DNA-binding fluorochromes are often used for vital staining of plant cell nuclei.However,it is not always sure whether the cells after staining still remain in living state.We chose several criteria to estimate the va...DNA-binding fluorochromes are often used for vital staining of plant cell nuclei.However,it is not always sure whether the cells after staining still remain in living state.We chose several criteria to estimate the validity of real vital staining for sexual cell nuclei.These were:the cytoplasmic streaming in pollen tubes whose nuclei were stained,the simultaneous visualization of fluo-rochromatic reaction and nucleus staining in isolated generative cells,and the capability of isolated,prestained generative or sperm cells to fuse with other protoplasts.The results confirmed that 4',6-diamidino-2-phenylindole(DAPI),Hoechst 33258 and mithramycin could be used as real vital stains,though their efficiency varied from case to case;among them DAPI showed best effect.The fluorescent vital staining technique offered a useful means fori-dentification and selection of heterokaryons in gametoplast manipulation studies.展开更多
The QBC techmique in diagnosing vivax malaria was compared with that of the Giemsa stained thick smear under field conditions in Sifang Village.Junlian County,Sichuan Province,China.Blood samples were collected from 1...The QBC techmique in diagnosing vivax malaria was compared with that of the Giemsa stained thick smear under field conditions in Sifang Village.Junlian County,Sichuan Province,China.Blood samples were collected from 161 volunteer villagers.Each sample was examined with both the QBC and Giemsa techniques.Each stained Giemsa thick smear(GTS)was prepared by spreading 10ul blood over an appropriate area on a slide and examined for 300 oil immersion fields,and each QBC tube was observed for 5 min.before considering a sample to be negative.Results showed that 34 blood samples were positive for vivax malaria and 127 were negative by GTS,whereas,there were 32 positives and 129 negatives by QBC.Taking GTS as standard,the sensjtivityand specificity of the QBC technique were 79.41%and 96.06%respectively,and the concordancewas 92.55%.Distributions of different developmental stages of P.raraz parasites in the centrifuged QBC tubes were cbserved and recorded,and the results revealed that all stages except schizonts,could be found in the lower part of the platelet zone,or the interphase between the monocyte and theplatelet layers,especially the ring forms.展开更多
In this work two different fluorochromes （Alexa 594 and Alexa 680） are conjugated to the same monoclonal antibody （Cetuximab） for obtaining a characteristic M-shaped dual-peak spectrum. Dual-labeling of Cetuximab ...In this work two different fluorochromes （Alexa 594 and Alexa 680） are conjugated to the same monoclonal antibody （Cetuximab） for obtaining a characteristic M-shaped dual-peak spectrum. Dual-labeling of Cetuximab by mixing both fluorochromes before the conjugation step gives spectral results similar to those of mixing of fluorochrome-labeled Cetuximab after the conjugation step （P 〉 0.05）. In conclusion, both methods may be used equivalently for producing a dual-labeled single-antibody probe. Future studies may test whether the M-shaped spectrum may increase the diagnostic confidence in tumor-targeted multispectral optical imaging.展开更多
The histological basis for acute osteocyte mechanosensitivity remains uncertain. A novel bone cell model of mechanotransduction and inorganic trafficking may be the powerful, silt-burrowing protozoan Spirostomum ambig...The histological basis for acute osteocyte mechanosensitivity remains uncertain. A novel bone cell model of mechanotransduction and inorganic trafficking may be the powerful, silt-burrowing protozoan Spirostomum ambiguum which when being physically challenged fabricates within vesicles populations of bone-like calcium phosphate microspheres, about 1 μm in diameter. These not only attribute considerable compression-resilience but also resemble the Golgi-directed mineral assemblies we recently reported in osteocytes. Advantageously, calcification in the protozoan (confirmed by ultramicroscopy with EDX elemental microanalysis) enabled Golgi comparison under overt, natural phases of both high (i.e. silt-tunnelling) and low (i.e free-swimming) stress. Established hard-tissue microscopy techniques previously positive in bone cells included quantitative fluorescent tetracycline labelling for bone salt together with the same metazoan Golgi body marker (Green Fluorescent Protein-tagged mannosidase II construct). Organellar modulation was monitored by transfection of live organisms in situ (some post-stained with red nuclear fluorochrome TOPRO-3). Results showed that GFP-tagged Golgi fluorescence increased from swimmers (mean 74.5 ± SD 6.7 AU) to burrowers (mean 104.6 ± SD 2.7;p < 0.0001) synchronous with juxtanuclear tetracycline-labelled mineral fluorescence (swimmers, mean 89.7 ± SD 3.3 AU;burrowers, mean 138.0 ± SD 4.0;p < 0.0001). Intracellular dense microspheres, single or bridged, were harvested as pellets rich in Ca, P (Ca:P 0.98) and Si, their polarised alignment moving from transaxial in swimmers to axial in burrowers. It was concluded that Golgi-directed mineral fabrication in the large, accessible, silt-enclosed ciliate resembles that in the smaller, less-accessible bone cell and may be a conserved early mechanobiological intracellular development predicating force translation into compression-resistant mineral fabrication in loaded segments of the osteocyte syncitium.展开更多
