Antimicrobial penetration in a dual-species oral biofilm after noncontact brushing: an in vitro study

OBJECTIVES

Oral biofilm is inevitably left behind, even after powered brushing. As a special feature, powered brushing removes biofilm in a noncontact mode. When the brushing distance becomes too large, biofilm is left behind. We hypothesize that biofilm left behind after brushing has different viscoelastic properties than before brushing, impacting antimicrobial penetration.

MATERIALS AND METHODS

In vitro grown dual-species biofilms were subjected to 20 % mechanical deformation before and after powered brushing at 4-mm brushing distance. Biofilm thickness and stress relaxation were measured for unbrushed and brushed biofilms. Stress relaxation was analyzed with a three-element Maxwell model. Antimicrobial penetration from five mouthrinses was microscopically evaluated for unbrushed and brushed biofilms.

RESULTS

Thicknesses of unbrushed and brushed biofilms were similar. Brushing decreased the prevalence of fast and increased the prevalence of slow relaxation elements, which was accompanied by deeper penetration of chlorhexidine and cetylpyridinium chloride. Penetration of antimicrobials from other mouthrinses was relatively low in unbrushed and brushed biofilms.

CONCLUSIONS

This confirmation of our hypothesis points to an additional advantage of powered toothbrushing in a noncontact mode, changing the viscoelastic properties of biofilm in a direction that increases antimicrobial penetration of chlorhexidine and cetylpyridinium.

CLINICAL RELEVANCE

The biofilm left behind after noncontact powered toothbrushing may have less recalcitrance toward penetration of chlorhexidine and cetylpyridinium chloride than prior to brushing.

Electronic situation report in a nuclear power plant

During the last years the introduction of an electronic situation report system in nuclear power plants has been intensively discussed in the working group emergency staff coordinators of the VGB (‘Verband der Großkraftwerksbetreiber’). In parallel, many federal state authorities as well as the German Ministry of the Environment already successfully started to operate such a system. Based on a solution developed for the ministry for environment Baden-Württemberg, the specific requirements are adapted and extended for the operation in a nuclear power plant. The most important features are easy handling, open interfaces to the systems of the authorities, and flexibility for functional extensions. The advantages recognized after the first test stages led the nuclear power plants Biblis and Neckarwestheim to the decision to introduce such a system at the plant site. First progress and experience gained are reported from the perspective of the crisis management group of the power plant.

Determination and evaluation of the radiological situation using mobile measurements during the ground phase

The nuclear reactor remote monitoring system of the state of Baden-Württemberg (Kernreaktor-Fernüberwachung Baden-Württemberg – KFÜ BW) is implemented according to the recently renewed “recommendations for remote monitoring of nuclear power plants”. In Baden-Württemberg, the application area of the system covers both, the surveillance of internal procedures on one hand, and the handling of incidents or accidents on the other. The following paper shows the role of the KFÜ regarding the determination and evaluation of the radiological situation in the range of off-site emergency response. Progress is reported on the measurement conception and the technical possibilities for the investigation of the radiological situation after the end of the deposition of radio nuclides (ground phase).

Comparative analysis of lifestyle factors, screening test use, and clinicopathologic features in association with survival among Asian Americans with colorectal cancer

Background:

Colorectal cancer (CRC) diagnoses and disease-specific survival (DSS) vary between ethnic groups in the United States. However, few studies have assessed differences among Asian subgroups.

Methods:

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify patients with invasive CRC between 1988 and 2008. Differences in clinicopathologic features, and DSS rates were compared among Asian subgroups. The California Health Interview Survey was used to examine risk factors and screening patterns for CRC.

Results:

The study included 359 374 patients with 8.4% Asian. Patients in all Asian subgroups were younger (median: 68 years) at diagnosis than non-Hispanic white (NHW) patients (median: 72 years). Most Asian subgroups, except Hawaiians, had better DSS than NHW patients although Asian subgroups had more advanced disease than NHW. Indian/Pakistani patients had a higher 5-year DSS than other Asian subgroups. Obesity proportions were lower in Asian subgroups (<50.2%) than in NHW (59.8%). Vietnamese men and Korean women had the lowest proportions of CRC screening. Advance tumour stages were highly associated with worse DSS in each ethnicity group. High tumour grades were associated with worse DSS in NHW, Filipino, and Chinese. Older age at diagnosis was associated with worse DSS in most ethnicity groups except Hawaiian and Vietnamese.

