RESUMEN
The discovery of new highly active molecules from natural products is a common method to create new pesticides. Celangulin V targeting Mythimna separate (M. separate) midgut V-ATPaseâ H subunit, has received considerable attention for its excellent insecticidal activity and unique mechanism of action. Therefore, combined with our preliminary work, thirty-seven sulfonamide derivatives bearing propargyloxy or pyridine groups were systematically synthesized to search for insecticidal candidate compounds with low cost and high efficiency on theâ H subunit of V-ATPase. Bioactive results showed that compounds A2-A4 and A6-A7 exhibited a better bioactivity with median effective concentration (LC50 ) values (2.78, 3.11, 3.34, 3.54 and 2.48â mg/mL, respectively) against third-instar larvae of M. separate than Celangulin V (LC50 =18.1â mg/mL). Additionally, molecular docking experiments indicated that these molecules may act on theâ H subunit of V-ATPase. Based on the above results, these compounds provide new ideas for the discovery of insecticides.
Asunto(s)
Insecticidas , Mariposas Nocturnas , Animales , Simulación del Acoplamiento Molecular , Insecticidas/farmacología , Larva , Sulfonamidas , Adenosina Trifosfatasas , Piridinas , Sulfanilamida , Estructura Molecular , Relación Estructura-ActividadRESUMEN
OBJECTIVE: To prepare porous core-shell composite particles (PCPs) in order to improve the flowability and compactibility of powder materials for direct compaction (DC), as well as the dissolution of tablets. SIGNIFICANCE: The results obtained are meaningful to boosting the development and further research of PCPs on DC. Methods: In this study, hydroxypropyl methylcellulose (HPMC E3) and polyvinylpyrrolidone (PVP K30) were selected as shell materials, the Xiao Er Xi Shi formulation powder (XEXS) was used as the core materials, ammonium bicarbonate (NH4HCO3), and sodium bicarbonate (NaHCO3) were employed as pore-forming agent. Using co-spray drying method to prepare composite particles (CPs). Then, the physical properties and comparison between different CPs were characterized comprehensively. Finally, the different CPs were directly compacted as tablets to explore the effect on the dissolution behavior of DC tablets, respectively. RESULTS: (i) The XEXS PCPs were prepared successfully by co-spray drying, and the yield of PCPs is almost 80%; (ii) The TS values of PCP-X-P-Na, PCP-X-P-NH4, PCP-X-H-Na and PCP-X-P-Na were 5.70, 7.56, 3.98, and 6.88 times higher than that of raw material (X); (iii) The disintegration time of PCPs tablets decreased 10-25% when compared with CPs tablets; (iv) The values of Carr's index (CI), Hausner ratio (HR), Caking strength (CS), and Cohesion index (CoI) of PCP-X-H-NH4 were 19.16%, 19.29%, 40.14%, and 6.39% lower than that of X, respectively. CONCLUSIONS: The PCPs prepared by co-spray drying did improve the flowability and compactibility of powder, as well as the dissolution of tablets.
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Povidona , Polvos , Porosidad , Composición de Medicamentos/métodos , Comprimidos , SolubilidadRESUMEN
Sixty-nine 4-propargyloxybenzene sulfonamide derivatives with different amino acids as amino substituent were synthesized and evaluated for their insecticidal activity against third-instar Mythimna separate. The bioassay results revealed that some derivatives bearing amino acid ester group performed good insecticidal activity against third-instar M.separata, such as the LC50 values of D18 and D19 were 4.28 and 2.96 mg/ml after 48 h, in particular, the LC50 of D16 was 2.38 mg/ml and the activity was improved by 14 times compared to celangulin V (34.48 mg/ml). The above results provided theoretical and experimental basis for the discovery of novel insecticidal active compounds.
