Comparison of clinical outcomes of patients with serial negative surveillance cultures according to a subsequent polymerase chain reaction test for carbapenemase-producing Enterobacterales

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) are of serious concern worldwide due to high morbidity and mortality.

AIM

To evaluate the impact of the result of a subsequent polymerase chain reaction (PCR) test for carbapenemase after serial negative surveillance cultures on positive culture conversion in patients with three consecutive negative surveillance cultures for CPE, and to identify risk factors for conversion.

METHODS

A retrospective study of patients with positive CPE cultures on CHROMagar KPC medium was performed in a Korean tertiary hospital from October 2018 to December 2022. PCR for blaKPC, blaNDM, blaIMP, blaVIM, blaGES, and blaOXA-48 was performed after three consecutive negative rectal swab cultures. Clinical characteristics and outcomes of patients were compared according to whether follow-up PCR was positive (CNPP) or negative (CNPN).

FINDINGS

Of 1075 patients with positive CPE cultures, 150 (14.0%) yielded three consecutive negative rectal swab cultures. Of these, 50 (33.3%) were CNPP, and 100 (66.7%) were CNPN. Risk factors associated with a positive PCR result on multivariate analysis were: age, central venous catheter, and Escherichia coli infection. CNPP patients were more likely to have positive culture conversion for CPE than CNPN patients (39/44 (88.6%) vs 21/50 (42.0%), P<0.001). In multivariate analysis, independent risk factors for culture conversion were: a positive PCR result after surveillance cultures, diabetes mellitus, central venous catheter, and Klebsiella pneumoniae.

CONCLUSION

CNPP patients have higher rates of culture conversion than CNPN patients, and a follow-up PCR test after serial negative surveillance cultures is useful in deciding whether or not to discontinue contact precautions.

Multifunctional 3D-Printed Pollen Grain-Inspired Hydrogel Microrobots for On-Demand Anchoring and Cargo Delivery

While a majority of wireless microrobots have shown multi-responsiveness to implement complex biomedical functions, their functional executions are strongly dependent on the range of stimulus inputs, which curtails their functional diversity. Furthermore, their responsive functions are coupled to each other, which results in the overlap of the task operations. Here, a 3D-printed multifunctional microrobot inspired by pollen grains with three hydrogel components is demonstrated: iron platinum (FePt) nanoparticle-embedded pentaerythritol triacrylate (PETA), poly N-isopropylacrylamide (pNIPAM), and poly N-isopropylacrylamide acrylic acid (pNIPAM-AAc) structures. Each of these structures exhibits their respective targeted functions: responding to magnetic fields for torque-driven surface rolling and steering, exhibiting temperature responsiveness for on-demand surface attachment (anchoring), and pH-responsive cargo release. The versatile multifunctional pollen grain-inspired robots conceptualized here pave the way for various future medical microrobots to improve their projected performance and functional diversity.

A Tissue Adhesion-Controllable and Biocompatible Small-Scale Hydrogel Adhesive Robot

Recently, the realization of minimally invasive medical interventions on targeted tissues using wireless small-scale medical robots has received an increasing attention. For effective implementation, such robots should have a strong adhesion capability to biological tissues and at the same time easy controlled detachment should be possible, which has been challenging. To address such issue, a small-scale soft robot with octopus-inspired hydrogel adhesive (OHA) is proposed. Hydrogels of different Young's moduli are adapted to achieve a biocompatible adhesive with strong wet adhesion by preventing the collapse of the octopus-inspired patterns during preloading. Introduction of poly(N-isopropylacrylamide) hydrogel for dome-like protuberance structure inside the sucker wall of polyethylene glycol diacrylate hydrogel provides a strong tissue attachment in underwater and at the same time enables easy detachment by temperature changes due to its temperature-dependent volume change property. It is finally demonstrated that the small-scale soft OHA robot can efficiently implement biomedical functions owing to strong adhesion and controllable detachment on biological tissues while operating inside the body. Such robots with repeatable tissue attachment and detachment possibility pave the way for future wireless soft miniature robots with minimally invasive medical interventions.

High-efficiency picosecond mode-locked laser using a thulium-doped nanoengineered yttrium-alumina-silica fiber as the gain medium

We report the theoretical and experimental investigation of a self-starting mode-locked fiber laser with a nanoengineered Tm³⁺-doped yttrium-alumina-silica (YAS) fiber as the gain medium. The YAS fiber exhibits a higher capability of Tm³⁺ cluster elimination than commercial silica fibers. The Tm³⁺ fluorescence properties and YAS dispersion are well characterized. As a result, an efficient picosecond mode-locked fiber laser is demonstrated with a slope efficiency of 14.14% and maximum pulse energy of 1.27 nJ. To the best of our knowledge, this is the first mode-locked fiber laser based on a Tm³⁺-doped YAS fiber. The experimental observation is also supported by the numerical analysis.

3D-Printed Multi-Stimuli-Responsive Mobile Micromachines

Magnetically actuated and controlled mobile micromachines have the potential to be a key enabler for various wireless lab-on-a-chip manipulations and minimally invasive targeted therapies. However, their embodied, or physical, task execution capabilities that rely on magnetic programming and control alone can curtail their projected performance and functional diversity. Integration of stimuli-responsive materials with mobile magnetic micromachines can enhance their design toolbox, enabling independently controlled new functional capabilities to be defined. To this end, here, we show three-dimensional (3D) printed size-controllable hydrogel magnetic microscrews and microrollers that respond to changes in magnetic fields, temperature, pH, and divalent cations. We show two-way size-controllable microscrews that can reversibly swell and shrink with temperature, pH, and divalent cations for multiple cycles. We present the spatial adaptation of these microrollers for penetration through narrow channels and their potential for controlled occlusion of small capillaries (30 μm diameter). We further demonstrate one-way size-controllable microscrews that can swell with temperature up to 65% of their initial length. These hydrogel microscrews, once swollen, however, can only be degraded enzymatically for removal. Our results can inspire future applications of 3D- and 4D-printed multifunctional mobile microrobots for precisely targeted obstructive interventions (e.g., embolization) and lab- and organ-on-a-chip manipulations.

Randomized, double-blind, active-controlled, multicentre, phase III clinical trial with two stages to assess the safety and efficacy of letibotulinum toxin a vs. onabotulinum toxin a for subjects with moderate to severe crow's feet

BACKGROUND

Letibotulinum toxin A (LeBA) was approved by the Ministry of Food and Drug Safety (known as the Korea Food & Drug Administration) for cosmetic indications in 2012. However, the efficacy and safety of this newly introduced LeBA have not been investigated in crow's feet lines (CFL) treatment and standardization before its universal use.

