First Search for Dark-Trident Processes Using the MicroBooNE Detector.

We present a first search for dark-trident scattering in a neutrino beam using a dataset corresponding to 7.2×10^{20} protons on target taken with the MicroBooNE detector at Fermilab. Proton interactions in the neutrino target at the main injector produce π^{0} and η mesons, which could decay into dark-matter (DM) particles mediated via a dark photon A^{'}. A convolutional neural network is trained to identify interactions of the DM particles in the liquid-argon time projection chamber (LArTPC) exploiting its imagelike reconstruction capability. In the absence of a DM signal, we provide limits at the 90% confidence level on the squared kinematic mixing parameter ϵ^{2} as a function of the dark-photon mass in the range 10≤M_{A^{'}}≤400 MeV. The limits cover previously unconstrained parameter space for the production of fermion or scalar DM particles χ for two benchmark models with mass ratios M_{χ}/M_{A^{'}}=0.6 and 2 and for dark fine-structure constants 0.1≤α_{D}≤1.

Search for Heavy Neutral Leptons in Electron-Positron and Neutral-Pion Final States with the MicroBooNE Detector.

We present the first search for heavy neutral leptons (HNLs) decaying into νe^{+}e^{-} or νπ^{0} final states in a liquid-argon time projection chamber using data collected with the MicroBooNE detector. The data were recorded synchronously with the NuMI neutrino beam from Fermilab's main injector corresponding to a total exposure of 7.01×10^{20} protons on target. We set upper limits at the 90% confidence level on the mixing parameter |U_{µ4}|^{2} in the mass ranges 10≤m_{HNL}≤150 MeV for the νe^{+}e^{-} channel and 150≤m_{HNL}≤245 MeV for the νπ^{0} channel, assuming |U_{e4}|^{2}=|U_{τ4}|^{2}=0. These limits represent the most stringent constraints in the mass range 35

Encapsulated droplet interface bilayers as a platform for high-throughput membrane studies.

Whilst it is highly desirable to produce artificial lipid bilayer arrays allowing for systematic high-content screening of membrane conditions, it remains a challenge due to the combined requirements of scaled membrane production, simple measurement access, and independent control over individual bilayer experimental conditions. Here, droplet bilayers encapsulated within a hydrogel shell are output individually into multi-well plates for simple, arrayed quantitative measurements. The afforded experimental throughput is used to conduct a 2D concentration screen characterising the synergistic pore-forming peptides Magainin2 and PGLa. Maximal enhanced activity is revealed at equimolar peptide concentrations via a membrane dye leakage assay, a finding consistent with models proposed from NMR data. The versatility of the platform is demonstrated by performing in situ electrophysiology, revealing low conductance pore activity (∼15 to 20 pA with 4.5 pA sub-states). In conclusion, this array platform addresses the aforementioned challenges and provides new and flexible opportunities for high-throughput membrane studies. Furthermore, the ability to engineer droplet networks within each construct paves the way for "lab-in-a-capsule" approaches accommodating multiple assays per construct and allowing for communicative reaction pathways.

Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam.

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

Associations between the chemokine biomarker CCL2 and knee osteoarthritis outcomes: the Johnston County Osteoarthritis Project.

OBJECTIVE: Our study analyzes the association between chemokine-ligand-2 (CCL2) serum concentrations at baseline and knee radiographic osteoarthritis (OA) (knee-rOA), knee-rOA progression, individual radiographic features and knee symptomatic OA at 5-year follow-up. DESIGN: OA outcomes were analyzed in a community-based cohort including a baseline enrollment and a 5-year follow-up. Baseline CCL2 serum concentrations were assessed by multiplex assay and associated with presence or progression of individual radiographic features at 5-year follow-up. Separate multiple logistic regression models were used to examine adjusted associations between baseline CCL2 and each of the knee OA variables at follow-up. CCL2 at baseline was modeled as an explanatory variable, whereas each of the knee OA variables at follow-up served as the response variables. Models were adjusted for age, BMI, race, and sex. Trend tests were conducted to assess any linear effect on outcomes across CCL2 tertiles. RESULTS: Participants (n = 168) had a median age of 57-years and median BMI of 29 kg/m2. About 63% of all participants were women, and 58% Caucasian (42% African American). In adjusted logistic models, continuous log-CCL2 was significantly associated with knee-rOA. For each unit increase in log CCL2, the odds of having knee-rOA at follow-up was increased by 72%. CCL2 tertiles showed significant linear associations with presence and progression of knee-rOA and medial joint space narrowing (JSN), but not with presence or progression of osteophytes, bone sclerosis, knee symptoms, or symptomatic knee-rOA. CONCLUSIONS: Serum CCL2 may help to elucidate some mechanisms of joint destruction and identify individuals with higher odds of structural knee changes.

