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(Figure Presented) Controlling the morphology of soluble small molecule organic semiconductors is crucial for the application of such materials in electronic devices. Using a simple dip-coating process we systematically vary the film drying speed to produce a range of morphologies, including oriented needle-like crystals. Structural characterization as well as electrical transistor measurements show that intermediate drying velocities produce the most uniformly aligned films. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA.

Senile graying of human hair has been the subject of intense research since ancient times. Reactive oxygen species have been implicated in hair follicle melanocyte apoptosis and DNA damage. Here we show for the first time by FT-Raman spectroscopy in vivo that human gray/white scalp hair shafts accumulate hydrogen peroxide (H(2)O(2)) in millimolar concentrations. Moreover, we demonstrate almost absent catalase and methionine sulfoxide reductase A and B protein expression via immunofluorescence and Western blot in association with a functional loss of methionine sulfoxide (Met-S=O) repair in the entire gray hair follicle. Accordingly, Met-S=O formation of Met residues, including Met 374 in the active site of tyrosinase, the key enzyme in melanogenesis, limits enzyme functionality, as evidenced by FT-Raman spectroscopy, computer simulation, and enzyme kinetics, which leads to gradual loss of hair color. Notably, under in vitro conditions, Met oxidation can be prevented by L-methionine. In summary, our data feed the long-voiced, but insufficiently proven, concept of H(2)O(2)-induced oxidative damage in the entire human hair follicle, inclusive of the hair shaft, as a key element in senile hair graying, which does not exclusively affect follicle melanocytes. This new insight could open new strategies for intervention and reversal of the hair graying process.

Estrogen plays an important role in skin homeostasis, as demonstrated by the changes seen in the skin of post-menopausal women, changes reversed by HRT. Estrogen also has a role in wound healing, since estrogen deficiency as occurs post-menopausally and in ovariectomised animals, is associated with a reduced rate of wound healing. Estrogen appears to modulate all phases of wound healing with effects on inflammatory cells, epithelialization, angiogenesis, extracellular matrix deposition and tissue remodelling. This study was designed to investigate the effects of 17beta-estradiol on cultured human dermal fibroblasts using an in vitro wound-healing assay. The end points investigated were cell migration, proliferation, total collagen secretion and active TGF-beta1 secretion. 17beta-estradiol significantly increased the migration and proliferation of cultured dermal fibroblasts following mechanical wounding, although the secretion of total soluble collagen was not altered. An increase in TGF-beta1 was demonstrated by unwounded confluent dermal fibroblast monolayers in response to 17beta-estradiol, but paradoxically, a decrease in the secretion of TGF-beta1 was demonstrated in the mechanically wounded dermal fibroblasts. These results identify human dermal fibroblasts as estrogen target cells and provide further evidence for a role by which estrogen regulates this particular cell type as part of the wound-healing process. However, the paradoxical nature of the effect of estrogen on TGF-beta1 secretion following mechanical wounding suggests that the cellular mechanism of action is complex. A greater understanding of the cell-specific action of estrogen may help to develop therapies that will improve cutaneous wound healing in the future.

The skin locally synthesizes significant amounts of sexual hormones with intracrine or paracrine actions. The local level of each sexual steroid depends upon the expression of each of the androgen- and estrogen-synthesizing enzymes in each cell type, with sebaceous glands and sweat glands being the major contributors. Sebocytes express very little of the key enzyme, cytochrome P450c17, necessary for synthesis of the androgenic prohormones dehydroepiandrosterone and androstenedione, however, these prohormones can be converted by sebocytes and sweat glands, and probably also by dermal papilla cells, into more potent androgens like testosterone and dihydrotestosterone. Five major enzymes are involved in the activation and deactivation of androgens in skin. Androgens affect several functions of human skin, such as sebaceous gland growth and differentiation, hair growth, epidermal barrier homeostasis and wound healing. Their effects are mediated by binding to the nuclear androgen receptor. Changes of isoenzyme and/or androgen receptor levels may have important implications in the development of hyperandrogenism and the associated skin diseases such as acne, seborrhoea, hirsutism and androgenetic alopecia. On the other hand, estrogens have been implicated in skin aging, pigmentation, hair growth, sebum production and skin cancer. Estrogens exert their actions through intracellular receptors or via cell surface receptors, which activate specific second messenger signaling pathways. Recent studies suggest specific site-related distribution of ERalpha and ERbeta in human skin. In contrast, progestins play no role in the pathogenesis of skin disorders. However, they play a major role in the treatment of hirsutism and acne vulgaris, where they are prescribed as components of estrogen-progestin combination pills and as anti-androgens. These combinations enhance gonadotropin suppression of ovarian androgen production. Estrogen-progestin treatment can reduce the need for shaving by half and arrest progression of hirsutism of various etiologies, but do not necessarily reverse it. However, they reliably reduce acne. Cyproterone acetate and spironolactone are similarly effective as anti-androgens in reducing hirsutism, although there is wide variability in individual responses.

The duration of physiologic action of topical glyceryl trinitrate in the management of anal fissure has been the source of some controversy. This study was designed to assess the manometric effect of glyceryl trinitrate on internal sphincter resting tone with continuous monitoring.Twenty-seven patients with a chronic anal fissure were assessed with fissure, pain, bleeding, and continence scores. Twenty-two were randomized to 1 cm of topical 0.2 percent glyceryl trinitrate paste, applied to the lower anal canal. Five patients were randomized to 1 cm of water-soluble lubricating jelly to the lower anal canal. Continuous stationary six radial channel water perfusion anorectal manometry was performed for 5 minutes before treatment and then for a further 30 minutes. The 22 glyceryl trinitrate patients were then advised to apply topical 0.2 percent glyceryl trinitrate, three times daily, for eight weeks. Twenty-four hours after completing treatment, all baseline assessments were repeated. The lubricant jelly cohort was discharged from the study after the initial assessment.During the initial manometric assessment, 21 glyceryl trinitrate patients (95 percent) had 20 percent or more reduction in mean and maximum anal resting pressure after treatment. However, there was no statistical difference at 20 minutes compared with 0 minutes (P0.1). After eight-week treatment, 16 patients (73 percent) reported symptom resolution and 15 (67 percent) were found to be healed on examination. Clinical healing and resolution of symptoms positively correlated with a higher pretreatment maximum anal resting pressure in the mid anal canal (P0.0001), lower fissure score (P0.0001), and greater percentage reduction of the maximum resting pressure after application of glyceryl trinitrate (P0.001). The mean and maximum anal resting pressure at Week 8 was not significantly different from the baseline values (P0.05). During continuous manometry, the anal resting pressure did not significantly change in the patients treated with lubricating jelly.In those patients with a lower fissure score, a higher mid anal canal anal resting pressure, and a greater resting pressure reduction after glyceryl trinitrate application, a favorable clinical outcome can be expected with glyceryl trinitrate treatment. However, because the physiologic response has resolved in fewer than 20 minutes, the dosing regime should be reassessed.