OBJECTIVE

The aim of this multicentre, double-blind, randomized, parallel, active-controlled Phase III clinical trial with two stages (ClinicalTrials.gov identifier: NCT03408236) was to investigate the non-inferiority of LeBA vs. the existing onabotulinum toxin A (OnBA) for the treatment of CFL.

METHODS

A total of 240 subjects were randomized to either the test (LeBA) or control (OnBA) group. At the baseline and at weeks 4 while maximum smiling (primary efficacy assessment), 8, 12 and 16, investigator's on-site evaluation, independent evaluator, evaluation by the subjects, subjects' satisfaction assessment and safety assessment were performed.

RESULTS

At week 4, the response rate of primary efficacy assessment was 69.75% and 68.33% in the test (LeBA) and control (OnBA) groups, respectively, without a significant difference. Other minor secondary evaluation results showed significant differences suggesting that LeBA offered better improvement than OnBA, but the overall results did not show significant differences between the two groups.

CONCLUSION

This study showed that LeBA was as effective and safe as OnBA for the treatment of CFL at the same doses.

Raman modes and dielectric relaxation properties of epitaxial BaBiO3 thin films

Perovskite BaBiO3 films are grown on MgO (100) substrate and SrTiO3 (001) and (110) substrates using pulsed laser deposition. The thickness of the films ranges from ∼10 nm up to 200 nm. X-ray diffraction and reciprocal space mapping show that the thin films are grown epitaxially but relaxed considerably particularly for the films on SrTiO3. The topography of the film surfaces are obtained with AFM and found to be atomically flat with the step and terrace structure of unit cell step height. Raman spectroscopy is performed on the BaBiO3 films in the temperature range from 50 K to 300 K. The phonon modes related to octahedral breathing, bond bending, and bond stretching are detected in the Raman spectra, and the distinctive features are found in the phonon modes below and above a structural transition around 140 K. Out-of-plane dielectric measurements are also carried out from 10 K to 400 K for the films on SrTiO3 with different orientations. In particular, the dielectric measurements demonstrate frequency as well as orientation dependent anisotropic dielectric relaxation behaviors in BaBiO3 films.

Intra-articular injection of magnesium chloride attenuates osteoarthritis progression in rats

OBJECTIVE

To explore the effects of Mg²⁺ on the expression of osteoarthritic markers in human cartilage and synovium tissue explants. To investigate the therapeutic effect of intra-articular injection of Mg²⁺ in an established rat OA (Osteoarthritis) model of anterior cruciate ligament transection with partial medial meniscectomy (ACLT + PMM).

DESIGN

Human cartilage and synovium explants were collected from total knee replacement surgeries and incubated with MgCl₂ (20 mmol/L) in vitro. A rat OA model was established by ACLT + PMM surgery in 450-500 g male Sprague Dawley (SD) rats. To select the optimal dose, intra-articular injections of MgCl₂ (0.05, 0.5, 5 mol/L) were performed at 4 weeks after the surgery every 3 days for 2 weeks. The effect of optimized MgCl₂ was further determined by histology, immunohistochemistry, and quantitative real-time polymerase chain reaction.

RESULTS

The expressions of osteoarthritic markers in human cartilage and synovium explants were inhibited by Mg²⁺in vitro. Immunohistochemical analysis further suggested the inhibitory effects of Mg²⁺ on the expression of MMP-13 and IL-6 in the human tissue explants. Cartilage degeneration and synovitis in ACLT + PMM rats were significantly improved by intra-articular injections of Mg²⁺ (0.5 mol/L). Immunohistochemical analysis also showed the regulatory effects of Mg²⁺ on osteoarthritic markers in both cartilage and synovium in rats, consistent with in vitro results.

CONCLUSION

Intra-articular injections of Mg²⁺ at 0.5 mol/L attenuate the progression of OA in the ACLT + PMM rat model. Such effect was at least in part explained by the promotion of cartilage matrix synthesis and the suppression of synovial inflammation.

Serum 25-Hydroxyvitamin D deficiency in Malaysian children with severe atopic dermatitis

BACKGROUND

Vitamin D deficiency has been shown to be a determinant of disease severity in patients with atopic dermatitis (AD). There is a lack of information on the prevalence of vitamin D deficiency in Malaysian children with AD. The objective of this study was to determine the association of vitamin D deficiency with AD severity, to compare vitamin D deficiency between children with and without AD and to determine prevalence of vitamin D deficiency in children with AD.

METHODS

A case-control study to examine serum 25- hydroxyvitamin D [25(OH)D] levels in children with and without AD was done. Serum 25-hydroxyvitamin D [25(OH)D] level was measured by immunoassay. AD severity was evaluated using the SCORing Atopic Dermatitis (SCORAD) index.

RESULTS

The serum levels of 25(OH)D, measured in 135 children with AD was not statistically different from 65 children without AD [median (IQR): 25.2ng/mL (15.45) vs 25.9ng/mL (15.87), p=0.616]. However, serum vitamin D levels were significantly lower in children with severe AD compared to those with mild-to-moderate AD [median (IQR): 16.0ng/mL (19.32) vs 26.3ng/mL (15.56), p=0.021]. The odds of having vitamin D deficiency in children with severe AD was 3.82 times that of children with non-severe AD (95% confidence level: 1.13, 12.87).

CONCLUSION

This study suggests that there is an inverse association between vitamin D level and the severity of AD in Malaysian children.

Efficacy and safety of PAC-14028 cream - a novel, topical, nonsteroidal, selective TRPV1 antagonist in patients with mild-to-moderate atopic dermatitis: a phase IIb randomized trial

Background

Transient receptor potential vanilloid subfamily, member 1 (TRPV1) may play an important role in pruritus and inflammation induction in atopic dermatitis (AD). The treatment effect of TRPV1 antagonist via topical application in patients with AD remains unknown.

Objectives

To assess the clinical efficacy and safety of PAC‐14028, a TRPV1 antagonist, via topical application in patients with AD.

Methods

In this 8‐week, phase IIb, randomized, double‐blind, multicentre, vehicle‐controlled study, patients with mild‐to‐moderate AD were randomized to receive PAC‐14028 cream 0·1%, 0·3%, 1·0% or vehicle cream twice daily. The primary efficacy end point was the Investigator's Global Assessment (IGA) success rate defined as the percentage of patients with an IGA score of 0 or 1 at week 8. The secondary efficacy end points included the severity Scoring of Atopic Dermatitis (SCORAD) index and Eczema Area and Severity Index (EASI) 75/90.

