Relationships among the Dosage of Erythropoiesis-Stimulating Agents, Erythropoietin Resistance Index, and Mortality in Maintenance Hemodialysis Patients.

BACKGROUND: Erythropoiesis-stimulating agents (ESAs) constitute an important treatment option for anemia in hemodialysis (HD) patients. We investigated the relationships among the dosage of ESA, erythropoietin resistance index (ERI) scores, and mortality in Chinese MHD patients. METHODS: This multicenter observational retrospective study included MHD patients from 16 blood purification centers (n = 824) who underwent HD in 2011-2015 and were followed up until December 31, 2016. We collected demographic variables, HD parameters, laboratory values, and ESA dosages. Patients were grouped into quartiles according to ESA dosage to study the effect of ESA dosage on all-cause mortality. The ERI was calculated as follows: ESA (IU/week)/weight (kg)/hemoglobin levels (g/dL). We also compared outcomes among the patients stratified into quartiles according to ERI scores. We used the Cox proportional hazards model to measure the relationships between the ESA dosage, ERI scores, and all-cause mortality. Using propensity score matching, we compared mortality between groups according to ERI scores, classified as either > or ≤12.80. RESULTS: In total, 824 patients were enrolled in the study; 200 (24.3%) all-cause deaths occurred within the observation period. Kaplan-Meier analyses showed that patients administered high dosages of ESAs had significantly worse survival than those administered low dosages of ESAs. A multivariate Cox regression identified that high dosages of ESAs could significantly predict mortality (ESA dosage >10,000.0 IU/week, HR = 1.59, 95% confidence intervals (CIs) (1.04, 2.42), and p = 0.031). Our analysis also indicated a significant increase in the risk of mortality in patients with high ERI scores. Propensity score matching-analyses confirmed that ERI > 12.80 could significantly predict mortality (HR = 1.56, 95% CI [1.11, 2.18], and p = 0.010). CONCLUSIONS: Our data suggested that ESA dosages >10,000.0 IU/week in the first 3 months constitute an independent predictor of all-cause mortality among Chinese MHD patients. A higher degree of resistance to ESA was related to a higher risk of all-cause mortality.

Fiber refractive index sensor based on dual polarized Mach-Zehnder interference caused by a single-mode fiber loop.

A novel refractive index (RI) sensor head is proposed and experimentally demonstrated in this paper. The proposed sensor head is composed of a segment of bared single-mode fiber and a fiber holder that is fabricated by a 3D printer. The mechanism of the sensor head is based on dual polarized Mach-Zehnder interference. According to the aforementioned mechanism, we derived that the RI responses of the resonance dips possess an exponential functional manner when the E field is along the fast or slow axes. In addition, based on the finite element method, we found that the resonance dips wavelength responses are more sensitive when the input E field is along the fast axis. A confirmation experiment was performed, and the results confirmed our hypothesis. The maximum arithmetic mean value of RI response is about 657.895 nm/RIU for the proposed sensor head when the ambient RI changes from 1.3350 to 1.4110. Moreover, in the case of the proposed liquid RI sensor head, aligning the E field along the fast axis is the potentially needed condition for polarization.

The correlation between peripheral leukocyte telomere length and indicators of cardiovascular aging.

OBJECTIVES: To investigate the relationship between telomere length in peripheral blood white cells and cardiovascular function in a healthy, aging Han Chinese population. METHODS: In 2012, peripheral blood leukocytes were obtained from 139 healthy individuals in Beijing, China, and telomere restriction fragment (TRF) length was assayed using a digoxigenin-labeled hybridization probe in Southern blot assays. Indicators of cardiovascular function were also evaluated, including electrocardiograms (ECG), (RR, P, PR, QRS, ST and T intervals); blood pressure (BP), (SBP, DBP, PP, PPI); cardiovascular ultrasound (left ventricular ejection fraction, LVEF); mitral early and late diastolic peak flow velocity (MVE and MVA); and lipid indices (TC, TG, HDL, LDL, LCI). The relationships of these cardiovascular indictors to telomere length were evaluated. RESULTS: No correlations were found between telomere length and ECG, BP or lipid indices even after adjustment for age. Correlations were found between TFR length and some cardiovascular ultrasound indictors (D, MVEA, MVEDT, MVES, MVEL, MVEI, IMT), but these were not seen after adjusting for age. CONCLUSIONS: We did not find that leukocyte TFR length was associated with cardiovascular ultrasound indictors, ECG, BP, or lipid indices in this population of healthy Han Chinese individuals. Telomere length may serve as a genetic factor in biological aging.

