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Olanzapine (OLZ) is a widely prescribed antipsychotic drug with a relatively ideal effect in the treatment of schizophrenia (SCZ). However, its severe metabolic side effects often deteriorate clinical therapeutic compliance and mental rehabilitation. The peripheral mechanism of OLZ-induced metabolic disorders remains abstruse for its muti-target activities. Endoplasmic reticulum (ER) stress is implicated in cellular energy metabolism and the progression of psychiatric disorders. In this study, we investigated the role of ER stress in the development of OLZ-induced dyslipidemia. A cohort of 146 SCZ patients receiving OLZ monotherapy was recruited, and blood samples and clinical data were collected at baseline, and in the 4th week, 12th week, and 24th week of the treatment. This case-control study revealed that OLZ treatment significantly elevated serum levels of endoplasmic reticulum (ER) stress markers GRP78, ATF4, and CHOP in SCZ patients with dyslipidemia. In HepG2 cells, treatment with OLZ (25, 50 µM) dose-dependently enhanced hepatic de novo lipogenesis accompanied by SREBPs activation, and simultaneously triggered ER stress. Inhibition of ER stress by tauroursodeoxycholate (TUDCA) and 4-phenyl butyric acid (4-PBA) attenuated OLZ-induced lipid dysregulation in vitro and in vivo. Moreover, we demonstrated that activation of PERK-CHOP signaling during ER stress was a major contributor to OLZ-triggered abnormal lipid metabolism in the liver, suggesting that PERK could be a potential target for ameliorating the development of OLZ-mediated lipid dysfunction. Taken together, ER stress inhibitors could be a potentially effective intervention against OLZ-induced dyslipidemia in SCZ.
Assuntos
Dislipidemias , Transdução de Sinais , Humanos , Olanzapina/farmacologia , Estudos de Casos e Controles , Estresse do Retículo Endoplasmático , Dislipidemias/induzido quimicamente , Lipídeos , eIF-2 Quinase/metabolismo , ApoptoseRESUMO
Although previous studies on the genotypic diversity and antifungal susceptibility of the Cryptococcus neoformans species complex (CNSC) isolates from China revealed ST5 genotype isolates being dominant, the information about the CNSC isolates from Chinese HIV-infected patients is limited. In this study, 171 CNSC isolates from HIV-infected patients in the Chongqing region of Southwest China were genotyped using the International Society for Human and Animal Mycology-multilocus sequence typing consensus scheme, and their antifungal drug susceptibilities were determined following CLSI M27-A3 guidelines. Among 171 isolates, six sequence types (STs) were identified, including the dominant ST5 isolates, the newly reported ST15, and four diploid VNIII isolates (ST632/ST636). Moreover, a total of 1019 CNSC isolates with STs and HIV-status information were collected and analyzed from Mainland China in the present study. A minimum spanning analysis grouped these 1019 isolates into three main subgroups, which were dominated by the ST5 clonal complex (CC5), followed by the ST31 clonal complex (CC31) and ST93 clonal complex (CC93). The trend of resistance or decreasing susceptibility of clinical CNSC isolates to azole agents within HIV-infected patients from the Chongqing region is increasing, especially resistance to fluconazole.
In this paper, novel ST15 and four diploid VNIII isolates (ST632/ST636) were found in 171 CNSC isolates in Southwest China, including evidence for resistance to fluconazole. Moreover, we clustered the 1019 clinical CNSC isolates reported so far from Mainland China into three major subgroups.
