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This study is aimed at revealing the dietary protein requirement for gonad production in the sea urchin Mesocentrotus nudus, with consideration of protein leaching from diets during seawater immersion. Feeding trials were performed on M. nudus using two diet types with low capacities for protein leaching: starch diets (STG) containing 0–40% gluten in 10%, 5%, and 4% increments (experiments 1–3) and alginate diets (ALG) containing 5–25% gluten in 5% increments (experiment 4). The protein content in the diets was determined after they were immersed in seawater for 24 h or 72 h. The gonad indices of urchins fed STG with 11.4–19.3% protein were significantly higher than those fed STG with 7.8% protein. The protein requirement was estimated to be 12% based on a broken-line regression analysis of urchins fed STG in experiments 1–3. In experiment 4, the gonads became larger as dietary protein content increased from 4.5% to 12.0%, and the sizes were similar to those of urchins fed ALG with 12.0–21.1% protein. The estimated value of 12% was much lower than that reported previously (>20%), indicating that the protein requirement for sea urchin gonad production is modest when the protein-leaching problem is addressed.

The dispersal processes of anatomically modern humans in Asia during the late Middle to early Upper Paleolithic periods have been a focus of intensive research in recent years through interdisciplinary approaches including genetic, paleoanthropological, and archeological studies. However, sparse datasets, often only available from limited time-space contexts have not produced a satisfactory picture of the vast geographic extension of this continent. This study investigated how the chrono-spatial patterning of lithic technological records, which are widely available across Asia, might contribute to our better understanding of the population dynamics in this period. The study is based on a large database (PaleoAsiaDB) recently developed by the authors to accommodate the relevant datasets, including geographical coordinates of each site and available radiometric dates, for the Middle and Upper Paleolithic periods in Asia. Each of the 895 lithic assemblages was characterized in terms of the presence/absence of 24 lithic modes/submodes that were adapted from the work of John Shea to fit our research objective. The dataset was analyzed using exploratory statistical methods, including principal component analysis. The results revealed marked spatiotemporal patterns in technological variability from the late Middle to early Upper Paleolithic periods. Some can be interpreted as a result of modern human dispersal, whereas others are better explained from ecological and other perspectives rather than authorships. Although this study has obvious limitations due to its reliance on the information sourced from the literature, it provides a global synthesis of lithic variability in the crucial period of the dispersals of modern humans on a continental scale for the first time. The results serve as a guide to be tested with evidence from other research strategies, such as genetics and fossil studies.

Elucidating the cultural transition of the Middle and Upper Palaeolithic in northern China (Northeast and North China) is extremely important in considering the emergence and diffusion of Anatomically Modern Humans in East Asia. This article discusses 25 assemblages from 11 sites before and after ca. 42–40 cal ka in northern China. Each assemblage was given the techno-cultural category of “industry” (Industries D, DQ, DP, DL, PF, B, TB, UP, M, MO) based on the scheme of PaleoAsia modes. The PaleoAsia modes are an expanded version of J. J. Shea's modes, which describe and categorize flaking and lithic tool-production technologies. Following the chronological dating of assemblages, this study proposes that an industrial transition took place from the Middle Palaeolithic (MP) to Upper Palaeolithic (UP) in northern China. Characteristic technical elements were noted for each assemblage, including the Levallois technique, polished bone tool, personal ornament, blade technique, and UP tools. The following four stages were established for the abovementioned industrial transition in northern China: MP (before 41.5–40.0 cal ka), IUP (41.5–40.0 cal ka), EUP (40.0–28.0 cal ka), and MUP/LUP (after 28.0–27.0 cal ka). With the Exception of the last stage, which is associated with a microblade industry, the main industry of each stage was affiliated with denticulate tools. As such, there was no discontinuity in the technological traditions found between these stages in northern China. Rather, industries continuously and gradually shifted from the MP to UP; that is, UP techno-elements were incrementally introduced. To understand the drivers behind this industrial transition, it is first necessary to verify whether anatomically modern humans migrated to northern China during the MP and if they then maintained the group of denticulate tool industries until the UP.

A 42-year-old man had been treated for granulomatosis with polyangiitis for eight years. He was referred to our department with the diagnosis of right pneumothorax on chest radiograph. After chest drainage, the surgical treatment was performed because of continuing air leak from chest tube. Under thoracoscopic approach, the pleural adhesions were carefully dissected and the air leak site was sutured and enforced by a polyglycolic acid sheet with fibrin glue. No recurrence of pneumothorax was observed six months after surgery.

