更多
In 5G systems, massive multiple-input multiple-output (MIMO) has been adopted in base stations (BSs) to improve spectral efficiency and coverage. The traditional conductive performance test techniques are challenging ...In 5G systems, massive multiple-input multiple-output (MIMO) has been adopted in base stations (BSs) to improve spectral efficiency and coverage. The traditional conductive performance test techniques are challenging due to the unaffordable cost and high complexity when testing a large number of antennas. To solve this problem, the over-the-air (OTA) test has been presented, in which probe selection is the key to reduce the number of channel emulators and probes. In this paper, a novel artificial bee colony (ABC) algorithm is introduced to enhance the efficiency and accuracy of probe selection procedure. A sectoring- based multi-probe anechoic chamber (MPAC) is built to evaluate the throughput performance of massive MIMO equipped in 5G BS. In addition, link level simulation is carried out to evaluate the proposal’s performance gain under the commercial network assumptions, where the average throughput of three velocity is given with different SNR region. The results suggest that OTA chamber and multi-probe wall are available not only for 5G BSs, but also for user equipments (UEs) with end-to-end communication.展开更多
Recently,the theoretically predicted lanthanum superhydride,LaH 10±δ,with a clathrate-like structure was successfully synthesized and found to exhibit a record high superconducting transition temperature T c≈25...Recently,the theoretically predicted lanthanum superhydride,LaH 10±δ,with a clathrate-like structure was successfully synthesized and found to exhibit a record high superconducting transition temperature T c≈250 K at∼170 GPa,opening a new route for room-temperature superconductivity.However,since in situ experiments at megabar pressures are very challenging,few groups have reported the∼250 K superconducting transition in LaH 10±δ.Here,we establish a simpler sample-loading procedure that allows a relatively large sample size for synthesis and a standard four-probe configuration for resistance measurements.Following this procedure,we successfully synthesized LaH 10±δwith dimensions up to 10×20μm^2 by laser heating a thin La flake and ammonia borane at∼1700 K in a symmetric diamond anvil cell under the pressure of 165 GPa.The superconducting transition at T c≈250 K was confirmed through resistance measurements under various magnetic fields.Our method will facilitate explorations of near-room-temperature superconductors among metal superhydrides.展开更多
文摘Anna was a vivid literature figure in the international literature history. Besides the obvious social factors of Anna 's tragedy, some internal roots of her tragedy shouldn't be neglected, such as her particular spiritual world, merit and drawback of her character, her love value and conflicts about her thought. Analyzing into internal factors for Anna 's tragedy would offer further appreciation to readers.
基金the National Natural Science Foundation of China(No.62173049)the Open Fund of the Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering(Yangtze University),YQZC202309.
文摘Conventional conductivity methods for measuring the void fraction in gas-liquid multiphase systems are typically affected by accuracy problems due to the presence of fluid flow and salinity.This study presents a novel approach for determining the void fraction based on a reciprocating dynamic conductivity probe used to measure the liquid film thickness under forced annular-flow conditions.The measurement system comprises a cyclone,a conductivity probe,a probe reciprocating device,and a data acquisition and processing system.This method ensures that the flow pattern is adjusted to a forced annular flow,thereby minimizing the influence of complex and variable gas-liquid flow patterns on the measurement results;Moreover,it determines the liquid film thickness solely according to circuit connectivity rather than specific conductivity values,thereby mitigating the impact of salinity.The reliability of the measurement system is demonstrated through laboratory experiments.The experimental results indicate that,in a range of gas phase superficial velocities 5–20 m/s and liquid phase superficial velocities 0.079–0.48 m/s,the maximum measurement deviation for the void fraction is 4.23%.
文摘Many students often raise questions, "Why it is so difficult to improve the listening comprehension?" This cannot be solved easily, because listening is a kind of complex and perceptual knowledge process. Listening does not only mean the ability to hear, it is also the ability to capture the information that the language carries through hearing organs and the ability of head. As far as I am concerned, such a problem is related to the complexity of various factors: listening itself covers, the language knowledge proficiency listeners possess, and also it is closely connected with the traditional foreign language style.
