Measurement of the cross section for direct-photon production in association with a heavy quark in pp[over ¯] collisions at sqrt[s]=1.96 TeV

We report on a measurement of the cross section for direct-photon production in association with a heavy quark using the full data set of sqrt[s]=1.96  TeV proton-antiproton collisions corresponding to 9.1  fb-1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron. The measurements are performed as a function of the photon transverse momentum, covering a photon transverse momentum between 30 and 300 GeV, photon rapidities |yγ|<1.0, a heavy-quark-jet transverse momentum pTjet>20  GeV, and jet rapidities |yjet|<1.5. The results are compared with several theoretical predictions.

Search for pair production of strongly interacting particles decaying to pairs of jets in pp collisions at √s=1.96 TeV

We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We consider both nonresonant production via an intermediate gluon as well as resonant production via a distinct nonstandard-model intermediate strongly interacting particle. We use data collected by the CDF experiment in proton-antiproton collisions at √[s]=1.96 TeV corresponding to an integrated luminosity of 6.6 fb(-1). We find the data to be consistent with nonresonant production. We report limits on σ(pp[over ¯]→jjjj) as a function of the masses of the hypothetical intermediate particles. Upper limits on the production cross sections for nonstandard-model particles in several resonant and nonresonant processes are also derived.

LXRα-mediated downregulation of FOXM1 suppresses the proliferation of hepatocellular carcinoma cells

Liver X receptors (LXRs), including LXRα and LXRβ isoforms, have important roles in the metabolic regulation of glucose, cholesterol and lipid. Moreover, activation of LXRs also represses the expression of cyclin D1 and cyclin B1, and thus suppresses the proliferation of multiple cancer cells, but the relevant mechanism is not well known. Forkhead box M1 (FOXM1) is a proliferation-specific member of forkhead box family, which is highly expressed in proliferating normal cells and numerous cancer cells. FOXM1 directly activates transcription of cyclin D1 and cyclin B1, resulting in the enhancement of cell cycle progression and cell proliferation. However, it is unclear whether LXRs are involved in the regulation of FOXM1. In this study, we demonstrated that specific LXRs agonists downregulated expression of FOXM1, cyclin D1 and cyclin B1 in hepatocellular carcinoma (HCC) cells, which led to cell cycle and cell proliferation arrest. Knockdown of FOXM1 significantly alleviated LXRs activation-mediated cell cycle arrest and cell growth suppression. Reporter assays showed that the activation of LXRs significantly reduced the transcriptional activity of FOXM1 promoter. Electrophoretic mobility shift assay and chromatin immunoprecipitation assays demonstrated that LXRα but not LXRβ could bind to an inverted repeat IR2 (-52CCGTCAcgTGACCT-39) in the promoter region of FOXM1 gene. Moreover, the xenograft tumor growth and the corresponding FOXM1 expression in nude mice were dramatically repressed by LXRs agonists. Taken together, we conclude that LXRα but not LXRβ functions as a transcriptional repressor for FOXM1 expression. The pathway 'LXRα-FOXM1-cyclin D1/cyclin B1' is a novel mechanism by which LXRs suppress the proliferation of HCC cells, suggesting that the pathway may be a novel target for HCC treatment.

Clinical remission following endoscopic placement of retrievable, fully covered metal stents in patients with esophageal achalasia

Metal stents may represent an alternative therapy in the treatment of achalasia. We therefore evaluated the effectiveness of retrievable, fully covered metal stents in patients with achalasia. Fifty-nine patients with achalasia were treated with retrievable, fully covered metal stents. Symptoms using a global symptom score (0-10), lower esophageal sphincter (LES) resting pressure, LES relaxation, and simultaneous contraction of the esophagus were analyzed before and 1 week and 1 month after intervention. Complications and treatment outcomes were followed up at 6, 12, 18, and 24 months postoperatively. Stent placement was successful, and clinical symptoms resolved (P < 0.01) in all patients. Regurgitation, dysphagia and chest pain improved significantly (all P < 0.01). Therapy improved LES resting pressure (51.4 ± 9.7 mmHg pretherapy vs. 20.9 ± 8.1 mmHg post-therapy), LES relaxation (58.1 ± 17.1% pretherapy vs. 84.5 ± 18.9% post-therapy), and simultaneous contraction of the esophagus (36.1 ± 8.6% pretherapy vs. 69.4 ± 23.1% post-therapy) 1 month after stent placement (all P < 0.01). The cumulative clinical remission rates 6, 12, 18, 24, 30, and 36 months after stent removal were 90.9%, 81.8%, 76.4%, 69.1%, 65.5%, and 49.1%, respectively. All patients tolerated stent placement. Twelve patients (25.5%) complained of substernal pain and five (10.6%) had substernal burning. Stents migrated in four patients (8.5%). Insertion of retrievable, fully covered metal stents is an effective and safe treatment in patients with achalasia.

