Proton-electron mass ratio from laser spectroscopy of HD+ at the part-per-trillion level.

Recent mass measurements of light atomic nuclei in Penning traps have indicated possible inconsistencies in closely related physical constants such as the proton-electron and deuteron-proton mass ratios. These quantities also influence the predicted vibrational spectrum of the deuterated molecular hydrogen ion (HD+) in its electronic ground state. We used Doppler-free two-photon laser spectroscopy to measure the frequency of the v = 0→9 overtone transition (v, vibrational quantum number) of this spectrum with an uncertainty of 2.9 parts per trillion. By leveraging high-precision ab initio calculations, we converted our measurement to tight constraints on the proton-electron and deuteron-proton mass ratios, consistent with the most recent Penning trap determinations of these quantities. This results in a precision of 21 parts per trillion for the value of the proton-electron mass ratio.

Precise test of quantum electrodynamics and determination of fundamental constants with HD+ ions.

Bound three-body quantum systems are important for fundamental physics1,2 because they enable tests of quantum electrodynamics theory and provide access to the fundamental constants of atomic physics and to nuclear properties. Molecular hydrogen ions, the simplest molecules, are representative of this class3. The metastability of the vibration-rotation levels in their ground electronic states offers the potential for extremely high spectroscopic resolution. Consequently, these systems provide independent access to the Rydberg constant (R∞), the ratios of the electron mass to the proton mass (me/mp) and of the electron mass to the deuteron mass (me/md), the proton and deuteron nuclear radii, and high-level tests of quantum electrodynamics4. Conventional spectroscopy techniques for molecular ions5-14 have long been unable to provide precision competitive with that of ab initio theory, which has greatly improved in recent years15. Here we improve our rotational spectroscopy technique for a sympathetically cooled cluster of molecular ions stored in a linear radiofrequency trap16 by nearly two orders in accuracy. We measured a set of hyperfine components of the fundamental rotational transition. An evaluation resulted in the most accurate test of a quantum-three-body prediction so far, at the level of 5 × 10-11, limited by the current uncertainties of the fundamental constants. We determined the value of the fundamental constants combinations [Formula: see text] and mp/me with a fractional uncertainty of 2 × 10-11, in agreement with, but more precise than, current Committee on Data for Science and Technology values. These results also provide strong evidence of the correctness of previous key high-precision measurements and a more than 20-fold stronger bound for a hypothetical fifth force between a proton and a deuteron.

Simplest molecules as candidates for precise optical clocks.

The precise measurement of transition frequencies in cold, trapped molecules has applications in fundamental physics, and extremely high accuracies are desirable. We determine suitable candidates by considering the simplest molecules with a single electron, for which the external-field shift corrections can be calculated theoretically with high precision. Our calculations show that H(2)(+) exhibits particular transitions whose fractional systematic uncertainties may be reduced to 5×10(-17) at room temperature. We also generalize the method of composite frequencies, introducing tailored linear combinations of individual transition frequencies that are free of the major systematic shifts, independent of the strength of the external perturbing fields. By applying this technique, the uncertainty of the composite frequency is reduced compared to what is achievable with a single transition, e.g., to the 10(-18) range for HD(+). Thus, these molecules are of metrological relevance for future studies.

[Purification of recombinant proteins with an example of tumor necrosis factor thymosin-alpha1].

Hybrid protein, cancer necrosis factor thymosin-alpha1 (CNF-T), when synthesizing in strain-producer of Escherichia coli SG200-50 with plasmid pThy315, was a part of "inclusion bodies" mostly in the form of a high-molecular complex with other proteins due to the S-S bonds formation. An approach of purification of CNF-T has been proposed, which is based on the destruction of the complex in the presence of sodium dodecylsulfate (DDS-NA) and dithiotreitol (DDT) followed by gel-filtration on Sephadex G-100 and renaturation by ultrafiltration on hollow fibers. The method allows the isolation of electrophoretically homogeneous CNF-T containing no DDS-Na and having high cytotoxic activity against cancer cells of mouse adenocarcinome L-929. The yield of CNF-T achieved 80% relative its content in biomass and 30% relative the total protein.

Relativistic correction to the 1ssigma and 2psigma electronic states of the H2 + molecular ion and the moleculelike states of the antiprotonic helium He+ -p.

Effective potentials of the relativistic Breit-Pauli corrections for the 1ssigma(g) and 2psigma(u) electron states of the H(2) (+) molecular ion and the 1ssigma, 2ssigma, and 3psigma states of the antiprotonic helium atom He(+)(-)p are calculated within the Born-Oppenheimer approximation. The variational expansion with randomly chosen exponents has been used for numerical studies. The results obtained for the Breit-Pauli effective potentials are accurate up to ten significant digits for the H(2) (+) molecular ion and eight digits for the He(+)(-)p atom.

[An electron microscopic study of the intercellular contact of a vaccinal strain of Francisella tularensis with gram-negative and gram-positive bacteria]. / Elektronno-mikroskopicheskoe izuchenie mezhkletochnogo kontakta vaktsinnogo shtamma Francisella tularensis s gramotritsatel'nymi i grampolozhitel'nymi bakteriiami.

The use of transmission electron microscopy (the negative contrast and ultrathin section techniques) has made it possible to show that F. tularensis vaccine strain is capable, under normal conditions and in mixtures with other gram-negative and gram-positive bacteria, of forming cell aggregations with close contacts between cells, this contact being probably irreversible. The ultrastructure of bacteria taking part in the formation of intercellular contacts remains intact.

[Isolation and purification of bovine and porcine cerebral cathepsin D]. / Vydelenie i ochistka katepsina D iz kory golovnogo mozga byka i svin'i.

Cathepsin D was isolated from the grey matter of bovine and porcine large cerebral hemispheres and purified by affinity chromatography on haemoglobin--Sepharose. The isolation and purification of the enzyme also included: acidic extraction, precipitation by ammonium sulfate, dialysis, affinity chromatography, concentration and gel-chromatography on Sephadex G-100. The degree of purification of bovine cerebral enzyme was 3280. The Km value for the enzyme was 2,06 . 10(-5) M. The purified enzyme from bovine brain showed three major and two minor adjacent bands, possessing the cathepsin D activities. The purified enzyme from porcine brain showed only one protein band.

[The radiological diagnosis of branched cancer of the lung]. / Rentgenodiagnostika raka legkogo razvetvlennoi formy rosta.

The data on 36 patients with branched cancer of the lung are reported, which made 0.8% of the total number of lung cancer patients. A detailed analysis of radiological manifestations of branched lung cancer, presented in the article, indicated that at early stages of the disease its diagnosis is especially difficult and must be based only on the results of bronchoscopy together with biopsy. Clinical signs, as a rule, are followed by radiological symptoms which make possible to establish a reliable diagnosis of branched lung cancer. Tomograms made in the typical bronchial planes of bronchograms yield the most valuable information.

[Exploratory thoracotomies in lung cancer]. / Probnye torakotomii pri rake legkogo

The causes of tentative thoractomies were analyzed in 56 patients with pulmonary cancer. Retrospectively, operative findings were compared with the results of clinicoroentgenological, bronchological studies and mediastinoscopy, The most frequent causes of uneffective interventions were as follows: massive metastatic involvement of lymph nodes of the lung hilus and mediastinum (in 26 patients) and perivasal tumor dissemination (in 18 patients).