文摘Olbers’s paradox, known as the dark night paradox, is an argument in astrophysics that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. Big-Bang theory was used to partially explain this paradox, while introducing new problems. Hereby, we propose a better theory, named Sun Matters Theory, to explain this paradox. Moreover, this unique theory supports and extended the Einstein’s static universe model proposed by Albert Einstein in 1917. Further, we proposed our new universe model, “Sun Model of Universe”. Based on the new model and novel theory, we generated innovative field equation by upgrading Einstein’s Field Equation through adding back the cosmological constant, introducing a new variable and modifying the gravitationally-related concepts. According to the Sun Model of Universe, the dark matter and dark energy comprise the so-called “Sun Matters”. The observed phenomenon like the red shift is explained as due to the interaction of ordinary light with Sun Matters leading to its energy and frequency decrease. In Sun Model, our big universe consists of many universes with ordinary matter at the core mixed and surrounded with the Sun Matters. In those universes, the laws of physics may be completely or partially different from that of our ordinary universe with parallel civilizations. The darkness of night can be easily explained as resulting from the interaction of light with the Sun Matters leading to the sharp decrease in the light intensity. Sun Matters also scatter the light from a star, which makes it shining as observed by Hubble. Further, there is a kind of Sun Matters named “Sun Waters”, surrounding every starts. When lights pass by the sun, the Sun Waters deflect the lights to bend the light path. According to the Sun Model, it is the light bent not the space bent that was proposed in the theory of relativities.
基金Funded by National Natural Science Foundation of China (Nos.51372179, 51772224)the Open Projects Foundation of Yangtze Optical Fiber and Cable Joint Stock Limited Company (YOFC)(No.SKLD1705)。
文摘The surface-enhanced Raman scattering(SERS) optical fiber probes were successfully prepared by self-assembling on polyelectrolyte multilayers. Gold nanorods(Au NRs) were used as SERS enhancement material to give excellent biological affinity and stability to the SERS optical fiber probes. Au NRs were synthesized by seed growth method. The synergistic effect between AgNO_(3) and surfactant was investigated, and the highest yield was found when AgNO_(3) was 500 uL. Meanwhile, different SERS optical fiber probes were obtained by selecting silane coupling agent, polyelectrolyte multilayer and graphene oxide(GO) to treat quartz fiber. It was found that the SERS optical fiber probes obtained by the self-assembled on polyelectrolyte multilayers method performed better than those by other methods. In addition, Mapping was combined with finite element simulation to analyze the electromagnetic field distribution at the fiber end face.The electromagnetic field distribution of Au NRs was investigated, the difference of electromagnetic field intensity around the Au NRs with different arrangements was compared, the strongest signal was obtained when the Au NRs were head-to-head. Finally, sensitivity of the optimized SERS optical fiber probes could reach 10^(-9)mol/L, with excellent stability and repeatability.
基金supported by the National Natural Science Foundation of China(21804050)the National Key R and D Program of China(2018YFD0901003)+2 种基金the Science and Technology Planning Project of Xiamen,China(3502Z20183031)the Fujian Provincial Fund Project(2018J01432)the Xiamen Science and Technology Planning Project,China(3502Z20183031)。
文摘A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 nm.Through the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by HPLC.The result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products.
基金supported by the National Key Research and Development Plan Project:Integrated research and demonstration on the technology of reducing application and increasing efficiency of chemical fertilizer and pesticide in apple cultivation(2016YFD0201120).
