Abstract-Prosthetic care is a vital aspect of healthcare and rehabilitation for veterans and servicemembers with major traumatic limb loss. Our survey queried 581 veterans and servicemembers with limb loss from the Vietnam and Operation Iraqi Freedom (OIF)/Operation Enduring Freedom (OEF) conflicts. Among survey participants, 78.2% from the Vietnam conflict and 90.5% from the OIF/OEF conflict currently use prosthetic devices. In Vietnam respondents, 78% received prosthetic care from private sources, 16% from Department of Veterans Affairs (VA) prosthetic laboratories, 0.9% from Department of Defense (DOD), and 5% from multiple sources. In OIF/OEF respondents, 42% received prosthetic care from private sources, 9% percent from VA, 39% from DOD, and 10% from multiple sources. Participants identified their satisfaction with current prosthetic devices and prosthetic services. Reports of pain, sweating, skin irritation, and problems with socket fit continue to be significant issues for participants from both conflicts regardless of level of amputation or site of service. In those with upper-limb loss who used myoelectric prostheses, minimal effect on prosthesis use and satisfaction was noted. Among lower-limb loss participants from both conflicts, notable differences existed in prosthesis satisfaction by source of care.

Background: The COVID-19 pandemic led to profound changes in the organization of health care systems worldwide. Aims: We sought to measure the global impact of the COVID-19 pandemic on the volumes for mechanical thrombectomy (MT), stroke, and intracranial hemorrhage (ICH) hospitalizations over a 3-month period at the height of the pandemic (March 1 to May 31, 2020) compared with two control 3-month periods (immediately preceding and one year prior). Methods: Retrospective, observational, international study, across 6 continents, 40 countries, and 187 comprehensive stroke centers. The diagnoses were identified by their ICD-10 codes and/or classifications in stroke databases at participating centers. Results: The hospitalization volumes for any stroke, ICH, and MT were 26,699, 4,002, and 5,191 in the 3 months immediately before versus 21,576, 3,540, and 4,533 during the first 3 pandemic months, representing declines of 19.2% (95%CI,-19.7 to -18.7), 11.5% (95%CI,-12.6 to -10.6), and 12.7% (95%CI,-13.6 to -11.8), respectively. The decreases were noted across centers with high, mid, and low COVID-19 hospitalization burden, and also across high, mid, and low volume stroke/MT centers. High-volume COVID-19 centers (-20.5%) had greater declines in MT volumes than mid- (-10.1%) and low-volume (-8.7%) centers (p<0.0001). There was a 1.5% stroke rate across 54,366 COVID-19 hospitalizations. SARS-CoV-2 infection was noted in 3.9% (784/20,250) of all stroke admissions. Conclusion: The COVID-19 pandemic was associated with a global decline in the volume of overall stroke hospitalizations, MT procedures, and ICH admission volumes. Despite geographic variations, these volume reductions were observed regardless of COVID-19 hospitalization burden and pre-pandemic stroke/MT volumes.

Mild gas‐phase acids C4H9+ and NH4+ protonate pyrrole at C‐2 and C‐3 but not at the nitrogen atom, as determined by deuterium labeling and neutralization–reionization mass spectrometry. Proton affinities in pyrrole are calculated by MP2/6–311G(2d, p) as 866, 845 and 786 kJ mol‐1 for protonation at C‐2, C‐3 and N, respectively. Vertical neutralization of protonated pyrrole generates bound radicals that in part dissociate by loss of hydrogen atoms. Unimolecular loss of hydrogen atom from C‐2‐and C‐3‐protonated pyrrole cations is preceded by proton migration in the ring. Protonation of gaseous imidazole is predicted to occur exclusively at the N‐3 imine nitrogen to yield a stable aromatic cation. Proton affinities in imidazole are calculated as 941, 804, 791, 791 and 724 for the N‐3, C‐4, C‐2, C‐5 and N‐1 positions, respectively. Radicals derived from protonated imidazole are only weakly bound. Vertical neutralization of N‐3‐protonated imidazole is accompanied by large Franck–Condon effects which deposit on average 183 kJ mol‐1 vibrational energy in the radicals formed. The radicals dissociate unimolecularly by loss of hydrogen atom, which involves both direct N‐H bond cleavage and isomerization to the more stable C‐2 H‐isomer. Potential energy barriers to isomerizations and dissociations in protonated pyrrole and imidazole isomers and their radicals were investigated by ab initio calculations.

We did not find evidence to support the hypothesis that multilingualism is associated with cognitive reserve.

