Modular Customization and Regulation of Metal-Organic Frameworks for Efficient Membrane Separations.

Metal-organic frameworks (MOFs) are considered ideal membrane candidates for energy-efficient separations. However, the MOF membrane amount to date is only a drop in the bucket compared to the material collections. The fabrication of an arbitrary MOF membrane exhibiting inherent separation capacity of the material remains a long-standing challenge. Herein, we report a MOF modular customization strategy by employing four MOFs with diverse structures and physicochemical properties and achieving innovative defect-free membranes for efficient separation validation. Each membrane fully displays the separation potential according to the MOF pore/channel microenvironment, and consequently, an intriguing H2 /CO2 separation performance sequence is achieved (separation factor of 1656-5.4, H2 permeance of 964-2745 gas permeation unit). Taking advantage of this strategy, separation performance can be manipulated by a non-destructive modification separately towards the MOF module. This work establishes a universal full-chain demonstration for membrane fabrication-separation validation-microstructure modification and opens an avenue for exclusive customization of membranes for important separations.

Structure Regulation of MOF Nanosheet Membrane for Accurate H2 /CO2 Separation.

High-purity H2 production accompanied with a precise decarbonization opens an avenue to approach a carbon-neutral society. Metal-organic framework nanosheet membranes provide great opportunities for an accurate and fast H2 /CO2 separation, CO2 leakage through the membrane interlayer galleries decided the ultimate separation accuracy. Here we introduce low dose amino side groups into the Zn2 (benzimidazolate)4 conformation. Physisorbed CO2 served as interlayer linkers, gently regulated and stabilized the interlayer spacing. These evoked a synergistic effect of CO2 adsorption-assisted molecular sieving and steric hinderance, whilst exquisitely preserving apertures for high-speed H2 transport. The optimized amino membranes set a new record for ultrathin nanosheet membranes in H2 /CO2 separation (mixture separation factor: 1158, H2 permeance: 1417 gas permeation unit). This strategy provides an effective way to customize ultrathin nanosheet membranes with desirable molecular sieving ability.

Flexible Soft-Solid Metal-Organic Framework Composite Membranes for H2 /CO2 Separation.

The development of a facile strategy to construct defect-free and flexible metal-organic framework (MOF)-based membranes with high selectivity and good scalability holds great appeal. Here we report the fabrication of soft-solid MOF composite membranes on polyvinylidene fluoride substrates. A representative membrane comprised of quasi-vertically grown lamellar Zn2 (Bim)4 (Bim=benzimidazolate) and lateral ultrathin polyamide film adhering to the MOF side facets. The straight interlayer galleries within unwrapped Zn2 (Bim)4 acted as predominant pathways, while the polyamide served the function of defect elimination, synergistically inducing an unprecedented H2 /CO2 selectivity of 1084 which set a new record for MOF-based membranes. Separation performance was held constant after membrane rolling up into a tube with a diameter of 3 mm or folding and unfolding at 90° for 50 times. ZIF-67 and ZIF-8 composite membranes based on this strategy also realized extremely high H2 /CO2 separation accuracies. These results, which demonstrate the intrinsic molecular sieving capability of MOFs, will promote the development of MOF-based membranes in practical separation applications.

Rational design and fabrication of a novel acid-resistant UZM-5 zeolite membrane for pervaporation dehydration processes.

Novel thin UZM-5 zeolite membranes with pure UFI phase were successfully fabricated using a charge density mismatch-assisted tertiary growth approach. Taking full advantage of the suitable Si/Al ratio and pore size, the obtained novel zeolite membranes revealed an outstanding acid-resistant capacity and provided great potential for acetic acid pervaporation dehydration applications.

Cumulative effect of risk and protective factors on unintentional injury for Chinese rural children: a nested case-control study.

BACKGROUND: Childhood unintentional injuries are the leading cause of death and disability for children. Despite the risk factors that lead to the occurrence of injuries have been identified, the relationship between cumulative effect of risk/protective factors and unintentional injuries is unclear. The aim of this study was to explore the cumulative effect of risk factors as well as protective factors and their interaction on unintentional injury to rural children. METHODS: We used a nested case-control study design from a cohort database. The study comprised 1696 children aged 6 to 14 years. Among them, 424 were cases with unintentional injury and 1272 were their matched control. After controlling for the significant sociodemographic variables, linear and logistic regression analyses were performed. RESULTS: The risk of unintentional injury increased with the increasing number of risk factors - RFI from 1 to 3 (ORRFI(1) = 0.978, 95% CI 0.739-1.296), (ORRFI(2) = 1.720, 95% CI 1.233-2.397), (ORRFI(3) = 5.162, 95% CI 3.129-8.517). PFI (1) was associated with lower risk of injury, but this association was at the edge of significance (p = 0.052). The increased risk in those with PFI (2) was not significant (p = 0.254). The severity of the unintentional injury significantly increased with the increasing number of the risk factors (p < 0.01), and significantly decreased with both the increasing number of protective factors (p = 0.001) and interaction of the risk and protective factors (p < 0.01).The interaction of RFI and PFI could explain 32.2% of the unintentional injury severity. CONCLUSIONS: According to the findings of the present study, cumulative risk factors and protective factors, as well as their interaction were associated with the occurrence and/ or severity of unintentional injury in children.

Single-Phase Covalent Organic Framework Staggered Stacking Nanosheet Membrane for CO2 -Selective Separation.