文摘Cytosolic Ca^(2+)plays a key role in signal transduction in plants.Calcium imaging is the most common approach to studying dynamic changes in the cytoplasmic Ca^(2+)content.Here,we used mature‘Fuji’apples(Malus pumila Mill.)to obtain viable protoplasts from flesh tissue cells by enzymatic hydrolysis;then,three small-molecule fluorescent probes(fluo-8/AM,fluo-4/AM,and rhod-2/AM)were loaded into the protoplasts.All three Ca^(2+)fluorescent probes successfully entered the cytoplasm but did not enter the vacuole.Both the Ca^(2+)chelator(EGTA)and Ca^(2+)channel blocker(La3+)reduced the fluorescence intensity in the cytoplasm.The calcium ionophore A23187 increased the fluorescence intensity in the cytoplasm at 5μmol/L but decreased it at 50μmol/L.Additionally,A23187 reversed the fluorescence intensity in the cytoplasm,which was decreased by La3+.Ionomycin is also a calcium ionophore that can increase the fluorescence intensity of calcium in the cytoplasm.These results suggest that small-molecule Ca^(2+)fluorescent probes can be used to detect changes in cytosolic calcium levels in the cells of fruit flesh tissue.In addition,the optimum concentration of fluo-8/AM was determined to be 5μmol/L.This was the first time that protoplasts have been isolated from apple flesh tissue cells and small-molecule fluorescent probes have been used to detect calcium in the cytoplasm of flesh tissue cells.This study provides a new method to study calcium signal transduction in fruit flesh tissue.
基金supported by the Natural Science Foundation of Shandong Province,No.ZR2022MH124the Youth Science Foundation of Shandong First Medical University,No.202201–105(both to YX)。
文摘Subarachnoid hemorrhage leads to a series of pathological changes,including vascular spasm,cellular apoptosis,blood–brain barrier damage,cerebral edema,and white matter injury.Microglia,which are the key immune cells in the central nervous system,maintain homeostasis in the neural environment,support neurons,mediate apoptosis,participate in immune regulation,and have neuroprotective effects.Increasing evidence has shown that microglia play a pivotal role in the pathogenesis of subarachnoid hemorrhage and affect the process of injury and the prognosis of subarachnoid hemorrhage.Moreover,microglia play certain neuroprotective roles in the recovery phase of subarachnoid hemorrhage.Several approaches aimed at modulating microglia function are believed to attenuate subarachnoid hemorrhage injury.This provides new targets and ideas for the treatment of subarachnoid hemorrhage.However,an in-depth and comprehensive summary of the role of microglia after subarachnoid hemorrhage is still lacking.This review describes the activation of microglia after subarachnoid hemorrhage and their roles in the pathological processes of vasospasm,neuroinflammation,neuronal apoptosis,blood–brain barrier disruption,cerebral edema,and cerebral white matter lesions.It also discusses the neuroprotective roles of microglia during recovery from subarachnoid hemorrhage and therapeutic advances aimed at modulating microglial function after subarachnoid hemorrhage.Currently,microglia in subarachnoid hemorrhage are targeted with TLR inhibitors,nuclear factor-κB and STAT3 pathway inhibitors,glycine/tyrosine kinases,NLRP3 signaling pathway inhibitors,Gasdermin D inhibitors,vincristine receptorαreceptor agonists,ferroptosis inhibitors,genetic modification techniques,stem cell therapies,and traditional Chinese medicine.However,most of these are still being evaluated at the laboratory stage.More clinical studies and data on subarachnoid hemorrhage are required to improve the treatment of subarachnoid hemorrhage.
基金financially supported by the Scientific Research Fund of Liaoning Provincial Education Department of China (No. LJC201908)the Natural Science Foundation of Liaoning Province (No.20180510016,2019-MS-153)。
文摘Curcumin and its derivatives have good electrical and optical properties due to the highly symmetric structure of delocalized π electrons. Apart from that, curcumin and its derivatives can interact with numerous molecular targets, thereby exerting less side effects on human body. The fluorescence emission wavelength and fluorescence intensity of curcumin can be enhanced by modifying its π-conjugated system and β-diketone structure. Some curcumin-based fluorescent probes have been utilized to detect soluble/insoluble amyloid-β protein, intracranial reactive oxygen species, cysteine, cancer cells, etc. Based on the binding characteristics of curcumin-based fluorescent probes with various target molecules, the factors affecting the fluorescence intensity and emission wavelength of the probes are analyzed, in order to obtain a curcumin probe with higher sensitivity and selectivity. Such an approach will be greatly applicable to in vivo fluorescence imaging.
