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1.
Suspension culture is an essential large-scale cell culture technique for biopharmaceutical development and regenerative medicine. To transition from monolayer culture on the culture surface of a flask to suspension culture in a bioreactor, a pre-specified cell number must first be reached. During this period of preparation for suspension culture, static suspension culture in a flask is generally performed because the medium volume is not large enough to use a paddle to circulate the medium. However, drawbacks to this static method include cell sedimentation, leading to high cell density near the bottom and resulting in oxygen and nutrient deficiencies. Here, we propose a suspension culture method with acoustic streaming induced by ultrasonic waves in a T-flask to create a more homogeneous distribution of oxygen, nutrients, and waste products during the preparation period preceding large-scale suspension culture in a bioreactor. To demonstrate the performance of the ultrasonic method, Chinese hamster ovary cells were cultured for 72 h. Results showed that, on average, the cell proliferation was improved by 40% compared with the static method. Thus, the culture time required to achieve a 1000-fold increase could be reduced by 32 h (a 14% reduction) compared with the static method. Furthermore, the ultrasonic irradiation did not compromise the metabolic activity of the cells cultured using the ultrasonic method. These results demonstrate the effectiveness of the ultrasonic method for accelerating the transition to large-scale suspension culture.  相似文献   
2.
A novel magnetic covalent organic framework was synthesized via a one-step coating approach with solvothermal reaction employing 2,4,6-tris(4-aminophen-yl)-1,3,5-triazine and 2,4,6-triformylphloroglucinol as two building blocks by covalent bonding. The prepared magnetic covalent organic frameworks were properly characterized by different techniques and employed as adsorbents of magnetic solid-phase extraction. An analytical method was developed for the simultaneous determination of five fungicides in two Chinese herbal medicine samples via magnetic solid-phase extraction coupled to ultra high performance liquid chromatography with tandem mass spectrometry analysis. Under optimized magnetic solid-phase extraction conditions, the method exhibited satisfactory recoveries (74.0−109.6%) with relative standard deviations of 0.4−4.6%, low limits of detection (0.003−0.015 μg/kg), and good linearity (R2 > 0.9960). Compared with the traditional extraction method, the proposed method required a lower amount of adsorbent (3 mg) and extraction time (5 min). The adsorbent also had favorable reusability (not less than eight times). Therefore, the magnetic covalent organic frameworks could be a promising adsorbent for the extraction and quantitation of fungicides in Chinese herbal medicines.  相似文献   
3.
Cell membrane chromatography is an effective method for screening bioactive components acting on specific receptors in complex systems, which maintains the biological activity of the membrane receptors and improves screening efficiency. However, traditional cell membrane chromatography suffers from poor stability, resulting in a limited life span and low reproducibility, greatly limiting the application of this method. To address this problem, cyanuric chloride-decorated silica gel was used for the covalent immobilization of the cell membranes. Cyanuric chloride reacts with amino groups on the cell membranes and membrane receptors to form covalent bonds. In this way, the cell membranes are not easy to fall off. The column life of the cyanuric chloride-decorated epidermal growth factor receptor/cell membrane chromatography column was extended to more than 8 days, whereas the column life of the normal cell membrane chromatography column dropped sharply in the first 3 days. A cyanuric chloride-decorated epidermal growth factor receptor/cell membrane chromatography online HPLC-IT-TOF-MSn system was applied for screening drug leads from Trifolium pratense L. One potential drug lead, formononetin, which acts on the epidermal growth factor receptor, was screened. Our strategy of covalently immobilizing cell membrane receptors also improved the stability of cell membrane chromatography.  相似文献   
4.
Semens of Astragali Complanati own anti-erectile dysfunction effect; however, the components which contribute to the anti-erectile dysfunction effect remain unclear. This work raised a strategy that integrates liquid chromatography coupled mass spectrometry-based quantitative analysis, anti-erectile dysfunction assessment on impotent rats, and their relationship analysis for pinpointing anti-erectile dysfunction components from semens of Astragali Complanati. For simultaneous quantification of seven major components in raw and salt-processed semens of Astragali Complanati, an accurate and reliable liquid chromatography–mass spectrometry method was developed under multiple reaction monitoring mode. Of note, chloramphenicol was employed as the internal standard. The method showed good linearity and repeatability, where the recovery rates of each component ranged from 98.1 to 104.7%, and the precisions of intra- and interday were all within 3.4%. The method has been used for quantification of the seven major components in 10 batches of raw and salt-processed semens of Astragali Complanati. Then, the anti-erectile dysfunction effects of raw and salt-processed semens of Astragali Complanati were evaluated on impotent rats. Gray relationship analysis and partial least squares regression were combined for elucidating the relationship. As a result, complanatuside, astragalin, complanatoside B, and kaempferol were found to be responsible for anti-erectile dysfunction effect of Astragali Complanati.  相似文献   
5.
