335 research outputs found
Research on the Growth of Internet SMEs Based on Entropy Theory
With the rapid development of Internet technology, Internet companies rise rapidly in all areas of the society, and have become a major economic way and also a new economic growth point in the modern era. This heralds the coming of network economy era. It is essential for both managers and investors to evaluate the growth of a listed company. Therefore, academics in China have been giving a lot of attention on the study about the growth of thoseInternet enterprises. First, on the basis of enterprise growth theory and entropy theory, this paper is aimed at recognizing the factors influencing the development of small and medium-sized Internet enterprises by analyzing questionnaires. Then, the concept of entropy is proposed based on the entropy theory. This research provides a new method for growth analysis and also has a far-reaching significance for the development of the Internet SME
GEE-Based Ecological Environment Variation Analysis under Human Projects in Typical China Loess Plateau Region
The China Loess Plateau (CLP) is a unique geomorphological unit with abundant coal resources but a fragile ecological environment. Since the implementation of the Western Development plan in 2000, the Grain for Green Project (GGP), coal mining, and urbanization have been extensively promoted by the government in the CLP. However, research on the influence of these human projects on the ecological environment (EE) is still lacking. In this study, we investigated the spatial–temporal variation of EE in a typical CLP region using a Remote Sensing Ecological Index (RSEI) based on the Google Earth Engine (GEE). We obtained a long RSEI time series from 2002–2022, and used trend analysis and rescaled range analysis to predict changing trends in EE. Finally, we used Geodetector to verify the influence of three human projects (GGP, coal mining, and urbanization). Our results show that GGP was the major driving factor of ecological changes in the typical CLP region, while coal mining and urbanization had significant local effects on EE. Our research provides valuable support for ecological protection and sustainable social development in the relatively underdeveloped region of northwest China
Thermodynamic properties of higher-dimensional dS black holes in dRGT massive gravity
On the basis of the state parameter of de Sitter space-time satisfying the
first law of thermodynamics,we can derive some effective thermodynamic
quantities.When the temperature of the black hole horizon is equal to that of
the cosmological horizon, we think that the effective temperature of the
space-time should have the same value. Using this condition, we obtain a
differential equation of the entropy of the de Sitter black hole in the
higherdimensional de Rham, Gabadadze and Tolley (dRGT) massive gravity. Solving
the differential equation, we obtain the corrected entropy and effective
thermodynamic quantities of the de Sitter black hole. The results show that for
multiparameter black holes, the entropy satisfied differential equation is
invariable with different independent state parameters. Therefore, the entropy
of higher-dimensional dS black holes in dRGT massive gravity is only a function
of the position of the black hole horizon, and is independent of other state
parameters. It is consistent with the corresponding entropy of the black hole
horizon and the cosmological horizon. The thermodynamic quantities of
self-consistent de Sitter spacetime are given theoretically, and the equivalent
thermodynamic quantities have the second-order phase transformation similar to
AdS black hole, but unlike AdS black hole, the equivalent temperature of de
Sitter space-time has a maximum value. By satisfying the requirement of
thermodynamic equilibrium and stability of space-time, the conditions for the
existence of dS black holes in the universe are obtained.Comment: 11 pages, 6 figure
Phase transition and entropic force of de Sitter black hole in massive gravity
It is well known that de Sitter(dS) black holes generally have a black hole
horizon and a cosmological horizon, both of which have Hawking radiation. But
the radiation temperature of the two horizons is generally different, so dS
black holes do not meet the requirements of thermal equilibrium stability,
which brings certain difficulties to the study of the thermodynamic
characteristics of black holes. In this paper, dS black hole is regarded as a
thermodynamic system, and the effective thermodynamic quantities of the system
are obtained. The influence of various state parameters on the effective
thermodynamic quantities in the massive gravity space-time is discussed. The
condition of the phase transition of the de Sitter black hole in massive
gravity space-time is given. We consider that the total entropy of the dS black
hole is the sum of the corresponding entropy of the two horizons plus an extra
