An optimal method of hydrogel spacer insertion for stereotactic body radiation therapy of prostate cancer.

PURPOSE: This study aimed to explore an ideal method for hydrogel spacer insertion by analyzing the efficacy and safety of our originally developed apex expansion method. MATERIALS AND METHODS: Overall, 100 patients with low- and intermediate-risk localized prostate cancer treated with stereotactic body radiation therapy were included. A hydrogel spacer was inserted in 64 and 36 patients using the conventional and apex expansion methods, respectively. For dosimetry, we trisected the rectum into the upper rectum, middle rectum, and lower rectum on the sagittal section of magnetic resonance imaging. We compared the dose to each part of the rectum between the two methods using dose-volume histograms. Genitourinary and gastrointestinal toxicity assessments were conducted until 3 months of follow-up. RESULTS: The whole rectal dose in the apex expansion method group was lower than that in the conventional method group, which was significant in all dose regions (V5-V35). Similarly, in the apex expansion method group, the dose to the middle rectum was lower in the low- to high-dose region (V10-V35), and the dose to the lower rectum was lower in the middle- to high-dose region (V15-35). No Grade ≥ 3 toxicity or procedure-related complications were observed. Additionally, Grade 2 genitourinary and gastrointestinal toxicities during the treatment showed no significant differences between the two methods. CONCLUSION: The apex expansion method may be safe and effective in achieving a more efficient rectal dose reduction by expanding the anterior perirectal space in the prostatic apex area.

Hydroxypyridinate-bridged paddlewheel-type dirhodium complex as a catalyst for photochemical and electrochemical hydrogen evolution.

Electrochemical and photochemical hydrogen (H2) evolution activities of a 6-fluoro-2-hydroxypyridinate (fhp-)-bridged paddlewheel-type dirhodium (Rh2) complex, [Rh2(fhp)4], were investigated through experimental and theoretical approaches. In DMF, the [Rh2(fhp)4] underwent a one-electron reduction (assigned to Rh24+/3+) at -1.31 V vs SCE in the cathodic region. Adding trifluoroacetic acid as a proton source to the electrochemical cell containing [Rh2(fhp)4], the significant catalytic current, i.e., electrochemical H2 evolution, was observed; the turnover frequency and overpotential of electrochemical H2 evolution were 18 244 s-1 and 732 mV, respectively. The reaction mechanism of electrochemical H2 evolution catalyzed by [Rh2(fhp)4] in DMF was examined in detail by theoretically predicting the redox potentials and pKa values of the reaction intermediates using density functional theory calculations. The calculations revealed that (i) the formation of a one-electron reduced species, [Rh2(fhp)4]-, triggered for H2 evolution and (ii) the protonation and reduction processes of [Rh2(fhp)4]- to further reduced hydride intermediates proceeded directly via a concerted proton-electron transfer mechanism. Moreover, [Rh2(fhp)4] was shown to be a highly efficient H2 evolution catalyst (HEC) for photochemical proton reduction reactions when combined with an artificial photosynthetic (AP) system containing [Ir(ppy)2(dtbbpy)]PF6 and triethylamine, which served as a photosensitizer and a sacrificial electron donor, respectively. Under visible light irradiation, the total amount of H2 evolved and its turnover number (per Rh ion) were 1361.0 µmol and 13 610, respectively, which are superior to those of previously reported AP systems with rhodium complexes as HEC.

Complete genome sequence of Mycolicibacterium mageritense strain H4_3_1 isolated from a hybrid biological-inorganic system reactor.

We report the complete genome of Mycolicibacterium mageritense strain H4_3_1, which was isolated from a reactor of a hybrid biological-inorganic system. This genome will provide useful information about hydrogen-oxidizing bacteria as well as mycolicibacteria in non-host environments.

Complete genome sequence of an Achromobacter xylosoxidans strain H1_3_1 isolated from a hybrid biological-inorganic system reactor.

We report the complete genome of Achromobacter xylosoxidans strain H1_3_1, which was isolated from a reactor of a hybrid biological-inorganic system. The complete genome comprised 7,071,873 bp, including 6,428 codings, 10 rRNA, and 70 tRNA, with 67.4% G + C content.

Enrichment of halotolerant hydrogen-oxidizing bacteria and production of high-value-added chemical hydroxyectoine using a hybrid biological-inorganic system.

