Evidence of a new narrow resonance decaying to χ(c1)γ in B→χ(c1)γK

We report measurements of B→χ(c1)γK and χ(c2)γK decays using 772×10(6) BB[over ¯] events collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. Evidence of a new resonance in the χ(c1)γ final state is found with a statistical significance of 3.8σ. This state has a mass of 3823.1±1.8(stat)±0.7(syst) MeV/c(2), a value that is consistent with theoretical expectations for the previously unseen 1(3)D(2) cc[over ¯] meson. We find no other narrow resonance and set upper limits on the branching fractions of the X(3872)→χ(c1)γ and χ(c2)γ decays.

Study of e+ e- → π+ π- J/ψ and observation of a charged charmoniumlike state at Belle

The cross section for ee+ e- → π+ π- J/ψ between 3.8 and 5.5 GeV is measured with a 967  fb(-1) data sample collected by the Belle detector at or near the Υ(nS) (n = 1,2,…,5) resonances. The Y(4260) state is observed, and its resonance parameters are determined. In addition, an excess of π+ π- J/ψ production around 4 GeV is observed. This feature can be described by a Breit-Wigner parametrization with properties that are consistent with the Y(4008) state that was previously reported by Belle. In a study of Y(4260) → π+ π- J/ψ decays, a structure is observed in the M(π(±)J/ψ) mass spectrum with 5.2σ significance, with mass M = (3894.5 ± 6.6 ± 4.5)  MeV/c2 and width Γ = (63 ± 24 ± 26)  MeV/c2, where the errors are statistical and systematic, respectively. This structure can be interpreted as a new charged charmoniumlike state.

Search for an H-dibaryon with a mass near 2mΛ in Υ(1S) and Υ(2S) decays

We report the results of a high-statistics search for H dibaryon production in inclusive Υ(1S) and Υ(2S) decays. No indication of an H dibaryon with a mass near the M(H)=2m(Λ) threshold is seen in either the H→Λpπ(-) or ΛΛ decay channels and 90% confidence level branching-fraction upper limits are set that are between one and two orders of magnitude below the measured branching fractions for inclusive Υ(1S) and Υ(2S) decays to antideuterons. Since Υ(1S,2S) decays produce flavor-SU(3)-symmetric final states, these results put stringent constraints on H dibaryon properties. The results are based on analyses of 102 million Υ(1S) and 158 million Υ(2S) events collected with the Belle detector at the KEKB e(+)e(-) collider.

Evidence for B- → τ- ν(τ) with a hadronic tagging method using the full data sample of Belle

We measure the branching fraction of B- → τ- ν(τ) using the full Υ(4S) data sample containing 772×10(6) BB pairs collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. Events with BB pairs are tagged by reconstructing one of the B mesons decaying into hadronic final states, and B- → τ- ν(τ) candidates are detected in the recoil. We find evidence for B- → τ- ν(τ) with a significance of 3.0 standard deviations including systematic errors and measure a branching fraction B(B- → τ- ν(τ))=[0.72(-0.25)(+0.27)(stat)±0.11(syst)]×10(-4).

X-ray waveguide mode in resonance with a periodic structure

We present a novel concept for x-ray waveguiding based on electromagnetism in photonic crystals, using a waveguide consisting of a pair of claddings sandwiching a core with a periodic structure. By confining the x rays undergoing multiple interference in the core by total reflection, a characteristic waveguide mode whose field distribution matches the periodicity of the core is formed. The distinctively low propagation loss enables the single-mode propagation of x rays. This concept opens broad application possibilities in x-ray physics from coherent imaging to x-ray quantum optics.

Evidence for the η(b)(2S) and observation of h(b)(1P)→η(b)(1S)γ and h(b)(2P)→η(b)(1S)γ

We report the first evidence for the η(b)(2S) using the h(b)(2P)→η(b)(2S)γ transition and the first observation of the h(b)(1P)→η(b)(1S)γ and h(b)(2P)→η(b)(1S)γ transitions. The mass and width of the η(b)(1S) and η(b)(2S) are measured to be m(η(b)(1S))=(9402.4±1.5±1.8) MeV/c(2), m(η(b)(2S))=(9999.0±3.5(-1.9)(+2.8)) MeV/c(2), and Γ(η(b)(1S))=(10.8(-3.7-2.0)(+4.0+4.5)) MeV. We also update the h(b)(1P) and h(b)(2P) mass measurements. We use a 133.4 fb(-1) data sample collected at energies near the Υ(5S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.

