Low muscle mass, low muscle function, and sarcopenia in the urban and rural elderly.

Health outcomes of the elderly vary between rural and urban areas. Sarcopenia is diagnosed as loss of muscle strength or impaired physical performance, namely "low muscle function" and low muscle mass. Outcomes of low muscle mass and low muscle function are not equal. This study aimed to investigate the prevalence of low muscle mass, low muscle function, and sarcopenia in rural and urban populations and to determine whether regional differences were associated with each of these components. Participants aged ≥ 69 years (n = 2354) were recruited from three urban districts and one rural district in Korea. Low muscle mass was defined by appendicular lean mass using bioelectrical impedance analysis. Low muscle function was defined by handgrip strength and 5-chair stand test. Sarcopenia was defined as low muscle mass plus low muscle function. The prevalence of low muscle function (53.7% vs. 72.8%), and sarcopenia (16.3% vs. 24.4%) were higher in the rural elderly population. Rural residence was associated with low muscle function (OR 1.63; 95% CI 1.13-2.37, P = 0.009), but not with low muscle mass (OR 0.58; 95% CI 0.22-1.54, P = 0.271) or with sarcopenia (OR 1.13; 95% CI 0.63-2.00, P = 0.683). Interventions to detect and improve low muscle function in rural elderly population are needed.

Cohort profile: Korean Urban Rural Elderly (KURE) study, a prospective cohort on ageing and health in Korea.

PURPOSE: The Korean Urban Rural Elderly (KURE) cohort was initiated to study the epidemiologic characteristics, physical performance, laboratory and imaging biomarkers and incidence of age-related diseases in an elderly population with respect to both clinical and social aspects to develop preventive and therapeutic strategies for combatting age-related diseases. PARTICIPANTS: A total of 3517 adults aged 65 or older participated in the cohort at baseline from 2012 to 2015, recruited from three urban districts and one rural district in Korea. The second-wave follow-up survey is now being conducted at a 4-year interval from baseline (2016-2019; follow-up rate 71.5%). The data set included detailed information on anthropometric and socioeconomic factors, functional assessments, image scans (plain radiography, dual-energy X-ray absorptiometry and CT), biospecimens (ie, serum, urine and DNA) and social support networks along with the feasibility of linkage to a national claims database. FINDINGS TO DATE: Mean age of participants at entry was 71.9±4.6 years and 67% were women. From the KURE participants enrolled in baseline recruitment, several studies were published in the fields of cardiometabolic diseases, musculoskeletal health and the association between social support network and diseases in ageing. FUTURE PLANS: Participants will be observed actively and passively every 4-5 years and the first follow-up will be completed in 2020. The KURE data set has strength in comprehensive physical function assessments, quantifiable imaging data sets using CT and detailed information regarding the social support networks of participants from a large community-based elderly Korean population.

Suppression of thermal wavelength drift in widely tunable DS-DBR laser for fast channel-to-channel switching.

We present a simple and effective method for suppressing thermally induced wavelength drift in a widely tunable digital supermode distributed Bragg reflector (DS-DBR) laser monolithically integrated with a semiconductor optical amplifier (SOA). For fast thermal compensation, pre-compensatory currents are injected into the gain medium section of the DS-DBR laser and the SOA. This method can be easily applied to existing commercial tunable lasers, since it is implemented without any modification to manufacturing process. Experimental results exhibit that wavelength stability is noticeably improved to ± 0.01 nm. We also experimentally demonstrate a fast channel-to-channel switching in a wavelength-routed optical switching system employing a 90 × 90 arrayed waveguide grating router (AWGR). The measured switching time is less than 0.81 µs.

All-fiber 6-mode multiplexers based on fiber mode selective couplers.

All-fiber 6-mode multiplexer composed of two consecutive LP11-mode selective couplers (MSC), two LP21-MSCs and an LP02-MSC is fully characterized by wavelength-swept interferometer technique. The MSCs are fabricated by polished-type fiber couplers coupling LP01 mode of a single mode fiber into a higher-order mode of a few mode fiber. A pair of the mode multiplexers has minimum mode dependent loss of 4 dB and high mode group selectivity of over 15 dB. Mode division multiplexed transmission enabled by the all-fiber mode multiplexers is demonstrated over fiber spans of 117 km employing an in-line multi-mode optical amplifier. 6 modes of 120 Gb/s dual polarization quadrature phase shift keying signals combined with 30 wavelength channels are successfully transmitted.

