Studies on the bacterial predation rate by rumen protozoa were carried out under laboratory conditions using a technique of fluorescence-labeled bacteria （FLB）. Four Xuhuai goats were used in this experiment to obta...Studies on the bacterial predation rate by rumen protozoa were carried out under laboratory conditions using a technique of fluorescence-labeled bacteria （FLB）. Four Xuhuai goats were used in this experiment to obtain rumen protozoa and bacteria. Two groups were designed as follows： One group was the whole bacteria which were labeled using fluorescence through removing free bacteria from rumen fluid （WFLB）; the other group was the bacteria which were labeled using fluorescence without removing free bacteria from rumen fluid （FLB）. The result indicated that the bacterial predation rates of rumen protozoa was 398.4 cells/（cell h） for the group WFLB, 230.4 cells/（cell h） for the group FLB, when the corresponding values expressed as bacteria-N, they were 2.15 pg N/（cell h） for the group WFLB, and 1.24 pg N/（cell h） for the group FLB, respectively. Extrapolating the assimilation quantity of nitrogen by ciliates on bacteria of Xuhuai goat, there were 103.2 mg N/（d capita） for the group WFLB, and 59.5 mg N/（d capita） for the group FLB, respectively. It was estimated that protein losses due to microbial recycling were 0.645 g pro/（d capita） for the group WFLB and 0.372 g pro/（d capita） for the group FLB, respectively. In addition, the fluorescence-labeled technique would be a potential assay for the determination of bacterial predation rate by rumen protozoa.展开更多
The content of berberine hydrochloride(BH)in compound berberine tablets(CBTs)is subject to strict requirements.Its content is usually measured based on chemical analysis.In this paper,the fluorescence spectral imaging...The content of berberine hydrochloride(BH)in compound berberine tablets(CBTs)is subject to strict requirements.Its content is usually measured based on chemical analysis.In this paper,the fluorescence spectral imaging method was used to study the relative content of BH from a physics perspective.By comparing the relative fluorescence intensity of self-made CBTs with di®erent mass percentages of BH,a linear positive relationship was observed between the BH content and the relative fluorescence intensity,and accordingly the quality of CBTs of different brands was evaluated.The results indicate that the fluorescence spectral imaging method can be a simple,fast and nondestructive semi-quantitative analysis method to determine the content of BH in CBTs,and this method has great potential in the quality control of CBTs.展开更多
The introduction of multi-methods of Geo-logging at wellsite has become the major measurement of oil & gas exploration. From the early stage of manually geo-logging to the modern mudlogging with new techonlogies o...The introduction of multi-methods of Geo-logging at wellsite has become the major measurement of oil & gas exploration. From the early stage of manually geo-logging to the modern mudlogging with new techonlogies of MWD, LWD and QFT etc. The new technologies have played very important roles in the exploring of oil & gas. Being one of the newest technology of mudlogging, QFT has been widely used in oilfield for about 3 years. When it is put in operation in some oilfields of China in 1997, its advantages in oil & gas detection at wellsite have been continuously recognized,especially in the detection of shows of light oil and condensed oil. A set of powerful classification standard of resource rock oil bearing grades and the interpretation standards have been summarized by the application of the quantitative fluorescencelogging techniques (QFT) in Basins of China, together with gas-logging data, and other information got from the Geo-logging procedures at wellsite.展开更多
The electrophysiological methods using microelectrodes are not appropriate for the simultaneous measurement of neural activities of many neurons. To overcome the difficulty, the fluorescent imaging technique using vol...The electrophysiological methods using microelectrodes are not appropriate for the simultaneous measurement of neural activities of many neurons. To overcome the difficulty, the fluorescent imaging technique using voltage sensitive dyes can be a powerful technique. The voltage sensitive dyes, however, generally exhibit a relatively small change in their fluorescence intensities, resulting in a low S/N ratio. Additionally, they often exhibit photobleaching and phototoxity. We have therefore improved the fluorescent voltage imaging technique by using a LED as the light source and an electron multiplying (EM)-CCD camera as the fluorescence detector. In this study, we applied our imaging system for the measurement of two kind of molluscan neural activities;one of which is involved in the olfactory processing of the land slug Limax valentianus and the other is involved in the feeding rhythm of the pond snail Lymnaea stagnalis. The system enabled us to measure the neural activities for a long time with a high speed and a high S/N ratio, and the obtained results showed some new physiological findings.展开更多
