Full characterization and optimization of a femtosecond ultraviolet laser source for time and angle-resolved photoemission on solid surfaces

A novel experimental apparatus for time and angle-resolved photoemission on solid surfaces is presented. A 6.28 eV laser source operating at 250 kHz repetition rate is obtained by frequency mixing in nonlinear beta barium borate crystals. This UV light source has a high photon flux of 10(13) photons/s with relatively low number of photons/pulse so that Fermi surface mapping over a wide region of the Brillouin zone is possible while mitigating space charge effects. The UV source has been fully characterized spatially, spectrally, and temporally. Its potential for time and angle-resolved photoemission is demonstrated through Fermi surface mapping and photoexcited electron dynamics in Bismuth. True femtosecond time resolution <65 fs is obtained while the energy resolution of 70 meV appears to be mainly limited by the laser bandwidth.

Establishment, characterization and viral susceptibility of a new cell line derived from goldfish, Carassius auratus (L.), tail fin

A continuous cell line [goldfish tail fin (GFTF)] derived from a goldfish tail fin, Carassius auratus, was established and characterized. GFTF cells predominantly consist of fibroblast-like cells that were maintained and subcultured more than 50 times over a period of 15 months. Cells grew at temperatures between 15 and 37°C, with an optimum temperature of 25°C. The growth rate of GFTF cells increased proportionally with the foetal bovine serum (FBS) concentration (5-20%), with optimum growth at 20% FBS. The chromosome numbers were 88-112, with a modal peak of 104 chromosomes. Five known fish viruses were tested to determine susceptibility. Results demonstrated that GFTF is susceptible to snakehead rhabdovirus, spring viraemia of carp virus and channel catfish virus (CCV). In addition, GFTF demonstrated a higher sensitivity to, and increased viral production of, CCV than that observed in the control cell line, channel catfish ovary cells. This suggests that GFTF cells would be useful as a diagnostic tool for viral diseases in this fish species, as well as for the isolation and study of goldfish viruses in the future. Furthermore, these cells were transfected with pEGFP-N1 vector DNA and some fluorescent signals were observed, suggesting that GFTF cells could be a useful tool for transgenic and genetic manipulation studies.

Effects of Merogel coverage on wound healing and ostial patency in endonasal endoscopic dacryocystorhinostomy for primary chronic dacryocystitis

PURPOSE

To investigate the effects of Merogel coverage on ostial patency in endonasal endoscopic dacryocystorhinostomy (EES-DCR) for primary chronic dacryocystitis (PCD).

METHODS

In all, 260 patients with unilateral PCD were randomized into two groups: the Merogel group and the control group. All patients underwent EES-DCR. The Merogel group received Merogel covering the wound 1-2 mm around the ostium and the control group received no treatment. Patients were followed up for 9 months. The mucosal epithelialization of the wound, the proliferation of fibrosis tissue, and the success rate of ostial patency were compared.

RESULTS

Our study included 112 patients in the Merogel group and 115 patients in the control group. At the 2-week review, intact mucosal epithelium lined the ostia in 96 Merogel patients compared with 80 control patients (ITT analysis: χ(2)=4.502, P=0.034). At the 9-month review, scars were present in 18 patients in the Merogel group compared with 39 patients in the control group (ITT analysis: χ(2)=9.909, P=0.002, ITT analysis). No differences were observed in the granulation formation between the two groups. The success rate of ostial patency reached 94.6% (106/112) in the Merogel group compared with 80% (92/115) in the control group (ITT analysis: χ(2)=4.151, P=0.042).

CONCLUSION

Merogel coverage may enhance the success rate of EES-DCR for PCD by promoting mucosal epithelial healing and preventing excessive scarring.

Effect of Forging Temperature on Microstructure and Tensile Properties in Fe3Al-Based Alloy

Forging processes at two different temperatures are performed to examine the relation between the microstructure and room temperature tensile properties in a Ce doped Fe3Al-based alloy. Results show that the microstructure and the ductility are sensitive to the forging temperature before annealing treatment. Higher yield strength and ductility can be obtained through forging at a relatively low temperature of 750°C followed by annealing at 800°C and 500°C. It is suggested that the formation of non-equilibrium grain boundaries and banded subgrains within carbide-free areas along grain boundaries enhances the local plastic deformation and results in the improvement of ductility. During the initial deformation at room temperature <111> slip is predominant for both microstructures.

Single-primer PCR correction: a strategy for false-positive exclusion

Polymerase chain reaction (PCR) technology plays an important role in molecular biology research, but false-positive and nonspecific PCR amplification have plagued many researchers. Currently, research on the optimization of the PCR system focuses on double-primer-based PCR products. This research has shown that PCR amplification based on single-primer binding to the DNA template is an important contributing factor to obtaining false-positive results, fragment impurity, and nonspecific fragment amplification, when the PCR conditions are highly restricted during PCR-based target gene cloning, detection of transgenic plants, simple-sequence repeat marker-assisted selection, and mRNA differential display. Here, we compared single- and double-primer amplification and proposed "single-primer PCR correction"; improvements in PCR that eliminate interference caused by single-primer-based nonspecific PCR amplification were demonstrated and the precision and success rates of experiments were increased. Although for some kinds of experiments, the improvement effect of single-primer PCR correction was variable, the precision and success rate could be elevated at 12-50% in our experiment by this way.

