Dose-volume histogram (DVH) results for 9 cases of post spine stereotactic body radiation therapy (SBRT) radiation myelopathy (RM) are reported and compared with a cohort of 66 spine SBRT patients ...without RM.
DVH data were centrally analyzed according to the thecal sac point maximum (Pmax) volume, 0.1- to 1-cc volumes in increments of 0.1 cc, and to the 2 cc volume. 2-Gy biologically equivalent doses (nBED) were calculated using an α/β = 2 Gy (units = Gy(2/2)). For the 2 cohorts, the nBED means and distributions were compared using the t test and Mann-Whitney test, respectively. Significance (P<.05) was defined as concordance of both tests at each specified volume. A logistic regression model was developed to estimate the probability of RM using the dose distribution for a given volume.
Significant differences in both the means and distributions at the Pmax and up to the 0.8-cc volume were observed. Concordant significance was greatest for the Pmax volume. At the Pmax volume the fit of the logistic regression model, summarized by the area under the curve, was 0.87. A risk of RM of 5% or less was observed when limiting the thecal sac Pmax volume doses to 12.4 Gy in a single fraction, 17.0 Gy in 2 fractions, 20.3 Gy in 3 fractions, 23.0 Gy in 4 fractions, and 25.3 Gy in 5 fractions.
We report the first logistic regression model yielding estimates for the probability of human RM specific to SBRT.
Display omitted
► Plasma electrolytic oxidation of AZ31 Mg alloy was conducted in CeO2 particle-containing electrolyte. ► Corrosion properties of CeO2-containing PEO were evaluated by potentiodynamic ...and EIS tests. ► Corrosion resistance of AZ31 Mg alloy was significantly improved by CeO2 incorporation. ► CeO2-containing PEO coating was more protective against Cl− ion penetration during immersion test.
Plasma electrolytic oxidation (PEO) of AZ31 Mg alloys was performed in CeO2 particle-containing Na2SiO3-based electrolytes, and electrochemical corrosion properties of CeO2-incorporated PEO coatings were investigated. The CeO2 particles were incorporated into the coatings at early stage and were preferentially located in the outer porous layer filling the defects such as pores. The potentiodynamic and electrochemical impedance spectroscopy tests in 3.5wt% NaCl solution indicated that the corrosion resistance of AZ31 Mg alloy was significantly improved by CeO2 incorporation. The high impedance of CeO2-containing PEO coated Mg alloy was still maintained after 40h immersion in 3.5wt% NaCl solution.
Polyurethane nanofibers functionalized by high amount of N-chloro hydantoin were prepared for the decontamination of chemical warfare agents. Azido-polyurethane was firstly synthesized using ...azido-polydiol with 4,4′-methylenebis(phenylisocyanate) and 1,4-butanediol via step-addition polymerization. Hydantoin was introduced into the polyurethane via click reaction, followed by electrospinning and chlorination to obtain the decontaminable fibers. This N-chlorinated hydantoin-polyurethane fiber is an active decontaminable species for 2-chloroethyl ethyl sulfide and demeton-S-methyl, the simulant of chemical warfare agent. The decontamination efficiency of each exhibits 69% and 16% for 2-chloroethyl ethyl sulfide and demeton-S-methyl, respectively, with molar ratio of 1/1 for 2 h at ambient condition. This N-chlorinated hydantoin-polyurethane fiber exhibited considerable potential as the decontaminable material against toxic chemical warfare agents.
N-chloro hydantoin functionalized polyurethane fibers synthesized from hydantoin functionalization of azido-polyurethane, electrospinning and chlorination can decontaminate the chemical warfare agents. Display omitted
•Polyurethane nanofibers functionalized by high amount of N-chloro hydantoin were prepared.•Nanofiber web is an active for decontamination of CEES and demeton-S-methyl.•Relatively high decontamination efficiency can be obtained using nanofiber web.•With great processibility of this polyurethane, it can be extended to actual army cloth.
We reviewed the treatment for patients with spine metastases who initially received conventional external beam radiation (EBRT) and were reirradiated with 1-5 fractions of stereotactic body ...radiotherapy (SBRT) who did or did not subsequently develop radiation myelopathy (RM).
Spinal cord dose-volume histograms (DVHs) for 5 RM patients (5 spinal segments) and 14 no-RM patients (16 spine segments) were based on thecal sac contours at retreatment. Dose to a point within the thecal sac that receives the maximum dose (P(max)), and doses to 0.1-, 1.0-, and 2.0-cc volumes within the thecal sac were reviewed. The biologically effective doses (BED) using α/β = 2 Gy for late spinal cord toxicity were calculated and normalized to a 2-Gy equivalent dose (nBED = Gy(2/2)).
The initial conventional radiotherapy nBED ranged from ~30 to 50 Gy(2/2) (median ~40 Gy(2/2)). The SBRT reirradiation thecal sac mean P(max) nBED in the no-RM group was 20.0 Gy(2/2) (95% confidence interval CI, 10.8-29.2), which was significantly lower than the corresponding 67.4 Gy(2/2) (95% CI, 51.0-83.9) in the RM group. The mean total P(max) nBED in the no-RM group was 62.3 Gy(2/2) (95% CI, 50.3-74.3), which was significantly lower than the corresponding 105.8 Gy(2/2) (95% CI, 84.3-127.4) in the RM group. The fraction of the total P(max) nBED accounted for by the SBRT P(max) nBED for the RM patients ranged from 0.54 to 0.78 and that for the no-RM patients ranged from 0.04 to 0.53.
SBRT given at least 5 months after conventional palliative radiotherapy with a reirradiation thecal sac P(max) nBED of 20-25 Gy(2/2) appears to be safe provided the total P(max) nBED does not exceed approximately 70 Gy(2/2), and the SBRT thecal sac P(max) nBED comprises no more than approximately 50% of the total nBED.
