Theory of Luminescent Emission in Nanocrystal ZnS:Mn with an Extra Electron

We consider the effect of an extra electron injected into a doped quantum dot $ZnS:Mn^{2+}$. The Coulomb interaction and the exchange interaction between the extra electron and the states of the Mn ion will mix the wavefunctions, split the impurity energy levels, break the previous selection rules and change the transition probabilities. Using this model of an extra electron in the doped quantum dot, we calculated the energy and the wavefunctions, the luminescence probability and the transition lifetime and compare with the experiments. Our calculation shows that two orders of magnitudes of lifetime shortening can occur in the transition $^4T_1-^6A_1$ when an extra electron is present.Comment: 15 pages, 2 Figs No change in Fig

Intra-Operative Experience using Magnetic Resonance Imaging (MRI) Based Patient Specific Cutting Guides during Total Knee Arthroplasty

Background. The incidence of malalignment in total knee arthroplasty(TKA) using conventional instrument has beenreported as high as 25%. A relatively new TKA system involvesthe use of a preoperative magnetic resonance image(MRI) to obtain accurate implant placement more consistently.For broad acceptance of this new technique, it iscrucial to analyze the initial intra-operative experience. Thespecific aim of this study was to evaluate the initial intra-operativeexperience of a single surgeon using this new technique. Methods. A total of 15 knees (12 patients: 6 female and 6male) were reviewed from TKA procedures using the selectedmanufacturer’s patient specific cutting guides between January2011 and April 2013 at a single institution. Patient demographicand specific parameters and intra-operative alterationsof component positioning were recorded and evaluated.Results. The preoperative plan was able to predict correctly thesize of the implanted femoral component in 87% (n = 13) andtibial component in 80% (n = 12) of the cases. However, 60% (n= 9) of cases required additional intra-operative corrections onfemoral resection, and 73% (n = 11) required an additional 2 - 4mm correction on the tibial proximal resection. Twenty percent(n = 3) required additional tibial varus/valgus correction, butthere were no tibial slope corrections for any of the 15 cases. Conclusions. The initial intra-operative experience of a singlesurgeon using current patient specific cutting guides for a selectedmanufacturer to align femoral and tibial components duringTKA has raised some concerns. We agreed with previous studiesthat caution should be taken when using patient specific cuttingguides without supportive data. The findings of this study providedadditional evidence to contest the accuracy of patient specificcutting guides with respect to the initial experience of an orthopaedicsurgeon who is trained in total joint replacement. Theresults provided more evidence to assist orthopaedic surgeonsin the decision of whether to use these patient specific systemsversus conventional TKA methods. KS J Med 2016;9(2):22-26

Neutrophil Trafficking in Pulmonary Inflammation: Monitoring Migration and Blockade with 111In-Labeled Leukocytes

AbstractAim: Although imaging of In vitro labeled leukocytes is commonly used for diagnosing inflammation and infection, data concerning the use of this technique to monitor neutrophil trafficking are scarce. Here we investigated thepotential of 111In-in vitro labeled leukocytes (InWBC) to monitor neutrophil trafficking in an animal model of pulmonary inflammation.Methods: F344 rats were divided into 3 groups: Controls (received only InWBC), Inflammation (intra-tracheally challenged with lipoteichoic acid (LTA)+peptidoglycan (PGN) two hours before InWBC injection), and Blockade(pulmonary challenge with receptor blockade [LTAPGN+Antileukinate, a CXC receptor 1 and 2 antagonist]). Leukocytes were obtained from donor rats and labeled with 111In-oxine using standard procedures. Labeling efficiencyand leukocyte integrity were determined. Animals were administered 3.7-4.6 MBq InWBC via the tail vein, and were imaged 18-30 hours later and then euthanized. Post mortem the lungs were lavaged and total and differential alveolar cell counts performed. Lung tissue myeloperoxidase (MPO) activity was determined. Lung, heart, liver, spleen, kidney, marrow, intestine, blood, and muscle were harvested and organ activity/gm tissue determined. Results: InWBC labeling efficiency and cell integrity were not significantly different among groups. InWBC pulmonary activity was significantly higher (p<0.0001) in the Inflammation group (17.10 ± 2.04%) than in the Controls (1.76 ± 0.60%) and the Blockade group (9.74 ± 1.14%). Hemocytometer assessment of the bronchoalveolar lavage fluid revealed that the total number of neutrophils was significantly higher in the Inflammation group than in Controls and the Blockade group. Pulmonary MPO activity (pg/mg tissue) was significantly higher (p<0.01) in the Inflammation group (14.11 ± 5.56%) than in Controls (5.22 ± 4.77%) and the Blockade group (3.66 ± 3.77%). InWBC splenic activity was significantly higher (p<0.0001) in the Controls than in the Inflammation and Blockade groups. In the remaining organs, InWBC activity was significantly higher in the Blockade group than in the Control and the Inflammation groups.Conclusions: In a rat model of pulmonary inflammation using Antileukinate to block neutrophil chemokine receptors, InWBC accurately characterized both pulmonary and extrapulmonary neutrophil trafficking. These data indicate that InWBC may be useful to monitor both pulmonary and extrapulmonary neutrophil trafficking associated with lung inflammation and its regulation

