A new sensitive fluorometric assay method for acetylcholinesterase （ACHE） and its inhibitor was developed us- ing a fluorescent dye, nile red （NR）. Due to the fluorescence resonance energy transfer between the NR ...A new sensitive fluorometric assay method for acetylcholinesterase （ACHE） and its inhibitor was developed us- ing a fluorescent dye, nile red （NR）. Due to the fluorescence resonance energy transfer between the NR and the gold nanoparticle （AuNPs）, the fluorescence was quenched. AChE can break down acetylthiocholine to produce a thiol-bearing compound, thiocholine. In the presence of thiocholine, the nile red is replaced from the AuNPs sur- faces and simultaneously transformed to a derivative of nile red. The fluorescence intensity of the derivative is much stronger than that of the native nile red with the same concentration and its maximum emission wavelength has a blue shift so that the sensor achieves a good signal-to-background ratio. In addition, when organophosphate pesticide （OPs） exists, the activity of AChE can be inhibited, the generation of thiocholine will be prevented and no fluorescence enhancement occurs. The results show that the method is sensitive to AChE and paraoxon with the de- tection limits of 0.2 mU/mL and 0.05 ng/mL, respectively.展开更多
A range-extended acidity detector based on Nile red was designed and analyzed in this work. In light of the good lasing property and solvatochromism characteristic of Nile red/ethanol solution, we have obtained laser ...A range-extended acidity detector based on Nile red was designed and analyzed in this work. In light of the good lasing property and solvatochromism characteristic of Nile red/ethanol solution, we have obtained laser spectra of sulfuric acid in different concentrations doped in this substrate. Moreover, to expand the acidity detection range, we proposed a tandem cuvette system containing rhodamine 6G/ethanol and Nile red/ethanol. Consequently, the detection range could be enlarged from 26 nm to 40 nm, by changing not only the wavelength peak but also by the intensity ratio of dual-wavelength laser output. In addition, by changing the detection and substrate materials, the whole detection range could be expanded, and therefore a wide range of applications in polarity and acidity detection could be implemented via this method.展开更多
Syzygium jambolanum is a promising natural treatment for diabetes.The potential benefits of S jambolanum for diabetes include lowering blood sugar levels,increasing insulin sensitivity,protecting pancreatic beta cells...Syzygium jambolanum is a promising natural treatment for diabetes.The potential benefits of S jambolanum for diabetes include lowering blood sugar levels,increasing insulin sensitivity,protecting pancreatic beta cells,and slowing the absorption of glucose into the bloodstream.The anti-diabetic activity of the crude extract of S jambolanum was evaluated in L6 myotubes and the lipid deposition in tissue was measured using Nile red Staining.Nile red staining confirmed that a considerable quantity of lipids had been deposited in the tissue treated with a crude extract of S jambolanum,comparable to the quantity of lipids deposited with a standard drug known as Rosiglitazone.This study analyzed the anti-diabetic activity of a crude extract of S jambolanum to understand its potential as a feedstock for extracting bioactive constituents to screen for bioactive molecules in the treatment of diabetes.展开更多
The formation of axonal spheroid is a common feature following spinal cord injury.To further understand the source of Ca^(2+)that mediates axonal spheroid formation,we used our previously characterized ex vivo mouse s...The formation of axonal spheroid is a common feature following spinal cord injury.To further understand the source of Ca^(2+)that mediates axonal spheroid formation,we used our previously characterized ex vivo mouse spinal cord model that allows precise perturbation of extracellular Ca^(2+).We performed twophoton excitation imaging of spinal cords isolated from Thy1YFP+transgenic mice and applied the lipophilic dye,Nile red,to record dynamic changes in dorsal column axons and their myelin sheaths respectively.We selectively released Ca^(2+)from internal stores using the Ca^(2+)ionophore ionomycin in the presence or absence of external Ca^(2+).We reported that ionomycin dose-dependently induces pathological changes in myelin and pronounced axonal spheroid formation in the presence of normal 2 m M Ca^(2+)artificial cerebrospinal fluid.In contrast,removal of external Ca^(2+)significantly decreased ionomycin-induced myelin and axonal spheroid formation at 2 hours but not at 1 hour after treatment.Using mice that express a neuron-specific Ca^(2+)indicator in spinal cord axons,we confirmed that ionomycin induced significant increases in intra-axonal Ca^(2+),but not in the absence of external Ca^(2+).Periaxonal swelling and the resultant disruption in the axo-myelinic interface often precedes and is negatively correlated with axonal spheroid formation.Pretreatment with YM58483(500 n M),a well-established blocker of store-operated Ca^(2+)entry,significantly decreased myelin injury and axonal spheroid formation.Collectively,these data reveal that ionomycin-induced depletion of internal Ca^(2+)stores and subsequent external Ca^(2+)entry through store-operated Ca^(2+)entry contributes to pathological changes in myelin and axonal spheroid formation,providing new targets to protect central myelinated fibers.展开更多
微藻作为21世纪生物柴油的理想燃料已被人们广泛的关注,但是目前微藻种类很多,如何从诸多的微藻中筛选油脂含量高的微藻已成为人们函待解决的问题。从东北地区水样中分离纯化出93种藻种,采用尼罗红染色法对其中30株藻种进行了筛选获得了...微藻作为21世纪生物柴油的理想燃料已被人们广泛的关注,但是目前微藻种类很多,如何从诸多的微藻中筛选油脂含量高的微藻已成为人们函待解决的问题。从东北地区水样中分离纯化出93种藻种,采用尼罗红染色法对其中30株藻种进行了筛选获得了8种具有产油潜力的藻种,并利用自制的柱式反应器微藻评价装置对这8株藻株进行了产油能力的评价,获得了一株总脂产率达到133.9 mg/(L·d)的产油能源微藻。在此基础上,对该藻株进行了18S r RNA的鉴定,确定为Chlorella sp.。展开更多
文摘A new sensitive fluorometric assay method for acetylcholinesterase （ACHE） and its inhibitor was developed us- ing a fluorescent dye, nile red （NR）. Due to the fluorescence resonance energy transfer between the NR and the gold nanoparticle （AuNPs）, the fluorescence was quenched. AChE can break down acetylthiocholine to produce a thiol-bearing compound, thiocholine. In the presence of thiocholine, the nile red is replaced from the AuNPs sur- faces and simultaneously transformed to a derivative of nile red. The fluorescence intensity of the derivative is much stronger than that of the native nile red with the same concentration and its maximum emission wavelength has a blue shift so that the sensor achieves a good signal-to-background ratio. In addition, when organophosphate pesticide （OPs） exists, the activity of AChE can be inhibited, the generation of thiocholine will be prevented and no fluorescence enhancement occurs. The results show that the method is sensitive to AChE and paraoxon with the de- tection limits of 0.2 mU/mL and 0.05 ng/mL, respectively.
