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Marine cyanobacteria contribute to approximately half of the ocean primary production, and their biomass is limited by low iron (Fe) bioavailability in many regions of the open seas. The mechanisms by which marine cyanobacteria overcome Fe limitation remain unclear. In this study, multiple Fe uptake pathways have been identified in a coastal strain of Synechococcus sp. strain PCC 7002. A total of 49 mutants were obtained by gene knockout methods, and 10 mutants were found to have significantly decreased growth rates compared to the wild type (WT). The genes related to active Fe transport pathways such as TonB-dependent transporters and the synthesis and secretion of siderophores are found to be essential for the adaptation of Fe limitation in Synechococcus sp. PCC 7002. By comparing the Fe uptake pathways of this coastal strain with other open-ocean cyanobacterial strains, it can be concluded that the Fe uptake strategies from different cyanobacteria have a strong relationship with the Fe bioavailability in their habitats. The evolution and adaptation of cyanobacterial iron acquisition strategies with the change of iron environments from ancient oceans to modern oceans are discussed. This study provides new insights into the diversified strategies of marine cyanobacteria in different habitats from temporal and spatial scales. IMPORTANCE Iron (Fe) is an important limiting factor of marine primary productivity. Cyanobacteria, the oldest photosynthetic oxygen-evolving organisms on the earth, play crucial roles in marine primary productivity, especially in the oligotrophic ocean. How they overcome Fe limitation during the long-term evolution process has not been fully revealed. Fe uptake mechanisms of cyanobacteria have been partially studied in freshwater cyanobacteria but are largely unknown in marine cyanobacterial species. In this paper, the characteristics of Fe uptake mechanisms in a coastal model cyanobacterium, Synechococcus sp. PCC 7002, were studied. Furthermore, the relationship between Fe uptake strategies and Fe environments of cyanobacterial habitats has been revealed from temporal and spatial scales, which provides a good case for marine microorganisms adapting to changes in the marine environment.

In order to improve the management of nitrogen (N) fertilization in pear orchards, we investigated the effects of application timing on the distribution, storage, and remobilization of N in mature pear trees in a field experiment at Jingtai County, Gansu Province, China. Nine trees were selected for the experiment and each received equal aliquots of 83.33 g N in the autumn, spring, and summer, with 15N-labeled (NH4)2SO4 used in one of the aliquots each season. Results showed that the (15N H4)2SO4 applied in the autumn remained in the soil during the winter. In the following spring this N was absorbed and rapidly remobilized into each organ, especially new organs (leaves, fruit and new shoots). The 15N supplied in spring was rapidly transported to developing fruit between the young fruit and fruit enlargement stages. 15N from the summer application of fertilizer was mainly stored in the coarse roots over the winter, then was mobilized to support growth of new organs in spring. In conclusion, for pear trees we recommend that the autumn application of N-fertilizer be soon after fruit harvest in order to increase N stores in fine roots. Spring application should be between full bloom and the young fruit stages to meet the high N demands of developing fruit. Summer application of fertilizer at the fruit enlargement stage does not contemporaneously affect the growth of pears, but increases the N stored in coarse roots, and in turn the amount available for remobilization in spring.

Global warming will be combined with predicted increases in thermal variability in the future surface ocean, but how temperature dynamics will affect phytoplankton biology and biogeochemistry is largely unknown. Here, we examine the responses of the globally important marine coccolithophore Emiliania huxleyi to thermal variations at two frequencies (one-day and two-day) at low (18.5 °C) and high (25.5 °C) mean temperatures. Elevated temperature and thermal variation decreased growth, calcification and physiological rates, both individually and interactively. One-day thermal variation frequencies were less inhibitory than two-day variations under high temperature, indicating that high frequency thermal fluctuations may reduce heat‐induced mortality and mitigate some impacts of extreme high temperature events. Cellular elemental composition and calcification was significantly affected by both thermal variation treatments relative to each other, and to the constant temperature controls. The negative effects of thermal variation on E. huxleyi growth rate and physiology are especially pronounced at high temperatures. These responses of the key marine calcifier E. huxleyi to warmer, more variable temperature regimes have potentially large implications for ocean productivity and marine biogeochemical cycles under a future changing climate.