Asunto(s)
Insecticidas , Mariposas Nocturnas , Animales , Aminoácidos , Sulfonamidas , Ésteres , Sulfanilamida , Larva , Relación Estructura-Actividad , Estructura MolecularRESUMEN
A series of 4-(propargyloxy) benzenesulfonamide derivatives with different substituents on the benzene ring were synthesized and evaluated for their insecticidal activity. Some of the compounds showed good insecticidal activity against Mythimna separata, and the LC50 value of the most active compound B2.5 was 0.235 mg/ml. Ultrastructural changes in the midgut epithelial cells of Mythimna separata were observed using transmission electron microscopy, and severe structural damage was found in microvilli, mitochondria and rough endoplasmic reticulum. It indicates that the possible site of action of these benzenesulfonamides is the cytoplasmic membrane and endomembrane system of the midgut epithelial cells. The above provides a basis for the development of novel insecticidal active compounds with a novel mechanism of action.
Asunto(s)
Insecticidas , Mariposas Nocturnas , Animales , Larva , Insecticidas/farmacología , Mariposas Nocturnas/ultraestructura , Estructura Molecular , BencenosulfonamidasRESUMEN
Large-scale measurements of soil moisture play a critical role in many fields, such as agriculture, hydrology, and engineering. The distributed temperature sensing (DTS) technology, based on a dual-probe heat pulse (DPHP), is a novel approach to realizing large-scale soil moisture estimation. However, the application of the method is limited by the complex optical cable layout, calculation algorithm, and lack of standardized heating strategy. In this paper, an improved DPHP-DTS method considering the soil bulk density was proposed. The measurement accuracy of the DPHP-DTS method under different heating strategies was studied in laboratory experiments, and its long-term stability in regard to the monitoring of soil moisture during natural evaporation in different soils was tested. The results show that the improved DPHP-DTS method can accurately measure the soil moisture, and the fitting algorithm can reduce the error caused by the accuracy of the DTS temperature measurement under the low-power heating strategy. Its measurement accuracy increases with the increase in the heating strength and duration. In addition, the improved DPHP-DTS method can describe soil evaporation in both sand and loess with good reliability and stability.
RESUMEN
In our previous studies, a kind of novel benzenesulfonamides was found to be a candidate insecticidal compounds. It was shown that propargyloxy and sulfonamide groups are pharmacodynamic groups. One hundred and twenty-six (126) naphthalenesulfonamides derivatives with propargyloxy functionality were designed and synthesized, and their insecticidal activities were determined. Some of them showed outstanding activity, with LC50 values as low as 0.202 mg ml-1, much lower than that of the positive control celangulin V (23.9 mg ml-1). In addition, the structure-activity relationships were discussed, and molecular docking was used to verify the binding mode of the compound and the target receptor.
Asunto(s)
Insecticidas , Diseño de Fármacos , Insecticidas/farmacología , Simulación del Acoplamiento Molecular , Estructura Molecular , Naftalenos/farmacología , Relación Estructura-Actividad , Sulfonamidas/farmacologíaRESUMEN
OBJECTIVE: Burnout is common in mental health nurses because of work-related stress. Burnout has a negative impact on nurses' health and work performance. The prevalence of high burnout in mental health nurses has been inconclusive across studies. This meta-analysis aimed to estimate the pooled prevalence of high burnout in mental health nurses in China. METHODS: Electronic databases (PubMed, EMBASE, PsycINFO, Web of Science, CNKI, WanFang and SinoMed) were independently and systematically searched from their commencement date up to 14 May 2018. Studies that reported the prevalence of any of the 3 burnout dimensions (high Emotional Exhaustion (EE), Depersonalization (DP), and low Personal Accomplishment (PA)) as measured by the Maslach Burnout Inventory (MBI) were included and analyzed using the random-effects model. RESULTS: A total of 19 studies were included in this meta-analysis. The pooled prevalence of high EE was 28.1% (95% CI: 20.4-35.8%), DP was 25.4% (18.1-32.6%) and low PA was 39.7% (28.3-51.1%). Subgroup analyses found that short working experience, use of MBI-Human Services Survey (HSS), and younger age had moderating effects on prevalence of high burnout. CONCLUSIONS: Burnout is common in mental health nurses in China. Considering its negative impact on health and work performance, regular screening, preventive measures and effective interventions should be implemented.
