Acute and repetitive fronto-cerebellar tDCS stimulation improves mood in non-depressed participants.

Transcranial direct current stimulation (tDCS) is a non-invasive form of brain stimulation, which allows for selective inhibition or excitation of neural structures. It has demonstrated some efficacy in the treatment of mood disorders. However, these studies have predominately focused on stimulation of the prefrontal cortex (PFC). The cerebellum has an increasingly recognized role in emotional control, affective state, and some psychopathologies. As such, tDCS research into mood modulation needs to expand beyond conventional PFC-focused paradigms. Using a contralateral stimulation electrode placement [anodal left dorsolateral(dl)PFC, cathodal right cerebellum], and a single-blind, repeated-measures design, we initially assessed changes in the mood of healthy participants in response to acute stimulation (n = 44) and three repeated stimulations delivered second-daily (n = 21). In a second experiment, we separately investigated the influence of reversed polarity upon these same measures, in response to acute stimulation (n = 23) and repeated stimulation (n = 11). We observed a systematic elevation of mood in both active conditions following single and repeated tDCS, the latter of which displayed a progressive elevation of mood from baseline. No mood change was noted in response to either single or repeated stimulation in the sham condition. Frontocerebellar tDCS stimulation advantageously influences mood in healthy participants, with an accumulative and potentiated effect following successive stimulations. The possibility that frontocerebellar stimulation may provide a novel therapeutic adjunctive or pre-emptive intervention in stress-related disorders and mood-related psychopathologies should be considered.

Hierarchical structures of cactus spines that aid in the directional movement of dew droplets.

Three species of cactus whose spines act as dew harvesters were chosen for this study: Copiapoa cinerea var. haseltoniana, Mammillaria columbiana subsp. yucatanensis and Parodia mammulosa and compared with Ferocactus wislizenii whose spines do not perform as dew harvesters. Time-lapse snapshots of C. cinerea showed movement of dew droplets from spine tips to their base, even against gravity. Spines emanating from one of the areoles of C. cinerea were submerged in water laced with fluorescent nanoparticles and this particular areole with its spines and a small area of stem was removed and imaged. These images clearly showed that fluorescent water had moved into the stem of the plant. Lines of vascular bundles radiating inwards from the surface areoles (from where the spines emanate) to the core of the stem were detected using magnetic resonance imaging, with the exception of F. wislizenii that does not harvest dew on its spines. Spine microstructures were examined using SEM images and surface roughness measurements (Ra and Rz) taken of the spines of C. cinerea It was found that a roughness gradient created by tapered microgrooves existed that could potentially direct surface water from a spine tip to its base.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'.

Dew harvesting efficiency of four species of cacti.

Four species of cacti were chosen for this study: Copiapoa cinerea var. haseltoniana, Ferocactus wislizenii, Mammillaria columbiana subsp. yucatanensis and Parodia mammulosa. It has been reported that dew condenses on the spines of C. cinerea and that it does not on the spines of F. wislizenii, and our preliminary observations of M. columbiana and P. mammulosa revealed a potential for collecting dew water. This study found all four cacti to harvest dew on their stems and spines (albeit rarely on the spines of F. wislizenii). Dew harvesting experiments were carried out in the UK, recording an increase in cacti mass on dewy nights. By applying a ranking relative to a polymethyl methacrylate (Plexiglas) reference plate located nearby, it was found that C. cinerea collected the most airborne moisture followed by M. columbiana, P. mammulosa and F. wislizenii respectively, with mean efficiency ratio with respect to the Plexiglas reference of 3.48 ± 0.5, 2.44 ± 0.06, 1.81 ± 0.14 and 1.27 ± 0.49 on observed dewy nights. A maximum yield of normalized performance of 0.72 ± 0.006 l/m(-2) on one dewy night was recorded for C. cinerea. Removing the spines from M. columbiana was found to significantly decrease its dew harvesting efficiency. The spines of three of the species were found to be hydrophilic in nature, while F. wislizenii was hydrophobic; the stems of all four species were hydrophilic. The results of this study could be translated into designing a biomimetic water collecting device that utilizes cactus spines and their microstructures.

