Frequency estimation for single tone complex sinusoid is a fundamental problem in signal processing. A simple and effective way is to directly interpolate the discrete Fourier transform (DFT) ...coefficients around the peak of the magnitude spectrum. In this paper, we use theoretical analysis to show that correcting a phase term on the DFT coefficients before interpolation can reduce the estimation bias and improve the accuracy of the estimation significantly. We derive the amount of bias reduction that can be achieved by the phase correction. We then show that the phase correction can be considered as a pre-estimation correction while the effect of the previously proposed post-estimation correction is also to reduce the bias caused by the phase. In the experiments, we find that the phase correction proposed here and the post-estimation correction previously proposed is effective in different regions of frequency offset. We theoretically derive the threshold between the regions and propose a hybrid estimator which uses different corrections in different regions of frequency offset. Experiments show that the hybrid estimator is superior among direct estimators across the entire range of frequency offset at moderate and high SNR.
•A phase term in DFT coefficient is a cause of bias in frequency estimation.•Propose three different ways to correct the phase and reduce bias.•Derive the amount of bias reduction that can be achieved by phase correction.•Derive frequency threshold between phase correction and post-estimation correction.•Propose a hybrid estimator which switches corrections at threshold.
This study examined the associations between perceived neighborhood and home environmental factors and excessive television (TV) viewing time among Taiwanese older adults. The sample data was ...collected by administering computer-assisted telephone interviewers to 980 Taiwanese older adults (aged ≥ 65 years) living in two regions. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to examine the associations between self-reported perceived neighborhood and home environmental attributions and TV viewing time by using logistic regression analyses. The results showed that perceived neighborhood and home environmental factors were associated with excessive TV viewing time (≥2 h/day) after adjusting for potential confounders. Compared with a reference group, older adults who perceived their neighborhoods to have unsafe traffic were more likely to report excessive TV viewing time (OR = 1.36, 95%CI = 1.02-1.82). Older adults who reported having two or more TV sets in the home (OR = 1.77, CI = 1.28-2.44) and having a TV in the bedroom (OR = 1.55, CI = 1.18-2.03) were also more likely to report excessive TV viewing time. Further longitudinal research can confirm these findings, and tailored interventions focusing on the perceptions of neighborhood traffic safety and TV access at home for older adults might be effective means of preventing excessive TV viewing time.
We have examined the spatial distributions of polymer chains in blend films of weakly segregated polystyrene-block-poly(methyl methacrylate) P(S-b-MMA) and deuterated polystyrene (dPS). By ...fine-tuning the composition (ϕPS+dPS = 63.8 vol %) of the total PS/dPS component and annealing temperature (230 and 270 °C), P(S-b-MMA)/dPS blend films mainly form perforated layers with a parallel orientation (hereafter PLs//). The distributions of dPS in PLs// were probed by grazing-incidence small-angle neutron scattering (GISANS) and time-of-flight neutron reflectivity (ToF-NR). GISANS and ToF-NR results offer evidence that dPS chains preferentially locate at the free surface and within the PS layers for blend films that were annealed at 230 °C. Upon annealing at 270 °C, dPS chains distribute within PS layers and perforated PMMA layers. Nevertheless, dPS chains still retain a surface preference for thin films. In contrast, such surface segregation of dPS chains is prohibited for thick films when annealed at 270 °C.
Tenofovir disoproxil fumarate (TDF) and entecavir (ETV) reduce the risk of hepatocellular carcinoma (HCC) in patients of hepatitis B. This study compared the difference between ETV and TDF on risk of ...HCC recurrence and mortality in patients with HBV-related HCC after curative intent treatment.
Patients with HBV-related HCC who received HCC treatment (surgery or radiofrequency ablation RFA) and underwent long-term ETV or TDF therapy were retrospectively included. Baseline characteristics including age, sex, antiviral therapy, liver reserve, HCC stages, pathology reports and treatment modality were obtained. The risk of tumor recurrence, all-cause mortality, HCC-related mortality, and liver function were compared.
