Mussel-inspired enzyme immobilization and dual real-time compensation algorithms for durable and accurate continuous glucose monitoring.

Blood glucose sensing is very important for diabetic management. It is shifting towards a continuous glucose monitoring because such a system can alleviate patient suffering and provide a large number of glucose measurements. Here, we proposed a novel approach for the development of durable and accurate enzymatic continuous glucose monitoring system (CGMS). For the long-term durable and selective immobilization of glucose oxidase on a microneedle electrode, a biocompatible engineered mussel adhesive protein was employed through efficient electrochemical oxidation strategy. For the accurate performance in in vivo environments, we also suggested dual real-time compensated algorithms to cover both temperature and time-lag differences. After pre-clinical and pilot-clinical evaluations, we confirmed that our proposed CGMS has an outstanding performance compared with various commercially available continuous systems and achieves comparable performance to disposable glucose sensors.

Observations on significant hemodynamic changes caused by a high concentration of epidurally administered ropivacaine: correlation and prediction study of stroke volume variation and central venous pressure in thoracic epidural anesthesia.

BACKGROUND: Thoracic epidural anesthesia (TEA) exacerbates hypotension due to peripheral vasodilator effects following the use of general anesthetics. This study aimed to compare the hemodynamic changes caused by three different concentrations of epidural ropivacaine and to evaluate the performance of the stroke-volume variation (SVV) and central venous pressure (CVP) during TEA with general anesthesia. METHODS: A total of 120 patients were administered 8 mL of ropivacaine solution via epidural injection, following randomization into one of three groups based on the concentration of ropivacaine in the study solution: 0.75%, 0.375%, or 0.2%. Hemodynamics were monitored for 30 min after loading. We analyzed the hemodynamic changes in the subgroups according to an age cutoff of 60 years. Receiver operating characteristic (ROC) analysis was performed to characterize the relationship of the SVV, CVP, and a 20% decrease in the mean arterial pressure (MAP) following TEA. RESULTS: Data from 109 patients were analyzed. MAP and systemic vascular resistance index were significantly decreased, and SVV was significantly increased after epidural loading only in the 0.75% ropivacaine group. There was a significant difference in hemodynamics between young and elderly subgroups in the 0.75% ropivacaine group. SVV showed a negative correlation with MAP, whereas CVP showed no correlation. The ROC analysis of SVV demonstrated a weak predictive ability of a 20% decrease in MAP at 10 min after the loading dose, with an area-under-the-curve of 0.687 and a 9.5% optimal cutoff value (sensitivity, 60.6%; specificity, 68.9%). CONCLUSIONS: A high concentration of ropivacaine through TEA caused a significant decrease in the systemic vascular resistance and blood pressure. More significant decreases were shown in the elderly patients. Though the change of SVV showed a negative correlation with hypotension and indicated functional hypovolemia after TEA, the predictability was limited. CLINICAL TRIALS REGISTRATION: Number: NCT01559285 , date: January 24, 2013.

Plasmon enhanced photoacoustic generation from volumetric electromagnetic hotspots.

This work reports plasmon enhanced photoacoustic generation by using a three dimensional plasmonic absorber. The 3D plasmonic absorber comprises a thin polymer film on glass nanopillar arrays with nanogap-rich silver nanoislands. The 3D plasmonic absorber clearly shows 24.6 times higher enhancement of photoacoustic signals at an excitation wavelength of 630 nm than a simple polymeric absorber. The photoacoustic enhancement results from the volumetric electromagnetic field enhancement on a light-absorbing polymer through 3D plasmonic nanostructures. This novel photoacoustic absorber provides a new direction for highly efficient ultrasonic generation.

Electrokinetic preconcentration of small molecules within volumetric electromagnetic hotspots in surface enhanced Raman scattering.

