Adaptive laboratory evolution of a genome-reduced Escherichia coli.

Synthetic biology aims to design and construct bacterial genomes harboring the minimum number of genes required for self-replicable life. However, the genome-reduced bacteria often show impaired growth under laboratory conditions that cannot be understood based on the removed genes. The unexpected phenotypes highlight our limited understanding of bacterial genomes. Here, we deploy adaptive laboratory evolution (ALE) to re-optimize growth performance of a genome-reduced strain. The basis for suboptimal growth is the imbalanced metabolism that is rewired during ALE. The metabolic rewiring is globally orchestrated by mutations in rpoD altering promoter binding of RNA polymerase. Lastly, the evolved strain has no translational buffering capacity, enabling effective translation of abundant mRNAs. Multi-omic analysis of the evolved strain reveals transcriptome- and translatome-wide remodeling that orchestrate metabolism and growth. These results reveal that failure of prediction may not be associated with understanding individual genes, but rather from insufficient understanding of the strain's systems biology

Clinico-pathological Characteristics of Congenital Pulmonary Lymphangiectasis: Report of Two Cases

Congenital pulmonary lymphangiectasis (CPL) is a rare, poorly documented disease, characterized by abnormal dilatation of pulmonary lymphatics without lymphatic proliferation. This disease is seen almost exclusively in infancy and early childhood. It can usually be divided into primary (congenital) and secondary forms. The primary form presents in neonates, and the patients mostly die due to the respiratory distress, shortly after birth. The authors experienced two cases of primary CPL in a 13-day-old male neonate and a one-day-old male neonate, showing prominent lymphatic dilatation in the septal, subpleural, and peri-bronchial tissue throughout both lungs. The latter case was associated with congenital cardiac anomaly including single ventricle. These are unique cases of CPL in Korea of which the diagnosis was established through post-mortem examination. Therefore, the authors report these two cases with primary CPL with a review of the literature

Phase Diagram and Transformations of Iron Pentacarbonyl to nm Layered Hematite and Carbon-Oxygen Polymer under Pressure

We present the phase diagram of Fe(CO)5, consisting of three molecular polymorphs (phase I, II and III) and an extended polymeric phase that can be recovered at ambient condition. The phase diagram indicates a limited stability of Fe(CO)5 within a pressure-temperature dome formed below the liquid- phase II- polymer triple point at 4.2 GPa and 580 K. The limited stability, in turn, signifies the temperature-induced weakening of Fe-CO back bonds, which eventually leads to the dissociation of Fe-CO at the onset of the polymerization of CO. The recovered polymer is a composite of novel nm-lamellar layers of crystalline hematite Fe2O3 and amorphous carbon-oxygen polymers. These results, therefore, demonstrate the synthesis of carbon-oxygen polymer by compressing Fe(CO)5, which advocates a novel synthetic route to develop atomistic composite materials by compressing organometallic compounds

Transformation and structure of silicatelike CO2−VCO_{2}-V

We report the evidence of two different polymorphs for polymeric CO 2-V in tridymitelike (VTD in P212 121) and ?-cristobalitelike (VCR in I-42d) structures. The VTD phase is produced by laser-heating phase III (Cmca) above 40 GPa, whereas the VCR phase by laser-heating highly compressed phase II (P42/mnm - iso-space group to stishovite) and IV (P41212 - iso-space group to ?-cristobalite) above 35 GPa. The density of the VCR (3.988 g/cm3) is ?12% larger than that of the VTD (3.559 g/cm3) at 50 GPa, while the density difference reduces to ?4% at ambient pressure. This results in a substantially smaller bulk modulus (Bo = 127 GPa, B′ = 5.6) for the VCR phase than that of the VTD (Bo = 270 GPa, B′ = 1.9). The smaller density of the VTD is due to the open structure of corner shared CO4 tetrahedra and a great level of distortion in C-O-C angles resulting in a highly buckled layer structure; yet, the structural relationship gives rise to the specific transition to occur depending on the initial phase, either displacively from phase IV to phase VCR or diffusively from phase III to phase VTD. The results also provide new constraints for the phase/chemical transformation diagram of carbon dioxide. © 2013 American Physical Society

Transformation and structure of silicatelike CO

We report the evidence of two different polymorphs for polymeric CO 2-V in tridymitelike (VTD in P212 121) and ?-cristobalitelike (VCR in I-42d) structures. The VTD phase is produced by laser-heating phase III (Cmca) above 40 GPa, whereas the VCR phase by laser-heating highly compressed phase II (P42/mnm - iso-space group to stishovite) and IV (P41212 - iso-space group to ?-cristobalite) above 35 GPa. The density of the VCR (3.988 g/cm3) is ?12% larger than that of the VTD (3.559 g/cm3) at 50 GPa, while the density difference reduces to ?4% at ambient pressure. This results in a substantially smaller bulk modulus (Bo = 127 GPa, B′ = 5.6) for the VCR phase than that of the VTD (Bo = 270 GPa, B′ = 1.9). The smaller density of the VTD is due to the open structure of corner shared CO4 tetrahedra and a great level of distortion in C-O-C angles resulting in a highly buckled layer structure; yet, the structural relationship gives rise to the specific transition to occur depending on the initial phase, either displacively from phase IV to phase VCR or diffusively from phase III to phase VTD. The results also provide new constraints for the phase/chemical transformation diagram of carbon dioxide. © 2013 American Physical Society

Time-resolved x-ray diffraction across water-ice-VI/VII transformations using the dynamic -DAC

We present recent time-resolved x-ray diffraction data obtained across the solidificationof water to ice-VI and -VII at different compression rates. The structural evolutionof ice-VI to ice-VII, however, is not a sharp transition, but occurs rather coarsely. Thediffraction data shows an anisotropic compression behavior for ice VI; that is, the c-axis is morecompressible than the a-axis at the same compression rate. Nevertheless, the present equationsof state of both ice-VI and ice-VII obtained under dynamic loadings agree well with thosepreviously obtained under static conditions. Hence, the present study demonstrates that timeresolvedx-ray diffraction coupled with the dynamic-DAC is an effective method for investigatingdetails of the structural response of materials over a wide range of well-controlled compressionrates. Finally, we found the evidence for an X-ray induced chemical reaction of water and ice-VI. The impurities, produced by the x-ray induced chemical reaction, inhibit the formation ofamorphous ice

Pressure-induced Transformations of Dense Carbonyl Sulfide to Singly Bonded Amorphous Metallic Solid

The application of pressure, internal or external, transforms molecular solids into non-molecular extended network solids with diverse crystal structures and electronic properties. These transformations can be understood in terms of pressure-induced electron delocalization; however, the governing mechanisms are complex because of strong lattice strains, phase metastability and path dependent phase behaviors. Here, we present the pressure-induced transformations of linear OCS (R3m, Phase I) to bent OCS (Cm, Phase II) at 9 GPa; an amorphous, one-dimensional (1D) polymer at 20 GPa (Phase III); and an extended 3D network above ~35 GPa (Phase IV) that metallizes at ~105 GPa. These results underscore the significance of long-range dipole interactions in dense OCS, leading to an extended molecular alloy that can be considered a chemical intermediate of its two end members, CO2 and CS2