In situ fabricated 3D micro-lenses for photonic integrated circuits.

Aspheric astigmatic polymer micro-lenses were fabricated directly onto photonic integrated circuits using two-photon lithography. We observed a 12.6 dB improvement in the free space coupling efficiency between integrated ridge laser pairs with micro-lenses to those without.

Photonic integration platform with pump free microfluidics.

Chip based particle sensing using 3D capillary fill microfluidics integrated with monolithically integrated lasers and photodetectors is used to demonstrate the feasibility of true chip scale photonic measurements of fluids. The approach is scalable and manufactured using industry standard compound semiconductor fabrication tools. The need for fluid speed regulation via external pumps is removed by measuring local particle velocity at the point of interrogation and particle position within the fluid flow is derived from multiple time resolved forward scattered light signals. Particle size discrimination of 10 and 15 µm polystyrene microbeads is used as an example.

Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target.

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7(16.3)×1020 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7×1020 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin2θ13 and the impact of priors on the δCP measurement. Both analyses prefer the normal mass ordering and upper octant of sin2θ23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin2θ13 from reactors, sin2θ23=0.561-0.032+0.021 using Feldman-Cousins corrected intervals, and Δm322=2.494-0.058+0.041×10-3eV2 using constant Δχ2 intervals. The CP-violating phase is constrained to δCP=-1.97-0.70+0.97 using Feldman-Cousins corrected intervals, and δCP=0,π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2σ credible level using a flat prior in δCP, and just below 2σ using a flat prior in sinδCP. When the external constraint on sin2θ13 is removed, sin2θ13=28.0-6.5+2.8×10-3, in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

An iron-regulated ferric reductase associated with the absorption of dietary iron.

The ability of intestinal mucosa to absorb dietary ferric iron is attributed to the presence of a brush-border membrane reductase activity that displays adaptive responses to iron status. We have isolated a complementary DNA, Dcytb (for duodenal cytochrome b), which encoded a putative plasma membrane di-heme protein in mouse duodenal mucosa. Dcytb shared between 45 and 50% similarity to the cytochrome b561 family of plasma membrane reductases, was highly expressed in the brush-border membrane of duodenal enterocytes, and induced ferric reductase activity when expressed in Xenopus oocytes and cultured cells. Duodenal expression levels of Dcytb messenger RNA and protein were regulated by changes in physiological modulators of iron absorption. Thus, Dcytb provides an important element in the iron absorption pathway.

Systemic cytokines are elevated in a subset of patients with irritable bowel syndrome but largely unrelated to symptom characteristics.

BACKGROUND: Serum levels of pro-inflammatory cytokines tend to be increased in irritable bowel syndrome (IBS) patients, or subgroups thereof. Still, the link between cytokine levels and IBS symptoms is unclear. We aim to determine systemic cytokine levels in IBS patients and healthy subjects (HS), confirm the presence of a subset of patients with an increased immune activity and to establish if cytokines are linked to IBS symptoms and pathophysiological factors. METHODS: Serum levels of interleukin (IL)-1ß, IL-6, IL-8, tumor necrosis factor (TNF), and IL-10 were measured. All subjects reported IBS symptoms using validated questionnaires and underwent colonic sensorimotor testing. Multivariate supervised orthogonal partial least squares-discriminant analysis (OPLS-DA) and unsupervised principal component analysis (PCA) and hierarchical cluster analysis (HCA) were implemented. KEY RESULTS: Irritable bowel syndrome patients (n = 246) had higher serum levels of IL-1ß, IL-6, IL-8, TNF, and IL-10 compared to HS (n = 21); however, serum cytokine profiles could not discriminate patients from HS. Moreover, cytokine levels were not correlated with symptoms among patients. Supervised OPLS-DA identified 104 patients (40% of patients) and unsupervised HCA analysis identified 49 patients (20%) with an increased immune activity indicated by elevated levels of serum cytokines compared to HS and the other patients. However, irrespective of how patients with increased immune activity were identified they were symptomatically similar to patients with no indication of increased immune activity. CONCLUSIONS & INFERENCES: Serum cytokines are elevated in IBS patients compared to HS. Immune activation characterizes a subset of patients, but modest associations between cytokine profile and symptoms suggest immune activity does not directly influence symptoms in IBS.

