Objective The changes in serum adipokines and cytokines related to oxidative stress were examined during 3 months ‘Off to On’ and ‘On to Off’ periods using negatively charged particle-dominant indoor air condition...Objective The changes in serum adipokines and cytokines related to oxidative stress were examined during 3 months ‘Off to On’ and ‘On to Off’ periods using negatively charged particle-dominant indoor air conditions（NCPDIAC）.Methods Seven volunteers participated in the study,which included ‘OFF to 3 months ON’ periods（ON trials） for a total of 16 times,and ‘ON to 3 months OFF’（OFF trials） periods for a total of 13 times.Results With the exception of one case,serum amyloid A（SAA） levels decreased significantly during the ON trials.Conclusion Considering that SAA is an acute phase reactive protein such as C reactive protein（CRP）,this observed decrease might indicate the prevention of cardiovascular and atherosclerotic changes,since an increase in high-sensitive CRP is associated with the subsequent detection of these events.展开更多
Objective:To investigate whether ethanol extracts of Hizikia fusiforme could induce apoptosis in human prostate cancer PC3 cells.Methods:Cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetr...Objective:To investigate whether ethanol extracts of Hizikia fusiforme could induce apoptosis in human prostate cancer PC3 cells.Methods:Cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.Apoptosis and mitochondrial membrane potential(MMP)were measured using flow cytometry in PC3 cells.DNA damage was assessed by nuclear staining and DNA fragmentation assay.Expressions of apoptosis-associated proteins were determined by Western blotting assays.Activities of caspase-3,-8,and-9 were determined by colorimetric assay.Moreover,intracellular reactive oxygen species(ROS)generation was detected using a flow cytometer and fluorescence microscope.Results:Treatment of PC3 cells with ethanol extracts of Hizikia fusiforme inhibited proliferation,which was associated with induction of apoptosis,and accompanied by increased expression of Fas,Fas-ligand(Fas L),Bax and t Bid,and decreased expression of Bcl-2.In addition,ethanol extracts of Hizikia fusiforme reduced c-Flip expression and activated caspase-8,-9 and-3,resulting in an increase in poly(ADP-ribose)polymerase(PARP)cleavage.However,in the presence of a pan-caspase inhibitor,ethanol extracts of Hizikia fusiforme-mediated growth inhibition and apoptosis were significantly attenuated.Ethanol extracts of Hizikia fusiforme also destroyed the integrity of mitochondria due to the loss of MMP,leading to cytosolic release of cytochrome c.Moreover,the levels of ROS were markedly increased by treatment with ethanol extracts of Hizikia fusiforme,which was significantly suppressed by the ROS scavenger N-acetyl-L-cysteine.Further investigation of whether ethanol extracts of Hizikia fusiforme-induced apoptosis was related to the generation of ROS was conducted and the results showed that N-acetyl-L-cysteine fully blocked ethanol extracts of Hizikia fusiforme-induced apoptotic events including loss of MMP,activation of caspase-3,the cytosolic release of cytochrome c and cytotoxicity.Conclusions:Ethanol extracts of Hizikia fusiforme have chemopreventive potential via induction of ROS-dependent apoptosis.Therefore,ethanol extracts of Hizikia fusiforme may be useful for developing effective and selective natural sources to inhibit cancer cell proliferation.展开更多
Theoretical calculations and preliminary measurements of vibrational Raman optical activity (ROA) spectra of different species of amphetamine (amphetamine and amphetamine-H+) are reported for the first time. The quant...Theoretical calculations and preliminary measurements of vibrational Raman optical activity (ROA) spectra of different species of amphetamine (amphetamine and amphetamine-H+) are reported for the first time. The quantum chemical calculations were carried out as hybrid ab initio DFT-molecular orbital calculations by use of the Gaussian 03W program, based on complete geometry minimizations of the conformational energy of the S-(+)-amphetamine molecule, the S-(+)-amphetamine-H+ ion, and the R-(–)-amphetamine molecule. Following this, harmonic frequency calculations have been made, providing information about the cation vibrational bands, expected in salts of single anions (chlorides) as well as in salts of anions with internal bonds (sulfates, hydrogen phosphates, etc.). It shows that the kind of anion should be given better attention, as so far it has often not been the case, when the spectra are employed for identification purposes. The DFT calculations show that the most stable conformations are those allowing for close contact between the aromatic ring and the amine hydrogen atoms. The internal rotational barrier within the same amphetamine enantiomer has a considerable influence on the Raman and ROA spectra. As predicted the experimental ROA spectra were found to depend on the chirality. Two street samples, provided by the London Police, were also measured and compared to the calculated ROA spectra. The street samples were found to contain different enantiomers of the protonated amphetamine-H+ sulfate. According to the present study the AMPH+ ion in aqueous sulfate solution seems to adopt a conformation in which the phenyl and ammonium groups are in transpositions, similar to what has been found in the solid state.展开更多
The yield of bremsstrahlung (BS) from collisions of fast electrons (energy at least 6 MeV) with a Tungsten target can be significantly improved by exploitation of Tungsten wall scatter in a multi-layered target. A sim...The yield of bremsstrahlung (BS) from collisions of fast electrons (energy at least 6 MeV) with a Tungsten target can be significantly improved by exploitation of Tungsten wall scatter in a multi-layered target. A simplified version of a previously developed principle is also able to focus on small angle scattered electrons by a Tungsten wall. It is necessary that the thickness of each Tungsten layer does not exceed 0.04 mm—a thickness of 0.03 mm is suitable for accelerators in medical physics. Further focusing of electrons results from suitable magnetic fields with field strength between 0.5 Tesla and 1.2 Tesla (if the cone with multi-layered targets is rather narrow). Linear accelerators in radiation therapy only need to be focused by wall scatter without further magnetic fields (a standard case: 31 plates with 0.03 mm thickness and 1 mm distance between the plates). We considered three cases with importance in medical physics: A very small cone with an additional magnetic field for focusing (the field diameter at 90 cm depth: 6 cm), a medium cone with an optional magnetic field (field diameter at 90 cm depth: 13 cm) and a broad cone without a magnetic field (the field diameter at 90 cm depth: 30 cm). All these cases can be positioned in a carousel. Measurements have been performed in the existing carousel positioned in the plane of the flattening filter and scatter foils for electrons.展开更多
