Protein synthesis inhibition in the basolateral nucleus of amygdala facilitates extinction of auditory fear memory

It is known that consolidation of fear conditioning requires de novo protein synthesis in the amygdala. However, there is controversy about the role of protein synthesis in post-retrieval extinction of fear memory. The present study investigated the effect of protein synthesis inhibition (PSI) in the baso- lateral nucleus of amygdala (BLA) on post-retrieval extinction of auditory fear memory. Intra-BLA infu- sion of the protein synthesis inhibitor anisomycin ‘0’ h post-retrieval facilitated the extinction, but was ineffective if the memory was not retrieved. Anisomycin had no effect on the extinction when it was infused 6 h post-retrieval. The present results suggest that there exists a protein-synthesis-dependent mechanism in the BLA that retards extinction of auditory fear memory.     

β2-Adrenoceptor affinity chromatography and its application in the screening of the active compounds from Semen Armeniacae Amarum

β2-Adrenoceptor （β2-AR） was purified from the rabbit lung tissue by sepherose-salbutamol affinity chromatographic column. To prepare the β2-AR stationery phase, β2-AR was evenly immobilized on the surface of macro-pore silica with e mild chemical coupling method through covalent bond. The retention properties of β2-AR stationery phase were characterized by four ligends, selbutamol sulfate, noredreneline bitartrete, adrenaline hydrochloride end proprenolol hydrochloride, to establish the β2-AR affinity chromatography. Then, the method was used to screen the active compounds from the total extracts of Semen Armeniacae Amarum. The results showed that β2-AR on the surface of the stationary phase could keep its original bioectivity end selectivity. Amygdalin retained in the chromatographic column was proved to be the active compound of the total extracts of Semen Armeniacae Amarum. Compared with the existing chromatographic screening approaches, this method showed e good stability end high selectivity. The active compounds which could interact with β2-AR in traditional Chinese medicine （TCM） could be screened efficiently by this method, providing e new way to screen the active compounds in complicated samples such as TCM.     

β_2-Adrenoceptor affinity chromatography and its application in the screening of the active compounds from Semen Armeniacae Amarum

β2-Adrenoceptor (β2-AR) was purified from the rabbit lung tissue by sepharose-salbutamol affinity chromatographic column. To prepare the β2-AR stationary phase, β2-AR was evenly immobilized on the surface of macro-pore silica with a mild chemical coupling method through covalent bond. The reten- tion properties of β2-AR stationary phase were characterized by four ligands, salbutamol sulfate, noradrenaline bitartrate, adrenaline hydrochloride and propranolol hydrochloride, to establish the β2-AR affinity chromatography. Then, the method was used to screen the active compounds from the total extracts of Semen Armeniacae Amarum. The results showed that β2-AR on the surface of the sta- tionary phase could keep its original bioactivity and selectivity. Amygdalin retained in the chroma- tographic column was proved to be the active compound of the total extracts of Semen Armeniacae Amarum. Compared with the existing chromatographic screening approaches, this method showed a good stability and high selectivity. The active compounds which could interact with β2-AR in traditional Chinese medicine (TCM) could be screened efficiently by this method, providing a new way to screen the active compounds in complicated samples such as TCM.     

Earthworm-like micro robot based on electromagnetic driver

According to the principle of bionics, a prototype of the earthworm-like micro robot was developed and manufactured for entering the small tube. Based on the process of the action and mechanics analysis, the controller was designed. This micro robot with 6mm diameter was driven directly by three electromagnetic linear drivers. Mobile cells were joined with two degree-of-freedom joint and the whole body was flexible and soft. The driving force reached 10.8g in normal working condition. The direction of movement and the angle of imaging can be controlled by the shape memory alloy （SMA）. The driving force, velocity and movement of micro robot in flexural tube were tested through experiments, which indicated that the driving force was in proportion to the range of frequency, and the micro robot could current, and the velocity reached a maximum in certain move in the thin tube flexibly.     

Development of the model of pancreatic β-cell membrane chromatography and its chromatographic characteristics

A new model of pancreatic β-cell membrane chromatography has been established by using a β-cell membrane stationary phase （β-CMSP） prepared by immobilizing the β-cell membrane onto the surface of silica carrier. The protein level and K^＋, Na^＋-ATP enzymatic activity of the β-CMSP were detected respectively. The surface characteristics of the β-CMSP were tested by using the scanning electron microscope and surface energy spectrometer. In this model, the column （10 mm × 2 mm, I.D.） packed with β-CMSP, 25 mmol/ammonium sulfate buffer solution （pH 7.4） as mobile phase with the flow rate of 0.2 mL/min at 37 ± 0.5℃ were used in the following studies. The retention characteristics of the sulfonylureas （gliquidone, glibenclamide, gliclazide and glipizide） were investigated under the chromatographic conditions above. The affinities of the sulfonylureas on β-cell membrane and receptor will be expressed by using the logk＇ values （the logarithm of capacity factor of a solute） in the model. The correlation of the affinity with the pharmacological effect of the sulfonylureas was analyzed also.     

