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To screen and identify the antimicrobial ingredients of Forsythia suspensa leaves (FL). A screening method based on a constituent knock-out/knock-in strategy was conducted. The antimicrobial activities of FL components against seven commonly infective strains were determined using the Oxford cup method. Their antimicrobial effects when used in combination with common antibiotics were investigated by a checkerboard titration method. Two of the seven strains, Staphylococcus aureus and methicillin-resistant S. aureus (MRSA), were considered to be the most sensitive to the inhibitory effect of FL. The main antimicrobial components in FL were forsythoside I and forsythoside A. The co-administration of vancomycin with forsythoside A was found to have a significant synergistic inhibiting effect on MRSA. Some phenylethanol glycoside components play a major contribution to the antimicrobial effect of FL. This provides a reference for the research and development of FL for both medicinal and food purposes.

In the present paper, an experimental program was carried out to develop J-R curves using clamped single edge notched tension (SENT) specimens. A wide range of geometrical parameter variations is considered including different crack depth to plate width ratios (a/W) and plate thickness to width ratios (B/W). The material studied is the oil and gas pipeline steel API X80. Power law curve fitting parameters and tearing modulus are obtained for the J-R curves using the unloading compliance (UC) method for the clamped SENT specimens. Moreover, in-plane and out-of-plane constraint effects on J-R curves using clamped SENT specimens are studied, the second terms in the Williams’ series expansion are used to quantify the constraint effects. Specifically, it is demonstrated that the normalized T11 and the independent portion of T33, which equals T33-νT11, can be used to quantify the in-plane and out-of-plane constraint effects, respectively. Comparisons show that the constraint dependent J-R curves can reproduce well with all experimental data for clamped SENT specimens. Finally, the present approach is applied to predict the J-R curves of ductile crack extension for other specimens or real engineering structures with varying in-plane and out-of-plane low constraint conditions.

In the present paper, a crack compliance analysis approach and extensive three-dimensional finite element analysis were conducted for clamped SENT specimens, which is one of the most widely used low-constraint specimens for less-conservative fracture toughness testing. A wide range of geometrical parameters variations are considered including in-plane crack depth to plate width ratio (a/W), out-of-plane plate thickness to width ratio (B/W), and daylight to width ratio (H/W). Complete solutions of stress intensity factor (K), in-plane T-stress (T11) and out-of-plane T-stress (T33) are obtained. The results obtained from above two methods are in good agreement. Furthermore, the combination of the effects of crack depths (a/W), plate thickness (B/W), and daylight to width ratio (H/W) on the stress intensity factor, T11 and T33 stress are thus illustrated. To better understand the difference between the derived stress intensity factor solutions and 2D plane strain results, fracture experiments were conducted for clamped SENT specimens with different crack depths. Solutions obtained will be very useful for analyzing fracture toughness test data and determining fatigue crack growth rate for clamped SENT specimens with different crack depths (a/W), plate thickness (B/W), and daylight to width ratio (H/W).

Phillygenin, as an active ingredient of Forsythia suspensa, possesses a wide range of biological and pharmacological activity. However, its development and application are restricted due to its poor bioavailability and low solubility. Our work aimed to develop a self-microemulsifying drug delivery system to improve the oral bioavailability of phillygenin. The composition of the self-microemulsifying drug delivery system was preliminary screened by the pseudo-ternary phase diagram. Subsequently, the central composite design method was employed to optimize the prescription of the self-microemulsifying drug delivery system loaded with phillygenin. The prepared self-microemulsifying drug delivery system of phillygenin was characterized in terms of morphology, droplet size distribution, polydispersity index and stability. Then, the in vitro dissolution and the oral bioavailability were analyzed. The optimized self-microemulsifying drug delivery system of phillygenin consisted of 27.8% Labrafil M1944CS, 33.6% Cremophor EL, 38.6% polyethylene glycol 400 (PEG-400) and 10.2 mg/g phillygenin loading. The prepared self-microemulsifying drug delivery system of phillygenin exhibited spherical and uniform droplets with small size (40.11 &plusmn, 0.74 nm) and satisfactory stability. The in vitro dissolution experiment indicated that the cumulative dissolution rate of the self-microemulsifying drug delivery system of phillygenin was significantly better than that of free phillygenin. Furthermore, after oral administration in rats, the bioavailability of phillygenin was significantly enhanced by the self-microemulsifying drug delivery system. The relative bioavailability of the self-microemulsifying drug delivery system of phillygenin was 588.7% compared to the phillygenin suspension. These findings suggest that the self-microemulsifying drug delivery system of phillygenin can be a promising oral drug delivery system to improve the absorption of phillygenin.

