Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
Eur J Pain ; 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38953581

RESUMEN

BACKGROUND: Visceral hypersensitivity is considered the core pathophysiological mechanism that causes abdominal pain in patients with irritable bowel syndrome (IBS). Fungal dysbiosis has been proved to contribute to visceral hypersensitivity in IBS patients. However, the underlying mechanisms for Dectin-1, a major fungal recognition receptor, in visceral hypersensitivity are poorly understood. This study aimed to explore the role of Dectin-1 in visceral hypersensitivity and elucidate the impact of Dectin-1 activity on the function of transient receptor potential vanilloid type 1 (TRPV1). METHODS: Visceral hypersensitivity model was established by the intracolonic administration of 0.1 mL TNBS (130 µg/mL in 30% ethanol) in the male mice. Fluconazole and nystatin were used as fungicides. Laminarin, a Dectin-1 antagonist and gene knockout (Clec7a-/-) mice were used to interrupt the function of Dectin-1. Colorectal distension-electromyogram recording was performed to assess visceral sensitivity. Immunostaining experiment was performed to determine the localization of Dectin-1 in dorsal root ganglion (DRG) neurons. Calcium imaging study was performed to assay TRPV1-mediated calcium influx in acutely dissociated DRG neurons. RESULTS: Pretreatment with fungicides, administration of laminarin or genetic deletion of Clec7a alleviated TNBS-induced visceral hypersensitivity in male mice. The expression of Dectin-1 was upregulated in the DRG and colon of TNBS-treated mice. Colocalization of Dectin-1 and TRPV1 was observed in DRG neurons. Importantly, pretreatment with curdlan, a Dectin-1 agonist, increased TRPV1-mediated calcium influx. CONCLUSIONS: Dectin-1 contributes to visceral hypersensitivity in IBS or in inflammatory bowel disease in remission and activation of Dectin-1 induces TRPV1 sensitization. SIGNIFICANCE STATEMENT: This work provides direct evidence for the functional regulation of TRPV1 channel by Dectin-1 activity, proposing a new mechanism underlying TRPV1 sensitization. Control of intestinal fungi might be beneficial for the treatment of refractory abdominal pain in patients with IBS or IBD in remission.

2.
Phytother Res ; 38(7): 3782-3800, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38839050

RESUMEN

Pediatric intestinal development is immature, vulnerable to external influences and produce a variety of intestinal diseases. At present, breakthroughs have been made in the treatment of pediatric intestinal diseases, but there are still many challenges, such as toxic side effects, drug resistance, and the lack of more effective treatments and specific drugs. In recent years, dietary polyphenols derived from plants have become a research hotspot in the treatment of pediatric intestinal diseases due to their outstanding pharmacological activities such, as anti-inflammatory, antibacterial, antioxidant and regulation of intestinal flora. This article reviewed the mechanism of action and clinical evidence of dietary polyphenols in the treatment of pediatric intestinal diseases, and discussed the influence of physiological characteristics of children on the efficacy of polyphenols, and finally prospected the new dosage forms of polyphenols in pediatrics.


Asunto(s)
Enfermedades Intestinales , Polifenoles , Humanos , Polifenoles/farmacología , Niño , Enfermedades Intestinales/tratamiento farmacológico , Enfermedades Intestinales/dietoterapia , Enfermedades Intestinales/prevención & control , Antioxidantes/farmacología , Microbioma Gastrointestinal/efectos de los fármacos , Antiinflamatorios/farmacología , Dieta
3.
Opt Express ; 32(4): 5031-5042, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38439240

