Constancy of Bond Dissociation Energy Ratios for AB₂/AB Systems

G2 and G2(MP2) theories have been used to study the bond dissociation energies D0m of a series of AB2, AB2+, AB2-, AB, AB+ and AB- systems. A total of fifty-four molecules and ions have been examined, for which B = O, S or Se and A = C, S, Ge, N+, P+, As+, B-, Al- or Ga-. Each triatomic system has sixteen valence electrons and each diatomic system has ten valence electrons. Both triplet and singlet spin states have been considered for each molecule and ion. For the triatomic systems, the preferred connectivity, i.e. B-A-B or B-B-A, has been determined. It has been observed experimentally that the ratio D0m(AB2)/2D0m(AB) is a nearly constant value of 0.8 for these neutral systems. One question of interest is whether the analogous ratios D0m(AB2+)/2D0m(AB+) and D0m(AB2-)/2D0m(AB-) for the isoelectronic cations and anions are also nearly constant. We have used ab initio molecular orbital calculations to probe this question and to find an explanation for the observed ratios. The results show that the ground state of each of these diatomic and triatomic molecules and ions is a singlet. The B-A-B connectivity is strongly favored for the ground state species but both B-A-B and B-B-A connectivities are found for the excited state species. Although stable cyclic, bent and linear structures have been located, the structures of the ground state singlet B-A-B molecules and ions are uniformly linear. These observations have been rationalized based on the compositions of the highest occupied and lowest unoccupied molecular orbitals. The computations reproduce the observed bond dissociation energy ratios for the neutral systems within experimental error. The agreement between experiment and theory for the actual bond dissociation energies is less satisfactory. In addition, the computations show that the ratios for the anionic and cationic systems differ in magnitude from those for the neutral systems (by -0.1 and +0.1, respectively) but are also nearly constant. The bond dissociation energy ratios are nearly constant for these systems because the ratio of the dissociation energy of the A=B bond to that of the A≡B bond is nearly constant

A transcriptomic analysis of Stylo [Stylosanthes guianensis (Aubl.) Sw.] provides novel insights into the basis of salinity tolerance

Tropical areas have a large distribution of saline soils and tidal flats with a high salinity level. Salinity stress is a key factor limiting the widespread use of tropical forage such as Stylosanthes guianensis (Aubl.) Sw. This study was designed to screen the salinity tolerance of 84 S. guianensis accessions; In a greenhouse experiment, plants were subjected to Hoagland solution or Hoagland solution with 200 mM NaCl for up to 15 days. Salinity tolerant accession CIAT11365 and salinity sensitive accession FM05-2 were obtained based on withered leaf rate (WLR). Further verification of salinity tolerance in CIAT11365 and FM05-2 with different salinity gradients showed that salinity stress increased WLR and decreased relative chlorophyll content (SPAD), maximum photochemical efficiency of photosystem II (Fv/Fm), and photosynthetic rate (Pn) in FM05-2, but CIAT11365 exhibited lower WLR and higher SPAD, Fv/Fm, and Pn. Leaf RNA-Seq revealed that Ca2+ signal transduction and Na+ transport ability, salinity tolerance-related transcription factors and antioxidant ability, an increase of auxin, and inhibition of cytokinin may play key roles in CIAT11365 response to salinity stress. The results of this study may contribute to our understanding of the molecular mechanism underlying the responses of S. guianensis to salinity stress and also provide important clues for further study and in-depth characterization of salinity resistance breeding candidate genes in S. guianensis

Skeleton extraction based on anisotropic partial differential equation

Skeleton extraction is of great significance for image recognition processes. In this paper, a novel skeleton extraction method is proposed based on the anisotropic diffusion of the gradient vector field. Firstly, the gradient vector is calculated for the original image. Then, the gradient vector field is updated by an anisotropic partial differential equation to strengthen the source point or sink point of the image energy. At last, according to the divergence property of the final gradient vector field, the skeleton of the initial image is obtained. The experimental results demonstrate that the proposed method is robust for noise and can give the exact skeleton for images

A recombinase polymerase amplification-lateral flow dipstick assay for rapid detection of the quarantine citrus pathogen in China, Phytophthora hibernalis

Phytophthora hibernalis, the causal agent of brown rot of citrus fruit, is an important worldwide pathogen and a quarantine pest in China. Current diagnosis of the disease relies on disease symptoms, pathogen isolation and identification by DNA sequencing. However, symptoms caused by P. hibernalis can be confused with those by other Phytophthora and fungal species. Moreover, pathogen isolation, PCR amplification and sequencing are time-consuming. In this study, a rapid assay including 20-min recombinase polymerase amplification targeting the Ypt1 gene and 5-min visualization using lateral flow dipsticks was developed for detecting P. hibernalis. This assay was able to detect 0.2 ng of P. hibernalis genomic DNA in a 50-µL reaction system. It was specific to P. hibernalis without detection of other tested species including P. citrophthora, P. nicotianae, P. palmivora and P. syringae, four other important citrus pathogens. Using this assay, P. hibernalis was also detected from artificially inoculated orange fruits. Results in this study indicated that this assay has the potential application to detect P. hibernalis at diagnostic laboratories and plant quarantine departments of customs, especially under time- and resource-limited conditions

