Methylated Biochemical Fulvic Acid-Derived Hydrogels with Improved Swelling Behavior and Water Retention Capacity.

Although humic acids (HAs) have been used to prepare absorbent hydrogels, their applications in many areas, such as agriculture, wastewater treatment and hygienic products, are not satisfactory due to their low solubility in organic solvents. In this work, biochemical fulvic acid (BFA), as a kind of HA, was initially methylated for preparation of the methylated BFA (M-BFA), which contributed to enhancing the solubility in organic solvents. Then, M-BFA reacted with N,N'-methylene diacrylamide (MBA) in the N,N-Dimethylacrylamide (DMAA) solution, and the expected hydrogel (M-BFA/DMAA) was successfully obtained. XPS confirmed that there were more C=O and C-N groups in M-BFA/DMAA than in DMAA; thus, M-BFA/DMAA was able to offer more reactive sites for the water adsorption process than DMAA. The combined results of BET and SEM further demonstrated that M-BFA/DMAA possessed a larger BET surface area, a larger pore volume and a more porous structure, which were favorable for the transfer of water and accessibility of water to active sites, facilitating water adsorption and storage. In addition, the swelling ratio and water retention were investigated in deionized (DI) water at different conditions, including test times, temperatures and pHs. Amazingly, the swelling ratio of M-BFA/DMAA was 10% higher than that of DMAA with the water retention time from 100 to 1500 min. Although M-BFA/DMAA and DMAA had similar temperature sensitivities, the pH sensitivity of M-BFA/DMAA was 0.9 higher than that of DMAA. The results proved that M-BFA/DMAA delivered superior water retention when compared to the pristine DMAA. Therefore, the resultant materials are expected to be efficient absorbent materials that can be widely used in water-deficient regions.

Expanded Vermiculite/D-Mannitol as Shape-Stable Phase Change Material for Medium Temperature Heat Storage.

Aiming to promote the application of D-mannitol in the field of phase change thermal storage, obstacles, including low thermal storage efficiency and high supercooling, should be properly disposed of. The adoption of adaptable and low-cost supporting materials to make shape-stable phase change materials (ss-PCMs) affordable is a primary solution to solve the above shortcomings. In this study, high-performance ss-PCM for effective medium-temperature heat storage was prepared using expanded vermiculite as the support for D-mannitol preservation. Among the three candidates that treated the raw vermiculite by dilute acid, calcination, and microwave heating, the calcinated expanded vermiculite (CV) was characterized as the most suitable one. After impregnating D-mannitol into the CV carrier by vacuum, a melting enthalpy of 205.1 J/g and a crystallization enthalpy of 174.1 J/g were achieved by the as-received CV/D-mannitol ss-PCM. Additionally, the supercooling of the ss-PCM was reduced to 45.6 °C. The novel CV/D-mannitol ss-PCM also exhibited excellent reusability and stability. All the findings indicate that the abundant and inexpensive CV exhibited great potential as the supporting material for D-mannitol-based ss-PCMs, which allow effective waste heat recovery and temperature regulation.

Spent Yeast-Derived 3D Porous Carbon Skeleton as Low-Cost D-Mannitol Supporting Material for Medium Temperature Thermal Energy Storage.

Shape-stable phase change materials (ss-PCMs) are extensively applied in renewable energy storage. The core for realizing high latent heat and good thermal stability of ss-PCMs is the designation of suitable supporting skeletons that can effectively preserve the PCMs from leaking out. In this study, ss-PCMs impregnated by D-mannitol were prepared using a waste yeast-derived carbon (YC) as the support material. YC possesses a large surface area (669.90 m2/g), which can provide sufficient phase transition space and nucleation sites for D-mannitol. The results indicated that a reduced supercooling of 44.76 °C for YC/D-mannitol ss-PCMs can be realized. The ss-PCMs also exhibited good cycling stability, with latent heat loss rates of 4.00% and 2.15% after 200 thermal cycles. We further demonstrate that YC provides restricted space for mannitol to inhibit the supercooling mechanism. The YC/D-mannitol ss-PCMs exhibited great promise for solar heat storage and industrial waste heat recovery in the medium temperature domain.

Waste Plastic Polypropylene Activated Jujube Charcoal for Preparing High-Performance Phase Change Energy Storage Materials.

