Modeling and prediction of the transmission dynamics of COVID-19 based on the SINDy-LM method.

The transmission dynamics of COVID-19 is investigated in this study. A SINDy-LM modeling method that can effectively balance model complexity and prediction accuracy is proposed based on data-driven technique. First, the Sparse Identification of Nonlinear Dynamical systems (SINDy) method is used to discover and describe the nonlinear functional relationship between the dynamic terms in the model in accordance with the observation data of the COVID-19 epidemic. Moreover, the Levenberg-Marquardt (LM) algorithm is utilized to optimize the obtained model for improving the accuracy of the SINDy algorithm. Second, the obtained model, which is consistent with the logistic model in mathematical form with small errors and high robustness, is leveraged to review the epidemic situation in China. Otherwise, the evolution of the epidemic in Australia and Egypt is predicted, which demonstrates that this method has universality for constructing the global COVID-19 model. The proposed model is also compared with the extreme learning machine (ELM), which shows that the prediction accuracy of the SINDy-LM method outperforms that of the ELM method and the generated model has higher sparsity.

Short-term hypoxia upregulated Mas receptor expression to repress the AT1 R signaling pathway and attenuate Ang II-induced cardiomyocyte apoptosis.

Hypertension-stimulated cardiac hypertrophy and apoptosis play critical roles in the progression of heart failure. Our previous study suggested that hypertensive angiotensin II (Ang II) enhanced insulin-like growth factor receptor II (IGF-IIR) expression and cardiomyocyte apoptosis, which are involved JNK activation, sirtuin1 (SIRT1) degradation, and heat-shock transcription factor 1 (HSF1) acetylation. Moreover, previous studies have implied that short-term hypoxia (STH) might exert cardioprotective effects. However, the effects of STH on Ang II-induced cardiomyocyte apoptosis remain unknown. In this study, we found that STH reduced myocardial apoptosis caused by Ang II via upregulation of the Mas receptor (MasR) to inhibit the AT1 R signaling pathway. STH activates MasR to counteract the Ang II pro-apoptotic signaling cascade by inhibiting IGF-IIR expression via downregulation of JNK activation and reduction of SIRT1 degradation. Hence, HSF could remain deacetylated, and repress IGF-IIR expression. These effects decrease the activation of downstream pro-apoptotic and hypertrophic cascades and protect cardiomyocytes from Ang II-induced injury. In addition, we also found that silencing MasR expression enhanced Ang II-induced cardiac hypertrophy and the apoptosis signaling pathway. These findings suggest a critical role for MasR in cardiomyocyte survival. Altogether, our findings indicate that STH protects cardiomyocytes from Ang II-stimulated apoptosis. The protective effects of STH are associated with the upregulation of MasR to inhibit AT1 R signaling. STH could be a potential therapeutic strategy for cardiac diseases in hypertensive patients.

[Simultaneous determination of six triterpenoid acids from Guizhi Fuling capsules by UPLC-MS/MS].

To establish a UPLC-MS/MS method for simultaneous determination of six triterpenoid constituents (pachymic acid, dehydropachymic acid, dehydrotumulosic acid, polyporenic acid C, dehydroeburicoic acid and dehydrotra metenolic acid) in Guizhi Fuling capsules (GFC). Chromatographic analysis was conducted on Agilent Porosheell 120 SB-C18 column (4.6 mm×150 mm, 2.7 µm), with 0.1% formic acid aqueous solution-methanol as the mobile phase for gradient elution at a flow rate of 0.4 mL•min-1. The column temperature was 30 ℃ and the sample size was 5 µL. The samples were analyzed by tandem mass spectrometer with negative electrospray ionization (ESI) source, and monitored under a multiple reaction monitoring (MRM) mode, with the quantitative ion pairs m/z 527.8→465.5 (pachymic acid), m/z 525.6→465.6 (dehydropachymic acid), m/z 483.4→337.3 (dehydrotumulosic acid), m/z 481.5→419.5 (polyporenic acid C), m/z 467.4→337.1 (dehydroeburicoic acid), m/z 453.4→337.0 (dehydrotra metenolic acid). Six triterpenoid acids showed good linear relationships within the investigated concentration ranges (r> 0.996 8), with RSDs of precision less than 6.2%, and all RSDs of repeatability less than 5.9%. The average recovery rate was 97.90%, 100.2%, 99.60%, 101.7%, 102.6% and 103.0% respectively. The method was rapid, accurate, repeatable and could be used as a method for quantitative determination of triterpenoid acids in Chinese medicine prescriptions, providing a reference method for the quality control of Guizhi Fuling capsules and providing a reference for the content determination for Chinese medicine prescriptions containing Poria cocos.