Hybrid biological-inorganic (HBI) systems show great promise as CO2 conversion platforms combining CO2 fixation by hydrogen-oxidizing bacteria (HOB) with water splitting. Herein, halotolerant HOB were enriched using an HBI system with a high-ionic-strength medium containing 180 mM phosphate buffer to identify new biocatalysts. The reactors were inoculated with samples from saline environments and applied with a voltage of 2.0 V. Once an increase in biomass was observed with CO2 consumption, an aliquot of the medium was transferred to a new reactor. After two successive subcultures, Achromobacter xylosoxidans strain H1_3_1 and Mycolicibacterium mageritense strain H4_3_1 were isolated from the reactor media. Genome sequencing indicated the presence of genes for aerobic hydrogen-oxidizing chemolithoautotrophy and synthesis of the compatible solute hydroxyectoine in both strains. Furthermore, both strains produced hydroxyectoine in the reactors under the high-ionic-strength condition, suggesting the potential for new HBI systems using halotolerant HOB to produce high-value-added chemicals.

Equivalent values between anterior vertebral height, wedge ratio, and wedge angle for evaluating vertebral mobility and deformity in osteoporotic vertebral fractures: a conventional observational study.

BACKGROUND: Vertebral mobility (V-mobility) has been used to diagnose fresh osteoporotic vertebral fractures (OVFs) and determine bone union by setting cutoff values for these purposes. V-mobility is the difference in vertebral height on dynamic radiographs taken in the sitting and lateral decubitus or supine positions. The dimensions for V-mobility were presented as anterior vertebral height (Ha; mm), wedge ratio (WR; %), and wedge angle (WA; °) in previous reports. This study was performed to obtain WR and WA values equivalent to V-mobility of 1.0 mm in Ha. METHODS: Lateral radiographs of 284 OVFs (grade 1-3 deformed vertebrae) from T11 to L2 were obtained from 77 patients with OVF. V-mobility presented as Ha, posterior vertebral height, and WA was obtained by the difference in these dimensions on dynamic radiographs. The WR and WA values equivalent to 1.0 mm in Ha were obtained by dividing the V-mobility values for WR and WA by that for Ha. RESULTS: The mean WR values corresponding to 1.0 mm in Ha for grade 1, 2, and 3 vertebrae were 3.2% ± 1.4%, 3.2% ± 0.9%, and 3.4% ± 1.0%, respectively, and the corresponding value for grade 1-3 vertebrae was 3.3% ± 1.0%. The mean WA values corresponding to 1.0 mm in Ha for grade 1, 2, and 3 vertebrae were 1.5° ± 0.8°, 1.5° ± 0.6°, and 1.5° ± 0.8°, respectively, and the corresponding value for grade 1-3 vertebrae was 1.5° ± 0.7°. CONCLUSIONS: The WR and WA values equivalent to V-mobility of 1.0 mm in Ha were 3.3% and 1.5°, respectively, in grade 1-3 vertebrae. These findings may be useful to secure a reliable value of V-mobility of OVFs using simultaneous measurements in three dimensions (Ha, WR, and WA) in clinical practice and to establish cutoff values for V-mobility to determine bone union.

Enrichment of hydrogen-oxidizing bacteria using a hybrid biological-inorganic system.

Hybrid biological-inorganic (HBI) systems comprising inorganic water-splitting catalysts and aerobic hydrogen-oxidizing bacteria (HOB) have previously been used for CO2 conversion. In order to identify new biocatalysts for CO2 conversion, the present study used an HBI system to enrich HOB directly from environmental samples. Three sediment samples (from a brackish water pond, a beach, and a tide pool) and two activated sludge samples (from two separate sewage plants) were inoculated into HBI systems using a cobalt phosphorus (Co-P) alloy and cobalt phosphate (CoPi) as inorganic catalysts with a fixed voltage of 2.0 V. The gas composition of the reactor headspaces and electric current were monitored. An aliquot of the reactor medium was transferred to a new reactor when significant consumption of H2 and CO2 was detected. This process was repeated twice (with three reactors in operation for each sample) to enrich HOB. Increased biomass concomitant with increased H2 and CO2 consumption was observed in the third reactor, indicating enrichment of HOB. 16S rRNA gene amplicon sequencing demonstrated enrichment of sequences related to HOB (including bacteria from Mycobacterium, Hydrogenophaga, and Xanthobacter genera) over successive sub-cultures. Finally, four different HOB belonging to the Mycobacterium, Hydrogenophaga, Xanthobacter, and Acidovorax genera were isolated from reactor media, representing potential candidates as HBI system biocatalysts.

