Biomechanical evaluation of caudally and buccally screwed customised reconstruction plates for lateral segmental defects of mandible.

The aim of this study was to compare locking reconstruction plates with caudobuccally screwed custom mandibular reconstruction plates in bridging lateral mandibular segmental defects. The in vitro study was conducted on 13 polyurethane mandibles. A total of 7 mandibles with lateral segmental defects were bridged with locking reconstruction plates in group I, 6 mandibles with the same standard defect were bridged with caudobuccally screwed customised reconstruction plates in group II. Mean yield displacement, yield load, and displacement at 80 N (Newtons), 100 N, 200 N, 300 N loading were compared among the 2 groups. The mean (SD) displacement for Group I was 11.27 (3.6) mm, Group II was 21.08 (2.5) mm. Group II had significantly greater (p=0.0001) displacement when compared with Group I. The mean (SD) force before failure for Group I was 638.4 N (127.2), Group II was 1398. 3 N (162.7). Group II withstood significantly greater force than Group I (p=0.0001). The study reveals that the caudobuccally screwed custom reconstruction plates can significantly enhance yield load as preserving the preoperative shape of the face and mandible.

Open database analysis of scaling and spatio-temporal properties of power grid frequencies.

The electrical energy system has attracted much attention from an increasingly diverse research community. Many theoretical predictions have been made, from scaling laws of fluctuations to propagation velocities of disturbances. However, to validate any theory, empirical data from large-scale power systems are necessary but are rarely shared openly. Here, we analyse an open database of measurements of electric power grid frequencies across 17 locations in 12 synchronous areas on three continents. The power grid frequency is of particular interest, as it indicates the balance of supply and demand and carries information on deterministic, stochastic, and control influences. We perform a broad analysis of the recorded data, compare different synchronous areas and validate a previously conjectured scaling law. Furthermore, we show how fluctuations change from local independent oscillations to a homogeneous bulk behaviour. Overall, the presented open database and analyses constitute a step towards more shared, collaborative energy research.

Effects of fullerenol nanoparticles on kidney tissue in sevoflurane­treated rats.

AIM: The aim of this study is to demonstrate whether fullerenol C60 protects renal injury in sevoflurane­administered rats. METHOD: Rats (n: 24) were randomly divided into four groups: Control (Group C), Fullerenol C60 (Group F), Sevoflurane (Group S), Fullerenol C60-Sevoflurane (Group FS). Thirty minutes before the procedure, Fullerenol C60, 100 mg/kg, was administered intraperitoneally. Sevoflurane (2.3 %) was applied for 3 hours to rats in S and FS groups. Biochemical and histopathological parameters were analyzed in renal tissue samples. Kruskal-Wallis and Mann-Whitney U tests were used in statistical analyzes. RESULTS: Malondialdehyde (MDA) level and catalase (CAT) enzyme activity in Group S were significantly higher than that in all other groups. Paraoxanase (PON) enzyme activity in Group S was significantly lower than in Groups C and FS. The histopathological examination showed that vascular vacuolization and hypertrophy (VVH) and lymphocyte infiltration (LI) were significantly higher in the Group S compared to the Group C. CONCLUSION: Renal histopathology revealed that the administration of Fullerenol C60 prior to sevoflurane inhalation reduced oxidative stress and partially corrected the damage caused by anesthesia. We concluded that Fullerenol C60 has a renal protective effect in rats when administered before sevoflurane anesthesia (Tab. 2, Fig. 4, Ref. 40).

SIRT4 prevents excitotoxicity via modulating glutamate metabolism in glioma cells.

Excitotoxicity is the presence of excessive glutamate, which is normally taken up by glutamate transporters on astrocytes. Glutamate transporter 1 (GLT-1) is the major transporter on glia cells clearing more than 90% of the glutamate. Sirtuin 4 (SIRT4) is a mitochondrial sirtuin which is expressed in the brain. Previously, it was shown that loss of SIRT4 leads to a more severe reaction to kainic acid, an excitotoxic agent, and also decreased GLT-1 expression in the brain. In this study, we aimed to investigate whether overexpression of SIRT4 is protective against excitotoxicity in glia cells. We overexpressed SIRT4 in A172 glioma cell line and treated with kainic acid in order to induce excitotoxicity. We observed that SIRT4 overexpression increased the cell viability after kainic acid treatment. In addition, reduced glutamate was detected in glutamate assay with overexpression of SIRT4 after kainic acid treatment since SIRT4 decreased cell death by preventing excitotoxicity. Our results show that overexpression of SIRT4 increased the protein levels of GLT-1 and glutamate dehydrogenase (GDH) after kainic acid (KA) treatment so that excess glutamate can be absorbed. However, overexpression of SIRT4 decreased glutamine synthetase (GS) levels. These results demonstrate that, by inhibiting GS, SIRT4 prevents glutamine formation, which will be converted to glutamate in neurons. SIRT4 prevents excitotoxicity via upregulating glutamate metabolism. Finally, our results may show that SIRT4 might prevent excitotoxicity and related cell death via reducing GS expression and upregulating GLT-1 and GDH levels. Therefore, it is important to develop therapeutics against excitotoxicity through SIRT4-related pathways in the cell.

