Large-Scale Computational Screening-Aided Development of High-Performance Adsorbent for Simultaneous Capture of Aromatic Volatile Organic Compounds.

The development of an efficient adsorbent for the simultaneous capture of large amounts of benzene, toluene, ethylbenzene, and xylene isomers (BTEX) is an important and challenging issue. Here, through a stepwise screening of 10,142 metal-organic framework (MOF) structures from the computation-ready, experimental (CoRE) MOF database, 65 MOFs are proposed as promising adsorbent candidates for BTEX capture by considering the structures with accessible pore sizes for BTEX adsorption, sufficient hydrophobicity, high benzene selectivity (>0.2), and large total BTEX uptake (>3 mmol/g). Among the top-performing MOFs in terms of the BTEXmatrix (total BTEX uptake × benzene selectivity), EGUELUY01 was synthesized, and it exhibited large uptakes (≈5 mmol/g) for all BTEX components at concentrations of 1200-1500 ppm, which are superior to the BTEX uptake of the benchmark adsorbent, activated carbon. Moreover, some structure-property relationships required for BTEX adsorbents are provided through the obtained large-scale simulation data and machine learning analysis. The determined relationships will be useful for the future development of efficient BTEX adsorbents.

Evaluation of dental status using a questionnaire before administration of general anesthesia for the prevention of dental injuries.

Background: Dental evaluation and protection are important for preventing traumatic dental injuries when patients are under general anesthesia. The objective of the present study was to develop a questionnaire based on dentition-related risk factors that could serve as a valuable tool for dental evaluation and documentation. Methods: We developed a questionnaire for dental evaluation before administration of general anesthesia, investigated the association between patient-and-dentist responses and mouthguard fabrication, and assessed response agreement between 100 patients. Results: Protective mouthguards were fabricated for 27 patients who were identified as having a high risk of dental injury. There was a strong association between dentists' responses and mouthguard fabrication, depending on the general oral health status, use of ceramic prosthesis, presence of masticatory pain related to periodontal diseases, gingival edema, and implants (P < 0.05). Response agreement between patients and dentists for items related to dental pain, loss of dental pulp vitality, root canal therapy, dental trauma, aesthetic prosthesis, tooth mobility, and implant prosthesis was high (Cohen's kappa coefficient κ ≥ 0.6). Conclusions: A high agreement was observed between patient-dentist responses and a strong association with mouthguard fabrication for items pertaining to ceramic prosthesis, masticatory pain, and dental implants. Patients with a "yes" response to these items are recommended to undergo a dental evaluation and use a dental protective device while under general anesthesia.

Discovery of High-Performing Metal-Organic Frameworks for On-Board Methane Storage and Delivery via LNG-ANG Coupling: High-Throughput Screening, Machine Learning, and Experimental Validation.

Liquefied natural gas (LNG) gasification coupled with adsorbed natural gas (ANG) charging (LNG-ANG coupling) is an emerging strategy for efficient delivery of natural gas. However, the potential of LNG-ANG to attain the advanced research projects agency-energy (ARPA-E) target for onboard methane storage has not been fully investigated. In this work, large-scale computational screening is performed for 5446 metal-organic frameworks (MOFs), and over 193 MOFs whose methane working capacities exceed the target (315 cm3 (STP) cm-3 ) are identified. Furthermore, structure-performance relationships are realized under the LNG-ANG condition using a machine learning method. Additional molecular dynamics simulations are conducted to investigate the effects of the structural changes during temperature and pressure swings, further narrowing down the materials, and two synthetic targets are identified. The synthesized DUT-23(Cu) and DUT-23(Co) show higher working capacities (≈373 cm3 (STP) cm-3 ) than that of any other porous material under ANG or LNG-ANG conditions, and excellent stability during cyclic LNG-ANG operation.

Novel benzylphosphate-based covalent porous organic polymers for the effective capture of rare earth elements from aqueous solutions.

