1,204 research outputs found
Synthesis of Zeolite Nanosheets and Applications in Membranes and Adsorption Separation Processes
University of Minnesota Ph.D. dissertation. May 2016. Major: Chemical Engineering. Advisor: Michael Tsapatsis. 1 computer file (PDF); x, 139 pages.In separation processes, desirable products with high purity are acquired at the expense of high energy cost procedures such as distillation. Alternative separation processes, such as zeolite membrane separation and adsorption processes, are promising to reduce the energy cost of production since zeolites can discriminate molecules on the basis of size/shape and functionality. Indeed, the high cost of zeolite membranes can be reduced by fabricating thin membranes with high throughput. High aspect ratio zeolite nanosheets can be used to fabricate zeolite membranes with high throughput on porous supports. To date, however, there is no published evidence that scientists have successfully achieved nanosheet synthesis under the direct hydrothermal treatment route. This dissertation documents a successful direct hydrothermal synthesis of zeolite nanosheets via seeded-growth—a process that leads to zeolite membranes that exhibit high performance on xylene isomer and butane isomer permeation. To the best knowledge, this is the first achievement to prepare zeolite nanosheets without complicated post treatment such as exfoliation and purification process (density gradient centrifugation). Extensive parametric studies are conducted in order to establish the optimal synthesis condition for high quality zeolite nanosheets. Additionally, in an effort to understand the mechanism of nanosheet formation, the sequential evolution of seed crystals into zeolite nanosheets is observed by time-resolved TEM imaging analysis. Keeping in mind that in the future polymers could be used to reduce the costs of membrane manufacture, the de-templation of MFI nanosheets without formation of aggregates is discussed in this dissertation. In addition to membrane applications, this dissertation probes the roles of hydrophobicity in ethanol adsorption when hydrophobic siliceous zeolites, and defective siliceous zeolite nanosheets with house-of-card architecture are provided as adsorbents. Vapor phase ethanol adsorption and aqueous phase ethanol adsorption are compared to investigate how water molecules affect ethanol adsorption onto siliceous zeolites in the aqueous phase
Genotypic Characterization of Vibrio vulnificus Clinical Isolates in Korea
AbstractObjectivesVibrio vunificus is known to cause septicemia and severe wound infections in patients with chronic liver diseases or an immuno-compromised condition. We carried out the molecular characterization of V. vulnificus isolates from human Vibrio septicemia cases based on pulsed-field gel electrophoresis (PFGE) using NotI and SfiI.Methods and ResultsPFGE was used to characterize a total of 78 strains from clinical cases after NotI or SfiI digestion. The geographical distribution of PFGE patterns for the strains from the southern part of Korea, a high-risk region for Vibrio septicemia, indicated that the isolates from southeastern Korea showed a comparatively higher degree of homology than those from southwestern Korea.ConclusionsWe report the genetic distribution of V. vulnficus isolated from Vibrio septicemia cases during 2000–2004 in Korea. This method has potential use as a subspecies-typing tool for V. vulnificus strains isolated from distant geographic regions
Revised Subjects of the Current Korean Oriental Pharmacists' Licensing Examination
This study is designed to draw out new integrated subjects of the Korean Oriental Pharmacists' Licensing Examination (KOPLE). In 2004, for the revision of subjects, we have analyzed the curriculums of the Oriental Pharmacy department, the oriental pharmacist's (OP's) job description book, and the elementary items of KOPLE. We also examined the system of the Chinese Herb Pharmacists' Examination and other health personnel licensing examinations and studied the data of items and compared them with KOPLE. We heard the public opinion on the present KOPLE. We developed a subfield of 18 subjects, a middle category of 188 items, and a small category of 1,026 items. We proposed a new KOPLE that consists of three subjects: basic oriental pharmacy, applied oriental pharmacy, and laws and regulations
Comparison of volume-controlled and pressure-controlled ventilation using a laryngeal mask airway during gynecological laparoscopy
