CO2 regulates molecular rotor dynamics in porous materials.

A crystalline hydrogen-bonded framework with permanent porosity, built by rod-like struts and engineered to bear ultra-fast molecular rotors between two triple bonds, offers the possibility of controlling the rotational rates upon CO2 adsorption. CO2 enters the pores from the gas phase and reduces the rotational rates from the extremely fast regime of 107 Hz at 216 K to 105 Hz. The CO2-rotor interaction was evident from the 2H NMR response to the dynamics of the rotors in contact with CO2 in the crystal structure.

Evolution of untreated mild rejection in heart transplant recipients.

To elucidate whether mild rejection requires treatment, we retrospectively examined the spontaneous natural history of this histologic feature without an increase of immunosuppression. During a 4-year period, 55 heart transplantations were performed in 54 patients on whom 958 endomyocardial biopsies were performed. Among these biopsies, 162 specimens showed features of mild rejection. We studied the results of subsequent biopsies performed 7 to 10 days later, without any change in immunosuppression. These revealed regression of lesions to minimal rejection in 51 cases (31%), the same histologic feature in 82 cases (51%), or progression to moderate or severe rejection in 29 cases (18%). In 82% of these cases, therefore, no aggravation of histologic feature was observed. We separated the cases in which current-study biopsies showed mild rejection into three groups according to the result of the most recent biopsy, that is, minimal, mild, or moderate-severe rejection. The percentage of good outcome was not modified by the nature of the previous biopsy specimen: 84%, if minimal rejection was preceding the study biopsy; 82%, in the cases of mild rejection; and 77%, for moderate or severe rejection. We did not find significant differences in this evolution between patients with fewer or more than two moderate or severe acute rejections in the first 4-month period after heart transplantation (respectively, 15% or 24% progression to moderate or severe acute rejection after nontreated mild rejection).(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation between disc potency and zone size in temafloxacin activity in vitro.

A multi-test disc potency evaluation of a new fluoroquinolone, temafloxacin, has been prepared in order to evaluate the variation of the zone dimension with the disc antibiotic concentration. A direct correlation between these parameters has been demonstrated. All pathogens have been isolated in hospitalized patients.