An evaluation of the effects of Tai Chi Chuan and Chi Kung training in patients with symptomatic heart failure: a randomised controlled pilot study.

OBJECTIVE: To study the effect of Tai Chi on exercise tolerance in patients with moderate heart failure. DESIGN: Randomised parallel group study balanced for baseline variables. SETTING: Cardiology Department, Royal Hallamshire Hospital. PATIENTS AND METHODS: 52 patients (42 men, mean age (68.9 years), range (46-90 years), and 10 women, mean age (70.0 years), range (58-82)) with chronic heart failure (New York Heart Association symptom class II-III) were studied. Patients were randomised to Tai Chi Chuan twice a week for 16 weeks or to standard medical care without exercise rehabilitation. MAIN OUTCOME MEASURES: The primary outcome measure was the change in the distance walked in the shuttle walk test. Secondary outcome measures were changes in symptom scores and quality of life indices. RESULTS: Objective measures of exercise tolerance did not improve significantly with Tai Chi, but patients having Tai Chi exercise had an improvement in symptom scores of heart failure measured by the Minnesota Living with Heart Failure Questionnaire (comparison of deltas, -2.4 control vs -14.9; p = 0.01), and depression scores measured by the SCL-90-R questionnaire (-2.9 vs -6.8; p = 0.12) compared with those patients in the control group. CONCLUSION: In patients with chronic heart failure, 16 weeks of Tai Chi training was safe, with no adverse exercise related problems. It was enjoyed by all taking part and led to significant improvements in symptoms and quality of life.

A new droplet-forming fluidic junction for the generation of highly compartmentalised capsules.

A new oscillatory microfluidic junction is described, which enables the consistent formation of highly uniform and complex double emulsions, and is demonstrated for the encapsulation of four different reagents within the inner droplets (called cores) of the double emulsion droplets. Once the double emulsion droplets had attained a spherical form, the cores assumed specific 3D arrangements, the orchestration of which appeared to depend upon the specific emulsion morphology. Such double emulsion droplets were used as templates to produce highly compartmentalised microcapsules and multisomes. Based on these construct models, we numerically demonstrated a model chemical reaction sequence between and within the liquid cores. This work could provide a platform to perform space/time-dependent applications, such as programmed experiments, synthesis, and delivery systems.

Development of strategies for the use of anti-growth factor treatments.

Aberrant signalling through the epidermal growth factor receptor (EGFR) is associated with increased cancer cell proliferation, reduced apoptosis, invasion and angiogenesis. Over-expression of the EGFR is seen in a variety of tumours and is a rational target for antitumour strategies. Among the classes of agent targeting the EGFR are small-molecule inhibitors, which include gefitinib (IRESSA), which acts by preventing EGFR phosphorylation and downstream signal transduction. De novo and acquired resistance, however, have been reported to gefitinib and here we describe evidence which indicates that the type II receptor tyrosine kinases (RTKs) insulin-like growth factor-I receptor (IGF-IR) and/or insulin receptor (InsR) play important roles in the mediation of responses to gefitinib in the de novo- and acquired-resistance phenotypes in several cancer types. Moreover, combination strategies that additionally target the IGF-IR/InsR can enhance the antitumour effects of gefitinib.

Growth factor signalling and resistance to selective oestrogen receptor modulators and pure anti-oestrogens: the use of anti-growth factor therapies to treat or delay endocrine resistance in breast cancer.

