Search

According to quantum chromodynamics, vacuum is not an empty space, because it is filled with quark–antiquark pairs. The pair has the same quantum numbers as the vacuum and forms a condensate because the strong interaction of the quantum chromodynamics is too strong to leave the vacuum empty. This quark–antiquark condensation, the chiral condensate, breaks the chiral symmetry of the vacuum. The expectation value of the chiral condensate is an order parameter of the chiral symmetry, which is expected to decrease at high temperatures or high matter densities where the chiral symmetry is partially restored. Head-on collisions of nuclei at ultra-relativistic energies have explored the high-temperature regime, but experiments at high densities are rare. Here we measure the spectrum of pionic 121Sn atoms and study the interaction between the pion and the nucleus. We find that the expectation value of the chiral condensate is reduced at finite density compared to the value in vacuum. The reduction is linearly extrapolated to the nuclear saturation density and indicates that the chiral symmetry is partially restored due to the extremely high density of the nucleus.

In this study, we consider a problem of modeling and manipulating hairy-brush characters based on the so-called ‘dynamic font’ method with control-theoretic B-spline approach, in which the characters are constituted as a result of trajectory curves using normalized uniform B-splines as basis function. First, typefaces of pre-designed dynamic font characters with one-pixel thickness are transformed to hairy-brush ones by introducing a deep learning method ‘Pix2Pix’. We then develop a method for modeling hairy-brush characters by formulating the problem as an optimal function-approximation problem, which minimizes an input energy of writing trajectory. Also, manipulations for generating cursive words as seen in Japanese calligraphy in a systematic way are described. A design example of cursive words is included.

A soft actuator is expected to be applied in the next generation of robotics. This study focuses on soft gel actuators hybridized with nanosheet liquid crystals. The resulting soft actuator has a highly hydrophilic property, and is suitable for underwater use. When the gel in water is heated to more than the transition temperature, the gel contracts; conversely, it swells when it is cooled. This gel actuator remarkably has an anisotropic contraction characteristic because the orientation of the nanosheets is uniformly arranged. However, little is known about its dynamic characteristics of the thermal contraction. As a basic analysis, this paper investigates the heating step response through experiments, and reveals the variation of the time constant against the dimensions.

This paper considers a problem of detecting nanosheets which are moving in colloidal liquid from confocal laser scanning microscopy (CLSM) images. Introducing the deep learning approach, we particularly develop a scheme for constructing the so-called `detection map’ consisting of the brightness value information on the area of nanosheets in CLSM images. Therein, we use an architecture of deep learning network ‘U-net’ and present how to implement such a network. The performance is demonstrated by some experimental studies.

We consider a problem of trajectory planning for road-like path on the two-dimensional plane. As the basic tool for constructing trajectories, we employ smoothing splines using normalized uniform B-splines as the basis functions. The pass is assumed to possess piecewise linear boundaries, specified by a series of pairs of right and left corner points. We allow two-fold corner points in order to allow flexible description of the path. On constructing smoothing splines, we impose the boundary constraints as a collection of inequality pairs by right and left boundary lines, yielding a set of linear inequality constraints on the so-called control point vector. Unlike standard smoothing spline settings, a piecewise linear centerline of the given path is provided as the data for the trajectory to follow, where the given entire time interval is divided into subintervals according to the centripetal distribution rule. Other constraints, typically as the initial and final conditions, can be imposed on the trajectory easily, and we see that the problem reduces to strictly convex QP (quadratic programming) problem. Efficient QP solvers are available for numerical solution, and the effectiveness of the proposed method is confirmed by three examples: two with piecewise linear boundaries including an example of obstacle avoidance problem, and the third with piecewise linear approximation of circular boundaries.

Navicular fracture is still challenging disorder to treat because there is a risk of nonunion, avascular necrosis and symptomatic osteoarthritis.

We consider the problem of optimal design of smoothing splines with constraints. Main concern is on constraints on derivatives over intervals as arising in monotone splines. The splines are constructed using normalized uniform B-splines as the basis functions. The authors show that the l-th derivative of the spline of degree k is obtained by using B-splines of degree k-l with the control points computed as the l-th difference of original control point sequence. This yields systematic treatment of equality and inequality constraints over intervals on derivatives of arbitrary degree, and the problem is formulated as convex quadratic programming. Thus the method is useful in various applications. The effectiveness is demonstrated by numerical examples of approximations of probability distribution function and concave function, and trajectory planning with the constraints on velocity and acceleration.