[Rapid analysis on chemical constituents in Yinyanghuo Zonghuangtong capsule by UPLC/Q-TOF-MS/MS].

To analyze and identify the chemical constituents from Yinyanghuo Zonghuangtong capsule by using UPLC/Q-TOF-MS/MS. Chromatographic separation was carried out on an Agilent SB-C18 column (2.1 mm×100 mm, 1.8 µm) at the temperature of 30 ℃. The mobile phase was 0.1% formic acid and acetonitrile by gradient elution, with a flow rate at 0.30 mL•min⁻¹, and the injection volume of 2 µL. The MS spectrum was acquired in both negative and positive ion modes using ESI ion source. Based on relative accurate molecular weight, secondary mass spectrometry pyrolysis fragments and chromatographic peak retention time, as well as fragmentation regularity summarized from reference substance and the literature, we could effectively identify the chemical structure of the components under test. As a result, a total of 46 compounds, including flavonoid glycosides, phenolic acids and alkaloids, were successfully identified or tentatively predicted. The results provide technical support for quality control and late-stage clinical application of Yinyanghuo Zonghuangtong capsule, and reference for further expound the pharmacodynamic material basis.

[Rapid identification of chemical components in Congrong Zonggan capsule by UPLC-Q-TOF-MS/MS].

This study was aimed to qualitatively analyze the chemical components in Congrong Zonggan capsule by using ultra-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry method (UPLC-Q-TOF-MS/MS). An Agilent SB-C18 Rapid Resolution HD (3.0 mm×100 mm,1.8 µm) was used with acetonitrile (A) - 0.1% formic acid solution (B) as the mobile phase for gradient elution. The flow rate was 0.2 mL•min⁻¹; the detection wavelength was set at 330 nm and the column temperature was maintained at 30 ℃. Electrospray ion (ESI) source was applied for the qualitative analysis under the negative ion mode. Finally, based on comparison with standard samples, database matching analysis and reviewing relevant literature, 41 compounds were identified from Congrong Zonggan capsule. This method could be used to rapidly detect the chemical components in Congrong Zonggan capsule, providing reference for the quality control of Congrong Zonggan capsule and laying a foundation for the further study on active components mechanism.

[Quality analysis of Guizhi Fuling capsule before and after application of in-process quality control in pharmaceutical production].

The effects of application of in-process quality control in Guizhi Fuling capsule production were evaluated by 192 batches data analysis. Using a statistical analysis method, each batch of data were to be counted to research for the difference between 96 samples adopting the technologies of in-process control or not. According to quality standards of Guizhi Fuling capsule, all measurements of the 192 batches of the drugs before and after the application of process control technology were analyzed, and they were within the rules. There was a significant difference between adopting the technologies of process control or not. Application of in-process control technology can improve the uniformity of lot-to-lot for Guizhi Fuling capsule.

[Fingerprint analysis of Resina Draconis from different manufactuers by UPLC coupled with chemometrics].