This paper presents the long-term morbidity, function and quality of life data for patients who have undergone dynamic graciloplasty (DGP) for faecal incontinence.All patients (n = 38) who had undergone DGP at one institution between 1993 and 2003 are presented. Thirty-three were available for long-term follow-up (median 60 months) and completed a telephone questionnaire assessing quality of life (QOL), bowel and sexual function and patient satisfaction. All patients had interval anorectal physiology studies.At a median follow-up of 5 years, 72% had pain, swelling or paraesthesia in the donor leg and 27% had sexual dysfunction. Sixteen percent of patients had been converted to an end-colostomy for persisting incontinence and 11% for obstructed defaecation. All other patients have a normally functioning graciloplasty. Sixteen percent of patients reported a faecal continence score12. Of those patients with a functioning graciloplasty, 50% had obstructed defaecation and 64% reported that their bowel dysfunction had a negative impacted on their QOL. Age, medical comorbidity and anal manometry did not correlate with functional outcome. Quality of life scores and patient satisfaction scores correlated significantly with continence scores. There was a trend toward higher QOL and satisfaction scores with conversion to colostomy compared with a continence score12. Sixty percent of patients rated their satisfaction with DGP as 50% or better on a visual analogue scale, and this correlated strongly with the continence score at the time of the assessment (P0.001).Dynamic graciloplasty significantly improves patient quality of life and anal continence for some patients. Despite increased experience, morbidity remains high and long-term continence scores are poor in a majority of cases. Obstructed defaecation is a significant problem after graciloplasty and antegrade colonic enemas may be needed. Significant prognostic factors for obstructed defaecation remain to be identified. The mechanism of both continence failure and surgical morbidity remains poorly defined in many patients and requires further investigation. The individual patient can expect a 16% chance of normal faecal continence at 5 years, with at least one surgical morbidity as a result of the procedure.

Oestrogens play a major role in non-classic target tissues in both sexes, yet there have been few studies on estrogens and skin. Recently a second oestrogen receptor (ERbeta) has been discovered. Therefore, we have compared the expression of oestrogen receptor alpha (ERalpha), beta (ERbeta), the androgen receptor (AR) and a cell proliferation marker in male and female non-balding scalp skin. ERbeta was the major steroid receptor expressed in human skin. It was highly expressed in epidermis, blood vessels and dermal fibroblasts, in contrast to ERalpha and AR. In the hair follicle, ERbeta expression was localized to nuclei of outer root sheath, epithelial matrix and dermal papilla cells, in contrast to ERalpha, and the AR, which was only expressed in dermal papilla cells. Serial sections also showed strong nuclear expression of ERbeta in the cells of the bulge, while neither ERalpha nor AR was expressed. In the sebaceous gland, ERbeta was expressed in both basal and partially differentiated sebocytes. ERalpha exhibited a similar pattern of expression, while the AR was expressed in the basal and very early differentiated sebocytes. There was no obvious difference in the expression of either oestrogen receptor in male or female skin. The wide distribution of ERbeta in human skin suggests that oestrogens may play an important role in the maintenance of skin and in the regulation of the pilosebaceous unit, and provides further evidence for oestrogen action in non-classic target tissues. The differential expression of ERalpha, ERbeta and AR in human skin suggests that the mechanisms by which steroid hormones mediate their effects may be more complex than previously thought.

This review is intended as an introduction to mesomagnetism, with an emphasis on what the defining length scales and their origins are. It includes a brief introduction to the mathematics of domains and domain walls before examining the domain patterns and their stability in 1D and 2D confined magnetic structures. This is followed by an investigation of the effects of size and temperature on confined magnetic structures. Then, the relationship between mesomagnetism and the developing field of spin electronics is discussed. In particular, the various types of magnetoresistance, with an emphasis on the theory and applications of giant magnetoresistance and tunnelling magnetoresistance, are studied. Single electronics are briefly examined before concluding with an outlook on future developments in mesomagnetism.

Red deer stags produce an androgen-dependent mane of long hairs only in the breeding season; in the non-breeding season, when circulating androgen levels are low, the neck hair resembles the rest of the coat. This study was designed to determine whether androgen receptors are present in deer follicles throughout the year or only in the mane (neck) follicles when circulating testosterone levels are high in the breeding season. Although androgens regulate much human hair growth the mechanisms are not well understood; they are believed to act on the hair follicle epithelium via the mesenchyme-derived dermal papilla. The location of androgen receptors in the follicle was investigated by immunohistochemistry and androgen binding was measured biochemically in cultured dermal papilla cells derived from mane and flank follicles during the breeding season and from neck follicles during the non-breeding season. Immunohistochemistry of frozen skin sections using a polyclonal antibody to the androgen receptor localised nuclear staining only in the dermal papilla cells of mane follicles. Saturation analysis assays of 14 primary dermal papilla cell lines using [(3)H]-mibolerone demonstrated high-affinity, low-capacity androgen receptors were present only in mane (breeding season neck) cells; competition studies with other steroids confirmed the specificity of the receptors. Androgen receptors were not detectable in cells from either the breeding season flank nor the non-breeding season neck follicles. The unusual biological model offered by red deer of androgen-dependent hair being produced on the neck in the breeding, but not the non-breeding season, has allowed confirmation that androgen receptors are required in follicle dermal papilla cells for an androgen response; this concurs with previous human studies. In addition, the absence of receptors in the non-breeding season follicles demonstrates that receptors are not expressed unless the follicle is responding to androgens. Androgen receptors may be induced in mane follicles by seasonal changes in circulating hormone(s).