基金supported by the National Key Research and Development Program of China(No. 2016YFB0401901)Major Science and Technology Special Project in Anhui (No. 17030901001)+2 种基金National Natural Science Foundation of China (Nos. 21574120and 21774115)Fundamental Research Funds for the Central Universities (No. WK2060200025)Science and Technological Fund of Anhui Province for Outstanding Youth (No. 1608085J01)。
文摘A range-extended acidity detector based on Nile red was designed and analyzed in this work. In light of the good lasing property and solvatochromism characteristic of Nile red/ethanol solution, we have obtained laser spectra of sulfuric acid in different concentrations doped in this substrate. Moreover, to expand the acidity detection range, we proposed a tandem cuvette system containing rhodamine 6G/ethanol and Nile red/ethanol. Consequently, the detection range could be enlarged from 26 nm to 40 nm, by changing not only the wavelength peak but also by the intensity ratio of dual-wavelength laser output. In addition, by changing the detection and substrate materials, the whole detection range could be expanded, and therefore a wide range of applications in polarity and acidity detection could be implemented via this method.
文摘Syzygium jambolanum is a promising natural treatment for diabetes.The potential benefits of S jambolanum for diabetes include lowering blood sugar levels,increasing insulin sensitivity,protecting pancreatic beta cells,and slowing the absorption of glucose into the bloodstream.The anti-diabetic activity of the crude extract of S jambolanum was evaluated in L6 myotubes and the lipid deposition in tissue was measured using Nile red Staining.Nile red staining confirmed that a considerable quantity of lipids had been deposited in the tissue treated with a crude extract of S jambolanum,comparable to the quantity of lipids deposited with a standard drug known as Rosiglitazone.This study analyzed the anti-diabetic activity of a crude extract of S jambolanum to understand its potential as a feedstock for extracting bioactive constituents to screen for bioactive molecules in the treatment of diabetes.
文摘The formation of axonal spheroid is a common feature following spinal cord injury.To further understand the source of Ca^(2+)that mediates axonal spheroid formation,we used our previously characterized ex vivo mouse spinal cord model that allows precise perturbation of extracellular Ca^(2+).We performed twophoton excitation imaging of spinal cords isolated from Thy1YFP+transgenic mice and applied the lipophilic dye,Nile red,to record dynamic changes in dorsal column axons and their myelin sheaths respectively.We selectively released Ca^(2+)from internal stores using the Ca^(2+)ionophore ionomycin in the presence or absence of external Ca^(2+).We reported that ionomycin dose-dependently induces pathological changes in myelin and pronounced axonal spheroid formation in the presence of normal 2 m M Ca^(2+)artificial cerebrospinal fluid.In contrast,removal of external Ca^(2+)significantly decreased ionomycin-induced myelin and axonal spheroid formation at 2 hours but not at 1 hour after treatment.Using mice that express a neuron-specific Ca^(2+)indicator in spinal cord axons,we confirmed that ionomycin induced significant increases in intra-axonal Ca^(2+),but not in the absence of external Ca^(2+).Periaxonal swelling and the resultant disruption in the axo-myelinic interface often precedes and is negatively correlated with axonal spheroid formation.Pretreatment with YM58483(500 n M),a well-established blocker of store-operated Ca^(2+)entry,significantly decreased myelin injury and axonal spheroid formation.Collectively,these data reveal that ionomycin-induced depletion of internal Ca^(2+)stores and subsequent external Ca^(2+)entry through store-operated Ca^(2+)entry contributes to pathological changes in myelin and axonal spheroid formation,providing new targets to protect central myelinated fibers.
文摘微藻作为21世纪生物柴油的理想燃料已被人们广泛的关注,但是目前微藻种类很多,如何从诸多的微藻中筛选油脂含量高的微藻已成为人们函待解决的问题。从东北地区水样中分离纯化出93种藻种,采用尼罗红染色法对其中30株藻种进行了筛选获得了8种具有产油潜力的藻种,并利用自制的柱式反应器微藻评价装置对这8株藻株进行了产油能力的评价,获得了一株总脂产率达到133.9 mg/(L·d)的产油能源微藻。在此基础上,对该藻株进行了18S r RNA的鉴定,确定为Chlorella sp.。
