研究旨在探讨环二肽Cyclo(Leu-Pro)对植物乳杆菌生长的影响。该研究以植物乳杆菌(Lactobacillus Plantarum T1)为研究对象,采用高效液相色谱法初步定性定量植物乳杆菌T1发酵液中的Cyclo(Leu-Pro),然后将植物乳杆菌T1分别接种于不含或含...研究旨在探讨环二肽Cyclo(Leu-Pro)对植物乳杆菌生长的影响。该研究以植物乳杆菌(Lactobacillus Plantarum T1)为研究对象,采用高效液相色谱法初步定性定量植物乳杆菌T1发酵液中的Cyclo(Leu-Pro),然后将植物乳杆菌T1分别接种于不含或含不同质量浓度(0.5、1、5、10μg/mL)Cyclo(Leu-Pro)的MRS肉汤培养基中培养18 h,采用96孔法和平板计数法测定不同培养条件下植物乳杆菌T1的生长曲线和活菌数。结果表明:不同质量浓度的Cyclo(Leu-Pro)对植物乳杆菌T1的生长均有明显的促生长作用,其中,1μg/mL Cyclo(Leu-Pro)的促生长效果最佳,可将活菌数提高到8.73×10^(10) CFU/mL,相比于对照组提高了一个数量级。在不同胁迫条件下,1μg/mL Cyclo(Leu-Pro)能使植物乳杆菌T1的延滞期缩短、生长速度提高,其活菌数和生物量显著增加(P<0.05)。综上所述,Cyclo(Leu-Pro)促进了植物乳杆菌T1的生长,增强了其抗胁迫能力。这将有利于植物乳杆菌T1作为发酵剂在食品发酵领域的应用。展开更多
A new cyclodipeptide, cyclo(phenylalanyl-N-methyltyrosyl) 1, was isolated from the mycelial solid cultures of Geotrichum candidum. Its structure was elucidated by spectroscopic methods. The antifungal activity of the ...A new cyclodipeptide, cyclo(phenylalanyl-N-methyltyrosyl) 1, was isolated from the mycelial solid cultures of Geotrichum candidum. Its structure was elucidated by spectroscopic methods. The antifungal activity of the new compound against Peronophythora litchii was assessed by microplate Alamar blue assay (MABA).展开更多
An easy and mild way to construct 13-hydroxy-9,15-cyclo GA skeletons was reported and it could be used as a general protocol in the synthesis of GAs with this structure.
This is a prospective interventional clinical study evaluating intraocular inflammation developed after Ultrasound Cyclo Plasty(UCP) for the treatment of glaucoma. Eighteen eyes of 18 patients were treated with UCP se...This is a prospective interventional clinical study evaluating intraocular inflammation developed after Ultrasound Cyclo Plasty(UCP) for the treatment of glaucoma. Eighteen eyes of 18 patients were treated with UCP second-generation probes(Eye OP1). After treatment, the mean intraocular pressure(IOP) significantly decreased from 26.8±7.2 to 18.8±6.1 mm Hg at day 1 and to 14.7±3.4 mm Hg at month 6(all P<0.001). Mean laser flare-cell photometry value steeply increased after surgery from 12.1±7.5 to 64.1±53.9 ph/ms(P=0.001) at day 1, and then progressively decreased to respectively 60.6±49.7 at day 7, 43.5±38.5 at day 14 and 28.2±18.3 at month 1(all P<0.05), returning at levels similar to baseline ones at month 3 and month 6(respectively 16.7±6.2 and 12.8±10.2, both P>0.05). A significant negative correlation was found between postoperative increase of aqueous flare values and anterior chamber depth(R=-0.568, P=0.014). This timeframe may be considered reasonable for repeating UCP treatment, when required.展开更多
Cyclocarbon fully consists of sp-hybridized carbon atoms,which shows quite unusual electronic and geometric structures compared to common molecules.In this work,we systematically studied strain energy(SE)of cyclocarbo...Cyclocarbon fully consists of sp-hybridized carbon atoms,which shows quite unusual electronic and geometric structures compared to common molecules.In this work,we systematically studied strain energy(SE)of cyclocarbons of different sizes using regression analysis method based on electronic energies evaluated at the very accurate DLPNO-CCSD(T)/ccp VTZ theoretical level.In addition,ring strain of two systems closely related to cyclocarbon,boron nitride(BN)ring,and cyclic polyacetylene(c-PA),is also explored.Very ideal relationships between SE and number of repeat units(n)are built for cyclo[2n]carbon,B_(n)N_(n),and[2n]c-PA as SE=555.0·n^(-1),145.1·n^(-1),and 629.8·n^(-1)kcal·mol^(-1),respectively,and the underlying reasons of the difference and similarity in their SEs are discussed from electronic structure perspective.In addition,force constant of harmonic potential of C-C-C angles in cyclocarbon is derived based on SE values,the result is found to be 56.23 kcal·mol^(-1)·rad^(-2).The