Results 31 to 40 of about 569,974 (248)

X-ray Properties of Pre--Main-Sequence Stars in the Orion Nebula Cluster with Known Rotation Periods

open access: yes, 2004
We re-analyze all archival Chandra/ACIS observations of the Orion Nebula Cluster (ONC) to study the X-ray properties of a large sample of pre--main-sequence (PMS) stars with optically determined rotation periods. Our goal is to elucidate the origins of X-
Bouvier J.   +9 more
core   +1 more source

X-RAY MONITORING OF ULTRALUMINOUS X-RAY SOURCES [PDF]

open access: yesThe Astrophysical Journal, 2009
X-ray monitoring observations were performed with the Swift observatory of the ultraluminous X-ray sources Holmberg IX X-1, NGC 5408 X-1, and NGC 4395 X-2 and also of the nuclear X-ray source in NGC 4395. Holmberg IX X-1 remains in the hard X-ray spectral state as its flux varies by a factor of 7 up to an (isotropic) luminosity of 2.8E40 erg/s.
Kaaret, Philip, Feng, Hua
openaire   +2 more sources

Structural insights into an engineered feruloyl esterase with improved MHET degrading properties

open access: yesFEBS Letters, EarlyView.
A feruloyl esterase was engineered to mimic key features of MHETase, enhancing the degradation of PET oligomers. Structural and computational analysis reveal how a point mutation stabilizes the active site and reshapes the binding cleft, expading substrate scope.
Panagiota Karampa   +5 more
wiley   +1 more source

Electron beam welder X-rays its own welds [PDF]

open access: yes, 1967
Beam of an electron beam welder X rays its own welds, enabling rapid weld quality checks to be made without removing the work from the vacuum chamber. A tungsten target produces X rays when hit by the beam.
Roden, W. A.
core   +1 more source

Interstellar Gas and X-rays toward the Young Supernova Remnant RCW 86; Pursuit of the Origin of the Thermal and Non-Thermal X-ray

open access: yes, 2017
We have analyzed the atomic and molecular gas using the 21 cm HI and 2.6/1.3 mm CO emissions toward the young supernova remnant (SNR) RCW 86 in order to identify the interstellar medium with which the shock waves of the SNR interact.
Fukuda, T.   +15 more
core   +1 more source

A methionine‐lined active site governs carbocation stabilization and product specificity in a bacterial terpene synthase

open access: yesFEBS Letters, EarlyView.
This study reveals a unique active site enriched in methionine residues and demonstrates that these residues play a critical role by stabilizing carbocation intermediates through novel sulfur–cation interactions. Structure‐guided mutagenesis further revealed variants with significantly altered product profiles, enhancing pseudopterosin formation. These
Marion Ringel   +13 more
wiley   +1 more source

X-ray Raman compression via two-stream instability in dense plasmas

open access: yes, 2011
A Raman compression scheme suitable for x-rays, where the Langmuir wave is created by an intense beam rather than the pondermotive potential between the seed and pump pulses, is proposed.
Borghesi M.   +3 more
core   +1 more source

AAA+ protein unfoldases—the Moirai of the proteome

open access: yesFEBS Letters, EarlyView.
AAA+ unfoldases are essential molecular motors that power protein degradation and disaggregation. This review integrates recent cryo‐electron microscopy (cryo‐EM) structures and single‐molecule biophysical data to reconcile competing models of substrate translocation.
Stavros Azinas, Marta Carroni
wiley   +1 more source

Solar X-ray spectrum reproduced in vacuum [PDF]

open access: yes, 1967
Desired low energy X rays are produced by modifying commercial ion tubes and combining them with standard power supplies and control circuitry.
Erdman, C. A., Kirchner, L. P.
core   +1 more source

Soft coronal X-rays from \beta{} Pictoris

open access: yes, 2012
A type stars are expected to be X-ray dark, yet weak emission has been detected from several objects in this class. We present new Chandra/HRC-I observations of the A5 V star \beta{} Pictoris.
Allen   +23 more
core   +1 more source

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