Computed tomography (CT) and ultrasonography (US) are ideally suited for demonstrating urachal remnant diseases. A patent urachus is demonstrated at longitudinal US and occasionally at CT as a tubular connection between the anterosuperior aspect of the bladder and the umbilicus. An umbilical-urachal sinus manifests at US as a thickened tubular structure along the midline below the umbilicus. A vesicourachal diverticulum is usually discovered incidentally at axial CT, appearing as a midline cystic lesion just above the anterosuperior aspect of the bladder. At US, it manifests as an extraluminally protruding, fluid-filled sac that does not communicate with the umbilicus. Urachal cysts manifest at both modalities as a noncommunicating, fluid-filled cavity in the midline lower abdominal wall located just beneath the umbilicus or above the bladder. Both infected urachal cysts and urachal carcinomas commonly display increased echogenicity at US and thick-walled cystic or mixed attenuation at CT, making it difficult to differentiate between them. Percutaneous needle biopsy or fluid aspiration is usually needed for diagnosis and therapeutic planning. Nevertheless, CT and US can help identify most disease entities originating from the urachal remnant in the anterior abdominal wall. Understanding the anatomy and the imaging features of urachal remnant diseases is essential for correct diagnosis and proper management.

Cellulose, the chain of glucose residues easily obtained from nature, is the most common natural polymer. Owing to its own unique material properties, compared to the conventional usage, nanocellulose (NC) with a crystalline structure can be considered to be used in various industrial applications. As a novel sustainable future material, we review the recent achievements of NC from the view point of material extraction and the composite processes to some extended important applications. While the mechanical properties of NCs and the energy consumption during their composite processing are the key considerations, their application potentials have never been limited to mechanical or commodity products as conventional celluloses. In the latter part of this review, emerging engineering applications of NCs such as energy storage, flexible electronics, and smart materials will be further discussed for readers searching future high-end eco-friendly functional materials. Also some suggestions for potential applications will be also discussed.

Owing to its high sensitivity and great applicability, the fluorescence phenomenon has been considered as an inevitable research tool in the modern scientific fields of chemistry, biology, materials science, biomedical science, and their interfaces. Many strategies have been pursued to understand and manipulate the photophysical properties of fluorescent materials, but the scientific community has been focused on the repeated application of existing organic fluorophores or the identification of unique fluorescence properties in a trial-and-error basis without systematic studies. Moreover, recent studies are emphasizing the necessity of deeper understanding about the structure-photophysical property relationship of organic fluorophores for the development of better fluorescent probes. Herein, we provide an overview of a novel fluorescent molecular framework, Seoul-Fluor, which can be rationally engineered to furnish a wide variety of fluorophores in terms of the photophysical properties. Seoul-Fluor is built on an indolizine-based fluorescent platform with three different positions to introduce various substituents: R(1) and R(2) substituents for electronic perturbation; R(3) substituent as a functional handle for bioconjugation. Over the past decade, we have demonstrated that the Seoul-Fluor system has (i) tunable and predictable emission wavelength covering a full visible-color range; (ii) controllable quantum yield via photoinduced electron transfer phenomenon; and (iii) environment-sensitive fluorogenic properties that can be modified through intramolecular charge transfer processes. We convincingly demonstrated the prediction of photophysical properties, that is, emission wavelength and quantum yield, through the construction of a systematic set of analogues and the subsequent analysis of their photophysical properties without the highly sophisticated theoretical support. Guided by quantifiable parameters such as the Hammett substituent constants or energy levels of the molecular orbitals, this unique organic fluorophore can serve as a versatile molecular platform for the development of novel fluorescent switchable biosensors and fluorogenic bioprobes. In this Account, we will discuss the discovery and recent progress made on Seoul-Fluor, the rational design of Seoul-Fluor-based bioprobes, and their practical applications to specific biological processes that are facilitated by systematic studies of the structure-photophysical property relationships.

