Detection of Audio Tampering Based on Electric Network Frequency Signal.

The detection of audio tampering plays a crucial role in ensuring the authenticity and integrity of multimedia files. This paper presents a novel approach to identifying tampered audio files by leveraging the unique Electric Network Frequency (ENF) signal, which is inherent to the power grid and serves as a reliable indicator of authenticity. The study begins by establishing a comprehensive Chinese ENF database containing diverse ENF signals extracted from audio files. The proposed methodology involves extracting the ENF signal, applying wavelet decomposition, and utilizing the autoregressive model to train effective classification models. Subsequently, the framework is employed to detect audio tampering and assess the influence of various environmental conditions and recording devices on the ENF signal. Experimental evaluations conducted on our Chinese ENF database demonstrate the efficacy of the proposed method, achieving impressive accuracy rates ranging from 91% to 93%. The results emphasize the significance of ENF-based approaches in enhancing audio file forensics and reaffirm the necessity of adopting reliable tamper detection techniques in multimedia authentication.

Clinical characteristics, antimicrobial resistance and capsular types of community-acquired, healthcare-associated, and nosocomial Klebsiella pneumoniae bacteremia.

Background: Klebsiella pneumoniae bacteremia is a major cause of morbidity and mortality worldwide. We aimed to compare the clinical characteristics, distribution of capsular types, and antimicrobial resistance of K. pneumoniae bacteremia among community-acquired (CA), healthcare-associated (HCA), and nosocomial infections. Methods: This retrospective study of patients with K. pneumoniae bacteremia was conducted at Taipei Veterans General Hospital from January to December 2015. Clinical characteristics of K. pneumoniae bacteremia were collected. The K. pneumoniae isolates were subjected to antimicrobial susceptibility testing and capsular genotyping. Results: In total, 337 patients with K. pneumoniae bacteremia were identified: 70 (20.8%), 102 (30.3%), and 165 (48.9%) presented with CA, HCA, and nosocomial infection, respectively. The 28-day mortality of HCA bacteremia was lower than that of nosocomial bacteremia (17.6% versus 30.9%, p = 0.016); however, that of the HCA and CA bacteremia was similar (17.6% versus 14.3%, p = 0.557). CA isolates had the highest prevalence of virulent capsular types (51.4%), followed by HCA (36.3%) and nosocomial isolates (19.4%). The proportion of multidrug-resistant (MDR) isolates was highest in nosocomial infections (41.8%), followed by HCA (23.5%) and CA infections (5.7%). Conclusion: CA, HCA and nosocomial K. pneumoniae are distinct entities, as evidenced by the differences in clinical characteristics, antimicrobial resistance, and capsular types found in this study.

Pharmacokinetics of breviscapine liposomes following intravenous injection in Beagle dogs / 药学学报

<p><b>AIM</b>To prepare the breviscapine liposomes and study the pharmacokinetics of breviscapine liposomes in Beagle dogs.</p><p><b>METHODS</b>The cross-over design (two periods) was employed. Six Beagle dogs were administrated a single intravenous dosage of 28 mg of breviscapine liposomes and reference preparation, respectively, scutellarin in plasma of 6 dogs at different sampling time was determined by RP-HPLC. The pharmacokinetic parameters were calculated by 3P97 program and compared by statistic analysis.</p><p><b>RESULTS</b>The mean concentration-time curves of breviscapine liposomes and reference preparation were both fitted to two-compartment model with the main pharmacokinetic parameters as follows: T 1/2 alpha were (4.4 +/- 0.7) min and (1.8 +/- 1.3) min respectively; T 1/2 beta were (55 +/- 27) min and (28 +/- 23) min respectively; V(c) were (1 580 +/- 265) mL and (2 460 +/- 2 200) mL respectively; CL(s) were (88 +/- 10) mL x min(-1) and (324 +/- 69) mL x min(-1) respectively; and AUC(0-720) were (363 +/- 42) microg x min x mL(-1) and (102 +/- 19) microg x min x mL(-1) respectively. The T 1/2 alpha, CL(s) and AUC(0-720) of breviscapine liposomes all had significant difference from those of reference preparation, after the data were examined by a one-way analysis of variance (ANOVA).</p><p><b>CONCLUSION</b>Compared with the reference preparation, breviscapine liposomes had a much more higher concentration in plasma and contained characteristic of sustained-release, which ameliorated the pharmacokinetic properties of scutellarin.</p>