In the production, supply, storage and marketing of natural gas industry, gas measurement is a key link. Aiming at solving the problems in the current ultrasonic gas flowmeter, such as high-power consumption, low measurement accuracy and difficult data transmission, an ultrasonic gas flowmeter based on MAX35104 is designed and implemented. The system takes STM32F103 microcontroller as the control core, adopts the time difference method and uses highprecision timing chip, MAX35104, FUS-200A ultrasonic transducers and PT1000 temperature sensor to acquire instantaneous flowrate and temperature. It also connects LCD through FSMC ports as display module to realize local visualization interface generation, and realizes the function of remote monitoring on cloud server through the EC20, a 4G module, based on LTE communication protocol. In addition, the system has the function of real-time early warning, which is realized by preset threshold as well as the function of errors online diagnosis by analyzing the special state of hardware, which can diagnose the probe connection error, whether the chip working abnormally and the cloud server transmits correctly. With the continuous improvement of the measurement accuracy of the system, it is bound to play a positive role in the development of the natural gas industry.

Because of the size limitation of weld joints in different regions, the traditional standard bar specimen is not suitable to investigate the mechanical properties of weld joints. In this study, miniature specimens were extracted from specific regions (base metal, weld metal, and three heat-affected zones) of API X80 and X70 weld joints. Uniaxial tensile tests were conducted to obtain the mechanical properties of different regions, and then uniaxial ratcheting tests were conducted to investigate the ratcheting behaviors of the different regions under the same peak and nominal stresses. Under both the tensile tests and ratcheting tests, the weld joints exhibit heterogeneous results, such as different mechanical properties and ratcheting behaviors, which were region dependent. Furthermore, the yield strength and yield-to-tensile strength ratio contribute differently to the ratcheting response.

Both unloading compliance method and normalization method specified in ASTM E1820-16 were conducted on the API 5L X70 and X80 pipeline steels. Extensive experimental measures of fracture toughness for different regions of weld joints were carried out. For comparison, the J–R curves and initiation fracture toughness determined using the normalization method are compared with those obtained by the elastic unloading compliance method for two different weld joints. The results show that good agreements exist between the two methods, and an average difference less than 10% is detected. Moreover, the comparison indicates that the J–R curves from the unloading compliance method are lower at the initial stage of crack extension, and as the crack grows, the J–R curves are higher compared with those of the normalization method. For different regions in weld joints, there is clear distinction of differences between the corresponding results from above two methods. A ductile brittle mixed fracture mechanism is found in weld metal and coarse grained heat affected zone, and a corresponding higher deviation is detected.

A series of triphenylene derivatives with six symmetric substituents was synthesized from hexabromotriphenylene. The synthesis was conducted by six-fold palladium-catalyzed Hagihara-Sonogashira cross- coupling reactions to yield the hexa-alkynyl substituted triphenylene derivatives of HTP1, HTP2, HTP3 and HTP4. The six symmetric substituents can not only endow the triphenylene the longer π-conjugated range, but also increase the solubility of the compounds. Their photophysical, electrochemical, thermal properties were investigated respectively. With the comparison of their properties, the structure-property relationships were established which demonstrated the influences of different substituents on the electronic nature and the mesomorphic phase of these disk-shaped molecules. In addition, with the scanning electron microscopy(SEM) and polarized optical microscopy( POM) characterization, the self-assembly behaviors of the compounds were also investigated.

Poly(ethylene oxide)-poly(propylene oxide)–poly(ethylene oxide) ((EO)n–(PO)m–(EO)n) block copolymers, commercially available as Pluronics (BASF Corp.) and Poloxamers (ICI Corp.), have been widely applied in medicine, biochemistry, and other fields because of their ability to form reversible micelles and physical gels in aqueous solution. Generally, for PEO–PPO–PEO block copolymers with higher ethylene oxide concentration, the micellization and gelation in aqueous solution are easier. However, if we introduce the reverse block copolymer PPO–PEO–PPO into PEO–PPO–PEO aqueous solutions, the micellization and gelation of the system will be more complex. In this work, the reverse block copolymer PO14–EO24–PO14 (17R4) was added to the Pluronics EO20–PO70–EO20 (P123), EO100–PO65–EO100 (F127), and EO133–PO50–EO133 (F108) aqueous solutions with different molar ratios. The rheological properties of different mixtures were measured to study the additive effect on the gelation behavior. The sol–gel transition temperat...

A series of novel asymmetrical pyrene derivatives with aralkyl and aldehyde groups have been successfully synthesized, and their spectroscopic parameters were investigated detailedly. The effects of aralkyl substituent amounts on the electronic absorption and emission spectra have been explored in evaluation of their potential as optical materials components. Moreover, the electrochemical properties of the new pyrene derivatives have been studied for the molecules' HOMO and LUMO levels by cyclic voltammograms. In particular, titration of anhydrous ethanol into dilute CH 2 Cl 2 solution of above compounds, an unusual change of the fluorescence value was observed. The change is believed to correlate strongly to intermolecular charge transfer. The morphological evolution of self-assembled pyrene derivatives with (arylethynyl)aldehyde substituents, from tamen-distinct-like morphologies to vesicular textures, was obtained by increasing aralkyl-substituted fragments. These asymmetrical discotic compounds represent an interesting set of candidates for optoelectronic device components.