In order to investigate the feasibility of semiclathrate hydrate-based precombustion CO2 capture, thermodynamic, kinetic, and spectroscopic studies were undertaken on the semiclathrate hydrates formed from a fuel gas mixture of H2 (60%) + CO2 (40%) in the presence of quaternary ammonium salts (QASs) such as tetra-n-butylammonium bromide (TBAB) and fluoride (TBAF). The inclusion of QASs demonstrated significantly stabilized hydrate dissociation conditions. This effect was greater for TBAF than TBAB. However, due to the presence of dodecahedral cages that are partially filled with water molecules, TBAF showed a relatively lower gas uptake than TBAB. From the stability condition measurements and compositional analyses, it was found that with only one step of semiclathrate hydrate formation with the fuel gas mixture from the IGCC plants, 95% CO2 can be enriched in the semiclathrate hydrate phase at room temperature. The enclathration of both CO2 and H2 in the cages of the QAS semiclathrate hydrates and the structural transition that results from the inclusion of QASs were confirmed through Raman and (1)H NMR measurements. The experimental results obtained in this study provide the physicochemical background required for understanding selective partitioning and distributions of guest gases in the QAS semiclathrate hydrates and for investigating the feasibility of a semiclathrate hydrate-based precombustion CO2 capture process.

Fluorogenic bioorthogonal probes are ideal for fluorescent imaging in live cell conditions. By taking advantage of the dual functionality of tetrazine (Tz), as a bioorthogonal reaction unit as well as a fluorescence quencher, a fluorophore-Tz conjugate (FL) has been utilized for fluorescent live cell imaging via inverse electron-demand Diels-Alder (iEDDA) type bioorthogonal reactions. However, most FL strategies rely on a donor-acceptor-type energy transfer mechanism, which limits red-shifting of probes' emission wavelength without deterioration of the fluorescent turn-on/off ratio. To address this constraint, herein we present a monochromophoric design strategy for making a series of FLs spanning a broad range of emission colors. For the systematic comparison of design strategies with minimized structural differences, we selected indolizine-based emission-tunable Seoul-Fluor (SF) as a model fluorophore system. As a result, by inducing strong electronic coupling between Tz and π-conjugation systems of an indolizine core, we efficiently quench the fluorescence of SF-tetrazine conjugates (SFs) and achieved more than 1000-fold enhancement in fluorescence after iEDDA reaction with trans-cyclooctene (TCO). Importantly, we were able to develop a series of colorful SFs with a similar turn-on/off ratio regardless of their emission wavelength. The applicability as bioorthogonal probes was demonstrated with fluorescence bioimaging of innate microtubule and mitochondria using docetaxel-TCO and triphenylphosphonium-TCO in live cells without washing steps. We believe this study could provide new insight for the reliable and generally applicable molecular design strategy to develop bioorthogonal fluorogenic probes having an excellent turn-on ratio, regardless of their emission wavelength.

Z-scheme in natural photosynthesis are promising for solar-driven CO 2 conversion. [2] By combining multiple photoelectrodes or photovoltaics (PV), the Z-scheme PEC cells can provide sufficient photopotential to simultaneously drive water oxidation and CO 2 reduction under minimal or no external bias. [3] Nevertheless, lowering the kinetic barrier of thermodynamically inert CO 2 remains a hurdle for efficient CO 2 reduction. The development of CO 2reducing biocatalyst-conjugated cathodes can improve chemoselectivity and increase yield under mild conditions. [4] Compared to synthetic catalysts that often require extreme conditions such as high pressure, pH, or temperature, enzymes show high catalytic activities and specificities under mild conditions, making them a valuable catalyst for sustainable and green applications. In particular, formate dehydrogenase (FDH) is an attractive redox enzyme that reduces CO 2 to formate, an alternative water-soluble feedstock that can be easily converted to other common fuels. [5] Previous studies have focused on mediated electron transfer (MET)-type reactions, [6] in which redox mediators such as nicotinamide adenine dinucleotide cofactor (NADH) and Rh-based complexes shuttle electrons between an electrode and FDH. However, the MET-based biocatalysis requires costly electron mediators and multiple electron transfer steps that cause side reactions and significant losses in efficiency. [7] Here, we report the development of 3D titanium nitride nanoshell (3D TiN) electrodes for biocatalytic PEC cells that convert CO 2 to formate through direct electron transfer (DET), as depicted in Scheme 1a. A highly ordered, porous TiN structure is employed as an electrically conductive scaffold for efficient DET to a W-containing FDH from Clostridium ljungdahlii (ClFDH) (inset, Scheme 1a). TiN was chosen as a scaffold for DET-based bioelectrode because it is highly conductive, electrochemically stable and exhibit high chemical and thermal resistance, as well as exceptional hardness. [8] The 3D TiN electrode simultaneously provides (i) a large electroactive surface area generated from an ultrathin (≈30 nm), 3D nanoshell structure with high porosity (92.1%) for high enzyme loading per geometric area, (ii) a continuous electron transfer network with high electrical Z-scheme-inspired tandem photoelectrochemical (PEC) cells have received attention as a sustainable platform for solar-driven CO 2 reduction. Here, continuously 3D-structured, electrically conductive titanium nitride nanoshells (3D TiN) for biocatalytic CO 2 -to-formate conversion in a bias-free tandem PEC system are reported. The 3D TiN exhibits a periodically porous network with high porosity (92.1%) and conductivity (6.72 × 10 4 S m −1 ), which allows for high enzyme loading and direct electron transfer (DET) to the immobilized enzyme. It is found that the W-containing formate dehydrogenase from Clostridium ljungdahlii (ClFDH) on the 3D TiN nanoshell is electrically activated through DET for CO 2 reduction. At a low overpotential...

