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1.
The development of biomimetic structures with integrated extracellular matrix (ECM) components represents a promising approach to biomaterial fabrication. Here, an artificial ECM, comprising the structural protein collagen I and elastin (ELN), as well as the glycosaminoglycan hyaluronan (HA), is reported. Specifically, collagen and ELN are electrochemically aligned to mimic the compositional characteristics of the dermal matrix. HA is incorporated into the electro-compacted collagen-ELN matrices via adsorption and chemical immobilization, to give a final composition of collagen/ELN/HA of 7:2:1. This produces a final collagen/ELN/hyaluronic acid scaffold (CEH) that recapitulates the compositional feature of the native skin ECM. This study analyzes the effect of CEH composition on the cultivation of human dermal fibroblast cells (HDFs) and immortalized human keratinocytes (HaCaTs). It is shown that the CEH scaffold supports dermal regeneration by promoting HDFs proliferation, ECM deposition, and differentiation into myofibroblasts. The CEH scaffolds are also shown to support epidermis growth by supporting HaCaTs proliferation, differentiation, and stratification. A double-layered epidermal-dermal structure is constructed on the CEH scaffold, further demonstrating its ability in supporting skin cell function and skin regeneration.  相似文献   

2.
合成了一种含吡唑啉酮的三脚架结构化合物 1,1,1 三 { 1′ [2′ 氧杂 5′ 氧代 5′ ( 1″ 苯基 3″ 甲基吡唑啉酮 4″ 基 )戊基 ] }丙烷 (H3 L)及其 7个稀土配合物。通过元素分析、摩尔电导、质谱、红外光谱、核磁共振谱、荧光光谱等对H3 L及其稀土配合物的组成及性质进行了表征。分析结果表明 :H3 L的分子式为C45H50 N6O9,配合物的组成比为REL·0 5H2 O (RE =La ,Sm ,Eu ,Gd ,Tb ,Dy ,Yb) ;该三脚架形配体分别以醚氧、烯醇氧及吡唑酮环上的羰基氧与稀土离子进行配位 ,形成内配型配合物。荧光光谱分析表明SmL·0 5H2 O ,EuL·0 5H2 O ,TbL·0 5H2 O ,DyL·0 5H2 O配合物具有三价稀土离子的特征线状荧光 ,其中TbL·0 5H2 O的荧光强度最强 ,表明T(配体 )→5D4(Tb)能级更为匹配 ,从而进行分子内能量有效传递 ;由EuL·0 5H2 O的荧光光谱图形推测 ,Eu3 +离子在该配合物中处于非对称中心  相似文献   

3.
Relying on analysis of experimental infrared, Raman, and ultraviolet spectra and on calculation of frequencies and forms of normal vibrations of polyfluorinated toluenes these compounds were established to be prone to quinoid structure, and the interaction of the CF3 group with the polyfluorinated benzene ring was found to occur predominantly through the -system.  相似文献   

4.
Here, the synthesis, photophysical characterization, and application of a new size-expanded thymine nucleoside, diox T , is described. diox T has desirable qualities as a T surrogate, including excellent quantum yield (0.36) and high environmental sensitivity. When incorporated into single- and double-stranded DNA, diox T showed excellent photophysical characteristics including a high quantum yield (average 0.20), and unlike BgQ, demonstrated dependence on neighboring bases without significant destabilization of the duplex. Interestingly, the matched base pair of adenine (A) and diox T has the unique property that it exhibits higher fluorescence than mismatched base pairs, and diox T has self-quenching effects. As one example of the possible applications of these promising features, single nucleoside polymorphism typing is demonstrated for discrimination of A by using diox T . The results suggest that diox T can be used for a broad range of applications in chemical biology.  相似文献   

5.
aza-BODIPY荧光染料是近10年发展起来并受到广泛关注的一类新型荧光化合物,它极有可能发展成可应用于光动力学治疗的光敏剂.本工作合成了5个aza-BODIPY 1a~1e,用IR,NMR,MS和元素分析对它们进行了表征.研究了它们的紫外吸收光谱与荧光发射光谱,结果表明1a~1e具有较高的摩尔吸光系数,在aza-BODIPY母环的3,5位或1,7位的苯环4位有供电子取代基时能使化合物的最大紫外吸收波长和荧光发射波长红移.测试了1a~1d的循环伏安曲线,根据各化合物的氧化还原电位讨论了它们的结构稳定性.  相似文献   

6.
Main observation and conclusion Chalcogenirenium cations,featuring an unsaturated three-membered organic ring,are limited but known to be synthesizable from alk...  相似文献   

