Highly efficient Rh(Ⅰ)/tris-H_8-binaphthyl monophosphite catalysts for hydroformylation of dicyclopentadiene to dialdehydes

Novel catalytic systems for the Rh‐catalyzed hydroformylation of dicyclopentadiene have been developed using tris‐H8‐binaphthyl monophosphite as ligands containing different ester substituents at the 2’‐binaphthyl position(OCOMe,OCOPh,OCOAdamantyl and OCOPhCl).The catalysts exhibited high activity(S/C=4000,TON=3286)with good to excellent selectivity towards dialdehydes.Remarkably,the Rh(I)complex bearing the ligands with chlorophenyl ester substituents led to 99.9%conversion and 98.7%selectivity for dialdehydes under relatively mild conditions(6 MPa,120°C).

Synthesis of 5-Substituted 2, 9-Dimethyl-1,10-Phenanthroline Dialdehydes and Their Schiff Bases with Sulfur-Containing Amines

Eight new Schiff bases of 5-nitro and 5-bromo-substituted 1,10-phenanthroline-2,9-dicarboxaldehydes with sulfur-containing amines, thiosemicarbazide, S-alkyl/aryl dithiocarbazates and 2-mercaptoaniline have been synthesized and characterized by a variety of spectroscopic methods. The condensation reactions of the dialdehydes with the amines were carried out both in the presence and absence of conc. sulfuric acid. A significant increase in yield of the Schiff bases was observed when the reactions were carried out in the presence of sulfuric acid.

The synthesis of dialdehydes from dicarboxylic acids via imidazolines

DIALDEHYDES are important chemical industrial materials, which are widely used in textile,medicine, dye, binder, coating and so on. The traditional method for preparing dialdehydes is the catalytic oxidation of glycol. We have reported the reduction ring-opening reaction of inndazoline by NaBH4.In this note, the reduction of imidazoline by sodium and ethanol is studied. A new synthetic method for the preparation of dialdehydes from dicarboxylic acids

Research on the Lectin in Muscle Tissue of Varicorhinus macrolepis

[Objective] The paper aimed at researching lectins in muscles of Varicorhinus macrolepis and providing scientific basis for researching the adaptation mechanism and immune response of V.macrolepis to environment,which were advantageous for the protection and reproduction of V.macrolepis.[Method] V.macrolepis was used as test materials for the hemagglutination test by dialdehyde fixation to prove the existence of lectins in muscle crude homogenate of Varicorhinus macrolepis and study the physical and chemical characters.[Result] Lectins in muscle crude homogenate of V.macrolepis had shown hemagglutination effects on erythrocytes of six types of animals and had the maximum hemagglutination activity against rabbit erythrocytes,which belonged to the S-type lectins with optimal pH ranged from 4 to 8 and optimal temperature at 60 ℃.Results from the saccharide inhibition test had indicated that the sucrose was the only kind of saccharide which had inhibited the hemagglutination,suggesting that sucrose had played an important role in the process of recognition and aggregation of lectins.[Conclusion] It had been speculated that the optimal pH ranges for thermal sensitivity and hemagglutination activity of lectins in different types of aquatic organisms were similar.

Acetalization of Poly(vinyl alcohol)/Soybean Protein Fibers

Acetalizatioin on the blend fibers of poly(vinyl alcohol) (PVA) and soybean protein (SP) was studied by using dialdehydes as cross-linking agents. The optimal acetalization conditions were determined by Latin square experiment, where the modified fibers with good mechanical properties can be achieved by treating in 41 g/L dialdehyde solution at 67 ℃ for 9 min. The cross-linking reactions of PVA and SP with dialdehydes were confirmed by Fourier transform infrared (FTIR) spectroscopy. Tensile test and boiling water shrinkage measurements showed that the physical properties of PVA/SP fibers crosslinked by dialdehydes were improved comparing with those formalized fibers.