Cystic fibrosis with multiple pulmonary arteriovenous malformations: A case report.

Cystic fibrosis is an autosomal recessive genetic disorder that damages the exocrine function of the body, resulting in alterations of multiple organs. In the respiratory system, it is known to cause bronchiectasis, recurrent bronchitis, and pneumonia; however, to the best of our knowledge, there are no reported cases of pulmonary arteriovenous malformations associated with this disease. Herein, we report a case of cystic fibrosis with multiple pulmonary arteriovenous malformations. A 16-year-old girl, who has been monitored since childhood for pancreatitis of unknown cause, experienced respiratory symptoms and hypoxemia (PaO2 = 57 mmHg). At 13 years of age, chest computed tomography revealed bronchiectasis, bronchial wall thickening, and tree-in-bud sign. Genetic testing was performed, and the patient was diagnosed with cystic fibrosis. However, the computed tomography scan also showed incidental nodular lesions in the left superior and both the inferior pulmonary lobes, suggesting multiple arteriovenous malformations. Dynamic computed tomography was performed which, confirmed the presence of 3 pulmonary arteriovenous malformations. Coil embolization was performed on all lesions, and the hypoxemia was corrected. Marked hypoxemia in a patient with cystic fibrosis may not be explained only by the presence of bronchiectasis and/or bronchial wall thickening; in such cases, it may be necessary to examine possible additional findings on computed tomography images, such as arteriovenous malformations.

Equivalent values between anterior vertebral height, wedge ratio, and wedge angle in osteoporotic vertebral fractures.

INTRODUCTION: Vertebral mobility (V-mobility) has been used to diagnose fresh osteoporotic vertebral fractures (OVFs), and determine or predict bone union by setting cutoff values for these purposes. V-mobility is defined as the difference in shape of vertebral bodies between lateral radiographs taken in weight-bearing and non-weight-bearing positions. The parameters for V-mobility have varied in previous reports among anterior vertebral height (Ha, mm), wedge ratio (WR, %), and wedge angle (WA, degrees). The present study aimed to clarify WR and WA equivalent to Ha of 1.0 mm, and to compare the reported cutoff values for V-mobility presented as Ha, WR, or WA. MATERIALS AND METHODS: Lateral radiographs of 446 normal vertebrae (grade 0) and 146 deformed vertebrae (grade 1-3) from T11 to L2 were obtained from 183 female patients aged > 60 years. WR (%) values equivalent to Ha of 1.0 mm were calculated by Ha (1.0 mm)/Hp × 100 (Hp: posterior vertebral height). Corresponding WA values were calculated by trigonometric function using vertebral dimensions. RESULTS: The mean WR values equivalent to Ha of 1.0 mm in the vertebrae from T11 to L2 were 3.2%, 3.2%, 3.5%, and 3.7% for grades 0, 1, 2, and 3, respectively, and the corresponding WA values were 1.6°, 1.6°, 1.5°, and 1.4°. CONCLUSION: The equivalent values for V-mobility presented as Ha, WR, and WA were obtained. The mean WR and WA values equivalent to Ha of 1.0 mm in grade 1-3 vertebrae were 3.5% and 1.5°, respectively.

Multisystem Imaging Manifestations of Kawasaki Disease.

Kawasaki disease (KD) is a common pediatric vasculitis syndrome involving medium- and small-sized arteries that is especially prevalent in early childhood (ie, age 6 months to 5 years). The diagnosis of KD is made on the basis of clinical features, such as fever, characteristic mucocutaneous changes, and nonsuppurative cervical lymphadenopathy. However, early diagnosis is often challenging because many children with KD present with atypical symptoms. The most serious complication of KD is coronary artery aneurysm caused by coronary arteritis. Prompt intravenous immunoglobulin therapy reduces the risk of cardiac morbidity. In addition, the systemic extension of KD-related vasculitis during the acute phase causes a variety of multisystem manifestations, including encephalopathy, stroke, retropharyngeal edema, pericarditis, myocarditis, KD shock syndrome, pulmonary lesions, intestinal pseudo-obstruction, gallbladder hydrops, arthritis, and myositis. These complications tend to be more common in affected children with atypical presentation. Radiologists can play an important role in the timely identification of diverse KD-associated morbidities and thus may contribute to the early diagnosis of atypical KD. Online supplemental material is available for this article. ©RSNA, 2021.