7.
Two α-septithiophenes substituted at the third position of the middle ring with polyethyleneglycol of different molecular weights (PEG 1000 and PEG 2000) were synthesized using Suzuki condensation. Their structural characterization was performed by 1H NMR and FT-IR. The thermal behavior of the new synthesized oligothiophenes was investigated by differential scanning calorimetry (DSC) and thermogravimetrical (TGA) analysis. Photophysical properties in solutions were evaluated by UV-vis and fluorescence measurements using different solvents. The amphiphilic nature of the synthesized oligothiophenes and the presence of the PEG side chains induced self-dispersibility in water and the possibility of fluorescent nanoparticles forming by self-assembling. The size of nanoparticles in water was assessed by DLS and AFM investigations.  相似文献   

8.
以丙烯酰胺为基体,N,N-甲叉双丙烯酰胺为交联剂,荧光分子Fura-2作为探针,构造荧光纳米微球。考察了乳化剂用量、引发剂用量、交联剂单体浓度对纳米微球直径和油水比对乳液稳定性的影响。含Fura-2的荧光纳米微球对钙离子非常敏感,可作为钙离子传感器。  相似文献   

9.
Ultraviolet germicidal irradiation can be used to prevent airborne transmission of infectious diseases. A common application is to irradiate upper‐room areas, by passing air from the lower room into the irradiated zone. Well‐designed systems do not expose people directly; however, some UV radiation may be reflected off ceiling tiles and wall paints into the lower room. Lower room exposure should be limited to the American Conference of Governmental Industrial Hygienists threshold limit value of 6 mJ·cm?2 of 254 nm radiation per day. To limit the lower room exposure, the reflectance of upper‐room surfaces must not be high. The reflective properties of wall paints have been studied, but less is known about the UV reflectance of ceiling tiles. Using a double monochromator spectroradiometer and an integrating sphere reflectance attachment, the UV spectral reflectance of 37 ceiling tiles was measured from 200 to 400 nm. The reflectances varied from 0.020 to 0.822 in this range, and from 0.035 to 0.459 at 254 nm, the main wavelength emitted by upper room low‐pressure mercury germicidal lamps. These data were then used to estimate an 8 h exposure based on several simplified workplace scenarios. The implications for workplace safety are then discussed.  相似文献   

10.
MgCoAl-hydrotalcite-like compounds(MgCoAl-HTLcs)were synthesized using the copre- cipitation method of variable pH values.The effect of each factor on the preparation of HTLcs was discussed systematically,which included pH values,mole ratios of Mg~(2 )to Co~(2 ),the concentrations of the solution,and the temperature and time of the hydrothermal treatment.Besides.the thermal de- composition of MgCoAl-HTLcs was discussed.X-ray diffraction,thermogravimetric analysis,and FT-IR spectroscopy were performed to characterize the MgCoAl-HTLcs samples.The results showed that when the pH=7.6-8.5 or 5.5-6.2,atomic ratios of(Mg~(2 ) Co~(2 ))/Al~(3 )=2 and Mg~(2 )/Co~(2 )ranging from 1.00 to 2.00,temperature and time of hydrothermal treatment being 110℃and 6 h,unique MgCoAl-HTLcs with high crystallinity could be obtained.When the calcination temperature was up to 250℃,the MgO phase was detected coexisting with Al_2O_3 and MgAl_2O_4 was highly spreaded on the derived mixed oxides. The synthesis reaction of benzoin methyl ether with methanol and benzaldehyde was chosen to study the catalytic activity of MgCoAl-HTLcs.The catalyst showed high activity and high stability in the synthesis of benzoin methyl ether in the feasible condition.  相似文献   

11.
Sodium and potassium methyl(nitroso)amide (M[CH3N2O], M = Na ( 1 ), K ( 2 )) were prepared by the reaction of monomethylhydrazine with iso‐pentyl nitrite or n‐butyl nitrite and a suitable metal ethoxide (M[CH3CH2O], M = Na, K) in an ethanol‐ether mixture. The reaction of monomethylhydrazine with a small excess of iso‐pentyl nitrite or n‐butyl nitrite and in the absence of a metal ethoxide led to the formation of N‐nitroso‐N‐methylhydrazine (CH3(NO)N–NH2, ( 3 )). Alternatively, compound 3 was prepared by the amination reaction of 1 or 2 using the sodium salt of HOSA in ethanol solution. Compounds 1–3 were characterized using elemental analysis, differential scanning calorimetry, mass spectrometry, vibrational (infrared and Raman) and UV spectroscopy and multinuclear (1H, 13C and 15N) NMR spectroscopy. For compounds 1–3 , several physical and chemical properties of interest and sensitivity data were measured and for compound 3 thermodynamic and explosive properties are also given. Additionally, the solid‐state structure of compound 3 was determined by single‐crystal X‐ray analysis and the structures of the cis‐ and trans‐[CH3N2O] anions and that of 3 were optimized using DFT calculations and used to calculate the NBO charges.  相似文献   

