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1.
Adv Mater ; 35(13): e2208423, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36600458

ABSTRACT

Understanding the local cation order in the crystal structure and its correlation with electrochemical performances has advanced the development of high-energy Mn-rich cathode materials for Li-ion batteries, notably Li- and Mn-rich layered cathodes (LMR, e.g., Li1.2 Ni0.13 Mn0.54 Co0.13 O2 ) that are considered as nanocomposite layered materials with C2/m Li2 MnO3 -type medium-range order (MRO). Moreover, the Li-transport rate in high-capacity Mn-based disordered rock-salt (DRX) cathodes (e.g., Li1.2 Mn0.4 Ti0.4 O2 ) is found to be influenced by the short-range order of cations, underlining the importance of engineering the local cation order in designing high-energy materials. Herein, the nanocomposite is revealed, with a heterogeneous nature (like MRO found in LMR) of ultrahigh-capacity partially ordered cathodes (e.g., Li1.68 Mn1.6 O3.7 F0.3 ) made of distinct domains of spinel-, DRX- and layered-like phases, contrary to conventional single-phase DRX cathodes. This multi-scale understanding of ordering informs engineering the nanocomposite material via Ti doping, altering the intra-particle characteristics to increase the content of the rock-salt phase and heterogeneity within a particle. This strategy markedly improves the reversibility of both Mn- and O-redox processes to enhance the cycling stability of the partially ordered DRX cathodes (nearly ≈30% improvement of capacity retention). This work sheds light on the importance of nanocomposite engineering to develop ultrahigh-performance, low-cost Li-ion cathode materials.

2.
Front Bioeng Biotechnol ; 10: 865545, 2022.
Article in English | MEDLINE | ID: mdl-35845393

ABSTRACT

The mammalian tissue extracellular matrix (ECM) has been used as a scaffold to facilitate the repair and reconstruction of numerous tissues. However, the material properties of decellularized ECM (dECM) from in vitro cell cultures and the effect of these properties on wound remodeling remain unclear. To elucidate its biological activity, we extracted dECM from human lung fibroblasts, fabricated it into a patch, and applied it to a full-thickness skin wound. The fibroblast-derived dECM (fdECM) maintained the content of collagen Ⅰ, collagen Ⅳ, and elastin, and the extraction process did not damage its critical growth factors. The fdECM-conjugated collagen patch (COL-fdECM) facilitated wound contraction and angiogenesis in the proliferative phase when applied to the in vivo full-thickness skin wound model. Moreover, the COL-fdECM treated wound showed increased regeneration of the epidermal barrier function, mature collagen, hair follicle, and subepidermal nerve plexus, suggesting qualitative skin remodeling. This therapeutic efficacy was similarly observed when applied to the diabetic ulcer model. fdECM was shown to help remodel the tissue by regulating fibroblast growth factors, matrix metalloproteinases, and tissue inhibitors of metalloproteinases via the p38 and ERK signaling pathways in an in vitro experiment for understanding the underlying mechanism. These results provide a biological basis for cell-derived ECM as a multi-functional biomaterial applicable to various diseases.

3.
Front Hum Neurosci ; 15: 647839, 2021.
Article in English | MEDLINE | ID: mdl-34349630

ABSTRACT

Brain-computer interfaces can provide a new communication channel and control functions to people with restricted movements. Recent studies have indicated the effectiveness of brain-computer interface (BCI) applications. Various types of applications have been introduced so far in this field, but the number of those available to the public is still insufficient. Thus, there is a need to expand the usability and accessibility of BCI applications. In this study, we introduce a BCI application for users to experience a virtual world tour. This software was built on three open-source environments and is publicly available through the GitHub repository. For a usability test, 10 healthy subjects participated in an electroencephalography (EEG) experiment and evaluated the system through a questionnaire. As a result, all the participants successfully played the BCI application with 96.6% accuracy with 20 blinks from two sessions and gave opinions on its usability (e.g., controllability, completeness, comfort, and enjoyment) through the questionnaire. We believe that this open-source BCI world tour system can be used in both research and entertainment settings and hopefully contribute to open science in the BCI field.