文摘By simple arguments, it is shown how alkaline types of atoms can be seen in dense molecular clouds depending on the average temperature of such regions of the Universe. This paper predicts infrared lines of such atoms that could be seen in molecular clouds. The theory is developed in the first part and the predicted experimental results will follow. It results that the alkaline atoms modelized using the short-range polarization potential are found in quantum states <em>n</em><sub>*</sub> > 2.
文摘Soft condensed-state physics is a disciplinary frontier of 20th-century physics. An interdiscipline in nature, it involves biology, chemistry and even pure mathematics. Taking the liquid crystal (LC) biomembrane as an example, this article expounds the current development trend of this new and promising branch of contemporary physics.
文摘At the present time, mass me- dia and new media play an important part in establish- ing and constructing a civil society. This paper will focus on educa- tional roles of the media and will probe the major experiences and challenges related to constructing news events with human rights as the framework.
基金Supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministrythe National Natural Science Foundation of China(No.21047001)the Standards Foundation of Shanghai City(No.10DZ0503900)~~
文摘[Objective] This paper aimed to improve the detection rate of probe EUB338 for eubacteria.[Methods] Sixteen strains were used as materials for the experiment and analyzed through fluorescence in situ hybridization.[Result] The average detection rate of probe EUB338 was 63.9%,which can be increased to 71.3% through modified FISH.[Conclusion] This research was able to provide scientific basis for the detection of eubacteria in soil from the perspective of molecular biology.
基金Supported by Deanship of Scientific Research at King Saud University through the Research Group Project number RGPVPP-279
文摘AIM:To review applications of confocal laser endomicroscopy(CLE) in pancreatobiliary lesions and studies that assessed training and interpretation of images. METHODS: A computerized literature search was performed using OVID MEDLINE, EMBASE, Cochrane library, and the ISI Web of Knowledge from 1980 to October 2014. We also searched abstracts from major meetings that included the Digestive Disease Week, Canadian Digestive Disease Week and the United European Gastroenterology Week using a combination of controlled vocabulary and text words related to p CLE, confocal, endomicroscopy, probe-based confocal laser endomicroscopy, and bile duct to identify reports of trials. In addition, recursive searches and crossreferencing was performed, and manual searches of articles identified after the initial search was also completed. We included fully published articles and those in abstract form. Given the relatively recent introduction of CLE we included randomized trials and cohort studies.R E S U LT S : In the evaluation of indeterminate pancreatobiliary strictures CLE with ERCP compared to ERCP alone can increase the detection of cancerous strictures with a sensitivity of(98% vs 45%) andhas a negative predictive value(97% vs 69%), but decreased the specificity(67% vs 100%) and the positive predictive value(71% vs 100%) when compared to index pathology. Modifications in the classification systems in indeterminate biliary strictures have increased the specificity of p CLE from 67% to 73%. In pancreatic cystic lesions there is a need to develop similar systems to interpret and characterize lesions based on CLE images obtained. The presence of superficial vascular network predicts serous cystadenomas accurately. Also training in acquiring and interpretation of images is feasible in those without any prior knowledge in CLE in a relatively simple manner and computer-aided diagnosis software is a promising innovation. CONCLUSION: The role of p CLE in the evaluation of pancreatobiliary disorders might be better suited for those with an intermediate and low probability.
基金financially supported by the National Science and Technology Supporting Program (No. 2012BAB10B08)the National High Technology Research and Development Program of China (No. 2012AA060501)
文摘To extract gold from a low-grade(13.43 g/t) and high-sulfur(39.94wt% sulfide sulfur) Carlin-type gold concentrate from the Nibao deposit, Guizhou, a bio-pretreatment followed by carbon-in-pulp(CIP) cyanide leaching process was used. Various methods were used to detect the low-grade gold in the concentrate; however, only time-of-flight secondary-ion mass spectrometry(TOF-SIMS) was successful. With bio-pretreatment, the gold recovery rate increased by approximately 70.16% compared with that obtained by direct cyanide leaching of the concentrate. Various attempts were made to increase the final gold recovery rate. However, approximately 20wt% of the gold was non-extractable. To determine the nature of this non-extractable gold, mineralogy liberation analysis(MLA), formation of secondary product during the bio-pretreatment, and the preg-robbing capacity of the carbonaceous matter in the ore were investigated. The results indicated that at least four factors affected the gold recovery rate: gold occurrence, tight junctions of gold-bearing pyrite with gangue minerals, jarosite coating of the ore, and the carbonaceous matter content.
