An Equivalent Condition on the Switching Construction of Differentially 44-uniform Permutations on \gf_{2^{2k}} from the Inverse Function

Differentially $4$-uniform permutations on \gf_{2^{2k}} with high nonlinearity are often chosen as substitution boxes in block ciphers. Recently, Qu et al. used the powerful switching method to construct permutations with low differential uniformity from the inverse function \cite{QTTL, QTLG} and proposed a sufficient but not necessary condition for these permutations to be differentially $4$-uniform. In this paper, a sufficient and necessary condition is presented. We also give a compact estimation for the number of constructed differentially $4$-uniform permutations. Comparing with those constructions in \cite{QTTL, QTLG}, the number of functions constructed here is much bigger. As an application, a new class of differentially $4$-uniform permutations is constructed. The obtained functions in this paper may provide more choices for the design of substitution boxes

Terrestrial-derived soil protein in coastal water: metal sequestration mechanism and ecological function.

Terrestrial fungi, especially arbuscular mycorrhizal (AM) fungi, enhance heavy metal sequestration and promote ecosystem restoration. However, their ecological functions were historically overlooked in discussions regarding water quality. As an AM fungi-derived stable soil protein fraction, glomalin-related soil protein (GRSP) may provide insights into the ecological functions of AM fungi associated with water quality in coastal ecosystems. Here, we first assessed the metal-loading dynamics and ecological functions of GRSP transported into aquatic ecosystems, characterized the composition characteristics, and revealed the mechanisms underlying Cu and Cd sequestration. Combining in situ sampling and in vitro cultures, we found that the composition characteristics of GRSP were significantly affected by the element and mineral composition of sediments. In situ, GRSP-bound Cu and Cd contributed 18.91-22.03% of the total Cu and 2.27-6.37% of the total Cd. Functional group ligands and ion exchange were the principal mechanisms of Cu binding by GRSP, while Cd binding was dominated by functional group ligands. During the in vitro experiment, GRSP sequestered large amounts of Cu and Cd and formed stable complexes, while further dialysis only released 25.74 ± 3.85% and 33.53 ± 3.62% of GRSP-bound Cu and Cd, respectively

Terrestrial-derived soil protein in coastal water: Metal sequestration mechanism and ecological function

Abstract(#br)Terrestrial fungi, especially arbuscular mycorrhizal (AM) fungi, enhance heavy metal sequestration and promote ecosystem restoration. However, their ecological functions were historically overlooked in discussions regarding water quality. As an AM fungi-derived stable soil protein fraction, glomalin-related soil protein (GRSP) may provide insights into the ecological functions of AM fungi associated with water quality in coastal ecosystems. Here, we first assessed the metal-loading dynamics and ecological functions of GRSP transported into aquatic ecosystems, characterized the composition characteristics, and revealed the mechanisms underlying Cu and Cd sequestration. Combining in situ sampling and in vitro cultures, we found that the composition characteristics of GRSP were significantly affected by the element and mineral composition of sediments. In situ , GRSP-bound Cu and Cd contributed 18.91–22.03% of the total Cu and 2.27–6.37% of the total Cd. Functional group ligands and ion exchange were the principal mechanisms of Cu binding by GRSP, while Cd binding was dominated by functional group ligands. During the in vitro experiment, GRSP sequestered large amounts of Cu and Cd and formed stable complexes, while further dialysis only released 25.74 ± 3.85% and 33.53 ± 3.62% of GRSP-bound Cu and Cd, respectively

Inverse design for material anisotropy and its application for a compact X-cut TFLN on-chip wavelength demultiplexer

Inverse design focuses on identifying photonic structures to optimize the performance of photonic devices. Conventional scalar-based inverse design approaches are insufficient to design photonic devices of anisotropic materials such as lithium niobate (LN). To the best of our knowledge, this work proposes for the first time the inverse design method for anisotropic materials to optimize the structure of anisotropic-material based photonics devices. Specifically, the orientation dependent properties of anisotropic materials are included in the adjoint method, which provides a more precise prediction of light propagation within such materials. The proposed method is used to design ultra-compact wavelength division demultiplexers in the X-cut thin-film lithium niobate (TFLN) platform. By benchmarking the device performances of our method with those of classical scalar-based inverse design, we demonstrate that this method properly addresses the critical issue of material anisotropy in the X-cut TFLN platform. This proposed method fills the gap of inverse design of anisotropic materials based photonic devices, which finds prominent applications in TFLN platforms and other anisotropic-material based photonic integration platforms

FAILURE ANALYSIS AND EXPERIMENTAL STUDY OF COMPOSITE MULTI-PIN CONNECTIONS BASED ON CONTINUUM DAMAGE MECHANICS

Composite multi-pin connection is a common connection form in engineering structure. In this paper, numerical analysis and experimental study on the failure and damage of composite multi-pin connection structure under tensile load are carried out. Firstly, different failure criteria are established for fiber, matrix and delamination. Based on fracture mechanics, the strength parameters of single-layer plate considering in-situ effect are derived. Combined with the method of stiffness exponential decay, the continuous damage mechanical constitutive model of composite single-layer plate is compiled by using finite element subroutine. In order to improve the calculation efficiency, this paper proposes to use the partition Newton method, which is different from the traditional Puck method and the partition golden section method, to calculate the angle of matrix failure fracture surface in Puck failure criterion. Secondly, the tensile properties of composite laminate plate and perforated plate are analyzed by using the above mechanical model, and the feasibility of the model is verified by comparing the test results. Finally, the failure and damage evolution process of the composite multi pin connection structure is analyzed by using the above mechanical model, and the results are compared with the experimental results. The results show that the mechanical model proposed in this paper can predict and calculate the mechanical response and damage mode of carbon fiber composite multi-pin connection structure under tensile load

