Decoupled CuO_2 and RuO_2 layers in superconducting and magnetically ordered RuSr_2GdCu_2O_8

Comprehensive measurements of dc and ac susceptibility, dc resistance, magnetoresistance, Hall resistivity, and microwave absorption and dispersion in fields up to 8 T have been carried out on RuSr_2GdCu_2O_8 with the aim to establish the properties of RuO_2 and CuO_2 planes. At ~130 K, where the magnetic order develops in the RuO_2 planes, one observes a change in the slope of dc resistance, change in the sign of magnetoresistance, and the appearance of an extraordinary Hall effect. These features indicate that the RuO_2 planes are conducting. A detailed analysis of the ac susceptibility and microwave data on both, ceramic and powder samples show that the penetration depth remains frequency dependent and larger than the London penetration depth even at low temperatures. We conclude that the conductivity in the RuO_2 planes remains normal even when superconducting order is developed in the CuO_2 planes below \~45 K. Thus, experimental evidence is provided in support of theoretical models which base the coexistence of superconductivity and magnetic order on decoupled CuO_2 and RuO_2 planes.Comment: 11 pages, 11 figures, submitted to PR

Systematic behaviour of the in-plane penetration depth in d-wave cuprates

We report the temperature T and oxygen concentration dependences of the penetration depth of grain-aligned YBa_2Cu_3O_{7-\delta} with \delta= 0.0, 0.3 and 0.43. The values of the in-plane \lambda_{ab}(0) and out-of-plane \lambda_{c}(0) penetration depths, the low temperature linear term in \lambda_{ab}(T), and the ratio \lambda_{c}(0) /\lambda_{ab}(T) were found to increase with increasing $\delta$. The systematic changes of the linear term in \lambda_{ab}(T) with T_c found here and in recent work on HgBa_2Ca_{n-1} Cu_nO_{2n+2+\delta} (n = 1 and 3) are discussed.Comment: 4 pages, 4 figure

Metabolic and endocrinologic complications in beta-thalassemia major: a multicenter study in Tehran

BACKGROUND: The combination of transfusion and chelation therapy has dramatically extended the life expectancy of thalassemic patients. The main objective of this study is to determine the prevalence of prominent thalassemia complications. METHODS: Two hundred twenty patients entered the study. Physicians collected demographic and anthropometric data and the history of therapies as well as menstrual histories. Patients have been examined to determine their pubertal status. Serum levels of 25(OH) D, calcium, phosphate, iPTH were measured. Thyroid function was assessed by T3, T4 and TSH. Zinc and copper in serum were determined by flame atomic absorption spectrophotometry. Bone mineral density (BMD) measurements at lumbar and femoral regions have been done using dual x-ray absorptiometry. The dietary calcium, zinc and copper intakes were estimated by food-frequency questionnaires. RESULTS: Short stature was seen in 39.3% of our patients. Hypogonadism was seen in 22.9% of boys and 12.2% of girls. Hypoparathyroidism and primary hypothyroidism was present in 7.6% and 7.7% of the patients. About 13 % of patients had more than one endocrine complication with mean serum ferritin of 1678 ± 955 micrograms/lit. Prevalence of lumbar osteoporosis and osteopenia were 50.7% and 39.4%. Femoral osteoporosis and osteopenia were present in 10.8% and 36.9% of the patients. Lumbar BMD abnormalities were associated with duration of chelation therapy. Low serum zinc and copper was observed in 79.6% and 68% of the study population respectively. Serum zinc showed significant association with lumbar but not femoral BMD. In 37.2% of patients serum levels of 25(OH) D below 23 nmol/l were detected. CONCLUSION: High prevalence of complications among our thalassemics signifies the importance of more detailed studies along with therapeutic interventions

Contribution to the parasites and associated pathology of wild Serranidae from the Aegean Sea

Parasites and associated pathology of wild caught Serranidae in the Aegean Sea were investigated in order to contribute to the scientific information regarding pathological findings of these fish. Various lesions and parasitic organisms, such as Digenean parasites, cysts and metacercaria, Cestode cysts and a nematode, were observed in the gills / pseudobranchs, liver, the wall of the digestive tract, the mesentery and the ovaries. None of these lesions were considered to be of pathogenic bacteria nature based on microscopic observation of stained tissue sections of affected organs. The most frequently observed parasitism among all the species studied was from Digenean parasites (11 out of 16 specimens examined) compared to infection by both cestodes and nematodes (3 out of 16 specimens examined). Heavier infestation was observed for the unidentified Digenean cysts that were found in the mesentery of one specimen (120 counts), followed by Didymozoan parasites (average 19.25 counts per specimen). © 2018 V Bakopoulos, A Nikolaidis, M Kolygas, F Athanassopoulou

Gonadal changes and blood sex steroids levels during natural sex inversion in the protogynous Mediterranean red porgy, Pagrus pagrus (Teleostei : Sparidae)