This study is to establish an UPLC fingerprint of Resina Draconis from different manufacturers, which can provide a comprehensive evaluation for its quality control. The analysis was performed on a Phenomenex Kinetex 2.6 µ C18 100A column by agradientelution program with acetonitrile-water as mobile phase at a flow rate of 1.7 mL x min(-1). The column temperature was 40 degrees C and the detection wavelengthwas 280 nm. The fingerprints of 18 batches of Draconis Resina were further evaluated by chemometrics methods including similarity analysis (SA), hierarchical clustering analysis (HCA) and principal component analysis (PCA). As a result, there were 15 common peaks, 13 of which had been identified by LC-Q-TOF MS, and the similarity degrees of 15 batches of the samples was more than 0.9, and the samples were divided into 4 clusters by their quality difference. The method is reproducible, simple and reliablethat it can be used for quality control and evaluation of Resina Draconis from different manufacturers.

[Qualitative and quantitative detection of Poria cocos by near infrared reflectance spectroscopy].

OBJECTIVE: The present study is concerning qualitative and quantitative detection of Poria cocos quality based on FT-near infrared (FT-NIR) spectroscopy combined with chemometrics. METHOD: The Poria cocos polysaccharides contents were determined by UV. Transmission mode was used in the collection of NIR spectral samples. The pretreatment method was first derivation and vector normalization. Then principal component analysis (PCA) was used to build classification model and partial least square (PLS) to build the calibration model. RESULT: The results showed that conventional criteria such as the R, root mean square error of calibration (RMSEC), and the root mean square error of prediction (RMSEP) are 0.944 0, 0.072 1 and 0.076 2, respectively. The misclassified sample is 0 using the qualitative model built by PCA. CONCLUSION: The prediction models based on NIR have a better performance with high precision, good stability and adaptability and can be used to predict the polysaccharose content of Poria cocos rapidly, which can provide a fast approach to discriminate the different parts of Poria cocos.

[Investigation of elemental concentration and extraction rate of polysaccharides from Liuwei Dihuang prescription" by ICP-MS].

A method was established for the simultaneous analysis of 25 trace elements and heavy metals in polysccharides from Liuwei Dihuang prescription, including Li, Be, B, Ti, Mg, Al, V, Cr, Mn, Co, Fe, Ni, Cu, Zn, Ga, As, Sr, Cd, Sn, Sb, Ba, Hg, Tl, Pb, Bi. The different rate of elemental extraction in Al, Fe, Mg, B, Ti, Mn, Zn, Sr, Ba was made in water and different concentration of alcohol. The samples, digested via microwave, calibrated by internal standard elements such as Ge and In, with bush branches and leaves as the controlled reference standard, were inlet into ICP-MS to analyze the contents of the 24 trace elements and heavy metals. The detection limits of the 24 elements were in the range of 0.007-2.225 µg · L(-1), while the RSD was below ≤ 4. 0%, with their recovery ranging from 84. 1% to 116%. Big different of the elemental extraction rates could be found by using different ethanol solutions. The method is simple, rapid and accurate, and can be used for the quality control of trace elements and heavy metals in Liuwei Dihuang polysccharides. With the aid of the obtained result, we may increase the extraction of necessary element while making an attempt at multi-element speciation in polysccharides from Liuwei Dihuang.

[Study on HPLC fingerprint of Congrong Zonggan capsule].

HPLC fingerprint of Congrong Zonggan capsule was established in order to provide basis for quality evaluation. With acteoside as the reference, HPLC was adopted for fingerprint analysis on Congrong Zonggan capsule. The chromatographic conditions wereas follows. Waters C18 column (4.6 mm x 150 mm, 5 µm) was used, with methylalcohol-0.1% formic acid as the mobile phase for gradient elution at the flow rate of 1.0 mL x min(-1). The detection wavelength was 330 nm, and the column temperature was 30 °C. This method was highly accurate and reproducible. All of the 13 components in tested samples reached the baseline resolved peak, and 15 batches of finished products showed the similarity of above 0.95. The method was accurate and feasible and could be used as a simple and effective method to evaluate the quality of the traditional Chinese medicines.

