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1.
Front Robot AI ; 8: 724138, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34765648

RESUMO

Dynamic quadrupedal locomotion over rough terrains reveals remarkable progress over the last few decades. Small-scale quadruped robots are adequately flexible and adaptable to traverse uneven terrains along the sagittal direction, such as slopes and stairs. To accomplish autonomous locomotion navigation in complex environments, spinning is a fundamental yet indispensable functionality for legged robots. However, spinning behaviors of quadruped robots on uneven terrain often exhibit position drifts. Motivated by this problem, this study presents an algorithmic method to enable accurate spinning motions over uneven terrain and constrain the spinning radius of the center of mass (CoM) to be bounded within a small range to minimize the drift risks. A modified spherical foot kinematics representation is proposed to improve the foot kinematic model and rolling dynamics of the quadruped during locomotion. A CoM planner is proposed to generate a stable spinning motion based on projected stability margins. Accurate motion tracking is accomplished with linear quadratic regulator (LQR) to bind the position drift during the spinning movement. Experiments are conducted on a small-scale quadruped robot and the effectiveness of the proposed method is verified on versatile terrains including flat ground, stairs, and slopes.

2.
Opt Lett ; 46(22): 5699-5702, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34780440

RESUMO

In this Letter, a two-dimensional (2D) beam steering on silicon nitride (SiNx) nanophotonic phased arrays from visible to near-infrared wavelengths is reported for the first time, to the best of our knowledge. In order to implement beam steering along the transverse direction for one-dimensional waveguide surface grating arrays, wavelengths from 650 to 980 nm provided by the supercontinuum laser are used to excite the phased array. Then the beams are parallel radiated with steering angles in a sequence of 26.84° to -16.54∘ along the transverse direction, and a continuous line in the far field consisting of parallel emitted spots is produced with a total view angle of 43.38°. Moreover, this continuous far-field line is steered along the longitudinal direction with massive wavelengths simultaneously tuned by phase shifts from -π/2 to over +π/2. This method with massive parallel wavelengths emitted paves a new way for 2D steering on SiNx nanophotonic phased arrays.

3.
Opt Lett ; 46(19): 4948-4951, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34598240

RESUMO

We report a simple concept to implement a single-wavelength beam steering based on a liquid-cladded one-dimensional (1D) optical phased array (OPA). The beam steering was realized by modifying the waveguide mode effective index through replacing the liquid upper claddings. A prototype of a 32-channel liquid-cladded OPA was fabricated and characterized. Owing to the high refractive index range of liquids (>0.625), a maximum steering angle of >10∘ was achieved with the liquid range from 1.0 to 1.63 at a wavelength of 940 nm. Moreover, the liquid-cladded OPA reveals a quasi-continuous beam steering range of >29∘ by combining the liquid cladding tuning and discrete wavelength tuning of λ=785nm, 852 nm, and 940 nm. Further integration with optofluidic systems offers the OPA potential for low power consumption and all-fluidic beam steering operating at a single wavelength.

4.
Bioinformatics ; 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34554186

RESUMO

MOTIVATION: Biomedical language models produce meaningful concept representations that are useful for a variety of biomedical natural language processing (bioNLP) applications such as named entity recognition, relationship extraction, and question answering. Recent research trends have shown that the contextualized language models (e.g., BioBERT, BioELMo) possess tremendous representational power and are able to achieve impressive accuracy gains. However, these models are still unable to learn high-quality representations for concepts with low context information (i.e., rare words). Infusing the complementary information from knowledge-bases (KBs) is likely to be helpful when the corpus-specific information is insufficient to learn robust representations. Moreover, as the biomedical domain contains numerous KBs, it is imperative to develop approaches that can integrate the KBs in a continual fashion. RESULTS: We propose a new representation learning approach that progressively fuses the semantic information from multiple KBs into the pretrained biomedical language models. Since most of the KBs in the biomedical domain are expressed as parent-child hierarchies, we choose to model the hierarchical KBs and propose a new knowledge modeling strategy that encodes their topological properties at a granular level. Moreover, the proposed continual learning technique efficiently updates the concepts representations to accommodate the new knowledge whilst preserving the memory efficiency of contextualized language models. Altogether, the proposed approach generates knowledge-powered embeddings with high fidelity and learning efficiency. Extensive experiments conducted on bioNLP tasks validate the efficacy of the proposed approach and demonstrates its capability in generating robust concept representations. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

