Short-Term Impact of Low-Intensity Exercise with Blood Flow Restriction on Mild Knee Osteoarthritis in Older Adults: A Pilot Study.

This pilot study aimed to investigate the immediate impact of low-intensity exercises with blood flow restriction (BFR) on older adults with knee osteoarthritis (KOA). Fifteen patients with KOA who were over 50 years old, participated and underwent low-intensity resistance knee exercises at 30% of their one-repetition maximum with BFR three times/week for two weeks. Pre- and post-exercise assessments included pain levels, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, isokinetic knee strength, lower extremity muscle volume (via leg circumference and muscle thickness), functional performance tests (timed up-and-go [TUG] and sit-to-stand [STS]), skeletal muscle index (SMI) using bioelectrical impedance analysis, and handgrip strength (HGS). Post-exercise, there was a significant reduction in pain. WOMAC scores showed significant improvements across all three domains: pain, stiffness, and physical function. In the TUG and STS tests, completion times were significantly reduced. Thigh and calf circumferences, as well as thigh muscle thickness significantly increased after exercise. Post-exercise SMI and HGS also significantly increased. However, isokinetic knee strength did not show significant changes. In conclusion, low-intensity BFR exercises provide immediate benefits in symptoms and physical performance for patients with KOA, potentially inducing local and systemic muscle mass increase, even after a short-term intervention.

SYMPATHETIC NERVE ENTRAPMENT POINT INJECTION AS AN ADJUVANT TREATMENT FOR INTRACTABLE CLUSTER HEADACHE: A CASE REPORT.

BACKGROUND: Cluster headache (CH) is characterized by severe unilateral pain ranging from the orbital to the temporal regions with ipsilateral autonomic manifestations. Although most patients respond to drugs or oxygen inhalation, some do not. In this case report, we introduce sympathetic nerve entrapment point injection (SNEPI), a new adjuvant treatment for CH. CASE REPORT: We introduce two CH patients who did not respond well to pharmacological treatment or 100% oxygen inhalation, but who improved after SNEPI. Patient 1, a 42-year-old man, visited the Emergency Department (ED) with severe periorbital right frontal headache accompanied by ipsilateral rhinorrhea, conjunctival injection, and eyelid edema. The symptoms did not fully respond to drugs or oxygen inhalation, but improved after SNEPI into the tender point of the splenius capitis (SC) muscle; there was no further pain for 1 month thereafter. Patient 2, a 26-year-old woman, presented to the ED complaining of severe headache in the right supraorbital-temporal-occipital region with ipsilateral lacrimation and conjunctival congestion. The patient was taking various drugs for CH, but there was no improvement; the symptoms improved dramatically after SNEPI into the tender points of the SC and paraspinal deep muscles (levels T1-2), and the pain was well managed with reduced drug doses for 3 months. Why Should an Emergency Physician Be Aware of This? CH can cause severe acute pain, and sometimes pharmacological treatment or oxygen inhalation is not effective. SNEPI, which is inexpensive and can be easily performed, may be considered as an adjuvant treatment for intractable CH in the ED.

Eosinophils protect against acetaminophen-induced liver injury through cyclooxygenase-mediated IL-4/IL-13 production.

BACKGROUND AND AIMS: A better understanding of the underlying mechanism of acetaminophen (APAP)-induced liver injury (AILI) remains an important endeavor to develop therapeutic approaches. Eosinophils have been detected in liver biopsies of patients with APAP overdose. We recently demonstrated a profound protective role of eosinophils against AILI; however, the molecular mechanism had not been elucidated. APPROACH AND RESULTS: In agreement with our previous data from experiments using genetic deletion of eosinophils, we found that depletion of eosinophils in wild-type (WT) mice by an anti-IL-15 antibody resulted in exacerbated AILI. Moreover, adoptive transfer of eosinophils significantly reduced liver injury and mortality rate in WT mice. Mechanistic studies using eosinophil-specific IL-4/IL-13 knockout mice demonstrated that these cytokines, through inhibiting interferon-γ, mediated the hepatoprotective function of eosinophils. Reverse phase protein array analyses and in vitro experiments using various inhibitors demonstrated that IL-33 stimulation of eosinophils activated p38 mitogen-activated protein kinase (MAPK), and in turn, cyclooxygenases (COX), which triggered NF-κB-mediated IL-4/IL-13 production. In vivo adoptive transfer experiments showed that in contrast to naive eosinophils, those pretreated with COX inhibitors failed to attenuate AILI. CONCLUSIONS: The current study revealed that eosinophil-derived IL-4/IL-13 accounted for the hepatoprotective effect of eosinophils during AILI. The data demonstrated that the p38 MAPK/COX/NF-κB signaling cascade played a critical role in inducing IL-4/IL-13 production by eosinophils in response to IL-33.