Results

A total of 194 patients were enrolled. IGA success rates at week 8 were 14·58% for vehicle cream, 42·55% for PAC‐14028 cream 0·1% (P = 0·0025 vs. vehicle), 38·30% for PAC‐14028 cream 0·3% (P = 0·0087 vs. vehicle) and 57·45% for PAC‐14028 cream 1·0% (P < 0·001 vs. vehicle). In particular, statistically significant differences were found between the vehicle and treatment groups in the IGA success rates with two‐grade improvement. The SCORAD index, EASI 75/90, sleep disturbance score and pruritus visual analogue scale showed a trend towards improvement. No significant safety issues were reported.

Conclusions

PAC‐14028 cream may be an effective and safe treatment modality for the treatment of patients with mild‐to‐moderate AD.

What is already known about this topic?

Atopic dermatitis (AD) is one of the most common inflammatory skin diseases characterized by pruritic erythematous skin lesions and barrier dysfunction.

Transient receptor potential vanilloid subfamily, member 1 (TRPV1) antagonists suppress the release of pruritic and proinflammatory mediators.

The preclinical results demonstrate the feasibility of TRPV1 as a potential therapeutic target for the treatment of AD.

What does this study add?

TRPV1 regulates inflammation and pruritus in patients with AD.

PAC‐14028 cream, a novel TRPV1 antagonist, was superior to vehicle in improving clinical symptoms and signs with a favourable safety profile in adults with mild‐to‐moderate AD.

TRPV1 antagonism may play a role as a promising nonsteroidal topical treatment target for AD with a new mechanism of action.

Linked Editorial:https://doi.org/10.1111/bjd.17777.

https://doi.org/10.1111/bjd.17802 available online

https://www.bjdonline.com/article/

Ex vivo magnetic resonance imaging using hyaluronic acid fillers: Differences between monophasic and biphasic fillers

BACKGROUND/PURPOSE

Hyaluronic acid (HA) is an anionic, non-sulfated glycosaminoglycan distributed throughout the human skin and injectable HA fillers are the most commonly used in aesthetic field. This study aimed to determine if differences in physical characteristics of HA products (monophasic or biphasic fillers) affect the patterns of magnetic resonance imaging (MRI).

METHODS

Twenty biphasic fillers and nine monophasic fillers were obtained from a commercial source, and examined with a 3.0 Tesla MRI scanner. Visual assessments and measurements of signal intensity for region of interest (ROI) were performed. A non-parametric Wilcoxon rank sum test was used to compare the ROI values.

RESULTS

Visual assessments by a radiologist did not show significant differences between the two types of fillers. While the signal intensity between the two types of filler did not differ significantly for T1-weighted images, the signal intensity of the biphasic filler was lower than that of the monophasic filler for T2-weighted images (P<.01).

CONCLUSION

Monophasic and biphasic HA fillers exhibited different MRI properties. Our findings may provide better insights into the use of in vivo MRI to evaluate aesthetic, procedure-related complications.

A preliminary study of new single polymorphisms in the T helper type 17 pathway for psoriasis in the Korean population

Psoriasis is a polygenic and multi-factorial disease showing ethnic differences in terms of its severity and frequency. Therapies targeting interleukin (IL)-17A, IL-17 receptor (IL-17R) and Janus kinases (JAKs) are in clinical development for the treatment of psoriasis, and their success suggests the essential role of these molecules in psoriasis. To investigate the genetic susceptibility in T helper type 17 (Th17) cell signal transduction pathways for promoting psoriasis, we performed candidate gene and linkage disequilibrium analysis. In 208 patients and 266 normal controls, we analysed 31 single nucleotide polymorphisms in 12 genes (CAMP, IL17A, IL17F, IL17RA, IL22, JAK1, JAK2, JAK3, STAT3, TLR7, TLR9 and TYK2; abbreviations: CAMP, human cathelicidin antimicrobial peptide; STAT-3, signal transducer and activator of transcription 3; TLR, Toll-like receptor; TYK2, tyrosine kinase 2). Patients with psoriasis showed a strong association for IL17F rs763780 [odds ratio (OR) = 3·27, P = 0·04], which results in a histidine-to-arginine substitution, and JAK2 rs2274471 (OR = 2·66, P = 0·02). In addition, JAK2 rs7849191 showed a protective pattern, met the significance threshold (OR = 0·77, P = 0·05) and showed a tendency for an inverse association with the frequency of early-onset psoriasis under age 40 years (P = 0·07). In haplotype analysis, JAK1 rs310241A/rs2780889T showed a protective effect (OR = 0·73, P = 0·03) in psoriasis. In conclusion, we report two new psoriasis-susceptibility loci, in IL17F and JAK2, as well as a newly identified late-onset associated protective JAK2 locus and a protective JAK1 haplotype in the Korean population.

Bipod flexure for 1-m primary mirror system

We present an analytical formulation of the bipod flexure for mounting the 1-m primary mirror in a space telescope. Compliance and stiffness matrices of the bipod flexure are derived to estimate theoretical performance and to make initial design guidelines. We use finite element analysis to optimize the bipod design satisfying the application requirements. Experimental verification is achieved by vibration test with a dummy mirror system.

Real time expression of ACC oxidase and PR-protein genes mediated by Methylobacterium spp. in tomato plants challenged with Xanthomonas campestris pv. vesicatoria

Biotic stress like pathogenic infection increases ethylene biosynthesis in plants and ethylene inhibitors are known to alleviate the severity of plant disease incidence. This study aimed to reduce the bacterial spot disease incidence in tomato plants caused by Xanthomonas campestris pv. vesicatoria (XCV) by modulating stress ethylene with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity of Methylobacterium strains. Under greenhouse condition, Methylobacterium strains inoculated and pathogen challenged tomato plants had low ethylene emission compared to pathogen infected ones. ACC accumulation and ACC oxidase (ACO) activity with ACO related gene expression increased in XCV infected tomato plants over Methylobacterium strains inoculated plants. Among the Methylobacterium spp., CBMB12 resulted lowest ACO related gene expression (1.46 Normalized Fold Expression), whereas CBMB20 had high gene expression (3.42 Normalized Fold Expression) in pathogen challenged tomato. But a significant increase in ACO gene expression (7.09 Normalized Fold Expression) was observed in the bacterial pathogen infected plants. In contrast, Methylobacterium strains enhanced β-1,3-glucanase and phenylalanine ammonia-lyase (PAL) enzyme activities in pathogen challenged tomato plants. The respective increase in β-1,3-glucanase related gene expressions due to CBMB12, CBMB15, and CBMB20 strains were 66.3, 25.5 and 10.4% higher over pathogen infected plants. Similarly, PAL gene expression was high with 0.67 and 0.30 Normalized Fold Expression, in pathogen challenged tomato plants inoculated with CBMB12 and CBMB15 strains. The results suggest that ethylene is a crucial factor in bacterial spot disease incidence and that methylobacteria with ACC deaminase activity can reduce the disease severity with ultimate pathogenesis-related protein increase in tomato.

