Development of similar materials for fluid-solid coupling model testing and application in damage constitutive models.

In order to provide suitable material selection for such fluid-solid coupling model tests, orthogonal experimental studies were conducted using iron concentrate powder and barite powder as aggregates, cement as cementitious materials, and gypsum and clay as modifiers. This research showed: (1) The ATC plays a dominant role in controlling the strength indexes and water absorption of the material, and these indexes show a significant decrease with the increase of the bone adhesive ratio. For each level of ATC increase, the compressive strength decreases by 0.2 MPa, the elastic modulus decreases by 10-20 MPa, and the cohesion decreases by 25-45 kPa. (2) Mixing gypsum and cement cannot jointly promote strength growth. (3) With the increase of GTC, the water absorption rate of the material increases, while the softening coefficient and permeability coefficient decrease obviously. Gypsum, which accounts for 4-16% of cement content, can be suitable for studying the hydraulic properties of similar materials for most sedimentary rock. Based on Weibull statistical damage theory, a damage constitutive model for the entire process of rock triaxial compression under the combined action of rainwater infiltration and load was established. Due to the influence of internal pores, the experimental and theoretical results have a certain deviation, the higher the confining pressure, the more obvious the deviation. In addition, the higher the rock strength, the less obvious the deviation caused by pores. This damage model can better describe the progressive failure process of rocks after rainwater infiltration, and can provide theoretical reference for the study of slope stability caused by rainwater infiltration.

An Experimental Study on the Preparation of Soft Rock Similar Materials Using Redispersible Latex Powder as a Modifier.

The engineering geological problems of soft rock are common in large slope engineering and underground engineering surrounding rock. In order to study the change in mechanical properties of soft rock under the action of loading, excavation and rainfall, this paper carried out experimental research on similar materials of soft rock. The similar material of soft rock is prepared by using iron fine powder, barite powder and quartz sand as aggregate, gypsum as binder and redispersible latex powder as regulator. A single-factor influence test was designed with the content of redispersible latex powder as variation parameter. Analysis the influence of redispersible latex powder from the perspectives of physical and mechanical indexes, failure forms, stress-strain states and changes after water seepage. In addition, evaluate the feasibility of this similar material in geomechanical model test. Experimental results show that the density, compressive strength and Poisson's ratio of similar materials can be improved to a certain extent by the redispersible latex powder with low dosage. However, the above indexes show a significant downward trend with the increase in dosage when the dosage exceeds 2%. The deformation modulus always shows a downward trend, and this trend becomes more significant especially when the dosage exceeds 2%. With the increase in the redispersible latex powder, the stress-strain curves of similar materials show obvious elastic and plastic stages. The failure mode gradually changes to X-shaped conjugate failure, which is common in soft rock, and the material changes from brittle failure to plastic failure. In addition, this type of similar material with gypsum as cementing agent will cause serious damage and loss of bearing capacity after seepage. These methods produce similar materials with low strength, low deformation modulus and plastic failure form, which can be used to simulate the stability of soft rock engineering caused by loading or excavation. At the same time, it also sheds lights on preparing similar materials of hard rock.

[Studying on purification technology of Resina Draconis phenol extracts based on design space method].

The "design space" method was used to optimize the purification process of Resina Draconis phenol extracts by using the concept of "quality derived from design" (QbD). The content and transfer rate of laurin B and 7,4'-dihydroxyflavone and yield of extract were selected as the critical quality attributes (CQA). Plackett-Burman design showed that the critical process parameters (CPP) were concentration of alkali, the amount of alkali and the temperature of alkali dissolution. Then the Box-Behnken design was used to establish the mathematical model between CQA and CPP. The variance analysis results showed that the P values of the five models were less than 0.05 and the mismatch values were all greater than 0.05, indicating that the model could well describe the relationship between CQA and CPP. Finally, the control limits of the above 5 indicators (content and transfer rate of laurine B and 7,4'-dihydroxyflavone, as well as the extract yield) were set, and then the probability-based design space was calculated by Monte Carlo simulation and verified. The results of the design space validation showed that the optimized purification method can ensure the stability of the Resina Draconis phenol extracts refining process, which would help to improve the quality uniformity between batches of phenol extracts and provide data support for production automation control.

[Evaluate effects of different drying methods on quality of Tianshu capsule on substance basis].