Asunto(s)
Agotamiento Profesional/epidemiología , Enfermería Psiquiátrica , China/epidemiología , Humanos , Prevalencia , Encuestas y CuestionariosRESUMEN
The α-galactosidases, which can catalyze the removal of α-1,6-linked terminal galactose residues from galactooligosaccharide materials, have good potential for industrial applications. The high-level and efficient secretion of the α-galactosidases into the extracellular space has greatly simplified the downstream bioengineering process, facilitating their bioapplications. In this study, the effects of gene dosage and endoplasmic reticulum secretion-associated factors (ERSAs) on the secretory expression of an α-galactosidase gene derived from a Aspergillus oryzae strain were investigated by constructing multicopy expression cassettes and coexpressing the α-galactosidase gene with ERSAs. With the increase in the gene copy-number in the host genome, the expression of GalA was improved. However, the secretory expression level was not linearly related to the copy number. When the number was higher than four copies, the expression level of GalA gene declined. The ERSAs factors HAC1, PDI, and Ero1 improved the secretory expression of α-galactosidase, while Hsp40 inhibited its secretion. After methanol-induced expression in a bench-top bioreactor, Pichia recombinants carrying four copies of GalA genes reached 3520 U/mL in the supernatant of the culture. We further optimized the parameters for α-galactosidase to hydrolyze two types of galactooligosaccharides: raffinose and stachyose. This study has fulfilled the scale-up production of α-galactosidase, thus facilitating its industrial applications.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Retículo Endoplásmico/química , Proteínas Fúngicas/genética , Glicoproteínas/genética , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/genética , Proteína Disulfuro Isomerasas/genética , Proteínas Represoras/genética , Proteínas de Saccharomyces cerevisiae/genética , alfa-Galactosidasa/genética , Aspergillus oryzae/química , Aspergillus oryzae/enzimología , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Clonación Molecular , Retículo Endoplásmico/metabolismo , Proteínas Fúngicas/metabolismo , Dosificación de Gen , Expresión Génica , Vectores Genéticos/química , Vectores Genéticos/metabolismo , Glicoproteínas/metabolismo , Humanos , Hidrólisis , Microbiología Industrial/métodos , Oligosacáridos/metabolismo , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/metabolismo , Pichia/genética , Pichia/metabolismo , Proteína Disulfuro Isomerasas/metabolismo , Rafinosa/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Represoras/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , alfa-Galactosidasa/metabolismoRESUMEN
A series of l-pyroglutamic acid analogues from natural product lead were designed and synthesized, as well as their antifungal activities against Phytophthora infestans, neuritogenic activities, antibacterial activities and anti-inflammatory activities are described. The bioassays and SAR study showed that the majority of l-pyroglutamic acid esters have a significant antifungal activity against P. infestans, especially 2d and 2j demonstrated the best activities with EC50 values of 1.44 and 1.21⯵gâ¯mL-1, which were about seven times that of commercial azoxystrobin (7.85⯵gâ¯mL-1). Moreover, compounds 2e, 2g and 4d displayed anti-inflammatory activity against LPS-induced NO production in BV-2 microglial cells; neuritogenic activity in NGF-induced PC-12 cells is the same activity. This study demonstrates that compounds 2d and 2j are potential drugs to control P. infestans.