Muscle satellite cells are activated after exercise to exhaustion in Thoroughbred horses

REASONS FOR PERFORMING STUDY

Although satellite cells are well known as muscle stem cells capable of adding myonuclei during muscle repair and hypertrophy, the response of satellite cells in horse muscles to a run to exhaustion is still unknown.

OBJECTIVES

To investigate the time course of satellite cell activation in Thoroughbred horse muscle after running to exhaustion. We hypothesised that this type of intense exercise would induce satellite cell activation in skeletal muscle similar to a resistance exercise.

METHODS

Nine de-trained Thoroughbred horses (6 geldings and 3 mares) aged 3-6 years were studied. Biopsy samples were taken from the gluteus medius muscle of the horses before and 1 min, 3 h, 1 day, 3 days, 1 week and 2 weeks after a treadmill run to exhaustion. The numbers of satellite cells for each fibre type were determined by using immunofluorescence staining. Total RNA was extracted from these samples, and the expressions of interleukin (IL)-6, paired box transcriptional factor (Pax) 7, myogenic differentiation 1 (MyoD), myogenin, proliferating cell nuclear antigen (PCNA), insulin-like growth factor (IGF)-I and hepatocyte growth factor (HGF) mRNA were analysed using real-time reverse transcription-PCR.

RESULTS

The numbers of satellite cells were significantly increased in type I and IIa fibres at 1 week and in type IIa/x fibre at 2 weeks post exercise. The expression of IL-6 mRNA increased significantly by 3 h post exercise. The expression of PCNA mRNA also increased by 1 day after running, indicating that running can initiate satellite cell proliferation. The expression of Pax7, MyoD, myogenin, IGF-I and HGF mRNA peaked at 1 week post exercise.

CONCLUSION

Satellite cell activation and proliferation could be enhanced after a run to exhaustion without detectable injury as assessed by the histochemical analysis. Understanding the response of satellite cell activation to running exercise provides fundamental information about the skeletal muscle adaptation in Thoroughbred horses.

Biological and biochemical characterization of mice expressing prion protein devoid of the octapeptide repeat region after infection with prions

Accumulating lines of evidence indicate that the N-terminal domain of prion protein (PrP) is involved in prion susceptibility in mice. In this study, to investigate the role of the octapeptide repeat (OR) region alone in the N-terminal domain for the susceptibility and pathogenesis of prion disease, we intracerebrally inoculated RML scrapie prions into tg(PrPΔOR)/Prnp(0/0) mice, which express mouse PrP missing only the OR region on the PrP-null background. Incubation times of these mice were not extended. Protease-resistant PrPΔOR, or PrP(Sc)ΔOR, was easily detectable but lower in the brains of these mice, compared to that in control wild-type mice. Consistently, prion titers were slightly lower and astrogliosis was milder in their brains. However, in their spinal cords, PrP(Sc)ΔOR and prion titers were abundant and astrogliosis was as strong as in control wild-type mice. These results indicate that the role of the OR region in prion susceptibility and pathogenesis of the disease is limited. We also found that the PrP(Sc)ΔOR, including the pre-OR residues 23-50, was unusually protease-resistant, indicating that deletion of the OR region could cause structural changes to the pre-OR region upon prion infection, leading to formation of a protease-resistant structure for the pre-OR region.

Observation of new resonant structures in γγ → ωϕ, ϕϕ, and ωω

The processes γγ → ωϕ, ϕϕ, and ωω are measured using an 870  fb(-1) data sample collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. Production of vector meson pairs is clearly observed and their cross sections are measured for masses that range from threshold to 4.0 GeV. In addition to signals from well established spin-zero and spin-two charmonium states, there are resonant structures below charmonium threshold, which have not been previously observed. We report a spin-parity analysis for the new structures and determine the products of the η(c), χ(c0), and χ(c2) two-photon decay widths and branching fractions to ωϕ, ϕϕ, and ωω.

Precise measurement of the CP violation parameter sin2φ1 in B0→(cc¯)K0 decays

We present a precise measurement of the CP violation parameter sin2φ1 and the direct CP violation parameter A(f) using the final data sample of 772×10(6) BB[over ¯] pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is reconstructed in a J/ψK(S)(0), ψ(2S)K(S)(0), χ(c1)K(S)(0), or J/ψK(L)(0) CP eigenstate and its flavor is identified from the decay products of the accompanying B meson. From the distribution of proper-time intervals between the two B decays, we obtain the following CP violation parameters: sin2φ1=0.667±0.023(stat)±0.012(syst) and A(f)=0.006±0.016(stat)±0.012(syst).

