Low-threshold 2†µm InAs/InP quantum dash lasers enabled by punctuated growth.

2 µm photonics and optoelectronics is promising for potential applications such as optical communications, LiDAR, and chemical sensing. While the research on 2 µm detectors is on the rise, the development of InP-based 2 µm gain materials with 0D nanostructures is rather stalled. Here, we demonstrate low-threshold, continuous wave lasing at 2 µm wavelength from InAs quantum dash/InP lasers enabled by punctuated growth of the quantum structure. We demonstrate low threshold current densities from the 7.1 µm width ridge-waveguide lasers, with values of 657, 1183, and 1944 A/cm2 under short pulse wave (SPW), quasi-continuous wave (QCW), and continuous wave operation. The lasers also exhibited good thermal stability, with a characteristic temperature T0 of 43 K under SPW mode. The lasing spectra is centered at 1.97 µm, coinciding with the ground-state emission observed from photoluminescence studies. We believe that the InAs quantum dash/InP lasers emitting near 2 µm will be a key enabling technology for 2 µm communication and sensing.

Drawing Guideline for JKMS Manuscripts (06): Scatter Plot.

The appropriate plot effectively conveys the author's conclusions to the readers. Journal of Korean Medical Science is providing a series of guidelines to show you how to make consistent and excellent plots more easily. In this article, we introduce scatter plots and more.

Graphene/III-V Quantum Dot Mixed-Dimensional Heterostructure for Enhanced Radiative Recombinations via Hole Carrier Transfer.

Fabrication of high quantum efficiency nanoscale device is challenging due to increased carrier loss at surface. Low dimensional materials such 0D quantum dots and 2D materials have been widely studied to mitigate the loss. Here, we demonstrate a strong photoluminescence enhancement from graphene/III-V quantum dot mixed-dimensional heterostructures. The distance between graphene and quantum dots in the 2D/0D hybrid structure determines the degree of radiative carrier recombination enhancement from 80% to 800% compared to the quantum dot only structure. Time-resolved photoluminescence decay also shows increased carrier lifetimes when the distance decreases from 50 to 10 nm. We propose that the optical enhancement is due to energy band bending and hole carrier transfer, which repair the imbalance of electron and hole carrier densities in quantum dots. This 2D graphene/0D quantum dot heterostructure shows promise for high performance nanoscale optoelectronic devices.

Acute cholecystitis in old adults: the impact of advanced age on the clinical characteristics of the disease and on the surgical outcomes of laparoscopic cholecystectomy.

BACKGROUND: Impact of advanced age on disease characteristics of acute cholecystitis (AC), and surgical outcomes after laparoscopic cholecystectomy (LC) has not been established. METHODS: This single-center retrospective study included patients who underwent LC for AC between April 2010 and December 2020. We analyzed the disease characteristics and surgical outcomes according to age: Group 1 (age < 60 years), Group 2 (60 ≤ age < 80 years), and Group 3 (age ≥ 80 years). Risk factors for complications were assessed using logistic regression analysis. RESULTS: Of the 1,876 patients (809 [43.1%] women), 723 were in Group 1, 867 in Group 2, and 286 in Group 3. With increasing age, the severity of AC and combined common bile duct stones increased. Group 3 demonstrated significantly worse surgical outcomes when compared to Group 1 and 2 for overall (4.0 vs. 9.1 vs. 18.9%, p < 0.001) and serious complications (1.2 vs. 4.2 vs. 8.0%, p < 0.001), length of hospital stay (2.78 vs. 3.72 vs. 5.87 days, p < 0.001), and open conversion (0.1 vs. 1.0 vs. 2.1%, p = 0.007). Incidental gallbladder cancer was also the most common in Group 3 (0.3 vs. 1.5 vs. 3.1%, p = 0.001). In the multivariate analysis, body mass index < 18.5, moderate/severe AC, and albumin < 2.5 g/dL were significant risk factors for serious complications in Group 3. CONCLUSION: Advanced age was associated with severe AC, worse surgical outcomes, and a higher rate of incidental gallbladder cancer following LC. Therefore, in patients over 80 years of age with AC, especially those with poor nutritional status and high severity grading, urgent surgery should be avoided, and surgery should be performed after sufficient supportive care to restore nutritional status before LC.