3D surface mapping of freeform optics using wavelength scanning lateral shearing interferometry

Freeform optics have emerged as promising components in diverse applications due to the potential for superior optical performance. There are many research fields in the area ranging from fabrication to measurement, with metrology being one of the most challenging tasks. In this paper, we describe a new variant of lateral shearing interferometer with a tunable laser source that enables 3D surface profile measurements of freeform optics with high speed, high vertical resolution, large departure, and large field-of-view. We have verified the proposed technique by comparing our measurement result with that of an existing technique and measuring a representative freeform optic.

Correction of rotational inaccuracy in lateral shearing interferometry for freeform measurement

A lateral shearing interferometer has an advantage over previous wavefront measuring interferometers since it requires no reference. Therefore the lateral shearing interferometer can be a powerful solution to measure a freeform surface. It, however, has some issues to be resolved before it can be implemented. One of them is the orthogonality problem between two shearing directions in LSI. Previous wavefront reconstruction algorithms assume that the shearing directions are perfectly orthogonal to each other and lateral shear is obtained simultaneously in the sagittal and tangential directions. For practical LSI, however, there is no way to guarantee perfect orthogonality between two shearing directions. Motivated by this, we propose a new algorithm that is able to compensate the rotational inaccuracy. The mathematical model is derived in this paper. Computer simulations and experiments are also displayed to verify our algorithm.

Erdheim-Chester disease: an uncommon cause of upper urinary tract obstruction

Erdheim-Chester disease is a rare non-Langerhans form of systemic histiocytosis of unknown origin. We describe a 45-year-old man presenting with bilateral hydronephrosis suggestive of extrinsic urinary tract obstruction. Computed tomography revealed extensive hypodense soft tissue infiltration in the retroperitoneum surrounding the kidneys. Needle biopsy of the retroperitoneal soft tissue revealed aggregates of lipid-laden histiocytes expressing CD68 but negative for CD1a and S100 protein. The diagnosis of Erdheim-Chester disease was supported by typical radionuclide bone scinitigraphic findings. Treatment with prednisolone, sirolimus, and regular ureteric stent revision was initiated to achieve adequate urinary tract drainage. To our knowledge, this is the second patient with Erdheim-Chester disease reported in Hong Kong. A high index of suspicion is required to avoid delay in the diagnosis of this rare disease.

Stem Canker of Giant Dogwood (Cornus controversa) Caused by Fusarium lateritium in Korea

In May 2012, a stem canker was observed on a ~20-year-old giant dogwood (Cornus controversa) in Suwon, Gyeonggi Province, South Korea, which consisted of necrotic lesions on stem bark with orange sporodochial fruiting bodies. A single fungal colony was obtained from hyphal tips that were grown out of affected tissues plated on potato dextrose agar (PDA) acidified with 0.1% lactic acid after surface sterilization with 1.0% NaOCl for 30 s and 70% ethanol for 30 s, and incubated at 25°C for 7 days in the dark. The fungal isolate was grown on PDA and carnation leaf agar (CLA) to examine its mycological characteristics. The fungal colonies grown on PDA at 25°C for 7 days had diameters of 31 to 36 mm, with the colony surface sparsely cottony or with little or no aerial mycelium, very pale brown to pink, becoming progressively lighter toward the center; the colony reverse was pinkish-white to reddish-yellow, producing very few hyaline microconidia that were ellipsoidal, mostly 1-celled, and 15.4 to 22.8 × 4.1 to 4.8 μm. It produced hyaline macroconidia that were slightly curved, frequently 3 septate, a hooked or beaked apical cell and a foot-shaped or notched basal cell, 28.0 to 35.5 × 4.0 to 5.5 μm, borne on pink sporodochia. On CLA, the colony surface was lighter toward the center with no or sparse aerial mycelium, growing to 33 to 43 mm diameter at 25°C for 7 days. Microconidia were ellipsoidal, mostly 1-celled, and 9.2 to 17.5 × 2 to 2.5 μm on CLA. Macroconidia were produced on pink sporodochia near or on carnation leaf pieces, falcate to almost straight or slightly curved, frequently 5 to 7 septate, with a hooked or beaked apical cell and a foot-shaped or notched basal cell, and 45.5 to 59 × 5.5 to 6.5 μm. Chlamydospores were rare or absent. Based on these morphological characters, the isolate was identified as Fusarium lateritium (1,2). Sequences of the internal transcribed spacer (ITS) rDNA region of the fungus (GenBank Accession No. KC453998) amplified using primers ITS1/ITS4 had 100% sequence identity to F. lateritium (JN198452). The DNA sequences of translation elongation factor-1α (EF-1α) amplified using primers EF1/EF2 (KC453997) also had 100% sequence identity to F. lateritium (AY707172 and AY707156). The culture was deposited in the Korean Collection for Type Cultures (KCTC 46029). Pathogenicity tests were conducted using 1-year-old giant dogwood seedlings grown for 3 weeks before inoculation in a 1:1:1 mixture of peat moss, perlite, and sand in 10" × 10" × 12" plastic pots. The stems of three seedlings were inoculated with the mycelial plugs from the edge of the fungal culture on PDA grown at 25°C for 7 days, which were placed on three barkless cuts per stem and sealed with Parafilm that was removed 3 weeks later. Canker symptoms on the inoculated seedlings developed after 30 days of incubation at 25 to 32°C and relative humidity of 50 to 60% in a glasshouse, from which the same fungus was isolated. Non-inoculated control seedlings showed no canker development. To our knowledge, this is the first report of stem canker on giant dogwood caused by F. lateritium in Korea and also the family Cornaceae as new host for the fungus. References: (1) D. M. Geiser et al. Mycologia 97:191, 2005. (2) J. F. Leslie and B. A. Summerall. The Fusarium Laboratory Manual. Blackwell Publishing. Ames, Iowa, 2006.

An 8-week face-split study to evaluate the efficacy of cosmeceuticals using non-invasive bioengineering devices

BACKGROUND/AIMS

Even with the increasing demand for functional cosmeceuticals in the recent years, objective standard criteria for assessing their efficacy are currently incomplete at best. In this 8-week face-split study, in which we topically applied high-priced cosmeceuticals on one side and more affordable cosmeceuticals on the other side of the face, we compared the efficacy of these two products using non-invasive bioengineering technology.

