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Currently, complex scene classification strategies are limited to high-definition image scene sets, and low-quality scene sets are overlooked. Although a few studies have focused on artificially noisy images or specific image sets, none have involved actual low-resolution scene images. Therefore, designing classification models around practicality is of paramount importance. To solve the above problems, this paper proposes a two-stage classification optimization algorithm model based on MPSO, thus achieving high-precision classification of low-quality scene images. Firstly, to verify the rationality of the proposed model, three groups of internationally recognized scene datasets were used to conduct comparative experiments with the proposed model and 21 existing methods. It was found that the proposed model performs better, especially in the 15-scene dataset, with 1.54% higher accuracy than the best existing method ResNet-ELM. Secondly, to prove the necessity of the pre-reconstruction stage of the proposed model, the same classification architecture was used to conduct comparative experiments between the proposed reconstruction method and six existing preprocessing methods on the seven self-built low-quality news scene frames. The results show that the proposed model has a higher improvement rate for outdoor scenes. Finally, to test the application potential of the proposed model in outdoor environments, an adaptive test experiment was conducted on the two self-built scene sets affected by lighting and weather. The results indicate that the proposed model is suitable for weather-affected scene classification, with an average accuracy improvement of 1.42%.
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The development of gel electrophoresis-based biodetection assays for point-of-care analysis are highly demanding. In this work, we proposed a ratiometric gel electrophoresis-based biosensing platform by employing catalytic hairpin assembly (CHA) process functions as both the signal output and the signal amplification module. Two types of nucleic acids, DNA and miRNA, are chosen for demonstration. The proposed strategy indeed provides a new paradigm for the design of a portable detection platform and may hold great potential for sensitive diagnoses.
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Técnicas Biossensoriais , DNA , MicroRNAs , MicroRNAs/análise , Catálise , Eletroforese , Ácidos Nucleicos/análiseRESUMO
During asymmetric division of Drosophila larval neuroblasts, the fate determinant Prospero (Pros) and its adaptor Miranda (Mira) are segregated to the basal cortex through atypical protein kinase C (aPKC) phosphorylation of Mira and displacement from the apical cortex, but Mira localization after aPKC phosphorylation is not well understood. We identify Kin17, a DNA replication and repair protein, as a regulator of Mira localization during asymmetric cell division. Loss of Kin17 leads to aberrant localization of Mira and Pros to the centrosome, cytoplasm, and nucleus. We provide evidence to show that the mislocalization of Mira and Pros is likely due to reduced expression of Falafel (Flfl), a component of protein phosphatase 4 (PP4), and defects in dephosphorylation of serine-96 of Mira. Our work reveals that Mira is likely dephosphorylated by PP4 at the centrosome to ensure proper basal localization of Mira after aPKC phosphorylation and that Kin17 regulates PP4 activity by regulating Flfl expression.
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Proteínas de Drosophila , Células-Tronco Neurais , Animais , Divisão Celular Assimétrica , Proteínas de Ciclo Celular/metabolismo , Polaridade Celular , Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Células-Tronco Neurais/metabolismoRESUMO
Various biological agents have been developed to target tumor necrosis factor alpha (TNF-α) and its receptor TNFR1 for the rheumatoid arthritis (RA) treatment, whereas small molecules modulating such cytokine receptors are rarely reported in comparison to the biologicals. Here, by revealing the mechanism of action of vinigrol, a diterpenoid natural product, we show that inhibition of the protein disulfide isomerase (PDI, PDIA1) by small molecules activates A disintegrin and metalloprotease 17 (ADAM17) and then leads to the TNFR1 shedding on mouse and human cell membranes. This small-molecule-induced receptor shedding not only effectively blocks the inflammatory response caused by TNF-α in cells, but also reduces the arthritic score and joint damage in the collagen-induced arthritis mouse model. Our study indicates that targeting the PDI-ADAM17 signaling module to regulate the shedding of cytokine receptors by the chemical approach constitutes a promising strategy for alleviating RA.