[Determination of polysorbate 80 in Reduning injection by HGPC-ELSD].

OBJECTIVE: To establish the method for determining polysorbate 80 in Reduning injection by HPLC-ELSD, and to control the mass of polysorbate 80 in Reduning injection. METHOD: It was performed by HGPC-ELSD with TOSHTSK-GEL G4000PWxl (7.8 mm x 300 mm, 10 µm). Water was used as mobile phase, the flow rate was 0.7 mL x min(-1), and the temperature was set at 30°C. The evaporated light scattering detector was adopted. The drift tube temperature was 55°C, and nitrogen was used as carrier gas, with the flow rate of 2.0 L x min(-1) and gain of 1.0. RESULT: The calibration curve showed good linearity of polysorbate 80 in the test range from 1.01 to 15.20 g x L(-1) (r2 = 0.999 3). The recovery rate was 98.10% with RSD of 2.0%. CONCLUSION: The method is simple, rapid, accurate and reliable and suitable for the determination of polysorbate 80 in Reduning injection.

[Analysis methodology of multi element in four herbs of guizhi fuling capsules].

This paper was focused on establishing a ICP-MS method with microwave digestion for simultaneous determination of lead, copper, arsenic, cadmium, mercury, magnesium, manganese, nickel, thallium in cassia tuckahoe capsule and its five raw herbal materials. Internal standard method was adopted to reduce matrix effect and other interference effects. The method established was shown to be simple with high sensitivity, strong specificity and good reproducibility. Linear relationship is good as R2 ≥ 0.999 3 while the average recovery was among 75.84% - 118.9%. The detection limit was 0.016 - 4.593 µg x L(-1). Data in this paper provided the basis for control of deleterious element in Guizhi Fuling capsules, and further more it was with referencing values for control of deleterious element in other crude drug.

[Study on HPLC fingerprint of jinzhen oral solution].

The HPLC fingerprint determination method of Jinzhen oral solution was established to provide a new method for quality control of Jinzhen oral solution. RP-HPLC was used for phenomenex Luna C18 (4.6 mm x 250 mm, 5 µm) chromatographic column, with 0.1% H3 PO4 water solution and acetonitrile as the mobile phase for gradient elution. The detection wavelength was 280 nm. HPLC fingerprint of Jinzhen oral solution was established to identify 17 common peaks in Jinzhen oral solution. The similarity of fingerprints of 10 batches of finished products was more than 0. 90. The established HPLC fingerprint has a better precision, reproducibility and stability, and can be applied in quality control of Jinzhen oral solution.

[Application of quantitative fingerprint to amino acids composition analysis of Xingnao Tongluo injection].

OBJECTIVE: To control the quality of the product, quantitative fingerprint was used to evaluate the composition of the amino acids in the Xingnao Tongluo injection. METHOD: The method of the quantitative fingerprint to the amino acids composition was established through AccQ Tag precolumn derivatization. The quality was evaluated by the quantitative test of the amino acids and the similarity in ten batches. RESULT: The Xingnao Tongluo injection contained 12 amino acids and the contents of these amino acids were stable. All the ten batches of the samples had similarity of more than 0.90. CONCLUSION: The method was accurate, feasible and could be a simple and effective way to evaluate the quality of the traditional Chinese medicine.

[Study on HPLC fingerprint of triterpene acids in different medicinal parts of Poria].

