High-Pressure Sorption of Hydrogen in Urea.

Hydrogen sorption in urea C(NH2)2O has been probed by direct measurements in Sievert's apparatus at 7.23 and 11.12 MPa as well as by Raman spectroscopy for the sample compressed and heated in a high-pressure gas-loaded diamond-anvil cell up to 14 GPa. Both these methods consistently indicate the occurrence of small nonstoichiometric sorption of hydrogen in urea phase I. The compression of urea in hydrogen affects the Raman shifts of the C-N bending mode δ and the stretching mode υs. The sorption affects the H2 vibron position too. The sorption of 1.3 × 10-2 at 11.12 MPa corresponds to a stochastic distribution of H2 molecules in channel pores of urea. The mechanism leading to this stochastic sorption involves strong correlations between the swollen nanodot regions around the pores accommodating H2 molecules and the squeezed neighboring pores too narrow to act as possible sorption sites. This study on the hydrogen-bonded framework (HOF) of urea marks the smallest pores capable of absorbing hydrogen documented so far. This observation also reveals a new class of compounds, which is located between those that absorb large stoichiometric amounts of certain guest molecules and those that do not absorb them at all, namely, the group of compounds that absorb the guests in a stochastic manner.

Lactation protects against myocardial ischemia-reperfusion injury in rats.

Some researchers have reported that lactation is effective in reducing cardiovascular disease risk factors. The purpose of this study was to investigate whether lactation may improve intrinsic tolerance against ischemia reperfusion (IR) injury. The rats were randomly divided into two groups (n = 8 in each group). In the lactation (Lact) group, the surgery was performed on postpartum day 21 (at the end of lactation period) and the results were compared with those of virgin female rats (control group). Cardiac IR injury was induced by means of left anterior descending coronary artery occlusion for 30 min followed by reperfusion for 120 min. Infarct size was measured using the staining agent 2,3,5-triphenyltetrazolium chloride. At the end of the experiment, Mean arterial pressure in the control group was significantly lower than that in the Lact group. Myocardial infarct size was significantly reduced in the Lact group (23 ± 3% vs. 45 ± 8%, p < 0.05 in the control group). Lactation reduced the extent of myocardial injury induced by ischemia and reperfusion. So, lactation may increase cardiac tolerance to ischemic injury.

Esophageal cancer in Iran; a population-based study regarding adequacy of cancer surgery and overall survival.

AIMS: Prognosis of esophageal cancer (EC) is poor. Population-based studies regarding EC survival and adequacy of cancer surgery (ACS) from developing countries are lacking. We aimed to evaluate EC patients' survival and ACS in a population-based setting for the first time from Iran. METHODS: We randomly selected 409 cases from all 3048 newly diagnosed EC patients who were registered in the nationwide cancer registry in calendar year 2005-2006 and followed them until 2009. An expert panel in Cancer Institute of Iran reviewed adequacy of esophageal cancer surgery on a national basis. RESULTS: Overall three-year survival rate was 17%. The median (95% CI) survival time of all patients and cases who underwent surgery alone were 8.5 (6.9-10.1) and 6.0 (3.1-8.9) months, respectively. The hospital mortality was 27.8% among the operated patients. Only 6.8% of cases had documented free circumferential resection margin and merely 4.0% of patients experienced resection of more than 15 lymph nodes during surgery. CONCLUSIONS: In Iran, the overall survival of EC patients with different treatment modalities are slightly less than those reported from high-income countries, but cases with surgery alone as the main treatment had worse outcome compared with their counterparts in developed countries. Surgery with curative intent has not been performed in most cases in Iran. It seems current clinical outcome of EC patients could be improved with surgical quality improvement and/or more use of chemoradiation in Iran.

Structure-activity relationship study of a series of N-substituted piperazinyl-fluoroquinolones as anti-Helicobacter pylori agents.

Helicobacter pylori is now recognized as the primary etiological factor associated with gastritis, peptic ulcer disease and gastric cancers. Fluoroquinolones have been shown to be active against H. pylori. For develop new anti-H. pylori agents, we have investigated the SAR of a series of N-(phenethyl)piperazinyl quinolones for their antimicrobial activity against H. pylori. The anti-H. pylori activity of synthesized compounds along with commercially available anti-H. pylori agents such as metronidazole, and parent quinolones was evaluated by the disc diffusion bioassay. The results indicated that the potency and anti-H. pylori activity profile of the quinolones is highly dependent on the type of substituent at N-1 and the structure of phenethyl unit on piperazine ring. Most compounds containing a cyclopropyl at N-1 exhibited good activity against H. pylori strains. Among them, ciprofloxacin derivative 13 containing 2-methoxyimino-2-(2-chlorophenyl)ethyl moiety was the most active compound.