Changes in left atrial deformation in hypertrophic cardiomyopathy: Evaluation by vector velocity imaging.

OBJECTIVES: Hypertrophic cardiomyopathy (HCM) represents a generalized myopathic process affecting both ventricular and atrial myocardium. We assessed the global and regional left atrial (LA) function and its relation to left ventricular (LV) mechanics and clinical status in patients with HCM using Vector Velocity Imaging (VVI). METHODS: VVI of the LA and LV was acquired from apical four- and two-chamber views of 108 HCM patients (age 40 ± 19years, 56.5% men) and 33 healthy subjects, all had normal LV systolic function. The LA subendocardium was traced to obtain atrial volumes, ejection fraction, velocities, and strain (ϵ)/strain rate (SR) measurements. RESULTS: Left atrial reservoir (ϵsys,SRsys) and conduit (early diastolic SRe) function were significantly reduced in HCM compared to controls (P  - 1.8s(- 1) was 81% sensitive and 30% specific, SRa> - 1.5s(- 1) was 73% sensitive and 40% specific. By multivariate analysis global LVϵsys and LV septal thickness are independent predictors for LAϵsys, while end systolic diameter is the only independent predictor for SRsys, P < .001. CONCLUSION: Left atrial reservoir and conduit function as measured by VVI were significantly impaired while contractile function was preserved among HCM patients. Left atrial deformation was greatly influenced by LV mechanics and correlated to severity of phenotype

The Cricothyroid Space: a Guide for Successful Thyroidectomy

ObjectiveThe frequent complications of thyroid surgery are mostly related to the anatomy of the region. This stimulated us to look for a starting point that makes exploration of the region easier and consequently reduces complications. We aimed to explore and define the anatomy of the cricothyroid (CT) region from cadaveric dissection and to present the outcome of 73 consecutive thyroidectomies starting from a space in the CT region.MethodsDissection in the thyroid gland region and creating a space in the CT region was performed on five cadavers (10 spaces), followed by 73 consecutive thyroidectomies through a standard approach beginning from the CT space.ResultsIn all cadavers, a space was easily created in the CT region. Vessels, nerves and the parathyroid glands were identified. Standard thyroidectomy starting from the CT space was performed on 73 patients. The external laryngeal nerve was seen in 40% of the cases. The recurrent laryngeal nerve was identified and preserved in all patients. Six patients had temporary hypocalcaemia and eight had a temporary voice change. None of the patients had permanent hypoparathyroidism or recurrent laryngeal nerve palsy.ConclusionThe CT space is an avascular space medial to the thyroid lobe and is a good starting point for thyroidectomy that allows easy and safe exploration of the region. (Asian J Surg 2002;25(3): 226-31

Evaluation of Geogrid-Reinforced Flexible Pavement System Based on Soft Subgrade Soils Under Cyclic Loading

Geogrids have been successfully used to improve soft subgrade and reinforce weak base course by providing lateral confinement. However, Soft saturated fine-grained subgrade soils are distinguished by their high compressibility and low undrained shear strength. Moreover, when the stress is applied on the soft foundation soil resulting from repeated traffic load causing the soil particles to press together and the volume of the soil will decrease resulting in settlements. While applying stress on saturated soft foundation soil due to the increase of the water stress is squeezed out of the soft subsoil causing settlements. In this regard, geogrid reinforcement is the soil improvement technique which proposed to be used in this study to provide a solution for this problem. Using these techniques has been contributing to enhancing the pavement performance systems including the increase of the pavement service life. To simulate the above-mentioned situation, the experimental work included two models: raw materials model and geogrid model. A laboratory model tests are carried out to simulate the asphalt pavement layers and design cycling load system equivalent to the standard single axle load, which were prepared throughout a design and assembling of steel Container model. In this study, development of three-dimensional finite element models for flexible pavement system based on the numerical study has been carried out throughout the application of elastic model using ABAQUS software ver.6.14.4 to simulate and analyze the relationship between the number of applied load cycles and permanent displacement for the pavement layers of two model. The test results that recorded at 1600 cycle load, showed that the permanent displacement at the surface of pavement for improved models and compared with the raw material model has seen decreases by (7.75%). Also, by using the reinforced model is found to be more effective to resist vertical strain under cyclic load at the surface of subgrade soil if compared with the raw material model. Moreover. The results of ABAQUS program are very close to results of laboratory tests. Keywords: Geo-Grid Reinforcement, Soft Subgrade, ABAQUS

Numerical Experimental Investigation of Solidification Thickness around Cylindrical Surfaces for HVAC Cold Storage Systems