Development of new TAK-285 derivatives as potent EGFR/HER2 inhibitors possessing antiproliferative effects against 22RV1 and PC3 prostate carcinoma cell lines.

Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) protein tyrosine kinases co-expressed in various cancers such as ovarian, breast, colon, and prostate subtypes. Herein, new TAK-285 derivatives (9a-h) were synthesised, characterised, and biologically evaluated as dual EGFR/HER2 inhibitors. Compound 9f exhibited IC50 values of 2.3 nM over EGFR and 234 nM over HER2, which is 38-fold of staurosporine and 10-fold of TAK-285 over EGFR. Compound 9f also showed high selectivity profile when tested over a small kinase panel. Compounds 9a-h showed IC50 values in the range of 1.0-7.3 nM and 0.8-2.8 nM against PC3 and 22RV1 prostate carcinoma cell lines, respectively. Cell cycle analysis, apoptotic induction, molecular docking, dynamics, and MM-GBSA studies confirmed the plausible mechanism(s) of compound 9f as a potent EGFR/HER2 dual inhibitor with an effective antiproliferative action against prostate carcinoma.

The relationship between exposure to environmental noise and risk of atopic dermatitis, asthma, and allergic rhinitis.

BACKGROUND: Noise is defined as unwanted sound. It may induce negative emotions and mental health problems and may even lead to increased suicide risk. However, the impact of noise exposure on environmental diseases and disease severity is not well understood. This study aimed to elucidate the association between night-time noise exposure and the prevalence of environmental diseases in South Korea. METHODS: We conducted an analysis of the Environmental Disease Database provide by the National Health Insurance Service (NHIS) from 2013 to 2017. After spatially interpolating the noise data provided by the National Noise Information System (NNIS), night-time noise values in the district level were obtained by calculating the mean noise values at the administrative district level. The linear regression analyses were performed to test the association between the age-standardized prevalence ratio (SPR) and the night-time noise exposure in the district level. RESULTS: In areas with high night-time noise exposure (≥55 dB), the SPR for atopic dermatitis and allergic rhinitis were 1.0515 (95 % confidence interval [CI]:1.0508-1.0521) and 1.0202 (95 % CI:1.0201-1.0204), respectively, which were higher than those in the general population. The SPR for environmental diseases, including atopic dermatitis, asthma, and allergic rhinitis, was 1.0104 (95 % CI:1.0103-1.0105). Additionally, a significant linear association was observed between the level of nocturnal noise exposure and the total hospitalization period for atopic dermatitis (ß = 399.3, p < 0.01). CONCLUSION: We provide evidence of a significant association between night-time environmental noise and environmental diseases, particularly atopic dermatitis and allergic rhinitis. Furthermore, we observed a significant linear association between night-time noise exposure and the severity of atopic dermatitis.

Drawing Guideline for JKMS Manuscripts (05): Plots for Numeric Data.

The appropriate plot effectively conveys the author's conclusions to the readers. Journal of Korean Medical Science will provide a series of special articles to show you how to more easily make consistent and excellent plots. In this article, we will cover plots with numeric data.

Galangin 3-benzyl-5-methylether derivatives function as an adiponectin synthesis-promoting peroxisome proliferator-activated receptor γ partial agonist.

