Unique water-water coordination tailored by a metal surface.

At low coverage of water on Cu(110), substrate-mediated electrostatics lead to zigzagging chains along [001] as observed with STM [T. Yamada, S. Tamamori, H. Okuyama, and T. Aruga, "Anisotropic water chain growth on Cu(110) observed with scanning tunneling microscopy" Phys. Rev. Lett. 96, 036105 (2006)]. Using x-ray absorption spectroscopy we find an anomalous low-energy resonance at ~533.1 eV which, based on density functional theory spectrum simulations, we assign to an unexpected configuration of water units whose uncoordinated O-H bonds directly face those of their neighbors; this interaction repeats over trough sites with enhanced electron density and is analogous to the case of a hydrated electron.

Comparative theoretical and experimental study of the radiation-induced decomposition of glycine.

The radiation-induced decomposition of glycine is studied using a combination of near-edge X-ray absorption fine structure (NEXAFS) measurements and DFT calculations. The measured spectra show strong dose- or time-dependent effects consistent with a complex, multistep decomposition. Principal component analysis was used to determine the number of distinct molecules that were needed to explain the observed changes in the measured spectra, and the emerging absorption features are assigned to various product molecules through comparison with simulated spectra of several model compounds. It is clear from the experiment that the major effect of soft X-ray irradiation is the fragmentation of the molecule, primarily at the carbonyl sites. Peptide formation is shown to occur under irradiation; a condensation reaction initiated by the removal of a carbonyl oxygen is the proposed mechanism. This study utilizes a novel approach to the study of radiation damage that can occur during measurements and suggests that it may be possible to use simulated model spectra to correct for these effects in measured spectra.

Experimental and theoretical investigation of the electronic structure of 5-fluorouracil compounds.

We present a comparison between experimental and theoretical X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) of 5-fluorouracil compounds, with an emphasis on the effects of the inclusion of nickel in the structure. By focusing on the 1s thresholds of carbon, nitrogen, oxygen, and fluorine it was possible to provide a complete picture of the occupied and unoccupied partial density of states of the 5-fluorouracil systems. Spectra calculated using density functional theory are compared to experimental results. Most experimental results agree well with our theoretical calculations for the XAS and XES of the compounds. All spectral features are assigned. Our results reveal that the nickel in the compound is coordinated with the nitrogen sites of the 5-fluorouracil ligands.

Combined X-ray absorption spectroscopy and density functional theory examination of ferrocene-labeled peptides.

A combination of soft X-ray absorption spectroscopy (XAS) measurements and StoBe density functional theory (DFT) calculations has been used to study the electronic structures of the ferrocene-labeled peptides Fc-Pro(n)-OBz (n = 1-4). Excellent agreement between the measured and the simulated data is observed in all cases, and the origin of all major spectral features was assigned. The breaking of the degeneracy of the ferrocene 3e(2u)-like unoccupied molecular orbital under the influence of a substituent attached to a Cp ring was observed experimentally. The influence of the bonding environment on the O 1s and N 1s XAS spectra was examined. A corrected assignment of one of the major features in the Fe 2p XAS spectra of ferrocene is proposed and supported by the DFT simulations, as well as the measured spectra.

Dependence of DNA electronic structure on environmental and structural variations.

We present experimental and theoretical evidence that varying the local environment and physical structure of dried DNA has a direct impact on its electronic structure. By preparing samples of DNA in various solutions, it was possible to alter the type of ions present during the production of the DNA samples. These variations resulted in differences in the local chemical environment of the dried DNA molecules. X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) were used to probe the variations in the electronic structure of DNA samples. DFT calculations of a stack of 10 adenine (A)-thymine (T) nucleobase pairs show that slight structural variations in stacking height have a direct influence on the electronic structure and result in changes to the HOMO-LUMO gap. The effects of these differences in the local environment on the electronic structure are discussed and are related to the results of conductivity measurements of DNA.

Synthesis of 1-palmitoyl and 1-stearoyl phosphatidylcholines from mixtures of acyl acceptors via acyl-CoA:1-acyl-sn-glycero-3-phosphorylcholine acyltransferase in liver microsomes.