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Artrite Reumatoide , Diterpenos , Camundongos , Humanos , Animais , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Proteômica , Artrite Reumatoide/tratamento farmacológico , Proteína ADAM17RESUMO
Objective: Necroptosis has recently been found to be associated with the pathogenesis of many autoimmune diseases, including rheumatoid arthritis (RA). This study was undertaken to explore the role of RIPK1-dependent necroptosis in the pathogenesis of RA and the potential new treatment options. Methods: The plasma levels of receptor-interacting protein kinase 1 (RIPK1) and mixed lineage kinase domain-like pseudokinase (MLKL) in 23 controls and 42 RA patients were detected by ELISA. Collagen-induced arthritis (CIA) rats were treated with KW2449 by gavage for 28 days. Arthritis index score, H&E staining, and Micro-CT analysis were used to evaluate joint inflammation. The levels of RIPK1-dependent necroptosis related proteins and inflammatory cytokines were detected by qRT-PCR, ELISA and Western blot, and the cell death morphology was detected by flow cytometry analysis and high-content imaging analysis. Results: The plasma levels of RIPK1 and MLKL in RA patients were higher than those in healthy people, and were positively correlated with the severity of RA. KW2449 could reduce joint swelling, joint bone destruction, tissue damage, and the plasma levels of inflammatory cytokines in CIA rats. Lipopolysaccharide combined with zVAD (LZ) could induce necroptosis in RAW 264.7 cells, which could be reduced by KW2449. RIPK1-dependent necroptosis related proteins and inflammatory factors increased after LZ induction and decreased after KW2449 treatment or knockdown of RIPK1. Conclusion: These findings suggest that the overexpression of RIPK1 is positively correlated with the severity of RA. KW2449, as a small molecule inhibitor targeting RIPK1, has the potential to be a therapeutic strategy for RA treatment by inhibiting RIPK1-dependent necroptosis.
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Artrite Experimental , Artrite Reumatoide , Ratos , Animais , Artrite Experimental/tratamento farmacológico , Artrite Experimental/patologia , Proteínas Quinases/metabolismo , Necroptose , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Citocinas/metabolismo , Artrite Reumatoide/tratamento farmacológicoRESUMO
BACKGROUND: Anterior branch of the obturator nerve transfer has been proven as an effective method for femoral nerve injuries, but the patient still has difficulty in rising and squatting, up and downstairs. Here, we presented a novel neurotization procedure of selectively repairing 3 motor branches of the femoral nerve by transferring motor branches of the obturator nerve in the thigh level and assessing its anatomical feasibility. METHODS: Eight adult cadavers (16 thighs) were dissected. The nerve overlap distance between the gracilis branch and the rectus femoris (RF) branch, the adductor longus (AL) branch and the vastus medialis (VM) branch, as well as the adductor magnus (AM) branch and the vastus intermedius (VI) branch were measured. Also, the axon counts of the donor and recipient nerve were evaluated by histological evaluation. RESULTS: In all specimens, nerve overlap of at least 2.1 cm was observed in all 16 dissected thighs between the donor and recipient nerve branches, and the repair appeared to be without tension. There is no significant difference in the axon counts between gracilis branch (598 ± 83) and the RF branch (709 ± 151). The axon counts of the AL branch (601 ± 93) was about half of axon counts of the VM branch (1423 ± 189), and the axon counts of AM branch (761 ± 110) was also about half of the VI branch (1649 ± 281). CONCLUSIONS: This novel technique of the combined nerve transfers below the inguinal ligament, specifically the gracilis branch to the RF branch, the AL branch to the VM branch, and the AM branch to the VI branch, is anatomically feasible. It provides a promising alternative in the repair of femoral nerve injuries and an anatomical basis for the clinical application of motor branches of the obturator nerve transfer to repair the motor portion of the injured femoral nerve.
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Nervo Femoral , Transferência de Nervo , Adulto , Humanos , Nervo Obturador/anatomia & histologia , Estudos de Viabilidade , Coxa da Perna , Músculo Esquelético/inervação , Transferência de Nervo/métodos , CadáverRESUMO
The transition efficiency of atomic Bragg diffraction as mirrors and beam splitters in Bragg atom interferometers plays an essential role in impacting the fringe contrast and measurement sensitivity. This can be attributed to the properties of atomic sources, Bragg pulse shapes, the pulse duration, and the relative position deviation of the atoms and Bragg pulses. Here, we investigate the effect of the atomic source's diffusion and velocity width on the efficiency of Bragg diffraction of the moving cold atomic cloud. The transfer efficiency of Bragg mirrors and beam splitters are numerically simulated and experimentally measured, which are well consistent in comparison. We quantify these effects of atomic diffusion and velocity width and precisely compute how Bragg pulses' efficiencies vary as functions of these parameters. Our results and methodology allow us to optimize the Bragg pulses at different atomic sources and will help in the design of large momentum transfer mirrors and beam splitters in atom interferometry experiments.
