Production of WZ events in pp collisions at square root(s) = 1.96 TeV and limits on anomalous WWZ couplings

We present results from a search for WZ production with subsequent decay to l nu l' l' (l and l' = e or mu) using 0.30 fb(-1) of data collected by the D0 experiment between 2002 and 2004 at the Fermilab Tevatron. Three events with WZ decay characteristics are observed. With an estimated background of 0.71 +/- 0.08 events, we measure the WZ production cross section to be 4.5(-2.6)(+3.8) pb, with a 95% C.L. upper limit of 13.3 pb. The 95% C.L. limits for anomalous WWZ couplings are found to be -2.0 < delta kappaZ < 2.4 for form factor scale lambda = 1 TeV, and -0.48 < lambdaZ < 0.48 and -0.49 < delta g(1)(Z) < 0.66 for lambda = 1.5 TeV.

Search for Randall-Sundrum gravitons in dilepton and diphoton final states

We report the first direct search for the Kaluza-Klein (KK) modes of Randall-Sundrum gravitons using dielectron, dimuon, and diphoton events observed with the D0 detector operating at the Fermilab Tevatron pp(-) Collider at sqrt[s]=1.96 TeV. No evidence for resonant production of gravitons has been found in the data corresponding to an integrated luminosity of approximately equal to 260 pb(-1). Lower limits on the mass of the first KK mode at the 95% C.L. have been set between 250 and 785 GeV, depending on its coupling to standard model particles.

Study of Zgamma events and limits on anomalous ZZgamma and Zgammagamma couplings in pp collisions at square root s = 1.96 TeV

We present a measurement of the Zgamma production cross section and limits on anomalous ZZgamma and Zgammagamma couplings for form-factor scales of lambda = 750 and 1000 GeV. The measurement is based on 138 (152) candidates in the eegamma (mumugamma) final state using 320(290) pb(-1) of pp(-1) collisions at square root of s = 1.96 TeV. The 95% C.L. limits on real and imaginary parts of individual anomalous couplings are /h(10,30)Z/ < 0.23, /h(20,40)Z/ < 0.020, /h(10,30)gamma/ < 0.23, and /h(20,40)gamma/ < 0.019 for lambda = 1000 GeV.

Measurement of inclusive differential cross sections for pp collisions at (square root)s = 1.96 TeV

We present measurements of the inclusive production cross sections of the Gamma(1S) bottomonium state in pp collisions at (square root)s = 1.96 TeV. Using the Gamma(1S) --> mu(+)mu(-) decay mode for a data sample of 159 +/- 10 pb(-1) collected by the D0 detector at the Fermilab Tevatron collider, we determine the differential cross sections as a function of the Gamma(1S) transverse momentum for three ranges of the Gamma(1S) rapidity: 0 < y(Gamma) < or = 0.6, 0.6 < y(Gamma) < or = 1.2, and 1.2 < y(Gamma) < or = 1.8.

Measurement of dijet azimuthal decorrelations at central rapidities in pp collisions at sqrt s =1.96 TeV

Correlations in the azimuthal angle between the two largest transverse momentum jets have been measured using the D0 detector in p (-)p collisions at a center-of-mass energy sqrt[s]=1.96 TeV. The analysis is based on an inclusive dijet event sample in the central rapidity region corresponding to an integrated luminosity of 150 pb(-1). Azimuthal correlations are stronger at larger transverse momenta. These are well described in perturbative QCD at next-to-leading order in the strong coupling constant, except at large azimuthal differences where contributions with low transverse momentum are significant.

Measurement of the ratio of B+ and B0 meson lifetimes

The ratio of the B+ and B0 meson lifetimes was measured using data collected in 2002-2004 by the D0 experiment in Run II of the Fermilab Tevatron Collider. These mesons were reconstructed in B-->mu(+)nuD(*-)X decays, which are dominated by B0 and B-->mu(+)nuD 0X decays, which are dominated by B+. The ratio of lifetimes is measured to be tau(+)/tau(0)=1.080+/-0.016(stat)+/-0.014(syst).

Measurement of the ratio of inclusive cross sections sigma(pp --> Z + b jet)/sigma(pp --> Z + jet) at square root(s) = 1.96 TeV

Using the data collected with the D0 detector at square root(s) = 1.96 TeV, for integrated luminosities of about 180 pb(-1), we have measured the ratio of inclusive cross sections for pp --> Z + b jet to pp --> Z + jet production. The inclusive Z + b-jet reaction is an important background to searches for the Higgs boson in associated ZH production at the Fermilab Tevatron collider. Our measurement is the first of its kind, and relies on the Z --> e+ e- and Z --> mu+ mu- modes. The combined measurement of the ratio yields 0.021+/-0.005 for hadronic jets with transverse momenta pT > 20 GeV/c and pseudorapidities absolute value(eta) < 2.5, consistent with next-to-leading-order predictions of the standard model.

Search for anomalous heavy-flavor quark production in association with W bosons

We search for anomalous production of heavy-flavor quark jets in association with W bosons at the Fermilab Tevatron pp Collider in final states in which the heavy-flavor quark content is enhanced by requiring at least one tagged jet in an event. Jets are tagged using one algorithm based on semileptonic decays of b/c hadrons, and another on their lifetimes. We compare e+jets (164 pb(-1)) and mu+jets (145 pb(-1)) channels collected with the D0 detector at sqrt[s]=1.96 TeV to expectations from the standard model and set upper limits on anomalous production of such events.

Measurement of the WW production cross section in pp collisions at square root[s]=1.96 TeV

We present a measurement of the W boson pair-production cross section in pp collisions at a center-of-mass energy of sqrt[s]=1.96 TeV. The data, collected with the Run II D0 detector at Fermilab, correspond to an integrated luminosity of 224-252 pb(-1) depending on the final state (ee, emu, or mumu). We observe 25 candidates with a background expectation of 8.1+/-0.6(stat)+/-0.6(syst)+/-0.5(lum) events. The probability for an upward fluctuation of the background to produce the observed signal is 2.3x10(-7), equivalent to 5.2 standard deviations. The measurement yields a cross section of 13.8(+4.3)(-3.8)(stat)+1.2-0.9(syst)+/-0.9(lum) pb, in agreement with predictions from the standard model.