RESUMEN

Modern X-ray free-electron lasers (XFELs) can generate pulses with durations ranging from femtoseconds to attoseconds. The numerical evaluation of ultra-short XFEL pulses through beamline systems is a critical process of beamline system design. However, the bandwidth of such ultra-short XFEL pulses is often non-negligible, and the propagation cannot be simply approximated using the central wavelength, especially in dispersive beamline systems. We developed a numerical model which is called Fourier optics based Ultrashort x-Ray pulse propagatION tool (FURION). This model can not only be used to simulate dispersive beamline systems but also to evaluate non-dispersive beamline systems. The FURION model utilizes Fresnel integral and angular spectrum integral to perform ultra-short XFEL pulse propagation in free space. We also present the method for XFEL pulse propagation through different types of dispersive gratings, which are commonly used in soft X-ray beamline systems. By using FURION, a start-to-end simulation of the FEL-1 beamline system at Shenzhen superconducting soft X-ray free electron laser (S3FEL) is carried out. This model can also be used to evaluate gratings-based spectrometers, beam splitters, pulse compressors, and pulse stretchers. This work provides valuable insights into the start-to-end simulation of X-ray beamline systems.

4.
J Integr Med ; 22(1): 22-31, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38199885

RESUMEN

BACKGROUND: Irritable bowel syndrome (IBS) is a functional bowel disease characterized by abdominal pain or discomfort associated with altered bowel habits. Several clinical studies have demonstrated the effectiveness of acupuncture and moxibustion for IBS. Many systematic reviews of acupuncture and moxibustion for IBS have been published in recent years, but their results are not entirely consistent. OBJECTIVE: To evaluate the methodological, reporting, and evidence quality of systematic reviews of acupuncture and moxibustion for IBS. SEARCH STRATEGY: Systematic reviews of acupuncture and moxibustion for IBS published before February 20, 2023 were searched in eight databases: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang Data, VIP Database for Chinese Technical Periodicals, and China Biology Medicine. The keywords used for literature search were acupuncture, moxibustion, systematic review, meta-analysis, and irritable bowel syndrome. INCLUSION CRITERIA: Systematic reviews and meta-analyses of randomized controlled trials of acupuncture and moxibustion for IBS were included. DATA EXTRACTION AND ANALYSIS: Relevant information was independently extracted by two investigators. The A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2), Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020), and Grading of Recommendations Assessment, Development and Evaluation (GRADE) were used to evaluate the methodological quality, reporting quality and evidence quality, respectively. RESULTS: A total of 342 studies were retrieved and 15 systematic reviews were included. The results of AMSTAR 2 showed low methodological quality in 2 studies and very low methodological quality in the remaining 13 studies, with main issues being failure to register a protocol, incomplete search strategy, not providing a list of excluded studies, incomplete consideration of the risk of bias in the included studies, and a failure to assess the publication bias. The results of PRISMA 2020 showed seriously deficient reporting quality of 2 studies, somewhat deficient reporting quality of 12 studies, and relatively complete reporting quality of 1 study, with the main problems being lack of a complete search strategy, non-availability of a list of excluded studies with justification for their exclusion, not conducting heterogeneity and sensitivity analyses, not evaluating the credibility of the evidence, and not registering the protocol. The results of GRADE showed that the quality of the evidence is low or very low. CONCLUSION: Most included systematic reviews interpreted findings to suggest that acupuncture and moxibustion have benefits for IBS. However, there is a need to improve the methodological, reporting and evidence quality of the systematic reviews. Larger, multicenter, rigorously designed randomized controlled trials and high-quality systematic reviews are required to obtain more robust evidence. PLEASE CITE THIS ARTICLE AS: Ma YY, Hao Z, Chen ZY, Shen YX, Liu HR, Wu HG, Bao CH. Acupuncture and moxibustion for irritable bowel syndrome: An umbrella systematic review. J Integr Med. 2024; 22(1): 22-31.


Asunto(s)
Terapia por Acupuntura , Síndrome del Colon Irritable , Moxibustión , Síndrome del Colon Irritable/terapia , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto
5.
Zhongguo Zhong Yao Za Zhi ; 47(20): 5434-5442, 2022 Oct.
Artículo en Chino | MEDLINE | ID: mdl-36471957