[Temporal and Spatial Variations in Black Carbon Aerosol in Different Atmospheric Background Stations in China from 2006 to 2020].

Black carbon (BC) aerosol emissions are complex and have important environmental and meteorological effects. In China, the temporal and spatial variations in BC in different atmospheric environmental conditions need to be fully understood. Based on the long-term observational BC data in seven atmospheric background stations in China from 2006 to 2020, combined with meteorological data, emission source data, enhanced vegetation index (EVI) data, and aerosol optical depth (AOD) data, we comprehensively analyzed the characteristics of temporal and spatial variations, long-term evolution, and influencing factors of BC in China. The results showed that the BC and AOD values of different atmospheric environments in China were quite different, and BC positively contributed to AOD. The spatial distribution was high in the east and low in the west owing to the differences in emission sources and meteorological conditions. The ρ(BC) and AOD values were higher to the east of the "Hu Huanyong" line, such as at the Mt. Longfeng, Shangdianzi, Lin'an, and Jinsha stations, where the average values were (1699±2213)-(3392±2131) ng·m-3 and 0.36±0.32-0.72±0.37, respectively. These values were lower to the west of the "Hu Huanyong" line, such as at the Akedala, Mt. Waliguan, and Shangri-La stations, where the average values were (287±226)-(398±308) ng·m-3 and 0.20±0.13-0.22±0.19, respectively. The interannual variability in BC included differences between different atmospheric background stations, which could be divided into four categories:low interannual variability, such as at the Akedala station; an initial increase followed by a decrease and subsequent stabilization, such as at the Mt. Waliguan station; an initial decrease followed by stabilization, such as at the Shangri-La station; and an initial stabilization followed by a decrease, such as at the Mt. Longfeng, Shangdianzi, Jinsha, and Lin'an stations. Seasonal variations in BC included differences in different atmospheric background stations. The BC mass concentrations were lowest in autumn and higher in winter and spring west of the "Hu Huanyong" line and were highest in winter and lowest in summer east of the "Hu Huanyong" line. BC contributed to the AOD being larger in all stations in the spring and summer and contributed less at the stations west of the "Hu Huanyong" line in autumn and the stations east of the "Hu Huanyong" line in winter. The diurnal variations in BC were mainly bimodally distributed in the different atmospheric background stations, but the peak times varied in different stations and seasons.

[Variation Characteristics and Potential Sources of the Mt. Haituo Aerosol Chemical Composition in Different Pollution Processes During Winter in Beijing, China].

In order to investigate the chemical composition and source apportionment of aerosols during winter in the Beijing-Tianjin-Heibei region, the particular matter (PM) and aerosol chemical composition at Mt. Haituo were observed by using a GRIMM 180, a single-particle soot photometer (SP2), and a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) from December 28, 2020 to February 3, 2021. Combining these observations with meteorological data and the HYSPLIT model, we calculated the potential source contribution factor (PSCF) and concentration weighted trajectory (CWT) and analyzed the temporal evolution and potential sources apportionment of PM and aerosol chemical composition under different pollution processes. The results showed that the dust storm process mainly affected PM10 and PM2.5 in Mt. Haituo during the winter and had a small impact on PM1; by contrast, haze pollution mainly affected PM1. Chemical components of aerosol accounted for 85.0% and 73.4% of PM1 on clean and haze days, respectively, but only 47.4% of PM1 in dust storm processes. NO3- was the chemical component with the largest mass concentration in haze, accounting for 25.2% of PM1; black carbon (BC) had the largest mass concentration on clean and dust storm days, accounting for 24.1% and 12.8% of PM1, respectively. The median diameters of BC were 209.7, 207.5, and 204.7 nm on clean, dust storm, and haze days, respectively. Dp/Dc was 2.15 in haze pollution, which was 1.38 and 1.39 times that on dust storm and clean days, respectively. Diurnal variations in PM and aerosol chemical components were different during the different processes. PM10 and PM2.5had high mass concentrations at night and low mass concentrations during the daytime on clean and dust storm days and had a unimodal distribution with a peak at 14:00 in haze. Diurnal variations in chemical composition had a unimodal distribution on clean days and a bimodal distribution on dust storm and haze days. The chemical compositions of the BC coating layer were different under different processes. The coating layers of BC were mainly NH4NO3, (NH4)2SO4, and organic matter on the clean, dust storm, and haze days, respectively. The distribution of potential sources of PM1 and its chemical components were different under different processes. The high-value area of the potential sources was mainly concentrated in the Beijing-Baoding-Shijiazhuang-Yangquan area in the southwestern portion of the site during dust storms and was mainly concentrated in Yanqing, Huailai, and Changping in the areas around the site during haze.