BackgroundHIV testing and early linkage to care are critical for reducing the risk of HIV transmission. HIV self-testing (HIVST) is an useful tool for increasing HIV testing frequency.This study aimed to investigate HIVST rates among men who have sex with men (MSM), the characteristics of MSM who had HIVST, and factors associated with HIVST uptake among MSM in Ningbo, China. MethodsA cross-sectional study was conducted from April to October 2019 in Ningbo,China. Participants were aged at least 18 years and having had sexual contact with men in the past year. Proportions were used for categorical variables. Adjusted Odds Ratio (AOR) and 95% Confidence Interval (CI) for characteristics associated with HIVST uptake was processed by multiple logistic regression models.ResultsAmong a sample of 699 MSM recruited, 38.2% had reported previous use of an HIV self-test kit. A greater proportion of HIVST Users had a higher frequency of HIV testing(≥2 times: 70.0% versus 41.2%, pConclusionsFurther HIVST education should be strengthened for school-aged children and teenagers, and free HIVST kits may be provided to low-income high-risk MSM through gay apps and NGOs to achieve the increased HIV testing frequency.

Objective: To study the effect of Xuebijing, thymopentin combined with symptomatic treatment on inflammatory response process in elderly patients with severe pneumonia. Methods: A total of 60 elderly patients with severe pneumonia who were treated in the hospital between August 2014 and July 2016 were collected and divided into control group and observation group according to the random number table, 30 cases in each group. Control group received clinical symptomatic treatment, and observation group received Xuebijing, thymopentin combined with symptomatic treatment. The differences in serum proinflammatory factors, anti-inflammatory factors as well as liver and kidney function indexes were compared between the two groups before and after treatment. Results: Before treatment, differences in serum levels of pro-inflammatory factors, anti-inflammatory factors as well as liver and kidney function indexes were not statistically significant between the two groups. After treatment, serum IL-1β, IL-6, IL-8, IL-4, IL-13, TB, ALT, AKP, Scr and CysC levels of both groups of patients were lower than those before treatment, and serum IL-1β, IL-6, IL-8, IL-4, IL-13, TB, ALT, AKP, Scr and CysC levels of observation group were lower than those of control group. Conclusion: Xuebijing, thymopentin combined with symptomatic treatment can effectively inhibit the degree of systemic inflammatory response and reduce the liver and kidney function injury in elderly patients with severe pneumonia.

The structural behavior of precast concrete segmental bridges (PCSBs) is affected by the joints between the concrete segments. In this study, a numerical model was established to investigate the direct shear behavior of single-keyed dry joints in PCSBs. The numerical model was validated by the full-scale test results published by the authors. It was found that the numerical results of the joints, such as the ultimate shear load, cracking pattern, and load-displacement curves, matched the test results well. The validated numerical model was further used for extending parametric studies. The factors affecting the shear behavior of single-keyed dry joints include the confining pressure, concrete strength, and key depth. It was found that the ultimate shear capacity increased about 121% when the confining pressure increased from 0.1 to 3.0 MPa, it was very low under confining pressure of 0.1 MPa; it increased about 44% when the concrete strength increased from C40 to C100; it increased about 203% when the key depth increased from 15 to 40 mm. However, the ultimate shear capacity decreased about 20% when the key depth increased from 40 to 60 mm, hence 40 mm was recommended for the design depth of the single-keyed dry joints in PCSBs. Finally, the parametric analysis results were compared with the AASHTO specification. When the key depth was 35, 40 and 45 mm, the AASHTO specification conservatively predict the shear strength capacity of single-keyed dry joints.