Observation of a charged charmoniumlike structure in e+ e- → π+ π- J/ψ at sqrt[s] = 4.26 GeV

We study the process ee+ e- → π+ π- J/ψ at a center-of-mass energy of 4.260 GeV using a 525  pb(-1) data sample collected with the BESIII detector operating at the Beijing Electron Positron Collider. The Born cross section is measured to be (62.9±1.9±3.7)  pb, consistent with the production of the Y(4260). We observe a structure at around 3.9  GeV/c2 in the π(±)J/ψ mass spectrum, which we refer to as the Z(c)(3900). If interpreted as a new particle, it is unusual in that it carries an electric charge and couples to charmonium. A fit to the π(±)J/ψ invariant mass spectrum, neglecting interference, results in a mass of (3899.0±3.6±4.9)  MeV/c2 and a width of (46±10±20)  MeV. Its production ratio is measured to be R = (σ(e+ e- → π(±)Z(c)(3900)(∓) → π+ π- J/ψ)/σ(e+ e- → π+ π- J/ψ)) = (21.5±3.3±7.5)%. In all measurements the first errors are statistical and the second are systematic.

Search for supersymmetry with like-sign lepton-tau events at CDF

We present a search for chargino-neutralino associated production using like electric charge dilepton events collected by the CDF II detector at the Fermilab Tevatron in proton-antiproton collisions at sqrt[s] = 1.96 TeV. One lepton is identified as the hadronic decay of a tau lepton, while the other is an electron or muon. In data corresponding to 6.0 fb(-1) of integrated luminosity, we obtain good agreement with standard model predictions and set limits on the chargino-neutralino production cross section for simplified gravity- and gauge-mediated models. As an example, assuming that the chargino and neutralino decays to taus dominate, in the simplified gauge-mediated model we exclude cross sections greater than 300 fb at 95% credibility level for chargino and neutralino masses of 225 GeV/c(2). This analysis is the first to extend the LHC searches for electroweak supersymmetric production of gauginos to high tanβ and slepton next-to-lightest supersymmetric particle scenarios.

VEGFR2-dependent Angiogenic Capacity of Pericyte-like Dental Pulp Stem Cells

Dental pulp stem cells (DPSCs) have previously demonstrated potential pericyte-like topography and function. However, the mechanisms regulating their pericyte function are still unknown. In this study, murine DPSC angiogenic and pericyte function were investigated. Tie2-GFP mouse DPSCs were negative for GFP, indicating the absence of endothelial cells in DPSC cultures. Endothelial cells co-cultured with DPSCs formed more mature in vitro tube-like structures as compared with those co-cultured with bone marrow stromal cells (BMSCs). Many DPSCs were located adjacent to vascular tubes, assuming a pericyte location. Subcutaneous DPSC transplants in mice with matrigel (MG) (DPSC-MG) induced more vessel formation than BMSC-MG. Soluble Flt (sFlt), an angiogenic inhibitor that binds VEGF-A, significantly decreased the amount of blood vessels in DPSC-MG, but not in BMSC-MG. sFlt inhibited VEGFR2 and downstream ERK signaling in DPSCs. Similar to sFlt inhibition, VEGFR2 knockdown in DPSCs resulted in down-regulation of Vegfa, Vegf receptors, and EphrinB2 and decreased angiogenic induction of DPSCs in vivo. Therefore, the capacity of DPSCs to induce angiogenesis is VEGFR2-dependent. DPSCs enhance angiogenesis by secreting VEGF ligands and associating with vessels resembling pericyte-like cells. This study provides first insights into the mechanism(s) of DPSC angiogenic induction and their function as pericytes, crucial aspects for DPSC use in tissue regeneration.