Asunto(s)
Antifúngicos/síntesis química , Productos Biológicos/química , Ácido Pirrolidona Carboxílico/análogos & derivados , Animales , Antiinflamatorios/síntesis química , Antiinflamatorios/química , Antiinflamatorios/farmacología , Antifúngicos/química , Antifúngicos/farmacología , Línea Celular , Lipopolisacáridos/farmacología , Ratones , Microglía/citología , Microglía/efectos de los fármacos , Microglía/metabolismo , Óxido Nítrico/metabolismo , Células PC12 , Phytophthora infestans/efectos de los fármacos , Ácido Pirrolidona Carboxílico/síntesis química , Ácido Pirrolidona Carboxílico/farmacología , Ratas , Relación Estructura-ActividadRESUMEN
Combined headspace solid-phase microextraction with gas chromatography-mass spectrometry (HS-SPME-GC-MS), this paper studied the volatiles of Artemisiae Argyi Folium that respectively collected from Kongdong, Huanglong, Ankang, Qichun and Tongbaiï¼and then explored the influence of climatic factors on the main components of the volatiles. The results showed that 54, 52, 57, 47 and 55 compounds were respectively identified from the leaves from five regions, mainly consist of monoterpenes, sesquiterpenoids and their oxygen-containing derivatives, a few aldehydes, alkanes and benzenes. It is different that the volatiles of Artemisiae Argyi Folium that collected in different habitats, neither composition nor content. There are total 18 kinds of compounds that exist in all five leaves. Eucalyptol, camphor, terpinen-4-ol, eugenol and caryophyllene could be considered to be the main conponents because of their efficacy or toxicity and relatively high content. Grey correlation analysis shows that the annual lowest temperature and annual sunshine duration have a great influence on the content of eucalyptol and camphor; the effect of annual precipitation and annual accumulated temperature on the content of terpinen-4-ol and caryophyllene was relatively significant; while the annual sunshine duration and the annual highest temperature are the main influencing factors for eugenol. The research suggests that long-day and extreme temperature may be more conductive to the accumulation of volatiles. According to the laws of effect of climatic factors on volatiles, we can optimize the cultivation conditions and select suitable locality to improve the quality of Artemisiae Argyi Folium.
Asunto(s)
Artemisia/química , Clima , Hojas de la Planta/química , Compuestos Orgánicos Volátiles/análisis , Ecosistema , Cromatografía de Gases y Espectrometría de Masas , Monoterpenos/análisis , Fitoquímicos/análisis , Sesquiterpenos/análisis , Microextracción en Fase SólidaRESUMEN
An improved synthetic route of canthin-6-one was accomplished. To further enhance the antibacterial potency and improve water solubility, a series of 3-N-alkylated and 3-N-benzylated canthin-6-ones were designed and synthesized, and their in vitro antibacterial activities were evaluated. A clear structure-activity relationship with peak minimal inhibitory concentration (MIC) values of 0.98 (µg·mL(-)(1)) was investigated. Particularly, compounds 6i-r and 6t were found to be the most potent compounds with minimal inhibitory concentration (MIC) values lower than 1.95 (µg·mL(-)(1)) against Staphylococcus aureus.
Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Carbolinas/química , Carbolinas/farmacología , Alcaloides Indólicos/química , Alcaloides Indólicos/farmacología , Staphylococcus aureus/efectos de los fármacos , Alquilación , Antibacterianos/síntesis química , Carbolinas/síntesis química , Humanos , Alcaloides Indólicos/síntesis química , Pruebas de Sensibilidad Microbiana , Infecciones Estafilocócicas/tratamiento farmacológico , Relación Estructura-ActividadRESUMEN
Ibuprofen lipid pellets prepared by melting method could mask the bitter taste of the drug to some extent. The pellets were further coated with chitosan (cationic) and gelatin (anionic) by ionic interaction layer- by-layer self-assembly (LBL) coating to improve masking effects. In this paper, the release percentage of drugs in short time (1 min) was utilized as an indicator for the taste-masking, and it had confirmed the LBL coating inhibited the release of model drug of ibuprofen. Synchrotron radiation-based Fourier-transform infrared spectromicroscopy (SR-FTIR) has been applied to investigate the material distributions on the cross section of pellets and film. Characteristic absorptions of the compositions were obtained by SR-FTIR single spectrum scanning. The distributions of the drug and materials in coated films were determined by SR-FTIR mapping. The FTIR absorptions of chitosan and gelatin on the surface of lipid pellets was examined to verify the existence of chitosan and gelatin on the surface and a film formed using SR-FTIR ratio analysis. Whilst pellets coated only by chitosan or gelatin did not show the typical absorption of chitosan or gelatin, which confirmed the effects of ionic interaction on the film forming process. In conclusion, the method of SR-FTIR established for the study of the existence and distribution of materials in coated film offers a new choice for researches on membranes/films in drug delivery systems and pharmaceutical preparations.