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Stimulated Raman transitions are often used in an atom interferometer (AI) for wave packet manipulation. Normally, two lasers with different frequencies contained in a Raman beam are combined first and then amplified by a single tapered amplifier (TA). This configuration can simplify the laser system of the AI, however, additional sidebands will be generated by the TA because of the nonlinear effect in the TA. In this work, the impact of additional sidebands generated with a single TA on the AI is studied. We first observe the additional sidebands in a Raman laser by a Fabry-Pérot interferometer (FPI), and the additional sidebands will be greatly suppressed by reducing the injection laser power of the TA. This is also confirmed by observing the position-dependent Raman transitions induced by additional sidebands at different injection power in an AI. However, the phase shifts induced by additional sidebands are not reduced obviously when the injection power of the TA is reduced. Therefore, it is necessary to separately amplify two lasers contained in the Raman laser by two TAs for a high precision AI. The spectroscopy of Raman laser generated by two TAs is also measured by the FPI, and the impact of additional sidebands on the AI is eliminated. This work has guiding significance for the design of the laser system in a high-precision AI.
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Location and properties of ligand binding sites provide important information to uncover protein functions and to direct structure-based drug design approaches. However, as binding site detection depends on the three-dimensional (3D) structural data of proteins, functional analysis based on protein ligand binding sites is formidable for proteins without structural information. Recent developments in protein structure prediction and the 3D structures built by AlphaFold provide an unprecedented opportunity for analyzing ligand binding sites in human proteins. Here, we constructed the CavitySpace database, the first pocket library for all the proteins in the human proteome, using a widely-applied ligand binding site detection program CAVITY. Our analysis showed that known ligand binding sites could be well recovered. We grouped the predicted binding sites according to their similarity which can be used in protein function prediction and drug repurposing studies. Novel binding sites in highly reliable predicted structure regions provide new opportunities for drug discovery. Our CavitySpace is freely available and provides a valuable tool for drug discovery and protein function studies.
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Proteoma , Sítios de Ligação , Fenômenos Biofísicos , Humanos , Ligantes , Ligação ProteicaRESUMO
Vibration correction provides a simple and flexible method of suppressing ambient vibration noise in transportable atom gravimeters. However, in the seismometers used for vibration correction, a spurious output may be induced by the magnetic field of the magnetic-optical trap, introducing errors to the gravity measurements. This paper evaluates the influence of the magnetic field on the seismometer and the corresponding errors in the gravity measurements. It is found that an error level of order 10 µGal may be present if the seismometer is not configured carefully. The dependence of the influence on the orientation of the seismometer and the lasting time of the magnetic field are investigated. The effective suppression of the influence by shielding the seismometer is also demonstrated. Our results focus attention on the possible errors related to seismometers in high-precision gravity measurements by using atom gravimeters.
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Precise information of positions and sizes of atom clouds is required for atom-interferometry-based G measurements. In this work, characterizing atom clouds using a charge-coupled device (CCD) is presented. The parameters of atom clouds are extracted from fluorescence images captured by the CCD. For characterization, in-situ calibration of the magnification of the imaging system is implemented using the free-fall distance of atom clouds as the dimension reference. Moreover, influence of the probe beam on measuring the positions of atom clouds is investigated, and a differential measurement by reversing the direction of the probe beam is proposed to suppress the influence. Finally, precision at sub-mm level for characterizing atom clouds is achieved.
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Intermediate neural progenitors (INPs) boost the number and diversity of neurons generated from neural stem cells (NSCs) by undergoing transient proliferation. In the developing Drosophila brains, INPs are generated from type II neuroblasts (NBs). In order to maintain type II NB identity and their capability to produce INPs, the proneural protein Asense (Ase) needs to be silenced by the Ets transcription factor pointed P1 (PntP1), a master regulator of type II NB development. However, the molecular mechanisms underlying the PntP1-mediated suppression of Ase is still unclear. In this study, we utilized genetic and molecular approaches to determine the transcriptional property of PntP1 and identify the direct downstream effector of PntP1 and the cis-DNA elements that mediate the suppression of ase. Our results demonstrate that PntP1 directly activates the expression of the transcriptional repressor, Tailless (Tll), by binding to seven Ets-binding sites, and Tll in turn suppresses the expression of Ase in type II NBs by binding to two hexameric core half-site motifs. We further show that Tll provides positive feedback to maintain the expression of PntP1 and the identity of type II NBs. Thus, our study identifies a novel direct target of PntP1 and reveals mechanistic details of the specification and maintenance of the type II NB identity by PntP1.