A 4-bit 36 GS/s ADC with 18 GHz Analog Bandwidth in 40 nm CMOS Process

This paper presents a 4-bit 36 GS/s analog-to-digital converter (ADC) employing eight time-interleaved (TI) flash sub-ADCs in 40 nm complementary metal-oxide-semiconductor (CMOS) process. A wideband front-end matching circuit based on a peaking inductor is designed to increase the analog input bandwidth to 18 GHz. A novel offset calibration that can achieve quick detection and accurate correction without affecting the speed of the comparator is proposed, guaranteeing the high-speed operation of the ADC. A clock distribution circuit based on CMOS and current mode logic (CML) is implemented in the proposed ADC, which not only maintains the speed and quality of the high-speed clock, but also reduces the overall power consumption. A timing mismatch calibration is integrated into the chip to achieve fast timing mismatch detection of the input signal which is bandlimited to the Nyquist frequency for the complete ADC system. The experimental results show that the differential nonlinearity (DNL) and integral nonlinearity (INL) are −0.28/+0.22 least significant bit (LSB) and −0.19/+0.16 LSB, respectively. The signal-to-noise-and-distortion ratio (SNDR) is above 22.5 dB and the spurious free dynamic range (SFDR) is better than 35 dB at 1.2 GHz. An SFDR above 24.5 dB and an SNDR above 18.6 dB across the entire Nyquist frequency can be achieved. With a die size of 2.96 mm * 1.8 mm, the ADC consumes 780 mW from the 0.9/1.2/1.8 V power supply

FERM domain-containing protein FRMD5 regulates cell motility via binding to integrin beta 5 subunit and ROCK1

FRMD5 is a novel FERM domain-containing protein depicted in tumor progression. However, the mechanisms underlying FRMD5 inhibition of cell migration is largely unknown. Here, we show that FRMD5 regulates cell migration by interacting with integrin beta 5 cytoplasmic tail and ROCK1 in human lung cancer cells. FRMD5 promotes cell-matrix adhesion and cell spreading on vitronectin, and thus inhibits cell migration. Furthermore, FRMD5 interacts with ROCK1 and inhibits its activation that leads to the inhibition of myosin light chain phosphorylation and the actin stress fiber formation. Taken together, these findings demonstrate that the putative tumor suppressive protein FRMD5 regulates tumor cell motility via a dual pathway involving FRMD5 binding to integrin beta 5 tail and to ROCK1. (C) 2014 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.Biochemistry & Molecular BiologyBiophysicsCell BiologySCI(E)[email protected]

Biofumigation by Mustard Plants as an Application for Controlling Postharvest Gray Mold in Apple Fruits

Gray mold caused by Botrytis cinerea is a critical disease that results in severe postharvest losses for the apple industry. In recent years, biological control has become an increasingly effective approach for controlling postharvest diseases in fruits. Brassica plants contain abundant natural compounds with known antimicrobial activity against numerous plant pathogens. In this study, a large-scale screening of 90 mustard cultivars was conducted to evaluate their biofumigation effects against B. cinerea. Among these, one mustard cultivar named Dilong-1, displayed the highest inhibitory effect against B. cinerea, and was able to completely inhibit mycelial growth. Further investigations showed that fumigation with Dilong-1 inhibited mycelial growth, sporulation, and spore germination of B. cinerea in vitro. In addition, fumigation using Dilong-1 showed a wide antifungal spectrum, including other fruit postharvest pathogens such as Phytophthora litchii. Furthermore, apple gray mold disease severity was significantly reduced by biofumigation using Dilong-1. Importantly, fumigation with Dilong-1 did not negatively impact final apple qualities, including weight loss, firmness, and total soluble solids. These results suggested that Dilong-1 significantly inhibited gray mold decay caused by B. cinerea without affecting the quality of apple fruits. In conclusion, biological fumigation of apple fruits with the mustard cultivar Dilong-1 is a promising eco-friendly approach for controlling apple gray mold during storage and shipment

Rapid and simple detection of Phytophthora cactorum in strawberry using a coupled recombinase polymerase amplification–lateral flow strip assay

Abstract Phytophthora cactorum is a devastating pathogen that infects a wide range of plants and causes Phytophthora rot disease, which has resulted in great economic losses in crop production. Therefore, the rapid and practicable detection of P. cactorum is important for disease monitoring and forecasting. In this study, we developed a lateral flow recombinase polymerase amplification (LF-RPA) assay for the sensitive visual detection of P. cactorum. Specific primers for P. cactorum were designed based on the ras-related protein gene Ypt1; all 10 P. cactorum isolates yielded positive detection results, whereas no cross-reaction occurred in related oomycete or fungal species. The detection limit for the LF-RPA assay was 100 fg of genomic DNA under optimized conditions. Combined with a simplified alkaline lysis method for plant DNA extraction, the LF-RPA assay successfully detected P. cactorum in naturally diseased strawberry samples without specialized equipment within 40 min. Thus, the LF-RPA assay developed in this study is a rapid, simple, and accurate method for the detection of P. cactorum, with the potential for further application in resource-limited laboratories

Skeleton extraction and phase interpolation for single ESPI fringe pattern based on the partial differential equations

A novel phase extraction method for single electronic speckle pattern interferometry (ESPI) fringes is proposed. The partial differential equations (PDEs) are used to extract the skeletons of the gray-scale fringe and to interpolate the whole-field phase values based on skeleton map. Firstly, the gradient vector field (GVF) of the initial fringe is adjusted by an anisotropic PDE. Secondly, the skeletons of the fringe are extracted combining the divergence property of the adjusted GVF. After assigning skeleton orders, the whole-field phase information is interpolated by the heat conduction equation. The validity of the proposed method is verified by computer-simulated and experimentally obtained poor-quality ESPI fringe pattern