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Objective To explore the effects of Scutellaria baicalensis on activity and biofilm formation of Klebsiella pneumonia (Kp).Methods The broth and agar dilution Methods were carried out to determine minimum inhibitory concentration and minimum bactericidal concentration of Scutellaria baicalensis for TW518. VITEK-32 system was used to assay TW518 susceptibility to antibiotics. Kp biofilms were formed in vitro and stained with BacLight Live/Dead stain. The class integron geneⅠ1 mRNA expression was analyzed with RT-PCR.Results The minimum inhibitory concentration of Scutellaria baicalensis on TW518 identified as a Kp colony was 32 mg/ml, and minimum bactericidal concentration was 64 mg/ml. Scutellaria baicalensis and broad-spectrum penicillin, cephalosporin, quinolones, or beta-lactamase had synergistic bactericidal effects. Biofilm formation activity of Kp treated with Scutellaria baicalensis was significantly lower than that of the control group. And class integron geneⅠ1 mRNA expression of TW518 was significantly inhibited by Scutellaria baicalensis.Conclusions Scutellaria baicalensis has sterilization effect on Kp, and Scutellaria baicalensis could effectively inhibit Kp biofilm formation with prolonged treatment. Scutellaria baicalensis might inhibit Kp biofilm formation through down-regulating integron geneⅠ1 expression.

The brain is one of the most vulnerable organs inside the human body. Head accidents often appear in daily life and are easy to cause different level of brain damage inside the skull. Once the brain suffered intense locomotive impact, external injuries, falls, or other accidents, it will result in different degrees of concussion. This study employs finite element analysis to compare the dynamic characteristics between the geometric models of an assumed simple brain tissue and a brain tissue with complex cerebral sulci. It is aimed to understand the free vibration of the internal brain tissue and then to protect the brain from injury caused by external influences. Reverse engineering method is used for a Classic 5-Part Brain (C18) model produced by 3B Scientific Corporation. 3D optical scanner is employed to scan the human brain structure model with complex cerebral sulci and imported into 3D graphics software to construct a solid brain model to simulate the real complex brain tissue. Obtaining the normal mode analysis by inputting the material properties of the true human brain into finite element analysis software, and then to compare the simplified and the complex of brain models.

Morin [2-(2,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopyran-4-one], a member of flavonols, is an important bioactive compound by interacting with nucleic acids, enzymes and protein. Its binding to human serum albumin was investigated by fluorescence quenching, fluorescence anisotropy, and UV–vis absorbance under the simulative physiological condition. Fluorescence quenching data show that the interaction of morin with HSA forms a non-fluorescent complex with the binding constants of 1.394 × 10 5 , 1.489 × 10 5 , 1.609 × 10 5 and 1.717 × 10 5 M −1 at 292, 298, 303 and 310 K, respectively. The thermodynamics parameters, enthalpy change (Δ H ) and entropy change (Δ S ) were calculated to be 8.97 kJ mol −1 and 129.15 J mol −1 K −1 via van’t Hoff equation. From the spectroscopic results and thermodynamics parameters, it is observed that van der Waals and hydrogen bonds are predominant intermolecular forces when forming the complex. The distance r = 4.25 nm between donor (Trp214) and accepter (morin) was estimated based on the Forster theory of non-radiative energy transfer. The red shift of UV–vis absorbance shows that morin is bound to several amino acids on the hydrophobic pocket of HSA. Moreover, the competitive probes, such as warfarin and ibuprofen (site I and II probes, respectively), reveal that the binding location of morin to HSA in the site I of the hydrophobic pocket, which corresponds to the results of UV–vis absorbance, while morin also binds other lower affinity binding sites on HSA from the fluorescence anisotropy spectroscopy.

The binding reaction between Vitamin B12 (B12, cyanocobalamin) and human serum albumin (HSA) was investigated by fluorescence quenching, UV-vis absorption and circular dichroism (CD) spectroscopy. Under simulative physiological conditions, fluorescence quenching data revealed that the quenching constants (Ksv) are 3.99 x 10(4), 4.33 x 10(4), 4.76 x 10(4) and 5.16 x 10(4) M(-1) at 292, 298, 304 and 310 K, respectively. The number of binding sites, n is almost constant around 1.0. On the basis of the results of fluorescence quenching the mechanism of the interaction of B12 with HSA has been found to be a dynamic quenching procedure. Thermodynamic parameters DeltaHTheta= -13.38 kJ mol(-1), DeltaSTheta=66.73 J mol(-1) K(-1) were calculated based on the binding constant. These suggested that the binding reaction was enthalpy and entropy driven, and the electrostatic interaction played major role in stabilizing the reversible complex. The binding distance r=5.5 nm between HSA and B12 was obtained according to Forster theory of energy transfer. The effect of B12 on the conformation of HSA was analyzed by synchronous fluorescence and CD spectroscopy. Synchronous spectra indicated that the polarity around the tryptophan (Trp214) residues of HSA was decreased and its hydrophobicity was increased; however, the alpha-helix content of the protein was predominant in the secondary structure but the CD spectra indicated that B12 induced minor conformational changes of HSA.