Aging of the geiger-muller counter due to particle conductance in an insulating gas

In this paper, the aging effect of commercially available Geiger-Muller counters under working conditions is being considered from both theoretical and experimental point of view. In the experimental part lifetime curves for the commercial Geiger-Muller counter chamber are first recorded. After detection of the aging phenomena, the commercial chamber response to an impulse voltage is tested along with recording of the same response of the Geiger-Muller chamber model with conductive particles included. The law of similarity for the gaseous discharge is fulfilled both by the commercial Geiger-Muller chamber and by the chamber model with conductive particles. The results obtained from the U-test indicate that the aging of the Geiger-Muller chamber is mainly caused by the occurrence of a great number of conductive particles hovering inside the chamber. Some suggestions of how to reduce the aging effect due to conductive particles inside the Geiger-Muller chamber are given in the conclusion

Aging of the geiger-muller counter due to particle conductance in an insulating gas

In this paper, the aging effect of commercially available Geiger-Muller counters under working conditions is being considered from both theoretical and experimental point of view. In the experimental part lifetime curves for the commercial Geiger-Muller counter chamber are first recorded. After detection of the aging phenomena, the commercial chamber response to an impulse voltage is tested along with recording of the same response of the Geiger-Muller chamber model with conductive particles included. The law of similarity for the gaseous discharge is fulfilled both by the commercial Geiger-Muller chamber and by the chamber model with conductive particles. The results obtained from the U-test indicate that the aging of the Geiger-Muller chamber is mainly caused by the occurrence of a great number of conductive particles hovering inside the chamber. Some suggestions of how to reduce the aging effect due to conductive particles inside the Geiger-Muller chamber are given in the conclusion

Mineral profile of the winter wheat grain: effects of soil tillage systems and nitrogen fertilization

The aim of this study was to analyze the impact of various systems of soil tillage and nitrogen doses on the mineral composition of the grain of the common winter wheat cultivar (Triticum aestivum ssp. vulgare), cv. Azra selected for the conventional intensive production. The field experiment was conducted on luvic chernozem in completely randomized blocks. Wheat was grown under three soil tillage systems: conventional tillage, mulch tillage and no -tillage, and the experiment included two doses of N fertilization (60 and 120 kg ha(-1)). Concentrations of eighteen elements (As, Al, Ba, Ca, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Ni, S, Sr, P, V and Zn) in wheat grain samples were determined by means of inductively coupled plasma with optical emission spectrometry (ICP OES). The results indicated that concentrations of the studied elements in the wheat grain were significantly affected by the tillage systems and fertilization rates (p lt 0.001), as well as by the interaction of these two factors. A smaller dose of nitrogen fertilizer (60 kg ha(-1)) had a significantly better impact on the concentration of macro- and microelements in the wheat grain than the dose of 120 kg N ha(-1). The reduced tillage systems and lower nitrogen rates in nutrition had a better effect on the increase of the content of the studied elements in the wheat grain than the conventional cultivation which applied higher nitrogen rates

Using honey to heal diabetic foot ulcers

Diabetic ulcers seem to be arrested in the inflammatory/proliferative stage of the healing process, allowing infection and inflammation to preclude healing. Antibiotic-resistant bacteria have become a major cause of infections, including diabetic foot infections. It is proposed here that the modern developments of an ancient and traditional treatment for wounds, dressing them with honey, provide the solution to the problem of getting diabetic ulcers to move on from the arrested state of healing. Honeys selected to have a high level of antibacterial activity have been shown to be very effective against antibiotic-resistant strains of bacteria in laboratory and clinical studies. The potent anti-inflammatory action of honey is also likely to play an important part in overcoming the impediment to healing that inflammation causes in diabetic ulcers, as is the antioxidant activity of honey. The action of honey in promotion of tissue regeneration through stimulation of angiogenesis and the growth of fibroblasts and epithelial cells, and its insulin-mimetic effect, would also be of benefit in stimulating the healing of diabetic ulcers. The availability of honey-impregnated dressings which conveniently hold honey in place on ulcers has provided a means of rapidly debriding ulcers and removing the bacterial burden so that good healing rates can be achieved with neuropathic ulcers. With ischemic ulcers, where healing cannot occur because of lack of tissue viability, these honey dressings keep the ulcers clean and prevent infection occurring

Tumor-Like Stem Cells Derived from Human Keloid Are Governed by the Inflammatory Niche Driven by IL-17/IL-6 Axis

Alterations in the stem cell niche are likely to contribute to tumorigenesis; however, the concept of niche promoted benign tumor growth remains to be explored. Here we use keloid, an exuberant fibroproliferative dermal growth unique to human skin, as a model to characterize benign tumor-like stem cells and delineate the role of their "pathological" niche in the development of the benign tumor.Subclonal assay, flow cytometric and multipotent differentiation analyses demonstrate that keloid contains a new population of stem cells, named keloid derived precursor cells (KPCs), which exhibit clonogenicity, self-renewal, distinct embryonic and mesenchymal stem cell surface markers, and multipotent differentiation. KPCs display elevated telomerase activity and an inherently upregulated proliferation capability as compared to their peripheral normal skin counterparts. A robust elevation of IL-6 and IL-17 expression in keloid is confirmed by cytokine array, western blot and ELISA analyses. The altered biological functions are tightly regulated by the inflammatory niche mediated by an autocrine/paracrine cytokine IL-17/IL-6 axis. Utilizing KPCs transplanted subcutaneously in immunocompromised mice we generate for the first time a human keloid-like tumor model that is driven by the in vivo inflammatory niche and allows testing of the anti-tumor therapeutic effect of antibodies targeting distinct niche components, specifically IL-6 and IL-17.These findings support our hypothesis that the altered niche in keloids, predominantly inflammatory, contributes to the acquirement of a benign tumor-like stem cell phenotype of KPCs characterized by the uncontrolled self-renewal and increased proliferation, supporting the rationale for in vivo modification of the "pathological" stem cell niche as a novel therapy for keloid and other mesenchymal benign tumors

Common variation near CDKN1A, POLD3 and SHROOM2 influences colorectal cancer risk

We performed a meta-analysis of five genome-wide association studies to identify common variants influencing colorectal cancer (CRC) risk comprising 8,682 cases and 9,649 controls. Replication analysis was performed in case-control sets totaling 21,096 cases and 19,555 controls. We identified three new CRC risk loci at 6p21 (rs1321311, near CDKN1A; P = 1.14 × 10(-10)), 11q13.4 (rs3824999, intronic to POLD3; P = 3.65 × 10(-10)) and Xp22.2 (rs5934683, near SHROOM2; P = 7.30 × 10(-10)) This brings the number of independent loci associated with CRC risk to 20 and provides further insight into the genetic architecture of inherited susceptibility to CRC.Swedish Research Council et al.Manuscrip