Correlation of Serum FGF23 and Chronic Kidney Disease-Mineral and Bone Abnormality Markers With Cardiac Structure Changes in Maintenance Hemodialysis Patients.

Background: CKD-MBD is a mineral and bone metabolism syndrome caused by chronic kidney disease. FGF23 is an important factor regulating phosphorus and is the main influencer in the CKD-MBD process. In this study, we observed the correlation among serum FGF23 and calcium, phosphorus and parathyroid hormone, and the correlation between FGF23 levels and cardiac structural changes in MHD patients. Methods: We examined serum FGF23 concentrations in 107 cases of MHD patients using the ELISA method, recorded demographic information and biochemical data, and analyzed the correlation between serum FGF23 levels and blood calcium and blood phosphorus and PTH levels. All patients were evaluated by cardiac color ultrasound, and we finally analyzed the association between the FGF23 level and cardiac structural changes. Results: In 107 cases of MHD patients, serum FGF23 levels were linearly associated with serum calcium (r = 0.27 P < 0.01) and parathyroid hormone levels (r = 0.25, P < 0.05). FGF 23 was negatively correlated with age (r = -0.44, P < 0.01).Serum FGF23 levels were correlated with right atrial hypertrophy in HD patients (P < 0.05). No correlation was found among FGF23, left ventricular hypertrophy/enlargement, and valve calcification stenosis (P > 0.05). Conclusion: Serum FGF23 showed a positive correlation among blood calcium levels and PTH levels in hemodialysis patients, and FGF23 levels can affect the incidence of right atrial hypertrophy in MHD patients.

Use of non-vitamin K antagonists oral anticoagulants in atrial fibrillation patients on dialysis.

Background: Non-vitamin K antagonist oral anticoagulants (NOACs) showed a benefit-risk profile superior to that of warfarin in atrial fibrillation (AF) patients with mild to moderate chronic kidney disease. However, the effectiveness and safety of NOACs in AF patients with end-stage renal disease (ESRD) on dialysis remain unclear. Therefore, we performed a meta-analysis regarding the effect of NOACs vs. warfarin in AF patients undergoing dialysis. Methods: A search of the Pubmed and EMBASE databases until November 2021 was performed. Adjusted risk ratios (RRs) and 95%confidence intervals (CIs) were pooled by a random-effects model with an inverse variance method. Results: Six studies involving 3,744 NOAC- and 26,973 warfarin- users were deemed to meet the criteria. In the pooled analysis, the use of mixed NOACs had similar incidences of effectiveness and safety outcomes compared with warfarin use. And factor Xa inhibitors (rivaroxaban or apixaban) did not have significantly better effectiveness than warfarin. For the safety outcomes, the use of factor Xa inhibitors was associated with a reduced risk of gastrointestinal bleeding (RR = 0.81, 95% CI 0.70-0.95), but not major bleeding and intracranial bleeding. Conclusion: Compared with warfarin, the use of NOACs, especially factor Xa inhibitors (rivaroxaban or apixaban), showed at least similar effectiveness and safety outcomes in AF patients on dialysis.

Astragaloside IV protects against ischemia/reperfusion (I/R)-induced kidney injury based on the Keap1-Nrf2/ARE signaling pathway.

Background: This study sought to investigate the protective effects of Astragaloside IV (AS-IV) on ischemia-reperfusion (I/R) renal injury based on the keap1-Nrf2/ARE signaling pathway. Methods: A total of 36 male Sprague-Dawley rats (aged: 8 weeks; weighing: 200-220 g) were randomly divided into the following 6 groups (n=6 per group): (I) the control group; (II) the sham operation group; (III) the kidney I/R injury group (the I/R group); (IV) the kidney I/R injury group treated with 2 mg/kg of AS-IV (the low-dose group); (V) the kidney I/R injury group treated with 5 mg/kg of AS-IV (the mid-dose group); and (VI) the kidney I/R injury group treated with 10 mg/kg of AS-IV (the high-dose group). Serum creatinine (CRE), serum urea, malondialdehyde (MDA), and superoxide dismutase (SOD) were examined using enzyme-linked immunoassay kits. Cell apoptosis and the pathological damage to the renal tissue were determined by terminal deoxynucleotidyl transferase dUTP nick end labeling, hematoxylin and eosin, and periodic acid-Schiff (PAS) staining. The immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR), and western blot methods were used to determine the expression of Nrf2, HO-1, Bcl-2 and Bax in the kidney tissue. Results: In the I/R rat model, the serum CRE level was increased. In the acute kidney injury (AKI) and chronic kidney disease (CKD) models, AS-IV treatment significantly decreased serum CRE levels in a dose-dependent manner. AS-IV treatment also reduced the injury of renal tubular epithelial cells, increased the expression levels of Nrf2 and HO-1, decreased the rate of apoptosis, downregulated the level of MDA, and elevated the activity of SOD. In the CKD rat model, the AS-IV treatment groups had reduced renal tubular epithelial cell injury, increased expression levels of Nrf2 and HO-1, decreased MDA levels, and increased SOD activity compared to the I/R group. Conclusions: AS-IV induced the expression of Nrf2, enhanced the activity of antioxidant enzymes, reduced apoptosis, protected against renal I/R injury, and prevented AKI from transforming into CKD. These findings suggest that AS-IV is a promising drug for treating kidney injury.