The new double projecting neurons were found in the cat spinal dorsal horn by the double retrograde fluorescent tracing technique.Fast Blue(FB)was injected into unilateral dorsal column nucleus(DCN)of adult cats anest...The new double projecting neurons were found in the cat spinal dorsal horn by the double retrograde fluorescent tracing technique.Fast Blue(FB)was injected into unilateral dorsal column nucleus(DCN)of adult cats anesthetized with pentobarbital.Nuclear Yellow(NY)was injected ipsilaterally into the lateral cervical nucleus(LCN)8-9 days later.After an additional 18-30 hrs.展开更多
When measuring reflectance spectra, it is very important to accurately extract chlorophyll fluorescence from elastic-scattering light in water-leaving radiance. The elastic scattering of light by water particles produ...When measuring reflectance spectra, it is very important to accurately extract chlorophyll fluorescence from elastic-scattering light in water-leaving radiance. The elastic scattering of light by water particles produces partially polarized light. In contrast, chlorophyll fluorescence in planktonic algae yields completely unpolarized light. These properties can be used to separate fluorescent signals from the water-leaving radiance and thus to determine chlorophyll concentration. The algal species Aureococcus anophagefferens was used to conduct a laboratory polarization experiment. For the tests, we used a field spectroradiometer and a polarizer; measurements were collected using two different observation modes. The chlorophyll fluorescence curve extracted through polarization shows an excellent match with the results obtained using the fluorospectro photometer for both measurement modes, suggesting that polarization-based chlorophyll fluorescence extraction may be feasible. The extracted fluorescence is more reliable at incident zenith angles ranging from 30? to 60?. For algae-containing water, the results improve with increasing chlorophyll concentration. This method could help improve chlorophyll concentration measurement and the remote-sensing detection of resulting harmful algae blooms.展开更多
AIM To assess potential contributions of biliary IgA for crystal agglomeration into gallstones, we visualized cholesterol crystal binding of biliary IgA.METHODS Crystal-binding biliary proteins were extracted from hum...AIM To assess potential contributions of biliary IgA for crystal agglomeration into gallstones, we visualized cholesterol crystal binding of biliary IgA.METHODS Crystal-binding biliary proteins were extracted from human gallbladder bile using lectin affinity chromatography. Biliary IgA was isolated from the bound protein fraction by immunoaffinity chromatography. Pure cholesterol monohydrate crystals were incubated with biliary IgA and fluoresceine isothiocyanate (FITC)-conjugated anti-lgA at 37C. Samples were examined under polarizing and fluorescence light microscopy with digital image processing.RESULTS Binding of biliary IgA to cholesterol monohydrate crystals could be visualized with FITC-conjugated anti-lgA antibodies. Peak fluorescence occurred at crystal edges and dislocations. Controls without biliary IgA or with biliary IgG showed no significant fluorescence.CONCLUSION Fluorescence light microscopy provided evidence for cholesterol crystal binding of biliary IgA. Cholesterol crystalbinding proteins like IgA might be important mediators of crystal agglomeration and growth of cholesterol gallstones by modifying the evolving crystal structures in vivo.展开更多
Our recent studies concerning the binding of ionic surfactants on oppositely charged polyelectrolytes observedwith fluorescence techniques are reviewed. The cationic surfactants cetyltrimethylammonium bromide (CTAB),d...Our recent studies concerning the binding of ionic surfactants on oppositely charged polyelectrolytes observedwith fluorescence techniques are reviewed. The cationic surfactants cetyltrimethylammonium bromide (CTAB),dodecyltrimethylammonium chloride (DTAC), and nonionic surfactant octaethylene glycol monododecyl ether (C_(12)E_8) wereallowed to bind on anionic poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) and its pyrene and/or naphthalenelabeled copolymers. The relative excimer emission intensity I_E/I_M of a cationic probe l-pyrenemethylamine hydrochloride(PyMeA·HCl) and the non-radiative energy transfer (NRET) I_(Py)/I_(Np) of naphthalene to