Fabrication of Coffee-Ring Nanostructured Membranes for Organic Solvent Nanofiltration.

Organic solvent nanofiltration (OSN) plays important roles in pharmaceutical ingredients purification and solvent recovery. However, the low organic solvent permeance under cross-flow operation of OSN membrane hampers their industrial applications. Herein, we report the construction of coffee-ring structured membrane featuring high OSN permeance. A water-insoluble crystal monomer that dissolved in EtOH/H2O mixed solvent was designed to react with trimesoyl chloride via interfacial polymerization. Owing to the diffusion of EtOH to n-hexane, coffee-ring nanostructure on the support membrane appeared, which served as the template for construction of coffee-ring structured membrane. The optimal nanostructured membrane demonstrated 2.6-fold enhancement in the effective surface area with reduced membrane thickness. Resultantly, the membrane afforded a 2.7-fold enhancement in organic solvent permeance, e.g., ~13 LMH/bar for MeOH, without sacrificing the rejection ability. Moreover, due to the rigid monomer structure, the fabricated membrane shows distinctive running stability in active pharmaceutical ingredients purification and the ability for concentration of medicines.

Rapid Fabrication of High-Permeability Mixed Matrix Membranes at Mild Condition for CO2 Capture.

Mixed matrix membranes (MMMs), conjugating the advantages of flexible processing-ability of polymers and high-speed mass transfer of porous fillers, are recognized as the next-generation high-performance CO2 capture membranes for solving the current global climate challenge. However, controlling the crystallization of porous metal-organic frameworks (MOFs) and thus the close stacking of MOF nanocrystals in the confined polymer matrix is still undoable, which thus cannot fully utilize the superior transport attribute of MOF channels. In this study, the "confined swelling coupled solvent-controlled crystallization" strategy is employed for well-tailoring the in-situ crystallization of MOF nanocrystals, realizing rapid (<5 min) construction of defect-free freeway channels for CO2 transportation in MMMs due to the close stacking of MOF nanocrystals. Consequently, the fabricated MMMs exhibit approximately fourfold enhancement in CO2 permeability, i.e., 2490 Barrer with a CO2 /N2 selectivity of 37, distinctive antiplasticization merit, as well as long-term running stability, which is at top-tier level, enabling the large-scale manufacture of high-performance MMMs for gas separation.

Graphene oxide membranes with stable porous structure for ultrafast water transport.

The robustness of carbon nanomaterials and their potential for ultrahigh permeability has drawn substantial interest for separation processes. However, graphene oxide membranes (GOms) have demonstrated limited viability due to instabilities in their microstructure that lead to failure under cross-flow conditions and applied hydraulic pressure. Here we present a highly stable and ultrapermeable zeolitic imidazolate framework-8 (ZIF-8)-nanocrystal-hybridized GOm that is prepared by ice templating and subsequent in situ crystallization of ZIF-8 at the nanosheet edges. The selective growth of ZIF-8 in the microporous defects enlarges the interlayer spacings while also imparting mechanical integrity to the laminate framework, thus producing a stable microstructure capable of maintaining a water permeability of 60 l m-2 h-1 bar-1 (30-fold higher than GOm) for 180 h. Furthermore, the mitigation of microporous defects via ZIF-8 growth increased the permselectivity of methyl blue molecules sixfold. Low-field nuclear magnetic resonance was employed to characterize the porous structure of our membranes and confirm the tailored growth of ZIF-8. Our technique for tuning the membrane microstructure opens opportunities for developing next-generation nanofiltration membranes.

Impact of Different Levels of iPTH on All-Cause Mortality in Dialysis Patients with Secondary Hyperparathyroidism after Parathyroidectomy.

BACKGROUND: Secondary hyperparathyroidism (SHPT) usually required parathyroidectomy (PTX) when drugs treatment is invalid. Analysis was done on the impact of different intact parathyroid hormone (iPTH) after the PTX on all-cause mortality. METHODS: An open, retrospective, multicenter cohort design was conducted. The sample included 525 dialysis patients with SHPT who had undergone PTX. RESULTS: 404 patients conformed to the standard, with 36 (8.91%) deaths during the 11 years of follow-up. One week postoperatively, different levels of serum iPTH were divided into four groups: A: ≤20 pg/mL; B: 21-150 pg/mL; C: 151-600 pg/mL; and D: >600 pg/mL. All-cause mortality in groups with different iPTH levels appeared as follows: A (8.29%), B (3.54%), C (10.91%), and D (29.03%). The all-cause mortality of B was the lowest, with D the highest. We used group A as reference (hazard ratio (HR) = 1) compared with the other groups, and HRs on groups B, C, and D appeared as 0.57, 1.43, and 3.45, respectively. CONCLUSION: The all-cause mortality was associated with different levels of iPTH after the PTX. We found that iPTH > 600 pg/mL appeared as a factor which increased the risk of all-cause mortality. When iPTH levels were positively and effectively reducing, the risk of all-cause mortality also decreased. The most appropriate level of postoperative iPTH seemed to be 21-150 pg/mL.

