Clinical Use of Hematoma Volume Based On Automated Segmentation of Chronic Subdural Hematoma Using 3D U-Net.

PURPOSE: To propose a method for calculating hematoma volume based on automatic segmentation of chronic subdural hematoma (CSDH) using 3D U­net and investigate whether it can be used clinically to predict recurrence. METHODS: Hematoma volumes manually measured from pre- and postoperative computed tomography (CT) images were used as ground truth data to train 3D U­net in 200 patients (400 CT scans). A total of 215 patients (430 CT scans) were used as test data to output segmentation results from the trained 3D U­net model. The similarity with the ground truth data was evaluated using Dice scores for pre and postoperative separately. The recurrence prediction accuracy was evaluated by obtaining receiver operating characteristic (ROC) curves for the segmentation results. Using a typical mobile PC, the computation time per case was measured and the average time was calculated. RESULTS: The median Dice score of the test data were preoperative hematoma volume (Pre-HV): 0.764 and postoperative subdural cavity volume (Post-SCV): 0.741. In ROC analyses assessing recurrence prediction, the area under the curve (AUC) of the manual was 0.755 in Pre-HV, whereas the 3D U­net was 0.735. In Post-SCV, the manual AUC was 0.779; the 3D U­net was 0.736. No significant differences were found between manual and 3D U­net for all results. Using a mobile PC, the average time taken to output the test data results was 30 s per case. CONCLUSION: The proposed method is a simple, accurate, and clinically applicable; it can contribute to the widespread use of recurrence prediction scoring systems for CSDH.

14N NMR of magnetically oriented microcrystals.

14N NMR of magnetically oriented microcrystals is reported. With a home-built 1H-13C-14N probe capable of modulating the rotation of the sample around the axis normal to the magnetic field, magnetically oriented microcrystal suspension (MOMS) of l-alanine is made. 14N NMR spectra acquired with various timings during intermittent rotation lead to a rotation pattern of the MOMS similar to that of a single crystal. The effect of orientational distribution of the microcrystals to broadening of the resonance line is discussed.

Development and validation of a recurrent prediction model for patients with unilateral chronic subdural hematoma without hematoma volumetric analysis.

OBJECTIVE: Approximately 10 % of patients with chronic subdural hematoma (CSDH) undergo reoperation after initial surgery. This study aimed to develop a predictive model for the recurrence of unilateral CSDH at initial surgery without hematoma volumetric analysis. METHODS: This single-center retrospective cohort study evaluated pre- and postoperative computed tomography (CT) images of patients with unilateral CSDH. The pre- and postoperative midline shift (MLS), residual hematoma thickness, and subdural cavity thickness (SCT) were measured. CT images were classified based on the internal architecture of the hematoma (homogenous, laminar, trabecular, separated, and gradation subtypes). RESULTS: Total 231 patients with unilateral CSDH underwent burr hole craniostomy. After receiver operating characteristic analysis, preoperative MLS and postoperative SCT showed better areas under the curve (AUCs) (0.684 and 0.756, respectively). According to the CT classification of preoperative hematomas, the recurrence rate was significantly higher in the separated/gradation group (18/97, 18.6 %) than in the homogenous/laminar/trabecular group (10/134, 7.5 %). Four-point score was derived from the multivariate model using the preoperative MLS, postoperative SCT, and CT classification. The AUC of this model was 0.796, and the recurrence rates at 0-4 points were 1.7 %, 3.2 %, 13.3 %, 25.0 %, and 35.7 %, respectively. CONCLUSION: Pre- and postoperative CT findings without hematoma volumetric analysis may predict CSDH recurrence.

Anionic ordering in Pb2Ti4O9F2 revisited by nuclear magnetic resonance and density functional theory.

A combination of 19F magic angle spinning (MAS) nuclear magnetic resonance (NMR) and density functional theory (DFT) were used to study the ordering of F atoms in Pb2Ti4O9F2. This analysis revealed that F atoms predominantly occupy two of the six available inequivalent sites in a ratio of 73 : 27. DFT-based calculations explained the preference of F occupation on these sites and quantitatively reproduced the experimental occupation ratio, independent of the choice of functional. We concluded that the Pb atom's 6s2 lone pair may play a role (∼0.1 eV per f.u.) in determining the majority and minority F occupation sites with partial density of states and crystal orbital Hamiltonian population analyses applied to the DFT wave functions.

Polyoxocationic antimony oxide cluster with acidic protons.

