809 research outputs found
Microbiological and host-derived biomarker evaluation following non-surgical periodontal therapy with short-term administration of systemic antimicrobials: secondary outcomes of an RCT.
Nonsurgical periodontal therapy with adjunctive use of systemic antimicrobials (for 7-14 days) showed improved clinical, microbiological and immunological results over the mechanical protocol alone. Considering the increasing risk for antimicrobial resistance with longer antibiotic regimes, it is important to establish the optimal antibiotic protocol with a maximum antimicrobial benefit and minimum risk for adverse effects. The aim of the study was to evaluate the microbiological and inflammatory outcomes 12-months after a 3-/7-day systemic antibiotic protocol [amoxicillin (AMX) + metronidazole (MET)] adjunctive to subgingival debridement in severe periodontitis compared to mechanical treatment alone. From the initially treated 102 patients, 75 subjects (Placebo group: n = 26; 3-day AMX + MET group: n = 24; 7-day AMX + MET group: n = 25) completed the 12-month examination. Clinical parameters, eight periodontal pathogens and inflammatory markers were determined at baseline and 3-, 6-, 12-months after therapy using real-time PCR and ELISA respectively. After 6 months, several periodontopathogens were significantly more reduced in the two antibiotic groups compared to placebo (p < 0.05). After 1 year, both antibiotic protocols showed significant reductions and detection of the keystone pathogen P. gingivalis compared to placebo. Antibiotic protocols, smoking, disease severity, baseline-BOP, -CAL and -IL-1β, as well as detection of T. denticola at 12-months significantly influenced the residual number of deep sites. The present data indicate that the systemic use of both short and longer antibiotic protocols (AMX + MET) adjunctive to nonsurgical periodontal therapy lead to higher microbiological improvements compared to subgingival debridement alone. The two investigated antibiotic protocols led to comparable microbiological and inflammatory results
Intermediate temperature dynamics of one-dimensional Heisenberg antiferromagnets
We present a general theory for the intermediate temperature (T) properties
of Heisenberg antiferromagnets of spin-S ions on p-leg ladders, valid for 2Sp
even or odd. Following an earlier proposal for 2Sp even (Damle and Sachdev,
cond-mat/9711014), we argue that an integrable, classical, continuum model of a
fixed-length, 3-vector applies over an intermediate temperature range; this
range becomes very wide for moderate and large values of 2Sp. The coupling
constants of the effective model are known exactly in terms of the energy gap
above the ground state (for 2Sp even) or a crossover scale (for 2Sp odd).
Analytic and numeric results for dynamic and transport properties are obtained,
including some exact results for the spin-wave damping. Numerous quantitative
predictions for neutron scattering and NMR experiments are made. A general
discussion on the nature of T>0 transport in integrable systems is also
presented: an exact solution of a toy model proves that diffusion can exist in
integrable systems, provided proper care is taken in approaching the
thermodynamic limit.Comment: 38 pages, including 12 figure
Diabetes is a Risk Factor for Pulmonary Tuberculosis: A Case-Control Study from Mwanza, Tanzania.