To investigate the effect of hot air circulation drying and spray drying on the quality of Tianshu capsule from the view point of chemical compositions. UPLC-DAD was used to establish the fingerprint of Tianshu capsules for the first time, and the main chemical constituents were identified by UPLC-Q-TOF-MS/MS. A total of 62 compounds were identified in this method, 21 of which were reported in Tianshu capsules for the first time. The results showed that there were no significant differences in the identification of the chemical constituents types between these two methods, but the contents of some constituents were different. The common patterns generated by the 10 batches of hot air cycle drying samples were used as the control fingerprint, and the similarity of the spray drying samples fingerprints was 0.877, with high similarity of the fingerprints between these two methods. UPLC-DAD combined with UPLC-Q-TOF-MS/MS technology was used for the first time to evaluate the chemical constituents of Tianshu capsule rapidly, comprehensively and accurately, providing technical support for the quality evaluation of Tianshu capsule.

[Optimization of vacuum belt drying process of Gardeniae Fructus in Reduning injection by Box-Behnken design-response surface methodology].

To optimize the belt drying process conditions optimization of Gardeniae Fructus extract from Reduning injection by Box-Behnken design-response surface methodology, on the basis of single factor experiment, a three-factor and three-level Box-Behnken experimental design was employed to optimize the drying technology of Gardeniae Fructus extract from Reduning injection. With drying temperature, drying time, feeding speed as independent variables and the content of geniposide as dependent variable, the experimental data were fitted to a second order polynomial equation, establishing the mathematical relationship between the content of geniposide and respective variables. With the experimental data analyzed by Design-Expert 8. 0. 6, the optimal drying parameter was as follows: the drying temperature was 98.5 degrees C , the drying time was 89 min, the feeding speed was 99.8 r x min(-1). Three verification experiments were taked under this technology and the measured average content of geniposide was 564. 108 mg x g(-1), which was close to the model prediction: 563. 307 mg x g(-1). According to the verification test, the Gardeniae Fructus belt drying process is steady and feasible. So single factor experiments combined with response surface method (RSM) could be used to optimize the drying technology of Reduning injection Gardenia extract.

[Advances in functional genomics studies underlying acetic acid tolerance of Saccharomyces cerevisiae].

Industrial microorganisms are subject to various stress conditions, including products and substrates inhibitions. Therefore, improvement of stress tolerance is of great importance for industrial microbial production. Acetic acid is one of the major inhibitors in the cellulosic hydrolysates, which affects seriously on cell growth and metabolism of Saccharomyces cerevisiae. Studies on the molecular mechanisms underlying adaptive response and tolerance of acetic acid of S. cerevisiae benefit breeding of robust strains of industrial yeast for more efficient production. In recent years, more insights into the molecular mechanisms underlying acetic acid tolerance have been revealed through analysis of global gene expression and metabolomics analysis, as well as phenomics analysis by single gene deletion libraries. Novel genes related to response to acetic acid and improvement of acetic acid tolerance have been identified, and novel strains with improved acetic acid tolerance were constructed by modifying key genes. Metal ions including potassium and zinc play important roles in acetic acid tolerance in S. cerevisiae, and the effect of zinc was first discovered in our previous studies on flocculating yeast. Genes involved in cell wall remodeling, membrane transport, energy metabolism, amino acid biosynthesis and transport, as well as global transcription regulation were discussed. Exploration and modification of the molecular mechanisms of yeast acetic acid tolerance will be done further on levels such as post-translational modifications and synthetic biology and engineering; and the knowledge obtained will pave the way for breeding robust strains for more efficient bioconversion of cellulosic materials to produce biofuels and bio-based chemicals.

Serum uric acid levels of patients with multiple sclerosis and other neurological diseases.

The serum uric acid (UA) levels were measured in 112 patients with multiple sclerosis (MS) and 794 patients with different types of other neurological diseases (OND) or healthy control group. Serum UA levels, along with relevant clinical parameters of MS and OND, were also investigated. MS patients had significantly lower UA levels than those with transient ischemia attack (344.6 +/- 130.6 micromol/L, P = 0.000), cerebral hemorrhage (311.9 +/- 104.7 micromol/L, P = 0.000), cerebral infarction (291.3 +/- 101.6 micromol/L, P = 0.014) and the healthy control group (312.1 +/- 92.8 micromol/L, P = 0.000). MS patients had significantly higher serum UA levels than those with cryptococcus meningitis or meningoencephalitis (178.9 +/- 107.0 micromol/L, P = 0.000) and tuberculous meningitis or meningoencephalitis patients (175.7 +/- 99.9 micromol/L, P = 0.000). There were no significant differences in UA levels between patients with MS and those with facial neuritis, viral meningitis or encephalitis, pulmonary tuberculosis, polymyositis or dermatomyositis, myasthenia gravis, subarachnoid hemorrhage, migraine, Guillain-Barre syndrome and myelitis. In addition, UA levels were independently correlated with gender and duration of MS, but neither with MRI activity, disability nor subtypes of the disease in MS patients. Our data suggest that UA has two biphasic functions: neuroprotective and injurious. Our studies may help physicians to deal with conditions having abnormal UA levels.