Androgens and oestrogens both have roles in skin physiology. Recently a second oestrogen receptor (ERβ) has been identified in androgen-dependent tissues. The red deer grows a breeding season, androgen-dependent mane when plasma testosterone rises; this is replaced with small neck hairs during the non-breeding season. In non-breeding season deer skin, ERβ was localised to the blood vessels and arrector pili muscle, but in contrast to human skin, not in the pilosebaceous unit or epidermis. The androgen receptor was not expressed. Further studies with breeding season skin may help to elucidate whether serum androgens or androgen receptor expression can modulate the expression of ERβ in skin.

The aim of our study was to evaluate a three-dimensional gadolinium-enhanced breath-hold MR angiography sequence using standard MR gradients in detecting renal artery stenosis.Forty-two patients referred for angiography for suspected renal artery stenosis underwent both conventional digital subtraction angiography (DSA) and MR angiography. MR angiography was performed on a 1.5-T scanner with standard gradients. A fast multiplanar spoiled gradient-echo sequence was used with the following parameters: TR/TE, 10.3/1.9; flip angle, 45 degrees; field of view, 36 x 32 cm; matrix size, 256 x 128; one excitation; volume thickness, 70 mm; and partitions, 28. Gadolinium was administered IV as a dynamic bolus of 30-40 ml. Conventional and MR angiographic images were interpreted by two radiologists in consensus.DSA revealed 87 renal arteries, of which 79 were in 35 patients with native kidneys and eight arteries were in seven patients with transplanted kidneys. Gadolinium-enhanced MR angiography showed 85 (98%) of 87 renal arteries. Seventeen patients had 20 significant (50% stenosis) renal artery stenoses and five patients had five occluded renal arteries revealed by DSA. MR angiography revealed 85 renal arteries (98%), 20 stenoses (100%), and five occlusions (100%). Gadolinium-enhanced MR angiography led to one false-positive interpretation for renal artery stenosis and no false-negative interpretations. Thus, the sensitivity, specificity, and accuracy of MR angiography for renal artery stenosis were 100%, 98%, and 99%, respectively.The MR angiography pulse sequence we used was an effective and reliable technique for the diagnosis of renal artery stenosis. The sequence can be performed on widely available MR equipment that does not require fast gradient hardware.

We evaluated the use of a three-dimensional gadolinium-enhanced MR venography technique in selected patients with suspected central venous abnormalities.Thirty-seven patients with suspected thrombosis, stenosis, occlusion, or compression of the axillary vein, subclavian vein, brachiocephalic vein, or superior or inferior vena cava or with suspected malfunction of central venous catheters were imaged. For all patients, we obtained a three-dimensional dynamic gadolinium-enhanced (bolus injection, 30 40 ml) breath-hold spoiled gradient-recalled acquisition in the steady state as well as conventional venous images from either Doppler sonography, CT, or digital subtraction venography. Breathhold fast multiplanar spoiled gradient-recalled acquisitions in the steady state were obtained using the following parameters: TR/TE, 10.3/1.9; flip angle, 45 degrees; matrix size, 256 x 128; number of excitations, one; field of view, 36-48 cm; number of partitions, 28; and slice thickness, 2.54 mm. MR venograms and conventional images were interpreted by two observers in consensus who were unaware of clinical information and the diagnosis.MR venograms were of diagnostic quality for all 37 patients. Thirteen patients had normal venous systems seen on both conventional and MR images. MR venography showed all nine venous stenoses, the one pericatheter fibrin sheath, and the one jugular vein thrombosis. Axillary or subclavian vein thrombosis was correctly diagnosed with MR venography in all four patients with this condition. Mediastinal venous compression was accurately depicted by MR venography in the five patients who had such compression. Finally, MR venography revealed the correct diagnosis in the three patients with inferior vena cava thrombus and tumor and the one patient with inferior vena cava compression. Thus, MR venography was 100% sensitive, specific, and accurate in the diagnosis of abnormalities affecting large central veins.Compared with conventional imaging, gadolinium-enhanced breathhold MR venography is easy to perform, well tolerated, and highly accurate in depicting central venous abnormalities.

Studies of the spin diffusion and magnetoresistance of multiwall carbon nanotubes contacted to by both cobalt and gold electrodes in magnetic fields of up to 4T are reported. The measured room temperature contact resistance of the Au and Co electrodes ranged from 10^3 to 10^[email protected] The magnetoresistance of tubes contacted to by Au electrodes and measured up to 4T at 4.2 and 2.2K was observed to be negative. The maximum negative magnetoresistance for the nanotubes contacted to by Co electrodes was 25%. As the temperature was increased the magnetoresistance decreased and disappeared above 25K. The spin diffusion length was calculated to be 650nm.

Androgens stimulate many hair follicles, e.g., beard, but may cause regression on the scalp; occipital areas are considered androgen independent. The mesenchyme-derived dermal papilla that regulates the hair follicle is considered the site of androgen action. Because hair size has been clearly related to dermal papilla size, one of the key functions androgens must regulate is the size of the dermal papilla. This implies that androgens stimulate dermal papilla cells to divide or to secrete autocrine mitogenic factors. As physiologic levels of androgens do not stimulate mitogenesis in cultured dermal papilla cells, this study was designed to determine whether dermal papilla cells cultured from human hair follicles with different responses to androgens in vivo, i.e., androgen-dependent beard and androgen-independent nonbalding scalp, produce soluble autocrine mitogenic factors and, if so, whether either cell type altered their secretion in response to testosterone in vitro. Conditioned medium was prepared by incubating individual primary lines of cells for 24 h with, and without, testosterone (10(-10)-10(-5) M). All conditioned media significantly increased [3H] thymidine incorporation by other dermal papilla cells; trypsin treatment significantly reduced the effect. Although both beard and scalp cell conditioned media had a similar stimulatory potential, beard cells incorporated approximately double the [3H]thymidine of scalp cells, in both types of media. Physiologic levels of testosterone increased mitogenic factor production by beard, but not scalp cells; only beard cells responded to these factor(s). Testosterone added after conditioning had no effect, indicating stimulation was not a synergistic effect of testosterone and conditioned medium. Thus, both beard and scalp cells release similar autocrine growth factor(s), but their response to these factor(s) is determined by their in vivo origin. Testosterone in vitro stimulates secretion of an autocrine growth factor(s) by beard, but not scalp cells, to which only beard cells are able to respond, reflecting the responses to androgens in vivo. These factors may be involved in the key increase of dermal papilla size necessary for androgen-induced changes in hair size.