Changes in gonadal structure and serum levels of sex steroids were investigated during natural sex inversion from female to male in reared populations of the protogynous Mediterranean red porgy, Pagrus pagrus. Four developmental phases were identified by histological observation: female, early transitional (ETr), late transitional (LTr), and male phases. At female phase, a few nests of spermatogonia were observed at the posterior-ventral part of the gonad mainly in females out of the breeding season. At ETr phase, spermatogonial proliferation occurred while perinucleolar oocytes showed signs of degeneration. At LTr phase, seminiferous lobules were formed and spermatogonial proliferation expanded along the ovary which degenerated. All types of male germ cells could be found. At male phase, functional testis underwent active spermatogenesis while small ovarian remnants associated to fat tissue could be detected. Both 17 beta-estradiol (E2) and estrone (E1) blood levels were significantly lower in fish at transitional and male phases in comparison to breeding females, while levels of 11-ketotestosterone (11-KT) and testosterone (T) gradually increased in the transitional and male phases. In conclusion, the protogynous P. pagrus possess a delimited type bisexual gonad with a medio-dorsal ovarian area and a latero-ventral testicular zone. Sex inversion starts mainly after the female breeding season with an active spermatogonial proliferation. The testis tissues develop while ovarian tissues regress to disappear completely in the functional male. This process is accompanied by a sharp decrease of estrogens levels and a progressive increase of androgens levels. The physiological significance of such endocrine changes is discussed. (c) 2006 Elsevier Inc. All rights reserved

Virulence Genes and In Vitro Antibiotic Profile of Photobacterium damselae Strains, Isolated from Fish Reared in Greek Aquaculture Facilities

Bacteria belonging to the species Photobacterium damselae are pathogens of cultured marine fish, causing diseases of high importance, such as Pasteurellosis. Thus, they are considered a major threat to the aquaculture sector. Despite the great importance of fish mariculture for the Greek economy, the distribution and abundance of these bacteria are not well documented in aquaculture units in Greece. Keeping this in mind, the scope of the present study was to investigate the presence, antibiotic profile, and virulence of Photobacterium bacteria originating from a representative sample of mariculture units throughout Greece. Samples were collected from diseased fish belonging to three different cultured fish species, namely Sparus aurata, Dicentrarchus labrax, and Pagrus pagrus, from both the Aegean and the Ionian Sea. Tissue samples were cultured in agar media, and bacteria were molecularly identified using both bacterial universal and species-specific primer pairs for Photobacterium spp. Additionally, the identified strains were characterized for the presence of virulence genes as well as antibiotic profiles. According to the results, the aforementioned bacteria are distributed in the Greek aquaculture units and are characterized by high pathogenicity based on the abundance of virulence genes. Furthermore, the majority of the detected strains exhibit some level of antibiotic resistance. In summary, our results indicate the need for systematic surveillance and study of their antibiotic profiles in Greek aquaculture since these bacteria constitute a major threat to the sector. © 2022 by the authors

Synthesis of Novel Pyrazolo[3,4-b]pyridines with Affinity for β-Amyloid Plaques

Three novel pyrazolo[3,4-b]pyridines were synthesized via the cyclization of 5-amino-1-phenylpyrazole with the corresponding unsaturated ketone in the catalytic presence of ZrCl4. The ketones were afforded by modifying a stabilized ylide facilitated Wittig reaction in fairly high yields. The novel compounds exhibited exciting photophysical properties with the dimethylamine phenyl-bearing pyrazolopyridine showing exceptionally large Stoke’s shifts. Finally, both the dimethylamino-and the pyrene-substituted compounds demonstrated high and selective binding to amyloid plaques of Alzheimer’s disease (AD) patient brain slices upon fluorescent confocal microscopy observation. These results reveal the potential application of pyrazolo[3,4-b]pyridines in the development of AD amyloid plaque probes of various modalities for AD diagnosis. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

USE OF PRUSSIAN CARP, CARASSIUS GIBELIO, PITUITARIES IN THE ARTIFICIAL PROPAGATION OF FEMALE COMMON CARP, CYPRINUS CARPIO

Background. The usage of common carp pituitaries has been associated with very high costs, resulting from sacrificing the valuable broodstock. A close taxonomic proximity between the Common carps Cyprinus carpio L. and Prussian carp, Carassius gibelio (Bloch, 1782), reflected in the presence of high levels of the homologous carp LH hormone in Prussian Carp pituitaries, was recently demonstrated. This prompted the present authors to evaluate the Prussian carp pituitaries as a less expensive alternative to carp pituitaries. for inducing spawning in common carp. Materials and Methods. Prussian carp were fished in Lake Pamvotis (NW Greece) on April 4, 2007 and 204 pituitaries were extracted and processed. Accordingly, the prepared pituitary liquid extract was injected in 30 female common carp (experimental group) in the State Carp Hatchery in Psathotopi, (western Greece). Common carp pituitary extract Was used tor the hypophysation of female common Carp ill the Control group (n = 30). In both groups, standard hatchery procedures were followed concerning broodstock handling during the artificial propagation of common carp. Fertilized eggs were incubated in 7-L Zugar jars after removing the sticky substrate and hatching percentage was calculated. Results. Spawning success was 73.3%, total egg yield was 5.94 kg, total relative fecundity was 112.5 g . kg(-1) of body weight (150.0 g . kg(-1) of body weight based on fertile broodstock), and hatching percentage reached 85.2%. Statistically, all the above performance values were not significantly different compared to the controls. Conclusion. Taking advantage of a natural resource practically unexploited, the use of Prussian carp pituitaries in the artificial propagation of common carp was equally effective to common carp pituitaries, contributing to lower running costs in the hatchery