Genetic variation for three Y-STR loci: DYS390, DYS518, and DYS643.

Y chromosome short tandem repeats (Y-STRs) are commonly used to analyze male-specific DNA. Although biallelic patterns due to duplication events have been detected at some loci, Y-STRs generally appear as a single peak except for DYS385 because the Y chromosome is haploid. STR loci in regions of segmental duplication by homologous recombination on the Y chromosome exhibit double allelic peaks, rather than single peaks. In this study, we report a bi- and triallelic pattern observed simultaneously in DYS390, DYS518, and DYS643. A bi- and triallelic pattern has not previously been observed simultaneously for these three loci. We also identified the copy number variation in the region including these loci by the microarray-based analysis. Given the peak balance pattern, the copy number variation, and the close position of these three loci on the Y chromosome, we consider that this phenomenon is caused by a segmental duplication in the euchromatin region. By ruling out mixed samples, a common interpretation of multiple peaks, these results have practical implications for the interpretation of Y-STR results in forensics analyses.

How Effective is Plasmonic Enhancement of Colloidal Quantum Dots for Color-Conversion Light-Emitting Devices?

Enhancing the fluorescence intensity of colloidal quantum dots (QDs) in case of color-conversion type QD light-emitting devices (LEDs) is very significant due to the large loss of QDs and their quantum yields during fabrication processes, such as patterning and spin-coating, and can therefore improve cost-effectiveness. Understanding the enhancement process is crucial for the design of metallic nanostructure substrates for enhancing the fluorescence of colloidal QDs. In this work, improved color conversion of colloidal green and red QDs coupled with aluminum (Al) and silver (Ag) nanodisk (ND) arrays designed by in-depth systematic finite-difference time domain simulations of excitation, spontaneous emission, and quantum efficiency enhancement is reported. Calculated results of the overall photoluminescence enhancement factor in the substrate of 500 × 500 µm2 size are 2.37-fold and 2.82-fold for Al ND-green QD and Ag ND-red QD structures, respectively. Experimental results are in good agreement, showing 2.26-fold and 2.66-fold enhancements for Al ND and Ag ND structures. Possible uses of plasmonics in cases such as white LED and total color conversion for possible display applications are discussed. The theoretical treatments and experiments shown in this work are a proof of principle for future studies of plasmonic enhancement of various light-emitting materials.

Evaluation of forensic genetic parameters of 12 STR loci in the Korean population using the InvestigatorⓇ HDplex kit.

We genotyped and calculated the forensic parameters of 10 non-CODIS loci and 2 CODIS loci of 990 Korean individuals using the InvestigatorⓇ HDplex kit. No significant deviations from Hardy-Weinberg equilibrium (after Bonferroni correction for multiple testing) or genetic linkage disequilibrium were observed. The calculated matching probability and power of discrimination ranged from 0.0080 to 0.2014, and 0.7986 to 0.9920, respectively. We conclude that the markers of the kit are highly informative corroborative tools for forensic DNA analysis.

A Digital Squamous Cell Carcinoma Mimicking a Diabetic Foot Ulcer, With Early Inguinal Metastasis and Cancer-Related Lymphedema.

Although squamous cell carcinoma (SCC) is the second most common nonmelanoma skin cancer, clinicians have difficulty diagnosing SCC of the toe because its clinical features can mimic other less serious diseases. Clinicians are especially prone to misdiagnose SCC of the toe as diabetic foot ulcer in patients with diabetes mellitus because of the clinical similarity of the 2 ailments. SCC of the toe is generally considered to have a low risk of metastasis. Locoregional or distant metastases without bone or tendon involvement are particularly rare. The authors report here an interesting case of rapidly spreading SCC of the toe with metastasis to multiple lymph nodes and cancer-related lymphedema. Physicians should be aware of the possibility of malignancy when they encounter chronic and recalcitrant ulcerative lesions of the digits.

Cosine apodization of dual-resonance all-fiber acousto-optic tunable filters.