The on-chip integration of a preconcentration chamber for ultrasensitive surface-enhanced Raman scattering (SERS) is shown. Small molecules are preconcentrated using 3D volumetric electromagnetic hotspots. The experimental results demonstrate an enhancement of the SERS signals of over two orders of magnitude, which allows the fingerprinting of neurotransmitter molecules at the nanomolar level and furthers the selective detection of oppositely charged molecules. This on-chip integration will provide new directions for ultrasensitive SERS applications.

Treatment of onychomycosis with a 1,064-nm long-pulsed Nd:YAG laser.

BACKGROUND: There are various treatment modalities of onychomycosis. Of these, however, oral antifungal therapies are complicated by potential drug interactions and systemic effects, and the surgical treatment can result in prolonged pain. Therefore, a new, safe and effective therapy is needed that can improve the aesthetic appearance of the nails. OBJECTIVE: The purpose of this study was to evaluate the effect of treatment of onychomycosis with a 1,064-nm long-pulsed Nd:YAG laser. METHODS: 13 patients (31 toenails, 12 fingernails) received five treatment sessions at 4-week intervals with a 1,064-nm long-pulsed Nd:YAG laser. Parameters for each treatment were 6 mm spot size, 5 J/cm(2) fluence, 0.3 ms pulse duration and 5 Hz pulse rate. RESULTS: Of the 13 patients, 8 (61.5%) were women and 5 were men. The mean age of the patients was 62. Of the 43 nails, 4 (9.3%) achieved a complete cure (9.3%), 8 had excellent treatment outcomes (18.6%) and 31 had good treatment outcomes (72%). None of the 13 patients experienced any discomfort except for a mild burning sensation and there were no adverse effects. CONCLUSIONS: Our results demonstrate that the 1,064-nm long-pulsed Nd:YAG laser could be a safe and effective treatment modality in the management of patients with onychomycosis.

A deformable nanoplasmonic membrane reveals universal correlations between plasmon resonance and surface enhanced Raman scattering.

A quantitative correlation between plasmon resonance and surface enhanced Raman scattering (SERS) signals is revealed by using a novel active plasmonic method, that is, a deformable nanoplasmonic membrane. A single SERS peak has the maximum gain at the corresponding plasmon resonance wavelength, which has the maximum extinction product of an excitation and the corresponding Raman scattering wavelengths.

Optofluidic SERS chip with plasmonic nanoprobes self-aligned along microfluidic channels.

This work reports an optofluidic SERS chip with plasmonic nanoprobes self-aligned along microfluidic channels. Plasmonic nanoprobes with rich electromagnetic hot spots are selectively patterned along PDMS microfluidic channels by using a Scotch tape removal and oxygen plasma treatment, which also provide the permanent bonding between PDMS and a glass substrate. A silver film with an initial thickness of 30 nm after oxygen plasma treatment creates nanotips and nanodots with a maximum SERS performance, which were successfully implanted with microfluidic concentration gradient generators. The novel device enables the label-free and solution-phase SERS detection of small molecules with low Raman activity such as dopamine at micromolar level in flow. This optofluidic SERS chip can be readily expanded for microfluidic networks with diverse functions for advanced optical biochemical assays.

Terahertz photoconductive antenna with metal nanoislands.

This work presents a nanoplasmonic photoconductive antenna (PCA) with metal nanoislands for enhancing terahertz (THz) pulse emission. The whole photoconductive area was fully covered with metal nanoislands by using thermal dewetting of thin metal film at relatively low temperature. The metal nanoislands serve as plasmonic nanoantennas to locally enhance the electric field of an ultrashort pulsed pump beam for higher photocarrier generation. The plasmon resonance of metal nanoislands was achieved at an excitation laser wavelength by changing the initial thickness of metal film. This nanoplasmonic PCA shows two times higher enhancement for THz pulse emission power than a conventional PCA. This work opens up a new opportunity for plasmon enhanced large-aperture THz photoconductive antennas.

