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Fabrication of line- and area-type laser-induced periodic surface structures (LIPSS) induced by a flat-top beam provides improved periodic uniformity in structure compared to fabrication with a Gaussian beam. Improved periodic uniformity induces high reproducibility and high performance through signal uniformity. Especially, this characteristic makes LIPSS induced by flat-top beam can be applied in structural color, hydrophobicity control and surface-enhanced Raman scattering. To demonstrate the improved periodic uniformity, the periods of the LIPSSs induced by Gaussian and flat-top beams are analyzed. Period uniformity is evaluated by applying the fast Fourier transformation to atomic force microscopy data. Improved periodic uniformity is observed in the area-type LIPSS induced by a flat-top beam. This is because of the peak of line width induced by the Gaussian beam profile characteristic. Consequently, area-type LIPSSs induced by a flat-top beam exhibit improved periodic uniformity.

In this study, we used an ultrafast laser with a wavelength of 1026 nm with the aim of analyzing the ablation threshold and morphologies of the irradiated surfaces of cemented carbide by varying the pulse duration and number of laser pulses. Specifically, we used pulse durations of 0.2, 2, and 10 ps and performed both gentle and strong ablations. For the same wavelength, laser pulse energy, and number of laser pulses, the lowest ablation threshold was 0.2 ps. When we performed a gentle ablation, we observed laser-induced periodic surface structures (LIPSSs) on the entire irradiated surface for all pulse durations. Thus, the pulse duration did not appear to affect the formation of LIPSSs. Strong ablation caused ridges to form at irradiated area outside. When the pulse duration increased, larger ridges were formed, whereas when the pulse duration decreased, coarser ridges were formed. The results obtained by using the ultrafast laser is expected to be helpful in the machining of cemented carbide.

BACKGROUND: Compared with healthy people, patients with chronic tension-type headache (CTTH) are likely to have forward head postures (FHP) and a higher number of active trigger points (aTrP) on the suboccipital muscle. OBJECTIVE: This study aims to verify how the suboccipital muscle inhibition (SMI) on aTrPs and the FHP correction exercise can effectively reduce symptoms of the CTTH patients. METHOD: The subjects of this study were 45 individuals with CTTH, divided into three groups of 15 patients each: a) the SMI group using the myofascial release technique; b) the SMIEx group subject to both the SMI therapy and FHP correction exercises; and c) the control group. Group A and B were given the relevant interventions twice a week for four consecutive weeks, and went through the headache impact test (HIT-6) and examinations on the pressure pain threshold (PPT) of the headache areas, the type and number of myofascial trigger points (TrP), the soft tissue PPT, and the posture before and after the intervention. RESULTS: There was a significant improvement in the HIT-6, the headache PPT, the soft tissue PPT, the TrP, and the posture in Group A and B patients to whom the SMI technique and SMIEx interventions were applied. The biggest reduction and increase in the HIT-6 and the headache PPT respectively were seen in the SMIEx group. CONCLUSION: According to this study, the SMIEx can be an effective intervention for patients with CTTH.

Theoretical and experimental investigations were performed on the fabrication and polarization property enhancement of a single-layer Au grating serving as a wire grid polarizer (WGP) in the mid-wavelength infrared (MWIR) range. Femtosecond laser (FSL) annealing was performed to overcome the performance limitations of the WGP fabricated by nanotransfer printing (NTP), and the results were compared with those of the conventional thermal annealing methods using scanning electron microscopy, atomic force microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. Consequently, the extinction ratio of the WGP annealed with FSL reached up to 1378 (∼31 dB) in the 3–5 μm wavelength range, which corresponds to a 2.18-fold improvement over the non-annealed WGP. This result suggests that it is possible to manufacture MWIR WGPs at a low cost and over large areas through a simple NTP and FSL annealing process, ultimately yielding WGPs with improved performances.

