Optical and structural properties of solution deposited nickel manganite thin films

Nickel manganite thin films of interest for microbolometer applications have been prepared using chemical solution and spin spray deposition and studied using transmission electron microscopy to quantify the material crystallinity and spectroscopic ellipsometry to extract the complex dielectric function (ε = ε₁ + iε₂) and film microstructure. A parameterization for ε over a spectral range from 0.04 to 5.15 eV has been developed to model well-crystallized nickel manganite, and the visible-range critical point features, infrared vibrations, and optical absorption onset have been identified. A multiple sample analysis structural model and procedure has been developed for spin spray deposited films exhibiting complicated void evolutions with thickness. Variations in ε and crystallite grain size have been observed as a function of film processing and indicate that the optical properties and microstructural information gained from spectroscopic ellipsometry is useful in process monitoring for this material system.     

Development, pharmacology and clinical experience with clomiphene citrate

This review describes the development and pharmacology of clomiphene and those specific characteristics of both drug and patients which determine its clinical efficacy. The studies reviewed describe clinical observation of patient characteristics (age, additional infertility diagnosis, semen quality), vaginal ultrasound observations of ovaries (number and size of pre-ovulatory follicles) and endometrial lining (thickness, pattern) in 2841 clomiphene cycles in patients who required intrauterine insemination (IUI) because of poor sperm quality or an unsatisfactory postcoital test. They show that (i) conception in clomiphene cycles is related to the number and size of pre-ovulatory follicles, endometrial thickness, patient age, pelvic adhesions, type of anovulatory disorder and semen quality; (ii) pregnancy rates per clomiphene-IUI cycle are constant through at least six cycles; (iii) multiple births cannot be prevented by withholding human chorionic gonadotrophin or advising against coitus when multiple pre-ovulation follicles are present unless all follicles down to 10-12 mm diameter are counted. We also reviewed pregnancy outcome (number of gestational sacs, babies, preclinical and clinical abortion, ectopic pregnancy and birth sex) in 1744 clomiphene pregnancies from our clinic. We found that (i) preclinical and clinical abortions are increased only slightly by clomiphene use, compared to spontaneous pregnancy; (ii) clinical abortions are decreased in patients with polycystic ovaries and luteal insufficiency who use clomiphene; (iii) conception and preclinical abortions are related to endometrial thickness prior to ovulation; (iv) ectopic pregnancies are not increased by clomiphene and (v) the ratio of male births is not altered by clomiphene, except possibly in timed insemination cycles. These studies repudiate many misconceptions regarding clomiphene. They also show that clinical outcome may be improved by pre-ovulation ultrasound monitoring of ovarian and endometrial response.     

Quantification of salmon alpha- and thyrotropin (TSH) beta-subunit messenger RNA by an RNase protection assay: regulation by thyroid hormones

Brightness discrimination of black-white stimuli (1-37 Cd/m; CIE-31 chromatic coordinate X = 0.340, Y = 0.304) were studied using choice conditioning paradigm in two monkey (Macaque Rhesus). Confusion matrices were composed of probabilities of instrument responses to conditioned and differential stimuli in ten series in which one of the ten intensities was employed as a conditioned one. Confusion matrices were transformed into the correlation matrices between the vectors corresponding to the stimuli. Factor analysis of correlation matrices revealed two-dimensional circular structure of monkey's brightness perceptual space. This space was principally similar with that in humans, fishes, and rabbits. Two eigenvectors which constituted two-dimensional Euclidean space of brightness can be interpreted as bright and dark neuronal channels.     