possibility of constructing homodesmotic reactions to calculate SEs of cyclocarbons is also explored in this work,although this method is far less rigorous than the regression analysis method,its result is qualitatively correct and has the advantage of much lower computational cost.In addition,comparisons show thatωB97XD/def2-TZVP is a good inexpensive alternative to the DLPNO-CCSD(T)/cc-p VTZ for evaluating energies used in deriving SE,while the popular and very cheap B3LYP/6-31G(d)level should be used with caution for systems with global electron conjugation such as c-PA.展开更多
Cyclo[18]carbon has received considerable attention thanks to its novel geometric configuration and special electronic structure.Superalkalis have low ionization energy.Doping a superalkali in cyclo[18]carbon is an ef...Cyclo[18]carbon has received considerable attention thanks to its novel geometric configuration and special electronic structure.Superalkalis have low ionization energy.Doping a superalkali in cyclo[18]carbon is an effective method to improve the optical properties of the system because considerable electron transfer occurs.In this paper,the geometry,bonding properties,electronic structure,absorption spectrum,and nonlinear optical(NLO)properties of superalkaline M_(3)O(M=Li,Na)-doped cyclo[18]carbon were studied by using density functional theory.M_(3)O and the C_(18) rings are not coplanar.The C_(18) ring still exhibits alternating long and short bonds.The charge transfer between M_(3)O and C_(18) forms stable[M_(3)O]+[C_(18)]-ionic complexes.C_(18)M_(3)O(M=Li,Na)shows striking optical nonlinearity,i.e.,their first-and second-order hyperpolarizability(βvec andγ||)increase considerably atλ=1907 nm and 1460 nm.展开更多
Treatment of 1,3-di- t -butylcyclopentadiene with rhodium trichloride in EtOH leads to the formation of binuclear half-sandwich complex [Cp t RhCl( μ -Cl)] 2 (1) (Cp t = η 5- t Bu 2C 5H 3) which reacts with trimethy...Treatment of 1,3-di- t -butylcyclopentadiene with rhodium trichloride in EtOH leads to the formation of binuclear half-sandwich complex [Cp t RhCl( μ -Cl)] 2 (1) (Cp t = η 5- t Bu 2C 5H 3) which reacts with trimethylphosphine to give Cp t Rh(PMe 3)Cl 2(2) in high yield. 2 reacts with ammonium polysulfide, (NH 4) 2S x to give cyclooligosulfido half-sandwich complexes Cp t Rh(PMe 3)(S n )( n =4(4a),6(4b)). Desulfurization of 4b by excess PPh 3 results in cyclotetrasulfido product 4a, while 4a takes up sulfur from polysulfide to convert cyclohexasulfido product 4b. The reaction of 2 with Et 4NI gives diiodide complex 3 which is determined by single crystal X-ray crystallographic analysis.展开更多
Carbon is an element with exceptional capacity for structural reinvention.This interesting characteristic,which has captivated numerous scientists in different areas of chemistry,is more than evident when the differen...Carbon is an element with exceptional capacity for structural reinvention.This interesting characteristic,which has captivated numerous scientists in different areas of chemistry,is more than evident when the different allotropes of carbon are considered[1].From the rigidity of diamond to the layered structure of graphite,from the curved architectures of fullerenes and carbon nanotubes to the two-dimensional sheets of graphene,carbon relentlessly fascinates chemists with its versatility.Each of these carbon allotropes arises because carbon atoms can hybridize their orbitals in different ways(i.e.,sp^(3),sp^(2),and sp)and combinations.展开更多