Assuntos
Criptococose , Cryptococcus neoformans , Infecções por HIV , Humanos , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Criptococose/microbiologia , Criptococose/veterinária , Diploide , Testes de Sensibilidade Microbiana/veterinária , Genótipo , China/epidemiologia , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infecções por HIV/veterináriaRESUMO
Lipid droplets (LDs) targeting probes are important for investigating the biological functions of LDs. The interplay between LDs and some other organelles can help to further understand the biological functions of these organelles. However, it is still a challenge to design functional probes that can specifically target LDs and are responsive to some other organelles. Herein, a multifunctional aggregation-induced emission luminogen (AIEgen), namely the TPA-CN, was prepared by the simple aldimine condensation reaction for lipid droplet-specific imaging and tracing. TPA-CN can be sensitively responsive to the acid environment of lysosomes due to the pH-response detachable connector in TPA-CN. With the assistance of this characteristic, it can be concluded from the fluorescence imaging and co-localization analysis results that the internalization of TPA-CN and the targeting of LDs does not involve the lysosome and the lysosomal escape process. At last, the TPA-CN was successfully used for the high-sensitivity imaging of dynamic information of LDs.
Assuntos
Gotículas Lipídicas , Lisossomos , Imagem Óptica , Concentração de Íons de Hidrogênio , Corantes FluorescentesRESUMO
Fault diagnosis of complex equipment has become a hot field in recent years. Due to excellent uncertainty processing capability and small sample problem modeling capability, belief rule base (BRB) has been widely used in the fault diagnosis. However, previous BRB models almost did not consider the diverse distributions of observation data which may reduce diagnostic accuracy. In this paper, a new fault diagnosis model based on BRB is proposed. Considering that the previous triangular membership function cannot address the diverse distribution of observation data, a new nonlinear membership function is proposed to transform the input information. Then, since the model parameters initially determined by experts are inaccurate, a new parameter optimization model with the parameters of the nonlinear membership function is proposed and driven by the gradient descent method to prevent the expert knowledge from being destroyed. A fault diagnosis case of laser gyro is used to verify the validity of the proposed model. In the case study, the diagnosis accuracy of the new BRB-based fault diagnosis model reached 95.56%, which shows better fault diagnosis performance than other methods.
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This study aimed to investigate the chemical constituents in the water extract of the whole herb of Hedyotis scandens by silica gel, ODS, and MCI column chromatographies together with preparative high-performance liquid chromatography(HPLC). The structures of isolated constituents were identified by NMR, HR-ESI-MS, etc. Thirteen compounds were isolated and identified as methyl 4-benzoyloxy-3-methoxybenzeneacetate(1), 4-benzoyloxy-3-methoxybenzeneacetic acid(2), 3-(4-hydroxy-3-methoxyphenyl)-propanoic acid(3), salicylic acid(4), 3-hydroxy-4-methoxypyridine(5), syringic acid(6), hydroxycinnamic acid(7),(R)-6-methyl-4,6-bis(4-methylpent-3-enyl)cyclohexa-1,3-dienecarbaldehyde(8), 1,2-bis(4-hydroxy-3-methoxyphenyl)-1,3-propanediol(9), 1H-indole-3-carboxaldehyde(10), isoscopoletin(11), syringaresinol(12), and pinoresinol(13). Among them, compounds 1 and 2 were new phenolic acid compounds, compounds 3-5, 8-11, and 13 were isolated from this genus for the first time, and compounds 6, 7, and 12 were obtained from H. scandens for the first time. The activity test showed that compounds 1 and 10 had a certain inhibitory effect on Mycobacterium smegmatis, with MIC_(50) values of 58.5 and 33.3 µg·mL~(-1), respectively.
Assuntos
Medicamentos de Ervas Chinesas , Hedyotis , Hedyotis/química , Medicamentos de Ervas Chinesas/química , Espectroscopia de Ressonância Magnética , Ácido SalicílicoRESUMO
Fungal hybrid terpenoid saccharides constitute a new and growing family of natural products with significant biomedical and agricultural activities. One representative family is the cosmosporasides, which feature oxidized terpenoid units and saccharide moieties; however, the assembly line of these building blocks has been elusive. Herein, a cos cluster from Fusarium orthoceras was discovered for the synthesis of cosmosporaside C (1) by genome mining. A UbiA family intramembrane prenyltransferase (UbiA-type PT), a multifunctional cytochrome P450, an α,ß-hydrolase, an acetyltransferase, a dimethylallyl transferase (DMAT-type PT) and a glycosyltransferase function cooperatively in the assembly of the scaffold of 1 using primary central metabolites. The absolute configuration at C4, C6 and C7 of 1 was also established. Our work clarifies the unexpected functions of UbiA-type and DMAT-type PTs and provides an example for understanding the synthetic logic of hybrid terpenoid saccharides in fungi.