The success and continued expansion of research on metal-oxo clusters owe largely to their structural richness and wide range of functions. However, while most of them known to date are negatively charged polyoxometalates, there is only a handful of cationic ones, much less functional ones. Here, we show an all-inorganic hydroxyiodide [H10.7Sb32.1O44][H2.1Sb2.1I8O6][Sb0.76I6]2·25H2O (HSbOI), forming a face-centered cubic structure with cationic Sb32O44 clusters and two types of anionic clusters in its interstitial spaces. Although it is submicrometer in size, electron diffraction tomography of HSbOI allowed the construction of the initial structural model, followed by powder Rietveld refinement to reach the final structure. The cationic cluster is characterized by the presence of acidic protons on its surface due to substantial Sb3+ deficiencies, which enables HSbOI to serve as an excellent solid acid catalyst. These results open up a frontier for the exploration and functionalization of cationic metal-oxo clusters containing heavy main group elements.

Risk and prognostic factors of post-catheterization pseudoaneurysm.

PURPOSE: To evaluate the risk and prognostic factors of post-catheterization pseudoaneurysm (PPA). MATERIAL AND METHODS: To identify the risk factors for PPA occurrence, clinical findings were compared between 22 consecutive patients with radiologically confirmed PPAs (PPA group) and 300 randomly extracted patients without PPA, who underwent transarterial angiography or intervention (sample group) between 1 January 2015 and 31 March 2020. The PPA group was further divided into those treated successfully with mechanical compression (group A) and those requiring ultrasound-guided thrombin injection after compression failed (group B). Univariate and multivariate analyses were used to compare patient demographics, preoperative laboratory findings, procedure details, PPA diameter, and time interval between the procedure and compression between groups A and B to evaluate the prognostic factors of PPA. RESULTS: The PPA group demonstrated significantly elevated prothrombin time international normalized ratios (PT/INR) (odds ratio [OR]: 6.27, 95% confidence interval [CI]: 2.020-19.5; p = 0.00151) and more frequent popliteal access (OR: 14.2, 95% CI: 1.040-195.0; p = 0.0467) compared to the sample group, and radial access decreased the risk of PPA (OR: 0.382, 95% CI: 0.0148-0.987; p = 0.0468). One of the 22 PPAs resolved spontaneously, and 11 others (52.4%) were successfully treated by mechanical compression. An interval exceeding 24 hours between the procedure and compression was the only significant prognostic factor (p = 0.0281) between groups A and B. CONCLUSIONS: Elevated PT/INR and popliteal access may predispose patients to PPA; close consideration of the site of access may lower the risk of refractory PPA.

Modified Computed Tomography Classification for Chronic Subdural Hematoma Features Good Interrater Agreement: A Single-Center Retrospective Cohort Study.

OBJECTIVE: The present study aimed to establish whether our modified Nakaguchi computed tomography (CT) classification improves the interrater agreement of chronic subdural hematoma (CSDH) classification and prediction of CSDH recurrence relative to 2 other CT classifications. METHODS: This retrospective study considered 277 consecutive patients with CSDH and 307 hematomas treated with burr-hole surgery between January 2009 and December 2018. Two neurosurgeons blinded to patients' clinical data classified the CT scans of patients with CSDH into 4 or 5 types according to the Nomura classification (high, iso, low, mixed, and layering), Nakaguchi classification (homogenous, laminar, separated, and trabecular), and our modified Nakaguchi classification (homogenous, gradation, laminar, separated, and trabecular). The κ statistic was used to evaluate the interrater agreement of the 3 CT classifications. Univariable and multivariable logistic regression analyses were used to calculate odds ratios for CSDH recurrence. RESULTS: κ values of the modified, Nakaguchi, and Nomura classification were 0.78, 0.63, and 0.70, respectively. During the 3 months follow-up, the recurrence rate for CSDH was 11.4% (35/307 hematomas). Of the types defined by the modified classification, the gradation type was associated with the highest recurrence (mean recurrence rate, 15.9% ± 0.3%). Multivariable logistic regression analyses showed that a gradation-type hematoma, as defined with the modified classification, was an independent risk factor associated with recurrence (odds ratio, 2.36; 95% confidence interval, 1.11-4.98; P = 0.025). CONCLUSIONS: The modified classification was useful for preoperative CT classification of CSDH and the prediction of recurrence, with high agreement between raters.

Rapid survey of nuclear quadrupole resonance by broadband excitation with comb modulation and dual-mode acquisition.