There is diverse opinion about the mechanism of bone mineralization with only intermittent reports of any direct organellar role played by the golgi apparatus (juxtanuclear body). Light and laser confocal microscopy w...There is diverse opinion about the mechanism of bone mineralization with only intermittent reports of any direct organellar role played by the golgi apparatus (juxtanuclear body). Light and laser confocal microscopy was combined with electron microscopy and elemental EDX (energy dispersive X-ray microanalysis) in comparing “young” osteocytes in situ in fresh and “slam” frozen developing mouse calvarium, with similar cells (MC3T3-E1) maintained in vitro. The distribution of “nascent” electron dense mineral was examined histochemically (von Kossa, GBHA), including tetracycline (TC) staining as a fluorescent complex with bone salt, while golgi body activity was demonstrated by transfection with a specific green fluorescent construct (GFP/mannosidase II). In tissue culture golgi body activity and mineralization were both blocked by brefeldin A (an established golgi inhibitor) and restored by forskolin, enabling an association with mineral fabrication to be quantified as changing fluorescence intensity (AU) of GFP or TC markers. Results from osteocytes in situ supported previous descriptions of intracellular electron dense objects (microspheres and nanospheres) in a juxtanuclear pattern, containing Ca, P and transitory Si, in a spectrum recapitulated in the calcifying culture after 10 days, when GFP fluorophore surged from 71.7 ± 1.4SD to 133.7 ± 2.7SD AU by 14 days (p < 0.0001). At this stage TC fluorophore mean intensity was 23.8 ± 3.7SD AU (14 days) rising to 45.0 ± 5.1SD AU by 17 days, compared to its stationary 21.7 ± 3.6SD when treated 3 days previously with BFA golgi inhibitor (p < 0.0001), until forskolin reversal. It was concluded from the changing juxtanuclear morphology, Si mineralization mediation and the variably controlled activity versus stasis that the inorganic phase of bone is a complex golgi-directed fabrication with implications for bone matrix biology and evolution.展开更多
In the present investigation, the sensitivity of different direct microbial count procedures applied on systems containing both planktonics and sessiles was tested. The direct count pour plate was compared with direct...In the present investigation, the sensitivity of different direct microbial count procedures applied on systems containing both planktonics and sessiles was tested. The direct count pour plate was compared with direct epifluorescent microscopic enumerations in order to evaluate the efficiency of the studied techniques in giving information about microbial activity or viability. Our results indicate that the standard plate count procedure is the most sensitive method to estimate viable and cultivable planktonic cells. On the other hand, direct enumeration by epifluorescent microscopy may become an interesting alternative to count sessile cells.展开更多
The different fluorescence behavior caused by the excited state proton transfer in 3-hydroxy-4-pyridylisoquinoline(2a)compound has been theoretically investigated.Our calculation results illustrate that the 2a monomer...The different fluorescence behavior caused by the excited state proton transfer in 3-hydroxy-4-pyridylisoquinoline(2a)compound has been theoretically investigated.Our calculation results illustrate that the 2a monomer in tetrahydrofuran solvent would not occur proton transfer spontaneously,while the 2a complex in methanol(MeOH)solvent can undergo an asynchronous excited state intramolecular proton transfer(ESIPT)process.The result was confirmed by analyzing the related structural parameters,infrared vibration spectrum and reduced density gradient isosurfaces.Moreover,the potential curves revealed that with the bridging of single MeOH molecular the energy barrier of ESIPT was modulated effectively.It was distinctly reduced to 4.80 kcal/mol in 2a-MeOH complex from 25.01 kcal/mol in 2a monomer.Accordingly,the ESIPT process induced a fluorochromic phenomenon with the assistant of proton-bridge.The elucidation of the mechanism of solvent discoloration will contribute to the design and synthesis of fluorogenic dyes as environment-sensitive probes.展开更多