Dynamical modeling of cascading failures in the Turkish power grid.

A reliable supply of electricity is critical for our modern society, and any large-scale disturbance of the electrical system causes substantial costs. In 2015, one overloaded transmission line caused a cascading failure in the Turkish power grid, affecting about 75×106 people. Here, we analyze the Turkish power grid and its dynamical and statistical properties. Specifically, we propose, for the first time, a model that incorporates the dynamical properties and the complex network topology of the Turkish power grid to investigate cascading failures. We find that the network damage depends on the load and generation distribution in the network with centralized generation being more susceptible to failures than a decentralized one. Furthermore, economic considerations on transmission line capacity are shown to conflict with stability.

Generalized statistical mechanics of cosmic rays: Application to positron-electron spectral indices.

Cosmic ray energy spectra exhibit power law distributions over many orders of magnitude that are very well described by the predictions of q-generalized statistical mechanics, based on a q-generalized Hagedorn theory for transverse momentum spectra and hard QCD scattering processes. QCD at largest center of mass energies predicts the entropic index to be [Formula: see text]. Here we show that the escort duality of the nonextensive thermodynamic formalism predicts an energy split of effective temperature given by Δ [Formula: see text] MeV, where T H is the Hagedorn temperature. We carefully analyse the measured data of the AMS-02 collaboration and provide evidence that the predicted temperature split is indeed observed, leading to a different energy dependence of the e+ and e- spectral indices. We also observe a distinguished energy scale E* ≈ 50 GeV where the e+ and e- spectral indices differ the most. Linear combinations of the escort and non-escort q-generalized canonical distributions yield excellent agreement with the measured AMS-02 data in the entire energy range.

Entropies for severely contracted configuration space.

We demonstrate that dual entropy expressions of the Tsallis type apply naturally to statistical-mechanical systems that experience an exceptional contraction of their configuration space. The entropic index [Formula: see text] describes the contraction process, while the dual index [Formula: see text] defines the contraction dimension at which extensivity is restored. We study this circumstance along the three routes to chaos in low-dimensional nonlinear maps where the attractors at the transitions, between regular and chaotic behavior, drive phase-space contraction for ensembles of trajectories. We illustrate this circumstance for properties of systems that find descriptions in terms of nonlinear maps. These are size-rank functions, urbanization and similar processes, and settings where frequency locking takes place.

Incidence of q statistics in rank distributions.

We show that size-rank distributions with power-law decay (often only over a limited extent) observed in a vast number of instances in a widespread family of systems obey Tsallis statistics. The theoretical framework for these distributions is analogous to that of a nonlinear iterated map near a tangent bifurcation for which the Lyapunov exponent is negligible or vanishes. The relevant statistical-mechanical expressions associated with these distributions are derived from a maximum entropy principle with the use of two different constraints, and the resulting duality of entropy indexes is seen to portray physically relevant information. Whereas the value of the index α fixes the distribution's power-law exponent, that for the dual index 2 - α ensures the extensivity of the deformed entropy.

Sensitively recorded breathing signals of rats and their nonlinear dynamics.

Nonlinear dynamical properties of sensitively recorded breathing signals (SRBS), which include cardiac induced air flow pulsations so-called pneumocardiogram (PNCG) signals, are investigated, in this methodological study. For this purpose, we assessed the SRBS of laboratory rat. The nonlinear behaviors of SRBS were investigated by the reconstructing phase space, using the autocorrelation function and the false nearest neighbor method. The chaotic SRBS attractors were discussed from the point of view of the cardiopulmonary system. This method can be used to assess the heart performance and respiratory mechanics, and might be useful to design for the physiological studies of cardiorespiratory system in small laboratory animals.

Determination of phenolphthalein and methylene blue by first derivative spectrophotometry and potassium nitrate by direct spectrophotometry in a pharmaceutical formulation.

A rapid first derivative visible spectrophotometric determination is described for the simultaneous determination of phenolphthalein (PHP) and methylene blue (MB) in the presence of potassium nitrate (KNO3). Potassium nitrate is also determined by direct visible spectrophotometric method in the presence of phenolphthalein and methylene blue without any interference. The methods have been applied to the determination of the three compounds in a commercial dosage form. The calibration graphs were linear in the range of 0.30-3.20 mg mL-1 for MB and 0.80-3.18 micrograms mL-1 for PHP and 0.80-8.10 micrograms mL1 for KNO3. The specificity, accuracy and precision of the methods have been assessed.

Studies on cis-DDP, [Pt(Dach)(MePhSO)Cl]+ and [PtNH3)2(N-Py)Cl]+ binding to fumarase.

Two platinum analogs which have suitable physical properties and show antineoplastic activities comparable or greater than that obtained with cis-DDP were synthesized: [cis-Pt A2 (Am) Cl] NO3 and [Pt (dach) (RR'SO) Cl] NO3 (A: ammonia, Am: pyridine, dach: transdiaminocyclohexane, RR'SO: methylphenylsulphoxide). Their interactions with fumarase were studied. The inhibition of fumarase activity by the platinum compounds was followed kinetically by a spectrophotometric method. These two platinum compounds generally inhibited fumarase less than cis-DDP at the concentrations and reaction media (phosphate buffer or NaCl-buffer) studied.