Changes in cognitive-motor interference during rehabilitation of cane walking in patients with subacute stroke: A pilot study.

No previous research has examined cognitive-motor interference (CMI) repeatedly in patients with subacute stroke. This pilot study aimed to report on the changes over time in CMI in patients with stroke who have recently learned to walk with a cane. The assessment started as soon as the participants could walk independently with a quad cane, and was repeated up to six sessions as long as the cane was still used. The dual-tasking paradigm required participants to walk and perform continuous subtractions by 3s. Data were analyzed for 9 participants 33-127 days post-stroke. All 9 participants showed CMI in walking velocity at baseline and 8 of these showed improvement over time (Z = -2.547; p = 0.011). The improvement in CMI was associated with baseline dual-tasking performance (ρ = 0.600; p = 0.044), motor control ability (ρ = -0.695; p = 0.019), walking velocity (ρ = -0.767; p = 0.008), and functional mobility (ρ = 0.817; p = 0.004). All participants showed decrements in both tasks (mutual interference) at baseline, 1 evolved to decrements in walking velocity (cognitive-related motor interference), and 3 finally evolved to decrements in cognitive performance but increments in walking velocity (motor-priority tradeoff). In conclusion, during rehabilitation with cane walking in patients with subacute stroke, the dual-tasking paradigm revealed CMI and its improvements in the majority of participants. Greater improvement in CMI was moderately to strongly associated with worse baseline performance of many variables. The evolution of the CMI pattern over time provides novel information relevant to neurological recovery.

Porphyrindiene-Based Tandem Diels-Alder Reaction for Preparing Low-Symmetry π-Extended Porphyrins with Push-Pull Skeletons.

Tandem Diels-Alder reactions of masked porphyrindienes (i.e., sulfolenoporphyrins) with benzoquinones and stilbenes, followed by aromatization, have been developed to load porphyrin with mixed annulation units (i.e., terphenyl and naphthoquinone), furnishing the low-symmetry π-extended porphyrins (DxAy) with push-pull skeletons. All low-symmetrical chromophores display panchromatic absorption spectra, which look like a spectral combination of symmetrical congeners (D4/A4) in a certain ratio. Among them, tD2A2 with trans-arrangement of push/pull units possesses the largest maximum centered at 766 nm with the onset around 900 nm. The fusion of the electron-deficient naphthoquinone moiety on the porphyrin core results in the approximately quantitative regulation of the Eox1 and HOMOs (i.e., 0.10-0.13 V increase for the Eox1 and 0.14-0.16 eV decrease for the HOMOs per naphthoquinone unit). In brief, this work provides a new way to construct low-symmetry π-extended porphyrins with tunable properties resorting to the ratios and locations of the annulated push-pull units.

A novel Janus sponge fabricated by a green strategy for simultaneous separation of oil/water emulsions and dye contaminants.

A novel Janus sponge with the ability to remove complex contaminants from water is reported. Firstly, a superhydrophilic sponge (PA@PEI-sponge) is prepared via synthesizing negatively charged phytic acid@polyethyleneimine (PA@PEI) nanoparticles and assembling them on the surface of polydopamine (PDA) and PEI-modified polyurethane (PU) sponge through electrostatic adsorption. The Janus sponge is generated by modifying one side of the PA@PEI-sponge with PDMS, which exhibits superior separation efficiency and high filtration flux toward both water-in-oil and oil-in-water emulsions due to its multiplex selective wettability and the interconnected and tortuous 3D porous channels. The numerous negatively charged active sites of PA@PEI nanoparticles and PDA layer impart the superhydrophilic PA@PEI-sponge with the removal efficiency of 39.95 ± 0.27% for malachite green (MG) via simple flow-through filtration, which can be improved to 99.92 ± 0.07% by Janus modification. More importantly, the Janus sponge exhibits an excellent treatment capacity for complex mixtures containing emulsified oil and dye, with the separation efficiency above 99.59%. The Janus sponge also demonstrates the effective separation of real industrial wastewater collected from an acrylic dyeing plant. Together with a facile and green preparation strategy, this Janus sponge shows excellent application potential for simultaneous dye removal and oil/water emulsion separation.

