J/psi and psi(2S) Radiative Transitions to eta_{c}

Using 2.45x10;{7} psi(2S) decays collected with the CLEO-c detector at the Cornell Electron Storage Ring we present the most precise measurements of magnetic dipole transitions in the charmonium system. We measure B(psi(2S)-->gammaeta_{c})=(4.32+/-0.16+/-0.60)x10;{-3}, B(J/psi-->gammaeta_{c})/B(psi(2S)-->gammaeta_{c})=4.59+/-0.23+/-0.64, and B(J/psi-->gammaeta_{c})=(1.98+/-0.09+/-0.30)%. We observe a distortion in the eta_{c} line shape due to the photon-energy dependence of the magnetic dipole transition rate. We find that measurements of the eta_{c} mass are sensitive to the line shape, suggesting an explanation for the discrepancy between measurements of the eta_{c} mass in radiative transitions and other production mechanisms.

Efficient Bragg diffraction in thin semiconductor two-dimensional gratings

Highly improved diffraction properties are demonstrated in a two-dimensional [2D] grating consisting of a transmission grating optically recorded in a semiconductor one-dimensional photonic crystal (1D-PC). Near unity internal diffraction efficiency, high wavelength selectivity, and Bragg diffraction regime operation are demonstrated when the read beam is set at Bragg incidence on the transmission grating while its wavelength corresponds to the band edge of the 3 microm thick 1D-PC. When the 2D grating is grown on a Bragg mirror, a single diffracted beam is obtained, which makes the device promising for optical signal processing.

Search for lepton flavor violation in upsilon decays

In this Letter, we describe a search for lepton flavor violation (LFV) in the bottomonium system. We search for leptonic decays Upsilon(nS)-->mutau (n=1, 2, and 3) using the data collected with the CLEO III detector. We identify the tau lepton using its leptonic decay nu_{tau}nu[over ]_{e}e and utilize multidimensional likelihood fitting with probability density function shapes measured from independent data samples. We report our estimates of 95% C.L. upper limits on LFV branching fractions of Upsilon mesons. We interpret our results in terms of the exclusion plot for the energy scale of a hypothetical new interaction versus its effective LFV coupling in the framework of effective field theory.

Observation of Upsilon(2S)-->etaUpsilon(1S) and search for related transitions

We report the first observation of Upsilon(2S)-->etaUpsilon(1S), with a branching fraction B=(2.1(-0.6)+0.7(stat)+/-0.3(syst)) x 10(-4) and a statistical significance 5.3sigma. Data were acquired with the CLEO III detector at the CESR e+e(-) symmetric collider. This is the first process observed involving a b-quark spin flip. For related transitions, 90% confidence limits in units of 10(-4) are B(Upsilon(2S)-->pi0Upsilon(1S)) < 1.8, B(Upsilon(3S)-->etaUpsilon(1S)) < 1.8, B(Upsilon(3S)-->pi0Upsilon(1S)) < 0.7, and B(Upsilon(3S)-->pi0Upsilon(2S)) < 5.1.

Precision measurement of the mass of the hc(1P1) state of charmonium

A precision measurement of the mass of the h_{c}(1P1) state of charmonium has been made using a sample of 24.5x10;{6} psi(2S) events produced in e;{+}e;{-} annihilation at the Cornell Electron Storage Ring (CESR). The reaction used was psi(2S)-->pi;{0}h_{c}, pi;{0}-->gammagamma, h_{c}-->gammaeta_{c}, and the reaction products were detected in the CLEO-c detector. Data have been analyzed both for the inclusive reaction and for the exclusive reactions in which eta_{c} decays are reconstructed in 15 hadronic decay channels. Consistent results are obtained in the two analyses. The averaged results of the present measurements are M(h_{c})=3525.28+/-0.19(stat.)+/-0.12(syst.) MeV, and B(psi(2S)-->pi;{0}h_{c})xB(h_{c}-->gammaeta_{c})=(4.19+/-0.32+/-0.45)x10;{-4}. Using the ;{3}P_{J} centroid mass, DeltaM_{hf}(1P) identical withM(chi_{cJ})-M(h_{c})=+0.02+/-0.19+/-0.13 MeV.

Measurement of the eta'-meson mass using J/psi-->gammaeta'

We measure the mass of the eta;{'} meson using psi(2S)-->pi;{+}pi;{-}J/psi, J/psi-->gammaeta;{'} events acquired with the CLEO-c detector operating at the CESR e;{+}e;{-} collider. Using three decay modes, eta;{'}-->rho;{0}gamma, eta;{'}-->pi;{+}pi;{-}eta with eta-->gammagamma, and eta;{'}-->pi;{+}pi;{-}eta with eta-->pi;{+}pi;{-}pi;{0}, we find M_{eta;{'}}=957.793+/-0.054+/-0.036 MeV, in which the uncertainties are statistical and systematic, respectively. This result is consistent with but substantially more precise than the current world average.