The research on the high-value utilization of biomass has good application prospects and is conducive to sustainable development. In this paper, three different types of activators (potassium hydroxide, phosphoric acid, and polypropylene) were used to carbonize jujube branches at high temperatures of 600 °C and 800 °C, and then the PEG/jujube charcoal composite phase change materials (PCM) were prepared by vacuum impregnation of polyethylene glycol (PEG). The results showed that the carbon support activated by polypropylene (PP) had a richer pore size distribution than the other two activation methods, and the 800 °C carbonization carrier loaded PEG had a higher phase change enthalpy than the composite material at 600 °C. The mesoporous and macroporous structures were staggered with PP-activated jujube charcoal at 800 °C, with a specific surface area of 1082.2 m²/g, the melting enthalpy of the composite material reached 114.92 J/g, and the enthalpy of solidification reached 106.15 J/g after PEG loading. The diffraction peak of the composite phase change material was the superposition of PEG and carbon matrix, which proved that the loading process was physical adsorption. After 200 thermal cycles, the melting enthalpy and crystallization enthalpy were only reduced by 4.3% and 4.1%, respectively, and they remained stable and leak-free at the melting point of PEG for 2 h, demonstrating good thermal stability of the composite phase change materials. In summary, PP has obvious advantages over traditional activation, and the carbon-supported PEG phase change composite after PP activation is a biochar energy storage material with excellent performance.

Multilayer Graphene Oxide Supported ZIF-8 for Efficient Removal of Copper Ions.

To address the performance deterioration of ZIF-8 for the adsorption of copper ions caused by powder volume pressure and particle aggregation, we employed multilayer graphene oxide (MGO) as a support to prepare composite adsorbents (MGO@ZIF-8) by using the in situ growth of ZIF-8 on MGO. Due to a good interfacial compatibility and affinity between ZIF-8 and graphene nanosheets, the MGO@ZIF-8 was successfully prepared. The optimal Cu2+ adsorption conditions of MGO@ZIF-8 were obtained through single factor experiments and orthogonal experiments. Surprisingly, the Cu2+ adsorption capacity was significantly improved by the integration of MGO and ZIF-8, and the maximum Cu2+ adsorption capacity of MGO@ZIF-8 reached 431.63 mg/g under the optimal adsorption conditions. Furthermore, the kinetic fitting and isotherm curve fitting confirmed that the adsorption law of Cu2+ by MGO@ZIF-8 was the pseudo-second-order kinetic model and the Langmuir isotherm model, which indicated that the process of Cu2+ adsorption was monolayer chemisorption. This work provides a new approach for designing and constructing ZIF-8 composites, and also offers an efficient means for the removal of heavy metals.

Preparation of Organic-Inorganic Coupling Phase Change Materials with Enhanced Thermal Storage Performance via Emulsion Polymerization.

The serious phase separation in inorganic phase change materials, and easy leakage of organic phase change materials are the main obstacles to the practical batch application of phase change heat storage materials. To solve these problems, in this work, emulsion polymerization is introduced as the method for preparing organic-inorganic coupling phase change material (oic-PCM) with high heat storage performance using polyacrylamide (PAM) as the wall material and organic phase change material of cetyl alcohol as the core material, and diatomite is used as a supporting substrate to absorb inorganic sodium sulfate decahydrate (SSD). A differential scanning calorimeter (DSC), X-ray diffractometer (XRD), dust morphology and dispersion analyzer, and thermal conductivity tester were used to characterize the prepared organic-inorganic coupled phase change materials and investigate their performance. The research results show that when the mass fraction of cetyl alcohol is 68.97%, the mass fraction of emulsifier is 3.38%, and the mass fraction of sodium sulfate decahydrate/diatomite is 3.40%. The phase change latent heat of the organic-inorganic coupled phase change material is as high as 164.13 J/g, and the thermal conductivity reaches up to 0.2061 W/(m·k), which proves that the prepared organic-inorganic coupled phase change material has good heat storage performance, showing its good application prospects.

Hypophosphatemia is an independent risk factor for AKI among hospitalized patients with COVID-19 infection.

