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J C Li

Publications and source records attributed to J C Li.

At least 19 recordsLinked to original sources
PubMed2006

Interfaces between metal and arylamine molecular films as probed with the anode interfacial engineering approach in single-layer organic diodes.

The interfaces between metal and arylamine molecular films were studied by measurement of current-voltage characteristics in single-layer organic diodes with the aid of the anode interfacial engineering method. The diode turn-on voltage is shown to be very sensitive to the arylamine/metal interface and thus can serve as a means for characterizing such organic/metal interfaces. We show that the diode electrical performance depends on the arylamine substituent groups and chemical/electrical properties of the anode. The conduction mechanism of the diodes is shown to be injection limited, which can be well described with the Richardson-Schottky thermionic emission model. This work may provide some insight into the use of single-layer organic diodes and the interfacial engineering method to rapidly probe the organic/metal and even organic/organic interfaces.

Journal Article↗
PubMed2006

Observation of two new N* peaks in J/psi-->ppi-n and ppi+n decays.

The decay J/psi-->NNpi provides an effective isospin 1/2 filter for the piN system due to isospin conservation. Using 58x10(6) J/psi decays collected with the Beijing Electromagnetic Spectrometer at the Beijing Electron Positron Collider, more than 100 thousand J/psi-->ppi-n+c.c. events are obtained. Besides the two well-known N* peaks at around 1500 MeV/c2 and 1670 MeV/c2, there are two new, clear N* peaks in the ppi invariant mass spectrum around 1360 MeV/c2 and 2030 MeV/c2 with statistical significance of 11sigma and 13sigma, respectively. We identify these as the first direct observation of the N*(1440) peak and a long-sought missing N* peak above 2 GeV/c2 in the piN invariant mass spectrum.

Journal Article↗
PubMed2006

Dose escalation of three-dimensional conformal radiotherapy for locally recurrent nasopharyngeal carcinoma: a prospective randomised study.

AIMS: To investigate prospectively the feasibility and efficacy of dose escalation using three-dimensional conformal radiotherapy (3D-CRT) boost technique for locally recurrent nasopharyngeal carcinoma (NPC) in a randomised study. MATERIALS AND METHODS: Thirty-six patients with locally recurrent NPC (>6 months interval from previous radical radiotherapy, no cervical lymph-node involvement and no distant metastasis) were enrolled. Treatment included conventional external-beam radiotherapy to 54 Gy, followed by a 3D-CRT boost to the gross tumour region. Patients were randomised to three boost dose levels: 16 Gy, 20 Gy and 24 Gy for groups I, II and III, respectively, with 12 patients in each group. All boost doses were delivered in 4-Gy fractions and 3 fractions per week. Median follow-up was 27 months (range 14-44 months). RESULTS: Three-year, local-recurrence-free survival rate was significantly higher (72%) for the high-dose group III than for groups I and II (37% and 28%, respectively, P = 0.047). No significant difference was found in the 3-year overall survival rate among the three groups (72%, 59% and 82% for groups I, II and III, respectively). Three-year distant metastases rates were 17%, 0% and 18%, respectively. Skull-base invasion (P = 0.017) and pathology (P = 0.0006) correlated with overall survival. Treatment was well tolerated and no significant difference was observed among the three groups in acute and late toxicities (grade III toxicity is minimal: 17%, 17%, 0% of oral mucositis and 25%, 17%, 17% of nasopharyngeal mucositis in groups I, II, III, respectively, and 8% leukocytopenia only in group II; no grade IV toxicity occurred in any of the groups except for a fatal bleeding in group III). CONCLUSIONS: Re-irradiation with high-dose 3D-CRT boost technique results in high local control rate and acceptable toxicity in patients with recurrent NPC. Dose escalation to the boost volume to 78 Gy (54 Gy + 24 Gy boost) results in improved recurrence-free survival compared with lower doses.

Adult↗
PubMed2005

Recovery of pyruvic acid from biotransformation solutions.

