61 research outputs found
Biosynthesis and Properties of PHA Containing Monomers 3-Hydroxy-4-Methylvalerate
ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½Π° ΡΠΏΠΎΡΠΎΠ±Π½ΠΎΡΡΡ ΠΏΡΠΈΡΠΎΠ΄Π½ΠΎΠ³ΠΎ ΡΡΠ°ΠΌΠΌΠ° Cupriavidus eutrophus B10646 ΡΠΈΠ½ΡΠ΅Π·ΠΈΡΠΎΠ²Π°ΡΡ ΡΠΎΠΏΠΎΠ»ΠΈΠΌΠ΅ΡΡ, ΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠΈΠ΅ 3-Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈ-4-ΠΌΠ΅ΡΠΈΠ»Π²Π°Π»Π΅ΡΠ°Ρ (3Π4ΠΠ) [Π(3ΠΠ/3ΠΠ/3Π4ΠΠ)]. ΠΠΎΠΊΠ°Π·Π°Π½Π° Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΡ ΡΠΈΠ½ΡΠ΅Π·Π° ΡΡΠ΅Ρ
ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠ½ΡΡ
ΡΠΎΠΏΠΎΠ»ΠΈΠΌΠ΅ΡΠΎΠ², ΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠΈΡ
ΠΌΠΎΠ½ΠΎΠΌΠ΅ΡΡ 3ΠΠ, 3ΠΠ ΠΈ ΠΌΠΎΠ½ΠΎΠΌΠ΅ΡΡ 3Π4ΠΠ ΠΏΡΠΈ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠΈ Π³Π»ΡΠΊΠΎΠ·Ρ ΠΈΠ»ΠΈ ΠΌΠ°ΡΠ»ΡΠ½ΠΎΠΉ ΠΊΠΈΡΠ»ΠΎΡΡ ΠΈ ΡΡΠ±ΡΡΡΠ°ΡΠ°-ΠΏΡΠ΅Π΄ΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΈΠΊΠ°. Π‘ΠΈΠ½ΡΠ΅Π·ΠΈΡΠΎΠ²Π°Π½ΠΎ ΡΠ΅ΠΌΠ΅ΠΉΡΡΠ²ΠΎ ΡΠΎΠΏΠΎΠ»ΠΈΠΌΠ΅ΡΠΎΠ² Ρ ΡΠ°Π·Π»ΠΈΡΠ½ΡΠΌ ΡΠΎΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΠ΅ΠΌ ΠΌΠΎΠ½ΠΎΠΌΠ΅ΡΠΎΠ² ΠΈ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠ΅ΠΌ 3Π4ΠΠ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎ Π΄ΠΎ 7,7 ΠΌΠΎΠ». %. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ ΡΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎΠ΅ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΠ΅ ΡΡΠ΅ΠΏΠ΅Π½ΠΈ ΠΊΡΠΈΡΡΠ°Π»Π»ΠΈΡΠ½ΠΎΡΡΠΈ ΠΏΡΠΈ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠΈ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΡ ΠΌΠΎΠ½ΠΎΠΌΠ΅ΡΠΎΠ² 3ΠΠ ΠΈ 3Π4ΠΠ Π½Π° ΡΠΎΠ½Π΅ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΡΠ΅ΡΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΏΠΎΠ²Π΅Π΄Π΅Π½ΠΈΡ ΡΠΎΠΏΠΎΠ»ΠΈΠΌΠ΅ΡΠΎΠ² ΠΈ ΠΏΠ°Π΄Π΅Π½ΠΈΡ Π²Π΅Π»ΠΈΡΠΈΠ½Ρ ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½ΠΎΠΉ ΠΌΠ°ΡΡΡThe ability of wild-type strain Cupriavidus eutrophus B10646 to synthesize copolymers containing 3-hydroxy-4-methylvalerate (3H4MV) [P(3HB/3HV/3H4MV)] was studied. The possibility of synthesis of terpolymers containing 3HB, 3HV and 3H4MV monomers using glucose, or butyric acid and co-substrate was shown. A family of copolymers with different content of 3H4MV monomer was synthesized. The highest content of 3H4MV was 7.7 mol. %. Increase of 3HV and 3H4MV content in copolymers caused the reduction of crystallinity degree and of molecular weight, and changes of thermal characteristics of copolymer
Dual Activation of Phosphodiesterases 3 and 4 Regulates Basal Spontaneous Beating Rate of Cardiac Pacemaker Cells: Role of Compartmentalization?