The friction characteristics of a shock absorber are very complex because the reciprocating motion is not always identical. In this study a device was developed and used to analyze the dynamic friction characteristics under various reciprocating sliding conditions to determine the sliding materials and hydraulic oils that improve the shock absorber performance. This study describes the influence of hydraulic oil additive on the fine reciprocating friction characteristics of steel and copper alloy. Hydraulic oils were prepared by blending a paraffinic mineral oil with zinc dithiophosphate (ZnDTP) and polyhydric alcohol ester as additives. The results show that the dynamic frictional characteristics vary mainly depending on the additive concentration. A specific additive formulation induces a unique amplitude-dependent friction behavior. In addition, the influence of different additives on the lubrication mechanism is investigated based on the instrumental analysis of the friction surface.

Bile acids exhibit strong antimicrobial activity as natural detergents, and are involved in lipid digestion and absorption. We investigated the mechanism of bile acid adaptation in Lactobacillus gasseri JCM1131T. Exposure to sublethal concentrations of cholic acid (CA), a major bile acid in humans, resulted in development of resistance to otherwise-lethal concentrations of CA by this intestinal lactic acid bacterium. As this adaptation was accompanied by decreased cell-membrane damage, we analyzed the membrane lipid composition of L. gasseri. Although there was no difference in the proportions of glycolipids (~70%) and phospholipids (~20%), adaptation resulted in an increased abundance of long-sugar-chain glycolipids and a 100% increase in cardiolipin (CL) content (to ~50% of phospholipids) at the expense of phosphatidylglycerol (PG). In model vesicles, the resistance of PG vesicles to solubilization by CA increased with increasing CL/PG ratio. Deletion of the two putative CL synthase genes, the products of which are responsible for CL synthesis from PG, decreased the CL content of the mutants, but did not affect their ability to adapt to CA. Exposure to CA restored the CL content of the two single-deletion mutants, likely due to the activities of the remaining CL synthase. In contrast, the CL content of the double-deletion mutant was not restored, and the lipid composition was modified such that PG predominated (~45% of total lipids) at the expense of glycolipids. Therefore, CL plays important roles in bile acid resistance and maintenance of the membrane lipid composition in L. gasseri.

This study aims to build a learning model based on a survey for the actual situation of the three stakeholders, students, faculty, and system administrator, using a VOD (Video-on-Demand) of a face-to-face lecture at two different locations for different purposes such as a supplement to the face-to-face lecture or as the primary learning material. As a result of the survey, we pointed out that there were two main styles of students, those who want to watch all videos in one way and those who want to watch only scenes of high importance through other information. We suggested a learning model for providing more realistic and concrete improvement proposals based on understanding both the faculty and the system administrator's constraints.

When the suspension deforms, damping force is generated as the piston of the shock absorber moves, but a time difference occurs before the large hydraulic damping force rises. At the same time the frictional force in the shock absorber is playing an important role in generating effective damping force against deformation of the suspension, the generated force itself is small but its response is high. The frictional force in the shock absorber occurs in reciprocating motion in various speed ranges from amplitude of less than one millimeter to larger amplitudes, its behavior changes dynamically and is non-linear. Recent studies have revealed that controlling the friction is more important than reducing it for improvement of the performance. Because of this we have investigated the dynamic friction characteristics of shock absorber oil and sliding parts, by the means of an own developed device that can measure the speed dependence of friction force in reciprocating motion with high accuracy.

Synchronous reluctance motors (SynRMs) have attracted much attention because they do not require magnets. Position sensorless control of SynRMs at low speeds is necessary, and several methods have been proposed in this regard. A new position sensorless control method for SynRMs operating in the very low-speed region is proposed. This approach superimposes a high-frequency current with a small and constant amplitude and a constant frequency to the torque current for driving the SynRMs, by using a high-frequency current control system. It has been shown that robust position sensorless control against inductance variations can be realized using this proposed method. In the position sensorless control method based on a superimposing signal, the current should be small. Therefore, in this paper, the capability of the presented approach to achieve a minimum constant amplitude of the high-frequency current is investigated. The experimental results indicate that the proposed method is a feasible one as position sensorless control of SynRMs in very-low speed region even if the superimposed current has a minimum constant amplitude.

