Abstract-Orthogonalfrequency division multiplexing (OFDM) offers high data rates and robust performance in frequency selective channels by link adaptation utilizing information about the channel quality. A crucial parameter required for adaptive transmission is the signal-to-noise ratio (SNR). In this paper, we propose a novel SNR estimation algorithm for wireless OFDM systems based on the reuse of the synchronization preamble. The periodic structure of the preamble is utilized for the computationally efficient SNR estimation algorithm, based on the second-order moments of received preamble samples. The performance of the proposed algorithm is compared with the MMSE algorithm and two preamble-based algorithms found in the literature. It is shown that the proposed algorithm is robust against frequency selectivity and may therefore be used for subchannel SNR estimation.

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Tibial SEPs produce the most abnormal results and the highest sensitivity in the RR-MS. We propose that this test as useful criterion for the diagnosis of MS.

Renal dysfunction is highly prevalent in the elderly CHF patients. It is associated with decreased functional capacity and therefore with poor prognosis. This study corroborates the use of eGFR not only as a powerful predictor of mortality in CHF, but also as an indicator of the functional capacity of cardiopulmonary system. However, clinicians underestimate a serial measurement of eGFR while it should be the part of a routine evaluation performed in every patient with CHF, particularly in the elderly population.

The optimization of wireless orthogonal frequency division multiplexing (OFDM) systems is based on the knowledge of the signal-to-noise ratio (SNR). Most of the existing methods for the SNR estimation operates in the frequency-domain and assumes perfect carrier frequency offset (CFO) synchronization. However, it has been shown that in real systems in the presence of the residual CFO this estimators are prone to performance degradation. This problem can be avoided by estimating the SNR in the time-domain. In this paper, a novel low-complexity time-domain SNR estimator based on time periodic Zadoff-Chu (ZC) sequence, named TDZCE, is proposed. When applied to the time periodic synchronization preamble, commonly used in packed based OFDM systems, the special property of a ZC sequence preserves the considered comb-type structure both in the frequency and time-domain. This allows for easy adaptation of previously proposed moment-based SNR estimator to be applied to the time-domain samples. The TDZCE outperforms the existing time-domain SNR estimators in frequency-flat channels in the presence of the CFO, and approaches the Cramer-Rao bound (CRB) as the number of periodic parts of the proposed preamble increases. Additionally, it offers considerable computational savings compared to the existing time-domain SNR estimators.

Background Besides classical and electrical toothbrushes market offers tooth brushes that can be chewed, like chewing gums. The aim of this study was to show the effectiveness of chewable toothbrush versus a conventional brush in the students’ population. Methods The prospective study included 346 students. For this research, we used a e-questionnaire for “smart” phones, that students completed outside the dental office. Respondents are divided into two groups: control group used conventional toothbrushes, respondents from the tested group used chewable toothbrush. For assessment of accumulation of the plaque we used TQHI index. For testing statistical hypotheses, the following were used: t-test for two independent samples and analysis of the variance of repeated measurements. Results Before brushing teeth, the average TQHI value for chewable brushes is 2.8 ± 0.3, while conventional is 2.7 ± 0.3, which is not a statistically significant difference ( p = 0.448). After brushing teeth, the average TQHI value for chewable brushes is 2.0 ± 0.1, while conventional 2.0 ± 0.3, which is also not statistically significant ( p = 0.729). Observing the index of the plaque values on the tooth surfaces in the upper jaw, in both groups, there was a statistically significant change in the amount of plaque in time ( p < 0.001). There is a statistically significant interaction between groups and changes in the amount of plaque in the observed period ( p = 0.013). Conclusions The fact that there is no significant difference in the effectiveness of the tested brushes indicates the benefits of using chewable toothbrushes in order to reduce plaque, primarily in the inability to use conventional brushes.

To date, many questions about the extent and cause of pharmacokinetic (PK) variability of even the most widely studied and prescribed β1-adrenergic receptor blockers, such as metoprolol and bisoprolol, remain unanswered. Given that there are still no published population pharmacokinetic (PopPK) analyses of bisoprolol in routinely treated patients with acute coronary syndrome (ACS), the aim of this study was to determine its PK variability in 71 Serbian patients with ACS. PopPK analysis was conducted using a nonlinear mixed-effects model (NONMEM), version 7.3.0 (Icon Development Solutions). In each patient, the same formulation of bisoprolol was administered once or twice daily at a total daily dose of 0.625–7.5 mg. We separately assessed the effects of 31 covariates on the PKs of bisoprolol, and our results indicated that only 2 covariates could have possible influence on the variability of the clearance of bisoprolol: the mean daily dose of the drug and smoking habits of patients. These findings suggest that possible autoinduction of drug metabolism by higher total daily doses and induction of cytochrome P450 isoform 3A4 (CYP3A4) by cigarette smoke in liver could be the potential causes of increased total clearance of bisoprolol in patients with ACS.