PubMed Health⌕ Search

Biomedical subjects

G Rong

Publications and source records attributed to G Rong.

At least 127 records · Page 7Linked to original sources
PubMed2002

Measurement of B --> K*gamma branching fractions and charge asymmetries.

The branching fractions of the exclusive decays B0-->K(*0)gamma and B+-->K(*+)gamma are measured from a sample of (22.74+/-0.36)x10(6) BB decays collected with the BABAR detector at the PEP-II asymmetric e(+)e(-) collider. We find B (B0-->K(*0)gamma) = [4.23+/-0.40(stat)+/-0.22(syst)]x10(-5), B(B+-->K(*+)gamma) = [3.83+/-0.62(stat)+/-0.22(syst)]x10(-5) and constrain the CP-violating charge asymmetry to be -0.170 K(*)gamma)<0.082 at 90% C.L.

Journal Article↗
PubMed2001

Search for the decay B0-->gammagamma.

We present a limit on the branching fraction for the decay B0-->gammagamma using data collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II asymmetric energy e+e- collider. Based on the observation of one event in the signal region, out of a sample of 21.3x10(6) e+e--->Upsilon(4S)-->BB decays, we establish an upper limit on the branching fraction of B(B0-->gammagamma)<1.7x10(-6) at the 90% confidence level. This result substantially improves upon existing limits.

Journal Article↗
PubMed2001

Measurement of the B--> J/psiK*(892) decay amplitudes.

We present a measurement of the decay amplitudes in B-->J/psiK*(892) channels using 20.7 fb(-1) of data collected at the Upsilon(4S) resonance with the BABAR detector at PEP-II. We measure a P-wave fraction R(perpendicular) = (16.0 +/- 3.2 +/- 1.4)% and a longitudinal polarization fraction (59.7 +/- 2.8 +/- 2.4)%. The measurement of a relative phase that is neither 0 nor pi, phi = 2.50 +/- 0.20 +/-0.08 radians, favors a departure from the factorization hypothesis. Although the decay B-->/psiK(pi) proceeds mainly via K*(892), there is also evidence for K2*(1430) and K(pi) S-wave contributions.

Journal Article↗
PubMed2001

Measurements of the branching fractions of exclusive charmless B meson decays with eta(') or omega mesons.

We present the results of searches for B decays to charmless two-body final states containing eta(') or omega mesons, based on 20.7 fb(-1) of data collected with the BABAR detector. We find the branching fractions Beta(B(+)-->eta(')K(+)) = (70+/-8+/-5) x 10(-6), Beta(B(0)-->eta(')K(0)) = (42(+13)(-11) +/- 4) x 10(-6), and Beta(B(+)-->omega pi(+)) = (6.6(+2.1)(-1.8) +/- 0.7) x 10(-6), where the first error quoted is statistical and the second is systematic. We give measurements of four additional modes for which the 90% confidence level upper limits are Beta(B(+)-->eta(')pi(+)) < 12 x 10(-6), Beta(B(+)-->omega K(+)) < 4 x 10(-6), Beta(B(0)-->omega K(0)) < 13 x 10(-6), and Beta(B(0)-->omega pi(0)) < 3 x 10(-6).

Journal Article↗
PubMed2001

Measurement of the B(0) and B(+) meson lifetimes with fully reconstructed hadronic final states.

The B(0) and B(+) meson lifetimes have been measured in e(+)e(-) annihilation data collected in 1999 and 2000 with the BABAR detector at center-of-mass energies near the Upsilon(4S) resonance. Events are selected in which one B meson is fully reconstructed in a hadronic final state while the second B meson is reconstructed inclusively. A combined fit to the B(0) and the B(+) decay time difference distributions yields tau(B(0)) = 1.546+/-0.032(stat)+/-0.022(syst) ps, tau(B(+)) = 1.673+/-0.032(stat)+/-0.023(syst) ps, and tau(B(+))/tau(B(0)) = 1.082+/-0.026(stat)+/-0.012(syst).

Journal Article↗
PubMed2001

Measurement of J/psi production in continuum e(+)e(-) annihilations near square root of s = 10.6 GeV.

The production of J/psi mesons in continuum e(+)e(-) annihilations has been studied with the BABAR detector at energies near the Upsilon(4S) resonance. The mesons are distinguished from J/psi production in B decays through their center-of-mass momentum and energy. We measure the cross section e(+)e(-)-->J/psi X to be 2.52+/-0.21+/-0.21 pb. We set a 90% C.L. upper limit on the branching fraction for direct Upsilon(4S)-->J/psi X decays at 4.7 x 10(-4).

Journal Article↗
PubMed2001

Measurement of branching fractions and search for CP-violating charge asymmetries in charmless two-body B decays into pions and kaons.