De novo insensitivity and acquired resistance to the selective oestrogen receptor modulator tamoxifen and the pure anti-oestrogen fulvestrant (faslodex) severely limit their effectiveness in breast cancer patients. This is a major clinical problem, since each year upward of 1 million women are dispensed anti-oestrogenic drugs. In order to investigate the phenomenon of anti-oestrogen resistance and to rapidly screen drugs that target the resistance mechanism(s), we have previously established several in vitro breast cancer models that have acquired resistance to anti-hormones. Such cells commonly develop an ability to proliferate after approximately 3 months of exposure to 4-hydroxytamoxifen or fulvestrant, despite an initial endocrine-responsive (i.e. growth-suppressive) phase. The current paper explores the role that growth factor signalling plays in the transition of oestrogen receptor-positive endocrine-responsive breast cancer cells to anti-oestrogen resistance or insensitivity and how we might, in the future, most effectively use anti-growth factor therapies to treat or delay endocrine-resistant states.

Large vesicle contamination in small, unilamellar vesicles.

Small, unilamellar phospholipid vesicles have been prepared using a new, high-powdered cup sonifier that avoids contact of the sample with a titanium probe. These vesicles have been characterized by gel filtration chromatography both before and after fractionation by high-speed centrifugation. Plots of the turbidity of centrifuged vesicles between 300 and 650 nm against the reciprocal fourth power of the scattering wavelength were linear with zero intercepts (extrapolated to infinite wavelength). In the presence of minute quantities of large, multilamellar vesicles, these plots remained linear but had intercepts quantitatively proportional to the amount of contaminating large vesicles. Since this measurement requires only a standard spectrophotometer and very small quantities of lipid, this method is suggested as a useful assay for determining contamination of small vesicle preparations by large vesicles. Two applications of this method as well as a practical limitation are discussed.

A model for the effect of lipid oxidation on diphenylhexatriene fluorescence in phospholipid vesicles.

We have determined by means of a standard spectrophotometric assay that lipid oxidation occurred at a significant rate in large, multilamellar vesicles containing egg phosphatidylcholine under normal experimental conditions. We have also observed that the fluorescence intensity of the vesicle-associated probe, 1,6-diphenyl-1,3,5-hexatriene, decreased with time in vesicles containing such oxidizing lipids. The spectrophotometric data utilized to monitor lipid oxidation were found to fit an apparent first-order kinetic model. The loss of diphenylhexatriene fluorescence intensity in oxidizing liposomes was analyzed in terms of a first-order event superimposed (and thus presumably dependent) upon the ongoing formation of oxidized lipid. These and other data were used to conclude that the oxidation-induced loss of diphenylhexatriene fluorescence intensity was due to chemical modification of the fluorophore rather than to excited-state quenching or ground-state complex formation. Finally, the loss of fluorescence intensity in oxidizable membranes was found to alter drastically the 'microviscosity' parameter as derived from diphenylhexatriene fluorescence anisotropy and relative intensity measurements.

Insulin-like growth factor-I receptor signaling in tamoxifen-resistant breast cancer: a supporting role to the epidermal growth factor receptor.

There is considerable evidence that the epidermal growth factor receptor (EGFR) and IGF-I receptor (IGF-IR) cross-talk in breast cancer cells. In the present study, we have examined whether EGFR/IGF-IR cross-talk exists in EGFR-positive tamoxifen-resistant variants of MCF-7 (Tam-R) and T47D (T47D-R) breast cancer cell lines. Although Tam-R cells expressed reduced IGF-IR protein levels compared with their wild-type MCF-7 counterparts, phosphorylated IGF-IR protein levels were equivalent in the two cell lines under basal growth conditions, possibly as a consequence of increased IGF-II expression in Tam-R cells. IGF-II activated both IGF-IR and EGFR in Tam-R cells, whereas only activation of IGF-IR was observed in wild-type cells. In contrast, epidermal growth factor rapidly induced EGFR, but not IGF-IR, phosphorylation in Tam-R cells. IGF-II promoted direct association of c-SRC with IGF-IR, phosphorylated c-SRC, and increased EGFR phosphorylation at tyrosine 845, a c-SRC-dependent phosphorylation site. Pretreatment with either AG1024 (IGF-IR-specific inhibitor) or an IGF-II neutralizing antibody inhibited basal IGF-IR, c-SRC, and EGFR phosphorylation, and AG1024 significantly reduced Tam-R basal cell growth. The c-SRC inhibitor SU6656 also inhibited growth, reduced basal and IGF-II-induced c-SRC and EGFR phosphorylation, and blocked EGFR activation by TGFalpha. Similarly, in T47D-R cells, AG1024 and SU6656 inhibited basal and IGF-II-induced phosphorylation of c-SRC and EGFR, and SU6656 reduced TGFalpha-induced EGFR activity. These results suggest the existence of a unidirectional IGF-IR/EGFR cross-talk mechanism whereby IGF-II, acting through the IGF-IR, regulates basal and ligand-activated EGFR signaling and cell proliferation in a c-SRC-dependent manner in Tam-R cells. This cross-talk between IGF-IR and EGFR is not unique to Tam-R cells because this mechanism is also active in a tamoxifen-resistant T47D-R cell line.

Growth factor signalling networks in breast cancer and resistance to endocrine agents: new therapeutic strategies.

Recent evidence demonstrates that growth factor networks are highly interactive with the estrogen receptor (ER) in the control of breast cancer growth and development. As such, tumor responses to anti-hormones are likely to be a composite of the ER and growth factor inhibitory activity of these agents, with alterations/aberrations in growth factor signalling providing a mechanism for the development of anti-hormone resistance. In this light, the current article focuses on illustrating the relationship between growth factor signalling and anti-hormone failure in our in-house tumor models of breast cancer and describes how we are now beginning to successfully target their actions to improve the effects of anti-hormonal drugs and to block aggressive disease progression.

Modulation of epidermal growth factor receptor in endocrine-resistant, oestrogen receptor-positive breast cancer.

There is an increasing body of evidence demonstrating that growth factor networks are highly interactive with oestrogen receptor (ER) signalling in the control of breast cancer growth. As such, tumour responses to anti- hormones are likely to be a composite of the ER and growth factor inhibitory activity of these agents. The current article examines the modulation of growth factor networks during endocrine response, and presents in vitro and clinical evidence that epidermal growth factor receptor signalling, maintained in either an ER-dependent or -independent manner, is critical to anti- hormonal-resistant breast cancer cell growth. The considerable potential of the epidermal growth factor receptor-selective tyrosine kinase inhibitor, ZD 1839 (Iressa; AstraZeneca) to efficiently treat, and perhaps even prevent, endocrine-resistant breast cancer is highlighted.

Insulin-like growth factor-I receptor signalling and acquired resistance to gefitinib (ZD1839; Iressa) in human breast and prostate cancer cells.

De novo and acquired resistance to the anti-tumour drug gefitinib (ZD1839; Iressa), a specific epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) has been reported. We have determined whether signalling through the IGF-I receptor (IGF-1R) pathway plays a role in the gefitinib-acquired resistance phenotype. Continuous exposure of EGFR-positive MCF-7-derived tamoxifen resistant breast cancer cells (TAM-R) to 1 microM gefitinib resulted in a sustained growth inhibition (90%) for 4 months before the surviving cells resumed proliferation. A stable gefitinib-resistant subline (TAM/TKI-R) was established after a further 2 months and this showed no detectable basal phosphorylated EGFR activity. Compared with the parental TAM-R cells, the TAM/ TKI-R cells demonstrated (a) elevated levels of activated IGF-1R, AKT and protein kinase C (PKC)delta, (b) an increased sensitivity to growth inhibition by the IGF-1R TKI AG1024 and (c) an increased migratory capacity that was reduced by AG1024 treatment. Similarly, the EGFR-positive androgen-independent human prostate cancer cell line DU145 was also continuously challenged with 1 microM gefitinib and, although substantial growth inhibition (60%) was seen initially, a gefitinib-resistant variant (DU145/TKI-R) developed after 3 months. Like their breast cancer counterparts, the DU145/TKI-R cells showed increases in the levels of components of the IGF-1R signalling pathway and an elevated sensitivity to growth inhibition by AG1024 compared with the parent DU145 cell line. Additionally, DU145/TKI-R cell migration was also decreased by this inhibitor. We have therefore concluded that in breast and prostate cancer cells acquired resistance to gefitinib is associated with increased signalling via the IGF-1R pathway, which also plays a role in the invasive capacity of the gefitinib-resistant phenotype.