Tuning Structure and Excitonic Properties of 2D Ruddlesden-Popper Germanium, Tin, and Lead Iodide Perovskites via Interplay between Cations.

The compositional tunability of 2D metal halide perovskites enables exploration of diverse semiconducting materials with different structural features. However, rationally tuning the 2D perovskite structures to target physical properties for specific applications remains challenging, especially for lead-free perovskites. Here, we study the effect of the interplay of the B-site (Ge, Sn, and Pb), A-site (cesium, methylammonium, and formamidinium), and spacer cations on the structure and optical properties of a new series of 2D Ruddlesden-Popper perovskites using the previously unreported spacer cation 4-bromo-2-fluorobenzylammonium (4Br2FBZ). We report eight new crystal structures and study the consequence of varying the B-site (Pb, Sn, Ge) and dimension (n = 1, 2, vs 3D). Dimension strongly influences local distortion and structural symmetry, and the increased octahedral tilting and lone pair effects in Ge perovskites lead to a polar n = 2 perovskite that exhibits second harmonic generation, (4Br2FBZ)2(Cs)Ge2I7. In contrast, the analogous Sn and Pb perovskites remain centrosymmetric, but the B-site metal influences the photoluminescence properties. The Pb perovskites exhibit broad, defect-mediated emission at low temperature, whereas the Sn perovskites show purely excitonic emission over the entire temperature range, but the carrier recombination dynamics depend on dimensionality and dark excitonic states. Wholistic understanding of these differences that arise based on cations and dimensionality can guide the rational materials design of 2D perovskites for targeting physical properties for optoelectronic applications based on the interplay of cations and the connectivity of the inorganic framework.

Random lasing in cesium lead iodide (CsPbI3) thin films with no surface passivation.

We report the CsPbI3 random lasing at room temperature fabricated by a chemical deposition method. The CsPbI3 thin films with high crystalline quality have intense PL emission and easily achieve the lasing behavior with the Q-factor value over 7000. The lasing behavior of CsPbI3 thin films can be classified as random lasing by measuring lasing spectra at different collective angles. The fast Fourier transform analysis of the lasing spectra is employed to determine the effective cavity length. Most important of all, the lasing stability investigation shows the prolonged lasing stability over 4.8 X 105 laser shots in air.

Thin Film Stoichiometry and Defects Management for Low Threshold and Air Stable Near-Infrared Perovskite Laser.

While significant efforts have been devoted to optimize the thin-film stoichiometry and processing of perovskites for applications in photovoltaic and light-emitting diodes, there is a noticeable lack of emphasis on tailoring them for lasing applications. In this study, it is revealed that thin films engineered for efficient light-emitting diodes, with passivation of deep and shallow trap states and a tailored energetic landscape directing carriers toward low-energy emitting states, may not be optimal for light amplification systems. Instead, amplified spontaneous emission (ASE) is found to be sustained by shallow defects, driven by the positive correlation between the ASE threshold and the ratio of carrier injection rate in the emissive state to the recombination rate of excited carriers. This insight has informed the development of an optimized perovskite thin film and laser device exhibiting a low threshold (≈ 60 µJ cm-2) and stable ASE emission exceeding 21 hours in ambient conditions.

The complete mitochondrial genome of Parotis chlorochroalis (Hampson, 1912) (Lepidoptera: Crambidae).

The complete mitochondrial genome of the Parotis chlorochroalis was sequenced, revaeling a length of 15239 bp with 37 genes and an A + T-rich region. All c13 PCGs begin with typical ATN codons, except COI gene, which starts with CGA. Eleven genes terminate with TAA, two with T-. All 22 tRNA genes exhibit typical cloverleaf structure except for trnS1 P. chlorochroalis has two relatively conserved intergenic regions and two relatively conserved overlapping regions. Phylogenetic analysis support P. chlorochroalis belongs to subfamily Spilomelinae, the topologies of Crambidae are highly congruent with previous studies. This newly sequences mitochondrial genome provides valuable resources for taxonomic inference and evolutionary studies of genus Parotis.

A taxonomic review of Attevidae (Lepidoptera: Yponomeutoidea) from China with descriptions of two new species and a revised identity of the Ailanthus webworm moth, Atteva fabriciella, from the Asian tropics.