There was lack of study which evaluated the effects of characteristics of subjects such as the body mass index (BMI) or waist circumference (WC), as well as sexual differences on trunk muscle activities. The purpose of the present study was to compare the abdominal muscle activities among the groups dividing criterion as the BMI, WC, and the gender. As a criterion of BMI and WC, subjects were arranged to three groups. Female subjects who were less than 25 kg/m2 BMI, and less than 90 WC were arranged as female with underweight group (FU), male subjects who were greater than 25 kg/m2 BMI and greater than 85 WC were arranged as male with overweight group (MO), male subjects who were less than 25 kg/m2 BMI and less than 85 WC were arranged in male with underweight group (MU). Surface electromyography responses of the rectus abdominis, internal oblique, external oblique muscles and lumbar level of erector spinae were obtained during the plank and maximal voluntary isometric contraction (MVIC). The MO group showed significantly higher %MVIC value of the internal oblique and lumbar level of erector spinae, compared to the MU group (P

Laser ablation in liquids (LAL) offers a facile technique to develop a large variety of surfactant-free nanomaterials with high purity. However, due to the difficulty in the control of the particle synthesis process, the as-prepared nanomaterials always have a broad size distribution with a large polydispersity (σ). Surfactant-free properties can also cause problems with particle growth, which further increases the difficulty in size control of the colloids. Therefore, searching for strategies to simultaneously unify the sizes of colloids and inhibit particle growth has become significantly important for LAL-synthesized nanomaterials to be extensively used for biological, catalytic, and optical applications, in which fields particle size plays an important role. In this work, we present a facile way to simultaneously realize these two goals by ex situ SU-8 photoresist functionalization. Ag nanoparticles (NPs) synthesized by femtosecond laser ablation of silver in acetone at laser powers of 300 and 600 mW were used as starting materials. The synthesized Ag NPs have a broad size distribution between 1 and 200 nm with an average size of ca. 5.9 nm and σ of 127-207%. After ex situ SU-8 functionalization and 6 months storage, most particles larger than 10 nm become aggregates and precipitate, which makes the size distribution narrow with an average diameter of 4-5 nm and σ of 48-78%. The precipitation process is accompanied by the decrease in colloid mass from the initial ∼0.2 to 0.10-0.11 mg after ex situ SU-8 functionalization and 6 months colloid storage. Morphology analysis indicates that ex situ SU-8 functionalization inhibits the particle growth into polygonal nanocrystals. Radical polymerization of SU-8 on Ag NPs is considered to be the reason for both spontaneous size separation and growth inhibition phenomena. Benefiting from Ag NPs embedment and acetone dissolution, the glass-transition temperature of SU-8 photoresist increased from 314 to 331 °C according to thermogravimetric analysis. The universality of ex situ SU-8 functionalization-induced growth inhibition and size separation behaviors is further proved using the Au colloids generated by LAL in acetone. This work is expected to provide a new route for better size control of LAL-synthesized colloids via ex situ photoresist functionalization, although a half of colloidal mass is wasted due to radical polymerization-induced colloidal precipitation.

Because of its potential uses, high aspect ratio nanostructures have been interested for last few decades. In order to generate nanostructures, various techniques have been attempted. Femtosecond laser ablation is one of techniques for generating nanostructures inside a transparent material. For generating nanostructures by femtosecond laser ablation, previous studies have been attempted beam shaping such as Bessel beam and temporal tailored beam. Both methods suppress electron excitation at near surface and initiate interference of photons at certain depth. Recent researches indicate that shape of nanostructures is related with temporal change of electron density and number of self-trapped excitons. In this study, we try to use the temporal change of electron density induced by femtosecond laser pulse for generating high aspect ratio nanoholes. In order to reveal the effect of temporal change of electron density, secondary pulses are irradiated from 100 to 1000 ps after the irradiation of first pulse. Our result shows that diameter of nanoholes is increasing and depth of nanoholes is decreasing as pulse to pulse interval is getting longer. With manipulating of pulse to pulse interval, we could generate high aspect ratio nanoholes with diameter of 250–350 nm and depth of 4∼6 µm inside a glass.

The purpose of this study was to compare the effects of Kinesio taping in each area of the ankle versus the knee to improve balance abilities and proprioception sense. The healthy twenty eight students were divided into two groups, Group A and B. Ankle taping was applied to Group A, and knee taping was applied to Group B. In the ankle taping group, significant increase of dynamic balance abilities was appeared in the forward, left ward and right ward (p