Conclusion:

Disparities exist between Asians and NHW with CRC, and among various Asian subgroups. Differences in cancer clinicopathologic features, patients' behavioural habits, lifestyle, and screening patterns may explain some differences in CRC survival observed among ethnic groups.

Incommensurate antiferromagnetism in a pure spin system via cooperative organization of local and itinerant moments

Materials with strong correlations are prone to spin and charge instabilities, driven by Coulomb, magnetic, and lattice interactions. In materials that have significant localized and itinerant spins, it is not obvious which will induce order. We combine electrical transport, X-ray magnetic diffraction, and photoemission studies with band structure calculations to characterize successive antiferromagnetic transitions in GdSi. GdSi has both sizable local moments and a partially nested Fermi surface, without confounding contributions from orbital effects. We identify a route to incommensurate order where neither type of moment dominates, but is rooted in cooperative feedback between them. The nested Fermi surface of the itinerant electrons induces strong interactions between local moments at the nesting vector, whereas the ordered local moments in turn provide the necessary coupling for a spin-density wave to form among the itinerant electrons. This mechanism echoes the cooperative interactions between electrons and ions in charge-density-wave materials, and should be germane across a spectrum of transition-metal and rare-earth intermetallic compounds.

Sirtuin 1 affects the transcriptional expression of adipose triglyceride lipase in porcine adipocytes

To investigate whether sirtuin 1 (Sirt1) could affect the transcriptional expression of the adipose triglyceride lipase (ATGL) gene, we treated porcine adipocytes with the general Sirt1 activator resveratrol (RES) with the Sirt1 inhibitor nicotinamide (NAM) or a knockdown of Sirt1 by Sirt1-specific small interfering RNA (siRNA). The RES (50 μM) activated Sirt1 gene expression and increased ATGL gene expression and glycerol release (P < 0.01). The Sirt1 inhibitor NAM or knockdown with Sirt1 siRNA further proved that the ATGL mRNA abundances were decreased (P < 0.05) after inhibition with Sirt1 in adipocytes. Furthermore, we found the opposite Sirt1 regulation pattern for PPARγ to that of ATGL in adipocytes. In summary, Sirt1 regulates the transcriptional expression of ATGL in adipocytes, and PPARγ appears to have an important role in this process. These results add to our understanding of the role of Sirt1 in adipose mobilization.

Development of FPV140 antigen-specific ELISA differentiating fowlpox virus isolates from all other viral pathogens of avian origin

The FPV140 gene encodes an envelope protein of fowlpox virus (FPV). In this study, the FPV140 gene of FPV Chinese isolate HH2008 was cloned and the comparison of its sequence with other FPV isolates showed it to be highly conserved across all FPV isolates. A recombinant plasmid pET-FPV140 carrying FPV140 gene was constructed and transformed into Escherichia coli. The optimal expression condition for the FPV140 gene was developed and purified FPV140 recombinant protein was used to produce rabbit polyclonal antibody. An indirect ELISA using this anti-FPV140 polyclonal antibody was capable of distinguishing avian FPV isolates from other common avian pathogens such as mycoplasma gallisepticum, infectious laryngotracheitis virus, avian influenza virus, infectious bursal disease virus, and avian infectious bronchitis virus. This ELISA will serve as a useful diagnostic tool for the detection of FPV in clinical samples.

Atomic-scale mechanisms of the glass-forming ability in metallic glasses

The issue, composition dependence of glass-forming ability (GFA) in metallic glasses (MG), has been investigated by systematic experimental measurements coupled with theoretical calculations in Cu-Zr and Ni-Nb alloy systems. It is found that the atomic-level packing efficiency strongly relates to their GFA. The best GFA is located at the largest difference in the packing efficiency of the solute-centered clusters between the glassy and crystal alloys in both MG systems. This work provides an understanding of GFA from atomic level and will shed light on the development of new MGs with larger critical sizes.

