Estimating eGFR using serum creatinine or cystatin C in healthy Vietnamese population.

Very few studies worldwide have assessed the estimated glomerular filtration rate (eGFR) using serum cystatin C (ScysC) in comparison to the gold standard measured glomerular filtration rate (mGFR) with a gamma camera technique using 99m-Technetium-Diethylene Triaminepentoacetic Acid (99mTc-DTPA). To determine the eGFR formula with the most accurate estimate of glomerular filtration rate when compared with mGFR in a healthy population in Vietnam. We conducted a cross-sectional descriptive study of more than 100 adults without hypertension.

Early detection of reduced left ventricular systolic function by 2D speckle tracking echocardiography in patients with primary mitral regurgitation in a Vietnamese cohort.

Mitral regurgitation (MR) is a common heart valve disease, causing many serious complications in several organ systems, especially the cardiovascular system. The 2D speckle tracking echocardiography (STE) is a new technique for detecting potential cardiac dysfunction when only tissue function abnormalities are present. The study aimed to assess left ventricular (LV) systolic function early by STE in patients with primary MR through global LV deformity along the global longitudinal strain (GLS).

Efficacy of Dyslipidemia Control by Combination Therapy with Rosuvastatin 10 Mg and Ezetimibe 10 Mg Compared with Rosuvastatin 20 Mg Monotherapy in Patients with Chronic Coronary Syndromes: A Randomized, Single-blind Controlled Trial.

Background: Studies have shown the combination treatment effectiveness of using rosuvastatin and ezetimibe in patients with chronic coronary artery disease. Our study aim to evaluate the effectiveness of dyslipidemia treatment with the combination of rosuvastatin and ezetimibe 10mg in patients with chronic coronary artery disease compared with 20 mg rosuvastatin.

Objectives: To evaluate the effectiveness of dyslipidemia treatment with the target of LDL-c < 1.

Prevalence, incidence of and risk factors for vertebral fracture in the community: the Vietnam Osteoporosis Study.

The epidemiology of vertebral fractures (VF) in underrepresented populations is not well-documented. This cohort study was part of a longitudinal osteoporosis research project with the aim of determining the prevalence, incidence, and risk factors for VF. 401 individuals (155 men) aged 50 years and older without a clinical diagnosis of VF were took radiographs at baseline and 2 years later.

The combination of CYP2C19 polymorphism and inflammatory cell ratios in prognosis cardiac adverse events after acute coronary syndrome.

Background: gene polymorphism combination with inflammatory cell ratios was significant in the prognosis of coronary heart disease.

Materials And Methods: A cross-sectional analysis study, with 6 months follow-up on 142 patients with acute coronary syndrome. Patients were analyzed for gene polymorphisms by real-time polymerase chain reaction (PCR) and complete blood count to determine inflammatory cell ratios and recorded cardiovascular events (CEs) after following up to 6 months.

Prevalence and Clinical Profile of Undiagnosed Diabetes Mellitus: Data from a Tertiary Hospital.

Background: The prevalence of diabetes mellitus in Vietnam is relatively low compared to other Asian countries, but it is accelerating with the economic and cultural transition. This study aimed to estimate the current prevalence and clinical profile of undiagnosed diabetes mellitus in a tertiary hospital in the south of Vietnam.

Methods: A cross-sectional investigation was conducted to recruit 1, 250 participants, who were at least 18 year-old and randomly sampled from Cho Ray Hospital, Ho Chi Minh City, Vietnam.

Flexible bandwidth DGD estimation for coherent optical OFDM system.

A Stokes vector based non-data-aided (NDA) differential group delay (DGD) estimation scheme with flexible bandwidth requirements is investigated. The scheme is demonstrated in both experiments and simulations for 40-Gb/s polarization-multiplexed coherent optical OFDM systems with up to 1000-km long haul transmission with an estimation error of less than 2.5 ps after 1000-km standard single-mode fiber transmissions.

Applying implicit training to polarization-division-multiplexed coherent optical systems.

We report the use of implicit training-aided channel estimation (ITA-CE) for polarization-division-multiplexed (PDM) single-carrier coherent optical systems. With the concept of ITA-CE, where the training sequence (TS) is arithmetically added onto the information symbols rather than appearing in separate time slots, overhead-free transmission can be achieved with minor optical signal to noise ratio (OSNR) penalty. ITA-CE system enables simple digital pilot-tone based frequency-offset compensation, and inherits the benefits from typical training-aided channel acquisition and data recovery.

Optical performance monitoring for OFDM using low bandwidth coherent receivers.

