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1.
Viruses ; 16(3)2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38543842

ABSTRACT

Coxsackievirus A6 (CV-A6) has emerged as the predominant causative agent of hand, foot, and mouth disease (HFMD) in young children. Since the declaration of coronavirus disease 2019 (COVID-19) as a global pandemic, the incidence of infectious diseases, including HFMD, has decreased markedly. When social mitigation was relaxed during the COVID-19 pandemic in 2022, the re-emergence of HFMD was observed in Gwangju, South Korea, and seasonal characteristics of the disease appeared to have changed. To investigate the molecular characteristics of enterovirus (EV) associated with HFMD during 2022, 277 specimens were collected. Children aged younger than 5 years accounted for the majority of affected individuals. EV detection and genotyping were performed using real-time RT-PCR and nested RT-PCR followed by sequence analysis. The EV detection rate was found to be 82.3%, and the main genotype identified was CV-A6. Sixteen CV-A6 samples were selected for whole genome sequencing. According to phylogenetic analysis, all CV-A6 strains from this study belonged to the sub-genotype D3 clade based on VP1 sequences. Analysis of 3D polymerase phylogeny showed that only the recombinant RF-A group was identified. In conclusion, circulating EV types should be continuously monitored to understand pathogen emergence and evolution during the post-pandemic era.


Subject(s)
Enterovirus , Hand, Foot and Mouth Disease , Child , Humans , Child, Preschool , Hand, Foot and Mouth Disease/epidemiology , Phylogeny , Pandemics , Enterovirus/genetics , Antigens, Viral/genetics , Real-Time Polymerase Chain Reaction , Genotype , China/epidemiology
2.
Chem Soc Rev ; 52(18): 6379-6416, 2023 Sep 18.
Article in English | MEDLINE | ID: mdl-37667818

ABSTRACT

Hybrid composite materials combining metal-organic frameworks (MOFs) and polymers have emerged as a versatile platform for a broad range of applications. The crystalline, porous nature of MOFs and the flexibility and processability of polymers are synergistically integrated in MOF-polymer composite materials. Covalent bonds, which form between two distinct materials, have been extensively studied as a means of creating strong molecular connections to facilitate the dispersion of "hard" MOF particles in "soft" polymers. Numerous organic transformations have been applied to post-synthetically connect MOFs with polymeric species, resulting in a variety of covalently connected MOF-polymer systems with unique properties that are dependent on the characteristics of the MOFs, polymers, and connection modes. In this review, we provide a comprehensive overview of the development and strategies involved in preparing covalently connected MOFs and polymers, including recently developed MOF-covalent organic framework composites. The covalent bonds, grafting strategies, types of MOFs, and polymer backbones are summarized and categorized, along with their respective applications. We highlight how this knowledge can serve as a basis for preparing macromolecular composites with advanced functionality.

3.
Korean J Ophthalmol ; 37(5): 387-394, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37562441

ABSTRACT

PURPOSE: To evaluate the effect of the Active Sentry handpiece of the Centurion Vision System compared to the Centurion Ozil handpiece for phacoemulsification in cataract surgery. METHODS: A retrospective study was conducted on 281 patients (449 eyes) who underwent cataract surgery between August 2020 and June 2021. Preoperative measurements, intraoperative parameters, complication rate, and postoperative outcomes were compared between the Active Sentry handpiece and the Centurion Ozil handpiece groups. Additionally, the parameters were compared in different cataract severity groups and multiple predictive factors for the number of active surge mitigation (ASM) actuations were assessed with the Active Sentry handpiece. RESULTS: There were 198 eyes in the Active Sentry group and 251 eyes in the Centurion Ozil group. There were no statistically significant differences between the two groups, as the cumulative dissipated energy in the Active Sentry and Centurion Ozil groups were 8.32 ± 7.74 and 7.87 ± 9.25 µJ, respectively (p = 0.576). Total surgery time, ultrasound usage time, aspiration time, amount of fluid aspirated, postoperative corrected distant visual acuity, and postoperative decrease in corneal endothelial cell density were comparable between the two groups. The significant contributors to the number of ASM actuations were age, preoperative corrected distant visual acuity, axial length, and total ultrasound time. CONCLUSIONS: There was no clear advantage of the Active Sentry handpiece compared to the Centurion Ozil handpiece. ASM actuation increases with age, poor visual acuity before surgery, short axial length, and prolonged ultrasound usage time. It is expected that in more severe and high-risk cataract surgery, the Active Sentry handpiece functions more effectively, possibly affecting the safety and prognosis.