The anomalous properties of the Kondo lattice are compared with the well behaved Kondo system, CePd. The low-temperature thermal expansion of CePd is in agreement with previous heat capacity data, showing a ferromagnetic transition at and a second transition at 3.5 K probably due to reorientation of the magnetic moments. The Gruneisen factor, calculated from thermal-expansion and heat capacity is , the same as the Gruneisen factor calculated from the pressure dependence and comparable to a previous measurement of . Thermal expansion measurements (in fields of up to 8 T) and ac susceptibility measurements (under pressures of up to 7.33 kbar) have been made on in the temperature range 1.6-40 K. The zero-pressure ac susceptibility measurements confirm that there is an antiferromagnetic transition at , as previously reported. The magnetic contribution to the linear thermal-expansion coefficient of polycrystalline in zero magnetic field has a maximum value near 17 K and becomes small by 29 K. There is no peak in at the Neel temperature. The Neel temperature is found to decrease under pressure at the rate of , which indicates that is a magnetic Kondo lattice (with ) on the right-hand side of the Doniach diagram.

Adapting commercial standards to aviation provides a number of advantages over implementing specialist solutions. There has been a steady increase in the capabilities of Ethernet, particularly a 100-fold increase in available bandwidth and the introduction of extra capabilities such as Class/Quality of Service (CoS/QoS) and Virtual Local Area Networks (VLANs.) Ethernet is non-deterministic and is not error-resistant and so there have been attempts to overcome these shortcomings. BAE Systems has developed the Deterministic Ethernet-based Fault Tolerant NETwork (DEFTNET) concept. Unlike Avionics Full-Duplex Switched Ethernet (AFDX), this represents a set of techniques that require no specialised hardware or software components in the end systems. This paper summarises recent efforts to identify suitable components to demonstrate an optical, deterministic Ethernet network suitable for avionics use, including legacy, electrical, systems.

Proximity Effects in electron beam lithography impact feature dimensions, pattern fidelity and uniformity. These effects are addressed using a mathematical model representing the radial exposure intensity distribution induced by a point electron source, commonly named as the Point Spread Function (PSF). PSF models are usually employed for predicting and compensating for effects up to 15μm. It is well known that there are also some process related phenomena that impact pattern uniformity that have a longer range, namely CMP effects, fogging, etc. Performing proximity effects corrections can result in lengthy run times as file size and pattern densities continue to increase exponentially per technology node. Running corrections for extreme long range phenomena becomes computational and file size prohibitive. Nevertheless, since extreme long range may reach up several millimeters, and new technology nodes require a high level of precision, a strategy for predicting and compensating these phenomena is crucial. In this paper a set of test patterns are presented in order to verify and calibrate the so called extreme long range effects in the electron beam lithography. Moreover, a strategy to compensate for extreme long range effects based on the pattern density is presented. Since the evaluation is based on a density map instead of the actual patterns, the computational effort is feasible. The proposed method may be performed off-line (in contrast to machine standard in-line correction). The advantage of employing off-line compensation relies on enhancing the employ of dose and/or geometry modulation. This strategy also has the advantage of being completely decoupled from other e-beam writer’s internal corrections (like Fogging Effect Correction - FEC).

In electron proximity effects correction (PEC), the quality of a correction is highly dependent on the quality of the model used to compute the effects. Therefore it is of primary importance to have a reliable methodology to extract the parameters and assess the quality of a model. Usually, model calibration procedures consist of one or more cycles of exposure and measurements on the calibration stage. The process and metrology variability may play a key role in the quality of the final model and, hence, of the PEC result. Therefore, it is important to determine at which level these variations may impact a calibration procedure and how a calibration design may be implemented in order to enable more robustness to the resulting model. In this work, metrology variability was evaluated by measuring the same wafer using two different CD-SEM tools. The information coming from these analyses was used as reference to a variation induced calibration test using synthetic data. By inserting variability in synthetic data it was possible to evaluate its impact on the resulting parameter values and in the final model error evaluation.

Proximity Effects in electron beam lithography impact feature dimensions, pattern fidelity and uniformity. Electron scattering effects are commonly addressed using a mathematical model representing the radial exposure intensity distribution induced by a point electron source, commonly named Point Spread Function (PSF). PSF models are usually employed for correcting “short-range” and “long-range” backscattering effects up to 10μm to 15μm. It is well known that there are also some process related phenomena impacting pattern uniformity that have a wider range (fogging, chemical mechanical polishing -CMP- effects, etc.) which impacts up to a few millimeters or more. There are a number of commercial strategies for mitigating such long range effects based on data density. However, those traditional ones are usually performed within a single chip on a reticle field and ignore the presence of adjacent fields, neglecting their influence. Full field reticles can contain several different designs or arrayed chips in a multitude of layout placements. Reticle level jobdeck placing each design at specific sites, independent of each other can be used to account for the density of each pattern that has a relative impact on its neighbors, even if they are several millimeters away from offending data. Therefore, full field density analysis accounting for scribe frames and all neighboring patterns is required for reaching fidelity control requirements such as critical dimension (CD) and line end shortening (LES) on the full plate. This paper describes a technique to compensate long range effects going across chip boundaries to the full reticle exposure field. The extreme long range effects are also represented with a model that is calibrated according to the characteristics of the user‟s process. Data correction can be based on dose and geometry modulation. Uniform pattern dimensional control matching the user's specific process long range variability can be achieved with the techniques described in this paper.

