Associations between sleep problems and cardiometabolic risk in maintenance hemodialysis patients: A multicenter study.

The incidence of cardiovascular disease is increasing around the world, and it is one of the main causes of death in chronic kidney diseases patients. It is urgent to early identify the factors of cardiometabolic risk. Sleep problems have been recognized as a risk factor for cardiometabolic risk in both healthy people and chronic patients. However, the relationship between sleep problems and cardiometabolic risk has not been clearly explored in hemodialysis patients. This study aimed to investigate the relationship between sleep problems and cardiometabolic risk in 3025 hemodialysis patients by a multicenter study. After adjusting for confounders, binary logistic regression models showed that hemodialysis patients reported sleep duration greater than 7 h were more likely to be with hypertension, hyperglycemia, hypertriglyceridemia, and hypercholesterolemia. Patients reported sleep duration less than 7 h were more likely to be with hypertriglyceridemia and hypercholesterolemia, but the risks of hyperglycemia and Low HDL-cholesterol were decreased. Poor sleep quality was negatively correlated to low HDL cholesterol and hypertriglyceridemia. Moreover, gender-based differences were explained.

Quantitative assessment of the variations in monthly precipitation trends induced by the impact of three gorges dam.

There are many studies that have examined the impact of the Three Gorges Dam (TGD) on changes in meteorological data, and most of them concluded that the TGD significantly reduced precipitation without taking into account the negative trends that had already existed before the impoundment. In this study, the investigation focused on the monthly precipitation data, and the Mann-Kendall (MK) trend analysis was conducted to show that the TGD had little effect on the trends of the precipitation data. Monthly data (1980-2018) from 19 stations upstream and downstream of the TGD and 5 stations located far from the main river were extracted. The analysis and results showed that although the linear long-term (1980-2018) precipitation trend upstream of the TGD was downward, the MK trend analysis showed that the precipitation trends became upward after impoundment. This situation existed even for station data located outside the region. Also, the analysis of monthly trends in different seasons showed that in spring and winter, there was only a very weak downward trend in monthly precipitation, while in summer and autumn, the trends were upward with steeper slopes. Following the upward trends of the monthly precipitation, the TGD generally positively intensified the monthly precipitation trends upstream and downstream of the dam, with the exception of a few months when total precipitation amounts were consistently low. In contrast to the trend analysis, which showed small and insignificant variations in precipitation data, the 12-month SPEI analysis showed a significant deterioration (about 20%) in the wetness index after impoundment both upstream and downstream of the TGD, while this situation did not occur outside the region. Thus, the TGD has extended dry periods both upstream and downstream of the dam over the past two decades.

Could long-term dialysis vintage and abnormal calcium, phosphorus and iPTH control accelerate aging among the maintenance hemodialysis population?

OBJECTIVE: Aging is a complex process of physiological dysregulation of the body system and is common in hemodialysis patients. However, limited studies have investigated the links between dialysis vintage, calcium, phosphorus, and iPTH control and aging. The purpose of the current study was to examine these associations. METHODS: During 2020, a cross-sectional study was conducted in 3025 hemodialysis patients from 27 centers in Anhui Province, China. Biological age was calculated by a formula using chronological age and clinical indicators. The absence of the target range for serum phosphorus (0.87-1.45 mmol/L), corrected calcium (2.1-2.5 mmol/L) and iPTH (130-585 pg/mL) were identified as abnormal calcium, phosphorus, and iPTH control. RESULTS: A total of 1131 hemodialysis patients were included, 59.2% of whom were males (669/1131). The mean (standard deviation) of actual age and biological age were 56.07 (12.79) years and 66.94 (25.88), respectively. The median of dialysis vintage was 4.3 years. After adjusting for the confounders, linear regression models showed patients with abnormal calcium, phosphorus, and iPTH control and on hemodialysis for less than 4.3 years (B = 0.211, p = .002) or on hemodialysis for 4.3 years or more (B = 0.302, p < .001), patients with normal calcium, phosphorus, and iPTH control and on hemodialysis for 4.3 years or more (B = 0.087, p = .013) had a higher biological age. CONCLUSION: Our findings support the hypothesis that long-term hemodialysis and abnormal calcium, phosphorus, and iPTH control may accelerate aging in the hemodialysis population. Further studies are warrant to verify the significance of maintaining normal calcium-phosphorus metabolism in aging.

Prediction of water quality under the impacts of fine dust and sand storm events using an experimental model and multivariate regression analysis.

