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H Ping

Publications and source records attributed to H Ping.

10 recordsLinked to original sources
PubMed2006

Measurement of the K0 charge radius and a CP-violating asymmetry and a search for CP-violating E1 direct photon emission in the rare decay KL--> pi+ pi- e+ e-.

Using the complete KTeV data set of 5,241 candidate K(L)--> pi(+) pi(-) e(+) e(-) decays (including an estimated background of 204 +/- 14 events), we have measured the coupling g(CR)= 0.163 +/- 0.0149(stat) +/- 0.023(syst) of the CP conserving charge radius process and from it determined a K(0) charge radius of = [-0.077 +/- 0.007(stat) +/- 0.011(syst)]fm(2). We have determined a first experimental upper limit of 0.04 (90% C.L.) /g(e1)/ / /g(M1)/ of the couplings for the E1 and M1 direct photon emission processes. We also report the measurement of /g(M1)/ including a vector form factor /g(M1)/(1 + (a(1)/a(2))/((M(2)(p)-(M(2)(k))= 2M(K)E(gamma*)), where vector /g(M1)/= 1.11+/- 0.12(stat) +/- 0.08(syst) and a(1)/a(2) = [-0.744 +/- 0.027(stat) +/- 0.032(syst)] GeV(2)/c(2). Finally, a CP-violating asymmetry of [13.6 +/- 1.4(stat) +/- 1.5(syst)]% in the CP and T odd angle phi between the decay planes of the e(+) e(-) and pi(+) pi(-) pairs in the K(L) center of mass is reported.

Journal Article↗
PubMed2005

Observation of the decay xi0 --> sigma+ mu- nu(mu).

The xi0 muon semileptonic decay has been observed for the first time with nine identified events using the KTeV beam line and detector at Fermilab. The decay is normalized to the xi0 beta decay mode and yields a value for the ratio of decay rates gamma(xi0 --> sigma+ mu- nu(mu))/gamma(xi0 --> sigma+ e- nu(e)) of [1.8(-0.5)(+0.7)(stat) +/- 0.2(syst)] x 10(-2). This is in agreement with the SU(3) flavor symmetric quark model.

Journal Article↗
PubMed2004

Search for the rare decay K(L)-->pi(0)e(+)e(-).

The KTeV/E799 experiment at Fermilab has searched for the rare kaon decay K(L)-->pi(0)e(+)e(-). This mode is expected to have a significant CP violating component. The measurement of its branching ratio could support the standard model or could indicate the existence of new physics. This Letter reports new results from the 1999-2000 data set. One event is observed with an expected background at 0.99+/-0.35 events. We set a limit on the branching ratio of 3.5x10(-10) at the 90% confidence level. Combining with the previous result based on the data set taken in 1997 yields the final KTeV result: BR(K(L)-->pi(0)e(+)e(-))<2.8x10(-10) at 90% C.L.

Journal Article↗
PubMed1999

The relationship between normal erythrocyte sedimentation rate of Chinese young people and geographical factors.

In order to provide a scientific basis for the layout of a unified standard of the reference value of Chinese young people's erythrocyte sedimentation rate (ESR), the relationship between the reference values of the Chinese healthy young's ESR and five geographical factors was tested according to the Wintrobe methods. The altitude was found to be the most important factor affecting the reference value of the Chinese young's ESR. The altitude increase correlates with the decrease of the reference value of the young's ESR. The method of stepwise regression analysis was used to deduce two multivariate regression equations. If the geographical index values of a particular area of China are known, the reference value of the young's ESR of this region can be calculated by means of the regression equations. Furthermore, the depending on geographical factors, China can be divided into six districts: Qingzang, Southwest, Northwest, Southeast, North and Northeast District, according to the reference values of the Chinese young's ESR.

Adult↗
PubMed1997

Responses of rat substantia nigra dopamine-containing neurones to (-)-HA-966 in vitro.

1. Extracellular single unit recording techniques were used to compare the effects of (-)-3-amino-1-hydroxypyrrolidin-2-one ((-)-HA-966) and (+/-)-baclofen on the activity of dopamine-containing neurones in 300 microns slices of rat substantia nigra. Electrophysiological data were compared with the outcome of in vitro binding experiments designed to assess the affinity of (-)-HA-966 for gamma-aminobutyric acid (GABAB) receptors. 2. Bath application of (-)-HA-966 produced a concentration-dependent inhibition of dopaminergic neuronal firing (EC50 = 444.0 microM; 95% confidence interval: 277.6 microM - 710.1 microM, n = 27) which was fully reversible upon washout from the recording chamber. Although similar effects were observed in response to (+/-)-baclofen, the direct-acting GABAB receptor agonist proved to be considerably more potent than (-)-HA-966 (EC50 = 0.54 microM; 95% confidence interval: 0.44 microM - 0.66 microM, n = 29) in vitro. 3. Low concentrations of chloral hydrate (10 microM) were without effect on the basal firing rate of nigral dopaminergic neurones but significantly increased the inhibitory effects produced by concomitant application of (-)-HA-966. 4. The inhibitory effects of (-)-HA-966 were completely reversed in the presence of the GABAB receptor antagonists, CGP-35348 (100 microM) and 2-hydroxysaclofen (500 microM). Bath application of CGP-35348 alone increased basal firing rate. However, the magnitude of the excitation (9.2 +/- 0.3%) was not sufficient to account for the ability of the antagonist to reverse fully the inhibitory effects of (-)-HA-966. 5. (-)-HA-966 (0.1-1.0 mM) produced a concentration-dependent displacement of [3H]-GABA from synaptic membranes in the presence of isoguvacine (40 microM). However, the affinity of the drug for GABAB binding sites was significantly less than that of GABA (0.0005 potency ratio) and showed no apparent stereoselectivity. 6. These results indicate that while (-)-HA-966 appears to act as a direct GABAB receptor agonist in vitro, its affinity for this receptor site is substantially less than that of GABA or baclofen and unlikely to account for the depressant actions of this drug which occur at levels approximately ten fold lower in vivo.