4.
J Vis Exp ; (196)2023 06 23.
Article in English | MEDLINE | ID: mdl-37427952

ABSTRACT

Metal-organic frameworks (MOFs) are a class of porous materials that are formed through coordination bonds between metal clusters and organic ligands. Given their coordinative nature, the organic ligands and strut framework can be readily removed from the MOF and/or exchanged with other coordinative molecules. By introducing target ligands to MOF-containing solutions, functionalized MOFs can be obtained with new chemical tags via a process called post-synthetic ligand exchange (PSE). PSE is a straightforward and practical approach that enables the preparation of a wide range of MOFs with new chemical tags via a solid-solution equilibrium process. Furthermore, PSE can be performed at room temperature, allowing the incorporation of thermally unstable ligands into MOFs. In this work, we demonstrate the practicality of PSE by using heterocyclic triazole- and tetrazole-containing ligands to functionalize a Zr-based MOF (UiO-66; UiO = University of Oslo). After digestion, the functionalized MOFs are characterized via various techniques, including powder X-ray diffraction and nuclear magnetic resonance spectroscopy.


Subject(s)
Metal-Organic Frameworks , Organometallic Compounds , Metal-Organic Frameworks/chemistry , Ligands , Organometallic Compounds/chemistry , Metals
6.
Materials (Basel) ; 15(16)2022 Aug 12.
Article in English | MEDLINE | ID: mdl-36013694

ABSTRACT

Since flexible devices are being used in various states of charge (SoCs), it is important to investigate SoCs that are durable against external mechanical deformations. In this study, the effects of a mechanical fatigue test under various initial SoCs of batteries were investigated. More specifically, ultrathin pouch-type Li-ion polymer batteries with different initial SoCs were subjected to repeated torsional stress and then galvanostatically cycled 200 times. The cycle performance of the cells after the mechanical test was compared to investigate the effect of the initial SoCs. Electrochemical impedance spectroscopy was employed to analyze the interfacial resistance changes of the anode and cathode in the cycled cells. When the initial SoC was at 70% before mechanical deformation, both electrodes well maintained their initial state during the mechanical fatigue test and the cell capacity was well retained during the cycling test. This indicates that the cells could well endure mechanical fatigue stress when both electrodes had moderate lithiation states. With initial SoCs at 0% and 100%, the batteries subjected to the mechanical test exhibited relatively drastic capacity fading. This indicates that the cells are vulnerable to mechanical fatigue stress when both electrodes have high lithiation states. Furthermore, it is noted that the stress accumulated inside the batteries caused by mechanical fatigue can act as an accelerated degradation factor during cycling.

7.
J Korean Med Sci ; 37(24): e196, 2022 Jun 20.
Article in English | MEDLINE | ID: mdl-35726147

ABSTRACT

BACKGROUND: Acinetobacter baumannii infections cause high morbidity and mortality in intensive care unit (ICU) patients. However, there are limited data on the changes of long-term epidemiology of imipenem resistance in A. baumannii bacteremia among pediatric ICU (PICU) patients. METHODS: A retrospective review was performed on patients with A. baumannii bacteremia in PICU of a tertiary teaching hospital from 2000 to 2016. Antimicrobial susceptibility tests, multilocus sequence typing (MLST), and polymerase chain reaction for antimicrobial resistance genes were performed for available isolates. RESULTS: A. baumannii bacteremia occurred in 27 patients; imipenem-sensitive A. baumannii (ISAB, n = 10, 37%) and imipenem-resistant A. baumannii (IRAB, n = 17, 63%). There was a clear shift in the antibiogram of A. baumannii during the study period. From 2000 to 2003, all isolates were ISAB (n = 6). From 2005 to 2008, both IRAB (n = 5) and ISAB (n = 4) were isolated. However, from 2009, all isolates were IRAB (n = 12). Ten isolates were available for additional test and confirmed as IRAB. MLST analysis showed that among 10 isolates, sequence type 138 was predominant (n = 7). All 10 isolates were positive for OXA-23-like and OXA-51-like carbapenemase. Of 27 bacteremia patients, 11 were male (41%), the median age at bacteremia onset was 5.2 years (range, 0-18.6 years). In 33% (9/27) of patients, A. baumannii was isolated from tracheal aspirate prior to development of bacteremia (median, 8 days; range, 5-124 days). The overall case-fatality rate was 63% (17/27) within 28 days. There was no statistical difference in the case fatality rate between ISAB and IRAB groups (50% vs. 71%; P = 0.422). CONCLUSION: IRAB bacteremia causes serious threat in patients in PICU. Proactive infection control measures and antimicrobial stewardship are crucial for managing IRAB infection in PICU.