Hypervalent dimethylammonium radical, (CH3)2NH2 •, and its deuterium-labeled isotopomers (CH3)2ND2 •, (CH3)2NHD•, (CD3)2NH2 •, and (CD3)2ND2 • were generated as transient species by collisional neutralization of their cations in the gas phase and studied by neutralization−reionization mass spectrometry, laser photoexcitation, and ab initio theory. (CH3)2ND2 •, (CH3)2NHD•, and (CD3)2NH2 • gave fractions of metastable species of ≥3.3 μs lifetimes, whereas (CH3)2NH2 • and (CD3)2ND2 • dissociated completely on the same time scale. Metastable (CD3)2NH2 • and (CH3)2ND2 • were photoexcited but not photoionized with the combined 488 and 514.5 nm lines from an Ar-ion laser. Ab initio calculations with effective PMP4(SDTQ)/6-311++G(3df,2p) identified the (X̃)2A1 ground state of vertical ionization energy, IEv = 3.70 eV. RRKM calculations on the ab initio potential energy surface of the (X̃)2A1 state predicted predominant N−H and N−D bond dissociations but did not allow for competitive loss of CH3 or CD3. The four lowest excited states of (CH3)2NH2 •, (Ã)2B1, (B̃)2A1, (C̃)2B2, and (D̃)2A1, were characterized by CIS/6-311++G(3df,2p) calculations, and their vertical ionization energies were calculated as 2.86, 2.57, 2.48, and 1.82 eV, respectively. The excited states were calculated to be strongly bound with respect to N−H bond dissociations. The N−C bond dissociations were interpreted by potential energy surface crossing of the B̃ and à states and transitions via conical intersection to the dissociative ground state.

Gas-phase protonation of pyridine with CH3NH3+, NH4+, t-C4H9+, H3O+ and CH5+ under thermal conditions was studied by variable-time neutralization-reionization mass spectrometry and ab initio calculations. N-Protonation was found to occur exclusively for CH3NH3+ through H3O+ and predominantly for CH5+. The calculated MP2/6-311G(2d,p) energies gave the proton affinities of N, C-2, C-3 and C-4 in pyridine as 924, 658, 686 and 637 kJ mol-1, respectively, which were in good agreement with previous experimental and theoretical results. Vertical neutralization of the N-protonated isomer (1H+) was accompanied by moderate Franck-Condon effects that deposited 20-21 kJ mol-1 in the 1H-pyridinium radicals (1H) formed. 1H was calculated by UMP2/6-311G(2d,p) and B3LYP/6-311G(2d,p) to be a bound species in its ground electronic state. A substantial fraction of stable 1H was detected in the spectra, which depended on the precursor ion internal energy. Deuterium labeling showed a specific loss of the N-bound hydrogen or deuterium in the radicals. The specificity increased with increasing internal energy in the radicals and decreasing contribution of ion dissociations following reionization. Variable-time measurements established specific loss of the N-bound deuterium also in dissociating low-energy 1D. Loss of hydrogen from 1H+ cations following reionization was highly endothermic and was accompanied by rearrangements that partially scrambled the ring hydrogens.

Background The cognitive reserve hypothesis would predict that use of written Japanese should confer protection against dementia because of the complexity of its ideograms compared with written English. We sought to test this hypothesis in analyses from a longitudinal study of Japanese-American men. Methods Participants were second-generation Japanese-American men (Nisei) on the island of Oahu, Hawaii, who were seen in 1965 and in subsequent examinations to detect dementia beginning in 1991-1993. Use of spoken and written Japanese was self-reported in 1965 (Analyses 1 and 2), and mid-life use of written Japanese and written English was self-reported in 1994-1996 (Analysis 3). We analyzed prevalent dementia outcomes in 1991-1993 (Analysis 1, n=3,139) using logistic regression, and incident dementia outcomes in 1994-2002 (Analysis 2, n=2,299) and in 1997-2002 (Analysis 3, n=1,655) using Cox proportional hazards regression. Dementia outcomes included all-cause dementia, probable and possible Alzheimer disease, and probable vascular dementia. We adjusted models for probable and possible confounders. Results Participants who reported proficiency with written Japanese were older and had lower incomes. For Analysis 1, there were 154 prevalent cases of dementia, 74 of Alzheimer disease, and 43 of vascular dementia; for Analysis 2, 236 incident cases of dementia, 138 of Alzheimer disease, and 45 of vascular dementia; and for Analysis 3, 125 incident cases of dementia, 80 of Alzheimer disease, and 20 of vascular dementia. There was no relationship in adjusted models between self-reported proficiency with written Japanese and any dementia outcomes. Conclusions Proficiency with written Japanese does not appear to be protective for dementia.

BackgroundDuring the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study’s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines.MethodsWe conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March–31 May 2020. The prior 1-year control period (1 March–31 May 2019) was obtained to account for seasonal variation.FindingsThere was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI −24.3% to −20.7%, p<0.0001). Embolisation of ruptured aneurysms declined with 1170–1035 procedures, respectively, representing an 11.5% (95%CI −13.5% to −9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI −28.0% to −22.1%, p<0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile.InterpretationThere was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction.