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Jian-Sheng Wang

Publications and source records attributed to Jian-Sheng Wang.

13 recordsLinked to original sources
PubMed2006

Material characterization and in vivo behavior of silicon substituted alpha-tricalcium phosphate cement.

The possibility and biological effects of substituting silicon in alpha-tricalcium phosphate (alpha-TCP) by way of solid-state reaction have been evaluated. alpha-TCP powders with varying substitution amounts (1 and 5 mol % Ca2SiO4) were synthesized by reacting mixtures of CaCO3, Ca2P2O7, and SiO2, at a rate of 4 degrees C(min)(-1) to 1100 degrees C, left to dwell for 2 h and then heated to 1325 degrees C at 4 degrees C(min)(-1) and left to dwell for a period of 4 h. The powders were then rapidly quenched in air. Si incorporation could be verified by X-ray diffraction analysis, indicating an increase of the lattice volume with increasing Si content from 4284.1(8) to 4334(1) A3 for pure alpha-TCP and alpha-Si5%TCP, respectively. The hydrolysis of milled alpha-SiTCP powders was monitored by isothermal calorimetry, and the compressive strength of set cements was tested. The results showed changes in speed and amount of heat released during reactivity tests and a decrease in mechanical strength (60, 50, and 5 MPa) with increasing Si content. In vitro bioactivity of the set cements after soaking in simulated body fluid for 4 weeks was also tested. The formation of a bonelike apatite layer on the surface of the set cements could be observed and was thickest for 1%Si (20 microm). These results were in good agreement with the in vivo studies performed, which showed strong evidence that the cement containing 1% silicon doped alpha-TCP enhanced mesenchymal cell differentiation and increased osteoblast activity compared with alpha-TCP.

Animals↗
PubMed2005

Worm algorithm for two-dimensional spin glasses.

A worm algorithm is proposed for the two-dimensional spin glasses. The method is based on a low-temperature expansion of the partition function. The low-temperature configurations of the spin glass on square lattice can be viewed as strings connecting pairs of frustrated plaquettes. The worm algorithm directly manipulates these strings. It is shown that the worm algorithm is efficient, particularly if free boundary conditions are used. We obtain accurate low-temperature specific heat data consistent with a form c approximately T-2 exp [-2J/( kB T) ] , where T is temperature and J is coupling constant, for the two-dimensional +/- J spin glass.

Journal Article↗
PubMed2005

In vivo and in situ detection of colorectal cancer using Fourier transform infrared spectroscopy.

AIM: Real-time and rapid identification of the malignant tissue can be performed during or before surgical operation. Here we aimed to detect in vivo and in situ colorectal cancer by using Fourier transform infrared (FTIR) spectroscopy and fiber-optic technology. METHODS: A total of five patients with large intestine cancer were detected in vivo and in situ. Of them, three cases of colon cancer and one case of cecum cancer were detected intraoperatively and in vivo by using a FTIR spectrometer during surgical operation, and one case of rectum cancer was explored non-invasively and in vivo before the surgical operation. Normal and malignant colorectal tissues were detected in vivo and in situ using FTIR spectroscopy on the basis of fundamental studies. RESULTS: There were significant differences between FTIR spectra of normal and malignant colorectal tissues detected in vivo and in situ. Experimental results revealed that the spectral characteristics of normal and malignant tissues found in vivo and in situ were similar to those obtained from in vitro measurement in our previous fundamental research. CONCLUSION: FTIR fiber-optic attenuated total reflectance (ATR) spectroscopy can identify in situ and in vivo colorectal cancer. FTIR spectroscopic method with fiber optics is a non-invasive, rapid, accurate and in vivo cancer detection technique in clinical diagnosis.

Aged↗
PubMed2004

Mode-coupling theory and molecular dynamics simulation for heat conduction in a chain with transverse motions.

We study heat conduction in a 1D chain of particles with longitudinal as well as transverse motions. The particles are connected by 2D harmonic springs together with bending angle interactions. The problem is analyzed by mode-coupling theory and compared with molecular dynamics. We find very good, quantitative agreement for the damping of modes between a full mode-coupling theory and molecular dynamics result, and a simplified mode-coupling theory gives qualitative description of the damping. The theories predict generically that thermal conductance diverges as N(1/3) as the size N increases for systems terminated with heat baths at the ends. The N(2/5) dependence is also observed in molecular dynamics, which we attribute to crossover effect.