Background:. Problems with poor circulation often occur when a large defect or a distant region, such as the apex of the nose, is covered with a paramedian forehead flap. Delay technique increases the safety of reconstruction procedures, but it has been used less frequently because a 2-stage surgery is necessary, and various other flaps and techniques have been developed. Method:. We performed the delay technique of paramedian forehead flap at the same time as tumor resection. For the flap, a narrow pedicle of about 1-cm was prepared on the supratrochlear artery and vein, and the incision was extended toward the lateral side conforming to the defect morphology, and a paramedian forehead flap with a design consistent with the esthetic unit containing the defect was prepared. The region below the flap was dissected to create the flap bipedicle, and surgery was completed. Result:. This procedure was used in 4 patients with malignant tumor of the external nose, and the flap survived perfectly in all patients. The postoperative esthetic outcome was also found to be good. Conclusions:. This procedure does not increase the frequency of surgery, circulation in the flap is maintained, the flap pedicle on the supratrochlear artery can be made narrow, and flap thinning can be performed from the beginning. Coverage of an extensive defect is possible because a large flap can be excised, and satisfactory esthetic appearance can be obtained by matching with the esthetic unit. The delay technique for various flaps (not limited to forehead flap alone) should be considered an effective technique for the current treatment of malignant tumors.

Resume Cet article presente la description des relations culturelles entre le Paleolithique chinois et le Paleolithique japonais. Dans ce numero special, Dr Takehana et ses collaborateurs evoquent les relations, les traditions paleolithiques de Hokkaido au Japon septentrional avec les cultures paleolithiques de la Siberie cotiere. Pour cette raison, nous nous concentrons sur les trois iles principales et le Paleolithique chinois. Actuellement, cette region consiste essentiellement en trois grandes iles, Honshu, Shikoku et Kyushu et plusieurs ilots a leur peripherie. Cependant, nous supposons que ces iles etaient presque toutes en continuite territoriale durant l’epoque glaciaire. Ainsi, nous devons considerer que ces iles etaient plus grandes encore. A present, la Mer de Chine orientale, la Mer Jaune, le golfe de Bohai et la Mer du Japon separent ces iles principales du continent asiatique. Il apparait que l’homme anterieur a Homo sapiens a du utiliser un pont terrestre alors apparu, la zone maritime etant tres etroite et peu profonde. Nous supposons que l’Homo sapiens a migre vers Honshu a partir du continent asiatique. Ce qui n'a pu se realiser que pendant une periode froide ayant provoque la regression des mers. Un premier itineraire correspond a la route meridionale alors que Taiwan, les iles Sakishima, les Iles Yaeyama, les iles Ryukyu, les iles Amami s’assechaient en formant un pont terrestre. Un deuxieme itineraire correspond a la route occidentale qui atteint Kyushu par la Peninsule coreenne, en passant par la Mer de Chine orientale , la Mer Jaune et la baie de Bohai alors assechees, c'est ce qu'on appelle "la plaine des trois mers". Un troisieme itineraire passe par le sud de l’ile Sakhalin et atteint la partie nord-est d’Honshu par Hokkaido. La possibilite d'atteindre l'archipel japonais depuis le continent asiatique est limitee a ces trois itineraires. Cependant, l’itineraire par le sud presentait une grande difficulte. Dans la partie septentrionale de cette serie d’iles, le detroit de Tokara interrompt le passage des iles Osumi aux iles Amami puisqu’il est si profond qu’il ne s'est jamais asseche, a aucune periode. La distribution des sites paleolithiques anterieurs a 62 000 ans en Chine avait ete arretee au sud du 40eme degre parallele. Par consequent, il apparait que l’homme paleolithique ne s’est installe qu’a partir de 62 000 ans en passant par la route septentrionale vers le nord du Japon. Pour cette raison, il est certain que la diffusion culturelle du Paleolithique s’est faite seulement par le pont terrestre correspondant a l’itineraire occidental.

In the Chinese context, pottery that predates ca. 9000 14 C BP is referred to as “early pottery”. Research on the early pottery of China had been conducted mostly in central and southern China; in contrast, research in northern China has been restricted, and only 5 sites had been discovered to date. Therefore, additional data is needed to foster the progress of research on early pottery in northern China. Given this situation, there is great value in the investigation of the many potsherds associated with microblade industry that have been found in secondary sediments of Layer 5 of the Lingjing site in Henan Province, on the Huang-Huai Plain at the southern end of the North China Plain. Based on AMS 14 C dates (ca. 9.8 cal ka), typological features of the pottery, and features of the other artifacts found at Lingjing, these potsherds are argued by this paper to be examples of early pottery, meaning that Lingjing constitutes a new site yielding early pottery in northern China. Other than these archaeological results, our research on Lingjing pottery has also yielded primary data on stable carbon/nitrogen isotope analysis and starch residue analysis. On the basis of archaeological research on early pottery, including examples from Lingjing, it appears that pottery in northern China generally emerged at the beginning of the Holocene (11.7 cal ka). Therefore, this emergence of pottery was likely related to the rapid warming just after the end of the last glacial period, after the Younger Dryas. The archaeological evidence also indicates increasing utilization of plant resources and diversification of food resources beginning prior to that time, suggesting that early pottery may have played a major role in this change in subsistence strategy in northern China. Archaeological comparisons between the early pottery of northern and central/southern China show substantial differences. Based on its association with microblade technology and on characteristic features such as vessels with a flat base, this early pottery from northern China may be related to that from regions further north, such as the Russian Far East.

