Measurement of the semileptonic charge asymmetry using B(s)(0) → D(s)μX decays

We present a measurement of the time-integrated flavor-specific semileptonic charge asymmetry in the decays of B(s)(0) mesons that have undergone flavor mixing, a(sl)(s), using B(s)(0)(B(s)(0)) → D(s)(-/+) μ(±) X decays, with D(s)(-/+) → [symbol: see text]π(-/+) and [symbol: see text]→ K(+) K(-), using 10.4 fb(-1) of proton-antiproton collisions collected by the D0 detector during Run II at the Fermilab Tevatron Collider. A fit to the difference between the time-integrated D(s)(-) and D(s)(+) mass distributions of the B(s)(0) and B(s)(0) candidates yields the flavor-specific asymmetry a(sl)(s) = [-1.12 ± 0.74(stat) ± 0.17(syst)]%, which is the most precise measurement and in agreement with the standard model prediction.

Search for the standard model Higgs boson in associated WH production in 9.7 fb(-1) of pp collisions with the D0 detector

We present a search for the standard model Higgs boson in final states with a charged lepton (electron or muon), missing transverse energy, and two or three jets, at least one of which is identified as a b-quark jet. The search is primarily sensitive to WH→ℓνbb production and uses data corresponding to 9.7 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron pp Collider at √s = 1.96 TeV. We observe agreement between the data and the expected background. For a Higgs boson mass of 125 GeV, we set a 95% C.L. upper limit on the production of a standard model Higgs boson of 5.2 × σ(SM), where σ(SM) is the standard model Higgs boson production cross section, while the expected limit is 4.7 × σ(SM).

Combined search for the standard model Higgs boson decaying to bb using the D0 run II data set

We present the results of the combination of searches for the standard model Higgs boson produced in association with a W or Z boson and decaying into bb using the data sample collected with the D0 detector in pp collisions at √s = 1.96 TeV at the Fermilab Tevatron Collider. We derive 95% C.L. upper limits on the Higgs boson cross section relative to the standard model prediction in the mass range 100 GeV ≤ M(H) ≤ 150 GeV, and we exclude Higgs bosons with masses smaller than 102 GeV at the 95% C.L. In the mass range 120 GeV ≤ M(H) ≤145 GeV, the data exhibit an excess above the background prediction with a global significance of 1.5 standard deviations, consistent with the expectation in the presence of a standard model Higgs boson.

Search for the standard model Higgs boson in ZH→ℓ(+)ℓ(-)bb production with the D0 detector in 9.7 fb(-1) of pp collisions at √s = 1.96 TeV

We present a search for the standard model (SM) Higgs boson produced in association with a Z boson in 9.7 fb(-1) of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider at √s = 1.96 TeV. Selected events contain one reconstructed Z→e(+)e(-) or Z→μ(+)μ(-) candidate and at least two jets, including at least one jet identified as likely to contain a b quark. To validate the search procedure, we also measure the cross section for ZZ production in the same final state. It is found to be consistent with its SM prediction. We set upper limits on the ZH production cross section times branching ratio for H→bb at the 95% C.L. for Higgs boson masses 90 ≤ M(H) ≤ 150 GeV. The observed (expected) limit for M(H) = 125 GeV is 7.1 (5.1) times the SM cross section.

Evidence for a particle produced in association with weak bosons and decaying to a bottom-antibottom quark pair in higgs boson searches at the tevatron

We combine searches by the CDF and D0 Collaborations for the associated production of a Higgs boson with a W or Z boson and subsequent decay of the Higgs boson to a bottom-antibottom quark pair. The data, originating from Fermilab Tevatron pp collisions at √s = 1.96 TeV, correspond to integrated luminosities of up to 9.7 fb(-1). The searches are conducted for a Higgs boson with mass in the range 100-150 GeV/c(2). We observe an excess of events in the data compared with the background predictions, which is most significant in the mass range between 120 and 135 GeV/c(2). The largest local significance is 3.3 standard deviations, corresponding to a global significance of 3.1 standard deviations. We interpret this as evidence for the presence of a new particle consistent with the standard model Higgs boson, which is produced in association with a weak vector boson and decays to a bottom-antibottom quark pair.

