Synthesis and evaluation of bisulfate/mesylate-conjugated chlortetracycline with high solubility and bioavailability

The aim of this work is to improve the solubility and bioavailability of chlortetracycline and the function of the immune response. Chlortetracycline bisulfate and chlortetracycline mesylate were successfully synthesized and characterized with several techniques, including spectroscopy, chromatography and mass spectrometry, which demonstrated that the C4-dimethylamino group of chlortetracycline can accept a proton from sulfuric acid and methanesulfonic acid to form the corresponding salts. In addition, chlortetracycline bisulfate and chlortetracycline mesylate were more soluble in water than chlortetracycline hydrochloride, but the antibacterial activity was not enhanced. The influences of chlortetracycline hydrochloride, chlortetracycline bisulfate and chlortetracycline mesylate on chlortetracycline and immunoglobulin concentrations in mouse serum were also investigated. These results suggested that the chlortetracycline bisulfate and chlortetracycline mesylate have good bioavailability and strong immune response and have potential applications in animal breeding and formulation technologies

Hot Stamping of High Strength Steel with Tailored Properties by Two Methods

AbstractHot stamped components with full martensite exhibit ultrahigh tensile strength and hardness, whereas the poor ductility restricts their application on certain components, such as B pillar, which needs multi strength in different regions. It is essential to partly achieve softer structure with high ductility, to enhance the crashworthiness and energy absorption of the whole component and thus improving the safety performance. This work described the hot stamping of high strength steel with tailored properties by two methods, namely applying different die temperatures and annealing processes. The hardness distribution, tensile strength and ductility in different regions of the hot stamped components were gained under the conditions of above two methods to realize the tailored properties. Regardless of the decrease of tensile strength, the total elongation of annealed zone can reaches 20.6% while the heating zone can only obtain its elongation of 10.8%. The results show that annealing hardened part to get tailored properties brings about better performance

Mover design and characteristics analysis of 2DoFDDIM

Two degree-of-freedom direct drive induction motor (2DoFDDIM), capable of rotary, linear and helical motion, has widespread application. A new mover structure is proposed, which is made from a hollow cylinder with copper cast in the axial slots and the circumferential slots on its surface. Then, three-dimensional finite element models of 2DoFDDIM are used to determine the performances of rotary, linear and helical motion developed by the motor. The results show that the new mover has a great improvement on the motor performances of all modes of motions compared with the initial mover. The researches on mover structure and characteristics of 2DoFDDIM present a new path of optimisation on 2DoFIM

Relationship between the Composition of Flavonoids and Flower Colors Variation in Tropical Water Lily (Nymphaea) Cultivars

Water lily, the member of the Nymphaeaceae family, is the symbol of Buddhism and Brahmanism in India. Despite its limited researches on flower color variations and formation mechanism, water lily has background of blue flowers and displays an exceptionally wide diversity of flower colors from purple, red, blue to yellow, in nature. In this study, 34 flavonoids were identified among 35 tropical cultivars by high-performance liquid chromatography (HPLC) with photodiode array detection (DAD) and electrospray ionization mass spectrometry (ESI-MS). Among them, four anthocyanins: delphinidin 3-O-rhamnosyl-5-O-galactoside (Dp3Rh5Ga), delphinidin 3-O-(2″-O-galloyl-6″-O-oxalyl-rhamnoside) (Dp3galloyl-oxalylRh), delphinidin 3-O-(6″-O-acetyl-β-glucopyranoside) (Dp3acetylG) and cyanidin 3- O-(2″-O-galloyl-galactopyranoside)-5-O-rhamnoside (Cy3galloylGa5Rh), one chalcone: chalcononaringenin 2′-O-galactoside (Chal2′Ga) and twelve flavonols: myricetin 7-O-rhamnosyl-(1→2)-rhamnoside (My7RhRh), quercetin 7-O-galactosyl-(1→2)-rhamnoside (Qu7GaRh), quercetin 7-O-galactoside (Qu7Ga), kaempferol 7-O-galactosyl-(1→2)-rhamnoside (Km7GaRh), myricetin 3-O-galactoside (My3Ga), kaempferol 7-O-galloylgalactosyl-(1→2)-rhamnoside (Km7galloylGaRh), myricetin 3-O-galloylrhamnoside (My3galloylRh), kaempferol 3-O-galactoside (Km3Ga), isorhamnetin 7-O-galactoside (Is7Ga), isorhamnetin 7-O-xyloside (Is7Xy), kaempferol 3-O-(3″-acetylrhamnoside) (Km3-3″acetylRh) and quercetin 3-O-acetylgalactoside (Qu3acetylGa) were identified in the petals of tropic water lily for the first time. Meanwhile a multivariate analysis was used to explore the relationship between pigments and flower color. By comparing, the cultivars which were detected delphinidin 3-galactoside (Dp3Ga) presented amaranth, and detected delphinidin 3′-galactoside (Dp3′Ga) presented blue. However, the derivatives of delphinidin and cyanidin were more complicated in red group. No anthocyanins were detected within white and yellow group. At the same time a possible flavonoid biosynthesis pathway of tropical water lily was presumed putatively. These studies will help to elucidate the evolution mechanism on the formation of flower colors and provide theoretical basis for outcross breeding and developing health care products from this plant