Baihe-Dihuang Tang is a commonly prescribed remedy for depression. In this study, component screening with untargeted and targeted metabolomics was used to identify potential biomarkers for depression in chronic unpredictable mildly stressed rats. Using this novel identification method, the screening of organic acids, lily saponins, iridoids, and other ingredients formed the basis for subsequent metabolomics research. Baihe-Dihuang Tang supplementation in chronic unpredictable mild-stress-induced depression models, increased their body weight, sucrose preference, brain-derived neurotrophic factor deposition, and spatial exploring. Untargeted metabolomics revealed that Baihe-Dihuang Tang exerts its antidepressant effects by regulating the levels of lipids, organic acids, and its derivatives, and benzenoids in the brain, plasma, and urine of the depressed rats. Moreover, it also modulates the d -glutamine and d -glutamate metabolism and purine metabolism. Targeted metabolomics demonstrated significant reduction in l -glutamate levels in the brains of depressed rats. This could be a potential biomarker for depression. Baihe-Dihuang Tang alleviated depression by regulating the levels of l -glutamate, xanthine, and adenine in the brains of depressed rats. Together, these findings conclusively established the promising therapeutic effect of Baihe-Dihuang Tang on depression and also unraveled the underlying molecular mechanism of its potential antidepressant function.  相似文献   
6.
历代本草,世代相传,距今已发展了两千多年,蕴藏着深厚的人文底蕴和科学精神,将其融入中学化学教学有利于实现化学学科的育人功能。挖掘提炼出本草古籍中与中学化学知识相契合的内容,结合药物化学、药理学等方面的知识,举例说明本草古籍在无机化学、有机化学及试题编制等方面的应用,探索将本草古籍融入中学化学教学的有效途径。  相似文献   
7.
In this study, α-glucosidase was successfully immobilized on cellulose filter paper and further applied to screening inhibitors from traditional Chinese medicines combined with capillary electrophoresis analysis. For α-glucosidase immobilization, a cellulose filter paper was used as the carrier and grafted with amino groups by coating chitosan, then α-glucosidase was covalently bonded on the amino-modified carrier via epoxy ring-opening reaction using polyethylene glycol diglycidyl ether as the crosslinker. Several parameters influencing the enzyme immobilization were optimized and the optimal values were enzyme concentration of 4 U/mL, polyethylene glycol diglycidyl ether concentration of 1.25%, chitosan concentration of 7.5 mg/mL, immobilization pH 7.0, crosslinking time of 4 h and immobilization time of 2 h. The immobilized α-glucosidase exhibited good batch-to-batch reproducibility (RSD = 2.1%, n = 5), excellent storage stability (73.5% of its initial activity after being stored at 4°C for 15 days), and reusability (75% of its initial activity after 10 repeated cycles). The Michaelis constant of immobilized α-glucosidase and half-maximal inhibitory concentration of acarbose were calculated to be 1.12 mM and 0.38 μM, respectively. Finally, the immobilized α-glucosidase was used for screening inhibitors from 14 kinds of Traditional Chinese Medicine extracts, and Sanguisorbae Radix showed the strongest inhibitory effect on α-glucosidase.  相似文献   
8.
Yinlan lipid regulatory capsule (YL) is a composite traditional Chinese medicine (TCM) new drug to alleviate hyperlipidemia, while its therapeutic mechanism in vivo was not clarified with nontargeted metabolomics investigation. An animal model was established in rats fed a high-fat diet, and their body weights, body mass index (BMI) and blood cholesterol levels were measured. Serum, liver and kidney tissue samples were also extracted for PXR-CYP3A4-ABCB1-FXR signaling pathway research using PCR and UHPLC–MS. The obtained plasma samples were analyzed by UHPLC-Q-TOF-MS metabolomic investigation, which revealed PXR-CYP3A4-related metabolites and changes induced by YL. Finally, the key metabolites were chosen as index components, and their levels in the serum, liver, small intestine and bile were used for simultaneous UHPLC–MS-MS determination. The results indicated that YL was effective in rebalancing blood TG and TC levels (compared to controls). With respect to the PXR-CYP3A4-ABCB1 pathway, as a result of YL’s effect, gene expression or activity of the two targets decreased significantly in both the liver and kidney. The same trend was observed in the serum samples mentioned above. Metabolomics screening and data revealed that 44 metabolites can be regarded as biomarkers related to hyperlipidemia, fatty acids synthesis, and body energy consumption, as well as synthesis, transportation and exertion of cholesterol. YL’s treatment focused on 26 of them, primarily bile acids, indicating that the antihyperlipidemic effect of this drug lies in its inhibitory activity of cholesterol metabolism. Subsequent analysis of those in vivo components revealed that significant increases (compared to the model group) occurred in the blood, liver, small intestine and bile in groups that received medium and high doses of YL (while the low dose was relatively unchanged). Those target components exhibit a close relationship with PXR and/or CYP3A4. The use of YL repressed PXR expression and subsequently decreased CYP3A4 activity. As a result, synthesis of related bile acids increased, while cholesterol levels decreased, consequently leading to the attenuation of hyperlipidemia. This study comprehensively investigated the antihyperlipidemia mechanism of YL based on its repression of PXR-CYP3A4 activity and related metabolite yield, establishing an accurate method for evaluating the therapeutic effect of YL.  相似文献   
9.
