Therapeutic effects of Bombax ceiba flower aqueous extracts against loperamide-induced constipation in mice.

CONTEXT: Bombax ceiba Linnaeus (Bombacaceae) is known as silk cotton tree, the flowers of which are used in many medicinal applications. OBJECTIVE: To investigate the therapeutic effect of B. ceiba flower aqueous extracts (BCE) against loperamide-induced constipation and characterize the chemical composition of BCE. MATERIALS AND METHODS: Sixty male Kunming mice were divided into control (saline), model (10 mg/kg loperamide + saline), phenolphthalein (10 mg/kg loperamide + 10 mg/kg phenolphthalein) and different dosage of BCE (10 mg/kg loperamide + 40, 80 and 160 mg/kg BCE, respectively) groups, and received intragastric administrations for eight days. Faecal water content, number of faeces, first black-stool defecation time and gastrointestinal transit rates were evaluated. Various biochemical and molecular biomarkers were assessed in blood and colon. UPLC-ESI-QTOF-MS/MS was used to tentatively identify the composition of the BCE. RESULTS: BCE treatment (160 mg/kg) could increase faecal water (15.75%), faeces number (11.65%), gastrointestinal transit rate (25.37%) and decrease first black-stool defecation time (24.04%). The BCE (80 mg/kg) increased the serum level of motilin (30.62%), gastrin (54.46%) and substance P (18.99%), and decreased somatostatin (19.47%). Additionally, the BCE (160 mg/kg) reduced the mucosal damage, restored colonic goblet cell function, down-regulated the protein expression of AQP3 (33.60%) and increased c-kit protein expression (11.63%). Twelve known compounds, including protocatechuic acid, chlorogenic acid and rutin, previously reported in B. ceiba, were identified in the BCE. DISCUSSION AND CONCLUSIONS: This study suggested that BCE is a promising agent for the treatment of constipation.

A Complete Key Management Scheme for LoRaWAN v1.1.

Security is one of the major concerns of the Internet of Things (IoT) wireless technologies. LoRaWAN is one of the emerging Low Power Wide Area Networks being developed for IoT applications. The latest LoRaWAN release v.1.1 has provided a security framework that includes data confidentiality protection, data integrity check, device authentication and key management. However, its key management part is only ambiguously defined. In this paper, a complete key management scheme is proposed for LoRaWAN. The scheme addresses key updating, key generation, key backup, and key backward compatibility. The proposed scheme was shown not only to enhance the current LoRaWAN standard, but also to meet the primary design consideration of LoRaWAN, i.e., low power consumption.

Enhanced trajectory tracking for quadrotors: disturbance observer state feedback control.

This study investigates the dynamics and trajectory tracking of quadcopters by utilizing the Disturbance Observer-based Control (DOBC) algorithm. The quadcopter's dynamic model, which consists of six degrees of freedom, includes both disturbances and uncertainties in the model. The DOBC approach incorporates the disturbance model into the system by introducing it at the input variables. It then compensates for disturbances to achieve accurate tracking of different reference trajectories. The simulated trajectories span a range of motion, varying from simple straight paths to complex spiral paths. In order to verify and evaluate the efficacy of the suggested control technique, simulations are performed using MATLAB. The simulations conclusively show that the disturbance observer-based method effectively achieves the tracking of specified reference trajectories in three-dimensional space. The study highlights the effectiveness of the DOBC algorithm in reducing the effects of disturbances and uncertainties, thereby improving the quadcopter's capacity to accurately track various trajectories.

Numerical Strength Analysis of Laser-Welded Differential Housing and Gear Considering Residual Stress.

In order to avoid slackening of differential housing and gear joined by bolts, the laser-welding process is proposed in this paper, and the strength of a connecting joint was estimated by numerical analysis with consideration of welding residual stress. The process parameters of laser welding for dissimilar materials QT600 cast iron and 20MnCr5 structural alloy steel were introduced, and chemical composition analysis and microstructure analysis were conducted on the welded joints. The finite element model of laser-welded differential housing and gear was established to obtain the welding residual stress by applying a moving heat source. To verify the accuracy of the simulated result, static pressing tests were employed. The maximum tensile residual stress was 319.4 MPa, located at the same point as the maximum temperature. The simulated stress agreed well with the experimental data. Finally, the dynamic strength of laser-welded differential housing and gear under forward, reverse, and start-up conditions was assessed by regarding welding residual stress as the initial stress field, which showed that all safety factors were greater than 1.4.

[Study on the fingerprint of Morus alba from different habitats by HPLC].