Assuntos
Produtos Biológicos , Dimetilaliltranstransferase , Terpenos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Dimetilaliltranstransferase/metabolismo , Metabolismo Secundário , Produtos Biológicos/metabolismoRESUMO
Apoptosis inhibition often leads to resistance to chemotherapeutics in bladder cancer (BC), resulting in poor prognosis of patients. Accumulating evidence suggests that induction of necroptosis, another type of programmed cell death, can be applied as an alternative strategy to kill apoptosis-insensitive BC cells. In this study, we showed that a novel Smac mimetic, ASTX660, also known as Tolinapant, can induce necroptosis in BC cells when apoptosis is inhibited. This is achieved by turning tumour necrosis factor (TNF)-α into a cytotoxic signal; ASTX660 then acts synergistically with TNF-α to induce necroptosis in BC cells. Mechanistic investigation showed that ASTX660 promoted the formation of the necrosome complex. Genetic or pharmacological inhibition of RIP1, RIP3, or MLKL, which are components of necrosome complex, provided protection against cell death induced by ASTX660 alone or ASTX660/TNF-α upon caspase inhibition. In addition, TNF-α/TNFR1 signalling and IRF1 are essential for the necroptosis induced by ASTX660 after the caspases are blocked. Our study highlights that ASTX660 can overcome the limitation of apoptosis induction via triggering necroptosis in BC cells. Therefore, our findings may provide some important clues for the design of a novel treatment strategy for BC.
Assuntos
Fator de Necrose Tumoral alfa , Neoplasias da Bexiga Urinária , Apoptose , Proteínas Reguladoras de Apoptose/metabolismo , Caspases/metabolismo , Feminino , Humanos , Masculino , Morfolinas , Necroptose , Necrose/induzido quimicamente , Piperazinas , Pirróis , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Neoplasias da Bexiga Urinária/tratamento farmacológicoRESUMO
Bladder cancer (BC) is a common malignancy of the urological system that still lacks effective treatment. It is frequently characterised by dysregulation of fibroblast growth factor receptor (FGFR) signalling. FGFR inhibitors have been proven as a promising treatment for BC in clinical settings. Besides the FGFR signalling, the therapeutic effects of FGFR inhibitors are often limited owing to various mechanisms, such as the activation of the Akt signalling pathway. Therefore, this study aimed to examine the synergistic effects of ipatasertib, a FGFR inhibitor, and erdafitinib, an Akt inhibitor, in BC cells. Ipatasertib and erdafitinib co-treatment synergistically inhibited cell proliferation and induced BC cell death. Mechanically, ipatasertib and erdafitinib induced the activation of Bax, an essential protein for cell death. Moreover, erdafitinib, which inhibited the Akt signalling pathway, is responsible for Bim upregulation, a condition critical to achieving the synergistic effects. Therefore, our data suggest that ipatasertib and erdafitinib co-treatment is a promising strategy for BC.