RESUMEN

Galli Gigerii Endothelium Corneum(GGEC) is commonly used for the clinical treatment of indigestion, vomiting, diarrhea, and infantile malnutrition with accumulation. In recent decades, omnivorous domestic chickens, the original source of GGEC, has been replaced by broilers, which may lead to significant changes in the quality of the yielding GGEC. Through subjective and objective sensory evaluation, biological evaluation, and chemical analysis, this study compared the odor and quality between GGEC derived from domestic chickens and that from broilers. The odor intensity between them was compared by odor profile analysis and it was found that the fishy odor of GGEC derived from domestic chickens was significantly weaker than that of GGEC from broilers. Headspace-solid phase microextraction-gas chromatography-triple quadrupole tandem mass spectrometry(HS-SPME/GC-QQQ-MS/MS) suggested that the overall odor-causing chemicals were consistent with the fishy odor-causing chemicals. According to the odor activity va-lue and the orthogonal partial least squares discriminant analysis(OPLS-DA) result, dimethyl trisulfide, 2-methoxy-3-isobutylpyrazine, and 2-methylisoborneol were responsible for the fishy odor(OAV≥1) and the content of fishy odor-causing chemicals in GGEC derived from broilers was 1.12-2.13 folds that in GGEC from domestic chickens. The average pepsin potency in GGEC derived from broilers was 15.679 U·mg~(-1), and the corresponding figure for the medicinal from domestic chickens was 26.529 U·mg~(-1). The results of pre-column derivatization reverse-phase high-performance liquid chromatography(RP-HPLC) assay showed that the content of total amino acids and digestion-promoting amino acids in domestic chickens-derived GGEC was 1.12 times and 1.15 times that in GGEC from broilers, and the bitter amino acid content was 1.21 times folds that of the latter. In conclusion, GGEC derived from domestic chickens had weaker fishy odor, stronger enzyme activity, higher content of digestion-promoting amino acids, and stronger bitter taste than GGEC from broilers. This study lays a scientific basis for studying the quality variation of GGEC and provides a method for identifying high-quality GGEC. Therefore, it is of great significance for the development and cultivation of GGEC as both food and medicine and breeding of corresponding varieties.


Asunto(s)
Odorantes , Compuestos Orgánicos Volátiles , Animales , Odorantes/análisis , Pollos , Cromatografía de Gases y Espectrometría de Masas/métodos , Espectrometría de Masas en Tándem , Microextracción en Fase Sólida , Aminoácidos , Endotelio/química , Compuestos Orgánicos Volátiles/análisis
6.
Zhongguo Zhong Yao Za Zhi ; 47(20): 5452-5459, 2022 Oct.
Artículo en Chino | MEDLINE | ID: mdl-36471959

RESUMEN

Despite the distinctive characteristics and remarkable efficacy, animal medicine is stenchy, which decreases the comp-liance of patients. At the moment, the research on the method for deodorizing animal medicines lags behind. To be specific, the components related to the odor and the basic properties transformation of the components are unclear and there is a lack of specific deodorizing method. This study aims to clarify the main components related to the stench of animal medicine, such as aldehydes, amines, trimethylamines and sulfur compounds, and their basic properties, and to explore their metabolism and transformation in vivo and in vitro, which is expected to serve as a reference for the research on deodorization of animal medicine and development of new techniques.


Asunto(s)
Aldehídos , Odorantes , Animales
7.
Andrology ; 10(5): 997-1007, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35466583

