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During photosynthesis, light energy is utilized to drive sophisticated biochemical chains of electron transfers, converting solar energy into chemical energy that feeds most life on earth. Cyclic electron transfer/flow (CET/CEF) plays an essential role in efficient photosynthesis, as it balances the ATP/NADPH ratio required in various regulatory and metabolic pathways. Photosystem I, cytochrome b

Trimap generation is currently playing an important role in the field of image matting. The current trimap generation methods cannot adaptively adjust the classification thresholds, and ignore the nonlocal correlations between pixels. Besides, they also need finely provided trimaps. This paper raises a dual-level trimap generation approach which requires sparse user inputs. The first level introduces a unary data term from adaptive learned thresholds combined with local spatial constraints to effectively overcome the drawback of fixed threshold methods. The second level introduces a smoothness term from a nonlocal affinity for foreground probability estimation , and a pixel correlation constraint is computed and added to the data term. The foreground probability is finally solved in a closed form solution and truncated to generate the final trimap. In the experiments, firstly, this approach raises a novel trimap evaluation criterion according to the two classic terms of missing and false classifications. Based on this criterion, the final trimaps generated by our approach are better than those generated by other methods. Secondly, in the final matting process from four typical matting algorithms, the matting results from the trimaps by our approach are still better than those from the trimaps by other trimap generation methods.

Photosystem II (PSII) catalyzes the light-driven oxygen-evolving reaction via its catalytic core and peripheral light-harvesting antennas. Oxyphototrophs have evolved diverse antenna systems, enabling them to adapt to different habitats. Recently, high-resolution structures of PSII-antenna supercomplexes from the green lineage (higher plants and green algae) and the red lineage (diatoms) were solved. The antenna complexes from the two lineages share similar protein folding, but differ in terms of the oligomeric states, pigment composition, and assembly patterns with the core. These differences result in distinct pigment-protein networks in PSII from different organisms. We herein summarize the similarities and differences in these structures and outline the molecular basis of the assembly, energy transfer, and regulation of the eukaryotic PSII-antenna supercomplexes.

The composition dependent magnetic structure in epitaxial BaFe12-xScxO19 (0 ≤ x ≤ 2.1, BaScM) thin films have been investigated. Results show that with increasing Sc3+ content, the out-of-plane c-axis lattice constants of BaScM films increase but do not follow the Vegard's law. The changes in hysteresis loops indicate a variation of magneto-crystalline anisotropy from the uniaxial-type for BaFe12O19 to the near-planar type for BaFe10.2Sc1.8O19. The remanent magnetic domains change from a mixture of dots and maze-like structure to more maze-like structure as the Sc3+ content increases. The above magnetic results can be explained by a composition dependent magnetic structure transition from collinear-type ferrimagnetic magnetic structure to the non-collinear conical magnetic structure which appears at Sc3+ content x ≥ 0.6. The ZFC/FC curves further show that the conical magnetic structure transition temperature (Tcone) of the films increases with the Sc3+ content until x ≥ 2.1. The above results may help better apply BaScM films in the electromagnetic devices.

An ultrathin layer of SiOx formed on the surface of a silicon solar cell can significantly reduce the potential induced degradation effect in solar cell modules. In this work, a liquid oxidation (LO) technique was developed to oxidize silicon surfaces by using a Ti/IrO2–CoO2 anode that can produce a large amount of hydroxyl radicals (•OH) and other species. Our results indicate that the LO SiOx (2.5 nm) layer is very dense, thus the modules made from LO treated cells are better able to mitigate potential induced degradation than modules made from ozone oxidized cells.

The magnetic properties of conical magnetic structure (CMS) hexaferrites BaFe10.2Sc1.8O19 (BFSO) and SrFe10.2Sc1.8O19 (SFSO) have been investigated under different magnetic fields and different temperatures. Results show that the single phase CMS hexaferrites BFSO and SFSO can be obtained as the sintering temperature exceeds 1473 K. Both the coercivity Hc and remanent magnetization Mr of the CMS BFSO and SFSO decrease sharply with increasing temperature below 100 K, and they become very small and almost invariant when the temperature exceeds 100 K. For both BFSO and SFSO, the field-cooling and zero-field-cooling curves differ greatly at low temperatures and resemble at high temperatures. A magnetic transition temperature Tz2 from noncollinear CMS to collinear ferrimagnetic structure is observed in both BFSO and SFSO with BFSO having higher Tz2 than that of SFSO. Moreover, the Tz2 decreases with increasing the magnetic field in both samples generally.