由中国化学会主办，北京大学承办的第一届全国生物物理化学会议（The First National Conferenceon Biophysical Chemistry，1st NCBPC）将于2010年7月5日-7日在北京召开．会议的目的是为生物物理化学同行提供一个学术交流的平台，促进...由中国化学会主办，北京大学承办的第一届全国生物物理化学会议（The First National Conferenceon Biophysical Chemistry，1st NCBPC）将于2010年7月5日-7日在北京召开．会议的目的是为生物物理化学同行提供一个学术交流的平台，促进我国生物物理化学学科的发展．热忱邀请相关领域的科学工作者和研究生投稿和参加．展开更多
A new alkylpyrrole derivative,fusariumin A(1),was isolated from the culture broth of the fungus Fusarium sp.The absolute configuration of fuasiumin A has been established as(2'R,3'R)using a combination of RDC(...A new alkylpyrrole derivative,fusariumin A(1),was isolated from the culture broth of the fungus Fusarium sp.The absolute configuration of fuasiumin A has been established as(2'R,3'R)using a combination of RDC(residual dipolar coupling)-based NMR and DFT-supported chiroptical spectroscopy.It is worth to note that in this study without the aid of the RDC analysis,an unambiguous determination of configuration and conformation was not feasible due to the excessive conformational possibilities of this open-chain compound.展开更多
AIM:To find a safe source for dopaminergic neurons,we generated neural progenitor cell lines from human embryonic stem cells.METHODS:The human embryonic stem(hES)cell line H9 was used to generate human neural progenit...AIM:To find a safe source for dopaminergic neurons,we generated neural progenitor cell lines from human embryonic stem cells.METHODS:The human embryonic stem(hES)cell line H9 was used to generate human neural progenitor(HNP)cell lines.The resulting HNP cell lines were differentiated into dopaminergic neurons and analyzed by quantitative real-time polymerase chain reaction and immunofluorescence for the expression of neuronal differentiation markers,including beta-III tubulin(TUJ1)and tyrosine hydroxylase(TH).To assess the risk of teratoma or other tumor formation,HNP cell lines and mouse neuronal progenitor(MNP)cell lines were injected subcutaneously into immunodeficient SCID/beige mice.RESULTS:We developed a fairly simple and fast protocol to obtain HNP cell lines from hES cells.These cell lines,which can be stored in liquid nitrogen for several years,have the potential to differentiate in vitro into dopaminergic neurons.Following day 30 of differentiation culture,the majority of the cells analyzed expressed the neuronal marker TUJ1 and a high proportion of these cells were positive for TH,indicating differentiation into dopaminergic neurons.In contrast to H9 ES cells,the HNP cell lines did not form tumors in immunodeficient SCID/beige mice within 6 mo after subcutaneous injection.Similarly,no tumors developed after injection of MNP cells.Notably,mouse ES cells or neuronal cells directly differentiated from mouse ES cells formed teratomas in more than 90%of the recipients.CONCLUSION:Our findings indicate that neural progenitor cell lines can differentiate into dopaminergic neurons and bear no risk of generating teratomas or other tumors in immunodeficient mice.展开更多
Conventional analysis of enzyme-catalyzed reactions uses a set of initial rates of product formation or substrate decay at a variety of substrate concentrations. Alternatively to the conventional methods, attempts hav...Conventional analysis of enzyme-catalyzed reactions uses a set of initial rates of product formation or substrate decay at a variety of substrate concentrations. Alternatively to the conventional methods, attempts have been made to use an integrated Michaelis-Menten equation to assess the values of the Michaelis-Menten KM and turnover kcat constants directly from a single time course of an enzymatic reaction. However, because of weak convergence, previous fits of the integrated Michaelis-Menten equation to a single trace of the reaction have no proven records of success. Here we propose a reliable method with fast convergence based on an explicit solution of the Michaelis-Menten equation in terms of the Lambert-W function with transformed variables. Tests of the method with stopped-flow measurements of the catalytic reaction of cytochrome c oxidase, as well as with simulated data, demonstrate applicability of the approach to de termine KM and kcat constants free of any systematic errors. This study indicates that the approach could be an alternative solution for the characterization of enzymatic reactions, saving time, sample and efforts. The single trace method can greatly assist the real time monitoring of enzymatic activity, in particular when a fast control is mandatory. It may be the only alternative when conventional analysis does not apply, e.g. because of limited amount of sample.展开更多
Nanoparticles can be used to purify proteins from plasma. We report here the purification of apolipoprotein A-I (apoA-I) with high specificity from human plasma using copolymeric nanoparticles. We present an optimized...Nanoparticles can be used to purify proteins from plasma. We report here the purification of apolipoprotein A-I (apoA-I) with high specificity from human plasma using copolymeric nanoparticles. We present an optimized protocol using 50:50 NiPAM:BAM copolymer nanoparticles with thermo-responsive properties as an affinity resin. Repeated pelleting and washing of nanoparticle-captured apoA-I is achieved through temperature cycling. The protein is then eluted using urea followed by an ion exchange step for protein concentration and depletion of nanoparticles.展开更多