RESUMEN

OBJECTIVE: To investigate the effect of low androgen status on mitochondria-associated membranes (MAMs) and its relationship with erectile function. METHODS: A total of 36 eight-week-old male Sprague-Dawley rats were randomly divided into six groups: the control (sham-operated) group, the castration group, the castration + testosterone (cast + T) group, the control + siRNA group, the cast + siRNA group, and the cast + empty vector group. Testosterone propionate (3 mg/kg) was subcutaneously injected into the rats in the cast + T group every other day starting from the second day after the surgery. Four weeks later, lentiviral vectors carrying phosphofurin acidic cluster sorting protein 2 (PACS-2) gene-specific siRNA (1 × 108 TU/ml, 10 µl) were injected into the rats in the siRNA groups. At the sixth week of castration, the ratio of the maximum intracavernous pressure/the mean arterial pressure (ICPmax/MAP), the levels of nitric oxide (NO), endothelial nitric oxide synthase (eNOS), phospho-eNOS (p-eNOS), fatty acid-CoA ligase 4 (FACL-4), PACS-2, and inositol 1,4,5-trisphosphate receptor type 1 (IP3R1) in the penile corpus cavernosum were determined. RESULTS: The FACL-4, PACS-2, and IP3R1 were primarily localized in the cytoplasm of endothelial cells and part of smooth muscle cells in the corpus cavernosum. The level of NO, the ratio of ICPmax/MAP, and p-eNOS/eNOS were decreased significantly in the castration group compared with the control group (p < 0.01). The expressions of FACL-4, PACS-2, and IP3R1 were increased significantly in the castration group compared with the control group (p < 0.01). The level of NO, the ratios of ICPmax/MAP, and the ratio of p-eNOS/eNOS were increased significantly in the cast + siRNA group compared with the castration group (p < 0.01). The expressions of FACL-4 and PACS-2 were decreased significantly in the cast + siRNA group compared with the castration group (p < 0.01). CONCLUSION: Low androgen status upregulated the expressions of patients in MAMs (FACL-4, PACS-2, and IP3R1) in the corpus cavernosum and inhibited the eNOS/NO/cGMP signaling pathway, resulting in impaired erectile function in rats. Erectile function may be improved by inhibiting the high expression of PACS-2 in the corpus cavernosum under low androgen state.


Asunto(s)
Andrógenos , Disfunción Eréctil , Andrógenos/metabolismo , Animales , Células Endoteliales , Masculino , Mitocondrias/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Erección Peniana , Pene , ARN Interferente Pequeño , Ratas , Ratas Sprague-Dawley , Testosterona/farmacología
8.
Front Immunol ; 13: 844001, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35281017

RESUMEN

Mesenchymal stem cells (MSCs) were reported to have strong immunomodulatory ability, and inhibit the proliferation of T cells and their immune response through cell-to-cell interactions and the generation of cytokines. With high differentiation potential and self-renewal ability, MSCs are considered to function in alleviating inflammatory responses, promoting tissue regeneration and inhibiting tissue fibrosis formation. As the most common malignancies, gastrointestinal (GI) cancers have high incidence and mortality. The accurate diagnosis, exact prognosis and treatment of GI cancers have always been a hot topic. Therefore, the potential applications of MSCs in terms of GI cancers are receiving more and more attention. Recently, there is increasing evidence that MSCs may serve as a key point in the growth, metastasis, inhibition, treatment and prognosis of GI cancers. In this review, we summarized the roles of MSCs in GI cancers, mainly focusing on esophageal cancer (EC), gastric cancer (GC), liver cancer (LC), colorectal cancer (CRC) and pancreatic cancer. Besides, we proposed MSCs as potential targets and treatment strategies for the effective treatment of GI cancers, which may provide better guidance for the clinical treatment of GI cancers.


Asunto(s)
Neoplasias Gastrointestinales , Células Madre Mesenquimatosas , Diferenciación Celular , Citocinas , Neoplasias Gastrointestinales/terapia , Humanos , Inmunomodulación
9.
Signal Transduct Target Ther ; 7(1): 19, 2022 01 20.
Artículo en Inglés | MEDLINE | ID: mdl-35046386

RESUMEN

Interleukin-37b (hereafter called IL-37) was identified as fundamental inhibitor of natural and acquired immunity. The molecular mechanism and function of IL-37 in colorectal cancer (CRC) has been elusive. Here, we found that IL-37 transgenic (IL-37tg) mice were highly susceptible to colitis-associated colorectal cancer (CAC) and suffered from dramatically increased tumor burdens in colon. Nevertheless, IL-37 is dispensable for intestinal mutagenesis, and CRC cell proliferation, apoptosis, and migration. Notably, IL-37 dampened protective cytotoxic T cell-mediated immunity in CAC and B16-OVA models. CD8+ T cell dysfunction is defined by reduced retention and activation as well as failure to proliferate and produce cytotoxic cytokines in IL-37tg mice, enabling tumor evasion of immune surveillance. The dysfunction led by IL-37 antagonizes IL-18-induced proliferation and effector function of CD8+ T cells, which was dependent on SIGIRR (single immunoglobulin interleukin-1 receptor-related protein). Finally, we observed that IL-37 levels were significantly increased in CRC patients, and positively correlated with serum CRC biomarker CEA levels, but negatively correlated with the CD8+ T cell infiltration in CRC patients. Our findings highlight the role of IL-37 in harnessing antitumor immunity by inactivation of cytotoxic T cells and establish a new defined inhibitory factor IL-37/SIGIRR in cancer-immunity cycle as therapeutic targets in CRC.