5.
Sci Rep ; 11(1): 16081, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34373468

RESUMO

Fresh-cut processing promotes enzymatic browning of fresh fruits and vegetables, which negatively affects the product appearance and impacts their nutrition. We used RNA-sequencing to analyze the transcriptomic changes occurring during the browning of fresh-cut eggplant fruit samples from both browning-sensitive and browning-resistant cultivars to investigate the molecular mechanisms involved in browning. A total of 8347 differentially expressed genes were identified, of which 62 genes were from six gene families (i.e., PPO, PAL, POD, CAT, APX, and GST) potentially associated with enzymatic browning. Furthermore, using qRT-PCR, we verified 231 differentially regulated transcription factors in fresh-cut eggplant fruits. The enzyme activities of PPO, POD, PAL, and CAT in '36' were significantly higher than those of 'F' fresh-cut for 15 min. Both PPO and POD play a major role in the browning of eggplant pulp and might therefore act synergistically in the browning process. Meanwhile, qPCR results of 18 browning related genes randomly screened in 15 eggplant materials with different browning tolerance showed variant-specific expression of genes. Lastly, gene regulatory networks were constructed to identify the browning-related genes. This work provides a basis for future molecular studies of eggplants, and lays a theoretical foundation for the development of browning-resistant fresh-cut fruits and vegetables.


Assuntos
Frutas/genética , Solanum melongena/genética , Transcriptoma/genética , Perfilação da Expressão Gênica/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Verduras/genética
6.
Front Neurosci ; 15: 713760, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34456678

RESUMO

Purpose: This study aimed to determine if people living with HIV (PLWH) in preclinical human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND), with no clinical symptoms and without decreased daily functioning, suffer from brain volumetric alterations and its patterns. Method: Fifty-nine male PLWH at the HAND preclinical stage were evaluated, including 19 subjects with asymptomatic neurocognitive impairment (ANI), 17 subjects with cognitive abnormality that does not reach ANI (Not reach ANI), and 23 subjects with cognitive integrity. Moreover, 23 healthy volunteers were set as the seronegative normal controls (NCs). These individuals underwent sagittal three-dimensional T1-weighted imaging (3D T1WI). Quantified data and volumetric measures of brain structures were automatically segmented and extracted using AccuBrain®. In addition, the multiple linear regression analysis was performed to analyze the relationship of volumes of brain structures and clinical variables in preclinical HAND, and the correlations of the brain volume parameters with different cognitive function states were assessed by Pearson's correlation analysis. Results: The significant difference was shown in the relative volumes of the ventricular system, bilateral lateral ventricle, thalamus, caudate, and left parietal lobe gray matter between the preclinical HAND and NCs. Furthermore, the relative volumes of the bilateral thalamus in preclinical HAND were negatively correlated with attention/working memory (left: r = -0.271, p = 0.042; right: r = -0.273, p = 0.040). Higher age was associated with increased relative volumes of the bilateral lateral ventricle and ventricular system and reduced relative volumes of the left thalamus and parietal lobe gray matter. The lower CD4+/CD8+ ratio was associated with increased relative volumes of the left lateral ventricle and ventricular system. Longer disease course was associated with increased relative volumes of the bilateral thalamus. No significant difference was found among preclinical HAND subgroups in all indices, and the difference between the individual groups (Not reach ANI and Cognitive integrity groups) and NCs was also insignificant. However, there was a significant difference between ANI and NCs in the relative volumes of the bilateral caudate and lateral ventricle. Conclusion: Male PLWH at the HAND preclinical stage suffer from brain volumetric alterations. AccuBrain® provides potential value in evaluating HIV-related neurocognitive dysfunction.