Retinoblastoma (RB) is a common neoplasm that is exhibited in individuals globally. Increasing evidence demonstrated that cyclin-dependent kinase regulatory subunit 1B (CKS1B) may be involved in the pathogenesis of various tumor types, including multiple myeloma and breast cancer. In the present study, the hypothesis that CKS1B down-regulation would effectively inhibit the proliferation, invasion and angiogenesis of RB cells through the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway was examined. Initial investigation of the expression profile of CKS1B in RB and adjacent retina tissues was performed using reverse transcription-quantitative polymerase chain reaction and western blot analysis. A total of three RB cell lines, SO-RB50, Y79 and HXO-RB44, were examined for selection of the cell line with the highest expression of CKS1B, and human normal retinal vascular endothelial cells (ACBRI-181) were also evaluated. CKS1B short hairpin RNA (shRNA) sequences (shRNA CKS1B-1, shRNA CKS1B-2 and shRNA CKS1B-3) and negative control shRNA sequences were constructed and transfected into cells at the third generation to evaluate the role of shCKS1B and the MEK/ERK signaling pathway in RB. Furthermore, the effect of shCKS1B on cell proliferation, migration, invasion, apoptosis and angiogenesis was investigated. CKS1B was determined to be highly expressed in RB tissue, compared with adjacent retina tissue. SO-RB50 and HXO-RB44 cells treated with shRNA CKS1B-1 and shRNA CKS1B-2 were selected for the present experiments. Activation of the MEK/ERK signaling pathway increases the expression of MEK, ERK, B-cell lymphoma 2, proliferating cell nuclear antigen, cyclin D1, vascular endothelia growth factor and basic fibroblast growth factor, enhances cell proliferation, migration, invasion and lumen formation, and decreases apoptosis. Following silencing CKS1B, the aforementioned conditions were reversed. The key observations of the present study demonstrated that shCKS1B can inhibit the proliferation, invasion and angiogenesis of RB cells by suppressing the MEK/ERK signaling pathway. Thus, CKS1B represents a potential research target in the development of therapeutics for RB.

Cyanobacteria are foundational drivers of global nutrient cycling, with high intracellular iron (Fe) requirements. Fe is found at extremely low concentrations in aquatic systems, however, and the ways in which cyanobacteria take up Fe are largely unknown, especially the initial step in Fe transport across the outer membrane. Here, we identified one TonB protein and four TonB-dependent transporters (TBDTs) of the energy-requiring Fe acquisition system and six porins of the passive diffusion Fe uptake system in the model cyanobacterium Synechocystis sp. strain PCC 6803. The results experimentally demonstrated that TBDTs not only participated in organic ferri-siderophore uptake but also in inorganic free Fe (Fe′) acquisition. (55)Fe uptake rate measurements showed that a TBDT quadruple mutant acquired Fe at a lower rate than the wild type and lost nearly all ability to take up ferri-siderophores, indicating that TBDTs are critical for siderophore uptake. However, the mutant retained the ability to take up Fe′ at 42% of the wild-type Fe′ uptake rate, suggesting additional pathways of Fe′ acquisition besides TBDTs, likely by porins. Mutations in four of the six porin-encoding genes produced a low-Fe-sensitive phenotype, while a mutation in all six genes was lethal to cell survival. These diverse outer membrane Fe uptake pathways reflect cyanobacterial evolution and adaptation under a range of Fe regimes across aquatic systems. IMPORTANCE Cyanobacteria are globally important primary producers and contribute about 25% of global CO(2) fixation. Low Fe bioavailability in surface waters is thought to limit the primary productivity in as much as 40% of the global ocean. The Fe acquisition strategies that cyanobacteria have evolved to overcome Fe deficiency remain poorly characterized. We experimentally characterized the key players and the cooperative work mode of two Fe uptake pathways, including an active uptake pathway and a passive diffusion pathway in the model cyanobacterium Synechocystis sp. PCC 6803. Our finding proved that cyanobacteria use ferri-siderophore transporters to take up Fe′, and they shed light on the adaptive mechanisms of cyanobacteria to cope with widespread Fe deficiency across aquatic environments.