Asunto(s)
Carcinogénesis/inmunología , Colitis/inmunología , Neoplasias Colorrectales/inmunología , Interleucina-1/inmunología , Proteínas de Neoplasias/inmunología , Receptores de Interleucina-1/inmunología , Linfocitos T Citotóxicos/inmunología , Animales , Carcinogénesis/genética , Colitis/genética , Colitis/patología , Neoplasias Colorrectales/genética , Interleucina-1/genética , Ratones , Ratones Transgénicos , Proteínas de Neoplasias/genética , Receptores de Interleucina-1/genética
10.
Front Pharmacol ; 12: 719758, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34899289

RESUMEN

The current Coronavirus disease 2019 (COVID-19) pandemic has become a global challenge, and although vaccines have been developed, it is expected that mild to moderate patients will control their symptoms, especially in developing countries. Licorice, not only a food additive, but also a common traditional Chinese herbal medicine, which has several pharmacological effects, such as anti-inflammation, detoxification, antibacterial, antitussive, and immunomodulatory effects, especially in respiratory diseases. Since the outbreak of COVID-19, glycyrrhizin, glycyrrhizin diamine and glycyrrhizin extract have been widely studied and used in COVID-19 clinical trials. Therefore, it is a very interesting topic to explore the material basis, pharmacological characteristics and molecular mechanism of licorice in adjuvant treatment of COVID-19. In this paper, the material basis of licorice for the prevention and treatment of COVID-19 is deeply analyzed, and there are significant differences among different components in different pharmacological mechanisms. Glycyrrhizin and glycyrrhetinic acid inhibit the synthesis of inflammatory factors and inflammatory mediators by blocking the binding of ACE 2 to virus spike protein, and exert antiviral and antibacterial effects. Immune cells are stimulated by multiple targets and pathways to interfere with the pathogenesis of COVID-19. Liquiritin can prevent and cure COVID-19 by simulating type I interferon. It is suggested that licorice can exert its therapeutic advantage through multi-components and multi-targets. To sum up, licorice has the potential to adjuvant prevent and treat COVID-19. It not only plays a significant role in anti-inflammation and anti-ACE-2, but also significantly improves the clinical symptoms of fever, dry cough and shortness of breath, suggesting that licorice is expected to be a candidate drug for adjuvant treatment of patients with early / mild COVID-19.

11.
Zhongguo Zhong Yao Za Zhi ; 46(21): 5533-5544, 2021 Nov.
Artículo en Chino | MEDLINE | ID: mdl-34951204

RESUMEN

Phyllanthi Fructus, a unique Chinese and Tibetan medicinal plant with both edible and medical values, has high potential of cultivation and development. The resources of Phyllanthi Fructus in China are rich, mainly distributed in Yunnan, Sichuan, Fujian, Guangdong, Guangxi, etc. Phyllanthi Fructus is widely used in the clinical practice of Chinese medicine and plays an important role in Tibetan medicine, Uyghur medicine, Yi medicine, and Mongolian medicine. Phyllanthi Fructus mainly contains phenolic acids,tannins, terpenes, sterols, fatty acids, flavonoids, amino acids and other compounds. Modern pharmacological studies show that Phyllanthi Fructus has antioxidant, anticancer, blood lipid-lowering, liver protective, antimicrobial, anti-inflammatory, and immune regulatory activities. In this paper, the research status of Phyllanthi Fructus was reviewed from the aspects of herbal textual research,chemical composition, and pharmacological action. The quality markers(Q-markers) of Phyllanthi Fructus were predicted and analyzed from the aspects of biogenic pathway, specificity and measurability of chemical components, efficacy, properties, new clinical uses, drug-food homology, and transformation of polyphenols. The results will provide a scientific basis for the quality control, quality evaluation, and standard formulation of Phyllanthi Fructus.