Syntheses and Crystal Structures of 4,4′Diformyl-diphenoxyethane and 4,4′4′′-Triformyl-triphenoxytriethylamine

Two title compounds, 4,4?diformyl-diphenoxyethane (compound 1, C16H14O4) and 4,4?4创-triformyl-triphenoxytriethylamine (compound 2, C27H27NO6), were synthesized by condensation of 4-hydroxybenzaldehyde with 1,2-dichloroethane and tris(2-chloroethyl)amine, respectively in dimethyl formamide in the presence of anhydrous potassium carbonate. The crystal data are: monoclinic, P21/c, a = 7.571(2), b = 12.608(3), c = 7.357(2) ? b = 105.823(6)? V = 675.7(2) 3, Mr = 270.3, Z = 2, Dc = 1.328 g/cm3, F(000) = 284, m(MoKa) = 0.096 mm-1, R = 0.0537 and wR = 0.2189 for compound 1; and monoclinic, P21/n, a = 11.7162(6), b = 9.0042(6), c = 22.908(2) ? b = 99.505(1)? V = 2383.5(3) ?, Mr = 461.50, Z = 4, Dc = 1.286 g/cm3, F(000)= 976, m(MoKa) = 0.091 mm-1, R = 0.0464 and wR = 0.1462 for compound 2. The molecule of compound 1 (dialdehyde) is located at the crystallographic inversion center nearby the midpoint of C(8)C(8A) single bond. The three chains in the molecule of compound 2 (trialdehyde) are of non-crystallographic pseudo-C3 symmetry, and each of them is quite planar.

Bioprinting and in vitro characterization of alginate dialdehyde-gelatin hydrogel bio‑ink

Cell-laden cardiac patches have recently been emerging to renew cellular sources for myocardial infarction(MI,commonly know as a heart attack)repair.However,the fabrication of cell-laden patches with porous structure remains challenging due to the limitations of currently available hydrogels and existing processing techniques.The present study utilized a bioprinting technique to fabricate hydrogel patches and characterize them in terms of printability,mechanical and biological properties.Cell-laden hydrogel(or bio-ink)was formulated from alginate dialdehyde(ADA)and gelatin(GEL)to improve the printability,degradability as well as bioactivity.Five groups of hydrogel compositions were designed to investigate the influence of the oxidation degree of ADA and hydrogels concentration on the properties of printed scaffolds.ADA-GEL hydrogels have generally shown favorable for living cells(EA.hy926 cells and hybrid human umbilical vein endothelial cell line).The hydrogel with an oxidation degree of 10%and a concentration ratio of 70/30(or 10%ADA70-GEL30)demonstrated the best printability among the groups examined.Formulated hydrogels were also bioprinted with the living cells(EA.hy926),and the scaffolds printed were then subject to the cell culture for 7 days.Our results illustrate that the scaffolds bioprinted from 10%ADA70–GEL30 hydrogels had the best homogenous cell distribution and also the highest cell viability.Taken together,in the present study we synthesized a newly formulated bio-ink from ADA and GEL and for the fist time,used them to bioprint cardiac patches,which have the potential to be used in MI repair.

The Synthesis of Dialdehyde from Sodium Hydrogen Telluride with 1,1',3,3'-Tetramethyl-2,2'-bis-benzimidazolium Salt

The reaction of bis-benzimidazolium salts with sodium hydrogen telluride is reported, and a new synthetic method for dialdehydes is provided.

Kinetic of Adsorption of Urea Nitrogen onto Chitosan Coated Dialdehyde Cellulose under Catalysis of Immobilized Urease

The adsorption of urea nitrogen onto chitosan coated dialdehyde cellulose (CDAC) under catalysis of immobilized urease in gelatin membrane (IE) was studied in batch system. The pseudo first-order and second-order kinetic models were used to describe the kinetic data, and the rate constants were evaluated. The experimental data fitted well to the second-order kinetic model.

PREPARATION OF UREA NITROGEN ADSORBENT OF COMPLEX TYPE AND ADSORPTION CAPACITY OF UREA NITROGEN ONTO THE ADSORBENT

The urea nitrogen adsorbent of complex type, which consists of chitosan coated dialdehyde cellulose （CDAC） and immobilized urease in gelatin membrane （IE）, was prepared. The cellulose, the dialdehyde cellulose （DAC） and the CDAC were characterized by scanning electronic microscope. The results indicate that the cellulose C2-C3 bond was broken under the oxidation of periodate and it was oxidated to DAC. The DAC was coated with chitosan and the CDAC was obtained. The adsorption of urea nitrogen onto the adsorbent in Na2HPO4-NaH2PO4 buffer solution was studied in batch system. The effects of the experiment parameters, including degree of oxidation of CDAC, initial urea nitrogen concentration, pH and temperature, on the adsorption capacity of urea nitrogen onto the adsorbent at CDAC/IE weight ratio 10：1 were investigated. The results indicate that these parameters affected significantly the adsorption capacity. The adsorption capacity of urea nitrogen onto the adsorbent was 36.7 mg/g at the degree of oxidation of CDAC 88%, initial urea nitrogen concentration 600 mg/L, pH 7.4 and temperature 37℃.