Interleukin-33 facilitates liver regeneration through serotonin-involved gut-liver axis.

BACKGROUND AND AIMS: Insufficient liver regeneration causes post-hepatectomy liver failure and small-for-size syndrome. Identifying therapeutic targets to enhance hepatic regenerative capacity remains urgent. Recently, increased IL-33 was observed in patients undergoing liver resection and in mice after partial hepatectomy (PHx). The present study aims to investigate the role of IL-33 in liver regeneration after PHx and to elucidate its underlying mechanisms. APPROACH AND RESULTS: We performed PHx in IL-33 -/- , suppression of tumorigenicity 2 (ST2) -/- , and wild-type control mice, and found deficiency of IL-33 or its receptor ST2 delayed liver regeneration. The insufficient liver regeneration could be normalized in IL-33 -/- but not ST2 -/- mice by recombinant murine IL-33 administration. Furthermore, we observed an increased level of serotonin in portal blood from wild-type mice, but not IL-33 -/- or ST2 -/- mice, after PHx. ST2 deficiency specifically in enterochromaffin cells recapitulated the phenotype of delayed liver regeneration observed in ST2 -/- mice. Moreover, the impeded liver regeneration in IL-33 -/- and ST2 -/- mice was restored to normal levels by the treatment with (±)-2,5-dimethoxy-4-iodoamphetamine, which is an agonist of the 5-hydroxytrytamine receptor (HTR)2A. Notably, in vitro experiments demonstrated that serotonin/HTR2A-induced hepatocyte proliferation is dependent on p70S6K activation. CONCLUSIONS: Our study identified that IL-33 is pro-regenerative in a noninjurious model of liver resection. The underlying mechanism involved IL-33/ST2-induced increase of serotonin release from enterochromaffin cells to portal blood and subsequent HTR2A/p70S6K activation in hepatocytes by serotonin. The findings implicate the potential of targeting the IL-33/ST2/serotonin pathway to reduce the risk of post-hepatectomy liver failure and small-for-size syndrome.

Higher Impulse Electromyostimulation Contributes to Psychological Satisfaction and Physical Development in Healthy Men.

Background and Objectives: This study investigated the various impulse effects of whole-body electromyostimulation (WB-EMS) on psychophysiological responses and adaptations. Materials and Methods: The participants included fifty-four men between 20 and 27 years of age who practiced isometric exercises for 20 min, three days a week, for 12 weeks while wearing WB-EMS suits, which enabled the simultaneous activation of eight muscle groups with three types of impulse intensities. Participants were allocated to one of four groups: control group (CON), low-impulse-intensity group (LIG), mid-impulse-intensity group (MIG), and high-impulse-intensity group (HIG). Psychophysiological conditions were measured at week 0, week 4, week 8, and week 12. Results: Compared with the CON, (1) three psychological conditions in LIG, MIG, and HIG showed positive tendencies every four weeks, and the analysis of covariance (ANCOVA) test revealed that body image (p = 0.004), body shape (p = 0.007), and self-esteem (p = 0.001) were significantly different among the groups. (2) Body weight, fat mass, body mass index, and percent fat in the CON showed decreasing tendencies, whereas those in LIG, MIG, and HIG showed a noticeable decrease, which revealed that there were significant differences among the groups. Specifically, a higher impulse intensity resulted in a greater increase in muscle mass. (3) Although there was no interaction effect in the abdominal visceral fat area, there were significant interactions in the abdominal subcutaneous fat (ASF) and total fat (ATF) areas. Both the ASF and ATF in the CON showed decreasing tendencies, whereas those in other groups showed a noticeable decrease. The ANCOVA revealed that the ASF (p = 0.002) and ATF (p = 0.001) were significantly different among the groups. In particular, the higher the impulse intensity, the greater the decrease in abdominal fat. Conclusions: This study confirmed that high-impulse-intensity EMS can improve psychophysiological conditions. In other words, healthy young adults felt that the extent to which their body image, body shape, and self-esteem improved depended on how intense their EMS impulse intensities were. The results also showed that higher levels of impulse intensity led to improved physical conditions.