Nuclear Quadrupole Resonance (NQR) provides spectra carrying information as to the electric-field gradient around nuclei with a spin quantum number I > 1/2 and offers helpful clues toward characterizing the electronic structure of materials of chemical interest. A major challenge in NQR is finding hitherto unknown resonance frequencies, which can scatter over a wide range, requiring time consuming repetitive measurements with stepwise frequency increments. Here, we report on an efficient, two-step NQR protocol by bringing rapid-scan and frequency-comb together. In the first step, wideband excitation and simultaneous signal acquisition, both realized by a non-adiabatic, frequency-swept hyperbolic secant (HS) pulse with comb modulation, offers a clue for the existence/absence of the resonance within the frequency region under investigation. When and only when the sign of the resonance has been detected, the second step is implemented to compensate the limited detection bandwidth of the first and to unambiguously determine the NQR frequency. We also study the spin dynamics under the comb-modulated HS pulse by numerical simulations, and experimentally demonstrate the feasibility of the proposed scheme, which is referred to as RApid-Scan with GApped excitation with Dual-mode Operation (RASGADO) NQR.

Probing dynamics of carbon dioxide in a metal-organic framework under high pressure by high-resolution solid-state NMR.

The application of high-resolution NMR analysis for CO2 adsorbed in a MOF under high pressure is reported for the first time. The results showed that CO2 adsorbed in MOF-74 had an unusually slow mobility (τ ∼ 10-8 s). CO2-CO2 interactions suppressed the mobility of CO2 under high pressure, which, in turn, would have contributed to the stability of CO2 at the adsorption sites.

Amorphous High-Surface-Area Aluminum Hydroxide-Bicarbonates for Highly Efficient Methyl Orange Removal from Water.

Amorphous high-surface-area aluminum hydroxide-bicarbonates were synthesized starting from AlCl3, base, and bicarbonate in water. Composites with a chemical formulas of [Al13O4(µ-OH)24(H2O)6.5(OH)5.5](HCO3)1.5 (I-NaOH) and [Al13O4(µ-OH)24(H2O)6(OH)6](HCO3) (I-NH3) were obtained by the use of NaOH/NaHCO3 and NH3/NH4HCO3 as base/bicarbonate, respectively. The surface area of the composites was highly dependent on the pH level of the synthetic solution, and composites with high surface areas (ca. 200 m2 g-1) were obtained around pH 7-8. Pore-size distributions determined from the N2 adsorption isotherms showed that I-NH3 and I-NaOH possess mainly large (pore radius rp > 3 nm) and small (rp < 3 nm) pores, respectively, despite similar surface areas. While SEM images showed that both I-NH3 and I-NaOH were aggregates of nanoparticles, the particles were more fused in I-NaOH, which is in line with the existence of small pores and the use of a stronger base (NaOH), which would facilitate the dehydration condensation reaction. The composites were applied as adsorbents to remove methyl orange (MO) from water. The time course of MO adsorption was readily fitted with a pseudo-second-order model, and over 90% MO removal was attained within 10 min with I-NH3, while I-NaOH showed much less MO removal (26%). The MO adsorption isotherm of I-NH3 was reproduced with a Langmuir model with an adsorption capacity of 154 mg g-1. Notably, the aluminum hydroxide-bicarbonates could not absorb methylene blue, which is a cationic dye, while anions (MO and PO43-) were readily absorbed. Solid-state 27Al MAS NMR spectra showed that the concentration of 5-coordinated aluminum species, which may serve as guest binding sites, was higher for I-NH3. These results show that electrostatic interaction between anionic MO and coordinatively unsaturated 5-coordinated cationic aluminum species and the large external surface area of I-NH3 contribute to the highly efficient MO adsorption.

Experimental and Computational Studies of the Structure of CdSe Magic-Size Clusters.

Experimental and computational studies of resonant Raman spectra of truly monosized (CdSe)33 and (CdSe)34 nanoclusters have been performed. First-principles calculations of vibrations are performed to account for the peculiarity of the spectrum and resonant Raman selection rules. The calculation method is based on the analysis of the spatial distribution of the electron density in the ground and excited states and the corresponding displacement of atoms after the electronic transition. The calculated vibrational density of states and resonant Raman spectra of CdSe nanoclusters in a core-cage arrangement are distinctively different from those of small nanocrystals in the bulk fragment model and reasonably agree with the experimentally observed spectral features. The agreement can be considered as experimental evidence for the shell structure of "magic" CdSe nanoclusters. The resonant conditions for the Raman measurements and two different kinds of samples stabilized with decylamine in toluene and with cysteine in water ensure the reliability of our measurements and the minor influence of the stabilizer.