METHODS

We assessed the efficacy of a skin-whitening and an anti-wrinkle cosmeceutical product on 25 and 19 healthy female volunteers, respectively. In a single blind split setting, each participant received an 8-week topical application of high-priced cosmeceuticals to the left side of the face, and cheaper cosmeceuticals to the right side. Then, the subjects' biophysical parameters were measured for an objective evaluation of the results. This was followed by a questionnaire to obtain a subjective assessment.

RESULTS

There was no significant difference in the change between the high-priced cosmeceuticals and the more affordable cosmeceuticals. At each measured site, there were variable changes including skin improvement and aggravation at the end of study. The subjective questionnaire demonstrated also that the participants perceived no difference in the efficacy between the two products.

CONCLUSIONS

Our results showed that there were no significant differences in the skin biophysical parameters following the application with high-priced functional cosmeceuticals or less expensive cosmeceuticals. The subject failed to differentiate between the two products. The development of objective standard criteria for assessing its efficacy is essential.

Alendronate reduced peri-tunnel bone loss and enhanced tendon graft to bone tunnel healing in anterior cruciate ligament reconstruction

Peri-tunnel bone loss after anterior cruciate ligament (ACL) reconstruction is commonly observed, both clinically and experimentally. We aimed to study the effect and mechanisms of different doses of alendronate in the reduction of peri-tunnel bone loss and promotion of graft-bone tunnel healing in ACL reconstruction. Eighty-four ACL-reconstructed rats were divided into 4 groups. Alendronate at different dosages, or saline, were injected subcutaneously weekly, for 2 or 6 weeks post-reconstruction, for vivaCT (computed tomography) imaging, biomechanical tests, histology and immunohistochemistry. Alendronate significantly increased bone mass and density of tissue inside bone tunnels except at the epiphyseal region of tibial tunnel. The femoral tunnel diameter decreased significantly in the mid-dose and high-dose alendronate groups compared to that in the saline group at week 6. Alendronate significantly increased the peri-tunnel bone mass and density along all tunnel regions at week 6. Better graft-bone tunnel integration and intra-tunnel graft integrity were observed in the alendronate groups. The ultimate load was significantly higher in the mid-dose and high-dose alendronate groups at week 2, but not at week 6. There was a reduction in matrix metalloprotein (MMP)1, MMP13 and CD68-positive cells at the peri-tunnel region and graft-bone interface in the alendronate-treated group compared to the saline group. Alendronate reduced peri-tunnel bone resorption, increased mineralised tissue inside bone tunnel as well as histologically and biomechanically promoted graft-bone tunnel healing, probably by reducing the expression of MMP1, MMP13 and CD68-positive cells. Alendronate might be used for reducing peri-tunnel bone loss and promoting graft-bone tunnel healing at early stage post-ACL reconstruction.

Adjustable bipod flexures for mounting mirrors in a space telescope

A new mirror mounting technique applicable to the primary mirror in a space telescope is presented. This mounting technique replaces conventional bipod flexures with flexures having mechanical shims so that adjustments can be made to counter the effects of gravitational distortion of the mirror surface while being tested in the horizontal position. Astigmatic aberration due to the gravitational changes is effectively reduced by adjusting the shim thickness, and the relation between the astigmatism and the shim thickness is investigated. We tested the mirror interferometrically at the center of curvature using a null lens. Then we repeated the test after rotating the mirror about its optical axis by 180° in the horizontal setup, and searched for the minimum system error. With the proposed flexure mount, the gravitational stress at the adhesive coupling between the mirror and the mount is reduced by half that of a conventional bipod flexure for better mechanical safety under launch loads. Analytical results using finite element methods are compared with experimental results from the optical interferometer. Vibration tests verified the mechanical safety and optical stability, and qualified their use in space applications.

Increased PHB productivity by high-cell-density fed-batch culture of Alcaligenes latus, a growth-associated PHB producer

Alcaligenes latus, a growth-associated PHB producer, was cultivated by a pH-stat modal fed-batch culture technique to attain high PHB productivity. Both sucrose solution and inorganic medium were fed in conjunction with the supply of ammonia solution which serves as a nitrogen source and as a means of pH control. Compositions of the inorganic medium were formulated by elemental analysis of A. latus cell mass. The effect on inoculum size was examined to reduce culture time. High concentrations of cell (142 g/L) and PHB (68.4 g/L) were obtained in a short culture time (18 h) with an inoculum size of 13.7 g/L. The PHB content and the PHB productivity at the end of the fed-batch culture were 50% of dry cell weight and 4.0 g PHB/(L . h), respectively.

Variation in 8-ketotrichothecenes and zearalenone production by Fusarium graminearum isolates from corn and barley in Korea

A total of 214 Fusarium graminearum isolates were obtained from corn and barley which were collected from Kangwon province and the southern part of Korea, respectively, and were tested for 8-ketotrichothecenes and zearalenone (ZEA) production on rice grains. The incidences of trichothecene production by 105 isolates of F. graminearum from corn were 59.0% for deoxynivalenol (DON), 37.1% for 15-acetyldeoxynivalenol(15-ADON), 13.3% for 3-acetyldeoxynivalenol (3-ADON), 7.6% for 3,15-diacetyldeoxynivalenol (3,15-DADON), 20.0% for nivalenol (NIV), 6.7% for 4-acetylnivalenol (4-ANIV), and 1.0% for 4,15-diacetylnivalenol (4,15-DANIV). DON chemotypes frequently produced 15-ADON as the major isomer rather than 3-ADON and 9 of the 61 DON chemotypes produced low levels of NIV. On the other hand, the incidences of trichothecene production of 109 isolates by F. graminearum from barley were 24.8% for DON, 72.5% for NIV, 62.4% for 4-ANIV, and 10.1% for 4,15-DANIV. Of these isolates, 78 were NIV chemotypes and only one isolate produced DON and 3-ADON as major toxins. In addition, 26 of the 78 NIV chemotypes produced low levels of DON. ZEA was frequently produced by the trichothecene-producing isolates and the incidences of ZEA were 51.4% and 31.2% for the isolates from corn and barley, respectively. There was a great regional difference in trichothecene production by F. graminearum isolates between corn- and barley-producing areas in Korea.

Novel compact dual-band LOROP camera with telecentricity

We report a new dual band compact oblique photography camera (LC11) that is the first to benefit from the incorporation of telecentricity. LC11 has a common front end F/6.6 telescope with 280 mm in aperture that forms its electro-optical (EO, F/7.5) and MWIR (F/5.6) modules. The design allows a substantial reduction in volume and weight due to i) the EO/MWIR compensator and relay lens groups arranged very close to the primary mirror (M1), and ii) light-weighted M1 and SiC main frame (MF) structure. Telecentricity of up to 2 and 0.2 degrees for the EO and MWIR modules, respectively, is achieved by balancing optical power among all lenses. The initial field test shows 0.32 ± 0.05 (EO)/0.20 ± 0.06 (MWIR) in measured MTF at 28 (EO) and 13 (MWIR) cycles/mm in target frequency, and an improved operability with a greater reduction in operational volume and mass than other existing LOROP cameras.