Effect of ytterbium on sodium current and its kinetics in rat hippocampal neurons

This study addressed the effects of Yb3＋ on voltage-gated sodium currents in rat hippocampal neurons using the whole-cell patch-clamp technique. Voltage-clamp recordings in single neurons were filtered and stored in a computer. Yb3＋ increased the amplitude of sodium currents in a concentration-dependent and voltage-dependent man- ner. The 50 % enhancement concentration of Yb3＋ on sodium currents was about 8.97 μmol/L, which was dif- ferent from the inhibitory effects of Yb3＋ on potassium current. The analysis on the activation and inactivation kinetics of Na＋ current showed that 100 μmol/L Yb3＋ did not change the process of activation and inactivation. In addition, the times reaching the peak of current （t） and inactivated time constant （τ） were voltage dependent. 100 μmol/L Yb3＋ significantly prolonged the time to peak at -70 and -80 mV. The effect disappeared at the positive direction of -70 mV. Furthermore, Yb3＋ decreased r val- ues to more positive values than -80 mV. In total, Yb3＋ did not change the process of activation, but impelled inacti- vated process. Yb3＋ mainly increased the Na＋ current through changing its conductance. It might be one of the mechanisms that Yb3＋ affected the hippocampal neurons.     

Can the memory of an object be enhanced by imagining its loss?

Previous investigations examining salient memories have demonstrated that personal memories that are important to individuals and contain emotional information are better remembered than neutral events.Using behavioral and brain-imaging experiments,the present studies explored whether the previous finding was applicable imagined loss.In a behavioral experiment,a free recall paradigm was used to compare the memory performance of individuals who imagined loss with that of individuals who imagined importance.The superior memory performance conferred by imagining loss was constrained to ordinary items of low to medium importance and did not generalize to vital items.Moreover,brain imaging evidence revealed that the activation in certain brain regions was stronger when participants were imagining the loss of ordinary items of low to medium importance compared to vital items.These brain regions included cognitive effort-related areas(such as the parietal cortex and middle prefrontal cortex) and areas related to emotional experiences and emotion-related memories(such as the amygdala,parahippocampal gyrus,and posterior cingulate gyrus).Our study provides a new way of exploring the superior memory performance when imagining loss and enriches the literature on memory enhancement by contributing to a deeper understanding of the psychological mechanisms related to the imagining of vital losses.     

Fabrication of Dex-Loaded Shape Memory Polymer Based Composite Nanofibers ：for Potential Bone Tissue Engineering

Biodegradable shape memory polymers （SMPs） are a class of intelligent materials with great potential for imparting biomaterial scaffolds multifunetionality in the field of tissue engineering and regenerative medicine. In this study, the biodegradable SMP poly（ D, L-lactide-co-trimethylene carbonate） （PLMC） incorporated with the ,dexamethasone （Dex）, which was a kind of synthetic bone-formation inducing factor, was fabricated into nanofibers via dectrospinning. The morphology, constituent, thermal and mechanical properties of the produced Dex/PLMC composite nanofibers were characterized by scanning electron microscopy （SEM）, Fourier transform ：infrared spectroscopy （ FTIR ）, differential scanning calorimetry （DSC）, and tensile testing, respectively. Then, ultrasound was ,employed as a remote stimulus to regulate the Dex releasing behavior from the composite nanofibers. It was found that the generated Dex/ PLMC composite nanofibers had a uniform and smooth morphology with a diameter of ca. 564 nm. Mechanical testing results showed that incorporation of the Dex gave rise to improved mechanical performance with the tensile strength, Young＇ s modulus and strain- at-break increased by 18.2 %, 20. 0 % and 64.4 %, respectively. DSC data revealed that the glass transition temperature （ Tg ） of the composite nanofibers, i. e., the thermal transition temperature （Ttrans） for activating shape memory effect, was 39. 7 ℃. Moreover, the release kinetics of the encapsulated Dex in the aanofibers could be manipulated by varying the acoustic power and insonation duration. These results suggested that the newly developed Dex/PLMC nanofibers could be a promising drug delivery system for applications in bone tissue engineering （BTE）.     