The endovascular treatment of cerebral aneurysms with coils poses significant technical challenges, particularly with respect to wide-necked aneurysms. We present the results of our initial experiences in using a stent for endovascular treatment of aneurysms, with an emphasis on potential applications, technical aspects, and associated complications. Twenty-three wide-necked aneurysms from 22 patients were treated during the 13-month study period. Seven patients presented with subarachnoid hemorrhage. Aneurysms were located at the internal carotid artery (n=14), the vertebral artery (n=3), the basilar artery (n=5), and the middle cerebral artery (n=1). A Neuroform stent2 was used for stent-assisted procedures. Premedication with antithrombotic agents was available for unruptured cases. Postprocedural antithrombotic medication was prescribed for all patients. Nineteen aneurysms were primarily stented, followed by coil placement. For five of these aneurysms, stenting was performed subsequent to failure of an attempt to frame with an initial coil. Stenting for the remaining four aneurysms was performed as a rescue procedure to prevent the migration of previously placed coils. Complete occlusion was obtained in ten aneurysms, nearly complete occlusion (95% or more occluded) in 11 aneurysms, and partial occlusion (less than 95% occluded) in one aneurysm. In one aneurysm, we failed to navigate the microcatheter into the aneurysmal sac through the interstices of the stent. Stent thrombosis was noted during the procedure in one patient. Hemorrhagic complication on the 25th day after the procedure was noted in one patient. No procedure-related complications were observed during the procedure or during follow-up in the remaining 20 patients, including seven patients who did not receive antithrombotic agents prior to endovascular treatment owing to recent subarachnoid hemorrhage. To overcome the technical limitation in the coiling of wide-necked aneurysms, stent-assisted coil embolization may be a technically feasible and relatively safe method, even though longer periods of follow-up are required.

In this study, guest gas enclathration behavior in semiclathrates of tetra-n-butylammonium bromide (TBAB) was closely investigated through phase equilibrium measurement and spectroscopic analysis. The three-phase equilibria of semiclathrate (H), liquid water (L(W)), and vapor (V) for the ternary CH(4) + TBAB + water and CO(2) + TBAB + water mixtures with various TBAB concentrations were experimentally measured to determine the stability conditions of the double TBAB semiclathrates. Equilibrium dissociation temperatures for pure TBAB semiclathrate were also measured at the same concentrations under atmospheric conditions. The dissociation temperature and dissociation enthalpy of pure TBAB semiclathrate were confirmed by differential scanning calorimetry. The experimental results showed that the double CH(4) (or CO(2)) + TBAB semiclathrates yielded greatly enhanced thermal stability when compared with pure CH(4) (or CO(2)) hydrate. The highest stabilization effect was observed at the stoichiometric concentration of pure TBAB semiclathrate, which is 3.7 mol%. From the NMR and Raman spectroscopic studies, it was found that the guest gases (CH(4) and CO(2)) were enclathrated in the double semiclathrates. In particular, from the cage-dependent (13)C NMR chemical shift, it was confirmed that CH(4) molecules were captured in the 5(12) cages of the double semiclathrates.