It has been a major challenge to develop stable and cost-effective porous materials that efficiently recover heavy rare earth elements (HREEs) due to ever-increasing demand, low availability and high cost of HREEs. This study presents two novel benzylphosphate-based covalent porous organic polymers (BPOP-1 and BPOP-2) that were prepared by facile one-pot Friedel-Crafts reactions. Various analytical techniques are used to investigate the successful syntheses of BPOP materials and establish their material properties, which include an unusual crystalline nature, large surface area, hierarchical pore structure, and superior chemical stabilities. The BPOPs effectively adsorb, and thus remove HREEs from aqueous media. In particular, BPOP-1 had higher phosphate content and exhibits superior adsorption capacities (Eu3+: 289.5; Gd3+: 292.7; Tb3+: 294.4; Dy3+: 301.9 mg/g) than BPOP-2, while BPOP-2 had higher mesoporosity and correspondingly supports faster adsorption kinetics. Remarkably, both BPOP materials exhibit some of the highest HREE adsorption capacities reported to date, the selective capture of Dy3+ ions, and excellent cyclic adsorption/desorption properties. We provide a potential adsorption mechanism for Dy3+ capture by the BPOP adsorbent. These demonstrate that introducing phosphate functionality into a robust porous polymer backbone with high surface area is a promising strategy for selective HREEs capture from wastewater.

Role of densin-180 in mouse ventral hippocampal neurons in 24-hr retention of contextual fear conditioning.

INTRODUCTION: Densin-180 interacts with postsynaptic molecules including calcium/calmodulin-dependent protein kinase IIα (CaMKIIα) but its function in learning and memory process has been unclear. METHODS: To investigate a role of hippocampal densin-180 in contextual fear conditioning (CFC) learning and memory processes, knockdown (KD) of densin-180 in hippocampal subareas was applied. RESULTS: First, ventral hippocampal (vHC) densin-180 KD impaired single-trial CFC (stCFC) memory one day later. stCFC caused freezing behaviors to reach the peak about one hour later in both control and KD mice, but then freezing was disappeared at 2 hr postshock in KD mice. Second, stCFC caused an immediate and transient reduction of vHC densin-180 in control mice, which was not observed in KD mice. Third, stCFC caused phosphorylated-T286 (p-T286) CaMKIIα to change similarly to densin-180, but p-T305 CaMKIIα was increased 1 hr later in control mice. In KD mice, these effects were gone. Moreover, both basal levels of p-T286 and p-T305 CaMKIIα were reduced without change in total CaMKIIα in KD mice. Fourth, we found double-trial CFC (dtCFC) memory acquisition and retrieval kinetics were different from those of stCFC in vHC KD mice. In addition, densin-180 in dorsal hippocampal area appeared to play its unique role during the very early retrieval period of both CFC memories. CONCLUSION: This study shows that vHC densin-180 is necessary for stCFC memory formation and retrieval and suggests that both densin-180 and p-T305 CaMKIIα at 1 ~ 2 hr postshock are important for stCFC memory formation. We conclude that roles of hippocampal neuronal densin-180 in CFC are temporally dynamic and differential depending on the pattern of conditioning stimuli and its location along the dorsoventral axis of hippocampal formation.

Bleeding related to dental treatment in patients taking novel oral anticoagulants (NOACs): a retrospective study.

OBJECTIVE: Several novel oral anticoagulants (NOACs) are currently prescribed for patients suffering from atrial fibrillation, pulmonary thromboembolism, and venous thrombosis. However, there is no clinical guideline for dental treatment in patients taking NOACs. This study investigated bleeding events related to various dental treatments. MATERIALS AND METHODS: This retrospective study included 120 patients (153 cases) who were prescribed NOACs and received dental procedures in the Department of Advanced General Dentistry at Yonsei University Dental Hospital from January 2014 to June 2017. The indication for NOACs, initiation of NOACs, duration of discontinuance, creatinine clearance, and type of dental treatment were investigated. Bleeding events were assessed at a follow-up visit to the clinic. RESULTS: Postoperative bleeding occurred in only 9 of the 153 included cases; they comprised 2 cases of scaling, 3 cases of simple extraction, 3 cases of the first stage of implant surgery, and 1 case of resin filling. The creatinine clearance (P = .111) and duration of discontinuance (P = .222) did not differ significantly between the groups with and without bleeding events. CONCLUSIONS: Our data indicate that most dental treatments may be performed in patients taking NOACs without an increased likelihood of bleeding events regardless of the discontinuance duration. Moreover, any postoperative bleeding can be stopped by applying compressive pressure or local hemostatic agents. CLINICAL RELEVANCE: Our study suggests that patients taking NOACs who need dental treatments may have a bleeding tendency based on our retrospective data. Preoperative history taking and treatment modification should therefore be considered before performing dental surgery.

