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Biomedical subjects

C B Yang

Publications and source records attributed to C B Yang.

18 recordsLinked to original sources
PubMed2006

Proton enhancement at large pT at the CERN large hadron collider without structure in associated-particle distribution.

The production of pions and protons in the pT range between 10 and 20 GeV/c for Pb+Pb collisions at CERN LHC is studied in the recombination model. It is shown that the dominant mechanism for hadronization is the recombination of shower partons from neighboring jets when the jet density is high. Protons are more copiously produced than pions in that pT range because the coalescing partons can have lower momentum fractions, but no thermal partons are involved. The proton-to-pion ratio can be as high as 20. When such high pT hadrons are used as trigger particles, there will not be any associated particles that are not in the background.

Journal Article↗
PubMed2005

Critical fluctuation of wind reversals in convective turbulence.

The irregular reversals of wind direction in convective turbulence are found to have fluctuating intervals that can be related, under certain circumstances, to critical behavior. In particular, by focusing on its temporal evolution, the net magnetization of a two-dimensional Ising lattice of finite size is observed to fluctuate in the same way. Detrended fluctuation analysis of the wind reversal time series results in a scaling behavior that agrees remarkably well with that of the Ising problem. The specific properties found here, as well as the lack of an external tuning parameter, also suggest that the wind reversal phenomenon exhibits signs of self-organized criticality.

Journal Article↗
PubMed2004

Final-state interaction as the origin of the Cronin effect.

The Cronin effect that refers to the enhancement of hadron spectra at intermediate p(T) with increasing A in pA collisions is traditionally explained in terms of the broadening of the parton transverse momentum in the initial state. We show that recent data on the nuclear modification factor at eta=0 for d+Au collisions can be understood in terms of the recombination of soft and shower partons in the final state. It is the centrality dependence of the soft parton density that leads to the Cronin effect.

Journal Article↗
PubMed2003

Centrality scaling of the p(T) distribution of pions.

From the preliminary data of PHENIX on the centrality dependence of the pi(0) spectrum in p(T) at midrapidity in heavy-ion collisions, we show that a scaling behavior exists that is independent of the centrality. It is then shown that degrades with increasing N(part) exponentially with a decay constant that can be quantified. A scaling distribution in terms of an intuitive scaling variable is derived that is analogous to the Koba-Nielsen-Olesen scaling. No theoretical models are used in any part of this phenomenological analysis.

Journal Article↗
PubMed2001

[Effect of lower body negative pressure and rotating-table simulated push-pull effect in flight on cardiovascular function].

Objective. To explore the effect of push-pull effect (PPE) simulated by lower body negative pressure (LBNP) rotating-table, and observe the physiological responses to push-pull maneuver. Method. A special LBNP rotating-table was used to simulate the push-pull maneuver. 8 healthy adults participated randomly in two experiments. One was simulated PPE test, which include a series of head-up stand (HUT, +1 Gz) for 1 min, then in head-down stand (HDT, -1 Gz) for 30 s and again in HUT combining LBNP (-50 mmHg) for 10 min. The other one was control test, which only consists of HUT combining LBNP (-50 mmHg) for 10 min. Changes of heart rate (HR), blood pressure (BP), basic impedance (Z0) , stroke output (SO) , cardiac output (CO) and total peripheral resistance (TPR) were monitored by electrical impedance instrument during the experiment. Result. During simulated PPE experiment, 3 subjects presented presyncopal symptoms, with average standing time of 8.99 +/- 1.47 min, while during control test, all the subjects completed HUT combining LBNP for 10 min. In simulated PPE experiment, as compared with HUT (control), HR, Z0 during HDT were significantly lowered, while SV and CO were increased significantly. During HUT + LBNP, HR, Z0 and TPR were significantly higher, while SV and CO were significantly lower than that of control and HDT. SBP was increased significantly than control value when "HUT + LBNP" started, but during the whole process of "HUT + LBNP ", it became significantly lowered. In control experiment, the above mentioned indexes showed the same trend of as change compared with the control, however, the percentage of the change was lower than simulated PPE test, the change percentage in HR was not including. Conclusion. After headstand, head-up stand combining LBNP caused cardiovascular function descends, the degree was larger than simple head-up stand combining LBNP. LBNP rotating-table can be used to simulated push-pull effect.