Merging tetraphenylethylene(TPE)into cyclic skeletons endows fluorescent sensing capabilities for pillar[6]arenes aggregates,but results in losing their host-vip recognition function in dilute solutions.Inspired by ...Merging tetraphenylethylene(TPE)into cyclic skeletons endows fluorescent sensing capabilities for pillar[6]arenes aggregates,but results in losing their host-vip recognition function in dilute solutions.Inspired by natural enzymes,here we describe a series of TPE-based cyclo[6]arenes(termed TPz,TDz,and TTz)with endo-functionalized cavities containing inward-directed diazine motifs(pyrazine,pyridazine,and phthalazine)that act as hydrogen-bond acceptor sites.Combining electrostatic potential analysis and host-vip binding studies reveals that subtle variations in these diazine motifs substantially affect charge distribution and hydrogen-bond interactions within the internal microenvironment.These differences translate into disparate host-vip affinities,with TTz exhibiting the optimal performance.Unlike TPz,which recognizes vips only in aggregate states,1,2-diazine-modified TDz and TTz possess dual-state recognition functionality.They enable size-selective binding for cationic vips in dilute solutions and sensitive fluorescence detection of nitrophenol pollutants in aggregate states through a photoinduced electron transfer-driven static quenching mechanism.This study underscores the potential of 1,2-diazine motifs as transformative hydrogen-bond acceptors for biomimetic host models with emergent properties.展开更多
Synthesizing polynitrogen compounds that remain stable at ambient conditions is particularly challenging because species beyond the N≡N triple bond are inherently unstable.In this study,we combine first-principles ca...Synthesizing polynitrogen compounds that remain stable at ambient conditions is particularly challenging because species beyond the N≡N triple bond are inherently unstable.In this study,we combine first-principles calculations with a machine-learning potential(MLP)to investigate the ambient stability of planar cyclo-N_(4) units embedded in a two-dimensional t-FeN_(4) monolayer.Our results show that strong Fe–N coordination inhibits N≡N reformation,enabling the square cyclo-N_(4) motif to remain dynamically stable and covalently bonded without high-pressure synthesis.Furthermore,this structure exhibits tunable magnetic anisotropy and a Néel temperature above 600 K,indicating potential for room-temperature spintronic applications.The MLP also enables the simulation of systems comprising over 100,000 atoms,including periodic sheets,nanoribbons,nanomatrices and nanosheets,revealing their structural integrity under thermal fluctuations.These results demonstrate that two-dimensional confinement provides a promising route to stabilize exotic nitrogen topologies,linking quantum-mechanical accuracy with mesoscale modelling for future spinbased technologies.展开更多
The authors did not obtain permission to use some of the data from Prof.Hiroyuki Isobe,who supervised the reported study in itsearlystages.The concept of cyclo[n]helicenes was initiated by Prof.Hiroyuki Isobe(The Univ...The authors did not obtain permission to use some of the data from Prof.Hiroyuki Isobe,who supervised the reported study in itsearlystages.The concept of cyclo[n]helicenes was initiated by Prof.Hiroyuki Isobe(The University of Tokyo),then at Tohoku University.Specifically,the molecules 1-a,1-t,2-c,and 2-r were synthesized by Yong Yang who was employed with the funding of Professor Isobe,and the crystal data,CCDC 2306989-2306991 and 2306993,were obtained and analyzed by Sota Sato who was working in Professor Isobe’s group.The necessary expenses for these parts of the work were covered by JST ERATO(JPMJER1301,H.I.).The concept of cyclo[n]helicenes was initiated years ago by Prof.Isobe,when Dr.Yong Yang was a postdoc and Dr.Sota Sata was also a member of the group.The starting materials used in this work,[4]CH and[5]CH,were synthesized by Dr.Yang and structurally characterized by Dr.Sato in the group.展开更多