Assuntos
Apoptose , Proteína 11 Semelhante a Bcl-2 , Mitocôndrias , Piperazinas , Pirazóis , Pirimidinas , Quinoxalinas , Neoplasias da Bexiga Urinária , Apoptose/efeitos dos fármacos , Proteína 11 Semelhante a Bcl-2/metabolismo , Humanos , Mitocôndrias/efeitos dos fármacos , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirazóis/farmacologia , Pirimidinas/farmacologia , Quinoxalinas/farmacologia , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Regulação para Cima , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/patologiaRESUMO
The amino sugar N-acetyl-d-glucosamine (GlcNAc) is the key constituent of cell wall components and plays an important role in pathogenesis in a wide range of fungi. However, catabolism of GlcNAc has not been studied in basidiomycete fungi. In this study, we identified and characterized a gene cluster essential for GlcNAc utilization in Cryptococcus deneoformans, an environmental human fungal pathogen. The C. deneoformans genome contains a GlcNAc transporter (Ngt1), a GlcNAc kinase (Hxk3), a GlcNAc-6-phosphate deacetylase (Dac1), and a glucosamine-6-phosphate deaminase (Nag1). Their expression levels were highly induced in cultures containing GlcNAc as the sole carbon source, and the corresponding mutants showed severe growth defects in the presence of GlcNAc. Functional and biochemical analyses revealed that HXK3 encodes a novel GlcNAc kinase. Site-directed mutations of conserved residues of Hxk3 indicated that ATP binding and GlcNAc binding are essential for GlcNAc kinase activities. Taken together, the results from this study provide crucial insights into basidiomycete GlcNAc catabolism. IMPORTANCEN-Acetylglucosamine (GlcNAc) is recognized as not only the building block of chitin but also an important signaling molecule in fungi. The catabolic pathway of GlcNAc also plays an important role in vital biological processes in fungi. However, the utilization pathway of GlcNAc in the phylum Basidiomycota, which contains more than 41,000 species, remains unknown. Cryptococcus deneoformans is a representative basidiomycetous pathogen that causes life-threatening meningitis. In this study, we characterized a gene cluster essential for GlcNAc utilization in C. deneoformans and identified a novel GlcNAc kinase. The results of this study provide important insights into basidiomycete GlcNAc catabolism and offer a starting point for revealing its role in pathogenesis.
Assuntos
Candida albicans , Cryptococcus , Acetilglucosamina/metabolismo , Parede Celular/metabolismo , Quitina/metabolismo , HumanosRESUMO
A new polyketide, coptaspin A(1), along with two known compounds 4-acetyl-3,4-dihydro-6,8-dihydroxy-3-methoxy-5-methylisocoumarin(2), and cytochalasin Z_(12)(3), was isolated from the endophytic fungi Aspergillus sp. ZJ-58, which was isolated from the genuine medicinal plant Coptis chinensis in Chongqing after solid-state fermentation on rice and silica gel, MCI, and HPLC-based separation. Their structures were elucidated by MS, NMR, IR, UV, and ECD. The newly isolated compound 1 showed moderate inhibitory activities against LPS-induced NO production in RAW264.7 macrophages with the IC_(50) value of 58.7 µmol·L~(-1), suggesting its potential anti-inflammatory activity.
Assuntos
Plantas Medicinais , Policetídeos , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Aspergillus/química , Coptis chinensis , Policetídeos/farmacologiaRESUMO
Two new polyketides, lasobutone A(1) and lasobutone B(2), along with three known compounds, guignardianone C(3), guignardic acid(4), and 4-hydroxy-17R-methylincisterol(5), were isolated from the endophytic fungi Xylaria sp. by silica gel, MCI, and preparative HPLC, which was separated from the Chinese medicinal material Coptis chinensis and cultivated through solid fermentation with rice. Their structures were elucidated on the basis of spectroscopic methods, such as MS, NMR, IR, UV, and ECD. Compounds 2 and 4 showed inhibitory activities against the nitric oxide(NO) production in the LPS-induced macrophage RAW264.7 with IC_(50) values of 58.7 and 42.5 µmol·L~(-1) respectively, while compound 5 exhibited cytotoxic activities against HT-29 with IC_(50) value of 14.3 µmol·L~(-1).