Background: Several publications have reported the successful, safe use of Laryngeal Mask Airway (LMA)-Classic devices in patients undergoing laparoscopic surgery. However, there have been no studies that have examined the application of volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) using a LMA during gynecological laparoscopy. The aim of this study is to compare how the VCV and PCV modes and using a LMA affect the pulmonary mechanics, the gas exchange and the cardiovascular responses in patients who are undergoing gynecological laparoscopy. Methods: Sixty female patients were randomly allocated to one of two groups, (the VCV or PCV groups). In the VCV group, baseline ventilation of the lung was performed with volume-controlled ventilation and a tidal volume of 10 ml/kg ideal body weight (IBW). In the PCV group, baseline ventilation of the lung using pressure-controlled ventilation was initiated with a peak airway pressure that provided a tidal volume of 10 ml/kg IBW and an upper limit of 35 cmH2O. The end-tidal CO2, the peak airway pressures (Ppeak), the compliance, the airway resistance and the arterial oxygen saturation were recorded at T1: 5 minutes after insertion of the laryngeal airway, and at T2 and T3: 5 and 15 minutes, respectively, after CO2 insufflation. Results: The Ppeak at 5 minutes and 15 minutes after CO2 insufflation were significantly increased compared to the baseline values in both groups. Also, at 5 minutes and 15 minutes after CO2 insufflation, there were significant differences of the Ppeak between the two groups. The compliance decreased in both groups after creating the pneumopertoneim (P < 0.05). Conclusions: Our results demonstrate that PCV may be an effective method of ventilation during gynecological laparoscopy, and it ensures oxygenation while minimizing the increases of the peak airway pressure after CO2 insufflation. ��� the Korean Society of Anesthesiologists, 2011
Development of a high yield purification process for the production of influenza virus vaccines
Production of influenza virus in animal cells has emerged as an alternative to conventional platforms such as egg-based production system. Animal cells, especially MDCK and VERO cell lines, are widely used as the primary production cell for influenza virus vaccine because of their high susceptibility to infection with various influenza viruses. Recently, a robust and reliable purification process was successfully developed for the production of quadri-valent HA proteins (from two strains of the type A virus and two strains of the type B virus) by using animal cell-based production system in Green Cross Corp., Korea. The UF/DF process, Benzonase treatment at high temperature as well as column chromatography strategy was optimized to maximize the final HA production yields. Benzonase treatment was conducted to reduce in hcDNA (host cell DNA) because hcDNA was main impurity for cell-based influenza virus vaccine. A simple and stable UF/DF process has been tested with membrane molecular weight cutoffs of 100 and 300 kDa as well as 0.2 and 0.45 um microfiltration membrane. Anion exchange chromatography (AEC) and size exclusion chromatography (SEC) were selected for acceptable reduction in hcDNA and HCP. AEC was used to separate hcDNA from virus at a salt concentration of 0.5 M sodium chloride. The HA yield through AEC & SEC combination process was sufficiently achieved under specific purification process condition. Overall, the amount of residual hcDNA was reduced to an acceptable level (10ng/dose) and the increased HA yield was maintained throughout the whole process. The performance, productivity and scalability of the purification process were successfully demonstrated in over 30 GMP batches using 4 different influenza virus strains
Copy number variation at leptin receptor gene locus associated with metabolic traits and the risk of type 2 diabetes mellitus
<p>Abstract</p> <p>Background</p> <p>Recent efforts have been made to link complex human traits and disease susceptibility to DNA copy numbers. The leptin receptor (LEPR) has been implicated in obesity and diabetes. Mutations and genetic variations of <it>LEPR </it>gene have been discovered in rodents and humans. However, the association of DNA copy number variations at the <it>LEPR </it>gene locus with human complex diseases has not been reported. In an attempt to study DNA copy number variations associated with metabolic traits and type 2 diabetes mellitus (T2DM), we targeted the <it>LEPR </it>gene locus in DNA copy number analyses.</p> <p>Results</p> <p>We identified DNA copy number variations at the <it>LEPR </it>gene locus among a Korean population using genome-wide SNP chip data, and then quantified copy numbers of the E2 DNA sequence in the first two exons overlapped between <it>LEPR </it>and <it>LEPROT </it>genes by the quantitative multiplex PCR of short fluorescent fragment (QMPSF) method. Among the non-diabetic subjects (n = 1,067), lower E2 DNA copy numbers were associated with higher fasting glucose levels in men (<it>p </it>= 1.24 × 10<sup>-7</sup>) and women (<it>p </it>= 9.45 × 10<sup>-5</sup>), as well as higher total cholesterol levels in men (<it>p </it>= 9.96 × 10<sup>-7</sup>). In addition, the significant association between lower E2 DNA copy numbers and lower level of postprandial 2hr insulin was evident only in non-diabetic women, whereas some obesity-related phenotypes and total cholesterol level exhibited significant associations only in non-diabetic men. Logistic regression analysis indicated that lower E2 DNA copy numbers were associated with T2DM (odds ratio, 1.92; 95% CI, 1.26~2.96; p < 0.003) in our nested case-control study. Interestingly, the E2 DNA copy number exhibited a negative correlation with LEPR gene expression, but a positive correlation with LEPROT gene expression.</p> <p>Conclusions</p> <p>This work suggests that a structural variation at the <it>LEPR </it>gene locus is functionally associated with complex metabolic traits and the risk of T2DM.</p