Animals↗
PubMed1996

Successful induction of severe destructive arthritis by the transfer of in vitro-activated synovial fluid T cells from patients with rheumatoid arthritis (RA) in severe combined immunodeficient (SCID) mice.

In order to investigate the role of pathogenic T cells in RA, the establishment of an RA model using patients' T cells is thought to be essential. In this study, multiple and severe destructive arthritis was established by transferring in vitro-stimulated synovial fluid T (SFT) cells from patients with RA through simultaneous injection into knee joint and peritoneal cavity of SCID mice without causing xenogeneic graft-versus-host disease (GVHD). Neither the transfer of unstimulated SFT cells nor sole i.p. injection was sufficient to induce severe arthritis. Interestingly, in contrast with SFT cells, in vitro-activated peripheral blood lymphocytes from RA patients failed to trigger such arthritis, suggesting that pathogenic T cells might be concentrated in synovial fluid of RA patients. This, the first severe arthritis model mimicking RA induced by RA patients' T cells, is expected to provide important information about RA pathogenesis and a possible therapeutic approach.

Aged↗
PubMed1990

Effects of feeding zearalenone to sows on rebreeding and pregnancy.

Two trials were conducted with a total of 91 lactating sows fed 0, 5 or 10 ppm dietary zearalenone (Z) and 0 or 15% dietary alfalfa in a factorial arrangement to evaluate their influence on reproductive performance to 40 d postbreeding. Feeding of Z did not alter the proportion of sows returning to estrus; however, the weaning-to-estrus interval increased when increased dietary Z was fed in Trial 2, with a similar trend at the highest level in Trial 1. The average number of fetuses per sow with fetuses tended to decrease (P less than .05) with increasing dietary Z in Trial 2, but not in Trial 1. Embryonic mortality did not appear to increase when the ratio of fetuses to corpora lutea was compared in sows with fetuses in Trial 1, but it did increase in Trial 2. The trend to increased numbers of bred sows that were non-pregnant at slaughter when dietary Z increased in Trial 1 was not observed in Trial 2. Dietary dehydrated alfalfa meal did not appear to modify the effects of Z in these trials.

Animal Feed↗
PubMed1987

Protein C functional assay using snake venom activator.

We report a functional assay of Protein C on whole plasma using a snake venom called Protac-C. This method is simple, avoids absorption-elution techniques. Also this method can be adopted to a microtitre plate system testing of large number of samples. Functional levels by this test correlated well with the antigenic levels (r = .8) measured by ELISA. Protein C functional and antigenic values in 58 healthy volunteers were 82% and 95.5% respectively. The warfarinized samples showed a lower mean.

Chromogenic Compounds↗
PubMedDate not supplied

An in vivo rat model for assessment of extrahepatic metabolism.

INTRODUCTION: Xenobiotic metabolism in extrahepatic tissues has been extensively studied in vitro, but it is difficult to estimate in vivo the share of xenobiotic transformation in extrahepatic tissues for lack of a suitable approach. In this paper an in vivo rat model for assessment of extrahepatic metabolism is described, and the model was investigated using the conversion of lidocaine to monoethylglycinexylidide (MEGX). METHODS: The rats were anesthetized with ethyl ether inhalation. The liver was exposed, the liver artery ligated, and the portal vein was clamped at its distal end. The left hepatic lobe was partly excised along its inferior margin, and a heparinized silicone catheter, diameter 0.2 cm, was inserted into the portal and left hepatic veins to allow the recirculation of portal vein blood. A sham operation was performed in the control group. RESULTS: Phenol red test showed that hepatic blood supply was absolutely blocked in model rats. At 30 min after establishing the portal-cavum bypass, the renal function and electrolytes did not change, but serum glucose decreased by 64.4 +/- 30.4%; 30 min after intravenous administration of 1.0% lidocaine 2 mg x kg(-1), serum MEGX in model rats was 32.0 +/- 7.14% of that in the control group, which mostly existed in a free form and was not induced by phenobarbital pretreatment. DISCUSSION: The model is easy to establish and provides an in vivo method to study the extrahepatic metabolism of xenobiotics.

Animals↗