应用气-质联用仪测定三种螺旋藻中的甾醇成分

应用GLC/MS联用仪对室内培养的钝顶螺旋藻(Spirulina platensis (Nordstedt) Geitler)、极大螺旋藻(S.maxima (Stechell & Gardiner) Geitler)和盐泽螺旋藻(S.subsalsa Oerst)的甾醇成分进行了测定。从钝顶螺旋藻和盐泽螺旋藻中共分出11个相同的甾醇组分:胆甾醇、胆甾烷醇、芸苔甾醇、麦角甾醇、海绵甾醇、菜子甾醇、豆甾醇、24-乙基-Δ~(5,7,22)-胆甾醇、β-谷甾醇、异岩藻甾醇和4α,23,24-三甲基Δ~(5,22)-胆甾醇;从极大螺旋藻中只分离出8个甾醇组分。其中胆甾醇含量最高。4α,23,24-三甲基-Δ~(5,22)-胆甾醇为蓝藻中首次报导。     

Characterisation and Regional Localisation of Pre- and Postsynaptic Glycoproteins of the Chick Forebrain Showing Changed Fucose Incorporation Following Passive Avoidance Training

To identify those glycoproteins whose synthesis or modification is necessary for memory formation, we have studied the uptake of radiolabelled fucose into synaptic plasma membranes (SPMs) and postsynaptic densities (PSDs) derived from two specific left and right forebrain loci, at two different times after training of 1-day-old chicks on a one-trial passive avoidance learning task. To increase the reliability of the comparison, a double-labelling method was used. Tissue samples from intermediate medial hyperstriatum ventrale (IMHV) and lobus parolfactorius (LPO) were isolated at 6 and 24 h after training. At both times, training resulted in region-specific changes, both increases and decreases, in incorporated radioactivity into pre- and postsynaptic glycoproteins. After 6 h, there was a relative decline in incorporation into both SPMs and PSDs of the right IMHV of trained chicks, a decline that persisted in the PSDs until 24 h. A small decline in incorporation in SPMs from the right LPO of trained chicks at 6 h was reversed by 24 h, by which time there was a 64% increase in incorporation into SPMs and a 24% increase into PSDs of the left LPO. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis of left and right hemisphere samples containing LPO revealed that 6 h after training the main effect was presynaptic, including a reduction of incorporation into high molecular mass glycoproteins, of 150-180 kDa, and an increase in a lower molecular mass (41 kDa) fraction. By 24 h after training, a left hemisphere presynaptic glycoprotein of molecular mass approximately 50 kDa showed the biggest increase in fucosylation. In addition, a wide group of postsynaptic glycoproteins of both hemispheres, in the ranges 150-180, 100-120, and 33 kDa now showed increases in incorporation. Some other fractions showed decreases. These results are in accord with previous data on incorporation obtained using the amnesic agent 2-deoxygalactose. They also support the hypothesis that memory formation involves the strengthening of connections between pre- and postsynaptic neurons of the LPO by growth or modulation of pre- and postsynaptic structures.     

Molecular nature of β-Galactosidase from different tissues in two strains of the house mouse

One inbred mouse strain, C57BL/Kl, has high galactosidase activities in all tissues while another strain, DBA/2/Kl, has low activities determined by the Bgs locus. Beta-Galactosidase from these two strains was partly purified by a five-step procedure: acidification, ammonium sulfate precipitation, gel filtration at two pHs, and isoelectric focusing. No qualitative differences were found between the enzyme preparations from the two strains. They had identical heat inactivation curves, pH optima, molecular weight, and isoelectric points, and the Km values were very similar. It thus seems that this genetic difference in enzyme activity probably cannot be explained by a variation of the galactosidase-specific activity but rather reflects a difference in number of enzyme molecules. Eight different isoenzymes were separated from liver, kidney, and spleen. Each isoenzyme has a different electrophoretic mobility and there is a stepwise increase in molecular weight from 143,000 to 380,000 beginning with the protein having the lowest isoelectric point. A likely interpretation is that the isoenzymes bind a smaller polypeptide in varying numbers in addition to the enzymatic polypeptide per se.     

A novel ABCB11 mutation in an Iranian girl with progressive familial intrahepatic cholestasis

Progressive familial intrahepatic cholestasis is an autosomal recessive liver disorder caused by (biallelic) mutations in the ATP8B1 of ABCB11 gene. A nine-year-old girl with cholestasis was referred for genetic counseling. She had a family history of cholestasis in two previous expired siblings. Genetic analysis of the ABCB11 gene led to the identification of a novel homozygous mutation in exon 25. The mutation 3593- A > G lead to a missense mutation at the amino acid level (His1198Arg). This mutation caused PFIC2 due to abnormal function in the bile salt export pump protein (BSEP).     

Identification of an Immunoglobulin M (IgM) Antibody Against Enolase 1 Protein (ENO1) Derived from HEK-293 Cells in Patients with Kidney Failure

Kidney failure is one of the most important challenges in medicine. In this study, we used HEK-293 kidney cells to evaluate and compare changes in the expr     

Pierce into the Native Structure of Ata,a Trimeric Autotransporter of Acinetobacter baumannii ATCC 17978

International Journal of Peptide Research and Therapeutics - Acinetobacter baumannii is an important pathogen responsible for nosocomial infections worldwide. Trimeric autotransporters, the...     

Efficiency Enhancement of Ultra-thin CIGS Solar Cells Using Bandgap Grading and Embedding Au Plasmonic Nanoparticles

The objective of this study is to enhance the efficiency of copper indium gallium selenide (CIGS) solar cells. To accomplish that, composition grading of absorber layer was carried out by using SILVACO’s technology aided computer design (TCAD) ATLAS program. Results showed a meaningful improvement of output parameters including open-circuit voltage (V_oc), short-circuit current (I_sc), fill factor (FF), and power conversion efficiency (η). For further performance improvement of the cell, Au plasmonic scattering nanoparticles were loaded on the top of the ZnO window layer. Plasmonic nanoparticles can restrict, absorb, navigate, or scatter the incident light. By using the spherical Au nanoparticles, a very good increase in the light absorption in the cell over the reference planar CIGS solar cell was observed. The highest η = 19.01% was achieved for the designed ultra-thin bandgap-graded CIGS solar cell decorated by Au nanoparticles.