高血压合并冠心病是高血压疾病的一类严重合并症。目前高血压患者对合并冠心病的情况检测不及时,容易导致严重事件的发生,其致残率、致死率极高,严重影响患者的生活质量。因此对高血压患者合并冠心病的早期发现对预防更严重事件的发生显得尤为重要。舌体信息与心血管功能关系密切,为此,提出一种基于舌体高光谱用于高血压患者中合并冠心病筛查新方法。采集154例心血管科门诊患者舌体377.8~1 049.1 nm高光谱数据并记录临床诊断信息。对高血压患者组及高血压合并冠心病患者组舌体光谱比较发现,在500~600 nm波段之间,两组光谱存在显著性差异。基于中医舌诊分区理论,对舌体进行区域划分,划分为舌尖、舌左、舌中、舌右以及舌根五个区域。各舌体分区在波长509.6和561.2 nm以及540.5和576.7 nm均存在极大和极小值,这与血红蛋白对光的吸收特征相吻合。对组间各舌体区域光谱特征进行差异性分析。T检验分析结果显示高血压患者组与高血压合并冠心病患者组舌尖与舌中区域光谱具有显著性差异。基于高血压患者组与高血压合并冠心病患者组舌体不同区域光谱特征的差异性,利用神经网络,选取500~600 nm舌尖与舌中光谱数据进行后续高血压患者组与高血压合并冠心病患者组分类辨识模型的建立。选用准确度、灵敏度以及特异性作为模型预测能力的评价指标。最终获得模型的预测准确度、灵敏度以及特异性分别为84.78%,86.95%和82.61%。实验结果表明高血压患者与高血压合并冠心病患者舌体高光谱信息之间存在显著性差异。利用舌体高光谱所建立的分类模型能够用于高血压以及高血压合并冠心病患者的无创辨识,为高血压患者中高血压合并冠心病的早期发现提供一种有效筛查手段。  相似文献   
10.
针对大白菜农药残留传统化学检测手段存在前期处理过程繁琐、检测周期长等不足,提出了一种快速无损识别大白菜农药残留种类的方法。以1组无农药残留和4组含有均匀喷洒农药(毒死蜱、乐果、灭多威和氯氰菊酯)的大白菜样本为研究对象(药液浓度配比分别为0.10,1.00,0.20和2.00 mg·kg-1),经12小时自然吸收后,利用高光谱成像系统获取400~1 000 nm高光谱图像,并选取ROI感兴趣区域后经多元散射校正(MSC)预处理;分别采用竞争性自适应重加权算法(CARS)、主成分分析算法(PCA)和离散小波变换(DWT)降维(分别基于db1,sym2,coif1,bior2.2和rbio1.5小波基函数);最后,将降维后的高光谱数据分别输入卷积神经网络(CNN)、多层感知机(MLP)、K最邻近算法(KNN)和支持向量机(SVM)建立模型并比较。结果显示,CNN,MLP,KNN和SVM算法均在降维算法DWT(小波基函数及变换层数分别为coif1-2,coif1-4,bior2.2-2和sym2-2)取得最优总体精度分别为91.20%,83.20%,66.40%和90.40%,Kappa系数分别为0.89,0.79,0.58和0.88,预测集用时分别为86.01,63.23,20.02和14.03 ms,总体精度和Kappa指标均优于基于CARS和PCA降维算法建模结果。可见,高光谱与离散小波变换和卷积神经网络相融合显著提高分类识别精度,改善“休斯”现象,为实现无损和快速检测识别大白菜农残提供一个新的方法。  相似文献   
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