Measurement of the Lambda0b lifetime in the decay lambda0b--> J/psiLambda0 with the D0 detector

We present measurements of the Lambda(0)(b) lifetime in the exclusive decay channel Lambda(0)(b)--> J/psiLambda(0), with J/psi--> mu(+)mu(-) and Lambda(0)--> ppi(-), the B0 lifetime in the decay B0-->J/psiK(0)(S) with J/psi--> mu(+)mu(-) and K(0)(S)-->pi(+)pi(-), and the ratio of these lifetimes. The analysis is based on approximately 250 pb(-1) of data recorded with the D0 detector in pp collisions at sqrt[s] = 1.96 TeV. The Lambda(0)(b) lifetime is determined to be tau(Lambda(0)(b)) = 1.22(+0.22)(-0.18)(stat) +/- 0.04(syst) ps, the B0 lifetime tau(B0) = 1.40(+0.11)(-0.10)(stat) +/- 0.03(syst) ps, and the ratio tau(Lambda(0)(b))/tau(B0) = 0.87(+0.17)(-0.14)(stat) +/- 0.03(syst). In contrast with previous measurements using semileptonic decays, this is the first determination of the Lambda(0)(b) lifetime based on a fully reconstructed decay channel.

Search for Wbb and WH production in pp collisions at square root [s]=1.96 TeV

We present a search for Wbb production in pp collisions at sqrt[s]=1.96 TeV in events containing one electron, an imbalance in transverse momentum, and two b-tagged jets. Using 174 pb(-1) of integrated luminosity accumulated by the D0 experiment at the Fermilab Tevatron collider, and the standard-model description of such events, we set a 95% C.L. upper limit on Wbb production of 6.6 pb for b quarks with transverse momenta p(b)(T)>20 GeV and bb separation in pseudorapidity-azimuth space DeltaR(bb)>0.75. Restricting the search to optimized bb mass intervals provides upper limits on WH production of 9.0-12.2 pb for Higgs-boson masses of 105-135 GeV.

Clinical outcome and virological characteristics of hepatitis B-related acute liver failure in the United States

The role of hepatitis B virus (HBV) genotypes in the outcome of acute HBV infection is unclear. In this study, we aimed to evaluate the clinical and virological features of patients with hepatitis B-related acute liver failure (HBV-ALF) in the US. Clinical and laboratory features of consecutive patients with HBV-ALF from the US ALF Study Group were analysed. Prevalence of HBV genotypes, precore stop (G1896A) and core promoter dual (T1762A, A1764T) variants among patients with HBV-ALF were compared with a cohort of 530 patients with chronic HBV infection. Thirty-four HBV-ALF patients were studied: mean age 41 years, 56% men, 25 had detectable HBV-DNA. HBV genotypes A, B, C and D were found in 36, 24, 8 and 32% patients, respectively. Precore stop and core promoter dual variants were detected in 32 and 44% of patients, respectively. Twenty-three (68%) patients survived: 14 after liver transplant, nine without transplant. Older age was the only independent factor associated with poor outcome. Compared with patients with chronic HBV infection, patients with ALF were more likely to be non-Asians (88% vs 44%, P = 0.005) and to have genotype D (32% vs 10%, P < 0.01). A higher prevalence of HBV genotype D persisted even after matching for race and HBeAg status (32% vs 16%, P = 0.007). We concluded that HBV genotype D was more frequently found in patients with HBV-ALF than those with chronic HBV infection in the US. Further studies are needed to determine if HBV genotypes play a role in the outcome of acute HBV infection.

Search for the flavor-changing neutral current decay B0s--> mu(+) mu(-) in pp Collisions at sqrt[s] = 1.96 TeV with the D0 detector

We present the results of a search for the flavor-changing neutral current decay B(0)(s)--> mu(+) mu(-) using a data set with integrated luminosity of 240 pb(-1) of pp collisions at sqrt[s] = 1.96 TeV collected with the D0 detector in run II of the Fermilab Tevatron collider. We find the upper limit on the branching fraction to be B(B(0)(s)--> mu(+) mu(-)) < or= 5.0 x 10(-7) at the 95% C.L. assuming no contributions from the decay B(0)(d)--> mu(+) mu(-) in the signal region. This limit is the most stringent upper bound on the branching fraction B(0)(s)--> mu(+) mu(-) to date.

Search for supersymmetry with gauge-mediated breaking in diphoton events at D0

We report the results of a search for supersymmetry (SUSY) with gauge-mediated breaking in the missing transverse energy distribution of inclusive diphoton events using 263 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2004. No excess is observed above the background expected from standard model processes, and lower limits on the masses of the lightest neutralino and chargino of about 108 and 195 GeV, respectively, are set at the 95% confidence level. These are the most stringent limits to date for models with gauge-mediated SUSY breaking with a short-lived neutralino as the next-to-lightest SUSY particle.

Measurement of the B0s lifetime in the exclusive decay channel B0s-->J/psiphi

Using the exclusive decay B0s-->J/psi(mu+mu-)phi(K+K-), we report the most precise single measurement of the B0s lifetime. The data sample corresponds to an integrated luminosity of approximately 220 pb(-1) collected with the D0 detector at the Fermilab Tevatron Collider in 2002-2004. We reconstruct 337 signal candidates, from which we extract the B0s lifetime, tau(B0s)=1.444(+0.098)(-0.090)(stat)+/-0.020(sys) ps. We also report a measurement for the lifetime of the B0 meson using the exclusive decay B0-->J/psi(mu+mu-)K*0(892)(K+pi-). We reconstruct 1370 signal candidates, obtaining tau(B0)=1.473(+0.052)(-0.050)(stat)+/-0.023(sys) ps, and the ratio of lifetimes, tau(B0s)/tau(B0)=0.980(+0.076)(-0.071)(stat)+/-0.003(sys).

Embryotrophic factor-3 from human oviductal cells enhances proliferation, suppresses apoptosis and stimulates the expression of the β1 subunit of sodium–potassium ATPase in mouse embryos

BACKGROUND

Embrytrophic factor-3 (ETF-3) from human oviductal cells enhanced the development of mouse preimplantation embryos. This report studied the embryotrophic mechanisms of the molecule.