The development of ink-based printing techniques has enabled the fabrication of electric circuits on flexible substrates. Previous studies have shown that the process method which uses a silver (Ag) precursor (AgCF3COO) and electrospun poly(styrene-block-butadiene-block-styrene) (SBS) can yield patterns with high conductivity and stretchability. However, the only method to reduce the Ag precursor absorbed in SBS is chemical reduction using a toxic solution. Here, we developed a process to fabricate a high-conductivity pattern via laser reduction by photo-chemical reaction without toxic solutions. The Ag precursor was absorbed in electrospun SBS to form a composite layer (composite SBS) with modified properties, that could more effectively absorb the photon energy than SBS without the Ag precursor. We analyzed the properties of this material, such as its light absorption coefficient, heat conductivity, and the density of both SBS and composite SBS to allow comparison of the two materials by numerical simulation. In addition, we fabricated patterns on highly heat-sensitive substrates such as burning paper and a polyethylene terephthalate (PET) thin film, as the pattern can be implemented using very low laser energy. We expect the proposed approach to become a key technology for implementing user-designed circuits for wearable sensors and devices on various flexible substrates.

BACKGROUND Recent clinical research has supported the use of suspension devices in rehabilitation procedures both in practice and in theory. Although a longitudinal study has reported on the use of suspension devices among asymptomatic subjects, it is necessary to investigate the immediate effects of suspension exercises in patients with CLBP. OBJECTIVE The present study aims to investigate changes in neuromuscular activation after the prescription of suspension exercises in patients with CLBP. A secondary aim was to determine whether practical flexion and extension strength can be effectively enhanced. METHODS Before and after suspension exercise, flexion extension (FE) ratio and trunk strength of flexion and extension were measured. Patients performed two types of suspension exercises: supine bridge and forward leaning exercises. The paired t-test was used to compare the FE ratio and strength data. Pearson correlation coefficient was performed to study the correlation between measured variables. RESULTS Compared to the pre-exercise measurements, the flexion-extension ratio and trunk extension strength was significantly increased at the post-exercise measurement (p< 0.05). The FE ratio in the right lumbar erector spine muscle was significantly correlated with post-exercise trunk extension strength (p< 0.05). CONCLUSIONS For patients with chronic lower back pain, stimulation of the lumbar extensor muscle and of proprioception is effective both for strengthening lumbar extensors and for improving the flexion-extension ratio. Consequently, forward leaning and supine bridge exercises with a suspension device are beneficial for normalising neuromuscular control of the erector spinae muscles.

We reported on the ablation depth control with a resolution of 40 nm on indium tin oxide (ITO) thin film using a square beam shaped femtosecond (190 fs) laser (λp=1030 nm). A slit is used to make the square, flat top beam shaped from the Gaussian spatial profile of the femtosecond laser. An ablation depth of 40 nm was obtained using the single pulse irradiation at a peak intensity of 2.8 TW/cm2. The morphologies of the ablated area were characterized using an optical microscope, atomic force microscope (AFM), and energy dispersive X-ray spectroscopy (EDS). Ablations with square and rectangular types with various sizes were demonstrated on ITO thin film using slits with varying x–y axes. The stereo structure of the ablation with the depth resolution of approximately 40 nm was also fabricated successfully using the irradiation of single pulses with different shaped sizes of femtosecond laser.

Since conventional mechanical punching technology for Flexible Printed Circuit Board (FPCB) drilling has restricted via-hole size and depth control for multi-layer circuit boards, CO 2 and Ultra Violet (UV) laser drilling technologies have been developed. However, the FPCBs for mobile phones and Personal Digital Assistants (PDAs) require smaller via-hole diameters, since the development of thinner and higher circuit density devices is demanded. Currently, UV laser systems are widely used for FPCB drilling of 75–105 μm diameter via-holes and inspectors performs quality test manually using microscopes. We developed a high-precision UV laser microfabrication system for next-generation FPCB drilling of 15 μm diameter via-holes. The degrees of the precision of the microfabricated via-holes of 15, 35, 50 and 85 μm were mean absolute error rate of 4.4, 2.2, 2.3, and 2.2 which was fully satisfied with industrial inspection specification ±10%. The drilling speed of the system of 2800 via-holes per second at stationary state was achieved. In addition, we applied modified Greedy 2-opt algorithm to find out optimal drilling path which reduced the total time of via-hole fabrication. We successfully reduced the production time by 25% compared with the result obtained in the normal Greedy 2-opt algorithm. Moreover, we designed very accurate inspection method using Canny edge detection and geometric pattern matching algorithms and successfully applied it to the Automated Optical Inspection (AOI) module for the inspections of 15 μm diameter via-hole which was required for the fabrication of high density FPCB.