Ge Solar Cells with Micro-Rod Arrays: Structural and Optical Properties.

Ge single-junction solar cell structures are grown on micro-patterned Ge substrates using lowpressure metalorganic chemical vapor deposition. 300 nm high micro-rod arrays are formed on the p-Ge substrates using photolithography and dry etching techniques. The micro-rod arrays are designed with rod diameter varying from 5 to 15 µm and arranged in a hexagonal geometry with rod spacing varying from 2 to 12 µm. Ge p-n junction structures are fabricated by phosphorus atomic diffusion process on the micro-patterned Ge substrates. 100 nm thick InGaP window and 300 nm thick GaAs cap layers are grown to reduce the surface recombination and the ohmic contact resistivity, respectively. Our results indicate that the micro-rod structures improve the performance of the Ge solar cells. An improvement of 16.1% in the photocurrent of the Ge micro-rod solar cell is observed compared to that of a reference Ge solar cell with planar surface. The improvement in the short circuit current density can be attributed to the light trapping effect, enlarged p-n junction area, and enhanced carrier collection efficiency. As a result, the conversion efficiency of the Ge solar cell with micro-rod arrays (5 µm diameter, 2 µm spacing, and 300 nm height) is improved from 3.84 to 4.78% under 1 sun AM 1.5G conditions.

TFEB regulates murine liver cell fate during development and regeneration.

It is well established that pluripotent stem cells in fetal and postnatal liver (LPCs) can differentiate into both hepatocytes and cholangiocytes. However, the signaling pathways implicated in the differentiation of LPCs are still incompletely understood. Transcription Factor EB (TFEB), a master regulator of lysosomal biogenesis and autophagy, is known to be involved in osteoblast and myeloid differentiation, but its role in lineage commitment in the liver has not been investigated. Here we show that during development and upon regeneration TFEB drives the differentiation status of murine LPCs into the progenitor/cholangiocyte lineage while inhibiting hepatocyte differentiation. Genetic interaction studies show that Sox9, a marker of precursor and biliary cells, is a direct transcriptional target of TFEB and a primary mediator of its effects on liver cell fate. In summary, our findings identify an unexplored pathway that controls liver cell lineage commitment and whose dysregulation may play a role in biliary cancer.

Improved Performance of Ge Solar Cell Using Graphene Quantum Dots.

We investigated the effect of graphene quantum dots (GQDs) on performance of single-junction Ge solar cell grown on (100) substrate by low pressure metalorganic chemical vapor deposition (LP-MOCVD). Isobutylgermane (IBuGe) is used as a Ge precursor for the Ge solar cell growth. By employing GQDs, the power conversion efficiency of the Ge solar cell is improved up to 3.90% (Voc of 0.22 V, Jsc of 28.52 mA/cm², and FF of 63.83%) through effective photon management as compared to bare Ge solar cells of 3.24% under AM 1.5G illumination.

Vitamin D Receptor Activation in Liver Macrophages Ameliorates Hepatic Inflammation, Steatosis, and Insulin Resistance in Mice.

BACKGROUND AND AIMS: Obesity-induced chronic inflammation is a key component in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and insulin resistance. Increased secretion of proinflammatory cytokines by macrophages in metabolic tissues promotes disease progression. In the diet-induced obesity (DIO) mouse model, activation of liver resident macrophages, or Kupffer cells (KCs), drives inflammatory responses, which recruits circulating macrophages and promotes fatty liver development, and ultimately contributes to impaired hepatic insulin sensitivity. Hepatic macrophages express the highest level of vitamin D receptors (VDRs) among nonparenchymal cells, whereas VDR expression is very low in hepatocytes. VDR activation exerts anti-inflammatory effects in immune cells. APPROACH AND RESULTS: Here we found that VDR activation exhibits strong anti-inflammatory effects in mouse hepatic macrophages, including those isolated from DIO livers, and mice with genetic loss of Vdr developed spontaneous hepatic inflammation at 6 months of age. Under the chronic inflammation conditions of the DIO model, VDR activation by the vitamin D analog calcipotriol reduced liver inflammation and hepatic steatosis, significantly improving insulin sensitivity. The hyperinsulinemic euglycemic clamp revealed that VDR activation greatly increased the glucose infusion rate, while hepatic glucose production was remarkably decreased. Glucose uptake in muscle and adipose did not show similar effects, suggesting that improved hepatic insulin sensitivity is the primary contributor to the beneficial effects of VDR activation. Finally, specifically ablating liver macrophages by treatment with clodronate liposomes largely abolished the beneficial metabolic effects of calcipotriol, confirming that VDR activation in liver macrophages is required for the antidiabetic effect. CONCLUSIONS: Activation of liver macrophage VDRs by vitamin D ligands ameliorates liver inflammation, steatosis and insulin resistance. Our results suggest therapeutic paradigms for treatment of NAFLD and type 2 diabetes mellitus.