The animal diet of the carnivorous Venus flytrap, Dionaea muscipula, contains a sodium load that enters the capture organ via an HKT1-type sodium channel, expressed in special epithelia cells on the inner trap lobe su...The animal diet of the carnivorous Venus flytrap, Dionaea muscipula, contains a sodium load that enters the capture organ via an HKT1-type sodium channel, expressed in special epithelia cells on the inner trap lobe surface. DmHKT1 expression and sodium uptake activity is induced upon prey contact. Here, we analyzed the HKT1 properties required for prey sodium osmolyte management of carnivorous Dionaea. Analyses were based on homology modeling, generation of model-derived point mutants, and their functional testing in Xenopus oocytes. We showed that the wild-type HKT1 and its Na^＋- and K^＋-permeable mutants function as ion channels rather than K^＋ transporters driven by proton or sodium gradients. These structural and biophysical features of a high-capacity, Na^＋-selective ion channel enable Dionaea glands to manage prey-derived sodium loads without confounding the action potential-based information management of the flytrap.展开更多
Surface patterning is very useful in biomaterial studies, yet it is not easy to prepare a micropattern with cell-adhesion contrast that is stable in a wet environment. Recently, a platform technique of transfer photol...Surface patterning is very useful in biomaterial studies, yet it is not easy to prepare a micropattern with cell-adhesion contrast that is stable in a wet environment. Recently, a platform technique of transfer photolithography was invented to fabricate stable metal microarrays on the surface of a cell-adhesion resistant and mechanically biomimetic poly（ethylene glycol） hydrogel; the linker is the key chemical in such a transfer strategy. This article reports the design and synthesis of a hetero-bifunctional macromonomer linker with a thiol group at one end and an acryloyl group at the other end. The bifunctional linker was char- acterized by GPC and ~H NMR, and the average number of thiol groups in the bifunctional linker was detected by Ellman＇s reagent. The regent stability under wet conditions was also confirmed by the model reactants. The resultant micropatterned surfaces are meaningful for future studies of cell behaviors on mechanically biomimetic matrixes.展开更多
Spectro-microscopy, a combination of fluorescence microscopy with spatially resolved spectroscopic techni- ques, provides new and exciting tools for functional cell biology in living organisms. This review focuses on ...Spectro-microscopy, a combination of fluorescence microscopy with spatially resolved spectroscopic techni- ques, provides new and exciting tools for functional cell biology in living organisms. This review focuses on recent devel- opments in spectro-microscopic applications for the investigation of living plant cells in their native tissue context. The application of spectro-microscopic methods led to the recent discovery of a fast signal response pathway for the brassi- nosteroide receptor BRI1 in the plasma membrane of living plant cells. Moreover, the competence of different plant cell types to respond to environmental or endogenous stimuli was determined in vivo by correlation analysis of different optical and spectroscopic readouts such as fluorescence lifetime （FLT）. Furthermore, a new spectro-microscopic technique, fluorescence intensity decay shape analysis microscopy （FIDSAM）, has been developed. FIDSAM is capable of imaging low- expressed fluorophore-tagged proteins at high spatial resolution and precludes the misinterpretation of autofluorescence artifacts. In addition, FIDSAM provides a very effective and sensitive tool on the basis of F6rster resonance energy transfer （FRET） for the qualitative and quantitative determination of protein-protein interaction. Finally, we report on the quan- titative analysis of the photosystem I and II （PSI/PSII） ratio in the chloroplasts of living Arabidopsis plants at room tem- perature, using high-resolution, spatially resolved fluorescence spectroscopy. With this technique, it was not only possible to measure PSI/PSII ratios, but also to demonstrate the differential competence of wild-type and carbohydrate-deficient plants to adapt the PSI/PSII ratio to different light conditions. In summary, the information content of standard microscopic images is extended by several dimensions by the use of spectro-microscopic approaches. Therefore, novel cell physiolog- ical and molecular topics can be addressed and valuable insights into molecular and subcellular processes can be obtained in living plants.展开更多
Post-transcriptional methylation of N6-adenine and Nl-adenine can affect transcriptome turnover and translation.Furthermore,the regulatory function of N6-methyladenine(m6A)during heat shock has been uncovered,includin...Post-transcriptional methylation of N6-adenine and Nl-adenine can affect transcriptome turnover and translation.Furthermore,the regulatory function of N6-methyladenine(m6A)during heat shock has been uncovered,including the enhancement of the phase separation potential of RNAs.In response to acute stress,e.g.heat shock,the orderly sequestration of mRNAs in stress granules(SGs)is considered important to protect transcripts from the irreversible aggregation.Until recently,the role of N1-methyladenine(m^(1)A)on mRNAs during acute stress response remains largely unknown.Here we show that the methyltransferase complex TRMT6/61A,which generates the tag,is involved in transcriptome protection during heat shock.Our bioinformatics analysis indicates that occurrence of the motif is increased in mRNAs known to be enriched in SGs.Accordingly,the m^(1)A-generating methyltransferase TRMT6/61A accumulated in SGs and mass spectrometry confirmed enrichment of in the SG RNAs.The insertion of a single methylation motif in the untranslated region of a reporter RNA leads to more efficient recovery of protein synthesis from that transcript after the return to normal temperature.Our results demonstrate far-reaching functional consequences of a minimal RNA modification on N1-adenine during acute proteostasis stress.展开更多