Measurement of the CP-violation parameter sin2φ1 with a new tagging method at the Υ(5S) resonance

We report a measurement of the CP-violation parameter sin2φ1 at the Υ(5S) resonance using a new tagging method, called "B-π tagging." In Υ(5S) decays containing a neutral B meson, a charged B, and a charged pion, the neutral B is reconstructed in the J/ψK(S)(0) CP-eigenstate decay channel. The initial flavor of the neutral B meson at the moment of the Υ(5S) decay is opposite to that of the charged B and may thus be inferred from the charge of the pion without reconstructing the charged B. From the asymmetry between B-π(+) and B-π(-) tagged J/ψK(S)(0) yields, we determine sin2φ1=0.57±0.58(stat)±0.06(syst). The results are based on 121 fb(-1) of data recorded by the Belle detector at the KEKB e(+)e(-) collider.

High expression of Lin28 is associated with tumour aggressiveness and poor prognosis of patients in oesophagus cancer

BACKGROUND

Lin28 is a negative regulator of the tumour suppressor microRNA, let-7, suggesting its role in tumourigenesis. However, the clinical significance of Lin28 expression in oesophageal cancer has not been elucidated.

METHODS

Lin28 and Lin28B expression was examined by immunohistochemistry in 161 tissues from patients with oesophageal cancer who had undergone curative surgery. The relationship between the expressions of Lin28 and Lin28B and various clinicopathological factors was examined. In vitro assays were conducted to determine the role of Lin28 in aggressiveness of oesophageal cancers using oesophageal cancer cell line.

RESULTS

Lin28 and Lin28B were overexpressed in oesophageal cancer cells compared with non-cancerous epithelial cells, especially in the invasive front. High expression of Lin28 and Lin28B correlated significantly with lymph node metastasis and poor prognosis. High expression of Lin28B expression correlated significantly with low expression of let-7. Multivariate analysis also identified Lin28B expression as an independent prognostic factor. In vitro assays showed that the proliferative and invasive activities were significantly reduced in Lin28B-knockdown cells, compared with control cells.

CONCLUSION

High expression of Lin28 is associated with poor prognosis and high tumour aggressiveness in oesophageal cancer and these effects are mediated through increased proliferation and invasiveness of oesophageal cancer cells.

Indication of reactor ν(e) disappearance in the Double Chooz experiment

The Double Chooz experiment presents an indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. An observed-to-predicted ratio of events of 0.944±0.016(stat)±0.040(syst) was obtained in 101 days of running at the Chooz nuclear power plant in France, with two 4.25 GW(th) reactors. The results were obtained from a single 10 m(3) fiducial volume detector located 1050 m from the two reactor cores. The reactor antineutrino flux prediction used the Bugey4 flux measurement after correction for differences in core composition. The deficit can be interpreted as an indication of a nonzero value of the still unmeasured neutrino mixing parameter sin(2)2θ(13). Analyzing both the rate of the prompt positrons and their energy spectrum, we find sin(2)2θ(13)=0.086±0.041(stat)±0.030(syst), or, at 90% C.L., 0.017<sin(2)2θ(13)<0.16.

Observation of two charged bottomoniumlike resonances in Υ(5S) decays

We report the observation of two narrow structures in the mass spectra of the π(±)Υ(nS) (n=1, 2, 3) and π(±)h(b)(mP) (m=1, 2) pairs that are produced in association with a single charged pion in Υ(5S) decays. The measured masses and widths of the two structures averaged over the five final states are M(1)=(10,607.2±2.0)  MeV/c2, Γ(1)=(18.4±2.4)  MeV, and M(2)=(10,652.2±1.5)  MeV/c2, Γ(2)=(11.5±2.2)  MeV. The results are obtained with a 121.4  fb(-1) data sample collected with the Belle detector in the vicinity of the Υ(5S) resonance at the KEKB asymmetric-energy e+ e- collider.

Search for CP violation in D± meson decays to ϕπ±

We search for CP violation in Cabibbo-suppressed charged D meson decays by measuring the difference between the CP-violating asymmetries for the Cabibbo-suppressed decays D(±)→K(+)K(-)π(±) and the Cabibbo-favored decays D(s)(±)→K(+)K(-)π(±) in the K(+)K(-) mass region of the ϕ resonance. Using 955  fb(-1) of data collected with the Belle detector, we obtain A(CP)(D+→ϕπ+)=(+0.51±0.28±0.05)%. The measurement improves the sensitivity of previous searches by more than a factor of 5. We find no evidence for direct CP violation.