We experimentally demonstrate a novel cosine apodization technique for dual-resonance all-fiber acoustic-optic tunable filter. The technique is based on a hybrid control of input acoustic polarization state and circumferential fiber twist. We will show that intrinsic sidelobe spectra occurring between dual filtering bands are successfully suppressed through our approach, which will be also theoretically confirmed via our analytical and numerical studies. The results illustrate that the spectral positions of each resonance are tuned linearly and continuously by the fiber twist, and that overall sidelobe spectra between two resonances are suppressed regardless of fiber twist angle. The proposed scheme is useful to minimize cross talk between adjacent wavelength channels in optical sensor systems. We highlight that our approach is directly applicable to low-noise matched filtering.

Flexible, compact WDM receivers using cascaded optical and electrical down-conversion.

We propose a super-channel flexible wavelength division multiplexing (WDM) receiver architecture. The receiver, which requires no optical filtering, only a pair (I and Q phases) of coherent optical detectors, and an electrical receiver system, can simultaneously recover multiple wavelength-multiplexed channels using cascaded optical and electrical down-conversion. The receiver data capacity increases in proportion to the number of electrical sub-carrier channels. The proposed receiver concept has been described using a six-channel WDM receiver, and a two-channel ( ± 25 GHz) receiver IC, which is a key block of the WDM receiver, has been successfully demonstrated with two and three 2.5 Gb/s binary-phase-shift-key (BPSK) modulated channels.

[Diagnosis and Treatment of GastroEsophageal Reflux Disease at the Primary Health Care Clinics in Korea].

Background/Aims: The prevalence of GERD and treatment costs are continuously rising in Korea, and the importance of primary health care clinics where the most treatment of actual patients is conducted is increasing. In this study, the diagnosis of GERD, selection of therapeutic drugs, and treatment methods in primary health care clininics were investigated through a large-scale multi-dimensional surveys. Methods: From January 2015 to December 2018, the study data of 18,010 patients with GERD were retrospectively investigated based on eletronic medical record at 542 primary health care clinics in Korea. Results: Among all GERD patients, endoscopy was used for diagnosis in 16.11% of cases, and the most frequently performed in gastroenterology department (28.85%). The average BMI and the proportion of patients in stages 1 to 3 of obesity were highest in the ERD group, and the majority of the severity of ERD group was mild. Symptoms of the patients with GERD were mainly heartburn, gastric acid reflux, and chest pain. Drug treatment was performed in most of the patients with GERD, and PPI was the main drug, and Esomeprazol was prescribed the most among the main ingredients, and the ratio of PPI alone was high. The rate of symptom improvement after GERD treatment was slightly higher in the ERD group (75.91%) and the NERD group (74.36%) than in the GERD diagnosed without endoscopy group (63.89%). Conclusions: In domestic primary health care clinics, the majority were diagnosed with GERD without endoscopy on the basis of symptoms. The most preferred treatment for GERD was PPI, which was prescribed alone in the majority.

40Gbit/s coherent optical receiver using a Costas loop.

A highly integrated 40 Gbit/s coherent optical receiver is reported using a Costas loop as a homodyne optical phase locked loop (OPLL). A photonic IC, an electrical IC, and a hybrid loop filter are characterized, and the feedback loop system is fully analyzed to build a stable homodyne OPLL. All components are integrated on a single substrate within the compact size of 10 × 10mm(2), and a 1.1 GHz loop bandwidth and a 120 psloop delay are achieved. The binary phase-shift keying receiver exhibits error-free (BER<10(-12)) up to 35 Gbit/s and BER<10(-7) for 40 Gbit/s with no latency, and consumes less than 3 W power.

Single-chip integrated transmitters and receivers.

Compared to traditional optics, photonic integrated circuits have advantages in size, weight, performance, reliability, power consumption, and cost. The size and stability also enable them to realize unique functions in coherent optics. Optical phase-locked loop (OPLL) based transmitters and receivers are examples. With photonic integration, the loop bandwidth of the OPLL can increase by orders of magnitude, and stable OPLLs have been achieved with closed-loop bandwidths >1 GHz.