Herein, a zwitterionic Gemini VES (named VES-C) with double ultra-long hydrophobic tails was designed and synthesized which aimed to construct WLM net-structures in high-salinity aqueous solution. Due to the carboxylic group on the spacer, it exhibits partial carboxyl betaine properties and performs well in high salinity environment. Molecular dynamic simulation was carried out and RDF curves were analyzed to predict and explain the mechanism of salinity tolerance of VES-C. Compared with cationic Gemini VESs, a series of experiments were conducted by varying salinity, including surface tension, DLS, 1H NMR and fluorescent probe, to explain the salt-tolerance mechanism of VES-C. The salinity cloudy point of VES-C surpasses 10 wt%, exhibiting superior salt-tolerance to those cationic Gemini VESs. Trough viscosity measurement, oscillatory measurement and microstructure observation, it proves that VES-C molecules can construct WLM netlike structures within the salinity range from 3 wt% to 10 wt% (optimal salinity: 4 wt%), thus VES-C can be applied as the clean thickener to prepared seawater or brine based fracturing fluid by constructing WLM netlike structure in high salinity aqueous environment, which leaves the preparation of clean fracturing fluid independent of freshwater resources.

The poor cyclability and high cost are the two major obstacles to the commercial applications of Si-based anode materials. Porous structure and carbon coating may facilitate the ion and electron conduction and also restrict the huge volume change of Si anodes. In addition, introducing a ceramic interlayer between Si and C can reduce the chemical reaction of Si with fluorine ions in the electrolyte and hence improve the cyclability. In this work, porous Si anode protected by SiC/C dual-interface is prepared by simply heating fine Mg2Si particles in pure CO2 at 650 °C, based on the conventional exothermic displacement reaction between Mg (released from Mg2Si) and CO2. The large amount of heat generated during the displacement reaction leads to sharp temperature rise, resulting in the formation of SiC at such a low temperature. The porous Si/SiC/C powders as well as the spherical sample prepared by subsequent spray-drying and pyrolysis process display much improved rate capability and cyclability as compared to the porous Si/C counterpart, due to the enhanced structural integrity induced synergistically by the porous structure, SiC/C dual-interface and spherical structure during the repeated lithiation/delithiation cycles.

The introduction of ozonated deionized water (DIO3 water) to the silicon wafer wet cleaning process has attracted interest from the photovoltaic industry. In this work, a simple and cost-effective approach to fabricate submicron-texture multicrystalline silicon (mc-Si) wafer is presented using Ag metal-catalyzed chemical etching (MCCE) in DIO3/HF solution, where DIO3 was used as a hole injecting agent. The submicron-texture was successfully applied to fabricate efficient mc-Si PERC solar cells with an average efficiency of 20.31%, which is 0.58%abs higher than those with an acid micron-texture and exceeds those with conventional MCCE submicron-textures using H2O2 as the hole injecting agent. We demonstrated that using DIO3 as a hole injection agent in metal-catalyzed chemical etching is feasible. This novel MCCE approach is simple, low-cost, and ecofriendly, making it an attractive alternative to conventional MCCE methods for use in industrial-scale production.

Alkali solutions are not suitable for texturing multi-crystalline silicon (mc-Si) wafer due to the anisotropic etching. In this study, a two-step alkali-etch process is developed to form a flat surface on the wafer, which can be quickly and nearly isotropically etched by immersion in a sodium hydroxide solution, followed by a sodium hydroxide-sodium hypochlorite solution. The etching process leads to the formation of homogenous nanostructure, thereby improving the cell's repeatability and performance by simultaneously increasing its short-circuit current and open-circuit voltage.

The absence of an effective texturing technique for diamond-wire sawn multi-crystalline silicon (DWS mc-Si) solar cells has hindered commercial upgrading from traditional multi-wire slurry sawn silicon (MWSS mc-Si) solar cells. In this paper, a nano-texture technique has been developed to achieve 18.31% efficient DWS mc-Si solar cells on a pilot production line. Their unique pyramidal nanostructure, which has the most close-packed {111} surface of Si diamond crystal, not only benefits both light-trapping and electric properties but also can effectively remove the saw-marks and amorphous layer of the cells. Therefore, the short-circuit current Isc of a nano-textured DWS mc-Si solar cell is ~324 mA higher than that of a micron-textured one, while its open-circuit voltage Voc does not show an evident decrease with the increase of its surface area. The technique has paved the way for the mass production of DWS mc-Si solar cells by satisfying the exact requirements of the PV industry for high efficiency and low cost.

A laser texturing process including laser ablation and post-etching has been developed to form a unique microstructure of pits in craters (PIC) on the front surface of the diamond wire sawn multi-crystalline silicon (DWS mc-Si) wafer. A laser ablation is applied to produce craters with size of tens of microns distributed at the front surface of the wafer, followed by a post-etching process to remove silicon slags produced in the laser process and to form the pits of size in few microns embedded in each crater. The structural, optical and electrical characteristics of the PIC structure are investigated and optimized to achieve a good trade-off between light trapping and recombination. Finally, an applicative laser texturing process is demonstrated for the industrial-grade DWS mc-Si solar cells with an increased efficiency of 19.26% compared with the standard acid textured ones (19.10%).