Incremental benefit of coronary artery calcium score above traditional risk factors for all-cause mortality in asymptomatic Korean adults.

BACKGROUND: Coronary artery calcium score (CACS) is a well-recognized marker for subclinical coronary atherosclerosis, particularly in asymptomatic populations. To date, however, the added prognostic benefit of CACS compared with traditional risk factors in an Asian population remains unknown. This study therefore investigated the benefit of CACS over traditional risk factors for all-cause mortality in a large multicenter registry of asymptomatic Korean adults. METHODS AND RESULTS: A total of 34,386 individuals were retrospectively enrolled to participate in a general health examination. The Framingham 10-year risk score (FRS) was calculated according to the traditional risk stratification algorithm and CACS was calculated in log(CACS+1) for continuous data and categorized as 0, 1-100, 101-400 and >400. During a median follow-up of 4.9 years (IQR, 3.0-7.1), there were 303 all-cause deaths (0.9%). Following adjustment, CACS was independently associated with all-cause death (hazard ratio, 1.10; 95% confidence interval (CI): 1.05-1.17; P<0.001). Notably, CACS added further prognostic value above and beyond FRS (likelihood ratio, χ(2)=75.42, P<0.001; continuous net reclassification improvement=0.40, 95% CI: 0.29-0.51, P≤0.001; improving C-statistic from 0.64, 95% CI: 0.61-0.67 to 0.68, 95% CI: 0.64-0.71; ∆C=0.04, 95% CI: 0.01-0.06, P=0.002). CONCLUSIONS: In an asymptomatic Korean population, CACS improved prediction of all-cause mortality over and above that of a conventional risk tool.

Effect of Triflusal on Primary Vascular Dysregulation Compared with Aspirin: A Double-Blind, Randomized, Crossover Trial.

PURPOSE: Primary vascular dysregulation (PVD) is a condition in which the response to cold temperature or external stimuli is abnormal. We investigated whether triflusal use results in amelioration of PVD symptoms and improvement of several related parameters compared with aspirin. MATERIALS AND METHODS: Eighty-eight PVD patients (54% female, 56±8 years) were randomly selected to receive either triflusal (300 mg, b.i.d.) or aspirin (150 mg, b.i.d.) for a period of 6 weeks followed by crossover. PVD was defined as both red-blood-cell standstill in video-assisted microscopic capillaroscopy during cold stimulation using carbon dioxide gas and a score of more than 7 points in a validated questionnaire. Efficacy of treatment was assessed by 1) cold intolerance symptom severity (CISS) score, 2) finger Doppler indices, and 3) indocyanine green perfusion imaging. RESULTS: The use of triflusal resulted in a greater improvement in CISS score (44.5±18.4 vs. 51.9±16.2; p<0.001) and in mean radial peak systolic velocity (69.8±17.2 vs. 66.1±16.4; p=0.011) compared to aspirin. Furthermore, significant differences were also observed in perfusion rates on indocyanine green perfusion imaging between triflusal and aspirin (45.6±25.8 vs. 51.6±26.9; p=0.020). CONCLUSION: Triflusal was more effective and demonstrated a more consistent impact on the improvement of symptoms and blood flow in patients with PVD than aspirin.

Mode- and wavelength-division multiplexed transmission using all-fiber mode multiplexer based on mode selective couplers.

We propose all-fiber mode multiplexer composed of two consecutive LP11 mode selective couplers that allows for the multiplexing of LP01 mode and two-fold degenerate LP11 modes. We demonstrate WDM transmission of 32 wavelength channels with 100 GHz spacing, each carrying 3 modes of 120 Gb/s polarization division multiplexed quadrature phase shifted keying (PDM-QPSK) signal, over 560 km of few-mode fiber (FMF). Long distance transmission is achieved by 6×6 multiple-input multiple-output digital signal processing and modal differential group delay compensated link of FMF. The all-fiber mode multiplexer has considerable potential to be used in mode- and wavelength-division multiplexed transmission.

Mode division multiplexed optical transmission enabled by all-fiber mode multiplexer.

Mode division multiplexed optical transmission enabled by all-fiber mode multiplexer is investigated. The proposed all-fiber mode multiplexer is composed of consecutive mode selective couplers. It multiplexes or demultiplexes LP01, LP11, LP21, and LP02 modes simultaneously. We demonstrate successful transmission of three spatial modes with 120 Gb/s PDM-QPSK signals over 15 km of four mode fiber by using 6x6 MIMO digital signal processing.