We develop a method of constructing trivariate optimal smoothing splines using normalized uniform B-spline as the basis functions. Such splines are useful particularly for modeling dynamic shape of 3-dimensional deformable object by using two variables for 3D shape and one for time evolution. The trivariate splines are constructed as a tensor product of three B-splines, and an optimal smoothing spline problem is solved together with typical examples of constraints as periodicity. The problem is formulated as convex quadratic programming (QP) problem in such a way that 3D array of control points is vectorized and a MATLAB QP solver is readily applicable for numerical solutions. We demonstrate usefulness of the method by dynamic shape modeling of red blood cell, where we will see that relatively small number of observation data yield satisfactory results.

In this paper, we consider the problem of recursively constructing smoothing spline surfaces with equality and/or inequality constraints each time when a new set of data is observed. The splines are constituted by using normalized uniform B-splines as the basis functions. Then various types of constraints are formulated as linear function of the so-called control points, and the problem is reduced to quadratic programming problem. Based on the results, we develop the recursive design method for constructing such constrained smoothing spline surfaces. The performance is examined by some numerical examples.

We present a rare case of stress fracture of the diaphysis of the ulna in a softball pitcher.

A case of bilateral pedicle stress fracture in a patient with lumbar spinal stenosis is reported, and the literature is reviewed.

Septic arthritis of a lumbar facet joint is a rare clinical entity and most articles have reported a single case. There have been few studies that have evaluated the clinical and imaging features of septic arthritis of lumbar facet joints. The clinical data of 5 patients diagnosed with septic arthritis of lumbar facet joints were retrospectively studied. The average age of 5 patients was 73.6 years. All patients had elevated temperature at admission (37.7°C). Leukocyte count was tested in all 5 patients and was elevated in only 2 patients. Erythrocyte sedimentation rate and C-reactive protein were examined and were elevated in all 5 cases. Magnetic resonance imaging was accurate in identifying the septic joint and associated abscess formation. All patients were treated with bed rest and received intravenous antibiotics for an average of 33.3 days. Four of 5 patients had positive outcomes with full recoveries and no evidence of recurrent infections. One patient exhibited evidence of recurrent infection and required open facet arthrotomy and paraspinal muscle debridement after intravenous administration of antibiotics. Septic arthritis of the lumbar facet joint is a rare cause of low back pain. It is important to ascertain the diagnosis at the earliest possible stage and to start intravenous antibiotics therapy as soon as possible. Magnetic resonance imaging is quite a sensitive modality for identifying infection of the lumbar facet joint. Familiarity with its clinical symptoms and radiographic features is necessary to avoid misdiagnosis of this condition.

Painful snapping of the elbows is rare. We report on a 12-year-old boy with a painful snap in both elbows. High-resolution magnetic resonance imaging of the elbow using microscopy coils detected a synovial fold interposed in each humeroradial joint and was very helpful in establishing the cause of symptoms. Resection of the synovial folds was performed with subsequent relief of symptoms.

Abstract. We tested the tensile strength of the Achilles tendon attachment to the calcaneus in skeletal mature and immature rabbits. The mean ultimate failure load was 179.6±28.6 N in the mature animals, and 138.5±36.1 N in the immature animals (P<0.05). Although direct insertion was clearly observed histologically in the mature animals, direct insertion was not obvious in the immature animals. In the mature animals, failure occurred partly at the attachment zone (50%) and partly at the tendon zone (50%). In the immature animals, failure occurred at the attachment zone in 85% and at the tendon zone in 15%. Résumé. Nous avons testé la résistance à la tension de l'insertion du tendon Achille au Calcanéum chez les lapins matures et immatures au plan squelettique. La charge de rupture moyenne était 179.6±28.6 N chez les animaux matures, et 138.5±36.1 N chez les immatures (P <0.05). Bien que l'insertion directe ait été clairement observée histologiquement chez les animaux matures, l'insertion directe n'était pas évidente chez les animaux immatures. Chez les animaux matures, la rupture s'est produite en partie a la zone d'attachement (50%) et en partie dans la zone tendineuse (50%). Chez les animaux immature la rupture s'est produite a la zone d'attachement dans 85% et en zone tendineuse dans 15%.

To compare the strength of interference screw fixation of the tendon to suture button fixation and staple fixation methods.