OBJECTIVE: To establish HPLC fingerprint of Morus alba from different habitats by HPLC and provide basis for its quality control. METHODS: HPLC analysis was performed on an Agilent XDB C18 Column (4.6 mm x 250 mm, 5 microm), gradient eluted composed of acetonitrile and 0.3% phosphate acid. The column temperature was set at 35 degrees C and the flow rate was 0.5 mL/min. The detective wavelength was 290 nm. The HPLC fingerprint for 10 batches of Morus alba was studied on their similarity. RESULTS: There were twelve common peaks in the fingerprint. The similarity of 7 batches was above 0.9 and the other batches had low similarity. CONCLUSION: The HPLC fingerprint can be used for quality control of Morus alba with high characteristics and specificity.

Life Prediction Method of Dissimilar Lightweight Materials Welded Joints with Precrack under Coupled Impact-Fatigue Loading.

This paper aims to explore the fatigue life estimation approach of welded joints with precrack under coupled impact and fatigue loading, and the base metal is dissimilar 5083H111 and 5754 aluminum alloy. Impact tests are first carried out on the dissimilar lightweight materials welded joint with precrack located in the middle of the specimen, and a stress and strain field is obtained to determine the fatigue damage model parameters by using finite element dynamic analysis to simulate the impact process. Based, on the S-N curve of welded joints, the predicted life expectancy is found to be inconsistent with the experimental results. According to the continuum damage mechanics, the lifetime assessment model is presented to calculate both impact and fatigue damage. The estimated results agree well with the experimental ones.

Cloning and expression of SgCYP450-4 from Siraitia grosvenorii.

CYP450 plays an essential role in the development and growth of the fruits of Siraitia grosvenorii. However, little is known about the SgCYP450-4 gene in S. grosvenorii. Here, based on transcriptome data, a full-length cDNA sequence of SgCYP450-4 was cloned by reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid-amplification of cDNA ends (RACE) strategies. SgCYP450-4 is 1677 bp in length (GenBank accession No. AEM42985.1) and contains a complete open reading frame (ORF) of 1422 bp. The deduced protein was composed of 473 amino acids, the molecular weight is 54.01 kDa, the theoretical isoelectric point (PI) is 8.8, and the protein was predicted to possess cytochrome P450 domains. SgCYP450-4 gene was highly expressed in root, diploid fruit and fruit treated with hormone and pollination. At 10 days after treatment with pollination and hormones, the expression of SgCYP450-4 had the highest level and then decreased over time, which was consistent with the development of fruits of S. Grosvenorii. Hormonal treatment could significantly induce the expression of SgCYP450-4. These results provide a reference for regulation of fruit development and the use of parthenocarpy to generate seedless fruit, and provide a scientific basis for the production of growth regulator application agents.

[Effects of electroacupuncture at "Zusanli" (ST 36) on Pharmacokinetics of paracetamol in rates].

OBJECTIVE: To investigate influence of electroacupuncture at "Zusanli" (ST 36) on pharmacokinetics after oral administration of Paracetamol in rats and explore the effect and mechanism of acupuncture combined with medicinal drugs. METHODS: Forty-eight SD rats, in half respectively male and female, were randomly divided into 6 groups: Paracetamol groups of low, moderate, and high doses (oral dose of Paracetamol 300, 600 or 1200 mg/kg, respectively), and electroacupuncture plus Paracetamol groups of low, moderate, and high doses (electroacupuncture at "Zusanli" (ST 36) acupoint for 20 min after oral dose of Paracetamol 300, 600 or 1 200 mg/kg, respectively). Serum specimens of rats in each group were obtained at different time points to determine the concentrations of Paracetamol by RP-HPLC after oral administration of Paracetamol at different dosage, and the pharmacokinetic parameters were calculated by software 3P87, so as to observe the influence of electroacupuncture on absorption and metabolism of Paracetamol. RESULTS: Except in electroacupuncture plus Paracetamol groups of high doses group showing a non-linear dynamics model, the pharmacokinetics parameters of Paracetamol in the other fives groups were all fitted to first order grade absorption of two-compartment open model. Compared with the Paracetamol groups of low and moderate doses, the time to peak concentration (T(max)) was advanced (P < 0.01), the peak values of plasma concentration (C(max)) were significantly higher (P < 0.01), and the absorption half-life (T1/2ka) speeded up apparently (P < 0.01), but the elimination half-life (T1/2ke) remained basically unchanged (P > 0.05), and the area under the curve (AUC) increased significantly (P < 0.01), and plasma clearance (Cl(s)) was lower (P < 0.01) in the electroacupuncture plus Paracetamol groups of low and moderate doses. Compared with the Paracetamol group of high doses, the AUC also increased significantly (P < 0.01) and the mean residence time (MRT) postponed relatively (P < 0.05) in the electroacupuncture plus Paracetamol group of high doses. CONCLUSION: It indicates that clinical consideration must be given to the drug dosage and the possible influence of electroacupuncture on the metabolism of some drugs in order to avoid and reduce adverse reactions.