Subject(s)
Acinetobacter Infections , Acinetobacter baumannii , Bacteremia , Cross Infection , Acinetobacter Infections/drug therapy , Acinetobacter Infections/epidemiology , Acinetobacter baumannii/genetics , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacteremia/drug therapy , Bacteremia/epidemiology , Child , Cross Infection/drug therapy , Cross Infection/epidemiology , Female , Humans , Imipenem/pharmacology , Imipenem/therapeutic use , Intensive Care Units, Pediatric , Male , Microbial Sensitivity Tests , Multilocus Sequence Typing , beta-Lactamases
8.
Chem Commun (Camb) ; 58(40): 5948-5951, 2022 May 17.
Article in English | MEDLINE | ID: mdl-35415736

ABSTRACT

A covalent connection between two orthogonal functional groups (-NH2 and -OH) in metal-organic frameworks (MOFs) has been developed. This post-synthetic ligand cyclization (PSLC) was successfully demonstrated to synthesize a benzoxazole-functionalized MOF from a Zr-based UiO-66-2,3-(NH2)(OH) under microwave irradiation. In contrast, the regioisomeric UiO-66-2,5-(NH2)(OH) only produces a non-cyclized formamide-functionalized MOF.

9.
Adv Mater ; 33(20): e2007412, 2021 May.
Article in English | MEDLINE | ID: mdl-33821527

ABSTRACT

Kinetic-quantum-sieving-assisted H2 :D2 separation in flexible porous materials is more effective than the currently used energy-intensive cryogenic distillation and girdle-sulfide processes for isotope separation. It is believed that material flexibility results in a pore-breathing phenomenon under the influence of external stimuli, which helps in adjusting the pore size and gives rise to the optimum quantum-sieving phenomenon at each stage of gas separation. However, only a few studies have investigated kinetic-quantum-sieving-assisted isotope separation using flexible porous materials. In addition, no reports are available on the microscopic observation of isotopic molecular transportation during the separation process under dynamic transition. Here, the experimental observation of a significantly faster diffusion of deuterium than hydrogen in a flexible pore structure, even at high temperatures, through quasi-elastic neutron scattering, is reported. Unlike rigid structures, the extracted diffusion dynamics of hydrogen isotopes within flexible frameworks show that the diffusion difference between the isotopes increases with an increase in temperature. Owing to this unique inverse trend, a new strategy is suggested for achieving higher operating temperatures for efficient isotope separation utilizing a flexible metal-organic framework system.

10.
J Am Chem Soc ; 143(10): 3703-3706, 2021 Mar 17.
Article in English | MEDLINE | ID: mdl-33683860

ABSTRACT

Controlling the alignment of metal-organic framework (MOF) particles is valueable for fully exploiting the anisotropic properties and porous structure of these materials. Herein, we propose a simple, one-step method that can control the two-dimensional (2D) alignment of MOF particles over large areas. Orientational control is achieved without consideration of the underlying lattice parameters or the need for particle surface modification, but instead was achieved by selection of the casting solvent on a water surface. Two distinct types of MOF particles, a hexagonal bifrustum morphology of MIL-96 and an octahedral morphology of the UiO-66 family were aligned and captured in a polydimethylsiloxane (PDMS) matrix using this approach. This work provides opportunities for studying and utilizing the anisotropic properties of MOFs in thin film applications.