We present measurements, based on a sample of approximately 23x10(6) BB pairs, of the branching fractions and a search for CP-violating charge asymmetries in charmless hadronic decays of B mesons into two-body final states of kaons and pions. We find the branching fractions B(B0-->pi(+)pi(-)) = (4.1+/-1.0+/-0.7)x10(-6), B(B0-->K+pi(-)) = (16.7+/-1.6+/-1.3)x10(-6), B(B+-->K+pi(0)) = (10.8(+2.1)(-1.9)+/-1.0)x10(-6), B(B+-->K0pi(+)) = (18.2(+3.3)(-3.0)+/-2.0)x10(-6), B(B0-->K0pi(0)) = (8.2(+3.1)(-2.7)+/-1.2)x10(-6). We also report 90% confidence level upper limits for B meson decays to the pi(+)pi(0), K+K-, and K0K+ final states. In addition, charge asymmetries have been found to be consistent with zero, where the statistical precision is in the range of +/-0.10 to +/-0.18, depending on the decay mode.

Journal Article↗
PubMed2001

Measurement of the decays B--> phiK and B--> phiK*.

We have observed the decays B--> phiK and phiK(*) in a sample of over 45 million B mesons collected with the BABAR detector at the PEP-II collider. The measured branching fractions are B(B+--> phiK+) = (7.7(+1.6)(-1.4)+/-0.8)x10(-6), B(B0--> phiK0) = (8.1(+3.1)(-2.5)+/-0.8)x10(-6), B(B+--> phiK(*+)) = (9.7(+4.2)(-3.4)+/-1.7)x10(-6), and B(B0--> phiK(*0)) = (8.7(+2.5)(-2.1)+/-1.1)x10(-6). We also report the upper limit B(B+--> phipi(+))<1.4x10(-6) ( 90% C.L.).

Journal Article↗
PubMed2001

Observation of CP violation in the B(0) meson system.

We present an updated measurement of time-dependent CP-violating asymmetries in neutral B decays with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. This result uses an additional sample of Upsilon(4S) decays collected in 2001, bringing the data available to 32 x 10(6) BB macro pairs. We select events in which one neutral B meson is fully reconstructed in a final state containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2 beta, is derived from the decay time distributions in such events. The result sin2 beta = 0.59+/-0.14(stat)+/-0.05(syst) establishes CP violation in the B(0) meson system. We also determine absolute value of lambda = 0.93+/-0.09(stat)+/-0.03(syst), consistent with no direct CP violation.

Journal Article↗
PubMed2001

Measurement of CP-violating asymmetries in B0 decays to CP eigenstates.

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst).

Journal Article↗
PubMed2000

[Fresh femoral shaft fractures treated with un-reamed intramedullary nail: 203 cases].

OBJECTIVE: To discuss the experience treating fresh femoral shaft fractures with un-reamed intramedullary nail. METHODS: 203 cases of fresh femoral shaft fractures who had been treated with un-reamed intramedullary nail from November. 1995 to January. 1999 were analyzed retrospectively. 18 cases were open, classified as Gustilo I, and. 185 cases were closed. Traction table and image intensifier were used during operation. Closed reduction, un-reamed and free hand distal locking technique were used. Active movements of nearby joints were encouraged and partial weight bearing of 10 - 15 kg were allowed right after operation. RESULTS: All 203 cases of fresh femoral shaft fractures got bone union within 4 - 6 months. No case of delayed union and infection happened. 1 distal locking screw was broken. All patients gained normal extremity functions. CONCLUSION: Un-reamed intramedullary nailing of fresh femoral shaft fracture has less damage to the local soft tissue and blood supply. It has a relative stable fracture fixation, and less interruption to the healing procedure. It is one of the best methods for treating femoral fracture.

Bone Nails↗
PubMed1999

Identification of a novel cardiac lineage-associated protein(cCLP-1): A candidate regulator of cardiogenesis.

We describe the isolation and characterization of a cDNA clone, called cCLP-1, that is a candidate for the previously described early cardiac-specific transcription factor BBF-1. BBF-1 binds the MEF2 (or element B) binding site within the cardiac myosin light chain 2 (MLC2) gene promoter. We used the element B sequence as a probe to screen an expression library constructed from mRNA obtained from the presumptive heart-forming regions of stage 6 chicken embryos. This yielded the cCLP-1 cDNA clone. Gel-shift analysis of stage 6 embryonic chicken protein extracts suggests that a protein that is recognized by the anti-cCLP-1 antibody binds to the same element B binding site to which BBF-1 binds. cCLP-1 mRNA was detected early in chicken development, prior to cardiac fate assignment at stage 4. The expression pattern of cCLP-1, based on whole mount in situ hybridization, coincides remarkably well with the established morphogenetic field of early heart formation. The nuclear localization of cCLP-1 is phosphorylation-dependent, suggesting that cCLP-1 may be a member of that class of transcription factors whose activity is regulated by cytoplasm to nucleus transport. Taken together, these data suggest that cCLP-1 may encode a novel transcription factor whose expression pattern is in agreement with that of the cardiogenic precursor cells of the early chicken embryo.

Amino Acid Sequence↗
PubMed1999

[Precise positioning for reconstruction of anterior cruciate ligament].