Hydrotalcite-Derived Copper-Based Oxygen Carrier Materials for Efficient Chemical-Looping Combustion of Solid Fuels with CO2 Capture.

Chemical-looping combustion (CLC) is a promising technology that utilizes metal oxides as oxygen carriers for the combustion of fossil fuels to CO2 and H2O, with CO2 readily sequestrated after the condensation of steam. Thermally stable and reactive metal oxides are desirable as oxygen carrier materials for the CLC processes. Here, we report the performance of Cu-based mixed oxides derived from hydrotalcite (also known as layered double hydroxides) precursors as oxygen carriers for the combustion of solid fuels. Two types of CLC processes were demonstrated, including chemical looping oxygen uncoupling (CLOU) and in situ gasification (iG-CLC) in the presence of steam. The Cu-based oxygen carriers showed high performance for the combustion of two solid fuels (a lignite and a bituminous coal), maintaining high thermal stability, fast reaction kinetics, and reversible oxygen release and storage over multiple redox cycles. Slight deactivation and sintering of the oxygen carrier occurred after redox cycles at an very high operation temperature of 985 °C. We expect that our material design strategy will inspire the development of better oxygen carrier materials for a variety of chemical looping processes for the clean conversion of fossil fuels with efficient CO2 capture.

Precursor engineering of hydrotalcite-derived redox sorbents for reversible and stable thermochemical oxygen storage.

Chemical looping processes based on multiple-step reduction and oxidation of metal oxides hold great promise for a variety of energy applications, such as CO2 capture and conversion, gas separation, energy storage, and redox catalytic processes. Copper-based mixed oxides are one of the most promising candidate materials with a high oxygen storage capacity. However, the structural deterioration and sintering at high temperatures is one key scientific challenge. Herein, we report a precursor engineering approach to prepare durable copper-based redox sorbents for use in thermochemical looping processes for combustion and gas purification. Calcination of the CuMgAl hydrotalcite precursors formed mixed metal oxides consisting of CuO nanoparticles dispersed in the Mg-Al oxide support which inhibited the formation of copper aluminates during redox cycling. The copper-based redox sorbents demonstrated enhanced reaction rates, stable O2 storage capacity over 500 redox cycles at 900 °C, and efficient gas purification over a broad temperature range. We expect that our materials design strategy has broad implications on synthesis and engineering of mixed metal oxides for a range of thermochemical processes and redox catalytic applications.

Prognostic Value of Serum Magnesium in Mortality Risk among Patients on Hemodialysis: A Meta-Analysis of Observational Studies.

BACKGROUND: Previous studies have reported that serum magnesium (Mg) deficiency is involved in the development of heart failure, particularly in patients with end-stage kidney disease. The association between serum Mg levels and mortality risk in patients receiving hemodialysis is controversial. We aimed to estimate the prognostic value of serum Mg concentration on all-cause mortality and cardiovascular mortality in patients receiving hemodialysis. METHODS: We did a systematic literature search in PubMed, EMBASE, Cochrane Library, and Web of Science to identify eligible studies that reported the prognostic value of serum Mg levels in mortality risk among patients on hemodialysis. We performed a meta-analysis by pooling and analyzing hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: We identified 13 observational studies with an overall sample of 42,967 hemodialysis patients. Higher all-cause mortality (adjusted HR 1.58 [95% CI: 1.31-1.91]) and higher cardiovascular mortality (adjusted HR 3.08 [95% CI: 1.27-7.50]) were found in patients with lower serum Mg levels after multivariable adjustment. There was marked heterogeneity (I2 = 79.6%, p < 0.001) that was partly explained by differences in age stratification and study area. In addition, subgroup analysis showed that a serum Mg concentration of ≤1.1 mmol/L might be the vigilant cutoff value. CONCLUSION: A lower serum Mg level was associated with higher all-cause mortality and cardiovascular mortality in patients receiving hemodialysis.

Tuning the Support Properties toward Higher CO2 Conversion during a Chemical Looping Scheme.

The chemical looping process is promising for CO2 conversion because of the much higher CO2 conversion efficiency than the photocatalytic and electrocatalytic processes. Conventional oxygen carriers have to include a high content of inert support, typically Al2O3, to avoid sintering, thus leading to a trade-off between reactivity and stability. Here, we propose the use of ion-conductive GdxCe2-xO2-δ (GDC) to prepare the supported oxygen carriers. The resulting Fe2O3/GDC materials achieve both high reactivity and stability. Fe2O3/Gd0.3Ce1.7O2-δ shows high CO productivity (∼10.79 mmol·g-1) and CO production rate (∼0.77 mmol·g-1·min-1), which are twofold higher than that of Fe2O3/Al2O3. The performance remains stable even after 30 cycles. The mechanism study confirmed the rate-limiting role of the oxygen-ion conductivity, and the GDC support enhanced the oxygen-ion conductivity of oxygen carriers during the redox reactions, thus leading to improved CO2 splitting performance. A roughly linear relationship between the oxygen-ion conductivity and CO2 yield is also obtained and verified in our testing conditions. This relation can be used to predict and select oxygen carriers with high CO2 splitting performance.