Androgens regulate the growth of many human hair follicles, but only pubic, axillary, and scalp hair growth occur in men with 5 alpha-reductase deficiency. This suggests that 5 alpha-dihydrotestosterone is the active intracellular androgen in androgen-dependent follicles, except in the axilla and pubis. Since the dermal papilla plays a major regulatory role in hair follicles and may be the site of androgen action, we have investigated androgen metabolism in six primary lines of cultured dermal papilla cells from pubic and axillary hair follicles; previous studies have shown that beard cells take up and metabolize testosterone, retaining and secreting 5 alpha-dihydrotestosterone. After 24 h preincubation in serum-free Eagle's medium 199, 100-mm dishes of confluent cells were incubated for 2 h with 5 nM [1,2,6,7-3H]testosterone. Media were collected and the cells washed with phosphate-buffered saline and extracted with chloroform: methanol (2:1). After the addition of unlabeled and 14C-labeled marker steroids, the extracts were analyzed by a two-step thin-layer chromatography system; steroid identity was confirmed by recrystallization to a constant 3H/14C ratio. Beard and pubic dermal papilla cells were also incubated for 24 h, and the medium was analyzed at various times. The results from pubic and axillary primary cell lines were similar. In both cells and media the major steroid identified was testosterone, but significant amounts of androstenedione were present, indicating 17 beta-hydroxysteroid dehydrogenase activity; androstenedione was also identified within the cells, but a small amount of 5 alpha-dihydrotestosterone was only identified in one pubic cell line. Beard dermal papilla cells secreted large amounts of 5 alpha-dihydrotestosterone into the medium over 24 h in contrast to pubic cells, which produced only very small amounts. The pubic and axillary cell results contrasts with the observations of pronounced 5 alpha-dihydrotestosterone in beard cells and confirm that androgen metabolism in cultured dermal papilla cells reflects the parent follicle's ability to respond to androgen in the absence of 5 alpha-reductase type II in vivo. This supports our hypothesis that androgen acts on hair follicles via the dermal papilla and suggests that cultured dermal papilla cells may offer an important model system for studies of androgen action.

Objective Androgens have paradoxically different effects on hair follicles depending on body site, stimulating beard growth while inducing regression in some areas of the scalp. The mesenchyme derived dermal papilla at the base of the hair follicle regulates many aspects of the growth of follicular epithelium, and is probably the site of androgen action. Since 5 alpha-dihydrotestosterone is considered to be the active intracellular androgen in many target tissues and is required for some androgen-mediated hair growth, such androgen-sensitive cells should contain 5 alpha-reductase. This study was designed to investigate whether cultured human dermal papilla cells contain 5 alpha-reductase and whether the metabolic capacity varies with the body site of the follicle in line with the clinical picture. Design Testosterone metabolism in cultured dermal papilla cells from androgen sensitive beard follicles was compared with less androgen dependent non-balding scalp follicles. Primary cell cultures were established from follicles of 11 patients with normal hair growth. The cells were grown to confluence in 10-cm Petri dishes and incubated with 5 nM 3H-testosterone in serum-free medium for 2 hours. The cells and the culture medium were collected separately for individual analysis. Measurements Unlabelled carrier and 14C-marker steroids were added to both the cell and medium extracts before separation by thin-layer chromatography. The individual steroid identities were confirmed by recrystallizing up to five times to a constant 3H/14C ratio. Results Testosterone was taken up by both cell types; significant amounts of 5 alpha-dihydrotestosterone were recovered inside beard cells, but not in scalp cells, whereas androstenedione was identified in both. An unidentified compound was present intracellularly in both cell types, but was not present in the culture medium. 5 alpha-Dihydrotestosterone was present only in the culture medium of beard cells but androstenedione was present in a similar amount in the medium from both cell types. The presence of other steroids could not be confirmed in either the cell extracts or the culture medium. Conclusions The production of 5 alpha-dihydrotestosterone by beard cells concurs with the poor beard growth in men with 5 alpha-reductase deficiency, supporting our hypothesis that androgens mediate their effects on the hair follicle via the mesenchyme-derived dermal papilla.

Many hair follicles produce different types of hair in response to environmental changes or the mammals age, that are translated to the follicle by hormones. Androgens cause many changes, such as transforming vellus follicles producing insignificant hairs on the face to terminal beard ones at puberty or the reverse on the scalp. In male red deer the breeding season rise in androgens causes the annual production of a mane on the neck that is lost during the spring. Because the dermal papilla situated at the base of the hair follicle is important in determining the type of hair produced, androgens may act via the dermal papilla. Therefore, primary cell lines of dermal papilla cells from human and red deer follicles with different responses to androgens have been established. Specific saturable androgen receptors were present in all human papilla cells examined, with higher levels in cells from androgen-dependent follicles, e.g., beard than in control, non-balding scalp cells. In preliminary investigations of red deer, androgen receptors were only present in cells derived from mane follicles and were undetectable in flank or spring neck follicles. These similar results from both species support the hypothesis that androgens are acting on hair follicles via the dermal papilla. They also suggest that dermal papilla cells are potentially useful models for investigating the mechanism of androgen action because cultured cells appear to retain differences that relate to the androgen responsiveness of their parent follicle. The red deer seems particularly interesting in view of the much shorter hair-growth cycle than human scalp or beard follicles.

A miniature, monolithic radiofrequency sensor operating with MESFET circuitry in the GHz range is able to detect a wide variety of magnetic, metallic and dielectric materials via the losses induced in the sensitive volume around a coil. Application of the sensor to detect plastic and metal gearwheels and falling liquid drops is illustrated; the signal-to-noise ratio falls off as the inverse distance from the coil to the liquid drop. (C) 2001 Elsevier Science B.V. All rights reserved.

Androgens are major regulators of human hair growth, but their effects vary: many follicles are stimulated by androgens, e.g., beard; some remain unaffected, e.g., eyelashes; whereas scalp follicles undergo regression and balding in genetically disposed individuals. Because the dermal papilla controls many aspects of the hair follicle, androgens may act via the dermal papilla, affecting the other follicular components indirectly. In this hypothesis androgens would alter dermal papilla cell production of regulatory substances, e.g., growth factors and/or extracellular matrix components. To test this theory the mechanism of androgen action has been compared in primary lines of dermal papilla cells cultured from androgen-dependent follicles and relatively androgen-independent non-balding scalp. Androgen receptor levels were assayed by saturation analysis (9-10 points; 0.05-10 nmol/l) using the synthetic androgen [3H]-mibolerone and specificity was confirmed by competition studies. Androgen metabolism was investigated both intracellularly and in the media after a 2-h incubation with 5 nM [3H]-testosterone. Carrier and [14C] steroids were added to the extracts before separation by thin-layer chromatography; steroid identity was confirmed by recrystallization. Dermal papilla cells from androgen-dependent follicles contained higher levels of specific, high-affinity, low-capacity androgen receptors than non-balding scalp cells. Testosterone metabolism also varied with beard, public and scalp cells containing testosterone and androstenedione intracellularly, but only beard cells producing 5 alpha-dihydrotestosterone, in line with the scanty beard growth found in 5 alpha-reductase deficiency. Elsewhere we have shown that cultured dermal papilla cells produce extracellular matrix components and mitogenic factors. These results all concur with our original hypothesis and suggest that further studies of such cells may elucidate the paradoxical effects of androgens on human hair follicles.

