6,196 research outputs found
Rich States, Poor States: ALEC-Laffer State Economic Competitiveness Index
Ranks states' business climates based on income, population growth, and employment and outlook based on current tax policies; analyzes their fiscal conditions; reviews 2010 fiscal reform initiatives; and recommends policies to spur economic growth
Unclamped hand-assisted laparoscopic partial nephrectomy for predominantly endophytic renal tumors
PURPOSE: To describe our initial experience with unclamped laparoscopic hand-assisted partial nephrectomy for predominantly endophytic renal masses in the setting of relative contraindication to warm ischemia.
MATERIALS AND METHODS: Unclamped laparoscopic hand-assisted partial nephrectomy was performed on eight consecutive patients from June 2009 to March 2010. All patients had predominantly endophytic renal masses with a preferential enhancing rim noted on the pre-operative computed tomography. The unclamped hand-assisted approach was utilized for no warm ischemia, minimal blood loss, and enhanced visualization of the tumor bed with improved operative exposure.
RESULTS: Mean age of the participants was 55.8 years. All patients underwent unclamped hand-assisted partial nephrectomy (ie, zero ischemia). Mean estimated blood loss was 368.8 cc (range, 100 to 800 cc) and mean operation time was 236.9 minutes (range, 175 to 272 minutes). There were no intra-operative complications and no open conversions. There was one grade II (ileus with small pneumothorax) and one grade IV (pulmonary embolism) in the 90-day peri-operative period. There was one positive surgical margin, which was recognized intra-operatively.
CONCLUSION: While our results are preliminary, we feel this technique provides superior visualization and adequate hemostasis while preserving oncologic efficacy and renal function in this patient population
Transcription-translation coupling: direct interactions of RNA polymerase with ribosomes and ribosomal subunits.
In prokaryotes, RNA polymerase and ribosomes can bind concurrently to the same RNA transcript, leading to the functional coupling of transcription and translation. The interactions between RNA polymerase and ribosomes are crucial for the coordination of transcription with translation. Here, we report that RNA polymerase directly binds ribosomes and isolated large and small ribosomal subunits. RNA polymerase and ribosomes form a one-to-one complex with a micromolar dissociation constant. The formation of the complex is modulated by the conformational and functional states of RNA polymerase and the ribosome. The binding interface on the large ribosomal subunit is buried by the small subunit during protein synthesis, whereas that on the small subunit remains solvent-accessible. The RNA polymerase binding site on the ribosome includes that of the isolated small ribosomal subunit. This direct interaction between RNA polymerase and ribosomes may contribute to the coupling of transcription to translation
Glueball enhancements in p(gamma,VV)p through vector meson dominance
Double vector meson photoproduction, p(gamma, G -> VV)p, mediated by a scalar
glueball G is investigated. Using vector meson dominance (VMD) and
Regge/pomeron phenomenology, a measureable glueball enhancement is predicted in
the invariant VV = rho rho and omega omega mass spectra. The scalar glueball is
assumed to be the lightest physical state on the daughter pomeron trajectory
governing diffractive vector meson photoproduction. In addition to cross
sections, calculations for hadronic and electromagnetic glueball decays, G -> V
V' (V,V'= rho, omega, phi, gamma), and gamma_v V -> G transition form factors
are presented based upon flavor universality, VMD and phenomenological
couplings from phi photoproduction analyses. The predicted glueball decay
widths are similar to an independent theoretical study. A novel signature for
glueball detection is also discussed
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A survey of patient motion in disorders of consciousness and optimization of its retrospective correction.