Asunto(s)
Medicamentos Herbarios Chinos , Frutas , China , Medicina Tradicional Tibetana , Control de Calidad
12.
Zhongguo Zhong Yao Za Zhi ; 46(13): 3188-3197, 2021 Jul.
Artículo en Chino | MEDLINE | ID: mdl-34396736

RESUMEN

Indigo Naturalis has a long history of medicinal use with particularity and complexity in its processing. Before the Ming dynasty,Indigo Naturalis was extracted from the top layer of zymotic fluid,called " purified Indigo Naturalis". In modern processing,the precipitate " crude Indigo Naturalis" is dried to produce Indigo Naturalis after impurity removal. The form of Indigo Naturalis slices has undergone significant changes in ancient and modern times. In view of this,the quality comparison between crude Indigo Naturalis and purified Indigo Naturalis was conducted in this study with modern analytical techniques. Firstly,chemical composition was analyzed with UPLC-Q-TOF-MS,and the chemical composition of scent with HS-SPME/GC-MS/MS. The content of indigo,indirubin,total ash,and water-soluble extract was determined as well as the inorganic composition in crude Indigo Naturalis and purified Indigo Naturalis. Then,their microscopic morphology was observed and the surface element composition was investigated. Finally,the antipyretic activities of crude Indigo Naturalis and purified Indigo Naturalis were compared in the fever rat model induced by lipopolysaccharide and 2,4-dinitrophenol. The results demonstrated that the purified Indigo Naturalis had a faster and more lasting antipyretic effect,while the crude Indigo Naturalis had almost no antipyretic effect. This study is of great significance to the research on processing technology of Indigo Naturalis and provides reference for the formulation of its quality standards,production specifications and calibration procedures.


Asunto(s)
Carmin de Índigo , Indigofera , Animales , Extractos Vegetales , Ratas , Espectrometría de Masas en Tándem
13.
Front Immunol ; 12: 711060, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34367173

RESUMEN

Psoriasis is an immune-mediated systemic disease with associated comorbidities, including metabolic syndrome (MetS) which contributes substantially to premature mortality in patients with psoriasis. However, the pathological mechanisms underlying this comorbidity are unclear. Studies have shown that the pathological parameters of psoriasis mediate the development of MetS. We reviewed the potential mechanisms which mediate the association between psoriasis and MetS, including endoplasmic reticulum stress, pro-inflammatory cytokine releases, excess production of reactive oxygen species, alterations in adipocytokine levels and gut microbiota dysbiosis. Here, we highlight important research questions regarding this association and offer insights into MetS research and treatment.


Asunto(s)
Síndrome Metabólico/etiología , Psoriasis/complicaciones , Adipoquinas/fisiología , Citocinas/fisiología , Estrés del Retículo Endoplásmico , Microbioma Gastrointestinal , Humanos , Síndrome Metabólico/metabolismo , Estrés Oxidativo , Psoriasis/metabolismo
14.
Front Robot AI ; 8: 652681, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34222349

RESUMEN

The increased complexity of the tasks that on-orbit robots have to undertake has led to an increased need for manipulation dexterity. Space robots can become more dexterous by adopting grasping and manipulation methodologies and algorithms from terrestrial robots. In this paper, we present a novel methodology for evaluating the stability of a robotic grasp that captures a piece of space debris, a spent rocket stage. We calculate the Intrinsic Stiffness Matrix of a 2-fingered grasp on the surface of an Apogee Kick Motor nozzle and create a stability metric that is a function of the local contact curvature, material properties, applied force, and target mass. We evaluate the efficacy of the stability metric in a simulation and two real robot experiments. The subject of all experiments is a chasing robot that needs to capture a target AKM and pull it back towards the chaser body. In the V-REP simulator, we evaluate four grasping points on three AKM models, over three pulling profiles, using three physics engines. We also use a real robotic testbed with the capability of emulating an approaching robot and a weightless AKM target to evaluate our method over 11 grasps and three pulling profiles. Finally, we perform a sensitivity analysis to demonstrate how a variation on the grasping parameters affects grasp stability. The results of all experiments suggest that the grasp can be stable under slow pulling profiles, with successful pulling for all targets. The presented work offers an alternative way of capturing orbital targets and a novel example of how terrestrial robotic grasping methodologies could be extended to orbital activities.