Two-dimensional covalent organic frameworks (2D COFs) are considered as potential candidates for gas separation membranes, benefiting from permanent porosity, light-weight skeletons, excellent stability and facilely-tailored functionalities. However, their pore sizes are generally larger than the kinetic diameters of common gas molecules. One great challenge is the fabrication of single-phase COF membranes to realize precise gas separations. Herein, three kinds of high-quality ß-ketoenamine-type COF nanosheets with different pore sizes were developed and aggregated to ultrathin nanosheet membranes with distinctive staggered stacking patterns. The narrowed pore sizes derived from the micro-structures and selective adsorption capacities synergistically endowed the COF membranes with intriguing CO2 -philic separation performances, among which TpPa-2 with medium pore size exhibited an optimal CO2 /H2 separation factor of 22 and a CO2 permeance of 328 gas permeation units at 298 K. This membrane performance reached the target with commercial feasibility for syngas separations.

The efficacy and safety of moderate aerobic exercise for patients with Parkinson's disease: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Exercise therapy is an important component of non-drug treatment for Parkinson's disease (PD). However, the impact of moderate aerobic exercise on PD remains unclear. The purpose of this systematic review was to evaluate the efficacy and safety of moderate aerobic exercise for patients with PD. METHODS: Databases including the Cochrane Library, PubMed, Web of Science, EMBASE, Chinese Biomedical Literature (CBM) Database, Chinese National Knowledge Infrastructure (CNKI), WanFang, and the Weipu Database for Chinese Technical Periodicals (VIP) were searched electronically from the date of inception of the database to June 2020 to recruit relevant randomized controlled trials (RCTs) investigating the efficacy and safety of moderate aerobic exercise on balance and other symptoms in patients with PD. Literature screening, data extraction, and quality evaluation were carried out. Revman5.1 (http:// ims.cochrane.org/revman) was used for data analysis. RESULTS: In total, nine RCTs with 444 patients were included in this study. Most of the included trials had a low risk of bias and high methodological quality. The meta-analysis suggested that moderate aerobic exercise is effective in improving balance [weighted mean difference (WMD) =-0.42, 95% confidence interval (CI): -0.59 to -0.25, P<0.001] and gait (WMD =49.97, 95% CI: 17.84-82.10, P<0.001) in patients with PD, but not in motor symptoms (WMD =-2.14, 95% CI: -4.86-0.58, P=0.12). Subgroup analysis showed that the improvement in the quality of life of PD patients was affected by different types of exercise, and the treadmill subgroup improved significantly (WMD =-3.90, 95% CI: -5.02 to -2.78), P<0.001). CONCLUSIONS: On the whole, moderate aerobic exercise effectively improves balance and gait in patients with PD, but the effect on motor symptoms is not obvious. Different exercise styles have varying effects on the quality of life of PD patients. It is necessary to standardize the exercise program further and carry out indepth research in the future.

Parent supervision attributes profile questionnaire (PSAPQ) for young children: psychometric properties of the Chinese version.

BACKGROUND: In China, thousands of children die from unintentional injury each year: the incidence rate of injury is from 19.4 to 64.3% which is the leading cause of mortality for children. An important factor to injury may be inadequate supervision. Thus, a linguistic and culturally appropriated, validated instrument to measure the supervision of children in Chinese primary caregiver is important and necessary. The purpose of this study was to translate and test the psychometric properties of the Chinese version of the Parent Supervision Attributes Profile Questionnaire (C-PSAPQ). METHODS: This is a two-phase study. In phase I, the C-PSAPQ was produced by for- and back-ward translation. A total of 296 primary caregivers of 3-6 years old children were invited to participate in the second phase of the psychometric study. In order to assess the reliability of the C-PSAPQ, internal consistency and test-retest methods were performed. Additionally, construct validity was examined by using confirmatory factor analysis (CFA). The averaged variance extracted (AVE) and Bootstrap were used to test the convergent and to discriminate validity. The concurrent validity was assessed by evaluating the association between the self-reported C-PSAPQ and naturalistic observations. RESULTS: The Cronbach's α and intraclass correlation coefficients were acceptable for the C-PSAPQ and four subscales. The CFA supported a 4-factor loading model; however, the convergent validity was not acceptable (AVE < .5 for two subscales). The concurrent validity was supported. CONCLUSIONS: Due to the unacceptable convergent validity of the C-PSAPQ, an exploratory factor analysis is needed to ensure that the same trait is measured by its indicators in different cultures.

Unintentional childhood injury: a controlled comparison of behavioral characteristics.

BACKGROUND: Childhood injury is a major public health problem around the world and those injuries have negative impacts on children and their families. The purpose of this study was to compare the behavioral characteristics between Chinese school-age children (6 to 11 years of age) with and without unintentional injuries and to identify behavioral risk factors for school-age children with unintentional injury. METHODS: This cross-sectional predictive study was conducted in five elementary schools in Daqing, China. The Achenbach Child Behavior Checklist (CBCL) was used to assess the children's behavioral characteristics. A total of 725 school-age children were screened. Of these, 116 children who had experienced unintentional injury in the past year were recruited as the study group, and 123 children who had not experienced an unintentional injury were randomly selected and assigned to the control group. RESULTS: The total scores of CBCL in the study group children were significantly higher than those in the control group. The significant behavior disorder predictors for unintentional injury in boys were schizoid behavior problem (OR = 2.43), anxiety/depression (OR = 2.76) and hyperactive (OR = 2.42). The predictors for unintentional injury in girls were anxiety/depression (OR = 2.12) and delinquent behavior (OR = 2.81). CONCLUSIONS: Children with behavior disorders are more likely to suffer from unintentional injuries. Teachers and pediatricians should identify the behavior disorders and assist parents to help children, thereby reducing the rate and severity of injuries.