We investigated alterations in the expression of mRNA for type II and type X collagen in fracture callus of experimentally induced diabetic animals compared with controls and performed radiographic, histological, immunocytochemical and biomechanical studies.Experimentally induced diabetic rats exhibited an alteration in the temporal expression of type II and type X collagen mRNA and a decrease in type X mRNA expression as compared to controls. Radiographs showed a more intense periosteal reaction and a more rapid reconstitution of cortices in control versus diabetic animals. Histologically there was a delay in chondrocyte maturation and hypertrophy seen in diabetics. Immunolocalization of type X collagen demonstrated a delay in type X collagen expression around the hypertrophic chondrocytes. Biomechanical analysis showed a decrease in the strength of healing fractures in diabetic animals.Fracture healing in diabetic patients is compromised and may lead to delays in bone union. Though the exact mechanisms are unknown, we present evidence of decreased mechanical strength of the fracture and suggest that associated changes in collagen expression and chondrocyte maturation are mechanisms leading to delayed healing in untreated and poorly controlled diabetes.

Both prostaglandin E2(PGE2) and low intensity pulsed ultrasound (U/S) exposure have been reported to accelerate fracture repair. We hypothesized that these two pathways are interactive. To verify this hypothesis, we examined the regulation of PGE2production by U/S exposure (sine wave of 1.5MHz repeating at 1kHz, 30mW/cm2, 20 minutes) in mouse osteoblastic cell line, MC3T3-E1. The production of PGE2in osteoblasts was augmented by U/S, which was threefold at 60 min. in comparison with unexposed samples. Then we evaluated the expression of cyclooxygenase-2 (COX-2) mRNA, which is a critical enzyme for PGE2production. U/S rapidly up-regulated the expression of COX-2 mRNA in a time dependent manner. In addition, PGE2production by U/S was drastically suppressed by a selective inhibitor of COX-2. These results provide strong evidence that PGE2production in osteoblasts is dependent upon the induction of COX-2 mRNA expression by U/S and offer a mechanistic insight into how U/S accelerates fracture repair.

To compare the mode of action of rasp21 with those of protein kinases A and C in the regulation of gene expression in NIH/3T3 cells, we investigated the transcriptional activity of various enhancer/promoters and enhancer motifs in the cells transfected with the c-Ha- rasval12complementary DNA (cDNA). The results indicate that the c-Ha- rasval12protein stimulates the enhancer/promoters of the c-fosgene, the metallothionein II Agene, the simian virus 40 (SV40) virus genome and the Rous sarcoma (RS) virus genome, and the serum-response element and the 12- O-tetradecanoylphorbol-13-acetate (TPA)-response element in a manner independent of protein kinases A and C in NIH/3T3 cells.

Two novel major heterodimeric Mu-class glutathione (GSH)S-transferases (GSTs), designated M1-2 and M1-3*, were isolated from guinea pig (gp) liver cytosol and purified to homogeneity together with a known majorhomodimeric Mu-class gpGSTM1-1 (reported as GST b by R. Oshino, K. Kamei, M. Nishioka, and M. Shin, 1990,J. Biochem.107, 105–110). These three gpGSTs were quantitatively retained on anS-hexyl-GSH affinity column and separated as homogeneous proteins by chromatofocusing. Subunits of the heterodimers were inseparable on sodium dodecyl sulfate–polyacrylamide gel electrophoresis, but could be completely separated by reverse-phase partition high-performance liquid chromatography. A molecular cloning study demonstrated that the gpGST subunit M2 consisted of 217 amino acid residues with a calculated molecular mass of 25,562 and shared 84% identity in overall amino acid sequence with gpGSTM1-1. N-terminal amino acid sequences of peptides from the gpGST subunit M3* with a blocked N-terminus strongly suggested that it should belong to the Mu class. Western blot analysis using antisera raised against purified rat (r) GSTsA1-2 (Alpha), M1-1, P1-1 (Pi), and T2-2 (Theta) indicated that gpGSTsM1-1 and M1-3* cross-reacted only with anti-rGSTM1 antibody. However, gpGSTM1-2 cross-reacted intensely to almostthe same extent with antibodies to both rGSTsM1-1and T2-2. A homodimeric gpGSTM2-2, artificially constructed from native gpGSTM1-2 by treatment with guanidine hydrochloride followed by dialysis, intensely cross-reacted with antibodies to both the rat Mu- and Theta-class GSTs. Thus, the gpGST subunit M2 provided the first evidence for the double immuno-cross-reaction of a GST with polyclonal antibodies to two different classes of GSTs.

To compare the mode of action of rasp21 with those of protein kinases A and C in the regulation of gene expression in NIH/3T3 cells, we investigated the transcriptional activity of various enhancer/promoters and enhancer motifs in the cells transfected with the c‐Ha‐rasval12complementary DNA (cDNA). The results indicate that the c‐Ha‐rasval12protein stimulates the enhancer/promoters of the c‐fosgene, the metallothionein IIAgene, the simian virus 40 (SV40) virus genome and the Rous sarcoma (RS) virus genome, and the serum‐response element and the 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)‐response element in a manner independent of protein kinases A and C in NIH/3T3 cells.

