Giant spin hydrodynamic generation in laminar flow.

Hydrodynamic motion can generate a flux of electron-spin's angular momentum via the coupling between fluid rotation and electron spins. Such hydrodynamic generation, called spin hydrodynamic generation (SHDG), has recently attracted attention in a wide range of fields, especially in spintronics. Spintronics deals with spin-mediated interconversion taking place on a micro or nano scale because of the spin-diffusion length scale. To be fully incorporated into the interconversion, SHDG physics should also be established in such a minute scale, where most fluids exhibit a laminar flow. Here, we report electric voltage generation due to the SHDG in a laminar flow of a liquid-metal mercury. The experimental results show a scaling rule unique to the laminar-flow SHDG. Furthermore, its energy conversion efficiency turns out to be about 105 greater than of the turbulent one. Our findings reveal that the laminar-flow SHDG is suitable to downsizing and to extend the coverage of fluid spintronics.

Bimatoprost for eyelash growth in Japanese subjects: two multicenter controlled studies.

BACKGROUND: Bimatoprost 0.03% has enhanced eyelash prominence in clinical trials enrolling mostly Caucasian subjects. The studies described in this report evaluated the efficacy and safety of bimatoprost in Japanese subjects with idiopathic and chemotherapy-induced eyelash hypotrichosis. METHODS: In two multicenter, double-masked, randomized, parallel-group studies (study 1: n=173 [idiopathic]; study 2: n=36 [chemotherapy-induced]), subjects received bimatoprost 0.03% or vehicle applied once daily to the upper eyelid margins. The primary efficacy measure was eyelash prominence measured by Global Eyelash Assessment (GEA) scores. Additional measures were eyelash length, thickness, and darkness, assessed by digital image analysis, and patient satisfaction (Eyelash Satisfaction Questionnaire-9). Safety assessments included adverse-event monitoring and ophthalmic examinations. RESULTS: Significantly more bimatoprost-treated subjects had at least a one-grade improvement in GEA score from baseline to month 4 compared with vehicle in study 1 (77.3 vs 17.6%; P<0.001) and study 2 (88.9 vs 27.8%; P<0.001). Bimatoprost-treated subjects had significantly greater increases in eyelash length, thickness, and darkness at the primary time point (month 4 in both studies; all P<0.001, study 1; P≤0.04, study 2). The bimatoprost group showed greater subject satisfaction in both studies. The incidence of adverse events was similar in the two groups. Ophthalmic examination showed slightly greater mean reductions in intraocular pressure (IOP) with bimatoprost than with vehicle, and the reductions were within the normal range for daily IOP fluctuations. CONCLUSION: Bimatoprost 0.03% was shown to be effective and safe in these studies of Japanese subjects with eyelash hypotrichosis. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

'Real angiosome' assessment from peripheral tissue perfusion using tissue oxygen saturation foot-mapping in patients with critical limb ischemia.

OBJECTIVES: The "tissue oxygen saturation (StO2) foot-mapping" method was developed using a non-invasive near-infrared tissue oximeter monitor to classify the foot regions as ischemic and non-ischemic areas. The purpose of this study was to evaluate StO2 foot-mapping as a reliable method to detect ischemic areas in the feet of patients with critical limb ischemia (CLI), and to compare the results with assessments from the angiosome model. METHODS: The foot areas of 20 CLI patients and 20 healthy controls were classified into four regions: (1) 0 ≤ StO2 < 30%, (2) 30 ≤ StO2 < 50%, (3) 50 ≤ StO2 < 70%, and (4) 70 ≤ StO2 ≤ 100% to perform StO2 foot-mapping. Each area occupancy rate was compared between the two groups, and the threshold StO2 value for detecting ischemia was set. Next, the locations of ulcers (in 16 patients) were compared to the predicted ischemic regions by the StO2 foot-mapping and by the angiosome model and angiography. RESULTS: In regions (1) and (2) (StO2 < 50%), the area occupancy rate was significantly higher in the CLI group and almost zero in the control group, so that the threshold StO2 value for detecting ischemia was set at 50%. The locations of ulcers were compatible with StO2 foot-mapping in 87.5% of the cases (14/16), while they were compatible with the assessment from the angiosome model in 68.8% of the cases (11/16). CONCLUSIONS: This study suggests that StO2 foot-mapping can successfully and non-invasively detect ischemic areas in the peripheral tissue of the foot, and also more appropriately than the assessment provided by the angiosome model. StO2 foot-mapping can be used to evaluate the real angiosome: the real distribution of the peripheral tissue perfusion in the CLI patient's foot, which is determined by the peripheral microvascular blood flow, rather than the main arterial blood flow.