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Proteínas de Ligação a DNA/fisiologia , Proteínas de Drosophila/genética , Proteínas de Drosophila/fisiologia , Regulação da Expressão Gênica/fisiologia , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/fisiologia , Neurônios/metabolismo , Proteínas Proto-Oncogênicas/fisiologia , Proteínas Repressoras/genética , Fatores de Transcrição/fisiologia , Animais , Sítios de Ligação , Proteínas de Ligação a DNA/metabolismo , Drosophila , Proteínas de Drosophila/metabolismo , Elementos Facilitadores Genéticos , Proteínas do Tecido Nervoso/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Repressoras/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , TransgenesRESUMO
As part of a program to determine the gravitational constant G using multiple independent methods in the same laboratory, an atom gravity gradiometer is being developed. The gradiometer is designed with two magneto-optical traps to ensure both the fast simultaneous launch of two atomic clouds and an optimized configuration of source masses. Here, the design of the G measurement by atom interferometry is detailed, and the experimental setup of the atom gravity gradiometer is reported. A preliminary sensitivity of 3 × 10-9 g/Hz to differential gravity acceleration is obtained, which corresponds to 99 E/Hz (1 E = 10-9 s-2) for the gradiometer with a baseline of 0.3 m. This provides access to measuring G at the level of less than 200 parts per million in the first experimental stage.
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As the existence of the gravity gradient, the output of gravimeters is actually the gravitational acceleration at the reference instrumental height. Precise knowledge of the reference height is indispensable in the utilization of gravity measurements, especially for absolute gravimeters. Here, we present an interferometric method to measure the distance between the atomic cloud and a reflecting mirror directly, which consequently determines the reference height of our atom gravimeter. This interferometric method is based on a frequency jump of Raman lasers applied at the π pulse of the atom interferometer, which induces an additional phase shift proportional to the interested distance. An uncertainty of 2 mm is achieved here for the distance measurement, and the effect of the gravity gradient on absolute gravity measurements can thus be constrained within 1 µGal. This work provides a concrete-object-based measurement of the reference height for atom gravimeters.
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Biomolecular condensates (biocondensates) formed via liquid-liquid phase-separation of soluble proteins have been studied extensively. However, neither the phase-separation of endoplasmic reticulum (ER) transmembrane protein nor a biocondensate with organized membranous structures has been reported. Here, we have discovered a spherical ER membranous biocondensate with puzzle-like structures caused by condensation of the ER-resident stimulator of interferon genes (STING) in DNA virus-infected or 2'3'-cGAMP (cyclic GMP-AMP)-treated cells, which required STING transmembrane domains, an intrinsically disordered region (IDR) and a dimerization domain. Intracellular 2'3'-cGAMP concentrations determined STING translocation or condensation. STING biocondensates constrained STING and TBK1 (TANK binding protein 1) to prevent innate immunity from overactivation, presumably acting like a 'STING-TBK1-cGAMP sponge'. Cells expressing STING-E336G/E337G showed notably enhanced innate immune responses due to impaired STING condensation after viral infection at later stages. Microtubule inhibitors impeded the STING condensate gel-like transition and augmented type I-interferon production in DNA virus-infected cells. This membranous biocondensate was therefore named the STING phase-separator.
