Due to lack of the practical technique to measure the biomechanical properties of the ocular cornea in vivo, clinical ophthalmologists have some difficulties in understanding the deformation mechanism of the cornea under the action of physiological intraocular pressures. Using Young's theory analysis of the corneal deformation during applanation tonometry, the relation between the elasticity moduli of the cornea and the applanated corneal area and the measured and true intraocular pressures can be obtained. A new applanation technique has been developed for measuring the biomechanical properties of the ocular cornea tissue in vivo, which can simultaneously acquire the data of the applanation area and displacement of the corneal deformation as well as the exerted applanation force on the cornea. Experimental results on a rabbit's eyeball demonstrated that the present technique could be used to measure the elasticity moduli and creep properties of the ocular cornea nondestructively in vivo.
Animals ; Biomechanical Phenomena ; Cornea ; Elastic Modulus ; Intraocular Pressure ; Muscles ; Rabbits ; Tonometry, Ocular

BACKGROUND:Silk fibroin/chitosan/nano hydroxyapatite (SF/CS/nHA) composite scaffold constructed in preliminary experiments has good physical and chemical properties.
OBJECTIVE:To study the capacity and mechanism of SF/CS/nHA composite scaffold for repair of rabbit radial bone defects.
METHODS:Thirty-six New Zealand white rabbits were selected to make animal models of right radial bone defects, and then randomly divided into SF/CS/nHA group, SF/CS group and blank control group. Blank control group had no treatment after modeling. X-ray radiography, gross observation and histopathological observation were performed at 4, 8, 12, 16 weeks postoperatively.
RESULTS AND CONCLUSION:Sixteen weeks after surgery, bone defects in the SF/CS/nHA group were completed replaced by normal bone tissue on X-ray images, and the bone marrow cavity showed complete recanalization with new bone formation;hematoxylin-eosin staining showed bone trabecula and many fusiform bone cells. In the SF/CS group, the bone mineral density in the defect area was slightly lower than that of the normal bone tissues, the bone marrow cavity was partly rehabilitated, and many chondrocytes were seen around bone cells that arranged irregularly with no bone trabecula or bone lamel a. In the blank control group, the images of bone calcification were consistent with normal bone tissues, and a closed bone ununion was formed at each end;hematoxylin-eosin staining showed that the blank control group was fil ed by fibrous connective tissue and a smal amount of bone-like tissues. SF/CS/nHA composite scaffold is better for repair of rabbit radial bone defects.

Objective To evaluate the Imaging diagnosis of SARS in death case.Methods 11 death patients of SARS in keeping with criteria from April to May 2003 were enrolled into the study. Imaging characteristics of chest x-ray film and CT in these patients were analysed.Results All cases were positive on chest X-ray film and CT,the lung shadows were marked.The extent of the pathological changes in lungs was 80%～90% in 6 cases and 90% above in 5 cases,multilobcs of bilateral lungs were involved in all cases.The lesions were diffuse spotty shadow or shaggy cloudy shadow in 8 cases,ground-glass opacification in one case and bronchogram structures could be seen.Conclusion Imaging findings in the cases with severe SARS mostly manifest as effusion,consolidation and interstitial inflammation in multilobes of bilateral lungs.

OBJECTIVETo establish the EST-SSR marker system for Cordyceps by using ESTs of C. bassiana and C. militaris.

METHODThe ESTs of Cordyceps were downloaded from the public database of NCBI, and the redundant ESTs with low quality were removed. The EST-SSR primers were designed by Sequece Seiner 1. 2. And the primers were screened through PAGE-Electrophoresis.

RESULTThe 4 556 non-redundant ESTs which from C. bassiana with total length of 2 953 173 bp were selected. 718 EST-SSRs distributed in 616 ESTs were totally screened out, accounting for 15.8% of the non-redundant ESTs. It was discovered that the average distance of EST-SSSR was 1/4 096 bp in EST-SSRs distribution of C. bassiana. Trinucleotide repeats were the most abundant types with 419 repeated sequences. Regarding to C. militaris, totally 1 363 non-redundant ESTs were acquired, from which 1 117 EST-SSRs were screened, and rate of SSR sites in ESTs was 81.95%. The leading motif of SSR was nucleotide A. The 50 pairs of EST-SSR primers were designed according to the ESTs of C. bassiana, and preliminary test showed the 34 pairs of primers amplified clear fragments,accounting for 68% of all primers. Furthermore, the 39 of the 40 pairs of primers from the ESTs of C. militaris were found to be amplified as the clear fragments, accounting for 97.5%. The phylogenetic analysis revealed that different anamorph of Cordyceps spieces were divided into four branches.

CONCLUSIONThe EST-SSR of Cordyceps had comparably higher utility value. The EST-SSR markers developed from ESTs of C. bassiana and C. militaris had well transferability in Cordyceps. And it was suggested that the EST-SSR markers should be an easy and effective way to assay molecular genetic structure of Cordyceps.

China ; Cordyceps ; classification ; genetics ; DNA Primers ; DNA, Fungal ; genetics ; Databases, Nucleic Acid ; Expressed Sequence Tags ; Genetic Markers ; genetics ; Genome, Fungal ; genetics ; Microsatellite Repeats ; genetics ; Phylogeny ; Polymorphism, Genetic ; Repetitive Sequences, Nucleic Acid ; genetics