During the Upper Paleolithic, many sites with microblade industries were distributed across northeastern China and the North China Plain in eastern China. Based on the composition of lithic raw materials (LRMs) and the site distributions of microblade industries, this study defined five territories of human groups in two regions of China: 1) the western Changbai Shan Mountains (Mount Paektu) and Song-Nen Plain in northeastern China and 2) the southern Yanshan Mountains, Yi-Shu River Basin, and western Huang-Huai Plain in the North China Plain. In northeastern China, high-quality LRMs, including various types of igneous rock and obsidian, were used in combination with local LRMs such as flint and agate. Based on the distribution range of high-quality LRMs, the territories of human groups in that region are estimated at 300–450 km. It is believed that residential systems were established for the long-distance transport of LRMs and the long-distance movement of human groups. One such system included microblade technology based on biface and flake-blade reduction systems. In contrast, the territory of human groups in the North China Plain was small, with an area estimated at 100–230 km. Given the numerous small sites in that region, it is believed that human groups moved frequently within their territories because they were highly mobile and dependent on local LRM sources (e.g., flint) near their occupation sites. Human groups might have employed various microcore reduction systems to produce microblades, even from limited LRMs. Preliminary conclusions suggest that the divergent activities of late Upper Paleolithic human groups in eastern China could reflect variations in regional economic strategies and ecological environments between the Last Glacial Maximum and the Younger Dryas.

A smart control method based on the phasor diagram for a voltage-type PWM rectifier is proposed in this paper. The proposed method uses no PI controller in order to produce the high power factor and the constant DC-link voltage. From simulation results, we can realize the constant DC-link voltage of 300 V, 600 V, 900 V or 1000 V and the high power factor over 0.98.

Objectives Dementia cafes are expected to serve as a new community resource based on the national dementia strategy in Japan. The objective of the present study was to examine effective ways to manage dementia cafes through an overview of dementia cafes in Japan and an analysis of the factors related to their effectiveness on attendees. Design Cross-sectional analysis. Setting and participants Representatives of 1477 dementia cafes in Japan. Measures Questionnaires regarding the dementia cafes' characteristics, management members, staff, their guests and effectiveness on people with dementia, their families, and community members were sent to the cafes, with instructions to have them completed by the cafe representatives. Logistic regression analysis was performed with the effect on each guest attribute as a dependent variable, and factors related to the effectiveness of dementia cafes were analyzed. Results Questionnaires were sent to a total of 2728 dementia cafes in Japan, and responses were received from 1477 (54.1%). The most common meeting frequency and meeting hours were once a month (64.8%) and 2 hours (53.8%), respectively. Analysis of the effectiveness of dementia cafes on 3 groups of guests indicated the following preferences for cafe program: people with dementia preferred frequent meetings and activities, families of people with dementia preferred having a place for private consultation and advice and peer meetings, and community members preferred frequent meetings and both mini-lectures and private consultation and advice. Logistic regression analysis further revealed that all types of guests preferred the presence of the same types of guests. Conclusions/Implications This study revealed the multicomponent nature of dementia cafes. The results suggest that a good balance of programs and guests would enhance the cafes' effectiveness among the multiple stakeholders in regard to dementia, especially in the early stage of the disease.

Synchronous reluctance motors (SynRMs) have attracted attention because they have no magnets. The position sensorless control of SynRMs at low speeds is desired, and several methods have been proposed. A new position sensorless control method for SynRMs in a very-low-speed region has been proposed by the authors. It involves superimposing a high-frequency current with a small constant amplitude, using a high-frequency current control system. This paper shows that robust position sensorless control against inductance variations can be realized using this proposed method. Experiments showed that the proposed method is very useful even in a very-low-speed region.

