Controllable Synthesis of Gold Nanoparticles in Aqueous Solution by Microwave Assisted Flow Chemistry

The development of energy efficient, reproducible, and high throughput approaches to gold nanoparticle (Au-NP) synthesis has gained increasing attention over the past decades due to applications in biomedicine, sensors, and catalysis. In this work, single mode microwave irradiation is for the first time combined with microflow chemistry to fabricate Au-NPs continuously and reproducibly with controllable size in an aqueous solution. The major experimental parameters including microwave power, citrate-to-gold molar ratio ([Cit]/[Au]), and reaction residence time have been investigated systematically. As indicated by TEM, the mean particle width of the synthesized Au-NPs is between 4 and 15 nm with mean aspect ratio between ∼1.4 and 2.2 after only 90 s of microwave irradiation. Furthermore, the Au particle morphology can be manipulated from nanowires to nanoparticles by adjusting the [Cit]/[Au] ratio. HRTEM analysis of the produced Au-NPs and UV–vis spectroscopy suggests a correlation between the red-shifted surface plasmon resonance peak and the particle aspect ratio that is probably dependent on the creation of particle–particle junctions, which alter both the size and the aspect ratio of the Au-NPs. The synthesis further demonstrated high reproducibility

Decoupling carrier concentration and electron-phonon coupling in oxide heterostructures observed with resonant inelastic x-ray scattering

We report the observation of multiple phonon satellite features in ultra thin superlattices of form $n$SrIrO$_3$/$m$SrTiO$_3$ using resonant inelastic x-ray scattering. As the values of $n$ and $m$ vary the energy loss spectra show a systematic evolution in the relative intensity of the phonon satellites. Using a closed-form solution for the cross section, we extract the variation in the electron-phonon coupling strength as a function of $n$ and $m$. Combined with the negligible carrier doping into the SrTiO$_3$ layers, these results indicate that tuning of the electron-phonon coupling can be effectively decoupled from doping. This work showcases both a feasible method to extract the electron-phonon coupling in superlattices and unveils a potential route for tuning this coupling which is often associated with superconductivity in SrTiO$_3$-based systems.Comment: 4 pages, 5 figure

Intrathecal Delivery of Ketorolac Loaded In Situ Gels for Prolonged Analgesic and Anti-Inflammatory Activity in Vertebral Fracture

Purpose: To develop biodegradable, polymeric in situ gels based on sodium alginate and hydroxypropyl methylcellulose for intrathecal delivery of ketorolac tromethamine (KT) for effective management of pain and inflammation in vertebral fracture.Method: Ion activated in situ gels were used as implants and were prepared from sodium alginate and hydroxypropyl methylcellulose. The fabricated gels were evaluated for visual appearance, clarity, pH, gelling capacity, drug content, viscosity (using Brookfield viscometer), in vitro drug release (using a fabricated KC cell) and in vivo analgesic and anti-inflammatory activity (by intrathecal administration of in situ gel near the fractured vertebra in a rat model).Results: The physicochemical properties (visual appearance, clarity, pH, gelling capacity, drug content and viscosity) of in situ gels were acceptable for therapeutic use. KT-loaded gels demonstrated high drug encapsulation efficiency (98.3 - 103.3 %). Further, KT-loaded gels exhibited viscosity in the range of 1.11 to 6 cps at 50 rpm and shear thinning property (rheology testing). Additionally, the gels demonstrated 84.43 to 96.98 % drug release at the end of 12 h. In particular, in situ gels prepared from 1.2 % alginate/0.4 % HPMC (G7) exhibited excellent analgesic (54.28 %) and anti-inflammatory activity (51.6 % inhibition of rat paw edema) in the animal model of vertebral fracture.Conclusion: The formulated in situ gels can potentially be used as implants for the treatment of patients with vertebral fracture.Keywords: Ketorolac, Orthopaedic implant, Extended release, Analgesic, Anti inflammation, Vertebral fractur

Lepton flavor violation decays τ−→μ−P1P2\tau^-\to \mu^- P_1 P_2 in the topcolor-assisted technicolor model and the littlest Higgs model with TT parity

The new particles predicted by the topcolor-assisted technicolor ($TC2$) model and the littlest Higgs model with T-parity (called $LHT$ model) can induce the lepton flavor violation ($LFV$) couplings at tree level or one loop level, which might generate large contributions to some $LFV$ processes. Taking into account the constraints of the experimental data on the relevant free parameters, we calculate the branching ratios of the $LFV$ decay processes $\tau^-\to\mu^- P_1 P_2$ with $P_1 P_2$ = $\pi^+\pi^-$, $K^+K^-$ and $K^0\bar{K^0}$ in the context of these two kinds of new physics models. We find that the $TC2$ model and the $LHT$ model can indeed produce significant contributions to some of these $LFV$ decay processes.Comment: 24 pages, 7 figure