Search for resonant top-antitop production in the lepton plus jets decay mode using the full CDF data set

This Letter reports a search for a narrow resonant state decaying into two W bosons and two b quarks where one W boson decays leptonically and the other decays into a quark-antiquark pair. The search is particularly sensitive to top-antitop resonant production. We use the full data sample of proton-antiproton collisions at a center-of-mass energy of 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron, corresponding to an integrated luminosity of 9.45 fb(-1). No evidence for resonant production is found, and upper limits on the production cross section times branching ratio for a narrow resonant state are extracted. Within a specific benchmark model, we exclude a Z' boson with mass, M(Z'), below 915 GeV/c(2) decaying into a top-antitop pair at the 95% credibility level assuming a Z' boson decay width of Γ(Z') = 0.012 M(Z'). This is the most sensitive search for a narrow qq-initiated tt resonance in the mass region below 750 GeV/c(2).

Search for a two-Higgs-boson doublet using a simplified model in pp collisions at sqrt[s] = 1.96 TeV

We present a search for new particles in an extension to the standard model that includes a heavy Higgs boson (H(0)), a lighter charged Higgs boson (H(±)), and an even lighter Higgs boson h(0), with decays leading to a W-boson pair and a bottom-antibottom quark pair in the final state. We use events with exactly one lepton, missing transverse momentum, and at least four jets in data corresponding to an integrated luminosity of 8.7 fb(-1) collected by the CDF II detector in proton-antiproton collisions at sqrt[s]= 1.96 TeV. We find the data to be consistent with standard model predictions and report the results in terms of a simplified Higgs-cascade-decay model, setting 95% confidence level upper limits on the product of cross section and branching fraction from 1.3 pb to 15 fb as a function of H(0) and H(±) masses for m(h)(0) = 126 GeV/c(2).

Trends in seroprevalence of antibodies to pandemic influenza H1N1 (2009) virus among patients seeking care in China

We determined seroprevalence of antibodies to pandemic influenza H1N1 (2009) virus in outpatients in China from December 2009 to March 2010. Serum antibody titers were determined by a hemagglutination-inhibition (HI) assay using the seroprevalence data for 2006-2008 (1.2%) as baseline. The overall seroprevalence was 7.6%, 18.6%, 20.5%, and 20.0% in December 2009, January 2010, February 2010, and March 2010, respectively. In comparison of monthly data, the seroprevalence values for the first three months exhibited statistically significant differences. As for the age-specific seroprevalence, the individuals aged demic virus.

Measurement of the cross section for prompt isolated diphoton production using the full CDF run II data sample

This Letter reports a measurement of the cross section for producing pairs of central prompt isolated photons in proton-antiproton collisions at a total energy sqrt[s] = 1.96 TeV using data corresponding to 9.5 fb(-1) integrated luminosity collected with the CDF II detector at the Fermilab Tevatron. The measured differential cross section is compared to three calculations derived from the theory of strong interactions. These include a prediction based on a leading order matrix element calculation merged with a parton shower model, a next-to-leading order calculation, and a next-to-next-to-leading order calculation. The first and last calculations reproduce most aspects of the data, thus showing the importance of higher-order contributions for understanding the theory of strong interaction and improving measurements of the Higgs boson and searches for new phenomena in diphoton final states.

Observation of the production of a W boson in association with a single charm quark

The first observation of the production of a W boson with a single charm quark (c) jet in pp[over ¯] collisions at √s=1.96  TeV is reported. The analysis uses data corresponding to 4.3  fb(-1), recorded with the CDF II detector at the Fermilab Tevatron. Charm quark candidates are selected through the identification of an electron or muon from charm-hadron semileptonic decay within a hadronic jet, and a Wc signal is observed with a significance of 5.7 standard deviations. The production cross section σ(Wc)(p(Tc)>20  GeV/c,|η(c)|<1.5)×B(W→ℓν) is measured to be 13.6(-3.1)(+3.4)  pb and is in agreement with theoretical expectations. From this result the magnitude of the quark-mixing matrix element V(cs) is derived, |V(cs)|=1.08±0.16 along with a lower limit of |V(cs)|>0.71 at the 95% confidence level, assuming that the Wc production through c to s quark coupling is dominant.