term from the correlation of the two horizons. By comparing the entropic force
of interaction between black hole horizon and the cosmological horizon with
Lennard-Jones force between two particles, we find that the change rule of
entropic force between the two system is surprisingly the same. The research
will help us to explore the real reason of accelerating expansion of the
universe.Comment: 14 pages,11 figure
ABCC3 as a marker for multidrug resistance in non-small cell lung cancer
Multidrug resistance (MDR) contributes to the failure of chemotherapy and high mortality in non-small cell lung cancer (NSCLC). We aim to identify MDR genes that predict tumor response to chemotherapy. 199 NSCLC fresh tissue samples were tested for chemosensitivity by MTT assay. cDNA microarray was done with 5 samples with highest resistance and 6 samples with highest sensitivity. Expression of ABCC3 mRNA and protein was detected by real-time PCR and immunohistochemisty, respectively. The association between gene expression and overall survival (OS) was examined using Cox proportional hazard regression. 44 genes were upregulated and 168 downregulated in the chemotherapy-resistant group. ABCC3 was one of the most up-regulated genes in the resistant group. ABCC3-positive expression correlated with lymph node involvement, advanced TNM stage, more malignant histological type, multiple-resistance to anti-cancer drugs, and reduced OS. ABCC3 expression may serve as a marker for MDR and predictor for poor clinical outcome of NSCLC
Design and control of pressure‐swing distillation for separating ternary systems with three binary minimum azeotropes
The separation of ternary nonideal systems with multi‐azeotrope is very important because they are often found in the waste of chemical and pharmaceutical industries, which is much more difficult due to the formation of multi‐azeotrope and distillation boundary. We propose a systematic procedure for design and control of a triple‐column pressure‐swing distillation for separating ternary systems with three binary minimum azeotropes. This procedure involves thermodynamic insights, a two‐step optimization method, and effective control strategy. The separation of tetrahydrofuran (THF)/ethanol/water is used to illustrate the capability of the proposed procedure. It is found that the pressure limits in columns can be determined through the analysis of residue curve maps, distillation boundary, and isovolatility curves. The optimal triple‐column pressure‐swing distillation is generated with the minimum total annual cost (TAC) of $2.181 × 106 in sequence A. The operating conditions are well controlled approaching their desired specifications in an acceptable time when disturbances occur
Chaperone Spy Protects Outer Membrane Proteins from Folding Stress via Dynamic Complex Formation
Gram-negative bacteria have a multicomponent and constitutively active periplasmic chaperone system to ensure the quality control of their outer membrane proteins (OMPs). Recently, OMPs have been identified as a new class of vulnerable targets for antibiotic development, and therefore a comprehensive understanding of OMP quality control network components will be critical for discovering antimicrobials. Here, we demonstrate that the periplasmic chaperone Spy protects certain OMPs against protein-unfolding stress and can functionally compensate for other periplasmic chaperones, namely Skp and FkpA, in the Escherichia coli K-12 MG1655 strain. After extensive; in vivo; genetic experiments for functional characterization of Spy, we use nuclear magnetic resonance and circular dichroism spectroscopy to elucidate the mechanism by which Spy binds and folds two different OMPs. Along with holding OMP substrates in a dynamic conformational ensemble, Spy binding enables OmpX to form a partially folded β-strand secondary structure. The bound OMP experiences temperature-dependent conformational exchange within the chaperone, pointing to a multitude of local dynamics. Our findings thus deepen the understanding of functional compensation among periplasmic chaperones during OMP biogenesis and will promote the development of innovative antimicrobials against pathogenic Gram-negative bacteria.; IMPORTANCE; Outer membrane proteins (OMPs) play critical roles in bacterial pathogenicity and provide a new niche for antibiotic development. A comprehensive understanding of the OMP quality control network will strongly impact antimicrobial discovery. Here, we systematically demonstrate that the periplasmic chaperone Spy has a role in maintaining the homeostasis of certain OMPs. Remarkably, Spy utilizes a unique chaperone mechanism to bind OmpX and allows it to form a partially folded β-strand secondary structure in a dynamic exchange of conformations. This mechanism differs from that of other E. coli periplasmic chaperones such as Skp and SurA, both of which maintain OMPs in disordered conformations. Our study thus deepens the understanding of the complex OMP quality control system and highlights the differences in the mechanisms of ATP-independent chaperones