Enhancement of height resolution in direct laser lithography

To address the requirements of multi-level semiconductors, we propose a new technique for overcoming the height limitation of direct laser lithography. In the proposed system, an original source beam is fed into an interference generator that divides the input beam by 50: 50 into two output beams. After going through an imaging lens, these two beams make two focusing spots, which are slightly separated in the axial direction. In the overlapped region, these two spots generate a small interferogram that shortens the depth of focus. By using this phenomenon, we are able to overcome the height limitation of direct laser lithography. The governing equations are also derived in this manuscript by using the Gaussian beam model.

Immunological impact of Taekwondo competitions

Immunological changes in elite adolescent female athletes during Taekwondo competitions were investigated on-field. 6 female athletes (16.7 ± 0.8 year-old) volunteered and performed 5 bouts of demonstration Taekwondo competitions simulating real tournaments in intensity, duration, and break-time intervals on the same day. Blood samples were taken before, after the competitions and during the recovery, respectively. Immunological changes and oxidative stress in peripheral blood mononuclear cells were evaluated by flow-cytometry. During the competitions, exercise intensity was 92.2 ± 3.8% (86.1~95.7) of the maximal heart rate. Blood lactate increased immediately after the competitions (p=0.0165) and decreased to baseline during recovery. Intracellular reactive oxygen species (ROS) in the peripheral blood increased continuously during recovery (p<0.05, respectively). Natural killer cells increased immediately after the competitions (p=0.0006), and decreased during recovery. B and T cells increased immediately after the competitions and remained elevated throughout recovery (p<0.05, respectively). CD4/CD8 ratio after the competitions was decreased (p=0.0091) and returned to baseline during recovery. These results suggest that the immunological function of the elite female adolescent athletes could be attenuated after Taekwondo competitions. Further large-scaled Taekwondo studies on immunologic and apoptotic changes related to oxidative stress should be performed for improving and protecting the health of adolescent athletes.

Three-shell-based lens barrel for the effective athermalization of an IR optical system

We have developed a new IR optical system that consists of three mirrors and four lenses, and that operates in the temperature range 8°C-32°C. This temperature range can induce thermoelastic deformation in the lenses and their mounting subassembly, leading to a large defocus error associated with the displacement of the lenses inside the barrel. We suggest using a new three-shell-based athermalization structure composed of two materials with different coefficients of thermal expansion (Invar and aluminum). A finite element analysis and the experiment data were used to confirm that this new athermalization barrel had a defocus error sensitivity of 11.6 nm/°C; this is an improvement on the widely used conventional single-shell titanium barrel model, which has a defocus error sensitivity of 29.8 nm/°C. This paper provides the technical details of the new athermalization design, and its computational and experimental performance results.

Activation of the transforming growth factor beta pathway in bacterial otitis media

OBJECTIVES

Granulation tissue is common in otitis media (OM), yet little is known about the signaling pathways in the formation of granulation tissue in response to infections. In this study, we sought to investigate the activation of the transforming growth factor beta (TGF-beta) signaling pathway in the formation of granulation tissue in response to middle ear pathogens.

METHODS

Rat OM models were made by inoculating pneumococcus type 6A or nontypeable Haemophilus influenzae into the middle ear cavity or by obstructing the eustachian tube. Various pathway activities in the middle ear mucosa were analyzed with microarrays.

RESULTS

The TGF-beta signaling pathway was highly regulated in the middle ear cleft with bacterial OM, but not in the ears with eustachian tube obstruction. In ears with bacterial OM, the TGF-beta signaling pathway products were higher in Haemophilus-infected ears than in pneumococcus-infected ears.

CONCLUSIONS

Bacterial OM triggers granulation tissue to thrive in the middle ear cleft of rats. Nontypeable H influenzae is more potent than pneumococcus type 6A in the formation of granulation tissue. Eustachian tube obstruction alone did not contribute to granulation tissue formation in the middle ear.

Optimization of selective emitter fabrication method for solar cells using a laser grooving

In this paper, screen-printing laser grooved buried contact (LGBC) method was applied, which is compatible with the existing screen-printed solar cell equipment and facilities. Experiments were performed in order to optimize short circuit current (I(sc)), open circuit voltage (V(oc)) and fill factor of high efficiency solar cells. To enhance I(sc), V(oc) and efficiency, heavy doping was performed at low sheet resistance in the laser grooved region of the cell. In contrast, light doping was carried out at a high sheet resistance in the non-laser grooved region. To increase fill factor, porous silicon found on the wafer after dipping in an HF solution to remove SiN(x), was cleared. The fabricated screen-printing LGBC solar cell using a 125 mm x 125 mm single crystalline silicon wafer exhibited an efficiency of 17.2%. The results show that screen-printing LGBC method can be applied for high efficiency solar cells.

Mosquitocidal activity of a native Bacillus thuringiensis isolate Bt ReX02 from Gunung Jerai Forest, Malaysia against Culex quinquefasciatus and Aedes albopictus

BACKGROUND AND OBJECTIVE

To evaluate the mosquito larvicidal potential of the native Bacillus thuringiensis isolate BtReXO2, which was isolated from a tropical rain forest ecosystem in Malaysia. This study also aimed at determining the phenotypic and biochemical characteristics of the isolate.

MATERIALS AND METHODS

The phenotypic characterization was carried out by growing the isolate in nutrient broth to observe the colonial morphology, vegetative cells, sporulation, motility and haemolytic activity. The parasporal crystal morphology was determined by Coomassie Brilliant Blue (CBB) staining of the sporulated cells and then observed under light microscope. The mosquito larvicidal assay was conducted with the second instar larvae of Culex quinquefasciatus and Aedes albopictus to determine the entomocidal potency of the isolate. The total protein profile was determined by SDS-PAGE.

RESULTS AND DISCUSSION

Preliminary phenotypic and biochemical characterization showed that the isolate is motile, an indirect indication of the virulence of the strain and exhibited hemolytic activity, an important feature of antidipteran Bacillus thuringiensis strains. Study on the crystal morphology showed the presence of cuboidal crystals, another characteristic feature of a mosquitocidal Bacillus thuringiensis strains. Bioassay with the second instar larvae of Culex quinquefasciatus, Aedes albopictus established the antidipteran activity of this native Bacillus thuringiensis isolate. Protein profile analysis revealed the unique pattern showing high molecular mass as well as low molecular mass proteins corresponding to the Cry and Cyt proteins respectively. The protein profile is strikingly different from other mosquitocidal strains such as Bacillus thuringiensis subsp.israelensis and Bacillus thuringiensis subsp. jegathesan Periodical introduction of such native strains of Bacillus thuringiensis will add a new weapon in the armoury to manage the vector borne diseases and also in the management of insect resistance.