The interplay between free electrons,light,and matter offers unique prospects for space,time,and energy resolved optical material characterization,structured light generation,and quantum information processing.Here,we...The interplay between free electrons,light,and matter offers unique prospects for space,time,and energy resolved optical material characterization,structured light generation,and quantum information processing.Here,we study the nanoscale features of spontaneous and stimulated electron–photon interactions mediated by localized surface plasmon resonances at the tips of a gold nanostar using electron energy-loss spectroscopy(EELS),cathodoluminescence spectroscopy(CL),and photon-induced near-field electron microscopy(PINEM).Supported by numerical electromagnetic boundary-element method(BEM)calculations,we show that the different coupling mechanisms probed by EELS,CL,and PINEM feature the same spatial dependence on the electric field distribution of the tip modes.However,the electron–photon interaction strength is found to vary with the incident electron velocity,as determined by the spatial Fourier transform of the electric near-field component parallel to the electron trajectory.For the tightly confined plasmonic tip resonances,our calculations suggest an optimum coupling velocity at electron energies as low as a few keV.Our results are discussed in the context of more complex geometries supporting multiple modes with spatial and spectral overlap.We provide fundamental insights into spontaneous and stimulated electron-light-matter interactions with key implications for research on(quantum)coherent optical phenomena at the nanoscale.展开更多
SNARE proteins mediate most membrane fusion reactions in eukaryotic cells,and are thereby vital for many functions,including synaptic transmission,cell growth,and cytokinesis.However,until recently it was still unclea...SNARE proteins mediate most membrane fusion reactions in eukaryotic cells,and are thereby vital for many functions,including synaptic transmission,cell growth,and cytokinesis.However,until recently it was still unclear how many of these proteins are required to catalyze membrane fusion in vivo.In a recent Science paper,Mohrmann et al.(2010)elegantly show that in chromaffin cells,three SNARE complexes are required for the synchronous release of granules,whereas only a single SNARE complex is sufficient for overall release.展开更多
Background:Misfolded oligomeric α-synuclein plays a pivotal role in the pathogenesis of a-synucleinopathies including Parkinson's disease and multiple system atrophy,and its detection parallels activation of micr...Background:Misfolded oligomeric α-synuclein plays a pivotal role in the pathogenesis of a-synucleinopathies including Parkinson's disease and multiple system atrophy,and its detection parallels activation of microglia and a loss of neurons in the substantia nigra pars compacta.Here we aimed to analyze the therapeutic efficacy of PD03,a new AFFITOPE■ immunotherapy approach,either alone or in combination with Anle138b,in a PLP-α-syn mouse model.Methods:The PLP-α-syn mice were treated with PD03 immunotherapy,Anle138b,or a combination of two.Five months after study initiation,the mice underwent behavioral testing and were sacrificed for neuropathological analysis.The treatment groups were compared to the vehicle group with regard to motor performance,nigral neuronal loss,microglial activation and α-synuclein pathology.Results:The PLP-α-syn mice receiving the PD03 or Anle138b single therapy showed improvement of gait deficits and preservation of nigral dopaminergic neurons associated with the reduced α-synuclein oligomer levels and decreased microglial activation.The combined therapy with Anle138b and PD03 resulted in lower lgG binding in the brain as compared to the single immunotherapy with PD03.Conclusions:PD03 and Anle138b can selectively target oligomeric α-synuclein,resulting in attenuation of neurodegeneration in the PLP-α-syn mice.Both approaches are potential therapies that should be developed further for disease modification in α-synucleinopathies.展开更多
The Darwin plant, also known as the Venus flytrap, Dionaea muscipula, has fascinated people since Darwin＇s time. The plant lives in nutrient-poor habitats but has been able to overcome the limitations of its surround...The Darwin plant, also known as the Venus flytrap, Dionaea muscipula, has fascinated people since Darwin＇s time. The plant lives in nutrient-poor habitats but has been able to overcome the limitations of its surroundings by evolving a carnivorous lifestyle, particularly by modifying its leaves into active traps to catch animals. When flies, ants, or other small animals touch mechano-sensitive hairs protruding from the inner surface of the bi-lobed trap, it shuts within a fraction of a second.展开更多
The structural basis of the regulation of serotonin(5-hydroxy-tryptamine,5-HT)receptors by ligands and lipids is only emerging.A recent study by Xu and colleagues1 published in Nature addresses this issue by resolving...The structural basis of the regulation of serotonin(5-hydroxy-tryptamine,5-HT)receptors by ligands and lipids is only emerging.A recent study by Xu and colleagues1 published in Nature addresses this issue by resolving five structures of 5-HT;receptor-G protein complexes.These include 5-HT1A in the apostate,i.e.not bound to a ligand,5-HT1A and 5-HT1D bound to serotonin or the atypical antipsychotic aripiprazole(for 5-HT1A),and 5-HT1E bound to its selective agonist BRL-54443.展开更多
基金supported by a Kawasaki Medical School Research Grant(28B051)
文摘Objective The changes in serum adipokines and cytokines related to oxidative stress were examined during 3 months ‘Off to On’ and ‘On to Off’ periods using negatively charged particle-dominant indoor air conditions（NCPDIAC）.Methods Seven volunteers participated in the study,which included ‘OFF to 3 months ON’ periods（ON trials） for a total of 16 times,and ‘ON to 3 months OFF’（OFF trials） periods for a total of 13 times.Results With the exception of one case,serum amyloid A（SAA） levels decreased significantly during the ON trials.Conclusion Considering that SAA is an acute phase reactive protein such as C reactive protein（CRP）,this observed decrease might indicate the prevention of cardiovascular and atherosclerotic changes,since an increase in high-sensitive CRP is associated with the subsequent detection of these events.