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Retículo Endoplasmático/genética , Imunidade Inata/genética , Extração Líquido-Líquido , Proteínas de Membrana/genética , Humanos , Nucleotídeos Cíclicos/genética , Ligação Proteica/genética , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais/genéticaRESUMO
BACKGROUND AND OBJECTIVES: Totally implantable venous access ports (TIVAPs) are essential in children who require long-term intermittent intravenous therapy. METHODS: Patients who needed to undergo TIVAP implantation were randomly assigned to the internal jugular vein group or the subclavian vein group. The medical histories, operative details and major complications from the time of port implantation to 48â¯h after port removal were collected. During the use of TIVAPs, satisfaction surveys were regularly conducted for the children and guardians and compared in the two groups. RESULTS: A total of 216 patients in the subclavian vein group and 199 patients in the internal jugular vein group were included. TIVAPs were successfully implanted in all children. The incidence of postoperative venous access occlusion in the subclavian vein group and internal jugular vein group was 1.5% and 5%, respectively, and the difference was statistically significant (Pâ¯<â¯0.05). The average satisfaction score of the children and guardians in the subclavian vein group was 9.6⯱â¯0.3, and that in the internal jugular vein group was 8.3⯱â¯0.8. There was a significant difference between the 2 groups (Pâ¯<â¯0.05). CONCLUSIONS: Subclavian vein should be the first choice for TIVAP implantation in children. THE LEVEL OF EVIDENCE RATING: Treatment study level I.
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Cateterismo Venoso Central , Veias Jugulares , Cateteres de Demora , Criança , Humanos , Estudos Prospectivos , PunçõesRESUMO
SARS-CoV-2 3C-like protease is the main protease of SARS-CoV-2 and has been considered as one of the key targets for drug discovery against COVID-19. We identified several N-substituted isatin compounds as potent SARS-CoV-2 3C-like protease inhibitors. The three most potent compounds inhibit SARS-CoV-2 3C-like protease with IC50's of 45 nM, 47 nM and 53 nM, respectively. Our study indicates that N-substituted isatin compounds have the potential to be developed as broad-spectrum anti-coronavirus drugs.
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Antivirais/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Isatina/uso terapêutico , Inibidores de Proteases/uso terapêutico , Proteínas não Estruturais Virais/antagonistas & inibidores , Antivirais/farmacologia , Proteases 3C de Coronavírus , Cisteína Endopeptidases , Humanos , Isatina/análogos & derivados , Isatina/síntese química , Modelos Moleculares , Simulação de Acoplamento Molecular , Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacologia , SARS-CoV-2 , Relação Estrutura-AtividadeRESUMO
Traumatic brain injury (TBI) is a prevalent public healthcare concern frequently instigated by mechanical shock, traffic, or violence incidents, leading to permanent nerve damage, and there is no ideal treatment for it yet. In this study, a series of Rolipram-Tranilast hybrids were designed and synthesized. The neuroprotective activities of the Rolipram-Tranilast hybrids were evaluated both in vitro and in vivo. Compound 5 has been identified as the strongest neuroprotective molecule among the series with robust anti-oxidant and anti-inflammatory potentials. Compound 5 significantly increased the heme oxygenase-1 (HO-1) levels and the phosphorylated cAMP response elements binding protein (p-CREB) while it down-regulated phosphodiesterase-4 B (PDE4B) expression in vitro. Furthermore, compound 5 remarkably attenuated TBI and had a good safety profile in mice. Taken together, our findings suggested that compound 5 could serve as a novel promising lead compound in the treatment of TBI and other central nervous system (CNS) diseases associated with PDE4B and oxidative stress.
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Lesões Encefálicas Traumáticas , Animais , Lesões Encefálicas Traumáticas/tratamento farmacológico , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4 , Camundongos , Rolipram/farmacologia , ortoaminobenzoatosRESUMO
Glutathione peroxidase 4 (GPX4) is essential for cell membrane repair, inflammation suppression, and ferroptosis inhibition. GPX4 upregulation provides unique drug discovery opportunities for inflammation and ferroptosis-related diseases. However, rational design of protein activators is challenging. Until now, no compound has been reported to activate the enzyme activity of GPX4. Here, we identified a potential allosteric site in GPX4 and successfully found eight GPX4 activators using a novel computational strategy and experimental studies. Compound 1 from the virtual screen increased GPX4 activity, suppressed ferroptosis, reduced pro-inflammatory lipid mediator production, and inhibited NF-κB pathway activation. Further chemical synthesis and structure-activity relationship studies revealed seven more activators. The strongest compound, 1d4, increased GPX4 activity to 150% at 20 µM in the cell-free assay and 61 µM in cell extracts. Therefore, we demonstrated that GPX4 can be directly activated using chemical compounds to suppress ferroptosis and inflammation. Meanwhile, the discovery of GPX4 activators verified the possibility of rational design of allosteric activators.