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A simple multiresidue method, HPLC with programmable fluorescence detection and gradient elution, has been developed for analysis of nine (fluoro)quinolones (FQs)—norfloxacin, ciprofloxacin, lomefloxacin, danofloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid, and flumequine in chicken muscle. The samples were extracted with phosphate-buffered saline (PBS, 0.01 mol L−1, pH 7.0) and cleaned by SPE. Cleaned extracts reconstituted in different solvents were tested to determine which gave the maximum fluorescence response for each drug. PBS (0.01 mol L−1, pH 7.0) was used as reconstitution solvent, because the sensitivity for FQs dissolved in PBS was 1.8–3.2 times greater than when dissolved in the mobile phase. Under the optimum conditions excellent linearity was obtained, with satisfactory correlation coefficients (r > 0.9994) for PBS. The “matrix effect” was eliminated. Limits of quantification for each drug were in the range 0.3–1.0 ng g−1. In fortification studies recoveries of the analytes were in the range 71.8–102.1% for 1–100 ng g−1 concentrations. Inter- and intra-day coefficients of variation were from 0.5 to 5.2% and from 1.7 to 9.0%, respectively. Short-term stability in PBS was also determined.

To analyze the epidemiological characteristics and related risk factors of allergic rhinitis in primary and middle school students in Changsha so that to provide the scientific basis for the disease control and intervention.From June 2011 to April 2012, we randomly chose primary and middle school students aged from 10 to 17 years old in Changsha as our research objects. Through stratified sampling and cluster sampling, we carried out epidemiological investigation using questionnaire investigation, physical examination and skin prick test. After statistical analysis of the data,we explored the related risk factors.(1) 7,023 copies of questionnaire were sent out and 6,407 copies of valid questionnaire were received in the stratified sampling survey. The prevalence of complaining about having got allergic rhinitis is 44.6% while the real rates is 20.5%; (2) 814 research objects were investigated in cluster sampling survey. The result of the incidence of allergic rhinitis is 26.3%, and the prevalence of allergic rhinitis is 17.2%. Analysis of Visual Analog Scale Questionnaire showed significant influence of allergic rhinitis on students character, memory, sleep quality, etc.The prevalence of allergic rhinitis in primary and middle school students aged at 10-17 years old in Changsha is 17%-20%. The occurrence and development of allergic rhinitis is related to environment, genetic background and living habits. Allergic rhinitis influenced the students' character, memory and sleep quality significantly.

To study the effect of tympanostomy tube surgery in cleft palate children with secretory otitis media (SOM).Cleft palate children complicated by SOM accepted palatoplasty combined tympanostomy tube surgery, and evaluated by tympanum examination, acoustic immittance measurement in the post-operation. The others with suited age constitute, who accepted palatoplasty only,received the same testing too.Compared with children who accepted palatoplasty only,the correlated index of SOM in post-operation of children who accepted palatoplasty combined with tympanostomy tube surgery had more improvements,there was a statistically significant difference between them. The recovery degree of middle ear function in younger group was better than elder group,there was a statistically significant difference between them.Tympanostomy tube surgery is helpful to increase cure rate of 0ME in children with cleft palate. The younger the patient is,the better the recovery degree of middle ear function will be. Palatoplasty combined with tympanostomy tube surgery should be an effective way in the management of cleft palate complicated by SOM, and good effect could be obtained when children accepted operation in early stage.

To investigate the behavior difference of allergic rhinitis with adenoid hypertrophy between study group and control group.One hundred and seventeen children diagnosed as allergic rhinitis with adenoid hypertrophy were enrolled in our study were divided into study group and control group. Forty-two children treated with local steroid nasal spray for two to three months and antihistamine were control group. Seventy-five children treated with endoscopic adenoidectomy and drug treatment were study group; All children' parents were inquired for their clinical presentation.No distinctive differences were found between the two groups (P0.05) in adenoid hypertrophy, accompanying nasal problems and clinical questionnaire scoring. Significant statistical distinction were found (P0.05) in snoring, sleep disturbance and frequent arousal, nasal obstructive moth-breathing, and recurrent respiratory tract infection between the two groups after three-month follow up.Endoscopic adenoidectomy should be taken into account for allergic rhinitis with adenoid hypertrophy in children. Adenoidectomy would be useful for the improvement of behavior symptoms.

Gradual degradation is the pivotal factor in prognostics analysis while the performance degradation is difficult to get with limit or blurry data. Based on the failure mechanism analysis of axial piston pump, the abrasion resulting from uneven contact between valve plate and cylinder barrel is the crux. With measured value, this paper presents a updated grey model and algorithm flow based on fix dimension updated technique and δ filter, in which the grey model overcomes the influence of uncertainty and disturbance and δ filter improves the quality of original data. Through renewing the information of grey model dynamically, the precision of prognostics increases greatly. Application indicates that the updated grey prediction algorithm could strengthen the scoring of new data and improve the prognostic accuracy with limit data.