Observation of chicJ radiative decays to light vector mesons

Using a total of 2.74 x 10(7) decays of the psi(2S) collected with the CLEO-c detector, we present a study of chi(cJ)-->gammaV, where V=rho(0), omega, phi. The transitions chi(c1)-->gammarho(0 and chi(c1)-->gammaomega are observed with B(chi(c1)-->gammarho(0))=(2.43+/-0.19+/-0.22) x 10(-4) and B(chi(c1)-->gammaomega)=(8.3+/-1.5+/-1.2) x 10(-5). In the chi(c1)-->gammarho(0) transition, the final state meson is dominantly longitudinally polarized. Upper limits on the branching fractions of other chi(cJ) states to light vector mesons are presented.

Search for very light CP-odd Higgs Boson in radiative decays of Upsilon(1S)

We search for a non-SM-like CP-odd Higgs boson (a(1)(0)) decaying to tau(+)tau(-) or mu(+)mu(-) in radiative decays of the Upsilon(1S). No significant signal is found, and upper limits on the product branching ratios are set. Our tau(+)tau(-) results are almost 2 orders of magnitude more stringent than previous upper limits. Our data provide no evidence for a Higgs state with a mass of 214 MeV decaying to mu(+)mu(-), previously proposed as an explanation for 3 Sigma(+)-->pmu(+)mu(-) events observed by the HyperCP experiment. Our results constrain NMSSM models.

Observation of J/psi-->3gamma

We report the first observation of the decay J/psi-->3gamma. The signal has a statistical significance of 6sigma and corresponds to a branching fraction of B(J/psi-->3gamma)=(1.2+/-0.3+/-0.2)x10;{-5}, in which the errors are statistical and systematic, respectively. The measurement uses psi(2S)-->pi;{+}pi;{-}J/psi events acquired with the CLEO-c detector operating at the CESR e;{+}e;{-} collider.

Sirolimus-based immunosuppressive therapy in liver transplant recipient with tacrolimus-related chronic renal insufficiency

BACKGROUND

While providing potent immunosuppression for liver transplant recipients, calcineurin inhibitors (CNI) exhibit nephrotoxicity as a major side effect. The purpose of this study was to evaluate the safety and efficacy of conversion from CNI to sirolimus (SRL) among liver transplant recipients with CNI-induced chronic nephrotoxicity.

METHODS

Between January 2004 and June 2005, we performed conversion in 16 recipients after a median period of 8.5 months after liver transplantation. The indication for conversion was CNI-related nephrotoxicity with a serum creatinine (sCr) value >132.6 umol/L. Renal function was measured before and after conversion to SRL. Clinical and laboratory data related to the clinical course of the patients were recorded to investigate the safety and efficacy of conversion.

RESULTS

Sixteen patients were converted to SRL after developing nephrotoxicity. Their renal function improved gradually after conversion. The levels of sCr decreased significantly within the first 30 days (164.1 +/- 12.48 micromol/L to 130.1 +/- 5.573 micromol/L), and over the next 60 days after conversion (97.86 +/- 11.69 micromol/L to 90.7 +/- 8.95 micromol/L) (P < .01). Similarly, the mean glomerular filtration rate (GFR) increased significantly during the same period. Four recipients experienced hypercholesterolemia, 1 with ankle edema, and 1 with acute rejection. The median follow-up was 2.4 years. No patient discontinued SRL due to side effects. No patient needed dialysis or kidney transplantation during the study period.

CONCLUSIONS

SRL is a safe, effective replacement agent as primary immunosuppressive therapy following withdrawal of CNIs in liver transplant recipients with CNI-induced chronic nephrotoxicity.

Molecular diversity and evolution of cystine knot toxins of the tarantula Chilobrachys jingzhao

Cystine knot toxins (CKTs) in spider venoms represent a rich source of novel ligands for varied ion channels. Here, we identified 95 novel putative CKT precursors by analyzing expressed sequence tags of the tarantula Chilobrachys jingzhao venom gland. Phylogenetics analyses revealed one orphan family and six families with sequence similarity to known toxins. To further investigate the relationships of their structures, functions and evolution, we assayed 10 representative toxins for their effect on ion channels, and performed structure model comparisons, evolution analysis and toxin distribution analysis. This study revealed two major types of CKTs: pore-blocking toxins and gating modifier toxins. A few blockers were observed with relatively high abundance and wide distribution, which may be a category of original toxins that block channels conserved in various preys with relatively high specificity. The gating modifier families contain advanced toxins, usually have many members and interact with diverse regulatory components of channels.