基金a part of the project titled‘Omics based on fishery disease control technology development and industrialization(20150242)’‘Development of functional food products with natural materials derived from marine resources(2017-0377)’funded by the Ministry of Oceans and Fisheries,Republic of Korea.
文摘Objective:To investigate whether ethanol extracts of Hizikia fusiforme could induce apoptosis in human prostate cancer PC3 cells.Methods:Cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.Apoptosis and mitochondrial membrane potential(MMP)were measured using flow cytometry in PC3 cells.DNA damage was assessed by nuclear staining and DNA fragmentation assay.Expressions of apoptosis-associated proteins were determined by Western blotting assays.Activities of caspase-3,-8,and-9 were determined by colorimetric assay.Moreover,intracellular reactive oxygen species(ROS)generation was detected using a flow cytometer and fluorescence microscope.Results:Treatment of PC3 cells with ethanol extracts of Hizikia fusiforme inhibited proliferation,which was associated with induction of apoptosis,and accompanied by increased expression of Fas,Fas-ligand(Fas L),Bax and t Bid,and decreased expression of Bcl-2.In addition,ethanol extracts of Hizikia fusiforme reduced c-Flip expression and activated caspase-8,-9 and-3,resulting in an increase in poly(ADP-ribose)polymerase(PARP)cleavage.However,in the presence of a pan-caspase inhibitor,ethanol extracts of Hizikia fusiforme-mediated growth inhibition and apoptosis were significantly attenuated.Ethanol extracts of Hizikia fusiforme also destroyed the integrity of mitochondria due to the loss of MMP,leading to cytosolic release of cytochrome c.Moreover,the levels of ROS were markedly increased by treatment with ethanol extracts of Hizikia fusiforme,which was significantly suppressed by the ROS scavenger N-acetyl-L-cysteine.Further investigation of whether ethanol extracts of Hizikia fusiforme-induced apoptosis was related to the generation of ROS was conducted and the results showed that N-acetyl-L-cysteine fully blocked ethanol extracts of Hizikia fusiforme-induced apoptotic events including loss of MMP,activation of caspase-3,the cytosolic release of cytochrome c and cytotoxicity.Conclusions:Ethanol extracts of Hizikia fusiforme have chemopreventive potential via induction of ROS-dependent apoptosis.Therefore,ethanol extracts of Hizikia fusiforme may be useful for developing effective and selective natural sources to inhibit cancer cell proliferation.
基金Dr.Thomas Norbygaard is thanked for help and advice during the ROA measurementsDirector Ib Henriksen's Foundation is thanked for maintenance of the Raman instrumentationThe Danish Fundamental Research Foun-dation as well as the Danish Agency for Science,Tech-nology and Innovation(#09-065038/FTP)helped con-tribute funding for this project.
文摘Theoretical calculations and preliminary measurements of vibrational Raman optical activity (ROA) spectra of different species of amphetamine (amphetamine and amphetamine-H+) are reported for the first time. The quantum chemical calculations were carried out as hybrid ab initio DFT-molecular orbital calculations by use of the Gaussian 03W program, based on complete geometry minimizations of the conformational energy of the S-(+)-amphetamine molecule, the S-(+)-amphetamine-H+ ion, and the R-(–)-amphetamine molecule. Following this, harmonic frequency calculations have been made, providing information about the cation vibrational bands, expected in salts of single anions (chlorides) as well as in salts of anions with internal bonds (sulfates, hydrogen phosphates, etc.). It shows that the kind of anion should be given better attention, as so far it has often not been the case, when the spectra are employed for identification purposes. The DFT calculations show that the most stable conformations are those allowing for close contact between the aromatic ring and the amine hydrogen atoms. The internal rotational barrier within the same amphetamine enantiomer has a considerable influence on the Raman and ROA spectra. As predicted the experimental ROA spectra were found to depend on the chirality. Two street samples, provided by the London Police, were also measured and compared to the calculated ROA spectra. The street samples were found to contain different enantiomers of the protonated amphetamine-H+ sulfate. According to the present study the AMPH+ ion in aqueous sulfate solution seems to adopt a conformation in which the phenyl and ammonium groups are in transpositions, similar to what has been found in the solid state.
文摘The yield of bremsstrahlung (BS) from collisions of fast electrons (energy at least 6 MeV) with a Tungsten target can be significantly improved by exploitation of Tungsten wall scatter in a multi-layered target. A simplified version of a previously developed principle is also able to focus on small angle scattered electrons by a Tungsten wall. It is necessary that the thickness of each Tungsten layer does not exceed 0.04 mm—a thickness of 0.03 mm is suitable for accelerators in medical physics. Further focusing of electrons results from suitable magnetic fields with field strength between 0.5 Tesla and 1.2 Tesla (if the cone with multi-layered targets is rather narrow). Linear accelerators in radiation therapy only need to be focused by wall scatter without further magnetic fields (a standard case: 31 plates with 0.03 mm thickness and 1 mm distance between the plates). We considered three cases with importance in medical physics: A very small cone with an additional magnetic field for focusing (the field diameter at 90 cm depth: 6 cm), a medium cone with an optional magnetic field (field diameter at 90 cm depth: 13 cm) and a broad cone without a magnetic field (the field diameter at 90 cm depth: 30 cm). All these cases can be positioned in a carousel. Measurements have been performed in the existing carousel positioned in the plane of the flattening filter and scatter foils for electrons.
