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In prevailing p-i-n perovskite solar cells (PSCs), solution-processible fullerene molecules are widely used as electron-transporting layers (ETLs) but they typically suffer from poor uniformity and undesirable stability issues. Additionally, a separate bathocuproine (BCP) layer is needed to block hole transfer, increasing fabrication complexity and cost. Here, we address these limitations by developing a novel polymeric ETL (named PFBCP) synthesized by polymerizing C60 with BCP. This innovative material achieves both efficient electron transport and hole blocking, while its excellent uniformity minimizes interface recombination and enhances stability. Consequently, our blade-coated PSCs utilizing PFBCP achieve a high power conversion efficiency exceeding 22% and retain 91% of initial efficiency after 1200 h of light exposure. This development not only paves the way for commercially viable PSCs but also opens avenues for future ETL design to realize even more efficient and stable PSCs. [ABSTRACT FROM AUTHOR]

Protein phosphatase-1 (PP1) constrains learning and memory formation in part through its effects on the induction threshold of long-term potentiation (LTP) and depression (LTD). LTD induction requires both the enzymatic activity of PP1 and its proper anchoring to synaptic spines. We have shown previously that neurabin, a major synaptic scaffolding protein, targets PP1 to synapses for LTD induction. Here, we show that PP1 bound on spinophilin, a close homolog of neurabin and another major synaptic PP1 anchoring protein, does not play a role in LTD induction, which suggests that neurabin plays a privileged role in nanodomain targeting of PP1 in LTD induction. We found that protein kinase A can significantly weaken the neurabin-PP1 interaction in neurons via phosphorylation of neurabin at serine 461, a phosphorylation site adjacent to the PP1-binding motif that is not conserved in spinophilin. Finally, we found that a neurabin mutation (S461E), which mimics phosphorylation, blocked AMPA receptor endocytosis and LTD induction. The results indicate the critical importance of nanodomain targeting of PP1 within synaptic spines and its regulation in LTD induction. [ABSTRACT FROM AUTHOR]

Thrombospondin-1 (TSP-1) is upregulated in several inflammatory diseases. Recent data have shown that macrophages from TSP-1-deficient mice have a reduced inflammatory phenotype, suggesting that TSP-1 plays a part in macrophage activation. DNA microarray approach revealed that Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS) may induce the enhanced TSP-1 expression in human monocytes, suggesting a role of TSP-1-mediated pathogenesis in periodontitis. Until recently, the function of TSP-1 has been a matter of debate. In this study, we explored the role of TSP-1 in inflammatory cytokine secretions and its putative mechanism in pathogenesis of periodontitis. We demonstrated that TSP-1 expression was significantly upregulated in gingival tissues with periodontitis and in P. gingivalis LPS-stimulated THP-1 cells. Deficiency of TSP-1 by transfecting siRNAs decreased IL-6, IL-1β, and TNF-α secretions in THP-1 cells, whereas overexpression of TSP-1 resulted in an upregulation of IL-6, IL-1β, and TNF-α productions. Additional experiments showed that Pyrrolidine dithiocarbamate (PDTC) inhibited IL-6, IL-1β, and TNF-α expression induced by overexpression of TSP-1, accompanying with downregulation of phosphorylated p65 and IκBα protein levels in response to P. gingivalis LPS. These results indicated that TSP-1 played a significant role in P. gingivalis LPS-initiated inflammatory cytokines (IL-6, IL-1β, and TNF-α) secretions of THP-1 cells, and the NF-κB signaling is involved in its induction of expression. Thus, TSP-1 effectively elevated P. gingivalis LPS-induced inflammation mediated by the NF-κB pathway and may be critical for pathology of periodontitis. [ABSTRACT FROM AUTHOR]

Finite element method was employed to calculate the macroflow velocity and temperature distribution of the pool domain's biting zone in twin-roll casting. Macroanalysis results were inducted as boundary conditions into microanalysis. Phase field method (PFM) was adopted to investigate the microstructure evolution. Based on the Kim-Kim-Suzuki model, the effect of metal flow velocity was coupled on the solute gradient item, and the real physical parameters of AZ31 were inducted into the numerical calculation. We used the marker and cell method in the discrete element solution of microstructural pattern prediction of AZ31 magnesium alloys. The different flow velocity values that predicted the columnar dendrite evolution were discussed in detail. Numerical simulation results were also compared with the experiment analysis. The microstructure obtained by PFM agrees with the actual pattern observed via optical microscopy. [ABSTRACT FROM AUTHOR]