METHODS AND RESULTS

Mouse embryos were incubated with ETF-3 for 24 h at different stages of development. ETF-3 treatment between 96 and 120 h post-HCG increased the cell count of blastocysts, whilst treatment between 72 and 96 h post-HCG enhanced the expansion and hatching of the blastocysts. ETF-3 increased the cell number of the embryos by suppressing apoptosis and increasing proliferation as determined by TUNEL and bromodeoxyuridine uptake assays, respectively. Real-time quantitative PCR showed that the in vivo developed and ETF-3-treated blastocysts had a significantly higher mRNA copy number of Na/K-ATPase-beta1, but not of hepsin, than that of blastocysts cultured in medium alone. The former gene was associated with cavitation of blastocysts while the latter was related to hatching of blastocyst. The beneficial effect of ETF-3 on blastocyst hatching was also seen when ETF-3-supplemented commercially available sequential culture medium for human embryo culture was used to culture mouse embryos.

CONCLUSIONS

ETF-3 improves embryo development by enhancing proliferation, suppressing apoptosis and stimulating expression of genes related to blastocyst cavitation. Supplementating human embryo culture medium with ETF-3 may improve the success rate in clinical assisted reproduction.

Observation and properties of the X(3872) decaying to J/psipi(+)pi(-) in pp collisions at sqrt[s]=1.96 TeV

We report the observation of the X(3872) in the J/psipi(+)pi(-) channel, with J/psi decaying to mu(+)mu(-), in pp collisions at sqrt[s]=1.96 TeV. Using approximately 230 pb(-1) of data collected with the Run II D0 detector, we observe 522+/-100 X(3872) candidates. The mass difference between the X(3872) state and the J/psi is measured to be 774.9+/-3.1(stat)+/-3.0(syst) MeV/c(2). We have investigated the production and decay characteristics of the X(3872) and find them to be similar to those of the psi(2S) state.

Search for doubly charged higgs boson pair production in the decay to mu(+)mu(+)mu(-)mu(-) in pp collisions at sqrt[s]=1.96 TeV

A search for pair production of doubly charged Higgs bosons in the process pp -->H(++)H(--) -->mu(+)mu(+)mu(-)mu(-) is performed with the D0 run II detector at the Fermilab Tevatron. The analysis is based on a sample of inclusive dimuon data collected at an energy of sqrt[s]=1.96 TeV, corresponding to an integrated luminosity of 113 pb(-1). In the absence of a signal, 95% confidence level mass limits of M(H(+/-+/-)(L))>118.4 GeV/c(2) and M(H(+/-+/-)(R))>98.2 GeV/c(2) are set for left-handed and right-handed doubly charged Higgs bosons, respectively, assuming 100% branching into muon pairs.

Optical vortex beam shaping by use of highly efficient irregular spiral phase plates for optical micromanipulation

Optical dark traps such as Laguerre-Gaussian beams, modulated optical vortices, and high-order Bessel beams have been used in the micromanipulation of microparticles. Such optical traps are highly versatile, as they are able to trap both high- and low-index microparticles as well as to set them into rotation by use of the orbital angular momentum of light. Holography has been widely used to modulate the shape of an optical vortex for new optical traps. We show that, by designing the shape of a spiral phase plate and using electron-beam lithography for fabrication, one can modulate the amplitude and the phase of an optical vortex with respect to the specific shape of the spiral phase plate as required. Furthermore, to the best of our knowledge this is the first report of transferring orbital angular momentum from a spiral phase plate to an absorptive microparticle in an experiment. Hence, with this technique, optical dark traps can easily be designed and fabricated.

A precision measurement of the mass of the top quark

The standard model of particle physics contains parameters--such as particle masses--whose origins are still unknown and which cannot be predicted, but whose values are constrained through their interactions. In particular, the masses of the top quark (M(t)) and W boson (M(W)) constrain the mass of the long-hypothesized, but thus far not observed, Higgs boson. A precise measurement of M(t) can therefore indicate where to look for the Higgs, and indeed whether the hypothesis of a standard model Higgs is consistent with experimental data. As top quarks are produced in pairs and decay in only about 10(-24) s into various final states, reconstructing their masses from their decay products is very challenging. Here we report a technique that extracts more information from each top-quark event and yields a greatly improved precision (of +/- 5.3 GeV/c2) when compared to previous measurements. When our new result is combined with our published measurement in a complementary decay mode and with the only other measurements available, the new world average for M(t) becomes 178.0 +/- 4.3 GeV/c2. As a result, the most likely Higgs mass increases from the experimentally excluded value of 96 to 117 GeV/c2, which is beyond current experimental sensitivity. The upper limit on the Higgs mass at the 95% confidence level is raised from 219 to 251 GeV/c2.

Search for narrow tt resonances in pp collisions at square root of (s)=1.8 TeV

A search for narrow resonances that decay into tt pairs has been performed using 130 pb(-1) of data in the lepton + jets channel collected by the Dphi detector in pp collisions at square root of (s)=1.8 TeV. There is no significant deviation observed from the standard-model predictions at a top-quark mass of 175 GeV/c2. We therefore present upper limits at the 95% confidence level on the product of the production cross section and branching fraction to tt for narrow resonances as a function of the resonance mass MX. These limits are used to exclude the existence of a leptophobic top-color particle with mass MX<560 GeV/c2, using a theoretical cross section for a width GammaX=0.012MX.

J/psi polarization in 800-GeV p-Cu interactions

We present measurements of the polarization of the J/psi produced in 800-GeV proton interactions with a copper target. Polarization of the J/psi is sensitive to the ccmacr; production and hadronization processes. A longitudinal polarization is observed at large x(F), while at small x(F) the state is produced essentially unpolarized or slightly transversely polarized. No significant variation of the polarization is observed versus p(T).

Dynamic optical manipulation with a higher-order fractional bessel beam generated from a spatial light modulator

Higher-order Bessel beams have been demonstrated to have the ability to trap and rotate low- and high-index particles simultaneously [Phys. Rev. A 66, 063402 (2002)]. The rotation and trapping is caused by the presence of orbital angular momentum arising from its azimuthal phase variation (that changes at integer multiples of 2pi) and the concentric rings of the Bessel mode. We demonstrate for the first time to our knowledge a branch from the family of higher-order Bessel beams that has fractional azimuthal variation at its beam axis. This new family of laser beams has the ability to perform dynamic optical manipulation with dynamic control of a spatial light modulator. Furthermore, we take the opportunity to explore the propagation characteristics of higher-order Bessel beams for which the azimuthal phase changes at noninteger multiples of 2pi.

