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Biomedical subjects

S K Kim

Publications and source records attributed to S K Kim.

At least 91 records · Page 5Linked to original sources

Degradation of phenanthrene and naphthalene by a Burkholderia species strain.

Burkholderia sp. TNFYE-5 was isolated from soil for the ability to grow on phenanthrene as sole carbon and energy source. Unlike most other phenanthrene-degrading bacteria, TNFYE-5 was unable to grow on naphthalene. Growth substrate range experiments coupled with the ring-cleavage enzyme assay data suggest that TNFYE-5 initially metabolizes phenanthrene to 1-hydroxy-2-naphthoate with subsequent degradation through the phthalate and protocatechuate and beta-ketoadipate pathway. A metabolite in the degradation of naphthalene by TNFYE-5 was isolated by high-pressure liquid chromatography (HPLC) and was identified as salicylate by UV-visible spectral and gas chromatography-mass spectrometry analyses. Thus, the inability to degrade salicylate is apparently one major reason for the incapability of TNFYE-5 to grow on naphthalene.

Biodegradation, Environmental↗

Observation of D+(s)K- and evidence for D+(s)pi- final states in neutral B decays.

We report the first observation of a B meson decay that is not accessible by a direct spectator process. The channel B(0)-->D(+)(s)K- is found in a sample of 85 x 10(6) BB; events, collected with the Belle detector at KEKB, with a branching fraction B(B(0)-->D(+)(s)K-)=(4.6(+1.2)(-1.1)+/-1.3) x 10(-5). We also obtain evidence for the B0-->D(+)(s)pi(-) decay with branching fraction B(B0-->D(+)(s)pi(-))=(2.4(+1.0)(-0.8)+/-0.7) x 10(-5). This value may be used to extract a model-dependent value of |V(ub)|.

Journal Article↗

Observation of B+/- -->omegaK+/- decay.

We report the first observation of the charmless two-body mode B+/--->omegaK+/- decay, and a new measurement of the branching fraction for the B+/--->omegapi(+/-) decay. The measured branching fractions are B(B+/--->omegaK+/-)=(9.2(+2.6)(-2.3)+/-1.0)x10(-6) and B(B+/--->omegapi(+/-))=(4.2(+2.0)(-1.8)+/-0.5)x10(-6). We also measure the partial rate asymmetry of B+/--->omegaK+/- decays and obtain A(CP)=-0.21+/-0.28+/-0.03. The results are based on a data sample of 29.4 fb(-1) collected on the Upsilon(4S) resonance by the Belle detector at the KEKB e(+)e(-) collider.

Journal Article↗

Observation of B(0)-->D((*)0)pp.

The B meson decay modes B-->Dpp; and B-->D(*)pp; have been studied using 29.4 fb(-1) of data collected with the Belle detector at KEKB. The B;(0)-->D(0)pp; and B;(0)-->D(*0)pp; decays have been observed for the first time with branching fractions B(B;(0)-->D(0)pp;)=(1.18+/-0.15+/-0.16)x10(-4) and B(B;(0)-->D(*0)pp;)=(1.20(+0.33)(-0.29)+/-0.21)x10(-4). No signal has been found for the B+-->D(+)pp; and B+-->D(*+)pp; decay modes, and the corresponding upper limits at 90% C.L. are presented.

Journal Article↗

Observation of double cć production in e+e- annihilation at squareroot[s] approximately 10.6 GeV.

We report the observation of prompt J/psi via double cc; production from the e+e- continuum. In this process one cc; pair fragments into a J/psi meson while the remaining pair either produces a charmonium state or fragments into open charm. Both cases have been experimentally observed. We find cross sections of sigma[e+e- -->J/psieta(c)(gamma)]xB(eta(c)-->>or=4 charged)=(0.033(+0.007)(-0.006)+/-0.009) pb and sigma(e+e- -->J/psiD(*+)X)=(0.53(+0.19)(-0.15)+/-0.14) pb and infer sigma(e+e- -->J/psicc;)/sigma(e+e- -->J/psiX)=0.59(+0.15)(-0.13)+/-0.12. These results are obtained from a 46.2 fb(-1) data sample collected near the Upsilon(4S) resonance, with the Belle detector at the KEKB collider.