Association of CKD-MBD Markers with All-Cause Mortality in Prevalent Hemodialysis Patients: A Cohort Study in Beijing.

The relationships between all-cause mortality and serum intact parathyroid hormone (iPTH), calcium, and phosphate are fairly diverse in patients on maintenance hemodialysis according to prior studies. This study evaluated the association of chronic kidney disease-mineral and bone disorder (CKD-MBD) markers with all-cause mortality in prevalent hemodialysis patients from 2007 to 2012 in Beijing, China. A cohort, involving 8530 prevalent hemodialysis patients who had undergone a 6-70 months follow-up program (with median as 40 months) was formed. Related data was recorded from the database in 120 hemodialysis centers of Beijing Health Bureau (2007 to 2012). Information regarding baseline demographics, blood CKD-MBD markers and all-cause mortality was retrospectively reviewed. By using multivariate Cox regression model analysis, patients with a low iPTH level at baseline were found to have greater risk of mortality (<75pg/ml, HR = 1.36, 95% confidence interval (CI) 1.16-1.60) than those with a baseline iPTH level within 150-300 pg/ml. Similarly, death risk showed an increase when the baseline serum calcium presented a low level (<2.1mmol/L, HR = 1.54; 95% CI 1.37-1.74). Levels of baseline serum phosphorus were not associated with the risk of death. Similar results appeared through the baseline competing risks regression analysis. Patients with a lower level of serum iPTH or calcium are at a higher risk of all-cause mortality compared with those within the range recommended by Kidney Disease Outcome Quality Initiative (KDOQI) guidelines.

[Type 2 diabetes prevalence and its risk factors among migrants and nonmigrants aged 35 years and older in Three Gorge Dam area, China].

OBJECTIVE: To explore type 2 diabetes prevalence and its risk factors among migrants and nonmigrants aged 35 years and older in Three Gorge Dam area in Yichang City of Hubei province, China. METHODS: A sample of 9865 rural residents (including 1949 Three Gorge Dam migrants and 7916 nonmigrants) aged 35 years old and over was selected from September to December in 2007 by the method of multi-stage cluster random sampling in Yiling district, Yichang City of Hubei province. The study subjects were assessed by interview, examination, and blood samples. Information on demographics, migrant information, lifestyle, history of diabetes and hypertension was obtained by a questionnaire interview. An overnight fasting blood specimen was collected to measure serum glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C) and low density lipoprotein-cholesterol (LDL-C). Height, weight, waist circumference, hip circumference and blood pressure were measured. Oral glucose tolerance test (OGTT) was carried out for those whose fasting glucose was equal to or exceeded 6.1 mmol/L. The standardized prevalence of type 2 diabetes was calculated based on national census in the year of 2000. Multiple logistic regression analysis was used to explore the potential risk factors of type 2 diabetes. RESULTS: The crude prevalence of type 2 diabetes among nonmigrants was 3.93% (310/7885) (male: 3.90% (129/3304), female: 3.95% (181/4581)), and that of migrants was 6.55% (127/1939) (male: 6.85% (52/759), female: 6.36% (75/1180)). The crude prevalence of type 2 diabetes among migrants was higher than that of nonmigrants (χ² = 25.10, P < 0.01 (male: χ² = 12.59, P < 0.01; female: χ² = 12.78, P < 0.01)). The prevalence of type 2 diabetes among nonmigrants was 3.87% in males and 4.15% in females. The standardized prevalence of type 2 diabetes among migrants was 6.92% in males and 6.33% in females. Logistic regression analysis showed that age (taking 35 - 44 years old as reference, 45 - 54 years old: OR = 1.45, 95%CI: 1.07 - 1.95; 55 - 64 years old: OR = 2.08, 95%CI: 1.53 - 2.84; 65 years old and over: OR = 1.85, 95%CI: 1.25 - 2.75), family history of diabetes (OR = 2.83, 95%CI: 1.70 - 4.72), overweight or obesity (overweight: OR = 1.36, 95%CI: 1.05 - 1.78; obesity: OR = 2.11, 95%CI: 1.47 - 3.01), central obesity (OR = 1.84, 95%CI: 1.39 - 2.44), abnormal triglyceride (OR = 1.54, 95%CI: 1.21 - 1.97), abnormal total cholesterol (OR = 1.40, 95%CI: 1.11 - 1.77) and abnormal LDL-C (OR = 1.82, 95%CI: 1.19 - 2.79) increased the risk of type 2 diabetes, and regular physical activity (OR = 0.57, 95%CI: 0.45 - 0.72) was the protective factor of type 2 diabetes. CONCLUSION: The prevalence of type 2 diabetes among Three Gorge Dam migrants was higher than that of nonmigrants. Increasing age, regular physical activity, family history of diabetes, overweight or obesity, central obesity, abnormal triglyceride, abnormal total cholesterol and abnormal LDL-C were related to type 2 diabetes.