PHYSIOLOGICAL FACTORS OF RESISTANCY AND SENSITIVITY OF ORGANISM TO MUTAGENS

Using micronuclear and DNA-reparative teststhere were made examinations of more than1000 healthy people having contacts with potential mutagens due to their occupation.In 2,5％ cases there were revealed

The Study of Influence of Silica and Polyethilene Glycols Organic-Inorganic Compounds on Free-Radical Processes in Vitro

In this study investigation of influence of hybrid nanosilica-polyethylene glycols materials (molecular weight 1500, 6000 and 15000), prepared by sol-gel synthesis, on lipid peroxidation and antioxidant activity of human serum in vitro was performed. Methods included chemiluminescence analysis and quantitative malonic dialdehyde estimation. It was revealed that nanosilica-PEG materials with different molecular weight had certain biological activity. Powders of SiO2-PEG 1500 and SiO2-PEG 6000 manifest prooxidant effects, whereas mesoporous (calcine) powders produced antioxidant effects in blood serum in vitro.

Theoretical and Experimental Study of the Mechanism of Reaction Formation of Cyanine Dyes

To study the theoretical bases of the mechanism of reaction formation of cyanine dyes, special importance is gained by methods of quantum chemistry. The use of these methods is provided with the known molecular and dynamic HyperChem program. The purpose of studying was quantum and chemical studying of features of a geometrical and electronic structure of model molecules of penicillin acid, of derivative of glutaconic dialdehyde (DGD), and the cyanine dyes, and also an assessment of power of process of their formation. For studying was carried out the experimental mark of chemism of course of reaction with theoretical justification of the mechanism of reaction formation of cyanine dyes. The results show that all studied model molecules are thermodynamic steady systems to what values of enthalpies of their formation, rather high on an absolute value, testify negative on a sign. Reaction goes by the mechanism of nucleophilic addition.

Antibacterial Activities of New Schiff Bases and Intermediate Silyl Compounds Synthesized from 5-Substituted-1,10-phenanthroline- 2,9-dialdehyde

Schiff bases are known to possess anticancer, antibacterial, antifungal, antitubercular, anti-inflammatory, antimicrobial and antimalarial properties. In this paper antibacterial studies against variety of plants and human pathogenic bacteria with eight newly synthesized Schiff bases and several intermediate silyl compounds have been reported. The antibacterial activities of the synthesized compounds were primarily determined by paper disc diffusion method. The minimum inhibitory concentration (MIC) of each compound was also determined by tube dilution process. Seven different human pathogenic bacteria and eighteen different plant pathogenic bacteria were used for the antibacterial activity studies. While all synthesized compounds have shown significant antibacterial activity, one intermediate silyl compound has shown remarkably high antibacterial property. 5-substituted derivatives have shown relatively higher activity than non-substituted compounds. Polar substituent which increases hydrophilicity may have a positive impact on the antibacterial property.

消炎三号方对进展期白癜风抗氧化作用的临床研究

目的:探究白癜风发病的氧化应激机制及中药方剂消炎三号方治疗进展期白癜风的抗氧化作用原理。方法:检测和比较稳定期白癜风患者、健康对照组、消炎三号方治疗进展期白癜风患者前后外周血中丙二醛(MalonicDialdehyde,MDA)、过氧化氢酶(Catalase,CAT)的水平。结果:外周血中,进展期白癜风患者较稳定期患者与健康对照组,其MDA水平明显偏高(P<0.05)、CAT水平明显偏低(P<0.05)。稳定期患者和健康对照组之间外周血MDA、CAT水平无差异性(P>0.05)。经消炎三号方治疗三个月后,进展期患者外周血MDA水平明显下降(P<0.05),CAT水平明显增高(P<0.05),与稳定期及健康对照组无差异性(P>0.05)。结论:氧化应激在白癜风发病之初发挥重要作用,消炎三号方可保护黑素细胞抵抗氧化应激损伤。

Natural polymers-enhanced double-network hydrogel as wearable flexible sensor with high mechanical strength and strain sensitivity