Several position sensorless control methods of interior permanent magnet synchronous motors (IPMSMs) using observers have been proposed. In the case of full-order observers, these designs are difficult because the order of the error equations of observers becomes an order of four. In this paper, to realize the position sensorless control of IPMSMs, a design method for full-order observers based on the extended electromotive force (EEMF) is proposed, and the pole assignment of the proposed observer is studied. Experimental results of the position sensorless control of an IPMSM show the usefulness of this proposed design method for the full-order observer compared to the case where poles are merely assigned on the left half plane.

We report a case diagnosed as both necrotizing fasciitis and frostbite of the male external genetalia. The patient was a 58-year-old man with diabetes mellitus. He was referred to our hospital with swelling of his penis and icing there for 3 weeks. We diagnosed his condition as necrotizing fasciitis of the external genitalia and decided to perform an emergency operation. Although we consulted plastic surgeons about debridement of a large area, they considered that there was no necessity for it because the scrotum, perineum and abdominal wall were frostbitten. The final clinical diagnosis was necrotizing fasciitis of the penile region and frostbite around the perineal region. We performed partial penectomy without debridement. Through collaboration with another medical department it was thus possible to avoid unnecessary invasive treatment.

The effects of the ligand used for fabricating palladium (Pd)-incorporated porous polymer composites on their catalytic performances were examined from the perspective of catalysis sustainability. To perform this research, poly(amidoamine) (PAMAM) dendrimers, which were generation zero (G0) and higher, up to G6, the breakdown structure of G0 (that is, the half (G0h) and quarter (G0q)) and a typical small molecule (that is, N,N-dimethyl ethylenediamine (DMEn)) were utilized as ligands. The catalytic performances of the polymer composites were investigated using the aqueous Suzuki–Miyaura carbon cross-coupling reaction as a model reaction. Concerning the efficiency, recyclability and Pd-leaching behavior of the catalytic reaction, polymer composites that were fabricated with PAMAM dendrimers (that is, G1 and higher generations) proved to possess the potential for application as sustainable heterogeneous catalysts. Effects of ligand used for fabricating palladium (Pd)-incorporated porous polymer composites were examined on their catalytic performances (efficiency, recyclability and Pd-leaching behavior). The composites fabricated with poly(amidoamine) (PAMAM) dendrimers (Gn, n≥1) as ligand were proved to have a function that was potentially applicable as sustainable heterogeneous catalysts.

Analyses of microblade industries shed light on the human dispersal and technological diffusion in the terminal Upper Paleolithic of East Asia. From ca. 27–17 ka, with the advances of the Last Glacial Maximum (LGM), the Mammoth Steppe and its associated mammoth fauna shifted southward. In the wake of these changes, human groups with the Northern Microblade Industries (NMI) also migrated southward to Northeast China. NMI did not appear in North China, so it is presumed that those migrating human groups did not extend their activity areas beyond NE China. Meanwhile, the human groups with small flake tool industries in North China appear to have interacted with those groups with NMI at the ecological border area between NE. China and N. China, and obtained the microblade technology of pressure flaking, wedge-shaped micro-cores, transverse burins with marginal retouch and other elements of NMI, leading to the formation of the microblade industries that are unique to N. China. Technological elements of the NMI that appeared in N. China are regarded as the result of external expansion diffusion. Among the distinct features of the microblade industries in N. China is the microblade technology based on pyramidal micro-cores. This technology was transferred to Southwest Japan. This transfer of microblade technology and its spread across SW Japan was carried out through the materials and information exchange network that had connected N. China and SW Japan since the pre-stage of microblade industry. This diffusion of microblade technology is also regard as an example of external expansion diffusion. From ca. 17–9 ka, human groups that were migrating with NMI through NE China were able to enter N. China because of their flexible “collector” subsistence strategy and high level of adaptability to the environment. The appearance of NMI in N. China is regard as the result of external relocation diffusion. The technological transfer also occurred between the migrating human groups and the indigenous groups. The indigenous ones in turn adopted the technology of NMI, invented small bifacial points. This process is an example of expansion diffusion.

Several position sensorless control methods of IPMSMs(Interior Permanent Magnet Synchronous Motors) using the observers have been proposed. In case of the full-order observers, these designs are difficult, because the order of the error equations of the observers becomes four. In this paper, for the position sensorless control of IPMSMs, a design method of the full-order observer based on the extended electromotive force (EEMF) is proposed. The experimental result shows that this design method of full-order observer is very useful.