The association of plasma free amino acids with liver enzymes in Type 2 diabetic patients

BACKGROUND

Elevated γ-glutamyl transpeptidase (GGT) and alanine aminotransferase (ALT) could predict the risk of Type 2 diabetes (T2D), but the reason for their elevation was unclear. GGT and ALT mediated the metabolism of many amino acids (AA). Up to now, it was not investigated whether abnormal AA concentration was associated with elevated liver enzymes.

AIM

This study was to investigate the status of AA in T2D and their relationship with liver enzymes.

SUBJECTS AND METHODS

A total of 132 T2D patients and 137 healthy controls were recruited. Plasma free AA were measured by high-performance liquid chromatography. The contribution of individual AA to liver enzymes was assessed by stepwise linear regression.

RESULTS

a) The levels of alanine, valine, leucine, isoleucine, phenylalanine, tyrosine, methionine, glutamate, and lysine were higher while the level of glycine was lower in T2D than in controls (all p<0.01). b) Glutamate contributed to GGT in T2D, and its contribution was even greater than that of waist circumference. Leucine, lysine, and glutamate contributed to ALT.

CONCLUSION

There were significant differences in plasma AA profile between T2D and controls. Abnormal AA might contribute to elevated liver enzymes. The interaction between AA, liver enzymes, and the risk of T2D should be further investigated by prospective studies.

Terahertz wavefronts measured using the Hartmann sensor principle

We demonstrate for the first time that the Hartmann wavefront sensor (HWS) principle can be applied for characterizing the wavefronts of terahertz (THz) electromagnetic radiation. The THz Hartmann wavefront sensor consists of a metallic plate with an array of holes and a two-dimensional scanable pyro-electric detector. The THz radiation with different wavefronts was generated by a far-infrared gas laser operated at 2.5 THz in combination with a number of objects that result in known wavefronts. To measure the wavefront, a beam passing through an array of holes generates intensity spots, for which the positions of the individual spot centroids are measured and compared with reference positions. The reconstructed wavefronts are in good agreement with the model expectations.

Molecular arrangement in water: random but not quite

Water defines life on Earth from the cellular to the terrestrial level. Yet the molecular level arrangement in water is not well understood, posing problems in comprehending its very special chemical, physical and biological properties. Here we present high-resolution x-ray diffraction data for water clearly showing that its molecular arrangement exhibits specific correlations that are consistent with the presence of rings of H(2)O molecules linked together by hydrogen bonds into tetrahedral-like units from a continuous network. This level of molecular arrangement complexity is beyond what a simple 'two-state' model of water (Bernal and Fowler 1933 J. Chem. Phys.1 515-48) could explain. It may not be explained by the recently put forward 'chains-clusters of completely uncorrelated molecules' model (Wernet et al 2004 Science 304 995-9) either. Rather it indicates that water is homogeneous down to the molecular level where different water molecules form tetrahedral units of different perfection and/or participate in rings of different sizes, thus experiencing different local environments. The local diversity of this tetrahedral network coupled to the flexibility of the hydrogen bonds that hold it together may explain well the rich phase diagram of water and why it responds non-uniformly to external stimuli such as, for example, temperature and pressure.

[Validity and reliability of digital diagnostic measurements on digital three-dimensional dental models]

Digital three-dimensional dental models are widely used for orthodontic diagnosis. The aim of this clinical study was to assess the validity and reliability of digital diagnostic measurements on digital three-dimensional dental models. Two types of digital three-dimensional dental models and a plaster dental model were made of 10 volunteers. Digital measurements of the tooth width were compared with the physical measurements of the plaster models. None of the digital diagnostic measurements appeared to differ significantly from the physical measurements.

Experimental observation of anisotropic magnetic turbulence in a reversed field pinch plasma

In this Letter we report an experimental study of fully developed anisotropic magnetic turbulence in a laboratory plasma. The turbulence has broad (narrow) spectral power in the perpendicular (parallel) direction to the local mean magnetic field extending beyond the ion cyclotron frequency. Its k[see symbol] spectrum is asymmetric in the ion and electron diamagnetic directions. The wave number scaling for the short wavelength fluctuations shows exponential falloff indicative of dissipation. A standing wave structure is found for the turbulence in the minor radial direction of the toroidal plasma.