Many regions of the world, especially arid and semiarid areas, occasionally experience fine dust and sandstorms, known environmental problems that make normal life difficult. Since the intrusion of large amounts of dust into treatment plants may significantly change the water quality indices, the main goal of this study was to estimate these indices during the events, which can help decision-makers to improve water quality. To achieve relationships using nonlinear multivariate regression analysis, a long-term (three years: April 2017-February 2020) experimental study of water quality parameters including total dissolved solids (TDS), hydrogen content (pH), electrical conductivity (EC), chlorine (Cl), total hardness, sodium (Na), and magnesium (Mg) for water samples from wastewater treatment plants in Sistan region (Iran) was conducted where is one of the most popular regions in the world with high amount of annual fine dust level. Analysis of ANOVA showed that of all the independent parameters considered in this study, water quality parameters strongly correlated with monthly mean sand and dust storm index (SDSI), wind speed, temperature, and the number of monthly windy days. For the regression analysis, 25 months of data were used for the simulation process and 10 months for validation. The final results showed that the relationships obtained from the nonlinear multivariate regression analysis could predict the water quality indices very well (with R2 more than 0.75) except for Mg with R2 equal to 0.55. In addition, the maximum mean relative error belongs to Mg (10.8%) and then Na (9.9%) whereas the minimum mean relative error belongs to pH (2.6%) and then EC (2.9%).

Investigation on maintenance hemodialysis patients with mineral and bone disorder in Anhui province, China.

BACKGROUND: Chronic kidney disease-mineral bone disorder (CKD-MBD) is a common comorbidity in patients with CKD. The study aims to describe the control rates of serum-corrected calcium (Ca), phosphate (P) and intact parathyroid hormone (iPTH) and its risk factors among maintenance hemodialysis (MHD) patients in Anhui Province of China. METHODS: The study was conducted in 27 hemodialysis centers of Anhui Province between January 1st 2020 and December 31th 2020. Chi-square test was used to compare the control rates of serum-corrected Ca, P and iPTH between the present study and DOPPS 4 or Anhui Province in 2014. Binary logistic regression analysis was used to explore the risk factors of the control rates of serum-corrected Ca, P and iPTH. RESULTS: A total of 3 025 MHD patients were recruited in this study, with a mean age of 54.8 (SD: 12.8) years, and 60.1% were males. According to the Chinese Diagnosis and Treatment Guidelines for CKD-MBD, the control rates of serum-corrected Ca, P and iPTH in the present study were 57.9%, 20.0% and 56.0%, respectively. Based on KDOQI guidelines (2003), the control rates of the above indicators were 43.1%, 35.3% and 22.3%, respectively. The control rates of serum-corrected Ca, P and iPTH in this study were lower than those of DOPPS 4 (P < 0.001). Compared to the results of Anhui Province in 2014, the control rate of corrected Ca was higher (P < 0.001) and the control rate of iPTH was lower (P = 0.005). Age, residential area, BMI, dialysis vintage, albumin and hemoglobin levels were factors of serum-corrected Ca, P and iPTH not within target range. CONCLUSION: The control rates of serum-corrected Ca, P and iPTH in MHD patients in Anhui Province are relatively low. Monitoring and management should be strengthened to improve the prognosis of patients undergoing dialysis.

A multi-center study on the association between serum magnesium levels and allostatic load in hemodialysis patients.

Objective: Serum magnesium (Mg2+) levels are associated with insulin resistance, hypertension, lipid abnormalities, and inflammation. However, limited studies have indicated the relationship between Mg2+ and multiple system indexes. The purpose of this study was to investigate the association between Mg2+ and allostatic load (AL) in hemodialysis patients. Methods: A cross-sectional survey was conducted on hemodialysis patients from different centers in Anhui Province, China, between January and December 2020. A total of 3,025 hemodialysis patients were recruited. Their clinical data were measured before hemodialysis. Information was collected by an online self-reported questionnaire and medical record. Serum Mg2+ was divided into three groups by tertiles. A score of AL greater than or equal to 3 was defined as high AL. A binary logistic regression model was applied to examine the relationship between serum Mg2+ and AL. Results: A total of 1,222 patients undergoing hemodialysis were included, 60% of whom were males (733/1,222). The mean (standard deviation) age of patients was 55.90 (12.75). The median level of serum Mg2+ was 1.22 mmol/L. The rate of high AL levels was 23.4%. Serum Mg2+ was negatively correlated with body mass index, fasting blood glucose (Glu), and C-reactive protein and positively correlated with high-density lipoprotein, low-density lipoprotein, total cholesterol, diastolic blood pressure (DBP), and serum phosphorus. After adjusting for gender, anxiety, diabetes, family residence, lipid-lowering agents, antihypertensive medications, albumin, and Glu, the binary logistic regression model showed that patients with lower levels of serum Mg2+ were more likely have high AL (OR for the T1 group of serum Mg2+:1.945, 95% CI: 1.365-2.773, and OR for the T2 group of serum Mg2+:1.556, 95% CI: 1.099-2.201). Conclusion: Our data support the hypothesis that higher serum Mg2+ concentrations may contribute to lower health risk in hemodialysis populations. Further randomized controlled trials and cohort studies are warranted to verify whether Mg2+ supplementation could be part of routine examinations in hemodialysis populations.