We identified 390 HBV-related HCC patients with curative intent treatment for HCC and treated with ETV (n = 328) or TDF (n = 62) between January 2011 and December 2020. The median age was 60 years, and 90.7% patients were males. After a median follow-up of 29 months, 186 patients developed recurrent HCC and 111 died. The baseline characteristics were comparable except more ALBI grade 3 patients in TDF group (76% vs. 48%, P < 0.001). Compared to ETV group, TDF users had lower all-cause mortality (adjusted hazard ratio aHR: 0.38, P = 0.003), and HCC-related mortality (aHR: 0.23, P = 0.005). Lower recurrence rate was noticed in TDF users after inverse probability of treatment weighting (IPTW). TDF users had improved ALBI grade and FIB-4 index compared with ETV groups.
TDF therapy is associated with a reduced risk of HCC-related outcomes among patients with HBV-related HCC after curative intent treatment compared with ETV usage.
•Multicentre surveillance of antimicrobial susceptibility among clinically important Gram-negative bacteria (GNB) in Taiwan.•Increasing carbapenem resistance among clinically important GNB, ...especially among nosocomial isolates.•blaKPC, especially the blaKPC-2 variant, was detected in 48.4% of carbapenem-resistant Klebsiella pneumoniae isolates.•Low prevalence of the mcr-1 gene.•mcr-1 was detected in different Enterobacteriaceae species, raising concern of potential dissemination.
Multicentre surveillance of antimicrobial susceptibility of clinically important Gram-negative bacteria (GNB) from 16 Taiwanese hospitals was performed. Escherichia coli (n = 398), Klebsiella pneumoniae (n = 346), Pseudomonas aeruginosa (n = 252) and Acinetobacter baumannii complex (ABC) (n = 188) bloodstream isolates, non-typhoidal Salmonella (n = 230) and Shigella flexneri (n = 18) from various sources were collected. Antimicrobial MICs were determined using broth microdilution. Genes encoding K. pneumoniae carbapenemases (KPCs), New Delhi metallo-β-lactamases (NDMs), Verona integron-encoded metallo-β-lactamase (VIM), OXA-48-like carbapenemase (OXA-48) as well as mcr-1–5 genes were detected by molecular methods. Rates of carbapenem non-susceptibility were 2.8%, 9.0%, 0.4%, 0%, 10.3% and 48.8% for E. coli, K. pneumoniae, Salmonella, Shigella, P. aeruginosa and ABC, respectively. For carbapenemases, one (0.3%) E. coli harboured blaNDM-1. Fifteen (4.3%), two (0.6%) and two (0.6%) K. pneumoniae contained blaKPC, blaOXA-48 and blaVIM, respectively. Two (0.5%) E. coli and fourteen (4.0%) K. pneumoniae were non-wild-type according to the colistin MIC. Among Enterobacteriaceae with a colistin MIC ≥ 2 mg/L, mcr-1 was detected in one E. coli, two K. pneumoniae and three Salmonella spp. All three mcr-1-positive Salmonella isolates were collected from community-acquired infections; none of the six mcr-1-positive Enterobacteriaceae were carbapenem-resistant. Carbapenem resistance has increased among clinically important GNB, especially among hospital-acquired infections. blaKPC, especially the blaKPC-2 variant, was detected in approximately one-half of the carbapenem-resistant K. pneumoniae isolates in this study. Although resistance rates to colistin remained low among Enterobacteriaceae, the finding of mcr-1 from different species raises concern of potential dissemination.
Hepatitis B virus (HBV) reactivation is a well-known complication after rituximab-based chemotherapy in patients with B cell lymphoma (BCL) who have resolved HBV infection. This retrospective cohort ...study used electronic medical records from the Kaohsiung Chang Gung Memorial Hospital. There were 128 patients with BCL and resolved HBV infection treated with 1st-line rituximab-containing therapy from 2008 to 2013. No patient received antiviral prophylaxis. Patients with high pretreatment hepatitis B surface antibody (anti-HBs titer ≥100 mIU/mL), had significantly less HBV reactivation (2.0%, 1/49) than patients with low (10-100 mIU/mL, 10.8%, 4/37) or negative anti-HBs (<10 mIU/mL, 23.8%, 10/42) (p = 0.001). No patient in the high group vs. 1 (2.7%) low group vs. 6 (14.3%) negative group developed HBV-related hepatitis (p = 0.002). Patients with high pretreatment anti-HBs have a low risk of HBV-related complications and may not require antiviral prophylaxis. We propose an algorithm for the management of HBV reactivation risk in BCL.