This review describes four species of Atteva (Lepidoptera: Yponomeutoidea: Attevidae) from China, including two new species: A. wallengreni n. sp. and A. yanguifella n. sp. The taxonomic identity of the Ailanthus webworm moth from South and Southeast Asia is revised with a designation of neotype for Phalaena (Tinea) fabriciella Swederus. Lectotypes of Atteva brucea Moore and A. niviguttella Walker are designated. Atteva brucea is synonymized with A. fabriciella. Synonymy of Atteva niviguttella and A. fabriciella is reconfirmed. The previous Chinese records of A. fabriciella were based on confusions with A. wallengreni n. sp. Confirmed specimens of A. fabriciella from China are reported. A pair of confused species, A. fabriciella and A. wallengreni n. sp., are distinguished by the number of white dots on the forewings and the genital features. Another confused pair, A. niveigutta and A. yanguifella n. sp., are compared by external and genital features. All type specimens of the described species are illustrated and compared with the conspecific specimens from various countries of the Asian tropics. Keys to all the species from China are provided.

Gold nanoparticle-based immuno dual probes for targeting proteomics.

Immunoprecipitation combined with mass spectrometry (MS) is a promising technique for targeting proteomics in characterizing submicrograms of target protein and interacting proteins in living cells. This method, however, is limited by interference arising from nonspecific binding. We report a novel gold nanoparticle (AuNP)-based immuno probe approach for immunoprecipitation. By cross-linking the antibody Fc domain to protein G covalently modified on AuNPs, the probe was fabricated and characterized to have 60 protein G and 30 immunoglobins per AuNP. We used human immunoglobin against the target and mouse immunoglobin with the same isotype (IgG) to fabricate the target and preclear probe, respectively, and termed it as the dual probe approach. Our results showed that the preclear probe (AuNP-IgG) and the target probe (AuNP-anti-ERα) share a similar panel of nonspecific binders but dramatic different specificity toward the target. Thus, using the dual probe method, we showed major nonspecific binders in the cell lysate could be largely removed without sacrificing the target protein. Compared to the conventional agarose gel-chromatography, the AuNP-based probe exhibited less nonspecific interference and higher recovery yield for ERα. Moreover, the AuNP-based probe is more inert than the agarose gel under harsh conditions and does not induce dissociation of the cross-linked IgG that could interfere with target identification. Using AuNP-based dual probes, ERα was shown to be purified from MCF-7 cells with minimum nonspecific binding. Moreover, the identity and phosphorylation sites on the C-terminus of the purified ERα could be positively confirmed by MS using only 1 mg of cellular protein.

The complete mitochondrial genome of the rice moth, Corcyra cephalonica.

The complete mitochondrial genome (mitogenome) of the rice moth, Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) was determined as a circular molecular of 15,273 bp in size. The mitogenome composition (37 genes) and gene order are the same as the other lepidopterans. Nucleotide composition of the C. cephalonica mitogenome is highly A+T biased (80.43%) like other insects. Twelve protein-coding genes start with a typical ATN codon, with the exception of coxl gene, which uses CGA as the initial codon. Nine protein-coding genes have the common stop codon TAA, and the nad2, cox1, cox2, and nad4 have single T as the incomplete stop codon. 22 tRNA genes demonstrated cloverleaf secondary structure. The mitogenome has several large intergenic spacer regions, the spacer1 between trnQ gene and nad2 gene, which is common in Lepidoptera. The spacer 3 between trnE and trnF includes microsatellite-like repeat regions (AT)18 and (TTAT)(3). The spacer 4 (16 bp) between trnS2 gene and nad1 gene has a motif ATACTAT; another species, Sesamia inferens encodes ATCATAT at the same position, while other lepidopteran insects encode a similar ATACTAA motif. The spacer 6 is A+T rich region, include motif ATAGA and a 20-bp poly(T) stretch and two microsatellite (AT)(9), (AT)(8) elements.

Visualization of Ion Migration in an Inorganic Mixed Halide Perovskite by One-Photon and Multiphoton Absorption: Effect of Guanidinium A-Site Cation Incorporation.

In this work, we present the ion migration of CsPbIBr2 under illumination and impede it by incorporating the large cations of guanidinium (GA). A series of "probe-set-probe" operations are applied to assess the photoluminescence (PL) behavior spectrally and spatially, which is correlated to the ion migration-induced phase separation, of CsPbIBr2 and GAxCs1-xPbIBr2 perovskites. The local lattice distortion introduced by GA could reduce the strain gradient in GAxCs1-xPbIBr2 to inhibit the ion migration, leading to a stable PL spectrum and enhanced device stability under light stimulation. A solar cell with an optimized stoichiometric composition of GA0.1Cs0.9PbIBr2 delivers comparable photovoltaic performance and improved stability compared to those of CsPbIBr2-based perovskite solar cells, retaining 80% of its initial power conversion efficiency after being continuously bathed in light for 8 h under ambient conditions without encapsulation, while the CsPbIBr2 counterpart shows an efficiency that is <30% of its initial value under the same test condition.