The fatty acid selectivity of the acyl-CoA:1-acyl-sn-glycero-3-phosphorylcholine acyltransferase in rat liver microsomes was studied using a mixture of the [1-(3)H]palmitoyl plus [1-(14C)stearoyl molecular species of 1-acylglyceryl-phosphorylcholine. At a 1-acyl-sn-glycero-3-phosphorylcholine concentration of 0.16 mM, the enzyme exhibited a selectivity of 3.5-fold for the 1-palmitoyl over the 1-stearoyl species of the acyl acceptor and reaction velocities with linoleoyl- and arachidonoyl-CoA were 38--47% greater than with oleoyl-CoA. Lowering the acceptor concentration to 0.016 mM gave reaction rates with the polyenoic thiolesters which were 174--187% greater than with oleoyl-CoA and the 1-palmitoyl-sn-glycero-3-phosphorylcholine was preferred by 2.2, 1.6, and 1.6-fold with oleoyl-, linoleoyl- and arachidonoyl-CoA, respectively. The results support the potential importance of the fatty acid selectivities of the acyl-CoA:1-acyl-sn-glycero-3-phosphorylcholine acyltransferase towards both acyl acceptor and donor in regulating the phosphatidylcholine species formed by the reaction in vivo.

Electronic structure of the nucleobases.

We present a comparison between experimental and calculated soft X-ray spectra of DNA's nucleobases, adenine (A), guanine (G), cytosine (C), and thymine (T) using X-ray absorption spectroscopy (XAS) and soft X-ray emission spectroscopy (XES). Spectra of the 1s thresholds of carbon, nitrogen, and oxygen give a complete picture of the occupied and unoccupied partial density of states of the nucleobases. A combination of both Hartree-Fock and density functional theory calculations are used in the comparison to experimental results. Most experimental results agree well with our theoretical calculations for the XAS and XES of all bases. All spectral features are assigned. A comparison of the experimental highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps is made to the diverse values predicted in the literature.

Follicle-stimulating hormone induces dose-dependant stimulation of immunoreactive inhibin secretion during the follicular phase of the human menstrual cycle.

To determine whether FSH is a physiological regulator of the serum immunoreactive inhibin (INH) concentration during the follicular phase of the normal menstrual cycle, purified FSH (Metrodin) was administered in doses of 100 IU (n = 6), 150 IU (n = 5), and 200 IU (n = 5) to normal, regularly cycling volunteers between days 3-7 of the menstrual cycle. A control group (n = 5) received normal saline. There was a linear dose-related increase in serum INH (and in serum FSH) in response to the three doses of FSH, with 200 IU leading to a 107% increase in INH and a 68% increase in FSH. Serum estradiol rose in response to the two higher doses of FSH. There was a significant correlation between the actual increases in INH and estradiol (r = 0.53; P < 0.01). It was concluded that FSH stimulates INH in the follicular phase of the normal menstrual cycle, consistent with a physiological role for FSH in the regulation of granulosa cell production of inhibin.

Perimenopausal patterns of gonadotrophins, immunoreactive inhibin, oestradiol and progesterone.

In order to assess the possible role of circulating immunoreactive inhibin (INH) during the menopausal transition, two groups of subjects were studied. Four were normal volunteers, three of whom had developed their first symptoms of cycle irregularity at age 45-46 years, the fourth being aged 37, a volunteer for a study involving daily blood sampling found to have a transient rise in serum follicle stimulating hormone (FSH). Six were patients with anovulatory infertility, aged 34-44 years, found to have transitory ovarian failure during attempts at ovulation induction. Intermittent blood samples were obtained for radioimmunoassay of serum FSH, luteinizing hormone (LH), INH, oestradiol (E2), and progesterone. Abrupt changes were observed, with transient elevations of FSH and LH and decreases of INH and E2 into the postmenopausal range, followed by levels more characteristic of reproductive-aged women. It was concluded that typical postmenopausal hormone patterns may occur at the time of entry into the normal menopausal transition, and in some women with anovulatory infertility, but may be completely and relatively abruptly reversible. Elevation of serum FSH into the postmenopausal range, with undetectable INH concentrations, does not provide reliable evidence that the menopause (or permanent ovarian failure) has occurred. INH contributes to elevations of serum FSH during the menopausal transition.

Chlamydia trachomatis in primary care: knowledge and practice in Glasgow.

A recent Department of Health report recommended the establishment of a selective screening programme for Chlamydia trachomatis infection. We report a survey which suggests that primary care clinicians may not yet be prepared for this task.

A Hole in the Heart: confronting the drive for evidence-based impact research in arts and health.

The field of arts and health, and associated academic discussion, is beset by a number of interlinked challenges which make it vulnerable to academic dismissal or, at best, poor visibility. One of these is a preoccupation with developing an evidence base of impact. This is compounded by resistance to definitions, disagreement over what constitutes appropriate evidence of success, and inadequate consideration of the mechanisms of arts and health practice, as opposed to outcomes. We argue that increased attention should be paid to the description, analysis and theorising of the practice itself as the basis upon which the findings of impact studies can be understood and accepted. A literature review identifies some important emerging themes in community arts and health practice, and some lacunae in need of further investigation. We conclude that an interdisciplinary theoretical framework for the practice could make a valuable contribution to the academic status of the field.