Observation of two new N* resonances in the decay ψ(3686)→ppπ0

Based on 106×10(6)ψ(3686) events collected with the BESIII detector at the BEPCII facility, a partial wave analysis of ψ(3686)→ppπ0 is performed. The branching fraction of this channel has been determined to be B(ψ(3686)→ppπ0)=(1.65±0.03±0.15)×10(-4). In this decay, 7 N* intermediate resonances are observed. Among these, two new resonances, N(2300) and N(2570) are significant, one 1/2+ resonance with a mass of 2300(-30-0)(+40+109)  MeV/c2 and width of 340(-30-58)(+30+110)  MeV/c2, and one 5/2- resonance with a mass of 2570(-10-10)(+19+34)  MeV/c2 and width of 250(-24-21)(+14+69)  MeV/c2. For the remaining 5 N* intermediate resonances [N(1440), N(1520), N(1535), N(1650) and N(1720)], the analysis yields mass and width values that are consistent with those from established resonances.

Is it necessary to dissect the lymph nodes around an abnormal hepatic artery in D2 lymphadenectomy for gastric cancer?

BACKGROUND

Surgical resection remains the principal treatment for advanced gastric cancer. However, one of the difficulties in radical D2 lymphadenectomy is the identification of the vascular abnormalities around the stomach, especially abnormal hepatic artery. The hepatic artery arising from the superior mesenteric artery shows great variations, and whether or not the lymphatic tissues around the abnormal artery should be dissected is still controversial.

METHOD

Eighty-six gastric cancer patients who underwent radical D2 lymphadenectomy by the same surgeon in our department in the past 2 years were included in this study. All patients underwent multislice spiral computed tomography angiography for preoperative evaluation of the abnormal hepatic artery arising from the superior mesenteric artery. Postoperative immunohistochemistry of the lymphoid tissues around the abnormal hepatic artery was performed using CK20 and CEA antibodies to determine the occurrence of lymph node micrometastasis around the abnormal artery.

RESULTS

In our study, we found 14 cases with an abnormal hepatic artery arising from the superior mesenteric artery. The hepatic artery ran in front of the pancreas in 1 case and behind the pancreas in 13 cases. Immunohistochemical analyses revealed no micrometastasis in the lymphoid tissues surrounding the abnormal artery.

CONCLUSIONS

Abnormal hepatic arteries arising from the superior mesenteric artery can be classified into pre-pancreas and post-pancreas types. Lymph nodes around the abnormal artery may not need to be dissected in radical D2 lymphadenectomy.

Measurements of the top-quark mass and the tt cross section in the hadronic τ+jets decay channel at sqrt[s] = 1.96 TeV

We present the first direct measurement of the top-quark mass using tt events decaying in the hadronic τ+jets decay channel. Using data corresponding to an integrated luminosity of 2.2 fb(-1) collected by the CDF II detector in pp collisions at sqrt[s] = 1.96 TeV at the Fermilab Tevatron, we measure the tt cross section, σ(tt), and the top-quark mass, M(top). We extract M(top) from a likelihood based on per-event probabilities calculated with leading-order signal and background matrix elements. We measure σ(tt) = 8.8 ± 3.3(stat) ± 2.2(syst) pb and M(top) = 172.7 ± 9.3(stat) ± 3.7(syst) GeV/c(2).

Search for the standard model Higgs Boson produced in association with top quarks using the full CDF data set

A search is presented for the standard model Higgs boson produced in association with top quarks using the full Run II proton-antiproton collision data set, corresponding to 9.45 fb(-1), collected by the Collider Detector at Fermilab. No significant excess over the expected background is observed, and 95% credibility-level upper bounds are placed on the cross section σ(ttH → lepton + missing transverse energy+jets). For a Higgs boson mass of 125 GeV/c(2), we expect to set a limit of 12.6 and observe a limit of 20.5 times the standard model rate. This represents the most sensitive search for a standard model Higgs boson in this channel to date.