Field trial of automatic bias control scheme for optical IQ modulator and demodulator with directly detected 112 Gb/s DQPSK Signal.

When optical transceivers employing in-phase and quadrature (IQ) modulators and demodulator are used in real transmission systems, it is very important to search optimum bias points and to prevent bias drift from their optimal points due to of temperature variation, stress, or device aging. We demonstrate a simple and cost-effective automatic bias control scheme for optical IQ modulator and demodulator based on RF power and peak voltage detection. The principle of control scheme and effects of bias voltage on monitoring parameters are presented. The dynamic performance of the control scheme, effects of optical signal-to-noise ratio (OSNR) of signal, and effects of temperature variation are also evaluated. For the evaluation of bias control scheme at real-environment, we implement the automatic bias control scheme in 112 Gb/s dual carrier-differential QPSK (DC-DQPSK) transceiver, and investigate its long-term stability performances in a field transmission experiment over 797-km of installed fiber and ROADM.

Impact of serum calcium and phosphate on coronary atherosclerosis detected by cardiac computed tomography.

AIMS: High calcium (Ca), phosphate (P), and Ca-P product (CPP) are associated with cardiovascular disease in patients with chronic kidney disease. Whether this relationship persists in individuals with normal kidney function is not yet elucidated. We explored the relationship of serum Ca, P, and CPP to coronary atherosclerosis assessed by cardiac computed tomography angiography (cCTA) in participants with normal kidney function. METHODS AND RESULTS: This study included 7553 participants (52 ± 10 years, male 57%) with near-normal kidney function (estimated glomerular filtration rate > 60 mL/min/1.73 m2) who underwent cCTA. The relationship of Ca, P, and CPP to coronary atherosclerosis [coronary artery Ca score (CACS) >100 and the presence of coronary artery disease (CAD)] was evaluated. Higher Ca, P, and CPP were significantly associated with CACS > 100 continuously [adjusted odds ratio (OR) per mg/dL: Ca 1.21, P = 0.026; P 1.29, P < 0.001; CPP 1.03, P < 0.001]. However, they correlate only weakly with the presence of CAD (OR: Ca 1.17, P = 0.001; P 1.05, P = 0.173; CPP 1.01, P = 0.034). This discrepancy was because calcified or mixed plaque and non-calcified plaque (NCP) were included in CAD. A significant relationship was demonstrated between calcified or mixed plaque and Ca, P, and CPP (OR: Ca 1.20, P = 0.001; P 1.13, P = 0.003; CPP 1.02, P = 0.001), but not NCP. CONCLUSION: Elevated serum levels of Ca, P, and CPP are significantly associated with the presence of calcified coronary atherosclerotic plaque. It is unclear if there is a causal relationship. This relationship is thought to contribute to vascular calcification, but is less closely associated with NCP.

Companding transform based SPM compensation in coherent optical OFDM transmission.

We demonstrate a mitigation of fiber nonlinearity based on µ-law companding transform in coherent optical OFDM transmissions. High peak-to-average power ratio (PAPR) increases fiber nonlinear impairments caused by the Kerr effect in optical fiber. The µ-law companding modifies amplitude profile of OFDM signal with time domain signal processing, which reduces high PAPR of OFDM signal. The effects of companding parameter on noise enhancement and PAPR variation are presented. The impacts of companding transform on system performances are evaluated in a single polarization system as well as polarization multiplexed system. The resolution of analog-to-digital converter (ADC), dispersion map of transmission link, and launch power tolerance are also considered. The results of bit-error-rate (BER) measurements show that the µ-law companding improves OSNR margin over 5.5 dB after transmission of 1,040 km over SMF.

6 x 86 Gb/s WDM transmission over 2 km multimode fiber using center launching technique and multi-level modulation.

We experimentally demonstrate transmission of 6 x 86 Gb/s DQPSK signals over 2 km of OM2 grade multimode fiber. The successful transmission of 86 Gb/s per wavelength over multimode fiber is the highest speed per wavelength ever reported to our knowledge. The transmission performance over OM2 grade multimode fiber is also compared with OM3 grade multimode fiber and conventional single mode fiber.

Digital non-data-aided symbol synchronization in optical coherent intradyne reception.

Digital symbol synchronization of optical binary phase shift keying signals is experimentally demonstrated. Algorithm of timing error feedback is proposed for coherent intradyne reception. The feedback loop operates stable in the range of symbol rate, 9.7 approximately 10.3 GSymbol/s with 20 GSampling/s at relatively high bit error rate of approximately 2x10(-2).