Search for large extra dimensions in the monojet+E(T) channel with the DØ detector

We present a search for large extra dimensions (ED) in pp collisions at a center-of-mass energy of 1.8 TeV using data collected by the DØ detector at the Fermilab Tevatron in 1994-1996. Data corresponding to 78.8+/-3.9 pb(-1) are examined for events with large missing transverse energy, one high-p(T) jet, and no isolated muons. There is no excess observed beyond expectation from the standard model, and we place lower limits on the fundamental Planck scale of 1.0 and 0.6 TeV for 2 and 7 ED, respectively.

Accuracy of electrical field measurement using the flexible Schottky diode sheet at 433 MHz

In this study, the accuracy of Schottky diode sensors mounted as a two-dimensional array on a flexible 125 micro m thick polyester foil has been studied. The diodes are placed at a distance of 2.5 x 2.5 cm, resulting in a measuring area of 20 x 20 cm. The diodes are placed across the gap between both arms (3 x 5 mm) of a dipole, total length 12 mm. High resistance (1 M Omega/m) carbon transmission lines printed on the sheet are used to connect each electrical (E) field sensor to the read-out electronics and a data-acquisition system. It is demonstrated that the flexible Schottky diode sheet can quantitatively measure E-field distributions at 433 MHz with an overall accuracy of approximately 6% (1 SD). The largest contribution to the inaccuracy is related to the phantom heterogeneity. The absolute sensitivity of this electrical field sensor is 0.71 V/m per V/m of the applied external electromagnetic field. The DC-voltage signal of the diodes shows a more or less square root relation to the RF-power applied to the applicator over a 15-fold range. An important feature of the system is that it provides the ability to perform on-line monitoring of the E-field, i.e. the SAR distribution of 433 MHz applicators. Further, it enables the introduction of fast and easy quality control protocols for superficial hyperthermia applicators.

Embryotrophic factor-3 from human oviductal cells affects the messenger RNA expression of mouse blastocyst

Our previous results showed that embryotrophic factor-3 (ETF-3) from human oviductal cells increased the size and hatching rate of mouse blastocysts in vitro. The present study investigated the production of ETF-3 by an immortalized human oviductal cell line (OE-E6/E7) and the effects of ETF-3 on the mRNA expression of mouse embryos. The ETF-3 was purified from primary oviductal cell conditioned media using sequential liquid chromatographic systems, and antiserum against ETF-3 was raised. The ETF-3-supplemented Chatot-Ziomek-Bavister medium was used to culture Day 1 MF1 x BALB/c mouse embryos for 4 days. The ETF-3 treatment significantly enhanced the mouse embryo blastulation and hatching rate. The antiserum, at concentrations of 0.03-3%, abolished the embryotrophic effect of ETF-3. Positive ETF-3 immunoreactivity was detected in the primary oviductal cells, OE-E6/E7, and blastocysts derived from ETF-3 treatment. Vero cells (African Green Monkey kidney cell line), fibroblasts, and embryos cultured in control medium did not possess ETF-3 immunoreactivity. The mRNA expression patterns of the treated embryos were studied at the blastocyst stage by mRNA differential display reverse transcription-polymerase chain reaction (DDRT-PCR). The DDRT-PCR showed that some of the mRNAs were differentially expressed after ETF-3 treatment. Twelve of the differentially expressed mRNAs that had high homology with cDNA sequences in the GenBank were selected for further characterization. The differential expression of seven of these mRNAs (ezrin, heat shock 70-kDa protein, cytochrome c oxidase subunit VIIa-L precursor, proteinase-activated receptor 2, eukaryotic translation initiation factor 2beta, cullin 1, and proliferating cell nuclear antigen) was confirmed by semiquantitative RT-PCR. In conclusion, immortalized oviductal cells produce ETF-3, which influences mRNA expression of mouse blastocyst.

Stability and accuracy of power and phase measurements of a VVM system designed for online quality control of the BSD-2000 (-3D) DHT system

Accurate control of power and phase is essential for the quality assurance of hyperthermia treatments. Hereto, an external measurement device was inserted, built around a Vector Voltmeter (VVM), in order to assess online the performance of the steering capability of the BSD-2000 and later the BSD-2000-3D system. This paper only concerns the power and phase calibration of the signal in the path between the power and phase detection probes of the BSD-system and power and phase measurement point of the VVM. The calibration is performed in the frequency range of 60-120 MHz using a network analyser with a frequency range of 0.01-500 MHz. More importantly, by repeating the calibration periodically over the last 3 years, the stability and accuracy of the power and phase measurements were determined using the VVM system. The results of the power calibration show that the VVM system, concerning its power and phase measurement, is stable in time. The variation of the power measured with the VVM system is less than 0.22 dB (5.2%) for the latest configuration of the BSD-2000-3D system. The variation of the VVM-based phase measurements of the latter configurations is 1.1 degrees or less. From the results of the power and phase measurements in the BSD 2000 system reported in previous studies using other measurement systems, it follows that the uncertainties of the power and phase measurements with the currently proposed VVM system are small enough to assess accurately the performance of the BSD system concerning its steering capability.

Pulsatile secretion pattern of growth hormone in dogs with pituitary-dependent hyperadrenocorticism

The amplitude and frequency of growth hormone (GH) secretory pulses are influenced by a variety of hormonal signals, among which glucocorticoids play an important role. The aim of this study was to investigate the pulsatile secretion pattern of GH in dogs in which the endogenous secretion of glucocorticoids is persistently elevated, i.e. in dogs with pituitary-dependent hyperadrenocorticism (PDH). Blood samples for the determination of the pulsatile secretion pattern of GH were collected at 10-min interval between 08:00 and 14:00 h in 16 dogs with PDH and in 6 healthy control dogs of comparable age. The pulsatile secretion patterns of GH were analyzed using the Pulsar program. GH was secreted in a pulsatile fashion in both dogs with PDH and control dogs. There was no statistical difference between the mean (+/-S.E.M.) basal GH level in dogs with PDH (0.7+/-0.1 microg/l) and the control dogs (0.6+/-0.1 microg/l). The mean area under the curve (AUC) for GH above the zero-level in dogs with PDH (4.6+/-0.6 microg/l per 6 h) was significantly lower than that in the control dogs (7.3+/-1.0 microg/l per 6 h). Likewise, the mean AUC for GH above the base-level in dogs with PDH (0.6+/-0.1 microg/l per 6 h) was significantly lower than that in the control dogs (3.7+/-1.0 microg/l per 6 h). The median GH pulse frequency in the dogs with PDH (2 pulses/6 h, range 0-7 pulses/6 h) was significantly lower (P = 0.04) than that (5 pulses/6 h, range 3-9 pulses/6 h) in the control group. The results of this study demonstrate that PDH in dogs is associated with less GH secreted in pulses than in control dogs, whereas the basal plasma GH concentrations were similarly low in both groups. It is discussed that the impaired pulsatile GH secretion in dogs with PDH is the result of alterations in function of pituitary somatotrophs and changes in supra-pituitary regulation.