2-Aminopurine Inhibits Lipid Accumulation Induced by Apolipoprotein E-Deficient Lipoprotein in Macrophages: Potential Role of Eukaryotic Initiation Factor-2␣ Phosphorylation in Foam Cell Formation
ABSTRACT We previously reported that apolipoprotein (Apo) E-deficient, ApoB48-containing (E Ϫ /B48) lipoproteins inhibited expression of lysosomal hydrolase and transformed mouse peritoneal macrophages (MPMs) into foam cells. The present study examined the effect of 2-aminopurine (2-AP), an inhibitor of eukaryotic initiation factor (eIF)-2␣ phosphorylation, on E Ϫ /B48 lipoprotein-induced changes in gene expression and foam cell formation. Our data demonstrated that E Ϫ /B48 lipoproteins enhanced phosphorylation of eIF-2␣ in macrophages. Incubation of MPMs with E Ϫ /B48 lipoproteins inhibited the translation efficiency of mRNAs encoding lysosomal acid lipase, cathepsin B, and cation-dependent mannose 6 phosphate receptor, with a parallel reduction in the level of these proteins. Addition of 2-AP to the culture media alleviated the suppressive effect of E Ϫ /B48 lipoproteins on lysosomal hydrolase mRNA translation, increased macrophage degradation of E Ϫ /B48 lipoproteins, and inhibited foam cell formation. Transfection of MPMs with a nonphosphorylatable eIF-2␣ mutant also attenuated the suppressive effect of E Ϫ /B48 lipoproteins on expression of lysosomal acid lipase, associated with a reduced accumulation of cellular cholesterol esters. This is the first demonstration that ApoE-deficient lipoproteins inhibit lysosomal hydrolase synthesis and transform macrophages into foam cells through induction of eIF-2␣ phosphorylation
Genome-wide identification and characterization of LcCCR13 reveals its potential role in lignin biosynthesis in Liriodendron chinense
IntroductionWood formation is closely related to lignin biosynthesis. Cinnamoyl-CoA reductase (CCR) catalyzes the conversion of cinnamoyl-CoA to cinnamaldehydes, which is the initiation of the lignin biosynthesis pathway and a crucial point in the manipulation of associated traits. Liriodendron chinense is an economically significant timber tree. Nevertheless, the underlying mechanism of wood formation in it remains unknown; even the number of LcCCR family members in this species is unclear.Materials and ResultsThis study aimed to perform a genome-wide identification of genes(s) involved in lignin biosynthesis in L. chinense via RT-qPCR assays and functional verification. Altogether, 13 LcCCR genes were identified that were divided into four major groups based on structural and phylogenetic features. The gene structures and motif compositions were strongly conserved between members of the same groups. Subsequently, the expression patterns analysis based on RNA-seq data indicated that LcCCR5/7/10/12/13 had high expression in the developing xylem at the stem (DXS). Furthermore, the RT-qPCR assays showed that LcCCR13 had the highest expression in the stem as compared to other tissues. Moreover, the overexpression of the LcCCR13 in transgenic tobacco plants caused an improvement in the CCR activity and lignin content, indicating that it plays a key role in lignin biosynthesis in the stems.DiscussionOur research lays a foundation for deeper investigation of the lignin synthesis and uncovers the genetic basis of wood formation in L. chinense
Recommended from our members
CO2 emissions from karst cascade hydropower reservoirs: mechanisms and reservoir effect
Carbon dioxide (CO2) emissions from aquatic surface to the atmosphere has been recognized as a significant factor contributing to the global carbon budget and environmental change. The influence of river damming on the CO2 emissions from reservoirs remains poorly constrained. This is hypothetically due to the change of hydraulic retention time (HRT) and thermal stratification intensity of reservoirs (related to the normal water level, NWL). To test this hypothesis, we quantified CO2 fluxes and related parameters in eight karst reservoirs on the Wujiang River, Southwest China. Our results showed that there was a significant difference in the values of pCO2 (mean = 3205.7 μatm, SD = 2183.4 μatm) and δ13CCO2 (mean = −18.9‰, SD = 1.6‰) in the cascade reservoirs, suggesting that multiple processes regulate CO2 production. Moreover, the calculated CO2 fluxes showed obvious spatiotemporal variations, ranging from −9.0 to 2269.3 mmol m−2 d−1, with an average of 260.1 mmol m−2 d−1. Interestingly, the CO2 flux and δ13CCO2 from reservoirs of this study and other reservoirs around the world had an exponential function with the reservoir effect index (Ri, HRT/NWL), suggesting the viability of our hypothesis on reservoir CO2 emission. This empirical function will help to estimate CO2 emissions from global reservoirs and provide theoretical support for reservoir regulation to mitigate carbon emission
- …