文摘由中国化学会主办，北京大学承办的第一届全国生物物理化学会议（The First National Conferenceon Biophysical Chemistry，1st NCBPC）将于2010年7月5日-7日在北京召开．会议的目的是为生物物理化学同行提供一个学术交流的平台，促进我国生物物理化学学科的发展．热忱邀请相关领域的科学工作者和研究生投稿和参加．
基金Support by the National Natural Science Foundation of China(U1132607)to J.K.L.the DFG(Forschergruppe FOR 934)to C.Gas well as the Chinese/German foundation(GZ1104)to H.S.and C.G.is acknowledged.
文摘A new alkylpyrrole derivative,fusariumin A(1),was isolated from the culture broth of the fungus Fusarium sp.The absolute configuration of fuasiumin A has been established as(2'R,3'R)using a combination of RDC(residual dipolar coupling)-based NMR and DFT-supported chiroptical spectroscopy.It is worth to note that in this study without the aid of the RDC analysis,an unambiguous determination of configuration and conformation was not feasible due to the excessive conformational possibilities of this open-chain compound.
基金Supported by The German Federal Ministry for Education and Research(BMBF),No.01GN0818 and No.01GN0819the Max-Planck Society,and initially by the Dr.Helmut Storz Stiftung
文摘AIM:To find a safe source for dopaminergic neurons,we generated neural progenitor cell lines from human embryonic stem cells.METHODS:The human embryonic stem(hES)cell line H9 was used to generate human neural progenitor(HNP)cell lines.The resulting HNP cell lines were differentiated into dopaminergic neurons and analyzed by quantitative real-time polymerase chain reaction and immunofluorescence for the expression of neuronal differentiation markers,including beta-III tubulin(TUJ1)and tyrosine hydroxylase(TH).To assess the risk of teratoma or other tumor formation,HNP cell lines and mouse neuronal progenitor(MNP)cell lines were injected subcutaneously into immunodeficient SCID/beige mice.RESULTS:We developed a fairly simple and fast protocol to obtain HNP cell lines from hES cells.These cell lines,which can be stored in liquid nitrogen for several years,have the potential to differentiate in vitro into dopaminergic neurons.Following day 30 of differentiation culture,the majority of the cells analyzed expressed the neuronal marker TUJ1 and a high proportion of these cells were positive for TH,indicating differentiation into dopaminergic neurons.In contrast to H9 ES cells,the HNP cell lines did not form tumors in immunodeficient SCID/beige mice within 6 mo after subcutaneous injection.Similarly,no tumors developed after injection of MNP cells.Notably,mouse ES cells or neuronal cells directly differentiated from mouse ES cells formed teratomas in more than 90%of the recipients.CONCLUSION:Our findings indicate that neural progenitor cell lines can differentiate into dopaminergic neurons and bear no risk of generating teratomas or other tumors in immunodeficient mice.
文摘Conventional analysis of enzyme-catalyzed reactions uses a set of initial rates of product formation or substrate decay at a variety of substrate concentrations. Alternatively to the conventional methods, attempts have been made to use an integrated Michaelis-Menten equation to assess the values of the Michaelis-Menten KM and turnover kcat constants directly from a single time course of an enzymatic reaction. However, because of weak convergence, previous fits of the integrated Michaelis-Menten equation to a single trace of the reaction have no proven records of success. Here we propose a reliable method with fast convergence based on an explicit solution of the Michaelis-Menten equation in terms of the Lambert-W function with transformed variables. Tests of the method with stopped-flow measurements of the catalytic reaction of cytochrome c oxidase, as well as with simulated data, demonstrate applicability of the approach to de termine KM and kcat constants free of any systematic errors. This study indicates that the approach could be an alternative solution for the characterization of enzymatic reactions, saving time, sample and efforts. The single trace method can greatly assist the real time monitoring of enzymatic activity, in particular when a fast control is mandatory. It may be the only alternative when conventional analysis does not apply, e.g. because of limited amount of sample.
基金This work was funded by an Irish Research Council for Science,Engineering and Technology Postdoctoral Fellowship(M.L.)the Marianne and Marcus Wallenberg Foundation(M.L.)+2 种基金the EU FP6 project NanoInteract(NMP4-CT-2006-033231)and the SFI SRC BioNanoInteract(07 SRC B1155)Centre for Nano-Vaccine,Copenhagen,Denmark,and the Swedish Research Council(VR).
文摘Nanoparticles can be used to purify proteins from plasma. We report here the purification of apolipoprotein A-I (apoA-I) with high specificity from human plasma using copolymeric nanoparticles. We present an optimized protocol using 50:50 NiPAM:BAM copolymer nanoparticles with thermo-responsive properties as an affinity resin. Repeated pelleting and washing of nanoparticle-captured apoA-I is achieved through temperature cycling. The protein is then eluted using urea followed by an ion exchange step for protein concentration and depletion of nanoparticles.