Search for the production of single sleptons through R-parity violation in pp; collisions at square root (s) =1.8 TeV

We report the first search for supersymmetric particles via s-channel production and decay of smuons or muon sneutrinos at hadronic colliders. The data for the two-muon and two-jets final states were collected by the D0 experiment and correspond to an integrated luminosity of 94+/-5 pb(-1). Assuming that R parity is violated via the single coupling lambda'211, the number of candidate events is in agreement with expectation from the standard model. Exclusion contours are given in the (m(0),m(1/2)) and (m(x),m(v)) planes for lambda(')(211)=0.09, 0.08, and 0.07.

Search for R-parity violating supersymmetry in two-muon and four-jet topologies

We present results of a search for R-parity-violating decay of the neutralino chi;01, taken as the lightest supersymmetric particle, to a muon and two jets. The decay proceeds through a lepton-number violating coupling lambda(')(2jk) (j=1,2; k=1,2,3), with R-parity conservation in all other production and decay processes. In the absence of candidate events from 77.5+/-3.9 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron in pp collisions at sqrt[s]=1.8 TeV, and with an expected background of 0.18+/-0.03+/-0.02 events, we set limits on squark and gluino masses within the framework of the minimal low-energy supergravity-supersymmetry model.

Search for leptoquark pairs decaying into nunu+jets in pp collisions at square root[s] = 1.8 TeV

We present the results of a search for leptoquark (LQ) pairs in (85.2+/-3.7) pb(-1) of pp* collider data collected by the D0 experiment at the Fermilab Tevatron. We observe no evidence for leptoquark production and set a limit on sigma(pp*-->LQLQ-->nunu+jets) as a function of the mass of the leptoquark (m(LQ)). Assuming the decay LQ-->nuq, we exclude scalar leptoquarks for m(LQ) < 98 GeV/c(2), and vector leptoquarks for m(LQ) < 200 GeV/c(2) and coupling which produces the minimum cross section, at a 95% confidence level.

Search for the scalar top quark in pp collisions at square root[s] = 1.8 TeV

We have performed a search for scalar top quark (stop) pair production in the inclusive electron-muon-missing transverse energy final state, using a sample of pp events corresponding to 108.3 pb(-1) of data collected with the D0 detector at Fermilab. The search is done in the framework of the minimal supersymmetric standard model assuming that the sneutrino is the lightest supersymmetric particle. For the dominant decays of the lightest stop, t-->b chi+1 and t-->blnu, no evidence for signal is found. We derive cross-section limits as a function of stop ( t ), chargino ( chi+1), and sneutrino ( nu) masses.

Influence of acute and chronic alcohol intake on the clinical course and outcome in acetaminophen overdose

BACKGROUND

Animal studies on acetaminophen toxicity suggest that chronic alcohol intake affects the outcome adversely, whereas acute alcohol intake seems protective. Few clinical data are available.

METHODS

We studied 209 consecutive patients with single-dose acetaminophen overdose. The combined influence of independent variables (gender, age, dose, delay to antidote treatment, chronic and acute alcohol intake and nomogram risk group) on dependent variables (death, development of hepatic encephalopathy and biochemical liver markers) was studied using multiple or logistic regression analysis.

RESULTS

Fifty-seven (27.3%) patients had chronic alcohol intake and 45 (21.5%) patients had acute alcohol intake. Forty-four (21.1%) patients developed hepatic coma and 20 (43.5%) of these patients died. Chronic alcohol intake was significantly and independently associated with the development of hepatic coma, with a lower prothrombin index, lower platelet count, higher creatinine and higher bilirubin. The relative risks for hepatic coma and death were 5.3 (95% confidence interval, 2.2-12.4) and 1.4 (95% confidence interval, 0.5-3.9), respectively, in the chronic alcohol intake group compared with the no chronic alcohol intake group. Acute alcohol intake was not significantly associated with any of the dependent variables studied.

CONCLUSIONS

Chronic alcohol intake enhances acetaminophen hepatotoxicity, whereas acute alcohol intake does not affect the clinical course.

A randomized trial of high-dose interferon alpha-2b, with or without ribavirin, in chronic hepatitis C patients who have not responded to standard dose interferon

BACKGROUND

Conventional interferon monotherapy fails to achieve virological clearance in most hepatitis C-infected patients. The use of high-dose induction regimens may improve the initial clearance of virus, while the addition of ribavirin appears to improve the rates of sustained response once clearance is achieved.

AIM

To compare the efficacy and safety of re-treatment with an induction regimen of high-dose interferon alpha-2b, with or without ribavirin, in chronic hepatitis C patients who have not responded to standard dose interferon monotherapy.

METHODS

Previous virological non-responders to standard dose interferon (3-5 MU three times weekly for > or = 12 weeks) were randomized to receive, unblind, either 10 MU interferon alpha-2b daily for 10 days, then 5 MU daily for 74 days, then 5 MU three times weekly for 24 weeks (total 36 weeks) (group A), or the above regimen with the addition of ribavirin, 1000-1200 mg/day, at day 11 (group B). All patients were followed up for 24 weeks after completion of therapy.

RESULTS

End of treatment virological response was noted in one of 10 (10%) patients in group A and in eight of 15 (54%) patients in group B (P=0.04). The sole end treatment responder in group A and three in group B relapsed on follow-up. The apparent improvement in response in group B compared to group A nearly reached statistical significance (group B 5/15 vs. group A 0/10; P=0.06).

CONCLUSIONS

In this small pilot study, a 36-week high-dose induction interferon monotherapy protocol did not yield sustained responses in previous non-responders to standard dose interferon. However, the same regimen with ribavirin yielded a 33% sustained response rate, nearly reaching statistical significance. The therapy was well tolerated, despite the higher doses of interferon used and the addition of ribavirin. High-dose interferon with ribavirin appears to be a therapeutic option for non-responders to conventional interferon monotherapy.