7.
Opt Express ; 29(13): 19340-19351, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34266044

RESUMO

In this paper, an effective method of underwater coherent optical wireless communication (UCOWC) with a simplified detection scheme is proposed. The proof-of-concept experiments with M-ary PSK have been conducted with a common laser used for the signal source and local oscillator (LO). The BER performance has been evaluated at different underwater channel attenuations and the maximum achievable attenuation length (AL) with a BER below the forward error correction (FEC) limit of 3.8×10-3 is investigated. The tested system offers data rates of 500 Mbps, 1 Gbps, and 1.5 Gbps with the BPSK, QPSK and 8PSK modulated signals, respectively. The corresponding maximum achievable attenuation lengths are measured as 13.4 AL 12.5 AL, and 10.7 AL. In addition, the performance degradation of the practical system with separate free running lasers for the signal and LO is also estimated. To the best of our knowledge, the UCOWC system is proposed and experimentally studied for the first time. This work provides a simple and effective approach to take advantages of coherent detection in underwater wireless optical communication, opening a promising path toward the development of practical UCOWC with next-generation underwater data transmission requirements on the capacity and transmission distance.

8.
Bioinformatics ; 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34156475

RESUMO

MOTIVATION: Genomic region sets summarize functional genomics data and define locations of interest in the genome such as regulatory regions or transcription factor binding sites. The number of publicly available region sets has increased dramatically, leading to challenges in data analysis. RESULTS: We propose a new method to represent genomic region sets as vectors, or embeddings, using an adapted word2vec approach. We compared our approach to two simpler methods based on interval unions or term frequency-inverse document frequency and evaluated the methods in three ways: First, by classifying the cell line, antibody, or tissue type of the region set; second, by assessing whether similarity among embeddings can reflect simulated random perturbations of genomic regions; and third, by testing robustness of the proposed representations to different signal thresholds for calling peaks. Our word2vec-based region set embeddings reduce dimensionality from more than a hundred thousand to 100 without significant loss in classification performance. The vector representation could identify cell line, antibody, and tissue type with over 90% accuracy. We also found that the vectors could quantitatively summarize simulated random perturbations to region sets and are more robust to subsampling the data derived from different peak calling thresholds. Our evaluations demonstrate that the vectors retain useful biological information in relatively lower-dimensional spaces. We propose that vector representation of region sets is a promising approach for efficient analysis of genomic region data. AVAILABILITY: https://github.com/databio/regionset-embedding.

9.
Artigo em Inglês | MEDLINE | ID: mdl-33886478

RESUMO

Inferring brain-effective connectivity networks from neuroimaging data has become a very hot topic in neuroinformatics and bioinformatics. In recent years, the search methods based on Bayesian network score have been greatly developed and become an emerging method for inferring effective connectivity. However, the previous score functions ignore the temporal information from functional magnetic resonance imaging (fMRI) series data and may not be able to determine all orientations in some cases. In this article, we propose a novel score function for inferring effective connectivity from fMRI data based on the conditional entropy and transfer entropy (TE) between brain regions. The new score employs the TE to capture the temporal information and can effectively infer connection directions between brain regions. Experimental results on both simulated and real-world data demonstrate the efficacy of our proposed score function.

10.
IEEE Trans Neural Netw Learn Syst ; 32(12): 5565-5574, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33657000

RESUMO

This article proposes a virtual leader-based coordinated controller for the nonlinear multiple autonomous underwater vehicles (multi-AUVs) with the system uncertainties. To achieve the coordinated formation, a virtual AUV is set as the leader, while the desired command is designed using the relative position between each AUV and the virtual leader. The controller is designed based on the back-stepping scheme, and the online data-based learning scheme is used for uncertainty approximation. The highlight is that compared with previous learning methods which mostly focus on stability, the learning performance index is constructed using the collected online data in this article. The index is further used in the composite update law of the neural weights. The closed-loop system stability is analyzed via the Lyapunov approach. The simulation test on the five AUVs under fixed formation shows that the proposed method can achieve higher tracking performance with improved approximation accuracy.