文摘The animal diet of the carnivorous Venus flytrap, Dionaea muscipula, contains a sodium load that enters the capture organ via an HKT1-type sodium channel, expressed in special epithelia cells on the inner trap lobe surface. DmHKT1 expression and sodium uptake activity is induced upon prey contact. Here, we analyzed the HKT1 properties required for prey sodium osmolyte management of carnivorous Dionaea. Analyses were based on homology modeling, generation of model-derived point mutants, and their functional testing in Xenopus oocytes. We showed that the wild-type HKT1 and its Na^＋- and K^＋-permeable mutants function as ion channels rather than K^＋ transporters driven by proton or sodium gradients. These structural and biophysical features of a high-capacity, Na^＋-selective ion channel enable Dionaea glands to manage prey-derived sodium loads without confounding the action potential-based information management of the flytrap.
基金supported by the National Natural Science Foundation of China(21034002,91127028,51273046)the Ministry of Science and Technology of China(2011CB606203)the Science and Technology Development Foundation of Shanghai(13XD1401000)
文摘Surface patterning is very useful in biomaterial studies, yet it is not easy to prepare a micropattern with cell-adhesion contrast that is stable in a wet environment. Recently, a platform technique of transfer photolithography was invented to fabricate stable metal microarrays on the surface of a cell-adhesion resistant and mechanically biomimetic poly（ethylene glycol） hydrogel; the linker is the key chemical in such a transfer strategy. This article reports the design and synthesis of a hetero-bifunctional macromonomer linker with a thiol group at one end and an acryloyl group at the other end. The bifunctional linker was char- acterized by GPC and ~H NMR, and the average number of thiol groups in the bifunctional linker was detected by Ellman＇s reagent. The regent stability under wet conditions was also confirmed by the model reactants. The resultant micropatterned surfaces are meaningful for future studies of cell behaviors on mechanically biomimetic matrixes.
文摘Spectro-microscopy, a combination of fluorescence microscopy with spatially resolved spectroscopic techni- ques, provides new and exciting tools for functional cell biology in living organisms. This review focuses on recent devel- opments in spectro-microscopic applications for the investigation of living plant cells in their native tissue context. The application of spectro-microscopic methods led to the recent discovery of a fast signal response pathway for the brassi- nosteroide receptor BRI1 in the plasma membrane of living plant cells. Moreover, the competence of different plant cell types to respond to environmental or endogenous stimuli was determined in vivo by correlation analysis of different optical and spectroscopic readouts such as fluorescence lifetime （FLT）. Furthermore, a new spectro-microscopic technique, fluorescence intensity decay shape analysis microscopy （FIDSAM）, has been developed. FIDSAM is capable of imaging low- expressed fluorophore-tagged proteins at high spatial resolution and precludes the misinterpretation of autofluorescence artifacts. In addition, FIDSAM provides a very effective and sensitive tool on the basis of F6rster resonance energy transfer （FRET） for the qualitative and quantitative determination of protein-protein interaction. Finally, we report on the quan- titative analysis of the photosystem I and II （PSI/PSII） ratio in the chloroplasts of living Arabidopsis plants at room tem- perature, using high-resolution, spatially resolved fluorescence spectroscopy. With this technique, it was not only possible to measure PSI/PSII ratios, but also to demonstrate the differential competence of wild-type and carbohydrate-deficient plants to adapt the PSI/PSII ratio to different light conditions. In summary, the information content of standard microscopic images is extended by several dimensions by the use of spectro-microscopic approaches. Therefore, novel cell physiolog- ical and molecular topics can be addressed and valuable insights into molecular and subcellular processes can be obtained in living plants.
基金This work was funded by the European Research Council grants MetaMeta_311522(R.M.V.)RIBOMYLOME_309545(G.G.T.)+5 种基金ASTRA_855923(G.G.T)G.G.T.acknowledges support of the H2020 projects IASIS_727658 and INFORE_825080the Spanish Ministry of Economy and Competitiveness BFU2017-86970-Pas well as the collaboration with Peter St.George-Hyslop financed by the Wellcome TrustR.M.V.acknowledges support by the Deutsche Forschungsgemeinschaft(DFG)grant EXC115M.H.is funded by DFG CRC902‘Molecular Principles of RNA-based Regulation’。
文摘Post-transcriptional methylation of N6-adenine and Nl-adenine can affect transcriptome turnover and translation.Furthermore,the regulatory function of N6-methyladenine(m6A)during heat shock has been uncovered,including the enhancement of the phase separation potential of RNAs.In response to acute stress,e.g.heat shock,the orderly sequestration of mRNAs in stress granules(SGs)is considered important to protect transcripts from the irreversible aggregation.Until recently,the role of N1-methyladenine(m^(1)A)on mRNAs during acute stress response remains largely unknown.Here we show that the methyltransferase complex TRMT6/61A,which generates the tag,is involved in transcriptome protection during heat shock.Our bioinformatics analysis indicates that occurrence of the motif is increased in mRNAs known to be enriched in SGs.Accordingly,the m^(1)A-generating methyltransferase TRMT6/61A accumulated in SGs and mass spectrometry confirmed enrichment of in the SG RNAs.The insertion of a single methylation motif in the untranslated region of a reporter RNA leads to more efficient recovery of protein synthesis from that transcript after the return to normal temperature.Our results demonstrate far-reaching functional consequences of a minimal RNA modification on N1-adenine during acute proteostasis stress.