Capping Structure of Ligand-Cysteine on CdSe Magic-Sized Clusters.

Ligand molecules capping on clusters largely affect the formation and stabilization mechanism and the property of clusters. In semiconductor CdSe clusters, cysteine is used as one of the ligands and allows the formation of ultrastable (CdSe)34 magic-sized clusters. Cysteine has sulfhydryl, amine, and carboxylate groups, all of which have coordination ability to the CdSe surface, and the bonding states of the three functional groups of ligand-cysteine on the CdSe core have not been determined. In this work, the capping structure of ligand-cysteine is examined by performing Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and multinuclear solid-state nuclear magnetic resonance (NMR) spectroscopy. FT-IR, XPS, and 1H, 13C, and 23Na magic-angle spinning NMR show that the sulfhydryl group of ligand-cysteine forms a sulfur-cadmium bond with a cadmium atom at the CdSe surface, while the carboxylate group does not contribute to the protection of the CdSe core and binds to a sodium ion contained as a counterion. 15N-{77Se} through-bond J-single quantum filtered NMR experiment reveals that the amine group of ligand-cysteine has no coordination to selenium atoms. By considering the N-Cd bond forming ratio (∼43%) revealed in our previous work, which is confirmed in this work by analyzing 13Cα signal intensity (∼42%), we concluded that cysteine capping on (CdSe)34 occurs in two ways: one involves both the sulfur-cadmium and nitrogen-cadmium bonds, and the other bears only the sulfur-cadmium bond.

Terminal and bridging fluorine ligands in TiF4 as studied by 19F NMR in solids.

To examine bonding nature of fluorine ligands in a metal coordinated system, 19F high-resolution solid-state NMR has been applied to TiF4, which bears both bridging and terminal fluorines. Observed 12 isotropic signals are assigned to 12 crystallographically different fluorines (6 terminal and 6 bridging fluorines) in TiF4 by referring to the calculated isotropic shifts using density functional theory (DFT). The isotropic chemical shift (δiso) for terminal F (FT) appears at high frequency (420-480 ppm from δ(CCl3F) = 0 ppm) with large shielding anisotropy Δσ ∼ 850 ppm. Whereas the δiso and Δσ values for bridging F (FB) are moderate; δiso ∼ 0-25 ppm and Δσ ∼ 250 ppm. The origin of the observed high-frequency shift for FT is ascribed to the second-order paramagnetic shift with increased covalency, shorter Ti-F bonds, and smaller energy difference between the occupied and vacant orbitals. Examination of the orientation of the shielding tensor relative to the molecular structure shows that the most deshielded component of the shielding tensor is oriented along the Ti-F bond. The characteristic orientation is consistent with a Ti-F σ bond formed by dYZ of Ti and pz of F. Further, we show that the selectively observed spinning sideband patterns and the theoretical patterns with the calculated Δσ and η (shielding asymmetry) values are not consistent with each other for FB, indicating deficiency of the present DFT calculation in evaluating Δσ.

Rapid formation of small mixed-valence luminescent silver clusters via cation-coupled electron-transfer in a redox-active porous ionic crystal based on dodecamolybdophosphate.

Redox-active porous ionic crystals based on polyoxometalate (POM) were utilized to form and stabilize small mixed-valence luminescent silver clusters via cation-coupled electron-transfer (CCET) reactions. Reduction-induced ion-exchange between Cs+ and Ag+via CCET took less than 1 min to complete and consisted of two steps: electron transfer from reduced POM to Ag+ and the subsequent formation of a silver cluster, and diffusion of the silver cluster and exchange with Cs+. Notably, the simple ion-exchange took more than 24 h. The compound containing the silver cluster showed high affinity toward unsaturated hydrocarbon guests.

Inner-product NMR spectroscopy: A variant of covariance NMR spectroscopy.

We propose a variant of covariance NMR spectroscopy, namely, inner-product NMR spectroscopy, originally suggested in Takeda (2015). The mathematical operation of inner-product NMR is the same as that of covariance NMR, except that subtraction of the average value of the variable is intentionally omitted, so that the correspondence of the spectrum with that of conventional two-dimensional Fourier-transformation is established without having to request the average to become vanishingly small. We demonstrate inner-product NMR for 13C DARR correlation experiments in a polycrystalline sample of 13C-labeled l-alanine. In covariance, we show that the mixing-time dependence of the peaks is influenced considerably by the choice of the carrier frequency and thereby the center of the spectrum, whereas the inner-product approach is free from such an undesirable effect, while keeping the merit of the covariance NMR.