Cyclodextrin was pretreated by methylaluminoxane (MAO) and subsequently reacted with 8 aminoquinoline nickel dichloride complex to yield the supported catalyst, which was characterized by ICP, IR and XPS methods. Usi...Cyclodextrin was pretreated by methylaluminoxane (MAO) and subsequently reacted with 8 aminoquinoline nickel dichloride complex to yield the supported catalyst, which was characterized by ICP, IR and XPS methods. Using MAO as cocatalyst, the catalytic activity of this supported catalyst was investigated at various reaction temperature and Al/Ni molecular ratio. The results showed that, despite possessing a number of polar groups, the supported catalyst displayed relatively high activity over 1×10 5 g ethylene/(mol Ni·h) under mild conditions.展开更多
In order to study the effect of dihydroxyacetophenone ( DHAP) on pulmonary hemodynamicsand its relationship to plasma atrial natriuretic peptide (ANP) as well as adenosine cyclophosphates in chron-ic obstractive pulmo...In order to study the effect of dihydroxyacetophenone ( DHAP) on pulmonary hemodynamicsand its relationship to plasma atrial natriuretic peptide (ANP) as well as adenosine cyclophosphates in chron-ic obstractive pulmonary disease (COPD) , right heart catheterization was used to examine some parametersof hemodynamics in 11 COPD patients before and after the application of DHAP, and at the same time ra-dioimmunoassay was used to measure the plasma ANP and cyclo-adenosine monophosphate/cyclic guanosinemonophosphate (cAMP/cGMP) . The results showed that DHAP 640 mg given intravenously could decreasemean pulmonary arterial pressure, pulmonary vascular resistance and systemic vascular resistance ( P <0 . 05) , but increase cardiac output from 4. 10 ±1 . 08 L/min to 5.13 ± 1 . 19 L/min ( P>0. 05) and without af-fecting systemic arterial blood pressure ( P >0. 05) as well as blood gas analysis; it could also reduce theplasma ANP and cGMP Ievel from 0. 73 ± 0. 42 pg/ml to 0. 41 ± 0. 33 pg/ml ( P<0. 01 ) and trom 9 . 82 ± 5. 75pm/ml to 8. 01 ± 4. 80 pm/ml( P< 0. 05) respectively, but did not affect the plasma cAMP level ( P>0. 05) .It is suggested that DHAP may relax pulmonary vessels by adjusting the ratio of cAMP to cGMP, and the low-ering of plasma ANP level might be a secondary reaction. So DHAP was considered a quick-acting, safe andpotential drug in treating pulmonary arterial hypertension by COPD.展开更多
This letter is a continuation of previous work(Scientia Sinica, 27(1984), 1: 16—23). By using number-theoretic and model-theoretic arguments, we establish the existence of Goldbach and nonGoldbach extension rings of ...This letter is a continuation of previous work(Scientia Sinica, 27(1984), 1: 16—23). By using number-theoretic and model-theoretic arguments, we establish the existence of Goldbach and nonGoldbach extension rings of certain cyclotomic rings of integers and of some related rings of integers. The results obtained are as follows (The following Lemma is cited from the author’s previous work to help the reader to comprehend Theorem 1).展开更多
Staphylococcus aureus(S.aureus)biofilms are of considerable interest in food safety due to the increase risk of the food contamination.This study aimed to explore the anti-biofilm mechanisms of cyclo(L-Phe-L-Pro)(cFP)...Staphylococcus aureus(S.aureus)biofilms are of considerable interest in food safety due to the increase risk of the food contamination.This study aimed to explore the anti-biofilm mechanisms of cyclo(L-Phe-L-Pro)(cFP)against S.aureus with respect to its changes on extracellular polymeric substances(EPS)and gene expression.Results showed that cFP decreased the viability of S.aureus biofilm,and inhibited the synthesis of EPS(extracellular proteins,extracellular polysaccharides,and extracellular DNA).Real-time qPCR revealed that cFP could affect the expression of polysaccharide intercellular