Study on overburden rock structure characteristics and surrounding rock control technology of island working face.

Based on the background of ZF2822 island working face in Xiagou Coal Mine, the characteristics of overburden fracture structure and surrounding rock control technology of island working face are explored by means of theoretical analysis, numerical simulation and field measurement. The results show that the ten morphological structures of the main roof fracture can be divided into four typical symmetrical structures and six asymmetric structures. According to the stress calculation formula of the key block B to the coal pillar, the stress characteristics of the 10 structures are classified and the risk classification is carried out. Four typical structures (a), (b), (c) and (d) were constructed to simulate the stress and strain characteristics of surrounding rock. The overlying strata subsidence displacement values of (a), (b), (c) and (d) at the roadway are 1.75 m, 1.5 m, 0.8 m and 0.6 m respectively, and the maximum stresses are 26.6 MPa, 19.5 MPa, 15.5 MPa and 10.0 MPa respectively, (a) > (b) > (c) > (d). Therefore, the surrounding rock control technology of gob-side roadway in island working face is put forward, the fracture structure of basic roof is determined and the reasonable applicable type of gob-side roadway is selected. The results after pressure relief show that the average daily microseismic energy of ZF2822 working face after pressure relief is 0.87 × 104 J, which is about 42.38% lower than that of April. The average stress is 1.13 MPa lower than that of the mining before the pressure relief area, and the decrease is 22.42%. It shows that the pressure relief has played a very good effect and provides a reference for the same type of mine.

[Metabolic syndrome increases Framingham risk score of patients with type 2 diabetes mellitus].

OBJECTIVE: To assess the impact of metabolic syndrome(MS) on Framingham risk score(FRS) in patients with type 2 diabetes mellitus (T2DM). METHODS: The anthropometric and biochemical data of 1708 patients with T2DM admitted in hospital from May 2008 to April 2013 were retrospectively analyzed, including 902 males and 806 females with a mean age of 57.1±11.8 years (20-79 years). Diagnosis of MS was made according to the criteria of the Adult Treatment Panel Ⅲ Criteria modified for Asians. RESULTS: Compared to non-MS/T2DM patients, MS/T2DM patients had higher waist circumference, body weight, body mass index, systolic and diastolic blood pressure, fasting C peptide, total cholesterol, triglyceride, and LDL-C (P<0.05), while lower HDL-C (P<0.01). Both FRS [13.0(10.0, 15.0) vs 11.0(9.0, 13.0) in male,15.0(12.0, 18.0) vs 12.0(6.0, 14.8) in female,P<0.01)] and 10-year cardiovascular risk [12.0%(6.0%, 20.0%) vs 8.0%(5.0%,12.0%) in male,3.0%(1.0%, 6.0%) vs 1.0%(0.0%, 2.8%) in female,P<0.01] were higher in MS/T2DM patients than those in non-MS/T2DM patients.Both FRS and 10-year cardiovascular risk were increased with the components of MS. CONCLUSION: T2DM patients with MS have more cardiovascular risk factors, higher FRS and 10-year cardiovascular risk.

Concentration of serum leptin and age in Chinese women and comparison with other races / 中南大学学报(医学版)

OBJECTIVE@#To determine the relationship between concentration of serum leptin and age in females, and to establish the reference value and compare it with other races.@*METHODS@#Serum leptin concentration of 690 adult healthy women (aged 20 approximately 81 years) was measured with ELISA.@*RESULTS@#The serum leptin concentration increased with age (r=0.224, P<0.001), and cubic regression was the best-fitting model. Leptin concentration had significant positive correlation with weight (r=0.574) and body mass index (r=0.618). The geometric mean of leptin concentration in normal weight, overweight and obesity was (8.94+/-1.82), (17.6+/-1.89), and (34.7+/-1.69) microg/L, respectively, with significant difference among the 3 groups (P<0.001). Leptin in pre-menopause, peri-menopause and post-menopause women was (9.68+/-1.81), (11.7+/-1.89), and (11.4+/-2.21) microg/L, respectively. The reference value of serum leptin in normal weight females was 5.30 approximately 12.6 microg/L. The curve-fitting of leptin with age in this group was significantly lower than American non Hispanic White (NHW), non Hispanic Black (NHB), and American Mexican (AM) females.@*CONCLUSION@#This study provides reliable reference value of serum leptin in adult women and discovers ethnic difference with American NHW, NHB, and AM females.