Assuntos
Antineoplásicos , Policetídeos , Coptis chinensis , Endófitos/química , Fungos , Policetídeos/químicaRESUMO
Penispidins A-C (1-3), new aromatic sesquiterpenoids with two classes of rare carbon skeletons, were isolated from the endophytic fungus Penicillium virgatum HL-110. 1 represents the first example of a dunniane-type aromatic sesquiterpenoid, possessing a novel 4/6/6 tricyclic system, while (±)-2 and 3 have a 7,12-cyclized bisabolene skeleton, featuring a 3,4-benzo-fused 2-oxabicyclo[3.3.1]nonane central framework. Their structures were elucidated on the basis of spectroscopic methods, single-crystal X-ray diffraction, and ECD calculations. 1 inhibited hepatic lipid accumulation in HepG2 cells.
Assuntos
Metabolismo dos Lipídeos/efeitos dos fármacos , Penicillium/química , Sesquiterpenos/farmacologia , China , Células Hep G2 , Humanos , Estrutura Molecular , Sesquiterpenos/isolamento & purificação , Triglicerídeos/metabolismoRESUMO
Brexpiprazole (Bre) is a new multi-target antipsychotic drug (APD) approved by the US FDA in 2015, and shows good therapeutic potential. But it lacks assessments on the metabolic side effects, which obstructs the treatment of schizophrenia. Glucagon-like peptide 1 (GLP1), an incretin associated with insulin action and metabolism, is involved in the metabolic syndrome (MS) caused by most APDs. In this study, we examined the adverse effects of Bre on glycolipid metabolism in rats and determined whether GLP1 was involved in Bre-caused MS. In the first part of experiments, rats were orally administered Bre (0.5 mg· kg-1· d-1) for 28 days with aripiprazole (1.0 mg· kg-1· d-1) or olanzapine (1.0 mg· kg-1· d-1) as the controls. Compared to vehicle, Bre administration significantly increased the weight gain, serum lipid (TG, TC, LDL, FFA), and blood glucose levels accompanied by the hormonal (insulin, glucagon, GLP1) imbalance, and the impaired glucose tolerance and insulin sensitivity. Moreover, we demonstrated that Bre administration significantly decreased the protein and mRNA levels of GLP1 in pancreas and small intestine by suppressing CaMKIIα, AMPK, and ß-catenin; Bre administration also caused islet dysfunction with decreased GLP1R, PI3K, IRß expression in pancreas, and the interference of IRS1, PI3K, p-AKT, and GLUT4 expression in the liver and skeletal muscle that represented the insulin resistance. In the second part of experiments, rats were orally administered Bre (0.5 mg· kg-1· d-1) for 42 days. We showed that co-administration with the GLP1 receptor (GLP1R) agonist liraglutide (0.125 mg· kg-1· d-1, ip) could ameliorate Bre-caused metabolic abnormalities. Our results demonstrate that GLP1/GLP1R signaling is involved in Bre-induced glycolipid metabolic disorders and co-treatment with liraglutide is an effective intervention against those abnormal metabolisms.
Assuntos
Peptídeo 1 Semelhante ao Glucagon/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Síndrome Metabólica/etiologia , Quinolonas/efeitos adversos , Transdução de Sinais/efeitos dos fármacos , Tiofenos/efeitos adversos , Animais , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Feminino , Insulina/metabolismo , Resistência à Insulina/fisiologia , Intestino Delgado/metabolismo , Intestino Delgado/patologia , Liraglutida/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Pâncreas/metabolismo , Pâncreas/patologia , RatosRESUMO
As the endogenous ligand for the GH secretagogue receptor (GHSR), Ghrelin is aberrant expressed in multiple malignant carcinoma, and involved in regulating a number of progression of cancer, especially in metastasis and proliferation. However, the precise role of Ghrelin in tumorigenesis of gastric cancer (GC) is still poorly understood. In this study, we extensively investigated the roles and mechanisms of Ghrelin in human gastric cancer. Ghrelin levels in cancer tissues and cell lines were analyzed by immunohistochemistry, qRT-PCR, and Western blot. Functional studies were performed after Ghrelin overexpressed or knockdown in AGS cell line. Cell proliferation was evaluated in by MTT and clone formation assays. The wound healing and Transwell system were used to assess the cell migration and invasive ability of GC cells. Cell apoptosis was detected by flow cytometry, and metabolic assays were performed to reveal the function of Warburg effect in the process. Ghrelin was lowly expressed in gastric cancer tissues and cell lines. Overexpression of Ghrelin inhibited gastric cancer cell proliferation, migration, invasion, and promoted apoptosis by activating the AMPK pathway, while D-[lys3]-GHRP-6 (a GHSR agonist) treatment relieved the effect, promoting tumorigenesis. Ghrelin knockdown increased the glucose uptake and lactic acid release, suggesting that Ghrelin elicited an anti-Warburg effect via AMPK pathway to inhibit gastric tumorigenesis. Ghrelin inhibits cell proliferation, migration, and invasion by eliciting an anti-Warburg effect via AMPK signaling pathway in gastric cancer cells.