OBJECTIVE: To establish an analytical method for the fingerprint of triterpenoid constituents of Poria by HPLC and compare the fingerprints of different medicinal parts of Poria in order to provide basis for controlling Poria quality. METHOD: The HPLC chromatographic conditions were Waters Symmetry C18 column (4.6 mm x 250 mm, 5 µm), 0.1% phosphoric acid (A) and acetonitrile (B) as gradient mobile phases, flow rate being 1.0 mL x min(-1), column temperature at 30 degrees C, The detection wavelength was set at 210 nm; The cluster analysis was carried on by SPSS 15.0. RESULT: The HPLC fingerprints of triterpenoid constituents of Poria were set up. There were 16 common peaks in different medicinal parts. The results of method validation met technical requirement of fingerprints; Triterpenoid constituents in White Poria and Poria cum Radix Pini were different from Poria. The content of pachymic acid was the highest in Poria. The effect of habitat on the quality was no obvious difference. CONCLUSION: The method is stable, reliable, reproducible, and can be used as an effective means of Poria quality evaluation.

[Chemical constituents of Poria cocos].

The chemical constituents of Poria cocos were studied by means of silica gel, ODS column chromatography, Sephadex LH-20 and preparative HPLC. Thirteen compounds were isolated from this plant. By analysis of the ESI-MS and NMR data, the structures of these compounds were determined as tumulosic acid (1), dehydrotumulosic acid (2), 3beta, 5alpha-dihydroxy-ergosta-7, 22-dien-6-one (3), 3beta, 5alpha, 9alpha-trihydroxy-ergosta-7, 22-diene -6-one (4), ergosta-7, 22-diene-3-one (5), 6, 9-epoxy-ergosta-7,22-diene-3-ol (6), ergosta-4,22-diene-3-one (7), 3beta, 5alpha, 6beta-trihydroxyl-ergosta-7,22-diene (8), ergosta-5, 6-epoxy-7,22-dien-3-ol (9), beta-sitosterol (10), ribitol (11), mannitol (12), and oleanic acid 3-O-acetate (13), respectively. Compounds 3-13 were isolated from the P. cocos for the first time.

[HPLC fingerprint of liuwei dihuang soft capsule].

In order to establish HPLC fingerprint of Liuwei Dihuang soft capsule, and to provide certain reference for an quality control of it, the HPLC method was performed on an Agilent C18 (4.6 mm x 250 mm, 5 µm) column with acetonitrile-0.02% trifluoroacetic acid as mobile phase, gradient elution volume flow of 1.0 mL x min(-1), column temperature was 30 degrees C, detection wavelength: 0-60 min, 238 nm, 60-70 min, 210 nm. The software for chromatographic fingerprint was applied to analysis different batches of Liuwei Dihuang soft capsule samples. Sixteen mutual peaks were selected as the fingerprint peaks in 12 samples with loganin as the reference peak, and all of the detected peaks were separated effectively. Cluster analysis (HCA) and similarity analysis (SA) were done based on data of 12 samples clustering analysis of 12 batches of samples were divided into 2 categories. Including 7 for the first class, the rest was second, similarities calculated by SA were all above 0.92, indicating a good similarity between the reference and twelve batches of samples, also, the analysis results of HCA and SA basically the same. This method is simple with good precision, repeatability and stability, and provides the basis for Liuwei Dihuang soft capsule quality control.

Quantitative assessment of aerosol contamination generated during tooth grinding with a speed-increasing handpiece.

OBJECTIVES: Tooth grinding produces a significant amount of aerosol particles. The aim of this study was to quantitatively assess particle contamination produced from tooth grinding with a speed-increasing handpiece across a real-world clinical setting. METHODS: All molar crowns were pretreated into cylinders with a uniform size. A novel computer-assisted numerical control system was used to parametrically study the bur speed: from 20,000 (20 K) to 200 K rpm at 20 K rpm intervals. 5-minute tooth grinding was performed in triplicate at each speed setting. Three online real-time particle counters (ORPC; TR-8301, TongrenCo.) were placed at 3 positions (0.5, 1, and 1.5 m) to evaluate particle production. All experimental instruments were controlled remotely. The data obtained were statistically analyzed using descriptive statistics and non-parametric tests (Scheirer-Ray-Hare and Kruskal-Wallis/ Dunn-Bonferroni tests, p < 0.05). RESULTS: The concentration level of aerosol particles production during the grinding experiment was elevated above the control group for all conditions, and increased with bur speed at any location (the maximum peak, reaching 5.59 × 107 particles/m3, at 200 K and 1 m), with differences between conditions. The effect of speed on the increment of particles across different channels compared to the control group was statistically significant among locations (p < 0.001). CONCLUSIONS: Statistically significant particle contamination was produced using a speed-increasing handpiece, but the contamination level for each experimental condition was reduced to baseline within 30 min, and most particles with a diameter greater than 1üm produced at low speeds (80 K or lower) tended to settle within 1 m. CLINICAL RELEVANCE: Our study suggested that the use of a speed-increasing handpiece below 80 K and 30 min of fallow time may lead to an adequate reduction in the health effects of particle contamination.

