A high efficiency and low vibration liquid nitrogen cooling system for silicon crystal based x-ray optics.

A compact low-cost cryocooling system has been designed, constructed, and tested at SLAC National Accelerator Laboratory. The cooling power is provided by natural convection and phase change of the liquid nitrogen. The initial application was to cool silicon crystal optics to the sub-100 K range. A silicon crystal of dimension (width × depth × height) 50 × 50 × 30 mm3 has been used with an electric heater on the top surface in this prototyping test. This system can effectively provide more than 80 W of cooling power to the optics with a consumption of liquid nitrogen less than 2.1 l/h. The vibration of the silicon crystal was monitored during the tests with added electric heater power on the crystal. The vibration of the silicon crystal due to liquid nitrogen boiling is negligible.

Correlation between serum melatonin and aMT6S level for age-related macular degeneration patients.

OBJECTIVE: To analyze the levels of serum melatonin (MLT) and assay of 6-sulfatoxymelatonin (aMT6S) of age-related macular degeneration (AMD) patients and study their correlation with AMD risk factors. PATIENTS AND METHODS: 58 AMD cases were selected and 58 healthy cases of the same time period were selected according to 1:1 closest matching method. ELISA method was used to test serum MLT and aMT6S level. RESULTS: Levels of MLT and aMT6S in AMD group were lower than those in the control group, and differences were statistically significant (p < 0.05). Based on analysis of AMD subgroup, differences on gender had no statistical significance compared with AMD type. For cases with smoking, cardiovascular disease and corrected visual acuity lower than 0.1, MLT and aMT6S levels were reduced at 0.05). Through the regression analysis, we concluded that smoking history, cardiovascular disease history, best corrected visual acuity, MLT and aMT6S level were independent risk factors, among which MLT [OR = 3.624 (odds ratio: OR)] and aMT6S (OR = 3.201). CONCLUSIONS: MLT and aMT6S may be related to the incidence of AMD.

Effect of prenatal exposure to LPS combined with pre- and post-natal high-fat diet on hippocampus in rat offspring.

OBJECTIVE: Prenatal exposure to lipopolysaccharide (LPS) or high-fat diet (HFD) results in hippocampal impairment and cognitive deficits in offspring rats. What is not clear is how prenatal exposure to LPS combined with pre- and post-natal HFD would affect the hippocampus in offspring rats. METHODS: 32 pregnant rats were randomly divided into four groups, including control group; LPS group (pregnant rats were injected with LPS 0.4 mg/kg intraperitoneally on the 8th, 10th and 12th day of pregnancy); HFD group (maternal rats had HFD during pregnancy and the lactation period, and their pups also had HFD up to the third month of life); LPS+HFD group (rats were exposed to the identical experimental scheme with LPS group and HFD group). The serum IL-6 and TNF-alpha concentration was measured in three-month-old offspring rats in all groups. Hippocampal morphology and expressions of glial fibrillary acidic protein (GFAP), Tau and synaptophysin (SYP) in offspring rats were measured. RESULTS: Serum IL-6 and TNF-alpha concentration in the HFD group increased significantly compared with the control group, LPS group and LPS+HFD group. Compared with the control group and the LPS+HFD group, cells in the LPS and HFD groups were smaller and arranged in disorder, and cell membrane was not complete, nucleoli and nuclear heterochromatin stained darkly with hematoxylin. GFAP and Tau expression in the hippocampus of the LPS and HFD groups increased significantly compared with the control group and LPS+HFD group. SYP expression in the LPS and HFD groups decreased significantly compared with the control group and HFD group, increased in the LPS+HFD group. CONCLUSION: Prenatal exposure to LPS combined with pre- and post-natal HFD result in a protective effect on the hippocampus in offspring rats, and it might be a benefit from the predictive adaptive response to prenatal inflammation.

Recombinant VP1 protein of duck hepatitis virus 1 expressed in Pichia pastoris and its immunogenicity in ducks.