Assuntos
Adenilato Quinase/metabolismo , Grelina/fisiologia , Transdução de Sinais , Neoplasias Gástricas/patologia , Apoptose/fisiologia , Carcinogênese , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Sobrevivência Celular/fisiologia , Progressão da Doença , Regulação para Baixo , Grelina/antagonistas & inibidores , Grelina/metabolismo , Glucose/metabolismo , Humanos , Metástase Neoplásica , Neoplasias Gástricas/enzimologia , Neoplasias Gástricas/metabolismo , Regulação para CimaRESUMO
Fungal polyketide-nonribosomal peptide (PK-NRP) hybrid macrolactones are a growing family of natural products with biomedical and agricultural activities. One of the most important families is the thermolides, which are produced by extreme thermophilic fungi and exhibit strong nematocidal activity. We show here that the genes ThmABCE from Talaromyces thermophilus NRRL 2155 are critical for thermolide synthesis. Two separate single-module hrPKS (ThmA) and NRPS (ThmB) enzymes collaborate to synthesize the core macrolactone backbone (6 or 7), and the NRPS ThmB-CT domain catalyzes the key macrocyclization step in PK-NRP intermediate release via ester bond formation, representing a novel function of fungal NRPS C domains. We also show that heterologous and engineered expression of the Thm genes in the type strains of Aspergillus nidulans and Escherichia coli not only dramatically enhances the yields of thermolides but also affords different esterified analogues, such as butyryl- (thermolides J and K, 15 and 16), hexanoyl-, and octanyl- derivatives or mixed thermolides. Thermolides L and M (18 and 19), discovered via genome mining-based combinatorial biosynthesis, represent the first l-phenylalanine-based thermolides. Our work shows a unique biosynthetic mechanism of PK-NRP hybrid macrolactones from extremophiles, which led to the discovery of novel compounds and furthers our biosynthetic knowledge.
Assuntos
Antinematódeos/metabolismo , Lactonas/metabolismo , Peptídeos/metabolismo , Policetídeos/metabolismo , Talaromyces/metabolismo , Aspergillus nidulans/genética , Ciclização , Escherichia coli/genética , EsterificaçãoRESUMO
Palladium-doped SnO2 nanomaterials, with palladium in fractions from 0 to 10 mol% were hydrothermally synthesized and characterized by XRD, FESEM, TEM, and XPS. Their gas sensing properties were studied in two temperature ranges of 75-95 °C and 160-210 °C. The sensor using 5 mol% Pd-doped SnO2 exhibits temperature-dependent sensing property. NO2 can be detected at 80 °C, while H2S is preferably detected at 180 °C. The response to 10 ppm H2S is 50 times higher than that of the undoped sample. Its detection limit is 500 ppb. For NO2, the sensor exhibited strong response and a lower detection limit of 20 ppb. In view of the selective detection of H2S and NO2 by regulating the temperature, palladium-doped SnO2 has great prospects in the detection of H2S and NO2. Graphical abstract Schematic of the gas sensing mechanism of the S-5% Pd doped SnO2.