Undiagnosed tracheomalacia accompanied with accidental expiratory central airway collapse after tracheal intubation.

BACKGROUND: A patient with undiagnosed tracheomalacia undergoing surgery experienced accidental expiratory central airway collapse after tracheal intubation. Here, we aimed to diagnose tracheomalacia from the preoperative data. CASE PRESENTATION: A 73-year-old man, scheduled for abdominal surgery, had a clinical history of chronic obstructive pulmonary disease. Preoperative chest computed tomography revealed a lateral narrowing of the tracheal shape. After tracheal intubation, we could not manually ventilate the inflated lung. Emergent bronchoscopy findings, including severe expiratory tracheal collapse, indicated a diagnosis of tracheomalacia. We could fully ventilate the patient by moving the endotracheal tube near the tracheal carina and finally changing it to a double-lumen tube. Airway collapse did not occur under spontaneous breathing. CONCLUSION: Accidental expiratory central airway collapse could occur in patients with undiagnosed tracheomalacia during surgery. A diagnosis of tracheomalacia should be presumed from a deformed trachea on preoperative imaging and history of chronic obstructive pulmonary disease.

Chromatic dispersion dependence of GAWBS phase noise compensation with pilot tone.

We describe experimental and numerical results regarding the influence of chromatic dispersion in optical fibers on guided acoustic-wave Brillouin scattering (GAWBS) phase noise compensation with a pilot tone (PT). We compared the compensation performance for GAWBS phase noise generated in an ultra-large-area fiber (ULAF) where DULAF = 21 ps/nm/km with that in a dispersion-shifted fiber (DSF) where DDSF = -1.3 ps/nm/km and found that the performance depends strongly on chromatic dispersion. The numerical analysis shows that the group delay between the signal and PT caused by chromatic dispersion reduces the GAWBS noise correlation between them, which degrades the compensation performance for GAWBS phase noise. It is clarified that a condition for effective GAWBS compensation is that the group delay between the signal and PT should be less than half the period of the GAWBS phase noise component.

Spectrally efficient pilot tone-based compensation of inter-channel cross-phase modulation noise in a WDM coherent transmission using injection locking.

We propose the precise and wideband compensation of the nonlinear phase noise caused by cross-phase modulation (XPM) among WDM channels using a pilot tone (PT) and injection locking for short-reach, higher-order QAM transmission. A high spectral efficiency is maintained by sharing a single PT among multiple channels. We describe a 60 ch, 3 Gbaud PDM-256 QAM transmission over 160 km, where the bit error rate was improved from 6 × 10-3 to 2 × 10-3 by employing the proposed XPM compensation technique, with a spectral efficiency of 10.3 bit/s/Hz. We also analyze the influence of the group delay caused by fiber chromatic dispersion that determines the compensation range achievable with a single PT. We obtained good agreement with the experimental results.

Analysis of a Methanogen and an Actinobacterium Dominating the Thermophilic Microbial Community of an Electromethanogenic Biocathode.

Electromethanogenesis refers to the bioelectrochemical synthesis of methane from CO2 by biocathodes. In an electromethanogenic system using thermophilic microorganisms, metagenomic analysis along with quantitative real-time polymerase chain reaction and fluorescence in situ hybridization revealed that the biocathode microbiota was dominated by the methanogen Methanothermobacter sp. strain EMTCatA1 and the actinobacterium Coriobacteriaceae sp. strain EMTCatB1. RNA sequencing was used to compare the transcriptome profiles of each strain at the methane-producing biocathodes with those in an open circuit and with the methanogenesis inhibitor 2-bromoethanesulfonate (BrES). For the methanogen, genes related to hydrogenotrophic methanogenesis were highly expressed in a manner similar to those observed under H2-limited conditions. For the actinobacterium, the expression profiles of genes encoding multiheme c-type cytochromes and membrane-bound oxidoreductases suggested that the actinobacterium directly takes up electrons from the electrode. In both strains, various stress-related genes were commonly induced in the open-circuit biocathodes and biocathodes with BrES. This study provides a molecular inventory of the dominant species of an electromethanogenic biocathode with functional insights and therefore represents the first multiomics characterization of an electromethanogenic biocathode.