The VP1 gene of duck hepatitis virus type 1 (DHV-1) strain VJ09 was amplified by reverse transcription PCR from the liver of a duckling with clinical symptoms of viral hepatitis. The resulting VP1 cDNA was 720 bp in length and encoded a 240-amino-acid protein. In VP1 gene-based phylogenetic analysis, the VJ09 strain grouped with DHV-1 genotype C. The VP1 gene was inserted into the expression vector pPICZαA and expressed in Pichia pastoris. The expressed VP1 protein was purified and identified by western blot analysis. To evaluate the recombinant VP1's immunogenic potential in ducklings, the antibodies raised in the immunized ducklings were titrated by ELISA, and lymphocyte proliferation and virus neutralization assays were performed. The results show that the recombinant VP1 protein induced a significant immune response in ducklings and this could be a candidate for the development of a subunit vaccine against DHV-1 genotype C.

Effects of zinc-methionine on growth performance, intestinal flora and immune function in pigeon squabs.

1. Different concentrations of zinc-methionine (Zn-Met) were given to pigeon squabs, and the resulting effects on growth, immune functions and intestinal microflora were investigated from hatching to 28 d of age. A total of 180 artificially hatched pigeon squabs were randomly allotted to each of three treatments with three replicates of 20 squabs. The three treatments given were either one ml (2 mg/ml) Zn-Met, one ml (10 mg/ml) Zn-Met or one ml 0.9% NaCl solution. 2. The results showed that Zn-Met improved the growth performance of squabs. The average daily and average weekly weight gain was significantly greater in squabs treated with Zn-Met than in the control group. 3. The group given 2 and 10 mg supplemental Zn-Met had heavier thymus, spleen and bursa of Fabricius than the control group at d 28. 4. Maternal antibody titres against Newcastle disease haemagglutination inhibition and alpha-naphthyl acetate esterase were significantly higher in squabs treated with supplemental 2 and 10 mg Zn-Met compared to the control group at d 14 and d 28. 5. Additionally, the squabs given supplemental 2 mg Zn-Met exhibited significantly higher Bacillaceae, Lactobacillus, Enterococcus and Bifidobacterium populations at d 14 and d 28, but lower Escherichia coli populations at d 28 compared to the control group. On the contrary, Lactobacillus, Enterococcus and Bifidobacterium populations were significantly decreased with 10 mg Zn-Met at d 28. 6. This study indicates that supplementation with Zn-Met has a positive effect on growth performance, immune function and regulation of intestinal flora in pigeons. An inclusion level of 2 mg seems to be better than 10 mg Zn-Met per day per bird.

[Non-coding RNAs and diseases].

With the completion of large scale genomic sequencing, a great number of non-conding RNAs (ncRNAs) have been discovered and capture the attention of the biological sciences community. All known ncRNAs may be divided into two groups, namely: i) small ncRNAs, which comprise microRNAs (miRNAs), PIWI-interacting RNAs (piRNAs) and short interfering RNAs (siRNAs), and ii) several thousands of long ncRNAs (IncRNAs). NcRNAs were shown to be involved in eukaryotic growth and development, cell proliferation and differentiation, apoptosis, epigenetic modifications, and also the complex control and pathogenesis of various diseases. In this paper, knowledge on the ncRNAs, which functioning is associated with human diseases, has been summarized.

Computational study of the proton transfer of phenyl urea.

The proton transfer between two nitrogen atoms (N1 and N3) in a molecule of phenyl urea is an important process in the synthesis of 1-phenylimidazolidine-2,4-dione. Three pathways of the proton transfer have been investigated using Density Functional Theory (DFT). With negative N1 phenyl urea, the transformed double bond of N1-C2 connects N1, C2, and N3 into a benzene conjugate system, making the structure more stable than negative N3 phenyl urea. Intermolecular proton transfer was found to be the primary manner of protein transfer at 300 K. Both negative N1 and negative N3 exist and the former is primal. The proton transfer is very fast, and the diluted solution may slow down the rate but produce much more negative N1 as well.

Synthesis and reaction mechanism of 3-(4-methoxyphenylazo)acrylic acid.