Evidence for the direct two-photon transition from ψ(3686) to J/ψ

The two-photon transition ψ(3686)→γγJ/ψ is studied in a sample of 1.06×10(8) ψ(3686) decays collected by the BESIII detector. The branching fraction is measured to be (3.1±0.6(stat)(-1.0)(+0.8)(syst))×10(-4) using J/ψ→e(+)e(-) and J/ψ→μ(+)μ(-) decays, and its upper limit is estimated to be 4.5×10(-4) at the 90% confidence level. This work represents the first measurement of a two-photon transition among charmonium states. The orientation of the ψ(3686) decay plane and the J/ψ polarization in this decay are also studied. In addition, the product branching fractions of sequential E1 transitions ψ(3686)→γχ(cJ) and χ(cJ)→γJ/ψ(J=0,1,2) are reported.

Measurement of the bottom-strange meson mixing phase in the full CDF data set

We report a measurement of the bottom-strange meson mixing phase β(s) using the time evolution of B(s)(0)→J/ψ(→μ(+)μ(-))φ(→K(+)K(-)) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at √s=1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb(-1) of integrated luminosity. We report confidence regions in the two-dimensional space of β(s) and the B(s)(0) decay-width difference ΔΓ(s) and measure β(s)∈[-π/2,-1.51]∪[-0.06,0.30]∪[1.26,π/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of β(s), we also determine ΔΓ(s)=0.068±0.026(stat)±0.009(syst) ps(-1) and the mean B(s)(0) lifetime τ(s)=1.528±0.019(stat)±0.009(syst) ps, which are consistent and competitive with determinations by other experiments.

Precision top-quark mass measurement at CDF

We present a precision measurement of the top-quark mass using the full sample of Tevatron √s = 1.96 TeV proton-antiproton collisions collected by the CDF II detector, corresponding to an integrated luminosity of 8.7 fb(-1). Using a sample of tt¯ candidate events decaying into the lepton+jets channel, we obtain distributions of the top-quark masses and the invariant mass of two jets from the W boson decays from data. We then compare these distributions to templates derived from signal and background samples to extract the top-quark mass and the energy scale of the calorimeter jets with in situ calibration. The likelihood fit of the templates from signal and background events to the data yields the single most-precise measurement of the top-quark mass, M(top)=172.85±0.71(stat)±0.85(syst) GeV/c(2).

Expression of interleukin-18 in a rat model of deep vein thrombosis

AIM

Interleukin-18 (IL-18) is an important proinflammatory cytokine. However, little is known about the roles of IL-18 in the process of venous thrombosis. This study aimed to investigate the roles of IL-18 during deep vein thrombosis (DVT).

METHODS

Fifty rats were randomly divided into 0 (control group), 12, 24, 36 and 48 h groups (10 rats in each group) by observation time. The inferior vena cava (IVC) was ligated to establish the DVT model. Serum samples were extracted to determine the levels of IL-18, tumor necrosis factor-alpha (TNF-α), thromboxane B2 (TXB2) and 6-keto-prostaglandin Fl alpha (6-keto-PG Flα) by enzyme-linked immunosorbent assay (ELISA). The weight and length of IVC was also measured.

RESULTS

The DVT model was successfully established by ligating IVC. The injury of vein endothelium was observed in the model groups. IL-18, TNF-α, TXB2, TXB2/6-keto-PG Flα levels and thrombus weight were significantly increased in the model groups as compared with the control group, and peaked at 24 h after IVC ligation. 6-keto-PG F1α slightly decreased in the model groups comparing with the control group. IL-18 was positively correlated with TNF-α, TXB2, TXB2/6-keto-PG Flα ratio and thrombus weight. However, IL-18 was negatively correlated with 6-keto-PG Flα. There was a positive correlation between TXB2/6-keto-PG Flα ratio and thrombus weight.

CONCLUSION

Serum IL-18 level increased in the process of DVT, which might impair venous endothelial cells and result in venous thrombosis. IL-18 might be a new potential therapeutic target of DVT prevention.