Electronic structures of semiconductor photocatalysts control the light absorbance, charge-carrier separation and mobility, activation energy and consequently, photocatalytic activity. Ion doping has been widely used to modify the electronic structure of a semiconductor photocatalyst. Here, we successfully synthesized Sn doped single crystalline anatase TiO2 particles dominated with {1 0 5} facets by a gas phase oxidation process, and their structure and composition were thoroughly analyzed by XRD/TEM/FESEM/XPS. The photoluminescence emission spectra measurements reveal that the small amount of doped Sn in TiO2 could suppress the recombination of photogenerated electron–hole pairs. Thus, the Sn doped TiO2 shows a significantly enhanced photocatalytic hydrogen evolution performance, with its hydrogen generation rate being 4.5 times higher than that of pure TiO2. First-principle simulation results suggest the doped Sn at the edge exhibit higher adsorption energy toward H, which could promote the H2 generation from the splitting of water.

Over the past decades, there have been many synthesis methods on producing well-defined crystals, due to their enormous application potentials in industrial field. Among them, high temperature gas-phase reactions (HTGR) approach may be one of the most promising processes for fabrication of well-defined crystals with controllable structure, size, shape, and composition. This review is focused on the recent progresses in synthesizing well-defined crystalline TiO2 dominated with, respectively, {001} facets and {105} facets, one-dimensional ZnO and SnO2 nanorods/nanowires, MoS2 nanosheets as well as GaP, InP, and GaAs nanowires via HTGR approach. Although these research works were currently carried out on experimental scale, it is worth to note that the industrial importance of this HTGR approach for design and fabrication of well-defined crystals in the future owing to its advantages of continuous and scalable production with controlled dimensions and low cost.

Cyanobacteria are important players in the global carbon cycle, accounting for approximately 25% of global CO 2 fixation. Their CO 2 -concentrating mechanisms (CCMs) are thought to play a key role in cyanobacterial calcification, but the mechanisms are not completely understood. In Synechocystis sp. strain PCC 6803, a single Ca 2+ /H + exchanger (Slr1336) controls the Ca 2+ /H + exchange reaction. We knocked out the exchanger and investigated the effects on cyanobacterial calcification and CCMs. Inactivation of slr1336 significantly increased the calcification rate and decreased the zeta potential, indicating a relatively stronger Ca 2+ -binding ability. Some genes encoding CCM-related components showed increased expression levels, including the cmpA gene, which encodes the Ca 2+ -dependent HCO 3 − transporter BCT1. The transcript level of cmpA in the mutant was 30 times that in wild type. A Western blot analysis further confirmed that protein levels of CmpA were higher in the mutant than the wild type. Measurements of inorganic carbon fluxes and O 2 evolution proved that both the net HCO 3 − uptake rate and the BCT1 transporter supported photosynthetic rate in the slr1336 mutant were significantly higher than in the wild type. This would cause the mutant cells to liberate more OH − ions out of the cell and stimulate CaCO 3 precipitation in the microenvironment. We conclude that the mutation of the Ca 2+ /H + exchanger in Synechocystis promoted the cyanobacterial calcification process by upregulating CCMs, especially the BCT1 HCO 3 − transporter. These results shed new light on the mechanism by which CCM-facilitated photosynthesis promotes cyanobacterial calcification.

Cyanobacteria are known to survive in iron-deficient environments, but the ways in which they acquire Fe and acclimate are not completely understood. Here we report a novel gene sll1263 that is required for Synechocystis sp. strain PCC 6803 to grow under iron-deficient conditions. sll1263 encodes a putative cation diffusion facilitator protein (CDF) that shows 50% amino acid similarity with ferrous iron efflux protein (FieF) of heterotrophic bacteria. In bacteria, the gene product is involved in metal export from the cell, but in Synechocystis sll1263 plays a role in iron uptake. The results show that expression of sll1263 was induced by iron-deficient conditions and its inactivation significantly decreased the growth rate of an sll1263(-) mutant. Other genes known to be required for Fe acquisition were also strongly up-regulated in the mutant even in the presence of high Fe. Overexpression of sll1263 increased growth under iron deficiency but reduced growth under high-iron stress, suggesting that the gene product was involved in iron uptake rather than detoxification. Expression of FieF in the sll1263(-) mutant was unable to rescue the Fe-deficient phenotype, but Sll1263 completely restored it. Measurements of cellular iron content and the iron uptake rate showed that they were significantly less in the sll1263(-) mutant than in the wild type, consistent with a role for sll1263 in iron uptake. We hypothesize that the low-iron habitats and high-iron requirements of cyanobacteria may be the reason why cyanobacterial CDF protein functions in Fe uptake and not efflux as in non-photosynthetic bacteria.