The relationship between masseter muscle thickness measured by ultrasonography and facial profile in young Korean adults.

PURPOSE: The purpose of this study was to evaluate the relationship between masseter muscle thickness, facial morphology, and mandibular morphology in Korean adults using ultrasonography. MATERIALS AND METHODS: Ultrasonography was used to measure the masseter muscle thickness bilaterally of 40 adults (20 males, 20 females) and was performed in the relaxed and contracted states. Facial photos and panoramic radiography were used for morphological analyses and evaluated for correlations with masseter muscle thickness. We also evaluated the correlations of age, body weight, stature, and body constitution with masseter muscle thickness. RESULTS: In the relaxing, the masseter was 9.8±1.3 mm in females and 11.3±1.2 mm in males. In the contracted state, it was 12.4±1.4 mm in females and 14.7±1.4 mm in males. Facial photography showed that bizygomatic facial width over facial height was correlated with masseter muscle thickness in both sexes in the relaxed state, and was statistically significantly correlated with masseter muscle thickness in males in the contracted state. In panoramic radiography, correlations were found between anterior angle length and posterior angle length and masseter muscle thickness in females, and between body length and posterior angle length, between anterior angle length and body length, between ramal length and body length, and between body length and condyle length in males. CONCLUSION: Masseter muscle thickness was associated with facial and mandibular morphology in both sexes, and with age in males. Ultrasonography can be used effectively to measure masseter muscle thickness.

Observation of Olefin/Paraffin Selectivity in Azo Compound and Its Application into a Metal-Organic Framework.

Olefin/paraffin separation is an important and challenging issue because the two molecules have similar physicochemical properties. Although a couple of olefin adsorbents have been developed by introducing inorganic nanoparticles into metal-organic frameworks (MOFs), there has been no study on the development of an olefin adsorbent by introducing a certain organic functional group into a MOF. In this study, we posited that azo compounds could offer olefin/paraffin selectivity. We have revealed using first-principles calculations that the simplest aromatic azo compound (azobenzene, Azob) has an unusual propylene/propane selectivity due to special electrostatic interactions between Azob and propylene molecules. On the basis of this interesting discovery, we have synthesized a novel propylene adsorbent, MIL-101(Cr)_DAA, by grafting 4,4'-diaminoazobenzene (DAA) into open metal sites in a mesoporous MIL-101(Cr). Remarkably, MIL-101(Cr)_DAA exhibited enhanced propylene/propane selectivity as well as considerably higher propylene heat of adsorption compared to pristine MIL-101(Cr) while maintaining the high working capacity of MIL-101(Cr). This clearly indicates that azo compounds when introduced into MOFs can provide propylene selectivity. Moreover, MIL-101(Cr)_DAA showed good C3H6/C3H8 separation and easy regeneration performances from packed-bed breakthrough experiments and retained its propylene adsorption capacity even after exposure to air for 12 h. As far as we know, this is the first study that improves the olefin selectivity of MOF by postsynthetically introducing an organic functional group.

Synthesis of a Zr-Based Metal-Organic Framework with Spirobifluorenetetrabenzoic Acid for the Effective Removal of Nerve Agent Simulants.