12.
A new macrocycle including pyrimidine fragments, 12,23,36-trimethyl-24,40-dioxo-15,33-dithia-2,9,13,22,26,35,38,39-octaazatetracyclo[32.3.1.110,14.122,26]tetraconta-1(38),10(39),11,13,23,34,36-heptaene, was synthesized. According to the data of IR and UV spectroscopy and HF/6-31G** quantum-chemical calculations, macrocyclic compounds of this series in crystal exist in the amino form, one NH group of which is likely to be involved in intramolecular hydrogen bond, and the other, in intermolacular hydrogen bond. The strength of the latter depends on the macroring size. In solution, the above structures are supplemented by conformers containing both intramolecularly H-bonded and free amino groups, predominantly with trans structure of the HÄNÄCÍN fragment. The imino form of the aminopyrimidine moieties is hardly probable.  相似文献   

13.
The preparation of ZnAlLa-hydrotalcite-like compounds [ZnAlLa-HTLcs] was studied.ZnAlLa-HTLcs were synthesized by a method of variable pH with the raw materials of Zn(NO3)2.Al(NO3)3, La(NO3)3, and NaOH. The effects of some factors (i.e. pH values, the mole ratio of Al^3- to La^3-.temperature and the period of hydrothermal treatment) on the preparation of HTLcs were discussed systematically. XRD. TG-DTA. FT-IR spectroscopy, and ICP were performed to characterize ZnAlLa-HTLcs samples, and the thermal stability of HTLcs was also discussed. It was shown that unique ZnAlLa-HTLcs with high crystallinity can be prepared, under the conditions of pH=5.5-6.5. n(Zn^2 )/n(Al^3 La^3 )=2 and the atomic ratio of La^3 to Al^3 ranging from 0.07 to 2. hydrothermal treatment at 120℃ for 5 h. When the calcination of the HTLcs is performed at temperatures above 200℃. ZnO phase is detected with Al2O3 and La2O3 spreading on its top. The complex metal oxides derived from ZnAlLa-HTLcs at 500℃ have higher catalytic activity and selectivity than those from ZnAl-HTLcs for the esterification of acetic acid with n-butanol under the same reaction conditions.  相似文献   

14.
The ultraviolet absorption spectra of berbines and ?-berbines consist of a single, weak and narrow band in which λmax position dependeds on the kind of auxochrome group i. e., methylenedioxy-or dimethoxy group attached to 2–3 position. The effect of the auxochrome group at 11–12 position or 12–13 position is very small. The shape of the band of oxyberberine, oxy-?-berberine and oxyprotoberberine are similar, especially those of the latter two substances resemble closely. Comparing with isoquinoline, the bands (b), (c) and (d) of G-berberines and protoberberine are considered as characteristic of isoquinoline structure, while the band (a) in visible region is of berberinium structure, however, the absorption curve of ?-berberines does not show any characteristic of isoquinoline or berberinium structure.  相似文献   

15.
New fluorescent nucleobase analogues (FBAs) are emerging as extraordinarily useful tools for DNA labelling technologies. The highly fluorescent adenine analogue 2-aminopurine (2AP) is still the most used within the few hundreds of newly FBAs synthesized, but its excitation in the UV region demands for high energy sources endangering living cells. New and highly fluorescent 2AP derivatives, 2-amino-6-cyanopurines, were obtained using simpler but efficient synthesis method. All the new compounds exhibit advantageous photophysical properties over 2AP, showing absorption and emission bands ranging the visible region (blue-green region), high fluorescence quantum yields and Stokes’ shifts, especially in non-protic organic solvents. Density Functional Theory calculations (DFT) of electronic and vibrational structure were performed, allowing to predict absorption and emission spectra. In addition, these 2-amino-6-cyanopurines exhibit little to no toxicity in assays using yeast cells.  相似文献   

