RESUMO
Bacterial infections are a major concern as antibiotic resistance poses a great threat, therefore leading to a race against time into finding new drugs or improving the existing resources. Nanomaterials with high surface area and bactericidal properties are the most promising ones that help combating microbial infections. In our case, graphene decorated with silver nanoparticles Gr-Ag (5 wt% Ag) exhibited inhibitory capacity against S. aureus and E. coli. The newly formed hybrid material was next incubated with high-efficiency particulate air (HEPA) filter, to obtain one with bactericidal properties. The modified filter had greater inhibitory action against the tested strains, compared to the control, and the effect was better against the Gram-negative model. Even if the bacteria remained attached to the filters, their colony forming unit capacity was affected by the Gr-Ag (5 wt% Ag) hybrid material, when they were subsequently re-cultured on fresh agar media. Therefore, the HEPA filter modified with Gr-Ag (5 wt% Ag) has high antibacterial properties that may substantially improve the existing technology.
RESUMO
Longitudinal studies have indicated an association between thyroid function and insulin resistance (IR) or a neutral relationship. Both the lowest tertile of free thyroxine (fT4) and the highest tertile of free triiodothyronine (fT3) were found to be associated with IR in cross-sectional studies. The aim of the present study was to analyze the association between IR and subclinical hypothyroidism in a female adult population from Bucharest, Romania. This is a retrospective pilot case-control study that included female patients examined by two endocrinologists and a diabetologist in an outpatient clinic. The retrospective follow-up had a one-year duration and included the evaluation of thyroid function tests and IR indices based on fasting insulinemia and C-peptide. The study included 176 women, 91 with subclinical hypothyroidism, with a median age of 60±17 years and a mean body mass index (BMI) of 27.79±4.76 kg/m2. The majority of the population (50%) was diagnosed with autoimmune thyroiditis, and 17.05% with goitre. The univariate logistic regression using hypothyroidism as the explaining variable found no evidence of a significant relationship between a decreased thyroid function and IR (OR 1.32; P=0.36). Metabolic syndrome was probably the most important determinant of IR in the population group studied. Thus, it was not the thyroid function per se, but the coexistence of other elements of this syndrome that prevailed in determining IR. Advantages to the study are the design that permitted evaluation of IR and the thyroid function at different moments in time as well as the uniformity of the blood tests. The multivariate analyses were adjusted for age, lipid profile and treatment; however, one limiting factor was the absence of other hormonal blood tests. In summary, there was no association between the thyroid function tests (TSH, fT4) and IR indices in adult Romanian women in a case-control study with one-year retrospective follow-up.