11.
J Am Chem Soc ; 142(31): 13278-13282, 2020 Aug 05.
Article in English | MEDLINE | ID: mdl-32649827

ABSTRACT

An isotope-selective responsive system based on molecular recognition in porous materials has potential for the storage and purification of isotopic mixtures but is considered unachievable because of the almost identical physicochemical properties of the isotopes. Herein, a unique isotope-responsive breathing transition of the flexible metal-organic framework (MOF), MIL-53(Al), which can selectively recognize and respond to only D2 molecules through a secondary breathing transition, is reported. This novel phenomenon is examined using in situ neutron diffraction experiments under the same conditions for H2 and D2 sorption experiments. This work can guide the development of a novel isotope-selective recognition system and provide opportunities to fabricate flexible MOF systems for energy-efficient purification of the isotopic mixture.

12.
Nat Commun ; 10(1): 3620, 2019 Aug 09.
Article in English | MEDLINE | ID: mdl-31399593

ABSTRACT

Composite metal-organic frameworks (MOFs) tend to possess complex interfaces that prevent facile and rational design. Here we present a joint computational/experimental workflow that screens thousands of MOFs and identifies the optimal MOF pairs that can seamlessly connect to one another by taking advantage of the fact that the metal nodes of one MOF can form coordination bonds with the linkers of the second MOF. Six MOF pairs (HKUST-1@MOF-5, HKUST-1@IRMOF-18, UiO-67@HKUST-1, PCN-68@MOF-5, UiO-66@MIL-88B(Fe) and UiO-67@MIL-88C(Fe)) yielded from our theoretical predictions were successfully synthesized, leading to clean single crystalline MOF@MOF, demonstrating the power of our joint workflow. Our work can serve as a starting point to accelerate the discovery of novel MOF composites that can potentially be used for many different applications.

13.
Inorg Chem ; 58(14): 8895-8899, 2019 Jul 15.
Article in English | MEDLINE | ID: mdl-31184874

ABSTRACT

Most well-known metal-organic frameworks (MOFs) possessing the magnetic Ni2O2(CO2)2 chains, called Ni-MOF-74, have been investigated with regard to magnetic properties at open-metal sites. We present the modulation of their magnetic phase and metamagnetism via imidazole molecule coordination.

14.
ACS Appl Mater Interfaces ; 11(4): 4385-4392, 2019 Jan 30.
Article in English | MEDLINE | ID: mdl-30615414

ABSTRACT

We report a new class of metal-organic framework (MOF) inks with a water-repellent, photocurable fluoropolymer (PFPE) having up to 90 wt % MOF loading. These MOF inks are enabled to process various MOFs through spray coating, pen writing, stencil printing, and molding at room temperature. Upon UV curing, the hydrophobic PFPE matrix efficiently blocks water permeation but allows accessibility of chemicals into the MOF pores, thereby freeing the MOF to perform its unique function. Moreover, by introducing functional MOFs we successfully demonstrated a water-tolerant chemosensor for a class of aromatic pollutants in water and a chemical-resistant thermosensor for visualizing temperature image. This approach would open up innumerable opportunities for those MOFs that are otherwise dormant.

15.
Autoimmun Rev ; 18(1): 1-8, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30408580

ABSTRACT

BACKGROUND: Adrenal insufficiency (AI) is associated with high morbidity and mortality. The aim of this systematic review was to enhance diagnostic approaches and summarize therapeutic strategies in the management of AI in patients with systematic lupus erythematosus (SLE) or antiphospholipid syndrome (APS). METHODS: A literature search of PubMed and Medline databases was performed and 91 publications containing 105 cases were included for the final analysis. RESULTS: The following frequency of clinical signs and symptoms was noted: abdominal pain (39.04%) was the leading symptom, followed by fever (33.33%), vomiting (23.81%), and nausea (19.05%). APS was present in 73%, SLE in 17% of the patients, while 2% had a diagnosis of both, SLE and APS. ACTH stimulation test (ACTHst) was performed in 18% of cases and 76.6% of them were unresponsive towards stimulation. Variable treatment approaches were used: hydrocortisone was most commonly used (38.09%), followed by fludrocortisone (26.67%), prednisolone (20.00%) and volume replacement treatment (11.43%), respectively. CONCLUSIONS: This analysis highlights the importance of an early diagnosis and initiation of therapeutic management when AI is suspected. In line, signs and symptoms related to autoimmune diseases in patients with AI should be reviewed crtitically.