Air drilling has many advantages over mud drilling in increasing penetration rate, decreasing formation damage, eliminating lost circulation, reducing pressure differential sticking and so on. Hole cleaning and pipe erosion failure are the two key problems for air drilling. Hence proper injecting parameters should not only meet the requirement of carrying cuttings, but also avoid the erosion of drillpipe. For example, if the standpipe pressure was much larger, high-speed air flow with cuttings would cause the erosion of drillpipe and destroy its internal coating, which is the main reason of shorting service time of drillpipe. Other parameters such as drillpipe rotational speed, borehole deviation, eccentricity, cutting size and cutting density also affect the cuttings transportation and pipe erosion. Previous published papers are limited to physical model dimensions and operating parameters, or no exact calculation results due to too many assumptions.In this paper, a model of gas-solid two-phase flow was built and a new approach to determine the injecting parameters was introduced. Based on the computational fluid dynamics and aerodynamics theory, the flow properties in 311.5mm wellbore, 1500m long, with 127mm drillpipe had been simulated with variable parameters. Then the distributions of pressure, velocity and cuttings volumetric concentration were obtained in drillstring and annulus. By analyzing multi-group calculation results, injecting parameters were optimized to meet the needs of the drilling job. Calculation results coincided well with the actual field data, and had been used to guide air drilling in Da-Wan 3 well, Lao-Jun 1 well, and Qing-Xi 1 well for Chuanqing Drilling and Exploration Corp.

Due to inherent delivery fluctuation of piston pump, its measurable signals are full of structure coupling and noise besides failure feature that make the system illegible and fault diagnosis difficult. This paper presents a contract support vector machine to extract the effective information from data and eliminate the redundant attribute among different data. Then utilize the support vector machine to classify the failures effectively on condition of limit samples. Application of piston head looseness indicates that the contract support vector machine not only can decrease the calculation of feature extraction but also can classify the failures effectively under limit samples.

An immunoaffinity chromatographic method was developed using an antibody mediated immunosorbent to selectively extract and purify 10 quinolones (marbofloxacin, norfloxacin, ciprofloxacin, lomefloxacin, danofloxacin, enrofloxacin, difloxacin, sarafloxacin, oxolinic acid, and flumequine) in chicken muscle followed by HPLC. The operating conditions of the immunoaffinity chromatography (IAC) column were optimized, and the IAC has been successfully used for the isolation and purification of 10 quinolones from chicken muscle tissue. The optimized immunoaffinity column sample cleanup procedure combined with HPLC coupling to fluorescence detection afforded low limits of detection (0.1 ng g(-1) for danfloxacin and 0.15 ng g(-1) for all other quinolones tested). The method was also applied to determine quinolone residues in commercial muscle samples.

The manipulating test-bed is a typical parallel mechanism, in which the three actuators move according to given regulation to change the gesture of swash plate. Directing to the triangle distribution of three actuators, the characteristic of the test-bed structure was analyzed, and the function of this test-bed was investigated. The coordinate system of the parallel mechanism was established, and the freedom of the parallel mechanism was calculated. According to the analysis of the manipulating test-bed aforementioned, the restriction condition of the parallel mechanism was analyzed when the gesture of the swash plate changed, and then the forward and inverse position solution were given. The position solution will guide the actuator control of test-bed with high precision.

A HPLC method using a modified sample preparation procedure was optimized and validated for the quantification of 10 quinolones (QNs), including marbofloxacin, ciprofloxacin, norfloxacin, lomefloxacin, danofloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid, and flumequine, in swine, chicken, and shrimp tissues. In this method, only a small mass (

A study of the tissue depletion of eprinomectin (EPR) subcutaneously administered to cattle at a dose of 500 mg per kg of body weight was carried out. EPR concentrations were determined in muscle, liver, kidney, and fat. Twenty-four parasite-free cross cattle were treated with the EPR injectable oil formulation. Three treated animals (two males and one female) were selected randomly to be sacrificed at 1, 3, 7, 14, 21, 28, 42, and 56 days withdrawal after injection. EPR residue concentrations were determined using HPLC with fluorescence detection. Muscle samples showed the lowest EPR concentrations throughout the study period. The highest EPR concentrations at all sampling times were measured in liver tissue, indicating that liver is a target tissue for EPR. EPR concentrations in all of the tissues analyzed were below the accepted maximum residue limits recommended by the European Union at 8 days posttreatment.