There are few reports on zero-field-cooled (ZFC) magnetization measurements for Fe@FeOx or FeOx particles synthesized by laser ablation in liquids (LAL) of Fe, and the minimum blocking temperature (TB) of 120 K reported so far is still much higher than those of their counterparts synthesized by chemical methods. In this work, the minimum blocking temperature was lowered to 52 K for 4&ndash, 5 nm &alpha, Fe2O3 particles synthesized by femtosecond laser ablation of Fe in acetone. The effective magnetic anisotropy energy density (Keff) is calculated to be 2.7&ndash, 5.4 &times, 105 J/m3, further extending the Keff values for smaller hematite particles synthesized by different methods. Large amorphous-Fe@&alpha, Fe2O3 and amorphous-Fe@C particles of 10&ndash, 100 nm in diameter display a soft magnetic behavior with saturation magnetization (Ms) and coercivities (Hc) values of 72.5 emu/g and 160 Oe at 5 K and 61.9 emu/g and 70 Oe at 300 K, respectively, which mainly stem from the magnetism of amorphous Fe cores. Generally, the nanoparticles obtained by LAL are either amorphous or polycrystalline, seldom in a single-crystalline state. This work also demonstrates the possibility of synthesizing single-crystalline &alpha, Fe2O3 hematite crystals of several nanometers with (104), (113), (116) or (214) crystallographic orientations, which were produced simultaneously with other products including carbon encapsulated amorphous Fe (a-Fe@C) and Fe@FeOx core-shell particles by LAL in one step. Finally, the formation mechanisms for these nanomaterials are proposed and the key factors in series events of LAL are discussed.

There are few reports on zero-field-cooled (ZFC) magnetization measurements for Fe@FeOx or FeOx particles synthesized by laser ablation in liquids (LAL) of Fe, and the minimum blocking temperature (TB) of 120 K reported so far is still much higher than those of their counterparts synthesized by chemical methods. In this work, the minimum blocking temperature was lowered to 52 K for 4–5 nm α-Fe2O3 particles synthesized by femtosecond laser ablation of Fe in acetone. The effective magnetic anisotropy energy density (Keff) is calculated to be 2.7–5.4 × 105 J/m3, further extending the Keff values for smaller hematite particles synthesized by different methods. Large amorphous-Fe@α-Fe2O3 and amorphous-Fe@C particles of 10–100 nm in diameter display a soft magnetic behavior with saturation magnetization (Ms) and coercivities (Hc) values of 72.5 emu/g and 160 Oe at 5 K and 61.9 emu/g and 70 Oe at 300 K, respectively, which mainly stem from the magnetism of amorphous Fe cores. Generally, the nanoparticles obtained by LAL are either amorphous or polycrystalline, seldom in a single-crystalline state. This work also demonstrates the possibility of synthesizing single-crystalline α-Fe2O3 hematite crystals of several nanometers with (104), (113), (116) or (214) crystallographic orientations, which were produced simultaneously with other products including carbon encapsulated amorphous Fe (a-Fe@C) and Fe@FeOx core-shell particles by LAL in one step. Finally, the formation mechanisms for these nanomaterials are proposed and the key factors in series events of LAL are discussed.

The technique of laser ablation in liquids (LAL) has already demonstrated its flexibility and capability for the synthesis of a large variety of surfactant-free nanomaterials with a high purity. However, high purity can cause trouble for nanomaterial synthesis, because active high-purity particles can spontaneously grow into different nanocrystals, which makes it difficult to accurately tailor the size and shape of the synthesized nanomaterials. Therefore, a series of questions arise with regards to whether particle growth occurs during colloid storage, how large the particle size increases to, and into which shape the particles evolve. To obtain answers to these questions, here, Ag particles that are synthesized by femtosecond (fs) laser ablation of Ag in acetone are used as precursors to witness the spontaneous growth behavior of the LAL-generated surfactant-free Ag dots (2–10 nm) into different polygonal particles (5–50 nm), and the spontaneous size separation phenomenon by the carbon-encapsulation induced precipitation of large particles, after six months of colloid storage. The colloids obtained by LAL at a higher power (600 mW) possess a greater ability and higher efficiency to yield colloids with sizes of &lt, 40 nm than the colloids obtained at lower power (300 mW), because of the generation of a larger amount of carbon ‘captors’ by the decomposition of acetone and the stronger particle fragmentation. Both the size increase and the shape alteration lead to a redshift of the surface plasmon resonance (SPR) band of the Ag colloid from 404 nm to 414 nm, after storage. The Fourier transform infrared spectroscopy (FTIR) analysis shows that the Ag particles are conjugated with COO– and OH– groups, both of which may lead to the growth of polygonal particles. The CO and CO2 molecules are adsorbed on the particle surfaces to form Ag(CO)x and Ag(CO2)x complexes. Complementary nanosecond LAL experiments confirmed that the particle growth was inherent to LAL in acetone, and independent of pulse duration, although some differences in the final particle sizes were observed. The nanosecond-LAL yields monomodal colloids, whereas the size-separated, initially bimodal colloids from the fs-LAL provide a higher fraction of very small particles that are &lt, 5 nm. The spontaneous growth of the LAL-generated metallic particles presented in this work should arouse the special attention of academia, especially regarding the detailed discussion on how long the colloids can be preserved for particle characterization and applications, without causing a mismatch between the colloid properties and their performance. The spontaneous size separation phenomenon may help researchers to realize a more reproducible synthesis for small metallic colloids, without concern for the generation of large particles.