Attentional demands of cane-free walking and cane walking in subacute stroke patients who have just learned to walk without a cane.

This study compared the attentional demands between cane-free walking and cane walking in patients with stroke during the transitional period of cane weaning. Patients with stroke who had just learned to walk cane-free were recruited. Cross-sectional measurement was scheduled within 30 days since the patients were able to walk independently without a quad cane. The dual-tasking paradigm required participants to walk with and without a cane, as well as perform continuous subtractions by 1 s (low-demand) or 3 s (high-demand). The cognitive-motor interference (CMI) of walking velocity was calculated as [(low-demand - high-demand)/low-demand] × 100%. Nine participants (average age, 53.4 ± 6.4 years; stroke onset, 38-131 days) were recruited, and eight showed positive CMI. The paired t-test confirmed a significantly smaller CMI during cane-free walking than during cane walking [t (8) = -3.168; P = 0.013]. The Pearson correlation tests revealed associations between age and CMI of cane walking (r = 0.751; P = 0.010) and CMI of cane-free walking (r = 0.584; P = 0.050). The time since independent cane-free walking was associated with CMI of cane walking (r = 0.699; P = 0.018). In conclusion, experience with cane-free walking leads to increased attentional demand for cane walking. In subacute stroke patients weaning use of a cane, the attentional demand for cane-free walking decreases to less than that of cane walking. During both cane and cane-free walking, the older the participant, the more the walking performance deteriorated due to dual-tasking.

Fabrication of superhydrophilic PVDF membranes by one-step modification with eco-friendly phytic acid and polyethyleneimine complex for oil-in-water emulsions separation.

Superhydrophilic membranes with simultaneous underwater superoleophobicity are highly desirable and worth exploring for separation of emulsified oil from water. In this work, combining the strong negative charges of phytic acid (PA) and the high cationic charge density of polyethyleneimine (PEI), an eco-friendly PA@PEI polyelectrolyte complex was synthetized in aqueous solution. And then the polyelectrolyte complex was deposited onto hydrophobic PVDF membranes through a one-step assembly approach with high convenience, endowing the membranes with superhydrophilic and underwater superoleophobic property. The as-prepared PA@PEI/PVDF membrane shows outstanding static and dynamic water stability, and was successfully used to separate multiple oil-in-water emulsions, with an average rejection rate exceeding 98.5% and a water flux up to 12203.6 L m-2∙h-1∙bar-1. Furthermore, the water flux can be recovered to a high level after four separation-washing cycles, showing excellent antifouling performance and recovery capability. Together with its natural raw materials and environmentally friendly preparation strategy, the PA@PEI/PVDF membrane shows great potential in practical treatment of emulsified oily wastewater.

Changes of cropland evapotranspiration and its driving factors on the loess plateau of China.

Agricultural water resource, mainly consumed through evapotranspiration, plays a critical role in agricultural production of arid and semiarid regions. Quantifying the changes of evapotranspiration in cropland (ETc), and its driving factors, may provide rich information for improving human land-use and water resource management. Here we first investigated the multi-year (2000-2015) changes in the ETc (mm yr-1) and associated driving factors of the Loess Plateau (LP), using a combination of the Vegetation Interfaces Processes model and a factorial analysis of variance. We found that the ETc of the LP showed a significant upward trend of 0.31 km3 yr-2 (3.33 mm yr-2) (p < .05) over the last 16 years, mainly driven by cropland changes (3.77% per year), which combined the contribution of cropland area changes and cropland leaf area index (LAIc) changes. We then examined the changes of the dominant driving factor: cropland, and results indicated that the cropland changes consisted of the decrease in cropland area (net decrease of 10.50 × 103 km2) and the increase in LAIc (increased by 10.72%), which suggest the actual contribution of the ETc uptrend was the increasing LAIc. Our further analysis on the causes of the increasing LAIc by correlating the LAIc with land-use management factors revealed that the cropland greening on the LP showed high positive correlations with the increasing inputs of total power of agriculture machinery and farm plastic film, followed by chemical fertilizer. The increase of LAIc was also promoted by the increased ratio of the garden fruits output to total crops output (increased by 67.12%) and multiple cropping (increased by 21.66%). These results suggest that the ETc uptrend can be related to the agricultural intensification. Our study highlights the need for a realistic representation of socio-economic development and human land-use practices in the sustainable optimal allocation of agricultural water resources on the LP.