adhesion(PIA)synthesis-related genes(icaR,icaA,icaB icaC and icaD)and quorum sensing-related genes(agrA,agrB,agrC,agrD,geh,hla and spa).In addition,molecular docking speculated that cFP could bind to AgrC,and the binding region was most likely between loop1 and loop2.The histidine kinase domain of AgrC may also played a role in the binding process.Finally,the application of cFP on food contact surface showed that cFP could inhibit the biofilm of S.aureus.These findings not only prove the practicable antibacterial activity of cFP,but provide new approach to decrease the risk of S.aureus contamination on food contact surface.展开更多
文摘A new cyclodipeptide, cyclo(phenylalanyl-N-methyltyrosyl) 1, was isolated from the mycelial solid cultures of Geotrichum candidum. Its structure was elucidated by spectroscopic methods. The antifungal activity of the new compound against Peronophythora litchii was assessed by microplate Alamar blue assay (MABA).
基金partly supported by the Natural Science Foundation of Yunnan Provence.(No.2000B0001 R).
文摘An easy and mild way to construct 13-hydroxy-9,15-cyclo GA skeletons was reported and it could be used as a general protocol in the synthesis of GAs with this structure.
文摘This is a prospective interventional clinical study evaluating intraocular inflammation developed after Ultrasound Cyclo Plasty(UCP) for the treatment of glaucoma. Eighteen eyes of 18 patients were treated with UCP second-generation probes(Eye OP1). After treatment, the mean intraocular pressure(IOP) significantly decreased from 26.8±7.2 to 18.8±6.1 mm Hg at day 1 and to 14.7±3.4 mm Hg at month 6(all P<0.001). Mean laser flare-cell photometry value steeply increased after surgery from 12.1±7.5 to 64.1±53.9 ph/ms(P=0.001) at day 1, and then progressively decreased to respectively 60.6±49.7 at day 7, 43.5±38.5 at day 14 and 28.2±18.3 at month 1(all P<0.05), returning at levels similar to baseline ones at month 3 and month 6(respectively 16.7±6.2 and 12.8±10.2, both P>0.05). A significant negative correlation was found between postoperative increase of aqueous flare values and anterior chamber depth(R=-0.568, P=0.014). This timeframe may be considered reasonable for repeating UCP treatment, when required.
文摘Cyclocarbon fully consists of sp-hybridized carbon atoms,which shows quite unusual electronic and geometric structures compared to common molecules.In this work,we systematically studied strain energy(SE)of cyclocarbons of different sizes using regression analysis method based on electronic energies evaluated at the very accurate DLPNO-CCSD(T)/ccp VTZ theoretical level.In addition,ring strain of two systems closely related to cyclocarbon,boron nitride(BN)ring,and cyclic polyacetylene(c-PA),is also explored.Very ideal relationships between SE and number of repeat units(n)are built for cyclo[2n]carbon,B_(n)N_(n),and[2n]c-PA as SE=555.0·n^(-1),145.1·n^(-1),and 629.8·n^(-1)kcal·mol^(-1),respectively,and the underlying reasons of the difference and similarity in their SEs are discussed from electronic structure perspective.In addition,force constant of harmonic potential of C-C-C angles in cyclocarbon is derived based on SE values,the result is found to be 56.23 kcal·mol^(-1)·rad^(-2).The possibility of constructing homodesmotic reactions to calculate SEs of cyclocarbons is also explored in this work,although this method is far less rigorous than the regression analysis method,its result is qualitatively correct and has the advantage of much lower computational cost.In addition,comparisons show thatωB97XD/def2-TZVP is a good inexpensive alternative to the DLPNO-CCSD(T)/cc-p VTZ for evaluating energies used in deriving SE,while the popular and very cheap B3LYP/6-31G(d)level should be used with caution for systems with global electron conjugation such as c-PA.