Improvement of linewidth in laser beam lithographed computer generated hologram

We propose a new laser lithographic technique with enhanced resolution. A calcite wave plate is introduced in our system to separate an input lithographic beam into two orthogonally polarized beams. After going through an imaging lens, these two beams meet again on the focal point, and generate a small interferogram that sharpens the shape of the focused beam spot. Using this phenomenon, we can overcome the diffraction limit of the imaging lens and achieve a 486-nm-linewidth.

Exercise-induced airway obstruction in young asthmatics measured by impulse oscillometry

BACKGROUND

Impulse oscillometry (IOS) is a good method for measuring airway resistance. It does not require special breathing skills and it can reflect different aspects of airway obstruction to those revealed by spirometry, which is an effort-dependent maneuver.

OBJECTIVE

To evaluate the characteristics of airway obstruction in young asthmatics after an exercise bronchial provocation test (EBPT) using IOS.

METHODS

Forty-seven young adults were enrolled in the study. All the participants underwent a methacholine bronchial provocation test (MBPT) and an EBPT for the evaluation of their asthma. IOS and spirometric parameters were collected at baseline and at 0, 5, 10, 20, and 30 minutes post-EBPT.The participants were divided into 2 groups according to MBPT positivity: an airway hyperresponsiveness (AHR) group and a no-AHR group.

RESULTS

There were differences in the percent decrease in forced expiratory volume in the first second (FEV1) between the 2 groups at 5, 10, and 20 minutes after exercise. Resistance at 5 Hz (R5) increased in the AHR group but not in the no-AHR group at 5 and 10 minutes after exercise. Integration of reactance from 5 Hz to resonance frequency (area of reactance, AX) was also increased in the AHR group at only 5 and 10 minutes post-EBPT. Delta R5 and delta AX at 5 and 10 minutes post-exercise were well correlated with the percent decrease in FEV1.

CONCLUSIONS

IOS parameters, especially delta R5 and delta AX, may be useful for performing objective evaluations and improving our understanding of exercise-induced airway obstruction in young asthmatics.

Realization and performance evaluation of high speed autofocusing for direct laser lithography

The autofocusing is one of the important parts in the automated vision inspection or measurement using optical microscopes. Moreover, laser micromachining or laser lithography requires a high speed and precision autofocusing. In this paper, we propose and realize an autofocusing system using two cylindrical lenses, which is the enhanced version of the previous astigmatism method. It shows very good performances, especially very high speed and the largest range in comparison with the previous astigmatic methods. The performance of our autofocusing system was evaluated by tracing the linear stage whose position was monitored by a commercial laser interferometer. Then we applied the autofocusing to the direct laser lithographic system, and successfully fabricated circular symmetry patterns on a 300 mm diameter surface with the resolution of less than 1 microm within the defocusing range of +/-50 microm. The speed of the autofocusing was 150 Hz.

Generation of intense proton beams from plastic targets irradiated by an ultraintense laser pulse

Proton beams generated from thin aluminum and Mylar foil targets that are irradiated by a 30fs Ti:sapphire laser pulse with an intensity of 2.2x10;{18}Wcm;{2} were investigated. Protons from the Mylar targets were observed to have an energy higher by a factor of 2 and were higher in number by an order of magnitude as compared with those generated from the aluminum targets. The maximum proton energy of 1.3+/-0.12MeV obtained from the Mylar target was found to be similar with previous observations that used laser pulses with different intensities. To address the anomalous behavior of the maximum proton energy for plastic targets, an acceleration model is proposed. In this model, the protons are accelerated by a resistively induced electric field in the front of the target, which can account for the experimental observations.

300 mm reference wafer fabrication by using direct laser lithography

We propose a new method based on direct laser lithography to fabricate reference chromium patterns on a silicon wafer. Our method is able to fabricate a maximum 360-mm-diameter pattern with 651-nm-position uncertainty. The minimum pattern size is about 0.8 microm (linewidth value) and the maximum available height of the pattern is slightly over 400 nm.

Change of biophysical properties of the skin caused by ultraviolet radiation-induced photodamage in Koreans

BACKGROUND/PURPOSE

Ultraviolet (UV) irradiation affects the function and complexion of the skin by inducing changes in physical properties through formation of erythema, proliferation of epithelial cells, DNA damage, activation or inactivation of various enzymes and proteins, and free radical formation. In this study, the authors intended to observe the overall course of changes in barrier function and reflectance of the skin induced by photodamage, and healing reaction in the course of time, and alteration of the skin complexion.

METHODS

The subjects were chosen from 15 healthy Korean men 20-35 in age, that fall into the category of Fitzpatrick's skin types II, III, and IV without history of recent exposure to sunlight, photosensitivity, or having taken any drugs that induce phototoxicity or photoallergic reactions. The subjects were artificially exposed to suberythemogenic dose [0.5 minimal erythemal dose (MED), 0.75 MED], 1 MED and high dose (2.5 MED) by solar simulator, and changes in skin barrier function and skin reflectance were assessed with a Tewameter, a Corneometer, and a Colorimeter for 4 weeks.

RESULTS

Transepidermal water loss (TEWL) increased abruptly at Day 1 of single solar UV (SSUV) exposure, and slowly returned to the original level from Day 2/Day 3. In the case of exposure with 0.75 MED, it returned to the original level at Day 4 of exposure, and at Days 7 and 28 in the cases of 1 MED and 2.5 MED exposure, respectively. Water-holding capacity sharply declined at Day 1 of exposure, hitting the lowest point at Day 2, and then slowly recovered starting on Day 3. In the case of exposure with 0.75 MED and 1 MED, it returned to the original level at Days 7 and 28 in the case of 2.5 MED exposure. The a(*) values abruptly increased and reached the peak at Day 1 and slowly returned to the original level at Day 2, while the b(*) values slowly increased at Day 3, peaking at Day 7 and slowly returning to the original level thereafter. The L(*) values abruptly declined at Day 1, maintaining plateau through Day 7 and slowly returning to the baseline level thereafter. The individual typology angle (ITA degrees ) were compatible with L(*) values change. The erythema index increased abruptly at Day 1 of SSUV exposure, peaking at Day 2 and slowly returned to the original level starting at Day 3. Melanin index slowly started to increase on Day 3 of SSUV exposure, peaking at Day 7 and gradually returned to the original level thereafter. However, L(*), a(*), b(*), erythema index, and melanin index did not return to the original level during the 28-day course of this study.

