Is the tetraneutron a bound dineutron-dineutron molecule?

In light of a new experiment which claims a positive identification, we discuss the possible existence of the tetraneutron. We explore a novel model based on a dineutron-dineutron molecule. We show that this model is not able to explain the tetraneutron as a bound state, in agreement with other theoretical models already discussed in the literature.Comment: 9 pages, 3 figures, J. Phys. G, in pres

The detection of neutron clusters

A new approach to the production and detection of bound neutron clusters is presented. The technique is based on the breakup of beams of very neutron-rich nuclei and the subsequent detection of the recoiling proton in a liquid scintillator. The method has been tested in the breakup of 11Li, 14Be and 15B beams by a C target. Some 6 events were observed that exhibit the characteristics of a multineutron cluster liberated in the breakup of 14Be, most probably in the channel 10Be+4n. The various backgrounds that may mimic such a signal are discussed in detail.Comment: 11 pages, 12 figures, LPCC 01-1

Analysis of G(‐174)C IL‐6 polymorphism and plasma concentrations of inflammatory markers in patients with type 2 diabetes and peripheral arterial disease

AIMS: To determine whether the G(−174)C interleukin 6 (IL‐6) polymorphism influences the development of peripheral arterial disease (PAD) in individuals with type 2 diabetes. This was investigated by comparing the distribution of G(−174)C genotypes between patients with type 2 diabetes and PAD (PAD(+)) and those with type 2 diabetes but without PAD (PAD(−)). Plasma concentrations of IL‐6, fibrinogen, C reactive protein (CRP), and vascular endothelial growth factor (VEGF) were also compared in PAD(+) and PAD(−) patients. METHODS: Blood samples were collected from 146 PAD(+) and 144 PAD(−) patients. SfaNI was used to determine the G(−174)C genotype. Plasma concentrations of IL‐6, fibrinogen, CRP, and VEGF were measured by an enzyme linked immunosorbent assay. RESULTS: The GG genotype was more common in PAD(+) patients than in PAD(−) patients. PAD(+) patients also had increased mean plasma concentrations of IL‐6, fibrinogen, CRP, and VEGF compared with PAD(−) patients. Mean plasma concentrations of IL‐6, fibrinogen, and CRP in both PAD(+) and PAD(−) patients were higher in those with the GG genotype than in those with the GC or CC genotypes. In contrast, mean plasma concentrations of VEGF in PAD(+) and PAD(−) patients were not significantly different between those with different G(−174)C genotypes. CONCLUSIONS: These results support a model in which the GG genotype promotes PAD development among individuals with type 2 diabetes by inducing increased release of IL‐6. Higher concentrations of IL‐6 among those with the GG genotype is associated with increased plasma concentrations of fibrinogen and CRP

Analysis of TIMP-1 gene polymorphisms in Italian sclerodermic patients.

Systemic sclerosis (SSc) is an autoimmune disease characterized by skin and internal organs fibrosis due to an extracellular matrix (ECM) accumulation of type I collagen. The turnover of the ECM is dependent on the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs). The disruption of this balance is involved in SSc because higher serum TIMP-1 levels have been demonstrated in SSc patients than in controls. On this basis, we analyzed three polymorphisms: -19A&rt;G, +261C&rt;T, and +372T&rt;C of the TIMP-1 gene in SSc patients (67 females, eight males) and controls (29 females, nine males). The C allele of the +372T&rt;C single nucleotide polymorphism (SNP) was observed at a higher frequency in male patients than in healthy individuals (P= 0,02), while no differences were observed in the female subjects. Our findings suggest that the +372T&rt;C polymorphism of the TIMP-1 gene is associated with SSc in male individuals. No association with the clinical characteristics of SSc Italian patients and TIMP-1 gene polymorphisms was observed. Thus, the role of TIMP-1 gene in predisposition to SSc remains controversial