A Magnetically Controlled Soft Microrobot Steering a Guidewire in a Three-Dimensional Phantom Vascular Network.

Magnetically actuated soft robots may improve the treatment of disseminated intravascular coagulation. Significant progress has been made in the development of soft robotic systems that steer catheters. A more challenging task, however, is the development of systems that steer sub-millimeter-diameter guidewires during intravascular treatments; a novel microrobotic approach is required for steering. In this article, we develop a novel, magnetically actuated, soft microrobotic system, increasing the steerability of a conventional guidewire. The soft microrobot is attached to the tip of the guidewire, and it is magnetically steered by changing the direction and intensity of an external magnetic field. The microrobot is fabricated via replica molding and features a soft body made of polydimethylsiloxane, two permanent magnets, and a microspring. We developed a mathematical model mapping deformation of the soft microrobot using a feed-forward approach toward steering. Then, we used the model to steer a guidewire. The angulation of the microrobot can be controlled from 21.1° to 132.7° by using a magnetic field of an intensity of 15 mT. Steerability was confirmed by two-dimensional in vitro tracking. Finally, a guidewire with the soft microrobot was tested by using a three-dimensional (3D) phantom of the coronary artery to verify steerability in 3D space.

Steering Algorithm for a Flexible Microrobot to Enhance Guidewire Control in a Coronary Angioplasty Application.

Magnetically driven microrobots have been widely studied for various biomedical applications in the past decade. An important application of these biomedical microrobots is heart disease treatment. In intravascular treatments, a particular challenge is the submillimeter-sized guidewire steering; this requires a new microrobotic approach. In this study, a flexible microrobot was fabricated by the replica molding method, which consists of three parts: (1) a flexible polydimethylsiloxane (PDMS) body, (2) two permanent magnets, and (3) a micro-spring connector. A mathematical model was developed to describe the relationship between the magnetic field and the deformation. A system identification approach and an algorithm were proposed for steering. The microrobot was fabricated, and the models for steering were experimentally validated under a magnetic field intensity of 15 mT. Limitations to control were identified, and the microrobot was steered in an arbitrary path using the proposed model. Furthermore, the flexible microrobot was steered using the guidewire within a three-dimensional (3D) transparent phantom of the right coronary artery filled with water, to show the potential application in a realistic environment. The flexible microrobot presented here showed promising results for enhancing guidewire steering in percutaneous coronary intervention (PCI).

Devising Mobile Sensing and Actuation Infrastructure with Drones.

Vast applications and services have been enabled as the number of mobile or sensing devices with communication capabilities has grown. However, managing the devices, integrating networks or combining services across different networks has become a new problem since each network is not directly connected via back-end core networks or servers. The issue is and has been discussed especially in wireless sensor and actuator networks (WSAN). In such systems, sensors and actuators are tightly coupled, so when an independent WSAN needs to collaborate with other networks, it is difficult to adequately combine them into an integrated infrastructure. In this paper, we propose drone-as-a-gateway (DaaG), which uses drones as mobile gateways to interconnect isolated networks or combine independent services. Our system contains features that focus on the service being provided in the order of importance, different from an adaptive simple mobile sink system or delay-tolerant system. Our simulation results have shown that the proposed system is able to activate actuators in the order of importance of the service, which uses separate sensors' data, and it consumes almost the same time in comparison with other path-planning algorithms. Moreover, we have implemented DaaG and presented results in a field test to show that it can enable large-scale on-demand deployment of sensing and actuation infrastructure or the Internet of Things (IoT).

Regular physical education class enhances sociality and physical fitness while reducing psychological problems in children of multicultural families.

