High-Tc superconductors in the two-dimensional limit:

The free modulation of interlayer distance in a layered high-transition temperature (high-Tc) superconductor is of crucial importance not only for the study of the superconducting mechanism but also for the practical application of high-Tc superconducting materials. Two-dimensional (2D) superconductors were achieved by intercalating a long-chain organic compound into bismuth-based high-Tc cuprates. Although the intercalation of the organic chain increased the interlayer distance remarkably, to tens of angstroms, the superconducting transition temperature of the intercalate was nearly the same as that of the pristine material, suggesting the 2D nature of the high-Tc superconductivity.     

Infiltrating Foxp3+ Regulatory T cells and Histopathological Features in Canine Classical and Spermatocytic Seminomas

In humans, regulatory T (T reg) cells are known to play a critical role in both the regulation of immune homoeostasis and the progression of cancer. However, there is little information about the identification, characterization and the function of T reg cells in canine tumours. We identified T reg cells in 28 canine seminoma samples using a Forkhead box P3 (Foxp3) antibody and investigated the relationship between T reg cell infiltration and histopathological features of classical and spermatocytic seminomas (SE and SS, respectively). The Foxp3 protein showed nuclear immunostaining in infiltrating lymphocytes, and Foxp3+ cells were diffused or focally distributed in seminoma tissues. Foxp3+ cells were frequently present in the SS histotype, in seminomas that showed no evidence of tumour cell invasion into the vessels and in seminomas showing a diffuse growth pattern with three cell types. Neither the SE/SS histotype nor the histopathological features of the tumour correlated with Foxp3+ cell counts. These results indicate that Foxp3+ T reg cells may be associated with a less malignant histological phenotype or may not play a critical role in the immune response of canine seminomas. Moreover, Foxp3+ T reg cells may be associated with SS seminoma, but further studies, involving a larger number of samples, are required to better understand whether these cells play a critical role in the immune response in canine seminomas. This is the first report to demonstrate the characteristics of T reg cell infiltration in canine seminoma.     

Effect of Dimethyl Sulfoxide on Cell Cycle Synchronization of Goldfish Caudal Fin Derived Fibroblasts Cells

Several studies have previously been conducted regarding cell cycle synchronization in mammalian somatic cells. However, limited work has been performed on the control of cell cycle stages in the somatic cells of fish. The aim of this study was to determine the cell cycle arresting effects of several dimethyl sulfoxide (DMSO) concentrations for different times on different cell cycle stages of goldfish caudal fin‐derived fibroblasts. Results demonstrated that the cycling cells or control group (68.29%) yields significantly higher (p < 0.05) arrest in G0/G1 phase compared with the group treated for 24 h with different concentrations (0.5%, 1.0% or 1.5%) of DMSO (64.88%, 65.70%, 64.22% respectively). The cell cycle synchronization in the treatment of cells with 1.0% DMSO at 48 h (81.14%) was significantly higher than that in the groups treated for 24 h (76.82%) and the control group (77.90%). Observations showed that treatment of DMSO resulted in an increase in the proportion of cells at G0/G1 phase for 48 h of culture. However, high levels of apoptotic cells can be detected after 48 h of culture treated with 1% concentration of DMSO.     

Molecular Basis of Gene-for-Gene Specificity in Bacterial Speck Disease of Tomato

Transient expression of the Pseudomonas syringae avirulence gene avrPto in plant cells resulted in a Pto-dependent necrosis. The AvrPto avirulence protein was observed to interact directly with the Pto resistance protein in the yeast two-hybrid system. Mutations in the Pto and avrPto genes which reduce in vivo activity had parallel effects on association in the two-hybrid assay. These data suggest that during infection the pathogen delivers AvrPto into the plant host cell and that resistance is specified by direct interaction of Pto with AvrPto.     

Sorption of 2,4-D and other phenoxy herbicides to soil, organic matter, and minerals

Purpose

We review 2,4-dichlorophenoxyacetic acid (2,4-D) and other phenoxy herbicide sorption experiments.

Methods

A database with 469 soil–water distribution coefficients K _d (in liters per kilogram) was compiled: 271 coefficients are for the phenoxy herbicide 2,4-D, 9 for 4-(2,4-dichlorophenoxy)butyric acid, 18 for 2-(2,4-dichlorophenoxy)propanoic acid, 109 for 2-methyl-4-chlorophenoxyacetic acid, 5 for 4-(4-chloro-2-methylphenoxy)butanoic acid, and 57 for 2-(4-chloro-2-methylphenoxy)propanoic acid. The following parameters characterizing the soils, solutions, or experimental procedures used in the studies were also compiled if available: solution CaCl₂ concentration, pH, pre-equilibration time, temperature, soil organic carbon content (f _oc), percent sand, silt and clay, oxalate extractable aluminum, oxalate extractable iron (Oxalate Fe), dithionite–citrate–bicarbonate extractable aluminum, dithionite–citrate–bicarbonate extractable iron (DCB Fe), point of zero negative charge, anion exchange capacity, cation exchange capacity, soil type, soil horizon or depth of sampling, and geographic location. K _d data were also compiled characterizing phenoxy herbicide sorption to the following well-defined sorbent materials: quartz, calcite, α-alumina, kaolinite, ferrihydrite, goethite, lepidocrocite, soil humic acid, Fluka humic acid, and Pahokee peat.

Results

The data review suggests that sorption of 2,4-D can be rationalized based on the soil parameters pH, f _oc, Oxalate Fe, and DCB Fe in combination with sorption coefficients measured independently for humic acids and ferrihydrite, and goethite.

Conclusions

Soil organic matter and iron oxides appear to be the most relevant sorbents for phenoxy herbicides. Unfortunately, few authors report Oxalate Fe and DCB Fe data.