pyrene for labeled polyelectrolyteswere chosen to monitor the binding process and the conformation change of surfactant-bound polyelectrolytes. The 1:1aggregation of polyelectrolyte-CTAB with respect to the charge was found as long as the CTAB concentration was slightlyhigher than its critical aggregation concentration (CAC). The intermolecular NRET indicated that the CTAB-boundpolyelectrolytes aggregated together through the hydrophobic interaction between the CTAB tails. However, neither 1:1polyelectrolyte-DTAC aggregation nor intermolecular aggregation of DTAC-bound polyelectrolyte was observed owing to itsweaker hydrophobicity of 12 carbon atoms in the tail, which is shorter than that of CTAB. As known from the fluorescenceresults, nonionic surfactant C_(12)E_8 did not bind on the anionic polyelectrolytes, but the presence of PAMPS promoted themicelle formation for C_(12)E_8 at the CAC slightly below its critical micelle concentration (CMC). The solid complex of dansyllabeled AMPS copolymer-surfactant exhibited a decrease in local polarity with increasing charge density of thepolyelectrolyte or with alkane tail length of the surfactant. SAXS suggested a lamella structure for the AMPS copolymer-surfactant solid complexes with a long period of 3.87 nm for CTAB and 3.04 nm for DTAC, respectively.展开更多
The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve fibers.Due to the complex structure and composition of myelin,various...The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve fibers.Due to the complex structure and composition of myelin,various histological techniques have been developed over the centuries to evaluate myelin under normal,pathological or experimental conditions.Today,methods to assess myelin integrity or content are key tools in both clinical diagnosis and neuroscience research.In this review,we provide an updated summary of the composition and structure of the myelin sheath and discuss some histological procedures,from tissue fixation and processing techniques to the most used and practical myelin histological staining methods.Considering the lipoprotein nature of myelin,the main features and technical details of the different available methods that can be used to evaluate the lipid or protein components of myelin are described,as well as the precise ultrastructural techniques.展开更多
基金carried out under the financial support from the National Natural Science Foundation of China(30571344).
文摘Studies on the bacterial predation rate by rumen protozoa were carried out under laboratory conditions using a technique of fluorescence-labeled bacteria （FLB）. Four Xuhuai goats were used in this experiment to obtain rumen protozoa and bacteria. Two groups were designed as follows： One group was the whole bacteria which were labeled using fluorescence through removing free bacteria from rumen fluid （WFLB）; the other group was the bacteria which were labeled using fluorescence without removing free bacteria from rumen fluid （FLB）. The result indicated that the bacterial predation rates of rumen protozoa was 398.4 cells/（cell h） for the group WFLB, 230.4 cells/（cell h） for the group FLB, when the corresponding values expressed as bacteria-N, they were 2.15 pg N/（cell h） for the group WFLB, and 1.24 pg N/（cell h） for the group FLB, respectively. Extrapolating the assimilation quantity of nitrogen by ciliates on bacteria of Xuhuai goat, there were 103.2 mg N/（d capita） for the group WFLB, and 59.5 mg N/（d capita） for the group FLB, respectively. It was estimated that protein losses due to microbial recycling were 0.645 g pro/（d capita） for the group WFLB and 0.372 g pro/（d capita） for the group FLB, respectively. In addition, the fluorescence-labeled technique would be a potential assay for the determination of bacterial predation rate by rumen protozoa.
基金The authors would like to acknowledge the support of the Ph.D.research startup foundation of Guangdong Medical University (2XB14006).
文摘The content of berberine hydrochloride(BH)in compound berberine tablets(CBTs)is subject to strict requirements.Its content is usually measured based on chemical analysis.In this paper,the fluorescence spectral imaging method was used to study the relative content of BH from a physics perspective.By comparing the relative fluorescence intensity of self-made CBTs with di®erent mass percentages of BH,a linear positive relationship was observed between the BH content and the relative fluorescence intensity,and accordingly the quality of CBTs of different brands was evaluated.The results indicate that the fluorescence spectral imaging method can be a simple,fast and nondestructive semi-quantitative analysis method to determine the content of BH in CBTs,and this method has great potential in the quality control of CBTs.