Using 4-methoxylphenylhydra zine hydrochloride (1a) as starting material, 2-[2-(4-methoxyphenyl) hydrazono] acetic acid (2a) was prepared after treatment with 1 equivalent of 2-oxoacetic acid, and 3-(4-methoxyphenyldiazo) acrylic acid (3a) was obtained with 2 equivalents of 2-oxoacetic acid through a novel reaction. The mechanism of reaction was analyzed with the help of charge distribution computation. This suggests that the novel reaction depends on the electronegativity of C9, which can be mainly affected by the substituents of the benzene ring.

Security enhancement of double-random phase encryption by amplitude modulation.

Conventional double-random phase encoding is vulnerable to a chosen or known plaintext attack owing to the linearity of the system. We introduce a technique to break down this linearity with an undercover amplitude modulation in the encryption scheme. As an additional key, this operation can significantly enhance the security of the system. A series of computer simulations have shown the effectiveness of this method and its resistance against the known plaintext attack. The design and parameter choice of the amplitude modulator is also discussed.

Simple direct extraction of unknown phase shift and wavefront reconstruction in generalized phase-shifting interferometry: algorithm and experiments.

An algorithm to extract the arbitrary unknown phase shift and then reconstruct the complex object wave in generalized phase-shifting interferometry (GPSI) without the iteration process and measurement of object wave intensity is proposed. This method can be used for GPSI of any frame number >or=2. Both computer simulations with smooth and diffusing object surfaces and optical experiments have verified the effectiveness of this method over a wide range of phase shifts with very satisfactory results.

Arenaric acid, a new pentacyclic polyether produced by a marine bacterium (Actinomycetales).

Arenaric acid (1a), a new pentacyclic polyether related to the antibiotics K-41A and oxolonomycin, was isolated as its sodium salt (1b) from the culture broth of an estuarine bacterial isolate of the genus Streptomyces. The structure of arenaric acid was established by spectroscopic methods involving comprehensive 2D NMR measurements.

Luisols A and B, new aromatic tetraols produced by an estuarine marine bacterium of the genus Streptomyces (Actinomycetales).

Luisols A (1) and B (2), two new aromatic tetraols, have been isolated from the cultivation broth of an estuarine marine actinomycete of the genus Streptomyces (strain #CNH-370). The structures of luisols A and B were assigned by combined spectroscopic methods, including extensive 2D NMR experiments. Luisol A appears related to the anthraquinone antibiotics of the granaticin class, while the structure of luisol B contains the rare epoxynaphtho[2,3c]furan, a structural feature found in only one natural product, the fungal metabolite anthrinone.

The structure of tautomycin, a dialkylmaleic anhydride antibiotic.

The chemical structure of tautomycin (C41H66O13) was determined by chemical degradation, spectroscopic analysis and 2D INADEQUATE of tautomycin labeled with [1,2-13C]acetate. Tautomycin exists in methanol-buffer solution (1% diethylamine-formic acid, pH 7.3) as an equilibrium mixture of a 2,3-dialkylmaleic anhydride and its dicarboxylic acid in a ratio of approximately 5:4.

The structure of tautomycetin, a dialkylmaleic anhydride antibiotic.

The chemical structure of tautomycetin (C33H50O10) was determined by chemical degradation and spectroscopic evidence. Tautomycetin exists in methanol-buffer solution (1% diethylamine-formic acid, pH 7.3) as an equilibrium mixture of a 2,3-dialkylmaleic anhydride and its dicarboxylic acid. The structure of tautomycetin is similar to tautomycin in many respects.

Induction of morphological change of human myeloid leukemia and activation of protein kinase C by a novel antibiotic, tautomycin.

A novel antibiotic tautomycin induced many blebs on the surface of K562 human chronic myeloid leukemia cells, similar to the morphological changes induced by phorbol esters. However, tautomycin did not induce nitroblue tetrazolium reducing activity, when HL60 human promyelocytic leukemia cells were caused to differentiate by quinomycin into mature granulocytes. It did not induce spread of HL60 cells, one of the phenotypes of mature macrophages. In addition, it did not compete with phorbol dibutyrate to bind to the cell surface of K562 cells. However, tautomycin significantly activated protein kinase C (PKC) extracted from K562 cells. These results indicate that tautomycin is a new activator of PKC, distinct from phorbol esters.