Nature's moisture harvesters: a comparative review.

Nature has adapted different methods for surviving dry, arid, xeric conditions. It is the focus of this comparative review to pull together the relevant information gleaned from the literature that could be utilized to design moisture harvesting devices informed by biomimetics. Most water harvesting devices in current use are not informed by nature and those that do are usually based on a biomimetic principle that has been based on one species only. This review draws on the published literature to establish a list of species (animals (vertebrates/invertebrates) and plants) whose habitat is in mainly dry or arid regions and that are known to harvest airborne moisture. Key findings have been outlined and review comments and discussion set out. Following this, surface feature convergences have been identified, namely hexagonal microstructures, groove-like and cone-like geometries. This has been coupled with direction of water flow that is driven by surface energy. As far as the authors are aware, this convergent evolution has not been brought together in this manner before. In the future this information could be translated into an engineered device for collecting water from airborne sources.

Pulsed-dye laser treatment for inflammatory acne vulgaris: randomised controlled trial.

BACKGROUND: Low-fluence (low irradiation energy density) pulsed-dye lasers (PDLs) have been used for atrophic acne scarring, and anecdotal experience suggests that long-term improvements in inflammatory acne can be seen after one PDL treatment. Our aim was to compare the efficacy and tolerability of such PDL treatment with sham treatment in patients with facial inflammatory acne in a double-blind, randomised controlled trial. METHODS: We recruited 41 adults with mild-to-moderate facial inflammatory acne. We randomly assigned patients to PDL (n=31) or sham treatment (n=10). Treatment was given at baseline and patients were seen after 2, 4, 8, and 12 weeks. Assessors and participants were unaware of treatment allocations. Primary outcome measures were acne severity after 12 weeks and adverse events at any time. Secondary measures were change in lesion counts after 12 weeks and change in acne severity with time. Analysis was by intention-to-treat. FINDINGS: After 12 weeks, acne severity (measured by Leeds revised grading system) was reduced from 3.8 (SD 1.5) to 1.9 (1.5) in the PDL group and 3.6 (1.8) to 3.5 (1.9) in the sham group (p=0.007). Treatment was well tolerated. Total lesion counts fell by 53% (IQR 19 to 64) in PDL patients and 9% (-16 to 38) in controls (p=0.023), and inflammatory lesion counts reduced by 49% (30 to 75) in PDL patients and 10% (-8 to 49) in controls (p=0.024). The most rapid improvements were seen in the first 4 weeks after treatment. INTERPRETATION: PDL therapy improves inflammatory facial acne 12 weeks after one treatment with no serious adverse effects.

Evaluation of the ruby 694 Chromos for hair removal in various skin sites.

Lasers have been established as effective treatment for hair removal, with possible long-term suppression of hair growth in treated areas. The purpose of this study was to assess long-term hair regrowth after treatment with the ruby laser. Volunteers recruited into the 1997-99 study were divided between three treatment groups, each having left and right treatment sides. Two treatments were given on both sides at monthly intervals. A third treatment was given randomly to one side. Hair counts of the experimental sites were made at monthly intervals for 1 year. The three patient groups were: top lip (25), axillae (25) and legs (19). Long-term hair reduction was achieved in all patients. A single treatment reduced hair counts by up to 75. Three treatments had an impact for 2 additional months, but not long term. Unexpected spontaneous hair reduction was found 5 months following treatment and lasted 2 months. This ruby laser produced a persistent two-thirds reduction in hair count over 8 months of follow-up. Extension of the follow-up to 12 months did not show significant regrowth. Existing experimental data, together with the results of this study, suggest that hair shaft damage is the key feature in achieving damage to the hair-producing mechanism. The correlation of treatment success and anagen growth phase is less likely.

Pulsed dye laser treatment of burn scars. Alleviation or irritation?