The upregulation of adiponectin production has been suggested as a novel strategy for the treatment of metabolic diseases. Galangin, a natural flavonoid, exhibited adiponectin synthesis-promoting activity during adipogenesis in human bone marrow mesenchymal stem cells. In target identification, galangin bound both peroxisome proliferator-activated receptor (PPAR) γ and estrogen receptor (ER) ß. Novel galangin derivatives were synthesized to improve adiponectin synthesis-promoting compounds by increasing the PPARγ activity of galangin and reducing its ERß activity, because PPARγ functions can be inhibited by ERß. Three galangin 3-benzyl-5-methylether derivatives significantly promoted adiponectin production by 2.88-, 4.47-, and 2.76-fold, respectively, compared to the effect of galangin. The most potent compound, galangin 3-benzyl-5,7-dimethylether, selectively bound to PPARγ (Ki, 1.7 µM), whereas it did not bind to ERß. Galangin 3-benzyl-5,7-dimethylether was identified as a PPARγ partial agonist in docking and pharmacological competition studies, suggesting that it may have diverse therapeutic potential in a variety of metabolic diseases.

Completion of single-incision laparoscopic cholecystectomy using the modified Konyang standard method.

BACKGROUND: To date, a surgical method for single-incision laparoscopic cholecystectomy (SILC) has not been standardized. Therefore, this study aimed to introduce a standardized surgical method for SILC, in addition to reporting our experience over 10 years. METHODS: Patients who underwent SILC at a single institution between April 2010 and December 2019 were included in this study. We analyzed the patient demographics and surgical outcomes according to the surgical method used: phase 1 (Konyang standard method, KSM) comprising initial 3-channel SILC, phase 2 (modified KSM, mKSM) comprising 4-channel SILC with a snake retractor, and phase 3 (commercial mKSM, C-mKSM) using a commercial 4-channel port. RESULTS: Of 1372 patients (mean age, 51.3 years; 781 [56.9%] women), 418 (30.5%) surgeries were performed for acute cholecystitis (AC), 33 (2.4%) were converted to multiport or open cholecystectomy, and 49 (3.6%) developed postoperative complications. The mean operation time (OT) and length of postoperative hospital stay (LOS) were 51.9 min and 2.6 days, respectively. Overall, 325 patients underwent SILC with the KSM, 660 with the mKSM, and 387 with the C-mKSM. In the C-mKSM group, the number of patients with AC was the lowest (26.8% vs. 38.2% vs. 20.4%, p < 0.001) and the OT (51.7 min vs. 55.4 min vs. 46.1 min, p < 0.001), estimated blood loss (24.5 mL vs. 15.5 mL vs. 6.1 mL, p < 0.001), and LOS (2.8 days vs. 2.5 days vs. 2.3 days, p = 0.001) were significantly improved. The surgical outcomes were better in the non-AC group than in the AC group. CONCLUSION: Based on our 10 year experience, C-mKSM is a safe and feasible method of SILC in selected patients, although there were lower percentage of patients with AC compared to other groups.

Nanomaterials for IoT Sensing Platforms and Point-of-Care Applications in South Korea.

Herein, state-of-the-art research advances in South Korea regarding the development of chemical sensing materials and fully integrated Internet of Things (IoT) sensing platforms were comprehensively reviewed for verifying the applicability of such sensing systems in point-of-care testing (POCT). Various organic/inorganic nanomaterials were synthesized and characterized to understand their fundamental chemical sensing mechanisms upon exposure to target analytes. Moreover, the applicability of nanomaterials integrated with IoT-based signal transducers for the real-time and on-site analysis of chemical species was verified. In this review, we focused on the development of noble nanostructures and signal transduction techniques for use in IoT sensing platforms, and based on their applications, such systems were classified into gas sensors, ion sensors, and biosensors. A future perspective for the development of chemical sensors was discussed for application to next-generation POCT systems that facilitate rapid and multiplexed screening of various analytes.

Laparoscopic surgery for fallopian tube torsion due to benign tumour in the third trimester of pregnancy: a case report and literature review.