Put your best face forward: The performance of TiO2 anatase crystals in energy and environmental applications is normally correlated with the TiO2 crystal facets exposed, and increasing the percentage of highly reactive surfaces is extremely important. A new gas-phase oxidation process using TiCl4 as precursor now yields anatase TiO2 single crystals with primarily high-index {105} facets, which can cleave water photocatalytically. Inorganic functional materials with tailor-made crystal facets have attracted great research interest owing to their applications in catalysis, sensors, batteries, and environmental remediation.1–6 Unfortunately, the surfaces with high reactivity usually diminish rapidly during the crystal growth process as a result of the minimization of surface energy. Thus, increasing the percentage of known highly reactive surfaces or creating new favorable surfaces is highly desirable. Crystalline titanium dioxide (TiO2) in the anatase phase is one of the most important semiconducting metal oxides, owing to its many promising energy and environmental applications.7–9 Conventionally, anatase TiO2 crystals are dominated by the thermodynamically stable {101} facets (ca. 94 percent, according to the Wulff construction) and a minority of {001} facets.10 Recently, we developed a new strategy to synthesize anatase TiO2 crystals with a large percentage of highly reactive {001} facets using fluorine-containing compounds, such as hydrofluoric acid, as capping agents, which made {001} energetically preferable to {101}.4 Gas-phase reactions with rapid heating and quenching were also reported recently to generate {001}-faceted decahedral anatase TiO2 crystals.11 Most recently, photocatalytically active {100} facets of anatase TiO2 crystals were synthesized using solid sodium titanates as the titanium source under hydrothermal conditions.12 However, all these breakthroughs contribute to the increase of the percentage of known low-index {001} or {100} facets only, which are the basic crystal surfaces in the Wulff construction model of anatase in a thermodynamically stable state and have been evidenced theoretically and experimentally.13 Because they usually have unique surface atomic structures, such as a high density of atomic steps, dangling bonds, kinks, and ledges, that can act as active sites, high-index planes of anatase may have the capability to be used in clean-energy and environmental applications. Unfortunately, owing to the high surface energies, which can lead to the elimination of high-index crystal planes, it is still an open challenge to synthesize tailor-made anatase TiO2 crystals bounded by high-index facets. Herein we report a facile process to prepare well-defined anatase TiO2 crystals with predominantly exposed high-index {105} facets, which have never been realized experimentally before. The anatase TiO2 crystals with exposed high-index {105} facets were prepared by a modified hightemperature gas-phase oxidation route using titanium tetrachloride (TiCl4) as the Ti source.11 A schematic reaction apparatus is given in Figure S1 in the Supporting Information. A straight static furnace pipe and a thin spiral tube were used as reactor and reactant feeder, respectively. In a typical experiment, the vapor-phase TiCl4 was liberated by bubbling oxygen (0.2 L min−1) into TiCl4 liquid at 98 °C and then passed through the furnace pipe at a temperature of 1000 °C. The experimental process was shown to be quite robust, and the reproducible synthesis of the anatase TiO2 crystals with exposed high-index {105} facets was also confirmed. Moreover, key synthesis conditions such as concentration of titanium precursor, reaction temperature, and oxygen flow were also explored extensively. In all experiments, the final white products were collected downstream by a bag filter and washed with deionized water three times to remove the adsorbed chlorine-containing species on the surface. Gram-scale production can be easily achieved if a furnace pipe with a diameter of about 5 cm is used (Figure S2 in the Supporting Information for digital camera images of the final white powder). Figure 1 shows the X-ray diffraction (XRD) pattern of the as-synthesized TiO2 crystals with exposed high-index {105} facets. All the main diffraction peaks can be indexed to the anatase crystal phase (space group I41/amd, JCPDS No. 21-1272), and only a very small amount of rutile impurity can be detected. Moreover, the peak indexed to {105} facets exhibits a higher intensity than in the calculated diffraction pattern of bulk anatase, which indicates that more {105} facets have been exposed (the corresponding peak has been marked with an asterisk (*) in Figure 1). Scanning electron microscopy (SEM) images in Figure 2 a–c show that the synthesized anatase TiO2 crystals display bipyramidal morphology with an average length of 2.42 μm (Figure S3 for the size distribution of these TiO2 crystals). The 3D schematic shape of a typical anatase TiO2 bipyramidal crystal with only high-index {105} facets exposed is shown in Figure 2 d. Statistically, the average interfacial angle indicated in Figure 2 d is 26.67°, which is close to that of {105} and {001} facets. The surfaces of all the crystals are very smooth, and some minority {101} facets can also be found occasionally, as indicated in Figure 2 b and Figure S4 in the Supporting Information. According to the symmetries of anatase TiO2, it can be concluded that the eight triangular surfaces in the bipyramidal crystals must be the high-index (105) facets. A transmission electron microscopy (TEM) image of a free-standing anatase TiO2 bipyramidal crystal and its corresponding selectedarea electron diffraction (SAED) pattern (Figure 3 a, b) demonstrate the single-crystal characteristics. The high-magnification TEM image in Figure 3 c clearly shows the (200) and (020) atomic planes with a lattice spacing of 0.189 nm. It should be noted that both the SAED pattern and the high-magnification TEM image were indexed along the [001] crystallographic direction of