Overexpression of PFTK1 predicts resistance to chemotherapy in patients with oesophageal squamous cell carcinoma

Background:

Recently, PFTK1 was identified as a member of the cyclin-dependent kinase family; however, its expression and clinical significance in oesophageal squamous cell carcinoma (ESCC) have not been evaluated.

Methods:

PFTK1 expression was initially examined by expression microarray in 77 ESCC patients. Using independent samples of 223 patients, PFTK1 expression was evaluated immunohistochemically to assess the relationship between expression and various clinicopathological parameters. The association between PFTK1 and the response to chemotherapy was also investigated in pretreatment samples of 85 patients who received chemotherapy as first treatment.

Results:

Significant upregulation of PFTK1 expression was noted in ESCC compared with normal epithelium. PFTK1 expression was positive in 51.6% (115 out of 223) of the tumours, but did not correlate with any clinicopathological parameter. The 5-year overall survival rate was poorer in patients positive for PFTK1 (43.6%) than those with negative expression (66.2%, P<0.001). Uni- and multivariate analyses identified PFTK1 as an independent marker of prognosis (RR=2.428, 95% CI=1.615–3.711, P<0.001). Out of 85 biopsy samples, 40 (47.1%) tumours showed PFTK1-positive expression, and the response rate to chemotherapy was significantly lower than PFTK1-negative tumours (27.9% vs 72.1%, P<0.001).

Conclusion:

PFTK1 is not only useful as a prognostic marker, but also as a predictor of the response to chemotherapy.

Ten cases of gastro-tracheobronchial fistula: a serious complication after esophagectomy and reconstruction using posterior mediastinal gastric tube

Gastro-tracheobronchial fistula (GTF) is a rare but life-threatening complication specifically observed after esophagectomy and reconstruction using posterior mediastinal gastric tube. Ten cases of GTF were encountered in three hospitals in 2000-2009. Their clinicopathological, surgical, and postoperative care are summarized, together with a review of previously reported cases. GTF was classified as anastomotic leakage (n= 5), gastric necrosis (n= 4), and gastric ulcer type (n= 1). The anastomotic leakage type appeared about 2 weeks (postoperative day [POD]: 8-35) after esophagectomy, was located in the cervical or higher thoracic trachea. Breathing and pneumonia were controlled by tracheal tube placed in the distal of fistula. The gastric necrosis type was noted in patients who developed necrosis of the upper part of the gastric tube and abscess formation behind the tracheal wall, at POD 20-36 around the carina, the site of pronounced ischemia. Due to the large fistula around the carina, emergency surgery with muscle patch repair was frequently required for the control of aspiration pneumonia. Patients of the gastric ulcer type had peptic ulcer in the lesser curvature of the gastric tube, which perforated into the right bronchus long after surgery (POD 630). With respect to tracheobronchial factors, preoperative chemoradiation (three cases) and pre-tracheal node dissection (three cases) tended to increase the risk of GTF. Closure of GTF by surgery (muscle patch repair) was successful in four cases and by nonsurgical treatment in three cases. In one case, stable oral intake was achieved by bypass operation without closure of GTF. Hospital death occurred in three cases. Understanding the pathogenesis and treatment options of GTF is important for surgeons who deal with esophageal cancer.

Evidence for direct CP violation in B±→ηh± and observation of B0→ηK0

We report measurements of the branching fractions and CP asymmetries for B(±)→ηh(±) (h=K or π) and the observation of the decay B(0)→ηK(0) from the final data sample of 772×10(6) B ̅B pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The measured branching fractions are B(B(±)→ηK(±))=(2.12±0.23±0.11)×10(-6), B(B(±)→ηπ(±))=(4.07±0.26±0.21)×10(-6), and B(B(0)→ηK(0))=(1.27(-0.29)(+0.33)±0.08)×10(-6), where the last decay is observed for the first time with a significance of 5.4 standard deviations (σ). We also find evidence for CP violation in the charged B modes, A(CP)(B(±)→ηK(±))=-0.38±0.11±0.01 and A(CP)(B(±)→ηπ(±))=-0.19±0.06±0.01 with significances of 3.8 σ and 3.0 σ, respectively. For all measurements, the first and second uncertainties are statistical and systematic, respectively.