Identification and validation of quantitative trait loci conferring tan spot resistance in the bread wheat variety Ernie

Tan spot, caused by Pyrenophora tritici-repentis, is a foliar disease of wheat, and it can inflict serious reduction in grain yield and quality. The bread wheat variety Ernie was found to be immune to this disease in Australia, and its genetic control was investigated by quantitative trait loci (QTL) analysis using a doubled haploid population. Eight QTL were identified in this population from three independent trials, and four of them were derived from the parent Ernie. The most significant QTL was located on chromosome arm 2BS, explaining 38.2, 29.8 and 36.2% of the phenotypic variance, respectively, in these trials. The effects of the 2BS QTL were further validated in four additional populations. The presence of this single QTL reduced disease severity by between 29.2 and 67.1% with an average of 50.5%. The significant effects of this QTL and its consistent detection across all the trials with different genetic backgrounds make it an ideal target for breeding programmes as well as for its further characterization. Data from this study also showed that neither plant height nor heading date significantly affects tan spot resistance.

Effects of the thyroid hormone responsive spot 14alpha gene on chicken growth and fat traits

The thyroid hormone responsive spot 14alpha (THRSPalpha) gene plays important roles in chicken growth and fat deposition. The aim of this study was to identify new variations in the gene to determine their effects on growth and fat traits in chicken and to observe the effects of the THRSPalpha gene on chicken lipid profile and lipoprotein and glucose and triiodothyronine effects on the THRSPalpha expression in liver and fat cells. Two new variations, namely A197835978G and G197836086A, and a reported 9-bp insertion-deletion (indel) of the THRSPalpha gene were genotyped by single-stranded conformational polymorphism in a Xinghua x White Recessive Rock F(2) full-sib resource population. The results showed that the A197835978G was significantly associated with hatch weight and BW at 28 d of age and breast muscle weight at 90 d of age in chickens (P < 0.05). The G197836086A was significantly associated with cingular fat width (P = 0.0349) and breast muscle crude fat content (P = 0.0349). The indel was significantly associated with abdominal fat weight (P = 0.0445). The above new THRSPalpha polymorphisms were also significantly associated with the total cholesterol and low-density lipoprotein, in which the THRSPalpha GA/AG genotype was associated with lipid and lipoprotein and the THRSPalpha BB indel genotype was significantly associated with liver weight in chicken breeds. The mRNA expression analysis in vivo and in vitro culture studies suggested that the THRSPalpha gene is more responsive to glucose than triiodothyronine. In conclusion, the 3 variations of the chicken THRSPalpha gene were associated with both growth and fat traits in this study. Such effects of the THRSPalpha gene were further supported from the data of observations in association analysis of the gene with phenotypic records and plasma lipid profiles, in the THRSPalpha gene expression in chicken development, and in vivo and in vitro cell culture observation of liver and abdominal fat tissues.

Ig heavy chain genes and their locus in grass carp Ctenopharyngodon idella

The cDNA and genomic sequences of IgD and IgZ were characterized in grass carp Ctenopharyngodon idella in the present study, and with the identification of a BAC clone covering zeta, mu, and delta genes, the IgH locus containing these Ig genes and other V, D, J genes was also illustrated in this fish. Secretory and membrane-bound IgZ were identified, with two transmembrane exons spliced within the CH4 exon, as reported in IgM of mammals and IgZ in other teleost fish. The first and second constant domains of IgZ shows more than 90% nucleotide identity with respective domains of grass carp IgM. The IgD has a structure of delta1-(delta2-delta3-delta4)(2)-delta5-delta6-delta7-TM-UTR, with the repeat of delta2-delta3-delta4; but intron was not found between the two repeat, i.e. between the first delta2-delta3-delta4 (delta2.1-delta3.1-delta4.1) and the second delta2-delta3-delta4 (delta2.2-delta3.2-delta4.2), and the intron between delta3.1 and delta4.1 was much shorter than the intron between delta3.2 and delta4.2. The genomic organization of the IgH locus has a pattern of Vn-Dn-Jn-Czeta-Dn-Jn-Cmu-Cdelta, as reported in other teleost fish. Thirteen V(H), fourteen D, and twelve J(H) genes were observed in this locus, with the similarity of three D segments and four J(H) segments being the same in the upstream of Czeta and Cmu. The transcriptional enhancer located at the mu-delta intergenic region was also analyzed and it seems possible that this enhancer is functional as verified in zebrafish and channel catfish.