Supercritical temperature synthesis of fluorine-doped VO2(M) nanoparticle with improved thermochromic property.

Fluorine-doped VO2(M) nanoparticles have been successfully synthesized using the hydrothermal method at a supercritical temperature of 490 °C. The pristine VO2(M) has the critical phase transformation temperature of 64 °C. The morphology and homogeneity of the monoclinic structure VO2(M) were adopted by the fluorine-doped system. The obtained particle size of the samples is smaller at the higher concentration of anion doping. The best reduction of critical temperature was achieved by fluorine doping of 0.13% up to 48 °C. The thin films of the fluorine-doped VO2(M) showed pronounced thermochromic property and therefore are suitable for smart window applications.

Quantitative Solid-State NMR Study on Ligand-Surface Interaction in Cysteine-Capped CdSe Magic-Sized Clusters.

Ligand-surface interaction of semiconductor nanoparticles (NPs) controls their optoelectronic properties, and thus examination of the interaction is essential for the nanoelectronic applications of NPs. Herein, solid-state nuclear magnetic resonance (NMR) is performed to unravel the ligand-surface interaction in cysteine-capped CdSe magic-sized clusters. 15N-113Cd through-bond J-filtered NMR directly shows the presence of the nitrogen-cadmium chemical bond for the first time and indicates that ∼43% of the amines form the chemical bond. 15N-113Cd through-space dipolar-correlated NMR reveals that ∼54% of the amines locate nearby the surface cadmium with the average nitrogen-cadmium distance of 0.247 nm. The average distance is comparable with that estimated by J-filtered NMR. The difference of the two ratios (∼11%) proposes that some amines locate on the surface without forming the chemical bond, and these amines affect the relatively long observed distance in the dipolar-based experiment. Our study shows effectiveness of solid-state NMR for investigation of the ligand-surface interactions of NPs.

Pressure-Stabilized Cubic Perovskite Oxyhydride BaScO2H.

We report a scandium oxyhydride BaScO2H prepared by solid state reaction under high pressure. Rietveld refinements against powder synchrotron X-ray and neutron diffraction data revealed that BaScO2H adopts the ideal cubic perovskite structure (Pm3̅m), where oxide (O2-) and hydride (H-) anions are disordered. 1H nuclear magnetic resonance (NMR) spectroscopy provides a positive chemical shift of about +4.4 ppm, which can be understood by the distance to the nearest (and possibly the next nearest) cation from the H nucleus. A further analysis of the NMR data and calculations based on ab initio random structure searches suggest a partial cis preference in ScO4H2 octahedra. The present oxyhydride, if compositionally or structurally tuned, may become a candidate for H- conductors.

Hydride in BaTiO2.5H0.5: A Labile Ligand in Solid State Chemistry.

In synthesizing mixed anion oxides, direct syntheses have often been employed, usually involving high temperature and occasionally high pressure. Compared with these methods, here we show how the use of a titanium perovskite oxyhydride (BaTiO2.5H0.5) as a starting material enables new multistep low temperature topochemical routes to access mixed anion compounds. Similar to labile ligands in inorganic complexes, the lability of H(-) provides the necessary reactivity for syntheses, leading to reactions and products previously difficult to obtain. For example, BaTiO2.5N0.2 can be prepared with the otherwise inert N2 gas at 400-600 °C, in marked contrast with currently available oxynitride synthetic routes. F(-)/H(-) exchange can also be accomplished at 150 °C, yielding the oxyhydride-fluoride BaTi(O, H, F)3. For BaTiO2.4D0.3F0.3, we find evidence that further anionic exchange with OD(-) yields BaTiO2.4(D(-))0.26(OD(-))0.34, which implies stable coexistence of H(+) and H(-) at ambient conditions. Such an arrangement is thermodynamically unstable and would be difficult to realize otherwise. These results show that the labile nature of hydride imparts reactivity to oxide hosts, enabling it to participate in new multistep reactions and form new materials.

COMPOZER-based longitudinal cross-polarization via dipolar coupling under MAS.

We propose a cross polarization (CP) sequence effective under magic-angle spinning (MAS) which is tolerant to RF field inhomogeneity and Hartmann-Hahn mismatch. Its key feature is that spin locking is not used, as CP occurs among the longitudinal (Z) magnetizations modulated by the combination of two pulses with the opposite phases. We show that, by changing the phases of the pulse pairs synchronized with MAS, the flip-flop term of the dipolar interaction is restored under MAS.