Glass nanopillar arrays with nanogap-rich silver nanoislands for highly intense surface enhanced Raman scattering.

The enhancement of surface enhanced Raman scattering (SERS) with nanogap-rich silver nanoislands surrounding glass nanopillars at wafer level is reported. High-density hot spots are generated by increasing the number of nanogap-rich nanoislands within a detection volume. The SERS substrate shows a high enhancement factor of over 10(7) with excellent signal uniformity (∼7.8%) and it enables the label-free detection of aqueous DNA base molecules at nanomolar level.

A Sporadic Case of Mal de Meleda Caused by Gene Mutation in SLURP-1 in Korea.

Mal de Meleda (MDM), also known as keratoderma palmoplantaris transgrediens, is a rare inherited form of palmoplantar keratoderma. It is characterized by erythema and hyperkeratosis of the palms and soles, extending to the dorsal aspects of the hands and feet. A 15-year-old Korean female presented with sharply demarcated hyperkeratotic plaques on the palms and soles, which extended to the dorsal surfaces of the hands and feet, in a "glove-and-socks" distribution. The histopathologic study showed marked hyperkeratosis, acanthosis, and normogranulosis, without epidermolysis. Her genetic study detected compound heterozygous mutation in exon 3 of the ARS gene encoding SLURP-1. Family history did not reveal any other affected members and no consanguineous relationship was found. In view of these findings, we diagnosed this case as the first reported sporadic case of MDM in Korea, the farthest location from the endemic island of Meleda.

In situ dynamic measurements of the enhanced SERS signal using an optoelectrofluidic SERS platform.

A novel active surface-enhanced Raman scattering (SERS) platform for dynamic on-demand generation of SERS active sites based on optoelectrofluidics is presented in this paper. When a laser source is projected into a sample solution containing metal nanoparticles in an optoelectrofluidic device and an alternating current (ac) electric field is applied, the metal nanoparticles are spontaneously concentrated and assembled within the laser spot, form SERS-active sites, and enhance the Raman signal significantly, allowing dynamic and more sensitive SERS detection. In this simple platform, in which a glass slide-like optoelectrofluidic device is integrated into a conventional SERS detection system, both dynamic concentration of metal nanoparticles and in situ detection of SERS signal are simultaneously possible with only a single laser source. This optoelectrofluidic SERS spectroscopy allows on-demand generation of 'hot spots' at specific regions of interest, and highly sensitive, reliable, and stable SERS measurements of the target molecules in a tiny volume (∼500 nL) of liquid sample without any fluidic components and complicated systems.

[Clinical usefulness of Rockall scoring system in patients with bleeding peptic ulcer--comparison with Forrest classification].

BACKGROUND/AIMS: The Rockall risk assessment score was developed to predict the risk of rebleeding and death in patients with upper GI hemorrhage. The validity of this score, however, was not established in Korea. We tried to assess the reliability of the Rockall score to predict outcomes in patients with bleeding peptic ulcer. METHODS: Medical records of 175 patients with benign peptic ulcer bleeding treated in Samsung Medical Center from January 2000 to May 2003 were retrospectively analyzed. They were classified into three groups: no rebleeding rebleeding, and death and mean Rockall score was compared. Forrest classification was also compared with the Rockall score regarding the clinical usefulness of predicting poor outcomes in patients with bleeding peptic ulcer. RESULTS: One hundred forty five patients did not show rebleeding, with mean Rockall score of 3.5 (SD=1.5). On the other hand, rebleeding occurred in 25 patients and the mean score was 6.4 (SD=1.44). There were 13 deaths with mean score of 7.0 (SD=1.08). The differences between the three groups were significant (p<0.001). In multivariate analysis, Rockall score was a independent risk factor of rebleeding and mortality (odds ratio, OR=2.73 and OR=8.74). CONCLUSIONS: The Rockall scoring system is useful to predict poor outcome such as rebleeding and death in patients with bleeding peptic ulcer.