1,511 research outputs found

    Possible link between Arctic Sea ice and January PM10 concentrations in South Korea

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    In this study, we investigated the possible teleconnection between PM10 concentrations in South Korea and Arctic Sea ice concentrations at inter-annual time scales using observed PM10 data from South Korea, NCEP R2 data, and NOAA Sea Ice Concentration (SIC) data from 2001 to 2018. From the empirical orthogonal function (EOF) analysis, we found that the first mode (TC1) was a large-scale mode for PM10 in South Korea and explained about 27.4% of the total variability. Interestingly, the TC1 is more dominantly influenced by the horizontal ventilation effect than the vertical atmospheric stability effect. The pollution potential index (PPI), which is defined by the weighted average of the two ventilation effects, is highly correlated with the TC1 of PM10 at a correlation coefficient of 0.75, indicating that the PPI is a good measure for PM10 in South Korea at inter-annual time scales. Regression maps show that the decrease of SIC over the Barents Sea is significantly correlated with weakening of high pressure over the Ural mountain range region, the anomalous high pressure at 500 hPa over the Korean peninsula, and the weakening of the Siberian High and Aleutian low. Moreover, these patterns are similar to the correlation pattern with the PPI, suggesting that the variability of SIC over the Barents Sea may play an important role in modulating the variability of PM10 in South Korea through teleconnection from the Barents Sea to the Korean peninsula via Eurasia

    Retroperitoneoscopic Partial Nephrectomy in a Horseshoe Kidney

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    A 21-year-old woman with a 4 cm enhancing cystic renal mass in the left moiety of a horseshoe kidney was treated through a retroperitoneal laparoscopic approach. The tumor was excised completely with cold scissors, and renal parenchyma suturing with a surgical bolster was done with Vicryl 2-0 sutures. Choosing the proper approach according to the location of the lesion and the surgeon's experience with both approaches are of importance in laparoscopic surgery in horseshoe kidney cases. A preoperative kidney computed tomography angiography was helpful for understanding the complex renal vasculature

    Quantifying gas emissions from the "Millennium Eruption" of Paektu volcano, Democratic Peoples Republic of Korea/China

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    Paektu volcano (Changbaishan) is a rhyolitic caldera that straddles the border between the Democratic People’s Republic of Korea and China. Its most recent large eruption was the Millennium Eruption (ME; 23 km3^{3} dense rock equivalent) circa 946 CE, which resulted in the release of copious magmatic volatiles (H2_{2}O, CO2_{2}, sulfur, and halogens). Accurate quantification of volatile yield and composition is critical in assessing volcanogenic climate impacts but is challenging, particularly for events before the satellite era. We use a geochemical technique to quantify volatile composition and upper bounds to yields for the ME by examining trends in incompatible trace and volatile element concentrations in crystal-hosted melt inclusions. We estimate that the ME could have emitted as much as 45 Tg of S to the atmosphere. This is greater than the quantity of S released by the 1815 eruption of Tambora, which contributed to the “year without a summer.” Our maximum gas yield estimates place the ME among the strongest emitters of climate-forcing gases in the Common Era. However, ice cores from Greenland record only a relatively weak sulfate signal attributed to the ME. We suggest that other factors came into play in minimizing the glaciochemical signature. This paradoxical case in which high S emissions do not result in a strong glacial sulfate signal may present a way forward in building more https://symplectic.admin.cam.ac.uk/objectedit.html?cid=1&oid=876954generalized models for interpreting which volcanic eruptions have produced large climate impacts.K.I. was supported by the NSF under award no. 1349486 and by AAAS. Fieldwork was supported by the Richard Lounsbery Foundation

    Mesenchymal stem cells and platelet-rich plasma-impregnated polycaprolactone-β tricalcium phosphate bio-scaffold enhanced bone regeneration around dental implants