Synthesis and evaluation of bisulfate/mesylate-conjugated chlortetracycline with high solubility and bioavailability

The aim of this work is to improve the solubility and bioavailability of chlortetracycline and the function of the immune response. Chlortetracycline bisulfate and chlortetracycline mesylate were successfully synthesized and characterized with several techniques, including spectroscopy, chromatography and mass spectrometry, which demonstrated that the C4-dimethylamino group of chlortetracycline can accept a proton from sulfuric acid and methanesulfonic acid to form the corresponding salts. In addition, chlortetracycline bisulfate and chlortetracycline mesylate were more soluble in water than chlortetracycline hydrochloride, but the antibacterial activity was not enhanced. The influences of chlortetracycline hydrochloride, chlortetracycline bisulfate and chlortetracycline mesylate on chlortetracycline and immunoglobulin concentrations in mouse serum were also investigated. These results suggested that the chlortetracycline bisulfate and chlortetracycline mesylate have good bioavailability and strong immune response and have potential applications in animal breeding and formulation technologies

Comparative Investigation of the Experimental Determination of AA5086 FLCs under Different Necking Criteria

The construction of a forming limit diagram (FLD) is a conventional approach to obtain limit strains and to evaluate the formability of sheet metal. Appropriate necking criteria should be applied to determine the forming limit curve (FLC) accurately. In recent years, deep research on the determination of the FLC has been carried out; meanwhile, several necking criteria have been proposed. However, the application of inappropriate necking criteria would cause deviations when determining FLCs. In this study, both Marciniak and Nakajima tests were carried out on the AA5086 aluminum sheet to make a comparative investigation of different necking criteria in the determination of FLCs. In the Marciniak test, four existing necking criteria were chosen to construct FLCs, and analyzed in detail. The well-performed time dependent and position dependent methods were selected for the Nakajima test. Meanwhile, the modified Wang method based on the height change of the adjacent points was proposed. The comparative results showed that the time and position dependent methods were relatively conservative in both experiments, while the modified Wang method could identify the onset of localized necking more accurately

Rod-like Cellulose Regenerated by Bottom-Up Assembly in Natural Rubber Latex and Its Reinforcement

As a renewable biomass material, nano-cellulose has been investigated as a reinforcing filler in rubber composites but has seen little success because of its strong inclination towards aggregating. Here, a bottom-up self-assembly approach was proposed by regenerating cellulose crystals from a mixture of cellulose solution and natural rubber (NR) latex. Different co-coagulants of both cellulose solution and natural rubber latex were added to break the dissolution equilibrium and in-situ regenerate cellulose in the NR matrix. The SEM images showed that the sizes and morphologies of regenerated cellulose (RC) varied greatly with the addition of different co-coagulants. Only when a 5 wt% acetic acid aqueous solution was used, the RC particles showed an ideal rod-like structure with small sizes of about 100 nm in diameter and 1.0 μm in length. The tensile test showed that rod-like RC (RRC)-endowed NR vulcanizates with pronounced reinforcement had a drastic upturn in stress after stretching to 200% strain. The results of XRD and the Mullins effect showed that this drastic upturn in stress was mainly attributed to the formation of rigid RRC-RRC networks during stretching instead of the strain-induced crystallization of NR. This bottom-up approach provided a simple way to ensure the effective utilization of cellulosic materials in the rubber industry

Dynamic Testing and Evaluation of Modulus of Elasticity (MOE) of SPF Dimensional Lumber

The key objective of this work was to develop a cost-effective and reliable non-destructive testing (NDT) method to measure lumber modulus of elasticity (MOE). Test samples comprised 300 pieces of randomly selected imported Canadian 2”×6” SPF (Spruce - lodgepole Pine - alpine Fir) dimensional lumber. This work first adopted a modal test to achieve a free suspension for a subsequent vibration test. Then, the first-order natural frequency of 300 SPF dimensional lumber specimens was measured by the transient excitation frequency method, based on which MOE was then calculated. The results were also validated by a stress wave method using a Hitman tool. The measured lumber MOE data were further fitted using a Weibull distribution. The results showed that the MOE of SPF dimensional lumber followed either a three-parameter Weibull distribution or a normal distribution. It was estimated that the probability that the MOE of this SPF dimensional lumber was less than 8,000 MPa was about 13.8% and 13.6%, respectively, using the above two distributions