Distribution and partition of polybrominated diphenyl ethers （PBDEs） in water of the Zhujiang River Estuary

The spatial, temporal, and vertical distributions of polybrominated diphenyl ethers （PBDEs） in water columns from the Zhujiang River Estuary were examined, and the partition behavior of PBDEs between particle and dissolved phases was investigated in the present study. The results show that the distributions of PBDEs concentrations in the water varied with the sampling seasons. The PBDEs concentrations in water samples were lower in May 2005, when the brackish water was dominant in the estuary, than in October 2005, when fresh water from river runoff dominated the estuary. The spatial distribution of PBDEs in October 2005 indicated that the river runoff was the major mode to input PBDEs to the estuary, and the concentration of PBDEs in water might be dissolved organic carbon （DOC） dependence. The spatial and vertical distributions of PBDEs in May 2005 were relatively homogeneous, and SPM was the major factor on controlling the levels of PBDEs in this sampling time. Both DOC and POC could play certain roles in determining the distribution and partition of PBDEs between particle and dissolved phases, but their effects varied with the water properties.     

补肾益智方对老年性痴呆模型大鼠学习记忆功能的改善作用

Aim Study on the effect of BYR on the animal model of alzheimer's disease in rats. Methods The animal model of Alzheimer's disease was made by D-galactose intraperitoneal injection and basal forebrain bilateral lesion with ibotenic acid microinjection in rats. Learning and memory deficits of these rats were assessed in the Morris water maze and treated with BYF. Results The escape latency of BYF group was significantly shorter than that of Hup-A group and the model control group. The swimming time in the quadrant contain platforrn was much longer than that of 　　Hup-A group and model control group. Conclusion BYF has great effect on the learning and memory deficits of this animal model of Alzheimer′s disease in rats.     

Extraction and Purification of Matrix Protein from the Nacre of Pearl Oyster Pinctada fucata

A soluble matrix protein P14 with an apparent molecular mass of 14.5 kDa was isolated from fragmented nacre of pearl oysters （Pinctada fucata） treated with 10% NaOH solution to investigate the nacre matrix proteins and their effect on the CaCO3 crystal. The protein was characterized by gel exclusion chromatography and reversed-phase high performance liquid chromatography after demineralization by 10% acetic acid. The X-ray diffraction pattern of P14 crystals indicates that P14 plays an important role in nacre biomineralization. P14 can induce aragonite formation, stimulate CaCO3 crystal formation, and accelerate aragonite precipitation. Heating of the acid insoluble nacre residue, which was named conchiolin, in 10% sodium dodecyl sulfate solution supplemented with 10% β-mercaptoethanol solution for 10-20 min at about 100℃ gave two other soluble proteins having molecular masses of 19.4 kDa and 25.0 kDa. The present study suggests that these two proteins are linked to the insoluble organic matrix by disulfide bridges because the extraction yield increases when β-mercaptoethanol is added to the medium.     

A study on poly (N-vinyl-2-pyrrolidone) covalently bonded NiTi surface for inhibiting protein adsorption

Near equiatomic NiTi alloys have been extensively applied as biomaterials owing to its unique shape memory effect, superelasticity and biocompatibility. It has been demonstrated that surfaces capable of preventing plasma protein adsorption could reduce the reactivity of biomaterials with human blood. This motivated a lot of researches on the surface modification of NiTi alloy. In the present work, following heat and alkaline treatment and silanization by trichlorovinylsilane (TCVS), coating of poly (N-vinyl-2-pyrrolidone) (PVP) was produced on the NiTi alloy by gamma ray induced chemical bonding. The structures and properties of modified NiTi were characterized and in vitro biocompatibility of plasma protein adsorption was investigated. The results indicated that heat treatment at 823 K for 1 h could result in the formation of a protective TiO2 layer with “Ni-free” zone on NiTi surface. It was found that PVP was covalently bonded on NiTi surface to create a hydrophilic layer for inhibiting protein adsorption on the surface. The present work offers a green approach to introduce a bioorganic surface on metal and other polymeric or inorganic substrates by gamma irradiation.     

Characterization of an endo-1,4-β-glucanase from Lilium longiflorum that functioned in pollen germination and pollen tube growth

Endo-β-glucanases play vital roles in the regulation of pollen tube growth. Here, a previously identified endo-l,4-β-glucanase from Lilium Iongiflorum （lily）, named LlpCell, was expressed in Escherichia coli, purified, and further investigated for its physiological function. The recombinant LlpCell protein hydrolyzed carboxy-methylcellulose （CMC） and exhibited activity towards laminarin from Eisenia. arborea and 1,3：l,4-β-glucan of barley. The pH for the optimum activity was 6.0 and the value of Km calculated from CMC was 5.0 mg/mL. Adding EDTA resulted in the total loss of the enzymatic activity, and this effect could be restored by the addition of Ca^2＋. Western blotting analysis showed that LlpCell protein was present in pollen grains and rehydrated pollen grains, and the amount of the protein was increased during pollen germinating, but not in the pollen tube. Consistently, the immunofluorescence labeling study with the antibody against LIpCell also indicated the presence of LIpCell at the begin-ning of germination, but not in the elongating pollen tube. Furthermore, incubation of LlpCell with pollen at the beginning of pollen germination increased the germination percentage and the length of pollen tube. All of these results suggested that LlpCell could play an important role in the regulation of lily pollen germination and the initiation of pollen tube growth.     