The development of printing technologies has enabled the realization of electric circuit fabrication on a flexible substrate. However, the current technique remains restricted to single-layer patterning. In this paper, we demonstrate a fully solution-processable patterning approach for multi-layer circuits using a combined method of laser sintering and ablation. Selective laser sintering of silver (Ag) nanoparticle-based ink is applied to make conductive patterns on a heat-sensitive substrate and insulating layer. The laser beam path and irradiation fluence are controlled to create circuit patterns for flexible electronics. Microvia drilling using femtosecond laser through the polyvinylphenol-film insulating layer by laser ablation, as well as sequential coating of Ag ink and laser sintering, achieves an interlayer interconnection between multi-layer circuits. The dimension of microvia is determined by a sophisticated adjustment of the laser focal position and intensity. Based on these methods, a flexible electronic circuit with chip-size-package light-emitting diodes was successfully fabricated and demonstrated to have functional operations.

The effect of the laser pulse width on the production of nanoparticles by laser fragmentation was investigated. Laser pulse widths of 164 fs, 5 ps, 4 ns, 36 ns, 64 ns, and 100 ns were used. To assess the effect of the laser pulse width on the energy distribution in the nanoparticles, the energy distribution was simulated using wave optics. Silver (Ag) nanoparticles were produced by laser irradiation of an Ag target in distilled water. The wavelength of the femtosecond, picosecond, and nanosecond lasers used was 1070 nm, and their fluences were 0.10–0.13 mJ/cm2. Nanoparticle microstructure was visualized by transmission electron microscopy and scanning electron microscopy, and the nanoparticle size distribution was evaluated using a particle size analyzer.

This study compares the ablation morphologies obtained with a femtosecond laser of both Gaussian and quasi-flat top beam profiles when applied to indium tin oxide (ITO) thin films for the purpose of OLED repair. A femtosecond laser system with a wavelength of 1030 nm and pulse duration of 190 fs is used to pattern an ITO thin film. The laser fluence is optimized for patterning at 1.38 J/cm2. The patterned ITO thin film is then evaluated through both optical microscope and atomic force microscope. Ablations with a square quasi-flat top beam are demonstrated using slits with varying x–y axes. With the Gaussian beam, the pattern width of the ablated area is shown to range from 9.17 to 9.99 μm when the number of irradiation pulse increases from one to six. In contrast, when slit control is used to obtain a quasi-flat top beam, the ablated pattern width remains constant at 10 μm, despite the increase in the number of pulse. The improved surface roughness is correlated with the quasi-flat top beam through measured Ra values. Furthermore, when using the Gaussian beam, the minimum resolution of the controllable ablation depth on the ITO thin film is found to be 60 nm. In contrast, when the quasi-flat top beam is used, the minimum ablation depth decreases to 40 nm.

The development of printing technologies has enabled the realization of electric circuit fabrication on flexible substrate. However, the current technique remains restricted to single-layer patterning. In this paper, we demonstrate a fully solution-processable patterning approach for multi-layer circuits using a combined method of laser sintering and ablation. Selective laser sintering of silver (Ag) nanoparticle-based ink is applied to make conductive patterns on a heat-sensitive substrate and insulating layer. The laser beam path and irradiation fluence are controlled to create circuit patterns for flexible electronics. Microvia drilling using femtosecond laser through the polyvinylphenol-film insulating layer by laser ablation, as well as sequential coating of Ag ink and laser sintering, achieves an interlayer interconnection between multi-layer circuits. The dimension of microvia is determined by a sophisticated adjustment of laser focal position and intensity. Based on these methods, the flexible electronic circuit with chip-size-package light-emitting diodes was successfully fabricated and demonstrated with functional operations.