This study investigated the influence of physical education class (PEC) as an intervention method for aggression, sociality, stress, and physical fitness levels in children from multicultural families. The hypothesis was that participating in PEC would result in reduced aggression and stress and improved sociality and physical fitness in multicultural children. A three-item questionnaire, a body composition test, and physical fitness tests were given three times. Eighty-four subjects were divided into four groups: multicultural children who participated in PEC (multi-PEG, n=12), multicultural children who did not participate in PEC (multi-NPEG, n=13), single-cultural children who participated in PEC (sing-PEG, n=11), and single-cultural children who did not participate in PEC (sing-NPEG, n=12), respectively. Parametric and nonparametric statistical methods were conducted on the collected data with a significance level set a priori at P<0.05. After 8 weeks of PEC, fat mass (F=2.966, P=0.045) and body mass index (F=3.654, P=0.021) had significantly different interaction effects. In the aspect of interaction effects from physical fitness variables, cardiopulmonary endurance (F=21.961, P=0.001), flexibility (F=8.892, P=0.001), muscular endurance (F=31.996, P=0.001), muscular strength (F=4.570, P=0.008), and power (F=24.479, P=0.001) were significantly improved in the multi-PEG compared to those of the other three groups. Moreover, sociality (F=22.144, P=0.001) in the multi-PEG was enhanced, whereas aggression (F=6.745, P=0.001) and stress (F=3.242, P=0.033) levels were reduced. As conclusion, the PEC reduced aggression and stress levels, and improved sociality and physical fitness levels after 8 weeks. This study confirmed that PEC for children from multicultural families can improve psychosocial factors and physical health.

Relationship between cardiopulmonary responses and isokinetic moments: the optimal angular velocity for muscular endurance.

Most protocols for testing and rehabilitation for recovery and improvement of muscular endurance have been set at 180°/sec, 240°/sec, and 300°/sec. These protocols can cause confusion to clinical providers or other researchers. This study was aimed at investigating the optimal isokinetic angular speed for measuring or developing muscular endurance after assessing the relationship between cardiopulmonary responses and isokinetic moments. This study was conducted with 31 male and female college students. Graded exercise test and body composition were measured as well as the isokinetic moments of the knee muscles at three angular speeds: 180°/sec, 240°/sec, and 300°/sec. The specific isokinetic moments of knee muscles that were measured included: peak torque (PT) and total work (TW) on extensor (e) and flexor (f) of knee joints, which were denoted as ePT180, fPT180, eTW180, fTW180, ePT240, fPT240, eTW240, fTW240, ePT300, fPT300, eTW300, and fTW300 according to the three angular speeds. Spearman correlation test was used to examine the relationship between the sum means of cardiopulmonary responses and the variables of isokinetic moments. This study confirmed that the optimal angular speed for testing or training for muscular endurance was 180°/sec, which showed a stronger relationship between cardiopulmonary responses and isokinetic moments. Therefore, this angular speed is recommended for testing and training for muscular endurance of the knee joints.

Ge nanopillar solar cells epitaxially grown by metalorganic chemical vapor deposition.

Radial junction solar cells with vertically aligned wire arrays have been widely studied to improve the power conversion efficiency. In this work, we report the first Ge nanopillar solar cell. Nanopillar arrays are selectively patterned on p-type Ge (100) substrates using nanosphere lithography and deep reactive ion etching processes. Nanoscale radial and planar junctions are realized by an n-type Ge emitter layer which is epitaxially grown by MOCVD using isobutylgermane. In situ epitaxial surface passivation is employed using an InGaP layer to avoid high surface recombination rates and Fermi level pinning. High quality n-ohmic contact is realized by protecting the top contact area during the nanopillar patterning. The short circuit current density and the power conversion efficiency of the Ge nanopillar solar cell are demonstrated to be improved up to 18 and 30%, respectively, compared to those of the Ge solar cell with a planar surface.

Influence of Growth Temperature on the Characteristics of Single-Junction p­i­n InGaP Solar Cells.

Single-junction p­i­n InGaP solar cells are grown at various temperatures from 620 to 700 °C by low pressure metalorganic chemical vapor deposition on GaAs (001) substrates. The short circuit current density of the p­i­n InGaP solar cells increases by up to 38.8% when the growth temperature is reduced from 700 to 620 °C, while the open circuit voltage and fill factor show relatively small changes. The external quantum efficiency, especially, in the wavelength regime below 500 nm, is improved for the p­i­n InGaP solar cells grown at lower temperatures. The improvement might be attributed to the reduced absorption loss of the photons in the n-InGaP emitter region. The highest conversion efficiency of 11.01% is attributed from the p­i­n InGaP solar cell grown at 640 °C. Electron mobility and concentration of undoped InGaP layers are investigated as a function of the growth temperature and correlated with the p­i­n InGaP solar cell performance.