Journal Article↗
PubMed2004

Intriguing heat conduction of a chain with transverse motions.

We study heat conduction in a one-dimensional chain of particles with longitudinal as well as transverse motions. The particles are connected by two-dimensional harmonic springs together with bending angle interactions. Using equilibrium and nonequilibrium molecular dynamics, three types of thermal conducting behaviors are found: a logarithmic divergence with system sizes for large transverse coupling, 1/3 power law at intermediate coupling, and 2/5 power law at low temperatures and weak coupling. The results are consistent with a simple mode-coupling analysis of the same model. We suggest that the 1/3 power-law divergence should be a generic feature for models with transverse motions.

Journal Article↗
PubMed2004

Diagnosis and treatment of polypoid lesions of the gallbladder: report of 194 cases.

BACKGROUND: With the wide use of B-ultrasonography in recent years, the polypoid lesion of the gallbladder (PLG) has been one of the most common diseases detected in biliary surgery. This study was to investigate the diagnostic method and operative indications of PLG. METHODS: The clinical and pathological data of 194 patients with PLG who had received operation at our hospital from January 1994 to September 2002 were analyzed retrospectively. Categorized data were analyzed by the chi-square test. RESULTS: All the patients received preoperative B-ultrasonography. 185 of the 194 PLG patients were diagnosed as having cholecystic polyp, and 9 adenomas. Among the 42 patients who received CT, 6 showed early gallbladder cancer. Pathologically, cholesterol polyps were mostly multiple lesions (64.7%) with a mean diameter of 3.86+/-2.2 mm in 136 patients. Of 16 patients with adenomas, 10 had a tumor diameter of more than 10 mm (62.5%). In 11 patients with gallbladder carcinoma, 7 were accompanied with gallbladder stone (63.6%). In addition, inflammatory polyps and adenomyomas were found in 25 and 6 patients respectively. CONCLUSIONS: B-ultrasonography is the most effective diagnostic method for detecting PLG. When large or irregular lesions are found, CT should be performed in order to avoid missing of gallbladder carcinoma. Operative indications for PLG include: a maximal tumor diameter of more than 10 mm; an over 50-year-old patient with a widebase and a single polyp lesion; a wide-base lesion or a lesion showing a tendency to enlargement; co-existing gallbladder stone or cholecystitis; a patient without other diseases but obvious clinical features and failure of general management; big or long pedicels or polyps at the neck of the gallbladder for preventing the empty of the gallbladder and a history of biliary colic; and PLG with irregularly thickened local gallbladder wall.

Adult↗
PubMed2003

Factors affecting the static shear strength of the prosthetic stem-bone cement interface.

Debonding of the stem-cement interface has been implicated in the initiation of failure of cemented femoral stems. The objective of this work was to examine some of the parameters which influence the interface static shear strength, including surface finish, cement type, pre-treatments and porosity. Surface finish was found to have the greatest effect on the interface strength. Increasing the surface roughness by a factor of 100 increases the interface shear strength by a factor of 20. However, increasing the surface roughness above a certain value was found to have no additional affect. This was due to failure in the cement itself rather than at the cement-stem interface. There were significant differences between some of the different cement types regarding the interface strength. Pre-heating the stem produced a six fold reduction in cement porosity at the stem-cement interface, however, resulting in only a minor influence on the static interface strength. Generally, no significant correlation was found between the cement porosity and the static interfacial shear strength.

Journal Article↗
PubMed2003

No augmentation of morselized and impacted bone graft by OP-1 in a weight-bearing model.

INTRODUCTION: Impacted morselized bone allograft is thought to be remodeled to a great extent. We have previously shown that load-bearing increases the remodeling of impacted morselized bone allografts in a rabbit knee prosthesis model. Bone Morphogenic Proteins (BMPs) also stimulate bone formation and bone allograft remodeling. In this study, our aim was to determine whether it was possible to increase further the remodeling of impacted morselized bone allografts by combining load-bearing with a BMP. EXPERIMENT: A solution of Osteogenic Protein-1 (OP-1, also called BMP-7) was added to freeze-dried bone allograft chips before impaction grafting in our rabbit knee prosthesis model. 23 skeletally mature rabbits received an uncemented tibial knee prosthetic component inserted into a bed of impacted morselized bone allograft. 12 rabbits were given OP-1-treated allograft (50 microg OP-1 per gram allograft), and 11 rabbits vehicle-treated allograft. Each rabbit received mean 0.53 g graft. The rabbits were killed after 3 or 6 weeks and the grafted region was examined by histomorphometric assessment of the volume fraction of newly formed bone and remaining graft. RESULTS AND INTERPRETATION: We found that OP-1 did not increase the bone density (graft plus new bone) to any substantial extent. However, we can not exclude that this might be due to a carrier problem, since the OP-1 was added as a solution directly to the dry graft.