Diabetes and TB are associated, and diabetes is increasingly common in low-income countries where tuberculosis (TB) is highly endemic. However, the role of diabetes for TB has not been assessed in populations where HIV is prevalent. A case-control study was conducted in an urban population in Tanzania among culture-confirmed pulmonary TB patients and non-TB neighbourhood controls. Participants were tested for diabetes according to WHO guidelines and serum concentrations of acute phase reactants were measured. The association between diabetes and TB, and the role of HIV as an effect modifier, were examined using logistic regression. Since blood glucose levels increase during the acute phase response, we adjusted for elevated serum acute phase reactants. Among 803 cases and 350 controls the mean (SD) age was 34.8 (11.9) and 33.8 (12.0) years, and the prevalence of diabetes was 16.7% (95% CI: 14.2; 19.4) and 9.4% (6.6; 13.0), respectively. Diabetes was associated with TB (OR 2.2, 95% CI: 1.5; 3.4, p<0.001). However, the association depended on HIV status (interaction, p = 0.01) due to a stronger association among HIV uninfected (OR 4.2, 95% CI: 1.5; 11.6, p = 0.01) compared to HIV infected (OR 0.1, 95% CI: 0.01; 1.8, p = 0.13) after adjusting for age, sex, demographic factors and elevated serum acute phase reactants. Diabetes is a risk factor for TB in HIV uninfected, whereas the association in HIV infected patients needs further study. The increasing diabetes prevalence may be a threat to TB control
Single-File Diffusion of Atomic and Colloidal Systems: Asymptotic Laws
In this work we present a general derivation of the non-Fickian behavior for
the self-diffusion of identically interacting particle systems with excluded
mutual passage. We show that the conditional probability distribution of
finding a particle at position after time , when the particle was
located at at , follows a Gaussian distribution in the long-time
limit, with variance for overdamped systems and with
variance for classical systems. The asymptotic behavior of the
mean-squared displacement, , is shown to be independent of the nature of
interactions for homogeneous systems in the fluid state. Moreover, the
long-time behavior of self-diffusion is determined by short-time and large
scale collective density fluctuations.Comment: 4 page
Transient peak-strain matching partially recovers the age-impaired mechanoadaptive cortical bone response
Mechanoadaptation maintains bone mass and architecture; its failure underlies age-related decline in bone strength. It is unclear whether this is due to failure of osteocytes to sense strain, osteoblasts to form bone or insufficient mechanical stimulus. Mechanoadaptation can be restored to aged bone by surgical neurectomy, suggesting that changes in loading history can rescue mechanoadaptation. We use non-biased, whole-bone tibial analyses, along with characterisation of surface strains and ensuing mechanoadaptive responses in mice at a range of ages, to explore whether sufficient load magnitude can activate mechanoadaptation in aged bone. We find that younger mice adapt when imposed strains are lower than in mature and aged bone. Intriguingly, imposition of short-term, high magnitude loading effectively primes cortical but not trabecular bone of aged mice to respond. This response was regionally-matched to highest strains measured by digital image correlation and to osteocytic mechanoactivation. These data indicate that aged bone’s loading response can be partially recovered, non-invasively by transient, focal high strain regions. Our results indicate that old murine bone does respond to load when the loading is of sufficient magnitude, and bones’ age-related adaptation failure may be due to insufficient mechanical stimulus to trigger mechanoadaptation
Electronic Raman scattering in YBCO and other superconducting cuprates
Superconductivity induced structures in the electronic Raman spectra of
high-Tc superconductors are computed using the results of ab initio LDA-LMTO
three-dimensional band structure calculations via numerical integrations of the
mass fluctuations, either in the whole 3D Brillouin zone or limiting the
integrations to the Fermi surface. The results of both calculations are rather
similar, the Brillouin zone integration yielding additional weak structures
related to the extended van Hove singularities. Similar calculations have been
performed for the normal state of these high-Tc cuprates. Polarization
configurations have been investigated and the results have been compared to
experimental spectra. The assumption of a simple d_(x^2-y^2)-like gap function
allows us to explain a number of experimental features but is hard to reconcile
with the relative positions of the A1g and B1g peaks.Comment: 14 pages, LaTeX (RevTeX), 5 PostScript figures, uses multicol.sty,
submitted to PR
NaAlH4 production from waste aluminum by reactive ball milling
Due to its thermodynamic properties and high reversibility, Ti doped sodium alanateis considered as a prototype hydrogen storage material. In this work we show how sodium alanate can be synthesized by reactive ball milling using aluminum particles obtained from recycled waste incineration slag. The synthesis was monitoredwith an in situ milling vial and characterized stepwise by PXD and DTA analyses. The sorption properties of the material were investigated using in situ synchrotron radiation PXD and volumetric analyses. A complete conversion of the starting reactants was obtained
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