Cyanobacteria are globally important primary producers that have an exceptionally large iron requirement for photosynthesis. In many aquatic ecosystems, the levels of dissolved iron are so low and some of the chemical species so unreactive that growth of cyanobacteria is impaired. Pathways of iron uptake through cyanobacterial membranes are now being elucidated, but the molecular details are still largely unknown. Here we report that the non-siderophore-producing cyanobacterium Synechocystis sp. PCC 6803 contains three exbB-exbD gene clusters that are obligatorily required for growth and are involved in iron acquisition. The three exbB-exbDs are redundant, but single and double mutants have reduced rates of iron uptake compared with wild-type cells, and the triple mutant appeared to be lethal. Short-term measurements in chemically well-defined medium show that iron uptake by Synechocystis depends on inorganic iron (Fe′) concentration and ExbB-ExbD complexes are essentially required for the Fe′ transport process. Although transport of iron bound to a model siderophore, ferrioxamine B, is also reduced in the exbB-exbD mutants, the rate of uptake at similar total [Fe] is about 800-fold slower than Fe′, suggesting that hydroxamate siderophore iron uptake may be less ecologically relevant than free iron. These results provide the first evidence that ExbB-ExbD is involved in inorganic iron uptake and is an essential part of the iron acquisition pathway in cyanobacteria. The involvement of an ExbB-ExbD system for inorganic iron uptake may allow cyanobacteria to more tightly maintain iron homeostasis, particularly in variable environments where iron concentrations range from limiting to sufficient.