Isolated fallopian tubal torsion is rare among women of reproductive age, and it is even rarer during pregnancy. Despite its rare incidence, it is important to consider this diagnosis to facilitate prompt and effective intervention. We present the case of a pregnant woman in her third trimester who presented with acute right abdominal pain. A 32-year-old primigravida woman at 29 weeks and four days of gestation visited the emergency department with acute right flank and abdominal pain. Sonography and MRI revealed the presence of a right adnexal cystic mass. Exploratory laparoscopy revealed isolated right tubal torsion and a normal ovary. To avoid torsion recurrence, we performed laparoscopic right salpingectomy. The remainder of her gestation was uneventful. Histopathological examination revealed serous cystadenoma with haemorrhagic infarction. We reviewed the literature for cases of isolated tubal torsion in the past 11 years. Twenty-three case reports were included in this study, and the average time from presentation to surgical intervention was 35.6 hours. In these cases, most of the patients underwent laparotomy and had good pregnancy outcomes. Although the approach may vary depending on the situation, the laparoscopic approach should be preferred to laparotomy in the third trimester of pregnancy.

Pharmacokinetic Properties of Moracin C in Mice.

Moracin C from Morus alba fruits, also known as the mulberry, has been proven to exhibit inhibitory activities against lipoxygenase enzymes, TNF-α and interleukin-1ß secretion, and proprotein convertase subtilisin/kexin type 9 expression. Despite the various pharmacological activities of moracin C, its pharmacokinetic characteristics have yet to be reported. Here, the pharmacokinetic parameters and tissue distribution of moracin C have been investigated in mice, and the plasma concentration of moracin C with multiple dosage regimens was simulated via pharmacokinetic modeling. Our results showed that moracin C was rapidly and well absorbed in the intestinal tract, and was highly distributed in the gastrointestinal tract, liver, kidneys, and lungs. Moracin C was distributed in the ileum, cecum, colon, and liver at a relatively high concentration compared with its plasma concentration. It was extensively metabolized in the liver and intestine, and its glucuronidated metabolites were proposed. In addition, the simulated plasma concentrations of moracin C upon multiple treatments (i.e., every 12 and 24 h) were suggested. We suggest that the pharmacokinetic characteristics of moracin C would be helpful to select a disease model for in vivo evaluation. The simulated moracin C concentrations under various dosage regimens also provide helpful knowledge to support its pharmacological effect.

Preoperative Oral Carbohydrate Loading in Laparoscopic Gynecologic Surgery: A Randomized Controlled Trial.

STUDY OBJECTIVE: To determine whether carbohydrate loading improves the postoperative quality of recovery (QoR) better than the midnight fasting policy in laparoscopic gynecologic surgeries. DESIGN: Randomized, parallel-group trial. SETTING: Tertiary university hospital. PATIENTS: Female patients scheduled for laparoscopic gynecologic surgery for nonmalignant gynecologic diseases. INTERVENTIONS: Eighty-eight women were randomly assigned to the midnight fasting group (nil per os, NPO group) or the carbohydrate loading group (carbohydrate group). Patients in both groups adhered to the enhanced recovery after surgery protocol except for carbohydrate intake in the carbohydrate group. MEASUREMENTS AND MAIN RESULTS: The postoperative QoR was evaluated using the QoR 15-item questionnaire on postoperative day 2. The times to readiness for discharge of the groups were compared. The QoR 15-item questionnaire scores were 97.7 ± 23.0 in the NPO group and 99.6 ± 22.4 in the carbohydrate group; they were not statistically different (p = .702). The times to readiness for discharge of both groups were also not different: 36.8 ± 12.2 hours in the NPO group and 37.6 ± 11.8 hours in the carbohydrate group (p = .684). CONCLUSION: The benefit of carbohydrate beverage intake was not significant in laparoscopic gynecologic surgeries when following the enhanced recovery after surgery protocol.

Association Between Carbon Monoxide Intoxication and Incidence of Ischemic Stroke: A Retrospective Nested Case-Control Study in South Korea.