The effect of α-helix comformation on interaction between model oligopeptides and polymers

The study of interactions between peptides and synthetic polymers has aroused considerable interest recently. In the present paper, the interaction mechanism between adsorbent DMAPAM and two peptides, VVRGCTWW（V8） and CTWW（C4）, was investigated at molecular level by NMR and molecular stimulation. The results demonstrated that the conformation of oligopeptides played a vital role in their adsorption capacity on the adsorbent. Weak interactions could incorporate with each other between V8 and DMAPAM because there was a hydrophobic cleavage in o-helix conformation of V8. So the ad- sorption capacity of DMAPAM to V8 was higher. This was significant to explore the interaction mechanism between peptides and biomaterials.     

Structures of Silk Fibers Grafted with Hexafluorobutyl Methacrylate

The relationship between the graft yield and the effect of hexafiuorobutyl methacrylate graft treatment on the structural changes of the silk fibers was studied on the basis of the results of scanning electron micrograph photographs （SEM）, infrared spectroscopy （IR）, Raman spectrum, wide-angle X-ray diffraction patterns （WAXD）, nuclear magnetic resonance（NMR） and amion acid analysis. The results showed that the crystalline regions of grafted fibers were hardly affected and the fiber fission occurred on the cross sections of grafted fibers. The surface of fibers was covered with a high polymer film. The Raman spectrum showed there was little change in the conformation of grafted fibers which mainly remained β-sheet conformation. The IR of the grafted silk fibers showed new absorption of bands occurred which belonged to the stretching-vibrationabsorption-peak bands of Vo-o and VC-F of aliphatic ester species. The CF3-, -CF2- and -CFH- grafted silk macromodecul were verified in the NMR spectrum. The amion acid analysis indicated fluoride monomers were inclined to graft with TYR, ARG and CLU silk fibers.     

Effect of La^3＋ on myocardiac potassium channels revealed by patch-clamp technique

The effect of La^3 on potassium channels in rat ventricular myocytes was investigated using the whole-cell patch-clamp recording mode. The Ca^2 -independent voltage-activated outward K~ current was activated by the depolar-izing pulse in enzymatically isolated rat ventricular myocytes. After addition of different concentrations La^3 to the bath solution, the outward K^ current was depressed gradually. The inhibition effect was in a concentration-dependent manner. The phenomena of the outward K^ current, being themain repolarizing current suppressed by La^3 , suggest that the effect of lanthanides on myocardial function should be exploited further.     

X-Ray Diffraction Characterization of the Microstructure in Close-Packed Hexagonal Nano Material

1 Results On the basis of previous work,the general theory,least square methods and computing programs have been proposed and developed,which can separate the two-fold broadening effect caused by crystallite-micro strain,crystallite-stacking faults,strain-faults and which can also separate the three fold broadening effect caused by crystallite-strain-faults in closed-parked hexagonal (CPH) nano-materials.The method is applied to characterize and investigate the microstructure in β-Ni(OH)2 as negative material for nickel/metal (Ni /MH) batteries.The results indicate that in the raw β-Ni(OH)2 there are only two-fold broadening effect of crystallite-faults,however after activation and cycle test three fold broadening effect of crystallite-strain-faults is available.     

Comparative study of microstructural remodification to porous β-TCP and HA in rabbits

To assess the remolding ability of repaired bone in hydroxyapatite （HA） and β-calcium phosphate （β-TCP） scaffold, two 75% porosity bioceramics with the same three-dimensional geometry were implanted into femoral condyles of rabbits. Histological and micro-computed tomography （micro-CT） results demonstrated abundant new bone formation in the porous HA scaffold along with indistinctive scaffold degradation. Results also indicated that scaffold resorption in the β-TCP group, which was followed by a replacement with newly formed bone, was significantly higher than that in the HA group. The crosslinking trabeculae remodeled from the mixtures of the newly formed bone and β-TCP scaffold remnants might be helpful to promoting even loading and reducing stress. The bone remodeling pattern resulted from bone formation and scaffold resorption was significantly different for the two bioceramics. The results demonstrated that the 75% porous β-TCP was more suitable for new bone remodification than HA scaffold.