Charged domain walls in ferroelectrics exhibit a quasi-two-dimensional conduction path coupled to the surrounding polarization. They have been proposed for use as non-volatile memory with non-destructive operation and ultralow energy consumption. Yet the evolution of domain walls during polarization switching makes it challenging to control their location and conductance precisely, a prerequisite for controlled read-write schemes and for integration in scalable memory devices. Here, we explore and reversibly switch the polarization of square BiFeO nanoislands in a self-assembled array. Each island confines cross-shaped, charged domain walls in a centre-type domain. Electrostatic and geometric boundary conditions induce two stable domain configurations: centre-convergent and centre-divergent. We switch the polarization deterministically back and forth between these two states, which alters the domain wall conductance by three orders of magnitude, while the position of the domain wall remains static because of its confinement within the BiFeO islands.

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Water scarcity has become an increasingly complex challenge with the global population growth, economic expansion, and climate changes, highlighting the demand for developing advanced water treatment technologies that can provide...

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Objective Determining the prognoses of patients with acute ischemic stroke is difficult. Therefore, the aim of this study was to evaluate whether the combined assessment of plasma N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and the National Institutes of Health Stroke Scale (NIHSS) variables is relevant to the prognosis of patients with acute cerebral ischemic infarction in-hospital. Methods We enrolled 122 patients who were within three days of onset of acute ischemic stroke. We measured the plasma NT-pro-BNP level of each patient within 72 hours and recorded the NIHSS score on admission. The factors associated with death were investigated using a multivariate logistic regression analysis. Results Twenty-three patients (18.85%) died during hospitalization. The frequency of atrial fibrillation (AF), the NIHSS score on admission (8.69±4.87 in the survival group vs. 14.48±2.54 in the deceased group, p<0.001) and the plasma NT-pro-BNP level (median: 926.30 pg/mL in the survival group vs. 3,280 pg/mL in the deceased group, p<0.001; Lg NT-pro-BNP 2.82±0.66 in the survival group vs. 3.46±0.52 in the deceased group, p<0.001) were each significantly higher in the deceased group than in the survival group. The optimal cut-off levels for the NT-pro-BNP level and NIHSS score to distinguish the deceased group from the survival group were 1,583.50 pg/mL and 12.5, respectively. Patients with both elevated NT-pro-BNP levels (>1,583.50 pg/mL) and NIHSS scores on admission (NIHSS >12.5) had a substantially higher mortality rate than those without elevated NT-pro-BNP levels and NIHSS scores (89.47% vs. 9.84%, p<0.001). A multivariate logistic regression analysis demonstrated that a NT-pro-BNP level >1,583.50 pg/mL (OR, 5.001; 95% CI, 1.233 to 20.287, p=0.024) and a NIHSS score >12.5 (OR, 1.465; 95% CI, 1.191 to 1.801, p<0.001) were each independent factors associated with in-hospital death. Conclusion The plasma NT-pro-BNP level and the NIHSS score added independent and incremental contributions to the prognostic stratification of patients with acute ischemic stroke.

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In nature, shrimp has an outstanding antifouling behavior since its shell possesses underwater superoleophobicity. As a major component of the shrimp shell, chitin might have the potential of self-cleaning and can be exploited for dealing with oily water. Hence, novel filtration membranes derived from shellfish wastes were constructed via filtration of chitin nanofiber suspension. The resultant chitin nanofibrous membrane (CNM) was evaluated as a highly efficient oil/water emulsion separation material for the first time. Similar to shrimp shell, CNM with excellent superhydrophilicity and underwater superoleophobicity displayed extremely low underwater-oil adhesion and self-cleaning performance. With controllable thickness and nanoscale pore size, CNM could effectively separate micrometer- and nanometer-sized oil/water emulsions with a high separation efficiency (>95%) and water flux (>1500 L·m–2·h–1·bar–1). Furthermore, CNM displayed multifunctional water remediation characteristics, i.e., it could simultaneously remove heavy metal ions from water phase in the course of oil/water emulsion separation. The CNM also exhibited excellent mechanical strength, recyclable performance, thermal stability, and pH-resistance. Therefore, CNM with unique characteristics, e.g., sustainability, chemical and thermal resistance, multifunctionality, and excellent oil/water separation efficiency has the high potential in the practical oily water treatment.