Such is the sophistication of many contemporary University Physics Courses that their followers are at ease with the finer details of the Dirac equation and have no difficulty in thinking in a many-dimensioned Hilbert-space: however they are often less confident when faced with knowing which end of a soldering iron gets hot. Spin Electronics is above all a practical science which ultimately promises to implement a new and revolutionary technology in a form which will ultimately impact everyday existence. Card-carrying theoretical physicists doubtless have their part to play in this new and exciting field, but for the rapid and successful development of this science, the importance of practical knowledge and experimental dexterity is paramount. Those who would claim proficiency as Spin Electronicians must, above all, be capable of the simple, basic skills with which every TV repair engineer is acquainted. To those devotees of Spin Electronics whose degree courses have left you electrically deprived, this chapter is dedicated to you. Evidently, in the few pages available, only the surface of this topic may be scratched, but at least the basics can be laid, topics of major confusion like transistors and transformers can be treated and signposts pointed to further study.

The thermal expansion coefficient of polycrystalline CePdSb shows no feature at the Curie point (17 K) but a broad peak near 10 K, in agreement with earlier measurements of the magnetic heat capacity. Single-crystal measurements show that the thermal expansion coefficient of the magnetically hard c direction is an order of magnitude greater than that of the a or b direction. The temperature dependence of the zero external field Sb NMR does not show any unusual behaviour near 10 K.

This study was designed to investigate the effect of extracorporeal magnetic stimulation on anorectal function and physiology. A pilot study comparing the physiology of ten incontinent (9 females) and five continent (4 females) patients with and without perineal magnetic stimulation (10 Hz and 50 Hz) was performed. The ten incontinent patients were treated with two sessions weekly for five weeks of perineal magnetic stimulation. At treatment completion, precontinent and postcontinent scores and resting and squeeze anal pressure were compared. Patients also reported symptom improvement and satisfaction on a linear analog scale. The patients’ mean age was 57 years. Sitting resting and squeeze anal pressures were significantly greater than lying pressures (P = 0.007, 0.047). Both 10-Hz and 50-Hz stimulation effected a significant increase in anal pressures compared with the baseline resting pressure (P = 0.005). The baseline squeeze pressures were significantly higher than the stimulated pressures compared with 50-Hz pressures (P = 0.022). After six weeks of treatment, there was a statistically significant increase in resting and squeeze anal pressures and a significant decrease in continence scores (P = 0.007, P = 0.008, P = 0.017). The mean percentage subjective improvement was 16 percent, and the mean patient satisfaction score was 3.3, positively correlating with an improvement in the continence score. Extracorporeal magnetic stimulation results in a significant increase in anal resting pressure irrespective of pretreatment continence. Although the subjective improvement in continence after treatment is small, there is a significant improvement in both resting pressures and patient continence scores.

The efficacy and pharmacokinetics of botulinum toxin for chronic anal fissure continues to be debated. Addressing both issues we prospectively assessed the manometric impact of botulinum toxin on internal anal sphincter pressure, correlating this impact with chronic anal fissure healing. Sixty patients with chronic fissures were assessed. Fifty-seven patients had a total of 20 units of botulinum toxin injected into the intersphincteric groove at four o’clock and eight o’clock. Patients were prospectively assessed with a linear analog pain score, bleeding score, clinical fissure score, modified St. Mark’s continence score, and anorectal manometry. Each parameter was reassessed two weeks following treatment and again at three months. Fifty-six patients (30 female), median age 43 (range, 17–80) years, were followed for a median of five (range, 3–15) months with fissure healing assessed 12 weeks after treatment. Physical healing and symptom control were dependent on the baseline maximum anal resting pressure and baseline fissure score (P = 0.003, P = 0.009, respectively). Although maximum anal resting pressure fell by 17 (mean, range, 0–71) percent, pressure reduction did not correlate with clinical outcome (P > 0.2). Seventeen patients reported a mean 17 percent increase in continence score. There was no correlation between deterioration in continence and baseline or subsequent reduction in maximum anal resting pressure. Patients with Grade 1 lower-pressure fissures are more likely to heal following treatment with 20 units of botulinum toxin. Healing does not appear to be dependent on a reduction in maximum anal resting pressure.

Oestrogens play a major role in non-classic target tissues in both sexes, yet there have been few studies on estrogens and skin. Recently a second oestrogen receptor (ERbeta) has been discovered. Therefore, we have compared the expression of oestrogen receptor alpha (ERalpha), beta (ERbeta), the androgen receptor (AR) and a cell proliferation marker in male and female non-balding scalp skin. ERbeta was the major steroid receptor expressed in human skin. It was highly expressed in epidermis, blood vessels and dermal fibroblasts, in contrast to ERalpha and AR. In the hair follicle, ERbeta expression was localized to nuclei of outer root sheath, epithelial matrix and dermal papilla cells, in contrast to ERalpha, and the AR, which was only expressed in dermal papilla cells. Serial sections also showed strong nuclear expression of ERbeta in the cells of the bulge, while neither ERalpha nor AR was expressed. In the sebaceous gland, ERbeta was expressed in both basal and partially differentiated sebocytes. ERalpha exhibited a similar pattern of expression, while the AR was expressed in the basal and very early differentiated sebocytes. There was no obvious difference in the expression of either oestrogen receptor in male or female skin. The wide distribution of ERbeta in human skin suggests that oestrogens may play an important role in the maintenance of skin and in the regulation of the pilosebaceous unit, and provides further evidence for oestrogen action in non-classic target tissues. The differential expression of ERalpha, ERbeta and AR in human skin suggests that the mechanisms by which steroid hormones mediate their effects may be more complex than previously thought.