Partitioning climate and human contributions to changes in mean annual streamflow based on the Budyko complementary relationship in the Loess Plateau, China.

Reliable attribution of changes in streamflow is fundamental to our understanding of the hydrological cycle and is needed to enable decision makers to manage water resources in a sustainable way. Here, we used a new attribution method based on the Budyko framework (complementary method) to quantify the contributions of climate change and human activities to the changes in annual streamflow in 22 catchments on China's Loess Plateau during the past three decades. Our results showed that after the Grain-for-Green (GFG) project, the annual streamflow decreased by 36% on average (3-72%), with reductions being more intense in northern catchments. The sensitivity of streamflow to precipitation and potential evapotranspiration also decreased, with a mean rate of -0.7 mm yr-1/mm yr-1 and -0.2 mm yr-1/mm yr-1, respectively. Using the upper and lower bounds of the human effects on streamflow from the complementary method as a reference, we found that these effects at half of the stations were under- or over-estimated by the total differential method. The contribution analysis from the complementary method showed that although human activities decreased streamflow by 26% (or 54% as a relative value) on average, the contribution of potential evapotranspiration alone to the decrease in streamflow was 9% (42%), highlighting the important role of increasing atmospheric moisture demand in the water cycle. In addition, the 5-year incremental analysis showed that the impacts of climate and human activities on streamflow had strong spatiotemporal variability.

Hierarchical architectures of wrinkle-like ZnFe2O4 nanosheet-enwrapped ZnO nanotube arrays for remarkably photoelectrochemical water splitting to produce hydrogen.

In this study, we show for the first time a hierarchical ZnO/ZnFe2O4 nanotube array photoanode for water splitting to produce hydrogen. In this photoanode, the wrinkle-like ZnFe2O4 nanosheets (NSs) are grown onto ZnO nanotube arrays through adsorption and annealing reaction. The hierarchical ZnO/ZnFe2O4 nanotube array photoanode exhibits outstanding PEC water splitting to produce hydrogen due to the remarkable visible-light harvesting ability and the large surface area of wrinkle-like ZnFe2O4 NSs. Under simulated solar light irradiation, the hierarchical ZnO/ZnFe2O4 nanotube arrays (NTAs) achieve a remarkably enhanced photocurrent density of 1.3 mA/cm2, which is 2.2-fold higher than that of pristine ZnO NTAs at 0 V vs Ag/AgCl. Moreover, the hydrogen production rate of the hierarchical ZnO/ZnFe2O4 nanotube array photoanode is 3.6-fold higher than that of pristine ZnO nanotube array photoelectrode at 0.6 V vs Ag/AgCl.

Vegetation changes in recent large-scale ecological restoration projects and subsequent impact on water resources in China's Loess Plateau.

Recently, relationship between vegetation activity and temperature variability has received much attention in China. However, vegetation-induced changes in water resources through changing land surface energy balance (e.g. albedo), has not been well documented. This study investigates the underlying causes of vegetation change and subsequent impacts on runoff for the Northern Shaanxi Loess Plateau. Results show that satellite-derived vegetation index has experienced a significantly increasing trend during the past three decades, especially during 2000-2012. Large-scale ecological restorations, i.e., the Natural Forest Conservation project and the Grain for Green project, are found to be the primary driving factors for vegetation increase. The increased vegetation coverage induces decrease in surface albedo and results in an increase in temperature. This positive effect can be counteracted by higher evapotranspiration and the net effect is a decrease in daytime land surface temperature. A higher evapotranspiration rate from restored vegetation is the primary reason for the reduced runoff coefficient. Other factors including less heavy precipitation, increased water consumption from town, industry and agriculture also appear to be the important causes for the reduction of runoff. These two ecological restoration projects produce both positive and negative effects on the overall ecosystem services. Thus, long-term continuous monitoring is needed.