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This study is concerned with the attitude control problem of variable-structure near-space vehicles (VSNSVs) with time-varying state constraints based on switched nonlinear system. The full states of vehicles are constrained in the bounded sets with asymmetric time-varying boundaries. Firstly, considering modeling uncertainties and external disturbances, an extended state observer (ESO), including two distinct linear regions, is proposed with the advantage of avoiding the peaking value problem. The disturbance observer is utilized to estimate the total disturbances of the attitude angle and angular rate subsystems, which are described in switched nonlinear systems. Then, based on the estimation values, the asymmetric time-varying barrier Lyapunov function (BLF) is employed to construct the active disturbance rejection controller, which can ensure the full state constraints are not violated. Furthermore, to resolve the 'explosion of complexity' problem in backstepping control, a modified dynamic surface control is proposed. Rigorous stability analysis is given to prove that all signals of the closed-loop system are bounded. Numerical simulations are carried out to demonstrate the effectiveness of the proposed control scheme.
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Protoberberine alkaloids belong to the quaternary ammonium isoquinoline alkaloids, and are the main active ingredients in traditional Chinese herbal medicines, like Coptis chinensis. They have been widely used to treat such diseases as gastroenteritis, intestinal infections, and conjunctivitis. Studies have shown that structural modification of the protoberberine alkaloids could produce derivative compounds with new pharmacological effects and biological activities, but the transformation mechanism is not clear yet. This article mainly summarizes the researches on the biotransformation and structure modification of protoberberine alkaloids mainly based on berberine, so as to provide background basis and new ideas for studies relating to the mechanism of protoberberine alkaloids and the pharmacological activity and application of new compounds.
Assuntos
Alcaloides , Alcaloides de Berberina , Berberina , Coptis , BiotransformaçãoRESUMO
The objective of this study is to mask the extremely bitter taste of tilmicosin, and the tilmicosin-resin complex (DRC) microsphere were prepared by entrapping tilmicosin into resins (Tulsion® 339 and Eudragit® RS/ RL 100) for further pharmacokinetics study in rat. The DRC was characterized by FTIR and X-ray diffraction, and the microsphere containing DRC and Eudragit® RS/RL 100 were characterized by scanning electron microscopy (SEM). The rats were orally administrated with tilmicosin phosphate (10 mg/kg) and the microsphere containing the same dose of tilmicosin, respectively. These microspheres do not taste bitter and the kinetics study suggests that the drug released from microsphere meet the first order kinetics (r = 0.9911). The experimental results showed that T½ and Tmax of microsphere were much longer than tilmicosin phosphate, which indicates that the oral microsphere can be a promising long-active formulation for taste masking of tilmicosin.
Assuntos
Resinas Acrílicas/química , Portadores de Fármacos , Tilosina/análogos & derivados , Administração Oral , Animais , Disponibilidade Biológica , Preparações de Ação Retardada , Composição de Medicamentos , Liberação Controlada de Fármacos , Masculino , Microesferas , Tamanho da Partícula , Ratos Sprague-Dawley , Solubilidade , Paladar , Tilosina/administração & dosagem , Tilosina/sangue , Tilosina/química , Tilosina/farmacocinéticaRESUMO
Recurrent neural networks (RNNs) have been widely adopted in research areas concerned with sequential data, such as text, audio, and video. However, RNNs consisting of sigma cells or tanh cells are unable to learn the relevant information of input data when the input gap is large. By introducing gate functions into the cell structure, the long short-term memory (LSTM) could handle the problem of long-term dependencies well. Since its introduction, almost all the exciting results based on RNNs have been achieved by the LSTM. The LSTM has become the focus of deep learning. We review the LSTM cell and its variants to explore the learning capacity of the LSTM cell. Furthermore, the LSTM networks are divided into two broad categories: LSTM-dominated networks and integrated LSTM networks. In addition, their various applications are discussed. Finally, future research directions are presented for LSTM networks.