Ternary Mixed Spinel Oxides as Oxygen Carriers for Chemical Looping Hydrogen Production Operating at 550 °C.

Operating chemical looping at moderate temperatures circumvents the issue that the sintering of oxygen carrier materials is serious at typical operating conditions, 800-950 °C. However, lower temperatures can lead to deterioration on the reaction kinetics and thereby the low H2 production rate and yield. Here, we present several doped spinel oxides consisting of earth-abundant elements for chemical looping water splitting. By virtue of the ability of the Cu dopant to improve the reduction of the Co-based binary spinel, the high reducibility of the dopants in the reduction period, as well as the phase reversibility in the water splitting period, Cu0.25Co0.25Fe2.5Oy shows a high hydrogen yield (∼11.9 mmol g-1) and an average hydrogen production rate (∼137.7 µmol g-1 min-1) at 550 °C, with negligible decays in repetitive redox cycles. The performance of this material is comparable to that of the state-of-the-art perovskites which usually contain rare-earth metals, enabling its potential in industrial implementation.

Synergistic photothermal/photodynamic suppression of prostatic carcinoma by targeted biodegradable MnO2 nanosheets.

The biodegradability and clearance of metal-based nanomaterials have been questioned worldwide, which have greatly limited their clinical translation. Herein, ultrathin manganese dioxide (MnO2) nanosheets with broad near-infrared (NIR) absorption and pH-dependent degradation properties were prepared. After being modified with polyethylene glycol-cyclic arginine-glycineaspartic acid tripeptide (PEG-cRGD), the MnO2 nanosheets were then used as photothermal agent and nanocarrier to encapsulate chlorin e6 (Ce6) for targeted photothermal (PTT) and photodynamic (PDT) of cancer. As expected, the MnO2-PEG-cRGD nanosheets show high Ce6 loading capacity (351 mg/g), superb photothermal conversion performance (37.2%) and excellent colloidal stability. These nanosheets also exhibit pH-dependent and NIR-induced Ce6 release. Furthermore, the MnO2 nanosheets can be degraded by reacting with hydrogen peroxide in the acidic microenvironment, which are able to elevate the oxygen concentration in situ and thus reverses the tumor hypoxia. Thanks to these favorable properties and the cRGD-mediated tumor-targeted ability, the fabricated MnO2-PEG-cRGD/Ce6 nanocomposites can be effectively up taken by alpha-v beta-3 (αvß3) integrin over-expressed prostatic carcinoma PC3 cells and achieve favorable therapeutic outcomes under a single 660 nm NIR laser, which is also verified by in vitro studies. The biodegradable MnO2-PEG-cRGD/Ce6 nanosheets developed in this work can be a promising nanoplatform for synergetic PTT/PDT cancer therapy.

Frequencies of apolipoprotein E alleles in depressed patients undergoing hemodialysis--a case-control study.

OBJECTIVE: To explore the relation between the frequencies of apolipoprotein E (ApoE) alleles and the occurrence of depression in patients undergoing hemodialysis in a Chinese population. METHODS: We examined the ApoE alleles in a sample of 288 subjects: 72 patients with depression under hemodialysis, 74 patients without depression under hemodialysis, 75 patients with depression under nondialytic treatment and 67 patients without depression under nondialytic treatment. The depression state was assessed using the Center for Epidemiological Studies Depression (CES-D) scale. Associations between the occurrence of depression and the frequencies of ApoE alleles were examined using multinomial logistic regression models with adjustment of relevant covariates. Information about sociodemographics, clinical data, vascular risk factors and cognitive function was also collected and evaluated. RESULTS: The frequencies of ApoE-ɛ2 were significantly different between depressed and non-depressed patients irrespective of dialysis (p < 0.05), but no significant difference was found in the frequencies of ApoE-ɛ4 (p > 0.05). Serum ApoE levels were significantly different between depressed and non-depressed patients in the whole sample (p < 0.05). Multinomial logistic regression models showed significant association between the frequency of ApoE-ɛ2 and the occurrence of depression in the Chinese population after control of relevant covariates, including age, sex, educational level, history of smoking and drinking, vascular risk factors and cognitive function. CONCLUSIONS: No association between the frequency of ApoE-ɛ4 and the occurrence of depression was found in patients undergoing hemodialysis. Further research is needed to find out if ApoE-ɛ2 acts as a protective factor in Chinese dialysis population since it might decrease the prevalence of depression and delay the onset age.