OBJECTIVES: Severe neurological sequelae occur in patients with carbon monoxide (CO) intoxication; however, whether the latter increases the long-term risk of developing ischemic stroke is unclear. We investigated the association between CO intoxication and ischemic stroke using data from the Korean National Health Information Database. MATERIALS AND METHODS: We performed a retrospective, nested case-control study of 27,984 individuals treated for CO intoxication and 27,984 sex- and age-matched controls. Initially, we calculated the overall incidence and hazard ratio (HR) of ischemic stroke using conditional logistic regression. Thereafter, we calculated the incidences and HRs according to covariates and follow-up periods. RESULTS: The CO intoxication group had a significantly higher risk of developing ischemic stroke than the control group (adjusted HR 2.31, 95% CI [confidence interval] = 2.01-2.65). Male sex (adjusted HR 2.73, 95% CI = 2.23-3.34), age <40 (adjusted HR 3.53, 95% CI = 2.15-5.82), low income (adjusted HR 2.55, 95% CI = 1.56-4.15), comorbidities (adjusted HR 2.59, 95% CI = 1.48-4.52), and current smokers (adjusted HR 3.55, 95% CI = 1.67-7.60) had a higher risk of ischemic stroke. The risk of ischemic stroke was highest within 2 years after CO intoxication (adjusted HR 7.47, 95% CI = 2.76-20.26), and even >6 years after, the risk remained significantly higher than in the control group (adjusted HR 1.84, 95% CI = 1.53-2.20). CONCLUSIONS: CO intoxication and the long-term risk of ischemic stroke are associated.

Marliolide Derivative Induces Melanosome Degradation via Nrf2/p62-Mediated Autophagy.

Nuclear factor erythroid 2-related factor 2 (Nrf2), which is linked to autophagy regulation and melanogenesis regulation, is activated by marliolide. In this study, we investigated the effect of a marliolide derivative on melanosome degradation through the autophagy pathway. The effect of the marliolide derivative on melanosome degradation was investigated in α-melanocyte stimulating hormone (α-MSH)-treated melanocytes, melanosome-incorporated keratinocyte, and ultraviolet (UV)B-exposed HRM-2 mice (melanin-possessing hairless mice). The marliolide derivative, 5-methyl-3-tetradecylidene-dihydro-furan-2-one (DMF02), decreased melanin pigmentation by melanosome degradation in α-MSH-treated melanocytes and melanosome-incorporated keratinocytes, evidenced by premelanosome protein (PMEL) expression, but did not affect melanogenesis-associated proteins. The UVB-induced hyperpigmentation in HRM-2 mice was also reduced by a topical application of DMF02. DMF02 activated Nrf2 and induced autophagy in vivo, evidenced by decreased PMEL in microtubule-associated proteins 1A/1B light chain 3B (LC3)-II-expressed areas. DMF02 also induced melanosome degradation via autophagy in vitro, and DMF02-induced melanosome degradation was recovered by chloroquine (CQ), which is a lysosomal inhibitor. In addition, Nrf2 silencing by siRNA attenuated the DMF02-induced melanosome degradation via the suppression of p62. DMF02 induced melanosome degradation in melanocytes and keratinocytes by regulating autophagy via Nrf2-p62 activation. Therefore, Nrf2 activator could be a promising therapeutic agent for reducing hyperpigmentation.

Synthesis of Moracin C and Its Derivatives with a 2-arylbenzofuran Motif and Evaluation of Their PCSK9 Inhibitory Effects in HepG2 Cells.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key factor in several cardiovascular diseases, as it is responsible for the elevation of circulating low-density lipoprotein cholesterol (LDL-C) levels in blood plasma by direct interaction with the LDL receptor. The development of orally available drugs to inhibit this PCSK9-LDLR interaction is a highly desirable objective. Here, we report the synthesis of naturally occurring moracin compounds and their derivatives with a 2-arylbenzofuran motif to inhibit PCSK9 expression. In addition, we discuss a short approach involving the three-step synthesis of moracin C and a divergent method to obtain various analogs from one starting material. Among the tested derivatives, compound 7 (97.1%) was identified as a more potent inhibitor of PCSK9 expression in HepG2 cells than berberine (60.9%). These results provide a better understanding of the structure-activity relationships of moracin derivatives for the inhibition of PCSK9 expression in human hepatocytes.