Early initiation of tacrolimus or cyclophosphamide therapy for idiopathic membranous nephropathy with severe proteinuria

BACKGROUND

Early initiation of therapy is warranted for patients with idiopathic membranous nephropathy (IMN) who have severe proteinuria. Therapy with tacrolimus (TAC) or intravenous cyclophosphamide (CYC) may be an option in treating such patients.

METHODS

This prospective cohort study included patients with IMN whose daily proteinuria was greater than 6.0 g with 3-6 months observation of nonimmunosuppressive therapy. One cohort received prednisone combined with oral TAC (target trough blood level of 4-8 ng/mL) for 24 weeks. The other cohort received prednisone combined with intravenous CYC (750 mg/m2 body surface) every 2 weeks for the first 8 weeks and then once per 4 weeks for the next 16 weeks.

RESULTS

Thirty patients met criteria for enrollment, and 25 patients completed therapy. The results of the 24-week therapeutic period were complete remission (CR) 4 patients (30.8%) on CYC and 8 patients (66.7%) on TAC; partial remission (PR) 7 patients (53.8%) on CYC and 3 patients (25%) on TAC; no response 2 patients (15.4%) on CYC and 1 patient (8.3%) on TAC. The percentages of remission (either PR or CR) by 4 and 8 weeks were significantly higher in TAC group than in CYC group (p<or=0.05). The probability of CR was significantly higher in the TAC group than in the CYC group (p=0.018, by log-rank test).

CONCLUSION

Earlier initiation of therapy with TAC or intravenous CYC (combined steroid) for 24 weeks was useful for Chinese adults with IMN in inducing remission of severe proteinuria, and quicker remission was seen in TAC therapy.

Study of the decays D0-->pi{-}e{+}nu{e}, D{0}-->K{-}e{+}nu{e}, D{+}-->pi{0}e{+}nu{e}, and D{+}-->K0e{+}nu{e}

By using 1.8x10{6} DDpairs, we have measured B(D{0}-->pi{-}e{+}nu{e})=0.299(11)(9)%, B(D{+}-->pi{0}e{+}nu{e})=0.373(22)(13)%, B(D{0}-->K{-}e{+}nu{e})=3.56(3)(9)%, and B(D{+}-->K{0}e{+}nu{e})=8.53(13)(23)% and have studied the q;{2} dependence of the form factors. By combining our results with recent lattice calculations, we obtain |V{cd}|=0.217(9)(4)(23) and |V{cs}|=1.015(10)(11)(106).

Determination of the strong phase in D0-->K+pi- using quantum-correlated measurements

We exploit the quantum coherence between pair-produced D0 and D[over]0 in psi(3770) decays to study charm mixing, which is characterized by the parameters x and y, and to make a first determination of the relative strong phase delta between D0-->K+pi- and D[over]0-->K+pi-. Using 281 pb(-1) of e+e- collision data collected with the CLEO-c detector at Ecm=3.77 GeV, as well as branching fraction input and time-integrated measurements of RM identical with (x2 + y2)/2 and RWS identical with Gamma(D0-->K+pi-)/Gamma(D[over]0-->K+pi-) from other experiments, we find cosdelta=1.03(-0.17)(+0.31)+/-0.06, where the uncertainties are statistical and systematic, respectively. By further including other mixing parameter measurements, we obtain an alternate measurement of cosdelta=1.10+/-0.35+/-0.07, as well as x sindelta=(4.4(-1.8)(+2.7)+/-2.9)x10(-3) and delta=(22(-12-11)(+11+9)) degrees .

First observation of the decay Ds+-->pn

Using e+e--->Ds*-Ds+ data collected near the peak Ds production energy, Ecm=4170 MeV, with the CLEO-c detector, we present the first observation of the decay Ds+-->pn. We measure a branching fraction B(Ds+-->pn)=(1.30+/-0.36(-0.16)+0.12)x10(-3). This is the first observation of a charmed meson decaying into a baryon-antibaryon final state.

Measurement of the absolute branching fraction of Ds+ --> tau+ nutau decay

Using a sample of tagged D(s)(+) decays collected near the D(s)(*+/-)D(s)(-/+) peak production energy in e(+)e(-) collisions with the CLEO-c detector, we study the leptonic decay D(s)(+)-->tau(+)nu(tau) via the decay channel tau(+)-->e(+)nu(e)nu(tau). We measure B(D(s)(+)-->tau(+)nu(tau))=(6.17+/-0.71+/-0.34)%, where the first error is statistical and the second systematic. Combining this result with our measurements of D(s)(+)-->mu(+)nu(mu) and D(s)(+)-->tau(+)nu(tau) (via tau(+)-->pi(+)nu(tau)), we determine f(D(s))=(274+/-10+/-5) MeV.