Unidirectional spin-wave heat conveyer.

When energy is introduced into a region of matter, it heats up and the local temperature increases. This energy spontaneously diffuses away from the heated region. In general, heat should flow from warmer to cooler regions and it is not possible to externally change the direction of heat conduction. Here we show a magnetically controllable heat flow caused by a spin-wave current. The direction of the flow can be switched by applying a magnetic field. When microwave energy is applied to a region of ferrimagnetic Y3Fe5O12, an end of the magnet far from this region is found to be heated in a controlled manner and a negative temperature gradient towards it is formed. This is due to unidirectional energy transfer by the excitation of spin-wave modes without time-reversal symmetry and to the conversion of spin waves into heat. When a Y3Fe5O12 film with low damping coefficients is used, spin waves are observed to emit heat at the sample end up to 10 mm away from the excitation source. The magnetically controlled remote heating we observe is directly applicable to the fabrication of a heat-flow controller.

Extravascular injection of sclerotic agents does not affect vessels in the rat: experimental implications for percutaneous sclerotherapy of arteriovenous malformations.

OBJECTIVES: Sclerotherapy is useful for the treatment of arteriovenous vascular malformations. However, intravascular administration of sclerotic agents into small arteriovenous niduses is often difficult. Extravascular administration of sclerotic agents causes reduction of vascular flow on Doppler echo during clinical sclerotherapy. Therefore, we aimed to investigate whether the extravascular injection of sclerotic agents affects tiny vessels. DESIGN: Animal study. MATERIALS: The effect of extravascular injection of sclerotic agents on vessels was investigated using rat femoral and superficial inferior epigastric vessels. METHODS: After surgical exposure of vessels, absolute ethanol, 5% ethanolamine oleate and 3% polidocanol were injected into perivascular surrounding tissues, and their effect on vessels was evaluated after 14 days using histology and coloured silicone rubber injection. RESULTS: The integrity of the vascular lumen, endothelial cells and vascular patency were not affected by injection of sclerotic agents. CONCLUSIONS: Attenuation of vascular flow of an arteriovenous shunt after extravascular injection of sclerotic agents is transient and/or trivial and does not cause disruption of vessels. Therefore, sclerotic agents should be delivered to obtain sufficient destruction of arteriovenous malformation lesions and blood flow.

Continuous generation of spinmotive force in a patterned ferromagnetic film.

We study, both experimentally and theoretically, the generation of a dc spinmotive force. By exciting a ferromagnetic resonance of a comb-shaped ferromagnetic thin film, a continuous spinmotive force is generated. Experimental results are well reproduced by theoretical calculations, offering a quantitative and microscopic understanding of this spinmotive force.

Transmission of electrical signals by spin-wave interconversion in a magnetic insulator.

The energy bandgap of an insulator is large enough to prevent electron excitation and electrical conduction. But in addition to charge, an electron also has spin, and the collective motion of spin can propagate-and so transfer a signal-in some insulators. This motion is called a spin wave and is usually excited using magnetic fields. Here we show that a spin wave in an insulator can be generated and detected using spin-Hall effects, which enable the direct conversion of an electric signal into a spin wave, and its subsequent transmission through (and recovery from) an insulator over macroscopic distances. First, we show evidence for the transfer of spin angular momentum between an insulator magnet Y(3)Fe(5)O(12) and a platinum film. This transfer allows direct conversion of an electric current in the platinum film to a spin wave in the Y(3)Fe(5)O(12) via spin-Hall effects. Second, making use of the transfer in a Pt/Y(3)Fe(5)O(12)/Pt system, we demonstrate that an electric current in one metal film induces voltage in the other, far distant, metal film. Specifically, the applied electric current is converted into spin angular momentum owing to the spin-Hall effect in the first platinum film; the angular momentum is then carried by a spin wave in the insulating Y(3)Fe(5)O(12) layer; at the distant platinum film, the spin angular momentum of the spin wave is converted back to an electric voltage. This effect can be switched on and off using a magnetic field. Weak spin damping in Y(3)Fe(5)O(12) is responsible for its transparency for the transmission of spin angular momentum. This hybrid electrical transmission method potentially offers a means of innovative signal delivery in electrical circuits and devices.