Adult↗
PubMed2001

[Clinical study on regulatory effect of liandai Capsule on p21ras and mutant p53 protein expression in gastrointestinal neoplasm].

OBJECTIVE: To study the regulatory effect of Liandai Capsule on p21ras and mutant p53 protein expression in gastrointestinal (GI) neoplasm. METHODS: Forty-five patients of GI neoplasm in middle or advanced stage were enrolled and divided randomly into the treated group and the control group to observe the changes of their serum p21ras and mutant p53 protein expression as well as their quality of life (QOL) before and after treatment. RESULTS: The content of p21ras and mutant p53 protein expression in the treated group decreased significantly and QOL improved after treatment, P < 0.05 or P < 0.01, while these changes in the control group were not shown. CONCLUSION: Liandai Capsule has regulatory effect on p21ras and mutant p53 protein expression in GI neoplasm.

Adenocarcinoma↗
PubMed2000

Excisional bleb revision to correct overfiltration or leakage.

OBJECTIVES: To evaluate the effectiveness of excisional revision of filtering blebs for hypotony or leakage when more conservative measures have failed. PATIENTS AND METHODS: Retrospective review of all patients who underwent excisional revision of a filtering bleb for hypotony (intraocular pressure [IOP] < 5 mm Hg) or leakage during a 3 year period. The revision consisted of excision of the avascular bleb, mobilization of the surrounding conjunctiva, and suturing of the conjunctiva at the limbus. RESULTS: Sixteen patients were included in the study. The average age was 66.3 +/- 14.8 years (range, 39-83). Revision followed trabeculectomy in 11 cases, combined phacoemulsification-trabeculectomy in three cases, and inadvertent blebs in two cases. Five cases had bleb leaks without hypotony, four cases had hypotony alone, and seven cases had both hypotony and a bleb leak. Average follow-up after bleb revision was 25 +/- 11 months (range, 9-43). Average IOP increased from 3.8 +/- 5.6 mm Hg (range, 0-22) to 11.9 +/- 4.1 mm Hg (range, 3-18), with an average of 1.1 +/- 1.1 medication (range, 0-3). The IOP at the last visit was < 15 mm Hg in all but two patients, with 10 of the 16 patients requiring medications. At the last follow-up examination, visual acuity had improved > or = two lines in nine patients and was reduced two lines in one patient. Five patients had early postoperative limbal wound leaks; resuturing was required in one case. CONCLUSIONS: Excisional bleb revision is an effective technique to correct hypotony or leakage after filtering surgery when other methods have failed. Intraocular pressure control is often maintained with the use of medications.

Adult↗
PubMed2000

Spatial-temporal correlations in the process to self-organized criticality.

A different type of spatial-temporal correlation in the process approaching the self-organized criticality is investigated for the two simple models for biological evolution. The changed behaviors of the position with minimum barrier are shown to be quantitatively different in the two models. Different results of the correlation are given for the two models. We argue that the correlation can be used, together with the power-law distributions, as criteria for self-organized criticality.

Biological Evolution↗
PubMed2000

Effects of acute exposure to mild or moderate hypoxia on human psychomotor performance and visual-reaction time.

Objective. The aim of this study was to determine whether psychomotor performance and visual reaction time were affected by acute exposure to mild or moderate hypoxia. Method. Eighteen healthy male volunteers performed finger tapping, simple reaction time (SRT) and 4-choice reaction time (CRT) tests at simulated altitude of 300 m (control), 2800 m, 3600 m and 4400 m for 1 h in a hypobaric chamber. Result. SaO2 decreased from 98% (control) to 90%, 82% and 74% respectively at the various altitudes. All the performance parameters showed no significant change after exposure to 2800 m for 1 h relative to ground level (P>0.05). However the mean reaction time of 4-CRT under 3600 m prolonged and performance decreased as compared with baseline value (P<0.05), and the performance decreased further under 4400 m (P<0.01). No significant difference was found in finger tapping and SRT even under exposure to 4400 m for 1 h. Furthermore, no decrease in correct rate were observed at any altitude (P>0.05). Conclusion. The results from this study demonstrated that there were no measurable impairment of visual reaction time and psychomotor performance under exposure to an altitude of 2800 m for 1 h. However, adverse effects on psychomotor performance were observed under 3600 m and over.