Comparative analysis of allele variation using allele frequencies according to sample size in Korean population.

BACKGROUND: Allele frequency using short tandem repeats (STRs) is used to calculate likelihood ratio for database match, to interpret DNA mixture and to estimate ethnic groups in forensic genetics. In Korea, three population studies for 23 STR loci have been conducted with different sample size for forensic purposes. OBJECTIVE: We performed comparative analysis to determine how the difference of sample size affects the allele frequency and allele variation within same ethnic population (i.e. Korean). Furthermore, this study was conducted to check how the sampling group and multiplex kit also affect allele variation such as rare alleles and population specific alleles. METHODS: To compare allele variation, we used allele frequencies of three population data published from three Korean forensic research groups. Allele frequencies were calculated using different sample sizes and multiplex kits: 526, 1000, and 2000 individuals, respectively. RESULTS: The results showed the different distribution of allele frequencies in some loci. There was also a difference in the number of rare alleles observed by the sample size and sampling bias. In particular, an allele of 9.1 in the D2S441 locus was not observed in population study with 526 individuals due to multiplex kits. CONCLUSION: Because the allele frequencies play an important role in forensic genetics, even if the samples are derived from the same population, it is important to consider the effects of sample size, sampling bias, and selection of multiplex kits in population studies.

A forensic case study for body fluid identification using DNA methylation analysis.

Recently, a method of identifying body fluids using DNA methylation has been developed (Frumkin et al., 2011). An existing multiplex assay using 9 CpG markers could differentiate 5 body fluids: semen, blood, saliva, menstrual blood, and vaginal fluid. To validate this technique, we evaluated the previously described body fluid identification method by means of single base extension (SBE). DNA methylation was applied to 22 samples in 18 forensic cases; seven of these were semen, three were blood, eight were saliva, three were vaginal fluid, and one was menstrual blood. Total of 18 samples were tested, the DNA methylation profiles were coincident from preliminary tests (acid phosphatase (AP), leucomalachite green (LMG, Sigma Aldrich, St Louis, MO, USA) and SALIgAE®) except one sample which displayed an all-negative result. After applying the DNA methylation method to forensic samples, we determined that it could be very useful for differentiating vaginal secretions from menstrual blood, for which there is no conventional preliminary testing method.

Colon Polyp Detection in Primary Health Care Institutions of Korea: Detection Rate and Issues with Following the Guidelines.

Background/Aims: There have been few multicenter studies on colonic polyps conducted by primary medical institutions. This study examined the detection rate of colonic polyps in primary health care institutions and the related factors while following the guidelines. Methods: The medical records of 14,029 patients who underwent colonoscopy between January-June 2020 at 40 primary medical institutions in Korea were analyzed. High-risk adenoma was defined as advanced adenoma, carcinoma, or ≥3 adenomas. Results: Most patients (71.2%) aged ≥50 years underwent re-colonoscopy within 5 years (51.3%) for diagnostic purposes (61.3%) in Korean primary medical institutions. The detection rates of colon polyps, adenoma, advanced adenoma, high-risk adenoma, and carcinoma was 59.9%, 38.9%, 5.9%, 11.4%, and 0.3% in all subjects and 59.8%, 37.5%, 8.5%, 12.9%, and 0.3% in average-risk patients, respectively. The incidences of adenoma in average-risk patients increased significantly with age (30s/40s/50s: 20.1%/29.4%/43% for adenoma, 4.4%/6.7%/10.3% for advanced adenoma, and 5.6%/9.5%/14.6% for high-risk adenoma; p<0.05). Before 50 years of age, high-risk adenoma was detected in 9.1% of patients in the first-time screening group, and the significant risk factors were being male and ≥40 years of age. The detection rate of high-risk adenoma in the normal index colonoscopy group within 5 years was 9.0%. The significant risk factors included older age, male sex, positive fecal occult blood test, stool form changes, and nonspecific symptoms (gas and indigestion). Conclusions: More colonic adenoma studies targeting real-world clinical practice will be needed to revise the Korean guidelines for colorectal cancer screening and surveillance.