Conductive hydrogels have shown great prospects as wearable flexible sensors.Nevertheless,it is still a challenge to construct hydrogel-based sensor with great mechanical strength and high strain sensitivity.Herein,an ion-conducting hydrogel was fabricated by introducing gelatin-dialdehydeβ-cyclodextrin(Gel-DACD)into polyvinyl alcohol-borax(PVA-borax)hydrogel network.Natural Gel-DACD network acted as mechanical deformation force through non-covalent cross-linking to endow the polyvinyl alcoholborax/gelatin-dialdehydeβ-cyclodextrin hydrogel(PGBCDH)with excellent mechanical stress(1.35 MPa),stretchability(400%),toughness(1.84 MJ/m3)and great fatigue resistance(200%strain for 100 cycles).Surprisingly,PGBCDH displayed good conductivity of 0.31 S/m after adding DACD to hydrogel network.As sensor,it showed rapid response(168 ms),high strain sensitivity(gage factor(GF)=8.57 in the strain range of 200%-250%)and reliable sensing stability(100%strain for 200 cycles).Importantly,PGBCDHbased sensor can accurately monitor complex body movements(knee,elbow,wrist and finger joints)and large-scale subtle movements(speech,swallow,breath and facial expressions).Thus,PGBCDH shows great potential for human monitoring with high precision.

Self-crosslinkable chitosan-hyaluronic acid dialdehyde nanoparticles for CD44-targeted siRNA delivery to treat bladder cancer

Bladder cancer is one of the concerning malignancies worldwide,which is lacking effective targeted therapy.Gene therapy is a potential approach for bladder cancer treatment.While,a safe and effective targeted gene delivery system is urgently needed for prompting the bladder cancer treatment in vivo.In this study,we confirmed that the bladder cancer had CD44 overexpression and small interfering RNAs(siRNA)with high interfere to Bcl2 oncogene were designed and screened.Then hyaluronic acid dialdehyde(HAD)was prepared in an ethanol-water mixture and covalently conjugated to the chitosan nanoparticles(CS-HAD NPs)to achieve CD44 targeted siRNA delivery.The in vitro and in vivo evaluations indicated that the siRNA-loaded CS-HAD NPs(siRNA@CS-HAD NPs)were approximately 100 nm in size,with improved stability,high siRNA encapsulation efficiency and low cytotoxicity.CS-HAD NPs could target to CD44 receptor and deliver the therapeutic siRNA into T24 bladder cancer cells through a ligand-receptor-mediated targeting mechanism and had a specific accumulation capacity in vivo to interfere the targeted oncogene Bcl2 in bladder cancer.Overall,a CD44 targeted gene delivery system based on natural macromolecules was developed for effective bladder cancer treatment,which could be more conducive to clinical application due to its simple preparation and high biological safety.

Investigations on the general properties of biomass-based aldehyde tanned sheep fur for its selective post-tanning processing

Dialdehyde sodium alginate(DSA)is an alternative chrome-free tanning material for fur production.To obtain satisfactory resultant fur and provide suggestions for the usage of DSA in fur making,the general properties of DSA tanned sheep fur were systematically investigated.The tanning mechanism of DSA was analyzed and it was verified that DSA was mainly combined with collagen fiber by forming Schiff base covalent bonds while supplemented by a small number of hydrogen bonds and ionic bonds.Due to the acid sensitivity of Schiff base structure,DSA tanned fur had poor resistance to acid rinsing but had excellent resistance to washing and good fatliquoring performance.Also,it had good resistances to yellowing and reductant.After being retanned by chrome tanning agent,the fur was capable of enduring a high-temperature dyeing process(68°C for 8 h).Overall,DSA tanned sheep fur had favorable properties under appropriate post-tanning processing conditions to manufacture light-colored or dark-colored fur products with desirable physical properties.

Dialdehyde in Heterocyclic Synthesis: Synthesis of Compounds Containing Two 4H-Benzopyran Building Blocks under Microwave Irradiation

The syntheses of 4H-benzopyran derivatives were investigated using dialdehyde as a key starting material. The reaction proceeds under microwave irradiation in good yield (87%—95%) with short reaction time (5—8 min), therefore providing a rapid and efficient method of synthesizing a variety of compounds containing two 4H-benzopyran units.

A NEW SYNTHETIC METHOD FOR α, β-UNSATURATED ALDEHYDES——A NEW APPLICATION OF NEF REACTION

One of the fundamental reactions in synthetic organic chemistry, Nef reaction, is the synthesis of saturated aldehydes from correspondingnitrocompounds by way of salt formation andacid hydrolysis. In this letter, the synthesis of a, β-unsaturated aldehydes from