Phase diagram of bismuth in the extreme quantum limit

Elemental bismuth provides a rare opportunity to explore the fate of a three-dimensional gas of highly mobile electrons confined to their lowest Landau level. Coulomb interaction, neglected in the band picture, is expected to become significant in this extreme quantum limit with poorly understood consequences. Here, we present a study of the angular-dependent Nernst effect in bismuth, which establishes the existence of ultraquantum field scales on top of its complex single-particle spectrum. Each time a Landau level crosses the Fermi level, the Nernst response sharply peaks. All such peaks are resolved by the experiment and their complex angular-dependence is in very good agreement with the theory. Beyond the quantum limit, we resolve additional Nernst peaks signaling a cascade of additional Landau sub-levels caused by electron interaction

Prevalence of HIV Drug Resistance Mutations in HIV Type 1 Isolates in Antiretroviral Therapy Naïve Population from Northern India

Objective. The increased use of antiretroviral therapy (ART) has reduced the morbidity and mortality associated with HIV, adversely leading to the emergence of HIV drug resistance (HIVDR). In this study we aim to evaluate the prevalence of HIVDR mutations in ART-naive HIV-1 infected patients from northern India. Design. Analysis was performed using Viroseq genotyping system based on sequencing of entire protease and two-thirds of the Reverse Transcriptase (RT) region of pol gene. Results. Seventy three chronic HIV-1 infected ART naïve patients eligible for first line ART were enrolled from April 2006 to August 2008. In 68 patients DNA was successfully amplified and sequencing was done. 97% of HIV-1 strains belonged to subtype C, and one each to subtype A1 and subtype B. The overall prevalence of primary DRMs was 2.9% [2/68, 95% confidence interval (CI), 0.3%–10.2%]. One patient had a major RT mutation M184V, known to confer resistance to lamivudine, and another had a major protease inhibitor (PI) mutation D30N that imparts resistance to nelfinavir. Conclusion. Our study shows that primary HIVDR mutations have a prevalence of 2.9% among ART-naive chronic HIV-1 infected individuals

Cancer cells exploit an orphan RNA to drive metastatic progression.

Here we performed a systematic search to identify breast-cancer-specific small noncoding RNAs, which we have collectively termed orphan noncoding RNAs (oncRNAs). We subsequently discovered that one of these oncRNAs, which originates from the 3' end of TERC, acts as a regulator of gene expression and is a robust promoter of breast cancer metastasis. This oncRNA, which we have named T3p, exerts its prometastatic effects by acting as an inhibitor of RISC complex activity and increasing the expression of the prometastatic genes NUPR1 and PANX2. Furthermore, we have shown that oncRNAs are present in cancer-cell-derived extracellular vesicles, raising the possibility that these circulating oncRNAs may also have a role in non-cell autonomous disease pathogenesis. Additionally, these circulating oncRNAs present a novel avenue for cancer fingerprinting using liquid biopsies

Stepwise complexometric determination of aluminium, titanium and iron concentrations in silica sand and allied materials

<p>Abstract</p> <p>Background</p> <p>This study aimed at measuring the quantities of Al, Ti and Fe in silica sand and allied materials employing a complexometric method in the same analyte and a stepwise indirect titration with EDTA. The method involves the complexation of Al, Ti and Fe with excess EDTA and the selective de-complexation of TiO-EDTA and Al-EDTA complexes with tartaric acid and NaF respectively. In addition to its simplicity, rapidity and accuracy, the proposed method does not require the use of a separation technique or any sophisticated instrumentation.</p> <p>Results</p> <p>Each of the test samples were analyzed five times using the proposed method. The method's accuracy was confirmed by analyzing the US National Institute of Standards and Technology's (NIST) Standard Reference Materials (SRM) 81a, 89 and IPT SRM 61 using the procedure proposed, in addition to analyzing Ti and Fe levels by spectrophotometry and that of Al by complexometry.</p> <p>Conclusion</p> <p>The study shows that there is good agreement between the proposed and existing methods. The standard deviations of the measurements were calculated by analyzing five replicates of each sample, and were found to be less than 1.5% in our method.</p

Effects of the Template Composition and Coating on the Photoluminescence Properties of ZnS:Mn Nanoparticles

Mn-doped ZnS nanocrystals based on low dopant concentrations (0–2%) and coated with a shell of Zn(OH)2 have been prepared via soft template and precipitation reaction. The results indicate that the ZnS:Mn nanocrystal is cubic zinc blende structure and its diameter is 3.02 nm as demonstrated by XRD. Measured by TEM, the morphology of nanocrystals is a spherical shape, and their particle size (3–5 nm) is similar to that of XRD results. Photoluminescence spectra under ultraviolet region shows that the volume ratio of alcohol to water in the template has a great effect on the luminescence properties of ZnS:Mn particles. Compared with unpassivated ZnS:Mn nanocrystals, ZnS:Mn/Zn(OH)2 core/shell nanocrystal exhibits much improved luminescence and higher absolute quantum efficiency. Meanwhile, we simply explore the formation mechanism of ZnS:Mn nanocrystals in alcohol and water system and analyze the reason why alcohol and water cluster structures can affect the luminescent properties of nanoparticle