Literature and the "good doctor" in Ian McEwan's Saturday.

There is widespread acceptance in medical humanities circles that reading is good for doctors and that, in medical educational terms, it is particularly good at making better doctors by widening perspective and developing the sensibilities. Recent recommendations on medical education in the UK have allowed medical students to take courses in literature as a component of their degrees, and some have suggested that this option should be compulsory for all doctors. It is possible, however, that in our eagerness to assert the primacy of a literary education for personal development, we can ignore other routes to enlightened, sensitive doctoring. This paper appraises the instrumental role of a literary education for doctors through an analysis of Ian McEwan's novel Saturday, which deals with the dramatic events in the day in the life of a neurosurgeon.

Should medical students read Plato?

In the United Kingdom, the General Medical Council has recommended that the medical curriculum should consist of a core of basic medical courses plus special study modules drawn from both medical and non-medical disciplines. One such study module at Glasgow University brought medical students together with arts students to study moral and political philosophy through a reading of Plato's Republic.

The vagina as an alternative to the rectum in measuring abdominal pressure during urodynamic investigations.

Pressure in the vagina as well as within the bladder and rectum was measured during urodynamic investigations. Rectal pressure is normally used to represent changes in abdominal pressure which, when subtracted from the total bladder pressure, provides a method of assessing detrusor function. This study showed that vaginal pressure represented changes in abdominal pressure more accurately and consistently than did rectal pressure, and the vagina is therefore recommended as an alternative site in conducting urodynamic studies.

Age related changes in follicle stimulating hormone, luteinizing hormone, oestradiol and immunoreactive inhibin in women of reproductive age.

OBJECTIVE: In women over the age of 45 years with continuing regular menstrual cycles, follicular phase FSH levels rise without an accompanying change in LH. We determined the effect of increasing age in women with regular cycles on the serum levels of FSH, LH, immunoreactive inhibin, progesterone and oestradiol. DESIGN: Single blood samples were taken during the early follicular phase (days 4-7) and again in the midluteal phase (3-12 days before the next menses) of the menstrual cycle. PATIENTS: Regularly cycling women aged 21-49 years participated in the study (and were grouped into four groups: 20-29, 30-39, 40-44 and 45-49 years in the follicular phase and three groups: 20-29, 30-39 and 40-49 years in the luteal phase. MEASUREMENTS: Serum levels of FSH, LH, oestradiol, progesterone and immunoreactive inhibin were measured from the blood samples obtained. RESULTS: Follicular phase Mean follicular phase levels of immunoreactive inhibin were significantly lower in the 45-49 year age group (P less than 0.05) than in the younger age groups (128 U/l in the 45-49 year age group vs 239, 235 and 207 U/l in the 20-29, 30-39, 40-44 year age groups respectively), while mean FSH levels were significantly higher in the 45-49 year age group (P less than 0.05, 13.0 IU/l in the 45-49, 4.9, 5.5 and 5.2 IU/l in the 20-29, 30-39 and 40-44 year age groups respectively). Mean oestradiol levels in the 45-49 year age group were significantly lower only when compared to age group 30-39 years (P less than 0.05, 130 vs 210 pmol/l). There was no significant difference in oestradiol levels between the 45-49 year age group and the 20-29 and 40-44 year age groups. LH levels did not differ significantly across age groups. There was also a significant negative correlation between serum immunoreactive inhibin and FSH (r = -0.45, P less than 0.05) and between oestradiol and FSH (r = -0.35, P less than 0.05). There was a significant negative relationship between immunoreactive inhibin and age (r = -0.46, P less than 0.05). For every 10-year increase in age, average immunoreactive inhibin decreased by an estimated 49.3 U/l. As age increased, average FSH levels exhibited a two-phase linear increase with the change-point estimated at 42.97 (1.42) (estimate (SE)) years. Prior to 42.97 years, FSH barely changed; after 42.97 years there was a significant (P less than 0.05) increase in FSH as age increased. Oestradiol levels did not change significantly until an estimated 37.9 years of age, but then decreased significantly (P less than 0.05) with increasing age. Luteal phase Levels of FSH, LH, serum immunoreactive inhibin, oestradiol and progesterone fell slowly with increasing age. There was a significant correlation between serum immunoreactive inhibin with progesterone (r = 0.41, P less than 0.05) but there was no correlation between serum immunoreactive inhibin LH or FSH. CONCLUSION: The results are consistent with a role for serum immunoreactive inhibin, in addition to oestradiol, in the regulation of FSH during the follicular phase of the menstrual cycle as a function of increasing age. This is postulated to reflect diminished folliculogenesis as age progresses with the known decline in the numbers of primordial follicles in the ovary as the menopause approaches.