5.
Yeungnam Univ J Med ; 38(1): 10-18, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32764213

ABSTRACT

Endometriosis is a chronic disease associated with pelvic pain and infertility. Several classification systems for the severity of endometriosis have been proposed. Of these, the revised American Society for Reproductive Medicine classification is the most well-known. The ENZIAN classification was developed to classify deep infiltrating endometriosis and focused on the retroperitoneal structures. The endometriosis fertility index was developed to predict the fertility outcomes in patients who underwent surgery for endometriosis. Finally, the American Association of Gynecological Laparoscopists classification is currently being developed, for which 30 endometriosis experts are analyzing and researching data by assigning scores to categories considered important; however, it has not yet been fully validated and published. Currently, none of the classification systems are considered the gold standard. In this article, we review the classification systems, identify their pros and cons, and discuss what improvements need to be made to each system in the future.

6.
Int J Clin Exp Pathol ; 13(7): 1750-1754, 2020.
Article in English | MEDLINE | ID: mdl-32782700

ABSTRACT

Malignant transformation is a rare complication of the mature cystic teratoma of the ovary. Most of these histologic types are squamous cell carcinoma, and other types are exceptionally rare. Here, we present an extremely rare histology of malignant transformation, an undifferentiated carcinoma, arising in mature cystic teratoma of the ovary. A 48-year-old woman was referred due to abdominal distension and palpable pelvic mass. Computed tomography showed 16- and 12-cm-diameter mixed solid and cystic tumors in bilateral ovaries. Surgical exploration revealed bilateral ovarian tumors with multiple nodules on the whole peritoneum, liver capsule, and diaphragm. Cytoreductive surgery was performed, leaving <1 cm tumors. On pathologic review, the tumor was confirmed as undifferentiated with an adenosquamous carcinoma component arising in mature cystic teratoma. The patient died 7 days postoperatively due to uncontrolled malignant ascites and pleural effusion. We report a case of undifferentiated carcinoma arising from mature cystic teratoma, and we review the clinicopathologic features of this rare case.

7.
Yeungnam Univ J Med ; 37(4): 308-313, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32326683

ABSTRACT

BACKGROUND: Hysterectomy is one of the major gynecologic surgeries. Historically, several surgical procedures have been used for hysterectomy. The present study aims to evaluate the surgical trends and clinical outcomes of hysterectomy performed for benign diseases at the Yeungnam University Hospital. METHODS: We retrospectively reviewed patients who underwent a hysterectomy for benign diseases from 2013 to 2018. Data included the patients' demographic characteristics, surgical indications, hysterectomy procedures, postoperative pathologies, and perioperative outcomes. RESULTS: A total of 809 patients were included. The three major indications for hysterectomy were uterine leiomyoma, pelvic organ prolapse, and adenomyosis. The most common procedure was total laparoscopic hysterectomy (TLH, 45.2%), followed by open hysterectomy (32.6%). During the study period, the rate of open hysterectomy was nearly constant (29.4%-38.1%). The mean operative time was the shortest in the single-port laparoscopic assisted vaginal hysterectomy (LAVH, 89.5 minutes), followed by vaginal hysterectomy (VH, 96.8 minutes) and TLH (105 minutes). The mean decrease in postoperative hemoglobin level was minimum in single-port LAVH (1.8 g/dL) and VH (1.8 g/dL). Conversion to open surgery or multi-port surgery occurred in five cases (0.6%). Surgical complications including wound dehiscence, organ injuries, and conditions requiring reoperation were observed in 52 cases (6.4%). CONCLUSION: Minimally invasive approach was used for most hysterectomies for benign diseases, but the rate of open hysterectomy has mostly remained constant. Single-port LAVH and VH showed the most tolerable outcomes in terms of operative time and postoperative drop in hemoglobin level in selected cases.

