Biomedical subjects

Hongbo He

Publications and source records attributed to Hongbo He.

7 recordsLinked to original sources

PubMed2006

Extended bidirectional reflectance distribution function for polarized light scattering from subsurface defects under a smooth surface.

By introducing the scattering probability of a subsurface defect (SSD) and statistical distribution functions of SSD radius, refractive index, and position, we derive an extended bidirectional reflectance distribution function (BRDF) from the Jones scattering matrix. This function is applicable to the calculation for comparison with measurement of polarized light-scattering resulting from a SSD. A numerical calculation of the extended BRDF for the case of p-polarized incident light was performed by means of the Monte Carlo method. Our numerical results indicate that the extended BRDF strongly depends on the light incidence angle, the light scattering angle, and the out-of-plane azimuth angle. We observe a 180 degrees symmetry with respect to the azimuth angle. We further investigate the influence of the SSD density, the substrate refractive index, and the statistical distributions of the SSD radius and refractive index on the extended BRDF. For transparent substrates, we also find the dependence of the extended BRDF on the SSD positions.

Journal Article↗

PubMed2006

[Effects of specific microbial biocides on N transformation in soil with glucose amendment].

In an incubation test of soil with glucose amendment, two kinds of nitrogenous fertilizer and three kinds of specific microbial biocides were applied, and the contents of soil NH(4+)-N, NO3(-)-N, glucosamine and muramic acid were measured to differentiate the relative contribution and timing characteristics of soil microbes in nitrogen immobilization. The results showed that penicillin and streptomycin decreased the transformation rate of NH(4+)-N markedly, with more significant effects than actidione. The amount ratio of glucosamine to muramic acid after applying penicillin and streptomycin rapidly increased first, and tended to equilibrium then. With the application of actidione, the transformation rate of NO3(-)-N decreased continuously, and the synthesis of glucosamine was inhibited, while penicillin and streptomycin had no significant effects on them. At the early stage of incubation, bacteria could rapidly immobilize both NH(4+)-N and NO3(-)-N, with NH(4+)-N preferred, while at the later stage of incubation, fungi were the dominant contributor to nitrogen transformation, and had much stronger ability of utilizing NO3(-)-N than bacteria.

Anti-Bacterial Agents↗

PubMed2006

[Soil carbohydrates: their determination methods and indication functions].

Soil carbohydrates are the important component of soil organic matter, and play an important role in soil aggregation formation. Their hydrolysis methods involve sulfur acid (H2SO4), hydrochloric acid (HCl), and trifluoroacetic acid (TFA) hydrolysis, and their determination methods include colorimetry, gas-liquid chromatography (GLC) , high performance liquid chromatography (HPLC), and high performance anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD). This paper summarized the methods of carbohydrates' hydrolysis, purification and detection, with focus on the derived methods of GLC, and briefly introduced the indication functions of carbohydrates in soil organic matter turnover.

Carbohydrates↗

PubMed2005

Stress analysis of ZrO2/SiO2 multilayers deposited on different substrates with different thickness periods.

The effects of repeating thickness periods on stress are studied in ZrO2/SiO2 multilayers deposited by electron-beam evaporation on BK7 glass and fused-silica substrates. The results show that the residual stress is compressive and decreases with an increase of the periods of repeating thickness in the ZrO2/SiO2 multilayers. At the same time, the residual stress in multilayers deposited on BK7 glass is less than that of samples deposited on fused silica. The variation of the microstructure examined by x-ray diffraction shows that microscopic deformation does not correspond to macroscopic stress, which may be due to variation of the interface stress.

Journal Article↗

PubMed2005

A gas chromatographic/mass spectrometric method for tracing the microbial conversion of glucose into amino sugars in soil.

Amino sugars in soils are heterogeneous and have been used as microbial residue biomarkers to investigate the microbial contribution to soil organic matter. However, it is not clear what the available carbon source is and how glucose is utilized for the synthesis of soil amino sugars. This paper presents a new gas chromatography/mass spectrometry (GC/MS) approach for the identification of 13C incorporation into three amino sugars, D-glucosamine, D-galactosamine, and muramic acid, in soil incubated with U-13C-glucose. Method evaluation showed that the chemical ionization (CI) mode was suitable for all these amino sugars, but that electron impact (EI) mode was applicable only to glucosamine and galactosamine. The 13C conversion rate was estimated based on the abundance ratio of the ions corresponding to the masses of the ions F+n and F (where n is the skeleton carbon number in the fragment ions F of the amino sugars) and calculated as atom percentage excess. The reproducibility of the method was excellent and clearly adequate for the present purpose. In addition, the new approach is highly accurate as tested with mixtures of U-13C-glucose and natural glucose.

Amino Sugars↗

PubMed2005

[Treatment of ischemic necrosis of the femoral head by transplantation of pedicled bone flap with deep iliac circumflex vessel].

OBJECTIVE: To investigate the treatment method of ischemic necrosis of the femoral head by the transplantation of pedicled bone flap with deep iliac circumflex vessel in adult and to assess its curative effect. METHODS: From February 1996 to September 2003, 46 adult patients with ischemic necrosis of the femoral head (58 coxas) were treated by transplantation of pedicled bone flap with deep iliac circumflex vessel. The locations were the left side in 34 coxas and the right side in 24 coxas(stage II in 16 coxas, stage III in 39 coxas and stage IV in 3 coxas). RESULTS: Thirty-seven patients (40 coxas) were followed up 6 months to 10 years after operation. According to the assess of FanQishen, the result was excellent in 19 cases (21 coxas), good in 11 cases (12 coxas), fair in 5 cases (5 coxas) and poor in 2 cases (2 coxas). The postoperative excellent and good rate was 81%. CONCLUSION: Operative treatment of ischemic necrosis of the femoral head in adult by transplantation of bone flap pedicled with deep iliac circumflex vessel has the characteristics of restoration of blood supply of the femoral head, decompression of marrow cavity, elimination of necrotic bone and support of the femoral head. It is an effective and advanced method for treatment of ischemic necrosis of the femoral head in adult.

Adult↗

PubMed2003

Study of the relationship between cigarette smoking, alcohol drinking and cognitive impairment among elderly people in China.

OBJECTIVE: the incidence of cognitive impairment is increasing; however, little is known about the prevalence and risk factors for cognitive impairment of elderly people in China. This report focuses on investigating the relationship between cigarette smoking, alcohol drinking and cognitive impairment in elderly people. METHODS: 3012 participants aged 60 years old and over were enrolled from six communities of Chongqing. Cognitive function was measured by the Mini-Mental State Examination and Activities of Daily Living. The chi(2) test and logistic regression was used to find the relationship between cigarette smoking, alcohol drinking and cognitive impairment. RESULT: the rate of abnormal cognitive function in elderly people was 11.95%. Smoking was closely related to cognitive impairment (chi(2)=6.59, P=0.027). Alcohol drinking was also associated with cognitive impairment (chi(2)=6.31, P=0.025). In all smokers, current smoking was associated with a significantly increased risk of cognitive impairment (RR 2.33; 95% CI=1.37-5.82). In all people who drink every day, there was a significantly increased risk of cognitive impairment (RR 3.47; 95% CI=1.79-6.71). CONCLUSION: smoking and drinking are risk factors for cognitive impairment among elderly people. Cessation of smoking and reduction of drinking could be considered as part of a strategy to reduce the incidence of cognitive impairment.

Aged↗