基金The National Natural Science Foundation Project of China "Sedimentary dynamic mechanism of the Huanghai Warm Current" under contract No.40906025the National Natural Science Foundation Project of China "Formation and development of the muddy deposition in the central south Huanghai Sea,and its relation to climate and environmental change" under contract No.41030856+1 种基金State Basic Research Program of China ("973" Program) under contract No.2005CB422304the Public Science and Technology Research Funds Projects of Ocean under contract Nos 200905001 and 201005019
文摘Water temperature,turbidity,chlorophyll-a and suspended sediment concentration (SSC) were investigated at 61 stations of eight sections in the southern Huanghai Sea (HS) and the East China Sea (ECS) during the summer (28 June to 15 July) of 2006.The horizontal distribution of suspended parti culate matter (SPM) displayed a high concentration inshore and a low value offshore.The maximum value can reach 10.4 mg/dm 3,which can be found at the Changjiang River mouth.For the same site,the SSC was generally higher at the bottom than on the surface.In the vertical direction,distribution characteristics of turbidity can be divided into two types:in the southern HS high values at the bottom while low values on the surface,and in the ECS high values inshore with low values offshore.The thermocline in the HS and the Taiwan Warm Current in the ECS could be important factors preventing the SPM from diffusing upward and seaward.Even the typhoon Ewiniar was not able to work on the major sediment transport under the thermocline during the observation.
基金supported by the State Major Science and Technology Special Projects under Grant No. 2018ZX03001028-003
文摘In 5G systems, massive multiple-input multiple-output (MIMO) has been adopted in base stations (BSs) to improve spectral efficiency and coverage. The traditional conductive performance test techniques are challenging due to the unaffordable cost and high complexity when testing a large number of antennas. To solve this problem, the over-the-air (OTA) test has been presented, in which probe selection is the key to reduce the number of channel emulators and probes. In this paper, a novel artificial bee colony (ABC) algorithm is introduced to enhance the efficiency and accuracy of probe selection procedure. A sectoring- based multi-probe anechoic chamber (MPAC) is built to evaluate the throughput performance of massive MIMO equipped in 5G BS. In addition, link level simulation is carried out to evaluate the proposal’s performance gain under the commercial network assumptions, where the average throughput of three velocity is given with different SNR region. The results suggest that OTA chamber and multi-probe wall are available not only for 5G BSs, but also for user equipments (UEs) with end-to-end communication.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB33000000 and XDB25000000)the Beijing Natural Science Foundation(Grant No.Z190008)+2 种基金the National Natural Science Foundation of China(Grant Nos.11575288, 11921004, 11888101, 11904391, 11834016 and 11874400)the National Key R&D Program of China(Grant Nos.2016YFA0401503 and 2018YFA0305700)the Youth Innovation Promotion Association,the Key Research Program of Frontier Sciences and the Interdisciplinary Innovation Team of Chinese Academy of Sciences(Grant Nos.2016006, JCTD-2019-01,and QYZDBSSW-SLH013)
文摘Recently,the theoretically predicted lanthanum superhydride,LaH 10±δ,with a clathrate-like structure was successfully synthesized and found to exhibit a record high superconducting transition temperature T c≈250 K at∼170 GPa,opening a new route for room-temperature superconductivity.However,since in situ experiments at megabar pressures are very challenging,few groups have reported the∼250 K superconducting transition in LaH 10±δ.Here,we establish a simpler sample-loading procedure that allows a relatively large sample size for synthesis and a standard four-probe configuration for resistance measurements.Following this procedure,we successfully synthesized LaH 10±δwith dimensions up to 10×20μm^2 by laser heating a thin La flake and ammonia borane at∼1700 K in a symmetric diamond anvil cell under the pressure of 165 GPa.The superconducting transition at T c≈250 K was confirmed through resistance measurements under various magnetic fields.Our method will facilitate explorations of near-room-temperature superconductors among metal superhydrides.