Middle cranial fossa sphenoidal region dural arteriovenous fistulas: anatomic and treatment considerations

BACKGROUND AND PURPOSE

DAVFs rarely involve the sphenoid wings and middle cranial fossa. We characterize the angiographic findings, treatment, and outcome of DAVFs within the sphenoid wings.

MATERIALS AND METHODS

We reviewed the clinical and radiologic data of 11 patients with DAVFs within the sphenoid wing that were treated with an endovascular or with a combined endovascular and surgical approach.

RESULTS

Nine patients presented with ocular symptoms and 1 patient had a temporal parenchymal hematoma. Angiograms showed that 5 DAVFs were located on the lesser wing of sphenoid bone, whereas the other 6 were on the greater wing of the sphenoid bone. Multiple branches of the ICA and ECA supplied the lesions in 7 patients. Four patients had cortical venous reflux and 7 patients had varices. Eight patients were treated with transarterial embolization using liquid embolic agents, while 3 patients were treated with transvenous embolization with coils or in combination with Onyx. Surgical disconnection of the cortical veins was performed in 2 patients with incompletely occluded DAVFs. Anatomic cure was achieved in all patients. Eight patients had angiographic and clinical follow-up and none had recurrence of their lesions.

CONCLUSIONS

DAVFs may occur within the dura of the sphenoid wings and may often have a presentation similar to cavernous sinus DAVFs, but because of potential associations with the cerebral venous system, may pose a risk for intracranial hemorrhage. Curative embolization through a transarterial or transvenous approach is the primary therapeutic strategy for these lesions. In incompletely embolized patients, exclusion of any refluxing cortical veins is necessary.

Search for violation of Lorentz invariance in top quark pair production and decay

Using data collected with the D0 detector at the Fermilab Tevatron Collider, corresponding to 5.3 fb(-1) of integrated luminosity, we search for violation of Lorentz invariance by examining the tt[over ¯] production cross section in lepton+jets final states. We quantify this violation using the standard-model extension framework, which predicts a dependence of the tt[over ¯] production cross section on sidereal time as the orientation of the detector changes with the rotation of the Earth. Within this framework, we measure components of the matrices (c(Q))(μν33) and (c(U))(μν33) containing coefficients used to parametrize violation of Lorentz invariance in the top quark sector. Within uncertainties, these coefficients are found to be consistent with zero.

WE-C-217BCD-06: In Vivo Targeting and Imaging of Tumor Vasculature with Radiolabeled, Antibody-Conjugated Nano-Graphene

PURPOSE

Our goal was to explore nano-graphene for in vivo tumor targeting and quantitatively evaluate the pharmacokinetics and tumor targeting efficacy through PET imaging, using ^{6 4} Cu and ⁶⁶ Ga as the radiolabel.

METHODS

Nano-graphene oxide (GO) sheets, with amino group- terminated PEG chains (10 kDa) covalently attached, were conjugated to NOTA (l,4,7-triazacyclononane-l,4,7-triacetic acid, a suitable chelator for ^{6 4} Cu and ^{6 6} Ga) and TRC105 (a mAb that binds to CD 105, overexpressed on neovasculature). FACS analyses, size measurements, and serum stability studies were performed to characterize the GO conjugates before in vivo investigation (PET, bio distribution, blocking studies, etc.) in 4T1 murine breast tumor-bearing mice. Findings from imaging studies were then validated by histology.

RESULTS

TRC105-conjugated GO, 20-30 nm in diameter, was specific for CD105 with little non-specific binding. Both ⁶⁴ Cu- and ⁶⁶ Ga- labled GO conjugates had excellent stability in mouse serum. Clearance of the GO conjugates in mice was via the hepatobiliary pathway. ^v Cu/^{6 6} Ga-NOTA-GO-TRC105 accumulated rapidly in the 4T1 tumor and tumor uptake remained stable over time (3.8±0.4, 4.5±0.4, 5.8±0.3, and 4.5±0.4 %ID/g at 0.5, 3, 7, and 24 h p.i. for⁶⁶ Ga; 5.8±0.6, 5.3±0.6, 4.0±0.4, and3.4±0.1 %ID/g at 0.5, 3,24, and 48 h p.i. for ^{6 4} Cu; n = 4). Blocking studies confirmed CD105 specificity of ^{6 4} Cu/^{6 6} Ga-NOTA- GOTRC105, which was corroborated by bio distribution studies. Furthermore, microscopy examination of GO in light view mode and immunofluorescence staining revealed that targeting of NOTA-GO-TRC105 is tumor vasculature CD105 specific with little extravasation.