Lepton flavor violating Z→l1+l2−Z\to l_1^+ l_2^- decay in the general two Higgs Doublet model with the inclusion of non-universal extra dimensions

We predict the branching ratios of Z -> e^{\pm} \mu^{\pm}, Z -> e^{\pm} \tau^{\pm} and Z -> \mu^{\pm} \tau^{\pm} decays in the model III version of the two Higgs doublet model, with the inclusion of one and two spatial non-universal extra dimensions. We observe that the the branching ratios are not sensitive to a single extra dimension, however, this sensitivity is considerably large for two extra dimensions.Comment: 21 pages, 7 Figure

Flavor changing scalar couplings and tγ(Z)t\gamma(Z) production at hadron colliders

We calculate the contributions of the flavor changing scalar ($FCS$) couplings arised from topcolor-assisted technicolor ($TC2$) models at tree-level to the $t\gamma$ and $tZ$ production at the Tevatron and $LHC$ experiments. We find that the production cross sections are very small at the Tevatron with $\sqrt{s}=1.96TeV$, which is smaller than 5 fb in most of the parameter space of $TC2$ models. However, the virtual effects of the $FCS$ couplings on the $t\gamma(Z)$ production can be easily detected at the $LHC$ with $\sqrt{s}=14TeV$ via the final state $\gamma l\bar{\nu}b$ ($l^{+}l^{-}l\bar{\nu}b$).Comment: 10 pages,5 figure

PGB pair production at LHC and ILC as a probe of the topcolor-assisted technicolor models

The topcolor-assisted technicolor (TC2) model predicts some light pseudo goldstone bosons (PGBs), which may be accessible at the LHC or ILC. In this work we study the pair productions of the charged or neutral PGBs at the LHC and ILC. For the productions at the LHC we consider the processes proceeding through gluon-gluon fusion and quark-antiquark annihilation, while for the productions at the ILC we consider both the electron-positron collision and the photon-photon collision. We find that in a large part of parameter space the production cross sections at both colliders can be quite large compared with the low standard model backgrounds. Therefore, in future experiments these productions may be detectable and allow for probing TC2 model.Comment: 26 pages, 16 figures. slight changes in the text; notations for curves changed; references adde

GIVE: portable genome browsers for personal websites.

Growing popularity and diversity of genomic data demand portable and versatile genome browsers. Here, we present an open source programming library called GIVE that facilitates the creation of personalized genome browsers without requiring a system administrator. By inserting HTML tags, one can add to a personal webpage interactive visualization of multiple types of genomics data, including genome annotation, "linear" quantitative data, and genome interaction data. GIVE includes a graphical interface called HUG (HTML Universal Generator) that automatically generates HTML code for displaying user chosen data, which can be copy-pasted into user's personal website or saved and shared with collaborators. GIVE is available at: https://www.givengine.org/

Probing Topcolor-Assisted Technicolor from Top-Charm Associated Production at LHC

We propose to probe the topcolor-assisted technicolor (TC2) model from the top-charm associated productions at the LHC, which are highly suppressed in the Standard Model. Due to the flavor-changing couplings of the top quark with the scalars (top-pions and top-Higgs) in TC2 model, the top-charm associated productions can occur via both the s-channel and t-channel parton processes by exchanging a scalar field at the LHC. We examined these processes through Monte Carlo simulation and found that they can reach the observable level at the LHC in quite a large part of the parameter space of the TC2 model.Comment: Version to appear in PRD (Rapid Communication

Single production of the vector-like top quark in the littlest Higgs model at TeV energy e−γe^{-}\gamma colliders

The new colored vector-like heavy fermion $T$ is a crucial prediction in little Higgs models, which plays a key role in breaking the electroweak symmetry. The littlest Higgs model is the most economical one among various little Higgs models. In the context of the littlest Higgs model, we study single production of the new heavy vector-like quark via $e^{-}\gamma$ collisions and discuss the possibility of detecting this new particle in the TeV energy $e^{+}e^{-}$ collider(LC). We find that the production cross section can vary in a wide range($10^{-3}-10^{1}fb$) in most parameter spaces. For the favorable parameter spaces, the possible signals of the vector-like top quark $T$ can be detected via $e^{-}\gamma$ collisions in future $LC$ experiment with $\sqrt{s}=3TeV$ and $\pounds=500fb^{-1}$.Comment: 10 pages,3 figure