[Evolution and Potential Source Apportionment of Atmospheric Pollutants of Two Heavy Haze Episodes During the COVID-19 Lockdown in Beijing, China].

To control the spread of the 2019 novel coronavirus(COVID-19), China imposed rigorous restrictions, which resulted in great reductions in pollutant emissions. However, two heavy haze pollution episodes still occurred in Beijing. In this study, we use the air pollutants, aerosol number concentration, and meteorological elements data in Beijing, combined with the HYSPLIT model, to calculate the potential source contribution factor(PSCF) and concentration weight trajectory(CWT), and analyze the characteristics of evolution and potential source apportionment of atmospheric pollutants during the two episodes. The COVID-19 lockdown restrictions had great impacts on the diurnal variations of PM2.5 and black carbon(BC), while small impacts on the diurnal variations of CO, NO2, SO2, and O3. The primary pollutant was PM2.5 during the two haze pollution episodes, and the haze1 episode was mainly local pollution, while haze 2 was mainly local and external transportation pollution. The spectrum of aerosol number concentration was unimodal under different processes, with the peak located at 0.3 µm. During the haze episodes, the number concentration in the size range of 0.2-0.5 µm increased 3.3-13.6 times that of the clean days. The mass concentration contributions of BCliquid to BC in different processes were 64.8%-85.1%. This mass concentration of BCliquid ranked in the order of haze 1(5.04 µg·m-3) >haze 1(3.20 µg·m-3) >clean day(before COVID-19) (2.31 µg·m-3) >clean day(COVID-19) (0.76 µg·m-3). The characteristics of PSCF and CWT distribution of PM2.5 and BC were different in different processes. The PSCF high value areas of PM2.5 on the clean day(before COVID-19) and the clean day(COVID-19) were mainly distributed in the southwest and western of Beijing, and the weight concentration exceeded 30 µg·m-3. The PSCF high value areas of PM2.5 during haze 1 and haze 2 were mainly distributed in Beijing and its surrounding areas and southwestern, when the weight concentration exceeded 90 µg·m-3. The PSCF high value areas of BC were mainly distributed in Beijing and its surrounding areas on clean days(before COVID-19), clean days(COVID-19) and haze 1, with weighted concentrations exceeding 2.4, 0.9 and, 4.5 µg·m-3, respectively. The PSCF high value areas of BC on haze 2 was distributed in the southwest of Beijing, and the weight concentration exceeded 5 µg·m-3.

Analysis of Factors Associated with Death in Maintenance Hemodialysis Patients: A Multicenter Study in China.

BACKGROUND: Patients on hemodialysis have a high-mortality risk. This study analyzed factors associated with death in patients on maintenance hemodialysis (MHD). While some studies used baseline data of MHD patients, this study used the most recent data obtained from patients just prior to either a primary endpoint or the end of the study period to find the characteristics of patients preceding death. METHODS: Participants were selected from 16 blood purification centers in China from January 2012 to December 2014. Patients' data were collected retrospectively. Based on survival status, the participants were divided into two groups: survival group and the death group. Logistic regression analysis was performed to determine factors associated with all-cause mortality. RESULTS: In total, 4104 patients (57.58% male, median age 59 years) were included. Compared with the survival group, the death group had more men and more patients with diabetic nephropathy (DN) and hypertensive nephropathy. The patients preceding death also had lower levels of diastolic blood pressure, hemoglobin, serum albumin, serum calcium, serum phosphate, Kt/V, and higher age. Multivariate analysis revealed that male sex (odd ratio [OR]: 1.437, 95% confidence interval [CI]: 1.094-1.886), age (OR: 1.046, 95% CI: 1.036-1.057), and presence of DN (OR: 1.837, 95% CI: 1.322-2.552) were the risk factors associated with mortality. High serum calcium (OR: 0.585, 95% CI: 0.346-0.989), hemoglobin (OR: 0.974, 95% CI: 0.967-0.981), albumin (OR: 0.939, 95% CI: 0.915-0.963) levels, and dialysis with noncuffed catheter (OR: 0.165, 95% CI: 0.070-0.386) were protective factors based on a multivariate analysis. CONCLUSIONS: Hemodialysis patients preceding death had lower hemoglobin, albumin, and serum calcium levels. Multivariate analysis showed that male sex, age, DN, low hemoglobin, low albumin, and low serum calcium were associated with death in hemodialysis patients.