11.
Sci Rep ; 11(1): 6937, 2021 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-33767263

RESUMO

Enzymatic browning is one of the crucial problems compromising the flavor and texture of fresh-cut fruit and vegetables. In this study, an untargeted metabolomics approach based on liquid chromatography-mass spectrometry (LC-MS) was used to explore the browning mechanism in fresh-cut eggplant. Metabolomics studies showed that with the increase of fresh-cut time, the contents of 946 metabolites changed dynamically. The metabolites having the same trend share common metabolic pathways. As an important browning substrate, the content of chlorogenic acid increased significantly, suggesting that may be more important to fresh-cut eggplant browning; all 119 common differential metabolites in 5 min/CK and 3 min/CK contrastive groups were mapped onto 31 KEGG pathways including phenylpropanol metabolism, glutathione metabolism pathway, et al. In physiological experiments, results showed that the Phenylpropanoid-Metabolism-Related enzymes (PAL, C4H, 4CL) were changed after fresh-cut treatment, the activities of three enzymes increased first and then decreased, and reached the maximum value at 5 min, indicating the accumulation of phenolic substances. At the same time, ROS were accumulated when plant tissue damaged by cutting, the activities of related antioxidant enzymes (SOD, APX and CAT) changed dynamically after oxidative damage. SOD and APX content increased significantly and reached the maximum value at 10 min after cutting, and then showed a downward trend. However, CAT activity increased sharply and reached the maximum value within 3 min after cutting, then maintained the same activity, and showed a downward trend after 30 min. These data fully demonstrated that the activities of browning related enzymes and gene expression increased with the prolonging of fresh cutting time. We explained the browning mechanism of fresh-cut eggplant by combining metabolomics and physiology, which may lay the foundation for better understanding the mechanism of browning during the fruits and vegetables during processing.


Assuntos
Frutas/enzimologia , Reação de Maillard , Solanum melongena/enzimologia , Expressão Gênica , Metabolômica
12.
Bioinformatics ; 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33532833

RESUMO

MOTIVATION: Many real-world biomedical interactions such as 'gene-disease', 'disease-symptom', and 'drug-target' are modeled as a bipartite network structure. Learning meaningful representations for such networks is a fundamental problem in the research area of Network Representation Learning (NRL). NRL approaches aim to translate the network structure into low-dimensional vector representations that are useful to a variety of biomedical applications. Despite significant advances, the existing approaches still have certain limitations. First, a majority of these approaches do not model the unique topological properties of bipartite networks. Consequently, their straightforward application to the bipartite graphs yields unsatisfactory results. Second, the existing approaches typically learn representations from static networks. This is limiting for the biomedical bipartite networks that evolve at a rapid pace, and thus necessitate the development of approaches that can update the representations in an online fashion. RESULTS: In this research, we propose a novel representation learning approach that accurately preserves the intricate bipartite structure, and efficiently updates the node representations. Specifically, we design a customized autoencoder that captures the proximity relationship between nodes participating in the bipartite bicliques (2 × 2 sub-graph), while preserving both the global and local structures. Moreover, the proposed structure-preserving technique is carefully interleaved with the central tenets of continual machine learning to design an incremental learning strategy that updates the node representations in an online manner. Taken together, the proposed approach produces meaningful representations with high fidelity and computational efficiency. Extensive experiments conducted on several biomedical bipartite networks validate the effectiveness and rationality of the proposed approach. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

13.
Opt Lett ; 46(2): 286-289, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33449009

RESUMO

In this Letter, the broadband operation in wavelengths from 520 nm to 980 nm is demonstrated on silicon nitride nanophotonic phased arrays. The widest beam steering angle of 65° on a silicon nitride phased array is achieved. The optical radiation efficiency of the main grating lobe in a broad wavelength range is measured and analyzed theoretically. The optical spots radiated from the phased array chip are studied at different wavelengths of lasers. The nanophotonic phased array is excited by a supercontinuum laser source for a wide range of beam steering for the first time to the best of our knowledge. It paves the way to tune the wavelength from visible to near infrared range for silicon nitride nanophotonic phased arrays.