A review of the genus Miresa Walker in China (Lepidoptera: Limacodidae).

Eight species of the genus Miresa Walker are recognized in China including two new species, M. fangae Wu & Solovyev and M. polargenta Wu & Solovyev, described herein. M. burmensis Hering species is reported for the first time in China. The M. argentifera kwangtungensis Hering, 1931 taxon is raised to full specific status. The lectotypes are designated for the following 5 taxa: M. bracteata Butler, 1880 (♂, Natural History Museum, London); M. fulgida Wileman, 1910 (♂, Natural History Museum, London); M. bracteata var. orientis Strand, 1915 (♂, Rijksmuseum van Natuurlijke Historie, Leiden); M. argentifera kwangtungensis Hering, 1931 (♂, Zoologisches Museum der Humboldt Universität zu Berlin) and M. urga Hering, 1933 (♂, Zoologisches Museum der Humboldt Universität zu Berlin). The photographs of moths and their genitalia are given, a key to the Chinese species of the genus is provided, and the distributional maps are also given.

Hemispherical Cesium Lead Bromide Perovskite Single-Mode Microlasers with High-Quality Factors and Strong Purcell Enhancement.

We realized a single-mode laser with an ultra-high quality factor in individual cesium lead bromide (CsPbBr3) perovskite micro-hemispheres fabricated by chemical vapor deposition. A series of lasing property analysis based on cavity size was reported under this material system. Due to good optical confinement capability of the whispering gallery resonant cavity and high optical gain of CsPbBr3 perovskite micro-hemispheres, single-mode lasing behavior was achieved with an ultra-high quality factor as large as 11,460 at room temperature. To study in detail the physical effects between lasing threshold and cavity, a set of cavity size dependence photoluminescence analyses were performed. We found that the lasing threshold increases while the cavity size decreases. Time-resolved PL analysis was conducted to confirm the relation between cavity size and lasing threshold. The larger cavity stands for longer PL lifetime and indicates easier-to-achieve carrier population inversion. Strong Purcell enhancement could be further investigated by the spontaneous emission coupling factor ß and internal quantum efficiency as a function of cavity size. A high ß-factor of 0.37 could be obtained from a 2.2 µm diameter hemisphere microcavity and a high Purcell factor of 14 in a 1.9 µm diameter hemisphere microcavity showing strong Purcell enhancement effect in our system.

Tree diversity and functional leaf traits drive herbivore-associated microbiomes in subtropical China.

Herbivorous insects acquire microorganisms from host plants or soil, but it remains unclear how the diversity and functional composition of host plants contribute to structuring herbivore microbiomes. Within a controlled tree diversity setting, we used DNA metabarcoding of 16S rRNA to assess the contribution of Lepidoptera species and their local environment (particularly, tree diversity, host tree species, and leaf traits) to the composition of associated bacterial communities. In total, we obtained 7,909 bacterial OTUs from 634 caterpillar individuals comprising 146 species. Tree diversity was found to drive the diversity of caterpillar-associated bacteria both directly and indirectly via effects on caterpillar communities, and tree diversity was a stronger predictor of bacterial diversity than diversity of caterpillars. Leaf toughness and dry matter content were important traits of the host plant determining bacterial species composition, while leaf calcium and potassium concentration influenced bacterial richness. Our study reveals previously unknown linkages between trees and their characteristics, herbivore insects, and their associated microbes, which contributes to developing a more nuanced understanding of functional dependencies between herbivores and their environment, and has implications for the consequences of plant diversity loss for trophic interactions.

A new species of the genus Caissa Hering, 1931 from Yunnan, China (Lepidoptera, Limacodidae).

A new species, Caissa yunnana sp. nov. is described from Yunnan Prov., China. The new species is illustrated with images of the adult habitus and male genitalia, and compared with the similar species C. caissa Hering, 1931. A world checklist of the genus Caissa Hering, 1931 is provided.

Sensing Escherichia coli O157:H7 via frequency shift through a self-assembled monolayer based QCM immunosensor.