Spontaneous firing of sinoatrial (SA) node cells (SANCs) is regulated by cyclic adenosine monophosphate (cAMP)-mediated, protein kinase A (PKA)-dependent (cAMP/PKA) local subsarcolemmal Ca2+ releases (LCRs) from ryanodine receptors (RyR). The LCRs occur during diastolic depolarization (DD) and activate an inward Na+/Ca2+ exchange current that accelerates the DD rate prompting the next action potential (AP). Basal phosphodiesterases (PDEs) activation degrades cAMP, reduces basal cAMP/PKA-dependent phosphorylation, and suppresses normal spontaneous firing of SANCs. The cAMP-degrading PDE1, PDE3, and PDE4 represent major PDE activities in rabbit SANC, and PDE inhibition by 3-isobutyl-1-methylxanthine (IBMX) increases spontaneous firing of SANC by βΌ50%. Though inhibition of single PDE1βPDE4 only moderately increases spontaneous SANC firing, dual PDE3 + PDE4 inhibition produces a synergistic effect hastening the spontaneous SANC beating rate by βΌ50%. Here, we describe the expression and distribution of different PDE subtypes within rabbit SANCs, several specific targets (L-type Ca2+ channels and phospholamban) regulated by basal concurrent PDE3 + PDE4 activation, and critical importance of RyR Ca2+ releases for PDE-dependent regulation of spontaneous SANC firing. Colocalization of PDE3 and PDE4 beneath sarcolemma or in striated patterns inside SANCs strongly suggests that PDE-dependent regulation of cAMP/PKA signaling might be executed at the local level; this idea, however, requires further verification
Extremely broadband ultralight thermally emissive metasurfaces
We report the design, fabrication and characterization of ultralight highly
emissive metaphotonic structures with record-low mass/area that emit thermal
radiation efficiently over a broad spectral (2 to 35 microns) and angular (0-60
degrees) range. The structures comprise one to three pairs of alternating
nanometer-scale metallic and dielectric layers, and have measured effective 300
K hemispherical emissivities of 0.7 to 0.9. To our knowledge, these structures,
which are all subwavelength in thickness are the lightest reported metasurfaces
with comparable infrared emissivity. The superior optical properties, together
with their mechanical flexibility, low outgassing, and low areal mass, suggest
that these metasurfaces are candidates for thermal management in applications
demanding of ultralight flexible structures, including aerospace applications,
ultralight photovoltaics, lightweight flexible electronics, and textiles for
thermal insulation
Lightweight Carbon Fiber Mirrors for Solar Concentrator Applications
Lightweight parabolic mirrors for solar concentrators have been fabricated
using carbon fiber reinforced polymer (CFRP) and a nanometer scale optical
surface smoothing technique. The smoothing technique improved the surface
roughness of the CFRP surface from ~3 {\mu}m root mean square (RMS) for as-cast
to ~5 nm RMS after smoothing. The surfaces were then coated with metal, which
retained the sub-wavelength surface roughness, to produce a high-quality
specular reflector. The mirrors were tested in an 11x geometrical concentrator
configuration and achieved an optical efficiency of 78% under an AM0 solar
simulator. With further development, lightweight CFRP mirrors will enable
dramatic improvements in the specific power, power per unit mass, achievable
for concentrated photovoltaics in space.Comment: IEEE Photovoltaic Specialist Conference (PVSC), DC, USA, 201
Extremely broadband ultralight thermally emissive metasurfaces
We report the design, fabrication and characterization of ultralight highly emissive metaphotonic structures with record-low mass/area that emit thermal radiation efficiently over a broad spectral (2 to 35 microns) and angular (0β60Β°) range. The structures comprise one to three pairs of alternating nanometer-scale metallic and dielectric layers, and have measured effective 300 K
hemispherical emissivities of 0.7 to 0.9. To our knowledge, these structures, which are all subwavelength in thickness are the lightest reported metasurfaces with comparable infrared emissivity. The superior optical properties, together with their mechanical flexibility, low outgassing, and low areal mass, suggest that these metasurfaces are candidates for thermal management in applications demanding of ultralight flexible structures, including aerospace applications, ultralight photovoltaics, lightweight flexible electronics, and textiles for thermal insulation
Extremely broadband ultralight thermally-emissive optical coatings
We report the design, fabrication, and characterization of ultralight highly emissive structures with a record-low mass per area that emit thermal radiation efficiently over a broad spectral (2 to 30 microns) and angular (0β60Β°) range. The structures comprise one to three pairs of alternating metallic and dielectric thin films and have measured effective 300 K hemispherical emissivity of 0.7 to 0.9 (inferred from angular measurements which cover a bandwidth corresponding to 88% of 300K blackbody power). To our knowledge, these micron-scale-thickness structures, are the lightest reported optical coatings with comparable infrared emissivity. The superior optical properties, together with their mechanical flexibility, low outgassing, and low areal mass, suggest that these coatings are candidates for thermal management in applications demanding of ultralight flexible structures, including aerospace applications, ultralight photovoltaics, lightweight flexible electronics, and textiles for thermal insulation
Lightweight Carbon Fiber Mirrors for Solar Concentrator Applications
Lightweight parabolic mirrors for solar concentrators have been fabricated using carbon fiber reinforced polymer (CFRP) and a nanometer scale optical surface smoothing technique. The smoothing technique improved the surface roughness of the CFRP surface from ~3 ΞΌm root mean square (RMS) for as-cast to ~5 nm RMS after smoothing. The surfaces were then coated with metal, which retained the sub-wavelength surface roughness, to produce a high-quality specular reflector. The mirrors were tested in an 11x geometrical concentrator configuration and achieved an optical efficiency of 78% under an AM0 solar simulator. With further development, lightweight CFRP mirrors will enable dramatic improvements in the specific power, power per unit mass, achievable for concentrated photovoltaics in space
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