Distinguishing Stoichiometric Homeostasis of Soil Microbial Biomass in Alpine Grassland Ecosystems: Evidence From 5,000 km Belt Transect Across Qinghai-Tibet Plateau.

The biogeographic characteristics of soil microbial biomass stoichiometry homeostasis and also its mechanisms are commonly thought to be key factors for the survival strategies and resource utilization of soil microbes under extreme habitat. In this work, we conducted a 5,000-km transect filed survey in alpine grassland across Qinghai-Tibet Plateau in 2015 to measure soil microbial biomass carbon (MBC) and nitrogen (MBN) across alpine steppe and meadow. Based on the differences of climate and soil conditions between alpine steppe and meadow, the variation coefficient was calculated to investigate the homeostatic degree of MBC to MBN. Furthermore, the "trade-off" model was utilized to deeply distinguish the homeostasis degree of MBC/MBN between alpine steppe and meadow, and the regression analysis was used to explore the variability of trade-off in response to environmental factors in the alpine grassland. The results showed that the coefficient of variation (CV) of MBC/MBN in alpine meadow (CV = 0.4) was lower than alpine steppe (CV = 0.7). According to the trade-off model, microbial turnover activity of soil N relative to soil C increased rapidly and then decreased slightly with soil organic carbon (SOC), soil total nitrogen (STN), and soil water content across alpine meadow. Nevertheless, in alpine steppe, SOC/STN had a positive effect on microbial turnover of soil N. These results suggested that water, heat, and soil nutrients availability were the key factors affecting the C:N stoichiometry homeostasis of soil microbial biomass in Qinghai-Tibet Plateau (QTP)'s alpine grassland. Since the difference of survival strategy of the trade-off demands between soil C and N resulting in different patterns and mechanism, the stoichiometry homeostasis of soil microbial biomass was more stable in alpine meadow than in alpine steppe.

Retraction of "Solid-to-Solid Crystallization of Organic Thin Films: Classical and Nonclassical Pathways".

[This retracts the article DOI: 10.1021/acsomega.8b00153.].

Solid-to-Solid Crystallization of Organic Thin Films: Classical and Nonclassical Pathways.

The solid-to-solid crystallization processes of organic molecules have been poorly understood in view of the complexity and the instability of organic crystals. Here, we studied the crystallization of a π-conjugated small molecular semiconductor, bis-(8-hydroxyquinoline) copper (CuQ2), by annealing the thin films at different temperatures. We observed a classical film-to-nanorods crystallization at 80 °C, a coexistence of classical and nonclassical nucleation and particle growth at 120 °C, and a nonclassical crystal growth at 150 °C. We found that the growth of the crystals followed the following processes: particle nucleation, particle growth, particle migration, nondirectional particle attachment, and structure reconstruction. We notice that the growth of CuQ2 particles follows an outside-to-inside process. More interestingly, our experiments suggest that the submicron CuQ2 particles are able to migrate dozens of micrometers at 150 °C.

Biomass partitioning and its relationship with the environmental factors at the alpine steppe in Northern Tibet.

Alpine steppe is considered to be the largest grassland type on the Tibetan Plateau. This grassland contributes to the global carbon cycle and is sensitive to climate changes. The allocation of biomass in an ecosystem affects plant growth and the overall functioning of the ecosystem. However, the mechanism by which plant biomass is allocated on the alpine steppe remains unclear. In this study, biomass allocation and its relationship to environmental factors on the alpine grassland were studied by a meta-analysis of 32 field sites across the alpine steppe of the northern Tibetan Plateau. We found that there is less above-ground biomass (M A ) and below-ground biomass (M B ) in the alpine steppe than there is in alpine meadows and temperate grasslands. By contrast, the root-to-shoot ratio (R:S) in the alpine steppe is higher than it is in alpine meadows and temperate grasslands. Although temperature maintained the biomass in the alpine steppe, precipitation was found to considerably influence M A , M B , and R:S, as shown by ordination space partitioning. After standardized major axis (SMA) analysis, we found that allocation of biomass on the alpine steppe is supported by the allometric biomass partitioning hypothesis rather than the isometric allocation hypothesis. Based on these results, we believe that M A and M B will decrease as a result of the increased aridity expected to occur in the future, which will reduce the landscape's capacity for carbon storage.

