Hydrolyses of acid derivatives (e.g., carboxylic acid chlorides and fluorides, fluoro- and chloroformates, sulfonyl chlorides, phosphorochloridates, anhydrides) exhibit pseudo-first order kinetics. Reaction mechanisms vary from those involving a cationic intermediate (SN1) to concerted SN2 processes, and further to third order reactions, in which one solvent molecule acts as the attacking nucle...

The rapid diffusion of technology and manufacturing processes to less developed nations has been one of the most significant devel­ opments in the interaction between advanced and less developed countries in recent years. Industries that were almost exclusively concentrated in the most advanced nations less than three decades ago are now commonplace in many developing countries. Thus, while tec...

The replacement of oxygen within a chloroformate ester (ROCOCl) by sulfur can lead to a chlorothioformate (RSCOCl), a chlorothionoformate (ROCSCl), or a chlorodithioformate (RSCSCl). Phenyl chloroformate (PhOCOCl) reacts over the full range of solvents usually included in Grunwald-Winstein equation studies of solvolysis by an addition-elimination (A-E) pathway. At the other extreme, phenyl chlo...

We evaluated cells and lipids recovered in the bronchoalveolar lavage fluid from seven patients with liquid paraffin pneumonitis. For each patient, the BALF was whitish with oil droplets on the surface. Alveolar macrophages contained numerous, large vacuoles that did not react with May-Grunwald-Giemsa, Papanicolaou, or periodic acid-Schiff but were stained in black with Sudan B, orange with Sud...

The aim of this study was to evaluate different methods for Trichomonas vaginalis diagnosis during pregnancy in order to prevent maternal and perinatal complications. A total of 386 vaginal exudates from pregnant women were analyzed. T. vaginalis was investigated by 3 types of microscopic examinations direct wet mount with physiologic saline solution, prolonged May-Grunwald Giemsa (MGG) stainin...

OBJECTIVE Ionizing radiation produces free radicals which induce DNA damage and cell death. Origanum vulgare leaf extract (OVLE) is a natural compound and its capability of scavenging free radicals and its antioxidant activity have been demonstrated by many researchers. In this study, using micronucleus assay, radioprotective effect of OVLE against clastogenic and cytotoxic effect of gamma irra...

By using a micromanipulator, single cells from blast cell colonies were individually transferred to 35-mm culture dishes for secondary colony formation. When individual colonies appeared to be mature, they were examined for cellular composition by May-Grunwald-Giemsa staining and were replated for determination of unexpressed hemopoietic potentials. We describe here a total of 50 mixed hemopoie...

Six patients with the acquired immunodeficiency syndrome (AIDS) who suffered eight spontaneous pneumothoraces between January 1990 and January 1993 underwent videothoracoscopy. The predominant macroscopic findings, found in four patients on five occasions, were white-yellow nodules dispersed throughout the lung surface. In addition, in one patient, these lesions were associated with multiple sm...

UNLABELLED Thyroid nodules are a common pathology of the thyroid gland. Thyroid fine-needle biopsy (FNB) is a technique used as the first step in the assessment of thyroid nodules. Some au- thors have demonstrated the superiority of nonaspiration compared with aspiration biopsy. AIM The objective was to assess whether there are significant differences between the two thyroid biopsy techniques...

A vector of continuous proportions consists of the proportions of some total accounted for by its constituent components. An example is the proportions of U.S. tax revenues from each of personal tax, corporate tax and social tax. We consider the situation where time series data are available and where interest focuses on theprop(}.rti?~srath7r thaIl.tbe ··actual aIl1ounts. Reasons foranaly:z;in...