There is still extensive disparity in our understanding of how estrogens exert their actions, particularly in non-reproductive tissues such as the skin. Although it has been recognized for some time that estrogens have significant effects on many aspects of skin physiology and pathophysiology, studies on estrogen action in skin have been limited. However, estrogens clearly have an important function in many components of human skin including the epidermis, dermis, vasculature, hair follicle and the sebaceous, eccrine and apocrine glands, having significant roles in skin aging, pigmentation, hair growth, sebum production and skin cancer. The recent discovery of a second intracellular estrogen receptor (ERbeta) with different cell-specific roles to the classic estrogen receptor (ERalpha), and the identification of cell surface estrogen receptors, has provided further challenges to understanding the mechanism of estrogen action. It is now time to readdress many of the outstanding questions regarding the role of estrogens in skin and improve our understanding of the physiology and interaction of steroid hormones and their receptors in human skin. Not only will this lead to a better understanding of estrogen action, but may also provide a basis for further interventions in pathological processes that involve dysregulation of estrogen action.

We present an analysis of spin injection efficiency that is of general application and relevant to a wide range of spin-electronic devices. By applying simple band structure ideas to a single interface between a metallic ferromagnet and a three-dimensional semiconductor, two conflicting figures of merit are identified - spin accumulation and polarization of injected current - and their validity to the analysis of different device types is discussed. The injected spin accumulation is smaller than the all-metal injection case by a factor (m*/me)3/2(kT/EF)1/2e^eD/kT. Moreover, the injected spin current at the interface is reduced by the factor (m*/me)3/2(kT/EF)(γS/γF) e^eD/kT, where γ for a particular material is the square root of its momentum scattering to spin-flip scattering ratio, m* and me are the effective and free masses, respectively, and eD is the donor binding energy. These results are consequent on the boundary condition that the spin channel electrochemical potentials are continuous at the interface. By inserting an insulating tunnel barrier between the ferromagnet and the semiconductor, not only is this boundary condition removed and the spin polarization of the injected current restored to the all-metal magnitude, but also the spin accumulations in the metal and the semiconductor even have opposite signs. This implies that thin or discontinuous tunnel barriers have the worst spin injection efficiency of any configuration. We finally note that for injected spin current into metals with polarization approaching 100%, the Fermi surface is polarized to a depth which exceeds the equilibrium carrier depth by a factor lSD/λ, hence >>1.

Androgens regulate many aspects of human hair growth in both sexes. After puberty they transform tiny vellus follicles in many areas, e.g. the face, to terminal ones producing long, thick, pigmented hairs. In genetically predisposed individuals, androgens also cause the reverse transformation of terminal scalp follicles into vellus ones, causing balding. In the current hypothesis for androgen action, androgens control most follicular cells indirectly acting via the mesenchyme-derived dermal papilla which regulates many aspects of follicular activity. In this model androgens binding to androgen receptors in dermal papilla cells alter their production of regulatory molecules which influence other follicular components; these molecules may be soluble paracrine factors and/or extracellular matrix proteins. This hypothesis is supported by immunohistochemical localisation of androgen receptors in dermal papilla cell nuclei and the demonstrations that androgen receptor content and testosterone metabolism patterns of cultured dermal papilla cells from various body sites reflect hair growth in androgen-insensitivity syndromes. The next question is whether androgens alter the paracrine factors secreted by dermal papilla cells. Cultured dermal papilla cells do release soluble, proteinaceous factors into their media which stimulate the growth of keratinocytes and other dermal papilla cells. This mitogenic potential can cross species from humans to rodents. Importantly, testosterone in vitro stimulates the mitogenic potential of beard cells, but in contrast inhibits production by balding scalp cells reflecting their in vivo androgenic responses. Since androgens in vitro do alter the secretion of paracrine factors the current focus lies in identifying specific factors produced, e.g. IGF-I and stem cell factor (SCF), using ELISA and RT-PCR, and comparing their expression in cells from follicles with varying responses to androgens in vivo or under androgen stimulation in vitro. This should lead to greater understanding of androgen action and enable the development of better treatment for androgen-potentiated disorders.

The purpose of our study was to evaluate the accuracy of MR myelography in depicting disc herniation in the lumbar spine when compared with conventional MRI in patients presenting with clinical evidence of disc herniation. One hundred patients referred for conventional MR imaging of the lumbar spine also had coronal MR (TR 9000 ms, TE 272 ms eff, NEX 3, echo train length 32) myelography performed. Three experienced observers compared magnetic resonance myelography (MRM) with conventional lumbar spine MR using the following variables: visibility of thecal sac and nerve roots, and the presence, location and severity of disc herniation. Disc protrusions were seen at 110 disc space levels on conventional MR images as opposed to 93 on MRM. However, only 72 % of lesions seen on conventional MR were diagnosed by MRM. Similarly, only 63.8 % of nerve root compression abnormalities seen at conventional MR were visualized when compared with conventional MRM. The sensitivity, specificity and accuracy of MRM when compared with conventional MR was 72, 93 and 85 %, respectively. The MRM technique yields images that resemble conventional myelography and may be used to help confirm abnormalities seen on conventional MR in selected cases; however, the large number of false-positive and false-negative examinations indicates that caution should be used in interpreting MRM images.

Following the introduction of a series of noninvasive imaging modalities (CT, MRI, Doppler sonography) during the last two decades the indications for cerebral angiography have been markedly reduced and, consequently, the number of examinations has been dramatically diminished, in most centres by more than 50%. Thus, angiography is usually not indicated in head trauma, or in brain tumours, both of which were important indications for cerebral angiography prior to the CT era. One may expect this trend to continue, since CT and MRI angiography will reduce the need for conventional cerebral angiography even further.

Androgens are major regulators of human hair growth with paradoxically different effects on hair follicles depending on their body site. They stimulate terminal growth in many regions including the face, have no effect on eyelashes, but may cause inhibition and balding on the scalp in genetically disposed individuals. How this occurs is unknown. However, androgens may act on the hair follicle via the cells of the dermal papilla; these would then influence the other cells of the hair follicle by altering the production of regulatory substances such as growth factors and/or extracellular matrix components. Therefore, primary lines of dermal papilla cells have been established from androgen-sensitive hair follicles, such as beard, and control, relatively androgen-independent, non-balding scalp cells and their mechanism of androgen action has been compared. Isolated beard dermal papillae were larger than those from scalp follicles. Although dermal papilla cells did not respond to in vitro androgens by alterations in growth, androgen-dependent dermal papilla cells contained higher levels of specific, low capacity, high affinity androgen receptors than non-balding scalp cells. The ability of the cells to metabolise testosterone to 5α-dihydrotestosterone in culture also varied in parallel to that predicted from studies of hair growth in the 5α-reductase deficiency syndrome. These results support the hypothesis that androgens act via the dermal papilla. They also show that dermal papilla cells retain differences in gene expression in culture which appear to correspond with their androgenic response in vivo. Further studies of such cells should help elucidate why bald men can grow beards!