Asunto(s)
Excipientes/química , Ibuprofeno/administración & dosificación , Espectroscopía Infrarroja por Transformada de Fourier , Gusto , Quitosano , Preparaciones de Acción Retardada/administración & dosificación , Composición de Medicamentos , Sistemas de Liberación de Medicamentos , Gelatina , SincrotronesRESUMEN
In this study, the Pickering emulsions were prepared using medium chain triglycerides(MCT) and α-cyclodextrin(α-CD) and the formation mechanism was studied by means of several physicochemical techniques. The MCT/α-CD microparticles, which stabilized the emulsions, were characterized by the measurement of interfacial tension and the contact angle(θ(ow)), powder X ray diffraction(XRD), scanning electron microscope(SEM), high performance liquid chromatography(HPLC), differential interference microscope(DIM), Cryo-scanning electron microscopy(Cryo-SEM). The physical stability of emulsions with different α-CD content in the continuous aqueous phase was investigated by determination of the droplet size and sedimentation rate, combined with the observation of droplet morphologies by the inverted phase contrast microscope. As a result, it was observed that the amphiphilic supramolecule of MCT and α-CD were indeed formed. Furthermore, MCT/α-CD microparticles formed by the aggregation of MCT/α-CD supramolecule absorbed at the oil/water interface, and then forming a membrane structure to stabilize emulsion. In addition, the average θ(ow) for the MCT/α-CD microparticles was(46.1 ± 3.4)° which stabilized O/W emulsion. When the content of α-CD was increased in the continuous phase, there were more microparticles formed at the oil/water interface and in the continuous aqueous phase, which resulted in smaller particle size of droplet and higher viscosity of the continuous phase. In summary, the study suggest that α-CD/MCT/water emulsions were of O/W Pickering emulsions and the physical stability was better for emulsions with higher content of α-CD in the continuous phase.
Asunto(s)
Triglicéridos/química , alfa-Ciclodextrinas/química , Emulsiones , Tamaño de la Partícula , Viscosidad , Agua , Difracción de Rayos XRESUMEN
The synthesis of Yanglingmycin and its enantiomer, along with eighteen Yanglingmycin analogues is reported. The structures were confirmed mainly by analyses of NMR spectral data. Antibacterial activity assays showed that Yanglingmycin and some of its analogues exhibited significant antibacterial activities against two important agricultural pathogenic bacteria, Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae, with minimum inhibitory concentration (MIC) values ranging from 3.91 to 15.62 µg/mL. The antibacterial activities exhibited by Yanglingmycin and its analogues are promising, suggesting potential in the development of compounds for novel bactericides.
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Antibacterianos/síntesis química , Oxazoles/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Oxazoles/química , Oxazoles/farmacología , Pseudomonas syringae/efectos de los fármacos , Ralstonia solanacearum/efectos de los fármacos , EstereoisomerismoRESUMEN
The association rate constant and dissociation rate constant are important parameters of the drug-cyclodextrin supermolecule systems, which determine the dissociation of drugs from the complex and the further in vivo absorption of drugs. However, the current studies of drug-cyclodextrin interactions mostly focus on the thermodynamic parameter of equilibrium constants (K). In this paper, a method based on quantitative high performance affinity chromatography coupled with mass spectrometry was developed to determine the apparent dissociation rate constant (k(off,app)) of drug-cyclodextrin supermolecule systems. This method was employed to measure the k(off,app) of meloxicam and acetaminophen. Firstly, chromatographic peaks of drugs and non-retained solute (uracil) on ß-cyclodextrin column at different flow rates were acquired, and the retention time and variance values were obtained via the fitting the peaks. Then, the plate heights of drugs (H(R)) and uracil (H(M,C)) were calculated. The plate height of theoretical non-retained solute (H(M,T)) was calculated based on the differences of diffusion coefficient and the stagnant mobile phase mass transfer between drugs and uracil. Finally, the k(off,app) was calculated from the slope of the regression equation between (H(R)-H(M,T)) and uk/(1+k)2, (0.13 ± 0.00) s(-1) and (4.83 ± 0.10) s(-1) for meloxicam and acetaminophen (control drug), respectively. In addition, the apparent association rate constant (k(on,app)) was also calculated through the product of K (12.53 L x mol(-1)) and k(off,app). In summary, it has been proved that the method established in our study was simple, efficiently fast and reproducible for investigation on the kinetics of drug-cyclodextrin interactions.