The microstructure and magnetic properties of Ta/Ni81Fe19/Ta tri-layer thin films on three types of mono-like cast silicon substrates (flat, upright pyramid and inverted pyramid surfaces) were investigated. Results show that the surface topography structures of the films followed those of the substrates generally. But the thickness of the film on pyramid surface increases from the pyramid tip to the bottom. This is caused by the anisotropical diffusion of incident atoms/ions on the pyramid surfaces during the film growth process. The films on pyramid structured substrates have smaller saturation magnetizations but larger in-plane coercivity than that of on the flat substrate. This should be mainly caused by the non-zero angle between the magnetic field and the substrates as suggested by the angular dependent magnetic properties of the films. The hysteresis loops measured from in-plane to out-of-plane directions show that the coercivities of films on all the mono-like cast silicons are highly angular dependent. A further post-annealing of the films suggests that the magnetic properties of the films are dominantly determined by the surface microstructure of substrates instead of the fabrication conditions. The above results can help better integration of NiFe thin films on mono-like cast silicon based devices.

An urgent challenge to popularize diamond-wire-sawn single-crystalline silicon (DWS sc-Si) wafers to PV industry is to develop a proper texture process, specially eliminating its severe saw marks and forming uniform pyramid texture. Using a simple pre-polishing step with TMAH plus routine texture process, the saw marks as well as amorphous silicon layer are removed effectively, thus benefiting the formation of a random pyramid structure on DWS sc-Si wafers, and the texturing mechanism beyond was discussed. With new texture surface, DWS sc-Si cells demonstrated similar reflection ~5% and same efficiency level ~19.15% to the traditional multi-wire-slurry-sawn solar cells. The techniques present in this article can be easily scaled up in PV industry.

IntroductionDetection of bone marrow micrometastasis (BMM) has been focused on as a prognostic parameter in various malignant neoplasms recently. This study was designed to evaluate the prognostic significance of BMM detection in patients with operable esophageal squamous cell carcinoma (ESCC) after long-term follow-up.MethodsIn 61 consecutive patients with ESCC who had undergone radical surgical resection, BMM was detected through reverse transcriptase-polymerase chain reaction (RT-PCR). Correlation between BMM detection and prognosis of the 61 patients was analyzed.ResultsBMM was found in 13 patients (21.3%). No significant correlation between BMM detection and tumor, node, metastasis (TNM) stage was found. The median survival time, 5-year overall survival rate, 5-year disease-free survival rate, and 5-year distant disease-free survival rate for cases with positive BMM were 13.0 months, 15.4%, 7.7%, and 34.2%, respectively, compared with that of 66.0 months, 59.7%, 49.1%, and 60.6% for cases with negative BMM (p < 0.05). In multivariate analysis, BMM were found to be an independent factor in the prediction of overall survival (odds ratio [OR] 3.928, p = 0.001), disease-free survival (OR 4.285, p < 0.001), and distant disease-free survival (OR 3.270, p = 0.013).ConclusionsBMM is an independent prognostic factor in the prediction of the subsequent development of metastatic disease and disease outcome for operable ESCC patients, and may be a useful adjunct to conventional tumor staging. Further studies are required to evaluate the value of neoadjuvant or adjuvant systemic therapy in ESCC patients with BMM.

The Mn cluster (Mn4CaO5) on the thylakoid luminal side of photosystem II (PSII) catalyzes the photosynthetic oxygen-evolving reaction, an essential process for life on Earth. In higher plants and green algae, the Mn cluster is surrounded by the membrane-extrinsic proteins PsbO (33 kDa), PsbP (23 kDa), and PsbQ (17 kDa) (Murata and Miyao, 1985). They shield the Mn cluster, protecting and stabilizing it from attack by exogenous reductants. PsbP plays an indispensable role in PSII function, and is necessary for the retention of Ca2+ and Cl– (Ghanotakis et al., 1984), the assembly of PSII complex (Yi et al., 2007), and the maintenance of normal thylakoid architecture (Yi et al., 2009).

A nanohill structure has been fabricated on a silicon surface via a micromask formed by a radio-frequency magnetron sputtering deposition of silver nanoparticles and a following dry etching under SF6 plasma. The proposed technique does not rely on oxygen gas to eliminate the damages from oxygen plasma and to increase the lifetime of the silicon crystal. The experiments indicate that the morphology and particle size distribution of silver nanoparticles determine the reflectivity of the textured silicon wafer. Interestingly, the nanohill structure exhibits a stronger light confinement ability than the columnar one, leading to a lower reflectivity. A longer minority carrier lifetime is obtained in such nanohill structures with a lower defect concentration on the surface. This work provides a pathway to fabricating black silicon of excellent light confinement structure, which may have potential for applications in some localized surface plasmons-relevant areas.