We have used nanoimprint lithography to fabricate organic in-plane diodes whose design and process are suitable for mass produced by roll to roll production for simple radio frequency circuitry. The diode characteristics are a result of a channel constriction with rectifying ratios up to 3.25 × 104. Above the threshold voltage their behavior is quadratic, and there is a non-quadratic relationship between the threshold voltage and channel width and channel length. The phenomenon is the resultant interaction of the distribution of the localized states and the additional in-plane transverse electric field through the device channel.

The positronium (Ps) formation cross-section, Q(Ps), for positron-argon interactions has been measured for incident positron energies from threshold to 60 eV, in an attempt to resolve the apparent discrepancy between earlier experimental results. Q(Ps) was found to vary smoothly with positron energy between 15 and 30 eV, in qualitative agreement with earlier results using methods involving the measurement of positron neutralization (as in the current experiment) and in disagreement with the double-peak energy dependence reported by Laricchia et al (2002 J. Phys. B: At. Mol. Opt. Phys. 35 2525-40), who used a positron-ion coincidence detection method. Possible reasons for this discrepancy, including Ps fragmentation and excited-state Ps formation, are discussed.

Background In 1999 an emergency vascular service for Bristol and Avon (including Weston-Super-Mare) (population approximately 1 million) was initiated. Methods Collaboration between Bristol Royal Infirmary, Frenchay and Southmead Hospitals provides week-on–week-off vascular cover for patients requiring urgent and emergency interventions within 24 h. The rota accommodates National Confidential Enquiry into Perioperative Deaths and Vascular Surgical Society of Great Britain and Ireland recommendations, governance issues, and enhances emergency vascular care for Avon residents. Prospectively collected data for the first year (May 1999 to April 2000) are reviewed. Results There were 289 emergency admissions. (In-hospital referrals were not transferred but contributed up to 40 per cent of the extra emergency workload per unit.) Referrals were also accepted from seven Trusts outside the designated catchment area. Caseload included 86 patients with a ruptured or acutely symptomatic aortic aneurysm, of whom 69 underwent operation (30 per cent mortality rate); 17 patients were not operated on. Some 136 patients had critical leg ischaemia (43 acute, 93 chronic); angiography or duplex ultrasonography was performed in 105 cases (77 per cent); 39 patients (29 per cent) had undergone previous intervention for peripheral vascular disease; the mortality rate was 18 (13 per cent) of 136; 18 (13 per cent) of 136 patients required an amputation. Other cases included: upper limb ischaemia, 20 (7 per cent); paediatric emergency, seven (2 per cent); symptomatic carotid disease, five (2 per cent; four endarterectomies with no death or stroke). Some 5 per cent of referrals were inappropriate (venous ulcer, spinal stenosis, etc.). No outcomes were compromised by interhospital transfers. Vascular surgeons operated on nine high-risk patients away from their ‘base’ hospital. A consultant was the principal or assistant operator in more than 95 per cent of operations but, despite trainee rota adjustments, a designated vascular trainee was present in only about 40 per cent of cases. Conclusion Interhospital provision of emergency vascular services for a large population is feasible, does not compromise quality of care, and regulates emergency workload. Further attention to training issues is indicated.

Androgens stimulate hair growth in many areas, e.g. the beard; they also induce regression and balding on the scalp with increasing age in genetically disposed individuals. The cause(s) of this biological conundrum is unknown but age-related; androgen-potentiated changes also occur in the prostate. The mesenchymederived dermal papilla situated at the base of the hair follicle is thought to play an important role in regulating the growth and development of the follicular epithelium. Since androgens probably act on the hair follicle via the dermal papilla, cultures of dermal papilla cells from human hair follicles with differing responses to androgens in vivo have been established and their ability to bind androgens assessed. Receptor binding was assayed by saturation analysis (0·05–10 nmol/l) using the synthetic non-metabolizable androgen, [3H]mibolerone. Shionogi 115 cells were also assayed as a positive control. Specific high-affinity low-capacity androgen receptors were identified in 12 dermal papilla primary cell lines with similar characteristics to established androgen receptors. Cells from androgen-sensitive follicles (beard, scrotum and pubis) contained higher levels of androgen receptors than those derived from relatively androgeninsensitive non-balding scalp follicles whether the receptor content was calculated in relation to cell number, protein or DNA content of the cells. These results support the hypothesis that androgens act on hair follicles via the dermal papilla in vivo and demonstrate that dermal papilla cells exhibit an altered phenotype in culture which depends on the body site from which they were derived. Cultured human dermal papilla cells should prove a useful model system for studies of the mechanism of androgen action, and further investigations may elucidate the paradox of why bald men can grow beards. Journal of Endocrinology (1992) 133, 141–147

The properties of polycrystalline CeAgSb2 have been investigated. The magnetic contribution to the linear thermal expansion coefficient of CeAgSb2 in zero magnetic field has a broad maximum value of 7.9×10−6 K−1 near 17 K but there is no peak at the Neel temperature T N 9.5 K. The Neel temperature is found to decrease under pressure at the rate ∂ ( ln T N )/ ∂ P=−10.1 Mbar−1 indicating that it is a magnetic Kondo lattice on the right-hand side of the Doniach diagram. Below TN the magnetostriction shows hysteresis with an average high field value ∂ ( ln V)/ ∂ B≈+6×10 −6 T−1.

A comparison of four different methods to make electrical contact to both 100nm gold nanowires and 50nm multiwall carbon nanotubes is given. The techniques are compared in terms of the success yield, contact resistance, complexity of the fabrication steps, and potential for creating novel device structures and architectures. The different methods compared are (i) in situ micromanipulation of wires onto prepatterned electrodes, (ii) ion and electron beam assisted deposition, (iii) electron beam lithography, and (iv) drop casting of wires from solution onto prepatterned electrodes.

Results are given for the analysis of particle size distribution of a sample of finely ground phenothiazine by four different methods. Each method is reproducible and is in use for the size analysis of phenothiazine in different laboratories, but the results differ considerably. The advantages and disadvantages of each method are discussed briefly, and a means of comparing the results with those obtained by surface area measurements is shown.