The evaluation and implementation of Direct Analysis in Real Time quadrupole time-of-flight tandem mass spectrometry for characterization and quantification of geniposide in Re Du Ning Injections.

RATIONALE: The Direct Analysis in Real Time (DART) ionization source coupled with a quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) system has the capability to desorb analytes directly from samples from complex Chinese herbal preparations without sample cleanup or chromatographic separation. METHODS: In this work, a method based on DART/Q-TOF MS/MS has been developed for rapid determination of geniposide present in 'Re Du Ning Injections', a Chinese herbal preparation. The method has been evaluated for both qualitative and quantitative analysis of geniposide in Re Du Ning Injections. RESULTS: Variables including polarity for ion detection, DART gas heater temperature, matrix effect and sample presentation speed were investigated. The quantitative method was validated with respect to linearity, sensitivity, repeatability, precision and accuracy by using both internal and external standards. A comparison of the results obtained using the DART-based method was made with those obtained using a conventional High-Performance Liquid Chromatography/Diode-Array Detector (HPLC/DAD) by analyzing geniposide in four batches of Re Du Ning Injections. CONCLUSIONS: The DART/Q-TOF MS/MS-based method provides a rapid, efficient and powerful method to analyze compounds from complex Traditional Chinese Medicines with limited sample preparation thus reducing time and complexity of quality control for those materials.

Effect of subzero-balanced ultrafiltration on lung gas exchange capacity after cardiopulmonary bypass in adult patients with heart valve disease.

OBJECTIVES: This study was conducted to evaluate the effect of a new ultrafiltration technique--the subzero-balanced ultrafiltration (SBUF)--on lung gas exchange capacity after cardiopulmonary bypass (CPB) in adult patients with heart valve disease. BACKGROUND: Attenuation of lung gas exchange capacity is one of the most common manifestations of an inflammatory response after CPB. METHODS: Ninety-four patients who required CPB for cardiac surgery were randomized into 2 groups according to whether they received SBUF. Gas exchange capacity expressed as the oxygen index (OI), the respiratory index (RI), and the alveolar-arterial oxygen pressure difference (P(A-a)O2) were measured after intubation (T1), at the termination of CPB (T2), on admission to the intensive care unit (ICU) (T3), at postoperative hour 6 (T4), and at postoperative hour 12 (T5). RESULTS: There were no significant differences in gas exchange capacity between the 2 groups at T1, T4, and T5. CPB produced significant changes in OI, RI, and P(A-a)O2 in the control group, whereas these changes were not significantly different in the study group. The OI in the study group was significantly higher at T2, and RI and P(A-a)O2 were significantly lower at T2 and T3. In the study group, the intubation time was shorter, and the transfusion volume within 24 hours postoperatively was less. The 2 groups were comparable with respect to the incidence of respiratory complications, length of stay in the ICU, duration of hospital stay, need for infusions of inotropic agents, and drainage volumes within 24 hours postoperatively. CONCLUSIONS: SBUF during CPB can produce an immediate improvement in lung gas exchange capacity, which may effectively minimize pulmonary dysfunction in adult patients undergoing cardiac surgery.