OBJECTIVE: To supply the basement for precise positioning for anterior cruciate ligament (ACL) reconstruction in the knee and recommend a precise measurement method during the operation. METHODS: Bone tunnels along ACL attachments were made in 20 cadaveric knees. Steel wire was introduced through the tunnel and the length changes were measured during passive knee flexion. We developed an Isometer for getting continuous parameters. RESULTS: Anterosuperior (AS) fibers were lengthened during knee flexion from 30 to 120 degrees, combined with the increase of anterior restraints. Length changes of the posterosuperior and central (C, PS) fibers were minimal. The length of the anteroinferior and posteroinferior (AI and PI) fibers were shortened with the decrease of the anterior restraints. CONCLUSIONS: The central and posterosuperior (C, PS) parts of femoral attachment would be the ideal reconstruction point. In case of old injury of ACL with ambiquous landmark, the Isometer is suggested in identifying the reconstruction point.

Anterior Cruciate Ligament↗
PubMed1999

[Operative treatment of acetabular fractures].

OBJECTIVE: To improve the level of the management of complicated acetabular fracture. METHODS: 56 acetabular fractures were treated operatively from March 1993 to May 1998. According to Letournel-Judet classification, 7 cases were posterior wall fracture, 6 posterior column fracture, 4 anterior column fracture, 6 transverse fracture, 6 T-shaped fracture, 10 posterior column combined posterior wall fracture, 6 transverse combined posterior wall fracture, 2 anterior combined posterior hemi-transverse fracture and 6 both column fracture. Kocher-Langebeck approach, illioinguinal approach, illiofemoral approach, extended illiofemoral approach and anterior combined posterior approach were adopted for different fractures with reconstruction plates and screws. RESULTS: 49 of 56 cases were followed up on an average of 26.4 months. According to Matta's evaluation, 19 cases (39%) showed excellent results, 24 (49%) good, 4 (8%) fair, and 2 (4%) poor. Avascular necrosis of the femoral head was found in 4 cases (8%) and heterotopic ossification in 15 cases (30.6%). No death and infection were found in this series. CONCLUSIONS: According to our experience, accurate analysis of fractures preoperatively, reasonable surgical approaches and timing of surgery are essential to good treatment of acetabular fractures.

Acetabulum↗
PubMed1998

[Operative treatment of tibial condylar fracture].

OBJECTIVE: To analyse operative treatment of fresh and closed tibial condylar fractures. METHOD: In 92 patients (93 fractures) 87 were followed-up for 12-36 months (average 18.6 months). A rasmussen's 30-point knee rating system was used. RESULT: 74 patients showed (84%) excellent results, 7 (8%) good and 7 (8%) poor. The success rate was 92%. CONCLUSION: To ensure excellent clinical results proper internal fixation should be based on (1) anatomic reduction; (2) adequate rigid internal fixation with screws or buttress plate(s) or both, and bi-condylar fixation if necessary; (3) bone grafting on all depressed areas; (4) early knee mobilization using CPM after the operation and avoiding external plaster fixation.

Adult↗
PubMed1998

[Clinical diagnosis of Colles fracture combined with dorsal subluxation of radial carpal joints].

OBJECTIVE: To study the criteria for evaluating Colles fracture combined with dorsal radiocarpal subluxation (DRS). METHOD: Fifty cases of Colles fracture combined with DRS, 100 cases of simple Colles fracture without DRS, and 100 normal wrist joint controls were included. We analysed central point displacement and perpendicular line ratio on the lateral view X-ray. For comminuted and severely displaced fracture, central point displacement (CPD) was not adopted because of difficulties in identifying the central point of the articular surface. Perpendicular line ratio (PLR) was suggested. RESULT: Prominent difference was seen in the CPDs and the PLRs between the Colles fracture combined with DRS group and the simple Colles fracture and the normal control group (P < 0.01). Prominent relevance between the CPD and the PLR was also found (P < 0.05). CONCLUSION: Central point displacement and perpendicular line ratio can be regarded as the diagnostic criteria for Colles fracture combined with DRS. PLR is especially valuable when the central point is hard to be identified in very comminuted and severely displaced fractures. DRS is suggested when CPD is more than 2.5 mm and PLR is less than 0.76.

Adolescent↗
PubMed1998

[Unreamed interlocking intra medullary nailing in treating tibial and fibular fractures].

OBJECTIVE: To report the experience in the use of unreamed interlocking intramedullary nails. METHOD: From 1995 to 1997, 54 tibial and fibular fractures were treated with unreamed interlocking intramedullary nails they included open fractures (9 cases) and close fractures (45). RESULT: All fractures healed within 6 months and showed good knee and ankle joint functions. Slight postoperation infection was found in one of the open fractures. Incomplete injury of peroneal nerve was noted in 1 case. CONCLUSION: Unreamed interlocking intramedullary nail can be used to treat diaphyseal fractures effectively. It can protect the soft tissue envelope around the fracture and prerent local blood supply from further damaginge.

Adolescent↗