Metabolic fate of S-(-)-pulegone in rat

1. S-(-)-pulegone was administered orally to rat (250 mg/kg) and the nature of the urinary metabolites was investigated. Eleven metabolites, namely S-(-)-menthofuran, piperitone, piperitenone, p-cresol, 5-hydroxypulegone, 4-methylcyclohexenone, 3-methylcyclohexanone, isopulegone, pulegol, 7-hydroxypiperitone and benzoic acid, have been isolated from rat urine. It is assumed that menthofuran, isopulegone and 4-methylcyclohexenone retain the stereochemistry of the parent compound, whereas in other metabolites the stereochemistry at the asymmetric centres is not known. 2. The relative amounts of various major metabolites present in the total urine extracts from the R-(+) and S-(-)-pulegone-treated rat were established by glc analyses. Urine samples of rats treated with R-(+)-pulegone contained higher levels of p-cresol and piperitenone than in similar experiment carried out with S-(-)-pulegone, whereas the levels of unmetabolized pulegone, piperitone and benzoic acid were considerably higher in the urine of rat treated with S-(-)-pulegone than in a corresponding experiment with R-(+)-pulegone. 3. Phenobarbital-induced rat liver microsomes converted S-(-)-pulegone to S-(-)-menthofuran (VII) and piperitenone (III) in the presence of NADPH and O2. The levels of VII and III were significantly higher in similar experiments carried out with R-(+)-pulegone. 4. Based on these studies, metabolic pathways for the biotransformation of S-(-)-pulegone in rat have been proposed and possible reasons for the observed difference in the toxicity mediated by these two enantiomers are discussed.     

Cystic fibrosis transmembrane conductance regulator (CFTR) anion binding as a probe of the pore

We compared the effects of mutations in transmembrane segments (TMs) TM1, TM5, and TM6 on the conduction and activation properties of the cystic fibrosis transmembrane conductance regulator (CFTR) to determine which functional property was most sensitive to mutations and, thereby, to develop a criterion for measuring the importance of a particular residue or TM for anion conduction or activation. Anion substitution studies provided strong evidence for the binding of permeant anions in the pore. Anion binding was highly sensitive to point mutations in TM5 and TM6. Permeability ratios, in contrast, were relatively unaffected by the same mutations, so that anion binding emerged as the conduction property most sensitive to structural changes in CFTR. The relative insensitivity of permeability ratios to CFTR mutations was in accord with the notion that anion-water interactions are important determinants of permeability selectivity. By the criterion of anion binding, TM5 and TM6 were judged to be likely to contribute to the structure of the anion-selective pore, whereas TM1 was judged to be less important. Mutations in TM5 and TM6 also dramatically reduced the sensitivity of CFTR to activation by 3-isobutyl 1-methyl xanthine (IBMX), as expected if these TMs are intimately involved in the physical process that opens and closes the channel.     

The plant cell cycle in context

Biological scientists are eagerly confronting the challenge of understanding the regulatory mechanisms that control the cell division cycle in eukaryotes. New information will have major implications for the treatment of growth-related diseases and cancer in animals. In plants, cell division has a key role in root and shoot growth as well as in the development of vegetative storage organs and reproductive tissues such as flowers and seeds. Many of the strategies for crop improvement, especially those aimed at increasing yield, involve the manipulation of cell division. This review describes, in some detail, the current status of our understanding of the regulation of cell division in eukaryotes and especially in plants. It also features an outline of some preliminary attempts to exploit transgenesis for manipulation of plant cell division.     

Pheochromocytomas that do not accumulate metaiodobenzylguanidine: localization with PET and administration of FDG

Many imaging methods can be used to detect pheochromocytoma, but some tumors are not detected with conventional modalities. To explore the possible usefulness of positron emission tomography (PET) after administration of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) to localize pheochromocytoma in patients with false-negative scintigrams obtained after administration of metaiodobenzylguanidine (MIBG), FDG was administered and PET was performed in two adult patients with pheochromocytomas that had never been localized despite administration of MIBG. In both patients, images were obtained dynamically for 50 minutes; then a limited truncal sequence was performed. PET enabled correct localization of the tumors. In patient 1, a tumor that had not been detected for 21 years was localized in the middle mediastinum; in patient 2, a pheochromocytoma was detected in the right adrenal gland. PET performed after administration of FDG may be useful for localization of pheochromocytomas that do not accumulate MIBG.