Responses of soil CO2 fluxes to short-term experimental warming in alpine steppe ecosystem, Northern Tibet.

Soil carbon dioxide (CO2) emission is one of the largest fluxes in the global carbon cycle. Therefore small changes in the size of this flux can have a large effect on atmospheric CO2 concentrations and potentially constitute a powerful positive feedback to the climate system. Soil CO2 fluxes in the alpine steppe ecosystem of Northern Tibet and their responses to short-term experimental warming were investigated during the growing season in 2011. The results showed that the total soil CO2 emission fluxes during the entire growing season were 55.82 and 104.31 g C m(-2) for the control and warming plots, respectively. Thus, the soil CO2 emission fluxes increased 86.86% with the air temperature increasing 3.74°C. Moreover, the temperature sensitivity coefficient (Q 10) of the control and warming plots were 2.10 and 1.41, respectively. The soil temperature and soil moisture could partially explain the temporal variations of soil CO2 fluxes. The relationship between the temporal variation of soil CO2 fluxes and the soil temperature can be described by exponential equation. These results suggest that warming significantly promoted soil CO2 emission in the alpine steppe ecosystem of Northern Tibet and indicate that this alpine ecosystem is very vulnerable to climate change. In addition, soil temperature and soil moisture are the key factors that controls soil organic matter decomposition and soil CO2 emission, but temperature sensitivity significantly decreases due to the rise in temperature.

Modeling effects of temperature and precipitation on carbon characteristics and GHGs emissions in Abies fabric forest of subalpine.

Abies fabric forest in the eastern slope of Gongga mountain is one type of subalpine dark coniferous forests of southwestern China. It is located on the southeastern edge of the Qinghai-Tibet plateau and is sensitive to climatic changes. A process-oriented biogeochemical model, Forest-DNDC, was applied to simulate the effects of climatic factors, temperature and precipitation changes on carbon characteristics, and greenhouse gases (GHGs) emissions in A. fabric forest. Validation indicated that the Forest-DNDC could be used to predict carbon characteristics and GHGs emissions with reasonable accuracy. The model simulated carbon fluxes, soil carbon dynamics, soil CO2, N2O, and NO emissions with the changes of temperature and precipitation conditions. The results showed that with variation in the baseline temperature from -2 degrees C to +2 degrees C, the gross primary production (GPP) and soil organic carbon (SOC) increased, and the net primary production (NPP) and net ecosystem production (NEP) decreased because of higher respiration rate. With increasing baseline precipitation the GPP and NPP increased slightly, and the NEP and SOC showed decreasing trend. Soil CO2 emissions increased with the increase of temperature, and CO2 emissions changed little with increased baseline precipitation. With increased temperature and decreased baseline temperature, the total annual soil N2O emissions increased. With the variation of baseline temperature from -2 degrees C to +2 degrees C, the total annual soil NO emissions increased. The total annual N2O and NO emissions showed increasing trends with the increase of precipitation. The biogeochemical simulation of the typical forest indicated that temperature changes strongly affected carbon fluxes, soil carbon dynamics, and soil GHGs emissions. The precipitation was not a principal factor affecting carbon fluxes, soil carbon dynamics, and soil CO2 emissions, but changes in precipitation could exert strong effect on soil N2O and NO emissions.

[Alien species invasion in Southern China and its countermeasures].

Alien species invasion may cause serious ecological damage, resulting in ecological crisis and biodiversity comedown, and further menacing existing human environment. At present, the invasion of alien species has brought very serious damage to China's environment and society. The direct annual loss of its agro-forestry industry accounts for 574 billion RMB. Taking the alien species in Southern China as an example, this paper analyzed the bio-invasion approaches, mechanics and damages, and aiming at the characters of invaded area and concerned ecosystems and species, proposed several prevention measurements, i.e., pay attention to the phenomena of bio-invasion and to the basic researches on it; intensify the legislation and establish scientific strategies for introducing alien species; enforce the quarantine on invasive species and establish countrywide monitoring system on alien species; enhance people's defending consciousness; and strengthen international cooperation and collaboration.