9.
Yeungnam Univ J Med ; 37(3): 179-185, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32131080

ABSTRACT

BACKGROUND: Approximately 100,000 women are diagnosed with cancer each year in Korea. According to a survey by the Korean central cancer registry in 2016, uterine cervical cancer, uterine corpus cancer, and ovarian cancer were the 5th, 7th, and 8th most prevalent cancers respectively among Korean women. The present study aims to review the clinico-pathologic characteristics of patients who were treated for major gynecological malignancies at Yeungnam University Medical Center. METHODS: Patients with invasive gynecological cancers from January 2012 to February 2019 were retrospectively identified. We analyzed the clinical features, demographic profiles, pathologic data, treatment modality used, adjuvant treatment used, complications, recurrence, and survival outcomes. RESULTS: A total of 287 patients (cervical cancer 115; corporal cancer 86; and ovarian, tubal, or primary peritoneal cancer 90) were included. Most cervical (82.7%) and corporal cancers (89.5%) were diagnosed in the early stages (stage I or II), while more than half (58.9%) the cases of ovarian, tubal or peritoneal cancers were diagnosed in the advanced stages (stage III or IV). Surgical complications were observed in 12.2% of cervical cancers, 16.3% of uterine corpus cancers, and 11.1% of ovarian, tubal, and peritoneal cancers, respectively. The 5-year overall survival rate was 94.1%, 91.0%, and 77.1% for cervical, corporal, and ovarian, tubal, or peritoneal cancers, respectively. CONCLUSION: Surgical treatment was satisfactory in terms of the incidence of complications, and survival outcomes were generally good. Clinicians should be aware of the clinical and histopathological characteristics of patients with gynecological cancers to be able to provide optimal strategies and counseling.

11.
PLoS One ; 13(12): e0208492, 2018.
Article in English | MEDLINE | ID: mdl-30533016

ABSTRACT

INTRODUCTION: The prognostic relevance of gender is undetermined in patients with small-cell lung cancer (SCLC). Therefore, we investigated whether gender is a prognostic factor in a SCLC cohort after controlling for confounding factors. MATERIALS AND METHODS: Fifteen prognostic factors were classified into four groups (patient, stage migration, tumor, and treatment). The prognostic relevance of gender was evaluated using propensity score matching, Cox proportional hazards regression, and stepwise fashion adjustments. RESULTS: Of 591 patients with SCLC, 88 were women (14.9%). Women were more likely than men to have no history of smoking (48.9% vs. 2.0%, P < 0.001) and limited disease (48.9% vs. 37.8%, P = 0.050). Women had less progressive disease in M stage than men (52.3% vs. 62.8%, P = 0.031). Women had better survival than men in the entire cohort (median survival times [MSTs] and 95% confidence intervals [CIs]: 9.7 months and 7.8-11.6 for women, 8.0 months and 7.0-8.9 for men, log-rank P = 0.034) and in the matched cohort (MSTs and 95% CIs: 8.8 months and 5.8-11.8 for women, 5.9 months and 4.5-7.4 for men, log-rank P = 0.013). Female gender was a prognostic factor predicting better survival, even after stepwise and full adjustment with all prognostic variables (adjusted hazard ratios and 95% CIs: 0.51 and 0.34-0.77, P = 0.001 for entire cohort, 0.42 and 0.24-0.75, P = 0.003 for matched cohort). CONCLUSIONS: Our results confirmed that gender is an independent prognostic factor in patients with SCLC.


Subject(s)
Lung Neoplasms/diagnosis , Lung Neoplasms/epidemiology , Small Cell Lung Carcinoma/diagnosis , Small Cell Lung Carcinoma/epidemiology , Adult , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , Lung Neoplasms/etiology , Lung Neoplasms/mortality , Male , Middle Aged , Prognosis , Propensity Score , Risk Factors , Sex Factors , Small Cell Lung Carcinoma/etiology , Small Cell Lung Carcinoma/mortality , Survival Analysis
12.
Digestion ; 92(4): 220-6, 2015.
Article in English | MEDLINE | ID: mdl-26488160