Experimental Leptospira interrogans serovar Kennewicki infection of horses

BACKGROUND

Little information is available about experimental induction of leptospirosis in horses.

OBJECTIVES

Determine serologic, hematologic responses of horses to Leptospira interrogans serovar Kennewicki infection.

ANIMALS

Four adult horses seronegative for leptospirosis.

METHODS

Experimental and observational study. Horses were challenged with an equine isolate of L. interrogans serovar Kennewicki at 2 different doses and different inoculation sites. After challenge, the horses were monitored for 60 days. Blood, urine, and aqueous humor samples were collected at intervals until euthanasia 60 days after infection.

RESULTS

Pyrexia (39.3-40 degrees C) occurred as early as 1 day after challenge with 10x10(8)Leptospira divided equally between topical ocular and intraperitoneal injection in 2 horses. Leptospires were recovered from the blood and urine but not from the aqueous humor of the 2 febrile horses. The sera of all 4 challenged horses developed microscopic agglutination test antibody after challenge and remained relatively constant for 21 days. Titer to cross-reacting strains declined earlier than titer to the challenge strain.

CONCLUSIONS

Clinical disease in experimentally infected horses can be mild or inapparent in Leptospira infected horses. Repeated serologic testing can allow recognition of the infecting serovar. In febrile horses, Leptospira can be isolated from blood while isolation from the urine can occur after fever has subsided.

Comparative human salivary and plasma proteomes

The protein compositions, or the proteomes, found in human salivary and plasma fluids are compared. From recent experimental work by many laboratories, a catalogue of 2290 proteins found in whole saliva has been compiled. This list of salivary proteins is compared with the 2698 proteins found in plasma. Approximately 27% of the whole-saliva proteins are found in plasma. However, despite this apparent low degree of overlap, the distribution found across Gene Ontological categories, such as molecular function, biological processes, and cellular components, shows significant similarities. Moreover, nearly 40% of the proteins that have been suggested to be candidate markers for diseases such as cancer, cardiovascular disease, and stroke can be found in whole saliva. These comparisons and correlations should encourage researchers to consider the use of saliva to discover new protein markers of disease and as a diagnostic non-proximal fluid to detect early signs of disease throughout the body.

TLR4 mediates early graft failure after intraportal islet transplantation

We have previously shown that islet emboli in the portal vein block blood flow and induce local inflammatory reaction, resulting in functional loss of islet grafts following intraportal transplantation. This study was designed to test whether Toll-like receptor (TLR) activation mediates early islet graft failure. Syngeneic islet grafts were transplanted into chemically induced diabetic mice, and TLR deficient mice were used as donors and/or recipients of islet grafts. Islet viability, proinflammatory cytokines, high-mobility group box-1 (HMGB1) and NF-kappaB activation were analyzed by bioluminesce imaging (BLI), quantitative RT-PCR (qRT-PCR) and histology. Early islet graft failure was observed in mice with intraportal islet engrafts with increased proinflammatory cytokines, HMGB1 expression, NF-kappaB activation, caspase-3 and TUNEL positive cells. Deficiency of TLR4 in donor, but not in recipient, inhibited NF-kappaB activation, reduced proinflammatory cytokines and improved viability of islet grafts. Blockade of HMGB1 with anti-HMGB1 monoclonal antibody (mAb, 2g7) inhibited inflammatory reactions, as evidenced by reduced TNFalpha and IL-1ss production, and improved islet viability. We conclude that TLR4 activation mediates early graft failure following intraportal islet transplantation. Inhibition of TLR4 activation represents a novel strategy to attenuate early graft failure following intraportal islet transplantation.

SNF5, a core component of the SWI/SNF complex, is necessary for p53 expression and cell survival, in part through eIF4E

SNF5, a core component of the SWI/SNF chromatin remodeling complex, is expressed as two isoforms, SNF5a and SNF5b. SNF5 is a tumor suppressor as mutation of SNF5 leads to tumor formation and cooperates with p53 deficiency to enhance cancer susceptibility. Interestingly, lack of SNF5 inhibits cell survival and embryonic development potentially via abnormal activation of p53. To further examine this, we generated cell lines in that SNF5a, SNF5b, or both can be inducibly knocked down. We found that SNF5 knockdown leads to cell cycle arrest in G1, and SNF5a and SNF5b are functionally redundant. We also showed that SNF5 knockdown impairs p53-dependent transcription of p21 and MDM2. However, contrary to earlier reports that p53 is activated by SNF5 knockout in murine cells, SNF5 knockdown leads to decreased, but not increased, expression of both basal and stress-induced p53 in multiple human cell lines. In addition, we showed that SNF5 knockdown induces AMPK activation and inhibits eIF4E expression. Finally, we demonstrated that SNF5 knockdown inhibits p53 translation via eIF4E and replacement of eIF4E in SNF5-knockdown cells restores p53 expression and cell survival. Together, our results suggest that the p53 pathway is regulated by, and mediates the activity of, SNF5 in tumor suppression and pro-survival.