The complete chloroplast genome sequence of Gomesa flexuosa

Gomesa flexuosa (Lodd) M.W.Chase & N.H.Williams is a new species of orchid revised in 2009. In this study, the chloroplast genome of G. flexuosa was sequenced to determine its genomic characteristics and phylogenetic relationship with other related species. G. flexuosa has a chloroplast genome size of 147,764 bp, comprising 25,757 bp of two inverted repeat (IR) regions, 83,579 bp of large single-copy (LSC) region, and 12,671 bp of small single-copy (SSC) region. Moreover, the whole genome contains 73 protein-coding genes, 38 tRNA genes, and eight rRNA genes. Phylogenetic analysis showed that G. flexuosa is closely related to Oncidium sphacelatum

Analysis on the Choice of Livelihood Strategy for Peasant Households Renting out Farmland: Evidence from Western Poverty-Stricken Areas in China

Investigating the choice of livelihood strategies has great significance for improving the living standards of peasant households who rent out farmland. This study evaluates the impact of renting-out land on households’ livelihood strategies in China’s western poverty-stricken areas. Data were obtained from cross sectional survey of 585 field survey data from peasant households who rent out land. The K-means clustering method was used to classify the livelihood strategies of the sample households. In view of sustainable livelihood framework, this paper used combination weighting model based on game theory to calculate the quo of households’ livelihood capital. The Multinomial Logistic Regression was used to explore the relationship between livelihood capitals and livelihood strategies. Results show that: livelihood strategy of households who rent out the land can be divided into “agricultural-led” livelihood strategy, “working-oriented” livelihood strategy and “part-time” livelihood strategy. Additionally, the results of Multinomial Logistic Regression show that the households with high human capital and financial capital tend to choose the “working-oriented” livelihood strategy and the households with high natural capital tend to choose the “agricultural-led” livelihood strategy. Therefore, in order to realize the sustainable livelihood of these households, different policy support should be proposed based on the heterogeneity of households in the process of land transfer

Exosomes from Bone Marrow Microenvironment-Derived Mesenchymal Stem Cells Affect CML Cells Growth and Promote Drug Resistance to Tyrosine Kinase Inhibitors

Although major advances have been achieved in the treatment of chronic myeloid leukemia (CML) by using tyrosine kinase inhibitors, patients relapse after withdrawal and need long-term medication. This reflects the CML clones have not been eliminated completely. The precise mechanisms for the maintenance of CML cells are not yet fully understood. The bone marrow microenvironment constitutes the sanctuary for leukemic cells. Mesenchymal stem cells (MSC) are an important component of the bone marrow microenvironment (BM). It plays an important role in the development and drug resistance of CML. Accumulating evidence indicates that exosomes play a vital role in cell-to-cell communication. We successfully isolated and purified exosomes from human bone marrow microenvironment-derived mesenchymal stem cells (hBMMSC-Exo) by serial centrifugation. In the present study, we investigated the effect of hBMMSC-Exo on the proliferation, apoptosis, and drug resistance of CML cells. The results demonstrated that hBMMSC-Exo had the ability to inhibit the proliferation of CML cells in vitro via miR-15a and arrest cell cycle in the G0/G1 phase. However, the results obtained from BALB/c nu/nu mice studies apparently contradicted the in vitro results. In fact, hBMMSC-Exo increased tumor incidence and promoted tumor growth in vivo. Further study showed the antiapoptotic protein Bcl-2 expression increased, whereas the Caspase3 expression decreased. Moreover, the in vivo study in the xenograft tumor model showed that hBMMSC-Exo promoted the proliferation and decreased the sensitivity of CML cells to tyrosine kinase inhibitors, resulting in drug resistance. These results demonstrated that hBMMSC-Exo supported the maintenance of CML cells and drug resistance in BM by cell-extrinsic protective mechanisms. They also suggested that hBMMSC-Exo might be a potential target to overcome the microenvironment-mediated drug resistance

Reactive molecular dynamics insight into the thermal decomposition mechanism of 2,6-Bis(picrylamino)-3,5-dinitropyridine

2,6-bis(picrylamino)-3,5-dinitropyridine (PYX) has excellent thermostability, which makes its thermal decomposition mechanism receive much attention. In this paper, the mechanism of PYX thermal decomposition was investigated thoroughly by the ReaxFF-lg force field combined with DFT-B3LYP(6–311++G) method. The detailed decomposition mechanism, small-molecule product evolution, and cluster evolution of PYX were mainly analyzed. In the initial stage of decomposition, the intramolecular hydrogen transfer reaction and the formation of dimerized clusters are earlier than the denitration reaction. With the progress of the reaction, one side of the bitter amino group is removed from the pyridine ring, and then the pyridine ring is cleaved. The final products produced in the thermal decomposition process are CO2, H2O, N2, and H2. Among them, H2O has the earliest generation time, and the reaction rate constant (k3) is the largest. Many clusters are formed during the decomposition of PYX, and the formation, aggregation, and decomposition of these clusters are strongly affected by temperature. At low temperatures (2500 K–2750 K), many clusters are formed. At high temperatures (2750 K–3250 K), the clusters aggregate to form larger clusters. At 3500 K, the large clusters decompose and become small. In the late stage of the reaction, H and N in the clusters escaped almost entirely, but more O was trapped in the clusters, which affected the auto-oxidation process of PYX. PYX’s initial decomposition activation energy (Ea) was calculated to be 126.58 kJ/mol. This work contributes to a theoretical understanding of PYX’s entire thermal decomposition process