Adolescent↗
PubMed2000

[Experimental study on effect of sanmiao mixture capsules on prostate hyperplasia in mice and rats].

OBJECTIVE: To observe the effect of Sanmiao Mixture Capsules(SMC) on prostate hyperplasia in mice and rats. METHOD: The model of prostate hyperplasia was made by injecting testosterone propionate in to male mice(5 g.kg-1.d-1, 21 d) and rats(3 g.kg-1.d-1, 14 d). The treated group was administered SMC(mice: 36.3 g.kg-1 and 18.2 g.kg-1; rats: 25.2 g.kg-1 and 12.6 g.kg-1), the normal control group 1.9 g.kg-1, and the model control group NS. hours after the last administration serum tests were carried out on E2, AKP and Zn2+. Then the animals were killed, prostates taken out and weighed, index of prostate was calculated and pathological examination performed. RESULT: In the SMC treated group, the prostate weight and index were lowered(P < 0.01) the mean activation of E2 was raised, and the mean concentration of AKP and Zn2+ was inhibited (P < 0.01). CONCLUSION: SMC are helpful in checking prostate hyperplasia in mice and rats, the mechanism being probably related to the raising of activation of E2 as well as to the inhibition of concentration of AKP and Zn2+.

Acid Phosphatase↗
PubMed2000

[Effects of repeated low body negative pressure (LBNP) exposures on LBNP tolerance].

OBJECTIVE: To investigate variation of low body negative pressure (LBNP) tolerance and the relationship with change of heart function after repeated LBNP exposures. METHOD: Ten healthy subjects were exposed to eight min consecutive daily LBNP (-50 mmHg). Before and after this exposures, tolerance to LBNP was determined by a cumulative stress index (CSI) and duration of negative pressure (DNP). RESULT: The pre- and post repeated exposure values of CSI and DNP were 1058 +/- 216 s, 1354 +/- 233 s and 45833 +/- 12546 s mmHg, 63433 +/- 13458 s mmHg, respectively. It showed that both were increased significantly (P<0.05), and the heart function was showed to have a tendency of being enhanced. CONCLUSION: It suggested that LBNP tolerance increased after repeated exposures, which might be achieved via strengthening of ventricular contractivity, decreasing the compliance of peripheral vascular, the hypotensive [correction of hypotentive] reflex compensatory mechanisms becoming more effective, and increasing arterial blood pressure on heart level.

Adaptation, Physiological↗
PubMed1998

Use of latanoprost in the treatment of glaucoma associated with Sturge-Weber syndrome.

PURPOSE: To determine if latanoprost reduces intraocular pressure in eyes with glaucoma associated with Sturge-Weber syndrome. METHODS: We conducted a prospective study in which eyes with uncontrolled intraocular pressure associated with Sturge-Weber syndrome were treated with latanoprost 0.005% once daily. All eyes were already receiving at least two other antiglaucoma medications. Intraocular pressure was measured at baseline and after treatment for at least 1 month. All intraocular pressure measurements were taken within 24 hours of drug instillation. RESULTS: Six eyes of six patients received latanoprost. Two (28%) of the six eyes demonstrated an intraocular pressure decrease that averaged 8.8 mm Hg. These two responders had juvenile onset glaucoma, whereas the four nonresponders had congenital onset glaucoma. CONCLUSIONS: Latanoprost may significantly reduce intraocular pressure in selected patients with glaucoma associated with Sturge-Weber syndrome.

Adolescent↗
PubMed1997

Humeral lengthening using the Ilizarov technique.