Journal Article↗

Observation of the decay B(0)-->D(+/-)D(*-/+).

We report the first observation of the decay B(0)-->D(+/-)D(*-/+) with the Belle detector at the KEKB e(+)e(-) Collider operated at the Upsilon(4S) resonance. The sum of branching fractions B(B(0)-->D(+)D(*-))+B(B(0)-->D(-)D(*+)) is measured to be (1.17+/-0.26(+0.22)(-0.25))x10(-3) using the full reconstruction method where both charmed mesons from B0 decays are reconstructed. A consistent value [(1.48+/-0.38(+0.28)(-0.31))x10(-3)] is obtained using a partial reconstruction technique that uses only the slow pion from the D(*-)-->D(-0)pi(-) decay and a fully reconstructed D(+) to reconstruct the B(0).

Journal Article↗

Study of CP-violating asymmetries in B0-->pi(+)pi(-) decays.

We present a measurement of CP-violating asymmetries in B0-->pi(+)pi(-) decays based on a 41.8 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We fully reconstruct one neutral B meson as a B0-->pi(+)pi(-) CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we obtain the CP-violating asymmetry parameters S(pipi)=-1.21(+0.38)(-0.27)(stat)+0.16-0.13(syst) and A(pipi)=+0.94(+0.25)(-0.31)(stat)+/-0.09(syst).

Journal Article↗

Observation of chi(c2) production in B meson decay.

We report the first observation of chi(c2) production in B meson decays. We find an inclusive B-->chi(c2)X branching fraction of (1.80(+0.23)(-0.28)+/-0.26) x 10(-3). The data set, collected with the Belle detector at the KEKB e(+)e(-) collider, consists of 31.9 x 10(6) BB events. We also present branching fractions and momentum spectra for both chi(c1) and chi(c2) production.

Journal Article↗

Observation of B(+/-) --> p(-)pK(+/-).

We report the observation of the decay mode B(+/-) --> p(-)pK(+/-)based on an analysis of 29.4 fb(-1) of data collected by the Belle detector at KEKB. This is the first example of a b-->s transition with baryons in the final state. The p(-)p mass spectrum in this decay is inconsistent with phase space and is peaked at low mass. The branching fraction for this decay is measured to be B(B+/--->p(-)pK+/-) = [4.3(+1.1)(-0.9)(stat)+/-0.5(syst)]x 10(-6). We also report upper limits for the decays B(0)-->p(-)pK(S) and B(+/-)-->p(-)p pi(+/-).

Journal Article↗

Precise measurement of B meson lifetimes with hadronic decay final states.

The lifetimes of the B(0) and B- mesons are extracted from 29.1 fb(-1) of data collected with the Belle detector at the KEK B factory. A fit to the decay length differences of neutral and charged B meson pairs, measured in events where one of the B mesons is fully reconstructed in several hadronic modes, yields tau(B(0)) = 1.554+/-0.030(stat)+/-0.019(syst) ps, tau(B-) = 1.695+/-0.026(stat)+/-0.015(syst) ps, and tau(B-)/tau(B(0)) = 1.091+/-0.023(stat)+/-0.014(syst).

Journal Article↗

Observation of the color-suppressed decay B( 0)-->D(0)pi(0).

We report the first observation of color-suppressed B( 0)-->D(0)pi(0), D(*0)pi(0), D0eta, and D0omega decays, and evidence for B( 0)-->D(*0)eta and D(*0)omega. The branching fractions are B(B( 0)-->D0pi(0)) = (3.1 +/- 0.4 +/- 0.5)x10(-4), B(B( 0) -->D(*0)pi(0)) = (2.7(+0.8+0.5)(-0.7-0.6))x10(-4), B(B( 0) --> D0eta) = (1.4(+0.5)(-0.4) +/- 0.3)x10(-4), B(B( 0) --> D0omega) = (1.8 +/- 0.5(+0.4)(-0.3))x10(-4), and we set 90% confidence level upper limits of B(B( 0) --> D(*0)eta)<4.6 x 10(-4) and B(B( 0)-->D(*0)omega)<7.9 x 10(-4). The analysis is based on a data sample of 21.3 fb(-1) collected at the Upsilon(4S) resonance by the Belle detector at the KEKB e(+)e(-) collider.