Sidelobe suppression in all-fiber acousto-optic tunable filter using torsional acoustic wave.

We propose two techniques to suppress intrinsic sidelobe spectra in all-fiber acousto-optic tunable filter using torsional acoustic wave. The techniques are based on either double-pass filter configuration or axial tailoring of mode coupling strength along an acousto-optic interaction region in a highly birefringent optical fiber. The sidelobe peak in the filter spectrum is experimentally suppressed from -8.3 dB to -16.4 dB by employing double-pass configuration. Axial modulation of acousto-optic coupling strength is proposed using axial variation of the fiber diameter, and the simulation results show that the maximum side peak of -9.3 dB can be reduced to -22.2dB. We also discuss the possibility of further spectral shaping of the filter based on the axial tailoring of acousto-optic coupling strength.

High-accuracy measurement of cladding noncircularity based on phase velocity difference between acoustic polarization modes.

A high-accuracy measurement method for the noncircularity (ellipticity) of silica glass fibers is demonstrated. This method makes use of the phase velocity difference between two eigen polarization modes of the lowest-order acoustic flexural wave in an optical fiber. The relationship between the acoustic phase velocity difference and the fiber ellipticity is formulated. Three types of optical fibers were examined; photonic crystal fiber, elliptical core fiber, and standard single-mode fiber. Fiber ellipticity of less than 0.001 was successfully measured.

Analyses of unintentional intensity modulation in all-fiber acousto-optic tunable filters.

We theoretically and experimentally analyze unintentional intensity modulation phenomena in two types of all-fiber acousto-optic tunable filters utilizing flexural and torsional acoustic waves. Output filter signal at a resonant wavelength shows time-varying oscillations with even- and odd-order harmonics of applied acoustic frequency, which are explained by two factors of static mode coupling and acoustic back reflection. The magnitudes of static coupling and acoustic reflection in our devices are estimated from the measured first and second harmonic modulation powers.

Experimental excitation and characterization of cladding modes in photonic crystal fiber.

We extend the previous theoretical study on the effect of outer silica cladding to the analysis on real field profiles in a practical PCF. Clear field profiles for the first higher-order cladding modes are presented and discussed. The observed mode fields are reproduced by numerical calculations, and it turns out that they correspond to LP(16) mode groups. Optical properties of the observed modes such as lobe direction and polarization are also investigated. The results of this study will be useful in the design of the PCF-based optical devices utilizing cladding mode coupling.

Axial strain dependence of all-fiber acousto-optic tunable filters.

We report the axial strain dependence of two types of all-fiber acousto-optic tunable filters based on flexural and torsional acoustic waves. Experimental observation of the resonant wavelength shift under applied axial strain could be explained by theoretical consideration of the combination of acoustic and optical effects. We discuss the possibility of suppressing the strain effect in the filters, or conversely, the possibility of using the strain dependence for wavelength tuning or strain sensors.

Tunable gratings in a hollow-core photonic bandgap fiber based on acousto-optic interaction.

We demonstrate a coherent intermodal coupling in a hollow-core photonic bandgap fibers (PBGF) using an acoustic grating. A theoretical study on the properties of acoustic and optical wave propagating the PBGF is performed indicating that the applied frequency higher than 10 MHz is required to obtain the acousto-optic interaction at the wavelength around 1550 nm. Wavelength-tunable coupling from fundamental mode to higher-order core modes is achieved with more than 90% coupling efficiency at the applied frequency of 11.54 MHz. The low dispersive properties and the mode filed distributions of the higher-order guided modes of the air-core PBGF in the experiment show reasonable agreement with the simulation results.

Polarization-coupling all-fiber acousto-optic tunable filter insensitive to fiber bend and physical contact.

We show that an all-fiber acousto-optic tunable filter based on polarization mode coupling using torsional acoustic wave is immune to the fiber bend and physical contact in the acousto-optic interaction region. We also propose and demonstrate a novel strain-free and size-reduced tunable filter with a 4-m-long fiber acousto-optic interaction region looped into a 5- cm-diameter coil.