ABSTRACT

BACKGROUND/AIMS: This study investigated the safety of endoscopic variceal ligation (EVL) under conscious sedation with midazolam and sequential flumazenil after procedure in these patients. METHODS: A total of 279 patients who underwent secondary prophylactic EVL at our institution between April 2012 and June 2014, were enrolled. Conscious sedation was achieved using intravenous midazolam, and flumazenil was routinely used as an antidote immediately after EVL. Patients with sleep (n = 165) and non-sleep (n = 55) endoscopy were matched using propensity score analysis (3:1). Frequencies of overt hepatic encephalopathy (HEP) and patient' satisfactions with EVL were compared between the 2 groups. RESULTS: Of the 279 patients, 155 (55.6%) were of Child-Turcotte-Pugh (CTP) class, B or C, and 224 (80.3%) patients underwent sleep endoscopy. After propensity score analysis, overt HEP was observed in 1 (0.4%) of the 165 patients in the sedated group, but not found in any in the non-sedated group. Patient' satisfaction with EVL was better in the sedated group (p < 0.001). Twenty-nine (65.9%) of the 44 patients with CTP class C underwent sleep endoscopy, and only one (3.4%) experienced overt HEP. CONCLUSIONS: Prophylactic EVL under conscious sedation using midazolam and flumazenil is probably safe in cirrhotic patients without experience of HEP, even in those of CTP class C.


Subject(s)
Antidotes/administration & dosage , Conscious Sedation , Esophagoscopy/methods , Flumazenil/administration & dosage , Hypnotics and Sedatives , Midazolam , Prophylactic Surgical Procedures/methods , Adult , Aged , Aged, 80 and over , Esophageal and Gastric Varices/surgery , Esophagoscopy/psychology , Female , Gastrointestinal Hemorrhage/prevention & control , Humans , Ligation , Liver Cirrhosis/complications , Male , Middle Aged , Patient Satisfaction , Prophylactic Surgical Procedures/psychology
13.
Am J Infect Control ; 43(5): e13-7, 2015 May 01.
Article in English | MEDLINE | ID: mdl-25726130

ABSTRACT

BACKGROUND: Medical devices inserted into the human body can be divided into single-use devices and reusable medical devices (RMDs) depending on the method of use. RMDs are applied to >1 patient, and users reprocess them prior to repeat use. Therefore, reprocessing of RMDs has become more difficult, and issues related to infection risk have become more prevalent. METHODS: Research was performed to compare differences in surface alterations between not-aged (NA) samples and accelerated-aging (AA) samples. NA and AA samples were exposed to potential contaminants and treated with the same cleaning conditions. Then the residual contaminants were analyzed, and adhesion characteristics were investigated. RESULTS: Significant differences between the 2 sample groups were observed in the pattern of physical surface alterations. Similar to the endoscope for clinical use, a deep crack was found in the surface of the AA sample. According to the binding affinity test, highly likely potential contaminants were found more frequently on AA samples. CONCLUSION: The results suggest the necessity of limiting the duration of time that RMDs may be used, considering the potential risk of infection from repetitive use of RMDs, and also raised the possibility of applying this simulation model of AA. This methodology can be applied to various RMDs, including endoscopes.


Subject(s)
Bacterial Load , Disinfection/methods , Endoscopes/microbiology , Equipment Reuse , Escherichia coli/isolation & purification , Mycobacterium/isolation & purification , Pseudomonas aeruginosa/isolation & purification , Humans
14.
Biomed Mater ; 9(2): 025002, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24487019

ABSTRACT

Many types of hemostatic agents have been studied for the effective control of bleeding. In this study, a powdery medical adhesive composed of aldehyded dextran and ε-poly (L-lysine) was used with the recombinant batroxobin. Batroxobin is a venomous component from the snake Bothrops atrox moojeni and catalyzes fibrinogen conversion to form soluble fibrin clots. This research aims to examine the performance of the batroxobin-containing adhesive for hemostasis, and evaluate its potential as a novel hemostatic adhesive. The fibrinogen conversion ability of batroxobin was evaluated by a fibrinogen clotting assay and a whole blood clotting assay. Both experiments demonstrated the effectiveness of the batroxobin-containing adhesive for blood clot formation. Animal experiments were also conducted. After a pricking wound was made in an ICR (imprinting control region) mouse liver, the adhesive and various concentrations of batroxobin were applied. The total amount of blood loss was reduced with increasing concentrations of batroxobin. For excessive bleeding conditions, the femoral artery wound model of SD (Sprague-Dawley) rats was adopted. With higher concentrations of batroxobin, hemostasis was more rapidly achieved. Histological analysis of the liver model also supports the hemostatic effects through fibrin clot formation. In conclusion, batroxobin and medical adhesive effectively facilitate blood coagulation, and could be developed for clinical use.