Transparent borosilicate glass (BK7) is extensively used in optics applications. Herein, we demonstrate that a brown-colored pattern is generated inside BK7 glass upon irradiation with a near-infrared Ti:sapphire femtosecond laser and reveal the importance of maintaining the laser power at values well below the BK7 damage threshold for color center formation. The use of low laser power prevents the occurrence of mechanical damage (e.g., micro-crack or thread formation) in the generated colored area, and Gaussian fitting of the absorbance spectrum of BK7 shows that this material exhibits a band gap of 4.21 eV with three absorption edges. Thus, the developed patterning method is expected to find numerous applications in the future color processing of lines and points in glass.

A hybrid material composed of silver nanowires (AgNWs) and carbon nanotubes (CNTs) is investigated by a laser direct patterning method. A femtosecond laser system with a wavelength of 1027 nm and a pulse width of 380 fs is applied for the patterning of AgNW/CNT hybrid film. The Gaussian and square quasi-flat-top beam profiles are used for the patterning lines. The laser fluence and overlapping rate were optimized for patterning at 67.9 mJ/cm2 and 70%, respectively. The patterned AgNW/CNT film is evaluated using an optical microscope and scanning electron microscope. The partially ablated area of AgNW/CNT films around the patterned line is observed and discussed. The measurement results explain that the uniformity of the laser beam profile and the beam shape are key factors for development of AgNW/CNT films with fine edges.

The purpose of this study is to conduct a comparative analysis of the right shoulder's muscle activity when lifting ipsilateral and contralateral legs during the Push Up Plus (PUP) exercise, which is a typical shoulder stabilizing exercise, and to provide effective data for a shoulder stabilization exercise. Upper trapezius, lower trapezius, levator scapula, supraspinatus, infraspinatus, deltoid posterior, serratus anterior and pectoralis major, which are eight main muscles of a shoulder, were analyzed for the left and right leg lifting by using an electromyogram (EMG). The study revealed that the muscle activities of the right shoulder's upper trapezius, levator scapula, supraspinatus, serratus anterior and pectoralis major were higher when lifting an ipsilateral (right side) leg, compared to lifting a contralateral (left side) leg. Therefore, lifting an ipsilateral leg can be an effective method for enhancing the maneuverability (mobility) of the right shoulder when lifting a single leg.

, 은 열확산계수를 가지는 재료에서 그 초음파 가진에 의한 표면 품질의 향상을 발견하였다. Abstract: The laser machining process has been proposed as an advanced process for the selective fabrication of electrodes without a mask. In this study, we adapt laser machining to metals that have different thermal properties. Based on the results, the metals exhibit a different surface morphology, heat-affected zone (HAZ), and a recast layer around the machined surface according to their thermal conductivity, boiling point, and thermal diffusivity. Then, we apply ultrasonic-assisted laser machining to remove the recast layer. The ultrasonic-assisted laser machining exhibits a better surface quality in metals with higher diffusivity than those having lower diffusivity.

Purpose: The purpose of this study was to investigate the effect of regularly strength exercise of spine in teenagers with tutor. Method: Study subjects were 24 middle school students. They were arranged to 2 groups(n=12, respectively). Then experimental group did regularly strength exercise of spine as the handout maneuver during 50min/day and 1day/week in 8 weeks with tutor, but control group did regularly exercise of spine as same maneuver without tutor. For muscle strength of both extensor and flexor of lumbar, the balancing ability and weight distribution index were measured before and after the intervention. Results: For muscle strength of both extensor and flexor of lumbar, there was not significant differences after the intervention, but both flexor and extensor increase mean value of muscle strength than control group. For balancing ability and weight distribution index, there were not significant difference after intervention(p>.05), but experimental group show a tendency to decrease in a few position than control group. Conclusion: When teenagers regularly exercise for spine strengthening for a long time with tutor, it may be increased muscle strength of lumbar and trunk balance.