14.
Opt Express ; 28(17): 24968-24980, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32907028

RESUMO

Underwater wireless optical communication (UWOC) will play an important role in the underwater environment exploration and marine resource development due to its advantages of high data rate and good mobility. However, the significant signal power attenuation in the underwater channel limits the transmission distance of UWOC. Attenuation length (AL) is widely used as an indicator for evaluating the UWOC system's long-distance transmission capability. At present, Gbps UWOC is limited within 7AL. Using a SiPM based receiver can dramatically increase the AL that UWOC can support. In this paper, a novel UWOC receiver built from an off-the-shelf SiPM has been demonstrated. The finite pulse width and limited bandwidth of SiPM limit the SiPM based UWOC system's data rate. To boost the system's data rate, an optimum method to process the SiPM's signal has therefore been investigated. Based on these methods, the communication capabilities of the SiPM based UWOC have been investigated experimentally. Results show that the SiPM based receiver can support 11.6AL without turbulence and 9.28AL within weak turbulence (scintillation index = 0.0447) at 1 Gbps.

15.
PLoS One ; 15(8): e0236980, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32780737

RESUMO

Global warming induces heat stress in eggplant, seriously affecting its quality and yield. The response to heat stress is a complex regulatory process; however, the exact mechanism in eggplant is unknown. We analyzed the transcriptome of eggplant under different high-temperature treatments using RNA-Seq technology. Three libraries treated at high temperatures were generated and sequenced. There were 40,733,667, 40,833,852, and 40,301,285 clean reads with 83.98%, 79.69%, and 84.42% of sequences mapped to the eggplant reference genome in groups exposed to 28°C (CK), 38°C (T38), and 43°C (T43), respectively. There were 3,067 and 1,456 DEGs in T38 vs CK and T43 vs CK groups, respectively. In these two DEG groups, 315 and 342 genes were up- and down-regulated, respectively, in common. Differential expression patterns of DEGs in antioxidant enzyme systems, detoxication, phytohormones, and transcription factors under heat stress were investigated. We screened heat stress-related genes for further validation by qRT-PCR. Regulation mechanisms may differ under different temperature treatments, in which heat shock proteins and heat stress transcription factors play vital roles. These results provide insight into the molecular mechanisms of the heat stress response in eggplant and may be useful in crop breeding.


Assuntos
Regulação da Expressão Gênica de Plantas , Solanum melongena/genética , Antioxidantes/metabolismo , Perfilação da Expressão Gênica , Genes de Plantas , Proteínas de Choque Térmico/genética , Resposta ao Choque Térmico/genética , Reguladores de Crescimento de Plantas/genética , Proteínas de Plantas/genética , RNA de Plantas/genética , RNA-Seq , Solanum melongena/fisiologia , Fatores de Transcrição/genética
16.
Leg Med (Tokyo) ; 47: 101748, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32682296

RESUMO

The identification of muscle hemorrhage in a cadaver that is in an advanced stage of decomposition is an important but challenging task. Our study investigated whether Fourier transform infrared (FT-IR) microspectroscopy in conjunction with chemometrics could identify muscle hemorrhage using rat cadavers with advanced decomposition. In this study, an intramuscular blood injection method, instead of a mechanical injury method, was used to construct a muscle hemorrhage model, and the modeling idea of muscle hemorrhage identification was to discriminate and classify hemoglobin-leaking myofibrils from negative myofibrils. First, the optical images of hematoxylin/eosin (H&E) stained hemorrhagic muscle at different postmortem intervals (PMIs) were observed and showed that the morphological features of whole erythrocytes disappeared since the PMI of 4 d. Subsequently, principle component analysis (PCA) was performed and indicated that the biochemical differences in protein structures between fresh erythrocytes and myofibrils can be detected by the IR spectroscopic method. Ultimately, several classification models based on the partial least square discriminant analysis (PLS-DA) algorithm were successfully constructed for different PMIs and PMI ranges and achieved great prediction performances in external validations. This preliminary study demonstrates the feasibility of using FT-IR microspectroscopy combined with chemometrics as a potential approach for identifying muscle hemorrhage in cadavers with advanced decomposition for offering vital evidences in judicial process.