Synechocystissp. PCC 6803 possesses only onesodgene,sodB, encoding iron superoxide dismutase (FeSOD). It could not be knocked out completely by direct insertion of the kanamycin resistance cassette. When the promoter ofsodBin WTSynechocystiswas replaced with the copper-regulated promoter PpetE, a completely segregated PpetE–sodBstrain could be obtained. When this strain was cultured in copper-starved BG11 medium, the chlorophyllacontent was greatly reduced, growth was seriously inhibited and the strain was nearly dead during the 8 days of growth, whilst the WT strain grew well under the same growth conditions. These results indicated thatsodBwas essential for photoautotrophic growth ofSynechocystis. The reduction ofsodBgene copies in theSynechocystisgenome rendered the cells more sensitive to oxidative stress produced by methyl viologen and norflurazon.sodBstill could not be knocked out completely after active expression ofsodC(encoding Cu/ZnSOD) fromSynechococcussp. CC9311 in the neutral siteslr0168under the control of thepsbAIIpromoter, which means the function of FeSOD could not be complemented completely by Cu/ZnSOD. Heterogeneously expressedsodCincreased the oxidation and photoinhibition tolerance of theSynechocystis sodBknockdown mutant. Membrane fractionation followed by immunoblotting revealed that FeSOD was localized in the cytoplasm, and Cu/ZnSOD was localized in the soluble and thylakoid membrane fractions of the transformedSynechocystis. Cu/ZnSOD has a predicted N-terminal signal peptide, so it is probably a lumen protein. The different subcellular localization of these two SODs may have resulted in the failure of substitution ofsodCforsodB.

Plastocyanin, encoded by the petE gene, can transfer electrons to photosystem I (PSI) and cytochrome c oxidase during photosynthetic and respiratory metabolism in cyanobacteria. We constructed a petE mutant of Synechocystis sp. strain PCC 6803 and investigated its phenotypic properties under different light conditions. When cultured under continuous light, inactivation of petE accelerated the plastoquinone pool reoxidation, slowed the reoxidation rate of the primary quinone-type acceptor, and decreased the connectivity factor between the individual photosystem II (PSII) photosynthetic units. Compared with the wild-type control, the petE mutant showed a decrease in its PSI/PSII fluorescence ratio and an increase in its dark respiration rate. When cultured under a light–dark photoperiod, the petE mutation caused an increase in the phycocyanin to chlorophyll ratio. Consequently, the mutant line was a darker blue than its wild-type counterpart. Moreover, the petE mutation increased the efficiency of light capture, nonphotochemical quenching, and linear electron transport activity, but decreased the functional absorption cross section of PSII. These results suggest that plastocyanin is involved in regulating the redox state of the photosynthetic electron transfer chain, and the petE mutation can induce interesting phenotypic properties that are specific to the light–dark photoperiod.

When multiple source node nodes need to transmit their data packets through a single relay to a common destination, distributed rateless codes can be employed. In this paper, a new kind of completely random rateless codes and its distributed encoding process is proposed based on random matrices theory. The proposed method is very easy to implement. The decoding performance is determined by the rank property of random matrices. Both theoretical analysis and simulation results show that the proposed method is effective.

Uniform anatase TiO(2) particles exposed by {001} facets were successfully synthesized by using EDTA together with F as morphology controlling agents. The crystallographic structure as well as the growth mechanism of anatase TiO(2) particles was investigated systematically by XRD, SEM, TEM and XPS, respectively.

A new synthetic strategy was developed to prepare large-sized well-defined anatase TiO(2) nanosheets wholly dominated with thermodynamically unfavorable high-reactive {001} and {100} facets, which has a percentage of 98.7% and 1.3%, respectively. The as-prepared anatase TiO(2) nanosheets show a well-faceted morphology and have a large size in length (ca. 4.14 μm). The formation mechanism of the anatase TiO(2) nanosheets was also analyzed and investigated.

As an important metal oxide, anatase titanium dioxide has been widely investigated because of its many promising properties for catalysis and photocatalysis. The properties of anatase TiO2 crystals are largely determined by external surfaces exposed. Many efforts have been made to improve the percentage of high-reactive facets like {001} facets of anatase TiO2 to enhance its catalytic properties. This review reports the recent progress in designing and fabricating high-reactive facets dominated anatase TiO2via various strategies including traditional vapor phase epitaxial processes, hydrothermal/solvothermal methods, nonhydrolytic alcoholysis methods and high temperature gas phase reactions. Furthermore, focusing on the (001) surface, the article also covers advances in the theoretic simulations of various high-reactive facets of anatase TiO2 crystals. Finally, we offer a summary and some perspectives on the challenges and new directions for future research in this emerging frontier.