15.
Front Robot AI ; 8: 639327, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34141728

RESUMEN

Conventional spacecraft Guidance, Navigation, and Control (GNC) architectures have been designed to receive and execute commands from ground control with minimal automation and autonomy onboard spacecraft. In contrast, Artificial Intelligence (AI)-based systems can allow real-time decision-making by considering system information that is difficult to model and incorporate in the conventional decision-making process involving ground control or human operators. With growing interests in on-orbit services with manipulation, the conventional GNC faces numerous challenges in adapting to a wide range of possible scenarios, such as removing unknown debris, potentially addressed using emerging AI-enabled robotic technologies. However, a complete paradigm shift may need years' efforts. As an intermediate solution, we introduce a novel visual GNC system with two state-of-the-art AI modules to replace the corresponding functions in the conventional GNC system for on-orbit manipulation. The AI components are as follows: (i) A Deep Learning (DL)-based pose estimation algorithm that can estimate a target's pose from two-dimensional images using a pre-trained neural network without requiring any prior information on the dynamics or state of the target. (ii) A technique for modeling and controlling space robot manipulator trajectories using probabilistic modeling and reproduction to previously unseen situations to avoid complex trajectory optimizations on board. This also minimizes the attitude disturbances of spacecraft induced on it due to the motion of the robot arm. This architecture uses a centralized camera network as the main sensor, and the trajectory learning module of the 7 degrees of freedom robotic arm is integrated into the GNC system. The intelligent visual GNC system is demonstrated by simulation of a conceptual mission-AISAT. The mission is a micro-satellite to carry out on-orbit manipulation around a non-cooperative CubeSat. The simulation shows how the GNC system works in discrete-time simulation with the control and trajectory planning are generated in Matlab/Simulink. The physics rendering engine, Eevee, renders the whole simulation to provide a graphic realism for the DL pose estimation. In the end, the testbeds developed to evaluate and demonstrate the GNC system are also introduced. The novel intelligent GNC system can be a stepping stone toward future fully autonomous orbital robot systems.

16.
Front Robot AI ; 8: 638849, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34017860

RESUMEN

This paper adds on to the on-going efforts to provide more autonomy to space robots and introduces the concept of programming by demonstration or imitation learning for trajectory planning of manipulators on free-floating spacecraft. A redundant 7-DoF robotic arm is mounted on small spacecraft dedicated for debris removal, on-orbit servicing and assembly, autonomous and rendezvous docking. The motion of robot (or manipulator) arm induces reaction forces on the spacecraft and hence its attitude changes prompting the Attitude Determination and Control System (ADCS) to take large corrective action. The method introduced here is capable of finding the trajectory that minimizes the attitudinal changes thereby reducing the load on ADCS. One of the critical elements in spacecraft trajectory planning and control is the power consumption. The approach introduced in this work carry out trajectory learning offline by collecting data from demonstrations and encoding it as a probabilistic distribution of trajectories. The learned trajectory distribution can be used for planning in previously unseen situations by conditioning the probabilistic distribution. Hence almost no power is required for computations after deployment. Sampling from a conditioned distribution provides several possible trajectories from the same start to goal state. To determine the trajectory that minimizes attitudinal changes, a cost term is defined and the trajectory which minimizes this cost is considered the optimal one.