Assuntos
Autopsia/métodos , Patologia Legal/métodos , Hemorragia/patologia , Músculos/patologia , Doenças Musculares/patologia , Mudanças Depois da Morte , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Animais , Modelos Animais de Doenças , Eritrócitos/patologia , Masculino , Miofibrilas/patologia , Análise de Componente Principal , Ratos Sprague-Dawley
17.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 42(3): 289-296, 2020 Jun 30.
Artigo em Chinês | MEDLINE | ID: mdl-32616122

RESUMO

Objective To analyze the expression of splicing factors in gastric cancer using bioinformatics methods and investigate the effect of aberrantly expressed serine/arginine-rich splicing factor(SRSF10)on the phenotype of gastric cancer cells. Methods The RNA-seq data of gastric cancer and paracancerous tissues were downloaded from The Cancer Genome Atlas(TCGA)cancer database,and bioinformatics analysis was performed to obtain the splicing factors differentially expressed in gastric cancer.The splicing factor SRSF10 was selected to investigate its effect on the development of gastric cancer.RNA interference technology was used to construct SRSF10 knockdown gastric cancer cells.MTS,Transwell,and cell scratches were used to study the effect of SRSF10 knockdown on gastric cancer cell phenotype. Results A total of 48 splicing factors were identified in gastric cancer by a series of bioinformatics techniques,of which 35 were up-regulated and 13 were down-regulated.The splicing factor SRSF10,which was up-regulated,was selected for further study.It was found that the gastric cancer cells after SRSF10 knockdown proliferated more slowly and had lower migration ability than normal gastric cancer cells. Conclusions Multiple splicing factors are found in gastric cancer and may play an important role in the development of gastric cancer.The splicing factor SRSF10 may contribute to the pathogenesis of gastric cancer.


Assuntos
Biologia Computacional , Neoplasias Gástricas , Processamento Alternativo , Proteínas de Ciclo Celular , Regulação Neoplásica da Expressão Gênica , Humanos , Fatores de Processamento de RNA , Proteínas Repressoras , Fatores de Processamento de Serina-Arginina
18.
J Clin Invest ; 130(7): 3901-3918, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32538894

RESUMO

Chronic infections can lead to carcinogenesis through inflammation-related mechanisms. Chronic infection of the human gastric mucosa with Helicobacter pylori is a well-known risk factor for gastric cancer. However, the mechanisms underlying H. pylori-induced gastric carcinogenesis are incompletely defined. We aimed to screen and clarify the functions of long noncoding RNAs (lncRNAs) that are differentially expressed in H. pylori-related gastric cancer. We found that lncRNA SNHG17 was upregulated by H. pylori infection and markedly increased the levels of double-strand breaks (DSBs). SNHG17 overexpression correlated with poor overall survival in patients with gastric cancer. The recruitment of NONO by overabundant nuclear SNHG17, along with the role of cytoplasmic SNHG17 as a decoy for miR-3909, which regulates Rad51 expression, shifted the DSB repair balance from homologous recombination toward nonhomologous end joining. Notably, during chronic H. pylori infection, SNHG17 knockdown inhibited chromosomal aberrations. Our findings suggest that spatially independent deregulation of the SNHG17/NONO and SNHG17/miR-3909/RING1/Rad51 pathways upon H. pylori infection promotes tumorigenesis in gastric cancer by altering the DNA repair system, which is critical for the maintenance of genomic stability. Upregulation of SNHG17 by H. pylori infection might be an undefined link between cancer and inflammation.


Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA , Infecções por Helicobacter/metabolismo , Helicobacter pylori/metabolismo , RNA Longo não Codificante/biossíntese , RNA Neoplásico/biossíntese , Neoplasias Gástricas/metabolismo , Animais , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Infecções por Helicobacter/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/biossíntese , Proteínas de Neoplasias/metabolismo , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologia , Regulação para Cima
19.
PLoS One ; 15(4): e0226537, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32302307

RESUMO

Enzymes of the chalcone synthase (CHS) family participate in the synthesis of multiple secondary metabolites in plants, fungi and bacteria. CHS showed a significant correlation with the accumulation patterns of anthocyanin. The peel color, which is primarily determined by the content of anthocyanin, is an economically important trait for eggplants that is affected by heat stress. A total of 7 CHS (SmCHS1-7) putative genes were identified in a genome-wide analysis of eggplants (S. melongena L.). The SmCHS genes were distributed on 7 scaffolds and were classified into 3 clusters. Phylogenetic relationship analysis showed that 73 CHS genes from 7 Solanaceae species were classified into 10 groups. SmCHS5, SmCHS6 and SmCHS7 were continuously down-regulated under 38°C and 45°C treatment, while SmCHS4 was up-regulated under 38°C but showed little change at 45°C in peel. Expression profiles of key anthocyanin biosynthesis gene families showed that the PAL, 4CL and AN11 genes were primarily expressed in all five tissues. The CHI, F3H, F3'5'H, DFR, 3GT and bHLH1 genes were expressed in flower and peel. Under heat stress, the expression level of 52 key genes were reduced. In contrast, the expression patterns of eight key genes similar to SmCHS4 were up-regulated at a treatment of 38°C for 3 hour. Comparative analysis of putative CHS protein evolutionary relationships, cis-regulatory elements, and regulatory networks indicated that SmCHS gene family has a conserved gene structure and functional diversification. SmCHS showed two or more expression patterns, these results of this study may facilitate further research to understand the regulatory mechanism governing peel color in eggplants.


Assuntos
Aciltransferases/genética , Flavonoides/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Solanum melongena/genética , Aciltransferases/metabolismo , Antocianinas/genética , Antocianinas/metabolismo , Vias Biossintéticas , Flavonoides/metabolismo , Resposta ao Choque Térmico , Família Multigênica , Filogenia , Proteínas de Plantas/metabolismo , Solanum melongena/fisiologia , Transcriptoma
20.
J Agric Food Chem ; 68(10): 3071-3078, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32078770

RESUMO

This work reports halogenated 5-(2-hydroxyphenyl)pyrazoles as pseudilin analogues with the potential to target the enzyme IspD in the methylerythritol phosphate (MEP) pathway. Such analogues were designed using the bioisosteric replacement of the pseudilin core structure and synthesized via an efficient three-step route. With AtIspD-based screening and pre- and post-emergence herbicidal tests, these compounds were demonstrated to have considerable activities against AtIspD, with IC50 up to 3.27 µM, and against model plants rape and barnyard grass, with moderate to excellent activities. At a rate of 150 g/ha in the greenhouse test, three compounds exhibited higher or comparable herbicidal activities than pseudilin. Molecular docking of representative compounds into the allosteric site of AtIspD revealed a binding mode similar to that of pseudilin. The established bioisosterism and synthesis method in this work may serve as an important tool for the development of new herbicides and antimicrobials targeting IspD in the MEP pathway.


Assuntos
Echinochloa/enzimologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Herbicidas/química , Herbicidas/farmacologia , Proteínas de Plantas/antagonistas & inibidores , Pirazóis/química , Pirazóis/farmacologia , Echinochloa/efeitos dos fármacos , Echinochloa/genética , Echinochloa/metabolismo , Inibidores Enzimáticos/síntese química , Eritritol/metabolismo , Halogenação , Herbicidas/síntese química , Simulação de Acoplamento Molecular , Estrutura Molecular , Fosfatos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Pirazóis/síntese química , Relação Estrutura-Atividade
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