Thermal Ice Storage System (TISS) is an innovative way of storing night-time off-peak energy for daytime peak USAge. In many locations, demand for electrical power peaks during summer time. Air-conditioning equipment are the main reason accounting for as much as half of the power demand during the hot mid-day hours when electricity is most expensive. Since utilities have spare electrical generating capacity at night, electricity generated during this ldquo;off-peakrdquo; is much less expensive. In this research a numerical model for Latent Heat Storage (LHS) cylindrical tank has been obtained from a numerical package, ANSYS software ver. 15, and compared to an experimental data gathered from similar tank. The data showed good agreement with the experimental data with an error of 9%. The numerical model can be used to estimate ice thickness and tank geometries for any future work

Directed evolution of rRNA improves translation kinetics and recombinant protein yield

In bacteria, ribosome kinetics are considered rate-limiting for protein synthesis and cell growth. Enhanced ribosome kinetics may augment bacterial growth and biomanufacturing through improvements to overall protein yield, but whether this can be achieved by ribosome-specific modifications remains unknown. Here, we evolve 16S ribosomal RNAs (rRNAs) from Escherichia coli, Pseudomonas aeruginosa, and Vibrio cholerae towards enhanced protein synthesis rates. We find that rRNA sequence origin significantly impacted evolutionary trajectory and generated rRNA mutants with augmented protein synthesis rates in both natural and engineered contexts, including the incorporation of noncanonical amino acids. Moreover, discovered consensus mutations can be ported onto phylogenetically divergent rRNAs, imparting improved translational activities. Finally, we show that increased translation rates in vivo coincide with only moderately reduced translational fidelity, but do not enhance bacterial population growth. Together, these findings provide a versatile platform for development of unnatural ribosomal functions in vivo

Negative selection and stringency modulation in phage-assisted constinuous evolution

Phage-assisted continuous evolution (PACE) uses a modified filamentous bacteriophage life cycle to dramatically accelerate laboratory evolution experiments. In this work we expand the scope and capabilities of the PACE method with two key advances that enable the evolution of biomolecules with radically altered or highly specific new activities. First, we implemented small molecule-controlled modulation of selection stringency that enables otherwise inaccessible activities to be evolved directly from inactive starting libraries through a period of evolutionary drift. Second, we developed a general negative selection that enables continuous counter-selection against undesired activities. We integrated these developments to continuously evolve mutant T7 RNA polymerase enzymes with ∼10,000-fold altered, rather than merely broadened, substrate specificities during a single three-day PACE experiment. The evolved enzymes exhibit specificity for their target substrate that exceeds that of wild-type RNA polymerases for their cognate substrates, while maintaining wild-type-like levels of activity

Orthogonal translation enables heterologous ribosome engineering in E. coli

The ribosome represents a promising avenue for synthetic biology, but its complexity and essentiality have hindered significant engineering efforts. Heterologous ribosomes, comprising rRNAs and r-proteins derived from different microorganisms, may offer opportunities for novel translational functions. Such heterologous ribosomes have previously been evaluated in E. coli via complementation of a genomic ribosome deficiency, but this method fails to guide the engineering of refractory ribosomes. Here, we implement orthogonal ribosome binding site (RBS):antiRBS pairs, in which engineered ribosomes are directed to researcher-defined transcripts, to inform requirements for heterologous ribosome functionality. We discover that optimized rRNA processing and supplementation with cognate r-proteins enhances heterologous ribosome function for rRNAs derived from organisms with ≥76.1% 16S rRNA identity to E. coli. Additionally, some heterologous ribosomes undergo reduced subunit exchange with E. coli-derived subunits. Cumulatively, this work provides a general framework for heterologous ribosome engineering in living cells

First report of grapevine dieback caused by Lasiodiplodia theobromae and Neoscytalidium dimidiatum in Basrah, Southern Iraq

In Basrah, grapevines suffer from dieback. Lasiodiplodia theobromae and Neoscytalidium dimidiatum were isolated from diseased grapevines, Vitis vinifera L. and identified based on morphological characteristics and DNA sequence data of the rDNA internal transcribed spacer (ITS) region. The results of the pathogenicity test conducted under greenhouse conditions for L. theobromae and N. dimidiatum reveal that both species were the causal agents of grapevines diebacks in Basrah, Southern Iraq. A brief description is provided for the isolated species.Key words: grapevine, dieback, Lasiodiplodia theobromae, Neoscytalidium dimidiatum, internal transcribed spacer (ITS), rDNA, Iraq