Experimental evaluation of the GE NM/CT 870 CZT clinical SPECT system equipped with WEHR and MEHRS collimator.

PURPOSE: A high-energy-resolution whole-body SPECT-CT device (NM/CT 870 CZT; C-SPECT) equipped with a CZT detector has been developed and is being used clinically. A MEHRS collimator has also been developed recently, with an expected improvement in imaging accuracy using medium-energy radionuclides. The objective of this study was to compare and analyze the accuracies of the following devices: a WEHR collimator and the MEHRS collimator installed on a C-SPECT, and a NaI scintillation detector-equipped Anger-type SPECT (A-SPECT) scanner, with a LEHR and LMEGP. METHODS: A line phantom was used to measure the energy resolutions including collimator characteristics in the planar acquisition of each device using 99m Tc and 123 I. We also measured the system's sensitivity and high-contrast resolution using a lead bar phantom. We evaluated SPECT spatial resolution, high-contrast resolution, radioactivity concentration linearity, and homogeneity, using a basic performance evaluation phantom. In addition, the effect of scatter correction was evaluated by varying the sub window (SW) employed for scattering correction. RESULTS: The energy resolution with 99m Tc was 5.6% in C-SPECT with WEHR and 9.9% in A-SPECT with LEHR. Using 123I, the results were 9.1% in C-SPECT with WEHR, 5.5% in C-SPECT with MEHRS, and 10.4% in A-SPECT with LMEGP. The planar spatial resolution was similar under all conditions, but C-SPECT performed better in SPECT acquisition. High-contrast resolution was improved in C-SPECT under planar condition and SPECT. The sensitivity and homogeneity were improved by setting the SW for scattering correction to 3% of the main peak in C-SPECT. CONCLUSION: C-SPECT demonstrates excellent energy resolution and improved high-contrast resolution for each radionuclide. In addition, when using 123I, careful attention should be paid to SW for scatter correction. By setting the appropriate SW, C-SPECT with MEHRS has an excellent scattered ray removal effect, and highly homogenous imaging is possible while maintaining the high-contrast resolution.

Vertebral mobility is a valuable indicator for predicting and determining bone union in osteoporotic vertebral fractures: a conventional observation study.

BACKGROUND: Conservative treatments for osteoporotic vertebral fractures (OVFs) have not been standardized, and criteria for determining bone union have not been established. To determine bone union, we have adopted a cutoff value of 1.0 mm for vertebral mobility (V-mobility), defined as the difference in anterior vertebral height (Ha) between lateral radiographs taken in weight-bearing and non-weight-bearing positions. The present study aimed to investigate the usefulness of V-mobility for determining bone union and predicting bone union at 6 months after OVF onset. METHODS: The study included 54 acute OVFs from T11 to L3 in 53 patients (12 males, 41 females; mean age 82 years; age range 55-97 years) who were hospitalized at ≤ 3 weeks after OVF onset. Vertebral deformity (V-deformity) and V-mobility were evaluated in accordance with Ha on lateral radiographs taken in the sitting position (SIT), lateral decubitus position (DEC), and supine position (SUP). OVFs showing V-mobility of ≤ 1.0 mm between SIT and DEC radiographs and no intravertebral cleft on DEC radiograph were defined as semi-union, while those showing V-mobility of ≤ 1.0 mm between SIT and SUP radiographs and no intravertebral cleft on SUP radiograph were defined as bone union. We calculated the bone union rates including semi-unions associated with V-mobility cutoff values of 1.0 mm, 1.5 mm, and 2.0 mm and estimated cutoff values for V-mobility at 5 weeks after OVF onset to predict bone union at 6 months after OVF onset. RESULTS: The cumulative number of bone unions including semi-unions was more influenced by the different V-mobility cutoff values in Ha for determining bone union in the earlier period compared with the later period in the time course of OVF. Receiver-operating characteristic curve analyses revealed that V-mobility cutoff value of 2.1 mm in Ha between SIT and DEC radiographs at 5 weeks after OVF had moderate accuracy for predicting bone union including semi-union at 6 months after OVF. The mean V-deformity value on SIT radiographs did not progress significantly. CONCLUSION: V-mobility in the early stage after OVF can predict bone union at 6 months after OVF and is a useful quantitative indicator for determining bone union.