Journal Article↗

Production of prompt charmonia in e(+)e(-) annihilation at square root of s approximately equals 0.6 GeV.

The production of prompt J/psi, psi(2S), chi(c1), and chi(c2) is studied using a 32.4 fb(-1) data sample collected with the Belle detector at Upsilon(4S) and at 60 MeV below the resonance. The yield of prompt J/psi mesons in the Upsilon(4S) sample is compatible with that of continuum production; we set an upper limit B(Upsilon(4S)-->J/psiX) < 1.9 x 10(-4) at the 95% confidence level, and find sigma(e(+)e(-)-->J/psiX) = 1.47 plus/minus 0.10 plus/minus 0.13 pb. The cross sections for prompt psi(2S) and direct J/psi are measured. The J/psi momentum spectrum, production angle distribution, and polarization are studied.

Journal Article↗

Observation of B+ --> chi(c0)K+.

Using a sample of 31.3x10(6) BB pairs collected with the Belle detector at the Upsilon(4S) resonance, we make the first observation of the charged B meson decay to chi(c0) and a charged kaon. The measured branching fraction is B(B+-->chi(c0)K+) = (6.0(+2.1)(-1.8)+/-1.1)x10(-4), where the first error is statistical, and the second is systematic.

Journal Article↗

Relationship between stress urinary incontinence and pelvic organ prolapse.

We investigated the objective coexisting rate of stress urinary incontinence and pelvic organ prolapse, and also compared the treatment outcomes in patients who had both conditions, treated by a corrective operation on the basis of a precise preoperative evaluation. We reviewed 97 cases who underwent urodynamic studies and evaluation of the prolapse according to the Pelvic Organ Prolapse Quantification (POP-Q) system from among patients who were admitted for treatment of either stress urinary incontinence or pelvic organ prolapse. A Burch urethropexy, either alone or with a parvaginal repair, was done to correct the stress urinary incontinence, as well as additional operations to correct prolapse of stage II or more. The patients were evaluated postoperatively for the stress urinary incontinence and the degree of prolapse at every visit. Nineteen of 30 (63.3%) patients who were admitted with stress urinary incontinence had a coexisting pelvic organ prolapse, most often of the anterior wall. In 42 of 67 (62.7%) cases admitted with pelvic organ prolapse there was a coexisting stress urinary incontinence. A total of 61 patients who had both conditions were followed for 12 months postoperatively. The recurrence rate of stress urinary incontinence and prolapse (all of which were stage II) was 3.3% and 18.0%, respectively. It was noted that the greater the preoperative stage, the higher the recurrence rate (stage II 4.35%; stage III 25.0%; stage IV 33.6%). The coexisting rates of pelvic organ prolapse in patients having stress urinary incontinence, and stress urinary incontinence in patients having a pelvic organ prolapse, were both high. Therefore, when a preoperative evaluation that simultaneously considers both conditions and the correcting surgery is based on this evaluation, the recurrence rates of both conditions could be lowered.

Aged↗

The effectiveness of modified six-corner suspension in patients with paravaginal defect and stress urinary incontinence.