文摘The introduction of multi-methods of Geo-logging at wellsite has become the major measurement of oil & gas exploration. From the early stage of manually geo-logging to the modern mudlogging with new techonlogies of MWD, LWD and QFT etc. The new technologies have played very important roles in the exploring of oil & gas. Being one of the newest technology of mudlogging, QFT has been widely used in oilfield for about 3 years. When it is put in operation in some oilfields of China in 1997, its advantages in oil & gas detection at wellsite have been continuously recognized,especially in the detection of shows of light oil and condensed oil. A set of powerful classification standard of resource rock oil bearing grades and the interpretation standards have been summarized by the application of the quantitative fluorescencelogging techniques (QFT) in Basins of China, together with gas-logging data, and other information got from the Geo-logging procedures at wellsite.
文摘The electrophysiological methods using microelectrodes are not appropriate for the simultaneous measurement of neural activities of many neurons. To overcome the difficulty, the fluorescent imaging technique using voltage sensitive dyes can be a powerful technique. The voltage sensitive dyes, however, generally exhibit a relatively small change in their fluorescence intensities, resulting in a low S/N ratio. Additionally, they often exhibit photobleaching and phototoxity. We have therefore improved the fluorescent voltage imaging technique by using a LED as the light source and an electron multiplying (EM)-CCD camera as the fluorescence detector. In this study, we applied our imaging system for the measurement of two kind of molluscan neural activities;one of which is involved in the olfactory processing of the land slug Limax valentianus and the other is involved in the feeding rhythm of the pond snail Lymnaea stagnalis. The system enabled us to measure the neural activities for a long time with a high speed and a high S/N ratio, and the obtained results showed some new physiological findings.
文摘The new double projecting neurons were found in the cat spinal dorsal horn by the double retrograde fluorescent tracing technique.Fast Blue(FB)was injected into unilateral dorsal column nucleus(DCN)of adult cats anesthetized with pentobarbital.Nuclear Yellow(NY)was injected ipsilaterally into the lateral cervical nucleus(LCN)8-9 days later.After an additional 18-30 hrs.
基金supported by the National Natural Science Foundation of China (Nos.41406199,41506197)the Program Foundation of Nanjing University of Information Science and Technology (No.KHYS1301)+1 种基金the Doctoral Scientific Research Foundation of Liaoning Province (No.201501190)the Fundamental Research Funds for the Central Universities (No.3132015081)
文摘When measuring reflectance spectra, it is very important to accurately extract chlorophyll fluorescence from elastic-scattering light in water-leaving radiance. The elastic scattering of light by water particles produces partially polarized light. In contrast, chlorophyll fluorescence in planktonic algae yields completely unpolarized light. These properties can be used to separate fluorescent signals from the water-leaving radiance and thus to determine chlorophyll concentration. The algal species Aureococcus anophagefferens was used to conduct a laboratory polarization experiment. For the tests, we used a field spectroradiometer and a polarizer; measurements were collected using two different observation modes. The chlorophyll fluorescence curve extracted through polarization shows an excellent match with the results obtained using the fluorospectro photometer for both measurement modes, suggesting that polarization-based chlorophyll fluorescence extraction may be feasible. The extracted fluorescence is more reliable at incident zenith angles ranging from 30? to 60?. For algae-containing water, the results improve with increasing chlorophyll concentration. This method could help improve chlorophyll concentration measurement and the remote-sensing detection of resulting harmful algae blooms.