Herein,we reported a Tb-carboxyl-imidazole coordination-crosslinked carboxylated nitrile butadiene rubber(XNBR)elastomer design that exhibits high mechanical robustness,fluorochromism,and white-light emission.Imidazol...Herein,we reported a Tb-carboxyl-imidazole coordination-crosslinked carboxylated nitrile butadiene rubber(XNBR)elastomer design that exhibits high mechanical robustness,fluorochromism,and white-light emission.Imidazole(Im),a toughening,sensitizing,and self-emissive ligand,highly intensified the fluorescence emission,remarkably toughened the elastomer,and imparted multistimuli responsiveness to the elastomer.The Tb^(3+)ions acted as cross-linking centers and provided high-temperature sensitivity of fluorescence emission(more sensitive than Eu^(3+)ions).The as-prepared XNBR/Tb/Im elastomer,with excellent puncture resistance,exhibited an ultimate extensibility of about 3100%and the highest tensile strength of 22 MPa.Experimental and theoretical investigations have demonstrated that Tb^(3+)ions are more likely to interact with Im ligands with increasing amounts of Im.The number of coordination cross-links with higher cross-linking functionalities showed an increasing trend during stretching.The elastomer exhibited an excitation wavelength and temperature-dependent green emission.By introducing redemissive Eu^(3+)into the elastomer,a white-light-emitting XNBR/Tb/Eu/Im elastomer with chemo-fluorochromism was fabricated.The XNBR/Tb/Eu/Im elastomer exhibited stable white-light emission during both heating and stretching.Changing the temperature only resulted in a variation in the intensity of the white light.We demonstrated the potential applications of these elastomers in patterning and information anticounterfeiting/encryption.This coordination crosslinked tough elastomer with fluorochromism and white-light emission paves a new way to fabricate soft devices and sensors,where optical information displays and optical signal responses are required.展开更多
Biomorphic supramolecular assemblies formedthrough the collaboration of rigid and flexible elements,akin to bones and ligaments, play a crucialrole in constructing advanced functional structures.Non-intertwined ring–...Biomorphic supramolecular assemblies formedthrough the collaboration of rigid and flexible elements,akin to bones and ligaments, play a crucialrole in constructing advanced functional structures.Non-intertwined ring–ring assemblies that rely oninduced fitting between rigid rings and conformationallyflexible rings have emerged as thriving representativesof this process. However, detailing howrigid and flexible rings adapt to each other for preciseself-assembly evolution under solely weak noncovalentinteractions remains limited and oftenposes challenges in structural design. We offer adistinctive solution by distorting the rigid cyclophane,thereby providing not only unique dualrecognition sites for flexible vips but also intrinsicsolid-state emission for in-situ visualization ofdynamic processes. Three adaptive self-assembliesranging from ring-within-ring, to ring-bridge-ringand finally to ring-in-ring were constructed and demonstratedto be dynamically responsive in the solidstate through harnessing the high selectivity of theinner rings.展开更多
Uni-directional multi-state fluorochromic scaffolds are valuable photofunctional molecules and yet scarce. We report a general approach for their design, i.e., mechanodonor-acceptor coupling(MDAC). A photochromic mole...Uni-directional multi-state fluorochromic scaffolds are valuable photofunctional molecules and yet scarce. We report a general approach for their design, i.e., mechanodonor-acceptor coupling(MDAC). A photochromic molecule is a mechanodonor, due to its capability to convert photonic energy into mechanical force. Upon proper coupling, it can be used to drive a mechanochromic molecule for uni-directional multi-state fluorochromism. The embodiment of this approach is a rhodamine-dithienylethylene hydride(RDH), which has been successfully employed in super-resolution localization microscopy.展开更多
文摘DNA-binding fluorochromes are often used for vital staining of plant cell nuclei.However,it is not always sure whether the cells after staining still remain in living state.We chose several criteria to estimate the validity of real vital staining for sexual cell nuclei.These were:the cytoplasmic streaming in pollen tubes whose nuclei were stained,the simultaneous visualization of fluo-rochromatic reaction and nucleus staining in isolated generative cells,and the capability of isolated,prestained generative or sperm cells to fuse with other protoplasts.The results confirmed that 4',6-diamidino-2-phenylindole(DAPI),Hoechst 33258 and mithramycin could be used as real vital stains,though their efficiency varied from case to case;among them DAPI showed best effect.The fluorescent vital staining technique offered a useful means fori-dentification and selection of heterokaryons in gametoplast manipulation studies.