By means of the specific immuno-recognition and ultra-sensitive mass detection, a quartz crystal microbalance (QCM) biosensor for Escherichia coli O157:H7 detection was developed in this work. As a suitable surfactant, 16-mercaptohexadecanoic acid (MHDA) was introduced onto the Au surface of QCM, and then self-assembled with N-hydroxysuccinimide (NHS) raster as a reactive intermediate to provide an active interface for the specific antibody immobilization. The binding of target bacteria with the immobilized antibodies decreased the sensor's resonant frequency, and the frequency shift was correlated to the bacterial concentration. The stepwise assembly of the immunosensor was characterized by means of the electrochemical techniques. Using the immersion-dry-immersion procedure, this QCM biosensor could detect 2.0x10(2) colony forming units (CFU)/ml E. coli O157:H7. In order to reduce the fabrication time, a polyelectrolyte layer-by-layer self-assembly (LBL-SA) method was adopted for fast construction. Finally, the reproducibility of this biosensor was discussed.

Description of a new species of the genus Caeneressa from China, with a checklist of the genus (Lepidoptera: Erebidae).

A new species, Caeneressa fangae C.-S. Wu, is described from Sichuan, China. Image of adult and genitalia of the new species is provided. Caeneressa serrata (Hampson) is excluded from the fauna of China. A checklist of the species and subspecies of the genus Caeneressa is given on a worldwide basis.

A two-step DNA barcoding approach for delimiting moth species: moths of Dongling Mountain (Beijing, China) as a case study.

DNA barcoding, based on a fragment of cytochrome c oxidase I (COI) mtDNA, is as an effective molecular tool for identification, discovery, and biodiversity assessment for most animals. However, multiple gene markers coupled with more sophisticated analytical approaches may be necessary to clarify species boundaries in cases of cryptic diversity or morphological plasticity. Using 339 moths collected from mountains surrounding Beijing, China, we tested a pipeline consisting of two steps: (1) rapid morphospecies sorting and screening of the investigated fauna with standard COI barcoding approaches; (2) additional analyses with multiple molecular markers for those specimens whose morphospecies and COI barcode grouping were incongruent. In step 1, 124 morphospecies were delimited into 116 barcode units, with 90% of the conflicts being associated with specimens identified to the genus Hypena. In step 2, 55 individuals representing all 12 Hypena morphospecies were analysed using COI, COII, 28S, EF-1a, Wgl sequences or their combinations with the BPP (Bayesian Phylogenetics and Phylogeography) multigene species delimitation method. The multigene analyses supported the delimitation of 5 species, consistent with the COI analysis. We conclude that a two-step barcoding analysis pipeline is able to rapidly characterize insect biodiversity and help to elucidate species boundaries for taxonomic complexes without jeopardizing overall project efficiency by substantially increasing analytical costs.

[Treatment of complex calcaneal fractures under computer navigation: report of 130 feet].

OBJECTIVE: To investigate the effects of computer navigation in the treatment of intra-articular calcaneal fractures. METHODS: 130 feet in 110 patients with intra-articular calcaneal fractures, 57 calcanei with fracture of Sander's type II, 45 of type III, and 28 cases of type IV, were treated with internal fixation under computer navigation, and were followed up for 16.3 months (6 - 24 months). RESULTS: According to the Maryland Foot Score system, excellent result was noted in 63 feet, good result in 57 feet, and fair result in 10 feet, with the excellent and good rates being 92.31% together. CONCLUSION: Using computer navigation to treat intra-articular calcaneal fractures is one of the best ways for treatment of calcaneal fractures.

Leaf miner-induced morphological, physiological and molecular changes in mangrove plant Avicennia marina (Forsk.) Vierh.

Avicennia marina (Forsk.) Vierh is a widespread mangrove species along the southeast coasts of China. Recently, the outbreak of herbivorous insect, Phyllocnistis citrella Stainton, a leaf miner, have impacted on the growth of A. marina. Little is reported about the responses of A. marina to leaf miner infection at the biochemical, physiological and molecular levels. Here, we reported the responses of A. marina to leaf miner infection from the aspects of leaf structure, photosynthesis, and antioxidant system and miner responsive genes expression. A. marina leaves attacked by the leaf miner exhibited significant decreases in chlorophyll, carbon and nitrogen contents, as well as a decreased photosynthetic rate. Scanning and transmission electron microscopic observations revealed that the leaf miner only invaded the upper epidermis and destroyed the epidermal cell, which lead to the exposure of salt glands. In addition, the chloroplasts of mined leaves (ML) were swollen and the thylakoids degraded. The maximal net photosynthetic rate, stomatal conductance (Gs), carboxylation efficiency (CE), dark respiration (Rd), light respiration (Rp) and quantum yields (AQE) significantly decreased in the ML, whereas the light saturation point (Lsp), light compensation point (Lcp), water loss and CO2 compensation point (Г) increased in the ML. Moreover, chlorophyll fluorescence features also had been changed by leaf miner attacks. Interestingly, higher generation rate of O2ˉ· and lower antioxidant enzyme expression in the mined portion (MP) were found; on the contrary, higher H2O2 level and higher antioxidant enzyme expression in the non-mined portion (NMP) were revealed, implying that the NMP may be able to sense that the leaf miner attacks had happened in the MP of the A. marina leaf via H2O2 signaling. Besides, the protein expression of glutathione S-transferase (GST) and the glutathione (GSH) content were increased in the ML. In addition, insect resistance-related gene expression such as chitinase 3, RAR1, topless and PIF3 had significantly increased in the ML. Taken together, our data suggest that leaf miners could significantly affect leaf structure, photosynthesis, the antioxidant system and miner responsive gene expression in A. marina leaves.