17.
Front Pharmacol ; 12: 583279, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33828481

RESUMEN

The coronavirus disease, 2019 (COVID-19), has spread rapidly around the world and become a major public health problem facing the world. Traditional Chinese medicine (TCM) has been fully committed to treat COVID-19 in China. It improved the clinical symptoms of patients and reduced the mortality rate. In light of the fever was identified as one of leading clinical features of COVID-19, this paper will first analyze the material basis of fever, including pyrogenic cytokines and a variety of the mediators of fever. Then the humoral and neural pathways of fever signal transmission will be described. The scattered evidences about fever recorded in recent years are connected in series. On this basis, the understanding of fever is further deepened from the aspects of pathology and physiology. Finally, combining with the chemical composition and pharmacological action of available TCM, we analyzed the mechanisms of TCMs to play the antipyretic effect through multiple ways. So as to further provide the basis for the research of antipyretic compound preparations of TCMs and explore the potential medicines for the prevention and treatment of COVID-19.

18.
Zhongguo Zhong Yao Za Zhi ; 46(5): 1034-1042, 2021 Mar.
Artículo en Chino | MEDLINE | ID: mdl-33787094

RESUMEN

Phyllanthus emblica is a kind of traditional medicine and medicinal and edible plant, with rich variety resources and high development value. It is a key poverty alleviation variety in China at present. As P. emblica processing industry is rising gradually in recent years, in order to fully develop and utilize its industrial resources, this paper systematically introduces current comprehensive development and utilization of P. emblica, discusses the problems in P. emblica processing industry, and puts forward comprehensive development and utilization strategies and industrial models in terms of cultivation, breeding, grading, quality evaluation and waste recycling, so as to provide a certain reference for promoting the high-quality development of P. emblica industry in China.


Asunto(s)
Medicina , Phyllanthus emblica , China , Medicina Tradicional , Fitomejoramiento , Extractos Vegetales
19.
J Anal Methods Chem ; 2021: 8816854, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33510929

RESUMEN

In this research, a very practical QuEChERS-GC-MS/MS analytical approach for 74 pesticide residues in herb based on retention index was established. This novel analytical approach has two important technical advantages. One advantage is to quickly screen pesticide compounds in herbs without having to use a large number of pesticide standard substances at the beginning of the experiment. The other advantage is to assist in identifying the target pesticide compound accurately. A total of 74 kinds of pesticides were quickly prescreened in all chuanxiong rhizoma samples. The results showed that three kinds of pesticides were screened out in all the samples, including chlorpyrifos, fipronil, and procymidone, and the three pesticides were qualitatively and quantitatively determined. The RSD values for interday and intraday variation were acquired to evaluate the precision of the analytical approach, and the overall interday and intraday variations are not more than 1.97% and 3.82%, respectively. The variations of concentrations of the analyzed three pesticide compounds in sample CX16 are 0.74%-4.15%, indicating that the three pesticides in the sample solutions were stable in 48 h. The spiked recoveries of the three pesticides are 95.22%, 93.03%, and 94.31%, and the RSDs are less than ± 6.0%. The methodological verification results indicated the good reliability and accuracy of the new analytical method. This research work is a new application of retention index, and it will be a valuable tool to assist quickly and accurately in the qualitative and quantitative analysis of multipesticide residues in herbs.

20.
Eur J Nutr ; 60(7): 3525-3542, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33439332

RESUMEN

Phyllanthus emblica is a fruit widely consumed in subtropical areas, which is rich in polyphenols and other nutrients. There are increasing evidences that as a daily and nutritious fruit, it may have a positive role in controlling diabetic complications. According to the new study, its mechanisms include enhancing the functioning of insulin, reducing insulin resistance, activating the insulin-signaling pathway, protecting ß-cells, scavenging free radicals, alleviating inflammatory reactions, and reducing the accumulation of advanced glycation end products. Owing to its few side effects, and low price, it should be easily accepted by patients and has potential for preventing diabetes. Taken together, Phyllanthus emblica may be an ideal fruit for controlling diabetic complications. This review highlights the latest findings of the role of Phyllanthus emblica in anti-diabetes and its complications, especially clarifies the molecular mechanism of the chemical components related to this effect, and prospects some existing problems and future research directions.


Asunto(s)
Diabetes Mellitus Tipo 2 , Phyllanthus emblica , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Frutas , Humanos , Extractos Vegetales/uso terapéutico , Polifenoles
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...