CONCLUSIONS

For the first time, we demonstrated that GO can be specifically directed to the tumor neovasculature in vivo through targeting of CD105, a marker of tumor angiogenesis. The versatile chemistry of graphene-based nanomaterials makes them suitable nanoplatforms for future biomedical research, such as cancer theranostics.

Response to the first wave of pandemic (H1N1) 2009: experiences and lessons learnt from China

More than 2 years after the start of pandemic H1N1, the world is fortunate that the impact, to date, has been moderate. An evaluation of the global response to the first wave of the pandemic is still ongoing. The results of an analysis of the situation in China is presented in order to gain a better understanding of the episode; to summarize the experiences in preparedness, control and mitigation of the pandemic; and to identify issues for further consideration and investigation in order to improve the response to possible next waves of the pandemic. China's response shows how a huge challenge can be transformed into an opportunity, and may offer some valuable lessons to face another wave of the pandemic or other potential public health emergencies in the future, not only for China but also for the international community.

Study of T cell subsets and IL-7 protein expression in HIV-1-infected patients after 7 years HAART

Objective

To study the changes in T cell subsets and IL-7 in HIV-1-infected patients after seven years of highly active antiretroviral therapy (HAART).

Methods

Seventy-five individuals were included in this study (25 with effective HAART, 18 with ineffective HAART, 17 untreated HIV+ patients, and 15 volunteers in the HIV negative control group). The counts of CD4⁺, CD8⁺, CD8/CD38⁺, and CD8/HLADR⁺ T cells as well as the IL-7 protein expression was measured at 5 time points during a period of seven years in patients starting HAART (baseline) and in the HIV negative control group. The expression of CD127 on CD3⁺ T cells was measured by flow cytometry at a single time point (after 7 years) in patients with HAART and was compared with untreated HIV+ patients and the HIV negative control group.

Results

At baseline CD4⁺ T cell counts of HIV-1-infected patients were lower than that in the control group (p < 0.01), whereas the CD8⁺, CD8/HLADR⁺ and CD8/CD38⁺ T cell counts were higher than those in the control group (p <0.01). After seven years of effective HAART, the CD4⁺ T cell counts had increased and the CD8⁺ T cell count had decreased, although not to the normal levels (p < 0.05). Both the CD8/HLADR⁺ and CD8/CD38⁺ T cell counts had gradually approached those of the control group (p > 0.05). In the ineffective HAART group, the CD8/CD38⁺ T cell count had not decreased significantly, and CD8/HLADR⁺ T cell count gradually decreased. Before treatment, IL-7 serum levels of patients were significantly higher than that in the control group (p < 0.01). After seven years of effective HAART, IL-7 levels had gradually decreased, but were still higher than in the control group (p < 0.01). The CD127 expression on CD3⁺ CD8⁺ T cells in effective HAART patients was higher than in untreated HIV+ patients (p < 0.05), but was lower than that in the control group (p < 0.05). CD127 expression on CD3⁺ CD4+ T cells was not significantly different among the control group, untreated HIV+ patients and effective HAART group.

Conclusion

After seven years of effective HAART, the quantity and capacity of T cell subsets and IL-7 in HIV-1-infected patients had been partially restored, and the abnormal immune activation has significantly diminished.

Measurement of the W boson mass with the D0 detector

We present a measurement of the W boson mass using data corresponding to 4.3  fb(-1) of integrated luminosity collected with the D0 detector during Run II at the Fermilab Tevatron pp collider. With a sample of 1,677,394 W → eν candidate events, we measure M(W) = 80.367 ± 0.026  GeV. This result is combined with an earlier D0 result determined using an independent Run II data sample, corresponding to 1  fb(-1) of integrated luminosity, to yield M(W) = 80.375 ± 0.023  GeV.