Highly efficient single-junction GaAs thin-film solar cell on flexible substrate.

There has been much interest in developing a thin-film solar cell because it is lightweight and flexible. The GaAs thin-film solar cell is a top contender in the thin-film solar cell market in that it has a high power conversion efficiency (PCE) compared to that of other thin-film solar cells. There are two common structures for the GaAs solar cell: n (emitter)-on-p (base) and p-on-n. The former performs better due to its high collection efficiency because the electron diffusion length of the p-type base region is much longer than the hole diffusion length of the n-type base region. However, it has been limited to fabricate highly efficient n-on-p single-junction GaAs thin film solar cell on a flexible substrate due to technical obstacles. We investigated a simple and fast epitaxial lift-off (ELO) method that uses a stress originating from a Cr/Au bilayer on a 125-µm-thick flexible substrate. A metal combination of AuBe/Pt/Au is employed as a new p-type ohmic contact with which an n-on-p single-junction GaAs thin-film solar cell on flexible substrate was successfully fabricated. The PCE of the fabricated single-junction GaAs thin-film solar cells reached 22.08% under air mass 1.5 global illumination.

Inhibition of pyrite oxidation by surface coating: a long-term field study.

Pyrite and other iron sulfides are readily oxidized by dissolved oxygen in aqueous phase, producing acidity and Fe(2+), which causes significant environmental problems. Applications of surface coating agents (Na2SiO3 and KH2PO4) were conducted at Boeun (Chungbuk, South Korea) outcrop site, and their efficiencies to inhibit the oxidation of sulfide minerals were monitored for a long-term period (449 days). The rock sample showed positive Net Acid Production Potential (NAPP = 20.23) and low Net Acid Generation pH (NAGpH = 2.42) values, suggesting that the rock sample was categorized in the potential acid-forming group. For the monitored time period (449 days), field study results showed that the application of Na2SiO3 effectively inhibited the pyrite oxidation as compared to KH2PO4. Na2SiO3 as a surface coating agent maintained pH 5-6 and reduced oxidation of pyrite surface up to 99.95 and 97.70 % indicated by Fe(2+) and SO4 (2-) release, respectively. The scanning electron microscope and energy-dispersive X-ray spectrometer analysis indicated that the morphology of rock surface was completely changed attributable to formation of iron silicate coating. The experimental results suggested that the treatment with Na2SiO3 was highly effective and it might be applicable on field for inhibition of iron sulfide oxidation.

Novel anti-reflection technology for GaAs single-junction solar cells using surface patterning and Au nanoparticles.

Single-junction GaAs solar cell structures were grown by low-pressure MOCVD on GaAs (100) substrates. Micro-rod arrays with diameters of 2 microm, 5 microm, and 10 microm were fabricated on the surfaces of the GaAs solar cells via photolithography and wet chemical etching. The patterned surfaces were coated with Au nanoparticles using an Au colloidal solution. Characteristics of the GaAs solar cells with and without the micro-rod arrays and Au nanoparticles were investigated. The short-circuit current density of the GaAs solar cell with 2 microm rod arrays and Au nanoparticles increased up to 34.9% compared to that of the reference cell without micro-rod arrays and Au nanoparticles. The conversion efficiency of the GaAs solar cell that was coated with Au nanoparticles on the patterned surface with micro-rod arrays can be improved from 14.1% to 19.9% under 1 sun AM 1.5G illumination. These results show that micro-rod arrays and Au nanoparticle coating can be applied together in surface patterning to achieve a novel cost-effective anti-reflection technology.

Asymmetric multiple-quantum-well laser diodes with wide and flat gain.

Asymmetric multiple-quantum-well laser diodes with wide and flat gain spectra were designed, fabricated, and analyzed. The active layer was composed of three 10-nm, one 8-nm, and two 6-nm 0.5% compressive strained wells and four 10-nm and one 5-nm 0.4% tensile strained barrier layer. Measured spectra of antireflection-coated ridge waveguide laser diodes with such quantum-well structures have shown that -1-dB spectral gain bandwidth can be as large as 90 nm.