Absolute measurement of hadronic branching fractions of the Ds+ meson

The branching fractions of D(s)(+/-) meson decays serve to normalize many measurements of processes involving charm quarks. Using 298 pb(-1) of e(+)e(-) collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for eight D(s)(+/-) decays with a double tag technique. In particular we determine the branching fraction B(D(s)(+)-->K(-)K(+}pi(+))=(5.50+/-0.23+/-0.16)%, where the uncertainties are statistical and systematic, respectively. We also provide partial branching fractions for kinematic subsets of the K(-)K(+)pi(+) decay mode.

Comparison of D--> KS0 pi and D--> KL0 pi decay rates

We present measurements of D--> KS0 pi and D--> KL0 pi branching fractions using 281 pb(-1) of psi(3770) data at the CLEO-c experiment. We find that B(D0--> KS0 pi 0) is larger than B(D0--> KL0 pi 0), with an asymmetry of R(D0)=0.108+/-0.025+/-0.024. For B(D+--> KS0 pi+) and B(D+--> KL0 pi+), we observe no measurable difference; the asymmetry is R(D+)=0.022+/-0.016+/-0.018. The D0 asymmetry is consistent with the value based on the U-spin prediction A(D0--> K0 pi 0)/A(D0--> K0 pi 0)=-tan2 theta C, where theta C is the Cabibbo angle.

Continuous veno-venous haemofiltration attenuates myocardial mitochondrial respiratory chain complexes activity in porcine septic shock

Increasing evidence indicates that mitochondrial dysfunction plays an important role in modulating the development of septic shock. In the present study, we investigated whether continuous veno-venous haemofiltration (CVVH) with high-volume might improve myocardial mitochondrial dysfunction in a porcine model of peritonitis-induced septic shock. Sixteen male Landrace pigs weighing 31 +/- 5 kg were randomly assigned to normal control group (n = 4), peritonitis group (n = 6) and peritonitis plus CVVH group (n = 6). All animals were anaesthetised and mechanically ventilated. After baseline examinations, the peritonitis group and the peritonitis plus CVVH group underwent induction of peritonitis. One hour later, the animals in the peritonitis plus CVVH group received treatment with high-volume CVVH. Twelve hours after treatment, the animals were sacrificed. Animals in the peritonitis group were killed 13 hours after induction of peritonitis. Peritonitis challenge induced septic shock associated with increased blood lactate and high-volume CVVH improved lactate acidosis. Compared with the peritonitis group, cardiac output, stroke volume and mean arterial pressure were better maintained in peritonitis plus CVVH group. More importantly, high-volume CVVH improved myocardial mitochondrial complex I activity (0.22 +/- 0.03 vs. 0.15 +/- 0.04, P = 0.04). These results suggest that high-volume CVVH improves haemodynamics and heart dysfunction in septic shock and the improvement may be attributed to amelioration of myocardial mitochondrial dysfunction.

Human papillomavirus (HPV) viral load and HPV type in the clinical outcome of HIV-positive patients treated with imiquimod for anogenital warts and anal intraepithelial neoplasia

OBJECTIVE

To evaluate the efficacy of 5% imiquimod in HIV-positive male patients with anogenital warts or anal intraepithelial neoplasia (AIN), and to elucidate whether human papillomavirus (HPV) type and viral load were important for clinical outcome and recurrences.

METHODS

Thirty-seven patients with histologically proven anogenital warts or AIN were enrolled. Topical 5% imiquimod was applied three times per week for more than 8 h overnight for 16 weeks, although patients were allowed to continue therapy for 4 more weeks if they did not have complete clearance of lesions.

RESULTS

Mean age was 34 years. The perianal area was the main lesion location. Thirty-three patients had CD4 counts of < 500 cells/mm(3). Eighteen patients had a histopathological diagnosis of AIN-1. Main HPV types detected corresponded to low-risk HPV types. At 20 weeks of therapy, 46% patients achieved total clearance whereas 14 patients had > 50% clearance. Recurrence was observed in 5 of 17 patients who cleared. Clearance was not influenced by patients' CD4 counts, wart location, HIV viral load or HPV viral load.

CONCLUSIONS

The assumption that visible perianal warts are benign lesions in HIV-positive patients has to be reevaluated since an important number of such lesions could correspond to low-grade anal disease, which in turn could progress to high-grade anal disease or cancer. In addition, our results in this preliminary study indicate that imiquimod appears to be effective in treating AIN in HIV-positive patients. Further studies are needed to document its utility to prevent high-grade dysplasia and/or anal cancer.