The purpose of our study was to evaluate the effectiveness of a modified six-corner suspension in patients with a paravaginal defect and stress urinary incontinence (SUI) by observing changes in the POP (pelvic organ prolapse) stage, substage, and the cure rates in SUI. Forty-two women patients who had a paravaginal defect and stress urinary incontinence were treated by a modified six-corner suspension at the urogynecology clinic, Yonsei University Medical Center between January 1999 and March 2000. Each patient underwent a complete physical examination and a standardized urogynecologic interview that asked about age, hormone replacement, parity, urinary symptoms and previous gynecologic surgery. From the 42 patients who had the operation, 30 patients with 1-year follow-up made up the study group. Changes from stage III ( n = 18, 60%) of the group to stage I ( n = 6, 33.3%) or stage 0 ( n = 12, 66.6%) were observed 3 months after surgery, and no further changes were observed up to 1 year after surgery, except in one case. Changes from stage IV ( n = 12) to stage 0 ( n = 3, 25%) or stage I ( n = 6, 50%) or stage II ( n = 6, 50%) were observed 3 months after surgery, but no further change was observed up to 1 year later. Changes from substage Aa (+2, +3) to -3 ( n = 27, 90%) and from substage Ba (+2,+3,+4,+5,+6,+7) to -3 ( n = 27, 90%) were observed 3 months after surgery. No further changes were observed up to 1 year. The average length of the genital hiatus was initially 4.95 cm and 2.5 cm 3 months after surgery. Little change (2.6 cm) was observed up to 1 year later. When the patients were assessed clinically by urodynamics and physical examination, none had urinary leakage symptoms up to 1 year after the operation. All patients had excellent functional results and no postoperative complaints of stress urinary incontinence. We observed that a modified six-corner suspension was surprisingly effective in patients having a paravaginal defect and a stress urinary incontinence.

Aged↗

Geographical distribution and accumulation features of organochlorine residues in bivalves from coastal areas of South Korea.

As a part of Mussel Watch Program in Korea, the contamination levels and accumulation features of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were assessed for 82 bivalve samples collected from 66 sites along the entire coast of Korea. The dry weight based sigmaPCBs and sigmaOCPs ranged from 4.4 ng g(-1) to 422.0 ng g(-1) (geometric mean = 36.9 ng g(-1)) and from 9.95 ng g(-1) to 131.37 (34.88) ng g(-1), respectively. PCB was predominant in Korean coast, followed by DDTs, HCHs, and Chlordanes. From the observed log normal distribution of PCB and each OCP, low- and high-levels were defined as geometric mean +/- 1 S.D., respectively. The levels at the sites near urban and/or industrial areas often exceeded the high-levels and the spatial distributions of sigmaDDTs and sigmaCHLs were correlated with that of sigmaPCBs, indicating terrestrial input pathways. Even distribution of sigmaHCHs suggested a possibility of atmospheric input pathway of HCHs. The observed isomer ratios of DDTs, HCHs, and CHLs indicated that aging has occurred.

Animals↗

Influence of calcium hydroxide intracanal medication on apical seal.

AIM: The aim of this study was to determine the influence of calcium hydroxide intracanal medication and various techniques for its removal on the sealing ability of gutta-percha root fillings with a zinc oxide-eugenol sealer. METHODOLOGY: Eighty extracted mature human mandibular molar roots were divided into three groups of similar root-canal configuration. Calcium hydroxide paste was made by mixing calcium hydroxide powder with distilled water at a powder to liquid ratio of 1:1.25. After root canals were prepared and enlarged to a minimum of size 30 with the Profile 0.06 system, calcium hydroxide paste was placed in the canals of two groups, but no medication was placed in the control group. The intracanal calcium hydroxide was removed with two different techniques, 1 week after medication: K-files one size larger than the master apical file (MAF) were used with 2.5% NaOCl and 15% EDTA solutions in one group, whilst K-files the same size as the MAF were used with 2.5% NaOCl solution in another group. Canals were obturated with gutta-percha and Tubli-Seal cement using the lateral condensation technique. The apical sealing-ability was assessed by dye leakage and cross-sections of the specimens were examined under a stereomicroscope. The dye-penetration level was measured and analyzed using Fisher's exact test and Duncan's multiple range test. RESULTS: The calcium hydroxide-medicated groups showed significantly more dye leakage than the non-medicated control group (P < 0.05). However, there was no significant difference between the two calcium hydroxide-medicated groups (P > 0.05). The stereomicroscopic views showed a relatively uneven and thicker layer of sealer in the calcium hydroxide-medicated groups. CONCLUSION: Calcium hydroxide intracanal medication may increase apical leakage of gutta-percha root fillings when a zinc oxide-eugenol sealer is used.

Calcium Hydroxide↗