Subject(s)
Adrenal Insufficiency/etiology , Antiphospholipid Syndrome/complications , Lupus Erythematosus, Systemic/complications , Adolescent , Adrenal Insufficiency/mortality , Adrenal Insufficiency/pathology , Adult , Aged , Aged, 80 and over , Antiphospholipid Syndrome/immunology , Child , Female , Humans , Lupus Erythematosus, Systemic/immunology , Male , Middle Aged , Young Adult
16.
Adv Mater ; 31(20): e1805293, 2019 May.
Article in English | MEDLINE | ID: mdl-30589123

ABSTRACT

One of the greatest challenges of modern separation technology is separating isotope mixtures in high purity. The separation of hydrogen isotopes can create immense economic value by producing valuable deuterium (D) and tritium (T), which are irreplaceable for various industrial and scientific applications. However, current separation methods suffer from low separation efficiency owing to the similar chemical properties of isotopes; thus, high-purity isotopes are not easily achieved. Recently, nanoporous materials have been proposed as promising candidates and are supported by a newly proposed separation mechanism, i.e., quantum effects. Herein, the fundamentals of the quantum sieving effect of hydrogen isotopes in nanoporous materials are discussed, which are mainly kinetic quantum sieving and chemical-affinity quantum sieving, including the recent advances in the analytical techniques. As examples of nanoporous materials, carbons, zeolites, metal-organic frameworks, and covalent organic frameworks are addressed from computational and experimental standpoints. Understanding the quantum sieving effect in nanospaces and the tailoring of porous materials based on it will open up new opportunities to develop a highly efficient and advanced isotope separation systems.

17.
J Am Chem Soc ; 139(49): 17743-17746, 2017 12 13.
Article in English | MEDLINE | ID: mdl-29179549

ABSTRACT

Breathing of MIL-53(Al), a flexible metal-organic framework (MOF), leads to dynamic changes as narrow pore (np) transitions to large pore (lp). During the flexible and reversible transition, the pore apertures are continuously adjusted, thus providing the tremendous opportunity to separate mixtures of similar-sized and similar-shaped molecules that require precise pore tuning. Herein, for the first time, we report a strategy for effectively separating hydrogen isotopes through the dynamic pore change during the breathing of MIL-53(Al), a representative of flexible MOFs. The experiment shows that the selectivity for D2 over H2 is strongly related to the state of the pore structure of MIL-53(Al). The highest selectivity (SD2/H2 = 13.6 at 40 K) was obtained by optimizing the exposure temperature, pressure, and time to systematically tune the pore state of MIL-53(Al).

18.
J Am Chem Soc ; 139(42): 15135-15141, 2017 10 25.
Article in English | MEDLINE | ID: mdl-28942653

ABSTRACT

Deuterium plays a pivotal role in industrial and scientific research, and is irreplaceable for various applications such as isotope tracing, neutron moderation, and neutron scattering. In addition, deuterium is a key energy source for fusion reactions. Thus, the isolation of deuterium from a physico-chemically almost identical isotopic mixture is a seminal challenge in modern separation technology. However, current commercial approaches suffer from extremely low separation efficiency (i.e., cryogenic distillation, selectivity of 1.5 at 24 K), requiring a cost-effective and large-scale separation technique. Herein, we report a highly effective hydrogen isotope separation system based on metal-organic frameworks (MOFs) having the highest reported separation factor as high as ∼26 at 77 K by maximizing synergistic effects of the chemical affinity quantum sieving (CAQS) and kinetic quantum sieving (KQS). For this purpose, the MOF-74 system having high hydrogen adsorption enthalpies due to strong open metal sites is chosen for CAQS functionality, and imidazole molecules (IM) are employed to the system for enhancing the KQS effect. To the best of our knowledge, this work is not only the first attempt to implement two quantum sieving effects, KQS and CAQS, in one system, but also provides experimental validation of the utility of this system for practical industrial usage by isolating high-purity D2 through direct selective separation studies using 1:1 D2/H2 mixtures.