We propose using low bandwidth coherent receivers for distributed optical performance monitoring. We demonstrate optical signal-to-noise ratio (OSNR) monitoring of both 20-Gb/s single-polarization and 40-Gb/s polarization-multiplexed coherent optical orthogonal frequency-division multiplexing (CO-OFDM) signals with a 0.8-GHz receiver using both data-aided (DA) and non-data-aided (NDA) approaches.

Combined utilization of partial-response coding and equalization for high-speed WDM-PON with centralized lightwaves.

In this paper, we investigate the transmission impairments in a high-speed single-feeder wavelength-division-multiplexed passive optical network (WDM-PON) employing low-bandwidth upstream transmitter. A 1-GHz reflective semiconductor optical amplifier (RSOA) is operated at the rates of 10 Gb/s and 20 Gb/s in the proposed WDM-PON. Since the system performance is seriously limited by its uplink in both capacity and reach owing to inter-symbol interference and reflection noise, we present a novel technique with simultaneous capability of spectral efficiency enhancement and transmission distance extension in the uplink via coding and equalization that exploit the principles of partial-response (PR) signal.

Mitigation of Rayleigh noise and dispersion in REAM-based WDM-PON using spectrum-shaping codes.

This paper presents a novel technique capable of Rayleigh backscattering (RB) mitigation and chromatic dispersion (CD) compensation for wavelength-division-multiplexed passive optical network (WDM-PON). The reduction of the interference caused by RB and CD in the uplink based on reflective electro-absorption modulator (REAM) is realized by the proposed correlative level (CL) coding. We investigate the RB-induced interferometric crosstalk for different fiber lengths.

Improved two-stage equalization for coherent Pol-Mux QPSK and 16-QAM systems.

We report a two-stage blind frequency domain equalization method for long-haul coherent polarization-multiplexed (pol-mux) systems using quadrature phase shift keying (QPSK) and 16-quadrature amplitude modulation (16-QAM). In the first stage, blind CD parameter prediction is conducted prior to a CD equalizer. This supports flexible path switching in optical networks.

Statistical moments-based OSNR monitoring for coherent optical systems.

We present a novel statistical moments-based method for optical signal-to-noise ratio (OSNR) monitoring in polarization-multiplexed (pol-mux) coherent optical systems. This technique only requires the knowledge of the envelope of the equalized signal before phase correction, which can be achieved by using any two arbitrary statistical moments, and it is suitable for both constant and non-constant modulus modulation formats. The proposed estimation method is experimentally demonstrated for 10-Gbaud pol-mux coherent systems using QPSK and 16-QAM.

Level coding technique for a wavelength-division-multiplexed optical access system using a remodulation scheme.

In the wavelength-division-multiplexed optical access network, the system architecture based on remodulating the downstream (DS) signal for upstream transmission resolves the issues of wavelength management and hardware cost . However, this amplitude remodulation scheme introduces intensity noise in the uplink and leads to a system performance penalty. Therefore, the DS extinction ratio (ER(d)) has to be optimized in order to balance the performance of up- and down- links.

Improving performance of MLSE in RSOA-based WDM-PON by partial response signaling.

High data-rate upstream transmission in wavelength division multiplexed passive optical network (WDM-PON) based on reflective semiconductor optical amplifier (RSOA) is limited by severe inter-symbol interference (ISI), owing to low-bandwidth transmitter and fiber dispersion. To overcome the limitations in RSOA-based WDM-PON, we propose a novel receiver based on partial response maximum likelihood (PRML) equalization which combines the use of partial response (PR) signaling with maximum likelihood sequence estimation (MLSE). MLSE has been long considered as the optimal reception technique to overcome various types of impairment in optical transmission such as dispersions.

Cost optimal allocation of amplifiers and DCMs in WDM ring networks.

Designing metropolitan wavelength division multiplexing (WDM) ring networks with minimum deployment cost is a demanding issue in Telecommunication Network planning . We have already presented amplifier placement methods to minimize the number of amplifiers in WDM rings for the case all amplifiers follow a unique gain model. In this paper, we take into account different types of amplifiers with predefined fixed characteristics and costs.

Bidirectional optical add-drop multiplexer based on Bragg gratings and circulators.

We propose and demonstrate a bidirectional optical add-drop multiplexer for use in single-fiber bidirectional networks. With effective use of multiport circulators, fiber-Bragg gratings, and a single amplifier element, the new structure can add and/or drop channels in both directions and achieves more than 16 dB of bidirectional gain. The device utilizes Bragg gratings and light absorber to remove Rayleigh backscattered and reflected light at the input stage.