Elimination of Chrysanthemum stunt viroid (CSVd) from an Viroid infected Chrysanthemum through Shoot Tip Culture
As the increase of chrysanthemum demand on chrysanthemum increases in Korea, the production of high quality chrysanthemum is needed. Chrysanthemum stunt viroid (CSVd) is one of the important viroid, which infects chrysanthemum and induces diseases that affects the decrease of quality and yield. To solve this problem, we used different size of meristem of chrysanthemum ‘Ency’ for shoot tip culture and also that of combined with heat treatment at 37οC. The efficiency of CSVd elimination was influenced by the size of shoot tip. The small-sized of meristems with 1 or 2 leaf primodia were regenerated into the highest number of CSVd-free plantlets. By RT-PCR, the 214-bp band corresponding to CSVd was not detected in 22.2% of the total number of tested regenerants from shoot tips with 2 leaf primordia. While, shoot tip culture combined with heat treatment of one-month-old in vitro shoots was not effective for CSVd-elimination. The CSVd-free plants grew more vigorously than CSVd-infected plants in the greenhouse
High-fidelity 3D Human Digitization from Single 2K Resolution Images
High-quality 3D human body reconstruction requires high-fidelity and
large-scale training data and appropriate network design that effectively
exploits the high-resolution input images. To tackle these problems, we propose
a simple yet effective 3D human digitization method called 2K2K, which
constructs a large-scale 2K human dataset and infers 3D human models from 2K
resolution images. The proposed method separately recovers the global shape of
a human and its details. The low-resolution depth network predicts the global
structure from a low-resolution image, and the part-wise image-to-normal
network predicts the details of the 3D human body structure. The
high-resolution depth network merges the global 3D shape and the detailed
structures to infer the high-resolution front and back side depth maps.
Finally, an off-the-shelf mesh generator reconstructs the full 3D human model,
which are available at https://github.com/SangHunHan92/2K2K. In addition, we
also provide 2,050 3D human models, including texture maps, 3D joints, and SMPL
parameters for research purposes. In experiments, we demonstrate competitive
performance over the recent works on various datasets.Comment: code page : https://github.com/SangHunHan92/2K2K, Accepted to CVPR
2023 (Highlight
Intracoronary versus intravenous glycoprotein IIb/IIIa inhibitors during primary percutaneous coronary intervention in patients with STEMI: a systematic review and meta-analysis
Background Intracoronary (IC) administration of glycoprotein IIb/IIIa inhibitors (GPIs) has been studied as an
adjunctive therapy to improve outcomes in patients with ST-segment elevation myocardial infarction (STEMI)
undergoing percutaneous coronary intervention. In this systematic review and meta-analysis, we aimed to evaluate
the efficacy and safety of IC administration of GPIs compared with those of intravenous (IV) administration in patients
with STEMI.
Methods We searched the MEDLINE, Embase, and Cochrane CENTRAL databases for relevant studies published
before September 21, 2022. In total, 22 randomized controlled trials involving 7,699 patients were included.
Results The proportions of patients achieving thrombolysis in myocardial infarction grade 3 flow, myocardial blush
grade 2/3, and complete ST-segment resolution were significantly higher in the IC group than in the IV group.
Major adverse cardiac events (MACE) (RR: 0.54, 95% CI: 0.37–0.80) and heart failure (RR: 0.48, 95% CI: 0.25–0.91)
within 1 month were significantly lower in the IC group than in the IV group; however, after 6 months, no difference
was observed in MACE risk. Additionally, the risks of death and bleeding did not differ between the two routes of
administration.
Conclusions When considering adjunctive GPI administration for patients with STEMI, the IC route may offer greater
benefits than the IV route in terms of myocardial reperfusion and reduced occurrence of MACE and heart failure
within 1 month. Nonetheless, when making decisions for IC administration of GPIs, the absence of a benefit for
bleeding risk and difficulty accessing the administration route should be considere
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