Ratio of isolated photon cross sections in pp macro collisions at square root of s = 630 and 1800 GeV

The inclusive cross section for production of isolated photons has been measured in pp macro collisions at square root of s = 630 GeV with the D0 detector at the Fermilab Tevatron Collider. The photons span a transverse energy (E(T)) range from 7-49 GeV and have pseudorapidity absolute value of eta < 2.5. This measurement is combined with the previous D0 result at square root of s = 1800 GeV to form a ratio of the cross sections. Comparison of next-to-leading-order QCD with the measured cross section at 630 GeV and the ratio of cross sections show satisfactory agreement in most of the E(T) range.

Search for new physics using QUAERO: a general interface to D0 event data

We describe QUAERO, a method that (i) enables the automatic optimization of searches for physics beyond the standard model, and (ii) provides a mechanism for making high energy collider data generally available. We apply QUAERO to searches for standard model WW, ZZ, and t t macro production, to searches for these objects produced through a new heavy resonance, and to the first direct search for W'-->WZ. Through this interface, we make three data sets collected by the D0 experiment at square root of [s] = 1.8 TeV publicly available.

A 22-amino acid synthetic peptide corresponding to the second extracellular loop of rat occludin perturbs the blood-testis barrier and disrupts spermatogenesis reversibly in vivo

When Sertoli cells were cultured in vitro on Matrigel-coated bicameral units, the assembly of the inter-Sertoli tight junction (TJ) permeability barrier correlated with an induction of occludin expression. Inclusion of a 22-amino acid peptide, NH(2)-GSQIYTICSQFYTPGGTGLYVD-COOH, corresponding to residues 209-230 in the second extracellular loop of rat occludin, at 0.2-4 microM into Sertoli cell cultures could perturb the assembly of Sertoli TJs dose-dependently and reversibly. This peptide apparently exerts its effects by interfering with the homotypic interactions of two occludin molecules between adjacent Sertoli cells at the sites of TJs, thereby disrupting TJs, which, in turn, causes a decline in transepithelial electrical resistance across the Sertoli cell epithelium. When similar experiments were performed using a 22-amino acid myotubularin peptide, NH(2)-TKVNERYELCDTYPALLAVPAN-COOH (residues 156-177), no effects on the assembly of inter-Sertoli TJs in vitro were noted. When a single dose of this synthetic occludin peptide was administered to adult rats intratesticularly at 1.5-10 mg/testis, germ cells began to deplete from the seminiferous epithelium within 8-16 days. By 27 days, virtually all tubules were devoid of germ cells. This antispermatogenic effect was reversible, because germ cells progressively repopulated the epithelium thereafter. Treated testes were indistinguishable from normal or control testes by 68 days post-occludin peptide treatment when assessed using histological analysis. In contrast, control rats receiving either no treatment, vehicle alone, or a 22-amino acid synthetic peptide of myotubularin displayed no changes in the testicular morphology at all time points. The occludin peptide-induced germ cell depletion was also accompanied by a disruption of the blood-testis barrier (BTB) when assessed by micropuncture techniques quantifying [(125)I]-BSA in rete testis fluid and seminiferous tubular fluid following i.v. administration of [(125)I]-BSA through the jugular vein. These results illustrate that the occludin peptide-induced disruption of the BTB may possibly affect the underlying adherens junctions, which causes premature release of germ cells from the epithelium and reversible infertility.

Quantitative T1rho magnetic resonance imaging of RIF-1 tumors in vivo: detection of early response to cyclophosphamide therapy

This study compares two potential magnetic resonance imaging (MRI) indices for noninvasive early detection of tumor response to chemotherapy: the spin-lattice relaxation in the rotating frame (T1rho) and the transverse relaxation time (T2). Measurements of these relaxation parameters were performed on a s.c. murine radiation-induced fibrosarcoma (RIF-1) model before and after cyclophosphamide treatment. The number of pixels exhibiting T1rho values longer than controls in viable regions of the tumor increased significantly as early as 18 h after drug administration and remained elevated up to 36 h after treatment (P < 0.005). Although a trend of increasing T2s relative to controls was noted in viable regions of the tumor 36 h after treatment, the changes were not statistically significant. Histological examination indicated a decrease in mitotic index that paralleled the changes in T1rho. We conclude that T1rho measurements may be useful for noninvasive monitoring of early response of tumors to chemotherapy.

Cholestatic presentation of chronic hepatitis C: a clinical and histological study with a review of the literature

Bile duct lesions are observed in the livers of chronic hepatitis C patients, but are inconstant and rarely associated with other features of chronic cholestasis and progressive bile duct injury or loss. We aimed to identify the clinical and biochemical characteristics of patients with chronic hepatitis C from our patient database presenting with prominent cholestatic features to determine if there is a correlation between histological evidence of bile duct injury and clinical or biochemical features observed in these patients. We retrospectively reviewed a hepatitis C database including 620 patients to identify those who presented with either alkaline phosphatase (AP) > or = 400 units/liter (normal 30-126 units/liter) or AP > or = 250 units/liter with pruritus. All patients were negative for anti-mitochondrial antibody (AMA). Appropriate exclusion criteria were used to exclude patients with other confounding factors. Histological features were compared with age- and sex-matched controls selected randomly from our hepatitis C database. Thirty-two patients were identified as meeting the above criteria. Twenty-four were excluded for the presence of other confounding factors and two for lack of liver biopsy. There were two men and four women. The mean age was 47 +/- 9 years. Four of the six presented with pruritus, which was severe in three. Liver biopsy showed evidence of moderate to severe fibrosis in all but one patient. Evidence of bile duct injury was seen in all patients and tended to be more severe than in controls. Bile ductular proliferation and mild ductopenia were the most commonly observed findings. A subset of patients with chronic hepatitis C may present with prominent cholestatic features. The majority of these patients present with pruritus and have histological evidence of bile duct injury, which may be progressive.

Relationship between sonographic and pathologic findings in epidermal inclusion cysts

PURPOSE

We evaluated the sonographic findings in epidermal inclusion cysts and related them to the pathologic findings.

METHODS

We retrospectively reviewed the sonograms and pathology specimens of 24 patients with pathologically proven epidermal inclusion cysts. We evaluated the lesions for shape, size, internal echogenicity, posterior sound enhancement, and presence of color Doppler signals. We classified the masses into 5 sonographic types according to their internal echogenicity. The relationship between the sonographic types and the pathologic findings was examined.