The aim of this investigation was to separate pyruvic acid of biotransformation solutions from lactic acid through complex extraction. For this purpose, complex extraction was investigated from model solutions. Tri-n-octanylamine (TOA) was used as the extractant. The effects of various diluents, the stoichiometry of pyruvic acid to TOA, and the initial pH of the aqueous phase on the extraction process were investigated in this study. The effects of sodium hydroxide (NaOH) and trimethylamine (TMA) on the back extraction process were also studied, respectively. The optimal conditions attained from the model solutions proved efficient on the biotransformation solutions of different concentrations. A total recovery of 71-82% of pyruvic acid was obtained, whereas 89-92% of lactic acid was removed. The purity of pyruvic acid reached 97% after the removal of TMA by a simple distillation.

Acinetobacter↗
PubMed2005

Effects of early feed restriction and cold temperature on lipid peroxidation, pulmonary vascular remodelling and ascites morbidity in broilers under normal and cold temperature.

Two experiments were conducted to evaluate the effects of early feed restriction on lipid peroxidation, pulmonary vascular remodelling and ascites incidence in broilers under normal and low ambient temperature. In experiment 1, the restricted birds were fed 8h per day either from 7 to 14 d or from 7 to 21 d, while the controlled birds were fed ad libitum. In experiment 2, the restricted birds were fed 80 or 60% of the previous 24-h feed consumption of full-fed controls for 7 d from 7 to 14 d. On d 14, half of the birds in each treatment both in experiment 1 and experiment 2 were exposed to low ambient temperature to induce ascites. Body weight and feed conversion ratio were measured weekly. The incidences of ascites and other disease were recorded to determine ascites morbidity and total mortality. Blood samples were taken on d 14, 21, 28, 35 and 42 to measure the plasma malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). On d 42, samples were taken to determine the right/total ventricular weight ratio (RV/TV), vessel wall area/vessel total area ratio (WA/TA) and mean media thickness in pulmonary arterioles (mMTPA). Low-temperature treatment increased plasma MDA concentration. When broilers were exposed to a cool environment for 3 weeks, plasma SOD and GSH-Px activity were decreased compared with normal-temperature chicks. RV/TV, WA/TA and mMTPA on d 42 were increased in birds exposed to cold, consistent with the increased pulmonary hypertension and ascites morbidity. Early feed restriction markedly decreased plasma MDA concentration. The plasma SOD and GSH-Px activity of feed-restricted birds were markedly higher than those fed ad libitum on d 35 and d 42. All early feed restriction treatments reduced ascites morbidity and total mortality. On d 42, the RV/TV, WA/TA and mMTPA of feed-restricted broilers were lower than that of the ad libitum-fed broilers. The results suggested that early feed restriction alleviated the lipid peroxidation, promoted the activity of enzymatic antioxidant and inhibited pulmonary vascular remodelling. These changes might be associated with reduced ascites incidence.

Animals↗
PubMed2005

The Lyapunov exponent of the EEG after administration of topiramate.

The objective of our study was to investigate the effect of topiramate (TPM) on the Lyapunov exponent of EEG by means of quantitative pharmacoelectroencephalography (QPEEG) and nonlinear analysis methods. One dose of TPM was administrated to epileptics and healthy adults. EEG samples were obtained prior to and at regular intervals (at 0.5, 1, 2, 4, 6, 8, 12, 24 hours) within the 24 hours following the administration of TPM. EEG activity was processed with nonlinear analysis methods. The Lyapunov exponent of the scalp areas was calculated through 60 s epochs without artifacts after each recording. The statistical difference between baseline predrug assessment and each postdrug control was calculated by computing the paired t test. Results showed that the Lyapunov exponent increased first, then decreased, then increased finally. We conclude that TPM can change the complexity of EEG.

Adult↗
PubMed2004

Observation of a threshold enhancement in the plambda invariant-mass spectrum.