Morphological-Electrical Property Relation in Cu(In,Ga)(S,Se)2 Solar Cells: Significance of Crystal Grain Growth and Band Grading by Potassium Treatment.

Solution-processed Cu(In,Ga)(S,Se)2  (CIGS) has a great potential for the production of large-area photovoltaic devices at low cost. However, CIGS solar cells processed from solution exhibit relatively lower performance compared to vacuum-processed devices because of a lack of proper composition distribution, which is mainly instigated by the limited Se uptake during chalcogenization. In this work, a unique potassium treatment method is utilized to improve the selenium uptake judiciously, enhancing grain sizes and forming a wider bandgap minimum region. Careful engineering of the bandgap grading structure also results in an enlarged space charge region, which is favorable for electron-hole separation and efficient charge carrier collection. Besides, this device processing approach has led to a linearly increasing electron diffusion length and carrier lifetime with increasing the grain size of the CIGS film, which is a critical achievement for enhancing photocurrent yield. Overall, 15% of power conversion efficiency is achieved in solar cells processed from environmentally benign solutions. This approach offers critical insights for precise device design and processing rules for solution-processed CIGS solar cells.

Flexible GaAs photodetector arrays hetero-epitaxially grown on GaP/Si for a low-cost III-V wearable photonics platform.

We demonstrate flexible GaAs photodetector arrays that were hetero-epitaxially grown on a Si wafer for a new cost-effective and reliable wearable optoelectronics platform. A high crystalline quality GaAs layer was transferred onto a flexible foreign substrate and excellent retention of device performance was demonstrated by measuring the optical responsivities and dark currents. Optical simulation proves that the metal stacks used for wafer bonding serve as a back-reflector and enhance GaAs photodetector responsivity via a resonant-cavity effect. Device durability was also tested by bending 1000 times and no performance degradation was observed. This work paves a way for a cost-effective and flexible III-V optoelectronics technology with high durability.

Are There Differences Between Intradermal and Intramuscular Injections of Botulinum Toxin on the Forehead?

BACKGROUND: The intradermal technique to inject botulinum toxin is a popular procedure in upper facial rejuvenation to minimize side effects, such as brow ptosis, and can sometimes result in a lifting effect. OBJECTIVE: The present study investigated differences in effects according to injection modality. METHODS AND MATERIALS: Fifteen women received intradermal injections of botulinum toxin (total dose, 8U) into the forehead, and 14 women received intramuscular injections. RESULTS: The maximal antiwrinkle effect was recorded at Week 2, and the duration of the effect was the same in both groups. The brow position was lowered at Weeks 2 and 4 in the intramuscular injection group and was preserved in the intradermal injection group throughout the follow-up period. The amount of maximal voluntary eyebrow movement was decreased at Weeks 2 and 4 and recovered at Week 16 in both groups. The change in the electromyographic amplitude of the frontalis muscle was prolonged until Week 16 in both groups. Subjective satisfaction with wrinkles was similar in both groups. However, the intradermal injection was more painful. CONCLUSION: Intradermal injection of botulinum toxin is a safe and effective method to improve forehead rhytides.

Directional Ostwald Ripening for Producing Aligned Arrays of Nanowires.

The remarkable electronic and mechanical properties of nanowires have great potential for fascinating applications; however, the difficulties of assembling ordered arrays of aligned nanowires over large areas prevent their integration into many practical devices. In this paper, we show that aligned VO2 nanowires form spontaneously after heating a thin V2O5 film on a grooved SiO2 surface. Nanowires grow after complete dewetting of the film, after which there is the formation of supercooled nanodroplets and subsequent Ostwald ripening and coalescence. We investigate the growth mechanism using molecular dynamics simulations of spherical Lennard-Jones particles, and the simulations help explain how the grooved surface produces aligned nanowires. Using this simple synthesis approach, we produce self-aligned, millimeter-long nanowire arrays with uniform metal-insulator transition properties; after their transfer to a polymer substrate, the nanowires act as a highly sensitive array of strain sensors with a very fast response time of several tens of milliseconds.