基金Project supported by the Natural Science Foundation of Anhui Province(Grant No.1908085MA12)the National Natural Science Foundation of China(Grant No.21703222)。
文摘Cyclo[18]carbon has received considerable attention thanks to its novel geometric configuration and special electronic structure.Superalkalis have low ionization energy.Doping a superalkali in cyclo[18]carbon is an effective method to improve the optical properties of the system because considerable electron transfer occurs.In this paper,the geometry,bonding properties,electronic structure,absorption spectrum,and nonlinear optical(NLO)properties of superalkaline M_(3)O(M=Li,Na)-doped cyclo[18]carbon were studied by using density functional theory.M_(3)O and the C_(18) rings are not coplanar.The C_(18) ring still exhibits alternating long and short bonds.The charge transfer between M_(3)O and C_(18) forms stable[M_(3)O]+[C_(18)]-ionic complexes.C_(18)M_(3)O(M=Li,Na)shows striking optical nonlinearity,i.e.,their first-and second-order hyperpolarizability(βvec andγ||)increase considerably atλ=1907 nm and 1460 nm.
基金Financial support by the National Natural Science Foundation of China and by the Special Funds for Major State Basic Research Projects(G1999064800)is gratefully acknowledged.
文摘Treatment of 1,3-di- t -butylcyclopentadiene with rhodium trichloride in EtOH leads to the formation of binuclear half-sandwich complex [Cp t RhCl( μ -Cl)] 2 (1) (Cp t = η 5- t Bu 2C 5H 3) which reacts with trimethylphosphine to give Cp t Rh(PMe 3)Cl 2(2) in high yield. 2 reacts with ammonium polysulfide, (NH 4) 2S x to give cyclooligosulfido half-sandwich complexes Cp t Rh(PMe 3)(S n )( n =4(4a),6(4b)). Desulfurization of 4b by excess PPh 3 results in cyclotetrasulfido product 4a, while 4a takes up sulfur from polysulfide to convert cyclohexasulfido product 4b. The reaction of 2 with Et 4NI gives diiodide complex 3 which is determined by single crystal X-ray crystallographic analysis.
文摘Carbon is an element with exceptional capacity for structural reinvention.This interesting characteristic,which has captivated numerous scientists in different areas of chemistry,is more than evident when the different allotropes of carbon are considered[1].From the rigidity of diamond to the layered structure of graphite,from the curved architectures of fullerenes and carbon nanotubes to the two-dimensional sheets of graphene,carbon relentlessly fascinates chemists with its versatility.Each of these carbon allotropes arises because carbon atoms can hybridize their orbitals in different ways(i.e.,sp^(3),sp^(2),and sp)and combinations.
基金support was provided by the National Natural Science Foundation of China(22401064 and 22161017)the Innovational Fund for Scientific and Technological Personnel of Hainan Province(KJRC2023D34)+1 种基金the Hainan Provincial Natural Science Foundation of China(224QN184)the Research Start-up Fund of Hainan University(KYQD(ZR)23037).