Observation of the spin Seebeck effect.

The generation of electric voltage by placing a conductor in a temperature gradient is called the Seebeck effect. Its efficiency is represented by the Seebeck coefficient, S, which is defined as the ratio of the generated electric voltage to the temperature difference, and is determined by the scattering rate and the density of the conduction electrons. The effect can be exploited, for example, in thermal electric-power generators and for temperature sensing, by connecting two conductors with different Seebeck coefficients, a device called a thermocouple. Here we report the observation of the thermal generation of driving power, or voltage, for electron spin: the spin Seebeck effect. Using a recently developed spin-detection technique that involves the spin Hall effect, we measure the spin voltage generated from a temperature gradient in a metallic magnet. This thermally induced spin voltage persists even at distances far from the sample ends, and spins can be extracted from every position on the magnet simply by attaching a metal. The spin Seebeck effect observed here is directly applicable to the production of spin-voltage generators, which are crucial for driving spintronic devices. The spin Seebeck effect allows us to pass a pure spin current, a flow of electron spins without electric currents, over a long distance. These innovative capabilities will invigorate spintronics research.

Electric manipulation of spin relaxation using the spin Hall effect.

Using the spin Hall effect, magnetization relaxation in a Ni_{81}Fe_{19}/Pt film is manipulated electrically. An electric current applied to the Pt layer exerts spin torque on the entire magnetization of the Ni81Fe19 layer via the macroscopic spin transfer induced by the spin Hall effect and modulates the magnetization relaxation in the Ni81Fe19 layer. This method allows us to tune the magnetization dynamics regardless of the film size without applying electric currents directly to the magnetic layer.

Topical negative pressure therapy for para-ileostomal ulceration in a patient with Behçet's disease.

BehCet's disease is a chronic, relapsing, inflammatory disorder. This case report describes how use of an improvised topical negative pressure (TNP) device in a patient with a non-healing para-ileostomal ulcer with Behçet's disease.

Efficacy of a skin-protection powder for use as a dressing for intractable ulcers.

OBJECTIVE: Stomahesive skin-protection powder has been reported to be useful as a skin-care and skin-barrier product for the management of stomas. This study aimed to evaluate its efficacy, in terms of wound healing, moisture retention and pain management, as an alternative to conventional dressing materials. Both clinical and animal studies were undertaken. METHOD: The efficacy of the Stomahesive powder was tested by measuring the thickness of granulation tissue formed in a total skin defect in a db/db mouse model. We then compared the healing process using either the skin-protection powder or a conventional film dressing material. In the clinical study 17 patients with various intractable ulcers were treated with Stomahesive powder, and healing was evaluated. RESULTS: In the mouse model, granulation tissue in the wounds treated with the powder was 2.86 times thicker than that of the wounds treated with the film dressing. In the clinical study, 16 out of 17 wounds healed completely. CONCLUSION: The Stomahesive powder could be an effective treatment modality for contact ulceration, superficial ulcers with complex contours and morphology, and superficial ulcers contaminated by liquid faeces or vaginal discharge that have not responded to conventional dressings. DECLARATION OF INTEREST: None.

Correlation between age and the secretions of melanocyte-stimulating cytokines in cultured keratinocytes and fibroblasts.