16.
Fluorescent Cd metal–organic frameworks (MOFs), [Cd2(dicarboxylate)2(NI-bpy-44)2] (dicarboxylate=benzene-1,4-dicarboxylate (1,4-bdc, 1 ), 2-bromobenzene-1,4-dicarboxylate (Br-1,4-bdc, 2 ), 2-nitrobenzene-1,4-dicarboxylate (NO2-1,4-bdc, 3 ), biphenyl-4,4′-dicarboxylate (bpdc, 4 ); NI-bpy-44=N-(pyridin-4-yl)-4-(pyridin-4-yl)-1,8-naphthalimide)), featuring non- and twofold interpenetrating pcu -type bipillared-layer open structures with sufficient free voids of 58.4, 51.4, 51.5, and 41.4 %, respectively, have been hydro(solvo)thermally synthesized. MOFs 1 – 4 emitted solid-state blue or cyan fluorescence emissions at 447±7 nm, which mainly arose from NI-bpy-44 and are dependent on the incorporated solvents. After immersing the crystalline samples in different solvents, that is, H2O and DMSO ( 1 and 2 ) as well as nitrobenzene and phenol ( 1 – 4 ), they exhibited a remarkable fluorescence quenching effect, whereas o-xylene and p-xylene ( 4 ) caused significant fluorescence enhancement. The sensing ability of MOFs 1 – 4 toward nitro compounds carried out in the vapor phase showed that nitrobenzene and 2-nitrophenol displayed detectable fluorescence quenching with 1 , 2 , and 4 whereas 4-nitrotoluene was an effective fluorescence quencher for 1 and 2 ; this is most likely attributed to their electron-deficient properties and higher vapor pressures. Moreover, MOFs 1 – 4 are highly reusable for quick capture of volatile iodine, as supported by clear crystal color change and also by immense fluorescence quenching responses owing to the donor–acceptor interaction. Low-pressure CO2 adsorption isotherms indicate that activated materials 1′ – 4′ are inefficient at taking up CO2.  相似文献   

17.
以Ca(NO3)2·4H2O,Eu2O3和(NH4)2HPO4为原料,采用反相微乳液-水热法制备出Eu3+掺杂羟基磷灰石纳米粒子.通过对产物纳米粒子的荧光光谱,TEM、XRD等测试分析,重点考察了Eu3+掺杂量对产物纳米结构和荧光性能的影响,并对荧光性能随其形貌变化的关系等进行了简要讨论.  相似文献   

18.
Two new imidazolidino Schiff base compounds, (E)-N-((quinoxalin-2-yl)methylene)- 2-(2-(quinoxalin-3-yl)imidazolidin-1-yl)ethanamine 1 and 2-(1-(2-(2-(quinoxalin-3-yl)imidazolidin- 1-yl)ethyl)imidazolidin-2-yl)quinoxaline 2, have been synthesized and characterized by elemental analysis, ^1H NMR, IR, MS and single-crystal X-ray diffraction. Crystallographic data for 1: C22H21N7, Mr = 383.46, monoclinic, space group P21, a = 7.0036(14), b = 6.9151(14), c = 19.701(4)A, β = 96.57(3)°, Z = 2, V = 947.9(3)A^3, Dc = 1.344 g/cm^3, F(000) = 404, μ = 0.085 mm^-1, Flack parameter = 0(2), R = 0.0464 and wR = 0.1055; and those for 2: C24H26N8, Mr = 426.53, triclinic, space group PI, a = 9.6680(19), b = 10.334(2), c = 11.389(2)A, α= 104.12(3), β = 102.95(3), γ= 100.48(3)°, Z= 2, V = 1041.2(4)A3, Dc= 1.361 g/cm^3, F(000) = 452, μ = 0.086 mm^-1, R = 0.0373 and wR = 0.1155. For the two compounds, the five-membered imidazolidine rings all adopt envelope conformation. Moreover, the title compounds show one-dimensional layered and three-dimensional supramolecular chainlike structures, respectively. Fluorescent properties of the two compounds have been investigated in the solid state at room temperature. Compound 1 exhibits strong fluorescence and thus may serve as excellent candidates of green fluorescent materials.  相似文献   

19.
以酮和硝基甲烷为原料,经3步反应合成了2种氮取代的二氮杂双环结构化合物N-二氯乙酰基-9-氧代-1,5-二氮杂二环[4.3.0]壬烷,采用红外光谱、核磁共振和元素分析对产物结构进行了表征。并利用土培法对化合物进行了初步的生物活性试验。结果表明,化合物能够减轻普施特对玉米的伤害。  相似文献   

20.
以N, N'-二芳基己二酰二肼类化合物为原料,用Fe(NO3)3·9H2O作氧化剂,在室温无溶剂条件下将N, N'-二芳基己二酰二肼类化合物氧化脱氢为N, N'-二芳基己二酰双偶氮化合物.产物结构经元素分析、IR、 1H NMR确证,原料的IR谱中在3200~3400cm-1出现的2个N-H吸收峰在氧化产物中消失,但在1455cm-1附近有-N=N-吸收峰;1H NMR谱中在δ7.3~10.5之间的2个N-H化学位移在氧化产物中也消失;产物的元素分析结果与理论值基本相符.收率80%~94%.  相似文献   

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