基金This project has received funding from the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(Grant Agreement No.695343 and Grant Agreement No.101017720(FET-Proactive EBEAM))The work at AMOLF was partly financed by the Dutch Research Council(NWO)+8 种基金The work at the University of Göttingen was funded by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)(217133147/SFB 1073 project A05 and 255652344/SPP 1840 project‘Kohärente Wechselwirkungen starker optischer Nahfelder mit freien Elektronen’)and the Gottfried Wilhelm Leibniz programThe work at URV was financed by Spanish Ministerio de Economia y Competitividad(MINECO)(CTQ2017-88648R and RYC-2015-19107)the Generalitat de Cataluña(2017SGR883)the Universitat Rovira i Virgili(2018PFR-URV-B2-02)the Banco Santander(2017EXIT-08)J.G.A.received funding from the ERC(Advanced Grant No.789104-eNANO)Spanish MINECO(MAT2017-88492-R and SEV2015-0522)Catalan CERCA ProgramFundacióPrivada Cellex.
文摘The interplay between free electrons,light,and matter offers unique prospects for space,time,and energy resolved optical material characterization,structured light generation,and quantum information processing.Here,we study the nanoscale features of spontaneous and stimulated electron–photon interactions mediated by localized surface plasmon resonances at the tips of a gold nanostar using electron energy-loss spectroscopy(EELS),cathodoluminescence spectroscopy(CL),and photon-induced near-field electron microscopy(PINEM).Supported by numerical electromagnetic boundary-element method(BEM)calculations,we show that the different coupling mechanisms probed by EELS,CL,and PINEM feature the same spatial dependence on the electric field distribution of the tip modes.However,the electron–photon interaction strength is found to vary with the incident electron velocity,as determined by the spatial Fourier transform of the electric near-field component parallel to the electron trajectory.For the tightly confined plasmonic tip resonances,our calculations suggest an optimum coupling velocity at electron energies as low as a few keV.Our results are discussed in the context of more complex geometries supporting multiple modes with spatial and spectral overlap.We provide fundamental insights into spontaneous and stimulated electron-light-matter interactions with key implications for research on(quantum)coherent optical phenomena at the nanoscale.
文摘SNARE proteins mediate most membrane fusion reactions in eukaryotic cells,and are thereby vital for many functions,including synaptic transmission,cell growth,and cytokinesis.However,until recently it was still unclear how many of these proteins are required to catalyze membrane fusion in vivo.In a recent Science paper,Mohrmann et al.(2010)elegantly show that in chromaffin cells,three SNARE complexes are required for the synchronous release of granules,whereas only a single SNARE complex is sufficient for overall release.
基金This study was supported by the Austrian Science Fund(FWF)12102(to GKW),W1206-08(to NS),and F4414(to NS)a grant of the European Seventh Framework Programme(FP7/2007-2013)under agreement 603646(Multisyn,to GKW).
文摘Background:Misfolded oligomeric α-synuclein plays a pivotal role in the pathogenesis of a-synucleinopathies including Parkinson's disease and multiple system atrophy,and its detection parallels activation of microglia and a loss of neurons in the substantia nigra pars compacta.Here we aimed to analyze the therapeutic efficacy of PD03,a new AFFITOPE■ immunotherapy approach,either alone or in combination with Anle138b,in a PLP-α-syn mouse model.Methods:The PLP-α-syn mice were treated with PD03 immunotherapy,Anle138b,or a combination of two.Five months after study initiation,the mice underwent behavioral testing and were sacrificed for neuropathological analysis.The treatment groups were compared to the vehicle group with regard to motor performance,nigral neuronal loss,microglial activation and α-synuclein pathology.Results:The PLP-α-syn mice receiving the PD03 or Anle138b single therapy showed improvement of gait deficits and preservation of nigral dopaminergic neurons associated with the reduced α-synuclein oligomer levels and decreased microglial activation.The combined therapy with Anle138b and PD03 resulted in lower lgG binding in the brain as compared to the single immunotherapy with PD03.Conclusions:PD03 and Anle138b can selectively target oligomeric α-synuclein,resulting in attenuation of neurodegeneration in the PLP-α-syn mice.Both approaches are potential therapies that should be developed further for disease modification in α-synucleinopathies.
文摘The Darwin plant, also known as the Venus flytrap, Dionaea muscipula, has fascinated people since Darwin＇s time. The plant lives in nutrient-poor habitats but has been able to overcome the limitations of its surroundings by evolving a carnivorous lifestyle, particularly by modifying its leaves into active traps to catch animals. When flies, ants, or other small animals touch mechano-sensitive hairs protruding from the inner surface of the bi-lobed trap, it shuts within a fraction of a second.
基金A.D.was supported by Bundesministerium fur Bildung und Forschung(BMBF:Energl project,TP 5,01GQ1421A),Deutsche Forschungsgemeinschaft(DFG:SFB 1436,TP AOS-Project-ID 425899996)E.P.was supported by DFG grant P0732+1 种基金MZ.was supported by DFG(FOR 2858,TP B1-Project-ID 422185457)the European Research Council(ERC)under the EU Horizon 2020 research and innovation program(grant agreement no.787679).
文摘The structural basis of the regulation of serotonin(5-hydroxy-tryptamine,5-HT)receptors by ligands and lipids is only emerging.A recent study by Xu and colleagues1 published in Nature addresses this issue by resolving five structures of 5-HT;receptor-G protein complexes.These include 5-HT1A in the apostate,i.e.not bound to a ligand,5-HT1A and 5-HT1D bound to serotonin or the atypical antipsychotic aripiprazole(for 5-HT1A),and 5-HT1E bound to its selective agonist BRL-54443.