INTRODUCTION: Burn scars are very common in both children and adults, causing great morbidity and often pose a difficult management problem. This study investigated the efficacy of the dye laser in patients with symptomatic burn scars and analysed the impact of the laser treatment on scar redness, surface texture and pruritus. METHODS: Patients were placed into four groups-adult new scar (n=8), adult old scar (n=10), children new scar (n=5) and children old scar (n=15). The area of scar was divided randomly into treatment and control. Photography, histology, surface textural analysis, Vancouver and pruritus scores were made. Each selected area received three laser treatments at monthly intervals (wavelength of 585 nm with a 5 mm diameter spot at 5-6J/cm(2)). Further assessments were made at 6 and 12 months. RESULTS: Pruritus improved significantly between treatment and control areas (P<0.001). Vancouver scores improved in all groups and sites (P<0.001), but not significantly between treatment and control at 6 (P=0.876) or 12 months (P=0.680). There was no statistical difference between treatment and control in photographic assessment at 6 (P=0.006) or 12 months (P=0.329) and surface profile measurements at 0 (P=0.552), 6 (P=0.107) or 12 months (P=0.227). One patient withdrew from the study because of scar breakdown and three patients were lost to complete follow-up. CONCLUSION: The 585 nm flashlamp-pumped pulsed dye laser is an effective treatment for the intense pruritus often experienced during the healing process after a burn injury. This study has not shown other benefits, such as reduction in scar redness, height and textural improvement to be statistically significant. There is evidence that blood vessel diameters in hypertrophic scar tissue are much smaller than the vessels in port wine stains for which this laser was designed to treat. Therefore, by decreasing the pulse width, more vascular specific damage in the scar may be possible. It is likely that the beneficial effects demonstrated thus far result from changes to the chemical signals that regulate the scar growth and symptoms.

The removal of unwanted hair using a ruby laser.

A ruby laser has been developed to remove unwanted hair. Melanin within the hair is used as a natural chromophore. It is postulated that photothermal damage destroys the hair itself and also key cells surrounding the hair follicle to prevent regrowth. A prospective study of laser depilation in 116 patients or 175 sites was performed over a period of 18 months. All the patients had tried other methods of hair removal and found them to be unsatisfactory. Hair counts (follicles/cm2) were used to judge the outcome. The mean follow-up time was 23.25 weeks (range 12-76 weeks). After a mean number of treatments of 1.92 (range 1-20) there was a 56.4% reduction in hair density. Comparing pre- and post-treatment hair density, there was a highly significant reduction (paired t-test: P < 0.00001). Laser removal of hair is now a realistic treatment option.

Carbon dioxide laser ablation of cutaneous metastases from malignant melanoma.

Multiple cutaneous and superficial subcutaneous metastases from malignant melanoma in 30 patients were treated palliatively by carbon dioxide laser ablation when lesions were to numerous, too large or recurring too rapidly for multiple local excisions. The number of lesions per patient ranged from three to 250 (median 30). Patients were treated under local or general anaesthetic and as day cases or inpatients. After a median follow-up interval of 8 months fewer than 1 per cent of lasered metastases have recurred locally. Sixteen patients have developed cutaneous metastases at other sites requiring further treatment. Approximately 2000 lesions have been treated on 64 occasions. Patients reported little or no pain after the operation and required only simple dry dressings. Wounds were completely healed in 2-6 weeks with good cosmetic results. This simple and effective treatment is becoming an alternative to isolated limb perfusion.

Reflection of CO2 laser radiation from typical surfaces encountered in hospital environments.

Measurements of the reflectivity of CO2 laser radiation (10.6 micron) from typical clinical surfaces are reported. The results obtained confirm that stray reflections from these surfaces could be a potential hazard to both patient and hospital staff. Some conducting surfaces, for example, reflect up to 95% of the radiation incident upon them and even dielectrics reflect over 50% in some cases. The results reported are for linearly polarised light only. Strong evidence is shown that the deposition of certain thin coatings dramatically reduces the percentage of 10.6 micron radiation reflected.