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S Jian

Publications and source records attributed to S Jian.

14 recordsLinked to original sources
PubMed2001

Doping and temperature dependence of the mass enhancement observed in the cuprate Bi(2)Sr(2)CaCu(2)O(8+delta).

High-resolution photoemission is used to study the electronic structure of the cuprate superconductor, Bi(2)Sr(2)CaCu(2)O(8+delta), as a function of hole doping and temperature. A kink observed in the band dispersion in the nodal line in the superconducting state is associated with coupling to a resonant mode observed in neutron scattering. From the measured real part of the self-energy it is possible to extract a coupling constant which is largest in the underdoped regime, then decreasing continuously into the overdoped regime.

Journal Article↗
PubMed2001

Mechanism of electroreduction of allyl alcohol at platinized platinum electrode in acidic aqueous solution.

The electroreduction of allyl alcohol to form propene at the platinized platinum electrode in acidic aqueous solution has been studied using CV plots, IR, ESR, and MS spectra, and a semiempricial MO method (MOPAC7/AM1, PM3). From the determinations of charge-transfer coefficients, reaction orders and apparent activation energy for the given reaction, the detection of the intermediates such as C(3)H(5)(+), C(3)H(5)(*), and C(3)H(5)(-) species, and PM3 calculations of charge distribution and frontier orbital energies of the reaction species C(3)H(5)OH and C(3)H(5)(+), the authors suggest that in acidic aqueous solution the production of propene via reductive splitting of the C-OH bond situated in the allyl position of allyl alcohol obeys a carbonium ion-carbanion mechanism.

Alkenes↗
PubMed2000

Effects of scanning and reconstruction parameters on image quality in electron-beam CT angiography: coronary artery phantom study.

RATIONALE AND OBJECTIVES: This study compared the image quality obtained with different scanning and reconstruction parameters for electron-beam computed tomographic (CT) angiography and sought optimal methods for visualizing the coronary artery lumen. MATERIALS AND METHODS: Electron-beam CT angiography with contrast material enhancement was used to image 35 branches of fresh postmortem swine coronary arteries. Different collimation widths, fields of view (FOVs), reconstruction kernels, and algorithms were employed to reconstruct the acquired raw data into CT angiographic images. Image quality was compared and analyzed. RESULTS: The contrast-to-noise ratios (C/Ns) for 1.5-, 2-, and 3-mm section thickness were 28.4 +/- 15.2, 31.9 +/- 9.3, and 33.8 +/- 14.5, respectively (P < .05). The lengths of visualized coronary artery lumina were significantly longer for 1.5-mm scanning (71.6 mm +/- 4.3) than for 2-mm (58.3 mm +/- 5.5) and 3-mm scanning (59.0 mm +/- 8.0) (P < .01). The C/Ns for 12.7-, 18.0-, and 26.0-cm FOV reconstruction were 32.8 +/- 9.9, 28.9 +/- 8.2, and 27.1 +/- 8.2, respectively (not significant), and the visualized luminal lengths were 76.1 mm +/- 12.5, 71.7 mm +/- 14.6, and 65.4 mm +/- 13.1, respectively (not significant). The highest C/N (48.2 +/- 13.3) was achieved with smooth kernels and a cone-beam algorithm, and the lowest (14.7 +/- 3.4) with very sharp kernels and a normal algorithm. Cone-beam algorithm images had significantly higher C/Ns than did normal algorithm images (P < .001), and they demonstrated longer coronary artery lumina (P < .01). CONCLUSION: Collimation width, FOV, reconstruction kernels, and algorithms are important in the processing of high-quality electron-beam coronary angiograms. A 1.5-mm collimation width, 12.7-cm FOV, cone-beam reconstruction algorithm, and very sharp kernels should help in obtaining the best image quality and depicting the longest segments of coronary artery lumen.

Algorithms↗
PubMed1999

[The study on clinical significance of human herpesvius 6 infection of NPC tissues].