文摘Merging tetraphenylethylene(TPE)into cyclic skeletons endows fluorescent sensing capabilities for pillar[6]arenes aggregates,but results in losing their host-vip recognition function in dilute solutions.Inspired by natural enzymes,here we describe a series of TPE-based cyclo[6]arenes(termed TPz,TDz,and TTz)with endo-functionalized cavities containing inward-directed diazine motifs(pyrazine,pyridazine,and phthalazine)that act as hydrogen-bond acceptor sites.Combining electrostatic potential analysis and host-vip binding studies reveals that subtle variations in these diazine motifs substantially affect charge distribution and hydrogen-bond interactions within the internal microenvironment.These differences translate into disparate host-vip affinities,with TTz exhibiting the optimal performance.Unlike TPz,which recognizes vips only in aggregate states,1,2-diazine-modified TDz and TTz possess dual-state recognition functionality.They enable size-selective binding for cationic vips in dilute solutions and sensitive fluorescence detection of nitrophenol pollutants in aggregate states through a photoinduced electron transfer-driven static quenching mechanism.This study underscores the potential of 1,2-diazine motifs as transformative hydrogen-bond acceptors for biomimetic host models with emergent properties.
基金support from Chongqing Jiaotong University (No. F1240018)Chongqing Graduate Tutor Team Construction Project (JDDSTD2022006)+1 种基金P.L. would like to thank the support from the Hunan Provincial Natural Science Foundation of China (2023JJ40621)Computing resources were provided by the National Supercomputer Centre (TianHe-3K) in Tianjin. The work also partially supported by e-INFRA CZ (ID:90140) for providing computational resources.
文摘Synthesizing polynitrogen compounds that remain stable at ambient conditions is particularly challenging because species beyond the N≡N triple bond are inherently unstable.In this study,we combine first-principles calculations with a machine-learning potential(MLP)to investigate the ambient stability of planar cyclo-N_(4) units embedded in a two-dimensional t-FeN_(4) monolayer.Our results show that strong Fe–N coordination inhibits N≡N reformation,enabling the square cyclo-N_(4) motif to remain dynamically stable and covalently bonded without high-pressure synthesis.Furthermore,this structure exhibits tunable magnetic anisotropy and a Néel temperature above 600 K,indicating potential for room-temperature spintronic applications.The MLP also enables the simulation of systems comprising over 100,000 atoms,including periodic sheets,nanoribbons,nanomatrices and nanosheets,revealing their structural integrity under thermal fluctuations.These results demonstrate that two-dimensional confinement provides a promising route to stabilize exotic nitrogen topologies,linking quantum-mechanical accuracy with mesoscale modelling for future spinbased technologies.
文摘The authors did not obtain permission to use some of the data from Prof.Hiroyuki Isobe,who supervised the reported study in itsearlystages.The concept of cyclo[n]helicenes was initiated by Prof.Hiroyuki Isobe(The University of Tokyo),then at Tohoku University.Specifically,the molecules 1-a,1-t,2-c,and 2-r were synthesized by Yong Yang who was employed with the funding of Professor Isobe,and the crystal data,CCDC 2306989-2306991 and 2306993,were obtained and analyzed by Sota Sato who was working in Professor Isobe’s group.The necessary expenses for these parts of the work were covered by JST ERATO(JPMJER1301,H.I.).The concept of cyclo[n]helicenes was initiated years ago by Prof.Isobe,when Dr.Yong Yang was a postdoc and Dr.Sota Sata was also a member of the group.The starting materials used in this work,[4]CH and[5]CH,were synthesized by Dr.Yang and structurally characterized by Dr.Sato in the group.
基金ProjectsupportedbytheCoreResearchforEngineeringInnovation (No .KGCX2 2 0 3 )fromtheChineseAcademyofSciences theNationalNat uralScienceFoundationofChina (No .2 0 2 72 0 62 )and"OneHundredTalents"FundforWen HuaSun
文摘Cyclodextrin was pretreated by methylaluminoxane (MAO) and subsequently reacted with 8 aminoquinoline nickel dichloride complex to yield the supported catalyst, which was characterized by ICP, IR and XPS methods. Using MAO as cocatalyst, the catalytic activity of this supported catalyst was investigated at various reaction temperature and Al/Ni molecular ratio. The results showed that, despite possessing a number of polar groups, the supported catalyst displayed relatively high activity over 1×10 5 g ethylene/(mol Ni·h) under mild conditions.