BACKGROUND: The majority of skin changes associated with ageing are caused by photoageing and reflect cumulative sun exposure. Although the actinic damage plays a major role in skin pigmentation, it is also important to examine the effects of chronological cellular ageing on the pigmentation. The chief cellular components of the skin other than melanocytes are keratinocytes and fibroblasts, and the influences of age-related changes in those cells on skin pigmentation have not been elucidated. OBJECTIVE: To clarify the effects of cellular ageing of keratinocytes and fibroblasts on age-related skin pigmentation. METHODS: Using ELISA analysis, we measured the level of melanogenic cytokines secreted by cultured keratinocytes and fibroblasts derived from skin of various chronological ages. We also compared the cytokine secretion by cultured keratinocytes between the second and fifth cultures. RESULTS: There was no correlation between age and hepatocyte growth factor (HGF), stem cell factor (SCF), and basic fibroblast growth factor (bFGF) secretion by fibroblasts. On the other hand, a significant positive correlation existed between age and interleukin ((IL)-1alpha secretion (R2=0.50, P=0.002), and a relatively weak correlation existed between age and endothelin-1 (ET-1) secretion (R2=0.17, P=0.051, not significant). The IL-1alpha secretion by keratinocytes was significantly increased in the fifth cultures compared with the second cultures (P<0.005). CONCLUSIONS: These findings suggest that IL-1alpha secretion increases as cells grow older, and the increased secretion of IL-1alpha by aged keratinocytes may stimulate HGF production in dermal fibroblasts paracrinely and ET-1 production in keratinocytes autocrinely, which stimulates melanocyte proliferation and induces an increase of tyrosinase activity in melanocytes. Because IL-1alpha is a primary mediator that responds to inflammation and injury, the transcription of genes involved in skin inflammation may be persistently induced in the aged skin. Thus the increased secretion of IL-1alpha by aged keratinocytes in the aged skin may play a role in the accentuated cutaneous pigmentation and other skin ageing.

The mechanism of epidermal hyperpigmentation in café-au-lait macules of neurofibromatosis type 1 (von Recklinghausen's disease) may be associated with dermal fibroblast-derived stem cell factor and hepatocyte growth factor.

BACKGROUND: The mechanism of the accentuated melanization in café-au-lait macules (CALMs) in patients with neurofibromatosis type 1 (NF1; von Recklinghausen's disease) has not been elucidated. OBJECTIVES: To clarify the mechanism involved in the hyperpigmentation of CALMs in NF1. METHODS: Using enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of cultured cells, we measured the levels of cytokines produced and secreted by keratinocytes and fibroblasts derived from CALMs (group RC: Recklinghausen CALM) skin, compared with cells derived from the skin of normal individuals (group NN: Normal skin of Normal individuals) and cells derived from non-CALM skin of NF1 patients (group RN: Recklinghausen Non-CALM). RESULTS: ELISA revealed that the secretion of hepatocyte growth factor (HGF) and stem cell factor (SCF) by cultured fibroblasts was significantly elevated in group RC compared with groups RN and NN. In parallel, semiquantitative real-time RT-PCR of HGF and SCF mRNAs demonstrated increased expression of both types of transcripts by cultured fibroblasts in group RC compared with group NN. In contrast, the secretion of endothelin-1 and granulocyte/macrophage colony-stimulating factor by cultured keratinocytes occurred at a similar level among all three groups, RC, RN and NN. CONCLUSIONS: These findings suggest that increased secretion of HGF and SCF by dermal fibroblasts may be associated with the accentuated epidermal melanization observed in CALMs in the skin of NF1 patients.

Ectopically localized HNK-1 epitope perturbs migration of the midbrain neural crest cells in Pax6 mutant rat.

Small eye rats, which have a mutation in a gene encoding transcription factor Pax6, exhibit impaired migration of the midbrain neural crest cells, thereby showing severe craniofacial defects. Orthotopic grafting of the midbrain neural crest cells taken from the wild-type into Pax6 mutant embryos has suggested environmental defects along the migratory pathway of the midbrain crest cells. In the present study we found that the HNK-1 carbohydrate epitope was ectopically localized in the frontonasal epithelium of Pax6 mutant embryos. The GlcAT-P gene, encoding an enzyme for the synthesis of the HNK-1 epitope, was also expressed ectopically in the frontonasal epithelium of the mutant. In explant cultures, the migration rate of neural crest cells from the midbrain, but not from the forebrain, was significantly less in HNK-1-coated dishes than in non-coated dishes. These results suggest that the arrested migration of the midbrain crest cells in Pax6 mutant embryos may, at least in part, be due to the inhibitory effect of the HNK-1 epitope ectopically localized in the frontonasal epithelium.