Influence of internal biogas production on hydrodynamic behavior of anaerobic fluidized-bed reactors.

Predictive models for describing the hydrodynamic behavior (bed-expansion and bed-pressure gradient) of a three-phase anaerobic fluidized bed reactor (AFBR) was developed according to wake theory together with more realistic dynamic bed-expansion experiments (with and without internal biogas production). A reliable correlation equation for the parameter k (mean volume ratio of wakes to bubbles) was also established, which is of help in estimating liquid hold up of fluidized beds. The experimental expansion ratio of three-phase fluidized beds (E(GLS)) was approximately 18% higher than that of two-phase fluidized beds (E(LS)); whereas the experimental bed-pressure gradient of the former [(-DeltaP/H)(GLS)] was approximately 9.3% lower than that of the latter [(-DeltaP/H)(LS)]. Both the experimental and modeling results indicated that a higher superficial gas velocity (u(g)) gave a higher E(GLS) and a higher E(GLS) to E(LS) ratio as well as a lower (-DeltaP/H)(GLS) and a lower (-DeltaP/H)(GLS) to (-DeltaP/H)(LS) ratio. As for the operation stability of the AFBR, the sensitivity of u(g) to expansion height (H(GLS)) and (-DeltaP/H)(GLS) is between the sensitivity of superficial liquid velocity and biofilm thickness. The model predictions of E(GLS), (-DeltaP)(GLS), and (-DeltaP/H)(GLS) agreed well the experimental measurements. Accordingly, the predictive models accounting for internal biogas production described fairly well the hydrodynamic behavior of the AFBR.

Consecutive reaction kinetics involving a layered structure of the granule in UASB reactors.

A consecutive-reaction kinetic model for the sucrose-fed upflow anaerobic sludge bed (UASB) reactor that accounts for a layered structure of the granule and the mass fraction of methanogens (f) is proposed. When the UASB reactor was maintained at the volumetric loading rates (VLR) of 7.9-13.8 kg chemical oxygen demand (COD)/m(3) d, the accumulated volatile fatty acids (VFAs) increased with increasing VLR, whereas the experimental f decreased with increasing VLR. This was primarily because methanogenesis was the rate-limiting step and the sucrose-fed granule was a layered structure. The calculated residual concentrations of sucrose and the intermediates VFAs using the layered-structure model are less deviated from the experimental measurements than those using the homogeneous-structure model. The calculated effectiveness factors for sucrose uptake and intermediates VFAs uptake (eta(1); eta(2)) ranged from 0.18 to 0.35 and 0.65 to 0.96, respectively, indicating that the overall substrate (sucrose or intermediates VFAs) removal in the UASB reactor was diffusion-controlled, especially at the VLRs of 7.9-10.6. kg COD/m(3) d. This finding was also confirmed by the simulated concentration profiles of sucrose and VFAs in the UASB-granule. From the simulation results, the effect of internal mass transfer resistance on overall substrate (sucrose) removal should not be neglected, especially for a granule size of greater than 2.0 mm.

The complete mitochondrial genome of Acleris fimbriana (Lepidoptera: Tortricidae).

The yellow tortrix, Acleris fimbriana belongs to Tortricidae in Lepidoptera. We described the complete mitogenome of A. fimbriana, which is typical circular duplex molecules and 15,933 bp in length containing the standard metazoan set of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and an A + T-rich region with macro-repeat sequences. All the inferred tRNA secondary structures show the common cloverleaf pattern, with the exception of trnS1(AGN) which lacks the DHU arm. The A. fimbriana mitochondrial genome has the same gene order with other lepidopterans.