OBJECTIVE: To study the infection of human herpesvirus 6(HHV-6) in NPC and its role in the carcinogensis of NPC. METHODS: By using polymerase chain reaction (PCR) and in situ hybridization (ISH) HHV-6 and EBV DNA to from the paraffin-embedded tissues of normal nasopharynx precancerous nasopharynx and nasopharyngeal carcinoma. EBV LMP1 was also detected in 36 tissues of NPC by immunohistochemistry (IHC). RESULTS: HHV-6 DNA PCR were detected in 30.9% (13/42) of tissues of NPC, 4.7% (1/21) of precancerous nasopharynx and non in the normal nasopharynx. Within the same tissues, EBV DNA positive rates were 95.2% (40/42), 66.6% (14/21) and 25.9% (7/27), respectively. By using ISH, HHV-6 DNA were detected only in 11 NPC tissues out of 13 HHV-6 DNA positive NPC cases and EBV DNA were detected in 47.6% (10/21) of precancerous nasopharynx tissues and 85.7% (36/42) of NPC cases. EBV LMP1 expression were detected in 47.2% (17/36) of NPC tissues. CONCLUSION: NPC tissues can be infected with both HHV-6 and EBV, HHV-6 infection is correlated with the expression of EBV LMP1, suggesting that HHV-6 plays a direct/or indirect role in carcinogenesis of NPC via upregulating the expression of EBV LMP1.

Adaptor Proteins, Signal Transducing↗
PubMed1999

[Maxillary pre-implant rehabilitation: a study of 55 cases using autologous bone graft augmentation].

Preprosthetic rehabilitation of the maxillary bone is sometimes difficult due to severe bone resorption in the posterolateral regions. The sinus lift with autogenous bony graft has given us satisfactory results since 1990 but requires a rigorous protocol before and during surgery to assure a lasting anchorage to the prosthesis. We describe morbidity and technical choices of this intervention in a series of 55 patients.

Adult↗
PubMed1998

[Therapeutic arthroscopy for recurrent temporomandibular luxation].

Surgery is sometimes indicated in cases of recurrent temporomandibular joint dislocation (luxation). Among the panel of available techniques, therapeutic arthroscopy with retrodiscal tissue and oblique protuberance coagulation has been used to prevent new episodes. Therapeutic arthroscopy was used for 6 patients. Outcome was considered to be satisfactory in 66% with a mean 3.1-year follow-up. This technique can be recommended as first line therapy when surgery is indicated. In case of failure, eminectomy is scheduled.

Adult↗
PubMed1995

Induction of c-fos protein by patterned visual stimulation in central visual pathways of the rat.

Localized patterned visual stimulation was used in rats to investigate the feasibility of stimulus-dependent induction of the immediate early gene c-fos in neurons of cortical and subcortical visual centers of this mammal. Moving and stationary visual patterns, consisting of gratings and arrays of dark dots, induced Fos-like immunoreactivity in populations of neurons in retinotopically corresponding stimulated regions of the dorsal and ventral lateral geniculate nucleus (dLGN, vLGN), stratum griseum superficiale of the superior colliculus, nucleus of the optic tract, and primary (striate) visual cortex. Only moving stimuli induced Fos-like immunoreactive (FLI) neurons in extrastriate visual areas, particularly in the anterolateral (AL) visual area. This suggests that area AL is equivalent to the motion sensitive areas MT and PMLS of the monkey and cat. Stimulus-induced FLI neurons in the striate cortex were predominantly distributed in layers 4 and 6, while few labeled neurons were present in layers 2-3, and almost none in layer 5. The laminar distribution of stimulus-induced FLI cells in the extrastriate cortical area AL was similar to that of the striate cortex, with the exception that more FLI cells were present in layer 5. Statistical comparison of somata size of the stimulus-induced FLI neurons in dLGN with that of Cresyl violet stained neurons in the same sections revealed that the population of geniculate FLI neurons is composed of relay cells and interneurons.