In traditional metal/ferroelectric film/metal structure, it is widely accepted that the photocurrent is originated from two factors: one is the remnant polarization, which produces a depolarization electric field extending over the whole film volume; the other is the top or bottom film/metal interface Schottky barrier. However, the high reflection of opaque or translucent metal electrodes, as well as almost symmetric Schottky barriers in the top and bottom metal/film interfaces result in a low photovoltaic output. In this paper, a transparent indium tin oxide (ITO) electrode was introduced in ITO/Pb(Zr 0.2 Ti 0.8 )O 3 (PZT)/Pt structure, in order to not only make more incident light absorbed by PZT film but also artificially enlarge the Schottky barrier difference between bottom ITO/PZT interface and top PZT/Pt one. The results show that the photocurrent of ITO/PZT/Pt structure is enhanced one order than that of Pt/PZT/Pt structure under the same irradiation of a simulative sunlight (AM 1.5G). The systematic studies present in this paper gave some principles to design ferroelectric film devices in considering higher optical-to-electronic conversion efficiency.

Control of the in-plane crystallographic orientation of YBa2Cu3O7-x (YBCO) films on (100) MgO substrates is of significant application value due to the selective enhancement of superconducting properties. In the present work, the preparation, crystallogra

The bursa of Fabricius is central immune organ unique to birds, and the extract is immunocompetent in stimulating B cell differentiation and enhancing antibody production. However, except for bursin, the active peptides from the bursa of Fabricius are little reported. In the paper, a novel bursal septpeptide (BSP-II) with the amino acids sequence of TPSGLVY was identified and similar to the MGC53864 protein of Gallus gallus. We investigated the effects of BSP-II on the immune response in terms of the antibodies titers (IgG1 and IgG2alpha), the levels of interferon-gamma and interleukin-4 cytokines, spleen cell lymphocyte proliferation, and the T-lymphocyte subtype composition. It was noteworthy that BSP-II potentiates the Th1 and Th2-type immune responses in dose-dependent manner. BSP-II had specific enhancing effects on the hybridoma SP2/0 cell proliferation at two different serum concentrations (20% and 5%), but had no connection with the dose of BSP-II. The antibody secreting level of hybridoma SP2/0 cells rose in 5% and 20% serum when the concentrations of BSP-II increased. Also, BSP-II had effect on the viabilities of tumor cells (Hela and SP2/0). All the results indicated that BSP-II was able to significantly induce various immune responses and involved in the cell viability of different tumor cell lines. Our observations implied that BSP-II might be a novel biological active factor from the bursa of Fabricius with immunomodulatory activities.

YBa 2 Cu 3 O 7– δ (YBCO) films were prepared on (1 0 0) MgO substrates by pulsed laser deposition (PLD) method. In order to eliminate the a -axis growth, which is commonly observed in the YBCO film thicker than a critical value, we developed a new PLD target that was sintered at a temperature far below YBCO 123 phase formation. The surface analysis made by AFM technique confirmed that very fine particles of around 20 nm size could be ejected from the new target to the substrate. The fine oxide clusters could be easily moved and incorporated into the YBCO phase thus benefited the c -axis growth even in the thick films. For instance, only the c -axis growth in the new film with a thickness of about 650 nm was larger than a critical thickness of the a -axis growth. However, in the standard film of the same thickness, there is ∼24.5% of the a -axis growth accompanying the main c -axis growth. Therefore, the c -axis growth could be preserved in the very thick YBCO film by a non-superconducting target.

In this paper, a capillary electrophoresis (CE) system with in-column fiber optics light-emitting diode (LED) induced fluorescence detection was developed for the determination of penicillamine (PA). The influence of buffer concentration, buffer pH, applied voltage and injection time was systematically investigated. Optimum separation conditions were obtained with 10 mM borate buffer at pH 9.1, applied voltage 20 kV and 8 s hydrodynamic injection at 30 mbar. The detection system displayed linear dynamic range from 3.2 × 10−7 to 4.8 × 10−5 mol L−1 with a correlation coefficient of 0.9991 and good repeatability (R.S.D. = 2.46%). The method was applied to the determination of PA in commercial tablets and human plasma, which the recoveries of standard PA added to tablets and human plasma sample were found to be in the range of 96.26–102.68 and 91.10–99.35%, respectively. The proposed method is cheap, rapid, easy, and accurate, and can be successfully applied to the formulation analysis and bioanalysis.