Anticoagulation treatments related different types of vascular access on maintenance hemodialysis patient: A multicenter epidemiological investigation.

OBJECTIVE: The objective was to increase the understanding of vascular access in hemodialysis and evaluate hemodialysis-related anticoagulation treatments and the associated hemorrhagic or thrombotic complications. MATERIALS AND METHODS: In this study, an epidemiological investigation was conducted in 1175 patients who underwent hemodialysis in seven blood purification centers in northern Chinese. The patients were divided into two groups based on the vascular access they used: Arteriovenous fistula (AVF) group and central venous catheter (CVC) group. The similarities and differences of anticoagulation and hemorrhagic, thrombotic complications were compared between two groups. RESULTS: Arteriovenous fistula was the most frequently used vascular access, and heparin was the most commonly used anticoagulant. Patients in CVC group experienced significantly greater rates of low molecular weight heparin (LMWH) administration and had a higher rate in achieving thrombotic complications than those in AVF group. There were no significant differences in LMWH dosages in patients with thrombotic complications, as well as the proportion of patients who received anti-platelet drugs. Heparinized catheter lock solutions were excessively high in this study, which may lead to a risk of hemorrhage. CONCLUSION: Hemodialysis-related anticoagulation treatments in China require additional improvements, especially for the patients using CVC as vascular access. There is an urgent need to develop clinical evaluation studies of anticoagulation treatments for achieving more standardized and targeted treatments.

A correlation study of telomere length in peripheral blood leukocytes and kidney function with age.

The current study aimed to investigate the association between telomere length in peripheral blood leukocytes and kidney function in various age groups of a healthy population. A total of 139 healthy individuals were divided into five groups according to their age: 35­44, 45­54, 55­64, 65­74 and >75 years old. Peripheral blood leukocytes were obtained and the telomere restriction fragment (TRF) length was assayed using a digoxigenin­labeled hybridization probe in Southern blot assays. Laboratory assays of kidney function were also performed. A correlation was observed between TRF length and age (r=­0.314, P<0.001), with the telomere length of the individuals >75 years group being significantly shorter than the telomere length of the 35­44, 45­54 and 55­64 years age groups (P<0.05). By contrast, the TRF length for males versus females did not differ for any of the age groups, while a correlation was observed between TRF length and serum levels of cystatin C (r=­0.195, P<0.05). There was also a correlation between TRF length and glomerular filtration rate (r=­0.184, P<0.05). The current study demonstrated that in this cohort, leukocyte telomere length reduced with age and was correlated with serum levels of cystatin C and glomerular filtration rate. Therefore, TRF length is associated with kidney function and may serve as a marker of aging.

Select aging biomarkers based on telomere length and chronological age to build a biological age equation.

The purpose of this study is to build a biological age (BA) equation combining telomere length with chronological age (CA) and associated aging biomarkers. In total, 139 healthy volunteers were recruited from a Chinese Han cohort in Beijing. A genetic index, renal function indices, cardiovascular function indices, brain function indices, and oxidative stress and inflammation indices (C-reactive protein [CRP]) were measured and analyzed. A BA equation was proposed based on selected parameters, with terminal telomere restriction fragment (TRF) and CA as the two principal components. The selected aging markers included mitral annulus peak E anterior wall (MVEA), intima-media thickness (IMT), cystatin C (CYSC), D-dimer (DD), and digital symbol test (DST). The BA equation was: BA = −2.281TRF + 26.321CYSC + 0.025DD − 104.419MVEA + 34.863IMT − 0.265DST + 0.305CA + 26.346. To conclude, telomere length and CA as double benchmarks may be a new method to build a BA.