Significant shortening of the humerus may cause cosmetic, psychologic and functional problems. From 1989 to 1993, we performed humeral lengthening using the Ilizarov technique on six patients. The indications were: 1) significant inequality (> 4-14 cm); 2) significant functional impairment; and 3) poor aesthetic appearance or related psychologic problems. THere were three females and three males, with a mean age of 17.7 years. The right humerus was affected in two patients, the left in four. Etiologies included sequelae of neonatal septic shoulder in three patients, sequelae of childhood trauma in one, malunion in one and congenital bone anomaly in one. Mean shortening of the humerus was 9.2 cm. Total average treatment time was 250 days. Mean lengthening was 8.7 cm. Complications included transient radial nerve palsy in one patient and delayed union in another. Bone grafting was performed on the patient who sustained delayed union. Fracture of the distraction site occurred after removing the Ilizarov device, and open reduction and internal fixation was performed. Functional and aesthetic status was improved in all six patients, over a minimum of 2 years follow-up. Lengthening of the humerus can be performed satisfactorily using the Ilizarov technique.

Adolescent↗
PubMed1993

[Deficiency and excess syndrome of chronic atrophic gastritis].

In this study, Syndrome of Deficiency revealed that gastric acid secretion, cellular immunity, hematopoietic and synthetic metabolism were all decreased. The RBC, Hb, TG, HDL-C, CD8, infection rate of HP, the degree of atypical hyperplasia and the staining intensity of PNA were different for Spleen-Kidney-Deficiency syndrome from spleen-Deficiency syndrome, the former was lower than the latter, while LPO was higher and ESR was faster for the former. Syndrome of Excess revealed that the serum gastrin level was higher, humoral immunity and catabolic metabolism were increased, its blood was in hyperviscosity and hypercoagulation state. The Qi Stagnation with Blood Stasis was different from the Qi stagnation alone which including the atrophic degree of the former was severer, the ESR was faster than that of the later. The Heat Stagnation (HS), retention of Dampness (RD) and Damp-Heat (DH) have some difference. First, for secretion of gastric acid. HS was the lowest, DH the next, RD the third. Second, for the level of LPO, HS was the highest.

Adult↗
PubMed1990

[Deficiency syndrome of chronic gastritis].

161 cases of chronic gastritis (including 59 superficial gastritis, 86 atrophic gastritis, 16 superficial gastritis combined with atrophic gastritis) typed in deficiency syndrome (including 64 Spleen-deficiency syndrome, 97 Spleen-Kidney-deficiency syndrome) were studied clinically with modern medicinal multiple-index. The gastroscope image, pathologic changes of gastric mucosa, stomach barium meal examination, gastric acid, serum gastrin, urine pepsinogen, urine 17-ketosteroid, vegetative nerve function, peripheral blood picture, etc. were selected as observation indices. The preliminary findings showed that in Spleen-deficiency patients, the superficial gastritis constituted the majority, the asthenic stomach constituted the minority, the gastric secretion and the serum gastrin were on the high side, the urine pepsinogen, the adrenocortical function and the hemoglobin were on the low side, but the white blood cell was rather normal; otherwise, in Spleen-Kidney deficiency patients, the atrophic gastritis and the asthenic stomach constituted the majority, the gastric secretion decreased, the serum gastrin level was higher, while the urine pepsinogen, the adrenocortical function, white blood cell and the hemoglobin were on the low side. It was also found that in certain same inflammation changes, the gastric secretion of the Spleen-Kidney-deficiency syndrome was markedly than that of Spleen-deficiency syndrome. With the treatment method of invigorating the Spleen and reinforcing the Spleen-Kidney, each index was relatively improved. The degree of seriousness to inflammation changes of gastric mucosa and the disturbance or imbalance of gastric secretion function were reflected from the Spleen-deficiency and the Spleen-Kidney-deficiency syndromes of chronic gastritis. It is suggested that hemopoiesis and hypothalamo-adenohypophysial-adrenal cortical axis be influenced.

Adult↗