Given a connected graph G = ( V,E) with a nonnegative cost on each edge in E, a nonnegative prize at each vertex in V, and a target set V′ ⊆ V, the Prize Collecting Steiner Tree (PCST) problem is to find a tree T in G interconnecting all vertices of V′ such that the total cost on edges in T minus the total prize at vertices in T is minimized. The PCST problem appears frequently in practice of operations research. While the problem is NP-hard in general, it is polynomial-time solvable when graphs G are restricted to series-parallel graphs. In this paper, we study the PCST problem with interval costs and prizes, where edge e could be included in T by paying cost x ∈ [ c, c] while taking risk ( c − x)/( c − c) of malfunction at e, and vertex v could be asked for giving a prize y ∈ [ p, p] for its inclusion in T while taking risk ( y − p)/( p − p) of refusal by v. We establish two risk models for the PCST problem with interval data. Under given budget upper bound on constructing tree T, one model aims at minimizing the maximum risk over edges and vertices in T and the other aims at minimizing the sum of risks over edges and vertices in T. We propose strongly polynomial-time algorithms solving these problems on series-parallel graphs to optimality. Our study shows that the risk models proposed have advantages over the existing robust optimization model, which often yields NP-hard problems even if the original optimization problems are polynomial-time solvable. [ABSTRACT FROM AUTHOR]

In order to better understand twin-roll casting process, a 3D finite element method (FEM) simulation was carried out, based on the conditions of the pilot vertical twin-roll caster, to study the thermal flow and solidification behavior in the twin-roll casting process. The simulation results show that non-uniform temperature and velocity distribution near the side dam region are the main reason for causing non-uniform solidification and non-uniform deformation along the cast sheet width. Therefore, it is necessary to preheat the side dams or improve the design of nozzle to compensate the effect of side dams on the casting process. High quality magnesium sheets have been cast after improved the casting devices. [ABSTRACT FROM AUTHOR]

Through analyzing the harm of the exhaust noise from the excavator, this paper illuminated the importance of the noise measurement and analysis work,. According to some correlative measurement standards, using some instruments in hand, a set of exhaust noise measurement system especially for the excavator was designed. The exhaust engine noise from an excavator produced by a construction machinery corporation was measured and analyzed, and then, seven mufflers with different structures were designed. After analyzing the frequency spectrums of seven impedance mufflers of different structures respectively, we selected the muffler j which was of best noise elimination performance among the seven mufflers. The highest noise elimination of muffler j was up to 16.3dB, which could reduce the exhaust noise from the excavator in a larger degree. At last, we analyzed the structures and corresponding effects of noise elimination for the seven mufflers and made some important conclusions. [ABSTRACT FROM AUTHOR]

The rectilinear Steiner minimal tree (RSMT) problem is one of the fundamental problems in physical design, especially in routing, which is known to be NP-complete. This paper presents an algorithm, called ACO-Steiner, for RSMT construction based on ant colony optimization (ACO). An RSMT is constructed with ants' movements in Hanan grid, and then the constraint of Hanan grid is broken to accelerate ants' movements to improve the performance of the algorithm. This algorithm has been implemented on a Sun workstation with Unix operating system and the results have been compared with the fastest exact RSMT algorithm, GeoSteiner 3.1 and a recent heuristic using batched greedy triple construction (BGTC). Experimental results show that ACO-Steiner can get a short running time and keep the high performance. Furthermore, it is also found that the ACO-Steiner can be easily extended to be used to some other problems, such as rectilinear Steiner minimal tree avoiding obstacles, and congestion reduction in global routing. [ABSTRACT FROM AUTHOR]

Micro-structures 3-D profile measurement is an important measurement content for research on micromachining and characterization of micro-dimension. In this paper, a new method involved 2-D structure template, which guides phase unwrapping, is proposed based on phase-shifting microscopic interferometry. It is fit not only for static measurement but also for dynamic measurement, especially for motion of MEMS devices. 3-D profile of active comb of micro-resonator is obtained by using the method. The theoretic precision in out-of-plane direction is better than 0.5 nm. The in-plane, theoretic precision in micro-structures is better than 0.5 μm. But at the edge of micro-structures, it is on the level of micrometer mainly caused by imprecise edge analysis. Finally, its disadvantages and the following development are discussed. [ABSTRACT FROM AUTHOR]

Given n terminals in the Euclidean plane and a positive constant, find a Steiner tree interconnecting all terminals with the minimum number of Steiner points such that the Euclidean length of each edge is no more than the given positive constant. This problem is NP-hard with applications in VLSI design, WDM optical networks and wireless communications. In this paper, we show that (a) the Steiner ratio is 1/ 4, that is, the minimum spanning tree yields a polynomial-time approximation with performance ratio exactly 4, (b) there exists a polynomial-time approximation with performance ratio 3, and (c) there exists a polynomial-time approxi-mation scheme under certain conditions. [ABSTRACT FROM AUTHOR]

For a given set of points P in a metric space, let wk( P) denote the weight of minimum-weight k-edge connected Steiner network on P divided by the weight of minimum-weight k-edge connected spanning network on P, and let rk=inf{ wk( P) | P}. We show in this paper that for any P, , for even k≥2 and , for odd k≥3. In particular, we prove that for any P in the Euclidean plane, w4( P) and w5( P) are greater than or equal to , and ; For any P in the rectilinear plane , for odd k≥5. In addition, we prove that there exists an O(| P|3)-time approximation algorithm for constructing a minimum-weight k-edge connected Steiner network which has approximation ratio of for even k and for odd k. [ABSTRACT FROM AUTHOR]