Synchronous reluctance motors (SynRMs) have attracted studies, because SynRMs have no magnets in the rotors. The position sensorless control at low speeds of SynRMs is now desired, and several methods have been proposed. In this paper, by using the high-frequency current control system, a new position sensorless control method of SynRMs at low speeds by superimposing high-frequency current whose amplitude is small constant value has been proposed. The experiments show that the proposed method is very useful even if the very low speeds region.

This Article reports on the ligand integration effect of poly(amidoamine) (PAMAM) dendrimers working in the solid composite systems, which is significant for stabilizing Pd nanoparticles (PdNPs). To carry forward this research, the fourth generation of PAMAM dendrimer (G4) was modified with polymerizable functions and tied to polymer networks constituting porous composites through the polymerization-induced phase separation (PIPS) strategy. The obtained results indicate that creation of PdNPs is strongly affected by the G4 template, and, consequently, unforeseen critical control of their sizes was definitely performed. Also, the crucial importance from perspective of catalytic applications is strong suppression of Pd leaching for the G4-utilized porous polymer composites (G4-p). This fact means that the catalytic event of G4-p entirely occurs on the polymer support. All of these characteristics are in marked contrast to those of the composite that was fabricated with a nonintegrated, small molecule ligand...

Synchronous reluctance motors (SynRMs) have attracted attention, because SynRMs have no magnets in the rotor. Position sensorless control at low speeds of SynRMs is now desired, and several methods have been proposed. The new position sensorless control method of SynRMs at low speeds by estimating a high-frequency extended e.m.f.(EEMF) caused by superimposed high-frequency current has been proposed by authors. The feature is that the amplitude of the superimposed high-frequency current is controlled to a small constant value. In this paper, the influence of inductance variation, which is large in the SynRMs, of the proposed position sensorless control method is investigated. And, in the proposed method, it is experimentally shown that the influence of the position estimation caused by the inductance variation is very small and the position sensorless control method is useful.

Background:. We have already reported surgical procedures for lobule-type microtia that provide an excellent contour and shape of the ear with minimum sacrifice of the donor. We have succeeded in establishing a standard surgical technique for almost all types of concha-type microtia that effectively uses the remnant ear and can use a unified costal cartilage frame. Methods and Results:. The concept of our technique is that remnant cartilage should be used maximally but that the deformed area should be completely replaced by the costal cartilage frame. The differences between the cartilage frame for lobule-type microtia and that for concha-type microtia are that the lower half beneath the antihelical area and the concha cymba in the base frame are omitted in concha-type microtia. The area from the tragus to the incisura of the tragus in the antihelical-tragal frame is also omitted. The area of the helical crus in the helical frame and the lower half in the antihelix are not immobilized in the base frame and are free edges. On the other hand, the remnant cartilage outside the concha is removed, but the antitragus is preserved. When the cartilage frame and the remnant are incorporated, all of the components of the ear can be provided. Conclusion:. The ears created by our technique have a natural appearance and clear contour.

A Bowden and Leben type sliding tester was used with a base oil to evaluate four types of friction modifier additives—acid phosphate, hydrogen phosphite, acid phosphate amine salt, and amine—as a fundamental study on hydraulic fluid additives for sliding of nitrile–butadiene rubber on Cr-plated metal. Acid phosphate showed the lowest friction coefficient among the phosphorus acids. After the sliding test, the formation of tribo-films on the Cr-plated surface was investigated by Fourier transform infrared reflection absorption spectroscopy and a time-of-flight secondary ion mass spectrometer. The analytical results suggest that tribo-films formed by the phosphorus acids effectively reduced friction.

Summary Z-plasty is one of the most widely employed techniques in plastic surgery and mainly serves the following purposes: elongation along the axis of the scar, dispersal of the scar followed by breaking up the straight-line scar and realigning the scar within the lines of minimal tension. It is useful especially to release linear-scar contracture, yet difficult for wide scars. This report describes a novel technique to release contracture effectively for any wide scars using a new design called double combined Z-plasty. The design is simple. The main limb is set to incise the wide scar, and this main limb is shared as a peripheral limb by two other Z-plasty designs. From the main limb, each central limb is designed along the margin of the scar in the opposite direction. The main and central limbs have 90° between them. Other peripheral limbs are then designed facing laterally to the intact skin to make 60° for the central limb. After skin incision, two triangular intact skin flaps could be inserted into the wide scar from both sides, making it possible to release contracture. We performed this technique on eight patients. All wounds healed well and scar contracture was satisfactorily released. This procedure is very useful for wide-scar contracture, compared to conventional Z-plasty.