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    Background Finding a material that supports bone regeneration is the concern for many investigators. We supposed that a composite scaffold of poly(ε) caprolactone and β-tricalcium phosphate (PCL-TCP) would entail desirable characteristics of biocompatibility, bioresorbability, rigidity, and osteoconductivity for a proper guided bone regeneration. Furthermore, the incorporation of mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) would boost the bone regeneration. We conducted this study to evaluate the bone regeneration capacity of PCL-TCP scaffold that is loaded with MSCs and PRP. Materials and methods Five miniature pigs received 6 implants in 6 created-mandibular bony defects in the right and left lower premolar areas. The bony defects were managed according to the following three groups: the PCL-TCP scaffold loaded with MSCs and PRP (MSCs+PRP+PCL-TCP) group (n = 10), PCL-TCP scaffold loaded with PRP (PRP+PCL-TCP) group (n = 10), and PCL-TCP scaffold group (n = 10). After 12 weeks, the bone regeneration was assessed using fluorochrome bone labeling, μCT bone morphogenic analysis, and histomorphometric analysis. Results All of the three groups supported the bone regeneration around the dental implants. However, the PCL-TCP scaffold loaded with MSCs and PRP (MSCs+PRP+PCL-TCP) group showed non-significant higher bone surface, bone specific surface, and bone surface density than the other two groups as revealed by the μCT bone morphogenic analysis. Histologically, the same group revealed higher bone-implant contact ratio (BIC) (p = 0.017) and new bone height formation (NBH, mm) (p = 0.0097) with statistically significant difference compared to the PCL-TCP scaffold group. Conclusions PCL-TCP scaffold is compatible for bone regeneration in bone defects surrounding dental implants. Moreover, the incorporation of MSCs and PRP optimized the bone regeneration process with respect to the rate of scaffold replacement, the height of the regenerated bone, and implant stability.This research was supported by a grant from the Korea Health Technology R&D Project through Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health and Welfare, Republic of Korea (grant number HI20C2114)

    A Case of Autoimmune Hemolytic Anemia Associated with an Ovarian Teratoma

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    Autoimmune hemolytic anemia associated with an ovarian teratoma is a very rare disease. However, treating teratoma is the only method to cure the hemolytic anemia, so it is necessary to include ovarian teratoma in the differential diagnosis of autoimmune hemolytic anemia. We report herein on a case of a young adult patient who had severe autoimmune hemolytic anemia that was induced by an ovarian teratoma. A 25-yr-old woman complained of general weakness and dizziness for 1 week. The hemoglobin level was 4.2 g/dL, and the direct and indirect antiglobulin tests were all positive. The abdominal computed tomography scan revealed a huge left ovarian mass, and this indicated a teratoma. She was refractory to corticosteroid therapy; however, after surgical resection of the ovarian mass, the hemoglobin level and the reticulocyte count were gradually normalized. The mass was well encapsulated and contained hair and teeth. She was diagnosed as having autoimmune hemolytic anemia associated with an ovarian teratoma. To the best of our knowledge, this is the first such a case to be reported in Korea

    Snake fang-inspired stamping patch for transdermal delivery of liquid formulations

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    A flexible microneedle patch that can transdermally deliver liquid-phase therapeutics would enable direct use of existing, approved drugs and vaccines, which are mostly in liquid form, without the need for additional drug solidification, efficacy verification, and subsequent approval. Specialized dissolving or coated microneedle patches that deliver reformulated, solidified therapeutics have made considerable advances; however, microneedles that can deliver liquid drugs and vaccines still remain elusive because of technical limitations. Here, we present a snake fang-inspired microneedle patch that can administer existing liquid formulations to patients in an ultrafast manner (< 15 s). Rear-fanged snakes have an intriguing molar with a groove on the surface, which enables rapid and efficient infusion of venom or saliva into prey. Liquid delivery is based on surface tension and capillary action. The microneedle patch uses multiple open groove architectures that emulate the grooved fangs of rear-fanged snakes: Similar to snake fangs, the microneedles can rapidly and efficiently deliver diverse liquid-phase drugs and vaccines in seconds under capillary action with only gentle thumb pressure, without requiring a complex pumping system. Hydrodynamic simulations show that the snake fang-inspired open groove architectures enable rapid capillary force-driven delivery of liquid formulations with varied surface tensions and viscosities. We demonstrate that administration of ovalbumin and influenza virus with the snake fang-inspired microneedle patch induces robust antibody production and protective immune response in guinea pigs and mice

    Hepatoprotective and Antioxidative Activities of Cornus officinalis against Acetaminophen-Induced Hepatotoxicity in Mice

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    The fruit of Cornus officinalis Sieb. et Zucc. is commonly prescribed in Asian countries as a tonic formula. In this study, the hepatoprotective effect of ethanolic extracts of the fruit of C. officinalis (ECO) was investigated in a mouse model of acetaminophen- (APAP-) induced liver injury. Pretreatment of mice with ECO (100, 250, and 500 mg/kg for 7 days) significantly prevented the APAP (200 mg/kg) induced hepatic damage as indicated by the serum marker enzymes (AST, ALT, and LDH). Parallel to these changes, ECO treatment also prevented APAP-induced oxidative stress in the mice liver by inhibiting lipid peroxidation (MDA) and restoring the levels of antioxidant enzymes (SOD, CAT, and HO-1) and glutathione. Liver injury and collagen accumulation were assessed using histological studies by hematoxylin and eosin staining. Our results indicate that ECO can prevent hepatic injuries associated with APAP-induced hepatotoxicity by preventing or alleviating oxidative stress
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