CONCLUSION

This study shows that in the skin of Korean subjects, changes in skin barrier function and delayed melanization do occur even in exposure to a suberythemogenic dose of SSUV. Also, given the fact that restoration of barrier function occurs as the process of melanization begins, melanization is considered to be a useful predictive indicator of the restoration of the skin barrier function after sunburn.

Silver-mirror-based multipass preamplifier for a broadband terawatt Ti:sapphire laser

We have developed a silver-mirror-based multipass preamplifier for a broadband amplification in a terawatt Ti:sapphire laser. With the extremely broad bandwidth of the silver mirrors, a very broad amplified spectrum can be generated at an amplified energy of 4 mJ; the amplified spectral width is 65 nm at half maximum and 160 nm at -25 dB without any spectral shaping technique. Such a broad amplification can be explained well by the simulation that includes gain narrowing and gain saturation. Even after a further amplification to an energy of 600 mJ, the amplified spectrum is broad enough to support an approximately 20 fs transform-limited pulse duration.

Laser output power stabilization for direct laser writing system by using an acousto-optic modulator

We present experimental results on the output power stabilization of an Ar(+) laser for a direct laser writing system (LWS). Instability of the laser output power in the LWS cause resolution fluctuations of being fabricated diffractive optical elements or computer-generated holograms. For the purpose of reducing the power fluctuations, we have constituted a feedback loop with an acousto-optic modulator, a photodetector, and a servo controller. In this system, we have achieved the stability of +/-0.20% for 12 min and the relative intensity noise level of 2.1 x 10(-7) Hz(-12) at 100 Hz. In addition, we applied our system to a 2 mW internal mirror He-Ne laser. As a consequence, we achieved the output power stability of +/-0.12% for 25 min.

Mimulus is an emerging model system for the integration of ecological and genomic studies

The plant genus Mimulus is rapidly emerging as a model system for studies of evolutionary and ecological functional genomics. Mimulus contains a wide array of phenotypic, ecological and genomic diversity. Numerous studies have proven the experimental tractability of Mimulus in laboratory and field studies. Genomic resources currently under development are making Mimulus an excellent system for determining the genetic and genomic basis of adaptation and speciation. Here, we introduce some of the phenotypic and genetic diversity in the genus Mimulus and highlight how direct genetic studies with Mimulus can address a wide spectrum of ecological and evolutionary questions. In addition, we present the genomic resources currently available for Mimulus and discuss future directions for research. The integration of ecology and genetics with bioinformatics and genome technology offers great promise for exploring the mechanistic basis of adaptive evolution and the genetics of speciation.

Merit function regression method for efficient alignment control of two-mirror optical systems

The precision alignment of high-performance, wide-field optical systems is generally a difficult and often laborious process. We report a new merit function regression method that has the potential to bring to such an optical alignment process higher efficiency and accuracy than the conventional sensitivity table method. The technique uses actively damped least square algorithm to minimize the Zernike coefficient-based merit function representing the difference between the designed and misaligned optical wave fronts. The application of this method for the alignment experiment of a Cassegrain type collimator of 900mm in diameter resulted in a reduction of the mean system rms wave-front error from 0.283 lambda to 0.194 lambda;, and in the field dependent wave-front error difference from +/-0.2 lambda to +/-0.014 lambda in just two alignment actions. These results demonstrate a much better performance than that of the conventional sensitivity table method simulated for the same steps of experimental alignment.

Absolute three-dimensional coordinate measurement by the two-point diffraction interferometry

We describe a method of absolute xyz-coordinates measurement based on the two-point diffraction interferometer. In this paper we use a new optimization algorithm to the interferometer. Experimental results show that the systematic error of the interferometer is less than 1 mum (peak-to- valley value) within a 60 mm by 60 mm by 20 mm working volume. To extract the systematic error and verify the absolute performance of the interferometer we applied the Fourier self-calibration concept.

Development of sequencing batch reactor with step feed and recycle

SBR process shows high nitrogen and phosphorus removal in countries where separated sewers are used. On the other hand, removal efficiency is low in countries where combined sewers are used though the same SBR is applied. This is because the organic concentration (as BOD), which is used as carbon source for denitrification, of combined sewers is much lower than that of separated sewers. Almost all sewers in Korea are combined, and their BOD is low by about 1/2 over the level needed for denitrification. In this study, a SBR process that can optimise organic usage by step feed and recycle is thus developed to increase the removal efficiency of nitrogen and phosphorus, and the results show that the removal rates of BOD, T-N and T-P are 95.4, 81.4 and 86.1%, respectively, though influent BOD is low.

Quantitative investigation on the distribution of Malassezia species on healthy human skin in Korea

This study concerns a culture research based on the data gathered from Korean subjects to examine distribution of Malassezia yeast. Malassezia yeast were cultivated out of samples from scalp, forehead, chest, arm and thigh. Malassezia restricta was recovered more frequently in the teens and young adults, while M. globosa was the predominant species in subjects older than 50 years of age. The population density of Malassezia yeast was significantly higher in the age group (AG) of 21-30 years compared with other AGs (P < 0.05). It was also significantly higher in the chest compared with the forehead, arm and thigh (P < 0.05). The key is to recognise the existence of a difference in the amount and type of Malassezia species in different AGs as well as body areas, which reflects differing skin lipid levels in various AGs and different body areas.

20 W single-mode Yb3+ -doped phosphate fiber laser

We report the demonstration of the first, to our knowledge, cladding-pumped continuous-wave Yb(3+)-doped phosphate-glass fiber laser. Phosphate hosts are of interest because they can be much more heavily doped than silica, and because of the possibility that they may have a higher photodarkening threshold. In an 84.6 cm double-clad fiber doped with 12 wt. % of Yb(2)O(3) and laser-diode pumped at 940 nm, nearly 20 W of single-mode 1.07 microm output power was generated with 60.2 W of absorbed pump power. The measured dependence of the output power on pump power is in excellent agreement with simulations.

Azimuthal position error correction algorithm for absolute test of large optical surfaces

Absolute test needs test part rotation to separate errors of the interferometer itself from errors due to the test surfaces. At this time, previous absolute test algorithms assume no azimuthal position error during part rotation. For large optics whose diameters are 0.6 m and over, however, exact rotations are physically difficult. Motivated by this, we propose a new algorithm that adopts least squares technique to determine the true azimuthal positions of part rotation and consequently eliminates testing errors caused by rotation inaccuracy.