基金This Investigation receivod financial support from the UNDP/World Bank/WHO Specal Programne for Rosearch and Trainng in Tropical Discascs(TDR)UNDP/World Bank/WHO/TDR提供基金
文摘The QBC techmique in diagnosing vivax malaria was compared with that of the Giemsa stained thick smear under field conditions in Sifang Village.Junlian County,Sichuan Province,China.Blood samples were collected from 161 volunteer villagers.Each sample was examined with both the QBC and Giemsa techniques.Each stained Giemsa thick smear(GTS)was prepared by spreading 10ul blood over an appropriate area on a slide and examined for 300 oil immersion fields,and each QBC tube was observed for 5 min.before considering a sample to be negative.Results showed that 34 blood samples were positive for vivax malaria and 127 were negative by GTS,whereas,there were 32 positives and 129 negatives by QBC.Taking GTS as standard,the sensjtivityand specificity of the QBC technique were 79.41%and 96.06%respectively,and the concordancewas 92.55%.Distributions of different developmental stages of P.raraz parasites in the centrifuged QBC tubes were cbserved and recorded,and the results revealed that all stages except schizonts,could be found in the lower part of the platelet zone,or the interphase between the monocyte and theplatelet layers,especially the ring forms.
文摘In this work two different fluorochromes （Alexa 594 and Alexa 680） are conjugated to the same monoclonal antibody （Cetuximab） for obtaining a characteristic M-shaped dual-peak spectrum. Dual-labeling of Cetuximab by mixing both fluorochromes before the conjugation step gives spectral results similar to those of mixing of fluorochrome-labeled Cetuximab after the conjugation step （P 〉 0.05）. In conclusion, both methods may be used equivalently for producing a dual-labeled single-antibody probe. Future studies may test whether the M-shaped spectrum may increase the diagnostic confidence in tumor-targeted multispectral optical imaging.
文摘The histological basis for acute osteocyte mechanosensitivity remains uncertain. A novel bone cell model of mechanotransduction and inorganic trafficking may be the powerful, silt-burrowing protozoan Spirostomum ambiguum which when being physically challenged fabricates within vesicles populations of bone-like calcium phosphate microspheres, about 1 μm in diameter. These not only attribute considerable compression-resilience but also resemble the Golgi-directed mineral assemblies we recently reported in osteocytes. Advantageously, calcification in the protozoan (confirmed by ultramicroscopy with EDX elemental microanalysis) enabled Golgi comparison under overt, natural phases of both high (i.e. silt-tunnelling) and low (i.e free-swimming) stress. Established hard-tissue microscopy techniques previously positive in bone cells included quantitative fluorescent tetracycline labelling for bone salt together with the same metazoan Golgi body marker (Green Fluorescent Protein-tagged mannosidase II construct). Organellar modulation was monitored by transfection of live organisms in situ (some post-stained with red nuclear fluorochrome TOPRO-3). Results showed that GFP-tagged Golgi fluorescence increased from swimmers (mean 74.5 ± SD 6.7 AU) to burrowers (mean 104.6 ± SD 2.7;p < 0.0001) synchronous with juxtanuclear tetracycline-labelled mineral fluorescence (swimmers, mean 89.7 ± SD 3.3 AU;burrowers, mean 138.0 ± SD 4.0;p < 0.0001). Intracellular dense microspheres, single or bridged, were harvested as pellets rich in Ca, P (Ca:P 0.98) and Si, their polarised alignment moving from transaxial in swimmers to axial in burrowers. It was concluded that Golgi-directed mineral fabrication in the large, accessible, silt-enclosed ciliate resembles that in the smaller, less-accessible bone cell and may be a conserved early mechanobiological intracellular development predicating force translation into compression-resistant mineral fabrication in loaded segments of the osteocyte syncitium.
