3,940 research outputs found
Coherent states \`a la Klauder-Perelomov for the P\"oschl-Teller potentials
In this paper we present a scheme for constructing the coherent states of
Klauder-Perelomov's type for a particle which is trapped in P\"oschl-Teller
potentials
Preventive Effects of Zoledronic Acid on Bone Metastasis in Mice Injected with Human Breast Cancer Cells
Bisphosphonates are used routinely to reduce bone-related events in breast cancer patients with bone metastasis. We evaluated the effects of zoledronic acid, a third generation, nitrogen-containing bisphosphonate, to prevent bone metastasis in breast cancer. Zoledronic acid or vehicle alone was administered to nude mice either simultaneously or after intracardiac injection of human breast cancer MDA-MB-231 cells. Nude mice treated with zoledronic acid at early time points showed a lower incidence of bone metastases than did vehicle-treated nude mice, but these differences were not statistically significant. Only 37.5% of mice treated with zoledronic acid at the time of tumor cell inoculation developed bone metastases compared to over 51.8% of mice receiving vehicle alone (P = 0.304). Cell count of apoptosis confirmed by immunohistochemical staining in metastatic bone tissue significantly increased in the zoledronic acid-treated groups compared to non-treated group (1,018.3 vs 282.0; P = 0.046). However, metastatic tumor cells, which invade soft tissue around the bone, did not show extensive apoptosis; there were no differences between the zoledronic acid-treated and control groups. These results suggest that zoledronic acid increases apoptosis of metastatic breast tumor cells in the bone and could therefore reduce metastatic tumor burden. These results support the use of zoledronic acid to reduce the incidence of bone metastasis in breast cancer
Phylogeography of Japanese encephalitis virus:genotype is associated with climate
The circulation of vector-borne zoonotic viruses is largely determined by the overlap in the geographical distributions of virus-competent vectors and reservoir hosts. What is less clear are the factors influencing the distribution of virus-specific lineages. Japanese encephalitis virus (JEV) is the most important etiologic agent of epidemic encephalitis worldwide, and is primarily maintained between vertebrate reservoir hosts (avian and swine) and culicine mosquitoes. There are five genotypes of JEV: GI-V. In recent years, GI has displaced GIII as the dominant JEV genotype and GV has re-emerged after almost 60 years of undetected virus circulation. JEV is found throughout most of Asia, extending from maritime Siberia in the north to Australia in the south, and as far as Pakistan to the west and Saipan to the east. Transmission of JEV in temperate zones is epidemic with the majority of cases occurring in summer months, while transmission in tropical zones is endemic and occurs year-round at lower rates. To test the hypothesis that viruses circulating in these two geographical zones are genetically distinct, we applied Bayesian phylogeographic, categorical data analysis and phylogeny-trait association test techniques to the largest JEV dataset compiled to date, representing the envelope (E) gene of 487 isolates collected from 12 countries over 75 years. We demonstrated that GIII and the recently emerged GI-b are temperate genotypes likely maintained year-round in northern latitudes, while GI-a and GII are tropical genotypes likely maintained primarily through mosquito-avian and mosquito-swine transmission cycles. This study represents a new paradigm directly linking viral molecular evolution and climate
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Efficacy of Low Dose Chemoprophylaxis for Coccidioidomycosis Infection in Liver Transplant Recipients
Background: Coccidioidomycosis (CM) infections among transplant recipients result in significant morbidity and mortality. The goal of our study was to establish the efficacy of low dose (LD) versus standard dose (LD, 50 mg daily) fluconazole in preventing CM infection. Methods: This was a retrospective study utilizing electronic medical records of liver transplant recipients at the University of Arizona. The primary end point was post-transplant CM status, such as infection, complications and survival. Results: We detected a statistically significant correlation between positive pre-transplant status and positive post-transplant status (hazards ratio: 8.25 (95% confidence interval: 1.028 - 66.192)). There was a trend towards improved survival in patients who had a positive post-transplant CM status in the SD group versus LD group (90.9% versus 81.3%), although not statistically significant. Conclusion: The risk of CM infection among transplant recipients in the absence of prophylaxis is associated with high morbidity and mortality. We currently use SD fluconazole as universal prophylaxis in all transplant recipients despite not establishing statistical significance between LD and SD. We believe that the survival trend detected may have not reached statistical significance due to low power impact. Since the standardization of SD prophylaxis at our institution, we have not diagnosed further new post-transplant CM infections.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Vegetation history and climatic fluctuations on a transect along the Dead Sea west shore and impact on past societies over the last 3500 years.
This study represents the vegetation history of the last 3500 years and conducts an analysis of the climatic fluctuations on a 75 km long transect on the western Dead Sea shore. Palynological and sedimentological data are available from six cores near Mount Sedom, Ein Boqueq, and Ein Gedi and from outcrops near Ze'elim and Ein Feshkha. The comparison of the pollen data with the lake levels shows synchronous trends. During the Middle Bronze Age, Iron Age and Hellenistic to Byzantine Period the high lake level of the Dead Sea signals an increase in precipitation. Contemporaneously, values of cultivated plants indicate an increase in agriculture. Lake level is low during the Late Bronze Age, within the Iron Age and at the end of the Byzantine period, indicating dry periods when all pds show a decrease of cultivated plants. Forest regeneration led by drought-resistant pines is observed in all pollen diagrams (pds) following the agricultural decline in the Byzantine period and, in the pds near Ein Boqeq, Ze'elim and Ein Feshkha, during the late Iron Age. The modern vegetation gradient is reflected in the palaeo-records: a stronger expansion of Mediterranean vegetation and cultivated plants in the northern sites is recognisable
Near-Atomic Scale Perspective on the Oxidation of TiCT MXenes: Insights from Atom Probe Tomography
MXenes are a family of 2D transition metal carbides and nitrides with
remarkable properties and great potential for energy storage and catalysis
applications. However, their oxidation behavior is not yet fully understood,
and there are still open questions regarding the spatial distribution and
precise quantification of surface terminations, intercalated ions, and possible
uncontrolled impurities incorporated during synthesis and processing. Here,
atom probe tomography analysis of as-synthesized TiCT MXenes
reveals the presence of alkali (Li, Na) and halogen (Cl, F) elements as well as
unetched Al. Following oxidation of the colloidal solution of MXenes, it is
observed that the alkalies enriched in TiO nanowires. Although these
elements are tolerated through the incorporation by wet chemical synthesis,
they are often overlooked when the activity of these materials is considered,
particularly during catalytic testing. This work demonstrates how the
capability of atom probe tomography to image these elements in 3D at the
near-atomic scale can help to better understand the activity and degradation of
MXenes, in order to guide their synthesis for superior functional properties
Improved charge storage performance of a layered Mo1.33C MXene/MoS2/graphene nanocomposite
The construction of nanocomposite electrodes based on 2D materials is an efficient route for property enrichment and for exploitation of constituent 2D materials. Herein, a flexible Mo1.33C i-MXene/MoS2/graphene (MOMG) composite electrode is constructed, utilizing an environment-friendly method for high-quality graphene and MoS2 synthesis. The presence of graphene and MoS2 between MXene sheets limits the commonly observed restacking, increases the interlayer spacing, and facilitates the ionic and electronic conduction. The as-prepared MOMG electrode delivers a volumetric capacitance of 1600 F cm(-3) (450 F g(-1)) at the scan rate of 2 mV s(-1) and retains 96% of the initial capacitance after 15 000 charge/discharge cycles (10 A g(-1)). The current work demonstrates that the construction of nanocomposite electrodes is a promising route towards property enhancement for energy storage applications
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