Functional magnetic resonance imaging (fMRI) can be seriously impaired by patient motion. The purpose of this study was to characterize the typical motion in a clinical population of patients in disorders of consciousness and compare the performance of retrospective correction with rigid-body realignment as implemented in widely used software packages. 63 subjects were scanned with an fMRI visual checkerboard paradigm using a 3T scanner. Time series were corrected for motion, and the resulting transformations were used to calculate a motion score. SPM, FSL, AFNI and AIR were evaluated by comparing the motion obtained by re-running the tool on the corrected data. A publicly available sample fMRI dataset was modified with the motion detected in each patient with each tool. The performance of each tool was measured by comparing the number of supra-threshold voxels after standard fMRI analysis, both in the sample dataset and in simulated fMRI data. We assessed the effect of user-changeable parameters on motion correction in SPM. We found the equivalent motion in the patient population to be 1.4mm on average. There was no significant difference in performance between SPM, FSL and AFNI. AIR was considerably worse, and took more time to run. We found that in SPM the quality factor and interpolation method have no effect on the cluster size, while higher separation and smoothing reduce it. We showed that the main packages SPM, FSL and AFNI are equally suitable for retrospective motion correction of fMRI time series. We show that typically only 80% of activated voxels are recovered by retrospective motion correction
Approximate Exponential Integrators for Time-Dependent Equation-of-Motion Coupled Cluster Theory
With growing demand for time-domain simulations of correlated many-body
systems, the development of efficient and stable integration schemes for the
time-dependent Schr\"odinger equation is of keen interest in modern electronic
structure theory. In the present work, we present two novel approaches for the
formation of the quantum propagator for time-dependent equation-of-motion
coupled cluster theory (TD-EOM-CC) based on the Chebyshev and Arnoldi
expansions of the complex, non-hermitian matrix exponential, respectively. The
proposed algorithms are compared with the short-iterative Lanczos method of
Cooper, et al [J. Phys. Chem. A. 2021 125, 5438-5447], the fourth-order
Runge-Kutta method (RK4), and exact dynamics for a set of small but challenging
test problems. For each of the cases studied, both of the proposed integration
schemes demonstrate superior accuracy and efficiency relative to the reference
simulations.Comment: 28 pages, 4 figure
Effect of Heat Shock, Pretreatment and Hsp70 Copy Number on Wing Development in Drosophila Melanogaster
Naturally Occurring Heat Shock (HS) during Pupation Induces Abnormal Wing Development in Drosophila; We Examined Factors Affecting the Severity of This Induction. the Proportion of HS-Surviving Adults with Abnormal Wings Varied with HS Duration and Intensity, and with the Pupal Age or Stage at HS Administration. Pretreatment (PT), Mild Hyperthermia Delivered Before HS, Usually Protected Development Against HS. Gradual Heating Resembling Natural Thermal Regimes Also Protected Wing Development Against Thermal Disruption. Because of the Roles of the Wings in Flight and Courtship and in View of Natural Thermal Regimes that Drosophila Experience, Both HS-Induction of Wing Abnormalities and its Abatement by PT May Have Marked Effects on Drosophila Fitness in Nature. Because PT is Associated with Expression of Heat-Inducible Molecular Chaperones Such as Hsp70 in Drosophila, We Compared Thermal Disruption of Wing Development among Hsp70 Mutants as Well as among Strains Naturally Varying in Hsp70 Levels. Contrary to Expectations, Lines or Strains with Increased Hsp70 Levels Were No More Resistant to HS-Disruption of Wing Development Than Counterparts with Lower Hsp70 Levels. in Fact, Wing Development Was More Resistant to HS in Hsp70 Deletion Strains Than Control Strains. We Suggest that, While High Hsp70 Levels May Aid Cells in Surviving Hyperthermia, High Levels May Also Overly Stimulate or Inhibit Numerous Signaling Pathways Involved in Cell Proliferation, Maturation and Programmed Death, Resulting in Developmental Failure
Therapeutic Targeting of Histone Modifications in Adult and Pediatric High-Grade Glioma
Recent exciting work partly through The Cancer Genome Atlas has implicated epigenetic mechanisms including histone modifications in the development of both pediatric and adult high-grade glioma (HGG). Histone lysine methylation has emerged as an important player in regulating gene expression and chromatin function. Lysine (K) 27 (K27) is a critical residue in all seven histone 3 variants and the subject of posttranslational histone modifications, as it can be both methylated and acetylated. In pediatric HGG, two critical single-point mutations occur in the H3F3A gene encoding the regulatory histone variant H3.3. These mutations occur at lysine (K) 27 (K27M) and glycine (G) 34 (G34R/V), both of which are involved with key regulatory posttranscriptional modifications. Therefore, these mutations effect gene expression, cell differentiation, and telomere maintenance. In recent years, alterations in histone acetylation have provided novel opportunities to explore new pharmacological targeting, with histone deacetylase (HDAC) overexpression reported in high-grade, late-stage proliferative tumors. HDAC inhibitors have shown promising therapeutic potential in many malignancies. This review focuses on the epigenetic mechanisms propagating pediatric and adult HGGs, as well as summarizing the current advances in clinical trials using HDAC inhibitors
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