文摘There is diverse opinion about the mechanism of bone mineralization with only intermittent reports of any direct organellar role played by the golgi apparatus (juxtanuclear body). Light and laser confocal microscopy was combined with electron microscopy and elemental EDX (energy dispersive X-ray microanalysis) in comparing “young” osteocytes in situ in fresh and “slam” frozen developing mouse calvarium, with similar cells (MC3T3-E1) maintained in vitro. The distribution of “nascent” electron dense mineral was examined histochemically (von Kossa, GBHA), including tetracycline (TC) staining as a fluorescent complex with bone salt, while golgi body activity was demonstrated by transfection with a specific green fluorescent construct (GFP/mannosidase II). In tissue culture golgi body activity and mineralization were both blocked by brefeldin A (an established golgi inhibitor) and restored by forskolin, enabling an association with mineral fabrication to be quantified as changing fluorescence intensity (AU) of GFP or TC markers. Results from osteocytes in situ supported previous descriptions of intracellular electron dense objects (microspheres and nanospheres) in a juxtanuclear pattern, containing Ca, P and transitory Si, in a spectrum recapitulated in the calcifying culture after 10 days, when GFP fluorophore surged from 71.7 ± 1.4SD to 133.7 ± 2.7SD AU by 14 days (p < 0.0001). At this stage TC fluorophore mean intensity was 23.8 ± 3.7SD AU (14 days) rising to 45.0 ± 5.1SD AU by 17 days, compared to its stationary 21.7 ± 3.6SD when treated 3 days previously with BFA golgi inhibitor (p < 0.0001), until forskolin reversal. It was concluded from the changing juxtanuclear morphology, Si mineralization mediation and the variably controlled activity versus stasis that the inorganic phase of bone is a complex golgi-directed fabrication with implications for bone matrix biology and evolution.
文摘In the present investigation, the sensitivity of different direct microbial count procedures applied on systems containing both planktonics and sessiles was tested. The direct count pour plate was compared with direct epifluorescent microscopic enumerations in order to evaluate the efficiency of the studied techniques in giving information about microbial activity or viability. Our results indicate that the standard plate count procedure is the most sensitive method to estimate viable and cultivable planktonic cells. On the other hand, direct enumeration by epifluorescent microscopy may become an interesting alternative to count sessile cells.
基金Project supported by the National Basic Research Program of China(Grant No.2019YFA0307701)the National Natural Science Foundation of China(Grant No.11874180)the Young and Middle-aged Scientific and Technological Innovation Leaders and Team Projects in Jilin Province(Grant No.20200301020RQ).
文摘The different fluorescence behavior caused by the excited state proton transfer in 3-hydroxy-4-pyridylisoquinoline(2a)compound has been theoretically investigated.Our calculation results illustrate that the 2a monomer in tetrahydrofuran solvent would not occur proton transfer spontaneously,while the 2a complex in methanol(MeOH)solvent can undergo an asynchronous excited state intramolecular proton transfer(ESIPT)process.The result was confirmed by analyzing the related structural parameters,infrared vibration spectrum and reduced density gradient isosurfaces.Moreover,the potential curves revealed that with the bridging of single MeOH molecular the energy barrier of ESIPT was modulated effectively.It was distinctly reduced to 4.80 kcal/mol in 2a-MeOH complex from 25.01 kcal/mol in 2a monomer.Accordingly,the ESIPT process induced a fluorochromic phenomenon with the assistant of proton-bridge.The elucidation of the mechanism of solvent discoloration will contribute to the design and synthesis of fluorogenic dyes as environment-sensitive probes.