RESULTS

The masses were ovoid or spherical in 17 cases (71%), lobulated in 5 (21%), and tubular in 2 (8%). The longest diameter ranged from 1 to 6 cm (mean, 3.1 cm). Twenty-three cases (96%) were associated with posterior sound enhancement. Color Doppler signals were absent in 20 cases, but some vascularity was noted in 4 ruptured epidermal cysts, in areas of granulation tissue. The most common sonographic type was a hypoechoic lesion with scattered echogenic reflectors (10 cases). Sonographic findings were related to the lamellation of keratin debris and the granulation tissue secondary to rupture. Most cases with a lobulated configuration (4 of 5) or color Doppler signals (4 of 4) were ruptured cysts.

CONCLUSIONS

Epidermal inclusion cysts most often appeared sonographically as a hypoechoic mass containing variable echogenic foci without color Doppler signals. Ruptured epidermal cysts, however, may have lobulated contours and show color Doppler signals, mimicking a solid mass.

Suppression of tumorigenicity in human ovarian carcinoma cell line SKOV-3 by microcell-mediated transfer of chromosome 11

To determine the pathogenic role of chromosomes 11 and 17 in the carcinogenesis of human ovarian cancers, neo(R)-tagged chromosome 11 or 17 was transferred from cell lines A9H11 or A9H17, respectively, into the ovarian carcinoma cell line SKOV-3 using microcell-mediated chromosome transfer. The chromosome transfer was verified by polymerase chain reaction detection of the neo(R) gene, fluorescence in situ hybridization detection of an extra chromosome 11, and microsatellite polymorphism detection of an exogeneous chromosome 11. Five SKOV-3/A9H11 hybrids and five SKOV-3/A9H17 hybrid clones were generated. For the chromosome 11 transfer, complete suppression of tumorigenicity was observed in four clones, (11)9-8 and 11(H)7-2, 11(H)8-3, and 11(H)7-2, 100 days post implantation. For the chromosome 17 transfer, no complete suppression of tumorigenicity was observed. However, an increased latency period ranging from 25 to 49 days in contrast to 7 days for the SKOV-3 parental line, and a significant reduction in tumor size was observed. There was no correlation between the in vitro growth rate and the tumorigenicity or length of latency period. Our results demonstrate functionally that chromosome 11 may carry a tumor suppressor gene(s) while chromosome 17 may carry a tumor growth-inhibitor gene(s) for the ovarian carcinoma cell line, SKOV-3.

Enhanced naphthalene solubility in the presence of sodium dodecyl sulfate: effect of critical micelle concentration

Surfactants can increase the solubility of non-polar compounds, and have been applied in areas such as soil washing and treatment of non-aqueous phase liquids (NAPLs). This investigation explored the feasibility of removing vapor phase polycyclic aromatic hydrocarbon (PAH) from gases using an anionic surfactant. The solubility of vapor phase naphthalene was measured herein using gas chromatograph (GC) with a photon ionization detector (PID). The measurement results indicated that surfactant molecules were not favorable to micelle formation when temperatures increased from 25 degrees C to 50 degrees C. Regardless of whether solutions were quiescent or agitated, equilibrium naphthalene apparent solubility increased linearly with surfactant concentrations exceeding critical micelle concentration (CMC). The pH effects on naphthalene apparent solubility were small. Agitation increased naphthalene apparent solubility and lumped mass transfer coefficients. Furthermore, lumped mass transfer coefficients decreased with increasing surfactant concentration owing to increase in interfacial resistance and viscosity and decreased spherical micelle diffusion coefficients. Finally, the net absorption rate increased because the solubilization effects of micelles exceeded the reduction effects of mass transfer coefficient above the CMC. The enhanced naphthalene apparent solubility from the addition of surfactant can be expressed by an enrichment factor (EF). The EF value of naphthalene for the surfactant solution at 0.1 M with agitation at 270 rpm relative to quiescent water could reach 18.6. This work confirms that anionic surfactant can improve the removal efficiency of hydrophobic organic compound (HOC) from the gas phase.

Rabbit sex hormone-binding globulin: expression in the liver and testis during postnatal development and structural characterization by truncated proteins

Although sex hormone binding globulin (SHBG) is found in the blood plasma of adult humans and rabbits and the gene is expressed in their livers, it is not detected in the plasma of adult rodents nor is it expressed in adult rodent livers. Thus the rabbit represents a good model to study the metabolism and function of SHBG in the blood. We have used a cloned rabbit SHBG cDNA to detect mRNA expression in rabbits during the postnatal period, and to construct truncated SHBG proteins for structure/function analysis. The SHBG mRNA appeared in the testis as early as 3 days after birth. The level increased gradually in abundance throughout postnatal development, and attained a maximum at 12 weeks of age when the gonads were fully matured. In contrast, SHBG mRNA in the livers of male and female animals increased to a maximum by 4 weeks of age, and were maintained at this level until 12 weeks before subsiding to the initial levels. The increase and decrease in SHBG mRNA levels in the liver were accompanied by similar changes in serum SHBG. This suggests that SHBG in the blood circulation comes from the liver and this might also provide a source of SHBG for the male reproductive tract before formation of the blood-testis barrier. To elucidate the minimal sequence of rabbit SHBG responsible for steroid-binding, a panel of 13 truncated SHBG proteins was constructed, expressed in Escherichia coli, and biochemically purified for study. It was shown that the complete protein sequence of rabbit SHBG was important for maintaining a stable steroid-protein complex. Unlike human SHBG for which a truncated protein of the first 206 residues of the 373 amino acid protein can still bind steroid, removal of 43 or more residues from the C-terminus of rabbit SHBG completely abolished steroid-binding.