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Tiazinas/química , Tiazoles/química , beta-Ciclodextrinas/química , Acetaminofén/química , Cromatografía de Afinidad , Interacciones Farmacológicas , Cinética , Espectrometría de Masas , Meloxicam , TermodinámicaRESUMEN
The shape and structure of granules are controlled by the granulation process, which is one of the main factors to determine the nature of the solid dosage forms. In this article, three kinds of granules of a traditional Chinese medicine for improving appetite and promoting digestion, namely, Jianwei Granules, were prepared using granulation technologies as pendular granulation, high speed stirring granulation, and fluidized bed granulation and the powder properties of them were investigated. Meanwhile, synchrotron radiation X-ray computed micro tomography (SR-µCT) was applied to quantitatively determine the irregular internal structures of the granules. The three-dimensional (3D) structure models were obtained by 3D reconstruction, which were more accurately to characterize the three-dimensional structures of the particles through the quantitative data. The models were also used to quantitatively compare the structural differences of granules prepared by different granulation processes with the same formula, so as to characterize how the production process plays a role in the pharmaceutical behaviors of the granules. To focus on the irregularity of the particle structure, the box counting method was used to calculate the fractal dimensions of the granules. The results showed that the fractal dimension is more sensitive to reflect the minor differences in the structure features than the conventional parameters, and capable to specifically distinct granules in structure. It is proved that the fractal dimension could quantitatively characterize the structural information of irregular granules. It is the first time suggested by our research that the fractal dimension difference (Df,c) between two fractal dimension parameters, namely, the volume matrix fractal dimension and the surface matrix fractal dimension, is a new index to characterize granules with irregular structures and evaluate the effects of production processes on the structures of granules as a new indicator for the granulating process control and optimization.
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Medicamentos Herbarios Chinos/análisis , Tomografía Computarizada por Rayos X , Fractales , Medicina Tradicional China , Polvos , Relación Estructura-Actividad Cuantitativa , Sincrotrones , Tecnología FarmacéuticaRESUMEN
The synthesis of Yanglingmycin and its enantiomer, along with eighteen Yanglingmycin analogues is reported. The structures were confirmed mainly by analyses of NMR spectral data. Antibacterial activity assays showed that Yanglingmycin and some of its analogues exhibited significant antibacterial activities against two important agricultural pathogenic bacteria, Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae, with MIC values ranging from 3.91 to 15.62 µg/mL. The antibacterial activities exhibited by Yanglingmycin and its analogues are promising, suggesting potential in the development of compounds for novel bactericides.
RESUMEN
The release behavior of single pellet was investigated by LC/MS/MS method with tamsulosin hydrochloride (TSH) as the model drug of the research and then the pellets were divided into four groups according to the drug loading. Comparison of dissolution profiles of each group and capsule were performed using f1 and f2 factor methods to study the difference and similarity. The release profiles of single pellet, each group and capsule were analyzed using principle component analysis (PCA). The particle system was built through Matlab to get the target release profile. The result of this research demonstrated the release behavior of single pellet correlated well with the drug loading. While the dissolution profile of capsule as a reference, the similarity factor of dissolution profiles of the lower drug loading groups were 62.2, 67.1, 53.9, respectively and, 43.3 for highest drug loading group. The particle systems with different pellet distribution and same release profiles were built through release behavior of single pellet. It is of significance to investigate the release behavior of single pellets for studying the release regularity of multiple-unit drug delivery system.