基金financially supported by the National Natural Science Foundation of China(Nos.22175100 and 52173020)the Natural Science Foundation of Zhejiang Province(No.LY22E030001)the Natural Science Foundation of Ningbo(No.2022J102)。
文摘Herein,we reported a Tb-carboxyl-imidazole coordination-crosslinked carboxylated nitrile butadiene rubber(XNBR)elastomer design that exhibits high mechanical robustness,fluorochromism,and white-light emission.Imidazole(Im),a toughening,sensitizing,and self-emissive ligand,highly intensified the fluorescence emission,remarkably toughened the elastomer,and imparted multistimuli responsiveness to the elastomer.The Tb^(3+)ions acted as cross-linking centers and provided high-temperature sensitivity of fluorescence emission(more sensitive than Eu^(3+)ions).The as-prepared XNBR/Tb/Im elastomer,with excellent puncture resistance,exhibited an ultimate extensibility of about 3100%and the highest tensile strength of 22 MPa.Experimental and theoretical investigations have demonstrated that Tb^(3+)ions are more likely to interact with Im ligands with increasing amounts of Im.The number of coordination cross-links with higher cross-linking functionalities showed an increasing trend during stretching.The elastomer exhibited an excitation wavelength and temperature-dependent green emission.By introducing redemissive Eu^(3+)into the elastomer,a white-light-emitting XNBR/Tb/Eu/Im elastomer with chemo-fluorochromism was fabricated.The XNBR/Tb/Eu/Im elastomer exhibited stable white-light emission during both heating and stretching.Changing the temperature only resulted in a variation in the intensity of the white light.We demonstrated the potential applications of these elastomers in patterning and information anticounterfeiting/encryption.This coordination crosslinked tough elastomer with fluorochromism and white-light emission paves a new way to fabricate soft devices and sensors,where optical information displays and optical signal responses are required.
基金supported by the National Natural Science Foundation of China(grant nos.22001006 and 22375002)the China Postdoctoral Science Foundation(grant no.2023M740010)+2 种基金the Anhui Provincial Natural Science Foundation(grant no.2308085Y10)the Shenzhen Key Laboratory of Functional Aggregate Materials(grant no.ZDSYS20211021111400001)the Science Technology Innovation Commission of Shenzhen Municipality(grant no.KQTD20210811090142053).
文摘Biomorphic supramolecular assemblies formedthrough the collaboration of rigid and flexible elements,akin to bones and ligaments, play a crucialrole in constructing advanced functional structures.Non-intertwined ring–ring assemblies that rely oninduced fitting between rigid rings and conformationallyflexible rings have emerged as thriving representativesof this process. However, detailing howrigid and flexible rings adapt to each other for preciseself-assembly evolution under solely weak noncovalentinteractions remains limited and oftenposes challenges in structural design. We offer adistinctive solution by distorting the rigid cyclophane,thereby providing not only unique dualrecognition sites for flexible vips but also intrinsicsolid-state emission for in-situ visualization ofdynamic processes. Three adaptive self-assembliesranging from ring-within-ring, to ring-bridge-ringand finally to ring-in-ring were constructed and demonstratedto be dynamically responsive in the solidstate through harnessing the high selectivity of theinner rings.
基金the National Natural Science Foundation of China(21822805,21922704,21877069,21908065,22078098)China Postdoctoral Science Foundation(2019M651427,2020T130197)the Commission of Science and Technology of Shanghai Municipality(18430711000)。
文摘Uni-directional multi-state fluorochromic scaffolds are valuable photofunctional molecules and yet scarce. We report a general approach for their design, i.e., mechanodonor-acceptor coupling(MDAC). A photochromic molecule is a mechanodonor, due to its capability to convert photonic energy into mechanical force. Upon proper coupling, it can be used to drive a mechanochromic molecule for uni-directional multi-state fluorochromism. The embodiment of this approach is a rhodamine-dithienylethylene hydride(RDH), which has been successfully employed in super-resolution localization microscopy.