19.
Proteomics ; 14(20): 2307-18, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25047395

ABSTRACT

Necrotrophic fungal pathogen Cochliobolus miyabeanus causes brown spot disease in rice leaves upon infection, resulting in critical rice yield loss. To better understand the rice-C. miyabeanus interaction, we employed proteomic approaches to establish differential proteomes of total and secreted proteins from the inoculated leaves. The 2DE approach after PEG-fractionation of total proteins coupled with MS (MALDI-TOF/TOF and nESI-LC-MS/MS) analyses led to identification of 49 unique proteins out of 63 differential spots. SDS-PAGE in combination with nESI-LC-MS/MS shotgun approach was applied to identify secreted proteins in the leaf apoplast upon infection and resulted in cataloging of 501 unique proteins, of which 470 and 31 proteins were secreted from rice and C. miyabeanus, respectively. Proteins mapped onto metabolic pathways implied their reprogramming upon infection. The enzymes involved in Calvin cycle and glycolysis decreased in their protein abundance, whereas enzymes in the TCA cycle, amino acids, and ethylene biosynthesis increased. Differential proteomes also generated distribution of identified proteins in the intracellular and extracellular spaces, providing a better insight into defense responses of proteins in rice against C. miyabeanus. Established proteome of the rice-C. miyabeanus interaction serves not only as a good resource for the scientific community but also highlights its significance from biological aspects.


Subject(s)
Ascomycota/physiology , Host-Pathogen Interactions , Oryza/microbiology , Plant Diseases/microbiology , Plant Proteins/metabolism , Proteomics/methods , Electrophoresis, Gel, Two-Dimensional , Electrophoresis, Polyacrylamide Gel , Oryza/metabolism , Plant Proteins/analysis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
20.
Clin Exp Reprod Med ; 40(3): 135-40, 2013 Sep.
Article in English | MEDLINE | ID: mdl-24179872

ABSTRACT

OBJECTIVE: To evaluate correlations between serum anti-Müllerian hormone (AMH) levels, phenotypes of polycystic ovary syndrome (PCOS), obesity, and metabolic parameters in patients with PCOS. METHODS: A total of 175 patients with PCOS were diagnosed according to the Rotterdam Consensus were included. Exclusion criteria were age over 40, FSH>25 mIU/mL, and 17a-OHP>1.5 ng/mL. The Phenotypes of PCOS were divided into a severe form (oligo-anovulation, ANOV/hyperandrogenism/polycystic ovary morphology [PCOM]; n=59) and a mild form without HA (ANOV/PCOM, n=105). The serum AMH levels were classified into 3 groups (<5 vs. 5-10 vs. >10 ng/mL). Obesity was defined as body mass index (BMI) ≥25 kg/m(2) (n=34). RESULTS: The mean age was 25.9±5.7 year and mean AMH level was 10.1±5.4 ng/mL. The BMI (kg/m(2)) was higher in group 1 (24.2±6.3) than in group 2 (21.9±4.3, p=0.046) or group 3 (21.6±3.3, p=0.019). There was no difference among the three groups in age, menstrual interval, antral follicle counts, androgens, or other metabolic parameters. The obesity group showed significantly lower AMH (7.7±3.9 ng/mL vs. 10.7±5.6 ng/mL), p=0.004) and low-density lipoprotein levels (93.1±21.2 mg/dL vs. 107.5±39.3 mg/dL, p=0.031), and showed higher total T (0.74±0.59 ng/mL vs. 0.47±0.36 ng/mL, p=0.001), free T (2.01±1.9 vs. 1.04±0.8 pg/mL, p=0.0001), and free androgen index (6.2±7.9 vs. 3.5±3.0, p=0.003). After controlling for age factors and BMI, the serum AMH levles did not show any significant correlations with other hormonal or metabolic parmeters. CONCLUSION: For PCOS patients under the age 40, serum AMH is not negatively correlated with age. High serum AMH levels can not predict the phenotype of PCOS and metabolic disturbances in PCOS patients in the non-obese group. Further study might be needed to define the relation more clearly.

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