An enhancement near the m(p)+M(Lambda) mass threshold is observed in the combined pLambda and pLambda invariant-mass spectrum from J/psi-->pK(-)Lambda;+c.c. decays. It can be fit with an S-wave Breit-Wigner resonance with a mass m=2075+/-12(stat)+/-5(syst) MeV and a width of Gamma=90+/-35(stat)+/-9(syst) MeV; it can also be fit with a P-wave Breit-Wigner resonance. Evidence for a similar enhancement is also observed in psi(')-->pK(-)Lambda;+c.c. decays. The analysis is based on samples of 5.8x10(7)J/psi and 1.4x10(7)psi(') decays accumulated in the BES II detector at the Beijing Electron-Positron Collider.

Journal Article↗
PubMed2004

Observation of the decay psi(2S)-->K0SK0L.

The decay psi(2S)-->K(0)(S)K(0)(L) is observed using psi(2S) data collected with the Beijing Spectrometer at the Beijing Electron-Positron Collider; the branching fraction is determined to be B(psi(2S)-->K(0)(S)K(0)(L))=(5.24+/-0.47+/-0.48)x10(-5). Compared with J/psi-->K(0)(S)K(0)(L), the psi(2S) branching fraction is enhanced relative to the prediction of the perturbative QCD "12%" rule. The result, together with the branching fractions of psi(2S) decays to other pseudoscalar meson pairs (pi(+)pi(-) and K+K-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.

Journal Article↗
PubMed2004

Sodium chloride-induced acute and chronic pulmonary hypertension syndrome in broiler chickens.

Two hundred forty 1-d-old Arbor Acres commercial broiler chicks were divided into control and experimental (T1 and T2) groups that, between 8 and 42 d of age, were provided drinking water containing 0, 600, or 1,200 mg/L sodium from sodium chloride, respectively. The pulmonary hypertension syndrome (PHS) incidence and the right to total ventricle weight ratio (RV/ TV) were calculated weekly, and blood samples and lung tissues were collected weekly from 10 birds per group to evaluate the structural and hemodynamic characteristics of pulmonary vessels. Saline drinking water significantly increased the incidence of PHS and RV/TV ratios. In the T2 group the PHS mortality exhibited 2 peaks, including an acute peak from 14 to 21 d of age and a chronic peak from 35 to 42 d of age. During the acute peak of PHS mortality the blood volume (BV), filtration index (FI), and packed cell volume (PCV) increased in groups T1 and T2 when compared with the control group. During the acute peak there were no differences among groups in the ratio of wall to total area (WA/TA), medial thickness of pulmonary arteriole walls (mMTPA), the percentage of thick-walled peripheral lung vessels (%TWPV), the percentage of muscular arterioles (%MA), or the percentage of nonmuscular arterioles (%NMA) in pulmonary arterioles. During the chronic peak of PHS mortality, group T2 exhibited the highest values for %TWPV, %MA, WA/TA, and mMTPA and the lowest values for %NMA when compared with the T1 and control groups. Also during the chronic peak the groups did not differ in BV or FI, whereas PCV remained elevated above control values in groups T1 and T2. These observations indicate that hemodynamic changes related to viscous resistance to blood flow (BV, FI, PCV) predominated throughout the acute peak of PHS mortality, whereas, during the chronic stages of PHS mortality, increased vascular resistance to blood flow also was imposed by remodeling of the pulmonary vasculature.

Aging↗
PubMed2003

Observation of a near-threshold enhancement in the pp mass spectrum from radiative J/psi-->gammapp decays.

We observe a narrow enhancement near 2m(p) in the invariant mass spectrum of pp pairs from radiative J/psi-->gammapp decays. No similar structure is seen in J/psi-->pi(0)pp decays. The results are based on an analysis of a 58 x 10(6) event sample of J/psi decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit with either an S- or P-wave Breit-Wigner resonance function. In the case of the S-wave fit, the peak mass is below 2m(p) at M=1859(+3)(-10) (stat)+5-25(syst) MeV/c(2) and the total width is Gamma<30 MeV/c(2) at the 90% confidence level. These mass and width values are not consistent with the properties of any known particle.