BACKGROUND: This study sought to investigate incidence and risk factors for acute kidney injury (AKI) in hospitalized COVID-19. METHODS: In this retrospective study, we enrolled 823 COVID-19 patients with at least two evaluations of renal function during hospitalization from four hospitals in Wuhan, China between February 2020 and April 2020. Clinical and laboratory parameters at the time of admission and follow-up data were recorded. Systemic renal tubular dysfunction was evaluated via 24-h urine collections in a subgroup of 55 patients. RESULTS: In total, 823 patients were enrolled (50.5% male) with a mean age of 60.9 ± 14.9 years. AKI occurred in 38 (40.9%) ICU cases but only 6 (0.8%) non-ICU cases. Using forward stepwise Cox regression analysis, we found eight independent risk factors for AKI including decreased platelet level, lower albumin level, lower phosphorus level, higher level of lactate dehydrogenase (LDH), procalcitonin, C-reactive protein (CRP), urea, and prothrombin time (PT) on admission. For every 0.1 mmol/L decreases in serum phosphorus level, patients had a 1.34-fold (95% CI 1.14-1.58) increased risk of AKI. Patients with hypophosphatemia were likely to be older and with lower lymphocyte count, lower serum albumin level, lower uric acid, higher LDH, and higher CRP. Furthermore, serum phosphorus level was positively correlated with phosphate tubular maximum per volume of filtrate (TmP/GFR) (Pearson r = 0.66, p < .001) in subgroup analysis, indicating renal phosphate loss via proximal renal tubular dysfunction. CONCLUSION: The AKI incidence was very low in non-ICU patients as compared to ICU patients. Hypophosphatemia is an independent risk factor for AKI in patients hospitalized for COVID-19 infection.

Epidemiological, Clinical, and Immunological Features of a Cluster of COVID-19-Contracted Hemodialysis Patients.

BACKGROUND: The outbreak of highly contagious coronavirus disease 2019 (COVID-19) has posed a serious threat to human life and health, especially for those with underlying diseases. However, the impact of COVID-19 epidemic on hemodialysis (HD) centers and HD patients has not been reported. METHODS: We reviewed the whole course of the COVID-19 in the HD center of Renmin Hospital, Wuhan University (from January 14, 2020, to March 12, 2020). We compared the clinical manifestation and immune profiles among different patient groups with healthy individuals. RESULTS: Forty-two of 230 HD patients (18.26%) and 4 of 33 medical staff (12.12%) were diagnosed with COVID-19 during the study period. Fifteen HD patients (6.52%), including 10 COVID-19 diagnosed, died. Only 2 deaths of the COVID-19 HD patients were associated with pneumonia/lung failure, others were ascribed to cardiovascular/cerebrovascular diseases or hyperkalemia. Except for 3 patients who were admitted to the intensive care unit for a severe condition (8.11%), including 2 who died, most COVID-19 diagnosed patients presented mild or nonrespiratory symptoms. The flow cytometric analysis of peripheral blood showed that multiple lymphocyte populations in HD patients were significantly decreased. HD patients with COVID-19 even displayed more remarkable reduction of serum inflammatory cytokines than other patients with COVID-19. CONCLUSIONS: Compared with the general population, HD patients and health care professionals are the highly susceptible population and HD centers are high-risk areas during the outbreak. Most HD patients with COVID-19 exhibited mild clinical symptoms and did not progress to severe pneumonia, likely due to the impaired cellular immune function and incapability of mounting cytokine storm. More attention should be paid to prevent cardiovascular events, which may be the collateral impacts of the COVID-19 epidemic on HD patients.

Non-invasive urinary metabolomics reveals metabolic profiling of polycystic ovary syndrome and its subtypes.

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder, which affects 4-10 % women of reproductive age. Though accumulating scientific evidence, its pathogenesis remains unclear. In the current study, metabolic profiling as well as diagnostic biomarkers for different phenotypes of PCOS was investigated using non-invasive urinary GCMS based metabolomics. A total of 371 subjects were recruited for the study. They constituted the following groups: healthy women, those with hyperandrogenism (HA), women with insulin-resistance (IR) in PCOS. Two cross-comparisons with PCOS were performed to characterize metabolic disturbances. A total of 23 differential metabolites were found. The altered metabolic pathways included glyoxylate and dicarboxylate metabolism, pentose and glucuronate interconversions, and citrate cycle and butanoate metabolism. For differential diagnosis, a panel consisting of 9 biomarkers was found from the comparison of PCOS from healthy subjects. The area under the receiver operating characteristic (ROC) curve (AUC) was 0.8461 in the discovery phase. Predictive value of 89.17 % was found in the validation set. Besides, a panel of 8 biomarkers was discovered from PCOS with HA vs IR. The AUC for 8-biomarker panel was 0.8363, and a panel of clinical markers (homeostasis model assessment-insulin resistance and free androgen index) had 0.8327 in AUC. While these metabolites combined with clinical markers reached 0.9065 in AUC from the discovery phase, and 93.18 % in predictive value from the validation set. The result showed that differences of small-molecule metabolites in urine may reflect underlying pathogenesis of PCOS and serve as biomarkers for complementary diagnosis of the different phenotypes of PCOS.