Asunto(s)
Liberación de Fármacos , Sulfonamidas/administración & dosificación , Sulfonamidas/química , Cápsulas , Química Farmacéutica , Cromatografía Liquida , Preparaciones de Acción Retardada , Sistemas de Liberación de Medicamentos , Análisis de Componente Principal , Tamsulosina , Espectrometría de Masas en Tándem , Tecnología FarmacéuticaRESUMEN
Paracetamol was used as a model drug in this study to investigate the synergetic effects of lipid coating and beta-cyclodextrin (beta-CD) inclusion for masking the bitter taste of poorly soluble drugs. To control the concentration as low as possible of the free drug which produced a bitter taste, a kinetic model was established to calculate the drug distribution theoretically among the free drug in medium, lipid coated particles and molecular inclusion on the basis of the preparation and characterization of the lipid microspheres, so as to select the proper amount of beta-CD. Finally, the synergetic drug delivery systems were prepared and characterized by 1H nuclear magnetic resonance (1H NMR), molecular simulation and the electronic tongue. As a result, the drug release rate constant (k) of the lipid microspheres coated with octadecanol was determined as 0.001 270 s(-1). Then, the synergetic drug delivery systems were prepared with the ratio of 6.74 : 1 (w/w) for beta-CD and paracetamol. The chemical shift values for the fingerprint peaks of paracetamol all increased and hydrogen bonds were formed between the oxygen on the phenolic hydroxyl group, the nitrogen on the imino in paracetamol and the hydrogens on the hydroxyl groups in beta-CD. The results tested by the electronic tongue indicated that the paracetamol, lipid microspheres, beta-CD inclusion and their mixture showed different taste characteristics, with the bitterness order of the synergetic drug delivery systems approximately lipid microspheres < beta-CD inclusion < paracetamol, which confirmed the synergetic taste masking effects of lipid coating and beta-CD molecular inclusion. In summary, the synergetic taste masking was jointly achieved through the retard of the drug release by the lipid coating and the inclusion of the free paracetamol by beta-CD through hydrogen bonds.
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Acetaminofén/química , Sistemas de Liberación de Medicamentos , Lípidos/química , Gusto/efectos de los fármacos , beta-Ciclodextrinas/química , Acetaminofén/administración & dosificación , Administración Oral , Equipos y Suministros Eléctricos , Técnicas Electroquímicas/instrumentación , Técnicas Electroquímicas/métodos , Enlace de Hidrógeno , Cinética , Microesferas , SolubilidadRESUMEN
Comprehending the spatial-temporal characteristics, contributions, and evolution of driving factors in agricultural non-CO2 greenhouse gas (GHG) emissions at a macro level is pivotal in pursuing temperature control objectives and achieving China's strategic goals related to carbon peak and carbon neutrality. This study employs the Intergovernmental Panel on Climate Change (IPCC) carbon emissions coefficient method to comprehensively evaluate agricultural non-CO2 GHG emissions at the provincial level. Subsequently, the contributions and spatial-temporal evolution of six driving factors derived from the Kaya identity were quantitatively explored using the Logarithmic Mean Divisia Index (LMDI) and Geographical and Temporal Weighted Regression (GTWR) methods. The results revealed that the distribution of agricultural non-CO2 GHG emissions is shifting from the central provinces to the northwest regions. Moreover, the dominant driving factors of agricultural non-CO2 GHG emissions were primarily economic factor (EDL) with positive impact (cumulative promotion is 2939.61 million metric tons (Mt)), alongside agricultural production efficiency factor (EI) with negative impact (cumulative reduction is 2208.98 Mt). Influence of EDL diminished in the eastern coastal regions but significantly impacted underdeveloped regions such as the northwest and southwest. In the eastern coastal regions, EI gradually became the absolute dominant driver, demonstrating a rapid reduction effect. Additionally, a declining birth rate and rural-to-urban population migration have significantly amplified the driving effects of the population factor (RP) at a national scale. These findings, in conjunction with the disparities in geographic and socioeconomic development among provinces, can serve as a guiding framework for the development of a region-specific roadmap aimed at reducing agricultural non-CO2 GHG emissions.