Display Omitted Polycarbonate is fabricated using CNC engraving machine to make microfluidic channel.We prepared gelatin-coated PET membrane.We make cancer cell capture device with polycarbonate plate and PET membrane.PET membrane is attached on the polycarbonate plate and negative pressure is applied on microfluidic channel.We successfully developed the new singular cell capture device for cancer cell manipulation. Although celltrapping devices have been microfabricated and widely used for manipulation of bio cells, devices that trap multiple cells simultaneously are difficult to design because fabrication is complicated and time consuming. We designed and manufactured a microfluidic device using a polycarbonate plate with a flatness less than 200µm and a gelatin-coated polyethylene terephthalate (PET) membrane. The device was used to capture colorectal cancer cells from one of the most common types of human malignant tumors. Microfluidic channels for the device were micromachined in minutes using a Computerized Numerically Controlled (CNC) engraving machine. We microfabricated multiple microholes on the PET membrane, which had a thickness of 13µm, using an ultrafast, 1025nm diode-pumped solid state femtosecond laser. The 100 microholes were drilled by spirally moving spot size of 4µm laser beam. It is very important to obtain smooth and clean surface to avoid cell damages when they are trapped on the device. The relationship between the diameter changes of the microholes and variations in laser output power as well as laser fluence were investigated through parametric analysis. The average diameter of the holes increased exponentially with laser power. The gelatin-coated PET membrane was attached to the polycarbonate device and a syringe with a tube controlled negative pressure inside the channels of the cell-trapping device. Maintaining negative pressure inside the channels under the microholes on the PET membrane, colorectal cancer cells were dropped using the cell dropping pipette and successfully captured for manipulation under same environmental condition.

[Purpose] This research explored the positive effects of self-myofascial release on hamstring muscular flexibility and proprioception and investigated the effectiveness of the stretch combined with therapeutic ultrasound. [Subjects and Methods] This study included 30 healthy university students with no history of pain in the Achilles tendon or hamstring within the recent 6 months. Each participant completed two experiments. In the first experiment (MS), they completed self-myofascial stretching using a foam roller for 7 days. In the second experiment (MSU), the same participants performed the self-myofascial stretching after the 15-minute application of ultrasound. This study involved a pre- and post-test on hamstring muscle flexibility and hip joint proprioception. [Results] The use of self-myofascial stretching in the MS experiment had a significant effect on hamstring muscle flexibility and hip joint proprioception. However, the addition of ultrasound in the MSU experiment had no additive effect. [Conclusion] Self-myofascial stretching immediately increased hamstring muscle flexibility and improved hip joint proprioception, but the addition of pre-stretch ultra sound provided no further benefit.

The demand for micro-scale surface machining has been steadily increasing, and various methods have been introduced. Among these, microcutting with a diamond tool removes material by making multiple cutting passes. However, many passes are needed to generate micropatterns over a large area. To overcome the drawbacks of this time-consuming process, we propose a novel method, which uses a micropatterned diamond tool. A 220-fs-pulsed Ti: Sapphire laser is used to create micropatterns on the edge line of a rectangular diamond tool. A six-axis motion stage is used to align the edge line and flank surface of the diamond tool with respect to the focal point of the laser beam. Using a simple laser direct-writing method and a 100× objective lens (NA: 0.8), lines ≤ 2 μm in width, 20 μm in length, and 10 μm in separation were fabricated along the 1-mm edge line of a bulk diamond tool. The micropatterned diamond cutting tool was then used to successfully produce micropatterns on the surface of nickel (Ni)-electroformed on SKD-61. This novel process provides an efficient means of multiple micropattern generation for molding applications, such as those required for optics and biotechnology, using only a single pass of a diamond cutting tool.

[Purpose] Although the Push-Up Plus is a useful exercise method for shoulder stabilization, few studies have examined its effects at different angles of shoulder rotation. Therefore, the present study investigated the most effective exercise method for shoulder stabilization by analyzing muscle activities of the rotator cuff muscles at different angles of shoulder rotation. [Subjects] Fifteen healthy university students in their 20s were the subjects of this study. [Methods] Changes in muscle EMG related to shoulder stabilization were analyzed by performing the Push-Up Plus in shoulder positions of neutral, internal and external rotation. [Results] The highest muscle activity was found in external rotation, and in internal rotation the pectoralis major and levator scapula showed significantly lower activities than the other positions. [Conclusion] Selectively changing the rotation angle of the shoulder for different purposes of the shoulder exercise would be an effective exercise method.