Organophosphate-based nerve agents are among the most toxic chemical compounds known to mankind. In this report, we studied the degradation of soman (GD) and VX, two of the major nerve agents, by ...Zr(OH)4 and Zr-based Metal-Organic Frameworks (MOFs) such as MOF-808, UiO-66 and UiO-66-NH2 in the neat condition and in non-buffered aqueous solution at room temperature. Unlike Zr(OH)4, relatively less hydrophilic Zr-based MOFs were found to maintain excellent nerve agent decomposition ability, even under high relative humidity and in water. This study's results demonstrated that these Zr-based MOFs are all-weather materials that can be used to decompose nerve agents in all humidity conditions and even in water. The enhancement effect by the amine group of UiO-66-NH2 was not observed for decomposition of nerve agents in the present study, unlike the results obtained in alkaline buffered solution, which were reported previously. It was also demonstrated that MOF-808 with a pore size larger than the UiO-66 series had a better ability to degrade nerve agents.
Display omitted
•In the case of Zr(OH)4, the degradation ability for GD and VX in the high humidity condition and water was remarkably decreased.•Zr-based MOFs were found to maintain the ability to degrade nerve agents in all atmospheric humidity conditions and even in water.•This difference in decomposition abilities is presumed to be due to the differences in the hydrophilicity between Zr(OH)4 and Zr-based MOFs.•There was no significant difference in the degradability between UiO-66 and UiO-66-NH2 for nerve agents in real field conditions.
Dosimetric data are reported for five cases of radiation-induced myelopathy after stereotactic body radiotherapy (SBRT) to spinal tumors. Analysis per the biologically effective dose (BED) model was ...performed.
Five patients with radiation myelopathy were compared to a subset of 19 patients with no radiation myelopathy post-SBRT. In all patients, the thecal sac was contoured to represent the spinal cord, and doses to the maximum point, 0.1-, 1-, 2-, and 5-cc volumes, were analyzed. The mean normalized 2-Gy-equivalent BEDs (nBEDs), calculated using an alpha/beta value of 2 for late toxicity with units Gy 2/2, were compared using the t test and analysis of variance test.
Radiation myelopathy was observed at the maximum point with doses of 25.6 Gy in two fractions, 30.9 Gy in three fractions, and 14.8, 13.1, and 10.6 Gy in one fraction. Overall, there was a significant interaction between patient subsets and volume based on the nBED (p = 0.0003). Given individual volumes, a significant difference was observed for the mean maximum point nBED (p = 0.01).
The maximum point dose should be respected for spine SBRT. For single-fraction SBRT 10 Gy to a maximum point is safe, and up to five fractions an nBED of 30 to 35 Gy 2/2 to the thecal sac also poses a low risk of radiation myelopathy.
Display omitted
•A new metal- and acid-free catalytic system is designed to selectively oxidize CEES.•Tribromide and nitrate exhibits a superior catalytic activity at ambient conditions.•Bromine is ...involved in the formation of key reactive intermediate.•Nitrate anion is further involved in the oxidation of the intermediate.•A fundamental kinetic model describing overall reaction behaviors is developed.
A new metal-free catalytic reaction system is developed to selectively oxidize 2-chloroethyl ethyl sulfide (CEES), a surrogate of sulfur mustard. The combination of two catalytic precursors, tribromide and nitrate, allows a rapid sulfoxidation of CEES even at ambient conditions. The kinetic behaviours at various reaction conditions are investigated to identify the most probable reaction pathways of the development of catalytic loop and the overall reaction steps of CEES sulfoxidation. The mechanistic study demonstrates that the catalytic loop does not require an addition of mineral acid or water, which is common in most other reaction systems. Incomplete catalytic systems with one precursor are also examined to uncover the complex network of sulfoxidation in the catalytic reaction system. The results reveal that the complex between CEES and bromine is a reactive intermediate, bromosulfonium, which can be further catalysed and converted into sulfoxide by nitrate. Based on the proposed reaction mechanism, a predictive kinetic model fully describing most reaction behaviours is developed.
The nerve agent, O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothioate (VX) must be promptly eliminated following its release into the environment because it is extremely toxic, can cause death ...within a few minutes after exposure, acts through direct skin contact as well as inhalation, and persists in the environment for several weeks after release. A mixture of hydrogen peroxide vapor and ammonia gas was examined as a decontaminant for the removal of VX on solid surfaces at ambient temperature, and the reaction products were analyzed by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance spectrometry (NMR). All the VX on glass wool filter disks was found to be eliminated after 2 h of exposure to the decontaminant mixtures, and the primary decomposition product was determined to be non-toxic ethyl methylphosphonic acid (EMPA); no toxic S-2-(diisopropylamino)ethyl methylphosphonothioic acid (EA-2192), which is usually produced in traditional basic hydrolysis systems, was found to be formed. However, other by-products, such as toxic O-ethyl S-vinyl methylphosphonothioate and (2-diisopropylaminoethyl) vinyl disulfide, were detected up to 150 min of exposure to the decontaminant mixture; these by-products disappeared after 3 h. The two detected vinyl byproducts were identified first in this study with the decontamination system of liquid VX on solid surfaces using a mixture of hydrogen peroxide vapor and ammonia gas. The detailed decontamination reaction networks of VX on solid surfaces produced by the mixture of hydrogen peroxide vapor and ammonia gas were suggested based on the reaction products. These findings suggest that the mixture of hydrogen peroxide vapor and ammonia gas investigated in this study is an efficient decontaminant mixture for the removal of VX on solid surfaces at ambient temperature despite the formation of a toxic by-product in the reaction process.