FTY720 Attenuates Angiotensin II-Induced Podocyte Damage via Inhibiting Inflammatory Cytokines.

FTY720, a new chemical substance derived from the ascomycete Isaria sinclairii, is used for treating multiple sclerosis, renal cancer, and asthma. Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid metabolite and exists in red blood cells. FTY720 is a synthetic S1P analog which can block S1P evoking physiological effects. Recently studies show that S1P was participating in activated inflammation cells induced renal injury. The objective of this study was to assess the protective effect of FTY720 on kidney damage and the potential mechanism of FTY720 which alleviate podocyte injury in chronic kidney disease. In this study, we selected 40 patients with IgA nephropathy and examined their clinical characteristics. Ang II-infusion rat renal injury model was established to evaluate the glomeruli and tubulointerstitial lesion. The result showed that the concentration of S1P in serum and urine was positively correlated with IgA nephropathy patients' renal injury. FTY720 could reduce renal histological lesions induced by Ang II-infusion in rats. Moreover, FTY720 decreased S1P synthesis in Ang II-infusion rats via downregulation of inflammatory cytokines including TNF-α and IL-6. In addition, FTY720 alleviated exogenous S1P-induced podocyte damage. In conclusion, FTY720 is able to attenuate S1P-induced podocyte damage via reducing inflammatory cytokines.

PCB77 Inducing Renal Tubular Cell Apoptosis.

PCBs are a family of persistent environmental toxicants with a wide spectrum of toxic features, such as neurotoxic, hepatoxicity, immunotoxicity, endocrine disruption effects, and oncogenic effects. The kidney is the most important organ involved in the elimination of toxins and drugs. To date, little has been done to investigate the potential influence of nephrotoxicity of 3,3',4,4'- tetrachlorobiphenyl (PCB77). By assessing cell viability and apoptotic cell death in renal tubular epithelial (NRK-52E) cells cultures, we found that PCB77 could decrease cellular viability at least at 30 µM concentration after 3 h exposure. PCB77 was demonstrated to promote DNA breakage resulting in apoptosis. Moreover, apoptotic subcellular morphological changes administration of PCB77 was observed using transmission electron microscopy. Appearance swelling of mitochondria, endoplasmic reticulum dilation and chromatin agglutinate, and other apoptosis cells morphological characteristics could be visible. Due to increased PCB77 concentration, cells viability was decreased. Collectively, our findings identified the morphological mechanism that PCB77-induced nephrotoxicity via promoting renal tubular epithelial cells apoptosis. It is suggested that using and production of PCB77 should be carefully managed to reduce public health risks.

Peritoneal catheter fixation to the abdominal wall in surgical catheter implantation to prevent malfunction.

BACKGROUND: Catheter failure, especially catheter displacement and obstruction remain the major barriers for peritoneal dialysis. We have developed a new surgery technique of catheter fixation on the lower abdominal wall in the catheter planting to avert the catheter mechanical complications. METHOD: A retrospective study was performed on 93 patients; among them, 52 patients underwent the traditional method of surgery for catheter insertion and 41 patients received additional catheter fixation. Comparisons of complications including infection, leak, infusion pains, catheter displacement, and obstruction occurred during a follow-up period of 6 months, were made between the fixed and non-fixed groups. RESULTS: Catheter fixation cost more time than the conventional operating procedure (94.2 ± 14.6 min vs. 83 ± 13.3 min, p = 0.043). Complications of infection, leak, and infusion pain that occurred in the fixed and unfixed groups are comparable. Catheter fixation reduced the complications of catheter displacement or obstruction to 0 episode in the fixed group, whereas those complications were encountered by 7 patients in the unfixed group (0/41 vs. 7/52, p = 0.022). All these 7 patients received re-exploration and catheter replacement with further catheter fixation. In the following time until now (ranging from 3 to 16 months), no catheter dysfunction was observed. CONCLUSIONS: These results suggest that catheter fixation is effective in preventing catheter displacement and obstruction in peritoneal dialysis.