A new microporous Zr(IV)-based metal-organic framework (MOF) containing 4,4',4″,4‴-(9,9'-spirobi[fluorene]-2,2',7,7'-tetrayl)tetrabenzoic acid (Spirof-MOF) was synthesized, characterized, and size-controlled for the adsorption and decomposition of a nerve agent simulant, dimethyl 4-nitrophenylphosphate (DMNP). Spirof-MOF showed a hydrolysis half-life (t1/2) of 7.5 min to DMNP, which was confirmed by using in situ 31P NMR spectroscopy. Additionally, size-controlled Spirof-MOFb (∼1 µm) exhibited a half-life of 1.8 min and 99% removal within 18 min for DMNP. The results show that Spirof-MOF is a new active material in removing nerve agent simulants by adsorption and hydrolytic decomposition.

Creating protective appliances for preventing dental injury during endotracheal intubation using intraoral scanning and 3D printing: a technical note.

Digital dentistry has influenced many dental procedures, such as three-dimensional (3D) diagnosis and treatment planning, surgical splints, and prosthetic treatments. Patient-specific protective appliances (PSPAs) prevent dental injury during endotracheal intubation. However, the required laboratory work takes time, and there is the possibility of tooth extraction while obtaining the dental impression. In this technical report, we utilized new digital technology for creating PSPAs, using direct intraoral scanners and 3D printers for dental cast fabrication.

Distribution of medical status and medications in elderly patients treated with dental implant surgery covered by national healthcare insurance in Korea.

BACKGROUND: The purpose of this study was to investigate the distribution of systemic diseases and medications in patients older than 65 years of age who visited the hospital for implant treatment, as well as to investigate basic information about surgical complications that may occur after insured implant treatment. METHODS: A total of 126 patients over 65 years of age were treated for implant surgery from October 1, 2013 to October 30, 2016. Electronic chart review was conducted to obtain medical records, which included sex, age, systemic diseases, medication(s) being taken, and control of the medications. Five patients were excluded due to lack of medical records giving information about systemic disease. RESULTS: Of the 126 patients, 112 (88.9%) were taking medication due to systemic disease and 9 patients (7.1%) were not. The sex distribution was 71 women and 55 men and the highest proportion of patients were between 65 and 69 years old. The most common diseases were, from most to least frequent, hypertension, cardiovascular disease, diabetes, and osteoporosis. The drug groups that can cause major complications after dental treatment were classified as hemorrhagic, osteoporotic, and immunosuppressive agents, and were taken by 45 (35.7%), 22 (17.5%) and 4 (3.2%) patients, respectively. CONCLUSION: Given that 88.9% of the elderly patients who were eligible for insurance implant treatment had systemic disease, it is necessary to carefully evaluate patients' medical histories and their general conditions in order to prevent emergencies during implant surgery.

Adsorptive separation of xenon/krypton mixtures using a zirconium-based metal-organic framework with high hydrothermal and radioactive stabilities.

The separation of xenon/krypton mixtures is important for both environmental and industrial purposes. The potential of three hydrothermally stable MOFs (MIL-100(Fe), MIL-101(Cr), and UiO-66(Zr)) for use in Xe/Kr separation has been experimentally investigated. From the observed single-component Xe and Kr isotherms, isosteric heat of adsorption (Qsto), and IAST-predicted Xe/Kr selectivities, we observed that UiO-66(Zr) has the most potential as an adsorbent among the three candidate MOFs. We performed dynamic breakthrough experiments with an adsorption bed filled with UiO-66(Zr) to evaluate further the potential of UiO-66(Zr) for Xe/Kr separation under mixture flow conditions. Remarkably, the experimental breakthrough curves show that UiO-66(Zr) can efficiently separate the Xe/Kr mixture. Furthermore, UiO-66(Zr) maintains most of its Xe and Kr uptake capacity, as well as its crystallinity and internal surface area, even after exposure to gamma radiation (2kGy) for 7h and aging for 16 months under ambient conditions. This result indicates that UiO-66(Zr) can be considered to be a potential adsorbent for Xe/Kr mixtures under both ambient and radioactive conditions.