363 research outputs found
Exploring Exchange Interactions in Two-Qubit System
We studied the effect of magnetic field and interdot distance on the exchange interaction in two systems of double qubits, one made of Si and the other made of GaAs. We found that the effect is the same for both systems, but the exchange value for Si qubits is smaller due to the larger effective mass of electrons. This study provides insights into the exchange interaction, which is essential for the development of quantum computers
Metagenomics approaches for the detection and surveillance of emerging and recurrent plant pathogens
Globalization has a dramatic effect on the trade and movement of seeds, fruits and vegetables, with a corresponding increase in economic losses caused by the introduction of transboundary plant pathogens. Current diagnostic techniques provide a useful and precise tool to enact surveillance protocols regarding specific organisms, but this approach is strictly targeted, while metabarcoding and shotgun metagenomics could be used to simultaneously detect all known pathogens and potentially new ones. This review aims to present the current status of high-throughput sequencing (HTS) diagnostics of fungal and bacterial plant pathogens, discuss the challenges that need to be addressed, and provide direction for the development of methods for the detection of a restricted number of related taxa (specific surveillance) or all of the microorganisms present in a sample (general surveillance). HTS techniques, particularly metabarcoding, could be useful for the surveillance of soilborne, seedborne and airborne pathogens, as well as for identifying new pathogens and determining the origin of outbreaks. Metabarcoding and shotgun metagenomics still suffer from low precision, but this issue can be limited by carefully choosing primers and bioinformatic algorithms. Advances in bioinformatics will greatly accelerate the use of metagenomics to address critical aspects related to the detection and surveillance of plant pathogens in plant material and foodstuffs
Comparative Study Between Antegrade Flexible Ureteroscopy and Reterograde Intrarenal Surgery in the Management of Impacted Upper Ureteric Stones 1.5 cm or Larger
OBJECTIVE: To prospectively investigate the safety and efficacy of antegrade flexible ureteroscopy (FURS) with the following criteria (supine, ultrasonic guided puncture through lower calyx with 14 fr tract, tubeless) versus retrograde intrarenal surgery (RIRS) in the management of large impacted upper ureteric stones ≥ 1.5 cm.
PATIENTS AND METHODS: This study recruited 61 patients with single large impacted upper ureteric stone of ≥ 1.5 cm. The patients were randomly allocated to two groups. Group A, included 31 patients who treated by antegrade FURS, all patients were put in supine modified galadako Valdivia position and the renal access is reached by ultrasonic guided puncture through the lower calyx with dilatation upto 14 fr to insert ureteric access sheath and all cases were tubless with JJ stent insertion. Group B, included 30 patients who were treated by RIRS with JJ stent insertion. Stone fragmentation was done by holmium laser in both group.
RESULTS: Group A was significantly associated with higher proportion of SFR (90.3%) compared to Group B (70%) (p = 0.046). Group B was significantly associated with shorter operative time and fluoroscopy time in comparison with Group A (p \u3c 0.001). No significant differences were found between studied groups regarding bleeding (p = 0.238). Urosepsis showed significantly higher proportion associated with retrograde approach when compared to antegrade approach (p = 0.024).
CONCLUSION: This study showed that antegrade FURS is safe and more effective than RIRS for the management of large impacted upper ureteric stones ≥ 1.5 cm
Zeb1 modulates hematopoietic stem cell fates required for suppressing acute myeloid leukemia
Zeb1, a zinc finger E-box binding homeobox epithelial-mesenchymal (EMT) transcription factor, confers properties of ‘stemness’, such as self-renewal, in cancer. Yet little is known about the function of Zeb1 in adult stem cells. Here, we used the hematopoietic system, as a well-established paradigm of stem cell biology, to evaluate Zeb1 mediated regulation of adult stem cells. We employed a conditional genetic approach using the Mx1-Cre system to specifically knockout (KO) Zeb1 in adult hematopoietic stem cells (HSCs) and their downstream progeny. Acute genetic deletion of Zeb1 led to rapid onset thymic atrophy and apoptosis driven loss of thymocytes and T cells. A profound cell-autonomous self-renewal defect and multi-lineage differentiation block was observed in Zeb1 KO HSCs. Loss of Zeb1 in HSCs activated transcriptional programs of deregulated HSC maintenance and multi-lineage differentiation genes, and of cell polarity, consisting of cytoskeleton, lipid metabolism/lipid membrane and cell adhesion related genes. Notably, Epithelial cell adhesion molecule (EpCAM) expression was prodigiously upregulated in Zeb1 KO HSCs, which correlated with enhanced cell survival, diminished mitochondrial metabolism, ribosome biogenesis, and differentiation capacity and an activated transcriptomic signature associated with acute myeloid leukemia (AML) signaling. ZEB1 expression was downregulated in AML patients and Zeb1 KO in the malignant counterparts of HSCs - leukemic stem cells (LSCs) - accelerated MLL-AF9 and Meis1a/Hoxa9-driven AML progression, implicating Zeb1 as a tumor suppressor in AML LSCs. Thus, Zeb1 acts as a transcriptional regulator in hematopoiesis, critically co-ordinating HSC self-renewal, apoptotic and multi-lineage differentiation fates required to suppress leukemic potential in AML
The Demand for Military Spending in Egypt
Egypt plays a pivotal role in the security of the Middle East as the doorway to Europe and its military expenditure reflects its involvement in the machinations of such an unstable region, showing considerable variation over the last 40 years. These characteristics make it a particularly interesting case study of the determinants of military spending. This paper specifies and estimates an econometric model of the Egyptian demand for military spending, taking into account important strategic and political factors. Both economic and strategic factors are found to play a role in determining military burden/spending, with clear positive effects of lagged military burden, suggesting some sort of institutional inertia, plus negative output and net exports effects. The strategic effect as a result of the impact of Israel's military burden is mostly positive and significant, though its impact is reduced when the impact of important strategic events are taken into account. The military spending of Egypt's allies Jordan and Syria generally seems to have had no effect on Egypt's spending. These results are consistent over a range of econometric techniques. © 2013 © 2013 Taylor & Francis
A Chemogenetic Approach for the Optical Monitoring of Voltage in Neurons
Optical monitoring of neuronal voltage using fluorescent indicators is a powerful approach for the interrogation of the cellular and molecular logic of the nervous system. Herein, a semisynthetic tethered voltage indicator (STeVI1) based upon nile red is described that displays voltage sensitivity when genetically targeted to neuronal membranes. This environmentally sensitive probe allows for wash-free imaging and faithfully detects supra- and sub-threshold activity in neurons
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