Clinical use of amrinone (a selective phosphodiesterase III inhibitor) in reconstructive surgery.

Amrinone is a selective phosphodiesterase III inhibitor that increases cyclic adenosine monophosphate by preventing its breakdown. It is effective in the treatment of congestive heart failure because of its ability to increase myocardial contractility and vascular smooth muscle relaxation. This study was designed to clarify the potential efficacy of amrinone in plastic surgery by clinically assessing its ability to enhance flap blood flow after reconstructive surgery and relieve intraoperative vasospasm. Its effects were compared with those of prostaglandin E1 and lidocaine, which are widely approved agents for improving the hemodynamics of flaps. In the first clinical study, the effects on flap blood flow after flap transfers were investigated. Twenty-six patients underwent reconstructive surgery with vascularized free or pedicled flaps. Blood flow was measured before and 60 minutes after intravenous infusion of lactated Ringer solution (control), amrinone (10 microg/kg/min), or prostaglandin E1 (10 ng/kg/min) using a laser Doppler flowmeter. In the second study, the effects on relief of vasospasm during operation were evaluated. The blood flow of 28 island flaps was measured by laser Doppler flowmetry immediately after flap elevation and 10 minutes after topical application of saline (control), amrinone (5 mg/ml), or lidocaine (10%) to the pedicle in an attempt to resolve the vasospasm. In both clinical studies, the effects of amrinone were statistically no less than those of prostaglandin E1 and lidocaine. The results show that amrinone positively influences the microcirculatory blood flow of transferred flaps and relieves intraoperative vasospasm in clinical cases. The present study suggests that amrinone could be useful for postoperative and intraoperative care in reconstructive surgery.

Mandibular reconstruction using microvascular free flaps: a statistical analysis of 178 cases.

For this article, 178 consecutive cases of mandibular reconstruction using microvascular free flaps and performed from 1979 to 1997 were studied. The purpose of this report is to compare flap success rates, complications, and aesthetic and functional results. The ages of the 131 men and 47 women ranged from 13 to 85 years, with an average of 55 years. Donor sites included the rib (11 cases), radius (one case), ilium (36 cases), scapula (51 cases), fibula (34 cases), and soft-tissue flaps with implant (45 cases). Complications included total flap necrosis, partial flap necrosis, major fistula formation, and minor fistula formation. The rate of total flap necrosis involving the ilium and fibula was significantly higher than that of all other materials combined (p < 0.05). The overall rate of implant plate removal, which resulted from the exposure or fracture of the plate, was 35.6 percent (16 of 45 cases). Each mandibular defect was classified by the extent of the bony defect and by the extent of the soft-tissue defect. The extent of the mandibular bony defect was classified according to the HCL method of Jewer et al. The extent of the soft-tissue defect was classified into four groups: none, skin, mucosal, and through-and-through. According to these classifications, functional and aesthetic assessments of deglutition and contour were performed on 115 subjects, and speech was evaluated in 110. To evaluate the postoperative results, points were assigned to each assessment of deglutition, speech, and mandibular contour. Statistical analysis between pairs of bone-defect groups revealed that there was no significant difference in each category. Regarding deglutition, statistical analysis between pairs of soft-tissue-defect groups revealed there were significant differences (p < 0.05) between the none and the mucosal groups and also between the none and the through-and-through groups. Regarding speech, there was a significant difference (p < 0.05) between the none and the through-and-through groups. Regarding contour, there were significant differences (p < 0.01) between the none and the through-and-through groups and between the mucosal and the through-and-through groups. The points given for each function, depending on the reconstruction material, revealed that there was no significant difference between pairs of material groups. From this prospective study, the authors have developed an algorithm for oromandibular reconstruction. When the bony defect is lateral, the ilium, fibula, or scapula should be chosen as the donor site, depending on the extent of the soft-tissue defect. When the bony defect is anterior, the fibula is always the best choice. When the soft-tissue defect is extensive or through-and-through with an anterior bony defect, the fibula should be used with other soft-tissue flaps.

[Microvascular anastomoses in cervical esophageal reconstruction].