Animals↗
PubMed2003

FT-IR spectroscopic analysis of normal and cancerous tissues of esophagus.

AIM: To investigate the special Fourier transform infrared spectroscopy (FT-IR) spectra in normal and cancerous tissues of esophagus. METHODS: Twenty-seven pairs of normal and cancerous tissues of esophagus were studied by using FT-IR and the special spectra characteristics were analyzed in different tissues. RESULTS: Different spectra were found in normal and cancerous tissues. The peak at 1 550/cm was weak and wide in cancerous tissues but strong and high in normal tissues. The ratio of I 1 647/I 1 550 was 2.0 in normal tissues and 2.36 in cancerous tissues (P<0.05). The ratio of I 1 550/I 1 080 was 4.5 in normal tissues and 3.4 in cancerous tissues (P<0.01). The peak at 1453 /cm was higher than at 1 402/cm in normal tissue and lower than at 1 402/cm in cancerous tissues. CONCLUSION: The results indicate that FTIR may be used in clinical diagnosis.

Case-Control Studies↗
PubMed2002

Sweeny and Gliozzi dynamics for simulations of Potts models in the Fortuin-Kasteleyn representation.

We compare the correlation times of the Sweeny and Gliozzi dynamics for two-dimensional Ising and three-state Potts models, and the three-dimensional Ising model for the simulations in the percolation representation. The results are also compared with Swendsen-Wang and Wolff cluster dynamics. It is found that Sweeny and Gliozzi dynamics have essentially the same dynamical critical behavior. Contrary to Gliozzi's claim [Phys. Rev. E 66, 016115 (2002)], the Gliozzi dynamics has critical slowing down comparable to that of other cluster methods. For the two-dimensional Ising model, both Sweeny and Gliozzi dynamics give good fits to logarithmic size dependences for the correlation times; for two-dimensional three-state Potts model, their dynamical critical exponent z is 0.49+/-0.01; the three-dimensional Ising model has z=0.37+/-0.02.

Journal Article↗
PubMed2002

Flow properties of driven-diffusive lattice gases: theory and computer simulation.

We develop n-cluster mean-field theories (1 < or = n < or = 4) for calculating the flux and the gap distribution in the nonequilibrium steady states of the Katz-Lebowitz-Spohn model of the driven diffusive lattice gas, with attractive and repulsive interparticle interactions, in both one and two dimensions for arbitrary particle densities, temperature as well as the driving field. We compare our theoretical results with the corresponding numerical data we have obtained from the computer simulations to demonstrate the level of accuracy of our theoretical predictions. We also compare our results with those for some other prototype models, notably particle-hopping models of vehicular traffic, to demonstrate the qualitative features we have observed in the Katz-Lebowitz-Spohn model, emphasizing, in particular, the consequences of repulsive interparticle interactions.

Journal Article↗
PubMed2002

Early diagnosis of primary gallbladder carcinoma.

OBJECTIVE: To improve early diagnosis of primary gallbladder carcinoma (PGC) and the understanding of its pathogenesis, pathological stages and prognosis. METHODS: The data from 679 patients with PGC treated in our hospital from 1956 to 1998 were analyzed retrospectively. RESULTS: The incidence of PGC has been increasing in recent years, and the treatment is not satisfactory. Upon diagnosis, most patients with PGC were at advanced stage. PGC was usually found in elderly women. The ratio of man to woman was 1:3. The gallstone, closely related to PGC, was found in 60% of the patients with PGC. The diagnostic accordance rate before and after operation was low. In most patients, PGC was found unexpectedly during operation for gallstone or acute cholecystitis. Many patients with PGC missed the opportunity of diagnosis and therapy because doctor only noticed the diagnosis of gallstone. Pathological classification revealed that PGC in most patients (84.4%) were adenocarcinoma. Imaging helped to find early-stage cases and improve prognosis. CONCLUSIONS: Understanding of pathogenesis, pathological stages and prognosis of PGC and proper use of various examinations are essential to the early diagnosis and treatment of the disease.

Adult↗