Animals↗
PubMed1994

CHARACTERISATION OF LARGE SECOND-ORDER OCELLAR NEURONES OF THE BLOWFLY CALLIPHORA ERYTHROCEPHALA

1. Blowflies have twelve large, second-order ocellar neurones (L-neurones) with axons in the single ocellar nerve. These neurones have fairly restricted arborizations in the posterior slope neuropile of the protocerebrum and cell bodies in the nerve, near to the fused ocellar retinae. 2. Like ocellar L-neurones of other insects, or large second-order neurones of the fly compound eye, blowfly L-neurones hyperpolarise in response to increases in light intensity and depolarise in response to decreases in light intensity. Both polarities of response have a strong phasic component. Adaptation to sustained illumination shifts the intensity&shy;response curve, with little change in its gradient. 3. The maximum responses of blowfly L-neurones to sinusoidal changes in light intensity occur at stimulus frequencies of 5&shy;10 Hz. 4. Hyperpolarising an L-neurone with small currents causes an increase in input resistance. Larger hyperpolarising currents cause oscillations in the membrane potential. The amplitude of the oscillations increases with current strength. Repolarisation generates brief rebound spikes of variable amplitude. 5. Injection of small hyperpolarising currents increases the amplitude of a response to a subsaturating pulse of light. This effect is not seen for saturating responses to light and is likely to be due to the increase in membrane resistance caused by hyperpolarisation.

Journal Article↗
PubMed1992

[Carcinoma of the cervical stump. Clinic analysis of 10 cases].

Ten cases of carcinoma of the cervical stumps from Jan. 1965 to Dec. 1990 were analysed. All of the patients received subtotal hysterectomy because majority of patients suffered from benign uterine tumors except one case of ovarian cystadenocarcinoma. The age range of the patients was 40-65 years old. The stump carcinoma was discovered 2-18 years later after primary operations. The average duration was 10.3 years. Only one patient died of 2 years after treatment, remaining patients have good health by surgical and radiotherapy. The authors emphasize that the key to prevent the cervical stump carcinoma is to avoid missing diagnoses of the precancerous lesion and cancer of the cervix, and to closely follow-up the patients with the stumps.

Adult↗
PubMed1991

[Inhibitory effects of enzymolytic product from normal human plasma on hematogenous metastasis of murine gastric carcinoma cells].

Enzymolytic product (EP) of normal human plasma (NHP), was prepared through combined digestion of alpha-chymotrypsin and pepsin. This product was studied with MGc 80-3 cells (human gastric carcinoma cell line) and FC cells (615-murine gastric carcinoma cell line). The adhesive rate of NHP to MGc 80-3 cells may reach 90%, while the capacity of NHP-EP to inhibit adhesion reached over 90%, being specific and non-cytotoxic. Intravenous coinjection of NHP-EP with FC murine gastric carcinoma cells remarkably inhibited the formation of lung tubercles in 615-mice, with an inhibitory rate of 83.3% and a median survival time prolonged 35 days, which was only 19 days in the controls. The results showed that NHP-EP can inhibit experimental hematogenous metastasis through interfering the adhesion of tumor cells to extracellular stroma. We believe that NHP-EP may have practical value in preventing, seeding of metastatic cells after surgical removal of a primary tumor.

Adenocarcinoma↗
PubMed1982

Calcifying epithelial odontogenic tumors: a clinicopathologic study of nine cases.

Nine cases of CEOT are reported. There are seven intra-osseous and two extraosseous tumors. All but one occurred in the mandible. The age range was 20 to 64 years; averaging 34.2 years. There were 7 females and 2 males. Radiographically, they appeared either as monocystic or polycystic translucent lesions with radiopaque spots or masses. Embedded teeth were seen in six cases. Microscopically, four different patterns are described. No recurrence has been found postoperatively within 2-14 years of follow-up study. The nature of the reddish homogeneous material, the histogenesis of the tumor and the treatment are briefly discussed.

Adult↗