文摘AIM To assess potential contributions of biliary IgA for crystal agglomeration into gallstones, we visualized cholesterol crystal binding of biliary IgA.METHODS Crystal-binding biliary proteins were extracted from human gallbladder bile using lectin affinity chromatography. Biliary IgA was isolated from the bound protein fraction by immunoaffinity chromatography. Pure cholesterol monohydrate crystals were incubated with biliary IgA and fluoresceine isothiocyanate (FITC)-conjugated anti-lgA at 37C. Samples were examined under polarizing and fluorescence light microscopy with digital image processing.RESULTS Binding of biliary IgA to cholesterol monohydrate crystals could be visualized with FITC-conjugated anti-lgA antibodies. Peak fluorescence occurred at crystal edges and dislocations. Controls without biliary IgA or with biliary IgG showed no significant fluorescence.CONCLUSION Fluorescence light microscopy provided evidence for cholesterol crystal binding of biliary IgA. Cholesterol crystalbinding proteins like IgA might be important mediators of crystal agglomeration and growth of cholesterol gallstones by modifying the evolving crystal structures in vivo.
基金The project was supported by the National Natural Science Foundation of China (No. 29725411, No. 29804003, No. 90206010) and Natural Science Foundation of Guangdong Province (015036).
文摘Our recent studies concerning the binding of ionic surfactants on oppositely charged polyelectrolytes observedwith fluorescence techniques are reviewed. The cationic surfactants cetyltrimethylammonium bromide (CTAB),dodecyltrimethylammonium chloride (DTAC), and nonionic surfactant octaethylene glycol monododecyl ether (C_(12)E_8) wereallowed to bind on anionic poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) and its pyrene and/or naphthalenelabeled copolymers. The relative excimer emission intensity I_E/I_M of a cationic probe l-pyrenemethylamine hydrochloride(PyMeA·HCl) and the non-radiative energy transfer (NRET) I_(Py)/I_(Np) of naphthalene to pyrene for labeled polyelectrolyteswere chosen to monitor the binding process and the conformation change of surfactant-bound polyelectrolytes. The 1:1aggregation of polyelectrolyte-CTAB with respect to the charge was found as long as the CTAB concentration was slightlyhigher than its critical aggregation concentration (CAC). The intermolecular NRET indicated that the CTAB-boundpolyelectrolytes aggregated together through the hydrophobic interaction between the CTAB tails. However, neither 1:1polyelectrolyte-DTAC aggregation nor intermolecular aggregation of DTAC-bound polyelectrolyte was observed owing to itsweaker hydrophobicity of 12 carbon atoms in the tail, which is shorter than that of CTAB. As known from the fluorescenceresults, nonionic surfactant C_(12)E_8 did not bind on the anionic polyelectrolytes, but the presence of PAMPS promoted themicelle formation for C_(12)E_8 at the CAC slightly below its critical micelle concentration (CMC). The solid complex of dansyllabeled AMPS copolymer-surfactant exhibited a decrease in local polarity with increasing charge density of thepolyelectrolyte or with alkane tail length of the surfactant. SAXS suggested a lamella structure for the AMPS copolymer-surfactant solid complexes with a long period of 3.87 nm for CTAB and 3.04 nm for DTAC, respectively.
基金supported by the Spanish“Plan Nacional de Investigación Científica,Desarrollo e Innovación Tecnológica,Ministerio de Economía y Competitividad(Instituto de Salud CarlosⅢ)”,Grant FIS PI20-0318 co-financed by“Fondo Europeo de Desarrollo Regional ERDF-FEDER European Union”Grant P18-RT-5059“Plan Andaluz de Investigación,Desarrollo e Innovación(PAIDI 2020),Consejería de Transformación Económica,Industria,Conocimiento y Universidades,Junta de Andalucía,Espana”(all to VC)Grant PPJIA202219“Ayudas del plan propio UGR 2022,Plan propio de investigación y transferencia,Universidad de Granada,Espana”(to JCA andóDGG)。
文摘The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve fibers.Due to the complex structure and composition of myelin,various histological techniques have been developed over the centuries to evaluate myelin under normal,pathological or experimental conditions.Today,methods to assess myelin integrity or content are key tools in both clinical diagnosis and neuroscience research.In this review,we provide an updated summary of the composition and structure of the myelin sheath and discuss some histological procedures,from tissue fixation and processing techniques to the most used and practical myelin histological staining methods.Considering the lipoprotein nature of myelin,the main features and technical details of the different available methods that can be used to evaluate the lipid or protein components of myelin are described,as well as the precise ultrastructural techniques.