Journal Article↗
PubMed2003

Quantitative EEG effects of topiramate.

OBJECTIVE: The study is to invesigate the effect of topiramate (TPM) on EEG by means of quantitative pharmacoelectroencephalography (QPEEG). METHODS: One dose of TPM was administrated to epileptics and healthy adults. The EEG samples were obtained prior to and at regular intervals within the 24 hours following the administration of TPM. The EEG activity was processed with power spectral analysis. RESULTS: The power of slow wave, alpha 1 bands and total power increased after the administration of TPM, the power or slow wave in both occipital areas, and the total power of all scalp areas also increased. The percent of power increased at the theta band and alpha 1 band (healthy adults) or delta band, theta band (patients). CONCLUSION: TPM can change the EEG background activity. These changes are different from other antiepileptic drugs.

Adult↗
PubMed2001

Transtympanic steroids for treatment of sudden hearing loss.

OBJECTIVES: To determine whether transtympanic steroid administration may be an effective treatment for sudden onset sensorineural hearing loss (SSNHL) in patients for whom systemic steroid treatment has failed or who were not candidates for systemic steroids. METHODS: The standard medical regimen for SSNHL usually involves systemic steroid therapy. Unfortunately, some patients do not respond successfully to or are poorly tolerant of systemic steroids. Transtympanic administration of steroids has been suggested as an alternative to systemic therapy. A prospective study was designed to evaluate the hearing outcomes in SSNHL patients treated with transtympanic steroids. Patients received transtympanic steroids if oral steroids had failed to work or if they were not able to tolerate oral steroids. Transtympanic steroids were administered through a ventilation tube placed with the patient under local anesthesia. Steroid administration was performed on 4 separate occasions over the course of 10 to 14 days. Hearing was assessed immediately before therapy and within 1 to 2 weeks after therapy. RESULTS: Hearing improvement was documented in 10 of 23 patients (44%) who underwent transtympanic steroid administration. This represents a 44% hearing salvage in patients for whom steroid treatment would otherwise have been considered a failure. CONCLUSION: Transtympanic steroid therapy may be an alternative treatment for patients with SSNHL for whom systemic steroid therapy had failed or who could not tolerate systemic steroid therapy.

Adult↗
PubMed2001

Expression of the cystic fibrosis transmembrane conductance regulator in rat spermatids: implication for the site of action of antispermatogenic agents.

To establish whether cystic fibrosis transmembrane conductance regulator (CFTR) is functionally expressed in the testis, we subjected spermatogenic cells from rat testes to analysis of CFTR mRNA, protein and channel activity. CFTR mRNA was detected in the testes of mature but not immature rats using reverse transcription-polymerase chain reaction analysis. Western blot analysis performed with a CFTR specific antibody revealed immunoreactivity in the membrane extract of spermatogenic cells. Immunohistochemical studies localized CFTR in round and elongated spermatids, but not in the fully developed spermatozoa. Using a whole-cell patch clamp technique, we recorded an inward current activated by intracellular cAMP (100 micromol/l) in round spermatids. The current displayed a linear I / V relationship and was inhibited by diphenylamine-2-carboxylate (DPC), a chloride channel blocker. Transfection of the rat germ cell CFTR cDNA into human embryonic kidney (HEK) 293 cells caused the expression of a cAMP-activated chloride current with CFTR characteristics. The current was completely blocked by the antispermatogenic agents 1-(2,4-dichlorobenzyl)-indazole-3-carboxylic acid, lonidamine (500 micromol/l) and 1-(2,4-dichlorobenzyl)-indazole-3-acrylic acid, AF2785 (250 micromol/l). These results taken together provide evidence that CFTR is differentially expressed in spermatids during spermiogenesis. We speculate that CFTR may interact with aquaporin to bring about cytoplasmic volume contraction which is an essential feature of spermiogenesis.