Transforming growth factor-beta3 perturbs the inter-Sertoli tight junction permeability barrier in vitro possibly mediated via its effects on occludin, zonula occludens-1, and claudin-11

Throughout spermatogenesis, inter-Sertoli tight junctions (TJs) that create the blood-testis barrier in the rat must be disassembled and reassembled to permit the timely passage of preleptotene spermatocytes from the basal to the adluminal compartment of the seminiferous epithelium. However, the mechanism(s) and the participating molecules that regulate this event are largely unknown. Although there is no in vitro model to study the event and regulation of inter-Sertoli TJ disassembly, primary cultures of Sertoli cells in vitro can be used to study junction assembly. In this study, we sought to investigate whether cytokines are involved in the inter-Sertoli TJ assembly in vitro. Sertoli cells isolated from 20-day-old rats were cultured at a density of 0.5-1.2 x 10(6) cells/cm(2) on Matrigel-coated dishes or bicameral units for 8-9 days. The steady-state messenger RNA levels of basic fibroblast growth factor (bFGF), transforming growth factor (TGF)-beta2, and TGF-beta3 at different time points were assessed by semiquantitative RT-PCR. In selected experiments, the assembly of inter-Sertoli TJs was monitored by transepithelial electrical resistance measurement. It was found that there was no change in the expression of basic fibroblast growth factor throughout the entire culture period. However, there was a 2-fold reduction in the expression of TGF-beta2 and TGF-beta3 at the time inter-Sertoli TJs were being assembled. On days 5-8, after the inter-Sertoli TJs had been assembled, the Sertoli cell steady-state messenger RNA levels of TGF-beta2 and TGF-beta3 increased by as much as 3- and 6-fold, respectively, when compared with Sertoli cells on days 1-3 when TJs were being assembled. Also, it was found that recombinant TGF-beta3 added to Sertoli cells cultured in vitro at 1.2 x 10(6) cells/cm(2) on Matrigel-coated bicameral units perturbed the inter-Sertoli TJ permeability barrier dose-dependently. Moreover, the presence of TGF-beta3 also inhibited the transient and/or basal expression of several TJ-associated proteins, which include occludin, zonula occludens-1, and claudin-11 when inter-Sertoli TJs were being assembled in vitro. These results suggest that TGF-beta plays a crucial role in regulating the complicated biochemical events of junction assembly in the testis.

Educating nurses to care for the dying in Hong Kong: a problem-based learning approach

Caring for dying patients is an essential and major aspect of nursing care. However, previous studies have revealed that nurses felt uncomfortable and inadequate in dealing with the dying patients and their families. This study reports the effectiveness of a problem-based learning approach in death education among a group of registered nurses in Hong Kong. Three problems, with three segmented scenarios related to cancer nursing, were used. Students went through the problem-based learning process and documented their learning throughout the course in journals. A total of 72 sets of journals were collected and analyzed. The strategies of within case and cross-case analysis were employed. The within case analysis explored the learning development of students for each problem. The cross-case analysis compared and contrasted findings of the within case analysis. Three themes have been derived from the findings. They were: nurses acknowledging their emotions in facing death and dying, a need for the nurses to be better equipped in communication and counseling, and a holistic and family-centered approach to care. This study provides evidence showing that problem-based learning is an effective strategy to enhance nurses' self-awareness of death and dying issues, and to stimulate nurses to formulate a plan that addresses the physical, psychological, and social aspects of care. Findings also reveal that nurses need to take into account the particular reactions of death and dying in the Chinese culture when planning care.

Doppler ultrasound imaging detects changes in tumor perfusion during antivascular therapy associated with vascular anatomic alterations

Noninvasive monitoring of antiangiogenic therapy was performed by serial power Doppler ultrasound imaging of murine tumors treated with recombinant interleukin 12, the results of which were correlated with assessments of tumor vascularity by microscopy. Growth of established K1735 tumors, but not of IFN-gamma-unresponsive K1735.N23 variants, was suppressed by treatment. Serial Doppler imaging of K1735 tumor vascularity during treatment revealed a progressive change from a diffuse perfusion pattern to a more punctate distribution. Quantitative analysis of the images revealed that color-weighted fractional average, representing overall tumor perfusion, consistently decreased in these tumors, primarily because of a decrease in fractional tumor cross-sectional area carrying blood flow. In contrast, these parameters increased in nonresponsive tumors during treatment. Confocal microscopy of thick tumor sections revealed a reduction in the density and arborization of vessels labeled in vivo by fluorochrome-conjugated lectin with effective treatment. Immunohistological examination of thin tumor sections confirmed the preferential loss of small vessels with successful therapy. Similar changes in tumor vascular anatomy and perfusion were also observed during recombinant interleukin 12 treatment of two other responsive murine tumor types. These results indicate that power Doppler ultrasound is a sensitive, noninvasive method for reporting functional consequences of therapy-induced vascular anatomical changes that can be used to serially monitor tumor perfusion and efficacy of antivascular therapy in clinical trials.

Hepatitis B infection in patients with acute liver failure in the United States

Occult hepatitis B virus (HBV) infection has been reported in 30% to 50% of patients with acute liver failure (ALF) in small case series. The aim of this study was to determine the prevalence of occult HBV infection in a large series of ALF patients in the United States and the prevalence of precore and core promoter variants in patients with ALF caused by hepatitis B. Sera from patients in the US ALF study and liver, when available, were tested using nested polymerase chain reaction (PCR) with primers in the HBV S and precore regions. PCR-positive samples were sequenced. Sera and/or liver from 139 patients (39 males, 100 females; mean age, 42 years) enrolled between January 1998 and December 1999 were studied. Twelve patients were diagnosed with hepatitis B, 1 with hepatitis B+C+D coinfection, and 22 had indeterminate etiology. HBV DNA was detected in the sera of 9 (6%) patients; all 9 had ALF caused by hepatitis B. HBV genotypes A, B, C, and D were present in 4, 3, 1, and 1 patients, respectively. Seven of these 9 patients had precore and/or core promoter variants. Liver from 19 patients were examined. HBV DNA was detected in the liver of 3 patients with ALF caused by hepatitis B, but in none of the remaining 16 patients with non-B ALF. Contrary to earlier reports, occult HBV infection was not present in this large series of ALF patients in the United States. HBV precore and/or core promoter variants were common among US patients with ALF caused by hepatitis B.

Observation of polarization in bottomonium production at square root of s = 38.8 GeV

We present a measurement of the polarization observed for bottomonium states produced in p-Cu collisions at square root of s = 38.8 GeV. The angular distribution of the decay dimuons of the Upsilon(1S) state shows no polarization at small values of the fractional longitudinal momentum x(F) and transverse momentum p(T) but significant positive transverse production polarization for either p(T)>1.8 GeV/c or for x(F)>0.35. The Upsilon(2S+3S) (unresolved) states show a large transverse production polarization at all values of x(F) and p(T) measured. These observations challenge NRQCD calculations of the polarization expected in the hadronic production of bottomonium states.