This study histologically and immunohistochemically demonstrated developmental changes in cell morphology and expression of type‐X collagen in the attachment of the Achilles tendon to the calcaneus in the rat. Although the site of attachment in the mature rat showed a well organized, direct insertion that was composed of tendon, fibrocartilage, calcified fibrocartilage, and bone, this four‐zone structure was not observed in the immature 1‐week‐old rat. Formation of fibrocartilage was observed at 2 weeks, together with the hypertrophy of chondrocytes and the appearance of the secondary center of ossification. Type‐X collagen was not detected either in chondrocytes in the attachment area at 1 week or in hypertrophic chondrocytes at the attachment at 2 weeks. In the 3‐week‐old rat, the secondary center of ossification extended to the area of attachment and type‐X, collagen was detected both in cartilage spicules within the secondary center of ossification and in cells found at the attachment adjacent to the secondary center of ossification. A four‐zone structure had been established by 6 weeks and remained through 20 weeks. After 6 weeks, type‐X collagen was identified both in the attachment of the tendon and beneath the calcaneal fibrocartilage. Type‐X collagen is produced by cells in transitional zones between calcified and noncalcified tissue, such as the interface between articular cartilage and subchondral bone. In these areas, the expression of this protein persists through maturity and is not transient.

The effects of surgical repair versus non-repair on cell morphology and type X collagen expression were investigated using a rat model of Achilles tendon avulsion. The animals were divided into four groups. In Group I, tendon was reattached to the original attachment site by suturing through a drill hole in the calcaneus; in Group II, tendon was not reattached and a drill hole was not made; in Group III, tendon was not reattached but a drill hole was made; and the animals in Group IV were sham operated.In Group I (tendon reattached), at 2 weeks postoperatively, many hypertrophic chondrocytes appeared at the reattachment site adjacent to bone and type X collagen was detected immunologically both in the cells and in the extracellular matrix. After 4 weeks, the cells at the original site of attachment were arranged in rows along the newly formed tendon fibers and were stained with type X collagen antibody. By contrast, when tendon was not reattached (Groups II and III), a gap between the original attachment site and the tendon stump was observed through the entire postoperative period. At 8 weeks, the original attachment site was covered by fibrocartilaginous tissue and tendon became attached to the calcaneal fibrocartilage area, which is proximal to the original attachment site. Type X collagen was detected in the cells which were adjacent to bone. In Group IV (sham operation), there were no changes in histology or type X collagen distribution, either at the attachment site or in tendon and bone, compared with the non-operated control rats. These results suggest that surgical reattachment of tendon to the original site is important to help reorganize cells during the repair process. Type X collagen was identified immunohistochemically in the cells adjacent to hone in all the groups, suggesting that it may play a role in maintaining distinct areas of calcified and non-calcified fibrocartilage.

Summary:

We report a rare case of posterior interosseous nerve (PIN) paralysis in a tennis player. The PIN, a 2 cm section from a bifurcation point of the radial nerve, presented increased stiffness in the surgical findings and treated with free sural nerve grafting after excision of the degenerative portion of the PIN. We speculate that PIN paralysis associated with hourglass-like constriction can be caused and exacerbated by repetitive forearm pronation and supination in playing tennis.

There are few reports on the clinical application of low intensity pulsed ultrasound (LIPUS) for fractures of the hand. The aim of this study was to investigate the clinical outcomes of carpal fractures treated with LIPUS.

Back-to-back pairs of a hyperon (Y) and a nucleon (N), from stopped kaon absorption on light nuclear targets, are studied with the FINUDA spectrometer. Such a pair with high momenta can be emitted from two nucleon absorption process (K-“NN” →YN). The invariant mass of the pair gives us additional information on the K-+“NN” system and possible existence of the kaon-bound state with two nucleons.

A novel method is proposed to measure η'(958) meson bound states in 11C nuclei by missing mass spectroscopy of the 12C (p,d) reaction near the η' production threshold. It is shown that peak structures will be observed experimentally in an inclusive measurement in case that the in-medium η' mass reduction is sufficiently large and that the decay width of η' mesic states is narrow enough. Such a measurement will be feasible with the intense proton beam supplied by the SIS synchrotron at GSI combined with the good energy resolution of the fragment separator FRS.

Laser-induced fluorescence has been used to measure the CF2radical ground-state densities after extinction of DC pulsed CF4/H2discharge plasma. From the measurement, the CF2radical was shown to be removed mainly by a diffusion process. Its diffusion coefficients are found to be D=430 cm2·Torr·s-1in H2and D=65 cm2·Torr·s-1in CF4at room temperature.