文摘In order to study the effect of dihydroxyacetophenone ( DHAP) on pulmonary hemodynamicsand its relationship to plasma atrial natriuretic peptide (ANP) as well as adenosine cyclophosphates in chron-ic obstractive pulmonary disease (COPD) , right heart catheterization was used to examine some parametersof hemodynamics in 11 COPD patients before and after the application of DHAP, and at the same time ra-dioimmunoassay was used to measure the plasma ANP and cyclo-adenosine monophosphate/cyclic guanosinemonophosphate (cAMP/cGMP) . The results showed that DHAP 640 mg given intravenously could decreasemean pulmonary arterial pressure, pulmonary vascular resistance and systemic vascular resistance ( P <0 . 05) , but increase cardiac output from 4. 10 ±1 . 08 L/min to 5.13 ± 1 . 19 L/min ( P>0. 05) and without af-fecting systemic arterial blood pressure ( P >0. 05) as well as blood gas analysis; it could also reduce theplasma ANP and cGMP Ievel from 0. 73 ± 0. 42 pg/ml to 0. 41 ± 0. 33 pg/ml ( P<0. 01 ) and trom 9 . 82 ± 5. 75pm/ml to 8. 01 ± 4. 80 pm/ml( P< 0. 05) respectively, but did not affect the plasma cAMP level ( P>0. 05) .It is suggested that DHAP may relax pulmonary vessels by adjusting the ratio of cAMP to cGMP, and the low-ering of plasma ANP level might be a secondary reaction. So DHAP was considered a quick-acting, safe andpotential drug in treating pulmonary arterial hypertension by COPD.
文摘This letter is a continuation of previous work(Scientia Sinica, 27(1984), 1: 16—23). By using number-theoretic and model-theoretic arguments, we establish the existence of Goldbach and nonGoldbach extension rings of certain cyclotomic rings of integers and of some related rings of integers. The results obtained are as follows (The following Lemma is cited from the author’s previous work to help the reader to comprehend Theorem 1).
基金supported by State Key Laboratory of Utilization of Woody Oil Resource(Grant no.2019 XK 2002)National Natural Science Foundation of China(Grant no.31972172)+2 种基金Natural Science Foundation of Jiangsu Province(Grant no.BK20201417)Jiangsu Province Research Fund(Grant no.JNHB-131)Jiangsu University Research Fund(Grant no.11JDG050).
文摘Staphylococcus aureus(S.aureus)biofilms are of considerable interest in food safety due to the increase risk of the food contamination.This study aimed to explore the anti-biofilm mechanisms of cyclo(L-Phe-L-Pro)(cFP)against S.aureus with respect to its changes on extracellular polymeric substances(EPS)and gene expression.Results showed that cFP decreased the viability of S.aureus biofilm,and inhibited the synthesis of EPS(extracellular proteins,extracellular polysaccharides,and extracellular DNA).Real-time qPCR revealed that cFP could affect the expression of polysaccharide intercellular adhesion(PIA)synthesis-related genes(icaR,icaA,icaB icaC and icaD)and quorum sensing-related genes(agrA,agrB,agrC,agrD,geh,hla and spa).In addition,molecular docking speculated that cFP could bind to AgrC,and the binding region was most likely between loop1 and loop2.The histidine kinase domain of AgrC may also played a role in the binding process.Finally,the application of cFP on food contact surface showed that cFP could inhibit the biofilm of S.aureus.These findings not only prove the practicable antibacterial activity of cFP,but provide new approach to decrease the risk of S.aureus contamination on food contact surface.