Subject(s)
Bandages , Batroxobin/administration & dosage , Blood Coagulation/drug effects , Hemorrhage/drug therapy , Hemostatics/administration & dosage , Adhesives , Aldehydes , Animals , Bothrops , Dextrans/chemistry , Femoral Artery/pathology , Fibrin/chemistry , Fibrinogen/chemistry , Hemostasis , Humans , Liver/metabolism , Male , Mice , Mice, Inbred ICR , Polylysine/chemistry , Rats , Rats, Sprague-Dawley , Recombinant Proteins/chemistry
15.
J Clin Neurol ; 8(3): 190-7, 2012 Sep.
Article in English | MEDLINE | ID: mdl-23091528

ABSTRACT

BACKGROUND AND PURPOSE: The objective of this study was to determine the benefits of cognitive training in patients with amnestic mild cognitive impairment (aMCI) and those with early Alzheimer's disease (AD). METHODS: Eleven patients with aMCI and nine with early AD (stage 4 on the Global Deterioration Scale) participated in this study. Six participants with aMCI and six with AD were allocated to the cognitive training group, while five participants with aMCI and three with AD were allocated to a wait-list control group. Multicomponent cognitive training was administered in 18 weekly, individual sessions. Outcome measures were undertaken at baseline, and at 2 weeks and 3 months of follow-up. RESULTS: In the trained MCI group, there were significant improvements in the delayed-recall scores on the Seoul Verbal Learning Test at both the 2-week and 3-month follow-ups compared with baseline (baseline, 1.6±1.5; 2 weeks, 4.4±1.5, p=0.04; 3 months, 4.6±2.3, p=0.04). The phonemic fluency scores (1.0±0.8 vs. 5.0±1.8, p=0.07) and Korean Mini-Mental State Examination scores (18.8±0.5 vs. 23.8±2.2, p=0.07) also showed a tendency toward improvement at the 2-week follow-up compared to baseline in the trained AD group. CONCLUSIONS: This study provides evidence of the effectiveness of cognitive training in aMCI and early AD. The efficacy of cognitive training programs remains to be verified in studies with larger samples and a randomized design.

16.
Mycobiology ; 36(2): 102-5, 2008 Jun.
Article in English | MEDLINE | ID: mdl-23990742

ABSTRACT

The acetylcholinesterase (AChE) inhibitor of Yarrowia lipolytica S-3 was maximally produced when it was incubated at 30℃ for 36 h in an optimal medium containing 1% yeast extract, 2% peptone and 2% glucose, with an initial pH 6.0. The final AChE inhibitory activity under these conditions was an IC50 value of 64 mg/ml. After partial purification of the AChE inhibitor by means of systematic solvent extraction, the final IC50 value of the partially purified AChE inhibitor was 0.75 mg/ml. We prepared a test product by using the partially purified AChE inhibitor and then determined its stability for the development of a new antidementia commercial product. The test product was stable at room temperature for 15 weeks.

17.
Org Lett ; 9(14): 2749-51, 2007 Jul 05.
Article in English | MEDLINE | ID: mdl-17555326

ABSTRACT

CuH-catalyzed enantioselective conjugate reduction of 3,3-diaryl-substituted acrylonitriles is described. A range of 3-aryl-3-pyridylacrylonitriles were reduced with high levels of enantioselectivity under optimal conditions employing a copper/Josiphos complex in the presence of polymethylhydrosiloxane (PMHS).


Subject(s)
Acrylonitrile/analogs & derivatives , Acrylonitrile/chemistry , Copper/chemistry , Catalysis , Chromatography, High Pressure Liquid , Indicators and Reagents , Ligands , Oxidation-Reduction , Siloxanes/chemistry , Stereoisomerism , Temperature
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