Ischemia or hemostasis in the gastric, jejunal, and colonic pedicle after esophagectomy is believed to contribute significantly to postoperative complications. With the advent of microvascular anastomoses, many surgeons have adopted vascular augmentation (supercharge) as a means of avoiding these difficulties. Microsurgical free tissue transfer represented by the free jejunum and forearm flap also plays an important role in esophageal reconstruction. In this paper, the authors introduce the technical points important for successful revascularization including the choice of recipient vessels, setting up of the reconstructive materials, and postoperative monitoring. In cases of gastric pull-up elevated via posterior mediastinum, the left gastroduodenal vessels are anastomosed to the cervical transverse or superior thyroidal vessels. In cases of duodenal or colonic pull-up elevated via the anterosternal route, the vascular pedicles are anastomosed to the internal mammary vessels which are dissected by resecting the costal cartilage. When the free jejunum flap is used, the cervical transverse or superior thyroidal vessels are most frequently used as recipients. Postoperative monitoring of free flaps is performed using Doppler ultrasound or through a small skin incision made above the transferred tissue. Although gastric or colonic pull-up is difficult to monitor, color Doppler sonography permits quantitative analysis of blood flow and may be a useful option.

Tattoo removal by grafting enzymatically separated epidermis.

A novel method of tattoo removal in which the enzymatically separated epidermis of an excised tattoo was grafted in situ was applied to 3 patients. Unlike the conventional skin-grafting procedure, this method resulted in the complete obliteration of the tattoos without donor site scars. In 1990, Hosokawa and colleagues first reported a technique similar to the one described, but the enzymatic process required surgery to be performed over two consecutive days and, thus, it did not become an established procedure. A modification of Hosokawa's method enabled the authors to reduce the enzymatic processing time to an hour using Dispase. The thinning of the tattooed skin using a Paget's-type dermatome before its exposure to an enzymatic solution facilitated the enzyme's infiltration of the basal layer of the epidermis. Hence, the time taken for the epidermis to separate from the tattooed skin was markedly shortened. Although laser removal continues to be the optimal treatment method, skin grafting or other abrasive procedures, including dermabrasion and cryosurgery, are still necessary for those patients who want complete tattoo obliteration over a shorter time frame and at less expense. In these patients the authors recommend that their procedure be offered as an alternative treatment to laser removal.

Deep circumflex iliac perforator flap with iliac crest for mandibular reconstruction.

The deep circumflex iliac myocutaneous perforator (DCIP) flap with iliac crest was used to reconstruct oromandibular defects in 10 patients. In seven of the patients a dominant perforator was found preoperatively using a Doppler flowmeter; in five of these seven patients a DCIP flap was successfully transferred. In two of the seven patients the dominant perforators were too narrow: one patient underwent a standard osteocutaneous flap transfer and one patient underwent a second flap transfer. In three patients no dominant perforator was found before or during surgery. The freedom of the DCIP flap from the harvested iliac crest facilitates correct positioning. However, to ensure that the DCIP flap can be safely elevated, the presence of perforators must be confirmed preoperatively. Even when a perforator has been identified, complicated dissection may be necessary. We stress the importance of a thorough knowledge of the anatomy of second flaps and of obtaining informed consent to use them.

Effects of all-trans retinoic acid on melanogenesis in pigmented skin equivalents and monolayer culture of melanocytes.

The effects of all-trans retinoic acid (RA) on melanogenesis and the mechanism of its action in topical treatment have not been elucidated. The purpose of this study was to determine the effects of RA on melanogenesis in the pigmented skin equivalent as well as in monolayer culture of melanocytes, and to determine whether RA, hydroquinone (HQ), and hydrocortisone (HC) show synergistic depigmenting effects in combined treatments of each other. The suppressing effect of RA on melanogenesis was not observed in pigmented skin equivalents and monolayer culture of murine and human melanocytes, although HQ showed strong inhibition of melanogenesis. The synergistic effects between RA, HQ, and HC were not particularly seen. The results suggested that RA neither has direct inhibitory effects on melanogenesis of melanocytes, nor influences the cell-cell interactions between melanocytes, keratinocytes and fibroblasts, such as paracrine actions with regard to melanin production. The role of RA in bleaching treatments appears to be in other specific actions, such as promotion of keratinocytes proliferation and acceleration of epidermal turnover.