Animals↗
PubMed2001

Clinical and prognostic significance of human papillomavirus in a Chinese population of cervical cancers.

OBJECTIVE: To investigate the clinical and prognostic significance of human papillomavirus (HPV) in a Chinese population of cervical cancers. METHODS: We studied 121 cervical cancer tissue samples from patients treated at our hospital. Identification and typing of HPV were done by polymerase chain reaction (PCR) using consensus primers MY11 and MY09 followed by direct DNA sequencing. The results were correlated with various clinical and prognostic parameters. RESULTS: We found HPV DNA in 95 (78.5%) cases, including HPV-16 in 59 (48.8%) and HPV-18 in 14 (11.6%) cases. chi(2) analysis revealed no significant correlation between the presence of HPV DNA and age at diagnosis, clinical stage, histologic type, tumor grading, 2-year and 5-year survival rate. Of the factors evaluated, age at diagnosis and histologic type were found to have a statistically significant relationship with HPV type. The mean age of the HPV-18 group was 48.6 years compared to 57.1 years for the HPV-16 group (p = 0.045) and 58.2 years for the HPV-negative group (p = 0.04). HPV-18 was detected more often in adenocarcinomas (AC) than in squamous cell carcinomas (SCC). Conversely HPV-16 was detected significantly more often in SCC (p < 0.0001). The HPV-negative group also had a higher incidence of SCC (p = 0.007). HPV-18-positive patients seemed to have more nodal involvement than both HPV-16-positive patients (45.5 vs. 20.8%) and HPV-negative patients (45.5 vs. 18.2%); however, it did not reach statistical significance. CONCLUSIONS: These observations suggest that the presence of HPV DNA does not bear any clinical or prognostic significance in a Chinese population of cervical cancers. HPV-18 is found more often in younger patients and is associated with AC.

Adenocarcinoma↗
PubMed2001

The development of colon innervation in trisomy 16 mice and Hirschsprung's disease.

AIM: To study the colon innervation of trisomy 16 mouse, an animal model for Down's syndrome, and the expression of protein gene product 9.5 (PGP 9.5) in the stenosed segment of colon in Hirschsprung's disease (HD). METHODS: Trisomy 16 mouse breeding;cytogenetic analysis of trisomy 16 mice; and PG P9.5 immunohistochemistry of colons of trisomy 16 mice and HD were carried out. RESULTS: Compared with their normal littermates, the nervous system of colon in trisomy 16 mice was abnormally developed. There existed developmental delay of muscular plexuses of colon, no submucosal plexus was found in the colon, and there was 5mm aganglionic bowel aparting from the anus in trisomy 16 mice. The mesentery nerve fibers were as well developed as shown in their normal littermates. Abundant proliferation of PGP 9.5 positive nerve fibers was revealed in the stenosed segment of HD colon. CONCLUSION: Trisomy 16 mice could serve as an animal model for Hirschsprung's disease for aganglionic bowel in the distal part of colon. Abundant proliferation of PGP 9.5 positive fibers resulted from extrinsic nerve compensation, since no ganglionic cells were observed in the stenosed segment of the colon in HD. HD has a genetic tendency.

Animals↗
PubMed2001

[The presence of the lymphatic stomata in ovarian bursa of guinea pig and the ultrastructure of ovarian bursa].

In order to explore its structure and speciality of species, the ovary bursa of guinea pig was studied by using dissecting microscopy and scanning electron microscopy. In this paper, the lymphatic stomata on both internal and external layer of the ovary bursa was frist reported in guinea pig. The results suggested that the stomata in bursa not only provided a pathway to connect the bursal cavity with the lymphatic vessels of bursa and the peritoneal cavity, but also may be involved in the reproduction and local immunity of the ovary. The stomata may play an important role in physiological function of the ovary. At the same time, the structural differences were identified in ovary bursa between guinea pig and golden hamster.

Animals↗