This study aimed to investigate the association of sleep regularity with time spent in sedentary behavior (SB) and physical activity (PA) in adults with full-time jobs.
This was a cross-sectional ...study. Adults aged 21-64 years with full-time jobs were recruited between August 2019 and December 2020 in Taiwan. The time spent in SB/PA was assessed using triaxial accelerometers (Actigraph wGT3x-BT), and PA was further classified into light-intensity physical activity (LPA) and moderate-to-vigorous intensity physical activity (MVPA). Each participant recorded their daily sleep patterns and work hours in a log, which was further used to measure sleep variability and social jet lag. Linear regression was applied to examine the associations of indicators of sleep regularity with SB time and PA time.
A total of 192 adults (men = 28.13%; mean age = 38.56 ± 8.89 years) were included in this study. After adjusting for potential covariates, greater social jet lag was related to more SB time (unstandardized coefficient B = 14.39, P = .005) and less LPA time (B = −0.02, P = .010). No evidence of an association between other indicators of sleep regularity with SB/PA time was found.
These results provide evidence for a relationship between sleep regularity and SB/PA time in working adults. Maintaining regular sleep, especially a small social jet lag, was suggested to promote physical activity and avoid a sedentary lifestyle. Future research is recommended to examine work-related influences on the associations and bidirectional relationship between sleep regularity and SB/PA.
The aim of this research was to investigate the relationships between objectively measured sleep duration and physical function in older adults.
We recruited community-dwelling older adults aged ≥ 60 ...years old in Taipei City, Taiwan. Sleep duration was measured with accelerometers and recorded as the total hours of sleep per night for each participant. The following physical functions were assessed: 1) grip strength (measured by handgrip dynamometer), 2) balance (1-leg standing test), 3) lower body strength (5-timed chair stand), 4) basic mobility (timed up and go test), 5) gait speed (5-m walk test). The relationships between sleep duration and physical function outcomes were analyzed using generalized additive models, controlling for objectively measured sedentary behavior and moderate-to-vigorous physical activity, and other sociodemographic variables.
A total of 121 older adults (men = 28.9%; mean age = 70.0 ± 5.0 years) was included in this study. A positive association of sleep duration with grip strength was found after adjusting for covariates (P = .005). No significant associations were observed between sleep duration and the other physical function outcomes.
For older adults, lengthening their sleep duration may be helpful to enhance the grip strength. This result has implications for improving their health by targeting better performance in specific physical functions. Further studies of sleep duration and physical function among older adults should investigate the underlying mechanisms.
Geriatric depression is a common but preventable psychiatric disorder; however, its association with specific sleep patterns remains unclear. Therefore, we examined the association of self-reported ...sleep duration and sleep timing with depressive symptoms in the older population.
A total of 1068 older Taiwanese adults (52.7% women; 72.2 ± 5.7 y) responded to a telephone survey during 2019–2020. Self-reported data on sociodemographic characteristics, sleep duration, bedtime, wake-up time (adapted items from Pittsburgh Sleep Quality Index), and depressive symptoms (five-item Center for Epidemiological Studies–Depression scale) were included. Generalized additive models were used to examine the nonlinear associations of sleep duration and midpoint sleep time (ie, the midpoint of bedtime and wake-up time) with depressive symptoms.
The means of sleep duration and midpoint sleep time in the participants were 6 h per night and 02:13 h, respectively. The results showed marked nonlinear associations of sleep patterns with depressive symptoms. Sleep duration shorter than 4 h per night was associated with a relatively higher level of depressive symptoms, with the highest risk (coefficient = 3.41; 95% confidence interval CI = 2.12, 4.70) while sleeping 2.06 h per night. The midpoint sleep time was positively associated with depressive symptom scores after 01:00 h.
The results showed that sleep duration and fitting sleep timing were nonlinearly associated with the risks of depressive symptoms in the general older adult population. These findings have implications for targeting nonpharmacological approaches by tackling modifiable behaviors, such as adequate sleep duration and timing, with decreased risks of depressive symptoms in the older adult population.
•Nonlinear associations between sleep patterns and depressive symptoms in older adults.•Sleep duration less than 4 h/night was associated with higher depressive risks.•The midpoint sleep time after 01:00 h was associated with higher depressive risks.•Sleep-related approach to reduce the depressive risks includes adequate duration and fitting timing.
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